JaLCDOI 10.18926/47028
フルテキストURL mfe_36_2_073_082.pdf
著者 Hidayat, Iip Syarif| Toyota, Yoshitaka| Torigoe, Osamu| Wada, Osami| Koga, Ryuji|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2002-03
36巻
2号
開始ページ 73
終了ページ 82
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120003497050
JaLCDOI 10.18926/47029
フルテキストURL mfe_36_2_083_089.pdf
著者 Watanabe, Tetsushi| Wada, Osami| Koga, Ryuji| Toyota, Yoshitaka| Miyashita, Takuya|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2002-03
36巻
2号
開始ページ 83
終了ページ 89
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120003497051
JaLCDOI 10.18926/48125
フルテキストURL mfe_046_001_009.pdf
著者 Kanatani, Kenichi| Niitsuma, Hirotaka|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2012-01
46巻
開始ページ 1
終了ページ 9
ISSN 1349-6115
言語 English
著作権者 Copyright © by the authors
論文のバージョン publisher
NAID 80022451620
JaLCDOI 10.18926/48126
フルテキストURL mfe_046_010_020.pdf
著者 Kanatani, Kenichi|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2012-01
46巻
開始ページ 10
終了ページ 20
ISSN 1349-6115
言語 English
著作権者 Copyright © by the authors
論文のバージョン publisher
NAID 80022451621
JaLCDOI 10.18926/48127
フルテキストURL mfe_046_021_033.pdf
著者 Kanatani, Kenichi| Niitsuma, Hirotaka|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2012-01
46巻
開始ページ 21
終了ページ 33
ISSN 1349-6115
言語 English
著作権者 Copyright © by the authors
論文のバージョン publisher
NAID 80022451622
JaLCDOI 10.18926/49320
フルテキストURL mfe_047_001_018.pdf
著者 Kanatani, Kenichi|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2013-01
47巻
開始ページ 1
終了ページ 18
ISSN 1349-6115
言語 English
著作権者 Copyright © by the authors
論文のバージョン publisher
NAID 120005232372
JaLCDOI 10.18926/49321
フルテキストURL mfe_047_019_024.pdf
著者 Nogami, Yasuyuki| Sumo, Taichi|
抄録 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.
キーワード pairing–friendly curve torsion point group structure rank
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2013-01
47巻
開始ページ 19
終了ページ 24
ISSN 1349-6115
言語 English
著作権者 Copyright © by the authors
論文のバージョン publisher
NAID 120005232373
JaLCDOI 10.18926/49322
フルテキストURL mfe_047_025_032.pdf
著者 Nekado, Kenta| Takai, Yusuke| Nogami, Yasuyuki|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2013-01
47巻
開始ページ 25
終了ページ 32
ISSN 1349-6115
言語 English
著作権者 Copyright © by the authors
論文のバージョン publisher
NAID 120005232374
JaLCDOI 10.18926/15423
フルテキストURL Mem_Fac_Eng_OU_26_1_95.pdf
著者 川上 浩司| 小西 忠孝|
抄録 This paper describes a method to construct IDEA BANK automatically. IDEA BANK is the data base of the "function-structure module" which is utilized in systematic conceptual design from Value Engineering perspectives. The method based on the Machine Learning EBL technique was evaluated and implemented for the IDEA BANK using SUN workstation. The practical implementation of the IDEA BANK acquisition was discussed after elucidating the problem and solution of the EBL technique in engineering design. In the IDEA BANK system, the structural features of an existing article are analyzed by hierarchically organized domain specific knowledge to yield a systematic explanation of how they function and attain their design goals. The explanation resulted in a generalized version of the Functional Diagram used in Value Engineering from which "function-structure module" can be extracted systematically.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1991-11-30
26巻
1号
開始ページ 95
終了ページ 108
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307756
JaLCDOI 10.18926/15513
フルテキストURL Mem_Fac_Eng_OU_25_2_81.pdf
著者 Totsuji, Hiroo|
抄録 Numerical methods for the analysis of the proximity effect in superconducting microstructures in the dirty limit are formulated on the basis of the finite element method. One- and two-dimensional cases are considered and third order Hermite shape functions are used. The results are also applicable to investigations of electronic states in semiconductor superlattice structures.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1991-03-28
25巻
2号
開始ページ 81
終了ページ 93
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307242
JaLCDOI 10.18926/15515
フルテキストURL Mem_Fac_Eng_OU_25_2_95.pdf
著者 Totsuji, Hiroo| Ishikura Satoshi| Takayama Norihisa|
抄録 Critical temperatures of two-dimensional microstructures with superconducting proximity effect in the dirty limit are evaluated for various geometrical constructions. As a numerical method, the finite element method is applied. Guidelines in estimating critical temperatures are given for the case where the decay of superconducting order parameter is either sufficiently slow or fast in comparison with the scale length of the structure.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1991-03-28
25巻
2号
開始ページ 95
終了ページ 113
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307413
JaLCDOI 10.18926/15517
フルテキストURL Mem_Fac_Eng_OU_25_2_123.pdf
著者 Taniguchi, Takeo| Ohta, Chikashi|
抄録 The aim of this investigation is the proposal of 3D mesh generation method based on the Delaunay triangulation. The method is valid for the finite element modelling of any convex 3D domain into tetrahedra with optimum geometrical configuration. This paper includes the mathematical background of the mesh generation method, its detail, proposal of some efficient tools for faster and more rigorous computations, and some examples of the mesh generation.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1991-03-28
25巻
2号
開始ページ 123
終了ページ 133
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307904