• 제목/요약/키워드: system identification

검색결과 5,942건 처리시간 0.033초

Identification of 18 flutter derivatives by covariance driven stochastic subspace method

  • Mishra, Shambhu Sharan;Kumar, Krishen;Krishna, Prem
    • Wind and Structures
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    • 제9권2호
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    • pp.159-178
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    • 2006
  • For the slender and flexible cable supported bridges, identification of all the flutter derivatives for the vertical, lateral and torsional motions is essential for its stability investigation. In all, eighteen flutter derivatives may have to be considered, the identification of which using a three degree-of-freedom elastic suspension system has been a challenging task. In this paper, a system identification technique, known as covariance-driven stochastic subspace identification (COV-SSI) technique, has been utilized to extract the flutter derivatives for a typical bridge deck. This method identifies the stochastic state-space model from the covariances of the output-only (stochastic) data. All the eighteen flutter derivatives have been simultaneously extracted from the output response data obtained from wind tunnel test on a 3-DOF elastically suspended bridge deck section-model. Simplicity in model suspension and measurements of only output responses are additional motivating factors for adopting COV-SSI technique. The identified discrete values of flutter derivatives have been approximated by rational functions.

Story-wise system identification of actual shear building using ambient vibration data and ARX model

  • Ikeda, Ayumi;Fujita, Kohei;Takewaki, Izuru
    • Earthquakes and Structures
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    • 제7권6호
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    • pp.1093-1118
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    • 2014
  • A sophisticated story-wise stiffness identification method for a shear building structure is applied to the case where the shear building is subjected to an actual micro-tremor. While the building responses to earthquake ground motions are necessary in the previous method, it is shown that micro-tremors can be used for identification within the same framework. This enhances the extended usability and practicality of the previously proposed identification method. The difficulty arising in the limit manipulation at zero frequency in the previous method is overcome by introducing an ARX model. The weakness of small SN ratios in the low frequency range is avoided by using the ARX model together with filtering and introducing new constraints on the ARX parameters.

한국방공식별구역(KADIZ) 발전방안 (The Development Option for Korea Air Defense Identification Zone(KADIZ))

  • 김동수;홍성표;정맹석
    • 항공우주시스템공학회지
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    • 제10권1호
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    • pp.127-132
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    • 2016
  • Recently, China & Japan have expanded their responding ADIZ(Air Defence Identification Zone) to implement each Government's maritime policy and to project their Air Power in preparation for maritime provocation & contingency, especially over the piled area where East Asia countries have claimed to have maritime jurisdiction one another. So this is to guide the Development Option for Korea Air Defence Identification Zone to cope with the maritime intentions of the neighboring countries, considering the international law for ADIZ, the maritime policy and the maritime sovereign & jurisdiction area of the Republic of Korea, etc.

Parameter Identification of Induction Motors using Variable-weighted Cost Function of Genetic Algorithms

  • Megherbi, A.C.;Megherbi, H.;Benmahamed, K.;Aissaoui, A.G.;Tahour, A.
    • Journal of Electrical Engineering and Technology
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    • 제5권4호
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    • pp.597-605
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    • 2010
  • This paper presents a contribution to parameter identification of a non-linear system using a new strategy to improve the genetic algorithm (GA) method. Since cost function plays an important role in GA-based parameter identification, we propose to improve the simple version of GA, where weights of the cost function are not taken as constant values, but varying along the procedure of parameter identification. This modified version of GA is applied to the induction motor (IM) as an example of nonlinear system. The GA cost function is the weighted sum of stator current and rotor speed errors between the plant and the model of induction motor. Simulation results show that the identification method based on improved GA is feasible and gives high precision.

Application to the design of reduced-order robust MPC and MIMO identification

  • Lee, Kwang-Soon;Kim, Sang-Hoon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.313-316
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    • 1997
  • Two different issues, design of reduced-order robust model predictive control and input signal design for identification of a MIMO system, are addressed and design techniques based on singular value decomposition(SVD) of the pulse response circulant matrix(PRCM) are proposed. For this, we investigate the properties of the PRCM, which is a periodic approximation of a linear discrete-time system, and show its SVD represents the directional as well as the frequency decomposition of the system. Usefulness of the PRCM and effectiveness of the proposed design techniques are demonstrated through numerical examples.

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비선형 시스템 식별을 위한 수정된 elman 신경회로망 구조 (Modified elman neural network structure for nonlinear system identification)

  • 정경권;권성훈;이인재;이정훈;엄기환
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 하계종합학술대회논문집
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    • pp.917-920
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    • 1998
  • In this paper, we propose a modified elman neural network structure for nonlinear system identification. The proposed structure is that all of network output feed back into hidden units and output units. Learning algorithm is standard back-propagation algorithm. The simulation showed the effectiveness of using the modified elman neural network structure in the nonlinear system identification.

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소형 무인 헬리콥터의 시스템 식별 (System Identification of a Small Unmanned Rotorcraft)

  • 류성숙;송용규
    • 제어로봇시스템학회논문지
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    • 제15권1호
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    • pp.44-53
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    • 2009
  • In this paper, Recursive Least Squares (RLS) and Fourier Transform Regression (FTR) methods for estimating stability and control derivatives of small unmanned helicopter are evaluated together with MMLE technique. Flight data simulated by using a commercial small-scale helicopter model are exploited to estimate the parameters with accuracies for hover and cruise modes. The performances of the system identification methods are also compared by analyzing the responses of the reconstructed systems using estimated derivatives.

System Identification 개념을 이용한 ECG 신호의 적응 잡음 제거 (Adaptive Noise Cancelling in ECG Signals Using System Identification Concepts)

  • 남현도;안동준
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1993년도 춘계학술대회
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    • pp.74-77
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    • 1993
  • Estimation and removal of power line interference in the electrocardiogram using adaptive noise cancelling techniques is presented. The system identification concepts are used to design the noise cancelling filter and the prediction error method is used to adjust filter coefficients. Computer simulation were performed to compare this method with the Lekov's method.

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과소제동 공정제어시스템의 식별에 대한 연구 (A Study on the Identification of Underdamped Process Control System)

  • 서병설
    • 한국정밀공학회지
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    • 제4권3호
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    • pp.35-43
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    • 1987
  • A new analytic method for the identification of process control system is presented. A second and a third order transfer function are considered as the estimated model function. For the second order transfer function, the new method is compared with the exisiting ones, simulation results show that the new method is superior to the existing ones. And also, In case of the third order transfer function which is difficult to analyze mathematically, system identification is tried.

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궐음병(厥陰病) 백호탕(白虎湯)으로 진단된 어지럼증 환자 1례 (A Case of a Patient with Dizziness Diagnosed with Guorem-byeong Baekho-tang)

  • 최운용
    • 대한상한금궤의학회지
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    • 제10권1호
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    • pp.143-152
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    • 2018
  • Objective : A Patient complaining of dizziness was diagnosed and treated with the Shanghanlun disease pattern identification diagnostic system and was analyzed to report cases Methods : Based on the Shanghanlun disease pattern identification diagnostic system, we analyzed a case treated with the Baekho-tang and counseling. Results : Baekho-tang showed a rapid improvement in the patient. During the period of 20 days, dizziness were greatly improved. Conclusions : The Baekho-tang, which is not well known yet, can show rapid effect and can be diagnosed frequently through the Shanghanlun disease pattern identification diagnostic system.

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