CHANGING ROAD TRAFFIC NOISE IN HANOI OF PREVIOUS 10 YEARS

Joint Research on Environmental Science and Technology for the Eart

A new stability results for the backward heat equation

In this paper, we regularize the nonlinear inverse time heat problem in the unbounded region by Fourier method. Some new convergence rates are obtained. Meanwhile, some quite sharp error estimates between the approximate solution and exact solution are provided. Especially, the optimal convergence of the approximate solution at t = 0 is also proved. This work extends to many earlier results in (f2,f3, hao1,Quan,tau1, tau2, Trong3,x1).Comment: 13 page

The effects of earning quality on sustainable reports: an empirical study from Vietnam

Sustainable Reports have been specifically concerned by related parties over the period, firstly by researchers in the developed countries and spreading to the developing jurisdictions. The aim of the research is to analyze the impact of the Earning Quality to Sustainable Reports of non-financial firms listed on Vietnam financial market. The authors have used the combining method to measure the Sustainable Reports disclosure level according to the Global Reporting Initiatives 4 (GRI4) standard for 312 enterprises in Vietnam during 2015- 2019. The research result has recognized the positive effect of Earning Quality to Sustainable Reports while measuring Earning Quality via the aspects of earnings management and the stability of earnings. Besides, the research has considered the impact of the state-owned, foreign-owned factors, the audit quality and how the legislation policy relates to Sustainable Reports in interaction with Earning Quality. The result of the study suggests a number of cognitive enhancement recommendations in the Sustainable Reports for Vietnam and similar countries

COMMUTERS' EXPOSURE TO PARTICULATE MATTER AND CARBON MONOXIDE IN HANOI : A PILOT STUDY

Joint Research on Environmental Science and Technology for the Eart

ANNOYANCE SCALES IN VIETNAMESE

Joint Research on Environmental Science and Technology for the Eart

Determine the source term of a two-dimensional heat equation

Let $\Omega$ be a two-dimensional heat conduction body. We consider the problem of determining the heat source $F(x,t)=\varphi(t)f(x,y)$ with $\varphi$ be given inexactly and $f$ be unknown. The problem is nonlinear and ill-posed. By a specific form of Fourier transforms, we shall show that the heat source is determined uniquely by the minimum boundary condition and the temperature distribution in $\Omega$ at the initial time $t=0$ and at the final time $t=1$. Using the methods of Tikhonov's regularization and truncated integration, we construct the regularized solutions. Numerical part is given.Comment: 18 page

Information adoption of skincare and makeup product reviews on social media platforms in Vietnam

Modern consumers have been familiar with using online product reviews for their pre-purchase information gathering. In response, brands are increasingly taking advantage of this opportunity by using influential individuals such as bloggers to post favourable product reviews to promote their products. However, these word-of-mouth marketing strategies are not always welcomed by consumers, especially when they prefer unbiased, organic reviews to make informed choices. Thus, it is important to understand how consumers make decisions to adopt product reviews and what factors might affect this process. This dissertation aims to explore consumers’ information adoption when receiving skincare and makeup product reviews from beauty bloggers on social media platforms. The study examined 8 sites of 4 beauty bloggers in Vietnam as well as interviewed users and beauty bloggers to uncover how reviews are adopted. The dissertation proposes an integrative model of information adoption on social media platforms and identifies complex interconnections between the factors. Moreover, this study takes into account new social media platforms and compares their effects on information adoption. The findings extend extant knowledge of information adoption and suggest the factors that marketers should pay attention to when designing an influential product review

Determination of the body force of a two-dimensional isotropic elastic body

Let $\Omega$ represent a two$-$dimensional isotropic elastic body. We consider the problem of determining the body force $F$ whose form $\phi(t)(f_1(x),f_2(x))$ with $\phi$ be given inexactly. The problem is nonlinear and ill-posed. Using the Fourier transform, the methods of Tikhonov's regularization and truncated integration, we construct a regularized solution from the data given inexactly and derive the explicitly error estimate. Numerical part is givenComment: 23 page

Market Competition and Innovation Premium Before and After the Financial Crisis: Evidence from Taiwan

This study explores the influence of innovation and market competition on stock returns in Taiwan before and after the 2008 financial crisis. This study offers marginal contributions to the important topic of innovation investment which is a vital driver of competitiveness and growth. The study employs Fama Macbeth regression and a sorting portfolio to examine a sample of 121,913 firm-month observations from 1991 to March 2021. A Two-Stage Least Squares estimation is also employed to address unobserved endogeneity issues. The empirical findings suggest that innovation premiums persist in Taiwan. However, the findings also report that higher market concentration reduces stock returns in Taiwan. The results support the information asymmetry theory and the resource-based view theory. This study can support policymakers and managers in developing innovative activities sustainably in emerging markets, while also helping individual investors to optimize their investment portfolios. &nbsp

SECURITY CAPABILITY ANALYSIS OF COGNITIVE RADIO NETWORK WITH SECONDARY USER CAPABLE OF JAMMING AND SELF-POWERING

This paper investigates a cognitive radio network where a secondary sender assists a primarytransmitter in relaying primary information to a primary receiver and also transmits its own information toa secondary recipient. This sender is capable of jamming to protect secondary and/or primary informationagainst an eavesdropper and self-powering by harvesting radio frequency energy of primary signals.Security capability of both secondary and primary networks are analyzed in terms of secrecy outageprobability. Numerous results corroborate the proposed analysis which serves as a design guidelineto quickly assess and optimize security performance. More importantly, security capability trade-offbetween secondary and primary networks can be totally controlled with appropriate selection of systemparameters