• 한국정밀공학회지
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• 제12권5호
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• pp.136-148
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• 1995

In this study, a model integration method is pressented as a new method for development of a parametric simulation model. This method enable us to integrate the special simulation models for each production subsystem into a large simulation model. Not only this large simulation model but also each special simulation model for each production subsytem can be used independently. Using this integration method man can reduce the development time and cost for simulation model development. To show the usefulness of this method, a simulation model for a production system with robots is developed by this model integration method. This simulation model is realized by the integration of two special simulation models, one model for a machining subsystem and the other model for a transport subsystem. The modeled production system consists of the robotic cells for machining and a transport subsystem which enable the material flow among the robotic cells. The flow of workpiece in each robotic cell is not fixed. All machines in a robotic cell are only served by robots.

• 비파괴검사학회지
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• 제31권5호
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• pp.459-465
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• 2011

대퇴골 근위부의 기하학적 형상은 대퇴골 경부 골절과 중요한 상관관계를 가지고 있는 것으로 보고되고 있다. 기존의 연구에서는 인장실험법과 유한요소해석법을 이용하여 상관관계를 분석해왔다. 그러나 이 방법들은 인체의 미리 정의된 대퇴골 형상을 변경할 수 없고, 다수의 시험편들을 확보하기 어렵기 때문에 다양한 시험편과 모델을 적용할 수 없다는 한계가 있다. 따라서 본 연구에서는 대퇴골 골절 해석에 폭넓게 사용할 수 있도록 매개변수로 기하학적 형상 변형이 가능한 대퇴골 모델을 이용하여 대퇴골 골절과 형상 매개변수의 관계를 분석하였다. 이 관계를 분석하기 위하여 4가지 주요 매개변수(대퇴골두 직경, 대퇴경부 직경, 대퇴경두간 길이, 대퇴경간각)를 이용하여 다양한 해석 모델을 생성하여 유한요소해석을 수행하였다. 이 후 대퇴골두에서의 반력(reaction force)과 경부에서의 응력 분포(stress distribution)를 분석함으로써 유한요 소해석을 수행하였고, 대퇴경부 직경이 대퇴골 경부 골절에 가장 큰 영향을 미치고 대퇴골두 직경이 가장 작은 영향을 미치는 결과가 나타났다.

• 한국정보통신학회논문지
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• 제12권2호
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• pp.299-308
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• 2008

본 논문에서는 RF 집적회로의 설계사양을 시간영역에서 테스팅이 가능한 구간고장모델링 기법을 제안한다. 먼저 구간고장모델을 정의하였고, 정상동작구간을 결정하여 구간고장모델이 될 수 있는 조건을 증명하였다. 그리고 구간고장모델 조건을 5.25 GHz 저잡음 증폭기에 적용하여 능동소자와 수동소자의 강고장과 파라메트릭 고장의 검출이 가능한 9개의 구간고장모델을 모의실험에 의하여 구하였다. 본 논문에서 얻어진 구간고장모델을 기반으로 출력에 나타나는 출력파형의 변화를 시간영역에서 관찰하여 설계사양 테스팅을 수행할 수 있으므로 RF 집적회로의 테스팅 시간과 비용을 줄일 수 있다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2000년도 추계 학술대회논문집
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• pp.15-24
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• 2000

The transient response of an airfoil to a rapidly deploying spoiler is numerically investigated using the turbulent compressible Navier-Stokes equations in two dimensions. Algebraic Baldwin-Lomax model, Wilcox $\kappa-\omega$ model, and SST $\kappa-\omega$ turbulence model are used to calculate the unsteady separated flow due to the rapid spoiler deployment. The spoiler motion relative to a stationary airfoil is treated by an overset grid hounded by a Dynamic Domain-Dividing Line which has been devised by the authors. The adverse effects of the spoiler influenced by the spoiler location and the hinge gap are expounded. The numerical results are in reasonably good agreement with the existing experimental data.

• 한국공작기계학회논문집
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• 제12권1호
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• pp.50-57
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• 2003

In this paper, an automated design and 3-D modeling system of an axial fan and a boss for cooling towers was developed. API and parametric design Provided by a commercial solid-modeler are engaged to automate modeling process. Design data of the boss are assumed to be given by a user with design experiences while the fan from the fan design program using three-dimensional flow analysis. An algorithm avoiding the interferences between fans and a boss is developed. The design data are registered on the database not only to remove duplicate design but also to transfer the data to ERP system.

• 제어로봇시스템학회논문지
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• 제8권7호
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• pp.556-562
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• 2002

This paper studies the identification of a combustion model, which is used to design a linear controller of a steam generation quantity and harmful exhaust gases of a Refuse Incineration Plant(RIP). Even though the RIP has strong nonlinearities and complexities, it is identified as a MIMO parametric ARX model from experimental input-output data sets. Unknown model parameters are decided from experimental input-output data sets, using system identification algorithm based on Instrumental Variables(IV) method. It is shown that the identified model well approximates the input-output combustion characteristics.

• 한국정밀공학회지
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• 제16권7호
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• pp.132-143
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• 1999

In this study, an intermediate model is presented as a new method for development of a parametric simulation program. This model enables us to analyze effectively the static and dynamic structure of a real production system. The static structure of the real system can be modelled in an entity-relationship diagram and the dynamic structure of the real system in a Petri net. The intermediate model consists of an entity-relationship diagram and a Petri net. Using this intermediate model man can not only reduce the time and cost for simulation program development, but also increase the modelling reliability of the developed simulation program. To show the usefulness of this intermediate model. the intermediate models for two production subsystems, manufacturing sub-system and transport subsystem, are set up.

• 한국CDE학회논문집
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• 제9권3호
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• pp.226-237
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• 2004

If the topology changes in the re-generation step of the history-based and feature-based CAD systems, it is difficult to identify an entity in the old model and find the same entity in the new model. This problem is known as 'persistent naming problem'. To exchange parametric CAD models, the persistent naming problem and the naming mapping problem must be solved among different CAD system, which use different naming scheme. For CAD model exchange the persistent naming has its own characteristics compare to that for CAD system development. This paper analyses previous researches and proposes a solution to the persistent naming problem for CAD model exchanges and to the naming mapping problem among different naming schemes.

• 한국CDE학회논문집
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• 제6권4호
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• pp.254-262
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• 2001

It is not possible to exchange parametric information of CAD (Computer Aided Design) models based on the current version of STEP (Standard leer the Exchange of Product model data). The design intent can be lost during the STEP transfer of CAD models. The ISO Parametrics Group has proposed the SMCH (Solid Model Construction History) schema in June 2000 that includes structures fur exchange of parametric information. This paper proposes the macro parametric approach that is intended to provide capabilities to transfer parametric information. In this approach, CAD models are exchanged in the form of macro files. The macro file contains user commands which are used in the modeling phase. To exchange CAD models using the macro parametric approach, modeling commands of commercial CAD systems are analyzed. Those commands are classified by the grouping method suggested by Bill Anderson. As a neutral file format, a standard modeling commands set has been defined. Mapping relations between the standard modeling commands set and the native modeling commands set of commercial CAD systems are defined.

• 한국CDE학회논문집
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• 제14권3호
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• pp.159-167
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• 2009

For the robust exchange of parametric CAD model data, it is very important to perform mapping rightly and accurately between different CAD models. However, data model mapping is usually performed on a case-by-case basis. This results in the problem that mapping quality fluctuates very widely depending on the abilities of developers. In order to solve this problem, the concept of symantic distance is adapted and applied to the translation of parametric CAD model data in order to measure the difference between different CAD models quantitatively in a computer-interpretable form and systematize the mapping process.