94 research outputs found

    Applying Simplex Algorithm for Ship’s Motion Simulation Optimization by Using Maneuvering Tests Data

    Get PDF
    This article demonstrates an effective method to find OHCs (optimal hydrodynamic coefficients) by applying the Simplex algorithm to reduce the errors of the ship’s motion simulation. The solution is to determine OHCs, which are also the coefficients of the ship’s motion equations. A ship’s motion simulation model was programed by contributing the mathematical model of the ship’s motion, applying the numerical method and MATLAB. In the optimization procedure, the form of Objective Function was contributed corresponding to the type of maneuvering test. The Sensitivity Analysis technique and Simplex algorithm are applied to filter and optimize the most sensitive hydrodynamic coefficients. The numerical model was validated by experimental maneuvering test data, including Turning Circle and Zigzag tests of Esso Bernicia 193000DWT Tanker. A good optimization solution was obtained: for Turning Circle test, after optimization, the ship’s simulation trajectory is close to the experimental trajectory with a RMSD of 5.8m, which reduced from an original value of 69m. In the Zigzag test, the RMSD between the ship’s simulation yaw angle and experimental data was reduced 17.3deg to 5.9deg. The other optimization results, such as the convergence of Objective Function, the number of iteration of Optimization Variables, calculated time, etc. are accepted. Therefore, the Simplex algorithm can be applied quite effectively to optimize ship movement (ship’s trajectory, the ship’s yaw angle, etc.). By defining a common set of values by merging the optimal value of the most sensitive coefficients of two tests, which may be used for the other ship’s motion simulation applications

    Scrambling for higher metrics in the Journal Impact Factor bubble period: a real-world problem in science management and its implications

    Get PDF
    Universities and funders in many countries have been using Journal Impact Factor (JIF) as an indicator for research and grant assessment despite its controversial nature as a statistical representation of scientific quality. This study investigates how the changes of JIF over the years can affect its role in research evaluation and science management by using JIF data from annual Journal Citation Reports (JCR) to illustrate the changes. The descriptive statistics find out an increase in the median JIF for the top 50 journals in the JCR, from 29.300 in 2017 to 33.162 in 2019. Moreover, on average, elite journal families have up to 27 journals in the top 50. In the group of journals with a JIF of lower than 1, the proportion has shrunk by 14.53% in the 2015–2019 period. The findings suggest a potential ‘JIF bubble period’ that science policymaker, university, public fund managers, and other stakeholders should pay more attention to JIF as a criterion for quality assessment to ensure more efficient science management

    MirrorNet: Bio-Inspired Camouflaged Object Segmentation

    Full text link
    Camouflaged objects are generally difficult to be detected in their natural environment even for human beings. In this paper, we propose a novel bio-inspired network, named the MirrorNet, that leverages both instance segmentation and mirror stream for the camouflaged object segmentation. Differently from existing networks for segmentation, our proposed network possesses two segmentation streams: the main stream and the mirror stream corresponding with the original image and its flipped image, respectively. The output from the mirror stream is then fused into the main stream's result for the final camouflage map to boost up the segmentation accuracy. Extensive experiments conducted on the public CAMO dataset demonstrate the effectiveness of our proposed network. Our proposed method achieves 89% in accuracy, outperforming the state-of-the-arts. Project Page: https://sites.google.com/view/ltnghia/research/camoComment: Under Revie

    STEM education and outcomes in Vietnam: Views from the social gap and gender issues

    Get PDF
    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

    Mobilising community-based research on zoonotic infections: A case study of longitudinal cohorts in Vietnam

    Get PDF
    We initiated the Vietnam Initiative on Zoonotic Infections (VIZIONS) research program to better understand the epidemiology of disease transmission at the human–animal interface in Vietnamese rural communities and to integrate One Health approaches to disease surveillance. We established a longitudinal community cohort study of individuals with occupational exposure to animals, which involves concurrent targeted sampling from domestic livestock species and follow-up monitoring of human clinical cases. The project was implemented by government agencies at the provincial and district levels of the public health and animal health sectors in Vietnam. Engaging with rural communities builds response capacity at the grassroots level, and has improved dialogue between local stakeholders responsible for monitoring human and animal health. Here we describe the process of initiating participatory research and cohort field implementation over the first year in two study sites in Vietnam.Keywords: Vietnam, participatory research, zoonoses, field epidemiolog

    Determinants Influencing Entrepreneurial Intention in Hanoi, Vietnam

    Get PDF
    This research employed survey data from 204 students between two groups of  economics and technical majors in Hanoi city for assessing the impact levels of determinants on entrepreneurial intention. The results show that a number of determinants including Need for achievement, Self-efficacy, and Instrumental readiness have positive impacts on student’s entrepreneurial intention. Besides, this study is also to create a basis for  comparative students among different economics and technical majors, work exoperience, and gender. These findings are the basis to recommend policies and solutions to promote entrepreneurship movement in Vietnam. Keywords: Entrepreneurial intention, need for achievement, self-efficacy, instrumental readiness. DOI: 10.7176/EJBM/12-15-10 Publication date:May 31st 2020

    On how religions could accidentally incite lies and violence: folktales as a cultural transmitter

    Get PDF
    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

    Policy Response, Social Media and Science Journalism for the Sustainability of the Public Health System Amid the COVID-19 Outbreak: The Vietnam Lessons

    Get PDF
    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

    How Digital Natives Learn and Thrive in the Digital Age: Evidence from an Emerging Economy

    Get PDF
    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
    • …
    corecore