• 상하수도학회지
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• 제22권1호
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• pp.149-157
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• 2008

The reduction of leakage is a major issue of the South Korea water industry. The inclusion of pressure dependent leakage terms in network analysis allows the application of optimization techniques to identify the most effective means of reducing water leakage in distribution networks. This paper proposes a method to find optimal setting and location of control valve for reducing leakage efficiently. The proposed search method differs from previous methods for addressing optimal valve location problem and improves the GA simulation time with guaranteeing for getting the global optimal solution. The strength of this method has been demonstrated by means of case studies. This allows the procedure of optimization to be more robust and computational efficient.

• 대한산업공학회지
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• 제20권2호
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• pp.39-50
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• 1994

Most research results on the throughput of unit-load automated storage retrieval (AS/R) systems assume the randomized storage; that is, all slots In the entire rack are equally likely to be selected for the storage location. However, for the most existing AS/R systems which use Closest Open location storage policy, Park[6] mathematically showed that this assumption results in a significant difference from the actual performance of AS/R systems. In this study, we present more details about the performance of the unit-load AS/R systems by considering the rack utilization and rack density; and examine their impact on the throughput of AS/R systems by using computer simulation. A new storage policy named Shortest Cycle Location(SCL) is proposed. Simulation results indicate that the performance of SCL policy consistently outperforms the Closest Open location storage policy. We also define the "Extra-Cost Zone" compared to the "No-Cost Zone"[3] and explore its geometric and practical meaning.

• 소음진동
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• 제9권4호
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• pp.738-746
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• 1999

The performance of muffler can be improved for a frequency range of interest by moving inlet and outlet locations. And optimal location of inlet and outlet can be determined to improve the acoustic performance. The optimum design using FEM, however, may take a very long time and be very hard to take inlet and outlet locations as design variables. In this paper, the acoustic performance of reactive type single expansion chamber muffler is predicted using higher order mode theory. The sensitivity analysis of transmission loss with respect to the location of inlet and outlet is suggested. And the acoustic power transmission coefficient for a frequency of interest is used as cost function. Optimum location of inlet and outlet is determined to minimize cost function by using SUMT algorithm.

• 한국경영과학회지
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• 제27권3호
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• pp.59-74
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• 2002

This study investigates two basic operations of mobility management of PCNs (Personal Communication Networks), i.e., the location update and the paging of the mobile terminal. From the realistic consideration that a user either moves through several cells consecutively or stays in a cell with long time, we model the mobility pattern by introducing two types of CRT (Cell Residence Time). Mobility patterns of the mobile terminal are classified Into various ways by using the ratios of two types of CRT. Cost analysis is performed for distance-based and movement-based location update schemes combined with blanket polling paging and selective paging scheme. It is demonstrated that in a certain condition of mobility pattern and call arrival pattern, 2-state CRT model produces different optimal threshold and so, is more effective than IID ( Independently-Identically-Distributed) CRT model. An analytical model for the new CRT model is compact and easily extendable to the other location update schemes.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.249-252
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• 2004

The automatic determination of vehicle operation status as well as continuous tracking of vehicle location with intelligent management is one of major elements to achieve the goals. Especially, vehicle operation status can only be analyzed in terms of expert experiences with real-time location data with scheduling information. However the scheduling information of individual vehicle is very difficult to be interpreted immediately because there are hundreds of thousand vehicles are run at the same time in the national wide range workplace. In this paper, we propose the location-based knowledge management system(LKMs) using the active trajectory analysis method with routing and scheduling information to cope with the problems. This system uses an inference technology with dispatching and geographic information to generate the logistics knowledge that can be furnished to the manager in the central vehicle monitoring and controlling center.

• 통상정보연구
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• 제19권2호
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• pp.85-107
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• 2017

The aim of this study is to empirically examine fundamental factors that drive FDI to a particular location. This study further explores operating conditions of Korean firms in Myanmar. A survey methodology and then a regression analysis are employed. The study finds that the factors such as transportation, production factor, market, and cost play an important role for the location of FDI. However, the Korean investment in Myanmar decreases from 2013. The decrease of Korean investment implies that investing in Myanmar has not been profitable. The empirical study finds a complicated pattern of FDI. Large Korean firms are located far from the consumer market, thus, bear an increased transport cost to reach the consumer market. They are rather located in a place where they can access to a transport means and raw materials with low cost to export final products. They place FDI into a host country to serve as a production platform for exports to neighboring countries.

• 전기학회논문지P
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• 제54권4호
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• pp.163-170
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• 2005

This paper deals with an improved fault location algorithm with compensation ground capacitance through distributed parameter for a long parallel T/L. For the purpose of fault locating algorithm non-influenced by source impedance and fault resistance, the loop method was used in the system modeling analysis. This algorithm uses a positive and negative sequence of the fault current for high accuracy of fault locating calculation. Power system model of 160km and 300km long parallel T/L was simulated using EMTP software. To evaluate of the proposed algorithm, we used the several different cases 64 sampled data per cycle. The test results show that the proposed algorithm was minimized the error factor and speed of fault location estimation.

• 교육녹색환경연구
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• 제8권2호
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• pp.22-39
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• 2009

The purpose of this study was to analyze the school location and site planning direction for land use planning of public land development. And this research proposed the direction of small park in school. So this research present the implication on urban planning and design for architecture, park-school complex. This study perform the relationship analysis on location of school and park. The result follows as this : 1) land use planning : Location and space of park-school must be checked in advance. Schools and parks are placed together. The park is located south of the school. 2) school site planning : Small field for dynamic activity is needed in school. The character of small park in school is relationship of educational programs. 3) management : CCTV is installed at school. Bright lights are placed in school. This result will be used in decision-making-process of land use planning, public land development construction, urban design and city policy.

• 한국생산제조학회지
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• 제19권2호
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• pp.191-197
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• 2010

In spite of a large amount of previous research, detail study on modified mass in proportional damping system is not well understood. It is common to predict structural dynamic design parameters due to the change of mass, but to predict the amount of modified mass and the location where the mass is being modified are rarely found in previous literature. Such inverse problem required detail analytical study in order to understand structural modification in proportional damping system. This paper predicts the modified mass and the modified mass location in proportional damping system using sensitivity coefficients and iterative method. The sensitivity coefficients are obtained from the change of eigenvectors due to mass modification. This method is applied to a horizontal beam and three degree of freedoms system. To validate the predicted changing mass and its location, the obtained results are compared to the reanalysis result which shows good agreement.

• 한국환경복원기술학회지
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• 제12권4호
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• pp.34-46
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• 2009

and to provide (case example-focused) guidelines for environment-friendly oriented plans. Key findings of this study are as follows : first, a total of 2,465 development projects covering $173km^2$ were undertaken in Gyeonggi province in last three years. Second, based on the analysis of 16 development projects in four types, about 20 alternative environment-friendly location were suggested. Thirdly, 56 environment-friendly criteria were suggested for the environmental assessment items by setting at least three alternatives. Going forward, if discussion case examples by project type, environment-friendly location criteria by project type, and environment friendly review criteria by assessment item suggested in this study are fully utilized when initiating or approving various development projects in the future, environment-friendliness will be enhanced in development projects.