JaLCDOI 10.18926/46976
フルテキストURL mfe_37_2_005_012.pdf
著者 Abe, Takeji| Sato, Takashi|
抄録 Cork is a material that has many characteristics, for instance, light weight, elasticity, insulation against heat, impermeability for liquid, and so forth. There are two types of cork, the natural and the agglomerated corks. In the present paper, compression tests of the natural and the agglomerated cork specimens were carried out. The compression test were done in various directions. Compressive stress was measured by a original compression apparatus, and stress-strain curves were obtained in various directions of the cork specimens. In the natural cork, there are differences between the radial and the non-radial direction. The recovery of dimensions after compression was also studied in respective directions. The structure of the deformed surface was observed by a scanning electron microscope.
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 5
終了ページ 12
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80015999990
JaLCDOI 10.18926/46983
フルテキストURL mfe_37_2_089_097.pdf
著者 Iokibe, Kengo| Toyota, Yoshitaka| Wada, Osami| Koga, Ryuji|
抄録 Aerosol extinction coefficients of clouds and dust were continuously measured in the year of 2002 with a polarized Mie-scattering lidar controlled by an automatic and remotely operating system utilizing internet services. Measured cloud extinctions were greater than 1.0 km(-1) below the altitude 6 km, 0.17 - 1.0 km(-1) between 6 and 10 km, and 0.091 - 0.3 km(-1) beyond 10km. Extinction of dust were 0.10 and 0.20 km(-1) for Asian dust and 0.057 km(-1) for urban dust.
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 89
終了ページ 97
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120003457336
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
著者 Faculty of Engineering, Okayama University|
発行日 2003-03
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
37巻
2号
資料タイプ その他
JaLCDOI 10.18926/46978
フルテキストURL mfe_37_2_029_044.pdf
著者 Imajo, Shuya| Konishi, Masami| Imai, Jun| Nishi, Tatsushi|
抄録 In hot strip rolling mills, the looper control system is automated. However, the looper's behavior tends to be unstable in threading. Therefore, human expert always intervenes and stabilizes the looper's behavior by tuning PID gains and interposing manipulation variable of looper control system. In this paper, we propose a method based on the recurrent neural network to express PID gains tuning action by human. Furthermore, we propose two methods to update the model by learning. To check the effectiveness of the proposed learning methods, numerical simulation applied to the looper height control is carried out.
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 29
終了ページ 44
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80016037880
JaLCDOI 10.18926/46981
フルテキストURL mfe_37_2_067_072.pdf
著者 Yamagiwa, Masashi| Sakai, Hiroshi|
抄録 An active form of Cry4A is a heterodimer of the 20- and 45-kDa fragments that are derived from the 130-kDa Cry4A protoxin. To investigate the function of these two fragments, several deletion mutants were constructed and expressed in E.coli as the GST (glutathione-S-transferase) fusion proteins. The results of the bioassay against Culex pipiens larvae showed that the interaction of two fragments of Cry4A was necessary for the toxicity, and that the C-terminal 67 amino acids of the 20-kDa fragment corresponding to the helices α4 and α5 were involved in determining the insecticidal activity. Surprisingly the lack of helix α5 did not affect the toxicity to C. pipiens, suggesting that the role of helix α5 of Cry4A was different from that postulated in the case of Cry4A toxins.
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 67
終了ページ 72
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80016019143
JaLCDOI 10.18926/46979
フルテキストURL mfe_37_2_045_060.pdf
著者 Xu, Wei| Zhao, Y.| Horikane, T.| Hayata, T.| Tosuji, H.| Kagawa, Y.|
抄録 Resistivity distribution sounding of the non-homogeneous earth is important for electrical ground system design, geophysical prospecting and survey or monitoring the groundwater flow level. The previous paper presented that the direct inversion of the electric resistivity distribution in a domain is possible from the impedance data measured over the domain boundary using the dual reciprocity boundary element modelling in two-dimentional field [1]. The proposed inversion technique is extended to the distribution in three-dimensional space [2]. This technique is capable of inversion without iteration and meshing of the domain. Electric field with spatially varying conductivity is governed by Laplace equation, which is transformed into a Poisson-type expression with an inhomogeneous term involving the conductivity difference as a source term. Dual reciprocity method (DRM) is a technique for transforming the domain integral associated with the inhomogeneous term in Poisson equation into the boundary integral expression. The resistivity distribution in the field can thus be identified from the data observed over its boundary, for which some examples are demonstrated [2]. In this paper, the examination is extended to the case where only the data measured over the single surface is used for the inversion.
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 45
終了ページ 60
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80016037881
JaLCDOI 10.18926/46977
フルテキストURL mfe_37_2_013_027.pdf
著者 Shibuta, Taizo| Konishi, Masami| Imai, Jun| Nishi, Tatsushi|
抄録 Nowadays, various kind of reactor furnaces are widely used for the production in industry. The raw materials charged into the furnace generate reaction heat produced by blowing gas. Generally speaking, the reaction heat generated in the furnace is remarkably high. Therefore the occurrence of an inappropriate temperature distribution in the furnace may make damege or serious accident of the furnace. This is the motivation of furnace control. The author is considering the application of studied results to the furnace control of Blast Furnace in steel industry. To the propose, the approximated and simplified Macro Model of the Blast Furnace is constructed which has the function of representation of qualitative characteristics of the furnace in dynamical sense. The furnace temperature, distribution greatly effects both on the producting and the product quality of the furnace. Needless to say, stable furnace operation is indispensable for the economical prosperity of the industry. In this paper, macro simulation of the furnace is developed to support the analysis and design of the furnace control. Using the simulator, the stability and the control characteristics for inner furnace temperature distribtion are analised quantitatively.
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 13
終了ページ 27
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80015999991
JaLCDOI 10.18926/46975
フルテキストURL mfe_37_2_001_004.pdf
著者 Sakakibara, Akira| Kanadani, Teruto|
抄録 Effect of addition of Fe on the occurrence of serration in Al-12mass%Zn alloys was investigated. Specimens aged at 293K for various periods after quenching from various temperatures (T(Q)), 398K to 823K, were tensile-tested at room temperature. Serration occurred more easily and more remarkably with decreasing T(Q) for as-quenched specimens: in the case that T(Q)=448K serration was observed both for the binary and Fe added alloys, while in the case that T(Q)=573K none of the three alloys showed serration. For the binary alloy serration was observed only when the aging period was short enough, but addition of Fe to the binary alloy prolonged the aging period where serration could be recognized. Aging rate measured by hardness was remarkably retarded with the increase of Fe addition. These results confirm the interpretation that the serration in Al-Zn alloy occurs in the early stage of aging where small GP zones or solute clusters are formed.
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 1
終了ページ 4
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80016019142
JaLCDOI 10.18926/46980
フルテキストURL mfe_37_2_061_066.pdf
著者 Vaillancourt, Chico|
抄録 In this case study, I will analyse and discuss the results of a survey concerning motivation towards learning a second language conducted in one Danish high school. The students surveyed were between the ages of 13-18. This section, part two of the study, was conducted in Copenhagen, Denmark. This region of the world was chosen because bilingualism is quite common there and a large portion of the school-aged community is learning a second language and often a third and even a fourth. Denmark, a European country, is different than Canada (Case Study-Part 1.) because it neighbours many countries, which use different mother tongues.
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 61
終了ページ 66
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120003457333
著者 Faculty of Engineering, Okayama University|
発行日 2003-03
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
37巻
2号
資料タイプ その他
著者 Faculty of Engineering, Okayama University|
発行日 2002-11
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
37巻
1号
資料タイプ その他
JaLCDOI 10.18926/46972
フルテキストURL mfe_37_1_051_060.pdf
著者 Namba, Akihiro| Toyota, Yoshitaka| Wada, Osami| Koga, Ryuji|
抄録 This paper presents pulse timing control method to reduce electromagnetic emission from multiple signal interconnections. Pulse timing control gives intentional skew between signals. Higher order harmonics are canceled because of the difference of the phase between the signals. Using this property, pulse timing control can reduce the EMI in wide frequency range. In this paper, we show that radiated electromagnetic field from multiple signal lines reduces its intensity to the same level of the field from one line by using pulse timing control. The result of measurement shows that EMI from four differential transmission lines can be reduced more than 9 dB in the 200 MHz to 800 MHz frequency range.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2002-11
37巻
1号
開始ページ 51
終了ページ 60
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80015683518
著者 Faculty of Engineering, Okayama University|
発行日 2002-11
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
37巻
1号
資料タイプ その他
JaLCDOI 10.18926/46971
フルテキストURL mfe_37_1_041_049.pdf
著者 Sugaya, Yasuyuki| Kanatani, Kenichi|
抄録 We study the problem of segmenting independently moving objects in a video sequence. Several algorithms exist for classifying the trajectories of the feature points into independent motions, but the performance depends on the validity of the underlying camera imaging model. In this paper, we present a scheme for automatically selecting the best model using the geometric AIC before the segmentation stage, Using real video sequences, we confirm that the segmentation accuracy indeed improves if the segmentation is based on the selected model. We also show that the trajectory data can be compressed into low-dimensional vectors using the selected model. This is very effective in reducing the computation time for a long video sequence.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2002-11
37巻
1号
開始ページ 41
終了ページ 49
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120003457326
JaLCDOI 10.18926/46970
フルテキストURL mfe_37_1_025_032.pdf
著者 Kanazawa, Yasushi| Kanatani, Kenichi|
抄録 We present a new method for detecting point matches between two images without using any combinatorial search. Our strategy is to impose various local and non-local constraints as "soft" constraints by introducing their "confidence" measures via "mean-field approximations". The computation is a cascade of evaluating the confidence values and sorting according to them. In the end, we impose the "hard" epipolar constraint by RANSAC. We also introduce a model selection procedure to test if the image mapping can be regarded as a homography. We demonstrate the effectiveness of our method by real image examples.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2002-11
37巻
1号
開始ページ 25
終了ページ 32
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80015664456
JaLCDOI 10.18926/46968
フルテキストURL mfe_37_1_011_014.pdf
著者 Totsuji, Chieko| Limant, Muhammad S.| Tsuruta, Kenji| Totsuji, Hiroo|
抄録 A theoretical approach which has been successful in reproducing results of molecular-dynamics simulations on dusty plasmas is applied to estimate the screening length and the electric charge of two-dimensional dust crystals of melamine particles in the discharge chamber experiment. It has been found that the screening length is of the same order of magnitude as the inter-particle distance and the electric charge decreases on increasing number density of dust particles.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2002-11
37巻
1号
開始ページ 11
終了ページ 14
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80015784816
JaLCDOI 10.18926/46969
フルテキストURL mfe_37_1_015_023.pdf
著者 Kanatani, Kenichi|
抄録 In order to facilitate smooth communications with researchers in other fields including statistics, this paper investigates the meaning of "statistical methods" for geometric inference based on image feature points, We point out that statistical analysis does not make sense unless the underlying "statistical ensemble" is clearly defined. We trace back the origin of feature uncertainty to image processing operations for computer vision in general and discuss the implications of asymptotic analysis for performance evaluation in reference to "geometric fitting", "geometric model selection", the "geometric AIC", and the "geometric MDL". Referring to such statistical concepts as "nuisance parameters", the "Neyman-Scott problem", and "semiparametric models", we point out that simulation experiments for performance evaluation will lose meaning without carefully considering the assumptions involved and intended applications.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2002-11
37巻
1号
開始ページ 15
終了ページ 23
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80015664455
JaLCDOI 10.18926/46967
フルテキストURL mfe_37_1_001_010.pdf
著者 Sotobayashi, Ken| Konishi, Masami| Nishi, Tatsushi| Imai, Jun|
抄録 Auto Guided Vehicles (AGVs) are widely used in a semi-conductor fabricating factory and contribute to the stable production of a high quality semi-conductor products. In the near future, further expansion of the transportation system is expected accompanied with the rapid growth of semi-conductor industries. In such situation, the necessity of performing quick planning of transportation route and transportation control will be elevated. In this paper, practicable planning of the transportation route and transportation control are studied based on the decentralized agent method. Especially, the geometrical sizes of AGVs are considered in the determination of transportation routes and control strategy avoiding the occurrence of mutual collisions or deadlock of AGVs.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2002-11
37巻
1号
開始ページ 1
終了ページ 10
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120003457322
JaLCDOI 10.18926/47025
フルテキストURL mfe_36_2_051_060.pdf
著者 Hikida, Masaki| Magari, Masaki| Nakayama, Yasunori| Kanayama, Naoki| Ohmori, Hitoshi|
抄録 A population of peripheral B cells have been shown to express recombination activating gene products, RAG-1 and RAG-2, which are considered to be involved in revising the B cell antigen receptor (BCR) in the periphery. BCR engagement has been reported to turn off RAG expression in peripheral B cells, whereas the same treatment has an opposite effect in immature B cells in the bone marrow. In contrast to receptor editing that is involved in the removal of autoreactivity in immature B cells, it has been shown that secondary V(D)J rearrangement in peripheral B cells, termed receptor revision, contributes to affinity maturation of antibodies. Here, we show that RAG-2 expression in murine splenic B cells was abrogated by the coligation of BCR with complement receptors (CD21/CD35) much more efficiently than by the engagement of BCR alone. On the other hand, the same coligation augmented proliferation of anti-CD40-stimulated B cells. Consistent with these observations, RAG-2 expression was lower in the draining lymph nodes of the quasi-monoclonal mice when they were immunized with a high-affinity antigen than with a low-affinity one. These findings suggest a crucial role for CD21/CD35 in directing the conservation or the revision of BCRs in peripheral B cells.
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 51
終了ページ 60
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80015582223