217 research outputs found

    System Dynamics Model on Urban Growth with an Application to Okayama City

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    A system dynamics model to forecast future movements of a city was studied. The model consists of three sections of population sector, industry sector, land use sector and some divisions of labor, income employment, housing land which connect each sections. Economic growth rate, public investment program, housing land supply program were incorporated in the model as political variables. The model was applied to Okayama city for thirty years from 1975 to 2005. The results of the simulation are summarized as follows: 1) The drift of peoples into Okayama city will advance in the future. 2) Tertiary industries will be given much weight as compared with secondary industries. 3) Because of the drift of peoples, housing problems will be serious in the future

    Implementation and evaluation of a simulation system based on particle swarm optimisation for node placement problem in wireless mesh networks

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    With the fast development of wireless technologies, wireless mesh networks (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless internet connectivity. This paper implements a simulation system based on particle swarm optimisation (PSO) in order to solve the problem of mesh router placement in WMNs. Four replacement methods of mesh routers are considered: constriction method (CM), random inertia weight method (RIWM), linearly decreasing Vmax method (LDVM) and linearly decreasing inertia weight method (LDIWM). Simulation results are provided, showing that the CM converges very fast, but has the worst performance among the methods. The considered performance metrics are the size of giant component (SGC) and the number of covered mesh clients (NCMC). The RIWM converges fast and the performance is good. The LDIWM is a combination of RIWM and LDVM. The LDVM converges after 170 number of phases but has a good performance.Peer ReviewedPostprint (author's final draft

    Node placement in Wireless Mesh Networks: a comparison study of WMN-SA and WMN-PSO simulation systems

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    (c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.With the fast development of wireless technologies, Wireless Mesh Networks (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless Internet connectivity. In our previous work, we implemented a simulation system based on Simulated Annealing (SA) for solving node placement problem in wireless mesh networks, called WMN-SA. Also, we implemented a Particle Swarm Optimization (PSO) based simulation system, called WMN-PSO. In this paper, we compare two systems considering calculation time. From the simulation results, when the area size is 32 × 32 and 64 × 64, WMN-SA is better than WMN-PSO. When the area size is 128 × 128, WMN-SA performs better than WMN-PSO. However, WMN-SA needs more calculation time than WMN-PSO.Peer ReviewedPostprint (author's final draft

    Investigation of fitness function weight-coefficients for optimization in WMN-PSO simulation system

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    (c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.With the fast development of wireless technologies, Wireless Mesh Networks (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless Internet connectivity. In our previous work, we implemented a simulation system based on Particle Swam Optimization for solving node placement problem in wireless mesh networks, called WMN-PSO. In this paper, we use Size of Giant Component (SGC) and Number of Covered Mesh Clients (NCMC) as metrics for optimization. Then, we analyze effects of weight-coefficients for SGC and NCMC. From the simulation results, we found that the best values of the weight-coefficients for SGC and NCMC are 0.7 and 0.3, respectively.Peer ReviewedPostprint (author's final draft

    Performance evaluation considering iterations per phase and SA temperature in WMN-SA system

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    One of the key advantages of Wireless Mesh Networks (WMNs) is their importance for providing cost-efficient broadband connectivity. There are issues for achieving the network connectivity and user coverage, which are related with the node placement problem. In this work, we consider Simulated Annealing Algorithm (SA) temperature and Iteration per phase for the router node placement problem in WMNs. We want to find the optimal distribution of router nodes in order to provide the best network connectivity and provide the best coverage in a set of Normal distributed clients. From simulation results, we found how to optimize both the size of Giant Component and number of covered mesh clients. When the number of iterations per phase is big, the performance is better in WMN-SA System. From for SA temperature, when SA temperature is 0 and 1, the performance is almost same. When SA temperature is 2 and 3 or more, the performance decrease because there are many kick ups.Peer ReviewedPostprint (published version

    Consistent anti-de sitter-space/conformal-field-theory dual for a time-dependent finite temperature system

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    Shunichiro Kinoshita, Shinji Mukohyama, Shin Nakamura, and Kin-ya Oda. Consistent Anti–de Sitter-Space/Conformal-Field-Theory Dual for a Time-Dependent Finite Temperature System. Phys. Rev. Lett. 102, 031601, 2009. https://doi.org/10.1103/PhysRevLett.102.031601

    Implementation of a new replacement method in WMN-PSO simulation system and its performance evaluation

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    (c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.With the fast development of wireless technologies, Wireless Mesh Networks (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless Internet connectivity. In our previous work, we implemented the Linearly Decreasing Vmax Method (LDVM) for our WMN-PSO simulation system. In this paper, we implement a new replacement method for mesh routers called Rational Decrement of Vmax Method (RDVM). We use Size of Giant Component (SGC) and Number of Covered Mesh Clients (NCMC) as metrics for optimization. From the simulation results, we found that RDVM converges faster to best solution than LDVM.Peer ReviewedPostprint (author's final draft

    A novel chiral porous metal–organic framework: asymmetric ring opening reaction of epoxide with amine in the chiral open space

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    A novel chiral metal–organic framework, [Cu2(5,5\u27-BDA)2] wassynthesized by treating chiral 2,2\u27-dihydroxy-1,1\u27-binaphthalene-5,5\u27-dicarboxylic acid (5,5\u27-H2BDA) with a Cu(II)ion, in which the asymmetric ring opening reaction of an epoxide with amine proceeds efficiently under solvent-free conditions
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