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This paper aims to investigate the temperature and wear properties of vertical ball screws and to discuss the surface design of ball screws in industrial applications.

The energy equation of the screw surface considering the frictional heat was established to verify the surface temperature of the ball screw. X-ray diffraction was used to examine the micro-contact temperature between the ball and screw. Debris size and density were examined to investigate wear properties of ball screws and to study the relationship of wear debris and temperature.

First, the main energy source for the surface temperature of high speed vertical ball screws is derived from friction force between ball and screw. Second, the temperature rise between the ball and screw has great relevance with wear debris concentration. Third, the surface temperature of the screw is higher than between the nut and ball for high speed vertical ball screws due to high convection heat transfer. The contact temperature of the nut near the flange is smaller than that of the nut away from the flange end due to the high contact load and thermal conduction. Finally, correlation of particle size and surface roughness value for vertical ball screws was established, and its effects on contact temperature were studied. The theoretical analysis and experiments will help to characterize the design and manufacture of vertical ball screws.

The surface temperature and micro-contact temperature analytical model were established to study the ball screw design. Based on the surface-particle micro-contact temperature balance, the optimal range of surface roughness was designed for vertical ball screws, considering the wear debris and micro-contact temperature.

This paper aims to experimentally study the external flow characteristic of an isolated two-dimensional synthetic jet actuator undergoing diaphragm resonance.

The resonance frequency of the diaphragm (40 Hz) depends on the excitation mechanism in the actuator, whereas it is independent of cavity geometry, excitation waveform and excitation voltage. The velocity response of the synthetic jet is influenced by excitation voltage rather than excitation waveform. Thus, this investigation selected four different voltages (5, 10, 15 and 20 V) under the same sine waveform as experiment parameters.

The velocity field along the downstream direction is classified into five regions, which can be obtained by hot-wire measurement. The first region refers to an area in which flow moves from within the cavity to the exit of orifice through the oscillation of the diaphragm, but prior to the formation of the vortex of a synthetic jet. In this region, two characteristic frequencies exist at 20 and 40 Hz in the flow field. The second region refers to the area in which the vortices of a synthetic jet fully develop following their initial formation. In this region, the characteristic frequencies at 20 and 40 Hz still occur in the flow field. The third region refers to the area in which both fully developed vortices continue traveling downstream. It is difficult to obtain the characteristic frequency in this flow field, because the mean center velocities (ū) decay downstream and are proportional to (x/w)^−1/2 for the four excitation voltages. The fourth region reveals variations in both vortices as they merge into a single vortex. The mean center velocities (ū) are approximately proportional to (x/w)⁰ in this region for the four excitation voltages. A fifth region deals with variations in the vortex of a synthetic jet after both vortices merge into one, in which the mean center velocities (ū) are approximately proportional to (x/w)⁻¹ in this region for the four excitation voltages (x/w is the dimensionless streamwise distance).

Although the flow characteristics of synthetic jets had reported for flow control in some literatures, variations of flow structure for synthetic jets are still not studied under the excitation of diaphragm resonance. This paper showed some novel results that our velocity response results obtained by hot-wire measurement along the downstream direction compared with flow visualization resulted in the classification of five regions under the excitation of diaphragm resonance. In the future, it makes valuable contributions for experimental findings to provide researchers with further development of flow control.

This paper aims to unveil the importance of knowledge management on a firm’s strategic emergency response during the great negative shock from global public health threats. Through analyzing how representative firms in China’s new economy industries dealt with the COVID-19 pandemic before, during and after the crisis, the significant problems confronted by these firms are pointed out, and the important role knowledge management capabilities played in solving these problems is proven.

The open data of listed companies regarding the important role knowledge management played in firms’ strategic emergency response during the COVID-19 pandemic are qualitatively analyzed. Based on theoretical sampling, this paper selects representative samples of enterprises and analyzes the positive response measures they took after being hit by this public health event to gain qualitative insight into the importance of knowledge management capabilities in strategic emergency response.

Three aspects of the important role of knowledge management capabilities in a firm’s strategic emergency response during the COVID-19 pandemic are introduced: before the crisis, firms should strengthen the acquisition, sharing and integration of knowledge so that they can intensify their monitoring for uncertain risks; during the crisis, firms should boost the transmission, transformation and diffusion of knowledge to improve emergency cooperation; and after the crisis, companies should reinforce knowledge evaluation, creation and application to enhance “immunity” in similar emergencies.

This paper has important implications for bolstering strategic emergency management practice and knowledge management capability among firms. Future research must focus on the following two aspects for further investigation: the dynamic relationship between firm knowledge management capability and strategic emergency response ability; and the collaboration system between firm knowledge management and strategic emergency response behaviors.

This paper discusses the important role knowledge management capabilities play in firms’ strategic emergency responses based on insights gained from the significant changes that the COVID-19 pandemic caused to representative Chinese new economy firms. By analyzing the three stages of before, during and after the emergency, this paper proposes the exact efforts that new economy companies should make in improving knowledge management capability.

With the increasing use of small unmanned aircrafts (SUAs), many countries have enacted laws and regulations to ensure the safe use of SUAs. However, there is a lack of industry-specific regulations accounting for the unique features of construction-related SUA operations. Operating SUAs in the construction industry is attributed to specific risks and challenges, which should be regulated to maximize the utility of SUAs in construction. This study, therefore, aims to develop a multi-dimensional regulatory framework for using SUAs in the construction industry.

A combination of quantitative and qualitative methods was used to compare seven selected national/regional SUA regulations to identify the applicability of implementing the existing regulations in construction. The interview surveys were then conducted to diagnose the challenges of construction-related SUA operations and gather interviewees' suggestions on the regulatory framework for SUA uses in construction.

The research found that some challenges of construction-related SUAs operations were not addressed in the current regulations. These challenges included the complex and time-consuming SUA operation permit, lack of regulation for special SUA operations in construction, insufficient regulatory compliance monitoring and a lack of construction-related remote pilots' training. A regulatory framework was then developed based on the findings of comparative analysis and interview surveys.

This study mainly compared seven representative countries/regions' regulations, leading to a small sample size. Further research should be carried out to study the SUA regulations in other places, such as South Africa, South America or Middle East countries. Besides, this study's respondents to the interviews were primarily concentrated in Hong Kong, which may cause the interview results to differ from the construction industry in other countries/regions. A large-scale interview survey should be conducted in other places in the future to validate the current findings.

The proposed regulatory framework provides a reference for the policy-makers to formulate appropriate industry-specific SUA regulations and improve the applicability of SUA regulations in the construction industry. It sheds light upon the future of SUA regulations and the development of regulatory practice in this area.

This study is the first to propose a multi-dimensional regulatory framework for operating SUAs in construction by comprehensive policy comparisons and interviews. The regulatory framework offers a fresh insight into the unexplored research area and points out the direction for subsequent studies on SUA regulations in the construction industry.

The purpose of this paper is to investigate students’ understandings of ocean sustainability and the pedagogical influence of higher education on those conceptions.

The conceptions of ocean sustainability of 54 university students of various academic disciplines enrolled in the 2014/2015 semester course “Sustainable Oceans” were assessed through use of auto-photography. Data were collected at the beginning and end of the course. Inter-rater reliability was measured by percentage of identical coding outcomes by two coders.

Auto-photography is effective in assessing notions of sustainability. Social and economic dimensions were captured less frequently than environmental aspects in the students’ photographs. Overall, students demonstrated vague perceptual awareness about who should take responsibility concerning lifeworld-related issues. Also, their perceptions were affected by their choice of academic discipline. Engaging students in inter-/transdisciplinary learning, integrating the arts, science and community, helped develop a more balanced, action-motivated conception of sustainability. Post-test patterns of change in students’ vision and action were observed.

Implementing sustainability education in a university’s coordinating bodies is effective in constructing a campus-based learning network, and participation in local community empowerment promotes a substantial and multidimensional concept of sustainability, and teaching material that includes content from the fine arts, literature or music stimulates students’ awareness of, and sensitivity to, lifeworld issues.

This paper provides an innovative, auto-photography-based methodology, including an operational procedure, coding book and method of analysis, for assessing students’ conceptions of sustainability. It also develops an interdisciplinary course that serves a “threshold” intervention role in ocean sustainability education.

The house money effect is proposed to describe that people appear to consider large or unexpected wealth gains to be distinct from the rest of their wealth, and are thus more willing to gamble with such gains than they ordinarily would be. On the other hand, the availability heuristic describes that people tend to have a cognitive and systematic bias due to their reliance on easily available or associational information. The purpose of this paper is to employ these behavioral perspectives in an empirical model regarding the January anomaly to explore investor behavior in Taiwanese stock market with bonus culture and well-known electronics industry.

This study uses the conventional and standard dummy variable regression model, as employed in prior studies, and further includes some control variables for firm, industry and macro-economic level factors. Moreover, 19 industrial indices for Taiwanese stock market over the period January 1990 to December 2014 are included in this study to examine the hypotheses, except for the 1997 Asian financial crisis and the global financial crisis period of 2007-2009 to avoid the potential effect. On the other hand, the authors also use the entire sample period of 1990-2014 for understanding whether the magnitude of January effect is different.

The empirical results indicate that Chinese bonus payments in January induce a strong January effect in the Taiwanese stock market, especially when most listed firms have positive earnings growth in the preceding year, suggesting a house money effect. Moreover, this study further provides some preliminary evidence that the higher January returns due to bonus culture are apparent only in the electronics industry when both Chinese New Year and bonus payments are in January, implying the role of availability heuristic based on the electronics stocks in investor behavior before the impending stock exchange holidays. Some robust tests show qualitative support.

The major contribution of this study is to extend the existing research by incorporating cultural and industrial factors with behavioral finance, thus enriching the literature on the causes of seasonality for Asian stock markets.

This study also has behavioral implications of investments for investors in the Taiwanese stock market, especially for foreign institutional investors which pay close attention to this market.

This study first applies and examines the culture bonus hypothesis with regard to how employees who receive culture bonuses in January can change their attitudes toward risk and induce the January effect from the concept of mental accounting. Moreover, this study further proposes and examines the extended culture bonus hypothesis related to how the January effect due to culture bonus is different for the electronics and non-electronics industries when taking into account the stock market holidays from the concept of availability heuristic.

In the last decades, various building information modeling–life cycle assessment (BIM-LCA) integration approaches have been developed to assess the environmental impact of the built asset. However, there is a lack of consensus on the optimal BIM-LCA integration approach that provides the most accurate and efficient assessment outcomes. To compare and determine their accuracy and efficiency, this study aimed to investigate four typical BIM-LCA integration solutions, namely, conventional, parametric modeling, plug-in and industry foundation classes (IFC)-based integration.

The four integration approaches were developed and applied using the same building project. A quantitative technique for evaluating the accuracy and efficiency of BIM-LCA integration solutions was used. Four indicators for assessing the performance of BIM-LCA integration were (1) validity of LCA results, (2) accuracy of bill-of-quantity (BOQ) extraction, (3) time for developing life cycle inventories (i.e. developing time) and (4) time for calculating LCA results (i.e. calculation time).

The results show that the plug-in-based approach outperforms others in developing and calculation time, while the conventional one could derive the most accuracy in BOQ extraction and result validity. The parametric modeling approach outperforms the IFC-based method regarding BOQ extraction, developing time and calculation time. Despite this, the IFC-based approach produces LCA outcomes with approximately 1% error, proving its validity.

This paper forms one of the first studies that employ a quantitative and objective method to determine the performance of four typical BIM-LCA integration solutions and reveal the trade-offs between the accuracy and efficiency of the integration approaches. The findings provide practical references for LCA practitioners to select appropriate BIM-LCA integration approaches for evaluating the environmental impact of the built asset during the design phase.

This study proposes a multilevel framework to test the mechanisms and boundary conditions of the relationships between positive group affective tone (PGAT) and individual/team creativity.

Data are collected from 122 research and development (R&D) teams (including 305 members and 122 team leaders). Hierarchical linear modeling analyses and hierarchical regression analyses are performed to test hypotheses.

The results show that PGAT facilitates individual creativity via enhanced work engagement, and increases team creativity via team information exchange. Supporting the substituting perspective, we found that the positive indirect effects of PGAT on individual/team creativity were attenuated when supervisory support is high.

Although all variables were collected at the same time and the individual-level variables were collected from the same source, our findings highlight the mechanisms explaining the beneficial effects of PGAT on individual/team creativity, and how supervisory support can substitute for such effects.

In order to make the individuals and teams more creative, the organizations need to promote PGAT via the selection of appropriated leader and members or team social events. Moreover, supervisors support is particularly salient in enhancing team creativity when PGAT is low.

This study is the one of the first study to test the motivational/social mechanisms linking the relationship between PGAT and individual/team creativity, and the competing theoretical perspectives regarding how supervisory support can moderate the PGAT–creativity linkage.

Giant orthogonal grid barrel vault is generated by deleting members in the inessential force transfer path of the two-layer lattice barrel vault. Consisting of members in the essential transfer path only, giant orthogonal grid barrel vault is a new type of structure with clear mechanical behavior and efficient material utilization. The paper aims to discuss this issue.

The geometrical configuration of this structure is analyzed, and the geometrical modeling method is proposed. When necessary parameters are determined, such as the structural span, length, vault rise, longitudinal and lateral giant grid number and section height to top chord length ratio of the lattice member, the structure geometrical model can be generated.

Numerical models of giant orthogonal grid barrel vaults with different rise–span ratios are built using the member model that can simulate the pre-buckling and post-buckling behavior. So the possible member buckle-straighten process and the plastic hinge form–disappear process of the structure under strong earthquake can be simulated.

Seismic analysis results indicate that when the structure damages under strong earthquake there are a large number of buckling members and few endpoint plastic hinges in the structure. Dynamic damage of giant orthogonal grid barrel vault under strong earthquake is caused by buckling members that weaken the structural bearing capacity.

This study aims to investigate the potential of an empathetic mindset aimed at empowering undergraduate students to work toward sustainable development (SD), addressing both theoretical and practical dimensions.

A mixed quantitative and qualitative research method was used in this study. Cross-sectional quantitative survey data on students’ mindsets and actions toward SD was collected to examine the theoretical relationship between belief and behavior. Qualitative inquiry using focus-group interviews explored students’ on-site learning experiences.

This study provides evidence for the impact of an empathetic mindset on education for sustainable development (ESD). Results showed that students with a more empathetic mindset showed better attitudes and behaviors toward SD actions. Findings suggest that developing an empathetic mindset improves students’ attitudes toward taking substantial action to protect the environment.

This study introduces a novel perspective extending the application of empathetic mindset in ESD.