• 한국건설관리학회논문집
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• 제7권1호
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• pp.168-175
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• 2006

2005년 1월 민간투자법의 개정에 따라 전국적으로 44개 국공립 시설 뿐 아니라 사립대학을 중심으로 BTL사업의 발주가 급증하고 있다. 그러나 BTL사업은 시설의 기획, 설계, 시공, 운영 및 관리까지 포함하여 20여년 이상의 프로젝트 관리 과정을 대상으로 하는 포괄적 사업방식이다. 따라서 각 단계별로 다양한 리스크 인자들이 발생하게 된다. 그러나 사업제안단계에서 재무적 리스크를 정량적으로 분석할 수 있는 민감요인은 공사비, 차입금리, 할인율, 부대사업 임대료, 운영비용 등이 있다. 본 연구에서는 BTL사업 제안단계에서 사업에 영향을 미치는 리스크 요인들의 특성을 고찰하고 이 요인들이 사업성에 미치는 영향도를 분석하고 이에 대한 대응방안을 제시하는 것을 목적으로 한다.

• Journal of Nutrition and Health
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• 제39권8호
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• pp.832-840
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• 2006

This study was performed to investigate the relationship between diet quality and food cost and identify the effects of food cost on healthy diet among Korean adult. Among the subjects of 2001 National Health and Nutrition Survey 1,641 men and 1,765 women aged from 30 to 49 years were selected and their information of dietary intakes, socio-demo-graphic information, and anthropometric data were analyzed. For the analysis, subjects were classified to quartile based on their daily food cost. Food guidelines provided by Korean Nutrition Society was regarded as a model of healthy diet. Subjects in the lowest quartile of food cost consumed inadequate amount of food from all food categories of the guidelines. Many subjects in the highest quartile not only satisfied the recommended amount of the Food Guide but also seemed to overeat high energy density foods. Even in the highest quartile, about 90% of subjects did not satisfied recommended amount of dairy products. According to the calculated cost of healthy diet, the average cost did not seem to be more expensive than the current mean food cost of the subjects, and most cost-sensitive food intake was observed in the meat fish beans eggs category. The implications of study results were: 1) all the high cost diets did not indicate the high quality of diet, 2) most practical matter of healthy diet in low income group seemed whether they could afford the expense of meat and fish, 3) nutrition education was required to most subjects for healthy diet.

• 경영과학
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• 제28권2호
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• pp.17-29
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• 2011

The purpose of this paper is to schedule elective surgery patients using a stochastic programming approach and to illustrate how operating room utilization behaves when a decision-maker varies costs associated with utilization. Because of the uncertainty in surgery durations, the underage and overage costs that a decision-maker considers plays an important role in allocating surgery cases into available operating room capacity. We formulate the problem as a stochastic mixed integer programming and propose a sampling-based approximation method for a computational purpose. Newsvendor model is employed to explain the results from numerical experiments that are conducted with the actual data from a hospital. The results show that the operating room utilization is more sensitive when the unit overtime cost is relatively larger than the unit cost for underutilized time.

• 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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.603-605
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• 2005

In this paper, we deal with a calibration method for low cost motion capture sensor using PSD (Position Sensitive Detection). The PSD sensor is employed to measure the direction of incident light from moving markers attached to motion body. To calibrate the PSD optical module, a conventional camera calibration algorithm introduced by Tsai. The 3-dimensional positions of the markers are measured by using stereo camera geometry. From the experimental results, the low cost motion capture sensor can be used in a real time system.

• 한국기계가공학회지
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• 제4권4호
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• pp.34-38
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• 2005

This is a widespread requirement for low cost lightweight thermal imaging sensors for both military and civilian applications. Today, a large number of uncooled infrared detector developments are under progress due to the availability of silicon technology that enables realization of low cost IR sensor. System prices are continuing to drop, and swelling production volume will soon drive process substantially lower. The feasibility of micromechanical optical and infrared (IR) detection using microcantilevers is demonstrated. Microcantilevers provide a simple Structurefor developing single- and multi-element sensors for visible and infrared radiation that are smaller, more sensitive and lower in cost than quantum or thermal detectors. Microcantilevers coated with a heat absorbing layer undergo bending due to the differential stress originating from the bimetallic effect. This paper reports a micromachined silicon uncooled thermal imager intended for applications in automated process control. This paper presents the design, fabrication, and the behavior of cantilever for thermomechanical sensing.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.31-34
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• 2007

Fuel cell with high electric efficiency has many probabilities of commercial use. Especially, polymer electrolyte or proton exchange membrane fuel cell (PEMFC) which is a low operating temperature and has less influence on $CO_2$ concentration is considered the power generation system of small building and household. We calculated the optimal operational plans of 1 kW household PEMFC power system based on daily electric and heat demand patterns of various size of apartments. Calculated results show that the economic feasibility of PEMFC power system is very sensitive to the cost policy of electricity and natural gas.

• 상하수도학회지
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• 제12권4호
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• pp.33-42
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• 1998

The optimum design and preliminary cost estimations of air stripping towers ASTs with granular activated carbon adsorption (GAC) systems as the off-gas treatment were done and compared to liquid-phase GAC system. The optimum design and preliminary cost estimations were done for either single or multicomponent systems. A computer program was developed for this study. 15 single compounds and their multicomponent systems were studies. Even with off-gas treatment, AST was generally a less expensive process for treatment of volatile organics than liquid-phase GAC system. Treatment costs of small systems were sensitive to system capacity. Accumulative effect of treatment costs was found in multicomponent systems. The cost of a multicomponent system was highly dependent on the least strippable component in ASTs even with gas-phase GAC or the least adsorbable component in liquid-phase GAC system.

• 한국신뢰성학회지:신뢰성응용연구
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• 제18권2호
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• pp.104-113
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• 2018

Purpose: This paper proposes the non-periodic preventive maintenance policy based on the level of cumulative hazard intensity. We aim to construct a cost-effectiveness on the proposed model with relaxing the constraint on reliability. Methods: We use the level of cumulative hazard intensity as a condition variable, instead of reliability. Such a level of cumulative hazard intensity can derive the reliability which decreases as the frequency of preventive maintenance action increases. We also model the imperfect preventive maintenance action using the proportional age setback model. Conclusion: We provide a numerical example to illustrate the proposed model. We also analyze how the parameters of our model affect the optimal preventive maintenance policy. The results show that as long as high reliability is guaranteed, the inefficient preventive maintenance action is performed reducing the system operation time. Moreover, the optimal value of the proposed model is sensitive to changes in preventive maintenance cost and replacement cost.

• 한국농공학회논문집
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• 제55권2호
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• pp.9-20
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• 2013

Many studies have reported additional treatment is needed to use wastewater for agricultural purpose. Economic considerations should be taken into account to establish infrastructure for agricultural reuse because of a large amount of water use in irrigation and relatively low water quality requirement. The objective of this study was to conduct economic analysis of wastewater reclamation and reuse systems for agriculture. A system dynamics approach considering complexity and dynamics in the wastewater reuse systems was used for the economic analysis, which are related with social, environmental, and economic problems. Sensitivity and benefit cost analysis for wastewater reuse systems was conducted through the established economic assessment model. The result of sensitivity analysis showed that water resources development and installation cost were the most sensitive for total benefits and costs, respectively. The scenario-based test of the organized economic assessment model shows marginal cost ranges and enables decision-makers to decide reasonable cost for the wastewater reuse systems for agriculture.