著者 Nisikado, Y.| Kimura, K.|
発行日 1940-07-31
出版物タイトル Berichte des Ohara Instituts für landwirtschaftliche Forschungen
8巻
4号
資料タイプ 紀要論文
JaLCDOI 10.18926/15575
フルテキストURL Mem_Sch_Eng_OU_2_43.pdf
著者 Takahashi Teruo| Fujita Kozo|
抄録 In this report, the analogies of the maximum allowable liquid and gas velocities in various countercurrent gas-liquid contactors of column type are considered analytically. That is, by plotting the flooding points of various columns in a gas-liquid separated coordinates, the similar curves have been obtained in each column. Because the difference of these curves is due to the shape of each column, the difference of each shape must be corrected and evaluated as a ahape factor. Then, by containing this factor in coordinate variables, various flooding points in each column may be correlated by a single curve. If this correlation curve is used, the flooding velocity can be estimated easily, and the maximum allowable liquid and gas velocities in these countercurrent contactors of column type can be compared.
出版物タイトル Memoirs of the School of Engineering, Okayama University
発行日 1967-04-01
2巻
1号
開始ページ 43
終了ページ 49
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307818
JaLCDOI 10.18926/fest/11593
フルテキストURL 002_001_008.pdf
著者 洞 彰人|
抄録 An aspect of the cut-off phenomenon is reviewed. It is a sort of critical phenomenon observed in a wide variety of diffusion. We introduce a framework in which such a phenomenon can be understood and analyzed in a rigorous manner. We illustrate the mechanism with some concrete models.
キーワード cut-off phenomenon critical time diffusion Markov chain on a graph symmetry
出版物タイトル 岡山大学環境理工学部研究報告
発行日 1997-01-10
2巻
1号
開始ページ 1
終了ページ 8
ISSN 1341-9099
言語 English
論文のバージョン publisher
NAID 120002313764
JaLCDOI 10.18926/15472
フルテキストURL Mem_Fac_Eng_OU_23_2_9.pdf
著者 Kuroda Tsutomu| 大崎 紘一| 松田 正明| Fujisawa Keita|
抄録 Multi-item flexible manufacturing systems have been spread to correspond the short life-cycle and the diversification of products. Part handling plays an important role to operate multi-functional robot efficiently in these systems, and many jigs are widely used to hold a part. They should be exchanged at once according to changing products. In this paper, we propose a pin jig which holds a part with two pins, and design method of the position, length and diameter of those pins for a cylindrical part. This jig has the following characteristics. As a surface of the jig is inclined to use gravity, the part can be fixed without any external forces. Therefore the structure of jig becomes simple, and loading and unloading of a part becomes easy for a robot hand.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1989-03-30
23巻
2号
開始ページ 9
終了ページ 19
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307693
著者 Nakamura, Ian|
発行日 2014-12
出版物タイトル 大学教育研究紀要
10巻
資料タイプ 紀要論文
JaLCDOI 10.18926/15721
フルテキストURL Mem_Sch_Eng_OU_12_53.pdf
著者 Fujitsuka Takeshi| Agusa Toru|
抄録 In recent years, the development of a high power transistor element is proceeding. A high power inverter circuit using power transistors are finding a good number of applications in induction heating and melting. Turn off time of power transistors occupies 5-lOμs of switching characteristics. A driving method to give base inputs for a half period is widely used for a inverter circuit. But this method has the following defects, the short-circuit current flows through two transistors because the other pair transistors turn on before one pair transistors turn off. So the switching loss is increased, the maximum output and the efficiency are decreased. In this paper, a driving method to give base inputs for the less period as compared with a half period is discussed. Using this method, the foregoing defects is lost and the driving frequency is able to become higher. In addition, it become clear that the square waveform output is given using this method in the case of R-L load.
出版物タイトル Memoirs of the School of Engineering, Okayama University
発行日 1978-02-25
12巻
開始ページ 53
終了ページ 58
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307552
著者 佐藤 豊信|
発行日 1988
出版物タイトル 岡山大学農学部学術報告
71巻
1号
資料タイプ 紀要論文
JaLCDOI 10.18926/46982
フルテキストURL mfe_37_2_073_087.pdf
著者 Nogami, Yasuyuki| Morikawa, Yoshitaka|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2003-03
37巻
2号
開始ページ 73
終了ページ 87
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80015999992
JaLCDOI 10.18926/15729
フルテキストURL Mem_Sch_Eng_OU_13_239.pdf
著者 Taniguchi Takeo|
抄録 In this paper the minimum fill-in problem which arises at the application of the sparse matrix method for linear sparse systems is discussed from the graphtheoretic viewpoint and the author gives some results which can be directly introduced in the design of, so called, the optimal elimination ordering algorithm which gives the minimum fill-in(the number of zeros in coefficient matrix which become non-zero during the elimination process). Through this investigation only graphs are treated instead of the coefficient matrices for linear systems, and the elimination process for a matrix is equivalated to the vertx eliminations for the graph. Then, the results by the theoretical investigation are summarized as following: 1. Optimal elimination for each subgraph which is subdivided appropriately from whole graph leads to the global optimum. 2. In each subgraph there are only two kind of eliminations. Furthermore, some numerical experiments show the characteristics of the subset of vertices, which subdivide a subgraph from the residual.
出版物タイトル Memoirs of the School of Engineering, Okayama University
発行日 1979-03-05
13巻
開始ページ 239
終了ページ 248
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307617
JaLCDOI 10.18926/15780
フルテキストURL Mem_Sch_Eng_OU_15_2_119.pdf
著者 Kaneda Masahiro| Akahori Ichiro| Egusa Masanori| Kuraoka Hiroaki|
抄録 A high speed and high accuracy simulator whose data-handling is light and whose weak stability is assured even for stiff systems is discussed. This work is a part of CAD package : CADPACS-T which has been under development for the purpose of designing control systems utilizing TSS of a large scale digital computer in our laboratory. This simulator realizes high accuracy, high computational speed and high reliability adopting A-stable extrapolation methods to transform into a difference system, a recursive formula of an output interval to solve the difference equation, automatic choice of an optimal step length such that minimizes an predicted error, and evaluating error bounds closely near the actual errors in the point of numerical calculation. Moreover, in the point of data management, this realizes separation of program modules from data, common utilization of data and separation of investigation from simulation.
出版物タイトル Memoirs of the School of Engineering, Okayama University
発行日 1981-03-30
15巻
2号
開始ページ 119
終了ページ 132
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307465
JaLCDOI 10.18926/15382
フルテキストURL Mem_Fac_Eng_OU_35_207.pdf
著者 中西 透| Fujiwara Toru|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2001-03-27
35巻
1-2号
開始ページ 207
終了ページ 212
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307232
JaLCDOI 10.18926/17849
フルテキストURL Mem_Fac_Eng_OU_43_99.pdf
著者 Kato, Hidehiro| Nogami, Yasuyuki| Morikawa, Yoshitaka|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2009-01
43巻
開始ページ 99
終了ページ 107
ISSN 1349-6115
言語 English
論文のバージョン publisher
NAID 120002308980
JaLCDOI 10.18926/14157
フルテキストURL Mem_Fac_Eng_39_1_82.pdf
著者 Wang, Feng| Nogami, Yasuyuki| Morikawa, Yoshitaka|
抄録 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)).
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2005-01
39巻
1号
開始ページ 82
終了ページ 92
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308422
JaLCDOI 10.18926/15741
フルテキストURL Mem_Sch_Eng_OU_14_2_13.pdf
著者 古賀 隆治| Ebara, Masami| Kosaka, Megumi| Sano, Hiroya|
抄録 A switch element has been developed so that a kilovolt step voltage should be supplied to a 50Ω transmission line with a subnanosecond rise time. The element is of silicon substrate with high purity and a pair of electrodes is attached by the evaporation process. The switch action is performed by the photoconductivity produced by the laser light pulse. This paper deals with a preliminary analysis, manufacturing processes and experimental results of the optoelectronic switch. A performance of 320V output with less than 4 ns risetime was obtained with sufficient persistence for more than 2×10(5) pulse shots. This switch was successfully applied to an optical waveform monitor for laser light pulses giving a resolution less than 2 ns.
出版物タイトル Memoirs of the School of Engineering, Okayama University
発行日 1980-03-01
14巻
2号
開始ページ 13
終了ページ 22
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307887
JaLCDOI 10.18926/CTED/58128
タイトル(別表記) 岡山大学教育学部特別支援教育教員養成における米国での海外研修プログラム
フルテキストURL cted_010_165_181.pdf
著者 OHTAKE, Yoshihisa| CHEATHAM, Gregory| TANJI, Takayuki|
抄録 This article delineates a faculty-led study abroad program that has been conducted for 15 years by a special needs education (SNE) teacher preparation program in Japan. A description of the content and context of the program is followed by a series of observations made by study abroad participants during site visits in the United States of America (U.S.). Finally, suggestions are proposed for how participants’ observations may be used to help them review the values and beliefs embedded in SNE practices in Japan in a way that sublates contradicting values and beliefs between the U.S. and Japan as a means of developing better practices in Japan.
抄録(別表記) 本稿は、岡山大学教育学部学校教育教員養成課程特別支援教育コース・専修学生を対象に行われている米国での海外研修プログラムの意義と課題について論じたものである。まず、プログラム実施の背景と目的、内容について述べた。続いて、海外研修に参加した学生の中で共通して浮かび上がる意識体験を描写し、その意味について論じた。最後に、参加学生が日本の特別支援教育実践の新たな価値を発見できるような授業の在り方について、若干の考察を試みた。
キーワード faculty-led study abroad program (海外研修プログラム) special education (特別支援教育) teacher preparation (教員養成)
出版物タイトル 岡山大学教師教育開発センター紀要
発行日 2020-03-20
10巻
開始ページ 165
終了ページ 181
ISSN 2186-1323
言語 English
著作権者 Copyright © 2020 岡山大学教師教育開発センター
論文のバージョン publisher
JaLCDOI 10.18926/15804
フルテキストURL Mem_Sch_Eng_OU_16_2_1.pdf
著者 Yokoyama Fumiyoshi|
抄録 A deconvolution method for the X-ray diffraction line profile is proposed, which is based on the conventional least-squares method. The true profile is assumed to be a functional form. The numerical values of parameters of the function assumed are determined so that the calculated profile, which is a convolution of the function and the instrumental profile, has a minimum deviation from the observed one. The method is illustrated by analysis of the X-ray powder diffraction profile of sodium chloride 222 reflexion under the assumption that the true profile is a Gaussian or a Cauchy function.
出版物タイトル Memoirs of the School of Engineering, Okayama University
発行日 1982-03-29
16巻
2号
開始ページ 1
終了ページ 16
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307445
JaLCDOI 10.18926/15367
フルテキストURL Mem_Fac_Eng_OU_30_1_9.pdf
著者 Ding Ronggui| 大崎 紘一|
抄録 Decision Support Systems (DSS) have been taken as hopeful support tools for decision making for more than 20 years. There are a lot of literatures on DSS, but most of them are not so practical as the designers expected. This paper points out the crux of this situation and argues that the research on DSS should pay some more attention to the decision making activities before the model using stage. A method named "Problem Situation Decomposing Graph (PSDG)" is presented in this paper for helping the decision maker(DM) elicit the decision making problems. A PSDG is an acycle AND/OR logical directed graph, and which includes all the factors affecting the problem situation based on the DM's knowledge. The logical nodes and parameter determining methods in PSDG can reflect the DM's decision making style. This paper introduces some basic concepts of PSDG, discusses some of its characteristics, and proposes a logical adjacency matrix for PSDG representation and analysis.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1995-12-28
30巻
1号
開始ページ 9
終了ページ 17
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307826
著者 Seo, Takuro| Ohtaki, Eiji| Maitani, Toshihiko|
発行日 1972
出版物タイトル Berichte des Ohara Instituts für landwirtschaftliche Biologie, Okayama Universität
15巻
3号
資料タイプ 紀要論文
JaLCDOI 10.18926/14071
フルテキストURL Mem_Fac_Eng_OU_42_110.pdf
著者 Nogami, Yasuyuki| Morikawa, Yoshitaka|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2008-01
42巻
1号
開始ページ 110
終了ページ 114
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308489
JaLCDOI 10.18926/15376
フルテキストURL Mem_Fac_Eng_OU_35_183.pdf
著者 Tabuchi Satoshi| 大崎 紘一| 梶原 康博| 宗澤 良臣|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2001-03-27
35巻
1-2号
開始ページ 183
終了ページ 189
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307173