JaLCDOI 10.18926/15447
FullText URL Mem_Fac_Eng_OU_28_1_129.pdf
Author Taniguchi, Takeo| Hirose, Sohichi| Ouchterlony Finn| Nakagawa Kohji| Miyaji Akihiko| Fukuoka Yasufumi|
Abstract The testing method of rock toughness is proposed by the international society of rock mechanics (ISRM), but the results may be influenced by the test pieces, and the details of the crack propagation and the stress intensity factors are not clarified through the testing. Also the experimental test requires tedious works for the preparation of test specimen and economical responsibility. The present study aims to simulate numerically the rock toughness testing which is proposed by ISRM. For this purpose, the authors propose a numerical method which can simulate the experimental testing, and they show the propriety of the proposed method by comparing the results with the experimental and other numerical methods. At the same time, they clarify the details of crack propagation behaviors in rocks, and show the change of the stress intensity factors. The proposed method is based on the displacement-type finite element method, and several techniques are introduced to obtain accurate solution of the mechanical behavior near the crack-tip area.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1993-11-30
Volume volume28
Issue issue1
Start Page 129
End Page 138
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307126
JaLCDOI 10.18926/15449
FullText URL Mem_Fac_Eng_OU_22_15.pdf
Author Furutani, Yoichiro| Totsuji, Hiroo| Komaki Kunitaka| Tanabe Masahiro|
Abstract An effective potential of an isolated partially ionized high-Z ion, calculated within the framework of the statistical models of atoms, is injected into the one-electron Schrödinger equation, in view of evaluating the electron density and comparing it with the results of statistical models. Starting from this initial value, a self-consistent electron density is obtained on the basis of the density functional theory, where quantum natures of electrons are fully taken into account.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-03-31
Volume volume22
Start Page 15
End Page 34
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307361
JaLCDOI 10.18926/15450
FullText URL Mem_Fac_Eng_OU_22_35.pdf
Author Totsuji, Hiroo|
Abstract Several methods to derive thermodynamic sum rules for a system including charged particle are proposed and applied to charged mixtures as well as one-component systems. The validity of the statements is examined carefully with respect to the ordering in the powers of the wave number. As for the mixture of electrons and ions, it is shown how the aspect of the one-component plasma or the ionic mixture appears when electrons become strongly degenerate.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-03-31
Volume volume22
Start Page 35
End Page 44
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307661
JaLCDOI 10.18926/15452
FullText URL Mem_Fac_Eng_OU_28_2_9.pdf
Author Sakakibara, Akira| Kanadani, Teruto| Nakagawa, K.| Yokota, Y.|
Abstract The state above the solubility temperature of GP zones of Al-3mass % Mg alloy, which has a tendency for precipitation and preprecipitation at low temperature, was studied by resistivity measurement. Homogenization treatment at high temperature reduced Mg atoms in the surface layer. After quenching from 623K, the specimen was annealed sequentially at various temperatures above the GP zone solvus. The stationary resistivity obtained in annealing at a temperature was the same irrespective of the starting state and increased with decreasing annealing temperature. No precipitation was observed in the annealing. The results are not in favor of the segregation of Mg atoms to the dislocation loops but of the short range clustering.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1994-03-15
Volume volume28
Issue issue2
Start Page 9
End Page 12
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307581
JaLCDOI 10.18926/15454
FullText URL Mem_Fac_Eng_OU_22_63.pdf
Author Myojin Syo| Kishino Keiichi| Yamada Masahito|
Abstract The paper is a case study mode choice in interregional occupational person trips. Disagregate behavioral model of logit type is applied to the occupational person trips from Tsuyama area in Okayama Prefecture to Osaka area. The model turned out to give asignificant explanation of the interregional mode choice characteristics. Travel time, travelling expenses and " with or wi thout heavy baggage " were found to be significant.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-03-31
Volume volume22
Start Page 63
End Page 70
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307421
JaLCDOI 10.18926/15455
FullText URL Mem_Fac_Eng_OU_23_1_1.pdf
Author Matsuda, Masaaki| Osaki, Hirokazu|
Abstract Display equipment has been used as communication media in the factory, office, and home. In order to communicate effectively, it is necessary to clarify the characteristics of eye movement in the case of looking at the display. The development of Eye Camera enables us to measure eye movement during work, so that we can collect the many data of eye movement during work. In this study, we proposed a method to evaluate the visual work using the distribution of visual points in X and Y axis. The cumulative distribution is approximated by the logistic curve which shows the symmetry and kurtosis by the parameter. The proposed method was applied to the three typical display models, that is, the digital meter model, reading model, and game model. In the digital meter model, the visual points were distributed symmetrically along the meters, and the symmetry and kurtosis of the distribution varied by the arranged direction of the meter. In the reading model, the visual points were distributed nearly symmetrically and uniformly in each axis and they were moved around the character and line from the period of spectrum analysis. In the game model, the visual points moved according to the target and were distributed symmetrically in the Y axis. And whether the target moved vertically or horizontally, the kurtosis of the distribution became equal in each axis.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 1
End Page 12
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307354
JaLCDOI 10.18926/15456
FullText URL Mem_Fac_Eng_OU_28_2_21.pdf
Author Yamamoto, Kyoji| Jiao Xuezhen|
Abstract An experimental investigation has been made of the cyclone dust collector with a perforated internal rotating cylinder. The size of the rotating cylinder is of 0.5D, where D is the diameter of the cyclone body, and is the same size as the outlet tube. The dust collection efficiency as well as the pressure loss has been measured when the inlet flow speed is 9 ~ 21 m/s and the rotating speed of the cylinder is 37 ~ 63 m/s. The velocity and pressure distributions were also measured. It is found that the collection efficiency decreases and the pressure loss increases as the rotating speed increases. It is also shown that both the inward radial velocity and the upward vertical velocity become large as the rotating cylinder increases its speed. As a whole, the rotation of the internal cylinder makes worse performance of the cyclone dust collector.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1994-03-15
Volume volume28
Issue issue2
Start Page 21
End Page 31
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307575
JaLCDOI 10.18926/15458
FullText URL Mem_Fac_Eng_OU_28_2_33.pdf
Author Wang, Ming| Ahmed, Anis| Wada, Osami| Koga, Ryuji|
Abstract Proposed here is a convenient optical system to collimate the crescent shaped blue laser beam radiated from a Cerenkov SHG in channel waveguide configuration. This collimation system is consisted of a parabolic mirror and has a very large tolerance to the mirror displacement. The anisotropy of the nonlinear crystal on which the waveguide is fabricated has been taken into account. The optimum mirror location is given to obtain a collimated blue laser beam with an aberration less than 0.07λ. By using an objective lens, the collimated beam can be focused down to a thin beam with the spot size less than 1μm.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1994-03-15
Volume volume28
Issue issue2
Start Page 33
End Page 44
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307149
JaLCDOI 10.18926/15461
FullText URL Mem_Fac_Eng_OU_28_2_53.pdf
Author Totsuji, Chieko| Matsubara Takeo| Miyata Satoru|
Abstract One of the best known solid solution of perovskites is the PbTiO(3)-PbZrO(3) system which is usually abbreviated as PZT. In the phase diagram of this system, there is a drastic phase change from tetragonal to rhombohedral at the molar ratio around 50:50. The PZT crystals are widely used as a practical piezoelectric material because of its very strong piezoelectric effect near this morphotropic phase boundary. We try to explain this anomaly in piezoelectric constant by a phenomenological theory.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1994-03-15
Volume volume28
Issue issue2
Start Page 53
End Page 58
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307223
JaLCDOI 10.18926/15467
FullText URL Mem_Fac_Eng_OU_23_1_61.pdf
Author Yamamoto, Yoshitake| Yamamoto, Tatsuma|
Abstract Skin impedance satisfies the Cole-Cole arc's law. The change of skin impedance during GSR (Galvanic Skin Reflex) can be expressed by the change of equivalent parallel resistance approximately. Using these characteristics, the complicated change of skin impedance during GSR can be determined continuously from the measurement value in one frequency point.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 61
End Page 68
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307322
JaLCDOI 10.18926/15468
FullText URL Mem_Fac_Eng_OU_23_1_69.pdf
Author Totsuji, Hiroo| Takei Makoto|
Abstract The statistical properties of two-dimensional systems of charges in semiconductor superlattices are analyzed and the dispersion relation of the plasma oscillation is calculated. The possibility to excite these oscillations by applying the electric field parallel to the structure is discussed.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 69
End Page 82
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307988
JaLCDOI 10.18926/15469
FullText URL Mem_Fac_Eng_OU_23_2_1.pdf
Author Kamiyabu, Hideto| Sakakibara, Akira| Maeda, Hironobu| Hida, Moritaka|
Abstract Surface tension (γ(L)) and contact angle (θ) of gallium related to wettability on Teflon and other substrates (Al(2)O(3), SiO(2), glass, graphite, BN, AI, Ni, As etc.) were investigated. The values of Teflon were 0.70(6)N/m and 158° in pure argon atmosphere, and the ones of other substrates were listed in a table in this text. We were interested especially in the relative values, γ(L)'s, on the substrates as compared with γ(L) on Teflon substrate. Liquid Ga showed spreading wetting on pure Ni metal and adhesional wetting on Al (supposed to be covered by A1(2)O(3)) and on metallic polycrystal As. Surface tension of Ga was remarkably decreased by a kind of oxide contamination due to oxygen in air. The surface layer coated by the contamination was of amorphous state nearly same as liquid Ga. The amorphous coat caused liquid Ga rather high supercooling of △T~35K. It seems that the contamination layer (oxide fi1m) smeared the crystal nucleation sites on the free surface of liquid Ga
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-03-30
Volume volume23
Issue issue2
Start Page 1
End Page 8
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307294
JaLCDOI 10.18926/15470
FullText URL Mem_Fac_Eng_OU_24_1_13.pdf
Author Uno, Yoshiyuki| Nakajima, Toshikatsu| Endo, Osamu|
Abstract The generation mechanism of crater in electrical discharge machining is analyzed with a single pulse discharge device for alloy tool steel, black alumina ceramics, cermet and cemented carbide, investigating the gap voltage, the discharge current, the shape of crater, the wear of electrode and so on. The experimental analysis makes it clear that the shape of crater has a characteristic feature for the kind of workpiece. The shape of electrode, which changes with the wear by an electric spark, has a significant effect on the shape of crater. The diameter and the depth of crater have a close relation to the discharge energy for alloy tool steel, black alumina ceramics and cermet, while those for cemented carbide are related to the discharge current. The shape factor which is the ratio of the depth to the diameter of crater is different for the work material.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 13
End Page 24
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307269
JaLCDOI 10.18926/15471
FullText URL Mem_Fac_Eng_OU_24_1_25.pdf
Author Kajihara, Yasuhiro| Osaki, Hirokazu|
Abstract An expert system, in which preconditions and rules are expressed in logical formulas, is developed to support the scheduling of an automated job shop type multi-item assembly line. This system has the foIIowing characteristics to apply any case of schedulings: (1)Forward scheduling orbackward scheduling can be made. (2)The criterion on the input order of products, the dispatching process at each assembly station, and the selection of products from a buffer can be selected from several priority criteria. (3)Layout, number and velocity of vehicles, and the capacity of each buffer can be changed.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 25
End Page 39
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307454
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 10.18926/15475
FullText URL Mem_Fac_Eng_OU_23_2_21.pdf
Author Myojin Sho| Yamada Masahito| Fujii Naoto|
Abstract Diversion model and disaggregate behavioral model of logit type are adopted as aggregate and disaggregate estimates, respectively. Diversion model is assumed as a binary choice process including diversion ratio function at each step in the process. Diversion ratio is assumed as a function of generalized-travel-time ratio. The function is identified with each of the two steps of diversion; diverson from rail and bus to car at first and from the rest undiverted to bus at second. The data used are those on inter-regional occupational person trips. Each function are found enough and/or critically significant in the statistical sense. At the begginning, sixteen characteristics variables are enrolled in disaggregate model, which are identified by use of the above data. Six variables are reached finally and are all reasonable. A brief comparison of goodness of fit to the data are made between two models.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-03-30
Volume volume23
Issue issue2
Start Page 21
End Page 32
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307168
JaLCDOI 10.18926/15477
FullText URL Mem_Fac_Eng_OU_23_2_33.pdf
Author Ishihara Yuji| Yamamoto, Kyoji|
Abstract This paper deals with the low Mach numbers flow of a rarefied vapour past a liquid sphere accompanied with condensation and evaporation at its surface. The linearized Bhatnager-Gross-Krook(B-G-K} equation is used for the analysis, and from it the integral equations of the density, temperature and flow velocities are derived. These integral equations are solved numerically over a wide range of the Knudsen number covering from the slip flow to the nearly free molecular flow. The drag on the sphere is also calculated and is compared with that of previous work.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-03-30
Volume volume23
Issue issue2
Start Page 33
End Page 44
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307401
JaLCDOI 10.18926/15478
FullText URL Mem_Fac_Eng_OU_23_2_45.pdf
Author Taniguchi, Takeo| Fujiwara, Kohji|
Abstract This paper includes a solver for a large sparse set of linear algebraic equations which are obtained by the application of the finite element method to static structural problems. Proposed method is a modification of Robust Incomplete Choleski-Conjugate Gradient Method, which belongs to Preconditioned Conjugate Gradient Method suitable for supercomputers. Through a number of numerical experiments the authors show that Robust Incomplete Choleski-Conjugate Gradient Method sometimes fails in to obtain the solutions, secondly they clarify the reason of the failures from the theoretical viewpoint, and finally they propose a modification of the robust method by the introduction of the theoretical result. Proposed method is as effective as the original, and it can overcome the demerit of Robust Method which is clarified through numerical experiments.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-03-30
Volume volume23
Issue issue2
Start Page 45
End Page 55
ISSN 0475-0071
language 日本語
File Version publisher
NAID 120002307820
JaLCDOI 10.18926/15480
FullText URL Mem_Fac_Eng_OU_25_1_1.pdf
Author Gao Hong| Wada, Tsutomu| Noritsugu, Toshiro|
Abstract How to reduce and simplify the calculation for image recognition is a very attractive and important issue in order to realize the real time control of a robot based on the image recognition results. This paper describes a method of extracting 2 - dimensional geometrical features of cubic objects based on the normal vector distributions from the visual information obtained with the laser range finder to reduce the calculation of the image recognition. In this research a laser beam is scanned in the horizontal plane to which the cubic objects stand vertically and the laser spot is detected with a TV camera every sampling time. These spots make an intermittent locus which includes some special lines corresponding to the cubic objects. To extract the features of the cubic objects, we utilize the normal vectors formed on the locus. If some normal vectors distribute in the same direction and the origin of the normal vectors are very close to their neighbor's, these normal vectors can be classified into the same class, -the straight line class. Because the normal vectors on the neighbor surfaces of the cubic objects are vertical to each other, we use this property to determine the pair of straight lines which belong to the cubic objects. Making the histogram based on the normal vectors with the same direction, we obtain the peaks which are supported by the points on the cubic object surfaces. Then, the points can be extracted from the set of points on the whole locus inversely according to the relations with the peaks and the features of the cubic object can be extracted by applying method of least square to these extracted points. The experiments proved the availability of the proposed processing algorithm.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 1
End Page 13
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308010
JaLCDOI 10.18926/15481
FullText URL Mem_Fac_Eng_OU_24_1_81.pdf
Author Wada, Osami|
Abstract Are calculated the radiation characteristics of two types of primary-feed waveguides of millimeter wave quasi-optical antennas, which transform circular TE(On) mode into a linearly polarized beam. These antennas are utilized for heating and diagnostics of fusion plasma. Analysis is based on the Huygens-Fresnel principle, which takes the diffraction effect into account. For Convenience in analysis, a feed waveguide is divided into two sections, an uniform waveguide section and a visor section. Assuming that the diameter of the waveguide is several times as large as the wavelength and that the structure of the visor is open, the radiation field is approximated by superposition of direct radiation, and first and second reflection on the visor. Numerical results are presented and compared with experimental results. In these types of waveguides, the shadow section on the visor has a great influence on the radiation field. The results of calculation show that the length of the visor should be longer than that obtained by the geometrical optics, and the longer visor reduces the side-lobe level in the direction of the waveguide axis. The results agree well with those in experiments.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 81
End Page 92
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307974