Online Identification with Least Square Method for Pseudo-Dynamic Tests

2011 ◽  
Vol 250-253 ◽  
pp. 2455-2459 ◽  
Author(s):  
Tao Wang ◽  
Bin Wu ◽  
Jian Zhang

Numerical substructures adopt predetermined hysteretic models for conventional substructure testing (CST). It is difficult to achieve accurate results in CST due to errors from modelling of numerial substructures. To diminish the negative effect caused by the assumed restoring model, online identification with least square method using experimental data was adopted to update the model of numerical substructure. The effectiveness of least square method are verified with pseudo-dynamic substructure testing for single story frame with a buckling-restrained brace. The results indicate that the on-line identification algorithm based least square method has good accuracy, stability, and efficiency.

2011 ◽  
Vol 135-136 ◽  
pp. 179-186
Author(s):  
Biao Wang ◽  
Chang Qing Wang ◽  
Feng Ru ◽  
Xiao Lan Ma

Multiple has accused of unknown parameter optimization problems of implementation of the object. Containing identification link should adaptive objective coordinate optimization control system. The local objects in decomposition based on optimizing, application target coordinate law to selected optimal criteria based on the minimum value to ensure coordinated operation in the process of making optimal index for global convergence, achieve the purpose of overall optimization. In order to execute real time on-line identification, Recursion least square method (RLS) could be used for the estimation of object parameter in the identification section.


1981 ◽  
Vol 20 (06) ◽  
pp. 274-278
Author(s):  
J. Liniecki ◽  
J. Bialobrzeski ◽  
Ewa Mlodkowska ◽  
M. J. Surma

A concept of a kidney uptake coefficient (UC) of 131I-o-hippurate was developed by analogy from the corresponding kidney clearance of blood plasma in the early period after injection of the hippurate. The UC for each kidney was defined as the count-rate over its ROI at a time shorter than the peak in the renoscintigraphic curve divided by the integral of the count-rate curve over the "blood"-ROI. A procedure for normalization of both curves against each other was also developed. The total kidney clearance of the hippurate was determined from the function of plasma activity concentration vs. time after a single injection; the determinations were made at 5, 10, 15, 20, 30, 45, 60, 75 and 90 min after intravenous administration of 131I-o-hippurate and the best-fit curve was obtained by means of the least-square method. When the UC was related to the absolute value of the clearance a positive linear correlation was found (r = 0.922, ρ > 0.99). Using this regression equation the clearance could be estimated in reverse from the uptake coefficient calculated solely on the basis of the renoscintigraphic curves without blood sampling. The errors of the estimate are compatible with the requirement of a fast appraisal of renal function for purposes of clinical diagknosis.


2015 ◽  
Vol 742 ◽  
pp. 252-256 ◽  
Author(s):  
Yuan Jin Li ◽  
Hua Zhong Shu ◽  
Tao Wang ◽  
Yang Wang ◽  
You Yong Kong

The distorted X-Ray Image Intensifier (XRII) image can introduce negative effect on following work for C-arm CT imaging system. In this paper, we propose an integrated approach based on least squares and Biharmonic spline interpolation to correct geometric distortions of XRII images. The method first uses morphology operation to extract the coordinate values of control points. Then the least square method fits the extracted coordinate values in every row and computes the more coordinate values by fixing the length in every row. Finally, The Biharmonic spline interpolation is used to interpolate the all coordinate values and correct the distortional XRII image. The experiment shows that the integrated method can effectively correct the distorted XRII image.


Author(s):  
Qi Lu ◽  
Ou Ma

The body segment parameters (BSP) of a human body are critical information for modeling, simulating, and understanding human dynamics. The determination of BSPs of human bodies has received increasing attention in biomechanics, sport science, ergonomics, rehabilitation and other fields. This paper presents a momentum-based identification algorithm for dynamically estimating the BSPs of a human body. The human body is modeled as a multibody dynamical system, and the momentum equation of the system can be derived by applying the principle of impulse and momentum. It is possible to formulate the momentum equations corresponding to a set of experiment tests into a linear regression form with respect to the unknown BSPs, which then can be solved using the least square method or other methods. The momentum-based algorithm requires inputting position, velocity, and external force data only. Since acceleration and all the internal force data is not needed, the algorithm is less demanding on measurements and is also less sensitive to measurement errors. As a result, it is practically more appealing than the algorithms depending on the equations of motion. The paper presents the momentum-based inertia identification algorithm along with a simulation study of the algorithm using a simplified trunk-leg model representing a main portion of a human body.


2014 ◽  
Vol 551 ◽  
pp. 237-243
Author(s):  
Yan Hua Cai ◽  
Jian Yong Liu ◽  
Lian Tong Ding ◽  
Shi Shan He ◽  
Shi Fu Zhang

The main structure and key components of the precision EDM equipment are analyzed and researched in this paper. Key components such as main structure, A-axis, W-axis and R-axis are designed. Aimed to machine several kinds of diameters on a work piece, an on-line electrode milling method is studied. And then test this method on an EDM machine. Based on the test results, the functional relation between diameters and the wears of the electrode is confirmed by the least square method. According to this function, the efficiency of the EDM machining for the precision micro-holes is improved.


2014 ◽  
Vol 490-491 ◽  
pp. 1391-1398
Author(s):  
Xiao Ping Li

This article proposes the necessity and feasibility of the use of Data Mining and Knowledge Discovery in CBR reasoning. This paper focuses on the method of empowering feature items based on least squares method parameter identification, and achieve the method of Similarity case retrieval on this basis, the object is the typical case database of railway rescue. The simulation results show that: the least square method can effectively make estimation and identification of the feature parameters, and can continuously correct on-line. High accuracy and fast convergence characteristics of the assigned parameters show that the algorithm has a certain application value.


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