• Title/Summary/Keyword: the least square method

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Modeling and Parameter Estimation of an Electrohydraulic Servo System by the Least Square Method (최소자승법에 의한 전기유압식 서보시스템의 모델링 및 파라미터 평가)

  • Roh, Hyoung-Woo;Song, Chang-Sup
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.10
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    • pp.125-131
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    • 2000
  • By using the test of signal error, model structure of an electrohydraulic servo system is determined. For determining parameter of the electrohydraulic servo system, using time discrete model of parametric method, parameters in time discrete model are searched by the least square method. By bilinear transform, we have found the model of electrohydraulic servo system in s domain. Afterwards, we have compared experimental data with simulation data by MATLAB having the identified parameter. As the result, experimental data is agreed with simulation data very well.

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Maximization average torque control of Switched Reluctance Motor using least square method (최소자승법을 이용한 Switched Reluctance Motor의 최대 평균토오크 제어)

  • 김춘삼;정연석
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.16 no.5
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    • pp.61-65
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    • 2002
  • RM(Switched Reluctance Motor)'s Torque is generated by phase-current and inductance profile. A new analytical concept is proposed to determine the turn-off angle for maximization of the torque output. This paper describes a new method to maximization the average torque of a current control Switched Reluctance Motor. It is based on the simplified turn-off angle equation using least square method. Simulations carried out on a three-phase 6/4 pole SRM justify the algorithm is described. The suggested maximization average torque is verified by simulation in this paper.

Nonlinear Channel Equalization Using Adaptive Neuro-Fuzzy Fiter (적응 뉴로-퍼지 필터를 이용한 비선형 채널 등화)

  • 김승석;곽근창;김성수;전병석;유정웅
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.366-366
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    • 2000
  • In this paper, an adaptive neuro-fuzzy filter using the conditional fuzzy c-means(CFCM) methods is proposed. Usualy, the number of fuzzy rules exponentially increases by applying the grid partitioning of the input space, in conventional adaptive neuro-fuzzy inference system(ANFIS) approaches. In order to solve this problem, CFCM method is adopted to render the clusters which represent the given input and output data. Parameter identification is performed by hybrid learning using back-propagation algorithm and total least square(TLS) method. Finally, we applied the proposed method to the nonlinear channel equalization problem and obtained a better performance than previous works.

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Unsupervised Endmember Selection Optimization Process based on Constrained Linear Spectral Unmixing of Hyperion Image (Hyperion 영상의 제약선형분광혼합분석 기반 무감독 Endmember 추출 최적화 기법)

  • Choi Jae-Wan;Kim Yong-Il;Yu Ki-Yun
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.211-216
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    • 2006
  • The Constrained Linear Spectral Unmixing(CLSU) is investigated for sub-pixel image processing, Its result is the abundance map which mean fractions of endmember existing in a mixed pixel. Compared to the Linear Spectral Unmixing using least square method, CLSU uses the NNLS (Non-Negative Least Square) algorithm to guarantee that the estimated fractions are constrained. But, CLSU gets Into difficulty in image processing due to select endmember at a user's disposition. In this study, endmember selection optimization method using entropy in the error-image analysis is proposed. In experiments which is used hyperion image, it is shown that our method can select endmember number than CLSU based on unsupervised endemeber selection.

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An Optimal Correction Balancing of A High-Speed Flexible Rotor (최적화기법을 이용한 고속 탄성회전체의 밸런싱)

  • 이용복;이동수;최동훈
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.6
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    • pp.1402-1410
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    • 1995
  • An influence coefficient method with an optimal correction balancing algorithm is developed for balancing a high-speed flexible rotor system. Conventional flexible balancing algorithms such as least square and weighted least square algorithms may not satisfy allowable residual vibration levels in certain speed ranges, while the optimal correction balancing method can be more effective in controlling vibration levels in a target speed. Related analyses were reviewed and applied to a test rig to show the effectiveness of the optimal correction balancing method.

Application SVD-Least Square Algorithm for solving astronomical ship position basing on circle of equal altitude equation

  • Nguyen, Van Suong;Im, Namkyun
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.10a
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    • pp.130-132
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    • 2013
  • This paper presents an improvement for calculating method of astronomical vessel position with circle of equal altitude equation based on using a virtual object in sun and two stars observation. In addition, to enhance the accuracy of ship position achieved from solving linear matrix system, and surmount the disadvantages on rank deficient matrices situation, the authors used singular value decomposition (SVD) in least square method instead of normal equation and QR decomposition, so, the solution of matrix system will be available in all situation. As proposal algorithm, astronomical ship position will give more accuracy than previous methods.

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An Efficient Method for Real-Time Broken Lane Tracking Using PHT and Least-Square Method (PHT와 최소자승법을 이용한 효율적인 실시간 점선차선 추적)

  • Xu, Sudan;Lee, Chang-Woo
    • Journal of KIISE:Computing Practices and Letters
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    • v.14 no.6
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    • pp.619-623
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    • 2008
  • A lane detection system is one of the major components of intelligent vehicle systems. Difficulties in lane detection mainly come from not only various weather conditions but also a variety of special environment. This paper describes a simple and stable method for the broken lane tracking in various environments. Probabilistic Hough Transform (PHT) and the Least-square method (LSM) are used to track and correct the lane orientation. For the efficiency of the proposed method, two regions of interest (ROIs) are placed in the lower part of each image, where lane marking areas usually appear with less intervention in our system view. By testing in both a set of static images and video sequences, the experiments showed that the proposed approach yielded robust and reliable results.

A Study on Improvement of Accuracy using Geometry Information in Reverse Engineering of Injection Molding Parts (사출성형품의 역공학예서 Geometry정보를 이용한 정밀도 향상에 관한 연구)

  • 김연술;이희관;황금종;공영식;양균의
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.546-550
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    • 2002
  • This paper proposes an error compensation method that improves accuracy with geometry information of injection molding parts. Geometric information can give an improved accuracy in reverse engineering. Measuring data can not lead to get accurate geometric model, including errors of physical parts and measuring machines. Measuring data include errors which can be classified into two types. One is molding error in product, the other is measuring error. Measuring error includes optical error of laser scanner, deformation by probe forces of CMM and machine error. It is important to compensate these in reverse engineering. Least square method(LSM) provides the cloud data with a geometry compensation, improving accuracy of geometry. Also, the functional shape of a part and design concept can be reconstructed by error compensation using geometry information.

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Study on optimization of real-time color gamut mapping method using Least Square Method (최소자승법을 이용한 실시간 색역폭 사상 기법의 Look up table 최적화에 관한 연구)

  • Kim, Joo-Young;Lee, Hak-Sung;Han, Dong-Il
    • Proceedings of the KIEE Conference
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    • 2005.07d
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    • pp.2867-2869
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    • 2005
  • 색역폭 사상은 디스플레이 장치간의 색재현성 차이를 보정하는 하나의 방법이다. 일반적으로 실시간 색역폭 사상은 3차원 Look-Up Table과 3차원 보간기로 구성되고 3차원 보간기의 성능은 3차원 Look-Up Table에 의해 결정된다. 본 논문에서는 실시간 색역 사상에 사용되는 3차원 Look-Up Table을 Least Square Method(최소자승법)를 이용하여 최적화하고자 한다. 시뮬레이션 결과 제안된 방법에 의해 생성된 Look-Up Table이 기존의 방법에 비해 우선된 색 재현 성능을 갖는다.

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Modeling of Blend Surfaces by Bezier Surface Patches (비지어곡면에 의한 블렌드곡면의 모델링)

  • 주상윤
    • Korean Journal of Computational Design and Engineering
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    • v.2 no.2
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    • pp.122-129
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    • 1997
  • Ball rolling blending is a popular technique for blending between parametric surfaces. The ball rolling blend surface is conceptually a trajectory of a ball rolling between two base sufaces. It is constructed by sweeping a circular arc along a ball contact curve pair. Since a ball rolling blend surfaces does not have a polynomial form like a Bezier surface patch, it is impossible to apply this method directly to a commercial CAD/CAM system. In this paper an algorithm is developed to approximate a ball rolling blend surface into Bezier surface patches. Least square method is applied to obtain proper Bezier surface patches under a given tolerance. The Bezier surface patches have degree three or more and guarantee VC1-continuity.

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