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The consolidation behavior of prefabricated vertical drain (PVD)-installed soft deposits mainly depends on the PVD performance. The purpose of this study is to propose a numerical solution for the consolidation of PVD-installed soft soil using the large-strain theory, in which the reduction of discharge capacity of PVD according to depth and time is simultaneously considered.

The proposed solution also takes into account the general constitute relationship of soft soil. Subsequently, the proposed solution is applied to analyze and compare with the monitoring data of two cases, one is the experimental test and another is the test embankment in Saga airport.

The results show that the reduction of PVD discharge capacity according to depth and time increased the duration required to achieve a certain degree of consolidation. The consolidation rate is more sensitive to the reduction of PVD discharge capacity according to time than that according to the depth. The effects of the reduction of PVD discharge capacity according to depth are more evident when PVD discharge capacity decreases. The predicted results using the proposed numerical solution were validated well with the monitoring data for both cases in verification.

In this study, the variation of PVD discharge capacity is only considered in one-dimensional consolidation. However, it is challenging to implement a general expression for discharge capacity variation according to time in the two-dimensional numerical solution (two-dimensional plane strain model). This is the motivation for further study.

A geotechnical engineer could use the proposed numerical solution to predict the consolidation behavior of the drainage-improved soft deposit considering the PVD discharge capacity variation.

The large-strain consolidation of PVD-installed soft deposits could be predicted well by using the proposed numerical solution considering the PVD discharge capacity variations according to depth and time.

With a considerable increase in international students studying in Asia, Taiwan has become one of the most popular study destinations. The purpose of this study is to investigate the factors and processes leading to the choice of international students studying in Taiwan. In addition, an appropriate model of students' choice that explored the impact of the motivation, career planning and the decision-making process on student's choice was constructed.

This study was conducted using the mixed-methods methodology. A qualitative approach was used for in-depth interviews with 15 international students studying in Taiwan. The data collected from the interviews were used to create questionnaires to survey over 500 participants. The responses were subsequently used for quantitative analysis.

The results revealed the main factors of the motivation of international students to study abroad in Taiwan. A model of how the students' choice process operated was also provided. The quantitative findings indicated that students' motivation and career planning were significantly correlated, whereas both factors directly affected the decision-making process. On another note, the students' decision-making process remained a mediator between motivation, career planning and students' choice.

This research contributed to methodology development and the practicality of HE management. In addition, a comprehensive model was developed that diagrammatically demonstrated international students' choice in Taiwan.

In late 2015, the El Nĩno phenomenon induced Vietnam’s worst drought in 60 years, which lasted until mid-2016 and intensified the most expansive saline intrusion in 90 years. The combination of the two hazards resulted in a large-scale disaster, which has led 18 provinces of Vietnam, most of them from the Mekong Delta, to water shortage, insanitation, human and animal diseases, food emergency need and a considerable disruption in local communities’ livelihoods. These devastating effects raise the question of what makes local households vulnerable to drought and saline intrusion. The chapter argues that vulnerability to the natural disaster is not something resulted from external threats, but rather, is derived from the interplay between social structures residing deeply inside the socio-economic systems and agency’s conditions presenting at the household level. Social structures are rules and procedures that constrain and/or enable human actions in agricultural production, risk taking and adaptation. Agency refers to the capacities of disaster-affected households in the Vietnamese Mekong Delta who cultivated third rice crop and suffered heavily from the 2015–2016 disaster. In addition to households’ lack of planning and coping capacities, the constitution of vulnerability to drought and saline intrusion can be attributed to the interaction between farmers’ choice of extra rice crops and the state’s policies and directions in agricultural and irrigation development since 1990s to date.

This article examines how farmers' assignment of responsibility for the disaster in late 2015 – early 2016 connects with reflexivity, habitus and local vulnerability.

This article uses semi-structured interviews with 28 disaster-affected households in the Vietnamese Mekong Delta to answer the question.

This article finds out that Vietnamese farmers actively accepted their responsibility for the disaster. In their explanation, they link their action with the root causes of vulnerability embedded in their socio-cultural traditions and collective identity.

This article makes a case for the importance of local culture and epistemologies in understanding disaster vulnerability and responsibility attribution.

This article is original in researching Vietnamese farmers' responsibility attribution, their aesthetic reflexivity, collective habitus and the socio-cultural root causes of disaster.

This paper aims to examine the influence of intrinsic motives (self-efficacy, reputation and reciprocity) on online knowledge sharing behaviour. Additionally, this research investigates the moderating role of individual innovation capability and top management support.

The methodology adopted was a questionnaire survey of employees working in Vietnamese telecommunications companies. A total of 501 employees completed a self-administered anonymous survey using a cross-sectional design. Confirmatory factor analysis and ordinary least squared – based hierarchical regression was used to test the conceptual framework.

Self-efficacy, reputation and reciprocity significantly impact online knowledge sharing behaviour. Specifically, self-efficacy has an inverted U-shape association while reputation and reciprocity have a positively, returns-to-scale association with online knowledge sharing behaviour. Individual innovation capability moderates the effect on these associations as does top management support, but to a lesser extent.

Data were obtained at a single point in time and self-reported. Furthermore, this study was conducted in a specific industry in Vietnam, i.e. telecommunications, which limits the generalisability of the research.

Organisations need to create a favourable environment for online knowledge sharing to foster reciprocal relationships and interpersonal interactions of employees. Encouraging and rewarding employees to actively engage in knowledge exchange will help facilitate reciprocal online knowledge sharing behaviour.

This study contributes to knowledge-sharing behaviour by uncovering an inverted U-shape association and positively, returns-to-scale associations between intrinsic antecedents and online knowledge sharing behaviour. Additionally, individual innovation capability was an important moderator which has been overlooked in past research.

Humanoid robots have been utilized in many fields such as medical, construction, and disaster response. While humanoid robots nowadays can achieve great capabilities, the one-leg balancing task still poses a challenging problem. This paper aims to propose a novel approach to solve the problem.

To aid the balance of one leg in humanoid robot, an external balance mechanism is inserted to the back of the humanoid robot. First, a dynamic model of the humanoid robot with balance mechanism and its simplified model are introduced. Second, a backstepping-based control method is utilized to build the proposed controller for one-leg stance system through two steps. For the first step, a minimum observer-based controller with a virtual control input is used to control the first sub-system reaching the desired reference input. For the second step, a virtual control input is considered as a reference input of a second sub-system, then a model reference adaptive controller (MRAC) is employed to control the second sub-system reaching the virtual control input in presence of uncertainties. By using the external balance mechanism, the sideway balancing task is separated from normal walking function. Furthermore, the utilization of the balance mechanism ensures the humanoid robot's hip adduction does not exceed the threshold of a human when walking. Finally, a simulation study is carried out to evaluate the effectiveness of the proposed method.

This paper proposes a model reference adaptive control using state observer for balancing one leg of humanoid robot in stance phase that extends our previous research (Tran et al., 2021).

The main research contents have been introduced.

In the COVID-19 outbreak periods, people's life has been deranged, leading to disrupt the world. Firstly, the number of deaths is growing and has the potential to surpass the highest level at any time. Secondly, the pandemic broke many countries' fortified lines of epidemic prevention and gave people a more honest view of its seriousness. Finally, the pandemic has an impact on life, and the economy led to a shortage in medical, including a lack of clinicians, facilities and medical equipment. One of those, a simple ventilator is a necessary piece of medical equipment since it might be useful for a COVID-19 patient's treatment. In some cases, the COVID-19 patients require to be treated by modern ventilators to reduce lung damage. Therefore, the addition of simple ventilators is a necessity to relieve high work pressure on medical bureaucracies. Some low-income countries aim to build a simple ventilator for primary care and palliative care using locally accessible and low-cost components. One of the simple principles for producing airflow is to squeeze an artificial manual breathing unit (AMBU) iterative with grippers, which imitates the motion of human fingers. Unfortunately, the squeezing angle of grippers is not proportional to the exhaust air volume from the AMBU bag. This paper aims to model the AMBU bag by a mathematical equation that enables to implement on a simple controller to operate a bag-valve-mask (BVM) ventilator with high accuracy performance.

This paper provides a curvature function to estimate the air volume exhausting from the AMBU bag. Since the determination of the curvature function is sophisticated, the coefficients of the curvature function are approximated by a quadratic function through the experimental identification method. To obtain the high accuracy performance, a linear regression model and a least square method are employed to investigate the characteristic of the BVM ventilator's grippers angle with respect to the airflow volume produced by the AMBU bag.

This paper investigates the correlation between the exhausting airflow of the AMBU bag and the grippers angle of the BVM ventilator.

The experimental results validated that the regression model of the characteristic of the exhausting airflow of the AMBU bag with respect to the grippers' angle has been fitted with a coefficient over 98% within the range of 350–750 ml.

Generally, humanoid robots usually suffer significant impact force when walking or running in a non-predefined environment that could easily damage the actuators due to high stiffness. In recent years, the utilization of passive compliant series elastic actuators (SEA) for driving humanoid's joints has proved the capability in many aspects so far. However, despite being widely applied in the biped robot research field, the stable control problem for a humanoid powered by the SEAs, especially in the walking process, is still a challenge. This paper proposes a model reference adaptive control (MRAC) combined with the back-stepping algorithm to deal with the parameter uncertainties in a humanoid's lower limb driven by the SEA system. This is an extension of our previous research (Lanh et al., 2021).

Firstly, a dynamic model of SEA is obtained. Secondly, since there are unknown and uncertain parameters in the SEA model, a Model Reference Adaptive Controller (MRAC) is employed to guarantee the robust performance of the humanoid's lower limb. Finally, an experiment is carried out to evaluate the effectiveness of the proposed controller and the SEA mechanism.

This paper proposes an effective control algorithm that can be widely applied for the humanoid-SEA system. Besides, the effect of the coefficients in the control law is analyzed to further improve the response's quality.

Even though the simulation shows good results with stable system response, the practical experiment has not been implemented to fully evaluate the quality of the controller.

The MRAC is applied to control the humanoid's lower limb and the back-stepping process is utilized to combine with an external SEA system but still maintain stabilization. The simplified model of the lower-limb system proposed in the paper is proven to be appropriate and can be taken for further research in the future.

With the advancement of technology, microlearning has emerged as a promising method to improve the efficacy of teaching and learning. This study aims to investigate the document types, volume, growth trajectory, geographic contribution, coauthor relationships, prominent authors, research groups, influential documents and publication outlets in the microlearning literature.

We adapt the PRISMA guidelines to assess the eligibility of 297 Scopus-indexed documents from 2002 to 2021. Each was manually labeled by educational level. Descriptive statistics and science mapping were conducted to highlight relevant objects and their patterns in the knowledge base.

This study confirms the increasing trend of microlearning publications over the last two decades, with conference papers dominating the microlearning literature (178 documents, 59.86%). Despite global contributions, a concentrated effort from scholars in 15 countries (22.39%) yielded 68.8% of all documents, while the remaining papers were dispersed across 52 other nations (77.61%). Another significant finding is that most documents pertain to three educational level categories: lifelong learning, higher education and all educational levels. In addition, this research highlights six key themes in the microlearning domain, encompassing (1) Design and evaluation of mobile learning, (2) Microlearning adaptation in MOOCs, (3) Language teaching and learning, (4) Workflow of a microlearning system, (5) Microlearning content design, (6) Health competence and health behaviors. Other aspects analyzed in this study include the most prominent authors, research groups, documents and references.

The finding represents all topics at various educational levels to offer a comprehensive view of the knowledge base.