検索結果 2801 件
JaLCDOI | 10.18926/15397 |
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フルテキストURL | Mem_Fac_Eng_OU_30_2_1.pdf |
著者 | 竹元 嘉利| 飛田 守孝| 榊原 精| |
抄録 | The mechanism of brittle fracture in Ti-14mass % Mo alloy aged for 1x10(6)s at 623K was studied using transmission electron microscopy (TEM) and dynamic hardness test (DHT) on the structure deformed by means of tensile elongation at elevated temperature or cold rolling. Many band products were observed by TEM in either deformed specimens. These band products were identified to neither slips nor twinning bands, moreover, they were different from α , α ' and α " phases. The band product consisted of β phase and granular unknown phase which was transformed by deformation from ω phase. The newly discovered phase, named β" phase, in the band products had a body-centered triclinic structure. The β" was similar to the ω zone with respect to the morphology and the concentration of Mo, but it resembled β in structure. The result of DHT on the band products and the matrix showed that the band products were softer than the matrix. It is suggested that the band products are easily deformed because of the disappearance of obstacles such as ω phase, and consequently behave like paths to lead cracks preferentially. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1996-03-29 |
巻 | 30巻 |
号 | 2号 |
開始ページ | 1 |
終了ページ | 7 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307225 |
JaLCDOI | 10.18926/15395 |
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フルテキストURL | Mem_Fac_Eng_OU_27_1_65.pdf |
著者 | 奈良 重俊| Hara Yuji| 東辻 浩夫| |
抄録 | 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. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1992-11-25 |
巻 | 27巻 |
号 | 1号 |
開始ページ | 65 |
終了ページ | 79 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307405 |
JaLCDOI | 10.18926/15392 |
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フルテキストURL | Mem_Fac_Eng_OU_27_1_45.pdf |
著者 | 香川 直己| 和田 修己| Hai, Xu| 古賀 隆治| Sano, Hiroya| Inubushi, Kazuyuki| |
抄録 | 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. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1992-11-25 |
巻 | 27巻 |
号 | 1号 |
開始ページ | 45 |
終了ページ | 53 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307877 |
JaLCDOI | 10.18926/15391 |
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フルテキストURL | Mem_Fac_Eng_OU_27_1_33.pdf |
著者 | 島田 行恭| 鈴木 和彦| 佐山 隼敏| |
抄録 | 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. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1992-11-25 |
巻 | 27巻 |
号 | 1号 |
開始ページ | 33 |
終了ページ | 44 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307902 |
JaLCDOI | 10.18926/15388 |
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フルテキストURL | Mem_Fac_Eng_OU_27_1_11.pdf |
著者 | Hirashima Masao| 稲葉 英男| |
抄録 | 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. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1992-11-25 |
巻 | 27巻 |
号 | 1号 |
開始ページ | 11 |
終了ページ | 26 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307419 |
JaLCDOI | 10.18926/15382 |
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フルテキストURL | Mem_Fac_Eng_OU_35_207.pdf |
著者 | 中西 透| Fujiwara Toru| |
抄録 | In the group signature scheme with a trusted party, a verifier can determine whether or not a signature is made by a member of the group, but cannot identify the member who signed the signature. In case of dispute later on, the signer can be identified by the trusted party. However, for efficient group signature schemes proposed so far, removing a member from the group can be not efficiently performed. In this paper, a group signature scheme with an easy membership canceling is proposed. By sending a request to use a resource together with the group signature on it to the manager of the resource, the manager can control anonymous accesses to the resource. In such an application, the proposed group signature scheme is suitable for canceling of the access privilege. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 207 |
終了ページ | 212 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307232 |
JaLCDOI | 10.18926/15380 |
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フルテキストURL | Mem_Fac_Eng_OU_35_197.pdf |
著者 | Nogami, Yasuyuki| Morikawa, Yoshitaka| |
抄録 | Modern communication engineerings, such as elliptic curve cryptographies, often requires algebra on finite extension field defined by modulus arithmetic with an irreducible polynomial. This paper provides a new method to detemine the minimal (irreducible) polynomial of a given proper element in finite extension field. In the conventional determination method, as we have to solve the simultaneous equations, the computation is very involved. In this paper, the well known "trace" is extended to higher degree traces. Using the new traces, we yield the coefficient formula of the desired minimal polynomial. The new method becomes very simple without solving the simultaneous equations, and about twice faster than the conventional method in computation speed. |
キーワード | finite field minimal polynomial irreducible polynomial higher degree trace trace cryptography |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 197 |
終了ページ | 205 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307992 |
JaLCDOI | 10.18926/15378 |
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フルテキストURL | Mem_Fac_Eng_OU_35_191.pdf |
著者 | Yoshida Takanobu| 宗澤 良臣| 大崎 紘一| 梶原 康博| Ohta Kazuharu| |
抄録 | We developed the disassembly system that uses the impulsive load and disassembly tools to disassemble used appliances economically. The main components of this system are impulse hammer, a lift table and developed disassembly tools. Several types of disassembly tools are developed to punch out fastened portion on a part and cut off the shaft of screw or connection pin of IC-chip. A simulation model is proposed to explain and formulate how the fastening point of product is broken and cut. Three kinds of disassembly tools are designed. The actual disassembly system is developed by using proposed simulation models and disassembly tools. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 191 |
終了ページ | 196 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307328 |
JaLCDOI | 10.18926/15377 |
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フルテキストURL | Mem_Fac_Eng_OU_30_1_47.pdf |
著者 | 加川 幸雄| Sun Yonghao| Mahmood Zaheed| |
抄録 | Regular boundary element method is employed for the variational formulation of Helmholtz equation that governs the waveguiding problems. Like in the Charge simulation method, in this method, the source points associated with the fundamental solutions are allocated outside the domain so that the singular integrals which occur in the standard boundary element procedure can be avoided. First, the formulation is developed for the two-dimensional scalar Helmholtz problem solving for the axial components of either electric or magnetic fields. The application of the formulation is shown for simple hollow rectangular waveguide and dielectric-slab-loaded rectangular waveguide. Then the formulation is extended for the analysis of dielectric waveguides of open type incorporating axial components of both electric and magnetic fields, for the solution of the propagating modes which are generally of hybrid types. To show the validity and quality of the formulation, it is applied to a circular step-index optical waveguide and a dielectric rectangular waveguide. Very close agreements have been found when the solutions are compared with the ones obtained by different methods. One distinct merit of the extended formulation is that it has been fixed to suppress the spurious solutions which are encountered while solved by the conventional boundary element method. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1995-12-28 |
巻 | 30巻 |
号 | 1号 |
開始ページ | 47 |
終了ページ | 62 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307187 |
JaLCDOI | 10.18926/15373 |
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フルテキストURL | Mem_Fac_Eng_OU_35_169.pdf |
著者 | Ueda Kiyotaka| 大崎 紘一| 梶原 康博| 宗澤 良臣| |
抄録 | We propose an image processing method for part handling robot for picking up subjects piled in a container. Line laser light is projected on subjects, and its external shape is detected by many segments of a line laser, and pitch, roll, and yaw angles of subject are recognized precisely. A priority rule is settled to choose one subject that is taken out. This rule is determined by considering the grasping space, the position of a subject, the movement space of hand and so on. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 169 |
終了ページ | 175 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307198 |
JaLCDOI | 10.18926/15370 |
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フルテキストURL | Mem_Fac_Eng_OU_27_2_73.pdf |
著者 | Kroumov Valeri T.| 井上 昭| 増田 士朗| |
抄録 | 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. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1993-03-25 |
巻 | 27巻 |
号 | 2号 |
開始ページ | 73 |
終了ページ | 85 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307731 |
JaLCDOI | 10.18926/15368 |
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フルテキストURL | Mem_Fac_Eng_OU_35_155.pdf |
著者 | Takahashi Hiromitsu| 宗澤 良臣| 梶原 康博| 大崎 紘一| Wada Yatarou| |
抄録 | This paper proposes a concept of a mobile type maintenance robot (MMR in shortly) that is controlled by the tele-operation for assuring the safety and health improvement of work forces. The main components of this system are the industrial robot, an image processing unit, vehicle and computers for tele-operation. Our focus is paid on a method that determine a pathway to move every places where troubles would occur. This method makes it possible that the MMR could arrive any place in the factory with three times of turns at most. Additionally, turning radius of the vehicle is considered for correcting the pathway near the corners to make it possible that it arrives to the place accurately. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 155 |
終了ページ | 161 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307844 |
JaLCDOI | 10.18926/15367 |
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フルテキストURL | Mem_Fac_Eng_OU_30_1_9.pdf |
著者 | Ding Ronggui| 大崎 紘一| |
抄録 | Decision Support Systems (DSS) have been taken as hopeful support tools for decision making for more than 20 years. There are a lot of literatures on DSS, but most of them are not so practical as the designers expected. This paper points out the crux of this situation and argues that the research on DSS should pay some more attention to the decision making activities before the model using stage. A method named "Problem Situation Decomposing Graph (PSDG)" is presented in this paper for helping the decision maker(DM) elicit the decision making problems. A PSDG is an acycle AND/OR logical directed graph, and which includes all the factors affecting the problem situation based on the DM's knowledge. The logical nodes and parameter determining methods in PSDG can reflect the DM's decision making style. This paper introduces some basic concepts of PSDG, discusses some of its characteristics, and proposes a logical adjacency matrix for PSDG representation and analysis. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1995-12-28 |
巻 | 30巻 |
号 | 1号 |
開始ページ | 9 |
終了ページ | 17 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307826 |
JaLCDOI | 10.18926/15364 |
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フルテキストURL | Mem_Fac_Eng_OU_35_137.pdf |
著者 | Sakiyama, Takaharu| Yoshimi, Tsuyoshi| Miyake, Akira| Umeoka, Midori| Tanaka, Atsushi| Ozaki, Sho| Nakanishi, Kazuhiro| |
抄録 | A monoacylglycerol lipase (MGL) was purified from Pseudomonas sp. LP7315 by ammonium sulfate precipitation, anion-exchange chromatography, and preparative electrophoresis. The purified enzyme was homogeneous on an SDS-polyacrylamide gel with a molecular mass of 59 kDa. Its hydrolytic activity was confirmed to be specific for monoglycerides: the enzyme did not hydrolyze diand triglycerides. MGL was found to be stable even after l-h incubation at 65℃. The hydrolytic activity depended not only on temperature and pH but also on the type of monoglyceride used. MGL also catalyzed monoglyceride synthesis at 65℃ in a solvent-free two-phase system, in which fatty acid droplets were dispersed in the glycerol phase with a low water content. The synthetic reaction proceeded at a constant rate for approximately 24 h and reached an equilibrium after 48 h of reaction. The initial rate of the synthetic reaction depended on several factors: the type of fatty acid used as the substrate, the amounts of fatty acid and glycerol, and the concentration of MGL in the glycerol phase. To analyze the effects of these factors, a kinetic model was developed based on the assumption that the adsorption equilibrium of MGL molecules at the interface between the two phases is the rate-determining factor for the synthetic reaction. The model was found to yield a good approximation of the initial synthetic rate under various reaction conditions. The analysis suggests that the adsorption behavior of MGL onto the interface had a large effect on the initial rate of the monoglyceride synthesis. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 137 |
終了ページ | 146 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307705 |
JaLCDOI | 10.18926/15362 |
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フルテキストURL | Mem_Fac_Eng_OU_35_97.pdf |
著者 | 山崎 進| 黒瀬 義則| |
抄録 | In this paper, we formulate a new integrity constraint in correlation with 3-valued stable models in an abduction framework based on general logic programs. Under the constraint, not every ground atom or its negation is a logical consequence of the theory and an expected abductive explanation, but some atom may be unspecified as a logical consequence by an adjustment. As a reflection of the integrity constraint with an adjustment, we augment an adjusting derivation to Eshghi and Kowalski abductive proof procedure, in which such an unspecified atom can be dealt with. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 97 |
終了ページ | 135 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307812 |
JaLCDOI | 10.18926/15361 |
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フルテキストURL | Mem_Fac_Eng_OU_35_77.pdf |
著者 | Kishimoto Tokunari| 東辻 千枝子| 鶴田 健二| 東辻 浩夫| |
抄録 | In order to perform the large-scale molecular dynamics simulation of the Yukawa system, a mathematical expression for molecular dynamics using the fast multipole method is described. The model simulations are also performed to test the performance of our implementation of the FMM. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 77 |
終了ページ | 95 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307940 |
JaLCDOI | 10.18926/15358 |
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フルテキストURL | Mem_Fac_Eng_OU_35_63.pdf |
著者 | Shinomiya Shigeru| 東辻 千枝子| 鶴田 健二| 東辻 浩夫| |
抄録 | We present a theoretical study of Si(1-x)Ge(x) alloys based on tight-binding molecular dynamics (TBMD) calculations. First, we introduce a new set of nonorthogonal tight-binding parameters for silicon and germanium based on the previous work by Menon and Subbaswamy [Phys. Rev. B 55, 9231 (1997); J. Phys: Condens. Matter 10, 10991 (1998)]. We then apply the method to structural analyses of Si(1-x)Ge(x) alloys. The equilibrium volume and atomic structure for a given x are obtained by the TBMD method. We also calculate the bulk modulus B, elastic constants C(11), C(12) and C(44) as a function of x. The results show that the moduli vary monotonically, but nonlinearly, between the values of Si crystal and Ge crystal. The validity of the results is also discussed. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 63 |
終了ページ | 75 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307673 |
JaLCDOI | 10.18926/15354 |
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フルテキストURL | Mem_Fac_Eng_OU_34_1.pdf |
著者 | Song Baoyin| 稲葉 英男| 堀部 明彦| Takahashi Takashi| |
抄録 | 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. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2000-03-27 |
巻 | 34巻 |
号 | 1-2号 |
開始ページ | 1 |
終了ページ | 12 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307686 |
JaLCDOI | 10.18926/15352 |
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フルテキストURL | Mem_Fac_Eng_OU_35_35.pdf |
著者 | 島村 薫| 内田 哲也| 井上 智博| |
抄録 | Rigid polymer, poly(p-phenylene benzobisthiazole), formed lamellar crystals where the molecular chains were oriented perpendicular to the lamellae. It was supposed that, because of wide distribution in the chain length, the lamellar surface bristled with the chain cilia among which many voids were included. Crystallographically, this region afforded us a transitional structure from full to deficient packings of chains. The structure was analyzed using the scanning probe microscope. In the course the method for imaging one molecular chain end was developed. From the images it was concluded that an isolated long cilius did not move so violently at room temperature. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 35 |
終了ページ | 40 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307784 |
JaLCDOI | 10.18926/15348 |
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フルテキストURL | Mem_Fac_Eng_OU_35_21.pdf |
著者 | S.kovalenko, Volodymyr| Uno, Yoshiyuki| Okamoto, Yasuhiro| Anyakin, M.| Lutay, A.| Shubul, Khaled Al.| |
抄録 | In electric power industry, there is a problem of achieving stable joint in different components using high productive and efficient technologies. One type of these components is packages of slices for magnetic circuit of electric motors, transformers etc., which need reliable means for their fixing. Laser welding is proposed to solve this problem as an alternative for existing technologies. The development of the laser welding process is presented based on process simulation, study of heat history and comparison with experimental results. Laser beam additional scanning technique is proposed to improve the quality and efficiency of the joining operation. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 21 |
終了ページ | 28 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307424 |