Direct Assessment of Effective Renal Plasma Flow from Renoscintigraphy with a Gamma Camera and an On-Line Computer

1981 ◽  
Vol 20 (06) ◽  
pp. 274-278
Author(s):  
J. Liniecki ◽  
J. Bialobrzeski ◽  
Ewa Mlodkowska ◽  
M. J. Surma
Keyword(s):  
Count Rate ◽  
Renal Plasma Flow ◽  
Early Period ◽  
Least Square Method ◽  
Least Square ◽  
Uptake Coefficient ◽  
Positive Linear Correlation ◽  
On Line ◽  
Best Fit ◽  
Plasma Activity

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.

Research on the EDM Equipment and the Machining Technology of the Precision Micro-Hole

2014 ◽  
Vol 551 ◽  
pp. 237-243
Author(s):  
Yan Hua Cai ◽  
Jian Yong Liu ◽  
Lian Tong Ding ◽  
Shi Shan He ◽  
Shi Fu Zhang
Keyword(s):  
Functional Relation ◽  
Least Square Method ◽  
Least Square ◽  
Work Piece ◽  
Test Results ◽  
Main Structure ◽  
Micro Holes ◽  
Milling Method ◽  
Micro Hole ◽  
On Line

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.

Research on Boundary Extraction of STL Models based on Genetic Algorithm

2012 ◽  
Vol 566 ◽  
pp. 78-81
Author(s):  
Jing Bin Hao ◽  
Zhong Bin Wang ◽  
Hai Feng Yang ◽  
Zhong Kai Li
Keyword(s):  
Genetic Algorithm ◽  
Extraction Method ◽  
Least Square Method ◽  
Least Square ◽  
Threshold Method ◽  
Boundary Extraction ◽  
Large Complex ◽  
Complex Models ◽  
Curvature Information ◽  
Best Fit

To efficiently decompose a large complex STL model, an improved boundary extraction method is proposed based on genetic algorithm. Three curvature parameters (dihedral angle, perimeter ration and convexity) were used to estimate the surface curvature information. Genetic Algorithm (GA) is used to determinate the threshold of feature edge. The discrete feature edges are grouped and filtered using the best-fit plane (BFP), which is calculated by Least Square Method (LSM). Several experimental results demonstrate that the amount of feature edges is about half of the preset threshold method, and useful feature edges were reserved. The extracted feature boundaries can be directly used to decompose large complex models.

Methods of Feature Weighting Calculation and Case Retrieval in CBR Case Base

2014 ◽  
Vol 490-491 ◽  
pp. 1391-1398
Author(s):  
Xiao Ping Li
Keyword(s):  
Least Squares Method ◽  
Least Square Method ◽  
High Accuracy ◽  
Typical Case ◽  
Feature Weighting ◽  
Least Square ◽  
Case Retrieval ◽  
Use Of Data ◽  
On Line ◽  
Simulation Results

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.

scholarly journals Modeling the effect of age at calving × breed group of dam's interaction on weaning weight of Charolais-Zebu crossbred calves

2010 ◽  
Vol 39 (5) ◽  
pp. 1046-1057 ◽  
Author(s):  
Fábio Luiz Buranelo Toral ◽  
Roberto Augusto de Almeida Torres Júnior ◽  
Paulo Sávio Lopes ◽  
Luiz Otávio Campos da Silva ◽  
João Cruz Reis Filho
Keyword(s):  
Group Interaction ◽  
Least Square Method ◽  
Genetic Group ◽  
Least Square ◽  
Regression Coefficients ◽  
Weaning Weight ◽  
Breed Group ◽  
Group Sex ◽  
Squared Residuals ◽  
Best Fit

The objective of this study was to evaluate alternatives for modeling the interaction between age of dam at calving (AOD) and the dam genetic group (DGG) on the weaning weight (W225) of Charolais-Zebu (Ch-Z) crossbred calves. Data from 56,965 crossbred calves were analyzed by the least square method. Regression coefficients for age of dam at calving were estimated nested into each class of the dam genetic group (CLA model); for age of dam at calving × dam Charolais percentage (age of dam at calving × FCh) and age of dam at calving × dam heterozygosity (age of dam at calving × FH) (FChFH model); for age of dam at calving × dam Charolais percentage (FCh model); for age of dam at calving × FH (FH model); or only for age of dam at calving (NINT model). Segmented polynomials were used to model the general shape of the age of dam at calving effect and its interaction with dam genetic group. The knots were at 6.33 and 10.66 years of age of dam at calving and general linear and quadratic coefficient regression and specific quadratic coefficient regression after each knot were fitted. The regression coefficients were estimated nested within sex of the calf in all situations. According to the F test for sum of squared residuals differences, the inclusion of the age of dam at calving × FH interaction did not improve the fit of the model and the CLA model provided the best fit. However, the estimates of the age of dam at calving and dam genetic group interaction from the CLA model for dam genetic group × sex of the calf classes with few records were not appropriate, but the estimates of the age of dam at calving and dam genetic group interaction from the FCh model for those classes were appropriate. The differences were small in the estimates of the age of dam of calving and dam genetic group interaction from the CLA or FCh models for dam genetic group × sex of the calf classes with many records.

On-Line Parameter Identification of an Induction Motor With Closed-Loop Speed Control Using the Least Square Method

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Rafael de Farias Campos ◽  
Eduardo Couto ◽  
Jose de Oliveira ◽  
Ademir Nied
Keyword(s):  
Control System ◽  
Induction Motor ◽  
Least Squares Method ◽  
Least Square Method ◽  
Parametric Identification ◽  
Least Square ◽  
Electrical Parameters ◽  
On Line ◽  
Single Matrix ◽  
Vector Control System

The control system of induction motors is designed to achieve dynamic stability, allowing accurate tracking of flux and speed. However, changes in electrical parameters, due to temperature rise or saturation level, can lead to undesirable errors of speed and position, eventually resulting in instability. This paper presents two modes for parametric identification of the induction motor based on the least squares method: batch estimator and recursive estimator. The objective is to update the electrical parameters during operation when the motor is driven by a vector control system. A drawback related to the batch estimator is the need for high quantity of available memory to make the process of identification robust enough. The proposed algorithm allows the batch estimator to be viewed as a single matrix problem reducing the need for processing memory. The identification procedure is based on the stator currents measurement and stator fluxes estimation. Basically, both modes of identification will be analyzed. Experimental results are presented to demonstrate the theoretical approach.

Development of Measurement System for Accuracy Control in Subsection Manufacture

2008 ◽  
Vol 381-382 ◽  
pp. 79-82
Author(s):  
F. Zhang ◽  
Xing Hua Qu ◽  
J.F. Dai ◽  
S. Ye
Keyword(s):  
Least Square Method ◽  
Least Square ◽  
Measuring System ◽  
Large Radius ◽  
Accuracy Control ◽  
Data Processing Software ◽  
Geometrical Information ◽  
Cloud Points ◽  
Processing Software ◽  
Best Fit

The computer aided measuring system is established to evaluate geometrical information of the structure in subsection manufacture. The cloud points data of surface are collected by laser tracker so as to explore continuing data processing software and evaluate the error of dimension and shape, and then the real measuring model, matched by the corner information, is compared with CAD through the best-fit algorithm. The lack of fitting information which will cause the low measuring precision is solved by the least square method constrained by radius in structure with large radius and small central angle. As the research object, the tunnel structure is used in the quality control of manufacturers.

Study of the On-Line Monitoring on the Effect of Laser Shock Processing for Residual Stress by the Properties of Acoustic Wave

2010 ◽  
Vol 44-47 ◽  
pp. 680-687
Author(s):  
Yang Li ◽  
Hai Yong Qin
Keyword(s):  
Residual Stress ◽  
Acoustic Wave ◽  
Acoustic Waves ◽  
Least Square Method ◽  
Correlation Equation ◽  
Least Square ◽  
Laser Shock ◽  
Laser Shock Processing ◽  
On Line ◽  
Shock Processing

In order to realize the on-line monitoring of the effect of laser shock processing(LSP),acoustic waves generated during the LSP of 45 steel are measured in real time by a wide-band microphone and digitized at a sampling frequency of 48KHz.The waveforms of the received acoustic signal imported to MATLAB are analyzed and in order to investigate the frequency characteristic of the acoustic wave, a power spectral density(PSD) analysis has been carried out. Based on the value of the largest peak of the PSD and compressive residual stress of metal materials induced by the laser shock processing, the correlation equation was established with the application of least square method for the on-line monitoring.

Sign in / Sign up

Export Citation Format

Share Document