Journal of Technical Education Science

Control of Rotary Inverted Pendulum (RIP) is a classic control problem and is considered a benchmark in control theory problems. It represents a broader class of under-actuated systems. Rotary inverted pendulum complex system, widely studied in many areas due to its complexity, nonlinearities and non-minimum-phase system. It relates to a class of real world system such as cart and pole, pendubot, missile launchers, human balance, bipedal robot, metronome and many more. The problems associated with it are always interesting topics in control engineering. This paper presents a back-stepping technique to control this system balancing at a vertical upright position-the unstable equilibrium point. Lyapunov-based back-stepping is proposed for a rotary inverted pendulum in this research. Both the simulation and experimental results on controllers-swing up and balancing- and system responses show the effectiveness of this method. And two methods swing-up will be proposed in this article are Furuta method and exponentiation of the pendulum position method.

Con lắc ngược quay là một mô hình quen thuộc và cơ bản trong lý thuyết điều khiển tự động. Tuy nhiên, giá tiền một mô hình là rất cao, không phù hợp điều kiện trang bị phòng thí nghiệm còn hạn chế ở Việt Nam. Các mô hình được tự chế tạo hiện nay thì không đáp ứng được thông số mô hình, dẫn tới việc áp dụng các giải thuật phụ thuộc vào mô hình không được thiết kế thành công. Bài báo đề xuất chế tạo mô hình con lắc ngược quay giá rẻ và dễ xây dựng cho các phòng thí nghiệm điều khiển trong hoàn cảnh Việt Nam. Mô hình rõ ràng trong cấu trúc, thông số hệ thống. Và khả năng ứng dụng hệ thống để hướng dẫn trong phòng thí nghiệm được chứng minh bằng cách áp dụng xây dựng giải thuật trên mô hình này với việc xây dựng giải thuật-swingup và cân bằng- dựa trên hệ động lực học hệ thống. Sau đó, khảo sát trên các bộ điều khiển và đáp ứng hệ thống sẽ cho thấy hiệu quả của mô hình thực này. Giải thuật cân bằng LQR được lựa chọn và giải thuật swing-up là phương pháp Furuta.

Corona pandemic has a strong influence on almost all fields all over the world, especially in education. In Vietnam, in the case study of the University of Technology and Education Ho Chi Minh City (HCMUTE), most of the lecturers being responsible for theoretical subjects are required to teach their students online during the outbreak of COVID 19. It is a crucial issue that needs efficiency from online learning. This study aims to evaluate the status and efficiency of online learning at HCMUTE. Altogether 108 students and 25 lecturers participated in the study. The qualitative data collection tool was a questionnaire that has open and closed questions related to the learning environment, the interaction relationships, and learning outcomes. The results show that there is a synchronous learning environment and plenty of digital tools used by most lecturers. About 74 percent of students are satisfied and keen on continuing online learning; a large number of lecturers would like to continue with blended learning. Besides, the study also found out some difficulties that focus on two main issues such as technical issues, and decreasing students’ activeness during online classes. The study also recommends three learning activities design stages that the lecturers can apply for their online teaching to encourage students to active learning. This research extends knowledge of pedagogy and orient the next online course design at UTEx.

Freeze drying is one of the most advanced drying technologies for food processing and preserving using temperature under 0oC or under the freezing point, and pressure of drying chamber environment under 4.58mmHg to process foods. This method helps to maintain the initial quality of proteins, lipids, carbohydrates, vitamins, bioactive substances and sensory activities… In this study, the calculation and design were carried out to find suitable technology parameters to make the freeze drying system in which the freezing process occurred inside the freeze drying chamber. Heat was transferred by short wavelength thermal radiation, l = 50´10-3 m. As a result, time of freeze drying had been shortened to 13.33h/batch. The system was successfully manufactured, showed the steadily working, producing the high quality products, and reduced products price. In the conditions of Vietnam, the freeze drying system replacing that of other countries is the indispensable factor to apply for processing and preserving foods.

Compliant constant-torque mechanism (CTM) can produce an output torque that does not change within a prescribed input rotation range. This stability is maintained regardless of complicated sensorized control systems. Owing to the monolithic nature of the compliant mechanism, the device is more compact, lightweight, and portable, which is favorable to human joint rehabilitative devices or mobility-assisting devices. However, before approaching the stable range, the mechanism has to undergo a pre-loading range which usually accounts for one-third of the entire operational journey. In addition, the deformation of flexible segments is restricted due to the yield strength of the materials. This limited working range hampers other potential applications of compliant CTMs. This paper presents a novel design of a compliant 2-stage CTM with long-stroke by using serially connected curved beams that deform sequentially. The design process is implemented via a shape optimization scheme using genetic algorithm. Finite element analysis is used to characterize the constant-torque behavior of the CTM under static loading. A general design formulation is also proposed to synthesize this special kind of compliant mechanism. The results show that this CTM gets the stable torque range from 300 to 1100 over two stages with the deviation less than 4.3%.

Adsorption kinetics is an essential part in adsorption studies. The pseudo-first-order (PFO) and pseudo-second-order (PSO) models are frequently used to model the experimental dataset of time-dependent adsorption. The differential equations (based on reaction rate and rate law) of the PFO and PSO models are similar to those of chemical reactions (i.e., first and second order-kinetic reactions). The adsorption kinetics is illustrated through the plot of qt (the amount of adsorbate adsorbed by adsorbent at time t) vs. time. This plot includes two important regions (kinetic and equilibrium). The adsorption rate constant (k1(PFO) or k2(PSO), respectively) of the PFO or PSO models needs to be calculated from two regions. The appropriate selection of initial adsorbate concentrations for studying adsorption kinetics should be based on adsorption isotherm to ensure that adsorption sites in adsorbent (material) are highly (nearly fully) covered by adsorbate (solute). Only in this case, the rate constant of the adsorption is accurately obtained.

The aim of this article is to describe the direct and potential impacts Erasmus+ Capacity Building Higher Education (CBHE) - Project called “Empowering Vietnamese VET teachers for transformation towards Education 4.0” (EMVITET)- after one year of implementation. Additionally, the survey findings also summarized the institutional and teachers’ personal experiences during the Covid-19 pandemic, which pushed Vietnamese institutions to rapidly transform their education to online environments. Qualitative data were collected with online questionnaires from six partner institutions and 35 teacher participants. The findings indicate that both individual teacher participants and partner institutions were given a boost to improve Education 4.0 competencies thanks to the participatory and collaborative approach of the EMVITET- project. The project was perceived as an useful external source for supporting the institutions’ management in organizing demanding online education during Covid-19 pandemic.

E-learning has become a trend in university education around the world. Also, the EMVITET Erasmus+ project in developing Education 4.0 has focused on developing e-learning. This study investigates the effect of critical success factors (CSFs) on e-learning at Da Nang University of Technology and Education (UTE-DN), a member of The University of Danang. Five categories were firstly identified via the literature and a questionnaire using the Likert scale was then carried out to evaluate the importance of each factor from students’ perspective. Analytical results indicated 20 CSFs that influence the success of e-learning. Internet quality, self-efficacy, content quality of the lectures, enthusiasm while teaching, and accessible and up-to-date learning materials are the top five influential factors that impact e-learning success. This study, thus, supports leaders and teachers at UTE-DN in making decisions and strategies about e-learning.

Online teaching or e-learning allows learners to participate in a virtual classroom environment based on web and based on digital applications or digital tools, to interact with learning content and (possibly) with teacher and other peers from a long distance to achieve learning goals defined by their learning needs. The article provides some theoretical backgrounds of online teaching related to the advantages and limitations of online teaching, the forms of online teaching (synchronous learning, asynchronous learning, blended learning), structure of implementing an online course supporting dialogical and deep learning. The article also shares the experiences of Ho Chi Minh City University of Technology and Education (HCMUTE) in implementing online teaching, especially asynchronous teaching on learning management systems (LMS, FHQLMS) and gives some recommendations for lecturers to improve the quality of organizing online courses. Based on the theoretical analysis method with the literature review and the synthesis of practical education experience from HCMUTE, a four-step and 5W-1H online course design process is suggested

The COVID-19 pandemic has been posing substantial challenges to every aspect of human society over the last two years. In Vietnam, all educational institutions have struggled to quickly build and operate their online systems while their teachers have tried their best to adapt to the online environment. Fortunately, the EMVITET Erasmus+ capacity-building project has been punctually and effectively implemented since early 2019 to provide its six partners in Vietnam with significant support to enhance their digital competencies. Several capacity-building activities in the project have been conducted so far. This paper aims at assessing the impacts of the project by evaluating the effectiveness of online teaching at the partner institutions from the teachers’ perspectives after about 3 years of project implementation. Based on the responses from 101 teachers collected with a self-completed online questionnaire, it is found that the EMVITET project has greatly supported the partner institutions in successfully deploying an online environment for their teaching-learning activities. Especially, online teaching has proved its effectiveness in improving the diversity of educational activities, collaboration among colleagues, knowledge transmission, faster interaction among lecturers and students as well as the diverse approaches for teachers to evaluate student learning, students’ diligence, students’ engagement in their studies and research, and soft skills during their study online, among others.