JaLCDOI 10.18926/15776
FullText URL Mem_Sch_Eng_OU_15_2_79.pdf
Author Koga, Ryuji| Nagase, Satoru| Kosaka, Megumi| Sano, Hiroya|
Abstract A method to monitor atmospheric gas concentration employing a tunable diode laser is proposed. An apparatus was built and experiments were made. The tunable diode laser employed was of'PbSnTe with its wavenumber about 1200 cm(-1) at a temperature of 77 K. Methane concentration in laboratory atmosphere was measured on the experiments. The inquired gas-density is obtained by a hardwired microcomputer incorporating the measured absorption spectrum over a prescribed range instead of an absorption at a single wavenumber. By this, drift type noises are suppressed. After an analysis based on experimental data, an attainable sensitivity for methane was found to be 1 ppb.m. This value may increase if an etalon fringe interference exists. The natural concentration, about 1 ppm, of atmospheric methane was actually measured with a short optical path of only one meter.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1981-03-30
Volume volume15
Issue issue2
Start Page 79
End Page 92
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307246
JaLCDOI 10.18926/15777
FullText URL Mem_Sch_Eng_OU_15_2_93.pdf
Author Totsuji Hiroo|
Abstract A method to obtain exact lower bounds for the correlation energy of one-component plasmas is extended to neutral mixtures of charged hard spheres. Upper bounds for the correlation functions of charge densities are derived. These upper bounds, the semi-positivity of correlation functions, and that of the charge-densityfluctuation spectrum are used to improve upon the known bound due to Onsager.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1981-03-30
Volume volume15
Issue issue2
Start Page 93
End Page 106
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307165
JaLCDOI 10.18926/15779
FullText URL Mem_Sch_Eng_OU_15_2_107.pdf
Author Totsuji Hiroo| Obata Takashi| Funahashi Takahiko|
Abstract The dynamic form factor and the transverse part of the fluctuation spectrum of momentum density are analysed on the basis of the generalized Langevin equation. According to the indication of the result, numerical experiments are extended and it is shown that the transverse fluctuation spectrum contains two kinds of excitations. The frequency moment sum rules are discussed in relation to one of these excitations.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1981-03-30
Volume volume15
Issue issue2
Start Page 107
End Page 118
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307901
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 10.18926/15841
FullText URL Mem_Sch_Eng_OU_10_1_61.pdf
Author School of Engineering, Okayama University|
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1975-07-01
Volume volume10
Issue issue1
Start Page 61
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307517
JaLCDOI 10.18926/15370
FullText URL Mem_Fac_Eng_OU_27_2_73.pdf
Author Kroumov Valeri T.| Inoue, Akira| Masuda, Shiro|
Abstract This report deals with the problem of designing an adaptive observer for estimating unknown periodical disturbances. This is very practical problem because in the area of control of servomechanisms such disturbances are always encountered. When the disturbance cannot be directly measured or eliminated at the source it is necessary to perform a prediction. When a periodical disturbance is present the frequencies appear as unknown parameters and they have to be identified. In order to identify the unknown parameters, it is necessary to transform the composite system model, which contains the models of the controlled system and the disturbances, into observable canonical form. In addition, an inverse transformation is required to calculate the estimates of the present disturbances. In this report, firstly, a review of an adaptive observer for estimation of unknown periodical disturbances is presented. Later a calculation of the disturbance estimate is derived using the algebraic programming system REDUCE. The proposed method here allows to perform all the necessary transformations and to obtain the disturbance estimation without using the transformation matrix. The calculations of these transformations are complicated and, hitherto, there is no simple method to perform them. The results of disturbance estimation are illustrated by two examples.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1993-03-25
Volume volume27
Issue issue2
Start Page 73
End Page 85
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307731
JaLCDOI 10.18926/15385
FullText URL Mem_Fac_Eng_OU_27_1_1.pdf
Author Uno, Yoshiyuki| Kubota, Shin-ichiro| Nakajima, Toshikatsu| Ogata, Kojiro| Tada, Nobuhiko|
Abstract Direct patterning of copper coated ceramic circuit board is experimentally investigated with Q-switched Nd:YAG laser in order to shorten the time of the trial manufacture of electronic circuit board and to adapt the flexible design change. It is pointed out that the fast direct patterning the speed of which reaches about 100 mm/s is possible if the repetition frequency and the average power are selected properly. Furthermore cutting off and/or drilling of ceramic board are also possible under the condition that the repetition frequency is less than 3kHz. This technique makes it possible the mask1ess patterning of ceramic circuit board which has been widely used recently in place of conventional glass-epoxy or phenolic resin circuit board, and it leads to the shorter time limit of delivery as compared with the conventional end-milling method.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-11-25
Volume volume27
Issue issue1
Start Page 1
End Page 10
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307702
JaLCDOI 10.18926/15388
FullText URL Mem_Fac_Eng_OU_27_1_11.pdf
Author Hirashima Masao| Inaba, Hideo|
Abstract To prevent freezing of road and aquaduct by extracting geothermal heat with two phase closed thermosiphon has been widely used in a cold area. Both heat transfer characteristics in the underground soil and function of the thermosiphon to extract geothermal heat have to be made clear for the purpose of the above system. This study is directed for the purpose to prevent freezing of fire hydrant and composed of the fundamental experiment and the empirical experiment. In the fundamental study, heat transfer behavior is studied experimentally in the small size filling bath representing the underground soil layer. After recording temperature distribution, heat transfer coefficient is measured, they are proceeded into the correlation between the dimensionless number of Nusselt, Rayleigh and Fourier. The fundamental study is described as the first report.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-11-25
Volume volume27
Issue issue1
Start Page 11
End Page 26
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307419
JaLCDOI 10.18926/15390
FullText URL Mem_Fac_Eng_OU_27_1_27.pdf
Author Hirashima Masao| Inaba, Hideo|
Abstract Heating and refrigerating technique such as snow melting of road and cold storage by utilizing temperature difference between underground soil and atmosphere is widely used[1-4] in a cold area. In the 1st Report, heat transfer characteristics of two phase closed thermosiphon for extracting geothermal energy is studied fundamentally. In the empirical study, heat extract rate is measured in connection with the change of atmospheric temperature utilizing real two thermosiphons on the site. Temperature distribution on the surface of the thermosiphon and underground soil around it is also measured. Based on the data of the empirical experiment, it is confirmed that prevention of freezing for fire hydrant can be achieved by geothermal heat utilizing two phase closed thermosiphon. Present paper describes the heat transfer behavior of the thermosiphon as the 2nd report.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-11-25
Volume volume27
Issue issue1
Start Page 27
End Page 32
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307336
JaLCDOI 10.18926/15391
FullText URL Mem_Fac_Eng_OU_27_1_33.pdf
Author Shimada, Yukiyasu| Suzuki, Kazuhiko| Sayama, Hayatoshi|
Abstract Neural nets have recently become the focus of much attention, largely because of their wide range of complex and nonlinear problems. This paper presents a new integrated approach using neural networks for diagnosing process failures. The fault propagation in process is modeled by causal relationships from the fault tree and its minimal cut sets. The measurement patterns required for training and testing the neural network were obtained from fault propagation model. The network is able to diagnose even in the presence of malfunction of certain sensors. We demonstrate via a nitric acid cooler process how the neural network can learn and successfully diagnose the faults.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-11-25
Volume volume27
Issue issue1
Start Page 33
End Page 44
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307902
JaLCDOI 10.18926/15392
FullText URL Mem_Fac_Eng_OU_27_1_45.pdf
Author Kagawa, Naoki| Wada, Osami| Hai, Xu| Koga, Ryuji| Sano, Hiroya| Inubushi, Kazuyuki|
Abstract A prototype device based on the tunable diode laser absorption spectrometry was constructed and the atmospheric methane concentration near the terrain in a rice paddy field was measured. An open optical path of 50 m length was employed along with a PbSnTe diode laser. Diurnal change of methane density with 30 seconds temporal resolution was recorded associated with meteorological parameters. A feasibility was proven for a practical application for in situ study of atmospheric methane.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-11-25
Volume volume27
Issue issue1
Start Page 45
End Page 53
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307877
JaLCDOI 10.18926/15394
FullText URL Mem_Fac_Eng_OU_27_1_55.pdf
Author Totsuji, Hiroo| Tachibana Hiroyuki| Hashimoto Seiji| Nara, Shigetoshi|
Abstract The ground state of a system of electrons accumulated in a pair of coupled symmetric quantum wires is analyzed on the basis of density functional theory. It is shown that, in a domain of physical parameters, electrons are localized in either of wires. The main contribution to the total energy of this system comes from the Hartree energy, or the electrostatic energy, and the exchange-correlation energy between electrons. The ground state is determined by a competition between these contributions: We have symmetric electron distributions when the Hartree energy dominates and asymmetric (localized) states are realized in the opposite case. This kind of simple system with bistable electronic states may be applied to semiconductor memory devices.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-11-25
Volume volume27
Issue issue1
Start Page 55
End Page 64
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307892
JaLCDOI 10.18926/15395
FullText URL Mem_Fac_Eng_OU_27_1_65.pdf
Author Nara, Shigetoshi| Hara Yuji| Totsuji, Hiroo|
Abstract Quantum mechnical electron wave transfer between two quantum wires which are weakly coupled via a thin potential barrier is considered. The total electronic states are calculated with both analytical ( no field case ) and numerical methods ( under applied electric fields ). The transfer efficiency is evaluated for several specified cases of geometrical structures, potential barrier heights and the externally applied electric field. Estimated trasfer time is of the order of one picosecond in typical mesoscopic structures. The model in this paper can be used to determine important structure parameters for experiments on electron directional coupler controled by external elctric field.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-11-25
Volume volume27
Issue issue1
Start Page 65
End Page 79
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307405
JaLCDOI 10.18926/15396
FullText URL Mem_Fac_Eng_OU_27_1_81.pdf
Author Abe, Hirofumi|
Abstract This paper aims to examine the impact of JR (Japan Railways) Seto Ohashi Line on residential land value. First, the study examines the trends in land value in the area along JR Seto Ohashi Line by applying the area comparison method. The method estimates the effect of JR Seto Ohashi Line on residential land value by comparing land values between the study area and the Okayama Metropolitan Area. Second, the property value method is applied to measure the effect of railroad construction. The effect is estimated with a residential land-value regression, which is calibrated using land value data along the Seto Ohashi Line. Finally, the results are compared with the empirical studies in the Greater Tokyo Region, and various features of the impact of railroad construction on land value are identified.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-11-25
Volume volume27
Issue issue1
Start Page 81
End Page 92
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307856
JaLCDOI 10.18926/15398
FullText URL Mem_Fac_Eng_OU_27_1_93.pdf
Author Nishigaki, Makoto| Sudinda Teddy| Hishiya Tomoyuki| Kohno, Ichiro|
Abstract In this paper the author will be describe phenomena of advection dispersion in subsurface flow by using Eulerian Lagrangian Finite Element Method. Where Finite Element Method with Galerkin formulation and weigthed residual method is used to solve seepage and advection dispersion equation. The problem of one dimensional and two dimensional rectangular wave are analyzed in this paper. And the result of numerical analyses will be compared with analytical solutions. The numerical results showed the very good agreement with the analytical solutions.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-11-25
Volume volume27
Issue issue1
Start Page 93
End Page 105
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307768
JaLCDOI 10.18926/15399
FullText URL Mem_Fac_Eng_OU_27_2_1.pdf
Author Kajihara, Yasuhiro| Osaki, Hirokazu|
Abstract Precedence relation in assembly has been determined by experience only. Now, an expert system is developed for determining such precedence relation. The conjugate states of the units of a product are shown in face frames and unit frames following the frame model. Seven rules are formulated. They consider geometrical interference of units, and make the precedence relation enable operation time to be shorter, and the number of JIG and substandards to be smaller. These rules are programized by computer language(PROLOG).
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1993-03-25
Volume volume27
Issue issue2
Start Page 1
End Page 9
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307210
JaLCDOI 10.18926/15400
FullText URL Mem_Fac_Eng_OU_27_2_11.pdf
Author Oka, Hisao| Yamamoto, Tatsuma| Saratani Keiji| Tanaka Masahiro| Kawazoe Takayoshi|
Abstract The use of dental implants has increased together with increases in the human life span and it has become an imperative subject for dentists to familiarize themselves with this treatment modality. Unfortunately, there has been no practical and quantitative method for in vivo evaluation of the stability of dental implants. In the tooth mobility examination, the tactile sense of natural teeth is different from that of dental implants. The authors have developed an automatic diagnosis system of tooth mobility for clinical use. The biomechanical mobility of peri-implantium is measured with a pseudo-random vibration, from which the viscoelasticity c1, c2, k of peri-implantium is obtained. The diagnosis system has been applied to the quantitative evaluation of the stability of implants : endodontics endosseous implants (titanium pin), endosseous implants (Bioceram). It has also been applied to the evaluation of the long-term prognoses of dental implantation (Bioceram) and the examination of Intramobile implant (IMZ), and the satisfactory results have been obtained.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1993-03-25
Volume volume27
Issue issue2
Start Page 11
End Page 17
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308018
JaLCDOI 10.18926/15403
FullText URL Mem_Fac_Eng_OU_27_2_19.pdf
Author Nara, Shigetoshi| Totsuji, Hiroo|
Abstract Numerical simulations of a single layer recurrent neural network model in which the synaptic connection matrix is formed by summing cyclic products of succesive patterns show that complex dynamics can occur with the reduction of a connectivity parameter which is the number of connection between neurons. The structure in these dynamics is discussed from the viewpoint of realizing complex function using complex dynamics.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1993-03-25
Volume volume27
Issue issue2
Start Page 19
End Page 40
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307451
JaLCDOI 10.18926/15404
FullText URL Mem_Fac_Eng_OU_27_2_41.pdf
Author Prokop Jiri| Myojin Sho|
Abstract The fundamental objective of this paper is to aggregate and establish a set of practical principles, guidelines, and procedures to clarify and improve classification yard design and to enhance the efficiency of the design process. The paper primarily addresses theoretical and technical aspects of hump yard height and grade design, placement of the switches and the retarders. It attempts to compile and document yard design procedures, based on the Theory of Energy Head and Energy Loss. This procedures are applicable to the design of new yards, rehabilitation of the existing yards of different types and sizes including manually operated as well as highly automated classification yards.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1993-03-25
Volume volume27
Issue issue2
Start Page 41
End Page 58
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307241
JaLCDOI 10.18926/15406
FullText URL Mem_Fac_Eng_OU_27_2_59.pdf
Author Prokop Jiri| Myojin Sho|
Abstract The paper presents methods for simulation and examination of the performance of a classification yard, including both manual and computer-aided methods. Presented methods are applicable to the simulation and examination of full range of yards of different types and sizes including manually operated as well as highly automated classification yards.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1993-03-25
Volume volume27
Issue issue2
Start Page 59
End Page 71
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307384