• 한국컴퓨터정보학회논문지
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• 제20권12호
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• pp.101-106
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• 2015

This paper suggests heuristic algorithm with polynomial time complexity for rigging elections problem that can be obtain the optimal solution using linear programming. The proposed algorithm transforms the given problem into adjacency graph. Then, we divide vertices V into two set W and D. The set W contains majority distinct and the set D contains minority area. This algorithm applies divide-and-conquer method that the minority area D is include into majority distinct W. While this algorithm using simple rule, that can be obtains the optimal solution equal to linear programing for experimental data. This paper shows polynomial time solution finding rule potential in rigging elections problem.

• 한국ITS학회:학술대회논문집
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• 한국ITS학회 2003년도 제2회 정기총회 및 추계학술대회
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• pp.253-256
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• 2003

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.307-310
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• 2005

Most of the electric power in the power system of South Korea is flowing from the south area to the north area, Seoul, in the capital of South Korea. Almost of the needs of the electric power in the capital area are about 43% of the total loads and generation plants are mainly located in the south area of South Korea. As mentioned the earlier characteristic, transmission congestion is one of the important research issues. Because of the limits of the power flows from the south to the north which are anticipated to be increased more and more in the future, these congestion situations may cause a serious voltage stability problem in emergency of the power system. Accordingly, we are interested in an interruptible load control program so as to solve this problem in emergency. This problem can be solved by an interruptible load management in emergency, however, the systematic and effective mechanism has not been presented yet. In this paper, the algorithm of interruptible load management plan using the line sensitivity to the loads for the transmission congestion management in emergency is presented. The proposed method is applied to 6-Bus sample system and their results are presented.

• 한국정보통신학회논문지
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• 제19권2호
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• pp.450-454
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• 2015

본 논문에서는 평면상에 가중치를 가진 점들이 주어질 때, 임의의 상수 r에 대해서 변의 길이 r인 정사각형 영역을 고려해서 이 안에 속하는 점들의 가중치 합이 최대가 되는 영역을 찾고자 한다. 변의 길이가 정해져 있지 않은 경우에 임의의 사각형 영역을 찾는 문제에 대한 연구가 있었다. 본 논문에서는 상수 r이 주어질 때, 변의 길이 r인 정사각형 영역을 찾는 문제를 다룬다. 우리는 동적 환경 하에서의 일차원 문제를 풀고, 이를 이용해서 O(nlogn+rn) 시간 복잡도를 갖는 알고리즘을 제안한다.

• 한국경영과학회지
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• 제22권2호
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• pp.13-29
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• 1997

This paper considers a new routing problem, successive max-min connection ratio problem (SMCRP), arised in circuit telecommunication networks such as SONET and WDM optical transport network. An optimization model for SMCRP is established based on link-flow formulation. It's first optimization process is an integral version of maximum concurrent flow problem. Integer condition does not give the same connection-ratio of each node-pair at an optimal solution any more. It is also an integral multi-commodity flow problem with fairness restriction. In order to guarantee fairness to every node-pair the minimum of connection ratios to demand is maximized. NP- hardness of SMCRP is proved and a heuristic algorithm with polynomial-time bound is developed for the problem. Augmenting path and rerouting flow are used for the algorithm. The heuristic algorithm is implemented and tested for networks of different sizes. The results are compared with those given by GAMS/OSL, a popular commercial solver for integer programming problem.n among ferrite-pearlite matrix, the increase in spheroidal ratio with increasing fatigue limitation, 90% had the highest, 14.3% increasing more then 70%, distribution range of fatigue.
ife was small in same stress level. (2) $\sqrt{area}_{max}$ of graphite can be used to predict fatigue limit of Ductile Cast Iron. The Statistical distribution of extreme values of $\sqrt{area}_{max}$ may be used as a guideline for the control of inclusion size in the steelmaking.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1992년도 가을학술발표회 논문집
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• pp.107-112
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• 1992

Housing lots and area for industrial construction are very serious problem because of narrow country area and high population density of Korea. Especially the form of Pusan is long from north to south. Since the city is surrounded by the sea, traffic trouble and housing lots problem is very serious condition. To solve these problems, Reclamation & Man-made island is needed. So Pusan city is planning for Man-made Island for 2000 year. I will consider about the content of Man-made Island, which is planned by Pusan, and the character of Geotechnical Engineering.

• 한국수학사학회지
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• 제14권1호
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• pp.1-16
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• 2001

To find one side of the square equal to the area of a circle is an unsolved problem. Likewise, to think one side of the cube equal to the volume of a sphere is another unsolved problem. There are four methods to find the area of the circle and the volume of the sphere. This paper aims to weigh each method against the other in finding the answers of the problems in the Chosun Dynasty and investigate their own characters.

• 경영과학
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• 제26권3호
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• pp.23-35
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• 2009

This study deals with the location management in WCDMA (Wideband Code Division Multiple Access) networks. The new location management method is the one of the many techniques used to provide the packet switched (PS) services effectively in WCDMA networks. WCDMA introduces RA (routing area) for the PS services in addition to LA (location area) for the circuit switched (CS) services. WCDMA system also adopts the cooperative paging and the combined area update which are to decrease signaling traffic using the PS network resources for the CS services. Considering the characteristics of the WCDMA networks, this study formulate into the mathematical programming problem for the location management. Rather than the existing researches which consider the single MSC/SGSN networks, we deal with the multi MSC/SGSN networks, where both MSC area and SGSN area should be determined as well. Fairness between traffic loads of MSC/SGSN and the system cost incurred to MSC/SGSN are also incorporated into our model, which make the model more realistic. We propose greedy algorithms for the problems, which consists of the merger of two neighboring areas and the movement of an area. Extensive experiment has been done based on the realistic problem examples. Followed by the analysis of parameter effect on the final solutions and the quality of final solutions obtained by our greedy algorithms. Our proposed model and analysis result can be used to determine WCDMA system areas and to predict the system performance measures by the determination.

• 전기학회논문지
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• 제57권10호
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• pp.1703-1707
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• 2008

Low frequency oscillation of inter-area system is important problem in power system areas because the operation conditions of power system depend on it. Generally, the analysis of the problem is used by small signal stability. Especially, the analysis results are affected by decision of load models. In this paper, the effect of the analysis results was studied according to load component characteristics. ZIP model, popular in large-scaled power system analysis, was used as the load model. Many cases were studied according to the combination of ZIP model in inter-area system.

• 대한산업공학회지
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• 제27권1호
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• pp.54-60
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• 2001

In this paper, a shape-based block layout (SBL) approach is presented to solve the facility layout problem with unequal-area and fixed shapes. The SBL approach employs hybrid genetic algorithm (Hybrid-GA) to find a good solution and the concept of bay structure is used. In the typical facility layout problem with unequal area and fixed shapes, the given geometric constraints of unequal-area and fixed shapes are mostly approximated to original shape by aspect ratio. Thus, the layout results require extensive manual revision to create practical layouts and it produces irregular building shapes and too much unusable spaces. Experimental results show that a SBL model is able to produce better solution and to create more practical layouts than those of existing approaches.