• 한국CDE학회논문집
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• 제9권2호
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• pp.122-132
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• 2004

Progressive mesh representation and generation have become one of the most important issues in network-based computer graphics. However, current researches are mostly focused on triangular mesh models. On the other hand, solid models are widely used in industry and are applied to advanced applications such as product design and virtual assembly. Moreover, as the demand to share and transmit these solid models over the network is emerging, the generation and the transmission of progressive solid models depending on specific engineering needs and purpose are essential. In this paper, we present a Cellular Topology-based approach to generating and transmitting progressive solid models from a feature-based solid model for internet-based design and collaboration. The proposed approach introduces a new scheme for storing and transmitting solid models over the network. The Cellular Topology (CT) approach makes it possible to effectively generate progressive solid models and to efficiently transmit the models over the network with compact model size. Thus, an arbitrary solid model SM designed by a set of design features is stored as a much coarser solid model SM/sup 0/ together with a sequence of n detail records that indicate how to incrementally refine SM/sup 0/ exactly back into the original solid model SM = SM/sup 0/.

• 한국인터넷방송통신학회논문지
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• 제13권2호
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• pp.9-14
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• 2013

모델 기반 설계는 제품의 안전성을 확보하고 제품의 개발기간을 단축시키는 장점이 있다. 이 논문에서는 Simulink를 사용하여 BLDC 모터제어기의 모델 기반 설계를 수행한 후 자동 코드 생성방법에 의해 C코드를 생성하여 제어기를 구성하였다. 시스템의 안전성확보를 위하여 MISRA AC SLSF의 가이드에 따라 모델을 구성을 하였으며 제작된 실제 제어기를 사용하여 생성된 코드를 검증하였으며 각 하부 제어기의 수행시간을 측정하여 기존의 설계 방법과 모델기반 제어기의 설계 방법으로 구성된 제어기를 비교하였다.

• 한국컴퓨터정보학회논문지
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• 제9권3호
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• pp.63-69
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• 2004

본 논문의 목적은 안전한 직무 기반 접근 제어 모델을 웹 기반 응용 시스템에 통합하기 위해 필요한 시스템 모델을 설계하는 것이다. 이를 위해 우선 시스템 아키텍처 설계에 본보기로 활용할 수 있는 유저풀 방식의 시스템 아키텍처 모델을 제안하고, 이 시스템 아키텍처가 웹 기반 응용 시스템에서 실제로 어떻게 직무 기반 접근 제어를 수행하는지를 보여주는 시스템 동작 모델을 제안하고자 한다. 그리고 본 논문에서 제안한 시스템 모델을 기존의 시스템과 비교 분석함으로써 기존 방식에 대한 개선 효과를 제시한다.

• 한국CDE학회논문집
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• 제16권1호
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• pp.21-30
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• 2011

Similarity assessment of a CAD model is one of important issues from the aspect of model re-using. In real practice, many new mechanical parts are designed by modifying existing ones. The reuse of part enables to save design time and efforts for the designers. Design time would be further reduced if there were an efficient way to search for existing similar designs. This paper proposes an efficient algorithm of similarity assessment for mechanical part model with design history embedded within the CAD model. Since it is possible to retrieve the design history and detailed-feature information using CAD API, we can obtain an accurate and reliable assessment result. For our purpose, our assessment algorithm can be divided by two: (1) we select suitable parts by comparing MSG (Model Signature Graph) extracted from a base feature of the required model; (2) detailed-features' similarities are assessed with their own attributes and reference structures. In addition, we also propose a indexing method for managing a model database in the last part of this article.

• 한국CDE학회논문집
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• 제11권6호
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• pp.429-439
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• 2006

The purpose of this study is to support the integration from current 2D drawing-based design to future 3D model-based design. In this paper, an important theme is the combination between the STEP-based 2D drawing standards (i.e., AP202) and the IFC-based 3D building model standards. To achieve the purpose, two methodologies are proposed as follows: the development of IFC extension model for the 2D shape data representation by harmonizing ISO/STEP AP202; and the development of mapping solution between IFC 2D extension model and KOSDIC by constructing the exchange scenario for 2D shape data representation. It is expected that the proposed IFC2X2 2D extension model and mapping solution will offer the basis of development of the integrated standards model in AEC industry.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 춘계학술대회 논문집
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• pp.102-106
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• 1997

Grinding has difficulty in satisfying the qualitative knowledge based on the skilled expert as well as quantitative data for all user. Design of grinding database is based on the frame-based model for utilizing the empirical and qualitative knowledge. Inthis paper, basic strategy to develop the grinding database by frame-based model, which is strongly dependent upon experience and intuition, frame-base model, which is strongly dependent upon experience and intuition, is described. Design of grinding database is based on the frame-based model for utilizing the ambiguous knowledge and inference is accomplised by the object-oriented paradigm system.

• Advances in Computational Design
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• 제1권3호
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• pp.235-251
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• 2016

We have performed a design optimization of a stiffened panel with curvilinear stiffeners using an artificial neural network (ANN) residual kriging based surrogate modeling approach. The ANN residual kriging based surrogate modeling involves two steps. In the first step, we approximate the objective function using ANN. In the next step we use kriging to model the residue. We optimize the panel in an iterative way. Each iteration involves two steps-shape optimization and size optimization. For both shape and size optimization, we use ANN residual kriging based surrogate model. At each optimization step, we do an initial sampling and fit an ANN residual kriging model for the objective function. Then we keep updating this surrogate model using an adaptive sampling algorithm until the minimum value of the objective function converges. The comparison of the design obtained using our optimization scheme with that obtained using a traditional genetic algorithm (GA) based optimization scheme shows satisfactory agreement. However, with this surrogate model based approach we reach optimum design with less computation effort as compared to the GA based approach which does not use any surrogate model.

• Nuclear Engineering and Technology
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• 제56권8호
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• pp.3286-3297
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• 2024

Traditional text-based system engineering, which has been used in the design and application of passive residual heat removal system (PRHRS) for lead-cooled fast reactors, is prone to several problems such as low development efficiency, long iteration cycles, and model ambiguity. This study aims to effectively address the abovementioned problems by adopting a model-based system engineering (MBSE) method, which has been preliminarily applied to meet the design requirements of a PRHRS. The design process has been implemented based on the preliminary design of the system architecture and consists of three stages: top-level requirement analysis, functional requirements analysis, and design requirements synthesis. The results of the top-level requirements analysis and the corresponding use case diagram can determine the requirements, top-level use cases, and scenario flow of the system. During the functional requirements analysis, the sequence, activity, and state machine diagrams are used to develop the system function model and provide early confirmation. By comparing these sequence diagrams, the requirements for omissions and inconsistencies can be effectively checked. In the design requirements synthesis stage, the Analytic Hierarchy Process is used to conduct preliminary trade-off calculations on the system architecture, after which a white box model is established during the system architecture design. Through these two steps, the analysis and design of the system architecture are ultimately achieved. The resulting system architecture ensures the consistency of the design requirements. Ultimately, a functional hazard analysis was conducted for a specific incident to validate case requirements and further refine the system architecture. Future research can further reduce the design risk, improve the design efficiency, and provide a practical reference for the design and optimization of PRHRS in digital lead-cooled fast reactors.

• 창의정보문화연구
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• 제7권3호
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• pp.129-144
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• 2021

본 연구는 예비교사를 위한 디자인싱킹 기반 캡스톤디자인 교수설계모형 개발을 목적으로 실시되었다. 이를 위해, 디자인싱킹 및 캡스톤디자인과 협력학습 등 학습자 중심 수업 관련 문헌분석을 실시하여 예비교사 교육을 위한 디자인싱킹 및 캡스톤디자인의 수업 설계 원리 및 수업모형을 탐색하고 핵심요소를 도출하였다. 이후 문헌분석을 통해 도출된 핵심 요소를 바탕으로 예비교사를 위한 디자인싱킹 기반 캡스톤디자인 교수설 계모형 및 교수·학습모형을 개발하였다. 개발된 교수설계모형과 교수학습모형은 디자인싱킹, 캡스톤디자인 외 교육관련 전문가 6명을 대상으로 전문가 타당화를 포함한 총 3회의 델파이 조사를 실시하여 수정 및 보완 후 최종안을 확정하였다. 본 연구의 주요 결과인 최종 교수설계모형에는 학습자 및 학습 환경 분석, 캡스톤디자인을 위한 산학협력기관 운영 협의, 수업 단계 및 전략, 평가 등 수업 전반에 대한 내용을 포함하고 있다. 교수학습모형 최종안의 경우 세부 단계별 교수자 활동, 학습자 활동에 대한 가이드라인을 포함하고 있다.

• International Journal of Aeronautical and Space Sciences
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• 제16권3호
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• pp.370-379
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• 2015

Handling constantly evolving configurations of aircraft can be inefficient and frustrating to design engineers, especially true in the early design phase when many design parameters are changeable throughout trade-off studies. In this paper, a physics-based design framework using parametric modeling is introduced, which is designated as DIAMOND/AIRCRAFT and developed for structural design of transport aircraft in the conceptual and preliminary design phase. DIAMOND/AIRCRAFT can relieve the burden of labor-intensive and time-consuming configuration changes with powerful parametric modeling techniques that can manipulate ever-changing geometric parameters for external layout of design alternatives. Furthermore, the design framework is capable of generating FE model in an automated fashion based on the internal structural layout, basically a set of design parameters describing the structural members in terms of their physical properties such as location, spacing and quantities. The design framework performs structural sizing using the FE model including both primary and secondary structural levels. This physics-based approach improves the accuracy of weight estimation significantly as compared with empirical methods. In this study, combining a physics-based model with parameter modeling techniques delivers a high-fidelity design framework, remarkably expediting otherwise slow and tedious design process of the early design phase.