• Journal of the Korean Geographical Society
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• v.46 no.3
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• pp.366-381
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• 2011

A competitive location problem in discrete space is computationally difficult to solve in general because of its combinatorial feature. In this paper, we address an alternative method for solving competitive location problems in discrete space, particularly employing deterministic allocation. The key point of the suggested method is to reducing the number of predefined potential facility sites associated with the size of problem by utilizing geometric concepts. The suggested method was applied to the existing broadband marketplace with increasing competition as an application. Specifically, we compared computational results and spatial configurations of two different sized problems: the problem with the original potential sites over the study area and the problem with the reduced potential sites extracted by a GIS-based geometric algorithm. The results show that the competitive location model with the reduced potential sites can be solved more efficiently, while both problems presented the same optimal locations maximizing customer capture.

• International Area Studies Review
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• v.14 no.2
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• pp.205-227
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• 2010

Where should a plant or service facility be located? The decision is crucial since the capital investment in land, factory construction, and facility is enormous. Once a firm has sunk a large sum of money into a factory, it lives with the decision for a long time. In this age of global markets and global production, this is a key decision problem for contemporary manufacturing and/or service. Using data from Korean and Chinese managers and the AHP (Analytic Hierarchy Process), this paper did study on the actual condition for identifying the differences of opinion between the two group's(Shanghai and Shenyang managers) in how to make decisions on the location problems. Since this study was carried out during recent global economy recession, and the limitation of the collected questionnaires, it is hard to avoid the possibility for those managers to show different view from their ordinary times. Nevertheless, this paper will provide managers with useful informations on successful facility location in China.

• Journal of the Korean Operations Research and Management Science Society
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• v.29 no.1
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• pp.57-70
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• 2004

Given a tree network on which each node has its own demand and also stands for a candidate location of a potential facility. such as plant or warehouse, the f-median problem on the network (PMPOT) is to select less than or equal to P number of facility locations so that the whole demand on a node is satisfied from only one facility and the total demand occurred on the network can be satisfied from those facilities with the minimum total cost, where the total cost Is the sum of transportation costs and the fixed costs of establishing facilities. Tamir(1996) developed an O(p n$^2$) algorithm for PMPOT which is known to be the best algorithm In terms of the time complexity, where n is the number of nodes in the network, but he didn't make any comments or explanation about implementation details for finding the optimal solution. In contrast to Tamir's work, Kariv and Hakimi(1979) developed O(p$^2$n$^2$) algorithm for PMPOT and presented O(n$^2$) algorithm for finding the optimal solution in detail. In this paper, we not only develop another O(p n$^2$) dynamic programming algorithm for PMPOT that is competitive to Tamir's algorithm in terms of the time complexity, but also present O(n) algorithm that is more efficient than kariv and Hakimi's algorithm in finding the optimal solution. finally, we implement our algorithm on a set of randomly generated problems and report the computational results.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.2
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• pp.205-215
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• 2008

convergence networks (BcN). The problem seeks to minimize the total cost of switch and cable while satisfying the requirement of demand and quality of service (QoS). We develop mixed integer programming models to obtain the optimal switch location of the access network. We develop a Tabu Search (TS) heuristic algorithm for finding a good feasible solution within a reasonable time limit. We propose real networks with up to 25 nodes and 180 demands. In order to demonstrate the effectiveness of the proposed algorithm, we generate lower bounds from nonlinear QoS relaxation problem. Computational results show that the proposed heuristic algorithm provides upper bounds within 5% optimality gap in 10 seconds.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.1
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• pp.17-30
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• 1992

This paper concerns with (p$_{1}$, p$_{2}$)-Plant Location problem in which entire set of candidate sites for facility locations is divided by two overlapping subsets, each of which with its own number of facilities to be established. We propose an algorithm which attempts to solve the Lagrangean dual of (p$_{1}$, p$_{2}$)-PLP by dividing sub-problem into twop-Plant Location Problems and solving them based on the convexity of the Lagrangean dual problem with respect to the number of facilities to be established. In doing so, Orthogonal Move procedure is proposed to provide easy-to-obtain lower bound to the Lagrangean Dual of (p$_{1}$, p$_{2}$)-PLP. Computational experience is reported.

• Journal of the Korean Operations Research and Management Science Society
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• v.6 no.1
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• pp.5-13
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• 1981

This paper considers a facility moving along a route of straight line to serve several facilities in xy plane. A route is obtained which minimizes the objective function expressed in terms of average rectilinear distance between the service facility and facilities to he served. The forms of the objective functions can be classified into several cases according to the initial and end points of the routes. In some cases, as in the problem of optimal location of new facility, the cordinates of the optimal routes are median of the cordinates of facilities to be served. In others, the optimal routes are obtained after examining the values of objective functions on the boundaries of slopes and intercepts. An overall optimal route is obtained by comparing these routes. The entire procedure has been programmed in BASIC language, and several case examples are given.

• Korean Institute of Interior Design Journal
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• v.14 no.4 s.51
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• pp.79-86
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• 2005

According to the new multi-media appeared as a result of rapid growth of the information and science technique, the school library must be changed to the integration of the teach-study media resource from the existing print media. It means that the school library has to play a role of the study center with a different media from the existing teaching material, teaching instrument, facility and opportunity. The Information education must be conducted in the way of an integrated education course and able to do both information transaction and problem settlement. The education facility to solve this problem is the school library. Therefore, the school library becomes important more and more. It means that the school library is the center of entire study and education material for the teacher and student is focused on it. It is urgent to make the standard of the school library In order to cope with the new education and information environments. And especially it is very important to make a plan about the location and scale of the school library to improve the quality of the children's studying activity. The location of the school library is decided under consideration of the relationship with other room of school house and the proper scale of it is between 2.5units and 7.0units of classroom based on the number of class.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1515-1526
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• 2022

Image-based 3D reconstruction is to restore the shape and color of real-world objects, and image sensors mounted on mobile platforms are used for positioning and mapping purposes in indoor and outdoor environments. Due to the increase in accidents in underground space, the location accuracy problem of underground spatial information has been raised. Image-based location estimation studies have been conducted with the advantage of being able to determine the 3D location and simultaneously identify internal damage from image data acquired from the inside of pipeline-type underground facilities. In this study, we studied 3D reconstruction based on the images acquired inside the pipe-type underground facility and reference data. An unmanned mobile system equipped with a stereo camera was used to acquire data and image data within a pipe-type underground facility where reference data were placed at the entrance and exit. Using the acquired image and reference data, the pipe-type underground facility is reconstructed to a geo-referenced 3D shape. The accuracy of the 3D reconstruction result was verified by location and length. It was confirmed that the location was determined with an accuracy of 20 to 60 cm and the length was estimated with an accuracy of about 20 cm. Using the image-based 3D reconstruction method, the position and line-shape of the pipe-type underground facility will be effectively updated.

• Journal of Korean Society of Transportation
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• v.8 no.1
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• pp.41-54
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• 1990

The rapid increase in the freight movement in Korea demands the improvement of the freight transportation system both in quantity and in quality. In recent studies integrated freight terminals have been suggested as the most relevant physical facility that solves this problem. This paper is aiming at the efficiency of the freight transportation system in Korea via integrated freight terminals. We develop a mixed integer programming model to determine simultaneously the most efficient freight flow patterns as well as the optimal locations and sizes of the integrated freight terminal facilities. The results of the model implication is also presented.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.1
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• pp.91-103
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• 2006

Given a bill of materials (BOM) tree T labeled by the breadth first search (BFS) order from node 0 to node n and a general network ${\Im}=(V,A)$, where V={1,2,...,m} is the set of production facilities and A is the set of arcs representing transportation links between any of two facilities, we assume that each node of T stands for not only a component. but also a production stage which is a possible stocking point and operates under a periodic review base-stock policy, We also assume that the random demand which can be achieved by a suitable service level only occurs at the root node 0 of T and has a normal distribution $N({\mu},{\sigma}^2)$. Then our integrated model of facility location problems and safety stock optimization problem (FLP&SSOP) is to identify both the facility locations at which partitioned subtrees of T are produced and the optimal assignment of safety stocks so that the sum of production cost, inventory holding cost, and transportation cost is minimized while meeting the pre-specified service level for the final product. In this paper, we first formulate (FLP&SSOP) as a nonlinear integer programming model and show that it can be reformulated as a 0-1 linear integer programming model with an exponential number of decision variables. We then show that the linear programming relaxation of the reformulated model has an integrality property which guarantees that it can be optimally solved by a column generation method.