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排序方式: 共有646条查询结果,搜索用时 15 毫秒
61.
62.
Shinya Yasumoto Andrew P. Jones Tomoki Nakaya Keiji Yano 《Computers, Environment and Urban Systems》2011,35(6):464-473
The development of virtual city models has provided novel possibilities for analyses that require consideration of building heights in urban areas. The study was undertaken to explore these possibilities by using the virtual Kyoto model to examine equity in access to views in the Japanese city. A sample of just over 5000 residences was selected by stratifying for population age and affluence. A series of viewsheds were computed to quantify the visibility of a range of environmental amenities (greenspaces, water bodies, historical buildings, mountains) and disamenities (factories and roads). Evidence of inequity in visual amenity was identified, whereby homes in areas with many old people were much less likely to have views of greenspaces and water bodies, although they were also less likely to see factories and roads and were more likely to view mountains. Homes in more affluent areas had better views of greenspaces, historical buildings, and mountains, and were less likely to see factories and water bodies. We discuss the potential of virtual city models for furthering analyses of the urban environment and raise some caveats regarding their use. 相似文献
63.
Hajime Araki Taichi Kaji Masahito Yamamoto Keiji Suzuki Azuma Ohuchi 《Electrical Engineering in Japan》2001,135(4):43-51
The optimal sequential problem is defined as the problem of finding the minimum cost partition of the nodes of a directed acyclic graph into subsets of a given size, subject to the constraint that the precedence relationships among the elements are satisfied. A heuristic algorithm based on tabu search has been proposed for this problem [2]. However, there is a tendency for the solutions obtained by tabu search to become trapped in bad local optima in parallel graphs with random edge costs. In this paper we present a genetic algorithm for the optimal sequential partitioning problem. We develop an effective two‐point partial order crossover satisfying sequential conditions, which preserve better blocks that have a larger sum of edge costs. In this crossover we introduce the roulette selection method to escape local optima. We also assess the effectiveness of the algorithm. The results show that this proposed algorithm outperforms any other algorithm using tabu search in terms of solution quality. © 2001 Scripta Technica, Electr Eng Jpn, 135(4): 43–51, 2001 相似文献
64.
Katsumi Hama Sadayoshi Mikami Keiji Suzuki Yukinori Kakazu 《Artificial Life and Robotics》2002,6(1-2):3-10
A distributed approach is shown to coordinate the motions of transport tables for the cellular warehouse problem. In this
approach, the tables are considered to be autonomous agents, and a built-in behavior function given by artificial neural networks
(ANNs) and the evolved problem-oriented connection weights navigate the agents to their specified goals. To determine the
agent to be moved, a measure of the priority to move is introduced. We show that distributed agents with the learned behavior
function and the negotiation value perform a similar strategy to a “serializable” solution forN-puzzle problems, which provides a good heuristic strategy for large-scale problems.
This work was presented, in part, at the Sixth International Symposium on Artificial Life and Robotics, Tokyo, Japan, January
15–17, 2001 相似文献
65.
Manabu Iguchi Tsuneo Kondoh Zen-Ichiro Morita Keiji Nakajima Kazuharu Hanazaki Tomomasa Uemura Fujio Yamamoto 《Metallurgical and Materials Transactions B》1995,26(2):241-247
Laser Doppler velocimeter (LDV) measurements were made to clarify the fluid flow behavior in a bath subject to centric bottom
gas injection. Correlations of the axial mean velocity and turbulence components in the gas-liquid two-phase flow region,i.e., in the bubbling jet region, were proposed as functions of the inner diameter of nozzle, gas flow rate, and densities of
gas and liquid. Measured values of the flow rate, momentum, and kinetic energy of water rising upward were approximated satisfactorily
by these empirical correlations. In addition, the Reynolds shear stress was calculated and compared with measured values.
Formerly Graduate Student, Osaka University, 相似文献
66.
Ragnhild E. Aune Miyuki Hayashi Keiji Nakajima Seshadri Seetharaman 《JOM Journal of the Minerals, Metals and Materials Society》2002,54(11):62-69
The optimization of metallurgical processes requires reliable data of the slag phase. This paper focuses on three properties
that are relevant to heat and mass-transfer calculations — viscosities,thermal diffusivities, and surface tensions of silicate melts. A brief account of the experimental techniques used for the
measurements of these properties, with special reference to the work carried out in the Division of Metallurgy, Royal Institute
of Technology, Stockholm, Sweden, are presented, along with the advantages and limitations. As these properties are structure-oriented,
the impact of structure on these properties is also presented. The paper is intended as a state-of-the-art review of the subject. 相似文献
67.
James A. Cheshire Paul A. Longley Keiji Yano Tomoki Nakaya 《Papers in Regional Science》2014,93(3):539-555
This paper uses an extended case study of Japan to illustrate how surnames, or family names, can be used as a basis for regionalization. We undertake a comparison between inductively surname regions of Japan with areal geographies based upon both contemporary and historical prefecture (administrative) units. The work is seen as using highly disaggregate framework data to evaluate the integrity of the areal units that are used in regional science. It also is relevant to understanding population distributions, past and present, and the consequences of local, regional and national residential mobility and migration. 相似文献
68.
Tie?Liu Qiang?WangEmail author Hong-Wei?Zhang Chang-Sheng?Lou Keiji?Nakajima Ji-Cheng?He 《Journal of Materials Science》2011,46(6):1628-1634
The effects of high magnetic fields on the solidification microstructure of Al–Si alloys were investigated. Al–7.2 wt%Si and
Al–11.8 wt%Si alloys were solidified in various high magnetic fields at different cooling rates. The secondary dendrite arm
spacing (SDAS) of the primary Al dendrites and the lamellar spacing (LS) of the eutectics were measured. It was found that
the application of a high magnetic field could decrease the SDAS of the primary Al dendrites in Al–7.2 wt%Si alloys and the
LS of the eutectics in Al–11.8 wt%Si alloys. The effects of the high magnetic field on the SDAS decreased with increasing
cooling rate. The decrease in the SDAS and LS can be attributed to the decrease of the solute diffusivity in the liquid ahead
of the solid/liquid interface during the growth of the dendrite and eutectic. This decrease is caused by the high magnetic
field which can damp the convection and avoid its contributions to the diffusion. 相似文献
69.
Male Fischer 344 rats were subcutaneously injected with azoxymethane (AOM) twice weekly at a dose of 15 mg/kg and were fed with freeze-dried (FD) samples of beer brewed without hops (non-hops beer), beer with hops at 4 times the amount of regular lager beer (x 4-hops beer), and isomerized hop extract (IHE) for the whole experimental period (I/PI) or for the post-initiation period (PI) only. Feeding FD beer samples at a dose of 1% significantly decreased the number of aberrant cryp foci (ACF) in the PI protocol over five weeks.x4-hops beer showed stronger inhibitory effects on the development of the numbers of aberrant crypts per focus and large ACF with four or more crypts than non-hops beer. Feeding IHE to rats at a dose of 0.01% or 0.05% in either the I/PI or PI experiment significantly reduced the numbers of ACF. Prostaglandin E2 (PGE2) levels in colonic mucosa of AOM-treated rats were significantly reduced by feeding of IHE. PGE2 production induced by lipopolysaccharide/interferon-gamma (LPS/IFN-gamma) in RAW264.7 cells was also reduced by treatment with IHE and isohumulone in a dose-dependent manner. These observations suggest that isohumulones show chemopreventive effects on ACF formation in rat colon by inhibiting the production of PGE2. 相似文献
70.
Yukari Totsuka Takashi Higuchi Toshio Imai Akiyoshi Nishikawa Takehiko Nohmi Tatsuya Kato Shuich Masuda Naohide Kinae Kyoko Hiyoshi Sayaka Ogo Masanobu Kawanishi Takashi Yagi Takamichi Ichinose Nobutaka Fukumori Masatoshi Watanabe Takashi Sugimura Keiji Wakabayashi 《Particle and fibre toxicology》2009,6(1):1-11