• Korean Journal of Construction Engineering and Management
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• v.5 no.3 s.19
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• pp.153-165
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• 2004

Most engineering tasks require collaboration between many users in major hospital construction projects that have many reconstructions. Loss and change orders occurred in factors such as information exchange, misunderstandings, advanced technology in hospital projects. Moreover, changes in context, costs, requirements, deadlines, etc. require negotiation of issues that may modify important project characteristics. The objective of this paper is to reduce reconstruction for the pre-construction process of hospital projects, reconstruction factors were analyzed in recent hospital construction project the system was established in order to solve reconstruction factors, and this system was validated through applying to the real project. Therefore it is a major challenge to make high level of communication and to have mutual understanding.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.246-250
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• 2004

국내 수자원의 지역적 불균형으로 가뭄 시 해안 지역은 제한급수지역의 대부분을 차지하였다(건교부, 2001). 또한 해안지역의 평균 상수도 보급률은 $40\%$대로서 전국 평균 $87.1\%$(환경부, 2001)의 절반 정도이다. 실제로 해안지역의 지하수 이용량은 전국 지하수 이용량 약 31억$m^3$/년(수자원공사, 2002)의 약 $21\%$를 차지하고 있지만, 1인당 지하수 이용량은 전국 평균 $65m^3$의 4배에 달하는 것으로 조사된 바가 있다(홍성훈, 2003). 즉, 용수공급원의 부족으로 해안지역에서는 지하수에 대한 의존도가 높으며, 이로 인해 해안 지역에서 무분별한 지하수 개발과 그로 인한 해수침입 등의 환경 장애와 더불어 폐공 발생수가 증가하고 있는 실정이다. 따라서, 이런 문제점들과 해안지역을 고려한 지하수의 지속적 확보가 절실히 필요하다. 국외 인구동향을 보면 밀도류나 해수침투와 같은 해안지역 특성을 고려한 지하수 최적개발 모델이 개랄 또는 적용되어지고 있다. 하지만 해안지역 지하수 개랄 및 관리에서 요구하는 다양한 충족조건 내신 하나의 목적함수(예를 들어 최적 양수량, 최적 비용 등)만을 고려하고 있다. 그렇지만 실제적인 문제에서는 어느 위치에서 얼마만큼 개발되어야 하는지를 고려해야만 한다. 따라서 본 연구에서는 관정의 최적 개발량과 치적 위치라는 두개의 최적해를 고려할 수 있는 최적 양수모델을 제시하고, 실험실 수리모형에서의 검증을 소개하고자 한다. 또한 해안 지하수의 지속적 확보를 위한 방안을 제시하고자 한다.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.1
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• pp.34-36
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• 1997

In this paper, we introduce the design method using CAE(Computer Aided Engineering) which is profitable in the compatibility and standardization of the developed product and the reduction of construction time and price to develop and design a machine equipment. Particularly, we select the standard model to design or develop from the large machinery to the super precision one, extract the peculiar characters of the model by the close analysis of the physical and technical part, can predict the previous result of experimental characteristics on objective dimensions through the analogical mathematical analysis, and can induce the design model demanded by user investigating optimal data in advance. We present the analogical algorithms and process method of design factors and restriction factors in the systematization design with computer. Then we analyze step functions for each systematization equipment and induce the process of technical data with actuator model.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.339-342
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• 2010

Doosan Heavy Industries & Construction Co., Ltd. constructed a gas turbine engine test cell to verify operating characteristics and design parameters of 5MW class gas turbine engine for power generation under developing. Engine test cell was designed to satisfy critical requirements to scrutinize all performance parameters of the engine with safe and reliability in accordance with design specification. As the test cell developed can effectively reproduce engine operation conditions covering from start-up to maximum power condition, it can be utilized to make a continuing design improvement of the engine based on practical test data at full stretch. Moreover, it is expected to be serviceable to develop derivative engines and be utilized to put them into serial production and contribute to a competitiveness reenforcement as a gas turbine engine manufacturer.

• Magazine of the Korea Concrete Institute
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• v.10 no.4
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• pp.101-111
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• 1998

This study presents test results of RC beams strengthened by carbon fiber sheet(CFS), carbon fiber reinforced plastics(CFRP) or glass fiber reinforced plastics(GFRP) for increasing shear resistance. Nineteen specimens were tested, and the test was performed with different parameters including the type of strengthening materials(CFS, GFRP, CFRP), shear-strengthening methods(wing type, jacket type, strip type), strip-spacing, strengthening direction of FRP. The test results show that shear-damaged RC beams strengthened by FRP(CFS, GFRP, CFRP) have more improved the shear capacity. The mathematical model based on plastic theory was also developed to predict shear strength of shear-damaged RC beams strengthened by FRP. The predictions using the mathematical model. are agreed with the observations from the observed shear strengths for 19 test beams.

• Construction Engineering and Management
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• v.12 no.6
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• pp.36-48
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• 2011

도로건설프로젝트에서의 VE는 도로시설물의 기능을 향상시키고 비용을 절감하기 위한 방법으로 지금까지 널리 활용되고 있다. 그러나, 실제 건설VE 실무에서는 VE Job Plan 중 일부 단계가 생략되거나 형식적으로 수행되는 문제점이 발생되어 VE 수행결과에 대한 신뢰성에 의문이 제기되고 있다. 이는 제조업과 달리 대규모이며 복합공종을 갖는 건설프로젝트의 특성을 반영하지 못하고 있기 때문이다. 건설프로젝트는 대규모 복합공종으로 구성되어 복잡하고 다양한 기능 및 요구성능이 있으며, 시설물이 갖는 기능(Function)과 요구성능(Required Performance)의 일부는 반복적으로 발생하는 특징을 가지고 있다. 이에 본 연구에서는 VE Process의 실효성을 높이기 위하여 품질모델(Quality Model)과 기능분석(Function Analysis)단계에서 이러한 특징을 반영한 개선방향을 제시하고, 수차례 실무 검증을 통하여 적용성 및 효율성을 확인하였다. 이와 더불어 고속도로 VE Job Plan은 고속도로 설계 업무절차에 부합하도록 개선하여 VE 수행효과가 극대화 되도록 제안하였으며, 또한 한국도로공사에서 시행하는 고속도로 대한 VE절차를 "Hi-Value"라 명명하고 실무활용성, 효율성을 확대하고 지속적으로 발전시켜 나아갈 계획이다.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.5
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• pp.413-419
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• 2004

In the induction motor direct vector control system using the Gopinath model flux observer, the deterioration of the dynamic response due to the detuned rotor time constant is investigated. To solve this problem, the on line estimation algorithm of the rotor time constant using model reference adaptive control is proposed. The effect of the motor parameter variation on the rotor time constant estimation is analyzed through experiment. The estimation error due to the parameter variation converges within 5%. Thus applying the proposed algorithm to the Gopinath model flux observer, the robust direct vector control system of the induction motor to the parameter variation can be implemented.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.5
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• pp.593-598
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• 2005

The standard Kalman filter has been used to estimate the states of the target, but in the presence of a maneuver, its error is occurred and performance may be seriously degraded. To solve this problem, this paper presents a new intelligent tracking algorithm using the fuzzy Kalman filter. In this algorithm, the unknown acceleration is regarded as an additive process noise by using the fuzzy logic based on genetic algorithm(GA) method. And then, the modified filter is corrected by the new update equation method which is a fuzzy system using the relation between the filter residual and its variation. To shows the feasibility of the suggested method with only one filter, the computer simulations system are provided, this method is compared with multiple model method.

• Journal of the Korea Society for Simulation
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• v.25 no.4
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• pp.1-12
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• 2016

The industry producing the parts of aircraft engines is a traditional order-made system with highly variety and small quantity, and the manufacturing system is the typical job shop with identical or non-identical multiple machines in a workstation. Furthermore, there are many alternative operations and alternative machines allowed in machining processes, and tremendous routings and assembly operations should be considered. Usually simulation is the most efficient technology to analyze such a complex system, and high modeling skills are required for developing the simulation models. In this paper, a case study on a company which produces the parts of aircraft engines is introduced, specially focused on simulation modeling methodologies for the complex system.

• Composites Research
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• v.32 no.1
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• pp.56-64
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• 2019

In this paper, a model is developed to simulate carbon/carbon composite fabrication using chemical vapor infiltration, considering density and porosity change in the preform and multi-step hydrocarbons reactions. The model considers the preform as a porous medium whose diffusion and flow properties changes due to the porosity. To verify the theoretical model, two numerical analyses were performed for the case that the flow inside the preform is zero and the case that the flow inside the preform is calculated by fluid mechanics. The numerical results showed good agreement with the experimental data.