• 융합보안논문지
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• 제13권5호
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• pp.97-105
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• 2013

국가에서 추진하는 모든 프로젝트는 예산이라는 변수에 영향이 크다. 정확한 소요예산 판단불가로 프로젝트 추진 중에 추가적인 예산소요가 발생하여 사업의 중단 혹은 재검토 사례가 빈번히 발생하고 있다. 이는 프로젝트 소요제기단계 및 이를 획득하기 위한 선행연구단계에 제시된 시스템요구사항의 평가와 소요예산의 부정확성으로 기인한다고 평가된다. 시스템요구사항은 사용자가 작성하는 사용자 요구사항과 구별하여 사용자 요구사항을 바탕으로 획득조직에서 시스템의 기술적 요구사항으로 전환하는 것을 말하며 획득조직과 개발자 혹은 제작자 사이에 의사소통을 위한 것이다. 시스템 요구사항 수준은 프로젝트 규모를 결정하는데 중요한 요소로, 시스템요구사항에 대한 비용측면의 적정성 확인은 필수적이다. 그러나 프로젝트 비용요소가 복잡하고 각 요소별로 기준이 상이하여 비용추정이 쉽지 않고 추정된 비용의 오차율도 커서 활용에 어려움이 있었으며, 특히 시스템요구사항을 도출하는 프로젝트 초기단계에는 프로젝트와 관련된 세부자료의 부족으로 비용추정에 어려움이 있었다. 본 연구에서는 요구공학과 비용추정방법에 대한 이론적인 근거를 바탕으로 시스템요구사항 도출 후 비용추정방법을 활용하여 적정성을 검증하고 대안을 비교 후 최적안을 선정하는 아키텍처를 솔루션으로 제시하였고, 이를 위하여 활용 가능한 모수비용추정방법(Parametric Cost Estimating)를 토대로한 비용추정 전산도구인 SEER Cost-IQ를 소개하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.387-390
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• 2008

The importance of the life cycle cost analysis for construction projects of bridge has been recognized over the last decades. Accordingly, theoretical models, guidelines, and supporting softwares have been developed for the life cycle cost analysis of bridges. However, it is difficult to predict life cycle cost considering uncertainties precisely. This paper presents methodology for optimal design of substructure for a steel box bridge. Total life cycle cost for the service life is calculated as sum of initial cost, damage cost considering uncertainty, maintenance cost, repair and rehabilitation cost. The optimization method is applied to design of a bridge substructure with minimal cost, in which the objective function is set to life cycle cost and constraints are formulated on the basis of Korean Bridge Design Specification. Initial cost is calculated based on standard costs of the Korea Construction Price Index and damage cost on the damage probabilities to consider the uncertainty of load and resistance. An advanced first-order second moment method is used as a practical tool for reliability analysis using damage probability. Maintenance cost and cycle is determined by a stochastic method and user cost includes traffic operation costs and time delay costs.

• 한국건설관리학회논문집
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• 제17권5호
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• pp.54-61
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• 2016

건설프로젝트에서는 초기에 계획된 년차별 사업비가 공사 수행과정에서 빈번히 조정된다. 년차별 사업비가 초기 계획보다 감소되면 수행가능한 공정도 초기 공정계획대비 감소하게 되므로, 변동 사업비 내에서 수행가능한 적정한 공정을 재수립하여야 한다. 그러나 대다수 현장에서는 공정 재수립 없이 당초계획대로 공정을 진행하면서 사업비가 소진되면 현장 작업을 쉬는 경우가 많다. 이에 본 연구에서는 변동된 사업비 내에서 적정 공정계획을 재수립하고, 재수립된 일정에 따라 비용투입현황을 시각화하는 능동형 5D CAD 시스템을 개발한다. 이는 공정계획 재수립을 위한 의사결정 지원도구로 활용될 수 있고, 기존의 단순 시각적 정보제공에 중점을 둔 5D CAD시스템의 실무 적용성을 높일 수 있을 것이다.

• 설비공학논문집
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• 제25권10호
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• pp.534-539
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• 2013

In general, entire supply air of the BSL3 laboratory should be vented to the outside for its biosafety and the air conditioning system should always be operating to maintain a room pressure difference. In this regard, annual energy consumption is approximately five or ten times greater than the magnitude of the office building. In addition, to adjust room pressure difference to the set value efficiently, the supply and exhaust duct system are installed in each room of the BSL3 lab. Thus, initial construction cost is extremely high. In this study, multizone simulation is performed to estimate maintaining the appropriate room pressure difference in the case of changing model A (each room supply and exhaust system) to model B (each zone supply and exhaust system) for verification of the BSL3 lab biosafety. Also, in the case of these two models, the multizone simulation for three kinds of biohazard scenario is performed as part of risk assessment. The analysis of initial construction cost of two models is conducted for comparison. According to the studies, initial construction cost of model B is less than about 22% of existing model A. Moreover, biosafety of the BSL3 lab is still maintaining in the case of the two models.

• 환경영향평가
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• 제21권6호
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• pp.927-939
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• 2012

Cool roofs are currently being emerged as one of important mechanism to save energy in relation to the building. Although green roof has already gained nation-wide recognition as a typical method of energy saving in the roof, this approach did not provide a realistic evidence that is economically feasible in terms of installation cost. This research is primarily intended to compare installation cost between the two techniques. This research proposes a comparative evaluation framework in a more objective and quantitative way for an installation cost between the two techniques. Kyungpook National University (KNU) was selected as a survey objective and an exhaustive and realistic comparison of installation cost between the two techniques was conducted, based on Life Cycle Cost analysis (initial investment cost, maintenance cost, dismantling and waste disposal expense). It was possible to identify that installation cost of cool roofs is 4.7 times cheaper than that of green roof. Also present value based on probabilistic approach was identified as 0.25 (4.95) higher than the installation cost on the assumption of constant price and interest. It is expected that much more installation cost for the large scale green roof will be required since small-size green roof selected as a survey objective in this study could be operated under less initial installation and maintenance condition.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 추계학술대회 논문집(I)
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• pp.684-689
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• 2002

This paper represents the life-cycle cost(LCC) of steel bridges which are located on the train-network. Corrosion problems are mainly considered in the steel members such as steel plate girder, box girder, truss and arch. Based on the current value, initial construction cost, maintenance cost and demolition cost are calculated and life-cycle costs are formulated for the several types of bridges. From the comparison on each LCC, an effective painting method is recommended for reducing the LCC of steel bridges. Even though the initial cost of Super Weather Resistance Heavy Duty Paintings (Resin Fluoride) is expensive, because of the long endurance, the LCC of steel bridges painted with Super Weather Resistance Heavy Duty Paintings (Resin Fluoride) is less than that painted with General Heavy Duty (Rubber Chloride).

• 한국지열·수열에너지학회논문집
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• 제9권2호
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• pp.25-31
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• 2013

It has become very important for unused energy to be used for building air conditioning. Economic evaluation on energy system by using river water as a heat source, which is one of the unused energy, was carried out. The floor area of the building and the distance between heat source equipment and river was assumed $50,000m^2$ and 200 m. General heat source system using absorption chiller-heater was used for comparing to the energy saving system, and payback period method using initial cost and running cost of two systems, was used to perform economic evaluation. According to development of high capacity of water source heat pump which is appropriate for using river water, initial cost for the system has been reduced. Payback period was about 3.2 years, and this period might be shortened if nation's economic support enact.

• 농촌계획
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• 제26권4호
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• pp.67-79
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• 2020

As globalization, international cooperation has grown in importance. In accordance with this trend, Korea has been receiving high demands from international organizations about expanding the scale of Official Development Assistance(ODA) in line with its improved national status. In addition, in the economic aspect of Korea, the ODA project is expected to provide new growth opportunities in the mid- to long-term by promoting cooperation with developing countries. Uganda is an area with high strategic value due to good agricultural conditions and favorable geographical conditions. The poultry industry is a business that is generally carried out to the Ugandan, but due to economic problems such as initial investment cost, most of them have raised poultry on a small scale which is not enough for main income. This paper proposes the construction and operation plan of adapting to small poultry farms in the village-intensive type to sustainable income for residents in Uganda through ODA project in Korea's agricultural technology. The economic feasibility was analyzed from the long-term perspective when the initial construction cost was supported or not and the poultry species ratio was adjusted in terms of initial and operating costs. Economic analysis was performed using Net Present Value(NPV) method. As of after 10 years, when operating in the form of shifting kuroiler to layers, it was estimated to earn about 700,000 ugx more than when only kuroiler is raised, and it is able to reduce about 14 million ugx from the initial cost than when only raising layers. As of 20 years, the most profitables scenario was the breeding of 100 kuroilers and 400 layers methods. however, this case was anlayzed to be unsuitable for Uganda farmers, with initial costs more than three times higher than the shifting method of the kuroiler to layers. If the initial construction cost is supported by ODA project, the initial investment cost can be recovered in the first year with the shifting method, whereas raising only layers take two years to recoup the cost. In the meantime, when studying livestock industry in Uganda, it was examined by relying on statistical data, but this paper is meaningful in that it predicted how much it is economically effective based on field experience.

• Carbon letters
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• 제1권2호
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• pp.82-86
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• 2000

The present research was undertaken to evaluate the possibility of water purification filter with activated carbon fibers (ACFs) using a very low cost precursor consisting of phenolic resin coated on glass fibers. The simplified procedure involving coating, curing and activation and a very low cost glass fiber as a raw material were adopted in order to reduce manufacturing cost. The breakthrough curves of the manufactured ACFs and the commercial activated carbon (AC, Calgon F-200) were investigated in the initial concentration range from 19 to 49 ppm for benzene, toluene and ethylbenzene. From breakthrough profiles, the manufactured ACFs had significantly faster adsorption kinetics than the AC. Especially the benzene breakthrough curves, the manufactured ACF (13 g of ACF with 32% of carbon on the glass) was over the limited level (5 ppb) after flowing of 32 l at initial concentration of 15 ppm, while the commercial AC was shown about 3 ppm in initial adsorption.

• 대한산업공학회지
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• 제30권2호
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• pp.120-129
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• 2004

This paper provides a simple but effective method, cost relaxation to escape from a local optimum of the traveling salesman problem. We would find a better solution if we repeat a local search heuristic at a different initial solution. To find a different initial solution, we use the cost relaxation method relaxing the cost of arcs. We used the Lin-Kernighan algorithm as a local search heuristic. In experimental result, we tested large instances, 30 random instances and 34 real world instances. In real-world instances, we found average 0.17% better above the optimum solution than the Concorde known as the chained Lin-Kernighan. In clustered random instances, we found average 0.9% better above the optimum solution than the Concorde.