• Industrial Engineering and Management Systems
• /
• 제8권4호
• /
• pp.221-227
• /
• 2009

There are customer services jointly provided by two facilities so that each customer will complete the course made up of both facilities' sub-services. The two facilities are assumed invested respectively by an infrastructure owner and one subordinate facility owner, whose partnership is built on their capital investments. This paper presents a mathematical model of Stackelberg competition between the two facility owners to derive their optimal Nash equilibrium. In this study, each facility owner's profit is consisted of fixed revenue fractions of sold services, operating costs (including depreciation cost) and maintenance costs of her facility. The maintenance costs of one facility are incurred both by failures and deterioration due to usage. Moreover, for both facilities, failures are rectified immediately by minimal repairs and preventive maintenance is carried out at a fixed time epoch. Additional assumptions are also employed to develop the model such as customer arrivals are manipulated to follow a Poisson process, and each facility's lifetime is independently Weibull-distributed. The Stackelberg game proceeds as follows. At the first stage of decision making process, the infrastructure owner (acting as a leader) decides the allocation of revenue shares based on her self-interest. After observing the allocation of revenue shares, the subordinate facility owner determines her own optimal price of services. This paper investigates actions and reactions of the two partners in the system. Then analytical conditions are proposed to achieve a unique optimal Nash equilibrium. Finally, some suggestions for further research are discussed.

• KIEE International Transactions on Power Engineering
• /
• 제5A권1호
• /
• pp.9-15
• /
• 2005

In the operation of distribution systems, DGs (Distributed Generations) are installed as an alternative to extension and the establishment of substations, transmission and distribution lines according to the increasing power demand. In the operation planning of DGs, determining optimal capacity and allocation achieves economical profitability and improves the reliability of power distribution systems. This paper proposes a determining method for the optimal number, size and allocation of DGs in order to minimize the operation costs of distribution systems. Capacity and allocation of DGs for economical operation planning duration are determined to minimize total cost composed with power buying cost, operation cost of DGs, loss cost and outage cost using the GA (Genetic Algorithm).

• 수산해양교육연구
• /
• 제26권2호
• /
• pp.444-454
• /
• 2014

The range of optimization problem in aquaculture is very wide, resulting from the range of species, mode of operation. Quite a few studies focus marine net-cages, but studies on land based culture farm are few or no. This paper considers a allocation problem to meet production planning in land based aquaculture system. A water pool allocation model in land based aquaculture system was developed. The solution finds the value of decision variable to minimize yearly production costs that sums up the water pool usage cost and sorting cost. The model inputs were (1) the fish growth rate (2) critical standing corp (3) number of water pool (4) number of fish. The model outputs were (5) number of water pool in growing phase (6) cost of cultivation (6) optimal facility allocation(number of water pool for each growing phase). To solve the problem, an efficient heuristic algorithm based on a greedy manner is developed. Branch and bound and heuristic is evaluated through numerical examples.

• 한국국방경영분석학회지
• /
• 제35권3호
• /
• pp.31-45
• /
• 2009

시스템의 성능과 안전성을 보장하기 위해서는 개발 초기부터 신뢰도에 대한 연구가 이루어져야 한다. 시스템의 목표 신뢰도를 수립하고, 이를 달성하기 위하여 하부시스템 및 부분품에 신뢰도를 할당해야 한다. 시스템의 획득 및 개발에 있어서 성능이 우수하고 비용이 저렴하더라도 고장이 빈번하게 발생한다면 원활한 임무 수행에 많은 영향을 미치고, 막대한 운영유지비용이 소요될 것이다. 본 연구에서는 신뢰도 할당 모형과 운영 유지비용과의 관계를 알아보기 위하여 기존의 알려진 신뢰도 할당 모형들을 검토 및 평가하였다. 신뢰도 할당모형의 평가는 차기 개발 함정용 디젤 엔진을 대상으로 하였으며, 다양한 신뢰도 할당 모형에 목표 신뢰도를 고려하여 신뢰도를 할당하고, 현재 운영하는 함정용 디젤 엔진의 자료를 바탕으로 시뮬레이션을 수행하여 운영유지비용을 최소화하는 신뢰도 할당 모형을 선정하였다.

• 국제학술발표논문집
• /
• The 3th International Conference on Construction Engineering and Project Management
• /
• pp.1100-1106
• /
• 2009

General contractors' overhead costs are increasing relative to direct costs. However, it is difficult to apply the traditional activity-based costing directly to the construction site overhead costing because the resource consumption rate per each activity is varied depending on the attributes of activities. The research develops a methodology of hybrid cost allocation system when resources are assigned to cost objects unlike the traditional activity-based costing. The study also develops a database program and demonstrates how it can be applied to the construction projects using a case study.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 춘계학술대회 논문집
• /
• pp.1134-1141
• /
• 2011

Costs have long since become a major issue in railway system analysis, attention is not limited to the acquisition costs alone, but encompasses all costs involved in the use and disposal of the systems. Concepts such as Life Cycle Cost(LCC), Costs Of Ownership(COO), or Total Ownership Cost(TOC) are more and more frequent in any document dealing with system analysis. Most of railway projects have applied this LCC Model to evaluate effectiveness of system acquisition cost. But these action of LCC model does not applied all the rest of system life cycle period due to the differences of its responsibility. This is why a study has been undertaken by the operation party to harmonize the most important aspects of the LCC model. This study focused on these and other objectives for introduction of method and needs for an action plan for maintenance actions involved relevant cost allocation.

• 한국항해학회지
• /
• 제8권1호
• /
• pp.1-16
• /
• 1984

The economical property of a shipping enterprise, as well as other transportation industries, is determined by the difference between the freight earned and expense paid. This study can be regarded as a division of optimizing ship allocation to routes under the integrated port transport system. Fleet planning and scheduling require complicated allocations of cargoes to ships and ships to routes in order to optimize the given criterion function for a given forecast period. This paper deals with the optimum ship allocation problem minimizing the operating cost of ships in a shipping company. Optimum fleet operating for a shipping enterprise is very important, since the marine transportation is a form of large quantity transport requiring long-term period, and there is a strong possibility to bring about large amount of loss in operation resulting from a faulty ship allocation. Where there are more than one loading and discharging ports, and a variety of ship's ability in speed, capacity, operating cost etc., and when the amount of commodities to be transported between the ports has been determined, then the ship's schedule minimizing the operating cost while satisfying the transport demand within the predetermined period will be made up. First of all a formula of ship allocation problems will be established and then will be constructed to solve an example by the Integer Programming application after consideration of the ship's ability, supply and demand of commodity, amount of commodity to be transported, operating costs of each ship etc. This study will give good information on deciding intention for a ship oprator or owner to meet the computerization current with shiping management.

• 한국통신학회논문지
• /
• 제34권4A호
• /
• pp.316-323
• /
• 2009

본 논문은 셀간 간섭을 제어하여 셀 경계 사용자의 데이터 전송율을 증가시키는 기술인 소프트 주파수 재사용시 전력 할당에 관한 것이다. 소프트 주파수 재사용 기술은 셀 경계 사용자의 데이터 전송율을 개선하는데 유용한 기술이나 주파수 재사용 지수가 증가되어 셀 평균 데이터 전송율을 감소시키는 문제가 있다. 본 논문에서는 하나의 중앙 제어기가 물리적 거리가 인접한 여러 개의 셀을 제어하는 환경에서, 셀 경계 사용자의 데이터 전송율 개선하면서도 셀 평균 전송율 감소를 최소화하도록 소프트 주파수 재사용을 위한 송신 전력 할당 기법을 제안한다. 시스템 시뮬레이션을 통하여 인접한 두 셀에 소프트 주파수 재사용 기술을 적용하여 소프트 주파수 재사용에 의한 셀 평균 데이터 전송율 감소 정도와 제안하는 전력 할당 기법에 의한 셀 평균 데이터 전송을 개선을 살펴본다.

• 한국병원경영학회지
• /
• 제26권1호
• /
• pp.71-82
• /
• 2021

Purpose: The purpose of this study is to estimate incomes and costs of the medical clinics by using secondary data. Methodology: The medical incomes and costs were estimated from 405 clinics operated by sole practitioner providing out-patient services among all clinics subject to the Medical Cost Survey on National Health Insurance Patients in 2017, excluding dental clinics and oriental medical clinics. The incomes and costs of the medical clinics were reflected with incomes and costs of health insurance benefits and were calculated by types of medical services (i.e., basic care, surgery, general treatment, functional test, specimen test and imaging test). The costs were classified as follows: labor costs, equipment costs, material costs and overhead costs. Secondary data was used to estimate the incomes and costs of the medical clinics. For allocation bases for costs for each type of the medical service, the ratio of revenue from health insurance benefits by types of medical services was applied. However, labor costs were calculated with the activity ratio by types of medical services and occupations, using clinical expert panel data. Finding: The percentage of health insurance income for all medical income was 73.1%. The health insurance cost per clinic was 401,864 thousand won. Labor cost accounted for the largest portion of the health insurance income was 191,229 thousand won (47.6%), followed by management cost was 170,018 thousand won (42.3%), materials cost was 35,434 thousand won (8.8%), and equipment costs was 5,183 thousand won (1.3%). Practical Implications: This study suggests a method of estimating incomes and costs of medical clinic services by using secondary data. It could efficiently provide incomes and costs to assess an appropriate level of the health insurance fee to the clinics.

• 한국정보처리학회논문지
• /
• 제4권7호
• /
• pp.1681-1693
• /
• 1997

분산 시스템에서 파일 할당 문제는 시스템의 운영비용을 최소화하기 위해 파일 및 그의 복제물의 최적 위치를 결정하는 것이다. 정적인 파일 할당 문제는 분산 시스템의 각 노드에서 특정 파일에 발생하는 질의 및 갱신에 관련된 비용이 일정하다는 가정에서 출발하고 있다. 그러나 실제로는 시간이 지남에 따라 질의 및 갱신 등에 관련된 매개변수들은 변하게 마련이다. 이 연구에서 다루고 있는 동적인 파일 할당 문제는 변화하는 매개변수들을 고려하고 있으며, 또한 시스템 내에 파일이 한 종류만 있는 경우뿐만 아니라 여러 종류가 있는 경우도 다루고 있다. 동적인 파일 할당 문제는 혼합 정수계획법으로 모형화 되었으며 문제 해결을 위해 Lagrange 함수를 이용한 분단탐색법(branch-and-bound method) 알고리즘이 개발되었다. 제시된 알고리즘은 포트란으로 프로그램화되었으며, 여러 종류의 문제 해결을 통하여 그의 유용성을 보여주고 있다.