• Title/Summary/Keyword: Optimum allocation

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A Generalized Markovian Based Framework for Dynamic Spectrum Access in Cognitive Radios

  • Muthumeenakshi, K.;Radha, S.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.5
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    • pp.1532-1553
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    • 2014
  • Radio spectrum is a precious resource and characterized by fixed allocation policy. However, a large portion of the allocated radio spectrum is underutilized. Conversely, the rapid development of ubiquitous wireless technologies increases the demand for radio spectrum. Cognitive Radio (CR) methodologies have been introduced as a promising approach in detecting the white spaces, allowing the unlicensed users to use the licensed spectrum thus realizing Dynamic Spectrum Access (DSA) in an effective manner. This paper proposes a generalized framework for DSA between the licensed (primary) and unlicensed (secondary) users based on Continuous Time Markov Chain (CTMC) model. We present a spectrum access scheme in the presence of sensing errors based on CTMC which aims to attain optimum spectrum access probabilities for the secondary users. The primary user occupancy is identified by spectrum sensing algorithms and the sensing errors are captured in the form of false alarm and mis-detection. Simulation results show the effectiveness of the proposed spectrum access scheme in terms of the throughput attained by the secondary users, throughput optimization using optimum access probabilities, probability of interference with increasing number of secondary users. The efficacy of the algorithm is analyzed for both imperfect spectrum sensing and perfect spectrum sensing.

Development of a Hospital Service-based Costing System and Its Application (병원서비스별 원가분석모형의 개발과 적용)

  • 박하영
    • Health Policy and Management
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    • v.5 no.2
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    • pp.35-69
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    • 1995
  • The managerial environment of hospitals in Korea characterized by low levels of medical insurance fees is worsening by increasing government regulations as to the utilization of medical services, rising costs of labor, material, and medical equipments, growing patient expectations concerning the quality of services, and escalating competitions among large hospitals in the market. Hospitals should seek for their survival strategies in this harsh environment and they should have information about costs of their products in doing so. However, it has not been available due to the complexity of the production process of hospital services. The objectives of this study were to develop a service-based cost accounting model and to apply the developed model to a study hospital to obtain cost information of hospital services. A model commonly used for the job-order product cost accounting in the manufacturing industry was modified for the use in hospitals in Korea. Actual costs, instead of standard costs, incurred to produce a unit of services during a given period of time were estimated in the model. Data required to implement the model included financial information, statistics for the allocation of supportive cost center costs to final cost centers, statistics for the allocation of final cost center costs to services, and the volume of each services charged to patients during a study period. The model was executed using data of a university teaching hospital located in Seoul for the fiscal year 1992. Data for financial information, allocation statistics fo supportive service costs, and the volume of services, most of them in electronic form, were available to the study. Data for allocation statistics of final cost center costs were collected in the study. There were 15 types of evaluation and management service, 2, 923 types of technical service, and 2, 608 types of drug and material service charged to patients in the study hospital during the fiscal year 1992. Labor costs of each of seven types of pesonnel, material costs of 611 types of drugs and materials, and depreciation costs of 212 types of medical equipments, miscellaneous costs, and indirect costs incurred in producing a unit of each services were estimated. Medical insurance fees for basic services such as evaluation and management of inpatients and outpatients, injection, and filling prescriptions, and for operating procedures were found to be set lower than costs. Infrequent services which use expensive medical equipments showed negative revenuse as well. On the other hand, fees for services not covered by the insurance such as CT, MRI and Sonogram, and for laboratory tests were higher than costs. This study has a significance in making it possible for a hospital to obtain cost information for all types of services which produced income based on all types of expenses incurred during a given period of time. This information can assist the management of a hospital in finding an effective cost reduction strategy, an efficient service-mix strategy under a given fee structure, and an optimum strategy for within-hospital resource allocations.

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Optimization of Low Power CMOS Baseband Analog Filter-Amplifier Chain for Direct Conversion Receiver

  • Lee, Min-Kyung;Kwon, Ick-Jin;Lee, Kwy-Ro
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.4 no.3
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    • pp.168-173
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    • 2004
  • A low power CMOS receiver baseband analog circuit based on alternating filter and gain stage is reported. For the given specifications of the baseband analog block, optimum allocation of the gain, IIP3 and NF of the each block was performed to minimize current consumption. The fully integrated receiver BBA chain is fabricated in $0.18\;{\mu}m$ CMOS technology and IIP3 of 30 dBm with a gain of 55 dB and noise figure of 31 dB are obtained at 4.86 mW power consumption.

A Negotiation Method Based on Opportunity Cost in the Trucking Cargo Transportation Market (육상화물운송시장에서 기회비용을 고려한 협상방법론 연구)

  • Kim, Hyun-Soo;Cho, Jae-Hyung
    • The Journal of Information Systems
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    • v.21 no.3
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    • pp.99-116
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    • 2012
  • As a way to allocate lots of orders to many participants for vehicle allocation problem, this study has used an agent negotiation based reverse auction model. This agent negotiation provides coordination functions allowing all participants to make a profit, and accomplishing Pareto optimum solution from the viewpoint of a whole trucking cargo transportation network. In order to build a strategic cooperation relationship based on information sharing, this agent negotiation provides a coordination mechanism in which all the participants including consignors, brokerage firms, and car owners are able to attain their own profits, and also that ensure a competitive market. This study has tried to prove that the result of an agent-based negotiation is the Pareto optimal solution under the present market environment. We established a mathematical formulation for a comparison with the Integer Programming model, and analysing e-Marketplace, structure of shipping expenses and brokerage system in the trucking cargo transportation industry.

An Application of River Basin Network Flow Model for Optimum Water Allocation Planning (유역의 최적 용수배분계획 수립을 위한 Network 모형의 적용)

  • Ahn, Sang-Jin;Choi, Byung-Man;Kwark, Hyun-Gu;Kim, Hyuk-Ho
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.365-369
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    • 2006
  • MODSIM 모형은 하천유역 네트워크 모형으로 최신의 네트워크 최적화 알고리즘을 적용함으로써 유역내에서 물리적 수문학적으로 그리고 수리권과 같은 제도적인 면을 동시에 고려한 물 배분이 가능하며, 네트워크 흐름 최적화 기법은 복잡한 유역 시스템의 모의 능력을 증대시켜 준다. 모형을 이용하여 링크와 노드 및 우선순위를 토대로 금강유역을 대상으로 3개의 저류노드, 57개의 비저류노드, 72개의 수요노드 및 127개의 링크로 구성된 네트워크를 구축하였다. 개발된 네트워크 모형의 적용성 평가를 위해 충청지역의 행정중심복합도시 건설전 후의 용수수급에 대해서 분석하였으며, 네트워크 설계, 우선순위의 설정, 모의운영의 시나리오 분석 등에 있어서 만족할만한 성과를 도출하였다.

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Optimum redundancy design for maximum system reliability: A genetic algorithm approach (최대 시스템 신뢰도를 위한 최적 중복 설계: 유전알고리즘에 의한 접근)

  • Kim Jae Yun;Shin Kyoung Seok
    • Journal of Korean Society for Quality Management
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    • v.32 no.4
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    • pp.125-139
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    • 2004
  • Generally, parallel redundancy is used to improve reliability in many systems. However, redundancy increases system cost, weight, volume, power, etc. Due to limited availability of these resources, the system designer has to maximize reliability subject to various constraints or minimize resources while satisfying the minimum requirement of system reliability. This paper presents GAs (Genetic Algorithms) to solve redundancy allocation in series-parallel systems. To apply the GAs to this problem, we propose a genetic representation, the method for initial population construction, evaluation and genetic operators. Especially, to improve the performance of GAs, we develop heuristic operators (heuristic crossover, heuristic mutation) using the reliability-resource information of the chromosome. Experiments are carried out to evaluate the performance of the proposed algorithm. The performance comparison between the proposed algorithm and a pervious method shows that our approach is more efficient.

Effective Variations of Simulated Annealing and Their Implementation for High Level Synthesis (Simulated Annealing 의 효과적 변형 및 HLS 에의 적용)

  • Yoon, B.S.;Song, N.U.
    • Journal of Korean Institute of Industrial Engineers
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    • v.21 no.1
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    • pp.33-49
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    • 1995
  • Simulated annealing(SA) has been admitted as a general purpose optimization technique which can be utilized for almost all kinds of combinatorial optimization problems without much difficulty. But there are still some weak points to be resolved, one of which is the slow speed of convergence. In this study, we carefully review various previous efforts to improve SA and propose some variations of SA which can enhance the speed of convergence to the optimum solution. Then, we apply the revised SA algorithms to the scheduling and hardware allocation problems occurring in high-level synthesis(HLS) of VLSI design. We confirm the efficiency of the proposed methods through several HLS examples.

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Energy Supply Systems for $CO_{2}$ Emission Control in Korea : An Application of MARKAL Model ($CO_{2}$ 배출량 저감을 고려한 국내 에너지공급시스템 분석 : 시장분배모형(MAEKAL)의 응용)

  • 신희성;홍종철;강희정
    • Journal of the Korean Operations Research and Management Science Society
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    • v.18 no.1
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    • pp.79-95
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    • 1993
  • MARKAL (MARKet ALlocation) Model, one of the most sophisticated energy technology assessment model is applied to finding the optimum mix of energy sources and evaluating energy technology competitiveness in Korea. The model is capable of handling Multiple Objective Linear Programming to test the related cost minimization and environmental control function. In this paper three environmental regulation scenarios are observed including 10% and 20% reduction of carbon dioxide emission level. For the purpose of establishing the basic data base, Korea Reference Engergy System is also developed on the base of the year 1989 with technology utilization and energy flow analysis.

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Decision-making support system for track maintenance (궤도 유지관리 의사결정 지원 시스템 개발)

  • Lee, Jee-Ha;Rim, Nam-Hyoung;Yang, Shin-Chu
    • Proceedings of the KSR Conference
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    • 2003.10b
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    • pp.454-459
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    • 2003
  • The process of determining whether, when, where and how to intervene, of deciding on optimum allocation of resources and minimizing the cost is a very complex problem: different track sections tend to behave differently under the effects of loading; decision-making processes for maintenance work are closely interrelated technically and economically; decision-making for maintenance plans is based on a large quantity of technical and economic information, extensive knowledge and above all experience. For that reason, It is considered very important to develope objective and computer-aided decision-making support system for track maintenance plan. On this paper, we reviewed ECOTRACK system and present the plan of develope decision-making support system for track maintenance appropriate to local condition.

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Optimunm Allocation Modeling of Rural Facilities by Decision-Making Technique - With Special Reference to Agriculturaal-cum-Industrial Complex - (의사결정기법을 이용한 농촌지역시설 적정 입지선정 모델에 관한 연구 - 농공단지를 중심으로 -)

  • Kim, Yeong-Ju;Choe, Su-Myeong;Hwang, Han-Cheol
    • Proceedings of the Korean Society of Rural Planning Conference
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    • 1998.03a
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    • pp.17-20
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    • 1998
  • For efficient development of rural facilities, 4 step optimum locational decision model was developed using agricultural-cum-industrial complex as a representative one ; formulation of locational goal system, ranking tabulation on components, determination of their significance values, calculation of their scores. The application results of the model to 3 typical case study areas(peri-urban flat, mountainous, coastal areas) showed relatively good representation of their areal characteristics.

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