Ampai Thongteeraparp | Kasetsart University (original) (raw)

Papers by Ampai Thongteeraparp

Research paper thumbnail of A Comparison of Nonparametric Statistics and Bootstrap Methods for Testing Two Independent Populations with Unequal Variance

International Journal of Analysis and Applications, Apr 17, 2023

Research paper thumbnail of The Generalized Distributions on the Unit Interval based on the T-Topp-Leone Family of Distributions

Trends in Sciences

The Topp-Leone (TL) distribution is introduced by Topp and Leone [1]. Its probability density fun... more The Topp-Leone (TL) distribution is introduced by Topp and Leone [1]. Its probability density function is a simple function with only one parameter. Even though the TL distribution has been discussed and applied in many research fields, but there is a limitation about its shape. In this article, we propose the T-TL family of distributions using quantile function of family of distributions to generate generalized TL distributions including the Weibull-TL{exponential}, the log-logistic-TL{exponential}, the logistic-TL{extreme value}, the exponential-TL{log-logistic} and the normal-TL{logistic} distributions. Some associated properties and inferences are discussed. Some graphical representations related to the probability density function are shown. Finally, 3 real datasets are applied to illustrate the generalized TL distributions. HIGHLIGHTS The Topp-Leone distribution is introduced in 1955. Its probability density function is a simple function with only one parameter. It has been d...

Research paper thumbnail of The Zero-Truncated Poisson-Weighted Exponential Distribution with Applications

Lobachevskii Journal of Mathematics, Dec 1, 2021

Research paper thumbnail of The new Poisson mixed weighted Lindley distributionwith applications to insurance claims data

Mixed Poisson distributions have been applied for overdispersed count data analysis. In this pape... more Mixed Poisson distributions have been applied for overdispersed count data analysis. In this paper, an alternative mixed Poisson distribution is proposed. The proposed distribution is derived by mixing the Poisson distribution with the new weighted Lindley distribution, named as the new Poisson mixed weighted Lindley distribution. Some special cases and several statistical properties have been derived including shape, factorial moments, probability generating function, moment generating function and moments. The maximum likelihood estimators of the parameters are obtained. Finally, two automobile insurance claims data sets are analyzed to compare the performance of the proposed distribution with some competitive distributions.

Research paper thumbnail of Authors

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Research paper thumbnail of Mixed distribution of negative binomial and two-parameter Lindley distributions

2016 12th International Conference on Mathematics, Statistics, and Their Applications (ICMSA), 2016

In this work, we propose a new mixed distribution, the negative binomial two-parameter Lindley di... more In this work, we propose a new mixed distribution, the negative binomial two-parameter Lindley distribution. Some properties such as but not limited to, factorial moment, mean, and variance, including a random variate generation are studied. Parameters of the proposed distribution are estimated by maximum likelihood estimation, which illustrated high-efficiency when a sample size is large. Moreover, when the negative binomial two-parameter Lindley distribution is used in application of count data modeling-especially for data with large number of zeros and overdispersion-it provides a better fit compared to the negative binomial distribution and negative binomial Lindley distribution.

Research paper thumbnail of Parameter Estimation of the Negative Binomial—New Weighted Lindley Distribution by the Method of Maximum Likelihood

Lobachevskii Journal of Mathematics, 2020

In this article we investigate the parameter estimation of the Negative Binomial-New Weighted Lin... more In this article we investigate the parameter estimation of the Negative Binomial-New Weighted Lindley distribution. We are interested in the maximum likelihood method because it provides estimators with many superior properties, such as minimum variance and asymptotically unbiased estimators. The simulation study is performed in order to investigate the accuracy of the maximum likelihood estimators of the parameters of the Negative Binomial-New Weighted Lindley distribution.

Research paper thumbnail of The Length-Biased Weighted Lindley Distribution with Applications

Lobachevskii Journal of Mathematics, 2020

In this paper, we propose a new length-biased distribution, which is a special case of weighted d... more In this paper, we propose a new length-biased distribution, which is a special case of weighted distributions. We derive some mathematical properties of the proposed distribution, including moment generating function, characteristic function and moments, and discuss parameter estimation by the method of moments and maximum likelihood estimation. We assess estimators via simulation, and show the potential of the proposed distribution by fitting it with some real-life data sets.

Research paper thumbnail of Students' Usage of Facebook for Academic Purposes: A Case Study of Public and Private Universities in Thailand

International Association for Development of the Information Society, 2013

The objective of this research was to examine how Thai university students used Facebook for acad... more The objective of this research was to examine how Thai university students used Facebook for academic purposes and how public university students differed from private university students in this regard. This was an exploratory research where a questionnaire was used to collect data from 460 undergraduate students in Bangkok, Thailand. The data were then analyzed using Multivariate Analysis of Variance. The study found that Thai students used Facebook more to communicate and to share than to collaborate. This communication or sharing of information was more among the students than with their professors. It also found that private university students used Facebook to collaborate more than their counterparts at public universities.

Research paper thumbnail of New statistics for detection of outliers using the last few principal components

Two test statistics are proposed for detecting outliers that are not extreme on any of the origin... more Two test statistics are proposed for detecting outliers that are not extreme on any of the original variables in multivariate data. The test statistics are derived via principal component analysis and some normal distribution properties. Moreover, the last few principal components or minor principal components from principal component analysis have an important role in these simple test statistics. Finally, the tests are applied to a simulated data and the real data of a financial institution in Thailand as examples. Moreover, a comparative study was carried out using data on milk from Daudin, Duby, and Trecourt (Statistics, 19, 241).

Research paper thumbnail of The zero inflated negative binomial – Crack distribution : some properties and parameter estimation

The zero inflated negative binomial-Crack (ZINB-CR) distribution is a mixture of Bernoulli distri... more The zero inflated negative binomial-Crack (ZINB-CR) distribution is a mixture of Bernoulli distribution and negative binomial-Crack (NB-CR) distribution, which is an alternative distribution for the excessive zero counts and overdispersion. In this paper, some properties of the ZINB-CR distribution are discussed. Statistical inference of the parameters is derived by maximum likelihood estimation (MLE) and the method of moments (MM). Monte Carlo Simulations are used to evaluate the performance of parameter estimation methods in term of mean squared error (MSE). An application of the distribution is carried out on a sample of excess zero-count data. Simulation results show that the MLE method outperforms the MM method in specific parameter values. Furthermore, the ZINB-CR provides a better fit compared to the zero inflated Poisson (ZIP), the zero inflated negative binomial (ZINB) and the negative binomial-Crack (NB-CR) distributions.

Research paper thumbnail of Zero inflated negative binomial-Sushila distribution and its application

AIP Conference Proceedings, 2017

In statistics literature, there is significant study of mixtures and compound probability distrib... more In statistics literature, there is significant study of mixtures and compound probability distributions used for count model especially for the data contains excess zeros. In this paper, we introduce a new probability distribution which is obtained as a compound of zero-inflated negative binomial (ZINB) distribution and Sushila distribution and it is named as zero-inflated negative binomial-Sushila (ZINB-S) distribution. It can be used as an alternative and effective way of modeling over dispersed count data. The probability mass function (PMF) and some vital characteristics of ZINB-S distribution are derived. MLE method is employed for estimating the model parameters. Further the example is given to show that ZINB-S provides better fit compare to traditional models for over dispersed count data.

Research paper thumbnail of Bayesian Inference for the Negative Binomial-Sushila Linear Model

Lobachevskii Journal of Mathematics, 2019

The aim of this article is to develop a new linear model for count data. The main idea is in an a... more The aim of this article is to develop a new linear model for count data. The main idea is in an application of a new generalized linear model framework, which we call the Negative Binomial-Sushila linear model. The Negative Binomial-Sushila distribution has been proposed recently and applied to count data. This distribution is constructed as a mixture of the Negative Binomial and Sushila distributions. The mixed distribution is a flexible alternative to the Poisson distribution when over-dispersed count data is analyzed. The parameters of this distribution are estimated using a Bayesian approach with R2jags package of the R language. The Negative Binomial-Sushila linear model is applied to fit two real data sets with an over-dispersion and its performance is compared with the performance of some traditional models. The results show that the Negative Binomial-Sushila generalized linear model fits the data sets better than the traditional generalized models for these data sets.

Research paper thumbnail of Inferences on The Standard Skew-Normal Distribution

It is a common practice among applied researchers to assume normal distribution for naturally occ... more It is a common practice among applied researchers to assume normal distribution for naturally occurring data over the real line. But often one is not sure about the assumption of normality for various reasons, including the fact that the standard goodness of fit tests are not effective enough always, especially for small sample sizes. In such a scenario one would be better off by starting with a more versatile skew-normal distribution which is defined over the whole real line, and is a natural generalization of the usual normal distribution. This paper deals with the standard skew-normal distribution which can reduce to the standard normal distribution if the skew parameter takes the value zero. Depending on the value of the skew parameter, the standard skew-normal distribution can be either positively skewed, symmetric (standard normal), or negatively skewed. This paper is devoted to various estimation and hypothesis testing methods for the skew parameter which, to the best of our ...

Research paper thumbnail of A Statistical Analysis of Intensities Estimation on the Modeling of Non-Life Insurance Claim Counting Process

Applied Mathematics, 2012

This study presents an estimation approach to non-life insurance claim counts relating to a speci... more This study presents an estimation approach to non-life insurance claim counts relating to a specified time. The objective of this study is to estimate the parameters in non-life insurance claim counting process, including the homogeneous Poisson process (HPP) and the non-homogeneous Poisson process (NHPP) with a bell-shaped intensity. We use the estimating function, the zero mean martingale (ZMM) as a procedure of parameter estimation in the insurance claim counting process. Then, Λ (t), the compensator of N (t) is proposed for the number of claims in the time interval (0, t]. We present situations through a simulation study of both processes on the time interval (0, t]. Some examples of the situations in the simulation study are depicted by a sample path relating N (t) to its compensator Λ (t). In addition, an example of the claim counting process illustrates the result of the compensator estimate misspecification.

Research paper thumbnail of A Bayesian Inference of Non-Life Insurance Based on Claim Counting Process with Periodic Claim Intensity

Open Journal of Statistics, 2012

The aim of this study is to propose an estimation approach to non-life insurance claim counts rel... more The aim of this study is to propose an estimation approach to non-life insurance claim counts related to the insurance claim counting process, including the non-homogeneous Poisson process (NHPP) with a bell-shaped intensity and a beta-shaped intensity. The estimating function, such as the zero mean martingale (ZMM), is used as a procedure for parameter estimation of the insurance claim counting process, and the parameters of model claim intensity are estimated by the Bayesian method. Then, , the compensator of   t    N t is proposed for the number of claims in a time interval     0,t. Given the process over the time interval 0,t , the situations are presented through a simulation study and some examples of these situations are also depicted by a sample path relating

Research paper thumbnail of Parameter Estimation of Fuzzy Linear Regression Model: The Extension of Chen and Hsueh Method

Journal of Applied Sciences, 2014

Research paper thumbnail of Number of Replications Required in Monte Carlo Simulation Studies: A Synthesis of Four Studies

Journal of Modern Applied Statistical Methods, 2011

Monte Carlo simulations are used extensively to study the performance of statistical tests and co... more Monte Carlo simulations are used extensively to study the performance of statistical tests and control charts. Researchers have used various numbers of replications, but rarely provide justification for their choice. Currently, no empirically-based recommendations regarding the required number of replications exist. Twenty-two studies were re-analyzed to determine empirically-based recommendations.

Research paper thumbnail of The Effects of Facebook Usage on Academic Achievement of Students in Bangkok Metropolitan Area

BU Academic Review, 2017

This study examined online social network usage of students in Bangkok Metropolitan Area regardin... more This study examined online social network usage of students in Bangkok Metropolitan Area regarding using time, Facebook usage pattern and Facebook usage intensity, and examined factors affecting the students’ academic achievement regarding to time spent using online social network, Facebook intensity, time management, and learning concentration. The survey research was used to collect data from 1,080 samples using a questionnaire. Data were analyzed using Path Analysis. The results reveal that the students were on Facebook many times a day, via smart phones, and would spend 10 - 20 minutes for each use. They usually used Facebook to talk with their friends. Time management was the only one factor affecting the students’ learning achievement. If they could manage time efficiently, they would have satisfactory learning outcomes. This study also found that the use of Facebook did not have any influence on students’ learning achievement. อทธพลของการใชเฟซบกทมตอผลการเรยนของนกศกษา ในเขตกรง...

Research paper thumbnail of A Power of Comparison of Goodness of Fit Tests for Exponential Distribution With Grouped Data

Thailand Statistician, 2011

This study compares the powers of Goodness of fit tests for grouped data from the exponential dis... more This study compares the powers of Goodness of fit tests for grouped data from the exponential distribution. These tests include the Weighted KolmogorovSmirnov statistic, Anderson-Darling statistic and Cramer-von Mises statistic. The sample sizes were 30, 50 and 100. These samples were grouped in intervals of 6, 7 and 10. The specified significance level for the tests was 0.05. Each sample of data was generated by simulation and each combination of sample size and interval was run 1,000 times. The simulation studies show that the best test for control the type l error is the Weighted Kolmogorov-Smirnov statistic. Next in rank is Anderson-Darling statistic followed by the Cramer-von Mises statistic. The Weighted Kolmogorov-Smirnov statistic has the highest power of test followed by the Anderson-Darling statistic then the Cramer-von Mises statistic.

Research paper thumbnail of A Comparison of Nonparametric Statistics and Bootstrap Methods for Testing Two Independent Populations with Unequal Variance

International Journal of Analysis and Applications, Apr 17, 2023

Research paper thumbnail of The Generalized Distributions on the Unit Interval based on the T-Topp-Leone Family of Distributions

Trends in Sciences

The Topp-Leone (TL) distribution is introduced by Topp and Leone [1]. Its probability density fun... more The Topp-Leone (TL) distribution is introduced by Topp and Leone [1]. Its probability density function is a simple function with only one parameter. Even though the TL distribution has been discussed and applied in many research fields, but there is a limitation about its shape. In this article, we propose the T-TL family of distributions using quantile function of family of distributions to generate generalized TL distributions including the Weibull-TL{exponential}, the log-logistic-TL{exponential}, the logistic-TL{extreme value}, the exponential-TL{log-logistic} and the normal-TL{logistic} distributions. Some associated properties and inferences are discussed. Some graphical representations related to the probability density function are shown. Finally, 3 real datasets are applied to illustrate the generalized TL distributions. HIGHLIGHTS The Topp-Leone distribution is introduced in 1955. Its probability density function is a simple function with only one parameter. It has been d...

Research paper thumbnail of The Zero-Truncated Poisson-Weighted Exponential Distribution with Applications

Lobachevskii Journal of Mathematics, Dec 1, 2021

Research paper thumbnail of The new Poisson mixed weighted Lindley distributionwith applications to insurance claims data

Mixed Poisson distributions have been applied for overdispersed count data analysis. In this pape... more Mixed Poisson distributions have been applied for overdispersed count data analysis. In this paper, an alternative mixed Poisson distribution is proposed. The proposed distribution is derived by mixing the Poisson distribution with the new weighted Lindley distribution, named as the new Poisson mixed weighted Lindley distribution. Some special cases and several statistical properties have been derived including shape, factorial moments, probability generating function, moment generating function and moments. The maximum likelihood estimators of the parameters are obtained. Finally, two automobile insurance claims data sets are analyzed to compare the performance of the proposed distribution with some competitive distributions.

Research paper thumbnail of Authors

See next page for additional authors

Research paper thumbnail of Mixed distribution of negative binomial and two-parameter Lindley distributions

2016 12th International Conference on Mathematics, Statistics, and Their Applications (ICMSA), 2016

In this work, we propose a new mixed distribution, the negative binomial two-parameter Lindley di... more In this work, we propose a new mixed distribution, the negative binomial two-parameter Lindley distribution. Some properties such as but not limited to, factorial moment, mean, and variance, including a random variate generation are studied. Parameters of the proposed distribution are estimated by maximum likelihood estimation, which illustrated high-efficiency when a sample size is large. Moreover, when the negative binomial two-parameter Lindley distribution is used in application of count data modeling-especially for data with large number of zeros and overdispersion-it provides a better fit compared to the negative binomial distribution and negative binomial Lindley distribution.

Research paper thumbnail of Parameter Estimation of the Negative Binomial—New Weighted Lindley Distribution by the Method of Maximum Likelihood

Lobachevskii Journal of Mathematics, 2020

In this article we investigate the parameter estimation of the Negative Binomial-New Weighted Lin... more In this article we investigate the parameter estimation of the Negative Binomial-New Weighted Lindley distribution. We are interested in the maximum likelihood method because it provides estimators with many superior properties, such as minimum variance and asymptotically unbiased estimators. The simulation study is performed in order to investigate the accuracy of the maximum likelihood estimators of the parameters of the Negative Binomial-New Weighted Lindley distribution.

Research paper thumbnail of The Length-Biased Weighted Lindley Distribution with Applications

Lobachevskii Journal of Mathematics, 2020

In this paper, we propose a new length-biased distribution, which is a special case of weighted d... more In this paper, we propose a new length-biased distribution, which is a special case of weighted distributions. We derive some mathematical properties of the proposed distribution, including moment generating function, characteristic function and moments, and discuss parameter estimation by the method of moments and maximum likelihood estimation. We assess estimators via simulation, and show the potential of the proposed distribution by fitting it with some real-life data sets.

Research paper thumbnail of Students' Usage of Facebook for Academic Purposes: A Case Study of Public and Private Universities in Thailand

International Association for Development of the Information Society, 2013

The objective of this research was to examine how Thai university students used Facebook for acad... more The objective of this research was to examine how Thai university students used Facebook for academic purposes and how public university students differed from private university students in this regard. This was an exploratory research where a questionnaire was used to collect data from 460 undergraduate students in Bangkok, Thailand. The data were then analyzed using Multivariate Analysis of Variance. The study found that Thai students used Facebook more to communicate and to share than to collaborate. This communication or sharing of information was more among the students than with their professors. It also found that private university students used Facebook to collaborate more than their counterparts at public universities.

Research paper thumbnail of New statistics for detection of outliers using the last few principal components

Two test statistics are proposed for detecting outliers that are not extreme on any of the origin... more Two test statistics are proposed for detecting outliers that are not extreme on any of the original variables in multivariate data. The test statistics are derived via principal component analysis and some normal distribution properties. Moreover, the last few principal components or minor principal components from principal component analysis have an important role in these simple test statistics. Finally, the tests are applied to a simulated data and the real data of a financial institution in Thailand as examples. Moreover, a comparative study was carried out using data on milk from Daudin, Duby, and Trecourt (Statistics, 19, 241).

Research paper thumbnail of The zero inflated negative binomial – Crack distribution : some properties and parameter estimation

The zero inflated negative binomial-Crack (ZINB-CR) distribution is a mixture of Bernoulli distri... more The zero inflated negative binomial-Crack (ZINB-CR) distribution is a mixture of Bernoulli distribution and negative binomial-Crack (NB-CR) distribution, which is an alternative distribution for the excessive zero counts and overdispersion. In this paper, some properties of the ZINB-CR distribution are discussed. Statistical inference of the parameters is derived by maximum likelihood estimation (MLE) and the method of moments (MM). Monte Carlo Simulations are used to evaluate the performance of parameter estimation methods in term of mean squared error (MSE). An application of the distribution is carried out on a sample of excess zero-count data. Simulation results show that the MLE method outperforms the MM method in specific parameter values. Furthermore, the ZINB-CR provides a better fit compared to the zero inflated Poisson (ZIP), the zero inflated negative binomial (ZINB) and the negative binomial-Crack (NB-CR) distributions.

Research paper thumbnail of Zero inflated negative binomial-Sushila distribution and its application

AIP Conference Proceedings, 2017

In statistics literature, there is significant study of mixtures and compound probability distrib... more In statistics literature, there is significant study of mixtures and compound probability distributions used for count model especially for the data contains excess zeros. In this paper, we introduce a new probability distribution which is obtained as a compound of zero-inflated negative binomial (ZINB) distribution and Sushila distribution and it is named as zero-inflated negative binomial-Sushila (ZINB-S) distribution. It can be used as an alternative and effective way of modeling over dispersed count data. The probability mass function (PMF) and some vital characteristics of ZINB-S distribution are derived. MLE method is employed for estimating the model parameters. Further the example is given to show that ZINB-S provides better fit compare to traditional models for over dispersed count data.

Research paper thumbnail of Bayesian Inference for the Negative Binomial-Sushila Linear Model

Lobachevskii Journal of Mathematics, 2019

The aim of this article is to develop a new linear model for count data. The main idea is in an a... more The aim of this article is to develop a new linear model for count data. The main idea is in an application of a new generalized linear model framework, which we call the Negative Binomial-Sushila linear model. The Negative Binomial-Sushila distribution has been proposed recently and applied to count data. This distribution is constructed as a mixture of the Negative Binomial and Sushila distributions. The mixed distribution is a flexible alternative to the Poisson distribution when over-dispersed count data is analyzed. The parameters of this distribution are estimated using a Bayesian approach with R2jags package of the R language. The Negative Binomial-Sushila linear model is applied to fit two real data sets with an over-dispersion and its performance is compared with the performance of some traditional models. The results show that the Negative Binomial-Sushila generalized linear model fits the data sets better than the traditional generalized models for these data sets.

Research paper thumbnail of Inferences on The Standard Skew-Normal Distribution

It is a common practice among applied researchers to assume normal distribution for naturally occ... more It is a common practice among applied researchers to assume normal distribution for naturally occurring data over the real line. But often one is not sure about the assumption of normality for various reasons, including the fact that the standard goodness of fit tests are not effective enough always, especially for small sample sizes. In such a scenario one would be better off by starting with a more versatile skew-normal distribution which is defined over the whole real line, and is a natural generalization of the usual normal distribution. This paper deals with the standard skew-normal distribution which can reduce to the standard normal distribution if the skew parameter takes the value zero. Depending on the value of the skew parameter, the standard skew-normal distribution can be either positively skewed, symmetric (standard normal), or negatively skewed. This paper is devoted to various estimation and hypothesis testing methods for the skew parameter which, to the best of our ...

Research paper thumbnail of A Statistical Analysis of Intensities Estimation on the Modeling of Non-Life Insurance Claim Counting Process

Applied Mathematics, 2012

This study presents an estimation approach to non-life insurance claim counts relating to a speci... more This study presents an estimation approach to non-life insurance claim counts relating to a specified time. The objective of this study is to estimate the parameters in non-life insurance claim counting process, including the homogeneous Poisson process (HPP) and the non-homogeneous Poisson process (NHPP) with a bell-shaped intensity. We use the estimating function, the zero mean martingale (ZMM) as a procedure of parameter estimation in the insurance claim counting process. Then, Λ (t), the compensator of N (t) is proposed for the number of claims in the time interval (0, t]. We present situations through a simulation study of both processes on the time interval (0, t]. Some examples of the situations in the simulation study are depicted by a sample path relating N (t) to its compensator Λ (t). In addition, an example of the claim counting process illustrates the result of the compensator estimate misspecification.

Research paper thumbnail of A Bayesian Inference of Non-Life Insurance Based on Claim Counting Process with Periodic Claim Intensity

Open Journal of Statistics, 2012

The aim of this study is to propose an estimation approach to non-life insurance claim counts rel... more The aim of this study is to propose an estimation approach to non-life insurance claim counts related to the insurance claim counting process, including the non-homogeneous Poisson process (NHPP) with a bell-shaped intensity and a beta-shaped intensity. The estimating function, such as the zero mean martingale (ZMM), is used as a procedure for parameter estimation of the insurance claim counting process, and the parameters of model claim intensity are estimated by the Bayesian method. Then, , the compensator of   t    N t is proposed for the number of claims in a time interval     0,t. Given the process over the time interval 0,t , the situations are presented through a simulation study and some examples of these situations are also depicted by a sample path relating

Research paper thumbnail of Parameter Estimation of Fuzzy Linear Regression Model: The Extension of Chen and Hsueh Method

Journal of Applied Sciences, 2014

Research paper thumbnail of Number of Replications Required in Monte Carlo Simulation Studies: A Synthesis of Four Studies

Journal of Modern Applied Statistical Methods, 2011

Monte Carlo simulations are used extensively to study the performance of statistical tests and co... more Monte Carlo simulations are used extensively to study the performance of statistical tests and control charts. Researchers have used various numbers of replications, but rarely provide justification for their choice. Currently, no empirically-based recommendations regarding the required number of replications exist. Twenty-two studies were re-analyzed to determine empirically-based recommendations.

Research paper thumbnail of The Effects of Facebook Usage on Academic Achievement of Students in Bangkok Metropolitan Area

BU Academic Review, 2017

This study examined online social network usage of students in Bangkok Metropolitan Area regardin... more This study examined online social network usage of students in Bangkok Metropolitan Area regarding using time, Facebook usage pattern and Facebook usage intensity, and examined factors affecting the students’ academic achievement regarding to time spent using online social network, Facebook intensity, time management, and learning concentration. The survey research was used to collect data from 1,080 samples using a questionnaire. Data were analyzed using Path Analysis. The results reveal that the students were on Facebook many times a day, via smart phones, and would spend 10 - 20 minutes for each use. They usually used Facebook to talk with their friends. Time management was the only one factor affecting the students’ learning achievement. If they could manage time efficiently, they would have satisfactory learning outcomes. This study also found that the use of Facebook did not have any influence on students’ learning achievement. อทธพลของการใชเฟซบกทมตอผลการเรยนของนกศกษา ในเขตกรง...

Research paper thumbnail of A Power of Comparison of Goodness of Fit Tests for Exponential Distribution With Grouped Data

Thailand Statistician, 2011

This study compares the powers of Goodness of fit tests for grouped data from the exponential dis... more This study compares the powers of Goodness of fit tests for grouped data from the exponential distribution. These tests include the Weighted KolmogorovSmirnov statistic, Anderson-Darling statistic and Cramer-von Mises statistic. The sample sizes were 30, 50 and 100. These samples were grouped in intervals of 6, 7 and 10. The specified significance level for the tests was 0.05. Each sample of data was generated by simulation and each combination of sample size and interval was run 1,000 times. The simulation studies show that the best test for control the type l error is the Weighted Kolmogorov-Smirnov statistic. Next in rank is Anderson-Darling statistic followed by the Cramer-von Mises statistic. The Weighted Kolmogorov-Smirnov statistic has the highest power of test followed by the Anderson-Darling statistic then the Cramer-von Mises statistic.