Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 47 2013 Overviews of Optimization Techniques for Geometric Estimation 1 18 EN Kenichi Kanatani We summarize techniques for optimal geometric estimation from noisy observations for computer vision applications. We first discuss the interpretation of optimality and point out that geometric estimation is different from the standard statistical estimation. We also describe our noise modeling and a theoretical accuracy limit called the KCR lower bound. Then, we formulate estimation techniques based on minimization of a given cost function: least squares (LS), maximum likelihood (ML), which includes reprojection error minimization as a special case, and Sampson error minimization. We describe bundle adjustment and the FNS scheme for numerically solving them and the hyperaccurate correction that improves the accuracy of ML. Next, we formulate estimation techniques not based on minimization of any cost function: iterative reweight, renormalization, and hyper-renormalization. Finally, we show numerical examples to demonstrate that hyper-renormalization has higher accuracy than ML, which has widely been regarded as the most accurate method of all. We conclude that hyper-renormalization is robust to noise and currently is the best method. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 47 2013 Rpresetation f Trsion Points on Pairing Curves of Embedding Degree 1 19 24 EN Yasuyuki Nogami Taichi Sumo Recent efficient pairings such as Ate pairing use two efficient rational point subgroups such that π(P) = P and π(Q) = [p]Q, where π, p, P, and Q are the Frobenius map for rational point, the characteristic of definition field, and torsion points for pairing, respectively. This relation accelerates not only pairing but also pairing–related operations such as scalar multiplications. It holds in the case that the embedding degree k divides r − 1, where r is the order of torsion rational points. Thus, such a case has been well studied. Alternatively, this paper focuses on the case that the degree divides r + 1 but does not divide r − 1. Then, this paper shows a multiplicative representation for r–torsion points based on the fact that the characteristic polynomial f(π) becomes irreducible over Fr for which π also plays a role of variable. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 47 2013 Lazy Random Walk Efficient for Pollard’s Rho Methoｄ Attacking on G3 over Barreto-Naehrig Curve (Corrected) 25 32 EN Kenta Nekado Yusuke Takai Yasuyuki Nogami Pairing–based cryptosystems are well implemented with Ate–type pairing over Barreto–Naehrig (BN) curve. Then, for instance, their securities depend on the difficulty of Discrete Logarithm Problem (DLP) on the so–denoted G3 over BN curve. This paper, in order to faster solve the DLP, first proposes to utilize Gauss period Normal Basis (GNB) for Pollard’s rho method, and then considers to accelerate the solving by an adoption of lazy random walk, namely tag tracing technique proposed by Cheon et al. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 47 2013 Contents EN Faculty of Engineering, Okayama University No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 46 2012 Contents EN Faculty of Engineering, Okayama University No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 46 2012 Calibration of Ultra-Wide Fisheye Lens Cameras by Eigenvalue Minimization 10 20 EN Kenichi Kanatani We present a new technique for calibrating ultra-wide fisheye lens cameras by imposing the constraint that collinear points be rectified to be collinear, parallel lines to be parallel, and orthogonal lines to be orthogonal. Exploiting the fact that line fitting reduces to an eigenvalue problem, we do a rigorous perturbation analysis to obtain a Levenberg-Marquardt procedure for the optimization. Doing experiments, we point out that spurious solutions exist if collinearity and parallelism alone are imposed. Our technique has many desirable properties. For example, no metric information is required about the reference pattern or the camera position, and separate stripe patterns can be displayed on a video screen to generate a virtual grid, eliminating the grid point extraction processing. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 46 2012 Optimal Computation of 3-D Similarity from Space Data with Inhomogeneous Noise Distributions 1 9 EN Kenichi Kanatani Hirotaka Niitsuma We optimally estimate the similarity (rotation, translation, and scale change) between two sets of 3-D data in the presence of inhomogeneous and anisotropic noise. Adopting the Lie algebra representation of the 3-D rotational change, we derive the Levenberg-Marquardt procedure for simultaneously optimizing the rotation, the translation, and the scale change. We test the performance of our method using simulated stereo data and real GPS geodetic sensing data. We conclude that the conventional method assuming homogeneous and isotropic noise is insufficient and that our simultaneous optimization scheme can produce an accurate solution. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 46 2012 Optimal Computation of 3-D Similarity: Gauss-Newton vs.Gauss-Helmert 21 33 EN Kenichi Kanatani Hirotaka Niitsuma Because 3-D data are acquired using 3-D sensing such as stereo vision and laser range finders, they have inhomogeneous and anisotropic noise. This paper studies optimal computation of the similarity (rotation, translation, and scale change) of such 3-D data. We first point out that the Gauss-Newton and the Gauss-Helmert methods, regarded as different techniques, have similar structures. We then combine them to define what we call the modified Gauss-Helmert method and do stereo vision simulation to show that it is superior to either of the two in convergence performance. Finally, we show an application to real GPS geodetic data and point out that the widely used homogeneous and isotropic noise model is insufficient and that GPS geodetic data are prone to numerical problems. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 45 2011 Optimal Computation of 3-D Rotation under Inhomogeneous Anisotropic Noise 36 45 EN Kenichi Kanatani Hirotaka Niitsuma We present a new method for optimally computing the 3-D rotation from two sets of 3-D data. Unlike 2-D data, the noise in 3-D data is inherently inhomogeneous and anisotropic, reflecting the characteristics of the 3-D sensing used. To cope with this, Ohta and Kanatani introduced a technique called “renormalization”. Following them, we represent a 3-D rotation in terms of a quaternion and compute an exact maximum likelihood solution using the FNS of Chojnacki et al. As an example, we consider 3-D data obtained by stereo vision and optimally compute the 3-D rotation by analyzing the noise characteristics of stereo reconstruction. We show that the widely used method is not suitable for 3-D data. We confirm that the renormalization of Ohta and Kanatani indeed computes almost an optimal solution and that, although the difference is small, the proposed method can compute an even better solution. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 45 2011 Bundle Adjustment for 3-D Reconstruction: Implementation and Evaluation 27 35 EN Kenichi Kanatani Yasuyuki Sugaya We describe in detail the algorithm of bundle adjustment for 3-D reconstruction from multiple images based on our latest research results. The main focus of this paper is on the handling of camera rotations and the efficiency of computation and memory usage when the number of variables is very large; an appropriate consideration of this is the core of the implementation of bundle adjustment. Computing the fundamental matrix from two views and reconstructing the 3-D structure from multiple views, we evaluate the performance of our algorithm and discuses technical issues of bundle adjustment implementation. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 45 2011 Hyper Least Squares and Its Applications 15 26 EN Kenichi Kanatani Prasanna Rangrajan Yasuyuki Sugaya Hirotaka Niitsuma We present a new least squares (LS) estimator, called “HyperLS”, specifically designed for parameter estimation in computer vision applications. It minimizes the algebraic distance under a special scale normalization, which is derived by rigorous error analysis in such a way that statistical bias is removed up to second order noise terms. Numerical experiments suggest that our HyperLS is far superior to the standard LS and comparable in accuracy to maximum likelihood (ML), which is known to produce highly accurate results in image applications but may fail to converge if poorly initialized. Our HyperLS is a perfect candidate for ML initialization. In addition, we discuss how image-based inference problems have different characteristics form conventional statistical applications, with a view to serving as a bridge between mathematicians and computer engineers. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 45 2011 Ordinary Pairing Friendly Curve of Embedding Degree 1 Whose Order Has Two Large Prime Factors 46 53 EN Yasuyuki Nogami Erika Yanagi Tetsuya Izuta Yoshitaka Morikawa Recently, composite order pairing–based cryptographies have received much attention. The composite order needs to be as large as the RSA modulus. Thus, they require a certain pairing–friendly elliptic curve that has such a large composite order. This paper proposes an efficient algorithm for generating an ordinary pairing–friendly elliptic curve of the embedding degree 1 whose order has two large prime factors as the RSA modulus. In addition, the generated pairing–friendly curve has an efficient structure for the Gallant–Lambert–Vanstone (GLV) method. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 45 2011 Optimal Digital Control Systems Design for Handling Machines using dsPIC 1 14 EN Tatsuro Akiyoshi Jun Imai Masami Konishi This paper presents a method of the controller design for the handling machine by using dsPIC(Digital Signal Processor + Peripheral Interface Controller). Recently, many manufacturing robots are operated in manufacturing facilities, with the aim of labor, cost saving, and improvement of the productivity. Such robots need to have positioning performance of high precision and simultaneously to save cost. In this paper, a digital optimal servo controller is designed, and it is implemented into our barebones controller which involves dsPIC. We have designed and manufactured the controller which is added suitable peripherals to improve the consistency between the mechanical machine operating in continuous time and controller in discrete time. The significance of this research is that digital implementation of the embedded system which has performance-limitation has ensured a comparable result, against the one with PC which has broad utility. When it is used as a controller, it is possible to restrain product prices greatly equivalent PC precision. We demonstrate potential that good control can be achieved even with low cost. Our research has lead to the viability of lower cost and higher performance system for the production process at factories. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 45 2011 Contents EN No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 45 2011 Squaring Algorithm Efficient for Cubic Extension Field Derived with Pseudo Gauss Period Normal Basis 54 59 EN Kenta Nekado Yusuke Takai Yasuyuki Nogami Yoshitaka Morikawa Recently, pairing–based cryptographies have attracted much attention. For fast pairing calculation, not only pairing algorithms but also arithmetic operations in extension field should be efficient. Especially for final exponentiation included in pairing calculation, squaring is more important than multiplication. This paper considers squaring algorithms efficient for cubic extension field which is often used for pairing implementaions. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 44 2010 Ecient Squaring Algorithm for Xate Pairing with Freeman Curve 69 72 EN Kenta Nekado Hidehiro Kato Yasuyuki Nogami Yoshitaka Morikawa Recently, pairing–based cryptographies have attracted much attention. For fast pairing calculation, not only pairing algorithms but also arithmetic operations in extension field should be efficient. Especially for final exponentiation included in pairing calculation, squaring is more important than multiplication. This paper proposes an efficient squaring algorithm in extension field for Freeman curve. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 44 2010 Effects of the Cultivation Method on the Characteristics or Gene Expression Profiles of Aspergillus oryzae Using mCD or DPY Media 73 83 EN Hiroyuki Imanaka Soukichi Tanaka Bin Feng Koreyoshi Imamura Kazuhiro Nakanishi We used modified Czapek-Dox (mCD) or dextrin-peptone-yeast extract (DPY) media to cultivate a filamentous fungus, Aspergillus oryzae IAM 2706 by three different cultivation methods, i.e., shaking-flask culture (SFC), agar-plate culture (APC), and membrane-surface liquid culture (MSLC), to identify the differences in cultivation behaviors and gene transcriptional profiles. The fungi cultivated by APC or MSLC secreted a greater number of different proteins/enzymes in larger quantities compared with fungi cultivated by SFC, particularly when DPY medium was used. In particular, the amounts of protease secreted by fungi cultivated via MSLC or APC were much greater compared with SFC. When mCD medium was used, α-amylase activity was barely detectable in all cultures while the activity was detected in MSLC and APC in a quantity that was several times higher than that in SFC using DPY medium. SDS-PAGE analysis and N-terminal amino acid sequences confirmed 6 proteins in the culture supernatants when DPY medium was used. Among these proteins oryzin (an alkaline protease) and α-amylase were detected at much higher levels in APC and MSLC compared with SFC, which was consistent with the measured activity of the secreted enzymes. However, when mCD medium was used, only oryzin was detected in significant amounts in MSLC and APC. Microarray analyses of the fungi cultivated by SFC, APC or MSLC using either mCD or DPY media indicated that the gene transcriptional profile of the MSLC sample was similar to that of the APC sample but different from that of the SFC sample. When mCD medium was used, most of the genes that were up-regulated 10-folds or greater in the MSLC sample relative to the SFC sample were unknown or predicted proteins. Transcription of the oryzin gene was only slightly up-regulated in the MSLC sample while transcription of the α-amylase gene was slightly down-regulated. On the other hand, when DPY medium was used, many known genes including the oryzin gene were up-regulated in the MSLC sample versus the SFC sample. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 44 2010 Ordinary Pairing Friendly Curve of Embedding Degree 3 Whose Order Has Two Large Prime Factors 60 68 EN Yasuyuki Nogami Yoshitaka Morikawa This paper proposes a method for generating a certain composite order ordinary pairing–friendly elliptic curve of embedding degree 3. In detail, the order has two large prime factors such as the modulus of RSA cryptography. The method is based on the property that the order of the target pairing–friendly curve is given by a polynomial as r(X) of degree 2 with respect to the integer variable X. When the bit size of the prime factors is about 500 bits, the proposed method averagely takes about 15 minutes on Core 2 Quad (2.66Hz) for generating one. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 44 2010 High Accuracy Homography Computation without Iterations 50 59 EN Kenichi Kanatani We present highly accurate least-squares (LS) alternatives to the theoretically optimal maximum likelihood (ML) estimator for homographies between two images. Unlike ML, our estimators are non-iterative and yield solutions even in the presence of large noise. By rigorous error analysis, we derive a “hyperaccurate” estimator which is unbiased up to second order noise terms. Then, we introduce a computational simplification, which we call “Taubin approximation”, without incurring a loss in accuracy. We experimentally demonstrate that our estimators have accuracy surpassing the traditional LS estimator and comparable to the ML estimator. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 44 2010 Hyperaccurate Ellipse Fitting without Iterations 42 49 EN Kenichi Kanatani This paper presents a new method for fitting an ellipse to a point sequence extracted from images. It is widely known that the best fit is obtained by maximum likelihood. However, it requires iterations, which may not converge in the presence of large noise. Our approach is algebraic distance minimization; no iterations are required. Exploiting the fact that the solution depends on the way the scale is normalized, we analyze the accuracy to high order error terms with the scale normalization weight unspecified and determine it so that the bias is zero up to the second order. We demonstrate by experiments that our method is superior to the Taubin method, also algebraic and known to be highly accurate. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 44 2010 Optimization without Search: Constraint Satisfaction by Orthogonal Projection with Applications to Multiview Triangulation 32 41 EN Kenichi Kanatani We present an alternative approach to what we call the “standard optimization”, which minimizes a cost function by searching a parameter space. Instead, the input is “orthogonally projected” in the joint input space onto the manifold defined by the “consistency constraint”, which demands that any minimal subset of observations produce the same result. This approach avoids many difficulties encountered in the standard optimization. As typical examples, we apply it to line fitting and multiview triangulation. The latter produces a new algorithm far more efficient than existing methods. We also discuss optimality of our approach. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 44 2010 FDTD Analysis on Optical Connement Structure with Electromagnetic Metamaterial 1 6 EN Kenji Tsuruta In this paper, we investigate a light-confinement phenomenon in the structure which has triangular latice composed of Double NeGative Metamaterial (DNGM). In geometrical optics consideration, this structure is expected to confine lights completely by sequential refractions in the structure. We demonstrate it by using the two dimensional finite-difference time-domain simulations. We introduce Drude-Lorentz model for dielectric and magnetic dispersion of the material at optical frequencies. We analyze quantitatively the effects of energy loss in the DNGM on the light-confinement efficiency. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 44 2010 Unified Computation of Strict Maximum Likelihood for Geometric Fitting 13 23 EN Kenichi Kanatani A new numerical scheme is presented for computing strict maximum likelihood (ML) of geometric fitting problems having an implicit constraint. Our approach is orthogonal projection of observations onto a parameterized surface defined by the constraint. Assuming a linearly separable nonlinear constraint, we show that a theoretically global solution can be obtained by iterative Sampson error minimization. Our approach is illustrated by ellipse fitting and fundamental matrix computation. Our method also encompasses optimal correction, computing, e.g., perpendiculars to an ellipse and triangulating stereo images. A detailed discussion is given to technical and practical issues about our approach. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 44 2010 Numerical Simulation of Acoustic Waves in a Two-Dimensional Phononic Crystal: Negative Refraction 7 12 EN Kenji Tsuruta The lens effect of acoustic waves in a two-dimensional (2D) phononic crystal is studied by numerical simulation based on the finite-difference time-domain (FDTD) method. We calculate the phonon band structure of 2D phononic crystals, consisting of metal cylinders placed periodically in water. Lens effect is observed by the negative refraction of acoustic waves, which results in refocusing of the waves at the point outside the crystal. To increase the focal intensity, we introduce a 2D phononic crystal shield with a different composition of material, which returns the incident waves back to the lens via the perfect reflection. Also, the dependence on filling fraction of metal in the crystal is studied. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 44 2010 Improved Multistage Learning for Multibody Motion Segmentation 24 31 EN Kenichi Kanatani We present an improved version of the MSL method of Sugaya and Kanatani for multibody motion segmentation. We replace their initial segmentation based on heuristic clustering by an analytical computation based on GPCA, fitting two 2-D affine spaces in 3-D by the Taubin method. This initial segmentation alone can segment most of the motions in natural scenes fairly correctly, and the result is successively optimized by the EM algorithm in 3-D, 5-D, and 7-D. Using simulated and real videos, we demonstrate that our method outperforms the previous MSL and other existing methods. We also illustrate its mechanism by our visualization technique. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 Experimental Conditions for Observation of Thermodynamic Instability and Critical Point of Fine Particle (Dusty) Plasmas 27 31 EN Hiroo Totsuji When the Coulomb coupling between fine particles becomes sufficiently strong in fine particle plasmas, the isothermal compressibility of the whole system diverges and we have a phase separation and an associated critical point. Experimental conditions of fine particle plasmas, densities and temperatures of components and the fine particle size, are obtained corresponding to characteristic parameters around the critical point and the dependency on ion species and other factors is discussed. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 Dispersion Models and Electromagnetic FDTD Analyses of Nanostructured Metamaterials using Parallel Computer 8 15 EN Chieko Totsuji Kenji Tsuruta Hiroo Totsuji Metamaterial which has negative permittivity and permeability is investigated via computer simulations. Effects of the nanostructure on dielectric and magnetic properties of the material are taken into account by introducing the Drude-Lorentz model in the materials dispersion. We include multi-band process in the dielectric response in order to reproduce accurately experimental values of bulk Au thin film. Size effect on the dispersion is examined by comparing the model with that of a noble metal particle. Based on the dispersion model constructed, we analyze the electromagnetic response of nanostructured metamaterials to evanescent waves at microwave and optical frequencies via finite-difference time-domain simulatioins on parallel computer. A re- focusing and an amplification of the evanescent waves propagating through a metamaterial, consisting of metal slab/vacuum stacking, is demonstrated for the frequencies of 30GHz and 744THz. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 FDTD Simulations of Acoustic Waves in Two-Dimensional Phononic Crystals using Parallel Computer 16 21 EN Kenji Tsuruta Chieko Totsuji Hiroo Totsuji The finite-difference time-domain (FDTD) method has been applied to the calculation of the phonon band structure of two-dimensional (2D) phononic crystals, consisting of metal cylinders placed periodically in liquid. By comparing several combinations of materials for metal cylinder and liquid, we analyze the dependence of the band structures on sound speed and density of liquid media. Moreover, the negative refraction of the acoustic waves is observed at the interfaces between phononic crystal slab and the liquid. We find that an acoustic“lens effect”with the slab appears due to the negative refractions. The relationship between the focal intensity in the lens effect and the band structure is discussed. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 Information Transfer and Entanglement Creation by Spin Chains: Effects of Noise and Asymmetry 22 26 EN Hiroo Totsuji Chieko Totsuji Kenji Tsuruta For the transfer of quantum information and the creation of entangled states, the application of tuned spin chains, systems of spins with the nearest-neighbor coupling tuned so as to give high efficiency, has been proposed and some examples of high performance have been given by several authors. In this article, the effect of deviations from tuned values and the effect of resultant asymmetry are investigated through numerical simulations and theoretical analyses. It is shown that there exists a system where the transfer efficiency is comparable with exactly tuned ones and, at the same time, robust to noises in the coupling constants. It is also shown that the effect of asymmetry on the efficiency of entanglement creation is of the second order when the asymmetry is small. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 Cost Evaluation of The Improvement of Twisted Ate Pairing That Uses Integer Variable X of Small Hamming Weight 113 116 EN Yumi Sakemi hidehiro Kato Yasuyuki Nogami Yoshikawa Morikawa Barreto–Naehrig (BN) curve has been introduced as an efficient pairing-friendly elliptic curve over prime field F(p) whose embedding degree is 12. The characteristic and Frobenius trace are given as polynomials of integer variable X. The authors proposed an improvement of Miller's algorithm of twisted Ate pairing with BN curve by applying X of small hamming weight in ITC–CSCC2008; however, its cost evaluation has not been explicitly shown. This paper shows the detail of the cost evaluation. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 Extension Field for Xate Pairing with Freeman Curve 108 112 EN Kenta Nekado Hidehiro Kato Yasuyuki Nogami Yoshitaka Morikawa Recently, pairing-based cryptographies such as ID-based cryptography and group signature have been studied. For fast pairing calculation, not only pairing algorithms but also arithmetic operations in extension field must be efficiently carried out. The authors show efficient arithmetic operations of extension field for Xate pairing especially with Freeman curve. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 A High-Speed Square Root Algorithm for Extension fields -Especially for Fast Extension Fields- 99 107 EN Hidehiro Kato Yasuyuki Nogami Yoshitaka Morikawa A square root (SQRT) algorithm in extension field F(p(m))(m = r(0)r(1)･･･r(n−1)･2(d), r(i) : odd prime, d : positive integer) is proposed in this paper. First, a conventional SQRT algorithm, the Tonelli-Shanks algorithm, is modified to compute the inverse SQRT in F(p(2d)), where most of the computations are performed in the corresponding subfields F(p(2i)) for 0 ≤ i ≤ d-1. Then the Frobenius mappings with addition chain are adopted for the proposed SQRT algorithm, in which a lot of computations in a given extension field F(p(m)) are also reduced to those in a proper subfield by the norm computations. Those reductions of the field degree increase efficiency in the SQRT implementation. The Tonelli-Shanks algorithm and the proposed algorithm in F(p(6)) and F(p(10)) were implemented on a Core2 (2.66 GHz) using the C++ programming language. The computer simulations showed that, on average, the proposed algorithm accelerated the SQRT computation by 6 times in F(p(6)), and by 10 times in F(p(10)), compared to the Tonelli-Shanks algorithm. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 Predictor Order and Error Distribution of MMAE Predictors for Lossless Image Coding 93 98 EN Hirokazu Ueno Yoshitaka Morikawa This paper investigates the relation between error distribution and predictive order of minimum mean abusolute error predictors (MMAE predictors) designed for lossless coding of grayscale images. Design of MMAE predictors reduces to the linear programming problem. Let k be the number of coefficients in a predictor (predictor order), we imagine that predictor order k may have a distribution shaping effect. Main purpose of this paper is to ensure that k has such an effect. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 Human Support Agent for Design and Diagnosis using Classifier System 75 92 EN Keita Ohe Masami Konishi Jun Imai As is well known, an advanced knowledge and know-how are needed in the design and the diagnosis work. Further, human experts can cope with the recent trend of customers needs. Therefore, the design and the diagnosis work have been privately performed in the past, and its information cannot be shared. In addition, the number of experts is decreasing. It is a very important problem to maintain and to extend experts technologies having been built up. For the purpose, methods and systems for technical inheritance of the advanced techniques of the skilled engineers are needed to train the unskilled operators and also can assist skilled operators. In this research, attention is focused on the design of analog filter circuit. To attain the target, the circuit structural classifier system to support design work is developed. Furthermore, simulation technology for hot strip rolling mills based on distributed agents is presented aimed to develop tools for the diagnosis of hot strip rolling mills operation. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 Human Interface Technology for Operation Support of LargeSized Crane 61 74 EN Mao Kawamura Masami Konishi Katuki Yamagata Koichi Shimomura In this research, a Human Interface system is designed intended to mobile crane. The intervention of human is unavoidable to attain the high performance of electro mechanical system. As is known, crane operation is complicated. Recently, the decrease of expert person induced crane accident. So in near future, it is required a partial automation of crane operation and human support technology. We are aiming at the development of the operation support system for a crane. In this research, development of the hydro mechanical models representing both of static and dynamics movements are made. Further, actual experimental data of operating mobile crane, which are electrical signal data and three-dimension (3D) position of moving load is measured. The actual operating data are compared with the model and it is found that the developed electromechanical model can explain the behaviors of actual data. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 Surface Defect Inspection of a Cutting Tool by Image Processing with Neural Networks 55 60 EN Shinichiro Inoue Masami Konishi Jun Imai In this research, an image processing method and a system for inspection support of a rod figured cutting tool are developed. As is well known, the visual inspection of a cutting tool by image processing is not easy, because cutting blade have a helical blade structure. To cope with the problem, an experimental facility with rotation and longitudinal tool shift functions to enable acquisition of blade surface pictures along a cutting rod is developed. The type of the defect treated in this paper is the spot of coating on blade surface. To judge the quality of the processed image of blade surface, neural network with autonomous learning is used. The processed image of cutting tool is divided into 64 × 64 blocks used for the input to the neural networks. Before input, each block data is preprocessed applying a edge detection filter and a transformation by the discrete fourier transform (DFT). Using these technologies, the experimental inspection system is built and tested to check the capabilities of the inspection algorithms. The diagnostic performance of the surface defect of a cutting tool was confirmed. There remained a problem to mis judge the normal tools as the defect. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 Position Control of 2-Link SCARA Robot by using InternalModel Control 49 54 EN Shinya Akamatsu Masami Konishi Jun Imai In this paper, the controlled target is the SCARA robot with two links, and the object is fine control of the arm head position of the robot. To attain the object, Internal Model Control (IMC) is introduced. A nonlinear equations are for robot dynamics formulated by solving Lagrange equation, and is linearized to design control system by IMC. The controller of IMC is designed or synthesisted as the inverse system of the linearized model, and IMC filter model is selected. Also, reference filter is introduced to make the improvement of performance. The result of control performance by IMC is compared with that of PID numerically, accuracy and incoherency are confirmed. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 Positioning Control of One Link Arm with ParametricUncertainty using Quantitative Feedback Theory 39 48 EN Takayuki Kuwashima Jun Imai Masami Konishi This paper presents method of the controller design for one link arm with parametric uncertainty. Recently, many manufacturing robots are operated in manufacturing facilities, with the aim of labor and cost saving or improvement of the productivity. Such robots need to have positioning performance of high precision. In condition that there is an uncertainty in plant dynamics, desired control performance may not be attained because the controller is designed according to the mathematical model of a plant. So it is important that the designed control system have a robust control performance. In this paper, the robust controller is designed using Quantitative Feedback Theory (QFT) for one link arm with parametric uncertainty. Simulation experiments are run for control system designed by using QFT and conventional method. The results are compared with each other and it is found that the control system designed by QFT shows a robust performance and can suppress the unevenness of output against parametric uncertainty. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 Tracking Control of Combination Vehicles with PreviewFeedforward Compensation 32 38 EN Shuji Mabuchi Masami Konishi Jun Imai A tractor-trailer vehicle in the factory might move on the route determined beforehand. However, automation of a tractor-trailer vehicle is difficult so that it is necessary to consider the nonlinearity of a vehicle and a trailer. In this research, the effective tracking control method of a tractor-trailer vehicle is proposed. The control method using time-state control form for a preview control is presented, and be applied a tractor-trailer vehicle with nonholonomic characteristics. Results of numerical experiments are presented to check effectiveness of the proposed control method. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 1349-6115 43 2009 Crystal rotation behavior with fatigue crack propagation in copper films 1 7 EN Kenichi Shimizu Tashiyuki Torii Koki Ishida Using a fatigue testing method by which fatigue cracks can be initiated and propagated in a film adhered to cover an elliptical through-hole in a base plate subjected to push-pull cyclic loads, annealed copper films with the thickness of 100μm and those reduced the thickness from the 100μm to 50μm by an electro-polishing were fatigued under a constant stress amplitude with a stress ratio of zero. The crystal rotation behavior with the fatigue crack propagation was investigated by measuring the crystal orientation around the fatigue crack initiated from the notch root before and after fatigue testing, using EBSD (Electron Back-scatter Diffraction) method. Then, the change of crystal orientation with fatigue testing was evaluated quantitatively from the misorientation between the crystal orientation matrix on the same point obtained before and after fatigue testing. As a result, the angle of the crystal rotation obtained from the region showing the high fatigue crack propagation rate was larger than that obtained from the region showing the low fatigue crack propagation rate for the film with the thickness of 100μm, while the fatigue crack propagated faster in the film with the thickness of 50μm than that with the thickness of 100μm regardless of the small crystal rotation angles with the fatigue testing for the film with the thickness of 50μm. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 Spin Polarization of Two-Dimensional Electron System in a Finite Domain 56 59 EN Chieko Totsuji Kenji Tsuruta Hiroo Totsuji We analyze the ground state of the two-dimensional quantum system of electrons confined in a parabolic potential with the system size around 100. We map the system onto a classical system on the basis of the classical-map hypernetted-chain (CHNC) method which has been proven to work in the integral-equation-based analyses of uniform unbounded systems and then apply classical numerical simulations. We find that the confined system undergoes the transition to the spin polarized state with the decrease of the average density and the corresponding critical value is as low as rs ∼ 0.3 in terms of the usual rs parameter estimated for the average density. As the ground state for given value of the rs parameter, our data give the critical value for the transition around 20 which is consistent with the known possibility. The advantage of our method is a direct applicability to geometrically complex systems which are difficult to analyze by integral equations. The application to the structure like quantum dots reported here is the first example of such applications. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 Vibrational Properties of Si Crystal with Vacancy : A Tight-Binding Study 44 47 EN Kenji Tsuruta Chieko Totsuji Hiroo Totsuji To analyze vibrational properties of Si crystal with a single charge-neutral vacancy, we perform large-scale simulations based on tight-binding molecular-dynamics method. Vibrational modes and frequencies are obtained by diagonalizing dynamical matrix within a harmonic approximation. Results indicate that there exist vibrational modes spatially localized around the vacancy and large frequency shifts associated with the localized modes contribute significantly to reduction of the vibrational free energy. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 Numerical Simulations of Two-dimensional Electron Fluid : An Application of Classical-map Hypernetted-chain Method 48 52 EN Chieko Totsuji Kenji Tsuruta Hiroo Totsuji Based on the mapping introduced by the classical-map hypernetted-chain (CHNC) method, classical numerical simulations, Monte Carlo and molecular dynamics, have been applied to the twodimensional electron fluid and the results are compared with those of quantum Monte Carlo simulations hitherto reported. It is shown that polarization properties of the ground state obtained by the diffusion Monte Carlo method are reproduced within the accuracy of quantum simulations by both of two mapping functions for the quantum temperature which have been proposed within the CHNC method. These results may serve as the basis of numerical simulations based on the CHNC method which are applicable to finite non-periodic systems like quantum dots and systems at finite temperatures. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 Structural Analysis of Minimum Weight Codewords of the (32, 21, 6) and (64, 45, 8) Extended BCH Codes Using Invariance Property 1 9 EN Takuya Koumoto Two typical examples, the (32, 21, 6) and (64, 45, 8) extended code of primitive permuted BCH codes, are considered. The sets of minimum weight codewords are analyzed in terms of Boolean polynomial representation. They are classied by using their split weight structure with respect to the left and right half trellis sections, and for each class, the standard form is presented. Based on the results, we can generate a proper list of the minimum weight codewords of the codes. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 Geometric BIC 10 17 EN Kenichi Kanatani The author introduced the "geometric AIC" and the "geometric MDL" as model selection criteria for geometric fitting problems. These correspond to Akaike’s "AIC" and Rissanen's "BIC", respectively, well known in the statistical estimation framework. Another criterion well known is Schwarz’ "BIC", but its counterpart for geometric fitting has been unknown. This paper introduces the corresponding criterion, which we call the "geometric BIC", and shows that it is of the same form as the geometric MDL. We present the underlying logical reasoning of Bayesian estimation. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 Fundamental Matrix Computation: Theory and Practice 18 35 EN Kenichi Kanatani We classify and review existing algorithms for computing the fundamental matrix from point correspondences and propose new effective schemes: 7-parameter Levenberg-Marquardt (LM) search, EFNS, and EFNS-based bundle adjustment. Doing experimental comparison, we show that EFNS and the 7-parameter LM search exhibit the best performance and that additional bundle adjustment does not increase the accuracy to any noticeable degree. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 Fast Exponentiation in Extension Field with Frobenius Mappings 36 43 EN Hidehiro Kato Kenta Nekado Yasuyuki Nogami Yoshitaka Morikawa This paper proposes an exponentiation method with Frobenius mappings. Our method is closely related to so-called interleaving exponentiation. Different from the interleaving exponentiation methods, our method can carry out several exponentiations using same base at the same time. The efficiency to use Frobenius mappings for an exponentiation in extension field is well introduced by Avanzi and Mihailescu. This exponentiation method is based on so-called simultaneous exponentiation and uses many Frobenius mappings. Their method more decreased the number of multiplications; however, the number of Frobenius mappings inversely increased. Compared to their method , the number of multiplications needed for the proposed method becomes about 20% larger; however, that of Frobenius mappings becomes small enough. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 A Method for Checking the Parity of (#Jc - 1)=2 of Genus 2 and 3 Hyperelliptic Curves 110 114 EN Yasuyuki Nogami Yoshitaka Morikawa This paper shows a method for checking the parity of (#Jc − 1)/2 without calculating the order #Jc, where #Jc is the order of genus 2 or 3 hyperelliptic curve. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 Fatigue Crack Propagation Evaluated by Electric Resistance and Ultrasonics in Copper Film Bonded to Base Metal with Resin 104 109 EN MA Donghui Tashiyuki Torii Kenichi Shimizu Akira Matsuba As model specimens of surface film-bonded materials, pure copper films with a thickness of 100μm were bonded to the surface of steel base with epoxy resin, where the tensile residual stress was measured by an X-ray on the surface copper film. The distribution of initial electric resistance was measured on both copper film and base specimen by a direct current potential drop technique. As a result, there was a good agreement between the measured and theoretical values. From the fatigue testing results, it was shown that the measured electric resistance increased with the fatigue crack length on the copper film, which was almost equal to the theoretical value calculated for a central slit in a plate with finite width. This was probably because the fatigue crack was opened due to the tensile residual stress on the film even under unloading condition. In addition, the internal crack length during fatigue was examined by ultrasonic testing for the film-bonded specimen. As a result, there was a difference in the fatigue crack length between the surface copper film and the inner base. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 Cooperation of Production, Product Handling and TransferScheduling for Semiconductor Fabrication 91 103 EN Hamana Ryohei Masami Konishi Jun Imai Various kind of productions are made in semiconductor fabrications, where it employs the production system with multiprocesses and multiple Automated Guided Vehicles(AGVs) for transportation. It is difficult to optimize planning of production and transportation simultaneously because of the complicated flow of semifinished products. This paper describes the formulations of production scheduling, transportation routing and sequence planning of material handling system, and algorithm for simultaneous optimization of plannings by using solution space reduction and simulated annealing method. In this paper, all production system is decomposed to the production scheduling problem, transportation routing problem by AGVs and sequence planning of material handling system with managing stockers and buffers. Production scheduling problem and transportation routing problem are solved by the optimization algorithm using the decomposition routing problem. Sequence planning of material handling robot problem is solved by the algorithm using simulated annealing method. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 Temperature Distribution Control of Reactor Furnace by StateSpace Method using FEM Modeling 79 90 EN Masami Konishi Jun Imai The operations of a reactor furnace such as a blast furnace still depend on the experiences and intuitions of skilled operators due to the complexity of internal furnace phenomena and high temperature. There is a great demand for stable operations under the circumstances of a decrease in the number of skilled operators and difficulty in technology inheritance. This paper aims to construct mathematical description for control of a reactor furnace. Further, the linear-quadratic-gaussian control system for a reactor furnace is proposed, which estimates inner furnace temperature distribution using measured data near furnace wall. Temperature distribution of a furnace is controlled based on the estimated inner temperature distribution changing of boundary conditions of a furnace. The practicability of the proposed control method was checked through numerical experiments. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 Optimization of Inventories for Multiple Companies by Fuzzy Control Method 71 78 EN Koichi Kawase Masami Konishi Jun Imai In this research, Fuzzy control theory is applied to the inventory control of the supply chain between multiple companies. The proposed control method deals with the amount of inventories expressing supply chain between multiple companies. Referring past demand and tardiness, inventory amounts of raw materials are determined by Fuzzy inference. The method that an appropriate inventory control becomes possible optimizing fuzzy control gain by using SA method for Fuzzy control. The variation of uncertain demand is given to the proposal method. Furthermore, the method of forecasting demand and the effectiveness of fuzzy control method are confirmed by numerical experiments. As the results, the proposal method suppressed increase in an unnecessary cost when demand varies. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 Transfer Planning of Molten Metals in Steel Worksby Decentralized Agent 60 70 EN Junji Kikuchi Masami Konishi Jun Imai In steel works, molten metals discharged from blast furnace are put into a pan for transportation called torpedo and transported to steel making factory by a locomotive. In molten metals transportation, it becomes issues to prevent temperature drop of molten metals for stable production of down stream plants to shorten transportation time. Therefore it is necessary to make an appropriate plan for molten metals transfer considering the production and the transportation simultaneously. In this paper, molten metals transfer planning method is proposed including production scheduling. That is, torpedo schedule, transfer request assignment and route plan of locomotives are optimized according to each objective. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 42 1 2008 Transfer of Quantum Information by Spin Chains : Effect of Noise 53 55 EN Hiroo Totsuji In order to transfer quantum information, the use of spin chains has been proposed and their transfer characteristics have been analyzed. As one of the latter, the maximum of the transfer probability over sufficiently long time period is often considered important and some examples with high maximum values have been given. In these examples, the coupling between neighboring spins are tuned so as to attain high efficiency. In this article, we discuss the effect of noise on the values of coupling constant. As a result, we propose a system where the efficiency is high and also the effect of noise is small. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 41 1 2007 An Algorithm for Generating Irreducible Cubic Trinomials over Prime Field 11 19 EN Yasuyuki Nogami Yoshitaka Morikawa This paper proposes an algorithm for generating irreducible cubic trinomials in the form x(3) + ax + b, b ∈ F(p), where a is a certain fixed non-zero element in the prime field F(p). The proposed algorithm needs a certain irreducible cubic trinomial over F(p) to be previously given as a generator; however, the proposed algorithm can generate irreducible cubic polynomials one after another by changing a certain parameter in F(p). In this paper, we compare the calculation cost and the average computation time for generating an irreducible cubic polynomial, especially trinomial, among Hiramoto et al. irreducibility testing algorithm, Berlekamp-Massey minimal polynomial determining algorithm, and the proposed algorithm. From the experimental results, it is shown that the proposed algorithm is the fastest among the three algorithms for generating irreducible cubic trinomials. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 41 1 2007 The Number of the Irreducible Cubic Polynomials in the Form of x(3) + ax + b with a Certain Fixed Element a 1 10 EN Yasuyuki Nogami Yoshitaka Morikawa In this paper, we first show the number of x's such that x(2) +u, u ∈ F(*)(p) , becomes a quadratic residue in F(p), and then this number is proven to be equal to (p+1)/2 if −u is a quadratic residue in Fp, which is a necessary fact for the following. With respect to the irreducible cubic polynomials over Fp in the form of x(3)+ax+b, we give a classification based on the trace of an element in F(p3) and based on whether or not the coefficient of x, i.e. the parameter a, is a quadratic residue in Fp. According to this classification, we can know the minimal set of the irreducible cubic polynomials, from which all the irreducible cubic polynomials can be generated by using the following two variable transformations: x=x + i, x=j−1x, i, j ∈ Fp, j ≠ 0. Based on the classification and that necessary fact, we show the number of the irreducible cubic polynomials in the form of x(3)+ax+b, b ∈ F(p), where a is a certain fixed element in F(p). No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 41 1 2007 Method for Production Planning and Inventory Control in OilRenery 20 30 EN Takuji Imamura Masami Konishi Jun Imai In this paper, we propose a simultaneous optimization method for inventory control and production planning problem for a chemical batch plant. The plant consists of blending process, intermediate storage tanks and filling process. In the proposed method, the original problem is decomposed into production planning sub-problem and inventory control sub-problem. Then the decision variables are optimized by alternately solving each sub-problem. The solution of the proposed method is compared with that of centralized optimization method. The effectiveness of the proposed method is investigated from numerical computational results. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 41 1 2007 Simultaneous Optimization of Production and TransportationPlanning by using Logic Cut Algorithm 31 43 EN Ryohei Hamana Masami Konishi Jun Imai Various kind of productions are made in semiconductor factories, where it employs the production system with multiprocess and multiple Automated Guided Vehicles(AGVs) for transportation. It is difficult to optimize planning of production and transportation simultaneously because of the complicated flow of semifinished products. This paper describes the formulations of production scheduling and transportation routing, and algorithm for simultaneous optimization of plannings by using logic cuts. The entire problem is decomposed to the master problem and the sub problem. If it derives the infeasible solutions, new constraints are added to the master problem to eliminate the solution area including infeasible solutions. The results of about optimality and computation time by using CPLEX solver are shown compared with conventional decomposition method to check up effectivity of proposed method in small size problem, and about optimality and computaion time for large scale problem. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 41 1 2007 Decomposition of Time Petri Nets for Solving Optimal FiringSequence Problem 44 51 EN Ryota Maeno Masami Konishi Jun Imai Petri net model is a frequently-used versatile tool which can represent a widely discrete event system. However, when the scale of the system becomes large, the calculation time for solving optimal problem (optimal firing sequence problem) is markedly increased. In this paper, we propose an approximation method that achieves the efficiency improvement of the solution by decomposing the Petri net for solving the optimal firing sequence problem. A timed Petri Net is decomposed into several subnets in which the optimal firing sequence for each subnet is solved by Dijkstra’s algorithm in polynomial computational complexity. The effectivity of the proposed method is verified by numerical experiments for the flowshop schedule problem. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 41 1 2007 Heat and Mass Transfer Analysis of Fluidized Bed Grain Drying 52 62 EN Hideo Inaba Akihiko Horibe Naoto Haruki The effects of heat and mass transfer parameters on the efficiency of fluidized bed drying have been studied to optimize the input and output conditions. The analysis was carried out using two different materials, wheat and corn. Energy and exergy models based on the first and second law of thermodynamic are developed. Furthermore, some unified non-dimensional experimental correlations for predicting the efficiency of fluidized bed drying process have been proposed. The effects of hydrodynamics and thermodynamics conditions such as the inlet air temperature, the initial moisture content and well known Fourier and Reynolds numbers on energy efficiency and exergy efficiency were analyzed using the developed model. A good agreement was achieved between the model predictions, non-dimensional correlations and the available experimental results. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 41 1 2007 Experimental Evaluation of Geometric Fitting Algorithms 63 72 EN Kenichi Kanatani Yasuyuki Sugaya The convergence performance of typical numerical schemes for geometric fitting for computer vision applications is compared. First, the problem and the associated KCR lower bound are stated. Then, three well known fitting algorithms are described: FNS, HEIV, and renormalization. To these, we add a special variant of Gauss-Newton iterations. For initialization of iterations, random choice, least squares, and Taubin’s method are tested. Numerical simulations and real image experiments and conducted for fundamental matrix computation and ellipse fitting, which reveals different characteristics of each method. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 41 1 2007 Statistical Optimization for Geometric Fitting: Theoretical Accuracy Bound and High Order Error Analysis 73 92 EN Kenichi Kanatani A rigorous accuracy analysis is given to various techniques for estimating parameters of geometric models from noisy data for computer vision applications. First, it is pointed out that parameter estimation for vision applications is very different in nature from traditional statistical analysis and hence a different mathematical framework is necessary in such a domain. After general theories on estimation and accuracy are given, typical existing techniques are selected, and their accuracy is evaluated up to higher order terms. This leads to a “hyperaccurate” method that outperforms existing methods. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 41 1 2007 Structure, Morphology and Color Tone Properties of the Neodymium Substituted Hematite 93 98 EN Makoto Nakanishi Tatsuo Fujii Jun Takada Co-precipitation method has been employed to fabricate neodymium substituted hematite with different compositions from the aqueous solution of their corresponding metal salts. Thermal analysis and X-ray diffraction studies revealed the coexistence of Fe(2)O(3) and Nd(2)O(3) phases up to 1050℃ and formation of solid solution phase among them at 1100℃ and above temperatures, which was evidenced by shifting of the XRD peaks. Unit cell parameters and the cell volumes of the samples were found to increase by adding Nd(3+) ions in the reaction process. FESEM studies showed the suppression of particle growth due to the presence of Nd(3+) ions. Spectroscopic measurement evidenced that neodymium substituted hematite exhibited brighter yellowish red color tone than that of pure α-Fe(2)O(3). No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 40 1 2006 Statistical Estimation Model for Product Quality of Petroleum 9 15 EN Takashi Nukina Masami Konishi Tatsushi Nishi Jun Imai Controls of the temperature, pressure and flowing quantity are important for the stable operation of the product quality in the distillation tower. The usual measuring way of product quality estimation is made by the off-line analysis. In this paper, online estimation method of product quality is studied for improving the product quality. The estimation method based on stochastic analysis was developed for online estimation. In this paper, the data of temperature, pressure and flow volum in the distillation tower are treated. As the estimation models, RNN (Recurrent Neural Net Work) and PLS (Partial Least Square Regression Method) were adopted. The actual plant data were used in the analysis. Both PLS and RNN models could compensate each other to improve the accuracy in estimation. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 40 1 2006 Distribution of Electrons in Quantum Dots Analyzed by Classical Mapping and Molecular Dynamics 40 43 EN Miyake Takashi Chieko Totsuji Kenji Tsuruta Hiroo Totsuji The electron system of arbitrary degeneracy can be mapped onto a classical system where electrons of the same spin are assigned an additional interaction and the effect of degeneracy is taken into account through an imaginative temperature. We apply this method to electrons in quantum dots modeled as two-dimensional electron liquid confined in a finite domain by a harmonic potential. We analyze distribution functions by molecular dynamics instead of solving integral equations which are not so useful in the case without translational invariance. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 40 1 2006 Stochastic-Dierence-Equation Method for Long Time-scale Molecular Dynamics Simulations 36 39 EN Atsushi Uchida Chieko Totsuji Kenji Tsuruta Hiroo Totsuji We present a Stochastic-Difference-Equation (SDE) approach to long time-scale molecular dynamics (MD) simulations, which are required for nanosecond-scale phenomena. In this method, the MD trajectory in a fixed time period is obtained as a stationary solution of an action functional based on an error accumulation of the equation of motion along the path, thus reducing the problem to a boundary-value problem, instead of an initial-value problem in the ordinary MD method. We apply the method to formation processes of Cu thin film via nanocluster deposition onto a substrate. The applicability of the SDE algorithm to the problem and the effects of the choice of SDE parameters on the optimization processes of configuration pathway are examined. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 40 1 2006 Melting of Spherical Yukawa Clusters Analyzed by Monte Carlo Simulation 31 35 EN Takafumi Ogawa Chieko Totsuji Kenji Tsuruta Hiroo Totsuji We analyze the melting of spherical Yukawa clusters by Monte Carlo simulations. Spherical clusters are expected to be found in dusty plasmas in an isotropic environment such as microgravity and serve as a model for classical clusters. We obtain the specific heat through fluctuations of the potential energy and identify its peak as the transition temperature. Melting temperatures are compared with those of bulk Yukawa systems and it is confirmed that the melting temperature increases and approaches the bulk value with the increase of the system size. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 40 1 2006 Transfer Routing of Ore Yard by Decentralized Agent Method 23 30 EN Junji Kikuchi Masami Konishi Tatsushi Nishi Jun Imai In steel works, iron ores are stored in ore yard and sent to various plants of down stream accoding to transfer requests. To attain stable operation, it is neccesary to keep a certain allowable stock level in ore tanks of all plants. To this purpose, ore transfer routing method has been developed based on decentralized agent method. In case of disaster such as a big earthquake or a big fire, damages in the facilities of industrial complex may be unavoidable. In this paper, decentralized optimization method is tested to cope with such emergencies. Decentralized agents corresponding to kind of ore make their own transfer route plan exchanging information with others. As the application of the proposed method, transfer scheduling in ore yard in steel works are made in case of destruction of transfer facilities. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 40 1 2006 Generating Dense Point Matches Using Epipolar Geometry 44 52 EN Yasuyuki Sugaya Kenichi Kanatani Yasushi Kanazawa Dense point matches are generated over two images by rectifying the two images to align epipolar lines horizontally, and horizontally sliding a template. To overcome inherent limitations of 2-D search, we incorporate the “naturalness of the 3-D shape” implied by the resulting matches. After stating our rectification procedure, we introduce our multi-scale template matching scheme and our outlier removal technique using tentatively reconstructed 3-D shapes. Doing real image experiments, we discuss the performance of our method and remaining issues. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 40 1 2006 Uncalibrated Factorization Using a Variable Symmetric Affine Camera 53 63 EN Kenichi Kanatani Yasuyuki Sugaya In order to reconstruct 3-D Euclidean shape by the Tomasi-Kanade factorization, one needs to specify an affine camera model such as orthographic, weak perspective, and paraperspective. We present a new method that does not require any such specific models. We show that a minimal requirement for an affine camera to mimic perspective projection leads to a unique camera model, which we call a symmetric affine camera, which has two free functions. We determine their values from input images by linear computation and demonstrate by experiments that an appropriate camera model is automatically selected. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 40 1 2006 Overview of 3-D Reconstruction from Images 64 77 EN Kenichi Kanatani This article summarizes recent advancements of the theories and techniques for 3-D reconstruction from multiple images. We start with the description of the camera imaging geometry as perspective projection in terms of homogeneous coordinates and the definition of the intrinsic and extrinsic parameters of the camera. Next, we described the epipolar geometry for two, three, and four cameras, introducing such concepts as the fundamental matrix, epipolars, epipoles, the trifocal tensor, and the quadrifocal tensor. Then, we present the self-calibration technique based on the stratified reconstruction approach, using the absolute dual quadric constraint. Finally, we give the definition of the affine camera model and a procedure for 3-D reconstruction based on it. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 40 1 2006 The Orders of Elliptic Curves y(2) = x(3) + b, b ∈ F(* q) 83 94 EN Yasuyuki Nogami Yoshitaka Morikawa This paper particularly deals with elliptic curves in the form of E(x, y) = y(2) − x(3) −b = 0, b ∈ F(* q) , where 3 divides q−1. In this paper, we refer to the well-known twist technique as x-twist and propose y-twist. By combining x-twist and y-twist, we can consider six elliptic curves and this paper proposes a method to obtain the orders of these six curves by counting only one order among the six curves. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 40 1 2006 An Eye-Contour Extraction Algorithm from Face Image using Deformable Template Matching 78 82 EN Nobuo Funabiki Megumi Isogai Teruo Higashino A variety of studies on face components such as eyes, lips, noses, and teeth have been proceeding in medicine, psychology, biometrics authentication, and other areas. In this paper, we present an algorithm of extracting eye contours from a face image using the deformable template matching method. Our template for an eye contour is composed of three quadratic functions for the perimeter and one circle for the pupil. In our algorithm, a digital color face image is rst converted to a binary image of representing eyes, after the region around eyes is identied on the face image by using hues and values of the color image. Then, parameters in the template are optimized by a local search method with a tabu period and a hill-climbing, so as to t the template to the eye contour in the binary image. The accuracy of our algorithm is evaluated through sample face images of students. In addition, the application of our proposal to eye shape indices is investigated in a face image database "HOIP", where recognizable dierence exists in index distributions between males and females. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 40 1 2006 Fatigue Crack Propagation Behavior Bent from Precrack under Mixed-Mode Conditions - Noting the Crack-Surface Contact due to a Compressive Residual Stress along a Precrack - 1 8 EN YouLi Ma Kenichi Shimizu Tashiyuki Torii A testing for bent fatigue crack propagation under mixed-mode conditions was carried out using fatigue and annealed slant precracks with different slant angles, β ,defined as the angle between loading and precrack directions in a rectangular plate. As a result, bent fatigue crack from the fatigue precrack with β =45deg. propagated under mixed-mode conditions with mode II stress intensity factor (K(II))(est) evaluated from the discontinuous displacement measured along the crack. On the other hand, bent fatigue crack from the fatigue precrack with β =60deg. and from the annealed precracks with both slant angles of β =60deg. and β =45deg. propagated under the mode I behavior. This was because the compressive residual stress near the fatigue precrack caused contact to each other between the upper and the lower surfaces of the precrack with the smaller slant angle β . Furthermore, the fatigue crack propagation rates indicated almost the same relationship for all the data, using the mixed-mode effective stress intensity factor (K(M))(est), calculated from the discontinuous displacement measured along the bent fatigue crack. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 40 1 2006 RNN Based Auto-tuning of PID Control Gains in Hot StripLooper Controller 16 22 EN Yoshihiro Abe Masami Konishi Tatsushi Nishi Jun Imai In this study, auto tuning of PID control gains in hot strip looper controller is made based on RNN model. Neuro emulator is employed to model the characteristics of looper dynamics. Combining neuro emulator and RNN model, auto tuning system of PID control gains is constructed. As the inputs to RNN, plural evaluation functions which reflect individual preference of human experts. Further, Self learning mechamism is embeded to RNN model which enables adaptation to the change in rolling chracteristics. Through numerical experiments, the effect of the proposed method is ascertained. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 39 1 2005 Electron Dynamics in Semiconducting Nanowires: A Real-Space, Polynomial-Expansion Approach 46 51 EN Keisuke Kadono Chieko Totsuji Kenji Tsuruta Hiroo Totsuji We present a real-space, polynomial-expansion approach to electron dynamics in nanostructured semiconductors. The Chebyshev expansion method is employed for efficient calculation of timeevolution of single-electron wave function. Details of the formulation are described. The method is applied to the electron transport in nanostructured semiconductors such as Si nanowires. The mean-square displacement and diffusivity of electron in Si chains are obtained as functions of length of the chains. The results show clearly ballistic behavior of electron in the pure Si chain. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 39 1 2005 Microscopic Surface Change of Polycrystalline Aluminum during Tensile Plastic Deformation 7 15 EN Xiaoqun Wang Takeji Abe Naoya Tada Ichiro Shimizu Roughening on free surface of polycrystalline metal during plastic deformation is closely related to the inhomogeneous deformation in the respective grain at the surface. Uniaxial tensile tests are carried out on annealed pure aluminum sheet specimens with various averaged grain sizes. The roughening is measured by a 3-dimensional stylus instrument to examine the roughness change in both sides of specimen surfaces at each strain. The irregularities on one side are reversed on the backside, when the averaged grain size is as large as the thickness of the specimen. Discussions are made on the relation between the surface shapes of both sides adopting the cross correlation factor. The strains of respective grains are also measured from the grain boundary shape before and after plastic deformation. There are some deviations in the strains of the grains and their standard deviation increases with the applied strain. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 39 1 2005 Improving Methods of Wear Resistance in Heavy Loaded Sliding Friction Pairs 1 6 EN Masahiro Fujii Akira Yoshida Improvement of wear resistance and durability of machine elements with sliding friction pairs is the important tribological problems. The wear resistance has been determined with many configurative parameters, technological parameters, and operational parameters. In this study kinematics of cylindrical joint (CJ), whose motion is reciprocating and rotating, and influence of various parameters on wear resistance of friction pair was investigated. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 39 1 2005 Immobilization of Photoelectric Dye on the Polyethylene Film Surface 16 20 EN Tetsuya Uchida Sanae Ishimaru Kaoru Shimamura Akihito Uji Toshihiko Matsuo Hiroshi Ohtsuki PE film was treated with fuming nitric acid at 80℃ for 20 min, resulting in introduction of COOH moieties on the film surface. The COOH’s were reacted with ethylenediamine, whose amino groups were used for linking with (2-[4-(dibutylamino)phenyl]ethenyl)-3-carboxy-methylbenzo-thiazolium, photoelectric dye (NK-5962), which absorbs visible light and converts the photon energy to electric potentials. The dye molecules were immobilized on the PE film surface and they were able to stimulate chick retinal tissues on incidence of visible light. These facts hopefully lead to development of an artificial retinal prosthesis. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 39 1 2005 Application of Neural Network to Fault Diagnosis ofElectro-Mechanical System 21 27 EN Takashi Torigoe Masami Konishi Jun Imai Tatsushi Nishi In this paper, neuro based intelligent diagnosis methods for electro-mechanical control system are proposed. A self organizing map neural network (SOM) is used to classify measured data of the target system as a qualitative diagnostic method. Besides of the above procedure, it is expected to attain more efficient maintenance by a quantitative estimation of failure. For the purpose, new method is proposed using a hierarchical neural network (HNN). In the method, classified results by SOM are processed for the quantitative diagnosis. Hierarchical neural network can identify inner structure of the relations between failure causes and its results that enables a quantitative diagnosis. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 39 1 2005 Application of Sequential Quadratic Programming Method toTemperature Distribution Control in Reactor Furnace 28 39 EN Kazuhito Ishimaru Masami Konishi Jun Imai Tatsushi Nishi In reactor furnace, due to high temperature and high pressure, data can be measured only near the furnace wall. In this paper, the way to estimate temperature distribution in a reactor furnace using measured data near the furnace walls and to control temperature distribution to the desired temperature distribution was studied. In the estimation, SQP method is employed using measured data near the furnace walls. As the result, the whole temperature distribution in a furnace could be obtained from such limited data. Furthermore, to control the temperature distribution in a reactor furnace, gas flow from multiple tuyeres and supplying material for controlling temperature distribution in a reactor furnace were determined by the SQP method. It was shown that temperature distribution in a furnace was regulated to achieve various desired distribution. Thus, it was verified that complicated temperature distribution in a reactor furnace could be controlled by combining furnace simulation and SQP method. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 39 1 2005 A Scheme to Classify Clouds with the Depolarization Ratio andBackscattering Coeffcient Measured by Lidar 93 101 EN Kengo Iokibe Yoshitaka Toyota Osami Wada Ryuji Koga The optical properties of clouds were measured with a polarization Mie lidar during April, 2004 and investigated to categorize the particles detected by the lidar. The cloud layers were categorized into five types according to the depolarization ratios, as follows: (I) constant and small (less than 5%); increasing with height (II) nearly from 0% and (III) from about 50%; (IV) large and varying with the backscattering coefficient; and (V) sharply decreasing. This categorization of clouds enabled us to separate aerosols from clouds in a lidar signal. Comparison of the backscattering coefficients between clouds of types (I) and (II) suggested that the depolarization ratio induced by multiple scattering in dense clouds does not depend on the particle density. Estimation of the particle phase for the five cloud categories was also examined. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 39 1 2005 A High-Speed Square Root Computation in Finite Fields with Application to Elliptic Curve Cryptosystem 82 92 EN Feng Wang Yasuyuki Nogami Yoshitaka Morikawa In this paper, we focus on developing a high-speed square root (SQRT) algorithm required for an elliptic curve cryptosystem. Examining Smart algorithm, the previously well-known SQRT algorithm, we can see that there is a lot of computation overlap in Smart algorithm and the quadratic residue (QR) test, which must be implemented prior to a SQRT computation. It makes Smart algorithm inefficient. The essence of our proposition is thus to present a new QR test and an efficient SQRT algorithm to avoid all the overlapping computations. The authors devised a SQRT algorithm for which most of the data required have been computed in the proposed QR test. Not only there is no computation overlap in the proposed algorithm and the proposed QR test, but also in the proposed algorithm over GF(p(2)) (4 | p − 1) some computations can be executed in GF(p); whereas in Smart algorithm over GF(p(2)) all the computations must be executed in GF(p(2)). These yield many reductions in the computational time and complexity. We implemented the two QR tests and the two SQRT algorithms over GF(pm) (m=1, 2) in C++ language with NTL (Number Theory Library) on Pentium4 (2.6GHz), where the size of p is around 160 bits. The computer simulations showed that the proposed QR test and the proposed algorithm over GF(p(m)) were about 2 times faster than the conventional QR test and Smart algorithm over GF(p(m)). No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 39 1 2005 A Method for Generating Prime Order Elliptic Curves over F(q(2c)) 71 81 EN Yasuyuki Nogami Yoshitaka Morikawa This paper proposes an algorithm for generating prime order elliptic curves over extension field whose extension degree is a power of 2. The proposed algorithm is based on the fact that the order of the twisted elliptic curve is able to be a prime number when the extension degree for the twist operation is a power of 2. When the definition field is F(2(40)−87)(4) , the proposed algorithm can generate a prime order elliptic curve within 5 seconds on PentiumIII (800MHz) with C language. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 39 1 2005 Optimality of Maximum Likelihood Estimation for Geometric Fitting and the KCR Lower Bound 63 70 EN Kenichi Kanatani Geometric fitting is one of the most fundamental problems of computer vision. In [8], the author derived a theoretical accuracy bound (KCR lower bound) for geometric fitting in general and proved that maximum likelihood (ML) estimation is statistically optimal. Recently, Chernov and Lesort [3] proved a similar result, using a weaker assumption. In this paper, we compare their formulation with the author’s and describe the background of the problem. We also review recent topics including semiparametric models and discuss remaining issues. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 39 1 2005 Extracting Moving Objects from a Moving Camera Video Sequence 56 62 EN Yasuyuki Sugaya Kenichi Kanatani We present a new method for extracting objects moving independently of the background from a video sequence taken by a moving camera. We first extract and track feature points through the sequence and select the trajectories of background points by exploiting geometric constraints based on the affine camera model. Then, we generate a panoramic image of the background and compare it with the individual frames. We describe our image processing and thresholding techniques. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 39 1 2005 Agent Based Plant Allocation and Transfer Routing of Productsin Case of Emergency 40 45 EN Sulaiman Al-Sehaim Masami Konishi Kazuo Nose In this paper, two problems, plant allocation problem and that of transfer routing from plants to customers, are considered simultaneously. Especially, adaptation scheme for emergency cases are checked. To solve these problems, decentralized agent based optimization procedures are used. In our study, oil production and products transfer in Saudi Arabia are treated. Through numerical experiments, practicability of the proposed method is verified. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 39 1 2005 Large-Scale Molecular Dynamics Simulation of Coulomb Clusters: A Finite-Temperature Analysis 52 55 EN Katsuya Kanamori Chieko Totsuji Kenji Tsuruta Hiroo Totsuji Thermal behavior of Coulomb clusters in a three dimensional confining potential is investigated by molecular dynamics simulations for system sizes of 1,000 to 20,288 ions. The specific heat of the system of shell-structured 20,000 ions is peaked almost at the same temperature as the system of bcc-structured 20,288 ions with much sharper structure for the latter. The diffusion coefficient and the peak to valley ratio of the two-dimensional pair distribution function on the outermost shell are obtained both as a function of temperature. The rotational movement of each shell in the system of 104 ions is observed. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 38 1-2 2004 Factorization without Factorization: Complete Recipe 61 71 EN Kenichi Kanatani Yasuyuki Sugaya The Tomasi-Kanade factorization for reconstructing the 3-D shape of the feature points tracked through a video stream is widely regarded as based on factorization of a matrix by SVD (singular value decomposition). This paper points out that the core principle is the affine camera approximation to the imaging geometry and that SVD is merely one means of numerical computation. We first describe the geometric structure of the problem and then give a complete programming scheme for 3-D reconstruction. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 38 1-2 2004 Generation of IgM and IgG1 monoclonal antibodies with identical variable regions: comparison of avidity 91 96 EN Naoki Kanayama Kimi Yamakoshi Masaaki Kiyomi Masaki Magari Hitoshi Ohmori Generally, IgM antibodies (Abs) produced in a primary immune response show lower affinity for an inducing antigen (Ag) compared with the corresponding IgG Abs that are major switched isotypes formed in the secondary response. An IgM molecule is a pentamer with 10 Ag-binding sites that will contribute to an increase of avidity for an Ag. To estimate the contribution of the pentameric structure to the avidity of an IgM Ab, we generated IgM and IgG1 monoclonal Abs (mAbs) with identical V regions that are specific for 4-hydroxy-3-nitrophenylacetyl (NP) by in vitro class switching of B cells followed by the cell fusion with a mouse myeloma cell line. Compared with an anti-NP IgG1 mAb, the corresponding IgM mAb showed much higher avidity for NP-conjugated bovine serum albumin, which was drastically reduced after being dissociated into monomers. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 38 1-2 2004 Feature Extraction and Classification of Operational Data for Diagnosis of Hot Strip Mill Looper Control 15 27 EN Takashi Torigoe Masami Konishi Jun Imai Tatsushi Nishi In these days, mechanical systems are becoming more complex and highly automated. So, there exist wide variety of demands for reliable diagnostic technology. A reliable data analysis and quantitative diagnosis method of mechanical system is necessary for the purpose. In this paper a quantitative diagnosis method for looper height control system has been developed based on neural network technologies. The wavelet transformation is used for pre-processing to analyze characteristics of looper height control system. And, self organizing map neural network is used for the purpose of classification based on the pre-processed data. After that, the classified results are used for quantitative diagnosis in hierarchical neural network. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 38 1-2 2004 contents / back cover EN No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 38 1-2 2004 Structure of Dusty Plasma under Microgravity 29 32 EN Hiroo Totsuji Chieko Totsuji Takafumi Ogawa Kenji Tsuruta The structure of dust particles in dusty plasmas under microgravity has been analyzed by molecular dynamics simulation. The charge neutrality condition satisfied by the system composed of dust particles and ambient plasma is properly taken into account. It is shown that dust particles form shell structures at low temperatures and the number of shells are obtained as a phase diagram in the plane of two parameters characterizing the system: the number of particles and the strength of screening. It is also shown that these structures are almost independent of the strength of screening. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 38 1-2 2004 The cytotoxicity of Bacillus thuringiensis subsp. coreanensis A2316 strain against the human leukemic T cell 97 100 EN Masashi Yamagiwa Taichi Hirao Masaaki Kiyomi Tetsuyuki Akao Eiichi Mizuki Michio Ohba Hiroshi Sakai Bacillus thuringiensis subsp. coreanensis A2316 is a newly isolated strain from Yonakunijima Island in Japan. It produces the proteinaceous inclusion body (crystal) which has no insecticidal and hemolytic activities. When the crystal proteins were digested by proteinase K, they exhibited the strong cytotoxicity against human leukemic T cell, MOLT-4. The proteinase K-digested A2316 crystal proteins have little damage upon the cell membrane of MOLT-4, suggesting that the cell death of MOLT-4 was induced through a mechanism other than the colloid-osmotic swelling and cell lysis as caused by hitherto known B. thuringiensis crystal proteins. The 29-kDa polypeptide proved to be an active component of the proteinase K-digested A2316 crystal proteins. EC(50) of the purified 29-kDa polypeptide was 0.0579 μg/ml. The N-terminal amino acid sequence of the 29-kDa polypeptide was identical with that of p29 produced by B. thuringiensis A1519 strain and shared no significant homology with all the known proteins, suggesting that this polypeptide belong to a new family of B. thuringiensis crystal proteins. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 38 1-2 2004 Dynamical Properties of Two-Dimensional Yukawa Liquids: A Molecular Dynamics Study 33 37 EN M. Sanusi Liman Chieko Totsuji Kenji Tsuruta Hiroo Totsuji The dynamic structure factor and the spectrum of the momentum-density fluctuations of 2D Yukawa liquids are analyzed in the domain of weak and intermediate coupling and screenlng parameters. The dispersion relations of the longitudinal and transverse collective excitations are obtained and compared with the random phase approximation (RPA) and harmonic approximation for triangular lattice. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 38 1-2 2004 Combinatorial Boundary Tracking of a 3D Lattice Point Set 73 89 EN Yukiko Kenmochi Atsushi Imiya Boundary tracking and surface generation are ones of main topological topics for three-dimensional digital image analysis. However, there is no adequate theory to make relations between these different topological properties in a completely discrete way. In this paper, we present a new boundary tracking algorithm which gives not only a set of border points but also the surface structures by using the concepts of combinatorial/algebraic topologies. We also show that our boundary becomes a triangulation of border points (in the sense of general topology), that is, we clarify relations between border points and their surface structures. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 38 1-2 2004 Control Method for Temperature Distribution in Reactor Furnace by Sequential Quadratic Programming Method 5 14 EN Kazuhito Ishimaru Masami Konishi Jun Imai Tatsushi Nishi Temperature distribution in the reactor furnace is mainly operated by gas blowing from multiple tuyeres and material charge distribution. The objective of our research is obtain the optimal profile of gas flow to control temperature distribution in the reactor furnace in the shortest possible time. We formulated the optimization problem to reduce deviation of temperature distribution from its desired one in the reactor furnace. Based on the formulation, gas blow conditions are optimized by a sequential quadratic programming method to realize the desired temperature distribution. The validity of the method was checked through numerical experiments. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 38 1-2 2004 Serration and Reversion Treatment in Al-10mass%Zn Alloy 1 4 EN Akira Sakakibara Teruto Kanadani The relationship between occurrence of serration and reversion heat treatment was studied by tensile test on Al-10mass%Zn alloy. Serration was observed for the furnace cooled specimen, but not for the as-quenched one and the shortly aged one, which result is difficult to be interpreted by the Cottrell theory. The stress amplitude in the serration increased with increasing the time of annealing for reversion up to 10ks and then stayed at a constant value which might be interpreted by the Cottrell theory. The stress amplitude in the serration decreased with increasing the annealing temperature, which is contrary to the prediction by the Cottrell theory. The specimen directly annealed without aging and the one annealed after aging agreed well with each other in the tensile strength and the stress amplitude in the serration, which suggests solute clusters as the cause of serration. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 38 1-2 2004 cover / title page EN No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 38 1-2 2004 Uncertainty Modeling and Geometric Inference 39 59 EN Kenichi Kanatani We investigate the meaning of "statistical methods" for geometric inference based on image feature points. Tracing back the origin of feature uncertainty to image processing operations, we discuss the implications of asymptotic analysis in reference to "geometric fitting" and "geometric model selection", We point out that a correspondence exists between the standard statistical analysis and the geometric inference problem. We also compare the capability of the "geometric AIC" and the "geometric MDL' in detecting degeneracy. Next, we review recent progress in geometric fitting techniques for linear constraints, describing the "FNS method", the "HEIV method", the "renormalization method", and other related techniques. Finally, we discuss the "Neyman-Scott problem" and "semiparametric models" in relation to geometric inference. We conclude that applications of statistical methods requires careful considerations about the nature of the problem in question. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 2 2003 contents / back cover EN Faculty of Engineering, Okayama University No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 2 2003 cover / title page EN Faculty of Engineering, Okayama University No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 2 2003 Serration in A l-Zn Alloys Containing a Small Amount of Fe 1 4 EN Akira Sakakibara Teruto Kanadani Effect of addition of Fe on the occurrence of serration in Al-12mass%Zn alloys was investigated. Specimens aged at 293K for various periods after quenching from various temperatures (T(Q)), 398K to 823K, were tensile-tested at room temperature. Serration occurred more easily and more remarkably with decreasing T(Q) for as-quenched specimens: in the case that T(Q)=448K serration was observed both for the binary and Fe added alloys, while in the case that T(Q)=573K none of the three alloys showed serration. For the binary alloy serration was observed only when the aging period was short enough, but addition of Fe to the binary alloy prolonged the aging period where serration could be recognized. Aging rate measured by hardness was remarkably retarded with the increase of Fe addition. These results confirm the interpretation that the serration in Al-Zn alloy occurs in the early stage of aging where small GP zones or solute clusters are formed. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 2 2003 Observation of Microscopic Deformation Behavior of Cork 5 12 EN Takeji Abe Takashi Sato Cork is a material that has many characteristics, for instance, light weight, elasticity, insulation against heat, impermeability for liquid, and so forth. There are two types of cork, the natural and the agglomerated corks. In the present paper, compression tests of the natural and the agglomerated cork specimens were carried out. The compression test were done in various directions. Compressive stress was measured by a original compression apparatus, and stress-strain curves were obtained in various directions of the cork specimens. In the natural cork, there are differences between the radial and the non-radial direction. The recovery of dimensions after compression was also studied in respective directions. The structure of the deformed surface was observed by a scanning electron microscope. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 2 2003 Sensitivity Analysis and its Application to the Control of Inner Furnace Temperature Distribution 13 27 EN Taizo Shibuta Masami Konishi Jun Imai Tatsushi Nishi Nowadays, various kind of reactor furnaces are widely used for the production in industry. The raw materials charged into the furnace generate reaction heat produced by blowing gas. Generally speaking, the reaction heat generated in the furnace is remarkably high. Therefore the occurrence of an inappropriate temperature distribution in the furnace may make damege or serious accident of the furnace. This is the motivation of furnace control. The author is considering the application of studied results to the furnace control of Blast Furnace in steel industry. To the propose, the approximated and simplified Macro Model of the Blast Furnace is constructed which has the function of representation of qualitative characteristics of the furnace in dynamical sense. The furnace temperature, distribution greatly effects both on the producting and the product quality of the furnace. Needless to say, stable furnace operation is indispensable for the economical prosperity of the industry. In this paper, macro simulation of the furnace is developed to support the analysis and design of the furnace control. Using the simulator, the stability and the control characteristics for inner furnace temperature distribtion are analised quantitatively. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 2 2003 Gain Tuning Model of Human Expert for Looper Height Control in Hot Strip Rolling 29 44 EN Shuya Imajo Masami Konishi Jun Imai Tatsushi Nishi In hot strip rolling mills, the looper control system is automated. However, the looper's behavior tends to be unstable in threading. Therefore, human expert always intervenes and stabilizes the looper's behavior by tuning PID gains and interposing manipulation variable of looper control system. In this paper, we propose a method based on the recurrent neural network to express PID gains tuning action by human. Furthermore, we propose two methods to update the model by learning. To check the effectiveness of the proposed learning methods, numerical simulation applied to the looper height control is carried out. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 2 2003 Estimation of Ground Resisitivity Distribution Using 3D DRM Charge Simulation Modelling 45 60 EN Wei Xu Y. Zhao T. Horikane T. Hayata H. Tosuji Y. Kagawa Resistivity distribution sounding of the non-homogeneous earth is important for electrical ground system design, geophysical prospecting and survey or monitoring the groundwater flow level. The previous paper presented that the direct inversion of the electric resistivity distribution in a domain is possible from the impedance data measured over the domain boundary using the dual reciprocity boundary element modelling in two-dimentional field [1]. The proposed inversion technique is extended to the distribution in three-dimensional space [2]. This technique is capable of inversion without iteration and meshing of the domain. Electric field with spatially varying conductivity is governed by Laplace equation, which is transformed into a Poisson-type expression with an inhomogeneous term involving the conductivity difference as a source term. Dual reciprocity method (DRM) is a technique for transforming the domain integral associated with the inhomogeneous term in Poisson equation into the boundary integral expression. The resistivity distribution in the field can thus be identified from the data observed over its boundary, for which some examples are demonstrated [2]. In this paper, the examination is extended to the case where only the data measured over the single surface is used for the inversion. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 2 2003 Motivation towards learning a second language (A Case Study-Part2. Denmark) 61 66 EN Chico Vaillancourt In this case study, I will analyse and discuss the results of a survey concerning motivation towards learning a second language conducted in one Danish high school. The students surveyed were between the ages of 13-18. This section, part two of the study, was conducted in Copenhagen, Denmark. This region of the world was chosen because bilingualism is quite common there and a large portion of the school-aged community is learning a second language and often a third and even a fourth. Denmark, a European country, is different than Canada (Case Study-Part 1.) because it neighbours many countries, which use different mother tongues. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 2 2003 The role of helices of domain I for the insecticidal activity of Bacillus thuringiensis Cry4A toxin 67 72 EN Masashi Yamagiwa Hiroshi Sakai An active form of Cry4A is a heterodimer of the 20- and 45-kDa fragments that are derived from the 130-kDa Cry4A protoxin. To investigate the function of these two fragments, several deletion mutants were constructed and expressed in E.coli as the GST (glutathione-S-transferase) fusion proteins. The results of the bioassay against Culex pipiens larvae showed that the interaction of two fragments of Cry4A was necessary for the toxicity, and that the C-terminal 67 amino acids of the 20-kDa fragment corresponding to the helices α4 and α5 were involved in determining the insecticidal activity. Surprisingly the lack of helix α5 did not affect the toxicity to C. pipiens, suggesting that the role of helix α5 of Cry4A was different from that postulated in the case of Cry4A toxins. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 2 2003 A Fast Implementation of Elliptic Curve Cryptosystem with Prime Order Defined over F(p8) 73 87 EN Yasuyuki Nogami Yoshitaka Morikawa Public key cryptosystem has many uses, such as to sign digitally, to realize electronic commerce. Especially, RSA public key cryptosystem has been the most widely used, but its key for ensuring sufficient security reaches about 2000 bits long. On the other hand, elliptic curve cryptosystem(ECC) has the same security level with about 7-fold smaller length key. Accordingly, ECC has been received much attention and implemented on various processors even with scarce computation resources. In this paper, we deal with an elliptic curve which is defined over extension field F(p2c) and has a prime order, where p is the characteristic and c is a non negative integer. In order to realize a fast software implementation of ECC adopting such an elliptic curve, a fast implementation method of definition field F(p2c) especially F(p8) is proposed by using a technique called successive extension. First, five fast implementation methods of base field F(p2) are introduced. In each base field implementation, calculation costs of F(p2)-arithmetic operations are evaluated by counting the numbers of F(p)-arithmetic operations. Next, a successive extension method which adopts a polynomial basis and a binomial as the modular polynomial is proposed with comparing to a conventional method. Finally, we choose two prime numbers as the characteristic, and consider several implementations for definition field F(p8) by using five base fields and two successive extension methods. Then, one of these implementations is especially selected and implemented on Toshiba 32-bit micro controller TMP94C251(20MHz) by using C language. By evaluating calculation times with comparing to previous works, we conclude that proposed method can achieve a fast implementation of ECC with a prime order. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 2 2003 Aerosol Extinction Coefficient Continuously Measured with Polarized Mie Scattering Lidar 89 97 EN Kengo Iokibe Yoshitaka Toyota Osami Wada Ryuji Koga Aerosol extinction coefficients of clouds and dust were continuously measured in the year of 2002 with a polarized Mie-scattering lidar controlled by an automatic and remotely operating system utilizing internet services. Measured cloud extinctions were greater than 1.0 km(-1) below the altitude 6 km, 0.17 - 1.0 km(-1) between 6 and 10 km, and 0.091 - 0.3 km(-1) beyond 10km. Extinction of dust were 0.10 and 0.20 km(-1) for Asian dust and 0.057 km(-1) for urban dust. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 1 2002 Agent Based Routing Control for Multi Mobile Robots in Transportation 1 10 EN Ken Sotobayashi Masami Konishi Tatsushi Nishi Jun Imai Auto Guided Vehicles (AGVs) are widely used in a semi-conductor fabricating factory and contribute to the stable production of a high quality semi-conductor products. In the near future, further expansion of the transportation system is expected accompanied with the rapid growth of semi-conductor industries. In such situation, the necessity of performing quick planning of transportation route and transportation control will be elevated. In this paper, practicable planning of the transportation route and transportation control are studied based on the decentralized agent method. Especially, the geometrical sizes of AGVs are considered in the determination of transportation routes and control strategy avoiding the occurrence of mutual collisions or deadlock of AGVs. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 1 2002 Estimation of the screening length and the electric charge on particles in single-layered dusty plasma crystals 11 14 EN Chieko Totsuji Muhammad S. Limant Kenji Tsuruta Hiroo Totsuji A theoretical approach which has been successful in reproducing results of molecular-dynamics simulations on dusty plasmas is applied to estimate the screening length and the electric charge of two-dimensional dust crystals of melamine particles in the discharge chamber experiment. It has been found that the screening length is of the same order of magnitude as the inter-particle distance and the electric charge decreases on increasing number density of dust particles. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 1 2002 contents / back cover EN Faculty of Engineering, Okayama University No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 1 2002 Pulse Timing Control of Multiple Signal Interconnections for Reduction of EMI 51 60 EN Akihiro Namba Yoshitaka Toyota Osami Wada Ryuji Koga This paper presents pulse timing control method to reduce electromagnetic emission from multiple signal interconnections. Pulse timing control gives intentional skew between signals. Higher order harmonics are canceled because of the difference of the phase between the signals. Using this property, pulse timing control can reduce the EMI in wide frequency range. In this paper, we show that radiated electromagnetic field from multiple signal lines reduces its intensity to the same level of the field from one line by using pulse timing control. The result of measurement shows that EMI from four differential transmission lines can be reduced more than 9 dB in the 200 MHz to 800 MHz frequency range. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 1 2002 Automatic Camera Model Selection for Multibody Motion Segmentation 41 49 EN Yasuyuki Sugaya Kenichi Kanatani We study the problem of segmenting independently moving objects in a video sequence. Several algorithms exist for classifying the trajectories of the feature points into independent motions, but the performance depends on the validity of the underlying camera imaging model. In this paper, we present a scheme for automatically selecting the best model using the geometric AIC before the segmentation stage, Using real video sequences, we confirm that the segmentation accuracy indeed improves if the segmentation is based on the selected model. We also show that the trajectory data can be compressed into low-dimensional vectors using the selected model. This is very effective in reducing the computation time for a long video sequence. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 1 2002 Robust Image Matching under a Large Disparity 25 32 EN Yasushi Kanazawa Kenichi Kanatani We present a new method for detecting point matches between two images without using any combinatorial search. Our strategy is to impose various local and non-local constraints as "soft" constraints by introducing their "confidence" measures via "mean-field approximations". The computation is a cascade of evaluating the confidence values and sorting according to them. In the end, we impose the "hard" epipolar constraint by RANSAC. We also introduce a model selection procedure to test if the image mapping can be regarded as a homography. We demonstrate the effectiveness of our method by real image examples. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 1 2002 For Geometric Inference from Images, What Kind of Statistical Model Is Necessary? 15 23 EN Kenichi Kanatani In order to facilitate smooth communications with researchers in other fields including statistics, this paper investigates the meaning of "statistical methods" for geometric inference based on image feature points, We point out that statistical analysis does not make sense unless the underlying "statistical ensemble" is clearly defined. We trace back the origin of feature uncertainty to image processing operations for computer vision in general and discuss the implications of asymptotic analysis for performance evaluation in reference to "geometric fitting", "geometric model selection", the "geometric AIC", and the "geometric MDL". Referring to such statistical concepts as "nuisance parameters", the "Neyman-Scott problem", and "semiparametric models", we point out that simulation experiments for performance evaluation will lose meaning without carefully considering the assumptions involved and intended applications. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 37 1 2002 cover / title page EN Faculty of Engineering, Okayama University No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 2 2002 Preparation of alginic acid layers on solid substrates for biomedical applications 67 72 EN Tomohiko Yoshioka Kanji Tsuru Satoshi Hayakawa Akiyoshi Osaka Alginic acid was immobilized on γ-aminopropyltriethoxysilane-coated glass as a model substrate since an alginic acid layer was known to prevent cell adhesion. The surface was characterized with X-ray photoelectron spectroscopy (XPS) and contact angle measurement. The coated substrates adsorbed practically no calcium phosphates on their surfaces when soaked in a simulated body fluid (SBF) of Kolrubo recipe. Since calcium ions are one of the factors for blood clotting, the present alginic acid coating is one of the candidates to improve blood compatibility of clinical materials. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 2 2002 Application of Transfer Matrix Method with Signal Flow-Chart to Analyze Optical Multi-Path Ring-Resonator 73 82 EN Iip Syarif Hidayat Yoshitaka Toyota Osamu Torigoe Osami Wada Ryuji Koga A multi-path ring-resonator (MPRR) was proposed to extend FSR of ring resonator. However, it is complicated to analyze the MPRR by using well-known analysis techniques such as scattering matrix or other numerical methods. This paper describes procedure for deriving transfer matrix by means of signal flow-chart to analyze the MPRR. We do not need complicated calculation for steady state analysis because transfer matrix elements are formulated clearly. As a result, The calcultaion time in this method can be reduced 1/3 to 1/20 times compared with using scattering matirx method. Furthermore, a transmittance characteristics of the MPRR at FSR extension-factor of 10 will also be shown. This suggests that analysis of other types of the MPRR by using this method can be performed simply and take a shorter time. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 2 2002 Cytotoxicity of the Bacillus thuringiensis Crystal Protein against Mammalian Cells 61 66 EN Masashi Yamagiwa Akitoshi Namba Tetsuyuki Akao Eiichi Mizuki Michio Ohba Hiroshi Sakai The crystal proteins produced by Bacillus thuringiensis subsp, israelensis (Bti) and subsp. coreanensis A1519 strain were examined for the cytotoxicity against MOLT-4 and HeLa cells by MTT assay and LDH assay, The A1519 crystal proteins processed by proteinase K exhibited the specific cell-killing activity toward MOLT-4 with little damage to the cell membrane, On the other hand, the Bti crystal proteins processed by proteinase K caused the substantial damage to the cell membrane of both MOLT-4 and HeLa, leading to the cell lysis. The non-digested crystal proteins of both strains exhibited no cytotoxicity, These data suggested that while the Bti crystal proteins caused the colloid-osmotic swelling and cell lysis of MOLT-4 and HeLa, the proteinase K-digested A1519 crystal proteins induced the specific cell death of MOLT-4 through a mechanism other than that of Bti. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 2 2002 Motivation towards learning a second language (A Case Study-Part 1. Canada) 43 49 EN Chico Vaillancourt In this case study, I will analyse and discuss the results of a survey concerning motivation towards learning a second language conducted in four Canadian schools. This section, part one of the study, was conducted in the Sudbury Region of Ontario, Canada. This region of the world was chosen because bilingualism is quite common there and a large portion of the community has learned a second language. Part two will be conducted in the winter of 2002, in Denmark, a European country that neighbours many countries with different mother tongues, I hope to conclude this case study with part three in the summer of 2002, in Japan, a monolingual island nation. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 2 2002 cover / title page EN Faculty of Engineering, Okayama University No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 2 2002 contents / back cover EN Faculty of Engineering, Okayama University No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 2 2002 Regulatory Role for Complement Receptors (CD21/CD35) in the Recombination Activating Gene Expression in Mouse Peripheral B Cells 51 60 EN Masaki Hikida Masaki Magari Yasunori Nakayama Naoki Kanayama Hitoshi Ohmori A population of peripheral B cells have been shown to express recombination activating gene products, RAG-1 and RAG-2, which are considered to be involved in revising the B cell antigen receptor (BCR) in the periphery. BCR engagement has been reported to turn off RAG expression in peripheral B cells, whereas the same treatment has an opposite effect in immature B cells in the bone marrow. In contrast to receptor editing that is involved in the removal of autoreactivity in immature B cells, it has been shown that secondary V(D)J rearrangement in peripheral B cells, termed receptor revision, contributes to affinity maturation of antibodies. Here, we show that RAG-2 expression in murine splenic B cells was abrogated by the coligation of BCR with complement receptors (CD21/CD35) much more efficiently than by the engagement of BCR alone. On the other hand, the same coligation augmented proliferation of anti-CD40-stimulated B cells. Consistent with these observations, RAG-2 expression was lower in the draining lymph nodes of the quasi-monoclonal mice when they were immunized with a high-affinity antigen than with a low-affinity one. These findings suggest a crucial role for CD21/CD35 in directing the conservation or the revision of BCRs in peripheral B cells. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 2 2002 Numerical Study on Deformation Behavior of Rigid-Plastic Inhomogeneous Material Using Three-Dimensional Models 7 13 EN Takeji Abe Makoto Nagao Tomoyuki Ohta Noriyuki Nagayama It is important to study the microscopic deformation behavior of inhomogeneous material, for most engineering materials are inhomogeneous. The aim of the present study is to clarify by numerical analysis some features of microscopic plastic strain distributions, the mean flow stress and the material factors affecting on it. The rigid-plastic solution is important not only for plastic deformation problems with large strain, but also for creep deformation problems through the plastic analogy in the creep analysis. The effects of material parameter and loading conditions on the deformation behavior of the material are examined and discussed based on the result of calculation. The effects of the aspect ratio of the inhomogeneous regions on the deformation mode are studied. The patterns of the strain concentration and the averaged flow stress of the inhomogeneous material are also discussed. The results of rigid-plastic material are compared with those of the elastic material. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 2 2002 A Study on the Planning and Scheduling of Production System Considering Demand Changes 15 42 EN Ryuji Ohtani Masami Konishi Jun Imai Tatsushi Nishi In this paper, we studied a planning and scheduling of production system considering demand changes. In the proposed system, planning part determines lot-size and amount of jobs in production. On the other hand, scheduling part determines the production sequence of jobs. In order to treat with the demand changes, both planning and scheduling should work well simultaneously. In the proposed system, preset and real time production control system is newly constructed from the view point of adaptive control. In the system, production planning is modified when the difference between production amount and demand becomes large. Moreover, production schedule is regenerated when the determined schedule is deviated from the prospected one. The scheduling system is characterized as the autonomous decentralized optimization system where each job works as agent and agent searches its appropriate starting time of processing. The effectiveness of the proposed system is confirmed by numerical examples. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 2 2002 Experimental Verification of Common-Mode Excitation Model for PCB Having Partially Narrow Return Path 83 89 EN Tetsushi Watanabe Osami Wada Ryuji Koga Yoshitaka Toyota Takuya Miyashita Suppression of common-mode current is important to achieve electromagnetic compatibility of high-speed and high-density electronic circuits. The authors have focused on the common mode current flowing on a printed circuit board (PCB) to explain the excitation mechanism. A narrow ground pattern in microstrip structure excites common-mode current. In the previous paper, the authors explained the mechanism of common mode generation by means of "current division factor" for simple PCBs. The estimated radiation from a simple PCB agreed well with measured one. In this paper, the authors extend the theory to be applied to generalize ground structure. The validity of the theory is confirmed by comparing the measured radiation and the estimated value using the common-mode model for a test PCB. The estimated radiation agrees well with the measured one within 3 dB up to 900 MHz. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 2 2002 Effect of Heat Treatment on the Serration of Low-Concentrated Al-Zn Alloys 1 6 EN Akira Sakakibara Teruto Kanadani Tsutomu Tashiro Kazumi Yoshioka The effect of heat-treatment conditions on occurrence of serration in Al-Zn alloys was investigated. Specimens were aged for various times up to 2.6Ms at 293K or 273K after quenching from various temperatures (T(Q)), 473K to 853K, and tensile-tested at room temperature. Serration occurred more easily according as T(Q) became lower and the aging time became shorter: in the case that T(Q)=473K serration was observed even after aging for 2.6Ms, while in the case that T(Q)=773K serration did not occur irrespective of aging conditions. Serration was also recognized when the specimens were furnace-cooled from 773K to room temperature. These results together with those obtained by the electrical resistometry suggest that the serration in the low'concentrated Al-Zn alloy is caused by the formation of small GP zones whose Guinier radius is less than 1nm or some sort of solute clusters. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 1 2001 Structure and Cohesive Energy of Large Spherical Coulomb Clusters 41 49 EN Hiroo Totsuji Tokunari Kishimoto Chieko Totsuji Kenji Tsuruta The ground state of spherical clusters of charged particles of one species confined by the three-dimensional parabolic potential is investigated by molecular dynamics simulations with the system size from N = 5000 to N = 1.2 × 10(5) . The cohesive energy per particle is compared between the shell-structured clusters and spherical finite bcc lattices with relaxed surfaces, the former and the latter being the ground states for small systems and for the large enough systems, respectively. It is shown that, when N > N(c)(N(c) > N), finite bcc lattices with relaxed surfaces (the shell structures) have stronger cohesion than the shell structures (finite bcc lattices with relaxed surfaces) and the critical value of the transition N(c) is estimated to be 10(4) < N(c) < 1.4 × 10(4) . The nucleation of the bcc lattice in the shell-structured cluster of 2 × 10(4) ions is observed. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 1 2001 Evaluation and Selection of Models for Motion Segmentation 91 106 EN Kenichi Kanatani Naoya Ohta We present a theoretically optimal linear algorithm for 3-D reconstruction from point correspondences over two views. We also present a similarly constructed optimal linear algorithm for 3-D reconstruction from optical flow. We then compare the performance of the two algorithms by simulation and real-image experiments using the same data. This is the first impartial comparison ever done in the sense that the two algorithms are both optimal, extracting the information contained in the data to a maximum possible degree. We observe that the finite motion solution is always superior to the optical flow solution and conclude that the finite motion algorithm should be used for 3-D reconstruction. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 1 2001 Automatic Detection of Circular Objects by Ellipse Growing 107 116 EN Kenichi Kanatani Naoya Ohta We present a new method for automatically detecting circular objects in images: we detect an osculating circle to an elliptic arc using a Hough transform, iteratively deforming it into an ellipse, removing outlier pixels, and searching for a separate edge. The voting space is restricted to one and two dimensions for efficiency, and special weighting schemes are introduced to enhance the accuracy. We demonstrate the effectiveness of our method using real images. Finally, we apply our method to the calibration of a turntable for 3-D object shape reconstruction. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 1 2001 contents / back cover EN Faculty of Engineering, Okayama University No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 1 2001 Observation of Orientation Change During Plastic Deformation of Polycrystalline Copper by EBSD Method 1 6 EN Ryouji Kondou Takeji Abe Naoya Tada Ichiro Shimizu Change in crystal orientation and strain of individual grains during tensile plastic deformation are studied to clarify on the microscopic deformation behavior of polycrystalline copper. The orientation of grain is measured by electron backscatter diffraction (EBSD) technique in the scanning electron microscope. The principal strain of grain is also measured by obtaining the approximated ellipse of strain distribution. The deformation of grains dependent on their initial orientation and the rotation of the principal strain during uniaxial tension are clarified. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 1 2001 Improvement of Biocompatibility of Silicone Elastomer by Surface Modification 117 121 EN Yuki Shirosaki Kanji Tsuru Satoshi Hayakawa Akiyoshi Osaka Seisuke Takashima γ-Methacryloxypropyltrimethoxysilane (γ-MPS) was grafted to silicone due to emulsion polymerization to induce Si-OH groups, in order to provide silicone with bioactivity spontaneous deposition of apatite in body fluid and to improve cytocompatibility. Apatite deposited on the grafted silicone within 7 days of soaking in 1.5 times as concentrated as the Kokubo solution. Osteoblastic cells (MC3T3-E1) were cultured on the specimens up to 7 days. After 5 days of culture, the number of MC3T3-E1 cells on the grafted specimen was much greater than that on the original specimen. These results indicated that the biocompatibility of silicone elastomer was improved by the grafting γ-MPS. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 1 2001 Evaluation and Selection of Models for Motion Segmentation 79 90 EN Kenichi Kanatani We first present an improvement of Kanatani's subspace separation [8] for motion segmentation by newly introducing the affine space constraint. We point out that this improvement does not always fare well due to the effective noise it introduces. In order to judge which solution to adopt if different segmentations are obtained, we present two criteria: one is the standard F test; the other is model selection using the geometric AIC of Kanatani [7] and the geometric MDL of Matsunaga and Kanatani [13]. We test these criteria doing real image experiments. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 1 2001 Microscopic Observation of Tensile Deformation Behavior of Polycrystalline Titanium with Scanning Probe Microscope 7 16 EN Yan Li Takeji Abe Naoya Tada Masanori Kanazawa The change in the surface morphology of polycrystalline titanium during tensile plastic deformation is studied, using the scanning probe microscope as well as the laser scanning microscope. The observation shows that the slip occurs mainly near grain boundary at the strain range of ε < 0.05. The slip develops with the applied strain, and the slip on the second slip system or the crossing of slip lines appear. The surface roughness increases linearly with the applied strain. The height difference between the grain boundary area and the inner grain area also increases with the applied strain, though the increase rate becomes low after the applied strain of about 0.3. The nano-scale height difference of the surface step of slip lines increases with the applied strain, though it remains almost constant after the applied strain of 0.4. The averaged surface roughness measured with the scanning probe microscope is in good agreement with that measured with the laser scanning microscope. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 1 2001 cover / title page EN Faculty of Engineering, Okayama University No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 1 2001 Application of Dead Beat Control method to the Water Level Control of Small-scale Hydroelectric Power Plant 17 28 EN Shinichiro Endo Masami Konishi Small Scale Hydroelectric Power Generation is made using the water drop caused by the gradient difference between that of the river and that of the penstock. The water flow in this system apt to vary with time. Especially, at the time of the flood or that of the dry, the flow in the water stream varies largely. To realize the stable generation, it is necessary to maintain the water level in the head tank located in the mid way in the stream channel at a constant level. In this paper, variation of water level is forecasted using two-tank model for the penstock and the head tank and the water level control algorithm is proposed by deadbeat control. The effectiveness of the algorithm is evaluated beforehand using the simulation program of the water environment for the hydroelectric generation system. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 1 2001 Modeling uncertainty for unknown modal parameters in large flexible structures 29 39 EN Jun Imai Kiyoshi Wada A procedure for control-oriented modeling is proposed for large flexible structures with unknown modal parameters. Techniques on quantification of errors in modal truncated nominal models are developed for the case where a finite number of upper and lower bounds of the unknown modal parameters are given. A feasible set of systems matching the conditions is introduced, and then error bounds covering the feasible set are established in the frequency domain. The bounds are easily checked using linear programming for any user-specified frequency. The feasibility of the proposed scheme is illustrated by numerical study on an ideal flexible beam example. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 1 2001 Structure and Cohesive Energy of Large Spherical Coulomb Clusters 51 57 EN Chico Vaillancourt This is a brief essay on using kinesthetic approaches to learning English as a second language. In the essay, I briefly discuss teaching philosophy and 2 small-scale Technical Engineering projects that I have introduced and completed with my 4(th) year engineering students in the spring of 2001. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 36 1 2001 Model Selection for Geometric Fitting: Geometric Ale and Geometric MDL 59 77 EN Kenichi Kanatani Contrasting "geometric fitting", for which the noise level is taken as the asymptotic variable, with "statistical inference", for which the number of observations is taken as the asymptotic variable, we give a new definition of the "geometric AIC" and the "geometric MDL" as the counterparts of Akaike's AIC and Rissanen's MDL. We discuss various theoretical and practical problems that emerge from our analysis. Finally, we show, doing experiments using synthetic and real images, that the geometric MDL does not necessarily outperform the geometric AIC and that the two criteria have very different characteristics. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 An Image Processing Method for Handling Subject Piled in a Container 169 175 EN Hirokazu Osaki Yasuhiro Kajihara Yoshiomi Munesawa We propose an image processing method for part handling robot for picking up subjects piled in a container. Line laser light is projected on subjects, and its external shape is detected by many segments of a line laser, and pitch, roll, and yaw angles of subject are recognized precisely. A priority rule is settled to choose one subject that is taken out. This rule is determined by considering the grasping space, the position of a subject, the movement space of hand and so on. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Development of Assembly Robot System for Flexible Belt-Shaped Subject 163 168 EN Hirokazu Osaki Yasuhiro Kajihara Yoshiomi Munesawa We develop an assembly robot system for assembling the flexible belt-shaped subject. An image processing method is developed to recognize the belt-shaped subject. This method is able to determine the grasping point and grasping angle for piking up a subject by a multiple hands unit. CAD information is used to determine the grasping point. The multiple hands unit is developed, which is able to grasp all grasping points of a subject at a time. In addition, the image processing method is used to judge whether a subject is fastened accurately at right position or not during the assembly. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Methods for Tele-Operation of Mobile Type Maintenance Robot 155 161 EN Yoshiomi Munesawa Yasuhiro Kajihara Hirokazu Osaki This paper proposes a concept of a mobile type maintenance robot (MMR in shortly) that is controlled by the tele-operation for assuring the safety and health improvement of work forces. The main components of this system are the industrial robot, an image processing unit, vehicle and computers for tele-operation. Our focus is paid on a method that determine a pathway to move every places where troubles would occur. This method makes it possible that the MMR could arrive any place in the factory with three times of turns at most. Additionally, turning radius of the vehicle is considered for correcting the pathway near the corners to make it possible that it arrives to the place accurately. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Microscopic Observation of Plastic Deformation of Polycrystalline Aluminum by Laser Scanning Microscope 1 8 EN Takeji Abe Ichiro Shimizu Free surface of polycrystalline metal becomes roughened after plastic deformation. The surface roughening is closely related to the inhomogeneity of polycrystalline metals, that is, to the inhomogeneous plastic deformation of respective grains. In the present study, inhomogeneous deformation on the free surface of polycrystalline aluminum specimen during uniaxial tension is studied. The inhomogeneous deformation of grains in the central area of the free surface of specimen is observed by the laser scanning microscope, while the inhomogeneous deformation perpendicular to the surface is studied by the laser scanning microscope as well as the stylus measuring instrument. It is shown that the surface roughness and the strain of respective grains increase with the applied strain. Discussions are made on the change in the surface roughness, the strain in each grain and the slip-line angles with the applied strain. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Ultra-Micro Hardness Testing and Microscopic Deformation of Polycrystalline Aluminum 9 19 EN Takeji Abe Tomoaki Tsuboi The evaluation of microscopic inhomogeneity of polycrystalline aluminum is performed by measuring the hardness in respective grains. The recently developed ultra-micro hardness tester is used and the effects of the test pattern, the indentation load and the indenting velocity are examined. Then, the relationship between the increase in the hardness caused by the work hardening and the deformation of respective grains are statistically investigated. The hardness testing mode in which the initial load is applied before the onset of measurement gives more stable results than the testing mode without the initial load. The test condition with the indentation load of 9.8mN and the indentation velocity of 0.2 μm/sec seems to be optimum and gives the least dispersion of the measured values in grains. It is shown that the hardness values of respective grains in polycrystalline aluminum as well as their dispersion increase with the applied plastic strain. Discussion is made on the microscopic deformation behavior of polycrystalline aluminum. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Laser Welding of Slices of Magnetic Circuit 21 28 EN Volodymyr S.kovalenko Yoshiyuki Uno Yasuhiro Okamoto M. Anyakin A. Lutay Khaled Al. Shubul In electric power industry, there is a problem of achieving stable joint in different components using high productive and efficient technologies. One type of these components is packages of slices for magnetic circuit of electric motors, transformers etc., which need reliable means for their fixing. Laser welding is proposed to solve this problem as an alternative for existing technologies. The development of the laser welding process is presented based on process simulation, study of heat history and comparison with experimental results. Laser beam additional scanning technique is proposed to improve the quality and efficiency of the joining operation. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Synthesis of Poly(ethylene-block-vinylalcohol)for Use as Amphiphilic Film Surface at High Temperature 29 34 EN Kaoru Shimamura Tetsuya Uchida Poly (ethylene-block-vinyl alcohol), which consisted of both hydrophobic and hydrophilic blocks, was prepared by using polyethylene single crystals as starting material. Polyethylene single crystals reacted with fuming nitric acid resulting in long methylene chains with functional groups such as COOH and NO(2) at the ends (the chain length were almost same as the lamellar thickness of polyethylene single crystal). The functionalized methylene chains were allowed to react with 4-aminostyrene to give corresponding amides, i.e., methylene chains with vinyl groups at the ends (macromer). The macromers were extended by block-copolymerization with vinyl acetate, then saponified resulting in PE/PVA block co-polymer. The block copolymer was molded into sheets which were subsequently heat-treated in contact with hydrophilic or hydrophobic media. Depending on the media, the sheet surface changed at high temperature reversibly from hydrophilic to hydrophobic and vice versa. The surface property was fixed by quenching because both blocks were able to crystallize. Thus the surface of this material can be tailored for various purposes at high temperature, and then used in stable at room temperature. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Scanning Probe Microscopy of Poly(p-phenylene benzobisthiazole) Lamellar Crystal 35 40 EN Kaoru Shimamura Tetsuya Uchida Tomohiro Inoue Rigid polymer, poly(p-phenylene benzobisthiazole), formed lamellar crystals where the molecular chains were oriented perpendicular to the lamellae. It was supposed that, because of wide distribution in the chain length, the lamellar surface bristled with the chain cilia among which many voids were included. Crystallographically, this region afforded us a transitional structure from full to deficient packings of chains. The structure was analyzed using the scanning probe microscope. In the course the method for imaging one molecular chain end was developed. From the images it was concluded that an isolated long cilius did not move so violently at room temperature. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Alkenylation and Allylation of Aldehydes by Using an Ni/Cr/TDAE Redox System 41 46 EN Manabu Kuroboshi Muneaki Tanaka Suguru Kishimoto Kentaro Goto Hideo Tanaka In 360 females, Bone mineral density (BMD) in lumbar vertebrae (L2-L4) was assessed by quantitative computed tomography (QCT), and the values obtained were compared with the frequency of vertebral transformation or fracture as assessed by lateral scan image (scanogram) by X-ray CT. A correlation was observed between the frequency of vertebral transformation (or fracture) and lumbar BMD values : BMD under 125 mg/cm(3) was observed over 90% of women with vertebral transformation, and BMD under 70mg/cm(3) was found about 50% of them. These results suggest that decrease in BMD in lumbar vertebrae leads to vertebral transformation or fracture. Thus, measurement of BMD by QCT would be very useful in predicting vertebral transformation or fractures. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Diagnostic method for induction motor using simplified motor simulator 47 51 EN Yukihiro Doumae Masami Konishi Jun Imai Hideki Asada Akira Kitamura In this paper, an identification method of motor parameters for the diagnosis of rotor bar defects in the squirrel cage induction motor is proposed. It is difficult to distinguish the degree of deterioration by a conventional diagnostic method such as Fourier analysis. To overcome the difficulty, a motor simulator is used to identify the degree of deterioration of rotors in the squirrel cage induction motor. Using this method, the deterioration of rotor bars in the motor can be estimated quantitatively. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Focusing Characteristic Analysis of Circular Fresnel Zone Plate Lens 53 61 EN Yukio Kagawa Fresnel zone plate lens (FZPL) has widely been used in electromagnetic antenna applications. Most analysis method based on the potential (scalar) wave approximation has been applied to a few very limited and simplified cases. The present paper analyzes the FZPL in more general form including the diffraction and transmission using the method of moments (MoM). The focusing gain characteristics in the oblique incidence as well as in the normal incidence are considered. The MoM solution using the three-dimensional vectorial formulation requires a large memory space for the FZPL as it is operated at a short wavelength. This is simply overcome by using an iterative conjugate gradient method for the numerical evaluation. The MoM solutions are compared with the other solutions. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Nonorthogonal Tight-Binding Molecular Dynamics for Si(1-x)Ge(x) Alloys 63 75 EN Chieko Totsuji Kenji Tsuruta Hiroo Totsuji We present a theoretical study of Si(1-x)Ge(x) alloys based on tight-binding molecular dynamics (TBMD) calculations. First, we introduce a new set of nonorthogonal tight-binding parameters for silicon and germanium based on the previous work by Menon and Subbaswamy [Phys. Rev. B 55, 9231 (1997); J. Phys: Condens. Matter 10, 10991 (1998)]. We then apply the method to structural analyses of Si(1-x)Ge(x) alloys. The equilibrium volume and atomic structure for a given x are obtained by the TBMD method. We also calculate the bulk modulus B, elastic constants C(11), C(12) and C(44) as a function of x. The results show that the moduli vary monotonically, but nonlinearly, between the values of Si crystal and Ge crystal. The validity of the results is also discussed. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Molecular Dynamics of Yukawa System using the Fast Multipole Method 77 95 EN Chieko Totsuji Kenji Tsuruta Hiroo Totsuji In order to perform the large-scale molecular dynamics simulation of the Yukawa system, a mathematical expression for molecular dynamics using the fast multipole method is described. The model simulations are also performed to test the performance of our implementation of the FMM. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 A Group Signature Scheme with Easy Membership Canceling 207 212 EN Toru Nakanishi In the group signature scheme with a trusted party, a verifier can determine whether or not a signature is made by a member of the group, but cannot identify the member who signed the signature. In case of dispute later on, the signer can be identified by the trusted party. However, for efficient group signature schemes proposed so far, removing a member from the group can be not efficiently performed. In this paper, a group signature scheme with an easy membership canceling is proposed. By sending a request to use a resource together with the group signature on it to the manager of the resource, the manager can control anonymous accesses to the resource. In such an application, the proposed group signature scheme is suitable for canceling of the access privilege. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Abductive Proof Procedure with Adjusting Derivations for General Logic Programs 97 135 EN Susumu Yamasaki Yoshinori Kurose In this paper, we formulate a new integrity constraint in correlation with 3-valued stable models in an abduction framework based on general logic programs. Under the constraint, not every ground atom or its negation is a logical consequence of the theory and an expected abductive explanation, but some atom may be unspecified as a logical consequence by an adjustment. As a reflection of the integrity constraint with an adjustment, we augment an adjusting derivation to Eshghi and Kowalski abductive proof procedure, in which such an unspecified atom can be dealt with. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Determining Minimal Polynomial of Proper Element by Using Higher Degree Traces 197 205 EN Yasuyuki Nogami Yoshitaka Morikawa Modern communication engineerings, such as elliptic curve cryptographies, often requires algebra on finite extension field defined by modulus arithmetic with an irreducible polynomial. This paper provides a new method to detemine the minimal (irreducible) polynomial of a given proper element in finite extension field. In the conventional determination method, as we have to solve the simultaneous equations, the computation is very involved. In this paper, the well known "trace" is extended to higher degree traces. Using the new traces, we yield the coefficient formula of the desired minimal polynomial. The new method becomes very simple without solving the simultaneous equations, and about twice faster than the conventional method in computation speed. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Characteristics of a Monoacylglycerol Lipase Isolated from Pseudomonas sp. LP7315 -Hydrolysis and Synthesis of Monoglycerides 137 146 EN Takaharu Sakiyama Tsuyoshi Yoshimi Akira Miyake Midori Umeoka Atsushi Tanaka Sho Ozaki Kazuhiro Nakanishi A monoacylglycerol lipase (MGL) was purified from Pseudomonas sp. LP7315 by ammonium sulfate precipitation, anion-exchange chromatography, and preparative electrophoresis. The purified enzyme was homogeneous on an SDS-polyacrylamide gel with a molecular mass of 59 kDa. Its hydrolytic activity was confirmed to be specific for monoglycerides: the enzyme did not hydrolyze diand triglycerides. MGL was found to be stable even after l-h incubation at 65℃. The hydrolytic activity depended not only on temperature and pH but also on the type of monoglyceride used. MGL also catalyzed monoglyceride synthesis at 65℃ in a solvent-free two-phase system, in which fatty acid droplets were dispersed in the glycerol phase with a low water content. The synthetic reaction proceeded at a constant rate for approximately 24 h and reached an equilibrium after 48 h of reaction. The initial rate of the synthetic reaction depended on several factors: the type of fatty acid used as the substrate, the amounts of fatty acid and glycerol, and the concentration of MGL in the glycerol phase. To analyze the effects of these factors, a kinetic model was developed based on the assumption that the adsorption equilibrium of MGL molecules at the interface between the two phases is the rate-determining factor for the synthetic reaction. The model was found to yield a good approximation of the initial synthetic rate under various reaction conditions. The analysis suggests that the adsorption behavior of MGL onto the interface had a large effect on the initial rate of the monoglyceride synthesis. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Disassembly System using an Impact Hammer for the Material Recycling 191 196 EN Yoshiomi Munesawa Hirokazu Osaki Yasuhiro Kajihara We developed the disassembly system that uses the impulsive load and disassembly tools to disassemble used appliances economically. The main components of this system are impulse hammer, a lift table and developed disassembly tools. Several types of disassembly tools are developed to punch out fastened portion on a part and cut off the shaft of screw or connection pin of IC-chip. A simulation model is proposed to explain and formulate how the fastening point of product is broken and cut. Three kinds of disassembly tools are designed. The actual disassembly system is developed by using proposed simulation models and disassembly tools. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 The role of interhelical cleavage for insecticidal activity of Bacillus thuringiensis Cry4A toxin 147 154 EN Masashi Yamagiwa Hiroshi Sakai The Cry4A toxin is a dipteran-specific insecticidal protein produced by Bacillus thuringiensis subsp. israelensis as a protoxin of 130 kDa. Its active form is a heterodimer of 20- and 45-kDa fragments which is generated by an interhelical cleavage of a 60-kDa intermediate at the position of Gln236 between α5 and α6 helices in domain I. On the other hand, Cry1Aa, which is also produced as a 130-kDa protoxin but toxic to lepidopteran larvae, was processed into the active 60-kDa fragment with no additional cleavage. To investigate the role of the intramolecular cleavage of Cry4A for its insecticidal activity, the loop between α5 and α6 of Cry4A which includes the cleavage site was substituted for the corresponding region of Cry1Aa. The resulting mutant designated GST-60Loop was expressed as a GST-fusion protein. A difference of the processing profile was observed between GST-60 and GST-60Loop in the in vitro digestion assay by trypsin, and the insecticidal activity of GST-60Loop was two-fold lower than that of GST-60. These results suggested that the interhelical cleavage of Cry4A promoted the toxicity against C. pipiens larvae. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 A Method for Design Production System with Multi Energy Resources 183 189 EN Hirokazu Osaki Yasuhiro Kajihara Yoshiomi Munesawa This research proposes a strategy for reducing both electricity charge and environmental load by considering multi energy sources. The reduction of the contract electric demand is considered, and its differential cost is used for purchasing substitute power sources. Some variables, such as the amount of reduced contract demand, and amount of electricity are generated by each substitute power source. By using those variables, we formulate a simulation model that enables to minimize the energy cost and environmental cost. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 35 1-2 2001 Cooperative Handling Robot with Human Beings 177 182 EN Hirokazu Osaki Yasuhiro Kajihara Yoshiomi Munesawa The focus of this paper is on the analysis of delivery motion of human, development of an image processing method based on the motion analysis and development of the cooperative delivery robot using the image processing method. The proposed image processing method uses two cameras, and it uses a stereo reconstruction technique for measuring position and postures of hands. In addition, this image processing method recognize the number of fingers extending consciously, so the cooperative human beings could choose the kind of tool which he wants by holding out his hand in front of cameras. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 34 1-2 2000 Falling Snow Melting Characteristics of Warm Water Flowing along Sheet Channels Spread on a Roof 1 12 EN Hideo Inaba Akihiko Horibe The experiment for investigating the falling snow melting characteristics of warm water flowing along sheet channels spread on a roof was performed in Tookamachi city, Nigata prefecture from February 6 to February 7, 1995. The sheet surface temperatures at 11 positions in 3 channels were measured. A physical model for a gas-water-snow system was constructed to compare the predicted results with the measured ones. A fully spread uniform water film in the sheet channel was observed in the experiments. The experimental results elucidated that it was feasible to use warm water flowing along sheet channels for melting falling snow on roofs. The temperature drop in the sheet channel mainly depended on the snowfall intensity, atmospheric temperature and wind speed. Under the influence of the roof edge, the temperature drop in the channel next to the side edge was much larger than that in middle channels. A water-snow two phase flow or a snow covered frozen water was experienced temporarily in the lower reaches of the water flowing channel. These suggest that a larger water flow rate is needed for the channel next to the roof edge, and a higher inlet temperature or a greater water flow rate is required for a severe weather condition. There was reasonably good agreement between the measured and predicted water temperatures. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 34 1-2 2000 Energy Distribution in Electrical Discharge Machining with Graphite Electrode 19 26 EN Akira Okada Yoshiyuki Uno Isao Okajima In EDM, the machining characteristics greatly depend on the energy distribution. Therefore, it is very important to clarify the energy distribution for understanding various phenomena in EDM. In this paper, the energy distribution in EDM with graphite electrode is investigated by measuring the temperatures of electrode and workpiece. Experimental analysis shows that the material removal rate depends on energy density while the electrode wear greatly depends on the adhesion of heat resolved carbon from machining fluid, and the energies distributed into electrode and workpiece are almost constant regardless of pulse duration. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 34 1-2 2000 Cytocompatibility of Silicone Elastomer Treated with Hydrogenperoxide Containing Tantalum Chloride 39 43 EN Satoshi Hayakawa Yuki Shirosaki Takeshi Yabuta Kanji Tsuru Akiyoshi Osaka Silicone elastomer was chemically treated at 60℃ for 7 days with 30 wt% H(2)O(2) solutions with or without TaCl(5) and soaked for various periods in a simulated body fluid(Kokubo solution) up to 21 days. Apatite formation ability of the surface of the silicone elastomer specimens was investigated with thin-film X-ray diffraction and FT-IR reflection spectroscopy. These silicone specimens did not deposit apatite or calcium phosphates, irrespective of chemical treatment. Osteoblast-like cells (MC3T3-El) derived from mouse were cultured on the specimens at 36.5℃ under 5%C0(2) and 95% humidity. Similar degree of proliferation of cells was observed at 7 days among three specimens, while the no treatment specimen after incubation for 5 days showed a lower degree of proliferation than the silicone treated with 30 wt% H(2)O(2) solutions with or without TaCl(5). Alkaline phosphatase activity of the cells proliferated on the no treatment specimen was lower than those of the silicone treated with 30 wt% H(2)O(2) solutions with or without TaCl(5). These results indicate that the cytotoxicity of the silicone could be improved by the chemical treatment with 30 wt% H(2)O(2) solutions with or without TaCl(5). No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 34 1-2 2000 Depolarization properties of Asian dust (KOSA) measured hyLIDAR in Okayama in the spring of 1998 27 37 EN He Wei Ryuji Koga Kengo Iokibe Osami Wada Yoshitaka Toyota In spring of 1998, Asian dust was observed with a Mie LIDAR in Okayama University, which can measure depolarization ratio. Three events of intense Asian dust were occurred in the period and medially detailed structure of atmosphere was found after examining records. Asian dust was distinguished from water droplets and the possibility to study three dimensional dynamic structure of atmosphere were demonstrated. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 34 1-2 2000 Effect of Specimen Thickness on Aging and Fatigue Strength of Al-Zn Alloys 13 17 EN Akira Sakakibara Tadashi Tanimoto Takahisa Matsushima Norio Hosokawa Teruto Kanadani Repeated tensile fatigue strength of the low temperature age-hardened Al-Zn alloys is investigated varying the specimen thickness. Fatigue strength of the age-hardened specimens decreases with the specimen thickness when the specimen is thinner than a certain thickness, whereas fatigue strength of non age-hardened specimens, i.e., pure aluminum and dilute Al-Zn alloy, does not depend the specimen thickness. The dependence of fatigue strength on the thickness of age-hardened specimen is considered to be caused by the decrease of the strength of specimen as a whole, as a result of increase in volume ratio of the soft surface layer formed after age-hardening with decreasing specimen thickness. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 Density Functional Molecular Dynamics of Hydrogen Plasma 51 59 EN Hiroo Totsuji Kenji Tsuruta Chieko Totsuji Density functional molecular dynamics method is applied to hydrogen plasma in the domain of liquid metallic hydrogen. Tentative results for the proton-proton pair distribution function and the electron-proton pair distribution function are obtained. It is shown that with the increase of the parameter γ(s), we have increasingly strong screening of proton charge by electrons and the decrease of electron density in the domain between protons. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 Apatite Formation on Electrochemically Treated Titanium 79 84 EN Akiyoshi Osaka Satoshi Hayakawa Kanji Tsuru A titanium oxide gel was electrochemically prepared on Ti with a cell consisting of Ti as the working electrode, Pt as the counter one, AgCl as the reference one, and an aqueous solution of 0.1 mol/L Ca(NO(3))(2) as the electrolyte solution. The Ti electrode was kept at 9.5V for 1 hr for oxidation and subsequently kept at-3.0V for 10 min (Ca9.5-3.0):calcium ions were expected to be adsorbed at the latter treatment. Other Ti specimen was kept at -3.0V for 10 min (Ca-3.0). Both specimens were found so bioactive as to deposit apatite in 12 hr (Ca9.5-3.0) and in 1 day (Ca-3.0) when soaked in a simulated body fluid (Kokubo solution). Calcium carbonate detected on the surface of Ca9.5-3.0 caused no harmful effects on spontaneous deposition of apatite in the fluid. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 Measurement System of Biomechanical Properties for Portable Use 45 50 EN Hisao Oka It is difficult to evaluate a biomechanical properties quantitatively. The authors developed the measurement system of biomechanical properties formerly but it is on a large scale because of the use of personal computer. In this study, the portable measurement system of biomechanical impedance/mobility is developed. To establish a rapid measurement, a random vibration is adopted in input signal. The system consists of the measuring probe, amplifier, and a note-typed personal computer. The measurement probe is developed newly, and has an overall length of 9 ㎝ (without a handle) and a total weight of about 500 g. The measurement program is also developed and is available to any computer which is worked under MS DOS compatible in Windows 95/98 operating system. The biomechanical spectra of thigh, temple and forehead are obtained and they show three typical spectrum patterns. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 Acousticmyogram Measured with Electrosimulation During Muscle Fatigue 39 44 EN Hisao Oka The acousicmyogram (AMG) is a mechanical phenomenon recorded at the surface of an active muscle. It is used to monitor force production, fatigue, and contractile properties of muscle. In this study, the new electrode with accelerometer for electrostimulation and acoustic detection. It consists of Ag-AgCl active electrode and solid-gel annular groud, and a very light piezoresistive accelerometer. The recorded AMG waveform depends on the pulse amplitude and duration of stimulation current and its lag from the electroatimulation is about 7 ms. The strengh-duration (S-D) curve (the threshold current for stimulation vs. pulse duration) describes the excitability of muscle. The left forearm is electrostimulated by using the same electrode and the muscle vibration (AMG) is recorded with accelerometer. During the muscle fatigue, the S-D curve changes and the current threshold increases under the same pulse duration. The rheobase of S-D curve increases gradually but the chronaxie hardly changes during muscle fatigue. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 Simulation of Deformation of Ni Twinned Nanocrystal Model by Molecular Dynamics 1 8 EN Yasuhiro Omura Moritaka Hida Akira Sakakibara Yoshito Takemoto Molecular dynamics simulation of nickel crystal under uniaxial tensile and compressive deformation was performed for single nenocrystal model and twinned nanocrystal model composed of 1550 atoms using EAM (embedded atom method) potential with the object of investigating deformation induced phase tranformation (especially twin deformation). In the case of single nanocrystal model, the evolution and development of twin deformation, (111)[11(2)], is observed under compressive loading in [001] direction, whereas either slip or twin deformation is not recognized under tensile loading. In the case of twinned nanocrystal model, twin, (111)[11(2)], decreases and disappears under tensile loading, and develops under compressive loading, It is suggested from the difference of results between single nanocrystal model and twinned nanocrystal model that it is easy for twin to induce local deformation. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 Rarefied Gas Flow Over a Solid Surface with Adsorbates 9 17 EN Kyoji Yamamoto The molecular dynamics study is applied for interaction of the gas molecule with the solid wall to analyse the flow of a rarefied gas between two wall. The wall consisting of Pt molecules is considered to be in a state of physical adsorbates. Two problems are considered : one is the flow problem and the other is the temperature problem. It is found that the tangential momentum accommodation coefficient is about 0.8 when the relative speed ratio of the two walls is unity, while it decreases with increasing Knudsen number when the relative wall speed ratio is 5.0. It shown that the temperature accommodation coefficient is about 0.85 at 300K wall, 0.75 at 450K wall, and 0.69 at 600K wall. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 Inspection Method by Comparing CAD Figure with Processed Image 97 103 EN Mitsuru Jindai Hirokazu Osaki Yasuhiro Kajihara Yoshiomi Munesawa We propose the recognition method of bridge soldering base metal on the circuits by comparing CAD figure and input image of image processing to locate the soldering iron tip accurately to secure the high quality Firstly, three dimensional CAD assembly drawing of circuits which are assembled perpendicularly in each other is projected on an imaginary two dimensional screen which is vertical to the optical axis of the camera The projected image is used as the standard CAD figure to inspect the location of the bridge soldering base metal. The positions among the bridge soldering base metals show the line state. So this line (connecting line) is used as the reference line to inspect the location of the bridge soldering base metal. The characteristics of the standard figure are represented by the connecting line, edge line and center points of base metal. Secondly, the position and gradient of connecting line among bridge soldering base metals in the input image is estimated. And the position of base metal and assembly accuracy of circuit units are calculated by comparing the shape and position of each base metal with its standard figure based on the connecting line Furthermore, the length between the opposite edges of the base metals are calculated to inspect the positions and the assemble accuracy of circuit units. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 Small Type Hydrocyclone with a Perforated Inner Cylinder 19 24 EN Kyoji Yamamoto A new type of hydrocyclone with a perforated inner cylinder is tested experimentally to study its performance for liquid-solid separation. The size of the cyclone is small so that it may be effective for small particle separation. Two types of the inner cylinder were made : the one has 39.5% void fraction of the perforated surface and the other has 73.5% . The mean particle diameter is 4.5 μ m. It is found that the pressure loss of the cyclone with the inner cylinder is reduced by about 25% compared with that of the ordinary type. The new type cyclone has better separation efficiency. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 A Numerical Study on the Performance of an Open-type Flat-plate Solar Collector 25 37 EN Hideo Inaba Akihiko Horibe A set mathematical models was developed for predicting the performance of an open-type flat-plate solar collector, and solved numerically through an implicit difference method. The effects of various parameters on the absorption of solar energy for the collector were investigated. The results showed that the solar energy absorptance of the open-type flat-plate collector was relatively high especially for the region where the weather was humid and hot, and there were an optimum length and an optimum tilt angle for the absorbing plate on which the collector could obtain the highest solar energy absorptance. It was found that the latent heat flux of water evaporation could be 5 to 15 times larger than the sensible heat flux. The effects of the magnitude of the solar incident flux, the atmospheric humidity, the atmospheric temperature, the absorbing plate tilt angle, and water film thickness on the temperature rising of the water film were clarified in numerical quantities. The increase of the solar incident flux, the atmospheric humidity or the atmospheric temperature also resulted in a rise in the energy absorptance of the collector. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 A Study of Facility Layout Method in Recycling Plant using AGV 111 119 EN Yoshiomi Munesawa Hirokazu Osaki Our country faces a serious problem of the environmental pollution by the production and the large quantity consumption of the industry product. The thoroughness of resources recycling has become necessary to solve these problems. As for the product design and the production control, how productivity should be improved has been discussed with extreme emphasis. But from now, as for the product design, both assemblability and disassemblability must be taken into consideration at the same time. And also in production management, it must be investigated how the products can be recycled in the low cost. Therfore, the facility layout method with two phases in recycling plant, which is composed of both the procedure for the layout of facility group and the procedure for the layout of intermal facility group by the optimal solution method and the suboptimal solution method by neural network is proposed in this paper. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 An Analytical Method of Human Motion by Image Processing 105 110 EN Hirokazu Osaki This paper deals with analytical method of human motion by image processing to make a model of the scooping process, Firstly, the scooping tool is the spoon, and while the scooping process is performing, the movement of the mouth center position and the spoon top position are measured by two cameras. As the amount of substance is over the uppermost area of the cup, the spoon is stuck obliquely into substance. Then the spoon is rotated and lifted up to the mouth. Secondly, we recognize the mouth center from the characteristic of the face image data and calculate the spoon top position to extract two points on the spoon handle from the time series images by two cameras. Finally, we describe the method of recognizing the coordinate of the mouth center and estimating the coordinate of the spoon top to analyse the scooping process. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 Intelligent Monitoring System Using Multiviewpoints for Teleperation 91 96 EN Yoshiomi Munesawa Hirokazu Osaki Yasuhiro Kajihara In this paper, we propose the method to determine the position of the 2 cameras for the multiviewpoints as the robot is the work place. The optical axit's direction of the 1st camera is determined in the base ot work contents in teleoperation. The multiviewpoints system uses the 2 camera units that aren't installed side by side, so that the direction of the 2nd camera is decided in the base of the angle between the optical axes' direction of 2 cameras. Next, the distance from the camera to the work place is determined according to the distance resolution of image on the monitor, and the camera type of which the point-blank range is not this distance is selected. And the efficacy ot this system is examined with an experiment. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 O(N) Tight-Binding Algorithm for Large-Scale Molecular Dynamics Simulations 71 77 EN Kenji Tsuruta Hiroo Totsuji Chieko Totsuji A parallel tight-binding molecular dynamics with an order-N [O(N))] algorithm is implemented to perform large-scale simulation of nanostructured materials. The algorithm is based on the Fermi-operator expansion of an electronic energy and force, and we present its basic formalisms. Accuracy necessary for molecular-dynamics simulations can be obtained by a proper truncation in the expansion. Parallel efficiency on a parallel PC cluster shows nearly ideal scaling behavior with respect to the number of processors. Applicability of the method to a silicon-carbide system is examined. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 Multicomponent Plasmas in Penning-Malmberg Traps 61 69 EN Hiroo Totsuji Kenji Tsuruta Chieko Totsuji The behavior of multicomponent plasmas in the Penning-Malmberg traps is discussed with the parameters corresponding to experiments with antiprotons and cryogenic electrons. The relaxation times for the energy transfer antiprotons to electrons and between parallel and perpendicular components of electrons are estimated. It is shown that, depending on the values of parameters, both the former and the latter can be the bottleneck in the cooling process. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 1 1998 Measurement of saturated solubilities and diffusion coefficients of pure gases to mineral oil 19 30 EN Seiichi Washio Satoshi Takahashi Chikashi Imoto Atsumasa Yoshida The present paper deals with measurements of the diffusion coefficients as well as the saturated solubilities of single component gases such as N(2), O(2) and CO(2) to a mineral oil. The method to determine the diffusivity is based upon measuring the pressure changes caused by the one-dimensional diffusion between the gas and the oil enclosed in an airtight container. For N(2) and O(2) the profiles of the measured pressure changes agree well with those predicted by diffusion theory, whereas that is not the case with CO(2). Although the reason why CO(2) does not seem to obey diffusion theory has yet to be studied, it may suggest the possibility that the diffusion coefficient varies with the pressure, considering that the range of pressure change in the diffusivity measurement was much obtained by this method fell within ±30% around the average. Moreover the solubility measurements have made clear that Henry's law holds true between the three pure gases and the oils tested, and that O(2) and CO(2) dissolve into the oil approximately two and ten times more, respectively, than N(2). No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 1 1998 Effect of Solute Clusters on Low Temperature Aging in Dilute Al-Ag Alloys 1 4 EN Akira Sakakibara Teruto Kanadani Aging of diolute Al-Ag alloys after quenching from low temperatures were studied mainly by electrical resistometry. Maximum resistivity observed in the aging curve of specimens quenched from high temeperature disappeared when the quenching temperature was lowered to 473 or 453K. When the quenching temperature was lowered further to 423K or lower, however, maximum resistivity reappeared. At the temperature lower than or equal to 423K but higher than the GP zone solvus, the alloys were not homogeneous but had clusters of solute atoms or fluctuation of solute concentration. Inhomogeneous distribution of solute atoms may affect the aging behavior after quenching from that temperature. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 1 1998 Rigid-Plastic Deformation of Inhomogeneous Material with Elliptic Inclusions Sliding along Boundary 5 17 EN Takeji Abe The influence of the slip between the inclusion and the matrix during the plastic deformation of inhomogeneous material with elliptic inclusions is investigated. The material is assumed to be rigid-plastic. The boundary slip region is modeled by assuming lower yield stress for the thin boundary region than those of the inclusion and the matrix. The rigid-plastic finite element method is used for the numerical calculation under the plane strain condition. The effects of the aspect ratio of the inclusion, the yield stress of the boundary region, and the volume fraction of the inclusion on the deformation mode are studied. The patterns of the strain concentration and the averaged flow stress of the inhomogeneous material are also discussed. The results may be helpful for understanding creep or superplastic deformation of metals with inclusions. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 1 1998 A Study on Robot System to Hand Surgical Intrument to a Surgeon in a Surgery (1st Report, Development of Surgical Instrument Recognition System) 31 37 EN Hirokazu Osaki Yasuhiro Kajihara Yoshiomi Munesawa Shuji Seki The nurse supporting robot system to prepare and hand surgical instruments to a surgeon is proposed to reduce work of nurse in a surgical operation. In this paper, the surgical instrument recognition system (SIRS) is developed to hand the surgical instruments to a surgeon by the robot. The characteristics ot the instruments are area of the instruments, ratio of minimum center-contour distance to maximum one and its outline contour, are recognized by using the image processing. Kinds of the instruments are distinguished by these characteristics. No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 1 1998 Recognition Index of Part and Unit by Discrimination Characteristics 39 45 EN Yoshiomi Munesawa Hirokazu Osaki Yasuhiro Kajihara In this paper, we propose a recognition index to evaluate the complexity of discrimination among parts and units. The parts and units are classified into some groups (the number of groups is shown as n) by one characteristic, such as color, shape, size and so on. The recognition index of each is denoted as log(2) (n+1) by the information quantity formula. The recognition diagram shows the classfication of parts and units into only one part and unit by the structure of a characteristic. Further we propose the line balancing method for assembly line based on the working time and recognition index. No potential conflict of interest relevant to this article was reported.