Search results

Hoping to uncover the physical principles of the vibration of the functionally graded material (FGM) microplate, by which the authors can make contributions to the design and manufacturing process in factories like micro-electro-mechanical system (MEMS) and other industries.

The authors design a method by establishing a reasonable mathematical model of the physical microplate composed of a porous FGM.

The authors discover that the porosity, the distributions of porosity, the power law of the FGM and the length-to-thickness ratio all affect the natural frequency of the vibration of the microplate, but in different ways.

Originally proposed a model of the micro FGM plate considering the different distributions of the porosity and scale effect and analyzed the vibration frequency of it.

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.

To present the detailed implementation processes of the IDEAL algorithm for two-dimensional compressible flows based on Delaunay triangular mesh, and compare the performance of the SIMPLE and IDEAL algorithms for solving compressible problems. What’s more, the implementation processes of Delaunay mesh generation and derivation of the pressure correction equation are also introduced.

Programming completely in C++.

Five compressible examples are used to test the SIMPLE and IDEAL algorithms, and the comparison with measurement data shows good agreement. The IDEAL algorithm has much better performance in both convergence rate and stability over the SIMPLE algorithm.

The detail solution procedure of implementing the IDEAL algorithm for compressible flows based on Delaunay triangular mesh is presented in this work, seemingly first in the literature.

This paper aims to focus on the accurate analysis of the fractional heat transfer in a two-dimensional (2D) rectangular monolayer tissue with three different kinds of lateral boundary conditions and the quantitative evaluation of the degree of thermal damage and burn depth.

A symplectic method is used to analytically solve the fractional heat transfer dual equation in the frequency domain (s-domain). Explicit expressions of the dual vector can be constructed by superposing the symplectic eigensolutions. The solution procedure is rigorously rational without any trial functions. And the accurate predictions of temperature and heat flux in the time domain (t-domain) are derived through numerical inverse Laplace transform.

Comparison study shows that the maximum relative error is less than 0.16%, which verifies the accuracy and effectiveness of the proposed method. The results indicate that the model and heat source parameters have a significant effect on temperature and thermal damage. The pulse duration (Δt) of the laser heat source can effectively control the time to reach the peak temperature and the peak slope of the thermal damage curve. The burn depth is closely correlated with exposure temperature and duration. And there exists the delayed effect of fractional order on burn depth.

A symplectic approach is presented for the thermal analysis of 2D fractional heat transfer. A unified time-fractional heat transfer model is proposed to describe the anomalous thermal behavior of biological tissue. New findings might provide guidance for temperature prediction and thermal damage assessment of biological tissues during hyperthermia.

This research proposes and examines a theoretical model grounded in anthropomorphism theory considering the curvilinear and linear relationships between service robot anthropomorphism and consumer usage intention and explores the mediating effect of perceived risk.

To examine the developed model, two complementary studies are designed. In Study 1, multi-time data of 511 participants show that service robot anthropomorphism inverts U-shaped (curvilinear) relationship on consumer usage intention and perceived risk mediates this curvilinear relationship. In Study 2, multi-source data of 460 volunteers are used to confirm the findings of Study 1 and examine that consumer empathy moderates the complex nonlinear effect of service robot anthropomorphism on perceived risk, and the indirect curvilinear effect of service robot anthropomorphism on consumer usage intention through perceived risk.

This research provides preliminary and yet important findings on how service robot anthropomorphism most likely is positively associated with consumer usage intention, i.e. the positively influence mechanism of service robot anthropomorphism on consumer usage intention.

This research provides preliminary and yet important findings on how service robot anthropomorphism most likely is positively associated with consumer usage intention, i.e. the positively influence mechanism of service robot anthropomorphism on consumer usage intention.

This paper aims to conduct an analysis of the influence of both the breadth and depth of outward foreign direct investment (OFDI) undertaken by Chinese high-tech listed companies during the period spanning 2010–2019. The data pertaining to these companies was used as a research sample to analyze the effects of OFDI on radical innovation performance.

Hierarchical regression analysis was used to test the proposed models, using survey data collected from 442 high-tech companies in China.

The findings of this study indicate a curvilinear (i.e. U-shaped) relationship between the breadth/depth of OFDI and radical innovation performance. Additional analysis reveals that OFDI plays a role in facilitating innovation breakthroughs by enhancing the internal dynamic capabilities of companies. Moreover, it is observed that a well-established institutional environment in the host country of investment can positively moderate the relationship between OFDI breadth/depth and radical innovation performance.

This study proffers a significant contribution to the understanding of the crucial role played by OFDI from emerging economy companies in enhancing radical innovation performance. Moreover, it offers theoretical guidance for multinational companies aiming to foster innovation breakthroughs.

In recent years, interest in analysing the conceptualisation, measurement, determinants and consequences of sustainability orientation (SO) has intensified. The authors respond to a growing demand for research that delves into external and relational factors of SO in the context of hospitality and tourism industry. This paper aims to analyse how market dynamism (MD) influences the SO of firms in heritage tourism destinations (HTDs) and how bridging capital affects this relationship.

The authors empirically analysed a sample of 238 companies in the UNESCO World Heritage Cities of Peru. The proposed hypotheses have been tested using partial least squares structural equation modelling.

The results show a curvilinear relationship between MD and SO. Furthermore, bridging capital enhances the effects of MD, reducing the focal width of the U-shaped curve. Specifically, when hospitality and tourism firms (HTFs) in tourist destinations operate in environments with low-medium levels of dynamism, the diverse links generated slow down the development of an SO. However, the more dynamic the environment, the greater is the SO of firms with large amounts of bridging capital.

The findings highlight the importance of conducting an analysis based on a contingent approach that considers the coherence between external elements of the environment and internal factors. Such an approach helps to understand how HTFs in developing countries establish their SO. Managers should be aware of changes in demand and seek coherence between the level of MD and their inter-organisational relationships, and so be able to assess potential opportunities through developing an SO.

This study contributes to a better understanding of the sustainability commitment of HTFs in the sustainability of HTDs. This study connects the population ecology and social capital approaches, explaining this relationship from a disaggregated perspective – social and environmental – in the context of a developing country.

Previous studies have shown that the application of information technology (IT) can help break through the innovation boundaries of firms and has undoubtedly become a key enabler of collaborative innovation. These studies, however, are mainly based on theoretical analysis and case studies, and little is empirically known about the relationship between IT investments and collaborative innovation. Therefore, the purpose of this study is to empirically explore how firms' IT investments affect the firms' collaborative innovation performance. The authors also examine the moderating roles of the top management team's (TMT's) educational background and absorptive capacity in this relationship.

The authors collected data on 2,097 listed Chinese manufacturing companies and used the ordinary least squares (OLS) method to perform regression analysis. In addition, the authors conducted robustness tests using the propensity score matching (PSM) method and the instrumental variable method.

The results show that the relationship between IT investments and collaborative innovation is inverted, U-shaped and curvilinear. In addition, the TMT's educational background and absorptive capacity positively moderate the inverted U-shaped relationship between IT investments and collaborative innovation.

The study's findings on the relationship between IT investments and collaborative innovation differ from previous mainstream findings that recognized a positive linear relationship. The authors' findings deepen the understanding of the dual role of IT investments. Moreover, this research helps expand the contingency perspective in IT investments and collaborative innovation research.

This paper aims to investigate the effect of top management’s customer interactions (TMCI) on customer satisfaction. This study argues that TMCI’s overall relationship with customer satisfaction follows an inverted-U shape due to its positive and disruptive effects on the customer relationship efforts of frontline service/sales employees (FSEs). This paper further investigates the frontline competence of both FSEs and the top management team (TMT) as moderators of the impact of TMCI on customer satisfaction.

The conceptual model was tested empirically using data from managers, frontline employees and customers of microfinance firms. A multilevel structural equation modeling approach was used to test the hypothesized model.

The results show that TMCI has a curvilinear relationship with customer satisfaction. The results also show that frontline employees’ collective efficacy attenuates this relationship by shifting the turning point of the curvilinear effect to the right. Furthermore, TMT frontline competence amplifies both the positive and negative effects of TMCI on customer satisfaction.

This study advances knowledge on the effects of TMCI on customer satisfaction and highlights the nuanced relationship between top management involvement and indicators of firm performance.

The findings show the importance of considering the frontline competence of both top management and frontline employees when encouraging TMCI in organizations.

To the best of the author’s knowledge, this study is one of the first to examine TMCI’s direct impact on customer satisfaction and propose the frontline competence of both top management and frontline employees as boundary conditions on this relationship.

Continuum robots modeling, be it from a hard or soft class, is giving rise to several challenges compared with rigid robots. These challenges are mainly due to kinematic redundancy, dynamic nonlinearity and high flexibility. This paper aims initially at designing a hard class of continuum robots, namely, cable-driven continuum robot (CDCR) and equally at developing their kinematic and dynamic models.

First, the CDCR prototype is constructed, and its description is made. Second, kinematic models are established based on the constant curvature assumption and inextensible bending section. Third, by using the Lagrange method, the dynamic model is derived under some simplifications and based on the kinematic equations, in which the flexible backbone’s elasticity modulus was identified experimentally. Finally, the static model of the CDCR is also derived based on the dynamic model.

Numerical examples are carried out using Matlab software to verify the static and dynamic models. Moreover, the static model is validated by comparing the simulation’s results to the real measurements that have been provided with satisfactory results.

To reduce the complexity of the dynamic model’s expressions and avoid the numerical singularity when the bending angle is close to zero, some simplifications have been taken, especially for the kinetic energy terms, by using the nonlinear functions approximation. Hence, the main advantage of this analytical-approximate solution is that it can be applied in the bending angle that ranges up to 2p with reasonable errors, unlike the previously proposed techniques. Furthermore, the resulting dynamic model has, to some extent, the proprieties of simplicity, accuracy and fast computation time. Ultimately, the obtained results from the simulations and real measurements demonstrate that the considered CDCR’s static and dynamic models are feasible.