• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.487-490
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• 2002

Wind farm paralleled with electric power network can supply the power into a power network not only the normal conditions, but also the fault conditions of distribution network. If the fault happened in the power line with wind farm, the fault current level measured in a relaying point might be lower than that of distribution network without wind turbine generator. Consequently, it is difficult to detect the fault happened in the distribution network connected with wind generator. This paper describes the influence of wind turbine generator on the protective relaying system for detecting the fault occurred in a power line network. Simulation results shows that the fault current depends on the fault impedance, location, and the capacity of wind farm and distribution network load.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.213-214
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• 2016

Based on the efficient supply chain management which will be derived the customer satisfaction, the developing strategies about the scale and location of distribution center(DC) is a very important decision factors to improve the logistics cost efficiency. To do this, we will analyze the conventional DCs' location and cost which belongs to 'D' grocery company operating in Korea and propose the useful way for relocating and establishing DC in company to satisfy the reduction target of logistics cost.

• The Journal of Industrial Distribution & Business
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• v.9 no.5
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• pp.25-35
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• 2018

Purpose - The purpose of this paper is to partition a last-mile delivery network into zones and to determine locations of last mile delivery centers (LMDCs) in Bangkok, Thailand. Research design, data, and methodology - As online shopping has become popular, parcel companies need to improve their delivery services as fast as possible. A network partition has been applied to evaluate suitable service areas by using METIS algorithm to solve this scenario and a facility location problem is used to address LMDC in a partitioned area. Research design, data, and methodology - Clustering and mixed integer programming algorithms are applied to partition the network and to locate facilities in the network. Results - Network partition improves last mile delivery service. METIS algorithm divided the area into 25 partitions by minimizing the inter-network links. To serve short-haul deliveries, this paper located 96 LMDCs in compact partitioning to satisfy customer demands. Conclusions -The computational results from the case study showed that the proposed two-phase algorithm with network partitioning and facility location can efficiently design a last-mile delivery network. It improves parcel delivery services when sending parcels to customers and reduces the overall delivery time. It is expected that the proposed two-phase approach can help parcel delivery companies minimize investment while providing faster delivery services.

• Journal of Radiation Protection and Research
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• v.26 no.3
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• pp.183-190
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• 2001

The activity concentration of primordial radionuclides i.e., $^{238}U$ series, $^{232}Th$ series and $^{40}K$, in soil samples collected from Udagamandalam environment, have been measured by employing NaI (Tl) Gamma ray Spectrometer. The absorbed gamma dose rate has also been simultaneously measured by using both Environmental Radiation Dosimeter at each soil sampling location (ambient gamma dose) as well as from the gamma dose derived from the activity concentration of the primordial radionuclides. The results of activity concentration of each radio nuclides in soil, absorbed dose rate in air due to soil activity and possible cosmic radiation at each location along with human effective dose equivalent for Udagamandalam environment are presented and discussed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.11
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• pp.7-13
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• 2010

For swiftness and economic feasibility of parcel delivery, optimal location of mail exchanging centers considering not only section delivery distance but also some weights like the number of delivery vehicles are necessary. In this paper, a mechanism with section delivery distance and vehicle number for locating of mail distribution centers which connect some mail centers of major cities in Republic Korea by applying GOSST theory is proposed. This mechanism for locating mail exchange centers can make the total delivery distance of postal matters less than not only present method which assigns Daejun as mail exchange center, but also Steiner tree method which does not consider weights like number of delivery vehicles. The mechanism is good for protecting the environment as well as rapid and economic delivery. In experiment, the proposed mechanism could curtail total delivery distance by 2.52 percentages compared with Steiner tree method and by 6.66 percentages compared with present method. The mechanism may be used in electric power transmission routing, distribution line topology design, power relay station locating where various voltages and other weights should be considered.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.15 no.3
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• pp.7-13
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• 2019

To improve the flow distribution at channel locations in the welded plate heat exchanger with "L"-type inflow, the flow visualization of Model 1 was carried out. Besides, the characteristics of flow distribution was investigated experimentally according to the header shape. The inlet flow rate for each channel location was increased at the side channels but decreased at the central channels. In the case of Model 2, which has a slant structure added to the basic header of Model 1, the unevenness of inlet flow increased by 23% from 0.019 to 0.023 as compared to Model 1. On the other hand, Model 3, which has a baffle structure added to Model 2, showed 0.064 unevenness in inlet flow, which was a 36% reduction one compared to Model 1. To improve the distribution at each channel in the welded plate heat exchanger with "L"-type flow, it is necessary to improve the header external shape for the guide of flow as well as the baffle structure for reduction of vortex flow.

• Environmental Engineering Research
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• v.21 no.3
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• pp.226-232
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• 2016

Rainfall is one of crucial factors that impact on our environment. Rainfall data is important in water resources management, flood forecasting, and designing hydraulic structures. However, it is not available in some rural watersheds without rain gauges. Thus, effective ways of interpolating the available records are needed. Despite many widely used spatial interpolation methods, few studies have investigated rainfall center characteristics. Based on the theory that the spatial distribution of convective rainfall event has a definite center with maximum rainfall, we present a mathematical interpolation method to estimate convective rainfall distribution and indicate the rainfall center location and the center rainfall volume. We apply the method to estimate three convective rainfall events in Santa Catalina Island where reliable hydrological data is available. A cross-validation technique is used to evaluate the method. The result shows that the method will suffer from high relative error in two situations: 1) when estimating the minimum rainfall and 2) when estimating an external site. For all other situations, the method's performance is reasonable and acceptable. Since the method is based on a continuous function, it can provide distributed rainfall data for distributed hydrological model sand indicate statistical characteristics of given areas via mathematical calculation.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.15-24
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• 2001

In order to achieve a desirable tooth movement, it is of great importance to control the M/F ratio and to know the location of the center of resistance. The purpose of this study was to locate the center of resistance and the axis of rotation, and to estimate the stress distribution in the periodontal ligament with experimental model. After preparing a model of an upper canine with a simulated periodontal ligament and alveolar bone, the force and moment were applied. The tooth movement was traced using measuring device with LVDTs(Linear variable differential transformers) that can measure three dimensional tooth movement in real time. The results were as follows. 1. The location of center of resistance by transverse force was $29\%$ of root length measured from alveolar crest to apex regardless of force magnitude. The position of the center of resistance is more coronal than that of two-dimensional model($42\%$). 2. The center of resistance and the axis of rotation coincide when couple moment was applied. 3. As the magnitude of moment increases, tooth tends to extrude irrespective of the direction of the moment. 4. The relationship between location of force and axis of rotation (a x b = $49.6\;mm^2$) was obtained. A tooth movement can be predicted through this formula. 5. The centers of rotation by transverse force were plotted linearly.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.11a
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• pp.125-128
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• 2003

This study aims to feasibility study of the Youth Center. Welfare of adolescents is appeared to a matter of concern and interest as social problems of various kinds related adolescents including the fire at a beer bar in Inchon occur recently. In view of government, in addition to fairness of facility location, location of such facilities arc to be determined the respect to cost of locating facilities and developmental direction in the future. A feasibility study is and effective tool in determining the decision of investment or not and the level of investment priority on projects requiring a sizeable investment and the feasibility of a project. The first, it is to select reasonable location. It was selected three and two by consideration of facilities distribution and connection with others. Five proposal selected was estimated by five element of approach, demand, symbol, reality, environment. In result proposal I was chosen. The next, it is to estimate scales. It was estimated by analysis of catchment area, similar facilities, programs, in result 7,260㎡ come into analysis to the best gross area. The finally, it is to study on economical efficiency. Income Statement estimated was came out ₩1,7billion. in addition, it offer various benefit by public facilities.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.125-128
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• 2003

This study aims to feasibility study of the Youth Center. Welfare of adolescents is appeared to a matter of concern and interest as social problems of various kinds related adolescents including the fire at a beer bar in Inchon occur recently. In view of government, in addition to fairness of facility location, location of such facilities are to be determined the respect to cost of locating facilities and developmental direction in the future. A feasibility study is an effective tool in determining the decision of investment or not and the level of investment priority on projects requiring a sizeable investment and the feasibility of a project. The first, it is to select reasonable location. It was selected three and two by consideration of facilities distribution and connection with others. Five proposal selected was estimated by five element of approach, demand, symbol, reality, environment. In result proposal I was chosen. The next, it is to estimate scales. It was estimated by analysis of catchment area, similar facilities, programs, in result 7,260$m^2$ cone into analysis to the best gross area The finally, it is to study on economical efficiency. Income Statement estimated was came out \1.7billion. in addition, it offer various benefit by public facilities.