• Title/Summary/Keyword: Redesign Model

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An Intelligent CAD System for Development of Controllers of Active Magnetic Bearings

  • Jang, Seung-Ho;Kim, Chang-Woo
    • Journal of Mechanical Science and Technology
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    • v.15 no.8
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    • pp.1108-1118
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    • 2001
  • The purpose of this study is to establish a CAD (Computer Aided Design) system for research and development(R&D) of a new product. In the R&D process of a new product, the design objects are frequently redesigned based on the experimental results obtained with prototypes. The CAD/CAE systems (which is based on computer simulation of physical phenomena) are effective in reducing the number of useless prototypes of a new product. These kinds of conventional CAD/CAE systems do not provide a function to reflect the experimental results to the redesign process, however. This paper proposes a methodology to establish the CAD system, which possesses the engineering model of a designed object in the model database, and refines the model on the basis of experimental results of prototype. The blackboard inference model has been applied to infer model refinement and redesign counterplan by using insufficient knowledge of R&D process of new products.

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A Study of Performance Improvement of a Vaporizer Sea-Water Pump (기화해수펌프 성능 개선에 대한 연구)

  • Kim, Yang-Ik;Chung, Kyung-Nam
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.645-649
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    • 2005
  • In this study, redesign of a vaporizer sea-water pump has been carried out using computational fluid dynamics. The flow field of the specified pump model is simulated and analyzed. In the flow analysis full pump model has been used, and multi-block grids are employed to solve the governing equations. In order to improve pump efficiency, systematic redesign has been performed to remove the flow recirculation near the hub of the diffuser vanes. The modified model shows about 4 % improvement in pump efficiency compared to the given model.

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Curriculum Redesign for Excellence in Medical Education (의학교육 수월성 제고를 위한 교육과정 재설계)

  • Yang, Eunbae B.
    • Korean Medical Education Review
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    • v.16 no.3
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    • pp.126-131
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    • 2014
  • The purpose of this study is to analyze the medical education system of Korea and to propose a method of curriculum redesign. Although there have been many attempts by medical educators to improve the quality of medical education, the results have not been fruitful. First, there exists a limitation to the dualistic curriculum design based on Flexnerianism, and thus, this model does not provide an integrated experience to medical students. Therefore, we propose a unidimensional model for curriculum redesign. Second, it is impossible to promote excellence in medical education without solving the structural problems of teaching and learning, such as the teaching competency of the faculty, large-scale lectures, and team teaching systems. A curricular strategy that emphasizes mutual interaction and teaching accountability is necessary to promote meaningful learning. Third, the current clinical training system, the circulation model, provides incomplete training as well as a lack of sequence and articulation experiences. This system needs to be redesigned in a way that allows only those students who have mastered both the knowledge and the application of medical education to advance to the next step. Fourth, norm-referenced assessments of a medical college distort the learning process and create unconstructive system energy. A criterion-referenced assessment that values cooperation, independent study, and intrinsic motivation is more important for the reliability and validity of the assessment. Medical students should not focus on formative and informative learning. Medical colleges should investigate the multifaceted potential of the students and provide transformative learning to grow students into change agents. For this to take place, curriculum redesign-not new methods of medical education-is required.

A Feature-based Reconstruction Algorithm for Structural Optimization (구조 최적화를 위한 특징형상 재설계 알고리즘)

  • Park, Sangkun
    • Journal of Institute of Convergence Technology
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    • v.4 no.2
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    • pp.1-9
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    • 2014
  • This paper examines feature-based reconstruction algorithm using feature-based modeling and based on topology optimization technology, which aims to achieve a minimal volume weight and to satisfy user-defined constraints such as stress, deformation related conditions. The finite element model after topology optimization allows us to remove some region of a solid model for predefined volume requirement. The stress or deformation distribution resulted from finite element analysis enables us to add some material to the solid model for a robust structure. For this purpose, we propose a feature-based redesign algorithm which inserts negative features to the solid model for material removal and positive features for material addition, and we introduce a bisection method which searches an optimal structure by iteratively applying the feature-based redesign algorithm. Several examples are considered to illustrate the proposed algorithms and to demonstrate the effectiveness of the present approach.

Fuzzy Controller for Nonlinear Systems Using Intelligent Digital Redesign (지능형 디지털 재설계기법을 이용한 비선형 시스템의 제어기 설계)

  • 이상준;이남수;주영훈;박진배
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2000.11a
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    • pp.176-179
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    • 2000
  • This paper addresses a fuzzy controller for nonlinear systems control using a pole placement in a specified disk and fuzzy controller is redesign for Intelligent digital redesign method. for nonlinear system, we obtain continuous time state feedback gain that guarantee stability of globally TS fuzzy system. The feedback gain is satified pole placement in a specified disk region so that the closed loop system is stable, For digital control redesgin of continuous time TS fuzzy model, we does state matching and obtain feedback gain of digital controller. Finally, it is shown that the proposed method is feasible through a computer simulation.

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Formation Control for Unmanned Surface Vessels Using Lyapunov Redesign Method (Lyapunov 재설계 방법을 이용한 무인 수상정의 군집 제어)

  • Woo, Sangbum;Lee, Jaeyong
    • Journal of Ocean Engineering and Technology
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    • v.28 no.4
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    • pp.363-369
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    • 2014
  • In this paper, a practical controller for a group of USVs is proposed in order to avoid matrix inversion problems in computation. Using nonlinear mapping, a formation composed of nonholonomic agents can be stabilized even when the formation is stationary. Since there is no matrix inversion in computing the control law, the computation complexity can be resolved. A controller for stabilizing the formation errors in the presence of model uncertainty is considered using the Lyapunov redesign method. The asymptotic stability of the formation errors is shown. It is also shown that the proposed controller can be applied to guide a formation to a different shape without modification.

Evaluation Model of the Value of Process Redesign: A Case Study of Manufacturing Company (프로세스 재설계에 대한 가치평가모형: 제조업체 사례연구)

  • 이상재
    • Journal of the Korean Operations Research and Management Science Society
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    • v.24 no.4
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    • pp.81-94
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    • 1999
  • Organization change projects such as Business Process Redesign(BPR) have been implemented by many firms for enhancing their organizational performance. However, management is reluctant to initiate these projects due to enterprise-wide impact and steeper project cost than the traditional system development projects. Thus, there emerges a need to accurately assess the value of the redesigned organizational process for the successful implementation of BPR projects. The purpose of this study is to assess the value of process redesign in the point of resource utilization and allocation, and cycle time and cost reduction. The candidate process and the design alternatives are identified from organizational requirements analysis. The variables and their relations are defined to perform task activity analysis, bottleneck analysis, cycle cost analysis, and resource utilization analysis. A Case study of a manufacturing company indicates that the assessments method proposed in this study is a promising approach to identify the business alternative process that lead to the highest organizational performance.

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Process Redesign Through Dynamic Modeling (동적 모델링을 통한 업무 재설계)

  • 김희웅;김영걸
    • Journal of the Korean Operations Research and Management Science Society
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    • v.22 no.3
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    • pp.175-190
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    • 1997
  • Organizational change projects such as Business Process Redisign (BPR) have been perceived to incur high risk due to their high management complexity, enterprise-wide impace, and steep project cost. This research intends to reduce such risk by developing a systematic process redesign methods, called Dynamic Process Modeling (DPM) method. DPM integrates the customer-oriented business process modeling technique with computerized visual simulation technique to promote better understanding of the target process and enable performance simulation of the proposed redesign alternatives prior to actual BPR implementations. For the cusstomer-oriented process modeling, we propose Dynamic-Event Process Chain (Dynamic-EPC) extending from the conceptual customer process model, Event-Process Chain (EPC). We compare DPM with four other implementation-level process modeling methods over eight criteria and demonstrate its effectiveness by applying it to the real-world hospital BPR case.

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Intelligent Digital Control of a Single Link Flexible-Joint Robot with Uncertainties (불확실성을 갖는 단일 링크 유연로봇의 지능형 디지털 제어)

  • Jang Kwon Kyu;Joo Young Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.3
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    • pp.318-323
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    • 2005
  • In this paper, we propose a systematic method of a fuzzy-model-based controller for continuous-time nonlinear dynamical systems which may contain uncertainties. The continuous-time uncertain TS fuzzy model is first constructed to represent the uncertain nonlinear system. A parallel distributed compensation (PDC) technique is then used to design a fuzzy model based controller for both stabilization and tracking. Finally, the designed continuous-time controller is converted to an equivalent discrete-time controller by using an intelligent digital redesign method. This new design technique provides a systematic and effective framework for integration of the fuzzy model based control theory and the advanced digital redesign technique for nonlinear dynamical systems with uncertainties. Finally, the single link flexible-joint robot arm is used as an illustrative example to show the effectiveness and the feasibility of the developed design method.

A Study on the Design Expert System for Research and Development Using Blackboard Inference Model (신제품개발용 전문가시스템에 있어서의 지식처리 기법으로서 흑판형 추론 모델의 적용 방법에 관한 연구)

  • Jang, Seung Ho
    • Journal of the Korea Society for Simulation
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    • v.22 no.1
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    • pp.87-95
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    • 2013
  • In the research and development processes of new product, the design objects are frequently redesigned on the basis of experimental results. Most of the conventional CAD systems are based on the computer simulation to reduce the number of redesign. However, these types of CAD systems do not have the functions to infer the cause of trouble in experiments of mock-up and the redesign counterplan of new product. This paper proposes a methodology to establish the DESYR ver. 1(Design Expert SYstem for Research and development) system, which possesses the engineering model of design object in the model database, and refines the model on the basis of experimental results of the prototype. The blackboard inference model has been applied to infer the redesign counterplan. And the validity of DESYR ver. 1 system has been verified by developing the new type of magnetic bearing.