JaLCDOI 10.18926/15592
FullText URL Mem_Sch_Eng_OU_2_127.pdf
Author Misaki Takayoshi| Kato Osamu| Yamamoto Hideki|
Abstract Described in this paper is a method of automatic washing for salt contaminated insulators. An average value of leakage current through the surface of the pilot insulator in a duration is measured, for this is a function of the quantity of salt adhered and its moisture content. In each cycle, the program signals give one by one the instructions on a start and an end of the integration of leakage current, a detection of the integrated value, a stop of the washing device and a reset of the integrator. The integrator consists of RC circuit and the main detecting part consists of the thyristor whose firing gate voltage is used as a reference value. If the integrator output rises above the firing gate voltage, the pulse signals are made in the signal conversion part at the same time that the thyristor turns on, which are distributed to the pump motor or the electromagnetic valve. Then the insulators on hot-line are washed all together in the appointed duration. Finally, by the various experiments this method was proved to have enough accuracy and reliability in practical use. The conclusions are summarized as follows. (1) An average value of leakage current is justified to be the detecting variable. (2) The RC circuit used as the integrator is proved to be easy in maintenance. (3) Because of the fairly short duration of the detecting action, the integrator is kept in a sufficiently safe condition under expected environment.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1967-04-01
Volume volume2
Issue issue1
Start Page 127
End Page 132
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307133
JaLCDOI 10.18926/15365
FullText URL Mem_Fac_Eng_OU_30_1_1.pdf
Author Dong Liu| Kajihara, Yasuhiro| Osaki, Hirokazu| Munesawa, Yoshiomi|
Abstract A method for standardizing parts is proposed. This method aims to reduce the sort of parts for cutting the manufacturing cost and for improving specifications of parts. Two linear mathematical programming models are proposed for standardizing the parts. One model aims at cutting cost half without causing any degradation of mechanical specifications of parts. The other model aims at doubling mechanical specifications of parts below the acceptable manufacturing cost. These models are formulated in 0-1 integer programming forms. The integer programming model shows which part is common to other parts. An example is shown to demonstrate the use of the developed method.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1995-12-28
Volume volume30
Issue issue1
Start Page 1
End Page 7
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307491
JaLCDOI 10.18926/14156
FullText URL Mem_Fac_Eng_39_1_71.pdf
Author Nogami, Yasuyuki| Morikawa, Yoshitaka|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2005-01
Volume volume39
Issue issue1
Start Page 71
End Page 81
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308036
JaLCDOI 10.18926/15411
FullText URL Mem_Fac_Eng_OU_29_2_13.pdf
Author Dwianto Gatot| Osaki, Hirokazu| Kajihara, Yasuhiro|
Abstract We propose a method to design the supplying method of parts to an assembly line. Three types of supplying model (Serial, Parallel, and Mixed) are proposed based on the relation between the area of part and that of the transportation equipment. The part is supplied by the pallet on which the all parts of one product are arranged or by the lot of one part. AGV or conveyor are used to transport the pallet. The supplying model is evaluated from the total transportation cost calculated from the price of the transportation equipment and of land.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1995-03-27
Volume volume29
Issue issue2
Start Page 13
End Page 21
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307903
JaLCDOI 10.18926/19616
FullText URL Mem_Fac_Eng_OU_33_1_53.pdf
Author Li Sen| Osaki, Hirokazu| Kajihara, Yasuhiro| Munesawa, Yosiomi|
Abstract A method for designing a monitoring system with multiple cameras is proposed in order to supervise and recognize the progress of wide work area. First, a wide view camera is deveeloped by combining several usual cameras so that its visual angle could cover more than π/2. Secondly, A method for determining the number and location points of cameras is proposed by considering the shape of monitored area and the installation cost of cameras. The monitored area is divided into three kinds of basic shape (rectangular form, L form and convex form). For every basic shape area, the camera is located at the vertex pasition, so that the whole area can be monitored by the camera.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1998-11-30
Volume volume33
Issue issue1
Start Page 53
End Page 57
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309122
JaLCDOI 10.18926/15376
FullText URL Mem_Fac_Eng_OU_35_183.pdf
Author Tabuchi Satoshi| Osaki, Hirokazu| Kajihara, Yasuhiro| Munesawa, Yoshiomi|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2001-03-27
Volume volume35
Issue issue1-2
Start Page 183
End Page 189
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307173
JaLCDOI 10.18926/14071
FullText URL Mem_Fac_Eng_OU_42_110.pdf
Author Nogami, Yasuyuki| Morikawa, Yoshitaka|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2008-01
Volume volume42
Issue issue1
Start Page 110
End Page 114
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308489
Author Seo, Takuro| Ohtaki, Eiji| Maitani, Toshihiko|
Published Date 1972
Publication Title Berichte des Ohara Instituts für landwirtschaftliche Biologie, Okayama Universität
Volume volume15
Issue issue3
Content Type Departmental Bulletin Paper
JaLCDOI 10.18926/15367
FullText URL Mem_Fac_Eng_OU_30_1_9.pdf
Author Ding Ronggui| Osaki, Hirokazu|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1995-12-28
Volume volume30
Issue issue1
Start Page 9
End Page 17
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307826
JaLCDOI 10.18926/15804
FullText URL Mem_Sch_Eng_OU_16_2_1.pdf
Author Yokoyama Fumiyoshi|
Abstract 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.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1982-03-29
Volume volume16
Issue issue2
Start Page 1
End Page 16
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307445
JaLCDOI 10.18926/CTED/58128
Title Alternative 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
FullText URL cted_010_165_181.pdf
Author OHTAKE, Yoshihisa| CHEATHAM, Gregory| TANJI, Takayuki|
Abstract 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.
Abstract Alternative 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。
Keywords 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)
Publication Title Bulletin of Center for Teacher Education and Development, Okayama University
Published Date 2020-03-20
Volume volume10
Start Page 165
End Page 181
ISSN 2186-1323
language 英語
Copyright Holders Copyright © 2020 岡山大学教師教育開発センター
File Version publisher
JaLCDOI 10.18926/15741
FullText URL Mem_Sch_Eng_OU_14_2_13.pdf
Author Koga, Ryuji| Ebara, Masami| Kosaka, Megumi| Sano, Hiroya|
Abstract 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.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1980-03-01
Volume volume14
Issue issue2
Start Page 13
End Page 22
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307887
JaLCDOI 10.18926/14157
FullText URL Mem_Fac_Eng_39_1_82.pdf
Author Wang, Feng| Nogami, Yasuyuki| Morikawa, Yoshitaka|
Abstract 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)).
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2005-01
Volume volume39
Issue issue1
Start Page 82
End Page 92
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308422
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 英語
File Version publisher
NAID 120002308980
JaLCDOI 10.18926/15382
FullText URL Mem_Fac_Eng_OU_35_207.pdf
Author Nakanishi, Toru| Fujiwara Toru|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2001-03-27
Volume volume35
Issue issue1-2
Start Page 207
End Page 212
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307232
JaLCDOI 10.18926/15780
FullText URL Mem_Sch_Eng_OU_15_2_119.pdf
Author Kaneda Masahiro| Akahori Ichiro| Egusa Masanori| Kuraoka Hiroaki|
Abstract 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.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1981-03-30
Volume volume15
Issue issue2
Start Page 119
End Page 132
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307465
JaLCDOI 10.18926/15729
FullText URL Mem_Sch_Eng_OU_13_239.pdf
Author Taniguchi Takeo|
Abstract 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.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1979-03-05
Volume volume13
Start Page 239
End Page 248
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307617
JaLCDOI 10.18926/46982
FullText URL mfe_37_2_073_087.pdf
Author Nogami, Yasuyuki| Morikawa, Yoshitaka|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2003-03
Volume volume37
Issue issue2
Start Page 73
End Page 87
ISSN 0475-0071
language 英語
File Version publisher
NAID 80015999992
Author Satoh, Toyonobu|
Published Date 1988
Publication Title 岡山大学農学部学術報告
Volume volume71
Issue issue1
Content Type Departmental Bulletin Paper
JaLCDOI 10.18926/15721
FullText URL Mem_Sch_Eng_OU_12_53.pdf
Author Fujitsuka Takeshi| Agusa Toru|
Abstract 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.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 53
End Page 58
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307552