• 제목/요약/키워드: Pseudo-inverse

검색결과 132건 처리시간 0.024초

박판보 요소와 셸 요소를 이용한 T 조인트 진동 해석 (Free Vibration Analysis of a T Joint Using Thin-Walled Beam and Shell Elements)

  • 김진홍;김현석;김윤영
    • 대한기계학회논문집A
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    • 제24권9호
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    • pp.2334-2343
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    • 2000
  • This paper proposes an efficient beam-shell modeling technique for the free vibration analysis of a T-joint thin-walled beam structure. Except a small portion of a T-joint which is modeled by shell elements, the structure is modeled by thin-walled beam elements that can describe warping and distortion. In order to match the shell and thin-walled beam elements at the interface of the dissimilar elements, a technique based on a pseudo inverse matrix is formulated. This paper also examines the role of the thin-walled element taking into account the distortion and warping deformation degrees of freedom in predicting accurately the dynamic characteristics of a T-joint thin-walled structure.

간접 힘 측정 방법과 가상 역행렬을 이용한 힘 예측 (Forces Prediction by Indirect Force Measurement and Pseudo-inverse Technique)

  • 안병하;심재술
    • 한국정밀공학회지
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    • 제19권6호
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    • pp.43-50
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    • 2002
  • In the design of structure, the forces acting on tai structure are key parameter fur noise and vibration control. However, in the complex structure, the forces at the injection point on the structure cannot be measured directly. So, it is necessary to find out Indirect force evaluation method. In this paper, forces have been measured with In-situ vibration responses and system information. And, three existing techniques of indirect force measurement, vita. direct inverse. principal component analysis and regularization have been compared. This paper shows that multi-vibration responses are essential for talc precise estimation of the forces. To check these conditions, rotary compressor is adopted as test sample, because it is very difficult to measure the injection forces from internal excitation to shell. It alas also been obtained that relatively higher force is transmitted through three welding paths to the compressor shell. It shows a good agreement between direct and indirect force evaluation with curvature shell and plate.

여유자유도 로봇의 주기적 운동제어를 위한 역기구학 해의 개발 (The Development of an Inverse Kinematic Solution for Periodic Motion of a Redundant Manipulator)

  • 정용섭;최용제
    • 대한기계학회논문집
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    • 제19권1호
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    • pp.142-149
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    • 1995
  • This paper presents a new kinematic control strategy for serial redundant manipulators which gives repeatability in the joint space when the end-effector undergoes some general cyclic motions. Theoretical development has been accomplished by deriving a new inverse kinematic equation that is based on springs being conceptually located in the joints of the manipulator. Although some inverse kinematic equations for serial redundant manipulators have been derived by many researchers, the new strategy is the first to include the free angles of torsional springs and the free lengths of the translational springs. This is important because it ensures repeatability in the joint space of a serial redundant manipulator whose end-effector undergoes a cyclic type motion. Numerical verification for repeatability is done in terms of Lie Bracket Condition. Choices for the free angle and torsional stiffness of a joint (or the free length and translational stiffness) are made based upon the mechanical limits of the joints.

여유자유도 유연 매니퓰레이터의 위치제어 (Position Control of a Redundant Flexible Manipulator)

  • 김진수
    • 한국공작기계학회논문집
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    • 제10권3호
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    • pp.83-89
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    • 2001
  • In this paper, we discuss the vibration suppression control of spatial redundant flexible manipulators through pseudo-inversed of Jacobian. In order to verify our method, the experiments are performed for PTP(Point To Point) motion of spa-tial flexible manipulators(1) with no redundancy(2) with one redundant DOF(degree of freedom). Finally, a comparison between these results is presented to show the performance of out approach.

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SOLUTIONS OF SYSTEMS OF VARIATIONAL INEQUALITIES ON FIXED POINTS OF NONEXPANSIVE MAPPINGS

  • Piri, Hossein
    • 대한수학회보
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    • 제51권3호
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    • pp.621-640
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    • 2014
  • In this paper, we introduce a new approximating method for finding the common element of the set of fixed points of nonexpansive mappings and the set of solution of system variational inequalities for finite family of inverse strongly monotone mappings and strictly pseudo-contractive of Browder-Petryshyn type mappings. We show that the sequence converges strongly to a common element the above two sets under some parameter controling conditions. Our results improve and extend the results announced by many others.

스테레오 비전을 이용한 마커리스 정합 : 특징점 추출 방법과 스테레오 비전의 위치에 따른 정합 정확도 평가 (Markerless Image-to-Patient Registration Using Stereo Vision : Comparison of Registration Accuracy by Feature Selection Method and Location of Stereo Bision System)

  • 주수빈;문정환;신기영
    • 전자공학회논문지
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    • 제53권1호
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    • pp.118-125
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    • 2016
  • 본 논문에서는 얼굴 영역 수술용 네비게이션을 위한 스테레오 비전과 CT 영상을 이용하여 환자-영상 간 정합(Image to patient registration) 알고리즘의 성능을 평가한다. 환자 영상 간 정합은 스테레오 비전 영상의 특징점 추출과 이를 통한 3차원 좌표 계산, 3차원 좌표와 3차원 CT 영상과의 정합 과정을 거친다. 스테레오 비전 영상에서 3가지 얼굴 특징점 추출 방법과 3가지 정합 방법을 사용하여 생성될 수 있는 5가지 조합 중 정합 정확도가 가장 높은 방법을 평가한다. 또한 머리의 회전에 따라 환자 영상 간 정합의 정확도를 비교한다. 실험을 통해 머리의 회전 각도가 약 20도의 범위 내에서 Active Appearance Model과 Pseudo Inverse Matching을 사용한 정합의 정확도가 가장 높았으며, 각도가 20도 이상일 경우 Speeded Up Robust Features와 Iterative Closest Point를 사용하였을 때 정합 정확도가 높았다. 이 결과를 통해 회전각도가 20도 범위 내에서는 Active Appearance Model과 Pseudo Inverse Matching 방법을 사용하고, 20도 이상의 경우 Speeded Up Robust Features와 Iterative Closest Point를 이용하는 것이 정합의 오차를 줄일 수 있다.

CONVERGENCE THEOREMS OF ITERATIVE ALGORITHMS FOR A GENERAL SYSTEM OF VARIATIONAL INEQUALITIES WITH APPLICATIONS

  • Kang, Shin Min;Kwun, Young Chel;Qin, Xiaolong
    • Korean Journal of Mathematics
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    • 제18권4호
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    • pp.441-464
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    • 2010
  • In this paper, we introduce an iterative method for finding common elements of the set of solutions to a general system of variational inequalities for inverse-strongly accretive mappings and of the set of fixed points of strict pseudo-contractions in a real Banach space. The results presented in this paper mainly improve and extend the corresponding results announced by many others.

보행로보트의 보행과 지면 반발력 (Locomotion and ground reaction forces of a warking machine)

  • 홍형주;윤용산;손웅희
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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    • pp.125-130
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    • 1988
  • This study presents a method to determine the ground reation forces of a quadruped walking machine on its foot ends caused by the body weight and the inertia forces from the commanded acceleration. The method shows the same result as the Pseudo-Inverse Method when the 4 feet stand on a plane. However method can be applied even when the 4 feet stand on a non-planar surface for which, no feasible solution can be obtained by the Pesudo-Inverse Method.

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CONTINUOUS SHADOWING AND STABILITY FOR GROUP ACTIONS

  • Kim, Sang Jin
    • 대한수학회지
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    • 제56권1호
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    • pp.53-65
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    • 2019
  • Recently, Chung and Lee [2] introduced the notion of topological stability for a finitely generated group action, and proved a group action version of the Walters's stability theorem. In this paper, we introduce the concepts of continuous shadowing and continuous inverse shadowing of a finitely generated group action on a compact metric space X with respect to various classes of admissible pseudo orbits and study the relationships between topological stability and continuous shadowing and continuous inverse shadowing property of group actions. Moreover, we introduce the notion of structural stability for a finitely generated group action, and we prove that an expansive action on a compact manifold is structurally stable if and only if it is continuous inverse shadowing.

L-곡선 기반의 Modified Wiener Filter(MWF)를 이용한 위성 영상의 MTF 보상 (A MTF Compensation for Satellite Image Using L-curve-based Modified Wiener Filter)

  • 전병일;김홍래;장영근
    • 대한원격탐사학회지
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    • 제28권5호
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    • pp.561-571
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    • 2012
  • 변조전달함수(MTF; Modulation Transfer Function)는 광학영상의 성능을 평가하는 중요한 품질 요소 중 하나이다. 영상의 MTF 증진을 위해 영상 복원이 필요하나, 이 과정은 대표적인 부적합문제(ill-posed problem)의 하나로 특정한 해를 갖지 않는다. 영상 복원을 위한 필터에는 역 필터(IF; Inverse Filter), 의사 역 필터(PIF; Pseudo Inverse Filter), Wiener Filter(WF) 등이 있다. 이들 중 가장 일반적으로 사용되고 있는 WF는 촬영된 영상 내에서 영상과 잡음을 정확히 구분하기 어렵다는 한계를 가지고 있다. 본 논문에서는 Modified Wiener Filter(MWF)를 사용하여 부적절 문제를 풀 수 있도록 문제를 정규화 하였으며, 정규화 변수(regularization parameter)의 값을 찾기 위한 방법으로 L-곡선(L-curve)을 사용하였다. MWF의 검증을 위해 Dubaisat-1 위성의 영상을 의사 역 필터(PIF), Wiener Filter(WF), MWF로 영상 복원을 수행하였다. 복원 결과, MWF를 사용했을 때가 PIF를 사용했을 때의 결과에 비해 20.93%, WF를 사용했을 때의 결과에 비해 10.85% 더 향상된 MTF를 얻을 수 있었다.