| 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 |
| 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 | 10.18926/14157 |
|---|---|
| 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 | 10.18926/46982 |
|---|---|
| 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 |
| JaLCDOI | 10.18926/15472 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_23_2_9.pdf |
| Author | Kuroda Tsutomu| Osaki, Hirokazu| Matsuda, Masaaki| Fujisawa Keita| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1989-03-30 |
| Volume | volume23 |
| Issue | issue2 |
| Start Page | 9 |
| End Page | 19 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002307693 |
| JaLCDOI | 10.18926/15439 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_26_2_77.pdf |
| Author | Wada, Osami| Nakajima Masamitsu| |
| Abstract | This paper describes a method to design an antenna to focus millimeter-wave beam generated by a gyrotron. The antenna, which has been proposed by the authors, consists of a stair-cut circular waveguide and two cylindrical reflectors; one is elliptic and the other is parabolic. Its principle is based on the geometrical optics though slightly modified to consider the diffraction effect. Results of low-power experiments agree well with the design on beam direction, beam width and the position of the focal point. At 35.5 GHz using TE(01) mode, a focused beam with half-power thickness of 13 mm x 10 mm was obtained. This type of antennas find applications to millimeter-wave scattering measurement in fusion plasma research and high- energy-density source for material heating. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1992-03-28 |
| Volume | volume26 |
| Issue | issue2 |
| Start Page | 77 |
| End Page | 92 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002307321 |
| JaLCDOI | 10.18926/15512 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_25_2_69.pdf |
| Author | Tsuchiya Takao| Kagawa, Yukio| |
| Abstract | A finite element approach to the calculation of nonlinear sound propagation is proposed. Under the assumption of a weak nonlinearity, a linearized one-dimensional equation is considered. The equation is discretized in space, and is then solved for time by using Newmark-β integration scheme, in which a numerical damping is devised. Some numerical demonstrations are made for the nonlinear sound propagation of a single-shot pulse in air. It is shown that the shock wave propagation is stably and accurately simulated by the introduction of the numerical damping. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1991-03-28 |
| Volume | volume25 |
| Issue | issue2 |
| Start Page | 69 |
| End Page | 80 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002307747 |
