• 산업경영시스템학회지
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• 제28권2호
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• pp.117-124
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• 2005

This study tries to develop the models of measuring the level of product availability accommodated for features of specific customers dividing customers into VIP customers and general customers. Functions of costs that the models are composed of are cost of holding safety stock and cost of lost opportunities. The existing model of measuring the level of product availability which focused on cost of holding safety stock for VIP customers should be reinforced by considering cost of lost opportunities caused by general customers' quitting trades with a company. This study tries to present realistic solutions for problems in making decisions related to the total inventory. This study concludes that the model of the level of product availability meeting general customers' needs is more efficient according to increasing of a latent demand of the general customers who quit trades with a company and the cost of lost opportunities.

• International Journal of Computer Science & Network Security
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• 제21권1호
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• pp.6-11
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• 2021

Routing protocols play a pivotal role in the energy management and lifespan of any Wireless Sensor Network. Lower network lifetime has been one of the biggest concerns in LEACH protocol due to dead nodes. The LEACH protocol suffers from uneven energy distribution problem due to random selection of a cluster head. The cluster head has much greater responsibility compared to other non- cluster head nodes and consumes greater energy for its roles. This results in early dead nodes due to energy lost for the role of cluster- head. This study proposes an approach to balance the energy consumption of the LEACH protocol by using a semi-deterministic opportunity coefficient to select the cluster head. This is calculated in each node with the battery energy level and node ID. Ultimately, based on the opportunity cost, cluster head will be selected and broadcasted for which other nodes with higher opportunity cost will agree. It minimizes the chances of nodes with lower battery level being elected as cluster head. Our simulation experiments demonstrate that cluster heads chosen using our proposed algorithm perform better than those using the legacy LEACH protocol.

• KIEE International Transactions on Power Engineering
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• 제4A권4호
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• pp.262-267
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• 2004

With the advent of electric power systems moving from a vertically integrated structure to a deregulated environment, calculating reactive power service charges has become a new and challenging theme for market operators. This paper examines various methods for reactive power management adopted throughout various deregulated foreign and domestic markets and then proposes an innovative method to calculate reactive power service charges using a reactive power market in a wholesale electricity market. The reactive power market is operated based on bids from the generating sources and it settles on uniform prices by running the reactive OPF programs of the day-ahead electricity market. The proposed method takes into account recovering not only the costs of installed capacity but also the lost opportunity costs incurred by reducing active power output to increase reactive power production. Based on the result of the reactive OPF program, the generators that produce reactive power within the obligatory range do not make payments whereas the generators producing reactive power beyond the obligatory range receive compensation by the price determined in the market. A numerical sample study is carried out to illustrate the processes and appropriateness of the proposed method.

• 자원ㆍ환경경제연구
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• 제11권3호
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• pp.345-375
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• 2002

The purpose of this paper is to measure the change of the production efficiency which may happen when environmental regulation incurs technological constraint in the process of production, and to compute the opportunity cost of pollution reduction with the lost products based on the change of efficiency. The patterns of production technoloy in the paper are divided into the technologies of strong disposability and weak disposabilty to grasp the effect of the technological constraint due to the environmental regulation. The endowment of the technolgical constraints in the process of production is considered to bring the greatest restriction on firm's production. When the environmental efficiencies of Korean regional manufactures were measured with linear programming model, the lost products related with the constraint of production technology that environmental regulation incurred, was average 148.1 billion dollar per year(5.87% of one year overall products) for total manufactures in 1991~1998. The ratio of the lost products for total products was spread from 0.78% to 1l.08%. The average lost products of 15 regions were changed from 4.66% to 18.35% of total products. Generally the environmental efficiency index of regional manufactures being decreased continuously since 1991, it is estimated that the environmental performance of Korean manufactures has been more and more deteriorating.

• 수산해양기술연구
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• 제45권4호
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• pp.276-286
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• 2009

The main purpose of this research is to analyze economic feasibility of biodegradable sonw crab gill net model project. The results of benefit/cost analysis show that use of the biodegradable gear is economically feasible. Assuming that the rate of gill net lost is 5 percent, net present value was estimated 311,898,282-590,533,375won, benefit-cost ratio 1.816-1.923 and internal rate of return 7.96-10.59%. The development and diffusion of biodegradable fishing gear appear to make a significant contribution to fisheries resource conservation and marine ecosystem protection. In addition, biodegradable gear production firms may have a good opportunity of exporting it to other coastal states, depending on the progress of WTO subsidy negotiation.

• 조명전기설비학회논문지
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• 제20권5호
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• pp.78-84
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• 2006

전력산업이 수직독점적인 구조에서 규제완화의 경쟁체제로 전환됨에 따라 무효전력서비스의 요금산정이 전력시장 운영자에게는 새로운 이슈가 되고 있다. 본 논문은 몇몇의 선진국과 국내에서 채용되는 무효전력서비스에 대한 요금산정방법을 검토하고, 무효전력시장을 이용하는 새로운 요금산정방법을 제안한다. 무효전력시장은 무효전력 발전원이 제시하는 입찰값을 바탕으로 하루전 전력시장 후에 무효전력 최적조류계산을 거쳐 단일가격으로 결정된다. 제안하는 방법은 무효전력 설치용량에 대한 투자비뿐만 아니라 무효전력 생산량을 늘리기 위해 발전기가 줄이게 되는 유효전력에 대한 기회비용을 함께 고려하고 있다. 26모선 모델계통에서의 사례연구를 통하여 제안하는 방법의 효용성을 입증하고 있다.

• 한국정보시스템학회:학술대회논문집
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• 한국정보시스템학회 2005년도 추계학술대회 발표 논문집
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• pp.307-313
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• 2005

According to the Policy for ' e-Korea construction ' of Korean government, investment of information system during the Past decay are dramatically increasing. More than a half of this investment is cost of hardware infrastructure. So, accurate hardware sizing are essential for higher efficiency of investment. Accurate hardware sizing benefits are generally viewed in toms of the avoidance of excess equipment and lost opportunity costs by not being able to support business needs. Unfortunately, however, little research effort to make the hardware sizing methodology are doing. We propose a sizing method for information system in public sector. This method is determinated empirical study that are gathering and analyzing cases, making method and reviewing expert. Finally we are proposed calculating method for hardware components that is CPU, memory, internal and external disk according to the application system type which is OLTP, Web, WAS. Our study certainly will act as a catalyst for higher investment-efficiency of the future information programs in public sector.

• 한국IT서비스학회지
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• 제5권1호
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• pp.47-59
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• 2006

According to the policy for "e-Korea construction" of Korean government, Investment of information system during the past decade are dramatically increasing. More than a half of this investment is cost of hardware infrastructure. So, accurate hardware sizing are essential for higher efficiency of investment. Accurate hardware sizing benefits are generally viewed in terms of the avoidance of excess equipment and lost opportunity costs by not being able to support business needs. Unfortunately, however, little research effort to make the hardware sizing methodology are doing. We propose a sizing method for information system in public sector. This method is determinate empirical study that are gathering and analyzing cases, making method and reviewing expert. Finally we are proposed calculating method for hardware components that is CPU, memory, internal and external disk according to the application system type which is OLTP, Web, WAS. Our study certainly will act as a catalyst for higher investment-efficiency of the future information programs in public sector.

• 산업경영시스템학회지
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• 제39권4호
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• pp.15-25
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• 2016

SCM activities in a company are considered as total innovation through synchronizing supply and demand while maintaining appropriate inventory level and reducing the business operating costs. Until now, even several researches are carried out on the SCM performance of the companies which have introduced and been operating SCM, the research on the cost analysis for the inventory which occurs frequently on supply chain is still insufficient. Especially, for the electronics industry in which the product depreciation is sharp caused by the short product life cycle and the complexity of distribution channels, even the inventory related costs are a major factor in business management, since the current estimated criteria of inventory costs are limited to the interest and maintenance management costs, the criteria do not reflect the total influence of the product depreciation and lost opportunity cost which are related to the business management. Furthermore, even though the rapid price drops of the distributor inventory caused by the frequent new model launch can be covered by the product manufacturers, the scale of total costs related to the inventory has not been conceived because the price compensation is traditionally considered as a market costs. In this research, we analyzed the inventory characteristics of electronics industry in which the price depreciation happens frequently, newly defining the estimated criteria of the product total inventory cost which includes price depreciation from the product manufacturers' view. Finally we focus on the case study of a representative electronics company and verify the scale of the influence on management performance.

• 한국식품위생안전성학회지
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• 제36권1호
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• pp.68-76
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• 2021

식중독에 의한 사회경제적 손실을 최소화하기 위해서는 식중독과 관련된 경제적 비용 손실을 추정하는 것이 중요하다. 하지만 자료의 부족과 다양한 비용 항목의 존재로 식중독과 관련된 사회경제적 손실비용을 정확하게 추정하기에 어려운 점 있다. 본 연구에서는 국내 식중독 발생에 의한 손실비용을 추정하기에 앞서 국외에서 사용되는 사회경제적 비용항목의 기반 자료 확보를 목적으로 수행되었다. 2009-2019년 국외 식중독과 관련된 사회경제적 손실비용 측정 연구의 사례 조사를 위해 문헌 조사를 실시하였다. 이 연구에서는 사회경제적 손실비용을 크게 의료기간에 방문한 외래/입원환자 및 의료기관에 미방문한 경험환자로 구분하였다. 또한 이들의 직접비용 및 간접비용을 고려하였고, 더 나아가 기업비용 및 행정비용 항목으로 구분하여 조사하였다. 조사 결과 문헌별, 나라별 상이한 비용항목을 사용하여 손실비용을 추정하는 것으로 관찰되었다. 직접의료비의 경우 모든 연구에서 외래 또는 입원진료비를 선정하여 비용을 산출한 것으로 관찰되었기 때문에 나라별 의료서비스의 체제 및 비용에 따라 항목을 선정해야 한다. 직접비의료비의 경우 몇 몇의 연구에서 외래 방문에 소요된 교통비만을 고려하였기 때문에 간병비 고려 여부에 대해서는 더 논의가 필요할 것으로 사료된다. 간접비용 중 조기사망비용, 작업손실비용, 여가손실비용 및 삶의 질 저하/고통비용은 고려하였으나, 병문안 기회비용은 모든 연구에서 고려하지 않았다. 직접의료비와 마찬가지로 행정비용의 경우에도 국가별 정부 예산이 상이하기 때문에 각 나라에 맞는 항목을 고려해야할 것이다. 따라서 이러한 조사 결과를 바탕으로 국내 식중독 발생에 의한 사회경제적 손실비용 분석을 위해 어떠한 비용 항목을 고려해야 할 것인지에 대한 검증절차가 필요할 것이다. 본 연구는 국내 식중독 발생에 의한 사회경제적 손실비용 분석을 위한 기초적인 정보를 제공할 것이다.