• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.54-69
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• 2021

Policy improvement such as the revision of the Road Traffic Act are proposed for personal mobility(especially e-scooter) usage. However, there is not enough discussion to solve the problem of using shared e-scooter. In this study, we analyze the influencing factors that amount of pick-up and drop-off of shared e-scooter by dividing the Seoul into a 200m grid. we develop spatial auotcorrelation model such as spatial lag model, spatial error model, spatial durbin model, and spatial durbin error model in order to consider the characteristics of the aggregated data based on a specific space, and the spatial durbin error model is selected as the final model. As a result, demographic factor, land use factor, and transport facility factors have statistically significant impacts on usage of shared e-scooter. The result of this study will be used as basic data for suggesting efficient operation strategies considering the characteristics of weekday and weekend.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.170-174
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• 2003

In this research, we consider an integrated manufacturing/distribution planning problem in supply chain (SC) which has non-integer time lags. We focus on a capacitated manufacturing planning and capacity allocation problem for the system. We develop a mixed binary integer linear programming (MBLP) model and propose an efficient heuristic procedure using an adaptive genetic algorithm, which is composed of a regeneration procedure for evaluating infeasible chromosomes and the reduced costs from the LP-relaxation of the original model. The proposed an adaptive genetic algorithm was tested in terms of the solution accuracy and algorithm speed during numerical experiments. We found that our algorithm can generate the optimal solution within a reasonable computational time.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.11
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• pp.54-64
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• 2002

This paper deals with the problem of synthesis of stable and optimal grasps with unknown objects by 3-finger hand. Previous robot grasp research has mainly analyzed with either unknown objects 2-dimensionally by vision sensor or known objects, such as cylindrical objects, 3-dimensionally. As extending the previous work, in this study we propose an algorithm to analyze grasp of unknown objects 3-dimensionally by using vision sensor. This is archived by two steps. The first step is to make a 3-dimensional geometrical model for unknown objects by using stereo matching. The second step is to find the optimal grasping points. In this step, we choose the 3-finger hand which has the characteristic of multi-finger hand and is easy to model. To find the optimal grasping points, genetic algorithm is employed and objective function minimizes the admissible force of finger tip applied to the objects. The algorithm is verified by computer simulation by which optimal grasping points of known objects with different angle are checked.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.7-11
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• 2007

This paper considers a shipment planning of products from manufacturers to a third-party warehouse for demands with production time windows where a demand must be replenished in its time window. The underling lot-sizing model also assumes cargo delivery cost in each inbound replenishment to the warehouse. For this model, an optimal O($nT^4$) is presented where n is the number of demands and T is the length of the planning horizon.

• Journal of Korean Society of Rural Planning
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• v.12 no.3 s.32
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• pp.67-80
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• 2006

The concept of RIS(Regional Innovation System) has widely been used in discourse and policy issues in Korea. But most studies of RIS concern on BT or IT industries combining with diverse regional agencies in urban areas. Some other studies were concentrated on general ideas or concept of the RIS. The purposes of this study are (1) to suggest a analytical method to select specialized industry in local autonomy, (2) to analyze the relationship between specialized industry and gross sales of agricultural products and stock farm products, (3) to analyze the relationship between gross sales of agricultural products and stock farm products and GRDP, and (4) to construct a model of RIS that fits particularly for rural areas. This study particularly accentuates that a specialized industry is more meaningful when it can raise GRDP, which eventually can give positive effect of RIS on regions.

• IE interfaces
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• v.16 no.2
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• pp.174-184
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• 2003

This paper addresses a fleet operation planning problem for a static freight container transportation system in which all the transportation requirements are predetermined at the beginning of a planning horizon. In the transportation system under consideration, a number of loaded containers are to be moved between container storage yards. An optimal fleet planning model is used to determine the minimum number of vehicles required. Based on the results from the optimal model, a tabu-search based algorithm is presented to perform a given transportation requirements with the least number of vehicles. The performance of the new procedure is evaluated through some experiments in comparison with two existing methods, and the it is found that our procedure produces good-quality solutions.

• Journal of Korean Society of Rural Planning
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• v.15 no.2
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• pp.69-80
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• 2009

The purpose of this paper is to estimate the regional economic impact of reverse mortgage system based on farmer's net asset of house and farmland together. The regional economic impact was estimated by using inter-regional input-output model. Major findings are as follows: 1) The result of input-output analysis shows that 49,130 million won of production effect, 20,040 million won of value added effect, and 24,759 number of employment effect, 2) Since the result shows that the elderly spend most of the reverse mortgage money for their living expenses, it seems necessary to adopt net asset based reverse mortgage system to improve and stabilize farmers' living conditions and regional economy.

• International Journal of Aeronautical and Space Sciences
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• v.8 no.1
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• pp.54-65
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• 2007

Parameter optimization technique is applied to planning UAVs(Unmanned Aerial Vehicles) path under artificial enemy radar threats. The ground enemy radar threats are characterized in terms of RCS(Radar Cross Section) parameter which is a measure of exposure to the radar threats. Mathematical model of the RCS parameter is constructed by a simple mathematical function in the three-dimensional space. The RCS model is directly linked to the UAVs attitude angles in generating a desired trajectory by reducing the RCS parameter. The RCS parameter is explicitly included in a performance index for optimization. The resultant UAVs trajectory satisfies geometrical boundary conditions while minimizing a weighted combination of the flight time and the measure of ground radar threat expressed in RCS.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.1035-1041
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• 2003

Recent studies among various activities taking place in order-picking warehouse system have shown various researches to reduce the order-picking costs occupying more than half the total costs. One way of improving the warehouse system performance is to separate from a picking area and a reserve area in one unit rack. This study is concerned on the performance evaluation model for picking and replenishing facility of refrigerated warehouse using simulation method. In this study, we developed a mathematical model to compute the system performance solve this problem using simulation method. We demonstrate the system performance using AutoMod Simulator and verify the results to compare mathematical results of the system performance of warehouse system. A systematic approach proposed n this study for an optimal planning of order-picking warehouse is known as an effective method for planning of order-picking warehouse and a performance evaluation problem considering both picking and replenishment.

• Proceedings of the KOR-KST Conference
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• 1995.02a
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• pp.58-82
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• 1995

This study providesd an empirical analysis of trip-chaining behavior and its application to transportation planning. In the empirical analysis, changes in trip-chaining patterns since 1970 have been examined and details of current trip-chaining behavior as they describe shopping trip-chaining behavior has changed. Individual trip-chaining has become longer and complex. It appears that the average number of trips per chains has substantially increased over the past 20 years. An increased number of trips in chains means fewer home-based trips. Changes in trip-chaining behavior have several consequences. Important consequences are for transportation and land-use planning. Up to now trips have been treated as if they are independent clusters of home-to-destination-to-home; this approach has not usually taken into account the trip-chaining behavior of individuals. this calls for a different approach to at least the trip generation and trip distribution part of transportation planning. In this study, application of trip-chaining behavior to trip distribution model formulation is proposed and its calibration results are presented.