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자기학습형 뉴럴-퍼지 제어기에 의한 유도전동기 서어보시스템 (A study on Induction Motor Servo System using Self-learning Neural-Fuzzy Networks)

  • 양승호;김세찬;원충연;김덕헌
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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    • pp.142-144
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    • 1993
  • In this study, a Self-learning Neural-Fuzzy Networks is presented, Because of the fuzzy controller property, the designing problems of fuzzy if-then rules, membership functions and inference methods are very complex task. Thus in this paper we proposed the Neural-Fuzzy Networks composed by Sugeno and Takagi's fuzzy inference method and learned by using temporal back propagation algorithm. The proposed method can refine automatically the fuzzy if-then rules without human expert's knowledges. The induction motor servo system is used to demonstrate the effectiveness of the proposed control scheme and the feasibility of the acquired fuzzy controller. All results are supported by simulation.

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가상현실 기술의 정신의학적 이용 (Virtual Reality in Current and Future Psychiatry)

  • 차경렬;김찬형
    • 생물정신의학
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    • 제14권1호
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    • pp.28-41
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    • 2007
  • Virtual reality technology is now being used in neuropsychological assessment and real-world applications of many psychiatric disorders, including anxiety disorders, schizophrenia, child psychiatric disorders, dementia, and substance related disorders. These applications are growing rapidly due to recent evolution in both hardware and software of virtual reality. In this paper, we review these current applications and discuss the future work of clinical, ethical, and technological aspects needed to refine and expand these applications to psychiatry.

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고차 지그재그 모델을 이용한 다중 층간 분리부가 내재한 복합재 평판의 동적 해석 (Dynamic analysis for delaminated composites using DKQ concept based on higher-order zig-zag theory)

  • 오진호;조맹효;김준식
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2002년도 추계학술발표대회 논문집
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    • pp.71-74
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    • 2002
  • A higher-order zig-zag theory is developed to refine the predictions of natural frequency and mode shape of laminated composite plates with multiple delaminations. By imposing top and bottom surface transverse shear stress-free and interface continuity conditions of transverse shear stresses including delaminated interfaces, the displacement field with minimal degree-of-freedoms are obtained. This displacement field can systematically handle the number, shape, size, and locations of delaminations. Through the dynamic version of variational approach, the dynamic equilibriums and variationally consistent boundary conditions are obtained. Through the numerical example of natural frequency analysis, the accuracy and efficiency of present theory are demonstrated. The present theory is suitable as an efficient tool to analyze the static and dynamic behavior of the composite plates with multiple delaminations.

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중공사형 질소 분리막 모듈의 최적 선정과 유량특성에 관한 연구 (A Study on Flow Rate Properties and Optimal Selection of Nitrogen Membrane Module of Hollow Fiber Type)

  • 김종도;이상수;김전하
    • Journal of Advanced Marine Engineering and Technology
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    • 제32권6호
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    • pp.915-922
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    • 2008
  • The gas separation technology using membrane is widely used to refine various gases in many industry fields and recently is being applying in $CO_2$ recovery technology. In the gas and chemical tanker. nitrogen generators for inerting, purging and padding are on board and most of them have membrane modules of hollow fiber type with long life and vibration resisting properties. Because a membrane module is a key component accounting for 50% of total manufacturing cost of nitrogen generator, adequate selection for it is an important problem. In this paper, the flow performance coefficient based on dimension and specification data of membrane module was relatively selected to compare nitrogen generating capacity of module and various performance tests about the selected PARKER ST6010 membrane module were conducted. As a result, the useful coefficient and basic data in selecting a membrane module were achieved.

폴리곤 기반 역공학 시스템의 후처리 기능에 관한 연구 (A study on the post-processing functions in a polygon-based reverse engineering system)

  • 박진표;박광현;최영;전용태;노형민
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.41-44
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    • 2001
  • In reverse engineering, the whole surfaces of the three-dimensional(3D) product are measured using 3D positional scanners. The raw triangle meshes constructed from a scanned point set are not well suited for direct use in the downstream activities. This is because the amount of triangle meshes may be very large(from millions to hundreds of millions) and usually distorted by scanning error. Furthermore, the triangle meshes may contain several holes that must be filled. Thus, several solutions have to be addressed and implemented before a complete CAD models can be acquired. This paper discusses on the algorithms of decimation, smoothing, and hole-filling that are crucial to refine the triangle meshes. Several examples are also given and discussed to validate the system.

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Impact를 이용한 정밀 고속 회전체 불평형 보정 (Correction of Mass Unbalance of a High Precision Rotor)

  • 이상봉;인용석;오동호;김하용;이호성;구자춘
    • 한국소음진동공학회논문집
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    • 제17권8호
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    • pp.720-725
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    • 2007
  • The unbalanced mass of a high precision rotor deteriorates mechanical performance of the rotor. The geometrical center of a rotor generally corresponds to the rotational axis of the rotor. However, this alignment carried out with a stationary rotor does not guarantee the dynamic rotor balance. There have been a number of schemes for the correction of the unbalance published for decades especially in the hard drive industry where the issues are directly affecting manufacturing costs and product performances. Realizing the significance of the problem, the present work tries to refine one of the methods that works by applying external impact during a rotor spins. A systematic way to apply the external impact to a rotating rotor has been introduced to minimize unbalance correction process time.

Automated yield-line analysis of beam-slab systems

  • Johnson, David
    • Structural Engineering and Mechanics
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    • 제3권6호
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    • pp.529-539
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    • 1995
  • The rigid-plastic yield-line analysis of isotropically reinforced concrete slabs acting in conjunction with torsionally weak supporting beams is developed as the lower-bound form of a linear programming formulation. The analysis is extended to consider geometric variation of chosen yield-line patterns by the technique of sequential linear programming. A strategy is followed of using a fine potential yield-line mesh to identify possible collapse modes, followed by analysis using a coarser, simplified mesh to refine the investigation and for use in conjunction with geometric optimization of the yield-line system. The method is shown to be effective for the analysis of three slabs of varying complexity. The modes detected by the fine and simplified analyses are not always similar but close agreement in load factors has been consistently obtained.

Stepwise Training for Reconstructive Microsurgery: The Journey to Becoming a Confident Microsurgeon in Singapore

  • Ramachandran, Savitha;Ong, Yee-Siang;Chin, Andrew Y.H.;Song, In-Chin;Ogden, Bryan;Tan, Bien-Keem
    • Archives of Plastic Surgery
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    • 제41권3호
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    • pp.209-212
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    • 2014
  • Microsurgery training in Singapore began in 1980 with the opening of the Experimental Surgical Unit. Since then, the unit has continued to grow and have held microsurgical training courses biannually. The road to becoming a full-fledged reconstructive surgeon requires the mastering of both microvascular as well as flap raising techniques and requires time, patience and good training facilities. In Singapore, over the past 2 decades, we have had the opportunity to develop good training facilities and to refine our surgical education programmes in reconstructive microsurgery. In this article, we share our experience with training in reconstructive microsurgery.

컴플라이언트 메커니즘을 이용한 플러터 실험 장치 설계 (Flutter Experiment Equipment Design with Compliant Mechanism)

  • 이주호;이준성;성열훈;한재흥
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2012년도 춘계학술대회 논문집
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    • pp.429-434
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    • 2012
  • This paper deals with a development of 2-DOF flutter experiment equipment which represents a 2-DOF typical section model. For a conventional 2-DOF flutter experiment equipment, it is hard to observe flutter boundary clearly due to the complexity of the experiment equipment. To refine our flutter experiment equipment system, a compliant mechanism based torsional spring is used. Well-designed extruded aluminum pipe works as a torsional spring. SolidWorks and ANSYS are used for modeling, analysis and design of the torsional spring. With this designed torsional spring, the 2-DOF flutter experiment equipment is developed and wind tunnel tests are performed. Clear flutter boundary which is estimated by classical flutter analysis is observed in the experiments.

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Lyapunov 안정성을 이용한 구동장치의 강인 최단시간 제어기 설계 (Robust Near Time-optimal Controller Design for a Driving System Using Lyapunov Stability)

  • 이성우;송오섭
    • 한국소음진동공학회논문집
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    • 제22권7호
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    • pp.650-658
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    • 2012
  • This paper proposes a high performance position controller for a driving system using a time optimal controller which has been widely used to control driving systems to achieve desired reference position or velocity in a minimum response time. The main purpose of this research lies in an improvement of transient response performance rather than that of steady-state response in comparison with other control strategies. In order to refine the scheme of time optimal control, Lyapunov stability proofs are incorporated in a controller of standard second order system model. This scheme is applied to the control of a driving system. In view of the simulation and experiment results, the standard second order system model exhibits better minimum-time control performance and robustness than double integral system model does.