scholarly journals Correlations for calculating the transport and thermodynamic properties of lead-bismuth eutectic

2020 ◽  
Vol 6 (2) ◽  
pp. 125-130
Author(s):  
Igor A. Chusov ◽  
Vladimir G. Pronyaev ◽  
Grigory Ye. Novikov ◽  
Nikolay A. Obysov
Keyword(s):  
Experimental Studies ◽  
Calculated Data ◽  
Statistical Processing ◽  
Least Square Method ◽  
Least Square ◽  
Temperature Ranges ◽  
State Corporation ◽  
Density Dynamic ◽  
Data Estimation ◽  
Local Speed

The paper presents recommended correlations for calculating the thermodynamic and transport properties of Pb-Bi eutectic (44.5% Pb + 55.5% Bi), namely: density, dynamic viscosity, specific heat, thermal conductivity, surface tension, specific electrical resistance, and local speed of sound as a function of temperature. These correlations are based on calculated data presented in 39 experimental studies performed in our country and abroad and published during the period from 1923 to 2015. The authors had information on 1103 experimental points; however, a direct assessment was performed on 1076 points. The main difficulty in processing the data was that the experiments considered in the work were performed at different times using a variety of measurement methods, non-unified methods of statistical processing, varying degrees of eutectic purity, etc. The basis of the data estimation technique was the modified least square method, which made it possible to take into account the errors of the experimental data involved. The paper gives the error values of the proposed correlations and the temperature ranges of their applicability. The paper was prepared based on the results of the work of the Thermodynamic Data Center (TDC INPE NRNU MEPhI) of Rosatom State Corporation.

scholarly journals Piecewise Curve Fitting Based on Least Square Method in 3D Space

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Lihong Xue
Keyword(s):  
Least Squares ◽  
Curve Fitting ◽  
Dimensional Space ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Least Square Method ◽  
Least Square ◽  
Least Square Fitting ◽  
Fitting In ◽  
Three Dimensional Space

Least squares curve fitting is widely used in various neighborhoods, such as industry, agriculture, and economy. The method of piecewise curve fitting is used to deal with some experimental studies with large amounts of data. It can not only be used for plane space points, but also for three-dimensional space points. Firstly, this article introduces the principles of curve fitting and least squares. Secondly, it clarifies the steps based on least square fitting and gives examples of improvements made based on the principle of least square fitting functions by some scientists. Finally, the piecewise curve fitting in the three-dimensional space is obtained using the least squares piecewise curve fitting. It lays a certain theoretical foundation for drawing the laws between data in three-dimensional space.

scholarly journals A study on modeling of a piezoelectric motor

2021 ◽  
Vol 12 (2) ◽  
pp. 695
Author(s):  
Youssef Baba ◽  
Mostafa Bouzi
Keyword(s):  
Model Comparison ◽  
Control Strategies ◽  
Fuzzy Model ◽  
Calculated Data ◽  
Least Square Method ◽  
Least Square ◽  
Driving Voltage ◽  
Unknown Parameters ◽  
Rotating Speed ◽  
Takagi Sugeno

n this paper, a study on modeling of a piezoelectric transducer type rotary traveling wave ultrasonic motor (USM) is presented. First a mathematical model and numerical simulation results are achieved. The model is based on the theory of piezoelectricity and physic theory. An experimental model is worked out and compared to the numerical model. The influence of the temperature on characteristics such as the rotational speed of the motor is considered. The speed of the USM is measured at temperature between 17°Cand 50°C. To develop suitable control strategies for the drive, a fuzzy model type Takagi-Sugeno is used. The unknown parameters of the output membership functions are determined by least square method. Experimental data are used to examine the validity of the fuzzy model. Comparison between experimental and calculated data of the fuzzy model indicates that the fuzzy model can well describe the nonlinear characteristics among the frequency of driving voltage and rotating speed.

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.

PENGARUH KNOWLEDGE MANAGEMENT, KOMPETENSI, MOTIVASI TERHADAP KINERJA KARYAWAN

2015 ◽  
Vol 5 (2) ◽  
pp. 1
Author(s):  
Miftahol Arifin
Keyword(s):  
Knowledge Management ◽  
Linear Regression ◽  
Significant Influence ◽  
Employee Performance ◽  
Least Square Method ◽  
Least Square ◽  
Analysis Tool ◽  
Ordinary Least Square ◽  
Competence Motivation ◽  
Performance Analyze

The purpose of this research is to analyze the influence of knowledge management on employee performance, analyze the effect of competence on employee performance, analyze the influence of motivation on employee performance). In this study, samples taken are structural employees PT.centris Kingdom Taxi Yogyakarta. The analysis tool in this study using multiple linear regression with Ordinary Least Square method (OLS). The conclusion of this study showed that the variables of knowledge management has a significant influence on employee performance, competence variables have an influence on employee performance, motivation variables have an influence on employee performance, The analysis showed that the variables of knowledge management, competence, motivation on employee performance.Keywords: knowledge management, competence, motivation, employee performance.

Peristaltic Carreau-Yasuda nanofluid flow and mixed heat transfer analysis in an asymmetric vertical and tapered wavy wall channel

2020 ◽  
Vol 1 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Mohammad Hatami ◽  
◽  
D Jing ◽  
Keyword(s):  
Heat Transfer ◽  
Least Square Method ◽  
Weissenberg Number ◽  
Least Square ◽  
Heat Transfer Analysis ◽  
Phase Method ◽  
Nanofluid Flow ◽  
Two Phase ◽  
Nanoparticles Concentration ◽  
The Right

In this study, two-phase asymmetric peristaltic Carreau-Yasuda nanofluid flow in a vertical and tapered wavy channel is demonstrated and the mixed heat transfer analysis is considered for it. For the modeling, two-phase method is considered to be able to study the nanoparticles concentration as a separate phase. Also it is assumed that peristaltic waves travel along X-axis at a constant speed, c. Furthermore, constant temperatures and constant nanoparticle concentrations are considered for both, left and right walls. This study aims at an analytical solution of the problem by means of least square method (LSM) using the Maple 15.0 mathematical software. Numerical outcomes will be compared. Finally, the effects of most important parameters (Weissenberg number, Prandtl number, Brownian motion parameter, thermophoresis parameter, local temperature and nanoparticle Grashof numbers) on the velocities, temperature and nanoparticles concentration functions are presented. As an important outcome, on the left side of the channel, increasing the Grashof numbers leads to a reduction in velocity profiles, while on the right side, it is the other way around.

Fast noise removal algorithm for HDR image based on least square method

2009 ◽  
Vol 29 (4) ◽  
pp. 994-996
Author(s):  
De-quan SUN ◽  
Jun ZHANG ◽  
Xiao-feng LI ◽  
Hui LI
Keyword(s):  
Least Square Method ◽  
Noise Removal ◽  
Least Square ◽  
Hdr Image

Model-based control of the substrate concentration in an aeration basin using the wastewater level

1998 ◽  
Vol 37 (12) ◽  
pp. 335-342 ◽  
Author(s):  
Jacek Czeczot
Keyword(s):  
Substrate Concentration ◽  
Consumption Rate ◽  
Least Square Method ◽  
Estimation Procedure ◽  
Adaptive Controller ◽  
Open Loop ◽  
Least Square ◽  
Substrate Consumption ◽  
Model Based ◽  
Effluent Flow Rate

This paper deals with the minimal-cost control of the modified activated sludge process with varying level of wastewater in the aerator tank. The model-based adaptive controller of the effluent substrate concentration, basing on the substrate consumption rate and manipulating the effluent flow rate outcoming from the aerator tank, is proposed and its performance is compared with conventional PI controller and open loop behavior. Since the substrate consumption rate is not measurable on-line, the estimation procedure on the basis of the least-square method is suggested. Finally, it is proved that cooperation of the DO concentration controller with the adaptive controller of the effluent substrate concentration allows the process to be operated at minimum costs (low consumption of aeration energy).

scholarly journals Performance evaluation of GPS / BDS combined single-point positioning based on RTKLIB

2020 ◽  
Vol 165 ◽  
pp. 03009
Author(s):  
Li Yan-yi ◽  
Huang Jin ◽  
Tang Ming-xiu
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Single Point ◽  
Least Square Method ◽  
Least Square ◽  
Filter Method ◽  
Single System ◽  
Positioning Error ◽  
Dual Mode ◽  
Kalman Filter Method

In order to evaluate the performance of GPS / BDS, RTKLIB, an open-source software of GNSS, is used in this paper. In this paper, the least square method, the weighted least square method and the extended Kalman filter method are respectively applied to BDS / GPS single system for data solution. Then, the BDS system and GPS system are used for fusion positioning and the positioning results of the two systems are compared with that of the single system. Through the comparison of experiments, on the premise of using the extended Kalman filter method for positioning, when the GPS signal is not good, BDS data is introduced for dual-mode positioning, the positioning error in e direction is reduced by 36.97%, the positioning error in U direction is reduced by 22.95%, and the spatial positioning error is reduced by 16.01%, which further reflects the advantages of dual-mode positioning in improving a system robustness and reducing the error.

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