• Title/Summary/Keyword: Local Minimum

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지방정부 노인복지서비스의 수요·공급간 격차분석

  • Kim, Su-Yeong;Mun, Gyeong-Ju;Ju, Su-Hyeon;Kim, Do-Yeop
    • Journal of Local Government Studies
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    • v.26 no.2
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    • pp.87-112
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    • 2014
  • The entry of aging society and the coming of (super) aged society need overall the elderly welfare policy and budget for quantitative expansion and qualitative increase to the elderly welfare services. However, financial limit to the elderly welfare and increase to elderly welfare services in local government rely on central government or private sector. This study is discussed the gap between demands and supplies of the elderly welfare services in Busan Metropolitan City and policy implications suggested by these results. The major findings of the study are summarized as follows. First, the rate of the poor elderly under minimum living standard and the elderly housing facilities in demand of the elderly welfare services is reduced, but other measuring indicators are generally increased. Second, a per 10,000 elderly welfare service officials and a per 10,000 elderly medical welfare facilities in supply of the elderly welfare services are generally increased, but other measuring indicators are reduced. The policy implications of the study is to reduce the poor elderly under minimum living standard, to expend the elderly welfare budget, and adequately to supply a variety of the elderly welfare facilities for reduce demand of the elderly welfare services.

Development of Potential Function Based Path Planning Algorithm for Mobile Robot

  • Lee, Sang-Il;Kim, Myun-Hee;Oh, Kwang-Seuk;Lee, Sang-Ryong
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2325-2330
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    • 2005
  • A potential field method for solving the problem of path planning based on global and local information for a mobile robot moving among a set of stationary obstacles is described. The concept of various method used path planning is used design a planning strategy. A real human living area is constructed by many moving and imminence obstacles. Home service mobile robot must avoid many obstacles instantly. A path that safe and attraction towards the goal is chosen. The potential function depends on distance from the goal and heuristic function relies on surrounding environments. Three additional combined methods are proposed to apply to human living area, calibration robots position by measured surrounding environment and adapted home service robots. In this work, we proposed the application of various path planning theory to real area, human living. First, we consider potential field method. Potential field method is attractive method, but that method has great problem called local minimum. So we proposed intermediate point in real area. Intermediate point was set in doorframe and between walls there is connect other room or other area. Intermediate point is very efficiency in computing path. That point is able to smaller area, area divided by intermediate point line. The important idea is intermediate point is permanent point until destruction house or apartment house. Second step is move robot with sensing on front of mobile robot. With sensing, mobile robot recognize obstacle and judge moving obstacle. If mobile robot is reach the intermediate point, robot sensing the surround of point. Mobile robot has data about intermediate point, so mobile robot is able to calibration robots position and direction. Third, we gave uncertainty to robot and obstacles. Because, mobile robot was motion and sensing ability is not enough to control. Robot and obstacle have uncertainty. So, mobile robot planed safe path planning to collision free. Finally, escape local minimum, that has possibility occur robot do not work. Local minimum problem solved by virtual obstacle method. Next is some supposition in real living area.

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Study on Minimum Heat Flux Point in Spray Cooling of Hot Plate (고온 강판의 분무냉각에 있어서 MHF 점에 관한 연구)

  • Kim, Yeung-Chan
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.175-180
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    • 2001
  • In this study, the minimum heat flux conditions are experimentally investigated for the spray cooling of hot plate. The hot plates are cooled down from the initial temperature of about $900^{\circ}C$, and the local heat flux and surface temperatures are calculated from the measured temperature-time history. The results show that the minimum heat flux point temperatures increase linearly resulting from the propagation of wetting front with the increase of the distance from the stagnation point of spray flow. However, in the wall region, the minimum heat flux point temperature becomes independent of the distance. Also, the experimental results show that the velocity of wetting front increases with the increase of the droplet flow rate.

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Study on Minimum Heat Flux Point in Spray Cooling of Hot Plate (고온 평판의 분무냉각에 있어서 MHF점에 관한 연구)

  • 김영찬
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.10
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    • pp.974-981
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    • 2001
  • In this study, the minimum heat flux conditions are experimentally investigated for the spray cooling of hot plate. The hot plates are cooled down from the initial temperature of about$ 900^{\circ}C$, and the local heat flux and surface temperatures are calculated from the measured temperature-time history. The results show that the minimum heat flux point temperatures increase linearly resulting from the propagation of wetting front with the increase of the distance from the stagnation point of spray flow. However, in the wall region, the minimum heat flux point temperature becomes independent of the distance. Also, the velocity of wetting front increases with the increase of the droplet flow rate.

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Stochastic Optimization Approach for Parallel Expansion of the Existing Water Distribution Systems (추계학적 최적화방법에 의한 기존관수로시스템의 병열관로 확장)

  • Ahn, Tae-Jin;Choi, Gye-Woon;Park, Jung-Eung
    • Water for future
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    • v.28 no.2
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    • pp.169-180
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    • 1995
  • The cost of a looped pipe network is affected by a set of loop flows. The mathematical model for optimizing the looped pipe network is expressed in the optimal set of loop flows to apply to a stochastic optimization method. Because the feasible region of the looped pipe network problem is nonconvex with multiple local optima, the Modified Stochastic Probing Method is suggested to efficiently search the feasible region. The method consists of two phase: i) a global search phase(the stochastic probing method) and ii) a local search phase(the nearest neighbor method). While the global search sequentially improves a local minimum, the local search escapes out of a local minimum trapped in the global search phase and also refines a final solution. In order to test the method, a standard test problem from the literature is considered for the optimal design of the paralled expansion of an existing network. The optimal solutions thus found have significantly smaller costs than the ones reported previously by other researchers.

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On the Configuration of initial weight value for the Adaptive back propagation neural network (적응 역 전파 신경회로망의 초기 연철강도 설정에 관한 연구)

  • 홍봉화
    • The Journal of Information Technology
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    • v.4 no.1
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    • pp.71-79
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    • 2001
  • This paper presents an adaptive back propagation algorithm that update the learning parameter by the generated error, adaptively and configuration of the range for the initial connecting weight according to the different maximum target value from minimum target value. This algorithm is expected to escaping from the local minimum and make the best environment for the convergence. On the simulation tested this algorithm on three learning pattern. The first was 3-parity problem learning, the second was $7{\times}5$ dot alphabetic font learning and the third was handwritten primitive strokes learning. In three examples, the probability of becoming trapped in local minimum was reduce. Furthermore, in the alphabetic font and handwritten primitive strokes learning, the neural network enhanced to loaming efficient about 27%~57.2% for the standard back propagation(SBP).

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A study on the global optimization in the design of a camera lens-system (사진 렌즈계 설계에서 전역 최적화에 관한 연구)

  • Jung, Jung-Bok;Jang, Jun-Kyu;Choi, Woon-Sang;Jung, Su-Ja
    • Journal of Korean Ophthalmic Optics Society
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    • v.6 no.2
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    • pp.121-127
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    • 2001
  • While SVD and Gaussian elimination method were applied to the additive damped least squares(DLS), the convergence and the stability of the optimization process were examined in a triplet-type camera lens-system where the condition number is well conditioned. DLS with SVD method generated a suitable merit function but this merit function may be trapped in a local minimum by the nonlinearity of error function. Therefore, the least camera lens-system was further designed by the global optimization method is grid method, and this method is adopted to get merit function that convergent to global minimum without local minimum trapping.

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Accurate Detection of a Defective Area by Adopting a Divide and Conquer Strategy in Infrared Thermal Imaging Measurement

  • Jiangfei, Wang;Lihua, Yuan;Zhengguang, Zhu;Mingyuan, Yuan
    • Journal of the Korean Physical Society
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    • v.73 no.11
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    • pp.1644-1649
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    • 2018
  • Aiming at infrared thermal images with different buried depth defects, we study a variety of image segmentation algorithms based on the threshold to develop global search ability and the ability to find the defect area accurately. Firstly, the iterative thresholding method, the maximum entropy method, the minimum error method, the Ostu method and the minimum skewness method are applied to image segmentation of the same infrared thermal image. The study shows that the maximum entropy method and the minimum error method have strong global search capability and can simultaneously extract defects at different depths. However none of these five methods can accurately calculate the defect area at different depths. In order to solve this problem, we put forward a strategy of "divide and conquer". The infrared thermal image is divided into several local thermal maps, with each map containing only one defect, and the defect area is calculated after local image processing of the different buried defects one by one. The results show that, under the "divide and conquer" strategy, the iterative threshold method and the Ostu method have the advantage of high precision and can accurately extract the area of different defects at different depths, with an error of less than 5%.

Bridge-edges Mining in Complex Power Optical Cable Network based on Minimum Connected Chain Attenuation Topological Potential

  • Jiang, Wanchang;Liu, Yanhui;Wang, Shengda;Guo, Jian
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.3
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    • pp.1030-1050
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    • 2021
  • The edges with "bridge characteristic" play the role of connecting the communication between regions in power optical cable network. To solve the problem of mining edges with "bridge characteristic" in provincial power optical cable network, the complex power optical cable network model is constructed. Firstly, to measure the generated potential energy of all nodes in n-level neighborhood local structure for one edge, the n-level neighborhood local structure topological potential is designed. And the minimum connected chain attenuation is designed to measure the attenuation degree caused by substituted edges. On the basis of that, the minimum connected chain attenuation topological potential based measurement is designed. By using the designed measurement, a bridge-edges mining algorithm is proposed to mine edges with "bridge characteristic". The experiments are conducted on the physical topology of the power optical cable network in Jilin Province. Compared with that of other three typical methods, the network efficiency and connectivity of the proposed method are decreased by 3.58% and 28.79% on average respectively. And the proposed method can not only mine optical cable connection with typical "bridge characteristic" but also can mine optical cables without obvious characteristics of city or voltage, but it have "bridge characteristic" in the topology structure.

Local Buckling Behavior of Pultruded Structural Flexural Members (펄트루젼 구조용 휨부재의 국부좌굴 거동)

  • 정재호;윤순종
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2003.04a
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    • pp.147-151
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    • 2003
  • In this study, we discussed the local buckling behavior of pultruded structural flexural members. Previous works were briefly reviewed and the local buckling behavior of orthotropic box-shape flexural members was discussed. The simplified form of equation for finding the width ratio of plate element of box-shape flexural members in which all plate components buckle simultaneously was proposed and the macro flow-chart for finding local buckling strength of pultruded flexural members was also suggested. To establish the design guide line for the local buckling of pultruded flexural members, further studies need to be performed as follows; the simplified form of solutions for finding the minimum buckling coefficient of orthotropic plate with various loading and boundary conditions including rotationally restrained boundary conditions, the simplified form of equation for calculating the coefficient of restraint provided by the adjacent plate elements.

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