• 제목/요약/키워드: Least Square Solution

검색결과 143건 처리시간 0.026초

Identification of reinforced concrete beam-like structures subjected to distributed damage from experimental static measurements

  • Lakshmanan, N.;Raghuprasad, B.K.;Muthumani, K.;Gopalakrishnan, N.;Basu, D.
    • Computers and Concrete
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    • 제5권1호
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    • pp.37-60
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    • 2008
  • Structural health monitoring of existing infrastructure is currently an important field of research, where elaborate experimental programs and advanced analytical methods are used in identifying the current state of health of critical and important structures. The paper outlines two methods of system identification of beam-like reinforced concrete structures representing bridges, through static measurements, in a distributed damage scenario. The first one is similar to the stiffness method, re-cast and the second one to flexibility method. A least square error (LSE) based solution method is used for the estimation of flexural rigidities and damages of simply supported, cantilever and propped cantilever beam from the measured deformation values. The performance of both methods in the presence of measurement errors is demonstrated. An experiment on an un-symmetrically damaged simply supported reinforced concrete beam is used to validate the developed method. A method for damage prognosis is demonstrated using a generalized, indeterminate, propped cantilever beam.

EEG신호를 이용한 뇌 신호원 국부화에 관한 연구 (Brain Source Localization using EEG Signals)

  • 정재철;송민;이희영
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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    • pp.133-136
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    • 2002
  • EEG(Electroencephalography) is generated by electrical activity between neurons in cortical. Waveform of EEG is changed according to body and mental states. Therefore EEG is used to diagnosis of encephalophyma and epilepsy, etc. Also EEG is used to HCI(Human-Computer Interface). This paper describes estimation of orientation and location of dipole sources. The forward model is three-layer spherical head model and current dipole model. Using analytical solution, EEG is generated. Using MNLS(Minimum-Norm Least-Square) method, orientation and location of dipole moment is estimated.

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천문항법의 전산화에 관한 연구 (Computer Application to Celestial Navigation System)

  • 신영길
    • 한국항해학회지
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    • 제13권2호
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    • pp.1-21
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    • 1989
  • The computer can be used to display a continuously updated list or plot of vessel position. The computer that accept input data from a number of different navigation systems, e.g., Loran , Satnav, Radar, Decca, Compass, Sextant with electrical output etc., can compute the position of a vessel relative to prerecorded objects. The celestial navigation system requires the computer to do not much calculation. Calculation are for trigonometeric, linear systems, finding roots of nonlinear equation and least square estimation etc, . In order to computerize the celestrial navigation system, these calculations must be programmed. The purpose of this thesis is to study the formulation, the design and the test of calculations of the coordinates of celestial bodies, the altitude correction and the solution of the navigational triangle processes.

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전자회절을 이용한 격자상수의 측정 정확도 향상 (Accuracy Improvement of Lattice Parameters Measured from Electron Diffraction Data)

  • 이상길;송경;김진규
    • Applied Microscopy
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    • 제41권1호
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    • pp.75-79
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    • 2011
  • For quantitative analysis of nano-crystal structure, we reported the accuracy improvement method of lattice parameters measured from electron diffraction. For calculation of Au lattice parameters used as a standard crystal structure, it was considered two different acquisition methods (detector and enegy-filter) and three different calculation methods (conventional, least-square and regression fit). As a result, the measurement reliability could be enhanced by using CCD camera which gives higher performance, while energy-filtering did not affect the improvement the camera constant accuracy. Also, the accuracy of lattice parameters could be improved up to $10^{-4}$ order by regression fitting with correction formula. Finally, it is expected that the combination of regression fitting and intensity extraction from energy-filtered precession electron diffraction gives a solution of quantitative structure analysis for unknown nano-crystals.

한전(韓電)EMS의 상태추정기법(狀態推定技法)과 MMI 형식(形式) (State Estimation Method and MMI Format of KEPCO EMS)

  • 이경재;유승철;김영한;이효상
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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    • pp.866-869
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    • 1988
  • In the operation of a power system, the security of the system has acquired significant importance to supply electric power of better quality. The State Estimator, a part of security functions, provides a complete real time solution estimate of the steady-state conditions of the power system for use by the Real Time Network Analysis functions. This paper briefly introduces the Fast Decoupled Weighted Least Square State Estimator which is adopted in the KEPCO EMS with features of Man-Machine Interface.

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제한조건을 갖는 케이블-네트 구조물의 형상결정에 관한 연구 (A Study on Shape Determination of Cable-Net Structures with Restrained Conditions)

  • 이장복;권택진;하창우
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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    • pp.325-332
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    • 1999
  • As part of the conceptual disign of cable and membrane structures, the adequate shape is decisive with respect to load bearing behaviour and aesthetic expression of the structure. The force densities which are the force-length ratio are very useful parameters for the description of equilibrium state of any general cable-net structures. Because equilibrium states are obtained by solving linear equations the force desity method has a advantage compared with other solution strategies. But if there are futher restrainted conditions in force density the linear method will be extended to nonlinear one. The numeriacl methods are based upon least square and general inverse method for sieving nonlinear eqations. In this paper, the results from two methods is compared through several examples.

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탄성지반 위의 축대칭 하중을 받는 원판의 접촉응력 해석에 관한 연구 (The Study on the Determination of the Contact Area of the Circular Plate Resting on Elastic Half-space under Axisymmetric Loading)

  • 조현영;정진환;김성철
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1997년도 가을 학술발표회 논문집
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    • pp.87-94
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    • 1997
  • The circular plate resting on Boussinesq's half-space model under axisymmetric loading is studied by a finite element procedure to evaluate the distribution of contact pressure between plate and elastic half-space. The displacement of half-space due to axisymmetric surface loading can be evaluated by double integration of Boussinesq's solution. On that case the analytical integration can be executed for the radial direction but the analytical integration for the circumferential direction is impossible and the numerical integration should be considered. With the radial integration we can get non-dimensional function. Then the numerical integration for the formula is executed for the circumferential direction and the results are approximated 5th order Polynomials by using the least square method. With these 5th order approximate formula, the flexibility matrix of half-space is constructed as the coefficient matrix of nodal contact pressure by the finite element procedures. Iteration procedures are attempted by using this method to determine the separated region.

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DLMS 알고리즘의 수렴에 관한 연구 (Almost-Sure Convergence of the DLMS Algorithm)

  • Ahn, Sang Sik
    • 전자공학회논문지B
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    • 제32B권9호
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    • pp.62-70
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    • 1995
  • In some practical applications of the LMS Algorithm the coefficient adaptation can be performed only after some fixed delay. The resulting algorithm is known as the Delayed Least Mean Square (DLMS) algorithm in the literature. There exist analyses for this algorithm, but most of them are based on the unrealistic independence assumption between successive input vectors. Inthis paper we consider the DLMS algorithm with decreasing step size .mu.(n)=n/a, a>0 and prove the almost-sure convergence ofthe weight vector W(n) to the Wiener solution W$_{opt}$ as n .rarw. .inf. under the mixing unput condition and the satisfaction of the law of large numbers. Computer simulations for decision-directed adaptive equalizer with decoding delay are performed to demonstrate the functioning of the proposed algorithm.m.

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Studies on Corneal Penetration of P-Hydroxybenzoic Acid Esters

  • Lee, Chi-Ho;Lee, Kyoung-Jin;Yun, Il;Shin, Young-Hee
    • Archives of Pharmacal Research
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    • 제14권4호
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    • pp.311-318
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    • 1991
  • Corneal permeability of various n-alkyl p-hydroxybenzoates (parabens) was studied in vitro using excised rabbit corneas, and the effect of lipophilicity of parabens on the corneal permeability was also investigated. Permeability coefficients were obtained from the least-square linear regression after the steady state had been reached. Lipophilicity of parabens was calculated by distribution coefficients determined in octanol-S | $12{\phi}{\parallel}$) rensen's buffer solution (pH 5.0). The relationship between lipophilicity and corneal permeability of parabens was not linear, but the optimum lipophilicity for the maximum permeation was found. The influence of tween 80 on corneal permeability of methyl and butylparaben was not significant.

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일정한 기준신호를 추적하는 MRAC시스템에 대한 파라미터 수렴특성 (Parameter convergence properties for MRAC system with a constant reference signal tracking)

  • 민병태;김성덕;양해원
    • 한국통신학회논문지
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    • 제13권1호
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    • pp.1-11
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    • 1988
  • 本 論文은 일정한 基準信號를 사용하는 基準모델 適應制御 시스템에 대한 可調節 파라미터의 有界性을 說明한다. 이 解析法은, Lyapunov函數의 또다른 性質로서 適應시스템의 安定度는 물론, 파라미터의 存在性, 有界性 및 有界領域을 밝힐 수 있다는 사실에 동기되었다. 2가지 適應則, 즉 一般的인 句配法(GGM) 및 最小自秉法(LSM)에 대하여, 여기서 提示된 새로운 方法에 의하여 파라미터 空間의 유일한 解集合을 확립할 수 있다. 파라미터 空間 解析法의 效率性을 證明하기 위한 電算機 시뮬레이션 結果도 역시 검토한다.

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