• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
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• pp.57-59
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• 2001

The restructuring of power industry is still going on all over the world for last several decades. Many kinds of restructuring model has been studied, proposed, and applied. Among those models, power pool is more popular than others. This paper assumes the power pool market structure having competitive generation sector and a new method is presented to build bidding strategy in that market. The utilities participating in the market have the perfect information on their cost and price functions, but they don't know the strategy to be chosen by others. To define one's strategy as a vector, we make utility's cost/price function into discrete step function. An utility knows only his own strategy, so he estimates the other's strategy using stochastic methods. For considering these conditions, we introduce the Bayesian rules and noncooperative game theory concepts. Also additional assumptions are included for simplification of solving process. Each utility builds the strategy to maximize his own expected profit function using noncooperative Bayesian game. A numerical example is given in case study to show essential features of this approach.

• 전기학회논문지
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• 제56권7호
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• pp.1199-1204
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• 2007

In a cost based pool market, the generation capacity can be used as strategic bids by generation companies (Gencos) with the cost functions open to the market. Competition using strategic capacities is modeled by Cournot and Perfect Competiton (PC) model, and transformed into two by two payoff matrix game with Gencos' decision variables of Cournot and PC model. The payoff matrices vary when capacity payments are given to Gencos in accordance with their capacity bids. Nash Equilibrium (NE) in the matrices also moves with capacity price changes. In order to maximize social welfare of the market, NE should locate in a certain position of the payoff matrices, which corresponds to a PC NE. A concept of a critical capacity price is proposed and calculated in this paper that is defined as a minimum capacity price leading to PC NE. The critical capacity price is verified to work as a tool for suppressing a strategic capacity withholding in simulations of a test system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
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• pp.183-185
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• 2005

This paper discusses an economic study analysis of captive power plant as a commercial plant in the cost based pool market. In this paper I assumed the conversion of a captive power plant owned by factories to a commercial plant and investigated the changes in profitability associated with this. I set the total electricity expense of a captive purpose plant as state A and the costs associated with converting to a commercial purpose plant as state B. Each state subdivided by case which is classified its plant variable cost, type of generation (combined cycle, single cycle) and type of power contract received. After set model for each case, different economic benefits by each case can be calculated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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• pp.108-111
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• 2001

The electric power industries in Korea are launched into deregulation by introducing the CBP(Cost Based Pool), where generation sector of KEPCO was divided into six generation companies and the other sectors of KEPCO remains vertically integrated system. In deregulated market, participants are concerned with maximization of their profit rather than minimization of system-wide costs. Consequently, there are difficulties in applying the cost minimization for the scheduling of generation resources to CBP, because of the operation of pumped-storage hydroplants. This paper presents an operation method of pumped storage hydroplants which is helpful for the economic operation of power system considering the market in the CBP.

• 전기학회논문지
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• 제57권8호
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• pp.1327-1333
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• 2008

Since Cost Based Pool markets has been continued to power markets, Genco. needs economic analysis about investment in power plants. Particularly most Private Genco.s have presently a construction plan about LNG combined cycle thermal power plants. In this paper, we propose a economic analysis method of LNG combined cycle thermal power plants using Economic Dispatch and Optimal Power Flow in CBP markets. Also we develope computation model using it for decision making to build a plant. This method can consider a variation of power facility like power plants and transmission lines in CBP markets. Finally, this dissertation provides a relevant case study to confirm the effect of cost factor to economical efficiency.

• 자원ㆍ환경경제연구
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• 제23권3호
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• pp.497-513
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• 2014

비용을 보상하는 원가규제 방식으로 알려진 투자보수율 규제 또는 총괄원가주의 규제의 경우 피규제자는 비용을 부풀리려는 유인을 갖게 마련이다. 그런데 생산공장별 원가를 규제자가 파악하고 이들 간의 경쟁을 유도하는 경우에는 단기적으로 '수인의 딜레마' 상황이 나타나 원가 과대보고와는 방향이 다른 원가 과소보고 방향으로의 비용왜곡 요인이 발생할 수 있다. 변동비 반영 전력시장의 경우 발전기의 운전시간이 늘어날수록 실제변동비와 등록변동비 간의 차이는 점점 커지게 되지만 복합화력 발전사들은 가동률과 발전량을 높게 유지하기 위해 등록변동비를 유지시키려는 전략적 선택을 할 수 있다. 그 결과 궁극적으로 수익성이 악화되고 신규설비에 대한 투자를 유도하지 못하며 설비예비율은 적정 이하로 떨어지는 '수인의 딜레마' 상황이 나타날 수 있다. 이에 따라 발전사들의 자기변동비가 실제 효율과 유사하도록 관련 규정을 개정할 필요가 있다.

• 간호행정학회지
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• 제14권2호
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• pp.118-130
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• 2008

Purpose: The purpose of this study was to estimate of home-visiting nursing costs for low-income elderly with chronic disease in a metropolitan city using the severity classification and ABC(active-based costing). Methods: First, the HHC activity pool was established. The performance time of each nursing activity were estimated. Second, nursing resources(labor costs, operating costs, and traffic expenses) were analyzed and nursing cost per minute was calculated. And then the cost of each activity was estimated. Third, 202 visiting cases were classified into three group by their severity. And then nursing cost per visit according to their severity was estimated. Results: 59 nursing activities were included in HHC activity pool. The average working time of 59 nursing activity was 6.7minutes and nursing cost per minute was 489 won. According severity, nursing cost per visit were in class I, 54,296 (won), class II 83,124(won), and class III 93,455(won).

• Journal of Communications and Networks
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• 제18권2호
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• pp.162-172
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• 2016

The placement of the complete baseband processing in a centralized pool results in high data rate requirement and inflexibility of the fronthaul network, which challenges the energy and cost effectiveness of the cloud radio access network (C-RAN). Recently, redesign of the C-RAN through functional split in the baseband processing chain has been proposed to overcome these challenges. This paper evaluates, by mathematical and simulation methods, different splits with respect to network level energy and cost efficiency having in the mind the expected quality of service. The proposed mathematical model quantifies the multiplexing gains and the trade-offs between centralization and decentralization concerning the cost of the pool, fronthaul network capacity and resource utilization. The event-based simulation captures the influence of the traffic load dynamics and traffic type variation on designing an efficient fronthaul network. Based on the obtained results, we derive a principle for fronthaul dimensioning based on the traffic profile. This principle allows for efficient radio access network with respect to multiplexing gains while achieving the expected users' quality of service.

• 한국정보통신학회논문지
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• 제18권11호
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• pp.2664-2669
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• 2014

인지무선 (cognitive radio) 환경에서 2차사용자 (secondary user) 들의 일시적인 서비스 요구를 효과적으로 다룰 수 있는 스펙트럼풀링 (spectrum pooling) 기법이 최근 주목을 받고 있다. 스펙트럼풀링은 WSP (wireless service provider) 에 의해서 관리되며, 사용자의 요구가 있을 때, 금전적인 지불을 받고 스펙트럼을 2차사용자에게 대여해 주는 방식이다. 여기서, WSP는 가급적 많은 이윤을 남기기를 원한다. 이 논문에서 우리는 WSP가 유지하는 스펙트럼 풀 (pool) 을 확률 인벤토리모델 (probabilistic inventory model) 로 표현하고 2차사용자의 스펙트럼 요구가 정규분포를 따를 때, WSP가 비용을 최소화시키는 방향으로 인벤토리를 운영하는 전략을 제시한다. WSP가 지불해야하는 비용에는 일반적인 인벤토리 모델과 마찬가지로, 주문비용, 보관비용, 스톡아웃비용이다. 우리는 시뮬레이션을 통해, 고정된 인벤토리 레벨을 유지하는 것보다 확률 인벤토리모델에 의해 결정되는 레벨에 맞추어 유지하는 것이 총 소요 비용을 절약할 수 있음을 보인다.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2006년도 추계공동학술대회
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• pp.373-383
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• 2006

Logistics is one of the most important factors to manage a stream of materials in economic environment. Establishing effective logistics system needs to consider some constraints which are fluctuation of materials volume, a long distance between makers and consumers, one way logistics and small quantity batch production. It is estimated that Unit Load System should be a powerful method to cope with those problems. It helps to realize the key issues which are Standardization and Logistics Pool System The Material Unification of Logistics System is able to participate in all kinds of industries including manufacturing, distribution and logistics. This system has some merits which are a long distance transportation cost down, product recovery, and treatment in the unbalance of demand and supply caused by unstable materials volume. Four strategies of Material Logistics Model are Packing Rationalization, Logistics Pool System, JIT System application and establishing effective infrastructure. The Material Unification Of Logistics System based on Unit Load System achieves efficiency of logistics and largely decreases moving cost.