This paper applies a proposed modified stochastic fractal search algorithm (MSFS) for dealing with all constraints of optimal reactive power dispatch (ORPD) and finding optimal solutions for three different cases including power loss optimization, voltage deviation optimization, and L-index optimization. The proposed MSFS method is newly constructed in the paper by modifying three new solution update mechanisms on standard stochastic fractal search algorithm (SSFS). The first modification is to keep only one formula and abandon one formula in the diffusion process (...) while the second modification and the third modification are used in the first update and the second update. In two updates of SSFS, solutions with low quality are updated with high probability while other solutions with high quality do not get chances to be updated. This manner results in the fact that some promising solutions around the high quality solutions can be missed. In order to tackle this restriction, the second modification of MSFS is to newly update the worst solutions in the first update and the best solutions in the second update. In the third modification, all existing formulas of SSFS in the two updates are abandoned and the same new proposed technique is used for updating such solutions in two updates. Compared to SSFS, the three modifications can bring advantages to MSFS such as using smaller number of produced solutions per iteration, spending shorter execution time, finding better optimal solutions, and owning more stable search ability. Furthermore, the proposed method also sees its effectiveness and robustness over SSFS by testing on IEEE 30-bus system and IEEE 118-bus system with three different single objectives for each system. The proposed method can find less minimum, average, and maximum for all the cases in addition to faster search speed. Besides, the proposed method is also compared to other methods such as PSO-based method group, GA-based method group, DE-based method group, and other recent methods. Result comparisons also indicate that the proposed method can be more efficient than almost all these methods with respect to less minimum and smaller values of control parameters. As a result, evaluation of the performance of the proposed method is that it should be used for seeking solutions of ORPD problem. (shrink)

This paper is an empirical analysis of how culture, specifically tradition, affects well-being, i.e., happiness, life satisfaction, and financial satisfaction, along with socioeconomic factors in East Asia. Ordered probit regression model results show that women have higher happiness and satisfaction levels than men even in Confucian cultures in which men generally receive more favourable conditions than women. Additionally, marital status or the impact of religion had strong and positive effects on happiness and sometimes on life satisfaction but not on financial (...) satisfaction. Interestingly, tradition has a statistically significant and important effect on both life and financial satisfaction. Finally, the results show that individuals who value tradition greater also have higher levels of financial satisfaction. (shrink)

This paper presents a novel improved firefly algorithm (IFA) to deal the problem of the optimal operation of thermal generating units (OOTGU) with the purpose of reducing the total electricity generation fuel cost. The proposed IFA is developed based on combining three improvements. The first is to be based on the radius between two solutions, the second is updated step size for each considered solution based on different new equations, and the third is to slightly modify a formula producing new (...) solutions by using normally distributed random numbers and canceling uniform random numbers of conventional firefly algorithm (FA). The effect of each proposed improvement on IFA is investigated by executing five benchmark functions and two different systems. The performance of IFA is investigated on six other study cases consisting of different types of objective function and complex level of constraints. The objective function considers single fuel with quadratic form and nonconvex form, and multifuels with the sum of several quadratic and nonconvex functions while a set of constraints taken into account are power loss, prohibited zone, ramp rate limit, spinning reserve, and all constraints in transmission power networks. The obtained results indicate the proposed improvements in terms of high optimal solution quality, stabilization of search ability, and fast convergence compared with FA. In addition, the comparisons with other methods also lead to a conclusion that the proposed method is a very promising optimization tool for systems with quadratic fuel cost function and with complicated constraints. (shrink)

Computational drug repositioning has been proven as a promising and efficient strategy for discovering new uses from existing drugs. To achieve this goal, a number of computational methods have been proposed, which are based on different data sources of drugs and diseases. These methods approach the problem using either machine learning- or network-based models with an assumption that similar drugs can be used for similar diseases to identify new indications of drugs. Therefore, similarities between drugs and between diseases are usually (...) used as inputs. In addition, known drug-disease associations are also needed for the methods as prior information. It should be noted that those associations are still not well established due to the fact that many of marketed drugs have been withdrawn and this could affect the outcome of the methods. In this study, we propose a novel method named RLSDR to find new uses of drugs. More specifically, it relies on a semi-supervised learning model, Regularized Least Square, thus it does not require definition of non-drug-disease associations as previously proposed machine learning-based methods. In addition, the similarity between drugs measured by chemical structures of drug compounds and the similarity between diseases which share phenotypes can be represented in a form of either similarity network or similarity matrix as inputs of the method. Moreover, instead of using a gold-standard set of known drug-disease associations, we construct an artificial set of the associations based on known disease-gene and drug-target associations. Experiment results demonstrate that RLSDR achieves better prediction performance on the artificial set of drug-disease associations than that on the gold-standard ones in terms of area under the Receiver Operating Characteristic curve. In addition, it outperforms two representative network-based methods irrespective of the prior information of drug-disease associations. Novel indications for a number of drugs are also identified and validated by evidences from a different data resource. (shrink)

We present a mathematical model of two competing marine species that are harvested. We consider three models according to different levels of complexity, without and with species refuge and density-independent and density-dependent species movement between fishing area and refuge. We particularly study the effects of the fishing pressure on the outcome of the competition. We focus on conditions that allow an inferior competitor to invade as a result of fishing pressure. The model is discussed in relationship to the case of (...) the thiof and the octopus along the Atlantic West African coast. At the origin, the thiof was abundant and the octopus scarce in that region. Since, the fishing pressure has strongly increased in some fishing areas leading to the depletion of the thiof and the invasion of its competitor, the octopus. (shrink)

This study investigated the impact of value consonance on employee-based brand equity through the mediating role of teachers' self-efficacy and belongingness. For this purpose, a deductive approach was followed, and data were collected under a cross-sectional research design from academia through a questionnaire. Prior approval from the administration was sought before administrating the questionnaire on a large scale and a sample of 520 teachers was approached in the first phase. At this stage, 418 answered questionnaires were received, while in the (...) second wave, questions related to the teacher's self-efficacy and employee-based brand equity were asked from the respondents. Out of these 418 re-distributed questionnaires, 387 were received back and after discarding the partially filled and incomplete questionnaires, the useable sample size was left as 372. Data have been analyzed by using the structural equation modeling technique, which was assessed through measurement and structural model. Results indicate that value consonance can promote positive behaviors in the workplace. Moreover, teachers with high self-efficacy can develop based on brand equity. Similarly, employees with high-value consonance develop a sense of belongingness with their academic institutes. Limitations and future directions are also discussed. (shrink)

We investigate a system of two species exploiting a common resource. We consider both abiotic (i.e. with a constant resource supply rate) and biotic (i.e. with resource reproduction and self-limitation) resources. We are interested in the asymmetric competition where a given consumer is the locally superior resource exploiter (LSE) and the other is the locally inferior resource exploiter (LIE). They also interact directly via interference competition in the sense that LIE individuals can use two opposite strategies to compete with LSE (...) individuals: we assume, in the first case, that LIE uses an avoiding strategy, i.e. LIE individuals go to a non-competition patch to avoids competition with LSE individuals, and in the second one, LIE uses an aggressive strategy, i.e. being very aggressive so that LSE individuals have to go to a non-competition patch. We further assume that there is no resource in the non-competition patch so that individuals have to come back to the competition patch for their maintenance, and the migration process acts on a fast time scale in comparison with demography and competition processes. The models show that being aggressive is efficient for LIE’s survival and even provoke global extinction of the LSE and this result does not depend on the nature of resource. (shrink)

In this paper, a proposed modified stochastic fractal search algorithm is applied to find the most appropriate site and size of capacitor banks for distribution systems with 33, 69, and 85 buses. Two single-objective functions are considered to be reduction of power loss and reduction of total cost of energy loss and capacitor investment while satisfying limit of capacitors, limit of conductor, and power balance of the systems. MSFS was developed by performing three new mechanisms including new diffusion mechanism and (...) two new update mechanisms on the conventional stochastic fractal search algorithm. As a result, MSFS can reduce 0.002%, 0.003%, and 0.18% of the total power loss from SFS for the three study systems. As compared to other methods, MSFS can reduce power loss from 0.07% to 3.98% for the first system, from 3.7% to 7.3% for the second system, and from 0.92% to 6.98% for the third system. For the reduction of total cost, the improvement level of the proposed method over SFS and two other methods is more significant. It is 0.03%, 1.22%, and 5.76% for the second system and 2.31%, 0.87%, and 3.77% for the third system. It is emphasized that the proposed method can find the global optimal solutions for all study cases while SFS was still implementing search process nearby or far away from the solutions. Furthermore, MSFS can converge to the best solutions much faster than these compared methods. Consequently, it can be concluded that the proposed method is very effective for finding the best location and size of added capacitors in distribution power systems. (shrink)

Network reconfiguration is one of the most effective methods to reduce line power loss in the distribution system, which causes higher losses than the other parts of the power system. This paper proposes a modified symbiotic organisms search algorithm to solve the NR problem. For the purpose of enhancing the effectiveness of MSOS, the mutualism and parasitism strategies of the original symbiotic organisms search have been modified to create better new solutions. In the mutualism strategy, the so-far best solution is (...) updated immediately as soon as new solutions are created. In the parasitism strategy, the update is only implemented for the first half of control variables, whereas another half still remains unchanged. The comparison results between MSOS and SOS on twenty-five benchmark functions and different scales of test distribution systems with 14, 33, 69, and 119 nodes show that the improvement level of MSOS over SOS is significant with higher success rates and better quality of gained solutions. Similarly, MSOS also reaches better results than other methods in the literature. Consequently, MSOS can be a favorable method for determining the most appropriate configurations for the distribution systems. (shrink)

Objectives: The official implementation of clinical pharmacy in Vietnam has arrived relatively late, resulting in various stressors. This study aims to evaluate job stress level and suggest viable solutions.Methods: A cross-sectional study was conducted on clinical pharmacists in 128 hospitals in Ho Chi Minh City. Job stress questions were derived from the Healthcare Profession Stress Inventory.Results: A total of 197 CPs participated, giving a response rate of 82.4%. Participants were found to have moderate job stress with an overall mean stress (...) score of 1.5 and stress rate of 52.8%. The sample size was statistically adequate and the HPSI was valid and reliable. Patient care responsibility was the main stressor, especially in public hospitals, followed by job conflicts. Lack of experience, low income, and inability to participate in clinical ward rounds caused significant stress to CPs regarding job recognition and job uncertainty. More practice-oriented training programs in bachelor curricula and clinical practice should be applied to help CPs gain more experience, self-confidence, and diminish job stress.Conclusion: CPs in HCMC have moderate stress. More practice-oriented training programs should be prioritized to lessen stress for CPs. (shrink)

As a generation of ‘digital natives,’ secondary students who were born from 2002 to 2010 have various approaches to acquiring digital knowledge. Digital literacy and resilience are crucial for them to navigate the digital world as much as the real world; however, these remain under-researched subjects, especially in developing countries. In Vietnam, the education system has put considerable effort into teaching students these skills to promote quality education as part of the United Nations-defined Sustainable Development Goal 4 (SDG4). This issue (...) has proven especially salient amid the COVID−19 pandemic lockdowns, which had obliged most schools to switch to online forms of teaching. This study, which utilizes a dataset of 1061 Vietnamese students taken from the United Nations Educational, Scientific, and Cultural Organization (UNESCO)’s “Digital Kids Asia Pacific (DKAP)” project, employs Bayesian statistics to explore the relationship between the students’ background and their digital abilities. Results show that economic status and parents’ level of education are positively correlated with digital literacy. Students from urban schools have only a slightly higher level of digital literacy than their rural counterparts, suggesting that school location may not be a defining explanatory element in the variation of digital literacy and resilience among Vietnamese students. Students’ digital literacy and, especially resilience, also have associations with their gender. Moreover, as students are digitally literate, they are more likely to be digitally resilient. Following SDG4, i.e., Quality Education, it is advisable for schools, and especially parents, to seriously invest in creating a safe, educational environment to enhance digital literacy among students. (shrink)

The digital era brings various benefits to adolescents. However, operating on the digital environment without sufficient knowledge and skills will expose them to multiple types of risks, especially in the country with low digital safety education rate like Vietnam. The current study examines factors that can contribute to cultivating adolescents’ digital resilience using the information-processing reasoning of the Mindsponge Theory. A UNESCO dataset of 1061 Vietnamese high school students was analyzed using the Bayesian Mindsponge Framework analytics. It is found that (...) adolescents’ daily Internet usage frequency, parents’ Internet safety guidance, and teachers’ safety guidance are positively associated with digital resilience. However, the effects of parents’ and teachers’ Internet safety guidance on digital resilience are conditional on the daily Internet usage frequency. Parents’ guidance only enhances adolescents’ digital resilience if they use the Internet less than four hours per day. In contrast, the positive effect of teachers’ guidance on adolescents’ digital resilience becomes stronger when the students spend more time on the Internet (more than 1 hour). Based on these findings, we suggest that adolescents can learn to minimize risks and protect themselves by exposing more to the digital environment. Parents’ and teachers’ supports are important in enhancing adolescents’ capability to deal with digital threats, but types of supports need to be carefully considered to avoid reverse impacts on adolescents’ resilience. (shrink)

Despite receiving a great deal of research attention, the effect of corporate philanthropy on shareholder value remains inconclusive. To address this issue, the present paper examines emotionality as an important factor based on which investors infer about the firm’s motive as well as the beneficiary’s worthiness and react accordingly. Consistent with attribution theory, our event study shows that announcements with more emotional expressions are associated with higher cumulative abnormal stock returns and the effect is stronger when investor attention is greater. (...) We further find that the positive interaction effect between emotionality and investor attention is more pronounced for scandal-free firms than for firms with corporate social irresponsibility (CSI). The empirical evidence remains consistent under various robustness tests. The paper concludes with implications for future research and managerial practices. (shrink)

A major challenge for research in artificial intelligence is to develop systems that can infer the goals, beliefs, and intentions of others (i.e., systems that have theory of mind, ToM). In this research, we propose a cognitive ToM framework that uses a well-known theory of decisions from experience to construct a computational representation of ToM. Instance-based learning theory (IBLT) is used to construct a cognitive model that generates ToM from the observation of other agents' behavior. The IBL model of the (...) observer distinguishes itself from previous models of ToM that make unreasonable assumptions about human cognition, are hand-crafted for particular settings, complex, or unable to explain a cognitive development of ToM compared to human's ToM. The IBL model learns from the observation of goal-directed agents' behavior in a gridworld navigation task, and it infers and predicts the behaviors of the agents in new gridworlds across different degrees of decision complexity in similar ways to the way human observers do. We provide evidence for the alignment of the IBL observer's predictions under various levels of decision complexity. We also advance the demonstration of the IBL predictions using a classic test of false beliefs (the Sally–Anne test), which is commonly used to test ToM in humans. We discuss our results and the potential of the IBL observer model to improve human–machine interactions. (shrink)

ObjectiveThe goal of the study was to explore the relationship between parent–children relationships related to using the internet among kids and potentially associated factors.Materials and MethodsA sample of 1.216 Vietnamese students between the ages of 12 and 18 agreed to participate in the cross-sectional online survey. Data collected included socioeconomic characteristics and internet use status of participants, their perceived changes in relationship and communication between parents and children since using the internet, and parental control toward the child’s internet use. An (...) Ordered Logistic Regression was carried out to determine factors associated with parent–children relationship since using the internet.ResultsThe characteristics of the relationship between children and their parents since using the Internet were divided into three levels: deterioration, stability, and improvement. The topics that children most often communicate with their parents include learning, housework, and future directions. Two-way interactive activities, such as supporting parents to use the Internet, have a positive impact on the parent–child relationship. Stubborn parental control, such as establishing rules about contact or allowing Internet access and setting up global positioning system to track negatively affecting parent–child relationships.ConclusionFindings indicated that changes in the quality of the parent–child relationship were self-assessed by participants regard to kids’ internet use, especially in the COVID-19 epidemic context. Educational campaigns and programs to raise awareness of parents as to the dangers and negative influences that their children may encounter online, psychology of children’s behaviors and effects of different responding strategies are recommended. (shrink)

This paper introduces a novel method to control the operation of the active suspension system. In this research, a quarter-dynamic model is used to simulate the vehicle’s vibrations. Besides, the sliding mode-PID-integrated algorithm with five state variables is proposed to be used. This is a completely original and novel algorithm. The process of establishing the control algorithm is clearly described. The simulation is performed by the MATLAB software. The results of the paper have shown the advantages of the sliding mode-PID (...) algorithm used in this research. Accordingly, the displacement and acceleration of the sprung mass were significantly reduced when this algorithm was used. The maximum and average values of the displacement of the sprung mass are only 1.31% and 1.29%, respectively, compared with the situation of the vehicle using a passive suspension. Similarly, the value of the acceleration is 6.98% and 2.94%, respectively. In addition, the phenomenon of “chattering” has also been significantly reduced when using this controller. In the future, some more complex algorithms can be proposed. (shrink)

Currently, although the implementation of corporate social responsibility (CSR) practices and its incorporation into business strategies is emphasised widely in developed countries as a key to sustainable growth and economic profitability, this term is still new to the Vietnamese market because of the low awareness of the importance of CSR practices, which leads to the failure of many firms. Since Vietnamese firms do not prioritise CSR implementation, Vietnam is experiencing an increasing shortage of skilled employees owing to a lack of (...) motivation. Therefore, this study examines the relationship between the corporate strategic objective (CSO), CSR practices and employee commitment, to provide recommendations to enhance motivation. This study used a quantitative approach and data from a questionnaire delivered to 869 enterprises in 2019 in Vietnam. Results suggest that the CSO had direct and indirect effects on employee commitment through the mediation of CSR practices. (shrink)

For consciousness to exist, an entity must have prerequisite characteristics and attributes to give rise to it. We explore these “building blocks” of consciousness in detail in this paper, which range from perceptive to computational to meta-representational characteristics of an entity’s cognitive architecture. We show how each cognitive attribute is strictly necessary for the emergence of consciousness, and how the building blocks may be used for any entity to be classified as being conscious. The list of building blocks is not (...) limited to human or organic consciousness and may be used to classify artificial and organisational conscious entities. We further explore a list of attributes that seem intuitively necessary for consciousness, but on further investigation, are neither required nor sufficient. The building blocks do not represent a theory of consciousness but rather a meta-theory on the emergence and classification of consciousness. (shrink)

This article addresses the problem of automatically extracting legal indices which express the important contents of legal documents. Legal indices are not limited to single-word keywords and compound-word keywords, they are also clause keywords. We approach index extraction using structural information of Japanese sentences, i.e. chunks and clauses. Based on the assumption that legal indices are composed of important tokens from the documents, extracting legal indices is treated as a problem of collecting chunks and clauses that contain as many important (...) tokens as possible. Each token is assigned a weight which is a statistical score, e.g. TF–IDF and Okapi BM25, to indicate its importance. The importance of a chunk or clause is determined based on the average weight of tokens included in that chunk or clause. Then, highly weighted chunks and clauses are recognized as the indices for legal documents. The experimental results on Japanese National Pension Act data show that our proposed method achieves better performance than TextRank, the most popular unsupervised method in extracting single-word and compound-word keywords. In addition, this approach is also applicable to extract clause keywords with high performance. (shrink)

Vietnam is home to a prospering technology community and numerous enterprises that range from small start-ups to development giants. Virtually all public services are offered online. In fact, the country even has a system for e-residency and “data embassies.” This achievement derives in part from the nation’s transparent and enduring political preferences, but more importantly from Vietnamese law and its regulatory system regarding information, the digital general public, and intellectual property rights (IPR) protection. In this examination of the most pertinent (...) aspects of Vietnam’s digital economy legislation, this study explores the nation’s regulatory structure regarding copyright and patents within the context of digital transformation. The study discusses the relationship between foreign and national regulations in terms of IPR protection and the advancement of digitalization. Research on Vietnamese regulations and the practical application of major patent and copyright regulations has revealed that in many respects, the nation is highly reliant on the effective operation of a broader foreign institutional and legal framework. Thus, in the near future, technological advancement will necessitate the establishment of additional transnational regulatory systems. (shrink)

The accession and implementation of new generation free trade agreements bring numerous opportunities as well as challenges to Viet Nam, regarding trade, labor and investment. The increasing number of workers abroad puts a pressure on Vietnamese government to support them in new working cultures and environments. The application of chatbot, which has been known to help certain vulnerable groups such as patients, women and migrants could be one of the tools to support Vietnamese migrant workers by providing immediate information, network (...) connection and consultation. Analyzing the results of the qualitative interviews with 11 migrant workers and the group discussion with two sections from three public social media groups and three active informants, the article argues that migrant workers as a vulnerable group who are supposed to be promising users of chatbot due to their great demand and needs, may have a complicated form of trust and expectation in chatbot. (shrink)

A critical issue in executive control is how the nervous system exerts flexibility to inhibit a prepotent response and adapt to sudden changes in the environment. In this study, force measurement was used to capture “partial” unsuccessful trials that are highly relevant in extending the current understanding of motor inhibition processing. Moreover, a modified version of the stop-signal task was used to control and eliminate potential attentional capture effects from the motor inhibition index. The results illustrate that the non-canceled force (...) and force rate increased as a function of stop-signal delay, offering new objective indices for gauging the dynamic inhibitory process. Motor response was a function of delay in the presentation of novel/infrequent stimuli. A larger lateralized readiness potential amplitude in go and novel stimuli indicated an influence of the novel stimuli on central motor processing. Moreover, an early N1 component reflects an index of motor inhibition in addition to the N2 component reported in previous studies. Source analysis revealed that the activation of N2 originated from inhibitory control associated areas: the right inferior frontal gyrus, pre-motor cortex, and primary motor cortex. Regarding partial responses, LRP and error-related negativity were associated with error correction processes, whereas the N2 component may indicate the functional overlap between inhibition and error correction. In sum, the present study has developed reliable and objective indices of motor inhibition by introducing force, force-rate and electrophysiological measures, further elucidating our understandings of dynamic motor inhibition and error correction. (shrink)

Vietnam is a communist country. For a Marxist ideologue, “religion is the opium of the masses.” But many communist countries—over the years—have evolved from a strictly atheistic persuasion to a tolerance for religious practices. Except probably in North Korea, this transformation from an atheistic perspective to religious tolerance has become a phenomenon in communist countries like Russia and China.Vietnam did not have that experience. This paper will show that religious pluralism was tolerated, even accepted, in communist Vietnam. I will show (...) how vibrant this religious amalgamation is in Vietnam and demonstrate, as in the case of market economics thriving in communist countries, that Vietnamese communism and religious pluralism can robustly coexist with each other. (shrink)

This research proposes a modified metaheuristic optimization algorithm, named as improved stochastic fractal search, which is formed based on the integration of the quasiopposition-based learning and chaotic local search schemes into the original SFS algorithm for solving the optimal capacitor placement in radial distribution networks. The test problem involves the determination of the optimal number, location, and size of fixed and switched capacitors at different loading conditions so that the network total yearly cost is minimized with simultaneous fulfillment of operating (...) constraints. Also, the hourly on/off scheduling plans of switched shunt capacitors considering a modified cost objective function are obtained. The proposed ISFS algorithm has been tested on two IEEE 69-bus and 119-bus RDNs and a practical 152-bus RDN. For clarifying the effectiveness and validation of the ISFS, the simulated results have been compared with those of other previously utilized solution approaches in the literature as well as the original SFS. From result comparison, the proposed ISFS outperforms other previous approaches regarding solution quality and statistical performance for the compared cases, especially in the complex and large-scale networks. Notably, compared with the original SFS, the proposed ISFS shows a significantly better performance in all the tested cases. (shrink)

AimHealthcare workers have directly provided care for COVID-19 patients, and have faced many additional sources leading to poor mental health. The study aimed to investigate the mental health problems and related factors among healthcare staff in Vietnam.MethodsA descriptive cross-sectional mixed methods study, combining quantitative and qualitative research methods, was performed among 400 healthcare workers working at the National Hospital for Tropical Diseases and Ninh Binh General Hospital from the first day of treatment for COVID-19 patients to May 01, 2020.ResultsThe results (...) showed that 8.0% of participants had stress, 17.5% of participants had anxiety, and 14.8% of participants had depression. Approximately 50% of participants reported that they had at least one of these symptoms. The findings illustrated that stress, anxiety, and depression were associated with the position in a hospital, health status during the COVID-19 pandemic, family members/relatives infected with COVID-19, physical and mental support from friends, family, and community, department, years of working, and the average work hours per day of healthcare workers exposed to COVID-19.ConclusionDuring the COVID-19 pandemic, healthcare workers who worked in the hospital providing treatment and care for COVID-19 patients dealt with mental health problems such as stress, anxiety, and depression. It is necessary to promote mental health among healthcare workers, to contribute to the fight against the COVID-19 outbreak in Vietnam. (shrink)

Online book fairs are being held in Vietnam to replace traditional offline events that have been shelved owing to the COVID-19 crisis. This study aims to explore book consumers’ perceptions regarding digital book fairs and their evaluation of the first-ever national online book fair held in Vietnam. In-depth interviews were conducted to obtain insights from people who had attended the online book event. The findings provide acceptance of and support for the organization of digital book fairs during the COVID-19 pandemic. (...) Attendees generally appreciated the convenience of the national online book fair and the promotional programmes offered by various publishers and distributors. Furthermore, some attendees enjoyed the novelty of the event and the feeling of being included in the reading community. Nevertheless, most of the attendees highlighted several limitations, especially the lack of social and face-to-face interaction. These findings have implications for online book fair organizers, publishers, and book distributors alike. (shrink)

Banks play a unique role in society. They not only maximize profits but also consider the interests of stakeholders. We investigate whether banks consider firms’ pollution records in their lending decisions. The evidence shows that banks offer significantly higher loan spreads, higher total borrowing costs, shorter loan maturities, and greater collateral to firms with higher levels of chemical pollution. The costly effects are stronger for borrowers with greater risk and weaker corporate governance. Further, the results show that banks with higher (...) social responsibility account for their borrowers’ environmental performance and charge higher loan spreads to those with poor performance. These results support the idea that banks with higher social responsibility can promote the practice of business ethics in firms. (shrink)

Central limit theorem for the functional of jump Markov process. Nguyễn Văn Hữu, Vương Quân Hoàng và Trần Minh Ngọc. Báo cáo: Hội nghị toàn quốc lần thứ III “Xác suất - Thống kê: Nghiên cứu, ứng dụng và giảng dạy” (tr. 34). Ba Vì, Hà Tây, ngày 12-14 tháng 05 năm 2005. Viện Toán học / Trường Đại học Khoa học tự nhiên / Đại học Quốc gia Hà Nội.

Some conditions are given to ensure that for a jump homogeneous Markov process $\{X(t),t\ge 0\}$ the law of the integral functional of the process $T^{-1/2} \int^T_0\varphi(X(t))dt$ converges to the normal law $N(0,\sigma^2)$ as $T\to \infty$, where $\varphi$ is a mapping from the state space $E$ into $\bbfR$.

Nowadays, the power systems are getting more and more complicated because of the delays introduced by the communication networks. The existence of the delays usually leads to the degradation and/or instability of power system performance. On account of this point, the traditional load frequency control approach for power system sketches a destabilizing impact and an unacceptable system performance. Therefore, this paper proposes a new LFC based on adaptive integral second-order sliding mode control approach for the large-scale power system with communication (...) delays. First, a new linear matrix inequality is derived to ensure the stability of whole power systems using Lyapunov stability theory. Second, an AISOSMC law is designed to ensure the finite time reachability of the system states. To the best of our knowledge, this is the first time the AISOSMC is designed for LFC of the LSPSwCD. In addition, the report of testing results presents that the suggested LFC based on AISOSMC can not only decrease effectively the frequency variation but also make successfully less in mount of power oscillation/fluctuation in tie-line exchange. (shrink)

The study of cultural evolution has taken on an increasingly interdisciplinary and diverse approach in explicating phenomena of cultural transmission and adoptions. Inspired by this computational movement, this study uses Bayesian networks analysis, combining both the frequentist and the Hamiltonian Markov chain Monte Carlo (MCMC) approach, to investigate the highly representative elements in the cultural evolution of a Vietnamese city’s architecture in the early 20th century. With a focus on the façade design of 68 old houses in Hanoi’s Old Quarter (...) (based on 78 data lines extracted from 248 photos), the study argues that it is plausible to look at the aesthetics, architecture, and designs of the house façade to find traces of cultural evolution in Vietnam, which went through more than six decades of French colonization and centuries of sociocultural influence from China. The in-depth technical analysis, though refuting the presumed model on the probabilistic dependency among the variables, yields several results, the most notable of which is the strong influence of Buddhism over the decorations of the house façade. Particularly, in the top 5 networks with the best Bayesian Information Criterion (BIC) scores and p<0.05, the variable for decorations (DC) always has a direct probabilistic dependency on the variable B for Buddhism. The paper then checks the robustness of these models using Hamiltonian MCMC method and find the posterior distributions of the models’ coefficients all satisfy the technical requirement. Finally, this study suggests integrating Bayesian statistics in the social sciences in general and for the study of cultural evolution and architectural transformation in particular. (shrink)

Sweetpotato-pig production is an important system that generates income, utilizes unmarketable crops, and provides manure for soil fertility maintenance. This system is widely practiced from Asia to Africa, with many local variations. Within this system, pigs are generally fed a low nutrient-dense diet, yielding low growth rates and low economic efficiency. Our project in Vietnam went through a process of situation analysis, participatory technology development (PTD), and scaling up over a seven-year period to improve sweetpotato-pig production and to disseminate developed (...) technologies. The situation analysis included a series of pig production assessments in several provinces in northern and southern Vietnam, and pig supply-market chain identification was conducted in 13 provinces. The analysis of these studies informed the project of the following: (1) appropriate locations for our activities; (2) seasonal available feedstuff and farmers’ feeding practices; (3) market fluctuation and requirements; and (4) feeding and management improvement needs based on which the subsequent phase of PTD was designed. The PTD involved a limited number of farmers participating in sweetpotato varietal selection, sweetpotato root and vine silage processing, seasonal feeding combination, and pig feeding with balanced crop-feed diet and silage. Six years of multi-location and multi-season sweetpotato selection resulted in a few promising varieties that yielded up to 75% more dry matter and have since been formally released. The most significant results of silage processing and feeding trials include improved growth, higher feeding efficiency, increased year-round local feedstuff, and considerable labor reduction from eliminated cooking and vine cutting. Once these technologies were developed, a farmer-to-farmer training model was designed for scaling up the adoption and impact. Farmer trainers from seven communes in seven provinces received training in these technologies. In turn, they undertook the responsibility of training other farmers on sweetpotato selection, processing, and feeding. An impact study was also administered to monitor and evaluate (M&E) the dissemination process and to document the impact of the new technologies and farmer-to-farmer training model on pig growth and farmer income generation. The results showed that both participating and non-participating farmers have taken up the technologies, although the former demonstrates higher rates of adoption than the latter. The participants also generated more income and saved more labor from the adoption of the technologies. While the scaling up and M&E activities are on-going, the project has since broadened from a sweetpotato-pig system perspective to a pig-cropfeed system perspective based on farmers’ needs. It has included other crop feeds such as cassava and peanut stems in the research portfolio. New technologies based on on-going PTD will continuously be incorporated into the future training curriculum. (shrink)

Vietnam, with a geographical proximity and a high volume of trade with China, was the first country to record an outbreak of the new Coronavirus disease (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 or SARS-CoV-2. While the country was expected to have a high risk of transmission, as of April 4, 2020—in comparison to attempts to contain the disease around the world—responses from Vietnam are being seen as prompt and effective in protecting the interests of its citizens, (...) with 239 confirmed cases and no fatalities. This study analyzes the situation in terms of Vietnam’s policy response, social media and science journalism. A self-made web crawl engine was used to scan and collect official media news related to COVID-19 between the beginning of January and April 4, yielding a comprehensive dataset of 14,952 news items. The findings shed light on how Vietnam—despite being under-resourced—has demonstrated political readiness to combat the emerging pandemic since the earliest days. Timely communication on any developments of the outbreak from the government and the media, combined with up-to-date research on the new virus by the Vietnamese science community, have altogether provided reliable sources of information. By emphasizing the need for immediate and genuine cooperation between government, civil society and private individuals, the case study offers valuable lessons for other nations concerning not only the concurrent fight against the COVID-19 pandemic but also the overall responses to a public health crisis. (shrink)

Folklore has a critical role as a cultural transmitter, all the while being a socially accepted medium for the expressions of culturally contradicting wishes and conducts. In this study of Vietnamese folktales, through the use of Bayesian multilevel modeling and the Markov chain Monte Carlo technique, we offer empirical evidence for how the interplay between religious teachings (Confucianism, Buddhism, and Taoism) and deviant behaviors (lying and violence) could affect a folktale’s outcome. The findings indicate that characters who lie and/or commit (...) violent acts tend to have bad endings, as intuition would dictate, but when they are associated with any of the above Three Teachings, the final endings may vary. Positive outcomes are seen in cases where characters associated with Confucianism lie and characters associated with Buddhism act violently. The results supplement the worldwide literature on discrepancies between folklore and real-life conduct, as well as on the contradictory human behaviors vis-à-vis religious teachings. Overall, the study highlights the complexity of human decision-making, especially beyond the folklore realm. (shrink)

United Nations’ Sustainable Development Goals 4 Quality Education has highlighted major challenges for all nations to ensure inclusive and equitable quality access to education, facilities for children, and young adults. The SDG4 is even more important for developing nations as receiving proper education or vocational training, especially in science and technology, means a foundational step in improving other aspects of their citizens’ lives. However, the extant scientific literature about STEM education still lacks focus on developing countries, even more so in (...) the rural area. Using a dataset of 4967 observations of junior high school students from a rural area in a transition economy, the article employs the Bayesian approach to identify the interaction between gender, socioeconomic status, and students’ STEM academic achievements. The results report gender has little association with STEM academic achievements; however, female students (αa_Sex[2] = 2.83) appear to have achieved better results than their male counterparts (αa_Sex[1] = 2.68). Families with better economic status, parents with a high level of education (βb(EduMot) = 0.07), or non-manual jobs (αa_SexPJ[4] = 3.25) are found to be correlated with better study results. On the contrary, students with zero (βb(OnlyChi) = -0.14) or more than two siblings (βb(NumberofChi) = -0.01) are correlated with lower study results compared to those with only one sibling. These results imply the importance of providing women with opportunities for better education. Policymakers should also consider maintaining family size so the parents can provide their resources to each child equally. (shrink)

BackgroundThe informed consent process in clinical trials has been extensively studied to inform the development processes which protect research participants and encourage their autonomy. However, ensuring a meaningful informed consent process is still of great concern in many research settings due to its complexity in practice and interwined socio-cultural factors.ObjectivesThis study explored the practices and meaning of the informed consent process in two clinial trials conducted by Oxford University Clinical Research Unit in collaboration with the Hospital for Tropical Diseases in (...) Ho Chi Minh City, Vietnam.MethodsWe used multiple data collection methods including direct observervations, in-depth interviews with study physicians and trial participants, review of informed consent documents from 2009 to 2018, and participant observation with patients’ family members. We recruited seven physicians and twenty-five trial participants into the study, of whom five physicians and thirteen trial participants completed in-depth interviews, and we held twenty-two direct observation sessions.ResultsWe use the concept “fragmented understanding” to describe the nuances of understanding about the consent process and unpack underlying reasons for differing understandings.ConclusionsOur findings show how practices of informed consent and different understanding of the trial information are shaped by trial participants’ characteristics and the socio-cultural context in which the trials take place. (shrink)