• Journal of the Korean Statistical Society
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• 제5권1호
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• pp.49-59
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• 1976

This paper is to present an iterative method for determining an optimum geographic location pattern for the warehouses (sources) that are employed to serve or supply, known quantities of its finished product to a set of custormer areas (destinations) that have fixed and known locations, where the number of sources is permitted to vary. What must be determined, in this paper, is the number and location of the sources or warehouses that will minimize the combined costs of transferring and storing the total quantity of products demanded in the destinations or customer areas.

• 산업경영시스템학회지
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• 제13권21호
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• pp.81-90
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• 1990

In stratified random sampling a simple random sample must be taken in each stratum to reduce the maximum gain in precision given the minimum cost. The purpose of this paper is to deal with the propertics of the estimates and variances and obtain the economic design of stratified random sampling through the optimum allocation of the sample sizes. In addition, the between stratum variation and the within stratum variation is stratifying the population are described.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.647-652
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• 2008

Railway signal system has been more complex, larger and required high reliability. So, maintenance by experience must be changed to optimize maintenance program or introduced systematic method for estabilish new maintenance program. In this paper, we introduced the maintenance period decision method which are Age based method and Block replacement method based on the failure distribution for the equipment. So, we allocated optimum maintenacne period for the railway signal equipment using block replacement method.

• 한국컴퓨터정보학회논문지
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• 제20권9호
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• pp.61-66
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• 2015

We investigate rate scheduling and power allocation problem for a delay constrained CDMA systems. Specifically, we determine an energy efficient scheduling policy, while each user maintains the short term (n time slots) average throughput. More importantly, it is shown that the optimal transmission strategy for the uplink is same as that of the downlink, called uplink and downlink duality. We then examine the performance of the optimum transmission strategy for the uplink and the downlink for various system environments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.363-365
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• 1991

This paper presents a method for feeder reconfiguration in order to operate distribution systems efficiently using heuristic rules. The reconfiguration method presented here not only eliminates various abnormal states but also achieves minimum power loss and optimum load balance of the distribution feeders under normal operating condition transfering loads from one feeder to anoter applying the experiences of the experts. To implement the method effectively, a best-first tree searching strategy based on heuristics is used to evaluate the various load transfer alternatives. The development of a rule-based system aimed at the reduction of the search space is presented as a means of implementing the best-first searching strategy. The results of the computer simulation of the above procedure are as follows; 1) achieving minimum power loss of the distribution feeder adopting the optimum load transfer alternative. 2) Enhencing system reliability and achieving load balance through rational allocation of the feeder loads.

• 대한전기학회논문지
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• 제33권10호
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• pp.410-422
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• 1984

This paper presents a new practical method for optimal active and reactive power control for the economic operation in electrical power system, and the programs are developed for digital computer solution. The major features and techniques of this paper are as follows: 1) The method is presented for finding the equivalent active power balance equation applying the sparse Jacobian matrix of power flow equation instead of using B constant as active power balance equation considering transmission loss, and thus for determining directly optimal active power allocation berween generator unitw satisfying the equality and inequality constraints. 2) The method is proposed for solving directly the optimum economim dispatch problem without using gradient method and penalty function for both active and reactive power control. As a result, the computing time are reduced and convergence characteristic is remarkably improved. 3) Unlike most of conventional methods which adopt the transmission loss as a objective function for reactive power control, the total fuel cost of themal power plant is adopted as objective function for both active and reactive power control. consequently, more reasonable and economic profit can be achieved.

• 한국측량학회지
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• 제14권1호
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• pp.69-80
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• 1996

본 연구는 지방중소도시 근교지역의 주거입지선정을 위한 최적대안을 제시하고자 하였다. 이를 위하여 가용 주거지의 파악은 물론, 주거지개발 우선순위 도출을 위하여 진주시를 대상으로 다음과 같은 3단계 과정을 거쳤다. 첫번째 단계에서는 지형 관련 데이터베이스 구축을 위하여 인공위성 화상데이타를 이용한 수치화상처리기법을 통하여 토지이용현황을 파악하였다. 두 번째 단계에서는 GIS기법 에 의한 진주시의 지형의 표고, 경사, 경사향, 법적 제한성, 인구밀도 및 지가의 평가를 통하여 가용주거지를 파악하였다. 세 번째 단계에서는 수학적 모형을 설정하고 통계적 분석과 정수계획법의 적용을 통하여 최적 주거지 개발 후보지를 선정하고 개발 우선순위를 도출하였다 본 연구의 결과는 지방중소도시의 주거지 입지선정을 위한 가용토지의 파악, 개발우선순위의 결정 및 효율적 토지이용정책을 수립하는데 유용한 자료로 활용될 수 있을 것으로 기대된다.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2005년도 추계학술대회
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• pp.537-557
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• 2005

The estimate on volatility of stock price is related with optimum of portfolio and Important for allocation of capital asset. If the volatility of stock price is varied according to macroeconomic variables on monetary policy and industrial production, it will assist capital asset to allocate. This paper is related with stock market volatilities on macroeconomic variables in U.S. and Europe, Korea. And, it Is pertain to vary in time of this variables. Thus, this paper is related with volatilities of monetary and physical macroeconomic variables on basis of statistics. And, it is ranged front capital investment to portfolio allocation. Also, this paper takes out of sample forecast and study more after this. In case Germany, France, Italy and the Netherlands, the relative importance of monetary policy and Industrial production Is different from these countries. In case Italy and the Netherlands, monetary policy is primary factor at stabilizing for volatility of stock price. In case Korea, increasing monetary policy and industrial production is positively affected stock market. It is that the positive effect of stock price is caused by mollifying monetary policy and economic growth. Specially, this conclusion is similar to US. In Korea, gradual increase in monetary and industrial production is necessary to stability of stock market. It is different to previous results on basis of increasing stock price of money in long period.

• 한국통신학회논문지
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• 제32권5A호
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• pp.441-450
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• 2007

본 논문에서는 위성망 자원할당 및 분석 툴(SNRAT : Satellite Network Resource Allocation & Analysis Tool)을 활용하여 위성통신체계에 대한 링크성능 분석결과를 제시하였으며, 모의위성망을 구성하여 성능분석 툴로 예측한 링크 성능을 검증하였다. 통신위성은 지상장비와 달리 정지궤도에 발사하여 궤도 내 운용을 시작하면, 더 이상 성능의 수정이나 수리가 불가능하고, 운용 가능한 수명이 제한되어 있기 때문에 적기에 배치하여 운용하는 것이 매우 중요하다. 따라서, 위성 발사 전 위성망 자원할당 및 분석 툴을 이용하여 통신품질, 지원용량 및 항재밍 성능 등을 예측하고, 모의위성망을 구축하여 지상단말과 망제어기와 같은 지상장비 및 중계기 규격의 적합성을 증명하였으며, 여러 망 운용 시나리오에 대한 시험을 통해 최적의 운용방안을 도출하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권9호
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• pp.2098-2117
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• 2012

This paper jointly investigates the bandwidth allocation, transmission strategy and relay positions for two-way transmission aware cellular networks with network coding (NC). Our goal is to minimize the transmission power of mobile terminals (MTs). Consider a cellular system, where multiple MTs exchange information with their common base station, firstly, we propose an efficient bandwidth allocation method and then give a transmission strategy for each MT to determine whether to use relay stations (RSs) for its two-way transmission with the BS or not. To further improve the system performance, the optimal positions of RSs are also jointly discussed. A GA-based algorithm is presented to obtain the optimum positions for RSs. Besides, the impacts of frequency reuse on MT's transmission power and system spectral efficiency (SE) under different number of relays are also discussed in our work. Numerical results show that the proposed NC aware scheme can extend MTs' battery life at least 6% more than traditional method.