An Improved Model-Free Sampling Technique Based on Bootstrap Methods

2016 ◽  
Author(s):  
Xinshui Yu ◽  
Zhaohui Yang ◽  
Kunling Song ◽  
Tianxiang Yu ◽  
Bozhi Guo
Keyword(s):  
Random Variables ◽  
Sampling Technique ◽  
Improved Method ◽  
Initial Sample ◽  
Bootstrap Methods ◽  
Local Characteristics ◽  
Model Free ◽  
Improved Model ◽  
Center Distance ◽  
Selection Of

The distribution and parameters of the random variables is an important part of conventional reliability analysis methods, such as Monte Carlo method, which should be known fist before using these methods, but it is often hard or impossible to obtain. Model-free sampling technique puts forward a method to get the distribution of the random variables, but the accuracy of the extended sample generated by it is not enough. This paper presented an improved model-free sampling technique, which is based on Bootstrap methods, to increase the accuracy of the extended sample and decrease the iteration times. In this improved model-free sampling technique, the method of the selection of initial sample points and the generation of iterative sample is improved. Meanwhile, a center distance criterion, which considers the local characteristics of the extended sample, is added to the generating criterion of dissimilarity measure. The effectiveness of this improved method is illustrated through some numerical examples.

A Probabilistic Representation Method for Interval Uncertainty

2018 ◽  
Vol 15 (05) ◽  
pp. 1850038 ◽  
Author(s):  
Changcong Zhou ◽  
Chenghu Tang ◽  
Fuchao Liu ◽  
Wenxuan Wang
Keyword(s):  
Sampling Technique ◽  
Small Sample ◽  
Interval Uncertainty ◽  
Statistical Characteristics ◽  
Density Estimator ◽  
Probabilistic Representation ◽  
Model Free ◽  
Two Samples ◽  
Representation Method ◽  
Improved Model

In this work, we consider the interval uncertainty from the probabilistic point of view, focusing on the establishment of probabilistic representation of interval uncertainty. A model-free sampling technique is first introduced, which can be used to produce a considerably larger sample from a given small sample. To make sure the local statistical characteristics of these two samples coincide, an improved model-free sampling technique is introduced based on probability weighted moments. The improved model-free sampling technique is then applied to obtain a large sample based on interval data, of which the probability distribution is produced by the kernel density estimator. Highest density regions based on estimated probability density function have been considered to further investigate the underlying information. The proposed probabilistic representation method is employed in the attempt of interval uncertainty propagation with the results compared with previous studies. The research adds a possible tool in the treatment of interval uncertainty.

Modified algorithm for fast bandwidth selection for kernel estimates of multidimensional probability densities

2020 ◽  
pp. 9-13
Author(s):  
A. V. Lapko ◽  
V. A. Lapko
Keyword(s):  
Probability Density ◽  
Optimal Parameter ◽  
Random Variables ◽  
Kernel Functions ◽  
Independent Random Variables ◽  
Functional Dependencies ◽  
Approximation Properties ◽  
Probability Density Estimation ◽  
Multidimensional Probability ◽  
Selection Of

An original technique has been justified for the fast bandwidths selection of kernel functions in a nonparametric estimate of the multidimensional probability density of the Rosenblatt–Parzen type. The proposed method makes it possible to significantly increase the computational efficiency of the optimization procedure for kernel probability density estimates in the conditions of large-volume statistical data in comparison with traditional approaches. The basis of the proposed approach is the analysis of the optimal parameter formula for the bandwidths of a multidimensional kernel probability density estimate. Dependencies between the nonlinear functional on the probability density and its derivatives up to the second order inclusive of the antikurtosis coefficients of random variables are found. The bandwidths for each random variable are represented as the product of an undefined parameter and their mean square deviation. The influence of the error in restoring the established functional dependencies on the approximation properties of the kernel probability density estimation is determined. The obtained results are implemented as a method of synthesis and analysis of a fast bandwidths selection of the kernel estimation of the two-dimensional probability density of independent random variables. This method uses data on the quantitative characteristics of a family of lognormal distribution laws.

An Economic Analysis of Tomato Production in South Gujarat

2020 ◽  
pp. 161-164
Keyword(s):  
Crop Insurance ◽  
Sampling Technique ◽  
Economic Viability ◽  
Production Economics ◽  
Net Income ◽  
Insurance Scheme ◽  
Tomato Production ◽  
Input Ratio ◽  
Selection Of ◽  
High Output

ABSTRACT The study was conducted in South Gujarat for examining the production economics of tomato in the study area. Multistage random sampling technique was employed for the selection of 120 tomato farmers from Kaparada, Mandvi and Vyara talukas of Valsad, Surat and Tapi district, respectively. The net income of 1.57 lakh/ha showed the economic viability of the crop in the study area with a high output-input ratio of 3.25. It was suggested that the timely supply of credit and crop insurance scheme could further encourage growers for tomato production.

Effect of Contact Ratio on Spur Gear Dynamic Load With No Tooth Profile Modifications

1996 ◽  
Vol 118 (3) ◽  
pp. 439-443 ◽  
Author(s):  
Chuen-Huei Liou ◽  
Hsiang Hsi Lin ◽  
F. B. Oswald ◽  
D. P. Townsend
Keyword(s):  
Dynamic Load ◽  
Spur Gear ◽  
Tooth Size ◽  
Contact Ratio ◽  
Gear Dynamics ◽  
Wide Range ◽  
Gear Contact ◽  
Center Distance ◽  
Selection Of ◽  
Better Than

This paper presents a computer simulation showing how the gear contact ratio affects the dynamic load on a spur gear transmission. The contact ratio can be affected by the tooth addendum, the pressure angle, the tooth size (diametral pitch), and the center distance. The analysis presented in this paper was performed by using the NASA gear dynamics code DANST. In the analysis, the contact ratio was varied over the range 1.20 to 2.40 by changing the length of the tooth addendum. In order to simplify the analysis, other parameters related to contact ratio were held constant. The contact ratio was found to have a significant influence on gear dynamics. Over a wide range of operating speeds, a contact ratio close to 2.0 minimized dynamic load. For low-contact-ratio gears (contact ratio less than two), increasing the contact ratio reduced gear dynamic load. For high-contact-ratio gears (contact ratio equal to or greater than 2.0), the selection of contact ratio should take into consideration the intended operating speeds. In general, high-contact-ratio gears minimized dynamic load better than low-contact-ratio gears.

Transparency Enhancement in Teleoperation: An Improved Model-Free Predictor for Varying Network Delay in Telerobotic Application

2021 ◽  
Author(s):  
Nithya Sridhar ◽  
Rolif Lima ◽  
Utsav Rai ◽  
Vismay Vakharia ◽  
Kaushik Das ◽  
...  
Keyword(s):  
Network Delay ◽  
Model Free ◽  
Improved Model

scholarly journals Improved Model-Free Adaptive Sliding-Mode-Constrained Control for Linear Induction Motor considering End Effects

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoqi Song ◽  
Dezhi Xu ◽  
Weilin Yang ◽  
Yan Xia ◽  
Bin Jiang
Keyword(s):  
Control Method ◽  
Sliding Mode ◽  
Dynamic Performance ◽  
Research Field ◽  
Constrained Control ◽  
End Effects ◽  
Linear Induction ◽  
Adaptive Sliding Mode ◽  
Model Free ◽  
Improved Model

As a kind of special motors, linear induction motors (LIM) have been an important research field for researchers. However, it gives a great velocity control challenge due to the complex nonlinearity, high coupling, and unique end effects. In this article, an improved model-free adaptive sliding-mode-constrained control method is proposed to deal with this problem dispensing with internal parameters of the LIM. Firstly, an improved compact form dynamic linearization (CFDL) technique is used to simplify the LIM plant. Besides, an antiwindup compensator is applied to handle the problem of the actuator under saturations in case during the controller design. Furthermore, the stability of the closed system is proved by Lyapunov stability method theoretically. Finally, simulation results are given to demonstrate that the proposed controller has excellent dynamic performance and stronger robustness compared with traditional PID controller.

scholarly journals Conscientiousness as a Predictor of Relative Longevity

2015 ◽  
Vol 8 (1) ◽  
pp. 33
Author(s):  
Felix Uchechukwu Udoh ◽  
Aloysius C. Anyichie
Keyword(s):  
Regression Analysis ◽  
Correlation Analysis ◽  
West Africa ◽  
Big Five ◽  
Sampling Technique ◽  
Pearson Product Moment Correlation ◽  
Anambra State ◽  
Data Analyses ◽  
The People ◽  
Selection Of

<p>This study examined the Conscientiousness domain (of the Big-Five Inventory [B5]) and its facets as predictors of Relative Longevity (RL). Its methods of investigation involved the administration of the B5 to a sample of 350 people from Anambra State (of Nigeria, West Africa) who had RL. These participants were drawn from the representative towns of the three senatorial zones in the State. Stratified sampling technique was employed in the selection of the respondents. Pearson Product-Moment Correlation analysis and Multiple Regression analysis were used in data analyses. The results of the research indicated that there was no significant correlation between Conscientiousness domain and RL. However, its (Conscientiousness) facet (of Thorough) correlated significantly with RL. Besides, Conscientiousness did not predict RL, but its facets (Thorough, Reliable, Organized, and Goal-directed) were found to be significant predictors of RL. The study’s conclusion is that although Conscientiousness was neither a correlate nor a predictor of RL among the people of Anambra State, some of its Facets were (correlate and/or predictor/s).</p>

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