ベトナム市場における取締役の独立性，外国人持ち株比率と株価変動性に関する研究

広島大学(Hiroshima University)博士(経済学)Doctor of Economicsdoctora

Foreign Ownership and Stock Return Volatility in Vietnam: the Destabilizing Role of Firm Size

This study aims to examine the relevance of foreign ownership to stock return volatility in the Vietnam stock market over ten years (2008 - 2017). After applying the fixed effects regressions and the extended instrumental variable regressions with fixed effects, we find that foreign ownership decreases the volatility of stock returns. However, the stabilizing impact of foreign ownership on stock return volatility becomes weaker in large firms since the coeffcient of the interaction term between firm size and foreign ownership turns out to be significantly positive. The estimated results remain robust when we use the future one-year volatility, other than the current one, as an alternative measure of the dependent variable

Applying Conflict Management Styles to Resolve Task Conflict and Enhance Team Innovation

Task conflicts among group members have a significant impact on team creativity, so it is critical to identify which conflict resolution styles should be used. This paper aims to examine how various conflict management styles influence team creativity via task conflict. The empirical research was conducted using the Structural Equation Model (SEM) for a sample of 257 employees working for Vietnamese organizations. The results show that dominating style increases task conflict while combining and obliging styles reduce it. To take advantage of the creativity-related benefits associated with task conflict, team leaders should develop an open atmosphere that encourages participants' integrating styles, rather than dominating styles. The negative influence of obliging style reflects Vietnamese culture's high collectivism. The study provides various approaches for task conflict management and also highlights the role of controlling task conflicts in enhancing team innovation. It implies that employees will be able to work better as a team in practice if conflict management strategies are used in a flexible manner. It helps them to build a good connection and successfully implement new ideas. Further research should extend the conclusion of this analysis in various contexts to generalize the findings. Doi: 10.28991/esj-2021-01303 Full Text: PD

Ownership Concentration and Accounting Conservatism: The Moderating Role of Board Independence

The purpose of this study is to examine the moderating effect of board independence on the relationship between ownership concentration and accounting conservatism. Using fixed-effect regressions for a sample of 165 Vietnamese listed companies from 2007 to 2017, the results revealed that the proportion of outstanding shares owned by the largest shareholder is negatively associated with accounting conservatism and board independence plays a moderating role in this relationship. Our results are robust after applying alternative measures of the largest ownership and correcting for potential endogeneity using fixed-effects regression with instrumental variables. Overall, our evidence shows that firms with concentrated ownership should keep a high non-executive ratio to maintain accounting conservatism. In other words, increasing the number of non-executive directors on boards in firms with a substantial proportion of shares held by the largest shareholder is likely to strengthen the information environment, giving financial reporting more credibility.JEL Classification: G30; G32. Doi: 10.28991/ESJ-2023-07-01-07 Full Text: PD

Para-Social Interaction and Trust in Live-Streaming Sellers

Live streaming is one of the modern methods that allows sellers to create, transmit, or broadcast some content on the internet in real-time, and it has been used by many small individual merchants. Understanding how live streaming contributes to online consumption is becoming increasingly important in social commerce as the live-streaming industry has grown more and more popular. However, the number of studies on live streaming is still quite limited in Vietnam. Therefore, this research will look at the mechanism that enables live streaming to boost customer trust in streamers. Using PLS-SEM on a sample of 360 respondents who viewed selling live streams on social network sites in Vietnam, we discovered that other members' endorsement, value similarity, hedonic value, and utilitarian value contribute to good para-social interaction. Next, utilitarian and hedonic values, streamer product expertise, and para-social interaction all positively affect trust in the streamers. The findings could help live-streaming sellers better understand their social interactions with viewers, resulting in increased customer trust. Doi: 10.28991/ESJ-2023-07-03-06 Full Text: PD

NGHIÊN CỨU THỰC NGHIỆM TÁC DỤNG GIẢM CHẤN CỦA CÔNG TRÌNH CHỊU TẢI TRỌNG SÓNG XUNG KÍCH DƯỚI NƯỚC Ở QUẦN ĐẢO TRƯỜNG SA

Research on the problem of load damping of the structures under the effect of shock waves in environment generally and in water particularly is important and necessary for military structures and buildings of inhabitants. If properly designed and having solution to reduce the effects of the blast wave, general structures will be increased markedly and reduce ability of being destroyed. One of the solutions to reduce the effects of the blast wave is to glue layers of material having capable of absorbing blast waves onto the structures. The theoretical and empirical studies are currently less pronounced due to many different reasons. This paper presents modeling and experimental results from the underwater explosion topic KC09.06/11-15 in Truong Sa archipelago to determine the damping effect of the structure modeling is designed with layers of featured material on  its surface.Nghiên cứu về vấn đề giảm chấn của công trình dưới tác dụng của sóng xung kích trong các môi trường nói chung và môi trường nước nói riêng đều quan trọng và cần thiết đối với công trình quân sự và dân sinh. Nếu được thiết kế hợp lý và có các biện pháp làm giảm tác dụng của sóng nổ thì sức sống của công trình được tăng lên rõ rệt, khả năng bị phá hủy giảm. Một trong những giải pháp giảm tác dụng của sóng nổ là dán lớp vât liệu có khả năng hấp thụ sóng nổ lên kết cấu công trình. Các công trình lý thuyết và thực nghiệm về vấn đề này hiện ít được công bố do nhiều nguyên nhân khác nhau. Bài báo trình bày mô hình và kết quả thí nghiệm nổ dưới nước từ đề tài KC09.06/11-15 tại khu vực Trường Sa nhằm xác định tác dụng giảm chấn của mô hình công trình được thiết kế lớp vật liệu đặc trưng trên bề mặt

Evaluation of microscopic observation drug susceptibility assay for diagnosis of multidrug-resistant Tuberculosis in Viet Nam

<p>Abstract</p> <p>Background</p> <p>Early diagnosis of tuberculosis (TB) and multidrug resistant tuberculosis (MDR TB) is important for the elimination of TB. We evaluated the microscopic observation drug susceptibility (MODS) assay as a direct rapid drug susceptibility testing (DST) method for MDR-TB screening in sputum samples</p> <p>Methods</p> <p>All adult TB suspects, who were newly presenting to Pham Ngoc Thach Hospital from August to November 2008 were enrolled into the study. Processed sputum samples were used for DST by MODS (DST-MODS) (Rifampicin (RIF) 1 μg/ml and Isoniazid (INH) 0.4 μg/ml), MGIT culture (Mycobacterial Growth Indicator Tube) and Lowenstein Jensen (LJ) culture. Cultures positive by either MGIT or LJ were used for proportional DST (DST-LJ) (RIF 40 μg/ml and INH 0.2 μg/ml). DST profiles on MODS and LJ were compared. Discrepant results were resolved by multiplex allele specific PCR (MAS-PCR).</p> <p>Results</p> <p>Seven hundred and nine TB suspects/samples were enrolled into the study, of which 300 samples with DST profiles available from both MODS and DST-LJ were analyzed. Cording in MODS was unable to correctly identify 3 Mycobacteria Other Than Tuberculosis (MOTT) isolates, resulting in 3 false positive TB diagnoses. None of these isolates were identified as MDR-TB by MODS. The sensitivity and specificity of MODS were 72.6% (95%CI: 59.8, 83.1) and 97.9% (95%CI: 95.2, 99.3), respectively for detection of INH resistant isolates, 72.7% (95%CI: 30.9, 93.7) and 99.7% (95%CI: 98.1, 99.9), respectively for detecting RIF resistant isolates and 77.8% (95%CI: 39.9, 97.1) and 99.7% (95%CI: 98.1, 99.9), respectively for detecting MDR isolates. The positive and negative predictive values (PPV and NPV) of DST-MODS were 87.5% (95%CI: 47.3, 99.6) and 99.3% (95%CI: 97.5, 99.9) for detection of MDR isolates; and the agreement between MODS and DST-LJ was 99.0% (kappa: 0.8, <it>P </it>< 0.001) for MDR diagnosis. The low sensitivity of MODS for drug resistance detection was probably due to low bacterial load samples and the high INH concentration (0.4 μg/ml). The low PPV of DST-MODS may be due to the low MDR-TB rate in the study population (3.8%). The turnaround time of DST-MODS was 9 days and 53 days for DST-LJ.</p> <p>Conclusion</p> <p>The DST-MODS technique is rapid with low contamination rates. However, the sensitivity of DST-MODS for detection of INH and RIF resistance in this study was lower than reported from other settings.</p