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Boundary Conditions for Combustion Field and LB Simulation of Diesel Particulate Filter

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Communications in Computational Physics 2013年第3期13卷 769-779页

作者： Kazuhiro yamamoto Department of Mechanical Science and Engineering Faculty of EngineeringNagoya UniversityFuro-choChikusa-kuNagoya464-8603 Japan

A diesel particulate filter(DPF)is a key technology to meet future emission standards of particulate matters(PM),mainly *** is generally consists of a wall-flow type filter positioned in the exhaust stream of a diesel *** is difficult to simulate the thermal flow in DPF,because we need to consider the soot deposition and combustion in the complex geometry of filter *** our previous study,we proposed an approach for the conjugate simulation of gas-solid *** is,the gas phase was simulated by the lattice Boltzmann method(LBM),coupled with the equation of heat conduction inside the solid filter ***,its numerical procedure was slightly *** this study,to reduce numerical costs,we have tested a new boundary condition with chemical equilibrium in soot combustion at the surface of filter *** on the soot oxidation rate with catalysts evaluated in experiments,the lattice Boltzmann simulation of soot combustion in the catalyzed DPF is firstly presented to consider the process in the after-treatment of diesel exhaust *** heat and mass transfer is shown to discuss the effect of catalysts.

关键词： Lattice Boltzmann method DPF heat conduction X-ray CT multiphase flow

Precipitation of Icosahedral Quasicrystalline Phase, R-phase and Laves Phase in Ferritic Alloys

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材料热处理学报 2004年第5期25卷 229-233页

作者： Keisuke yamamoto Yoshisato Kimura Yoshinao Mishima Department of Materials Science and Engineering Tokyo Institute of Technology Yokohama JapanDepartment of Materials Science and Engineering Tokyo Institute of Technology Yokohama JapanDepartment of Materials Science and Engineering Tokyo Institute of Technology Yokohama Japan

Ferritic heat resistant steels involving precipitation of intermetallic phases have drawn a growing interest for the enhancement of creep strength, while the brittleness of the intermetallic phases may lower the toughness of the alloy. Therefore, it is necessary to optimize the dispersion characteristics of the intermetallics phase through microstructural control to minimize the trade-off between the strength and toughness. The effects of -Fe matrix substructures on the precipitation sequence, morphology, dispersion characteristics, and the stability of the intermetallic phases are investigated in Fe-Cr-W-Co-Si system. The precipitates of the Si-free Fe-10Cr-l.4W-4.5Co (at%) alloy aged at 873K are the R-phase but those of the Si-added Fe-10Cr-l.4W-4.5Co-0.3Si (at%) alloy are the icosahedral quasicrystalline phase. The precipitates in both the Si-free and Si-added alloys aged at 973K are the Laves phase. Matrix of the alloys is controlled by heat treatments as to provide three types of matrix substructures; ferrite, ferrite/martensite mixture and martensite. The hardening behavior of the alloys depends on the matrix substructures and is independent of the kinds of precipitates. In the alloys with ferrite matrix, the peak of hardness during aging at 873K shifts to longer aging time in comparison with that in the alloys with lath martensite matrix which contain numbers of nucleation sites.

关键词：过渡电子扫描仪准晶体 R相拉夫斯相铁素体钢

Numerical Investigation on Detonation Wave through U-bend

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Journal of Thermal Science 2010年第6期19卷 540-544页

作者： Shinobu Otsuka Masaya Suzuki Makoto yamamoto Department of Mechanical Engineering Tokyo University of Science

Pulse detonation engine (PDE) is expected for a next-generation propulsion system. PDE is a promising engine that can generates power and thrust by using intermittent detonation. Promotion of deflagration to detonation transition (below DDT) is a key issue to realize this system. PDE has experimentally been investigated, and it was confirmed that detonation tubes with U-shaped bends are useful for fast DDT. However, the mechanism of DDT promotion due to U-bends has not been well clarified. In the present study, the influence of a U-bend on detona-tion wave propagation is researched with computational fluid dynamics (CFD). The numerical results show that detonation wave disappears once near the U-bend inlet and restarts after passing through it. In addition, it was found that the use of the U-bend with small channel width and curvature radius can induce fast DDT.

关键词： Detonation Deflagration to Detonation Transition (DDT) U-bend Computational Fluid Dynamics

A study of optimal switching problem in limited-cycle with multiple periods

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第12期11卷 933-937页

作者： Jing SUN Hisashi yamamoto Masayuki MATSUI Graduate School of Engineering Nagoya Institute of Technology Gokiso-cho Showa-ku Nagoya Aichi 466-8555 Japan Department of System Design Management Systems Engineering Tokyo Metropolitan University 6-6 Asahigaoka Hino Tokyo 191-0065 Japan Department of lnformatics Graduate School of lnformatics and Engineering The University of Electro-Communications 1-5-1 Chofugaoka Chofu-shi Tokyo 182-8585 Japan

In a social system or production line,the restrictions of the cost and the due-time exist in each ***,whether these restrictions are satisfied is dependent not only on the risks of this period,but also on the risks generated *** consider controlling the production process by switching the processing rate to a faster one at a given *** paper deals with the optimal switching period to minimize the total expected cost of the production *** first propose the optimal switching period model,and then the mathematic formulation of the total expectation is ***,the policy of optimal switching period is investigated in detail by numerical experiments.

关键词： Limited-cycle problem Multi-period Optimal switching period Production seat system Manufacturing line

PIV MEASUREMENTS FOR GAS FLOW UNDER GRADIENT MAGNETIC FIELDS

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Acta Mechanica Sinica 2004年第6期20卷 591-596页

作者：阮晓东吴锋 F.yamamoto The State Key Laboratory of Fluid Power Transmission and Control Zhejiang UniversityHangzhou 310027China The College of Mechanical and Energy Engineering Zhejiang UniversityHangzhou 310027China 3 Department of Mechanical Engineering Fukui UniversityFukui 910-8507Japan

Particle Image Velocimetry(PIV)techniques were developed to measure the convec- tive N_2-air flow under gradient magnetic *** velocity fields were calculated by the Minimum Quadratic Difference(MQD)algorithm and spurious vectors were eliminated by Delaunay Tessellation. The N_2-air flow was measured as the magnetic flux density varying from 0～1.5 T.A strengthened vortex flow of air was observed under the condition that the magnetic field was applied,and the ve- locity of N_2 jet rose with the increase of the magnetic *** experimental results show that the magnetic force will induce a vortex flow and cause a convection flow of the air mixture when both gradients of the O_2 concentration and the magnetic field intensity exist.

关键词： PIV magnetic field magnatoaerodynamics air convection

Study of older male drivers’driving stress compared with that of young male drivers

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Journal of Traffic and Transportation Engineering(English Edition) 2020年第4期7卷 467-481页

作者： Yannmq Zhao Toshiyuki yamamoto Ryo Kanamori Department of Civil Engineering Nagoya UniversityNagoya 464-8603Japan Institute 0f Materials and Systems for Sustainability Nagoya UniuersityNagoya 464-8603Japan Institute of Innovation for Future Society Nagoya UniversityNagoya 464-8603Japan

In this study,older male drivers’stress while driving in straight links and while proceeding through intersections is *** area network(CAN),self-reported stress(SRS),and physiological data was collected in 22.4 km-long experimental trips among older and young ***,this study finds that older drivers reported much less stress than young ***,principal components(PCs)of the physiological data demonstrate that older drivers might underrate their driving stress in entire trips,except regarding turning at ***,following other vehicles reduced older drivers’driving stress because preceding vehicles might help them control driving speed,detect the path,and prevent road *** contrast,the similar condition increased the stress level of young *** results of random effects regression models confirm that age was the significant impact factor on SRS and physiological *** examining whether the stress at intersections could affect their driving behaviors,significant difference between two age groups was found neither in turning time nor in the driving *** study also confirms that physical and mental changes with aging can negatively affect older adults’*** the relationships among stress,speed,and accidents,we suggest the provision of more driver assistance systems,training,and education and improving intersection design for older drivers.

关键词： Driving behavior Driving stress Older driver Intersection Straight road

Tubulopapillary adenoma of the gallbladder accompanied by bile duct tumor thrombus

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World Journal of Gastroenterology 2014年第26期20卷 8736-8739页

作者： Kentaroh yamamoto Fumio yamamoto Atsuhiro Maeda Hirotsune Igimi Mami yamamoto Ryosuke Yamaguchi Yuichi Yamashita Department of Surgery Yamamoto Memorial Hospital Department of Internal Medicine Maeda Hospital Department of Gastroenterological Surgery Fukuoka University School of Medicine

Intraductal papillary mucinous neoplasm of the bile duct(IPNB)is recognized as a precancerous lesion;however,both its pathogenesis and progression remain *** present here a case of IPNB arising from the gallbladder accompanied by bile duct tumor thrombus in a 79-year-old *** resected specimen revealed a tubulopapillary adenoma with no malignant *** case suggests that even in the absence of malignant cells,these tumors can behave as malignant tumors requiring aggressive *** if no malignant cells are present,intraepithelial neoplasms occurring in the ampullopancreatobiliary tract can behave as malignant tumors.

关键词： Intraductal papillary mucinous neoplasm of the bile duct Tumor thrombi

Color Correction for Multi-view Video Using Energy Minimization of View Networks

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International Journal of Automation and computing 2008年第3期5卷 234-245页

作者： Kenji yamamoto Ryutaro Oi National Institute of Information and Communications Technology

Systems using numerous cameras are emerging in many fields due to their ease of production and reduced cost, and one of the fields where they are expected to be used more actively in the near future is in image-based rendering （IBR）. Color correction between views is necessary to use multi-view systems in IBR to make audiences feel comfortable when views are switched or when a free viewpoint video is displayed. Color correction usually involves two steps： the first is to adjust camera parameters such as gain, brightness, and aperture before capture, and the second is to modify captured videos through image processing. This paper deals with the latter, which does not need a color pattern board. The proposed method uses scale invariant feature transform （SIFT） to detect correspondences, treats RGB channels independently, calculates lookup tables with an energy-minimization approach, and corrects captured video with these tables. The experimental results reveal that this approach works well.

关键词： Multi-view color correction image-based rendering (IBR) view networks (VNs) scale invariant feature transform (SIFT) energy minimization.

Computational Complexity of a Solution for Directed Graph Cooperative Games

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Journal of the Operations Research Society of China 2013年第3期1卷 405-413页

作者： Ayumi Igarashi Yoshitsugu yamamoto Graduate School of Systems and Information Engineering University of TsukubaTsukubaIbaraki 305-8573Japan Faculty of Engineering Information and SystemsUniversity of TsukubaTsukubaIbaraki 305-8573Japan

Abstrac Khmelnitskaya et *** recently proposed the average covering tree value as a new solution concept for cooperative transferable utility games with directed graph *** average covering tree value is defined as the average of marginal contribution vectors corresponding to the specific set of rooted trees,and coincides with the Shapley value when the game has complete communication *** this paper,we discuss the computational complexity of the average covering tree *** show that computation of the average covering tree value is#P-complete even if the characteristic function of the game is{0,1}-*** prove this by a reduction from counting the number of all linear extensions of a partial order,which has been shown by Brightwell et *** be a#P-complete counting *** implication of this result is that an efficient algorithm to calculate the average covering tree value is unlikely to exist.

关键词： #P-complete Digraph game Average covering tree value Coalition Communication structure Linear extension