JaLCDOI 10.18926/15354
FullText URL Mem_Fac_Eng_OU_34_1.pdf
Author Song Baoyin| Inaba, Hideo| Horibe, Akihiko| Takahashi Takashi|
Abstract The experiment for investigating the falling snow melting characteristics of warm water flowing along sheet channels spread on a roof was performed in Tookamachi city, Nigata prefecture from February 6 to February 7, 1995. The sheet surface temperatures at 11 positions in 3 channels were measured. A physical model for a gas-water-snow system was constructed to compare the predicted results with the measured ones. A fully spread uniform water film in the sheet channel was observed in the experiments. The experimental results elucidated that it was feasible to use warm water flowing along sheet channels for melting falling snow on roofs. The temperature drop in the sheet channel mainly depended on the snowfall intensity, atmospheric temperature and wind speed. Under the influence of the roof edge, the temperature drop in the channel next to the side edge was much larger than that in middle channels. A water-snow two phase flow or a snow covered frozen water was experienced temporarily in the lower reaches of the water flowing channel. These suggest that a larger water flow rate is needed for the channel next to the roof edge, and a higher inlet temperature or a greater water flow rate is required for a severe weather condition. There was reasonably good agreement between the measured and predicted water temperatures.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2000-03-27
Volume volume34
Issue issue1-2
Start Page 1
End Page 12
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307686
JaLCDOI 10.18926/14057
FullText URL Mem_Fac_Eng_OU_42_36.pdf
Author Kato, Hidehiro| Nekado, Kenta| Nogami, Yasuyuki| Morikawa, Yoshitaka|
Abstract This paper proposes an exponentiation method with Frobenius mappings. Our method is closely related to so-called interleaving exponentiation. Different from the interleaving exponentiation methods, our method can carry out several exponentiations using same base at the same time. The efficiency to use Frobenius mappings for an exponentiation in extension field is well introduced by Avanzi and Mihailescu. This exponentiation method is based on so-called simultaneous exponentiation and uses many Frobenius mappings. Their method more decreased the number of multiplications; however, the number of Frobenius mappings inversely increased. Compared to their method , the number of multiplications needed for the proposed method becomes about 20% larger; however, that of Frobenius mappings becomes small enough.
Keywords exponentiation Frobenius mapping extension field
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2008-01
Volume volume42
Issue issue1
Start Page 36
End Page 43
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308105
JaLCDOI 10.18926/14096
FullText URL Mem_Fac_Eng_OU_40_1_1.pdf
Author Ma, YouLi| Shimizu, Kenichi| Torii, Tashiyuki|
Abstract A testing for bent fatigue crack propagation under mixed-mode conditions was carried out using fatigue and annealed slant precracks with different slant angles, β ,defined as the angle between loading and precrack directions in a rectangular plate. As a result, bent fatigue crack from the fatigue precrack with β =45deg. propagated under mixed-mode conditions with mode II stress intensity factor (K(II))(est) evaluated from the discontinuous displacement measured along the crack. On the other hand, bent fatigue crack from the fatigue precrack with β =60deg. and from the annealed precracks with both slant angles of β =60deg. and β =45deg. propagated under the mode I behavior. This was because the compressive residual stress near the fatigue precrack caused contact to each other between the upper and the lower surfaces of the precrack with the smaller slant angle β . Furthermore, the fatigue crack propagation rates indicated almost the same relationship for all the data, using the mixed-mode effective stress intensity factor (K(M))(est), calculated from the discontinuous displacement measured along the bent fatigue crack.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2006-01
Volume volume40
Issue issue1
Start Page 1
End Page 8
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308402
JaLCDOI 10.18926/14069
FullText URL Mem_Fac_Eng_OU_42_104.pdf
Author Donghui, MA| Torii, Tashiyuki| Shimizu, Kenichi| Matsuba, Akira|
Abstract As model specimens of surface film-bonded materials, pure copper films with a thickness of 100μm were bonded to the surface of steel base with epoxy resin, where the tensile residual stress was measured by an X-ray on the surface copper film. The distribution of initial electric resistance was measured on both copper film and base specimen by a direct current potential drop technique. As a result, there was a good agreement between the measured and theoretical values. From the fatigue testing results, it was shown that the measured electric resistance increased with the fatigue crack length on the copper film, which was almost equal to the theoretical value calculated for a central slit in a plate with finite width. This was probably because the fatigue crack was opened due to the tensile residual stress on the film even under unloading condition. In addition, the internal crack length during fatigue was examined by ultrasonic testing for the film-bonded specimen. As a result, there was a difference in the fatigue crack length between the surface copper film and the inner base.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2008-01
Volume volume42
Issue issue1
Start Page 104
End Page 109
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308537
JaLCDOI 10.18926/15506
FullText URL Mem_Fac_Eng_OU_25_2_17.pdf
Author Sakakibara, Akira| Kanadani, Teruto| Kaneeda, Toshiaki| Hosokawa, Norio|
Abstract Effect of the soft surface layer that was formed on low temperature aging of Al-Zn alloy on fatigue strength was studied under repeated tensile loading. Vickers microhardness test revealed that there existed less hardened region in the vicinity of grain boundary and surface, and that the region extends 50 to 100μm from the surface inward. From the plot of the stress amplitude against the number of cycles to failure, it is concluded that the presence of less hardened surface layer strengthens fatigue resistance of the age hardened Al-Zn alloys containing 8 to 16mass % Zn under the repeated tensile loading.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1991-03-28
Volume volume25
Issue issue2
Start Page 17
End Page 23
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307685
JaLCDOI 10.18926/46948
FullText URL mfe_38_1-2_015_027.pdf
Author Torigoe, Takashi| Konishi, Masami| Imai, Jun| Nishi, Tatsushi|
Abstract In these days, mechanical systems are becoming more complex and highly automated. So, there exist wide variety of demands for reliable diagnostic technology. A reliable data analysis and quantitative diagnosis method of mechanical system is necessary for the purpose. In this paper a quantitative diagnosis method for looper height control system has been developed based on neural network technologies. The wavelet transformation is used for pre-processing to analyze characteristics of looper height control system. And, self organizing map neural network is used for the purpose of classification based on the pre-processed data. After that, the classified results are used for quantitative diagnosis in hierarchical neural network.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2004-03
Volume volume38
Issue issue1-2
Start Page 15
End Page 27
ISSN 0475-0071
language 英語
File Version publisher
NAID 80016785934
JaLCDOI 10.18926/15493
FullText URL Mem_Fac_Eng_OU_24_2_17.pdf
Author Konishi, Tadataka| Baba, Mitsuru|
Abstract Pressure distribution has been measured and analyzed to clarify the fundamental characteristics of "continuous oil-film" formed in a transparent journal bearing, into which oil in general use is supplied. Measured pressure mostly shows quasi-Sommerfeld distribution, which is characterized by downstream shift of pressure profile and underdevelopment of pressure trough compared with Sommerfeld distribution for perfect oil-film. Sommerfeld distribution is approximately observed only under limited conditions : low eccentricity and low speed. Quasi-Sommerfeld state is rather common in "continuous oil-film", unruptured film formed by using practical lubricants, than Sommerfeld state. Continuous oil-film is accompanied by fine bubbles and is controlled by the growing up or down of the bubbles.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-03-29
Volume volume24
Issue issue2
Start Page 17
End Page 30
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307431
JaLCDOI 10.18926/15489
FullText URL Mem_Fac_Eng_OU_24_2_1.pdf
Author Umemoto, Masayuki| Takemoto, Yoshito| Sakakibara, Akira| Hida, Moritaka|
Abstract Fine particles of Ti-Mo alloy were prepared by evaporation. When Ti-40at % Mo alloy was evaporated on tungsten filament, fine particles of Ti contaminated with W were obtained. These particles were polyhedron in shape and 10~250nm in diameter. Average diameter and size distribution increased with pressure of argon gas (100~600 Torr). When pure Ti was placed on the Mo filament and evaporated from melt down of heated Mo filament in helium gas, fine particles of pure Ti and of Ti-Mo alloy were obtained. In this case, Ti particles were of indeterminate form and of several tens nm in diameter, and their diffraction pattern was of common α-Ti. On the other hand, composition of the Ti-Mo particles was determined to be 18at % Mo by an analysis of EDX. Structure of Ti-Mo particles could not be determined because their diameters were more than 600nm. The temperature of Mo filament, for the most part, was about 1800℃, and there pure Ti particles were produced. The temperature of the fused part of the filament was locally higher than 2600℃, and there Ti-Mo particles were produced. Fine structures of contact region among some Ti particles were observed with HRTEM.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-03-29
Volume volume24
Issue issue2
Start Page 1
End Page 9
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307765
JaLCDOI 10.18926/15379
FullText URL Mem_Fac_Eng_OU_30_1_63.pdf
Author Koshimoto Marcos| Mahmood Zaheed| Kagawa, Yukio|
Abstract Optical fibers or integrated optical waveguides have arbitrary cross-sectional index or refraction distribution. An efficient finite element method for analyzing the propagation characteristics of dielectric / optical waveguides with open boundary is presented. The propagation modes are hybrid, for which a variational expression is formulated in terms of the longitudinal electric and magnetic field components. Infinite elements are introduced to consider open boundary or to extend the region to infinity. Several specific examples are given and the results are compared with those obtained by other approximate methods. Very close agreements have been found.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1995-12-28
Volume volume30
Issue issue1
Start Page 63
End Page 73
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307545
JaLCDOI 10.18926/15374
FullText URL Mem_Fac_Eng_OU_30_1_35.pdf
Author Mahmood Zaheed| Kagawa, Yukio|
Abstract Divergence-free shape functions are proposed for the finite elements, with which inhomogeneously-loaded and arbitrarily-shaped waveguides are analysed. The method is based on vectorial finite element formulation employing edge elements. The shape functions used for the approximation of the fields are shown analytically to be divergence-free and as an evidence, the non-physical solutions that appeared in the longitudinal component finite element formulation have been shown to be absent. To show the validity of the elements, application is made for the analysis of rectangular waveguides loaded with dielectric slab and a waveguide with curved structure. The solutions obtained are compared with the analytical ones or the solutions reported elsewhere. The degree of accuracy has been found satisfactory.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1995-12-28
Volume volume30
Issue issue1
Start Page 35
End Page 46
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307293
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 10.18926/15357
FullText URL Mem_Fac_Eng_OU_35_53.pdf
Author Kim Tae Yong| Kagawa, Yukio|
Abstract Fresnel zone plate lens (FZPL) has widely been used in electromagnetic antenna applications. Most analysis method based on the potential (scalar) wave approximation has been applied to a few very limited and simplified cases. The present paper analyzes the FZPL in more general form including the diffraction and transmission using the method of moments (MoM). The focusing gain characteristics in the oblique incidence as well as in the normal incidence are considered. The MoM solution using the three-dimensional vectorial formulation requires a large memory space for the FZPL as it is operated at a short wavelength. This is simply overcome by using an iterative conjugate gradient method for the numerical evaluation. The MoM solutions are compared with the other solutions.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2001-03-27
Volume volume35
Issue issue1-2
Start Page 53
End Page 61
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307849
JaLCDOI 10.18926/46969
FullText URL mfe_37_1_015_023.pdf
Author Kanatani, Kenichi|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2002-11
Volume volume37
Issue issue1
Start Page 15
End Page 23
ISSN 0475-0071
language 英語
File Version publisher
NAID 80015664455
JaLCDOI 10.18926/15427
FullText URL Mem_Fac_Eng_OU_26_2_17.pdf
Author Feng Yibu| Inaba, Hideo| Nozu, Shigeru|
Abstract Heat transfer measurements were conducted during freezing of quiescent water in a horizontal cylinder. A horizontal cylinder with inner diameter of 61.1 mm is cooled by air in a constant low temperature room and time variations of the radial distribution of fluid temperature were observed. Experimental results for the velocity of the phase change interface, the time taken for complete freezing and apparent freezing heat transfer coefficient were compared with the simple theoretical model based on the quasisteady assumption.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-03-28
Volume volume26
Issue issue2
Start Page 17
End Page 24
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307382
JaLCDOI 10.18926/15505
FullText URL Mem_Fac_Eng_OU_24_2_89.pdf
Author Yokohira, Tokumi|
Abstract This paper considers a test set for an ALU with look ahead carry generators(LCGs). The ALU is logically partitioned into two groups of blocks, the group of one-bit operation units and LCG group. Each group is tested in parallel and exhaustively, independent of the other. And an easily testable design is applied to several blocks for decreasing the number of the input combinations of them. Under the easily testable design, a minimum test set for each group is generated, and the upper and lower bounds for a minimum test for the ALU are derived. The difference of the lower and upper bounds is not large, and a test set whose number of test vectors is equal to the upper bound can be easily obtained as the union of minimum test sets for two groups. Hence, the union can be used as a complete and practical test set for the ALU.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-03-29
Volume volume24
Issue issue2
Start Page 89
End Page 98
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307212
JaLCDOI 10.18926/14056
FullText URL Mem_Fac_Eng_OU_42_18.pdf
Author Kanatani, Kenichi| Yasuyuki Sugaya|
Abstract We classify and review existing algorithms for computing the fundamental matrix from point correspondences and propose new effective schemes: 7-parameter Levenberg-Marquardt (LM) search, EFNS, and EFNS-based bundle adjustment. Doing experimental comparison, we show that EFNS and the 7-parameter LM search exhibit the best performance and that additional bundle adjustment does not increase the accuracy to any noticeable degree.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2008-01
Volume volume42
Issue issue1
Start Page 18
End Page 35
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308468
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 10.18926/46978
FullText URL mfe_37_2_029_044.pdf
Author Imajo, Shuya| Konishi, Masami| Imai, Jun| Nishi, Tatsushi|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2003-03
Volume volume37
Issue issue2
Start Page 29
End Page 44
ISSN 0475-0071
language 英語
File Version publisher
NAID 80016037880
JaLCDOI 10.18926/14122
FullText URL Mem_Fac_Eng_OU_40_1_44.pdf
Author Sugaya, Yasuyuki| Kanatani, Kenichi| Kanazawa, Yasushi|
Abstract Dense point matches are generated over two images by rectifying the two images to align epipolar lines horizontally, and horizontally sliding a template. To overcome inherent limitations of 2-D search, we incorporate the “naturalness of the 3-D shape” implied by the resulting matches. After stating our rectification procedure, we introduce our multi-scale template matching scheme and our outlier removal technique using tentatively reconstructed 3-D shapes. Doing real image experiments, we discuss the performance of our method and remaining issues.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2006-01
Volume volume40
Issue issue1
Start Page 44
End Page 52
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308593
JaLCDOI 10.18926/46955
FullText URL mfe_38_1-2_091_096.pdf
Author Kanayama, Naoki| Yamakoshi, Kimi| Kiyomi, Masaaki| Magari, Masaki| Ohmori, Hitoshi|
Abstract Generally, IgM antibodies (Abs) produced in a primary immune response show lower affinity for an inducing antigen (Ag) compared with the corresponding IgG Abs that are major switched isotypes formed in the secondary response. An IgM molecule is a pentamer with 10 Ag-binding sites that will contribute to an increase of avidity for an Ag. To estimate the contribution of the pentameric structure to the avidity of an IgM Ab, we generated IgM and IgG1 monoclonal Abs (mAbs) with identical V regions that are specific for 4-hydroxy-3-nitrophenylacetyl (NP) by in vitro class switching of B cells followed by the cell fusion with a mouse myeloma cell line. Compared with an anti-NP IgG1 mAb, the corresponding IgM mAb showed much higher avidity for NP-conjugated bovine serum albumin, which was drastically reduced after being dissociated into monomers.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2004-03
Volume volume38
Issue issue1-2
Start Page 91
End Page 96
ISSN 0475-0071
language 英語
File Version publisher
NAID 80017001822