• International Journal of Reliability and Applications
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• 제4권2호
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• pp.79-95
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• 2003

Manufacturers collect and analyze field reliability data to enhance the quality and reliability of their products and to improve customer satisfaction. To reduce the data collecting and maintenance costs, the amount of data maintained for evaluating product quality and reliability should be minimized. With this in mind, some industrial companies assemble warranty databases by gathering data from different sources for a particular time period. This “marginal count failure data” does not provide (i) the number of failures by when the product entered service, (ii) the number of failures by product age, or (iii) information about the effects of the operating season or environment. This article describes a method for estimating age-based claim rates from marginal count failure data. It uses covariates to identify variations in claims relative to variables such as manufacturing characteristics, time of manufacture, operating season or environment. A Poisson model is presented, and the method is illustrated using warranty claims data for two electrical products.

• 에너지공학
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• 제24권1호
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• pp.58-68
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• 2015

상향식 모형을 이용하여 국내 주거부문의 온실가스 배출특성과 감축 잠재량을 도출하고 이를 바탕으로 한계감축 비용 분석을 수행하였다. 이를 위하여 먼저 상향식 모형의 필수 입력요소인 주거부문의 최종수요, 기준에너지시스템 (Reference Energy System; RES) 등을 정의하고 국내 통계데이터를 분석하여 필요한 활동량 데이터를 도출하였다. 기준 시나리오에서의 연도별 에너지 사용량 및 온실가스 배출량을 구하고 감축수단의 도입에 따른 감축잠재량 및 관련 비용을 분석하였다. 한계감축비용 분석 결과는 중장기적으로 부문별 온실가스 감축목표 달성을 위한 감축정책의 수립에 기여할 것으로 기대된다.

• 전기학회논문지
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• 제65권6호
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• pp.969-978
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• 2016

Around the world are increasing the demand for ESS. Currently, the domestic is expected to benefit by operating ESS. In the domestic, it is expected to benefit from operations of the installed ESS because of the introduction of ESS less capacity. However ESS capacity to the maximum profit occurs is unknown. ESS is different from the charge-discharge characteristics and the reserve to replace, depending on the application. Therefore, it should be established in accordance with the ESS optimal capacity according to the purpose used because it can maximize the quality and efficiency of the electric energy. To the ESS optimal capacity estimation by the purpose used, It should compare the investment cost caused by ESS facility installation and operation cost caused by operating ESS. In this paper, the operation mathematical model for estimating marginal operation costs established. In operation mathematical model, operating cost is considered fuel cost and no-load cost start-up cost. Because no-load cost and start-up cost are not related to cost and power plant output, there are expressed an integer variable costs as a step function.

• 조명전기설비학회논문지
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• 제22권6호
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• pp.134-140
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• 2008

국내 전력시장에서 현 혼잡처리방법은 혼잡비용(congestion cost)을 부가비용(uplift)형태로 전력 사용량에 비례하여 시장 전체의 모든 소비자가 부담하고 있다. 반면 다수의 해외 전력시장에서 채택하고 있는 지역한계가격 (Locational Margnal Pricing)방식은 혼잡으로 인한 비용을 시장 참여자들에게 차등적으로 배분하고 있다. 현재 국내 전력시장에서는 송전 혼잡처리방법의 변경으로 인한 시장참여자 수익에 미치는 영향에 대한 체계적인 연구가 미흡한 실정이다. 본 논문에서는 혼잡처리방법의 변경이 국내 전력시장의 소비자 비용과 발전기 잉여에 미치는 영향에 대해서 분석한다.

• 경영과학
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• 제32권1호
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• pp.83-100
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• 2015

We analyze a duopoly competition when two firms face input cost increases. The objective of this study is to determine the firms' optimal strategy between a price increase and downsizing under conditions of a spatially differentiated market and consumers' diminishing utility on the product size. We develop a theoretical model of two competing firms offering homogenous products using the standard Hotelling model to determine how firms' optimal strategies change when facing input cost increases. In this paper, there are two types of duopoly competitions: symmetric and asymmetric. In the symmetric case, the two firms have the same marginal cost and are producing and selling identical products. In the asymmetric case, the two firms have different marginal costs. The results show that the optimal strategy decision depends on the size of the input cost increase and the cost differences between the two firms. We find that when two firms are asymmetric (i.e., they have different marginal costs), the two firms might choose asymmetric pairs of strategies in equilibrium under certain conditions. When the cost differences between the two firms are sufficiently large and the cost increase is sufficiently small, the cost leader chooses price increase, and the cost-disadvantaged firm chooses downsizing in equilibrium. This asymmetric strategy reduces price competition between two firms, and consumers are better off. When the cost differences between the two firms are sufficiently large, downsizing is the dominant strategy for the cost-disadvantaged firm. The cost-disadvantaged firm finds it more profitable to reduce the product size than to increase its price to reduce price competition, because consumers prefer downsizing to price increases. This paper might be a good starting point for further analytical research in this area.

• 보건행정학회지
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• 제10권4호
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• pp.116-143
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• 2000

Considerable attention has been devoted in the accounting literature to identify the factors that cause or drive the costs of overhead activities. This paper extends recent cost driver research to the health care provider. In various case studies, it has been suggested that overhead costs are driven by volume and complexity variables. This paper investigates the significance of these variables in determining hospital overhead costs, how they are structurally related and how the cost impacts of these variables can be estimated in practice. This paper analyzes the determinants of hospital costs using the sample of South Korea hospitals for seven year during the period 1952－1997. The paper focuses on the extent to which hospital overhead costs depend on complexity, efficiency in addition to depending on more conventional volume based measures of hospital activity. The results of regression analysis suggest that volume and complexity factors positively and significantly affect overhead costs in the hospital industry. The results show that the complexity-related cost drivers strongly affected on the overhead costs in tile health care provider industry more than manufacturing industry which is mainly affected by volume-related cost drivers. That means each Industry may have different cost structures. Therefore it Is Important to find their proper cost structures and cost drivers and use them. Futhermore identification of overhead or indirect cost drivers is likely to be particularly useful in heath care. The identification of cost drivers can be of benefit to all health care stakeholders because these facilitates more efficient management of the national resources devoted to health care. While this study has documented that the level of service complexity is a significant determinant of hospital overhead costs, caution should be exercised in interpreting this as supportive of the cost accounting procedures associated with ABC. It is an open question whether even a well-designed ABC system will provide suitable proxies for marginal costs for decision making purposes.

• 대한전기학회논문지:전력기술부문A
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• 제49권11호
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• pp.549-557
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• 2000

This study proposes a new numerical analysis method for assessing the outage cost of the composite power system with considering transmission system at load points. The proposed method comes from combination of the expected energy not served curve(EENSC) with the marginal outage cost function obtained at load points. Uncertainty of the outages of the generation and transmission systems was also included in this study. This study can be categorized into three processing parts as like as follows. Firstly, EENSC at load points was developed newly from the composite power system effective load duration curve which has been proposed by the authors. Secondly, this study proposes a new technical method for determining the coefficients of the marginal outage cost functions at load points in the composite power system(Generation and Transmission systems). It is a main key point that the mathematical expression for the marginal outage cost function at a load point is formulated and evaluated using relations between the GNP (or GDP) and the electrical energy demand at the load pint. Finally, the outage cost was calculated in this paper by combining the proposed EENSC with the marginal outage cost function evaluated at each load point. It is another important feature that the average costs for future at load points can be forescasted using the proposed approach. The effectiveness of the proposed new approach is demonstrated by the case studies with the IEEE-RTS.

• 대한전기학회논문지:전력기술부문A
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• 제54권10호
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• pp.500-506
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• 2005

With the advent of electric power systems moving to a deregulated retail electricity market environment, calculating distribution service tariffs has become a challenging theme for distribution industries and tariff regulators. As distribution business remains as a monopoly, it is necessary to be regulated. And as multiple distribution companies compete with each other, it would be efficient to adopt competition to the determination of distribution service tariffs. This paper proposes a method to calculate distribution service tariffs using yardstick regulation, which can lead to competition among multiple distribution companies. The proposed method takes into account not only recovering revenue requirements but also the advantages of the yardstick regulation based on long-term marginal costs of distribution network expansion algorithms. A computer simulation is carried out to illustrate effectiveness of the proposed method and it is estimated that the algorithm can be applied to compute the distribution service tariffs under retail electricity markets.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2022년도 춘계학술발표대회
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• pp.114-116
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• 2022

The advent of the Multi-access Edge Computing (MEC) paradigm allows mobile users to offload resource-intensive and delay-stringent services to nearby servers, thereby significantly enhancing the quality of experience. Due to erratic roaming of mobile users in the network environment, maintaining maximum quality of experience becomes challenging as they move farther away from the serving edge server, particularly due to the increased latency resulting from the extended distance. The services could be migrated, under policies obtained using Deep Reinforcement Learning (DRL) techniques, to an optimal edge server, however, this operation incurs significant costs in terms of service downtime, thereby adversely affecting service quality of experience. Thus, this study addresses the service mobility problem of deciding whether to migrate and where to migrate the service instance for maximized migration benefits and marginal service downtime.

• 대한지리학회지
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• 제30권4호
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• pp.352-363
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• 1995

본 연구는 서울시를 연구대상지역으로 하여 지하철 이용에 따른 이용자간 비용의 차이에 의 하여 발생할 수 있는 이용자간 형평성의 문제를 승객거리당 비용을 비교 지표로 사용하여 지하철의 노선과 구간 및 지역에 따라 분석하였다. 분석결과 연구지역 지하철 이용에 따른 비용은 노선과 구간에 따라 상당한 정도의 차이를 나타내고 있는 것으로 나타났다. 즉 노선 에 따른 승객거리당 비용을 비교한 결과 1호선과 4호선의 경우 전체 평균치를 훨씬 상회하 는 반면 2호선과 3호선의 경우 전체 평균치에 미치지 못함으로서 노선에 따라 이용자간의 보조가 발생 할 수 있음을 시사한다. 또한 이용자들의 이용지역에 따른 비교에 의하면 전반 적으로 도시 중심지에 위치한 구간의 승객거리당 비용이 도시 외곽에 위치한 구간의 승객거 리당 비용에 비하여 훨씬 낮은 것으로 나타나 이용자들의 이용지역에 따라 이용자간 보조가 발생할 수 있음을 알 수 있다. 이러한 이용자간의 불합리한 보조에 따른 이용자간의 형평성 문제를 완화하기 위하여는 지하철의 요금체계에 이용자들의 이용에 따른 비용이 적절히 반 영되어야 한다. 따라서 현재 통행거리에 따라 2원화되어 있는데 불과한 단순운임체계를 개 선하여 이용자들의 이용에 따른 한계비용이 보다 적절히 반영될 수 있는 합리적인 운임체계 가 요구된다고 할 수 있다.