result 989 件
| 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 | English |
| File Version | publisher |
| NAID | 120002307617 |
| JaLCDOI | 10.18926/15728 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_225.pdf |
| Author | Kaneda Masahiro| Shinji Hiroshi| Aoyama Mikio| |
| Abstract | This paper deals with the adaptive observer which estimates the states and parameters of unknown system. It is shown that the adaptive observer problem is reduced to the identification of the transformation matrix for an arbitrary designable observer. Moreover, the adaptive process of the unknown parameters is reduced to the linear optimal regulator problem. As the result, a new method is presented to obtain an appropriate adaptive process with good insight. And, in this identification, a linear filter is found to be also useful against noises in input-output data. To achieve high accuracy, a particular nonlinear filtering can improve SN ratio only in the direction of the unknown vector. Even if SN ratio of input-output data has zero dB, sufficient accuracy can be accomplished within suitable correction time. This design algorithm seems to be rather straightforward and practical. Since input sequence is required to be only sufficiently general, the method is applicable to on-line identification also. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 225 |
| End Page | 238 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307984 |
| JaLCDOI | 10.18926/15727 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_12_77.pdf |
| Author | Ohta, Mutsuo| Kobayashi, Toshinori| Sakakibara, Akira| |
| Abstract | The clustering phenomenon was observed when dilute Al-Zn alloys were annealed at temperatures higher than the solvus of the G.P.zones. In this report the apparent activation energy for clustering is estimated and compared with the experimental results. The estimated value of the apparent activation energy for clustering in several Al-Zn alloys comes to 0.51 eV, which is larger than the effective migration energy 0.43 eV of Zn atoms in Al-Zn alloys. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1978-02-25 |
| Volume | volume12 |
| Start Page | 77 |
| End Page | 88 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307178 |
| JaLCDOI | 10.18926/15726 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_219.pdf |
| Author | Totsuji Hiroo| Kakeya Hideyuki| |
| Abstract | The dynamic form factor and the dispersion relation of the plasma oscillation of two-dimensional classical systems of electrons with ordinary Coulomb interaction are obtained by numerical experiments in the domain of the plasma parameter 2.24≤√=(πn)(1/2)e(2)/T≤70.7, where n, e, and T are the areal number density, the electronic charge, and the temperature in energy units, respectively. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 219 |
| End Page | 224 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307942 |
| JaLCDOI | 10.18926/15725 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_12_59.pdf |
| Author | Ohta, Mutsuo| Kanadani, Teruto| Sakakibara, Akira| |
| Abstract | Several Al-Zn alloys containing 0.041-4.4 at % Zn were studied by means of measurements of electrical resistivity. The results obtained are as follows : (1) The electrical resistivity increases when the specimen is annealed at temperatures higher than the solvus temperature of the G.P. zones. The increase of the resistivity is due to the formation of fluctuation. (2) The electrical resistivity of the specimen containing fluctuation is dependent upon annealing temperature only and independent of quenching temperature. (3) The fluctuation is formed in very dilute alloys as 0.041 at % Zn at temperatures higher than the solvus temperature of the G.P. zones. (4) The formation energy of vacancy and the migration energy of the Zn atom in the alloys determined by the formation process of fluctuation are in good agreement with those by the formation process of G.P. zones. (5) In spite of the result (4), it seems that the fluctuation is not the same as the small G.P. zones which are observed in the early stage of aging. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1978-02-25 |
| Volume | volume12 |
| Start Page | 59 |
| End Page | 75 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307636 |
| JaLCDOI | 10.18926/15724 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_209.pdf |
| Author | Totsuji Hiroo| |
| Abstract | Exact lower bounds are given for thermodynamic quantities of ionic mixtures in the uniform background in d dimensions with three-dimensional (1/r) Coulomb interaction (d=2 and 3) and with d-dimensional Coulomb interaction (d=1, 2, and 3). It is shown that these lower bounds improve upon known ones and give values close to experimental results which are available in the case of d=3. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 209 |
| End Page | 218 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307762 |
| JaLCDOI | 10.18926/15723 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_195.pdf |
| Author | Sano, Hiroya| Koga, Ryuji| Tanada Yoshihiro| Kosaka, Megumi| |
| Abstract | The maximally attainable accuracy of an airpollution monitoring system is investigated. The system is composed of a tunable pulsed dye laser as the light source, photodiodes as the opto-electric converter and a low noise electronic signal processor specifically designed by the authors. The extreme value of the accuracy is given in terms of the standard deviation of the attenuation. The value is 3.4×10(-4)[Nep√(pulse number)] for an averaged value for multiple laser shots. Also the wavelength reproduceability of a dye laser was examined, which resulted in that a computer should take a part in the wavelength control in order that this method should be feasible. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 195 |
| End Page | 207 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307857 |
| JaLCDOI | 10.18926/15722 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_181.pdf |
| Author | Sano, Hiroya| Koga, Ryuji| Tanada, Yoshihiro| Kosaka, Megumi| |
| Abstract | This report deals with a notion of adjoint spectrum which is applicable to air-pollution monitoring by using pulsed lasers. Both Raman and absorption spectra of multiple gas complex are linear combinations of the spectra, each of which is specific to a gas species and its magnitude is proportional to the density. An extended formulation of the method of least squares is made in terms of a new notion, adjoint spectra, which visualizes the structure of the numerical filter. Applications of the derived numerical filters to the two methods are shown and features are described about the synthesized filters. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 181 |
| End Page | 193 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307476 |
| 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 | English |
| File Version | publisher |
| NAID | 120002307552 |
| JaLCDOI | 10.18926/15720 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_12_45.pdf |
| Author | Himei Toyoji| Nakanishi Senichiro| Funabiki Shigeyuki| |
| Abstract | In this paper, an AC chopper circuit, using a power transistor, is described which chops the AC voltage with a commercial frequency. The circuit is composed of a diode bridge and a power transistor in series with a load and capable of adjusting the switching frequency, fc, and the time ratio, T=ton/(ton+toff). The switching frequency and the time ratio of the AC chopper circuit depend on switching-times, that is, delay time, rise time, carrier storage time and fall time, especially in the high frequency. The upper limit of the switching frequency (about 150kHz) and the output characteristics of the circuit are investigated. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1978-02-25 |
| Volume | volume12 |
| Start Page | 45 |
| End Page | 52 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307334 |
| JaLCDOI | 10.18926/15719 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_163.pdf |
| Author | Tanada Yoshihiro| Sano Hiroya| |
| Abstract | A new waveform analyzer based on the Walsh transform is developed and is applied to a real-time filtering of fast pulse signals, and the linear filterings of time signals through the Walsh transform is discussed. The analyzer converts a solitary waveform during 16 μs into the 16 Walsh amplitude spectra in a hybrid manner: it has the sequency band from 62.5 kzps to 500 kzps. The spectra are parallelly held during 16 μs by analog integrators, while serially displayed by the CRT, and one of them is digitally read out. The spectra of the test waves are measured within the error rate of several per cent. The analyzer is applied to the correlative detection of the photoelectric pulse signals in a gasspectroscopic system using a pulse laser, and there composes the matched filter, which is useful for measuring the signals superposed by Gaussian noises with a high accuracy. For the real-time filtering of fast signals, the arithmetic convolution and the frequency power spectra are approximated using the complex Walsh transform. These approximations are of practical use in 16 or 32 dimensions. Then, the matched filters for pulse peaking are given by the approximate convolution and by the dyadic convolution. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 163 |
| End Page | 180 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307519 |
| JaLCDOI | 10.18926/15717 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_153.pdf |
| Author | Fukui, Kiyoshi| Nogi, Shigeji| Yamada, Masuo| Sakakibara, Akira| |
| Abstract | A unified treatment of injection and mutual phase locking phenomena in microwave oscillators coupled by a network characterized by a Y-matrix is presented. Under certain simplifying assumptions, steady state solutions such as locking frequency and oscillation phase relation are given with emphasis placed on the coupling-network dependence of locking bandwidth. Also, some examples of locking system specified by y(21)=0, Y(21)= Y(12) and y21= -Y12 are briefly discussed. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 153 |
| End Page | 162 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307532 |
| JaLCDOI | 10.18926/15716 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_12_29.pdf |
| Author | Yamamoto Tatsuma| Yamamoto Yoshitake| Nishida Hideki| Yasuhara Kiyotaka| |
| Abstract | The distributed circuit properties based on pores in the etched aluminum oxide film of the electrolytic capacitor have been analysed by the mathematical equation. This paper proposes the selection and the determining method of the parameters appearing in the analysis. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1978-02-25 |
| Volume | volume12 |
| Start Page | 29 |
| End Page | 36 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307968 |
| JaLCDOI | 10.18926/15715 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_133.pdf |
| Author | Ohta, Mutsuo| Kanadani, Teruto| Yamada, Masuo| Sakakibara, Akira| |
| Abstract | Aging and reversion in dilute Al-Ag alloys are studied by means of the measurements of electrical resistivity. Results obtained are as follows: 1) Increase in the as-quenched resistivity is found for a low quenching temperature. This increase may be due to the fluctuation of solute concentration at the quenching temperature. 2) When the fluctuation exists in the alloy, the aging rate becomes slow and the maximum resistivity in the isothermal aging curve becomes small as the vacancyconcentration becomes low. The maximum resistivity becomes large again when the vacancy concentration becomes further lower, and finally the maximum does not appear. 3) These behaviors are explained in terms of the difference in the rate of growth of the G.P. zones in the regions of higher and lower solute concentration induced by the fluctuation and in terms of the change of this difference with vacancy concentration. 4) G.P. zones may be formed by the spinodal decomposition with indefinite surfaces at first, grown to larger ones with difinite surfaces and changed to ordered nzones in the alloy. 5) It is confirmed that G.P. zones are formed by the nucleation-and-growth mechanism also in Al-Ag alloys above the spinodal temperature. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 133 |
| End Page | 152 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307468 |
| JaLCDOI | 10.18926/15714 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_12_23.pdf |
| Author | Yamashita Yuhiko| Monobe Kazuo| |
| Abstract | A new realistic, structural model is proposed for the glassy solid state of poly(ethylene terephthalate) (PET). The model is considered basing on crystallization behaviors from the glassy state of PET, and in particular including the evidence from the estimation of chain folding energy in this report. When PET is quenched from its melt into the glassy state, irregular folds with lower conformational energy remain in glassy structure and disturb the three dimensional arrangement of the chains connected with the folds. In conclusion, we suggested that the structure of glassy PET is not in amorphous state which is represented by the interpenetrating random coil model, but in frozen metastable state which can be approached from the chain folded structure of polymer crystals. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1978-02-25 |
| Volume | volume12 |
| Start Page | 23 |
| End Page | 28 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307771 |
| JaLCDOI | 10.18926/15713 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_11_2_51.pdf |
| Author | Inouye Hiroshi| |
| Abstract | In this paper some computational methods of traffic assignment are proposed. At first solutions of traffic assignment by the equal travel times principle used nonlinear programmings are showed. They are a method to approximate by a quadratic programming, a method to use the SUMT transformation, a method to apply Rosen's gradient projection method and a method to apply the conjugate gradient projection method. Through a computational example the efficiency of them are compared. To decide route flows uniquely in traffic assignment by the equal travel times principle, a method requesting route flows such that the joint probability is a maximum under supposed a priori probabilities is proposed. In case of a traffic assignment in a large scale road network, it is significant to improve the efficiency of route searches. For this purpose a technique of minimum time route search by division of a network is proposed. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1977-01-25 |
| Volume | volume11 |
| Issue | issue2 |
| Start Page | 51 |
| End Page | 71 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307829 |
| JaLCDOI | 10.18926/15712 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_119.pdf |
| Author | Ohta, Mutsuo| Yamada, Masuo| Kanadani, Teruto| Sakakibara, Akira| |
| Abstract | The effects of the fluctuation of solute concentration on the process of aging in Al-10wt % Zn alloy were studied by measurements of the intensity of small-angle X-ray scattering and by electron microscopy. Specimen was quenched from a higher temperature(T(Ql), mainly 300℃) to an intermediate temperature (T(Q2), 110~230℃), held there for a time, quenched again into iced water and aged isothermally at 0℃ or 40℃. Results obtained are as follows: (1) When the specimen was held at T(Q2) for a sufficient time and aged at relatively high temperatue(e.g. Ihr at 125℃ and aged at 40℃), a two-step increasing of both resistivity and integrated intensity was found. (2) Each of the steps has characteristics of the formation of G.P. zones by the spinodal decomposition. (3) When the maximum resistivity(p(max)) takes a minimum, Size distribution of the G.P. zones, estimated from the difference between Guinier and Porod radii, is much broader than that at p(max) in the usual direct quenching. (4) When the holding time at T(Q2) is long enough, the size distribution at p(max) is as broad as that at p(max) in the usual case. (5) After a prolonged aging under the condition that P(max) takes minimum, G.P. zones grow markedly and become oblate ellipsoidal with a major axis of about 20nm. (6) These results are consistently understood in terms of the fluctuation of solute concentration at T(Q2) and the change in the concentration of vacancies during annealing at T(Q2). That is, it is considered that these results are due to the difference in aging behavior between the regions of relatively high concentration and the ones of low concentration induced by the fluctuation. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 119 |
| End Page | 132 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307931 |
| JaLCDOI | 10.18926/15711 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_11_2_37.pdf |
| Author | Kawara Osami| |
| Abstract | In this paper, we compare ozone with chlorine regarding following respects; (1)Disinfection efficiency (2)Oxidation power (3)Effects of secondary effluents treated by ozone or chlorine on aerobic microorganisms. Both ozone and chlorine are powerfull oxidizing agents. However,those are greatly different from each other in effects of treatment. Ozone is superior to chlorine in oxidation of organics, perfection of disinfection and effects on aerobic microorganisms. On the other hand, chlorine is superior in disinfection of Coliform group bacteria. Based on these results,it may be concluded that chlorination will be effective in disinfection of effluents which do not contain so much contaminants. However in case of rather highly cotaminated effluents, ozonation will be suitable. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1977-01-25 |
| Volume | volume11 |
| Issue | issue2 |
| Start Page | 37 |
| End Page | 49 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307819 |
| JaLCDOI | 10.18926/15710 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_11_2_27.pdf |
| Author | Nago Hiroshi| |
| Abstract | In this paper the influence of a vertical lip upon the contraction coefficients of underflow gates is discussed. The coefficients of inclined gates with a vertical lip are investigated theoretically by using the method of conformal mapping. Solutions are obtained numerically for several values of the inclination of gate bottom. Theoretical solutions show that;as the length of a lip increases, the coefficient rapidly decreases from the value for the inclined gate, and when the length becomes of the order of a gate openning,it takes a value to be nearly equal to that for a vertical gate. These theoretical results are verified by experiments. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1977-01-25 |
| Volume | volume11 |
| Issue | issue2 |
| Start Page | 27 |
| End Page | 36 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307779 |
| JaLCDOI | 10.18926/15709 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_13_95.pdf |
| Author | Ohta, Mutsuo| Kanadani, Teruto| Yamada, Masuo| Sakakibara, Akira| |
| Abstract | Aging process in Al-Zn alloys was studied by the measurements of the electrical resistivity when the alloy was quenched from a high temperature, about 300℃ (the first quenching temperature), to an intermediate temperature, between 110℃ and 230℃ (the second quenching temperature), held at this temperature for a time, quenched again into iced water and aged at a low temperature. Variation of the holding time at the second quenching temperature brings about the variation of the isothermal aging curves. Maximum resistivity of the isothermal aging curve, p(max) , decreases at first, passes a minimum and then increases to reach a stationary value as the holding time at the intermediate temperature increases. It is pointed out that this phenomenon is mainly due to the fluctuation of solute concentration and the vacancy concentration decreasing at the intermediate temperature. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1979-03-05 |
| Volume | volume13 |
| Start Page | 95 |
| End Page | 117 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002307526 |
