Hien Tran - Academia.edu (original) (raw)

Papers by Hien Tran

Multinational Business Review, 2018

Purpose This paper aims to investigate the effects of board model and board independence on corpo... more Purpose This paper aims to investigate the effects of board model and board independence on corporate social responsibility (CSR) disclosure of multinational corporations (MNCs). Design/methodology/approach The authors developed an empirical model in which CSR disclosure is the dependent variable and board model (two-tier vs one-tier), board independence (a proportion of independent directors on a board) and the interaction variable of board model and board independence together with several variables conventionally used as control variables are independent variables. The authors collated the panel dataset of 244 Fortune World’s Most Admired (FWMA) corporations from 2005 to 2011 of which 117 MNCs use the one-tier board model, and 127 MNCs use the two-tier board model from 20 countries. They used the random-effect regression method to estimate the empirical models with the data they collated and also ran regressions on the alternative models for robustness check. Findings The authors...

Annals of Operations Research, 2017

Copulas are one of the most powerful tools in modeling dependence structure of multivariate varia... more Copulas are one of the most powerful tools in modeling dependence structure of multivariate variables. In Tran et al. (Integrated uncertainty in knowledge modelling and decision making. Springer, Berlin, pp 126-137, 2015), we have constructed a new measure of dependence, λ(C), based on Sobolev norm for copula C which can be used to characterize comonotonicity, countermonotonicity and independence of random vectors. This paper aims to use the measure λ(C) to study how dependence structure of a distorted copula after being transformed by a distortion function is changed. Firstly, we propose two methods to estimate the measure λ(C), one for known copula C using conditional copula-based Monte Carlo simulation and the latter for unknown copula dealing with empirical data. Thereafter, PHtransform g PH of extreme value copulas and Wang's transform g γ of normal and product copula are studied, and we observe their dependence behaviors changing through variability of the measure λ(C). Our results show that dependence structure of distorted copulas is subject to comonotonicity as increasing the parametric γ .

Studies in Computational Intelligence, 2017

In support of the American Statistical Association’s statement on p-value in 2016, see [8], we in... more In support of the American Statistical Association’s statement on p-value in 2016, see [8], we investigate, in this paper, a classical question in model selection, namely finding a “best-fit” probability distribution to a set of data. Throughout history, there have been a number of tests designed to determine whether a particular distribution fit a set of data, for instance, see [6]. The popular approach is to compute certain test statistics and base the decisions on the p values of these test statistics. As pointed out numerous times in the literature, see [5] for example, p values suffer serious drawbacks which make it untrustworthy in decision making. One typical situation is when the p value is larger than the significance level \(\alpha \) which results in an inconclusive case. In many studies, a common mistake is to claim that the null hypothesis is true or most likely whereas a big p value merely implies that the null hypothesis is statistically consistent with the observed data; there is no indication that the null hypothesis is “better” than any other hypothesis in the confidence interval. We notice this situation happens a great deal in testing goodness of fit. Therefore, hereby, we propose an approach using the Akaike information criterion (AIC) or the Bayesian information criterion (BIC) to make a selection of the best fit distribution among a group of candidates. As for applications, a variety of stock price data are processed to find a fit distribution. Both the p value and the new approach are computed and compared carefully. The virtue of our approach is that there is always a justified decision made in the end; and, there will be no inconclusiveness whatsoever.

BioMed Research International, 2017

Biological self-assembly is a process in which building blocks autonomously organize to form stab... more Biological self-assembly is a process in which building blocks autonomously organize to form stable supermolecules of higher order and complexity through domination of weak, noncovalent interactions. For silk protein, the effect of high incubating temperature on the induction of secondary structure and self-assembly was well investigated. However, the effect of freezing and thawing on silk solution has not been studied. The present work aimed to investigate a new all-aqueous process to form 3D porous silk fibroin matrices using a freezing-assisted self-assembly method. This study proposes an experimental investigation and optimization of environmental parameters for the self-assembly process such as freezing temperature, thawing process, and concentration of silk solution. The optical images demonstrated the possibility and potential of −80ST48 treatment to initialize the self-assembly of silk fibroin as well as controllably fabricate a porous scaffold. Moreover, the micrograph imag...

We emphasize the need to model rigorously uncertain coarse data in systems such as decision-suppo... more We emphasize the need to model rigorously uncertain coarse data in systems such as decision-support systems and intelligent machines. We exemplify the framework of continuous lattices by formulating human perception-based information as coarsening schemes using fuzzy partitions. Specifically, the formal concept of random fuzzy sets is treated as random elements with values in the space of upper semicontinuous functions which is endowed with a continuous lattice structure. As a result, random fuzzy (closed) sets on locally compact, Hausdorfff and second countable spaces are special random elements taking values in separable metric spaces.

Annals of Operations Research, 2011

Page 1. Ann Oper Res DOI 10.1007/s10479-011-0848-9 On some claims related to Choquet integral ris... more Page 1. Ann Oper Res DOI 10.1007/s10479-011-0848-9 On some claims related to Choquet integral risk measures Hung T. Nguyen · Uyen H. Pham · Hien D. Tran © Springer Science+Business Media, LLC 2011 Abstract We ...

Multinational Business Review, 2018

Purpose This paper aims to investigate the effects of board model and board independence on corpo... more Purpose This paper aims to investigate the effects of board model and board independence on corporate social responsibility (CSR) disclosure of multinational corporations (MNCs). Design/methodology/approach The authors developed an empirical model in which CSR disclosure is the dependent variable and board model (two-tier vs one-tier), board independence (a proportion of independent directors on a board) and the interaction variable of board model and board independence together with several variables conventionally used as control variables are independent variables. The authors collated the panel dataset of 244 Fortune World’s Most Admired (FWMA) corporations from 2005 to 2011 of which 117 MNCs use the one-tier board model, and 127 MNCs use the two-tier board model from 20 countries. They used the random-effect regression method to estimate the empirical models with the data they collated and also ran regressions on the alternative models for robustness check. Findings The authors...

Annals of Operations Research, 2017

Copulas are one of the most powerful tools in modeling dependence structure of multivariate varia... more Copulas are one of the most powerful tools in modeling dependence structure of multivariate variables. In Tran et al. (Integrated uncertainty in knowledge modelling and decision making. Springer, Berlin, pp 126-137, 2015), we have constructed a new measure of dependence, λ(C), based on Sobolev norm for copula C which can be used to characterize comonotonicity, countermonotonicity and independence of random vectors. This paper aims to use the measure λ(C) to study how dependence structure of a distorted copula after being transformed by a distortion function is changed. Firstly, we propose two methods to estimate the measure λ(C), one for known copula C using conditional copula-based Monte Carlo simulation and the latter for unknown copula dealing with empirical data. Thereafter, PHtransform g PH of extreme value copulas and Wang's transform g γ of normal and product copula are studied, and we observe their dependence behaviors changing through variability of the measure λ(C). Our results show that dependence structure of distorted copulas is subject to comonotonicity as increasing the parametric γ .

Studies in Computational Intelligence, 2017

In support of the American Statistical Association’s statement on p-value in 2016, see [8], we in... more In support of the American Statistical Association’s statement on p-value in 2016, see [8], we investigate, in this paper, a classical question in model selection, namely finding a “best-fit” probability distribution to a set of data. Throughout history, there have been a number of tests designed to determine whether a particular distribution fit a set of data, for instance, see [6]. The popular approach is to compute certain test statistics and base the decisions on the p values of these test statistics. As pointed out numerous times in the literature, see [5] for example, p values suffer serious drawbacks which make it untrustworthy in decision making. One typical situation is when the p value is larger than the significance level \(\alpha \) which results in an inconclusive case. In many studies, a common mistake is to claim that the null hypothesis is true or most likely whereas a big p value merely implies that the null hypothesis is statistically consistent with the observed data; there is no indication that the null hypothesis is “better” than any other hypothesis in the confidence interval. We notice this situation happens a great deal in testing goodness of fit. Therefore, hereby, we propose an approach using the Akaike information criterion (AIC) or the Bayesian information criterion (BIC) to make a selection of the best fit distribution among a group of candidates. As for applications, a variety of stock price data are processed to find a fit distribution. Both the p value and the new approach are computed and compared carefully. The virtue of our approach is that there is always a justified decision made in the end; and, there will be no inconclusiveness whatsoever.

BioMed Research International, 2017

Biological self-assembly is a process in which building blocks autonomously organize to form stab... more Biological self-assembly is a process in which building blocks autonomously organize to form stable supermolecules of higher order and complexity through domination of weak, noncovalent interactions. For silk protein, the effect of high incubating temperature on the induction of secondary structure and self-assembly was well investigated. However, the effect of freezing and thawing on silk solution has not been studied. The present work aimed to investigate a new all-aqueous process to form 3D porous silk fibroin matrices using a freezing-assisted self-assembly method. This study proposes an experimental investigation and optimization of environmental parameters for the self-assembly process such as freezing temperature, thawing process, and concentration of silk solution. The optical images demonstrated the possibility and potential of −80ST48 treatment to initialize the self-assembly of silk fibroin as well as controllably fabricate a porous scaffold. Moreover, the micrograph imag...

We emphasize the need to model rigorously uncertain coarse data in systems such as decision-suppo... more We emphasize the need to model rigorously uncertain coarse data in systems such as decision-support systems and intelligent machines. We exemplify the framework of continuous lattices by formulating human perception-based information as coarsening schemes using fuzzy partitions. Specifically, the formal concept of random fuzzy sets is treated as random elements with values in the space of upper semicontinuous functions which is endowed with a continuous lattice structure. As a result, random fuzzy (closed) sets on locally compact, Hausdorfff and second countable spaces are special random elements taking values in separable metric spaces.

Annals of Operations Research, 2011

Page 1. Ann Oper Res DOI 10.1007/s10479-011-0848-9 On some claims related to Choquet integral ris... more Page 1. Ann Oper Res DOI 10.1007/s10479-011-0848-9 On some claims related to Choquet integral risk measures Hung T. Nguyen · Uyen H. Pham · Hien D. Tran © Springer Science+Business Media, LLC 2011 Abstract We ...