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A mathematical model to describe the principle of layered manufacturing and layered fabrication error is presented in this paper. In this model, the layered manufacturing process is characterized by the model decomposition and material accumulation. A 3D design model is represented by a set of points with sequence functions to correlate the layered processing information. Iso‐sequence planes are defined as the processing layers to collect points with the same processing sequence and to define the material accumulation along its gradient direction. Examples of using the proposed model to describe the layered manufacturing to process flat and no‐flat surfaces and the description of the layered processing error are also presented.

In this study, the authors argue that because of female traits, the proportion of female directors in the board helps the governing body make more cautious decisions, thus improving the investment efficiency of the firm. Therefore, this research aims to propose the mediating role of caution in reexamining the relationship between the proportion of female directors and the efficiency of the investment of a firm.

This study uses data on 100 nonfinancial listed firms in Malaysia between 2015 and 2018. The authors use several multivariate regression analyses to test the mediating effect.

The result shows that female directors significantly affect investment efficiency. Moreover, the findings in this research confirm the mediating role of caution in the relationship between the proportion of female directors and the efficiency of firm investment.

This study proves that increasing the proportion of females in the board of directors is an effective governance method to improve the investment efficiency of listed firms in Malaysia.

In general, this study contributes to the literature by extending the current understanding of risk propensity differences between male and female directors and introducing the concept of caution.

The purpose of this paper is to study the multi-phase flow behaviors in solid fluidization exploitation of natural gas hydrate (NGH) and its effect on the engineering safety.

In this paper, a multi-phase flow model considering the endothermic decomposition of hydrate is established and finite difference method is used to solve the mathematical model. The model is validated by reproducing the field test data of a well in Shenhu Sea area. Besides, optimization of design parameters is presented to ensure engineering safety during the solid fluidization exploitation of NGH in South China Sea.

To ensure the engineering safety during solid fluidization exploitation of marine NGH, taking the test well as an example, a drilling flow rate range of 40–50 L/s, drilling fluid density range of 1.2–1.23 g/cm3 and rate of penetration (ROP) range of 10–20 m/h should be recommended. Besides, pre-cooled drilling fluid is also helpful for inhibiting hydrate decomposition.

Systematic research on the effect of multiphase flow behaviors on the engineering safety is scare, especially for the solid fluidization exploitation of NGH in South China Sea. With the growing demand for energy, it is of great significance to ensure the engineering safety before the large-scale extraction of commercial gas from hydrate deposits. The result of this study can provide profound theoretical bases and valuable technical guidance for the commercial solid fluidization exploitation of NGH in South China Sea.

While the relationship between non-family CEOs and corporate innovation in China has been widely studied, the results remain inconclusive. This study explores the relationship between non-family CEOs and corporate innovation in the context of intergenerational succession. It considers the background and background characteristics of non-family CEOs in an attempt to provide a theoretical foundation for human resource management and innovative strategic management that can be applied in the transformation of family companies.

The authors develop, then test, a series of hypotheses using an econometric analysis of a large sample of Chinese listed family firms. To control for endogeneity problems, such as missing variables in the model and the selectivity bias of the sample, propensity score matching (PSM) model is applied to analyze the panel data of 452 listed family firms from 2009–2019.

This study first validates the mechanism by which non-family CEO background characteristics affect innovation performance in family firms. It then reveals the varying moderating effects of two stages of intergenerational succession (i.e. later-generation participation in management and later-generation take-over management) that influence the relationship between non-family CEOs and corporate innovation.

The study's findings based on upper echelon and imprinting theory complement and extend existing research by revealing the impact of non-family CEOs from different backgrounds, and also identifying the role of intergenerational succession in the relationship between non-family CEO background characteristics and innovation performance.

This paper aims to define the concept, composition, connotation, functional technology and development path of autonomous transportation systems (ATS) and provide theoretical basis and support for the construction and development of ATS.

The research analyzes the concept and connotation of ATS, studies the composition and structure of ATS, sorts out pillar function technology system including perception, digitization, interoperability, computing and integration in ATS hierarchically, and looks forward to the future development path of ATS from human participation and systems intelligence.

This paper puts forward the concept, composition, connotation and structure of ATS, proposes the pillar functional technology system of ATS and proposes four development stages of ATS.

The research can provide a theoretical and scientific basis for the high-quality, efficient, orderly construction and development of ATS.

The primary purpose of this paper is to identify the antecedent (i.e. leader's self-transcendent value) and outcomes (i.e. follower's environmental commitment and behavior) of transformational leadership. The second purpose is to examine the mediating role of transformational leadership plays in the relationship between leader's self-transcendent value and follower's environmental commitment and behavior.

Multi-source data were collected at multiple times in China. A total of 262 employees and their 64 supervisors completed the survey. The authors conducted a series of confirmatory factor analyses (CFAs) to verify the validity of the constructs and adopted the SPSS PROCESS macro with bootstrapping techniques to test the hypotheses.

The authors find that leader's self-transcendent value is an important antecedent of transformational leadership, and transformational leadership can enhance followers' environmental commitment and foster their environmental behavior. Besides, transformational leadership plays a significant mediating role between leader's self-transcendent value and follower's environmental commitment and behavior.

This study has developed an integrated model of the antecedents and outcomes of transformational leadership in the Chinese context. It also confirmed that transformational leadership mediates the process through which leader's self-transcendent value has a positive impact on follower's environmental commitment and behavior.

It is particularly important to study the learner cognition based on information technology and change of learning environment in e-learning. Therefore, based on the combination of knowledge management and e-learning, the purpose of this paper is to discuss the basic rules and existing problems of virtual learning community (VLC).

In this study, a set of principles and basic framework of VLC was proposed, which could effectively instruct the construction of knowledge and collective wisdom development of VLC. Meantime, this paper revealed and constructed the theoretical framework and learning model for facilitating the advance of collective intelligence, described the main characteristics of collaborative knowledge building and traced the trajectory of convergence of collective intelligence and verified them through case studies and field studies.

The author analyzed the characteristics of VLC assisting knowledge construction and traced the trajectory of convergence of collective intelligence. In this way, the learners not only construct the meaning of knowledge in the process of participation from the edge to the center, but also complete the transformation from a green hand to an old hand. As a result, the learners form a sense of belonging to the community and complete the identity construction as a member of the community in the process of co-constructing the cultural tradition and value orientation of the community.

The analysis of the framework is made relatively in general terms, and lacks of the concrete, practical analysis. Therefore, it is necessary to adopt the social network analysis method to carry out systematic research on the framework, so as to make the actual operation of the VLC more practical.

It is significant to adopt the construction of the research system and theoretical framework in building VLC so as to improve the learner’s abilities of knowledge building and make full use of the advantages of the VLC.

This paper revealed and constructed the theoretical framework and learning model for facilitating the advance of collective intelligence. Besides, it provides a model reference for the follow-up construction of a new collective learning model.

The purpose of this paper is to examine the effects of exchange rate shock on the broad spectrum of the US economy using a factor-augmented VAR model (FAVAR).

The authors developed a two-factor FAVAR model and estimated it with the single-step Bayesian likelihood approach using the Gibbs sampling technique. The two factors represented, respectively, the economic activity and price pressures. The exchange rate shock was identified with the Choleski decomposition method for VARs. The authors used the data of 117 time series for the period from 1973:02 to 2007:12. Impulse responses and variance decompositions were computed as the main results.

The authors found that exchange rate shock has pervasive effects on the US economy as the following: depreciation does not appear to help reduce the US trade deficit as both import and export rise with the depreciation shock; in the short run, depreciation appears expansionary as industrial production, manufacturing and employment all increase within a year; in the medium run, depreciation appears inflationary, as consumer price, producer price, import price and export price all increase; and in the medium run, depreciation appears contractionary as personal consumption, consumer confidence, stock price and housing start tend to fall.

Some caveats remain: first, our simple model symmetrically estimates depreciation shock and appreciation shock and, hence, cannot draw inferences for how exchange rate appreciation and depreciation may affect the US economy asymmetrically. Second, the simple model used did not distinguish the different possible sources of exchange rate depreciation shock, the knowledge of which may lead to richer policy implications and is the direction of research for the future.

This research contributes to the literature of whether exchange rate is expansionary or contractionary to the US economy using the FAVAR model. This is the first comprehensive study in the literature studying the pervasive effects of the exchange rate on the broad spectrum of the US economy in one integrated model.

In many cases, the external pipelines of aero-engine are subjected to random excitation. The purpose of this paper is to reduce the vibration response of the pipeline system effectively by adjusting the hoop layout.

In this paper, a spatial pipeline supported by multi-hoops is taken as the object, the methods of solution of the vibration response of the pipeline system by using pseudo excitation and hoop layouts optimization with amplitude reduction of vibration response as the goal are presented. First, the finite element model of the spatial pipeline system is presented. Then, an optimization model spatial pipeline is established. Finally, a case study is carried out to prove the rationality of the random vibration response analysis of the pipeline system. Furthermore, the proposed optimization model and genetic algorithm are applied to optimize the hoop layout.

The results show that the maximum response variance after optimization is reduced by 32.8%, which proves the rationality of the developed hoop layout optimization method.

The pseudo excitation method is used to solve the vibration response of aero-engine pipeline system, and the optimization of the hoop layout for aero-engine spatial pipelines under random excitation to reduce random vibration response is studied systematically.

The purpose of this study is to enhance audience experience in museum by using three-dimensional (3D) virtual simulation technology.

In this study, a large space museum building tourism demonstration system based on 3D virtual simulation technology was proposed. Starting from the concept of virtual reality (VR), the characteristics of VR and the classification of VR systems were introduced, and the research status of VR technology at home and abroad and the application of 3D virtual simulation were discussed. Then the key technologies of 3D modeling, 3D scene optimization and 3D simulation driving of 3D virtual simulation were expounded, and the characteristics and application scope of different technical methods were analyzed. Finally, an example of the Hongzhou Kiln 3D network museum was listed.

The research results showed that 3D virtual simulation has a wide range of applications in the field of VR. Different elements need to be considered for different types of applications, and different contents need to be integrated to achieve the corresponding interaction modes.

Virtual image; multimedia; large space museum; tourism demonstration system; 3D virtual simulation technology.