JaLCDOI 10.18926/19962
フルテキストURL Mem_Fac_Eng_OU_44_73.pdf
著者 Imanaka, Hiroyuki| Tanaka, Soukichi| Feng, Bin| Imamura, Koreyoshi| Nakanishi, Kazuhiro|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2010-01
44巻
開始ページ 73
終了ページ 83
ISSN 1349-6115
言語 English
論文のバージョン publisher
NAID 120002309053
JaLCDOI 10.18926/19961
フルテキストURL Mem_Fac_Eng_OU_44_69.pdf
著者 Nekado, Kenta| Kato, Hidehiro| Nogami, Yasuyuki| Morikawa, Yoshitaka|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2010-01
44巻
開始ページ 69
終了ページ 72
ISSN 1349-6115
言語 English
論文のバージョン publisher
NAID 120002309070
JaLCDOI 10.18926/19960
フルテキストURL Mem_Fac_Eng_OU_44_60.pdf
著者 Nogami, Yasuyuki| Morikawa, Yoshitaka|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2010-01
44巻
開始ページ 60
終了ページ 68
ISSN 1349-6115
言語 English
論文のバージョン publisher
NAID 120002309063
JaLCDOI 10.18926/19959
フルテキストURL Mem_Fac_Eng_OU_44_50.pdf
著者 金谷 健一| Niitsuma Hirotaka| Rangrajan Prasanna|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2010-01
44巻
開始ページ 50
終了ページ 59
ISSN 1349-6115
言語 English
論文のバージョン publisher
NAID 120002308986
JaLCDOI 10.18926/19958
フルテキストURL Mem_Fac_Eng_OU_44_42.pdf
著者 金谷 健一| Rangrajan Prasanna|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2010-01
44巻
開始ページ 42
終了ページ 49
ISSN 1349-6115
言語 English
論文のバージョン publisher
NAID 120002309054
JaLCDOI 10.18926/19957
フルテキストURL Mem_Fac_Eng_OU_44_32.pdf
著者 金谷 健一| Niitsuma Hirotaka| Sugaya Yasuyuki|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2010-01
44巻
開始ページ 32
終了ページ 41
ISSN 1349-6115
言語 English
論文のバージョン publisher
NAID 120002309124
JaLCDOI 10.18926/19956
フルテキストURL Mem_Fac_Eng_OU_44_24.pdf
著者 金谷 健一| Sugaya Yasuyuki|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2010-01
44巻
開始ページ 24
終了ページ 31
ISSN 1349-6115
言語 English
論文のバージョン publisher
NAID 120002309159
JaLCDOI 10.18926/19955
フルテキストURL Mem_Fac_Eng_OU_44_13.pdf
著者 金谷 健一| Sugaya Yasuyuki|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2010-01
44巻
開始ページ 13
終了ページ 23
ISSN 1349-6115
言語 English
論文のバージョン publisher
NAID 120002309170
JaLCDOI 10.18926/19954
フルテキストURL Mem_Fac_Eng_OU_44_7.pdf
著者 Maetani Noriaki| Kurose Tomoyuki| 鶴田 健二|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2010-01
44巻
開始ページ 7
終了ページ 12
ISSN 1349-6115
言語 English
論文のバージョン publisher
NAID 120002309019
JaLCDOI 10.18926/19953
フルテキストURL Mem_Fac_Eng_OU_44_1.pdf
著者 Nagai Shinji| Umeda Ryosuke| 鶴田 健二|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2010-01
44巻
開始ページ 1
終了ページ 6
ISSN 1349-6115
言語 English
論文のバージョン publisher
NAID 120002309117