• Title/Summary/Keyword: Perturbation matrix

검색결과 119건 처리시간 0.032초

수중운동체의 $H_\infty$ 심도제어기 설계 ($H_\infty$ Depth Controller Design for Underwater Vehicles)

  • 이만형;정금영;김인수;주효남;양승윤
    • 제어로봇시스템학회논문지
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    • 제6권5호
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    • pp.345-355
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    • 2000
  • In this paper, the depth controller of an underwater vehicle based on an $H_\infty$ servo control is designed for the depth keeping of the underwater vehicle under wave disturbances. The depth controller is designed in the form of the $H_\infty$ servo controller, which has robust tracking property, and an $H_\infty$ servo problem is considered for the $H_\infty$ servo controller design. In order to solve the $H_\infty$ servo problem for the underwater vehicle, this problem is modified as an $H_\infty$ control problem for the generalized plant that includes a reference input mode, and a suboptimal solution that satisfies a given performance criteria is calculated with the LMI (Linear Matrix Inequality) approach. The $H_\infty$ servo controller is designed to have robust stability about the perturbation of the parameters of the underwater vehicle and the robust tracking property of the underwater vehicle depth under wave force and moment disturbances. The performance, robustness about the uncertainties, and depth tracking property, of the designed depth controller is evaluated by computer simulation, and finally these simulation results show the usefulness and applicability of the proposed $H_\infty$ depth control system.

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H$_\infty$ 서보제어를 이용한 무인 수중운동체의 심도 및 방향제어기 설계 (Depth and Course Controller Design of Autonomous Underwater Vehicles using H$_\infty$ Servo Control)

  • 김인수;정금영;양승윤;조상훈;정찬희;이만형
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.215-215
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    • 2000
  • In this paper, depth and course controllers of autonomous underwater vehicles using H$_{\infty}$ servo control are proposed. An H$_{\infty}$ servo problem is formulated to design the controllers satisfying a robust tracking property with modeling errors and disturbances. The solution of the H$_{\infty}$ servo problem is as follows: first, this problem is modified as an H$_{\infty}$ control problem for the generalized plant that includes a reference input mode, and then a sub-optimal solution that satisfies a given performance criteria is calculated by LMI(Linear Matrix Inequality) approach. The H$_{\infty}$ depth and course controllers ate designed to satisfy with the robust stability about the modeling error generated from the perturbation of the hydrodynamic coefficients and the robust tracking property under disturbances(wave force, wave moment, tide). The performances(the robustness to the uncertainties, depth and course tracking properties) of the designed controllers are evaluated with computer simulations, and finally these simulation results show the usefulness and application of the proposed H$_{\infty}$ depth and course control systems.

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Smart tracking design for aerial system via fuzzy nonlinear criterion

  • Wang, Ruei-yuan;Hung, C.C.;Ling, Hsiao-Chi
    • Smart Structures and Systems
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    • 제29권4호
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    • pp.617-624
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    • 2022
  • A new intelligent adaptive control scheme was proposed that combines the control based on interference observer and fuzzy adaptive s-curve for flight path tracking control of unmanned aerial vehicle (UAV). The most important contribution is that the control configurations don't need to know the uncertainty limit of the vehicle and the influence of interference is removed. The proposed control law is an integration of fuzzy control estimator and adaptive proportional integral (PI) compensator with input. The rated feedback drive specifies the desired dynamic properties of the closed control loop based on the known properties of the preferred acceleration vector. At the same time, the adaptive PI control compensate for the unknown of perturbation. Additional terms such as s-surface control can ensure rapid convergence due to the non-linear representation on the surface and also improve the stability. In addition, the observer improves the robustness of the adaptive fuzzy system. It has been proven that the stability of the regulatory system can be ensured according to linear matrix equality based Lyapunov's theory. In summary, the numerical simulation results show the efficiency and the feasibility by the use of the robust control methodology.

Microarray Data Analysis of Perturbed Pathways in Breast Cancer Tissues

  • Kim, Chang-Sik;Choi, Ji-Won;Yoon, Suk-Joon
    • Genomics & Informatics
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    • 제6권4호
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    • pp.210-222
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    • 2008
  • Due to the polygenic nature of cancer, it is believed that breast cancer is caused by the perturbation of multiple genes and their complex interactions, which contribute to the wide aspects of disease phenotypes. A systems biology approach for the identification of subnetworks of interconnected genes as functional modules is required to understand the complex nature of diseases such as breast cancer. In this study, we apply a 3-step strategy for the interpretation of microarray data, focusing on identifying significantly perturbed metabolic pathways rather than analyzing a large amount of overexpressed and underexpressed individual genes. The selected pathways are considered to be dysregulated functional modules that putatively contribute to the progression of disease. The subnetwork of protein-protein interactions for these dysregulated pathways are constructed for further detailed analysis. We evaluated the method by analyzing microarray datasets of breast cancer tissues; i.e., normal and invasive breast cancer tissues. Using the strategy of microarray analysis, we selected several significantly perturbed pathways that are implicated in the regulation of progression of breast cancers, including the extracellular matrix-receptor interaction pathway and the focal adhesion pathway. Moreover, these selected pathways include several known breast cancer-related genes. It is concluded from this study that the present strategy is capable of selecting interesting perturbed pathways that putatively play a role in the progression of breast cancer and provides an improved interpretability of networks of protein-protein interactions.

Regulated Expression of Nebulin by Transfection of Green Fluorescent Protein-Tagged Nebulin Fragments in Cultured Chicken Myoblast

  • Park, Su-Jung;Kim, Ji-Hee;Ko, Han-Suk;Kim, Chong-Rak;Kim, Han-Do;Kang, Ho-Sung
    • 대한의생명과학회지
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    • 제7권4호
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    • pp.167-172
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    • 2001
  • Nebulin is an approximately 700 kDa filamentous protein in vertebrate skeletal muscle. It binds to the Z line and also binds side-by-side to the entire thin actin filament in a sarcomere. The correlation of nebulin size with thin filament length have led to the suggestion that nebulin acts as a molecular ruler for the length of thin filaments. The C-terminal part of human nebulin is anchored in the sarcomeric Z-disk and contains an SH3 domain. SH3 domains have been identified in an ever-increasing number of proteins important for a wide range of cellular processes, from signal transduction to cytoskeleton assembly and membrane localization. However, the exact physiological role of SH3 domains remains, in many cases, unclear. To explore the role of nebulin SH3 in the cytoskeletal rearrangement that accompanies myoblast differentiation, we transfected sense and antisense nebulin SH3 domain fused to enhanced green fluorescent protein in myoblast. Cells expressing nebulin SH3 fragment showed decrease of cell-cell adhesion, and cells transfected with antisense nebulin SH3 gene showed a rounded cell morphology and loss of cell-matrix adhesion. No alteration in cell shape and differentiation were observed in control cells expressing enhanced green fluorescent protein. Perturbation of nebulin altered the cell shape and disrupted cell adhesion in myoblast, demonstrating that nebulin can affect cytoskeleton rearrangement.

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증분형(增分形) 유한요소법(有限要素法)에 의한 축대칭(軸對稱) Shell구조(構造)의 좌굴해석(挫屈解析) (Buckling Analysis of Axisymmetric Shells by Incremental Finite Element Mothod)

  • 김재복;김창렬
    • 대한조선학회지
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    • 제22권1호
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    • pp.21-30
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    • 1985
  • This paper deals whth the buckling as well as postbuckling analysis of axisymmertric shells taking the initial deflection effects into account. Incremental equilibrium equations, based on the principle of virtual work, were derived by the finite element method, the successive step-by-step Newton-Raphson iterative technique was adopted. To define the transition pattern of postbuckling behavior from the prebuckling state more accurately, a simple solution method was developed, i.e. the critical load was calculated by the load extrapolation method with the determinant of tangent stiffness matrix and the equilibrium configuration in the immediate postbuckling stage was obtained by perturbation scheme and eigenvalue analysis. Degenerated isoparametric shell elements were used to analyse the axisymmetric shell of revolution. And by the method developed in this paper, the computer program applicable to the nonlinear analysis of both thin and moderately thick shells was constructed. To verify the capabilities and accuracies of the present solution method, the computed results were compared with the results of analytical solutions. These results coincided fairly well in both the small deflection and large deflection ranges. Various numerical analyses were done to show the effect of initial deflection and shape of shells on buckling load and postbuckling behavior. Futhermore, corrected directions of applied loads at every increment steps were used to determine the actual effects of large deflection in non-conservative load systems such as hydrostatic pressure load. The following conclusions can be obtained. (1) The method described in this paper was found to be both economic and effective in calculating buckling load and postbuckling behavior of shell structure. (2) Buckling and postbuckling behavior of spherical caps is critically dependent upon their geometric configuration, i.e. the shape of spherical cap and quantities of the initial deflection. (3) In the analysis of large deflection problems of shells by the incremental method, corrections of the applied load directions are needed at every incremental step to compensate the follower force effects.

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Robot Manipulator Visual Servoing via Kalman Filter- Optimized Extreme Learning Machine and Fuzzy Logic

  • Zhou, Zhiyu;Hu, Yanjun;Ji, Jiangfei;Wang, Yaming;Zhu, Zefei;Yang, Donghe;Chen, Ji
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제16권8호
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    • pp.2529-2551
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    • 2022
  • Visual servoing (VS) based on the Kalman filter (KF) algorithm, as in the case of KF-based image-based visual servoing (IBVS) systems, suffers from three problems in uncalibrated environments: the perturbation noises of the robot system, error of noise statistics, and slow convergence. To solve these three problems, we use an IBVS based on KF, African vultures optimization algorithm enhanced extreme learning machine (AVOA-ELM), and fuzzy logic (FL) in this paper. Firstly, KF online estimation of the Jacobian matrix. We propose an AVOA-ELM error compensation model to compensate for the sub-optimal estimation of the KF to solve the problems of disturbance noises and noise statistics error. Next, an FL controller is designed for gain adaptation. This approach addresses the problem of the slow convergence of the IBVS system with the KF. Then, we propose a visual servoing scheme combining FL and KF-AVOA-ELM (FL-KF-AVOA-ELM). Finally, we verify the algorithm on the 6-DOF robotic manipulator PUMA 560. Compared with the existing methods, our algorithm can solve the three problems mentioned above without camera parameters, robot kinematics model, and target depth information. We also compared the proposed method with other KF-based IBVS methods under different disturbance noise environments. And the proposed method achieves the best results under the three evaluation metrics.

생식생물학에세 프로테오믹스의 응용 (Potential Importance of Proteomics in Research of Reproductive Biology)

  • 김호승;윤용달
    • 한국발생생물학회지:발생과생식
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    • 제8권1호
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    • pp.1-9
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    • 2004
  • 프로테오믹스(proteomics, 단백질체학이라고도 함)의 잠재적 중요성은 간질환, 심장질환, 몇몇 종류의 암 등의 의학, 생식 독성, 발생 독성, 생체 독성 연구 분야에서도 명백하게 제시되었다. 그러나 단백질을 대상으로 연구하여 유전자 기능을 연구하는 프로테오믹스 연구를 각각의 분야에 접목시키려는 노력은 아직까지 빈약하다. 프로테오믹스는 기능을 갖는 단백질들의 발현을 종합적이고 정량적으로 측정하는 가장 직접적인 수단이고, 질병, 약물투여, 쇼크, 내분비계 장애물질 등 생물학적인 동요(perturbation)에 의하여 변하는 단백질들의 발현 양상 변화를 정확하게 관찰할 수 있게 한다. 그리고 생체내 유전자 발현의 궁극적인 양상을 규명할 수 있으며, 또한 유전자, 단백질 및 질병간의 연결고리를 제공한다. 기존의 biomarker는 다른 질병 표지자와 연관성이 높아 직접적인 biomaker와 정확한 연관을 판정하기 어렵다. 따라서 대량 발굴 탐색(high-throughput screening)이 가능한 2차원 전기 영동 분석과 MALDI-TOF또는 protein chip array와 SELDI-TOF에 의한 단백질 분자 구조 분석 기술 및 이들을 지원하는 생물정보학(bioinformatics)의 발전을 이용하여, 생식학 연구에 이용할 수 있는 표적 단백질 발굴 및 정성 정량적 연구에 적절한 이용이 가능할 것이다. 이러한 연구는 생식과정 중 배아 발생 및 조직 기관 발생 중 유전자 발현의 변화, 내분비계 장애물질 등 호르몬 및 독성 물질의 작용 기전, ecotoxicogenomics지표 marker의 변동 분석, 중간대사물질체학(metabolomics)에의 이용 등등의 연구에 필수적인 방법으로 발전할 것이다.

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라만증폭기의 효율적인 성능분석을 위한 라만방정식의 적분형 전개와 수치해석 알고리즘 (Closed Integral Form Expansion for the Highly Efficient Analysis of Fiber Raman Amplifier)

  • 최락권;박재형;김필한;박종한;박남규
    • 한국광학회지
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    • 제16권3호
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    • pp.182-190
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    • 2005
  • 본 논문은 효율적으로 라만 증폭기의 이득을 예측하고 잡음 특성을 분석하기 위해서 라만 증폭기 상관된 상미분방정식 (Ordinary Differential Equation: ODE)을 유효거리(Effective Length) 기반의 상관된 적분형(closed integral form)방정식 및 매트릭스로 전개하고 이 전개를 활용한 라만 증폭기 모델링 및 수치해석 알고리즘을 기술한다. 광섬유 라만 증폭기는 유연하고 넓은 이득 대역폭 및 낮은 잡음 등의 장점 때문에 최근 광통신 시스템에서 핵심기술로 각광받고 있으며, 특히 멀티채널 펌핑구조에서 성능예측을 위해 많은 라만 증폭기 모델링 방법들이 연구되어 왔다. 그러나 기존의 많은 연구들은 라만 증폭기 상관된 상미분방정식의 해를 "fiber propagation axis"를 기반으로 구해왔기 때문에 광섬유 길이에 의존적이고 복잡한 계산으로 상당히 많은 시간이 필요했으며, 실제 전송 시스템에서의 활용이 어려웠다. 이러한 문제점을 해결하기 위해서 본 논문에서는 기존의 상관된 상미분방정식을 접근이 용이한 "유효거리" 기반의 적분형 방정식으로 전개하고 매트릭스 및 벡터 형태로 알고리즘을 공식화하여 빠른 라만 이득 계산과 "iteration axis"를 이용한 해의 도출을 통해 새로운 라만 증폭기 모델링 방법과 수치해석 알고리즘을 제시하였다. 제안한 수치해석 알고리즘을 전방, 후방 및 양방향 펌핑구조의 라만 증폭기가 도입된 시스템에 적용하는 컴퓨터 모의실험을 수행한 결과 기존의 "Average power method와 비교하여 라만 이득과 광선로 내의 펌프 및 신호 광의 진행정도를 18배 이상의 정밀도에서 0.03 dB 이내의 매우 작은 오차범위 및 100배 이상 단축된 짧은 시간으로 정확히 예측하였다. 또한, 수치해석 알고리즘을 통해서 얻은 신호 광 파워의 분포를 바탕으로 Amplified Spontaneous Emission(ASE), 후방 ASE의 레일레이 산란 및 신호의 이중 레일레이 산란과 같은 라만 증폭기 잡음 요소들을 분석하였다. 새롭게 제안한 수치해석 알고리즘은 실제 광통신 시스템에 적용되어 신속하고 효율적으로 라만 증폭기 성능을 예측하고 분석할 수 있을 것으로 기대된다.