• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.475-480
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• 1998

계면면적 밀도는 two-fluid 모델에서 각 상 간의 상호작용에 영향을 주는 중요한 인자로서 이상유동 현상의 해석을 위하여는 이의 적절한 모델링이 필요하다. 계면면적 밀도의 모델링은 크게 상관식에 의존하는 방법론과 수송 방정식을 사용한 이론적인 접근방식으로 개발되어왔다. 후자는 시간적, 공간적으로 변하고 있는 동적 유동조건에 대하여 계면면적 밀도를 효과적으로 예측할 수 있는 방법론으로서 flow regime의 의존성을 줄이거나 없앨 수 있는 장점을 가진다. 계면면적 수송 방정식은 유체입자의 수밀도에 대한 수송 방정식의 통계적인 모델로부터 유도되며 입자들의 상호작용 및 상변화와 관련된 생성항을 포함하고 있다. 본 연구에서는 계면면적 밀도 수송 방정식 및 그 구성 모델들에 대한 연구현황을 정리하였다.

• Journal of Energy Engineering
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• v.21 no.2
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• pp.144-151
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• 2012

A district heating system produces thermal energy and supplies it to a large region. District heating systems can provide higher efficiencies and better pollution control than localized boilers. The heat generated by a district heating system is distributed to the customer via a network of insulated pipes. For the optimal operation of a district heating system, it is important to predict the distributions of pressure, flow rate and temperature of heating fluid within the network of pipes at various operating conditions. In this work, a mathematical modeling was performed to predict the dynamic hydraulic-thermal behaviors of heating fluid in the network of pipes for a district heating system. The mathematical model accounts for the conservations of mass, momentum and energy. In order to verify the validity of modeling, the modeling results were compared with the monitoring data of Gang-nam Branch of District Heating.

• Journal of the Korea Society of Computer and Information
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• v.7 no.2
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• pp.59-67
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• 2002

Major Characteristic of the 7th National Curriculum in science is to provide deep and supplementary learning, depending on the level of each learner. In the level-oriented curriculum, coursewares are used to present teaching materials to various levels. In most coursewares, however, they provide their contents at a uniform level and hence it is hard to expect level-oriented learning. This paper presents learner's modeling for developing student's level-oriented dynamic tutoring system for science class , Instructional module of this system made by component unit is able to be reconstructed dynamically. Learning module is constructed using a hybrid model mixed of Overlay and Bug model. Testing module interprets diagnostic errors to be established by given differentiated weight in accordance with item's difficulty and discrimination. Through ITS student modeling, this system presents various problem solving methods reconstructed by learner's level differentiated.

• Journal of KSNVE
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• v.26 no.2
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• pp.10-17
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• 2016

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1999.04a
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• pp.63-64
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• 1999

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.42 no.12
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• pp.34-39
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• 2013

• 한국도로학회:학술대회논문집
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• 2000.11a
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• pp.9-13
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• 2000

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.331-333
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• 2003

UML(Unified Modeling Language) 액티비티 다이어그램은 시스템의 동적인 측면을 표현하는데 적합하기 때문에 비즈니스 프로세스와 워크플로우를 모델링 하는데 유용하게 사용된다. 워크플로우 모델링은 이해하기 쉽고. 작업하기 쉬운 보편성을 갖고 있도록 개발되어져야 한다. 또한 모델링을 하는 기법 자체에는 정형적인 의미를 내포하고 있어야 하며 분석이 가능해야 한다. 이에 본 논문에서는 워크플로우 시스템의 특성에 맞도록 ASM(Abstract State Machine) 시멘틱을 이용하여 액티비티 다이어그램 기반의 워크플로우 모델링에 대한 시멘틱 표현을 제안한다. 이와 같은 ASM 시멘틱을 기반으로 하는 정형적인 시멘틱 표현을 통하여 보다 효율적인 워크플로우 모델링이 가능하다.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.4
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• pp.46-54
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• 1998

In this paper, the erect of notch geometries on dynamic stress concentration was investigated by using the dynamic photoelasticity and the drop weight loading system Dynamic stress fields arisen by elastic wave through the loading system around various types of notch geometries were captured by using $10^6/sec$ frame rate Cranz-Shardin camera system with 12 photographic frames. We found that dynamic stress concentrations around the notch tip and comer were highly dependent on the change in notch geometries. The elders of dynamic stress singularity ware determined with respect to varying geometries of notches and we explained dynamic stress concentration in terms of the orders of dynamic stress singularity.

• Journal of the military operations research society of Korea
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• v.32 no.2
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• pp.56-77
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• 2006

This paper suggests more improved war-game modeling methodology for close combat attrition modeling. Military operation analysts have been using equation-based modeling techniques such as Lanchester-type differential equation modeling, for combat attrition evaluation. This modeling methodology is easy to analyze and evaluate the war-game simulation results but has several limitations to simulate the dynamic combat environment. To overcome these shortcomings, we propose the agent-based modeling methodology. This methodology is modeling close combat based in attrition behaviors instead of attrition coefficients. The simulation analysis & evaluation is executed for these two kinds of modeling methodology on the similar close combat situation.