| JaLCDOI | 10.18926/19958 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_42.pdf |
| Author | Kanatani, Kenichi| Rangrajan Prasanna| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 42 |
| End Page | 49 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002309054 |
| JaLCDOI | 10.18926/19959 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_50.pdf |
| Author | Kanatani, Kenichi| Niitsuma Hirotaka| Rangrajan Prasanna| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 50 |
| End Page | 59 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308986 |
| JaLCDOI | 10.18926/19953 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_1.pdf |
| Author | Nagai Shinji| Umeda Ryosuke| Tsuruta, Kenji| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 1 |
| End Page | 6 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002309117 |
| JaLCDOI | 10.18926/19956 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_24.pdf |
| Author | Kanatani, Kenichi| Sugaya Yasuyuki| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 24 |
| End Page | 31 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002309159 |
| JaLCDOI | 10.18926/19960 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_60.pdf |
| Author | Nogami, Yasuyuki| Morikawa, Yoshitaka| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 60 |
| End Page | 68 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002309063 |
| JaLCDOI | 10.18926/17849 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_99.pdf |
| Author | Kato, Hidehiro| Nogami, Yasuyuki| Morikawa, Yoshitaka| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 99 |
| End Page | 107 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308980 |
| JaLCDOI | 10.18926/17851 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_108.pdf |
| Author | Nekado, Kenta| Kato, Hidehiro| Nogami, Yasuyuki| Morikawa, Yoshitaka| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 108 |
| End Page | 112 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308904 |
| JaLCDOI | 10.18926/17843 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_61.pdf |
| Author | Kawamura, Mao| Konishi, Masami| Yamagata, Katuki| Shimomura, Koichi| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 61 |
| End Page | 74 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308930 |
| JaLCDOI | 10.18926/17839 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_49.pdf |
| Author | Akamatsu, Shinya| Konishi, Masami| Imai, Jun| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 49 |
| End Page | 54 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308854 |
| JaLCDOI | 10.18926/17841 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_55.pdf |
| Author | Inoue, Shinichiro| Konishi, Masami| Imai, Jun| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 55 |
| End Page | 60 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308973 |
| JaLCDOI | 10.18926/17844 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_75.pdf |
| Author | Ohe, Keita| Konishi, Masami| Imai, Jun| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 75 |
| End Page | 92 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308900 |
| JaLCDOI | 10.18926/17831 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_22.pdf |
| Author | Totsuji, Hiroo| Chai Hong| Totsuji, Chieko| Tsuruta, Kenji| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 22 |
| End Page | 26 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308966 |
| JaLCDOI | 10.18926/17826 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_8.pdf |
| Author | Umeda Ryosuke| Totsuji, Chieko| Tsuruta, Kenji| Totsuji, Hiroo| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 8 |
| End Page | 15 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308833 |
| JaLCDOI | 10.18926/17833 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_27.pdf |
| Author | Totsuji, Hiroo| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 27 |
| End Page | 31 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308947 |
| JaLCDOI | 10.18926/17822 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_1.pdf |
| Author | Shimizu, Kenichi| Torii, Tashiyuki| Ishida, Koki| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 1 |
| End Page | 7 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308710 |
| JaLCDOI | 10.18926/17835 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_32.pdf |
| Author | Mabuchi, Shuji| Konishi, Masami| Imai, Jun| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 32 |
| End Page | 38 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308736 |
| JaLCDOI | 10.18926/17847 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_93.pdf |
| Author | Ueno, Hirokazu| Morikawa, Yoshitaka| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 93 |
| End Page | 98 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308979 |
| JaLCDOI | 10.18926/17829 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_16.pdf |
| Author | Kurose Tomoyuki| Tsuruta, Kenji| Totsuji, Chieko| Totsuji, Hiroo| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 16 |
| End Page | 21 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308928 |
| JaLCDOI | 10.18926/17837 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_39.pdf |
| Author | Kuwashima, Takayuki| Imai, Jun| Konishi, Masami| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 39 |
| End Page | 48 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308875 |
| JaLCDOI | 10.18926/17853 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_113.pdf |
| Author | Sakemi, Yumi| Kato, hidehiro| Nogami, Yasuyuki| Morikawa, Yoshikawa| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 113 |
| End Page | 116 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308945 |
