• 지능정보연구
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• 제15권3호
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• pp.137-150
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• 2009

본 연구는 시간 제약조건을 가지는 차량 경로 탐색과 스케줄링 문제(VRSPTW, the Vehicle Routing and Scheduling Problem with Time Window)를 해결하기 위하여, 기회시간(Opportunity time)을 반영한 하이브리드 휴리스틱을 제안하였다. 기회시간은 각 고객 노드에서 요구하는 하역 서비스를 수행 한 뒤에도 남아 있는 여유시간이다. 제안된 휴리스틱은 기회시간에 대한 제약조건을 추가하고, 기회시간을 고려한 비용 평가함수를 삽입 전략에 적용함으로써 초기 해를 구하였다. 또한 고객 노드 교환에 의한 타부 탐색 전략에도 기회시간을 반영함으로써 해를 개선 시켰다. 마지막으로 지리적, 시간적, 용량적으로 다양한 데이터 유형들에 대하여 각각 효과적으로 최적 해를 구할 수 있는 초기 경로 생성 전략들을 소개하고 비교하였다. 본 연구의 실험에서는 제안된 휴리스틱이 Solomon I1 휴리스틱 보다 효율적으로 최근사 해를 얻을 수 있음을 보였다.

• 한국안전학회지
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• 제16권2호
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• pp.103-109
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• 2001

When workers get accidents in doing their works, industrial accident insurance covers the compensation for the accidents. Generally, this kind of costs is applied in terms of Direct Cost. In our society circumstance to terminate the accident, many kinds of cost (Non-Insurance Cost) are also discharged. Non-Insurance Cost resulted from additional compensation for insurance allowance, is the important basic data source to estimate Loss Cost. Several studies have been done for the output of accident cost, but companies have difficult to apply these studies into practice and generalize the amount of accident loss cost. This study means to suggest improving solutions for the output of Accident Loss Cost and to reduce Opportunity Cost caused by Industrial Accident.

• International Journal of Advanced Culture Technology
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• 제9권3호
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• pp.271-276
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• 2021

In this paper we analyze the effect of the credit period on inventory policy under trade credit with ordering cost including a fixed cost and freight cost, where the freight cost has a quantity discount. For marketing purposes, some supplier offers credit period to his buyer to stimulate the demand for the product he produces. The delay in payments during the credit period has the effect of reducing the buyer's capital opportunity cost. It is also assumed that the buyer pays the freight cost for the order and hence, the ordering cost consists of a fixed ordering cost and a variable freight cost which depends on the order quantity. As a result, the possibilities of trade credit and discounts on freight costs are expected to play an important role in the buyer's inventory policy. Based on the economic order quantity inventory model, we analyze how the buyer can determine the optimal inventory policy and we examine the effect of the length of credit period on the buyer's inventory policy.

• 경영과학
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• 제18권1호
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• pp.29-39
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• 2001

Traditionally, companies have been concerned with making an investment decision either to go now or never to go forever. However, owing to the development of the theory of options pricing in a financial investment field and its introduction to the appraisal of real investments in these days, we are now partially allowed to derive the value of a managerial flexibility of real investment projects. In this paper, we derived a general mathematical model to price the option value of real investment projects assuming that they have only one-period of time under which uncertainty exists. This mathematical model was developed based on the opportunity cost concept. We will show a simple numerical example to illustrate how the mathematical model works comparing it with the existing models.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.55-58
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• 2007

An adaptive subcarrier allocation scheme based on comparative superiority of opportunity cost between groups is proposed for the enhancement of system capacity and its simple implementation at the base station of a multiuser OFDM system. The proposed algorithm is similar to the blockwise or the decentralized subcarrier allocation algorithm proposed by Xiaowen et al and Alen et al, respectively. In the proposed algorithm, however, all subcarriers are grouped according to the coherence bandwidth and the comparative superiority concept, which swaps the groups between users if the system capacity is increased, is adopted for the enhancement of system capacity. In addition, the proposed algorithm provides a simple solution for the conflict problem among users by reallocating only the conflicted groups and unassigned groups instead of reallocating entire groups. Simulation results demonstrate that the proposed algorithm increases the system capacity effectively over a static, an adaptive blockwise, and a decentralized subcarrier allocation algorithms.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.352-358
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• 2010

When the Trans-Korea Railway (Gyeong-eui Line and Dong-hae Line) initiative is completed, Korea will become one of the major trading partners of Russia through the Trans-Siberian Railway (TSR). This will be an opportunity for Korea to take-off to a 'Traffic and Logistics Center in 21st Century. The opening of the Eurasia Continental Railway will provideKorea with the opportunity to develop into the logistics center of Asia-Pacific area and the benefit of reduced cost of unification by improving the correlation between South and North Korea through the cooperation in railway business. However, there exist the uncertainties for its demand and innovative reduction in transportation time and cost, due to the practical problems including economic efficiency and transportation technology. In this paper, the practical problems of TSR are discussed in the economic and social perspectives to develop the methodology for the Korea-Russia railway cooperation and for the improvement of the competitive power of TSR.

• 대한안전경영과학회지
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• 제21권2호
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• pp.15-23
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• 2019

Among service industries of knowledge based economic era, the roles of educational service field are becoming more important and standard of educational service makes a direct effect on economic development and social growth. Therefore, accurate measurement of service quality is the most important assignment and the measurement of the service quality remains difficult assignment. So, this researcher classified quality attributes applying weighted value and found potential satisfaction level(PSL) and potential customer demand improvement index(PCDI) for trainees participating in national manpower business so as to suggest measurement of service quality and easiness of use and then, calculated satisfaction position and opportunity cost by quality factor with Taguchi's loss fraction. And, improvable satisfaction level was measured, opportunity cost by degree of customer dissatisfaction was quantitatively measured, and a model that can indicate with economic factors was suggested. In addition, methodology of measuring quality cost that can be reduced by quality improvement and direction of strategic decision-making for deciding items to be improved preferentially were suggested with qualitative index that can indicate the degree of customers' dissatisfaction by loss.

• 가족자원경영과 정책
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• 제17권2호
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• pp.55-74
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• 2013

This research developed standardized satellite accounts for household production to measure the entire production in Korea using representative Korean data. This study utilized standardized methods for measuring the expenditure and consumption of expendable supplies as an element of intermediate goods in household production. The results of this research can be summarized as follows. First, the total value of household production in Korea in 2009 turned was 268 trillion won, which would be 10.16% of the GDP, based on using the method of replacement by specialty for estimating the value of housework, while it was 356 trillion won, which would be 13.5% of the GDP (2,636 trillion won), based on the method of opportunity cost. Second, the economic value of labor invested in household production was 220 trillion won when using the data from 12 main corresponding wages in the market, while it was 203 trillion won when using the method of total replacement, which used the wages of housekeepers, and 290 trillion won when using the method of opportunity cost in measuring the value of housework labor. Third, in estimating the proportion by section in terms of the total value of household production, the portion of labor in household production was measured from 76% to 82%, depending on the methods used, which is the most significant section. These results indicate that housework has the characteristics of labor-centered work. On the other hand, the value of expenditure on and consumption of expendable supplies, as one element of intermediate goods, is 63 trillion won, which is 17.7% (using the method of opportunity cost in measuring the labor of housework) of household production. Also, the value of capital goods, as the other element of intermediate goods is 2.3 trillion won, which is 0.9% (using the method of opportunity cost) of household production. In conclusion, as an element of household production, housework labor was higher in household production than expenditures on expendables, especially for cooking, cleaning, and caring for children. In the future, people should be cautious about estimating that the amount of household work could be reduced, as women's labor in the market and the household work produced by the market will increase.

• 수산경영론집
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• 제25권1호
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• pp.1-17
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• 1994

Coastal economic activities usually generate externalities to other economic activities. The conflicts between coastal economic activities, especially land fillings and reclamations, and fisheries in coastal waters pose a typical one, which sometimes causes some social conflicts. In this regard, as the contents and requirements for rules and regulations on fisheries compensation may have important implications for solving such problems, important is to review rationales fur the formulas in calculating fisheries compensation. The purpose of this paper is to review the formulas for fisheries compensation from the economic view points, to highlight some problems and to suggest more appropriate formulas. It is found that the current formulas of fisheries compensation are not properly based on economic concepts and valuation techniques. Main problems are related, as followings, to the coefficient(0.8) employed in the formula, to fishermen's own wages and to current values of invested assets such as fishing boats and nets, etc.. First, it is not clear what the coefficient(0, 8) means. In Japan's case, the coefficient was assumed to reflect the opportunity cost of fishermen's own wages, but it was disappeared from the formula after the self-wage came to be included in totaling fishing cost. As our new formula will include the self-wage in fishing cost, the coefficient(0.8) should be excluded. Second, according to our formula, the current value of invested assets is added to total operating compensation, which will overestimate total compensation. Therefore, it is suggested that total present value of the assets to be invested during the business life should be deducted from total operating compensation. Third, as the self-wage will be included in total cost, opportunity cost for finding new jobs should be newly added to the formula. Finally, this paper also conducted a comparative case study considering above-mentioned factors. The case study showed that the current formulas overestimated total fisheries compensation.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2012년도 한국컴퓨터종합학술대회논문집 Vol.39 No.1(D)
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• pp.265-267
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• 2012

This paper analyzes network selection issues of secondary users (SUs) in Cooperative Cognitive Radio Networks (CRNs) by utilizing Queuing Model. Coordinating with Handover Cost-Based Network selection, this paper also addresses an opportunity for the secondary users (SUs) to enhance QoS as well as economics efficiency. In this paper, network selection of SUs is the optimal association between Overall System Time Minimization Problem evaluation of Secondary Connection (SC) and Handover Cost-Based Network selection. This will be illustrated by simulation results.