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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.

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.

This study aims to evaluate blast loads on and the response of submerged structures.

An arbitrary Lagrangian–Eulerian method is developed to model fluid–structure interaction (FSI) problems of close-in underwater explosions (UNDEX). The “fluid” part provides the loads for the structure considers air, water and high explosive materials. The spatial discretization for the fluid domain is performed with a second-order vertex-based finite volume scheme with a tangent of hyperbola interface capturing technique. The temporal discretization is based on explicit Runge–Kutta methods. The structure is described by a large-deformation Lagrangian formulation and discretized via finite elements. First, one-dimensional test cases are given to show that the numerical method is free of mesh movement effects. Thereafter, three-dimensional FSI problems of close-in UNDEX are studied. Finally, the computation of UNDEX near a ship compartment is performed.

The difference in the flow mechanisms between rigid targets and deforming targets is quantified and evaluated.

Cavitation is modeled only approximately and may require further refinement/modeling.

The results demonstrate that the proposed numerical method is accurate, robust and versatile for practical use.

Better design of naval infrastructure [such as bridges, ports, etc.].

To the best of the authors’ knowledge, this study has been conducted for the first time.

Social commerce has brought about a significant transformation in consumer experience due to diverse factors. As a result, users often find themselves prone to impulsive buying behaviour when exposed to such an environment. Prior research was limited to demonstrating the expanding influence of celebrities on social media and the linkage between social engagement and impulse buying context. Furthermore, the impulse buying tendency of consumers on social media in the context of celebrity posts has yet to be validated. This paper aims to assess the influence of consumer awareness, consumer trust and observational learning on the latent state-trait (LST) theory regarding celebrity posts on impulse buying tendencies.

The empirical research builds on a sample survey involving 750 students from the “Big Four” economics universities in Hanoi. The proposed model was analysed using a partial least squares structural equation modelling technique.

The authors find that consumer trust and observational learning from celebrity’ posts positively affect impulse buying tendency. Yet celebrity influence awareness directly impacts trust in celebrity’ posts rather than directly impacting impulse buying tendency. Perceiving the importance of interactive and authentic posts by a celebrity in influencing consumers’ purchase behaviour on social media, this research offers valuable insights for stakeholders in the digital celebrity sphere of communication and marketing.

Perceiving the importance of interactive and authentic posts by a celebrity in influencing consumers’ purchase behaviour on social media, this research offers valuable insights for stakeholders in the digital celebrity sphere of communication and marketing.

From a theoretical perspective, this expands the applicability of the LST theory in social commerce to promote impulse buying tendencies. Second, this contributes to the literature on the emerging phenomenon of social media celebrities, as existing literature does not clarify their influence on impulse buying behaviour. Third, this research applies the concept of observational learning in online shopping through key features of social media platforms, namely, likes, shares and comments, to investigate their influence on the impulse buying tendency of consumers. Concerning managerial implications, the authors propose practical recommendations for practitioners, particularly those involved or interested in the commercial services industry and social media marketing (namely, celebrities and partner companies).

This study covers all banks listed on the Amman Stock Exchange. It used (1) dividend-paying status, dividend changes and dividend persistence to measure dividend quality, (2) a checklist instrument consisting of 40 items to measure financial disclosure quality, (3) nationality and (4) the percentage of females and males on the board of directors to measure board diversity. Hierarchical regression analysis was employed to investigate the influence of the board diversity on the relationship between financial disclosure quality and dividend quality.

This study investigates the relationship between financial disclosure quality and dividend quality among Jordanian-listed banks. Moreover, it examines the moderating effect of board diversity on the relationship between financial disclosure quality and dividend quality.

The results in this work imply that banks with high financial disclosure quality have high-quality dividends. Furthermore, nationality and females on the board of directors play a main role as moderators that influence managers' motivations toward the quality of financial disclosure practices and bank dividends. This paper shows that the boards in Jordanian banks have not changed dividend policies and tend to follow a long-term fixed strategy for paying earnings.

Because of the limited number of practical research on the nexus between financial disclosure quality and dividends quality, this study fills a gap in the literature by examining the relationship between them. In addition, a lack of research exists on the effects of board diversity on the nexus of financial disclosure quality and dividends quality. Therefore, this study makes an original contribution to the literature by using nationality and females and males on the board of directors as moderating variables to investigate the effects of board diversity on the relationship between financial disclosure quality and dividend quality among Jordanian banks.

This study implements the fourth-order phase field method (PFM) for modeling fracture in brittle materials. The weak form of the fourth-order PFM requires C¹ basis functions for the crack evolution scalar field in a finite element framework. To address this, non-Sibsonian type shape functions that are nonpolynomial types based on distance measures, are used in the context of natural neighbor shape functions. The capability and efficiency of this method are studied for modeling cracks.

The weak form of the fourth-order PFM is derived from two governing equations for finite element modeling. C⁰ non-Sibsonian shape functions are derived using distance measures on a generalized quad element. Then these shape functions are degree elevated with Bernstein-Bezier (BB) patch to get higher-order continuity (C¹) in the shape function. The quad element is divided into several background triangular elements to apply the Gauss-quadrature rule for numerical integration. Both fourth-order and second-order PFMs are implemented in a finite element framework. The efficiency of the interpolation function is studied in terms of convergence and accuracy for capturing crack topology in the fourth-order PFM.

It is observed that fourth-order PFM has higher accuracy and convergence than second-order PFM using non-Sibsonian type interpolants. The former predicts higher failure loads and failure displacements compared to the second-order model due to the addition of higher-order terms in the energy equation. The fracture pattern is realistic when only the tensile part of the strain energy is taken for fracture evolution. The fracture pattern is also observed in the compressive region when both tensile and compressive energy for crack evolution are taken into account, which is unrealistic. Length scale has a certain specific effect on the failure load of the specimen.

Fourth-order PFM is implemented using C¹ non-Sibsonian type of shape functions. The derivation and implementation are carried out for both the second-order and fourth-order PFM. The length scale effect on both models is shown. The better accuracy and convergence rate of the fourth-order PFM over second-order PFM are studied using the current approach. The critical difference between the isotropic phase field and the hybrid phase field approach is also presented to showcase the importance of strain energy decomposition in PFM.

Property developers identify the vital role of social media brand engagement (SMBE) in sustaining their businesses in competitive marketplaces, but it remains underexplored. This paper examines how SMBE mediates the effects of firm-generated content (FGC) and user-generated content (UGC) on brand trust, considering the moderating effects of social media influencer endorsement (SMIE) and self-image congruence (SIC) for luxury residential properties (LRPs).

Around 516 high-income homebuyers in Vietnam who shared information about LRP on social media were targeted to test the research model empirically. The primary data collected from paper-based surveys were analysed using SPSS 26 and AMOS 24.

Results indicate that FGC and UGC positively impact SMBE and consequently significantly affect brand trust. Further, results confirm the moderating roles of SMIE and SIC in the effects of FGC and UGC on SMBE.

Data and sample size were limited to meet the generalisation from different nations and cross cultures.

The authors' findings suggest that marketers should apply the authors' integrated SMBE model to strengthen brand–consumer interactions and increase their sales revenue.

This study is the first in its application of the uses and gratifications theory and self-congruence theory to investigate how SMBE mediates the relationship between FGC and brand trust as well as between UGC and brand trust. Noticeably, this study makes a novel contribution as the first to quantitatively explore the moderating effects of SMIE and SIC in the authors' research model.

This study aims to determine barriers to innovation and to develop a quantitative model for the barrier to innovation in Vietnamese construction organizations of different sizes.

A literature review and discussions with experienced practitioners were implemented to determine barriers to innovation in construction organizations. The rank-based non-parametric test analyzed collected data from a questionnaire survey to examine if there were significant differences between the three groups of organizations, including small, medium and large construction organizations. The fuzzy synthetic evaluation (FSE) technique was employed to develop barrier indexes (BIs) for organizations of different sizes in Vietnam.

The findings showed 17 barriers to innovation which were categorized into four groups, including organizational, human resources, economic and market barriers. Statistical analysis revealed significant differences regarding barriers to innovation between small, medium and large construction organizations in Vietnam. The post hoc test highlighted barriers to innovation differently separated into two groups: SMEs and large construction organizations. The FSE analysis integrated the identified barriers into the comprehensive BIs for SMEs and large construction organizations. The FSE analysis illustrated that the organizational barrier is the most critical barrier for SMEs. On the other hand, the market barrier received the most significant attention in large construction organizations.

This research is one of the first integrated barriers to innovation into a comprehensive formulation. The indexes provide the decision-makers with a practical and reliable tool to evaluate barriers to innovation in construction organizations of different sizes.

Although there are many efforts within organisations to improve the financial performance of business processes, the results of studies on the impact of internal factors on the financial performance of business processes in an organisation are inconsistent, even contradictory. Therefore, this paper aims to examine the extent and trends of the impact of factors inside companies on the financial performance of business processes and discover lessons learned to improve the financial performance of business processes.

This analysis was done through a quantitative study of listed companies in Vietnam. Pooled OLS regression, REM, FEM and robust regression were performed on 566 companies.

The results provide four main findings. First, firm size and operational efficiency strongly correlate with financial performance. Second, financial leverage has a negative, significant connection with financial performance. Third, net working capital has a positive and meaningful relationship with EPS and a negative association with ROE. Fourth, liquidity does not have any significant association with financial performance.

This study only restricts the internal factors affecting the financial performance of business processes without mentioning the external factors. Furthermore, this study is limited to one emerging country and has not been compared with companies in different countries.

The findings of this study may help inform users inside and outside the organisation to understand the factors that affect the financial performance of business processes. As a result, information users will focus more on aspects that can improve their financial performance to make informed decisions.

This study has many differences compared to previous studies. First, it focuses on the internal factors affecting the financial performance of business processes in non-financial listed companies in Vietnam, which has an emerging economy. First, it focuses on the internal factors affecting the financial performance of business processes in non-financial listed companies in Vietnam, which has an emerging economy. Second, this study analyses data in companies' financial statements for the ten years from 2012 to 2021, when the Vietnamese economy, in particular, and the world economy experienced many fluctuations due to the impact of the post-financial crisis 2007–2008 and the COVID-19 pandemic. Third, this study provides empirical evidence to support RBV, RDT theories and the trade-off theory of capital structure.