• Computers and Concrete
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• 제25권1호
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• pp.67-73
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• 2020

Traditionally used analytical approach to predict the fatigue failure of reinforced concrete (RC) structure is generally conservative and has certain limitations. The nonlinear finite element method (FEM) offers less expensive solution for fatigue analysis with sufficient accuracy. However, the conventional implicit dynamic analysis is very expensive for high level computation. Whereas, an explicit dynamic analysis approach offers a computationally operative modelling to predict true responses of a structural element under periodic loading and might be perfectly matched to accomplish long life fatigue computations. Hence, this study simulates the fatigue behaviour of RC beams with finite element (FE) assemblage presenting a simplified explicit dynamic numerical solution to show computer aided fatigue behaviour of RC beam. A commercial FEM package, ABAQUS has been chosen for this complex modelling. The concrete has been modelled as a 8-node solid element providing competent compression hardening and tension stiffening. The steel reinforcements are simulated as two-node truss elements comprising elasto-plastic stress-strain behaviour. All the possible nonlinearities are duly incorporated. Time domain analysis has been adopted through an automatic Newmark-β time incremental technique. The program consists of twelve RC beams to visualize the real behaviour during fatigue process and to obtain the reliability of the study. Both the numerical and experimental results indicate a redistribution of stresses along the time and damage accumulation of beam which severely affect the serviceability and ultimate capacity of RC beam. The output of the FEM analysis demonstrates good match with the experimental consequences which affirm the efficacy of the computer aided model. The controlled fatigue damage evolution at service fatigue load limits makes the FE model an efficient tool in predicting high cycle fatigue behaviour of RC structures.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2000년도 추계학술발표논문집 (상)
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• pp.539-542
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• 2000

본 논문에서는 기존에 구현한 유닉스 버전 CASE(Computer Aided Software Engineering) 도구인 OODesigner를 윈도 버전으로 이식한 연구 결과에 대하여 논한다. 유닉스 버전 OODesigner는 Rumbaugh가 제안한 OMT(Object Modeling Technique) 기법을 지원하기 위해 구현되었지만 윈도 버전은 UML(Unified Modeling Language)을 지원할 수 있도록 기능이 향상되었다. 본 논문은 구현된 윈도 버전 OODesigner의 설계 문서와 구현 결과를 제시하는 것을 목적으로 한다.

• 치위생과학회지
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• 제11권4호
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• pp.299-303
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• 2011

The purpose of this case report was to present an example of an esthetic and functional rehabilitation of anterior teeth with tetracycline discoloration and minor morphological abnormality of a 39-year old female. A chairside computer-aided design/computer-aided manufacturing (CAD/CAM) system with CEREC AC was applied for the prosthetic procedure and all ceramic crowns made with lithum disilicate (IPS e.max CAD) restored the esthetic and functional features of sixteen anterior teeth successfully.

• 한국정밀공학회지
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• 제7권3호
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• pp.66-74
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• 1990

This paper presents a knowledge-based computer aided process planning system that automatically selects machine tools, machining operations and cutting tools and determines sequences of the machining operations for prismatic parts in die manufacturing. In the proposed system, parts are described by manufacturing features and grouped into part families based on the functions. Each part is repressented by a part frame which consists of basic data and manufacturing features. Knowledge for manufacturing is acquired from the domain expert and represented by frames. A decision model for selection of machine tools, machining operations and cutting tools and for determining sequences of the machining operations are developed by employing the Mealy machine in finite automata with output. The decision procedure and the order of priority which inputs manufacturing features into the Mealy machine are represented by rule for each part family. Backward chaining is used for the proposed system. The proposed system is implemented by using TURBO-PROLOG on the IBM PC/AT. A case study for the slide core is presented to show the function of the proposed system.

• 한국정밀공학회지
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• 제14권4호
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• pp.145-150
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• 1997

A computer-aided process design system for axisymmetric deep drawing products has been developed. An approach to the system is based on the knowledge based system. The hypothesized process outline of the deep drawing operations is generated in the geometrical design module of the system. In this paper, the module has been expanded. The rules of process design sechems for complex cup drawings are formulated from handbooks, experimental results and empirical knowhow of the field experts. The input to the system is final sheet-metal objects geometry and the output from the system is process sequence with intermediate objects geometries and process parameters, such as drawing load, blank holding force, clearance and cup-drawing coefficient.

• 한국해양공학회지
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• 제21권2호
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• pp.81-86
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• 2007

This paper presents a computer aided process planning system integrating case-based reasoning and expert system for block assembly in shipbuilding. Expert rules are extracted from the case-base where cases are represented as a set of constraint-satisfaction problems. Rules for the expert system are extracted by generalizing the constraints. In generalizing the constraints, parts are generalized as variables or as part-types. The system was developed with CLIPS, an expert system shell. As more cases are collected, more rules will be extracted and the existing rules will be updated.

• Advances in materials Research
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• 제3권2호
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• pp.91-103
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• 2014

A study that demonstrates how to investigate the molded part quality and the consistency of injection process based on the rheological concept is proposed. It is important for plastic material whose melt viscosity is variable with respect to the processing condition. The formulations to couple the melt viscosity with injection pressure and fill time are derived first. Taking calculations of the measured pressure and the time by using these formulations, the melt viscosity in injection process can be determined on machine. As the relation between the injection speed and the melt viscosity is constructed, the influences of the setting parameter of injection machine on the molded part quality can be investigated through evaluating the state of the melt viscosity. In addition, a pressure sensor bushing (PSB) designed with a quick installation feature is also provided and validated. The results show that a higher injection speed improves the tensile strength of the molded part but also the consistency of the molded part quality. This work provides an alternative to evaluate the molding quality scientifically.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2007년도 춘계학술대회
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• pp.276-280
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• 2007

점차 고성능화 되어가는 Display 제품들을 더욱 저렴하고 일반화하기 위해 제품 공정수를 줄이고 설계 기간을 단축하여야 한다. PCB(Printed Circuit Board) 층수(Stack-up)를 줄이고 회로개발 면에서는 회로를 간략히 하고 부품소자를 최소화하여야 한다. 그리고 기구개발 면에서는 공정을 최소화하고 견고하게 하는 것이 시장 추세이다. 불량 없으면서 초단납기 설계와 대량 생산을 위해 일원화를 추진하고 있다. 곧, 어떤 Customer에게 나가도 A/S 문제가 발생되지 않도록 초기부터 적용하는 최적설계가 필요하다. 본 연구는 Display의 대표라 할 수 있는 PDP(Plasma Display Panel)를 CAE(Computer Aided Engineering)를 이용해 설계함으로써 PDP 회로 최적설계를 하는데 CAE의 활용 사례를 알 수 있다.

• 한국정밀공학회지
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• 제3권4호
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• pp.23-29
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• 1986

CAD라 함은 computer Aided Design의 약자로서, 종종 컴퓨터 지원설계로 번역되고 있다. 그리고, CAM도 computer Aided Manufacturing의 약자로서 컴퓨터 지원제조로 번역된다. 컴퓨터가 실용화되고 설계에의 이용이 가능해졌을 당시는 설계의 자동화(DA : Design Automation)에 대한 기대가 컸다. 그러나 현실로는, 설계자가 설계하는데 있어서 컴퓨터와 주변장치들을 가까이 두고 도구로 이용하게 되었으나, 그것은 주로 제한된 비교적 단순한 제품의자동설계로서, DA의 발전은 예상외로 제자리 걸음을 하고 있었다. 인간을 대신하여 컴퓨터에 설계를 시킨다는 것이 얼마나 어렵다는 것, 특히, 그와같은 Software 개발이 어럽다는 것을 인식하게 되었다. 그래서 <생각하는 일>과 <창조하는 일>과 같이 본래 인간의 본질적인 기능 에 속하는 것을 인간(설계자) 이 하고, <설계하는 일> <제도하는 일> 과 같은 기계적 인 일을 컴퓨터에 시키는 분업이 생각하게 되었다. 이것이 컴퓨터 지원설계(CAD)인 것이다. CAC에 있어서, 설계의 주역은 어디까지나 인간(설계자)에 있으며, 컴퓨터는 설계자의 기계적(비인간적)인 일을 도와주는 도구인 것이다. 이와같이 설계에 있어서 컴퓨터의 위치가 정의된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.271-275
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• 1996

In this paper, an automatic spot inspection system has been developed for camera target lens using the computer aided vision system. The developed system comprises: light source, magnifying optics, vision camera, XY robot, and a PC. An efficient algotithm for the spot detection has been implemented, thus up tof ew micrometer size spots can be effectively identified in real time. The developed system has been fully interfaced with XY robot systenm, PLCs, thus the practical spot inspection system has been implemented. The system has been applied to a practical camera manufacturing process, and showed its efficiency.