• 한국농공학회논문집
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• 제50권6호
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• pp.75-81
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• 2008

The purpose of this study was to develop an optimum equipment model considering various objective functions and variables of agricultural reservoir. Traditional optimum function for feasibility assessment is based on economic benefit, but we tried new approach of feasibility assessment based on the number of beneficiary. The data of Yuraimi reservoir and Yongbong reservoir in Yesan-gun such as numbers of related people, construction costs, safe diagnosis have been gathered for applying developed model. Data are used for determining optimum strategy with restricted cost. For verifying results of optimum maintenance, real maintenance data of Yuraimi reservoir were compared with simulated strategy. Results show that simulated maintenance strategies are 3 times more effective than real maintenance data.

• Korea-Australia Rheology Journal
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• 제21권4호
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• pp.289-297
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• 2009

We numerically analyzed flow characteristics of the polymer melt in the screw equipment using a proper modeling and investigated design parameters which have influence on the mixing performance as the capability of the screw equipment. We considered the non-Newtonian and non-isothermal flow in a single rotor equipment to investigate the mixing performance with respect to screw dimensions as shape parameter of the single rotor equipment and screw speed as process parameter. We used Bird-Carreau-Yasuda model as a viscous model of the polymer melt and the particle tracking method to investigate the mixing performance in the screw equipment and considered four mixing performance indexes: residence time distribution, deformation rate, total strain and particle standard deviation as a new mixing performance index. We compared these indexes to determine design parameters and object function. On basis of the analysis results, we carried out the optimal design by using the response surface method and design of experiments. In conclusion, the differences of results between the optimal value and numerical analysis are about 5.0%.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.226-230
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• 2013

In the tall building construction, the slab formwork largely impacts on construction cost. Because productivity of a slab formwork is influenced by a number of and the efficiency of equipment, using the equipment-based construction method, an appropriate equipment input planning is crucial for the productivity. Meanwhile, the general equipment input planning is conducted by intuition based on experience due to the lack of equipment productivity data. Thus, this study develop a simulation model to analyze table formwork productivity and to propose an optimum equipment input plan that reflects the construction process, based on the full consideration of the economic factors. This study developed a simulation model by using CYCLONE and the data for the model was collected by measuring the duration of each unit activity in the tall building where table forms were applied. It is expected that a simulation model helps users to make better decision on the equipment input planning of slab formwork.

• 한국농공학회논문집
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• 제62권3호
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• pp.63-69
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• 2020

Recently, the Yedang reservoir needs reflecting the demands of the public and administration, including change of reservoir status and paradigm shift of users, as well as planning programs to activate the area as a special health zone for tourism, leisure, recreation and experience at the local government level. Previous Optimum Equipment model (OEM) preferentially considers the creation of waterfront. This study shows the operation model for readjustment of water supply facilities according to the limit of the level of the beneficiaries. Results show the renovation cycle of Yedang tourist resort and the suspension bridge through developed model simulation. In addition to securing quantity for the supply of agricultural water and the function of water protection, the multi-function of the agricultural reservoir shall be re-evaluated to enhance the diverse availability of the agricultural reservoir. The county office should also boost various availability at various levels to revitalize the local economy, such as producing pleasant and safe places and offering safe food for people.

• 한국안전학회지
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• 제21권1호
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• pp.1-5
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• 2006

The damage of important equipments for the nuclear power plant by the earthquake brings the loss of human lives and economic losses. Therefore safety-related equipment of nuclear power plant must be proved that function must be designed and structural integrity so that it can be maintained also from accident condition of various kinds. In this study, the computer room air conditioner to be delivered at the nuclear power plant applied to this qualification, try to develop an optimum model. This model ended up with good results which were under suitably allowable conditions about structurally safe earthquake.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2006년도 정기학술발표대회 논문집
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• pp.467-470
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• 2006

모든 건설공사의 기초를 이루는 토공사는 건설기계의 사용으로 오늘날까지 많은 발전을 이루어 왔으나, 공기단축 및 원가절감에 있어 중요한 요소인 토공장비의 적정한 조합시공방안이 체계적으로 정립되어 있지 않고 경험에 의존하여 수행되는 상태로 관련분야에 대한 체계적인 연구가 필요한 실정이다. 합리적인 기계화 토공은 공사에 투입될 장비의 성능 및 특성, 공사의 종류, 규모 및 주위의 여건 등을 사전에 철저히 파악해야 하며, 사용 가능한 몇 가지 규격의 장비를 선정하여 최적조합시공을 계획해야 한다. 이에 본 연구에서는 시스템 다이내믹스 기법을 활용하여 토공작업의 여러 단계 중 기계화 토공장비의 굴착 후 적재 및 운반단계를 대상으로 토공장비의 최적조합시공에 의한 토공량 산정 모형을 구축한다. 이 연구의 결과로 도출되는 토공장비의 최적조합시공모형은 토공계획을 담당하는 관리자가 토공장비의 선정에 있어 최단시간에 합리적인 판단을 하게 해줄 것으로 기대된다.

• Structural Engineering and Mechanics
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• 제31권1호
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• pp.11-24
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• 2009

In China, the oil and natural gas resources of Bohai Bay are mainly marginal oil fields. It is necessary to build both ice-resistant and economical offshore platforms. However, risk is involved in the design, construction, utilization, maintenance of offshore platforms as uncertain events may occur within the life-cycle of a platform under the extreme ice load. In this study, the optimum design model of the expected life-cycle cost for ice-resistant platforms based on cost-effectiveness criterion is proposed. Multiple performance demands of the structure, facilities and crew members, associated with the failure assessment criteria and evaluation functions of costs of construction, consequences of structural failure modes including damage, revenue loss, death and injury as well as discounting cost over time are considered. An efficient approximate method of the global reliability analysis for the offshore platforms is provided, which converts the implicit nonlinear performance function in the conventional reliability analysis to linear explicit one. The proposed life-cycle optimum design formula are applied to a typical ice-resistant platform in Bohai Bay, and the results demonstrate that the life-cycle cost-effective optimum design model is more rational compared to the conventional design.

• 한국국방경영분석학회지
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• 제34권3호
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• pp.41-51
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• 2008

현대전에 있어서 첨단 정밀 고가장비가 전투력에 미치는 영향은 지대하다. 그러나 평상시 지속적인 정비활동이 이루어지지 않으면 장비가동률은 저하되고 유사시 목표하는 전투력 발휘효과는 기대하기 어려울 것이다. 따라서 적정 장비유지비 소요를 예측하여 예산에 반영하는 것은 전투준비태세 완비를 위해서 필수적인 과제라 하겠다. 본 연구에서는 K-111 1/4톤 기동장비의 야전 운영 실적자료를 분석하여 장비유지비 발생추세를 분석하고, 이 분석 결과를 기초로 장비유지비 예측모델을 설계하였으며, 이 예측모델을 적용하여 장비유지비 소요 예측 기법과 향후 발전 방향에 대한 제언을 제시하였다.

• 경영과학
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• 제34권2호
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• pp.103-113
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• 2017

The artillery is a key element of the ground forces operation during wartime, and the military engineers support the artillery position development operation to support the smooth operation of the artillery. In establishing the artillery position development operation plan, the commander requires more than his intuition to find the best option reflecting a number of elements of the battlefield situation which changes every minute. Moreover, the number of available equipment is smaller than the number of required position developments, and the effective equipment operation becomes essential element of this issue. This study quantified the capability of the available engineering equipment, organized a number of teams enabling equipment to put out the maximum capacity based on the quantified figures, and formed the model which allocates the team to the developing points to minimize the developing time. The goal programming method was applied to resolve the problem. The developed model was applied to compare the total mission duration following the number of teams, the variable for commander's decision, and the result of this study can be used as the quantitative data for commander's decision making process in establishing the artillery position development support operation through effective equipment management.

• Journal of Electrical Engineering and Technology
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• 제6권1호
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• pp.25-31
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• 2011

The purpose of power system maintenance is to prevent equipment failure. The maintenance strategy should be designed to balance costs and benefits because frequent maintenance increases cost while infrequent maintenance can also be costly due to electricity outages. This paper proposes maintenance modeling of a power distribution system using reliability centered maintenance (RCM). The proposed method includes comprehensive equipment modeling and impact analysis to evaluate the effect of equipment faults. The problem of finding the optimum maintenance strategy is formulated in terms of dynamic programming. The applied power system is based on the RBTS Bus 2 model, and the results demonstrate the potential for designing a maintenance strategy using the proposed model.