• Title/Summary/Keyword: SPSA알고리즘

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SPSA Approach to Image Reconstruction in Electrical Impedance Tomograhpy (전기 임피던스 단층촬영법에서 SPSA를 이용한 영상복원)

  • 김호찬;부창진;이윤준
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.2
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    • pp.23-28
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    • 2004
  • In EIT, various image reconstruction algorithms have been used in order to compute the internal resistivity distribution of the unknown object with its electric potential data at the boundary. Mathematically the EIT image reconstruction algorithm is a nonlinear ill-posed inverse problem. In this paper, a SPSA approach is proposed for the solution of the EIT image reconstruction. Results of numerical experiments of EIT solved by the SPSA approach are presented and compared to that obtained by the modified Newton-Raphson(mNR) method.

Analyzing the Changes in Speed Due to High Occupancy Vehicles Using Median Bus Lane (다인승차량의 중앙버스전용차로 이용에 따른 영향분석)

  • Lee, Jung-Beom
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.4
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    • pp.87-94
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    • 2013
  • This study estimated the changes in delays and speeds of vehicles in exclusive bus lane and road when the High Occupancy Vehicles(HOV) use the median bus lane. Synchro simulation tool was used to optimize the traffic signal time on the network and VISSIM was applied to simulate various scenarios. Here, drivers behavior parameters in VISSIM was optimized using Simultaneous Perturbation Stochastic Approximation(SPSA) algorithm in order to represent real traffic condition. Based on the simulation results, the delay in Doan daero was decreased when the volume of HOV in current condition runs on the median bus lane, whereas delay in Doan dongro was increased in all scenarios. The changes in bus speed was not sharply decreased for both study sites, even though the number of HOV increased to 10%. Thus, it could be allowed that the HOV use the median bus lane in Doan dongro and Doan daero. Future research tasks include studying about changes in delay when the HOV use the curb bus lane.