• 자원ㆍ환경경제연구
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• 제20권3호
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• pp.567-593
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• 2011

2005년 5개 발전사업자는 변동비 반영시장에 기존의 연료비 외에 연료사용 전후에 관련된 부대비용도 포함시킬 것을 건의하였다. 발전량과의 OLS 분석을 통해 관련을 검토한 결과 이 같은 변동비 희망항목이 발전량과 통계적으로 유의한 관계를 갖고 있다는 일반적인 성향을 발견할 수 없어서 변동비로 인정할만한 종합적인 근거는 취약하였다. 변동비 희망항목 중 몇몇 항목이 특정 발전설비에 대해 OLS 분석에서 통계적 유의성을 갖는 등 변동비가 될 수 있는 가능성을 보이고 있다. 그러나 비용산정의 시차, 재고관리와 이에 따른 회계처리 방법 등의 문제로 인하여 발전량과 유의적인 통계적 관계를 보이지 못할 수 있다. 따라서 변동비 희망항목에 대해서는 통일된 기준을 세우고 자료를 표준화하는 작업이 선행되어야 할 것으로 판단된다.

• 산업공학
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• 제20권2호
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• pp.103-111
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• 2007

A heterogeneous VRP which considers various capacities, fixed and variable costs was suggested in this study. The transportation cost for vehicle is composed of its fixed and variable costs incurred proportionately to the travel distance. The main objective is to minimize the total sum of transportation costs. A mathematical programming model was suggested for this purpose and it gives an optimal solution by using OPL-STUDIO (ILOG CPLEX). A genetic algorithm which considers improvement of an initial solution, new fitness function with weighted cost and distance rates, and flexible mutation rate for escaping local solution was also suggested. The suggested algorithm was compared with the results of a tabu search and sweeping method by Taillard and Lee, respectively. The suggested algorithm gives better solutions rather than existing algorithms.

• 수산경영론집
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• 제14권1호
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• pp.1-18
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• 1983

This study has examined the principle of rationalization as a guiding principle in fisheries management. Generally speaking, the guiding principle of business management is the principle of profitability which is oriented to the profit maximization, but it has been insisted by Dr, Mohri that the principle of profitability should be translated into the maximization of ratio of added value on gross capital, According to Dr. Durcker, added value (contributed value) can be used to analyze productivity only if the allocation of costs which together make up the figures is economically meaningful. Therefore, the rationalization of fisheries management can be measured as a result of economic allocation of costs, The analysis of economic allocation of costs divides into macro-allocation of costs and micro-allocation of costs. In fisheries management, the former makes use of the analysis of break-even point, and the latter analyzes the efficiency of individual cost respectively and the state of division of costs which allocate into above-the-line expenses of lay system and management's burden expenses. In macro-allocation of costs, it is advisable that fixed costs be converted into variable costs. This is characteristically possible in fisheries management, because wages belong to variable costs in fisheries management while they are regarde as fixed cost in the other industires. Because we could find that all costs would belong to above-the-line expenses, in micro-allocation analysis, the very costs which are directly related to fisherman's poduction activity should be classified into above-the-line expenses, and the other costs into management's burden expenses. This is a central problem in the rationalization of fisheries management.

• 디지털산업정보학회논문지
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• 제15권3호
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• pp.89-100
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• 2019

Uniform and integrated college desks and chairs have low efficiency of loading for transportation and delivery and low efficiency of storage for warehousing due to their simple uniform physical properties, thus increasing logistics costs for companies and decreasing their competitiveness. In an effort to overcome the limitations of previous studies, this study analyzed the stages of logistics for desks and chairs in college lecture rooms via the transportation route including the factory warehouses and local warehouses and via the delivery route from local warehouses by the region to the orderers including college lecture rooms. The study developed a model for the rationalization of corporate logistics by making a variable folding desk and chair capable of distance adjustment according to height to replace the uniform and integrated college desks and chairs in lecture rooms. A model was developed between the old uniform and integrated college desks and chairs and the new variable folding desks and chairs for three scenarios of cost development including product storage costs, transportation costs from the specialized factory warehouses to the local warehouses by the region, and delivery costs from the local warehouses to college lecture rooms as the orderer. For the generalization of the model, it was applied to each of the 90%, 95%, and 99% service levels.

• 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.

• 대한산업공학회지
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• 제22권1호
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• pp.17-36
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• 1996

An economic two-stage screening procedure is presented when both lower and upper specification limits are given on the performance variable. A screening variable which is highly correlated with the performance variable is used first to decide whether an item should be accepted, rejected, or undecided. The performance variable is then used to classify the undecided items. The two variables are assumed to be jointly normally distributed. A cost model is constructed on the basis of six cost components; inspection costs of screening and performance variables and costs caused by type I and type II misclassification errors related with lower and upper specification limits. Optimal cutoff values on the screening variable are determined so that the average outgoing quality exceeds a prespecified level. Solution methods are provided for both known-parameter and unknown-parameter cases.

• 수산경영론집
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• 제39권1호
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• pp.63-85
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• 2008

The objective of this study is to review the methodology of economic analysis of fishing ports by examining the economical feasibilities of a national fishing port (Jeongja Port) in Ulsan. This study utilized market value evaluation method to measure the benefits and costs related to the development of ports. The benefit variables are income effects resulting from the developments while the cost variables are sum of construction costs and maintenance costs. The income effects are measured in two ways: (1) income from individual project resulting from the developments, (2) the income effects by utilizing investment multipliers. The results shows that the BC ratio (Benefits/Costs) of Jeongja port by using (1) income from individual project resulting from the developments was 1.07 while the BC ratio by using (2) the income effects by utilizing investment multipliers was 1.10 due to a relative short period of useful life for investment multipliers. However, the income variable utilizing investment multipliers is more sensitive to the period of duration than the income variable from individual project.

• 품질경영학회지
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• 제28권3호
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• pp.18-30
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• 2000

Recent studies have shown that the $\bar{X}$ chart with variable sampling intervals(VSI) and the $\bar{X}$ chart with variable sample size(VSS) are much quicker than Shewhart $\bar{X}$ chart in detecting shiks in the process. Shewhart $\bar{X}$ chart has been beneficial to detect large shifts but it is hard to apply Shewhart $\bar{X}$ chart in detecting moderate shifts in the process mean. In this article the $\bar{X}$ chart using variable sample size(VSS) and variable sampling Intervals(VSI) has been proposed to supplement the weak point mentioned above. So the purpose of this paper is to consider finding the design parameters which minimize expected loss costs for unit process time and measure the performance of VSSI(variable sample size and sampling interval) $\bar{X}$ chart. It is important that assignable causes be detected to maintain the process controlled. This paper has been studied under the assumption that one cycle is from starting of the process to eliminating the assignable causes in the process. The other purpose of this article is to represent the expected loss costs in one cycle with three process parameters(sample size, sampling interval and control limits) function and find the three parameters.

• 도시과학
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• 제6권2호
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• pp.59-72
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• 2017

Studies on the calculation of accident costs include the approach on calculating damage costs covering all accidents regardless of first or secondary party and the one calculating damage costs generated by a single victim. These two approaches have a limitation of considering a subject for costs analysis as a single entity. In addition, research on estimating the interaction effects caused in the relationship between diverse traffic accident features and factors remains inadequate since most studies focused on calculating costs incurred in a single entity such as a victim, damaged building, or social organization in charge of managing car accident. This study intends to identify the expected range of old age where a specific interaction effect would remain, compare accidents between old age section and the entire age section, and discover an exogenous variable to be applied in accident drop effects in senior people and reduced benefits by calculating and testing additional accident costs in case the first party and the second party all pertain to the senior age section. By classifying the entire accidents caused by old drivers according to the types of cars, significant coefficients representing the influence that affects car accidents according to the characteristics are calculated and set them as the representative variables by selecting top variable in accordance with from low to high order. Furthermore, characteristics on five age groups such as a group of over 65 and less than 70, a group of over 70 and less than 75, a group of over 75 and less than 80, a group of over 80 and less than 85, and a group of over 85 are elicited and compared them with these preselected accident characteristics variables, thereby identifying what changing effects come out.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권11호
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• pp.4347-4366
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• 2015

Distinguished with traditional strategies which offload an application's computation to a single server, parallel computation offloading can promote the performance by simultaneously delivering the computation to multiple computing resources around the mobile terminal. However, due to the variability of communication and computation environments, static application component multi-partitioning algorithms are difficult to maintain the optimality of their solutions in time-varying scenarios, whereas, over-frequent algorithm executions triggered by changes of environments may bring excessive algorithm costs. To this end, an adaptive application component mapping algorithm for parallel computation offloading in variable environments is proposed in this paper, which aims at minimizing computation costs and inter-resource communication costs. It can provide the terminal a suitable solution for the current environment with a low incremental algorithm cost. We represent the application component multi-partitioning problem as a graph mapping model, then convert it into a pathfinding problem. A genetic algorithm enhanced by an elite-based immigrants mechanism is designed to obtain the solution adaptively, which can dynamically adjust the precision of the solution and boost the searching speed as transmission and processing speeds change. Simulation results demonstrate that our algorithm can promote the performance efficiently, and it is superior to the traditional approaches under variable environments to a large extent.