Testing the Capital Asset Pricing Model (CAPM) in the Vietnamese stock market: an analysis of two sub-periods from 2006 to 2016

Objectives The main objective of this study was to explore the relationship between the beta values of stocks and its actual returns in order to investigate CAPM validity in Vietnamese stock market in the last 10 years. The study also aims to provide investors with fundamental knowledge of this basic financial modelling technique therefore to contribute in helping them evaluate investments effectively. Moreover, the research attempts to provide some beneficial contributions to the study of the application of the CAPM. Summary To achieve the purpose of the study, the researcher collected historical daily/weekly/monthly stock prices in order to estimate the correlative beta values over two five-year periods in Vietnamese security market. The linear relationship of these rate of returns with betas was tested by conducting the simple regression analysis. The research implications were disclosed relying not only on previous literature but also on empirical findings. Conclusions The results of the thesis reject the positive linear relationship between beta and returns. That means, based on the main findings of the research, the CAPM model is not valid in the Vietnamese market from 2006 to 2016

VC-dimension and pseudo-random graphs

Let $G$ be a graph and $U\subset V(G)$ be a set of vertices. For each $v\in U$, let $h_v\colon U\to \{0, 1\}$ be the function defined by h_v(u)=\begin{cases} &1 ~\mbox{if}~u\sim v, u\in U\\&0 ~\mbox{if}~u\not\sim v, u\in U\end{cases}, and set $\mathcal{H}(U):=\{h_v\colon v\in U\}$. The first purpose of this paper is to study the following question: What families of graphs $G$ and what conditions on $U$ do we need so that the VC-dimension of $\mathcal{H}(U)$ can be determined? We show that if $G$ is a pseudo-random graph, then under some mild conditions, the VC dimension of $\mathcal{H}(U)$ can be bounded from below. Specific cases of this theorem recover and improve previous results on VC-dimension of functions defined by the well-studied distance and dot-product graphs over a finite field

Factors contributing to animal health risks: Implication for smallholder pig production in Vietnam

In Vietnam, there are about four million households producing pigs of which more than half are producing at small scale, i.e., about one to two pigs per production cycle. One of the most critical constraints to pig production, especially for small scale, is the presence of animal disease. Many types of diseases have been reported by smallholder pig producers in Hung Yen such as diarrhea, pneumonia, fever, blue ear, head edema and pasteurellosis. The percentage of sick pigs is highest among piglets (27 percent), as compared with growing pigs and fatteners (five percent each). Diseases could lead to death of pigs, resulting in economic losses to the pig producers. Estimates of the cost of mortality in pig production in Hung Yen were about 3.3 million VND per household, accounting for about 13.6 percent of total income from pig production. Results of this study suggest that there are some practices that contribute to mitigating disease risk and those practices can be easily applied at small scale of pig production. These practices are related to applying a suitable production scale, isolating different age classes of pigs, designing pig houses and using specialized livestock farming tools and sanitation. The value of losses avoided from the above practices is estimated at 320.3 USD per household per year

Synthesis of some derivatives of n-(2,3,4,6-tetra-o-acetyl-õ-d-glucopyranosyl)-n’-(benzothiazole-2’-yl) thioureas

Some compounds of N-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-N’-(benzothiazole-2’-yl)thioureas have been synthesized from corresponding 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate and the substituted derivatives of  2-aminobenzothiazoles executing in home microwave oven. Their spectroscopic properties have been recorded and the relationships between their structures and spectral properties (IR, 1H- and 13C-NMR) have been discussed

Financial Performance and Corporate Governance in Microfinance: Evidence from Vietnam

Good corporate governance is considered a building block of success for microfinance institutions (MFIs) as it is presumed to help them in achieving their social and financial goals. This study analyzes the corporate governance and financial performance relationship for MFIs in Vietnam. We construct a corporate governance index based on seven measures pertaining to board size and composition, CEO characteristics, and ownership type. We then estimate the two-way relationship between this index and each of five different financial performance indicators. To address the likely simultaneity between corporate governance and financial performance, we adopt a two-stage least squares estimation approach with instrumental variables. The results confirm the endogenous nature of corporate governance and financial performance. We conclude that profitability and sustainability of MFIs improve with good governance practices and conversely that more profitable and sustainable MFIs have better governance systems. Keywords: Corporate governance, financial performance, microfinance. DOI: 10.7176/EJBM/12-3-12 Publication date: January 31st 2020

LEARNING IDIOMS FOR ENGLISH MAJORS: VIETNAMESE STUDENTS’ PERCEPTIONS OF DIFFICULTIES AND LEARNING STRATEGIES

Learning idioms play an influential role in language generally and in English notably. Comprehending idioms assists language learners in integrating culture, enhancing skills, and ameliorating English levels. Numerous studies have analyzed the function of idioms in second language acquisition (Cieślicka, 2015). This study investigates the difficulties and strategies used in learning idioms by English-majored students at a regional public university (PU) in the south of Vietnam. This paper furnishes data showing learners’ perceptions of facing complications and learning methods. The samples consisted of 150 undergraduate EFL students from English-medium instruction programs. The data was analyzed by utilizing descriptive and inferential statistics. The findings reveal that students struggle to understand idiomatic terms without specific, understandable contexts. Furthermore, the results indicate that the most frequently employed strategies are guessing the meaning of idioms, learning idioms through keywords, and learning from a range of sources, particularly via media. The findings also mentioned that low-proficiency and high-proficiency students encounter identical challenges, with no significant differences. The study's results revealed that the majority of students have difficulty acquiring, recognizing, and interpreting idioms. The findings indicated that guessing the implication of idioms is the most used strategy.  Article visualizations

BIODIVERSITY ASSESSMENT OF MICROORGANISMS ASSOCIATED WITH TWO MARINE SPONGES (Haliclona oculata AND Amphius huxleyi) COLLECTED AT THE LANG CO BAY OF VIETNAM

Sponges (Phylum Porifera) are ancient sedentary and filter-feeding animals which harbour very diverse and abundant associated microbial community in their tissues with density up to 40–50% of sponge tissue volume. In this study, the diversity of associated microorganisms with two marine sponges Haliclona oculata and Amphius huxleyi collected at the Lang Co bay of Vietnam was assessed by analysis of hypervariable V3 and V4 regions of the 16S rRNA gene using Illumina MiSeq system. The taxonomic diversity of sponge-associated microorganisms was classified to different taxonomic levels (kingdom, phylum, class, order, family, and genus). Based on Bayesian classification method and reference sequences derived from Greengenes database, the associated microorganisms in studied sponges were assigned to 17 phyla (H. oculata) and 13 phyla (A. huxleyi). Many microbial taxa were detected in two sponge species, however, they were distinctive by the abundance. Proteobacteria was the most dominant phylum in both sponge species, and all of 4 classes Epsilonproteobacteria, Gammaproteobacteria, Alphaproteobacteria, and Deltaproteobacteria were found in H. oculata and A. huxleyi

Using metagenomics tool to evaluate the enrichment efficiency of methanogens in marine sediment in Truong Sa archipelage, Khanh Hoa province, Vietnam

Methanogens (archaea bacteria that produce methan) play an important role in the anaerobic digestion of organic waste, however, in marine environment, the low density of methanogens makes anaerobic digestion very slow. In this study, we used methagenomics tool to evaluate the enrichment efficiency of methanogens communities in marine sediments as a basis for building a anaerobic microbial formulation to treat organic waste in marine environment. The results of determination of methanogen density by MPN method have shown that methanogen has been accumulated with higher density (up to 3.2.107 MNP/ml) through 2 times of enrichment in artificial seawater with CH3COONa 10 mM substrate. In addition, metagenomics data have also shown a decrease in the number of archaea species through each enrichment, indicating that methanogenic species have gradually dominated the microbial community. This is the first study on using metagnenomics tools to evaluate the enrichment of methanogens in marine sediment samples in Truong Sa archipelago, Vietnam. Metagenomics data help provide more reliable evidence in microbial studies, especially in obligate anaerobes such as methanogens