• Journal of Korean Society of Industrial and Systems Engineering
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• v.14 no.23
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• pp.1-6
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• 1991

The physical distribution service(PDS) is essential to evaluate the business logistics system. The PDS combines the inventory service with the lead time to deliver. This paper is presented to model Mixed Zero-One integer programming which is to determine distribution center location and to allocation products, considering delivery lead time, from given candidate locations to given customer markets. A numerical example is given to demonstrate the applicability of Mixed Zero-One integer programming for Distribution-Location problem.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.197-202
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• 2014

In order to operate multiple UAVs for multiple tasks efficiently, we need a task allocation algorithm with minimum cost, i.e.,total moving distance required to accomplish the whole mission. In this paper, we have proposed the MCBAA (Modified Consensus Based Auction Algorithm) which can be suitably applied to the operation of multiple UAVs. The key idea of proposed algorithm is to minimize sum of distance from current location of agents to location of tasks based on the conventional CBAA. Several simulation test performed on three UAV agents with multiple tasks demonstrates the overall efficiency both in time and total distance.

• Spatial Information Research
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• v.12 no.2
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• pp.211-228
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• 2004

The purpose of this study is to analyze the sales area of gas stations to see the quality and the efficiencies of spatial distribution structure for petroleum products in Tae-jeon City. Location pattern of gas station is classified by factors of competitive facilities, transportation, population and landuse in Tae-jeon City. As a result, High profit pattern and low profit pattern is classified. The characteristics of the distribution pattern of gas station are that the while densely populated has a small sales area, the thinly populated region has huge ones. Location-allocation model is used in order to minimize the travel distance from consumer location to gas station and balance the spatial distribution of gas station in case studies. The result reveals that the model-based locations of gas stations are more dispersed and balanced in the whole Tae-jeon City compared with the actual location of gas stations. This study shows the characteristics and spatial distribution patterns of sales area and location in petroleum products distribution facilities.

• Journal of environmental and Sanitary engineering
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• v.18 no.3 s.49
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• pp.11-20
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• 2003

There are two ways of reducing air pollution. One is the approach of the pollutant source control and the other one is the traffic demand decreasing approach. This study is focusing on the approach of land use planning and optimal location of urban facilities because those are the basic cause to generate transportation demands. So, the purpose of this study would be to analyze the changes of NOx and CO distribution on environmental air by functional hierarchy of urban roads and to make evaluation model of 'Transportation-Land Use -Air Pollution'. It will contribute to improve the air pollution level at same actual traffic generation according to different location.

• Journal of the Korean Operations Research and Management Science Society
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• v.36 no.2
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• pp.1-14
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• 2011

In this paper, we deal with an access network design problem of fiber-to-the-home passive optical network (FTTH-PON). The FTTH-PON network design problem seeks to minimize the total cost of optical splitters and cables that provide optical connectivity between central office and subscribers. We develop a flow-based mixed integer programming (MIP) model with nonlinear link cost. By developing valid inequalities and preprocessing rules, we enhance the strength of the proposed MIP model in generating tight lower bounds for the problem. We develop an effective Tabu Search (TS) heuristic algorithm that provides good quality feasible solutions to the problem. Computational results demonstrate that the valid inequalities and preprocessing rules are effective for improving the LP-relaxation lower bound and TS algorithm finds good quality solutions within reasonable time bounds.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.2
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• pp.112-121
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• 2001

In this study, a spatial location-allocation model of center villages (SLAMCV) was developed for selecting spatial center villages and allocating their rear villages. In SLAMCV, rural space was considered as a network with villages for nodes and roads for connecting lines. For quantification of residents’ accessibilities in the network, a disutility index (DUI) was developed and used, which is dependent upon travelling distance between the center and its hinter villages, design vehicle speed in connecting road and population of hinter villages. SLAMCV was verified to Christaller’s hexagonal hierachical settlement system to test the theoretical reasonability and computing algorithm of the model.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.131-135
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• 2008

In this paper, we deal with a hierarchical location-allocation problem in designing the broadband convergence networks (BcN). The objective is to minimize the total cost of switch and cable while satisfying the quality of service (QoS). We formulate the problem as an integer programming model and develop the Tabu Search (TS) heuristic algorithm to find a good feasible solution within a reasonable time limit. Initial solution is obtained by using the tree structure. Three neighborhood generation mechanisms are used by local search heuristic: insertion, switch up, and switch down. In order to demonstrate the effectiveness of the proposed algorithm, we generate lower bounds from nonlinear QoS relaxation problem. We present promising computational results of the proposed solution procedures.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.3
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• pp.65-75
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• 1998

We consider connection-oriented wireless cellular networks such as the second generation wireless cellular networks and wirelss ATM networks. In these networks, a separate forward signaling channel is provided for the transmission of paging and channel allocation packets. When a call destined to a user is requested, all the base stations in the user's current location area broadcast the corresponding paging packet across forward signaling channels. By slot mode operation and paging group allocation for fusers in a location area, we can reduce relative power consumption level at battery-operated terminals. However, a sthe number of paging groups is increased for lowering relative power consumption level, a paging packet experiences higher delay to access the forward signaling channel. For the pre-negotiated quality-of-service level, paging packet delay level must be limited. In this paper, we consider static and dynamic multiplexing schemes for paging packets, and develop an analytical method for calculating paging packet delay and relative power consumption levels. Using this analytial method, we investigate the effect of network parameters on the paging packet delay and relative power consumption levels.

• Journal of Communications and Networks
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• v.13 no.3
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• pp.250-256
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• 2011

A two-way relaying (TWR) system is analyzed, where two source terminals with unequal numbers of antennas exchange data via an amplify-and-forward relay terminal with a single antenna. In the system considered herein, the link quality between the sources and relay can generally be asymmetric due to the nonidentical antenna configuration, power allocation, and relay location. In such a general setup, accurate bounds on the average sum rate (ASR) are derived when beamforming or orthogonal space time block coding is employed at the sources. We show that the proposed bounds are almost indistinguishable from the exact ASR under various system configurations. It is also observed that the ASR performance of the TWR system with unequal numbers of source antennas is more sensitive to the relay location than to the power allocation.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.3
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• pp.46-55
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• 2001

Following the previous paper on development of the spatial location-allocation model of center villages (SLAMCV), this paper, the 2nd stage of the this study, aims to check up its applicability for several planning scenarios by the case study. Among 72 natural villages of Ucheon-myeon, Gangwon-do, Korea the highest single center was simulated as Uhang village and the higher double centers as Uhang and Jeonggeum villages, which coincided exactly with the existing centers. The SLAMCV was well operated for three planning scenarios such as selection of the 3rd center village and its hinter villages for Ucheon-myeon, Gargwon-do, Korea by dividing three living spheres, impact assessment evaluation of road improvement projects on the spatial accessibility, and analysis of centerality changes of settlement units by new road construction.