• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권8호
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• pp.1913-1925
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• 2012

In order to efficiently utilize limited radio resources, resource allocation schemes in OFDMA-based wireless networks have gained intensive attention recently. Instead of improving the throughput performance, the utility is adopted as the metric for resource allocation, which provides reasonable methods to build up the relationship between user experience and various quality-of-service (QoS) metrics. After formulating the optimization problem by using a weighted bipartite graph, a modified bipartite matching method is proposed to find a suboptimal solution for the resource allocation problem in OFDMA-based wireless systems with feasible computational complexity. Finally, simulation results are presented to validate the effectiveness of the proposed method.

• 품질경영학회지
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• 제33권1호
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• pp.64-72
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• 2005

The ever increasing demand for enhanced competitiveness of engineered products requires "designing-in-quality" strategies that can effectively and efficiently incorporate concepts of uncertainty and quality into design. Multi-attribute utility function is commonly used to represent the decision-maker's preference on multiple design attributes under conditions of uncertainty and risk. One of the major issues in implementing this approach concerns the generation of appropriate utility function, especially in a complex engineering design environment. Typically, the decision maker's preference is revealed through lottery questions rather than being structured on the deductive reasoning to reflect the nonlinear tradeoffs among the attributes. The use of such intuitive procedures can lead to inexact preference information that may result in inaccuracy and rank reversal problems. This paper presents an alternative procedure based on the pair-wise comparisons between design alternatives towards a consistent preference presentation in assessing multiplicative utility function. The effectiveness of the overall procedures is tested with the aid of an injection-molding process design for a capacitor can and the results are discussed.

• 대한간호학회지
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• 제34권3호
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• pp.449-457
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• 2004

Purpose: The aim of this study was to analyze economical efficiency of home care service by comparing a cost-utility ratio(CUR) between home care and hospitalization. Method: The analytic framework of this study was constructed in 5 stages: Identifying the analytic perspectives, measurement of costs, measurement of utility, analysis of CUR, and sensitivity test. Data was collected by reviewing medical records, home care service records, medical fee claims, and other related research. Result: The mean of the annual total cost was 23,317,636 Won in home care and 73,739,352 Won in hospital care. QALY was 0.389 in home care and 0.474 in hospital care, so CUR was 299,712,545 QALY in home care and 777,841,266 QALY in hospital care. Conclusion: The findings affirmed that home care had an economical efficiency in the aspect of utility compared to hospitalization. Therefore, the findings of this study can be used to develop a governmental health policy or to expand the home care system. In addition, the cost-utility analysis framework and process of this study will be an example model for cost-utility analysis in nursing research. Therefore, it will be used as a guideline for future research related to cost-utility analysis in nursing.

• 한국산학기술학회논문지
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• 제19권3호
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• pp.260-266
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• 2018

고객의 기술 채택에 영향을 미치는 고객효용도의 개념에 대한 이해는 다세대 기술의 확산 및 대체 과정을 이해하는데 중요하다. 본 연구에서는 다세대 기술의 속성 기반 고객효용도의 개념에 대해 정의하고, 고객효용도를 측정할 수 있는 모형을 개발하였다. 문헌리뷰 및 모형화를 바탕으로 다세대 기술의 속성 기반 고객효용도에 대해 정의 및 측정 모형을 제시하였고, 도출한 모형의 정합성을 반도체 산업 사례를 바탕으로 검증하였다. 다세대 기술에서 속성 기반 고객효용도는 세대별로 또는 같은 세대 내에서 시간별 변화를 고려해야하고, 기술적 속성과 경제적 속성에 대해 가중치를 고려한 모든 효용도들의 합으로 정의된다. 또한 속성 기반 고객효용도는 효용도 변환표를 통해 속성들의 값을 효용도로 전환한 후 가중치를 고려한 모든 속성들의 효용도의 합으로 모형화 가능하다. 본 연구를 통해 다세대 기술이 확산 및 대체되는 과정에서 고객의 기술 채택의 근본 동인으로서 영향을 미치는 고객효용도에 대해 이해 가능하고, 고객효용도를 바탕으로 확산 및 대체 경로를 예측하여 기술전략을 수립하는데 유용할 것이다.

• 한국항만학회지
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• 제9권1호
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• pp.33-43
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• 1995

Korean economic and industrial structure has been seperated into some areas with the trend of the change to the bloc system of international economy: the Gyeongin including the capital area, the Middle-West, the South-West, the South-East, and the Eastern sea areas. Mokpo port has played a major role as the central one of the South-West area and the entrance of Yeong-san river of Jeonnam province gate. Some studies has been done on the Mokpo port, but there is no research of the analytical approach about it. In this paper, we analyze the data of 1994's on the domestic and oceangoing piers in the Mokpo port and simulate the transportation process of it through a queueing model. The results of the simulation are summarized as follows: The average arrival interval of the domestic vessel is 6.034 hours. The average service time and the berth utility rate are 24.056 hours and over 100%, respectively. The average arrival interval of the oceangoing vessel is 34.48 hours. The average service time and the berth utility rate are 120.04 hours and the 34.91%, respectively. The proposal to improving of the Mokpo port as follows: It is desirable to extend the capacity of domestic pier to about 50% for the optimal utility rate of 70% and in the case of oceangoing pier to be increase 65% of the vessel capacity for the optimal utility rate of 70%.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 제17회 워크샵 및 추계학술대회
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• pp.665-665
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• 2005

The existing DSP for utility interactive photovoltaic generation system control generally uses floating point process type. Because it is easy to use for number crunching, however, it is too late and too expensive. Fixed point process DSP TMS320F2812, has high control speed and is rather inexpensive. A very complicated real system can be simulated using hardware-in-the-loop (HIL) system in a virtual environment Therefore, HIL system can speed up research and development process with a little effort. Also current DSP for utility interactive photovoltaic generation system adopts floating point process type, which is easy to use for number crunching. However, fixed point process DSF, TMS320F2812, has high control speed and is rather inexpensive. This paper presents more efficient method for MPPT control using TMS320F2812 along with HIL System.

• 대한수학회보
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• 제56권6호
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• pp.1467-1483
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• 2019

This paper analyzes a robust optimal reinsurance and investment strategy for an Ambiguity-Averse Insurer (AAI), who worries about model misspecification and insists on seeking robust optimal strategies. The AAI's surplus process is assumed to follow a jump-diffusion model, and he is allowed to purchase proportional reinsurance or acquire new business, meanwhile invest his surplus in a risk-free asset and a risky-asset, whose price is described by an Ornstein-Uhlenbeck process. Under the criterion for maximizing the expected exponential utility of terminal wealth, robust optimal strategy and value function are derived by applying the stochastic dynamic programming approach. Serval numerical examples are given to illustrate the impact of model parameters on the robust optimal strategies and the loss utility function from ignoring the model uncertainty.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권8호
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• pp.3606-3629
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• 2018

The discovered high potential utility itemsets (HPUIs) have significant influence on a variety of areas, such as retail marketing, web click analysis, and biological gene analysis. Thus, in this paper, we propose an algorithm called HPUIM-QGA (Mining high potential utility itemsets based on a quantum genetic algorithm) to mine HPUIs over uncertain datasets based on a quantum genetic algorithm (QGA). The proposed algorithm not only can handle the problem of the non-downward closure property by developing an upper bound of the potential utility (UBPU) (which prunes the unpromising itemsets in the early stage) but can also handle the problem of combinatorial explosion by introducing a QGA, which finds optimal solutions quickly and needs to set only very few parameters. Furthermore, a pruning strategy has been designed to avoid the meaningless and redundant itemsets that are generated in the evolution process of the QGA. As proof of the HPUIM-QGA, a substantial number of experiments are performed on the runtime, memory usage, analysis of the discovered itemsets and the convergence on real-life and synthetic datasets. The results show that our proposed algorithm is reasonable and acceptable for mining meaningful HPUIs from uncertain datasets.

• 한국터널지하공간학회 논문집
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• 제20권2호
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• pp.317-329
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• 2018

기존의 공동구에 관한 연구에서는 공동구 내부의 수용시설물들의 최적설계 및 타당성 분석 보다는 공동구 설치와 관련된 전반적인 사항에 대하여 검토 하였다. 공동구 도입과 관련된 기본계획 단계에서의 관련 지표 및 자료 등의 부족으로 수용시설물을 결정하기가 어려운 한계점을 해결하고자, 본 논문에서는 공동구 내 수용시설물의 최적 대안 결정을 위하여 VE/LCC 분석 방법을 제시하였다. 개별 수용시설물의 항목에 대한 분석 및 LCC 비용에 대한 가치지수를 종별 대안에 적용하여 검토 하였으며, 각 종별 우선순위를 분석하였다. 또한, 국내 공동구와 각 종별 시설물의 분석된 결과를 비교하였으며, 본 연구의 결과는 공동구의 도입 시에 최초 설계자를 포함한 사용자들이 수용시설물을 결정하는 과정에서 소요되는 시간을 단축하고 편의성을 높이는데 도움이 될 것으로 판단된다.

• 지능정보연구
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• 제18권4호
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• pp.79-95
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• 2012

금융기관들에서 개발한 신용 대출 상품이 증가함에 따라 사기 거래의 수 또한 급속히 증가하고 있다. 따라서, 재정적 위험을 성공적으로 관리하기 위해 금융기관들은 대출 승인 심사를 강화하고 신용 대출 사기를 사전에 탐지할 수 있는 능력을 증대시켜 나가야 한다. 신용 대출 사기를 탐지하기 위한 분류 모델을 구축하는 과정에서 분류 결과에 따른 유틸리티(즉, 정분류에 따른 이익과 오분류에 따른 비용)는 분류의 정확도보다 더 중요하다. 본 연구는 개인별 유틸리티에 기반하여 신용 대출 사기를 탐지하기 위한 분류 모델을 구축하는 것을 목적으로 하였다. 다양한 실험을 통해, 본 연구에서 제시한 모델이 기회 유틸리티와 현금 흐름의 두 관점 모두에서 개인별 유틸리티에 기반하지 않은 모델보다 더 높은 유틸리티를 제공하며, 평균 유틸리티에 기반한 모델보다 더 정확한 유틸리티를 제공한다는 것을 보였다. 본 연구는 기회 유틸리티와 현금 흐름의 두 관점에서 얻어진 실험 결과를 다양한 측면에서 살펴보았다.