117 research outputs found

    The Influence of Entrepreneurial Ecosystems on Entrepreneurs' Perceptions and Business Success

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    Entrepreneurship continues to grow and receives a great deal of interest from business researchers and practitioners for its importance in the modern economy. This study aims to contribute to the body of knowledge that the entrepreneurial ecosystem correlates with founders' perceptions and startup success. Data were gathered from surveys of 200 founders or CEOs of SMEs and startups in Tay Ninh City (Vietnam), who have operated their own companies for at least five years. The primary data analysis was performed using the partial least squares (PLS) technique. Five out of six ecosystem factors significantly affect entrepreneurs' perceptions and startups’ success, based on the results of the empirical data. Besides, the founders' perceptions also positively affect the success of a startup. The implications show the need to enhance entrepreneurship in a nation

    Evaluating the effect of self-interference on the performance of full-duplex two-way relaying communication with energy harvesting

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    In this paper, we study the throughput and outage probability (OP) of two-way relaying (TWR) communication system with energy harvesting (EH). The system model consists two source nodes and a relay node which operates in full-duplex (FD) mode. The effect of self-interference (SI) due to the FD operation on the system performance is evaluated for both one-way full duplex (OWFD) and two-way full duplex (TWFD) diagrams where the amplify-and-forward (AF) relay node collects energy harvesting with the time switching (TS) scheme. We first propose an individual OP expression for each specific source. Then, we derive the exact closed-form overall OP expression for the OWFD diagram. For the TWFD diagram, we propose an approximate closed-form expression for the overall OP. The overall OP comparison among hybrid systems (Two-Way Half-Duplex (TWHD), OWFD, TWFD) are also discussed.  Finally, the numerical/simulated results are presented for Rayleigh fading channels to demonstrate the correction of the proposed analysis

    Clustering lifestyle risk behaviors among Vietnamese adolescents and roles of school : a Bayesian multilevel analysis of global school-based student health survey 2019

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    Background: Adolescence is a vulnerable period for many lifestyle risk behaviors. In this study, we aimed to 1) examine a clustering pattern of lifestyle risk behaviors; 2) investigate roles of the school health promotion programs on this pattern among adolescents in Vietnam. Methods: We analyzed data of 7,541 adolescents aged 13–17 years from the 2019 nationally representative Global School-based Student Health Survey, conducted in 20 provinces and cities in Vietnam. We applied the latent class analysis to identify groups of clustering and used Bayesian 2-level logistic regressions to evaluate the correlation of school health promotion programs on these clusters. We reassessed the school effect size by incorporating different informative priors to the Bayesian models. Findings: The most frequent lifestyle risk behavior among Vietnamese adolescents was physical inactivity, followed by unhealthy diet, and sedentary behavior. Most of students had a cluster of at least two risk factors and nearly a half with at least three risk factors. Latent class analysis detected 23% males and 18% females being at higher risk of lifestyle behaviors. Consistent through different priors, high quality of health promotion programs associated with lower the odds of lifestyle risk behaviors (highest quality schools vs. lowest quality schools; males: Odds ratio (OR) = 0·67, 95% Highest Density Interval (HDI): 0·46 – 0·93; females: OR = 0·69, 95% HDI: 0·47 – 0·98). Interpretation: Our findings demonstrated the clustering of specific lifestyle risk behaviors among Vietnamese in-school adolescents. School-based interventions separated for males and females might reduce multiple health risk behaviors in adolescence. Funding: The 2019 Global School-based Student Health Survey was conducted with financial support from the World Health Organization. The authors received no funding for the data analysis, data interpretation, manuscript writing, authorship, and/or publication of this article. © 2021 The Author(s

    Combined effects of a simulated marine heatwave and an algal toxin on a tropical marine aquaculture fish cobia (Rachycentron canadum)

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    Ongoing global warming is one of the major challenges for the development of aquaculture in the tropical regions where species are already cultured in the water temperature close to their upper physiological thresholds. Furthermore, warming can trigger blooms of toxic algae, yet we do not know how extreme warming such as a marine heatwave (MHW) and algal toxins may affect marine aquaculture species. To address this issue, we investigated the effects of a simulated MHW in combination with exposure to trans-4-trans-decadienal (PUA), a diatom-derived toxin, on survival, growth, development and biochemical composition of cobia larvae and juveniles. Cobia larvae were exposed for 48 hr to one of two temperatures (29 vs. 34°C) and two PUA treatments (0 vs. 0.5 µM). Surviving larvae from each treatment were divided into two subsets: three replicates were used for the feeding test and five replicates were used for the recovery test in a non-contaminated environment at the respective temperatures of 29 or 34°C. Survival of cobia larvae was reduced by 16% in either MHW or PUA, but it dropped by 60% when both stressors were present, indicating a synergistic effect. MHW, but not PUA, reduced the feeding of cobia larvae. PUA had no delayed effects on growth rate and biochemical composition of the fish. MHW strongly reduced specific growth rate, body protein and lipid contents in cobia. Our results provide the first empirical evidence of how MHW and toxic algae may interact and challenge cobia and marine aquaculture production in tropical countries.publishedVersio

    El trauma de los niños vietnamitas que viven en familias incompletas

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    Children living in incomplete families have to suffer from more hardships than others including psychological trauma that could never be cured without safe approaches. In this paper, we used the Children Behavior Checklist (CBCL test) by Achenbach to initially filter the incidence of children in incomplete families with psychological trauma, the extent of childhood trauma, and the signs of trauma. Moreover, the Self-esteem scale of Toulouse was also utilized to investigate children's self-esteem and determine the impact of psychological trauma on the self-assessment of children. Based on these tools, the research conducted a correlation analysis of psychological trauma of children in incomplete families through indicators of awareness of, emotions with, and behaviors towards family and social life (self-evaluated by children). The results showed that there are differences in psychological trauma of children in terms of awareness, emotions, and behaviors. The differences allow for a better definition of children's causes, influences, and degrees of psychological trauma. This is the basis for proposing timely filtering solutions and effective psychological support measures for these children. Keywords: correlation analysis; signs of psychological trauma; children; incomplete family; Vietnam.Los niños que viven en familias incompletas tienen que sufrir más dificultades que otros, incluido el trauma psicológico que nunca podría curarse sin enfoques seguros. En este artículo, se utiliza la Lista de Verificación de Comportamiento Infantil (prueba CBCL) de Achenbach para filtrar inicialmente la incidencia de niños en familias incompletas con trauma psicológico, el alcance del trauma infantil y los signos de trauma. Además, la escala de autoestima de Toulouse también se utilizó para investigar la autoestima de los niños y determinar el impacto del trauma psicológico en la autoevaluación de los niños. Con base en estas herramientas, la investigación realizó un análisis de correlación del trauma psicológico de los niños en familias incompletas a través de indicadores de conciencia, emociones y comportamientos hacia la vida familiar y social (autoevaluados por los niños). Los resultados mostraron que existen diferencias en el trauma psicológico de los niños en términos de conciencia, emociones y comportamientos. Las diferencias permiten una mejor definición de las causas, influencias y grados de trauma psicológico de los niños. Esta es la base para proponer soluciones de filtrado oportunas y medidas de apoyo psicológico eficaces para estos niños. Palabras clave: análisis de correlación; signos de trauma psicológico; niños; familia incompleta; Vietnam

    On The Performance of Underlay Relay Cognitive Networks

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    The bit error rate (BER) performance of underlay relay cognitive networks in the presence of Rayleigh fading is thoroughly analyzed in this paper. New exact and asymptotic analytic expressions under consideration of both interference power constraint and maximum transmit power constraint are derived in closed-form and are extensively corroborated by Monte-Carlo simulations. These expressions facilitate in evaluating effectively the network performance behaviour in key operation parameters as well as in optimizing system parameters. A multitude of analytical results expose that underlay relay cognitive networks experience the performance saturation phenomena while their performance considerably depends on the number of hops for the linear network model. Additionally, optimum relay position is significantly dependent of maximum transmit power, maximum interference power, and licensee location. Moreover, the appropriate order of locating unlicensees with different maximum transmit power levels can dramatically improve the network performance

    The effect of polyamine 70000 (BT70) on the zinc plating process in the non-cyanide alkaline plating bath

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    The effect of polyamine having molecular weight 70,000u (BT70) in the non-cyanide alkaline plating bath on the morphological zinc electrodeposited coating was investigated. The obtained results from the reflectance of electrodeposited zinc coating by a suitable range of electro-current density and SEM images showed that BT70 had effect on the zinc plating in comparison with the zinc deposits from plating bath without BT70. The electrodeposited coating surface was rough and poor adhesion. However, adding BT70 into the plating bath led to the surface roughness of electrodeposited coating and grand size being reduced. Zinc electrodeposited coating from a plating bath containing BT70 at 0.5 g/L, respectively, experienced the highest reflectance, equal 46 % of the electrodeposited coating from the bath containing commercial additives. Hull method showed that the zinc deposited coating surface became smoother with the presence of polyamine in non-cyanide alkaline zinc plating solution. The zinc deposited coating had a semi-gloss scope at 10 A/dm2. If the BT70 content increased, the semi-gloss scop and the gloss of samples’ surfaces also grew up. Keywords. Polyamine, additive, non-cyanide alkaline zinc plating, zinc coating

    Identifying Key Factors influencing cost variation of construction projects in Ho Chi Minh City

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    Cost variation is one of the most concerns of the stakeholders in the construction projects, because it always presents in every construction projects, especially in Vietnam. However, the factors that make the project cost variation are not easy to identify. This study aimed to identify the key factors that influence to the project cost variation. A survey questionnaire was used to collect data from construction practitioners. The analysis results show that there are five groups of factors that influence to project cost variation: Government policies, nature, resources, fraud and theft, and ability of stakeholders. Recommendations are also mentioned to deal with the project cost variation

    Trends in, projections of, and inequalities in reproductive, maternal, newborn and child health service coverage in Vietnam 2000-2030: A Bayesian analysis at national and sub-national levels

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    Background: To assess the reproductive, maternal, newborn and child health (RMNCH) service coverage in Vietnam with trends in 2000-2014, projections and probability of achieving targets in 2030 at national and sub-national levels; and to analyze the socioeconomic, regional and urban-rural inequalities in RMNCH service indicators. Methods: We used national population-based datasets of 44,624 households in Vietnam from 2000 to 2014. We applied Bayesian regression models to estimate the trends in and projections of RMNCH indicators and the probabilities of achieving the 2030 targets. Using the relative index, slope index, and concentration index of inequality, we examined the patterns and trends in RMNCH coverage inequality. Findings: We projected that 9 out of 17 health service indicators (53%) would likely achieve the 2030 targets at the national level, including at least one and four ANC visits, BCG immunization, access to improved water and adequate sanitation, institutional delivery, skilled birth attendance, care-seeking for pneumonia, and ARI treatment. We observed very low coverages and zero chance of achieving the 2030 targets at national and sub-national levels in early initiation and exclusive breastfeeding, family planning needs satisfied, and oral rehydration therapy. The most deprived households living in rural areas and the Northwest, Northeast, North Central, Central Highlands, and Mekong River Delta regions would not reach the 80% immunization coverage of DPT3, Polio3, Measles and full immunization. We found socioeconomic, regional, and urban-rural inequalities in all RMNCH indicators in 2014 and no change in inequalities over 15 years in the lowest-coverage indicators. Interpretation: Vietnam has made substantial progress toward UHC. By improving the government\u27s health system reform efforts, re-allocating resources focusing on people in the most impoverished rural regions, and restructuring and enhancing current health programs, Vietnam can achieve the UHC targets and other health-related SDGs
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