316 research outputs found

    A New Approach of the Online Tuning Gain Scheduling Nonlinear PID Controller Using Neural Network

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    This chapter presents the design, development and implementation of a novel proposed online-tuning Gain Scheduling Dynamic Neural PID (DNN-PID) Controller using neural network suitable for real-time manipulator control applications. The unique feature of the novel DNN-PID controller is that it has highly simple and dynamic self-organizing structure, fast online-tuning speed, good generalization and flexibility in online-updating. The proposed adaptive algorithm focuses on fast and efficiently optimizing Gain Scheduling and PID weighting parameters of Neural MLPNN model used in DNN-PID controller. This approach is employed to implement the DNN-PID controller with a view of controlling the joint angle position of the highly nonlinear pneumatic artificial muscle (PAM) manipulator in real-time through Real-Time Windows Target run in MATLAB SIMULINKƂĀ® environment. The performance of this novel proposed controller was found to be outperforming in comparison with conventional PID controller. These results can be applied to control other highly nonlinear SISO and MIMO systems. Keywords: highly nonlinear PAM manipulator, proposed online tuning Gain Scheduling Dynamic Nonlinear PID controller (DNN-PID), real-time joint angle position control, fast online tuning back propagation (BP) algorithm, pneumatic artificial muscle (PAM) actuator

    Space Vector Modulation for Induction Motor on ARM-based Microcontroller

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    This article presents the review and the implementation of Space Vector Modulation (SVM) in a low-cost microcontroller-based motor drive system. The output three-phase voltages are obtained from a reference voltage vector in the polar coordinate system using the PWM technique; these voltages can reach up to the level of the DC voltage source (experimentally 16 VDC or practically 237 V with an inverter module). The article also provides a detailed presentation of the pre-calculations and the computations required for SVM on a STM32F1 ARM-based microcontroller. For achieving high frequency precision, a novel method for vector rotation based on the fixed-point arithmetic is proposed and tested. The experimental results highlight that the presented implementation including vector rotation can reach 1 Hz without significant error and it requires only 0.684 MIPS at 5 kHz computation rate for a 72 MIPS 32-bit microcontroller with single-cycle multiplication. The maximum instantaneous output phase-to-phase voltages could be as high as the DC voltage source

    Entrepreneurial Finance: Insights from English Language Training Market in Vietnam

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    Entrepreneurship plays an indispensable role in the economic development and poverty reduction of emerging economies like Vietnam. The rapid development of technologies during the Fourth Industrial Revolution (Industry 4.0) has a significant impact on business in every field, especially in the innovation-focused area of entrepreneurship. However, the topic of entrepreneurial activities with technology applications in Vietnam is under-researched. In addition, the body of literature regarding entrepreneurial finance tends to focus on advanced economies, while mostly neglecting the contextual differences in developing nations. Therefore, this research contributes to these topics by investigating the main characteristics of a high potential market for entrepreneurs in Vietnam, which is the English language training market (ELTM). It also aims at indicating the impacts of technology on the entrepreneurial firms within this market, with an emphasis on financing sources. To answer the research questions, this study employs a qualitative analysis and conducts 12 in-depth, semi-structured interviews with entrepreneurs and researchers in the field. The key findings in our study highlight the main contributing factors to the growth of the market, both universally and context-specific for a developing nation like Vietnam. It also lists the leaders in each market segment and the industryā€™s potential profit margin. The results also show that most entrepreneurs in the ELTM utilized private sources of finance rather than external ones, such as bank loans. It again confirms the idea from previous works that even with the rapid development of the economic and technological landscape, entrepreneurial activities in general barely benefit from additional sources of funding. However, it also points out the distinct characteristics of the ELTM that may influence these financing issues; for example, English training services usually collect revenues from customers before delivering their classes. This is of advantage for entrepreneurs in this area and helps significantly reduce the financial barriers. These findings, which are among the first attempts to contribute to a better understanding of entrepreneurial opportunities in the Industry 4.0 in Vietnam, provide valuable insights for policymakers and entrepreneurs, as well as investors

    Factors affecting farmers' decisions to participate in agricultural tourism activities: a case study in the Mekong Delta, Vietnam

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    Agricultural tourism, or agritourism, creates jobs for household members, diversifies farming activities and sources of revenue, and lowers the household's reliance on nature. This study uses Binary Logistic regression analysis to conduct a direct survey of 450 agricultural households in the Mekong Delta, Vietnam. The findings indicate that influencing factors include the following: support for local government policies; membership in farmer associations, unions, and extension clubs; awareness of the benefits of agritourism; a variety of production models; Internet access; education level; and membership in tourism associations, travel organisations. Distance between farms and agritourism destinations.Ho Phi Dinh (Phan Thiet University), Phuoc Huu Vo (Academy of Politics Region II), Duong Ngoc Pham (University of Finance and Marketing), Thanh Quang Ngo (School of Government, University of Economics)Includes bibliographical references

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

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    As a generation of ā€˜digital natives,ā€™ 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 COVIDāˆ’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)ā€™s ā€œDigital Kids Asia Pacific (DKAP)ā€ project, employs Bayesian statistics to explore the relationship between the studentsā€™ background and their digital abilities. Results show that economic status and parentsā€™ 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. Studentsā€™ 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

    The employment of self-regulated strategies in writing process by English-major freshmen at Ho Chi Minh City Open University

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    The current study aims to investigate the employment of self-regulated strategies (SRS) and the gender differences in using SRS in learnersā€™ writing processes. Zimmermanā€™s model of selfregulated learning and thirty SRS are used. This is the survey study and its research instruments are the questionnaire and the interview. The participants of the study are ninety-three first-year students who major in English language of Faculty of Foreign Languages at HCMC Open University. This study finds that learners used twenty-seven SRS in their writing processes including fifteen sub-strategies of self-efficacy strategies and twelve other SRS such as organizing and transforming strategies, goal setting and planning strategies, seeking information strategies, environmental structuring strategies, time management strategies, imagery strategies, self-instruction strategies, self-consequence strategies, keeping records and monitoring strategies, seeking for social assistance strategies from friends, seeking for social assistance strategies from teachers, and self-evaluation strategies. Also, the study finds the gender differences in using five SRS including self-efficacy strategy to write the introduction paragraph, organizing and transforming strategies, seeking information strategies, self-efficacy strategy to refocus on writing when the distractions are occurred, and keeping record and monitoring strategies for note taking

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

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    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, 2020ā€”in comparison to attempts to contain the disease around the worldā€”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 Vietnamā€™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 Vietnamā€”despite being under-resourcedā€”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

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

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    United Nationsā€™ 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 citizensā€™ 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 studentsā€™ STEM academic achievements. The results report gender has little association with STEM academic achievements; however, female students (Ī±a_Sex[2] = 2.83) appear to have achieved better results than their male counterparts (Ī±a_Sex[1] = 2.68). Families with better economic status, parents with a high level of education (Ī²b(EduMot) = 0.07), or non-manual jobs (Ī±a_SexPJ[4] = 3.25) are found to be correlated with better study results. On the contrary, students with zero (Ī²b(OnlyChi) = -0.14) or more than two siblings (Ī²b(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
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