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Random point-contact between the space bearing retainer and the rolling elements may cause wear of the space bearing retainer. The paper aims to clarify the friction and wear behaviors of polyimide bearing retainer under point-contact condition.

Space bearing retainers were cut into flat specimens and the tribological behaviors of the specimens were studied under point-contact condition using a friction and wear testing machine. Different sliding velocities and normal loads were used to simulate the running state of space bearing retainer. The wear behaviors of the space bearing retainer were analyzed by SEM and white light interferometer.

The friction coefficient of the polyimide composites decreased with increase in sliding velocity from 1  to 5 mm/s. Moreover, with increase in sliding velocity and normal load, the wear rate of the polyimide composites decreased and increased, respectively. Moreover, the wear behaviors of the polyimide composites were mainly determined by the combined actions of ploughing friction and adhesive friction. The lubricating properties of transfer film and wear debris were limited under point-contact condition.

The paper includes implications for the understanding of the wear mechanism of the polyimide composites space bearing retainer under point-contact condition and then to optimize space bearing retainer materials further.

Under point-contact condition, wear debris can hardly participate in the friction process because of limited contact area. Consequently, the wear debris has limited impact on the wear process to decrease the friction and wear.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0017/

The indentation behaviour of sandwich panels is significant to incipient damage and is known to be affected by a number of dominant parameters. However, it is challenging not only to demonstrate how those few dominant parameters influence the indentation behaviour but also to ascertain that such influence was coupled to the variation of the other dominant parameters. The paper aims to discuss these issues.

In this work, the authors adopted a controllable quasi-static testing to carry out a diagnostic interrogation on the nature of incipient damage in laminate-skinned sandwich panels using hemispherical indenter and used photographs taken from the cross-sections of all the cut-up tested specimens, which were stopped both just before and after the initial critical loads, respectively, to confirm the mechanism of the incipient damage. Sandwich panels with aluminium honeycomb core had carbon/epoxy skins of two different thicknesses and lay-ups and hemispherical nosed indenter had three different diameters.

The authors found that: the incipient damage mechanism in all the panels was combined delamination in the skin and core crushing without debonding; doubling the skin thickness had the significant enhancement on critical load and indentation and this enhancement became greater for the larger indenter diameters; the indenter diameter had the moderate effect on critical load in the thick panels from 8 to 14 mm but had the negligible effect on thin panels and no effect on the thick panels from 14 to 20 mm; varying the skin lay-up or support had little effect on the indentation behaviour.

These findings were limited to the constant core density and core thickness. Varying the former significantly could alter the findings accordingly.

The results of this work should be tremendously useful to design and analysis in industrial applications of sandwich structures in aircraft, vehicles, marine vessels and transport carriages for situations involving localised loading and deformation.

The results of this research work is one of the very few that demonstrated a systematic understanding of the indentation behaviour characteristics of sandwich construction, which is vital to the establishment of indentation law for sandwich structures in future.

This study aims to empirically examine the effect of supply chain innovation (SCI) announcements on shareholder value within the context of Industry 4.0 and Industry 5.0.

This study uses an event study method to examine the effect of SCI announcements on shareholder value of the 156 listed companies in China.

First, SCI announcements have a positive effect on shareholder value. Second, SCI with an integrated form more positively affects shareholder value than SCI with an independent form. SCI at the strategy level more positively affects shareholder value than SCI at the operation level. Technology-type SCI more positively affects shareholder value than process-type SCI. Third, this study finds that investors pay more attention to the SCI of companies in the service industry than that of in the manufacturing industry. Finally, the post-hoc analysis finds that digital SCI more positively affects shareholder value than intelligent SCI.

First, most scholars use questionnaire data rather than second-hand data to conduct empirical research to explore the impact of SCI on performance. Second, although scholars focus on performance comprehensively, including operational, financial, relational and environmental performance, no scholars use an event study to explore the impact of SCI on the stock market. Third, no scholars have explored the differential impact of SCI in different industries. Forth, few scholars have classified SCI according to the characteristics to explore the differential impact of SCI. Finally, the differences between SCI of Industry 4.0 and SCI of Industry 5.0 have been described, but no scholars have used empirical research to explore the differences.

The purpose of this paper is to investigate the evolution of the permeability of spherical packing during cold compaction by pore-scale modeling.

The discrete element method (DEM) is used to generate spherical packing structure under different compressive pressures and the Lattice Boltzmann method (LBM) is adopted to calculate the permeability of each spherical assembly.

It is found that the decrease of the porosity is the main reason of the reduction in permeability in the initial compression stage, but its influence becomes insufficient in the late compression stages. Besides, two empirical formulas are obtained, which describe the relation between the permeability and the equivalent mean diameter and the variation of normalized permeability with compressive pressure, respectively.

In this study, the authors study the spherical particles and ignore the non-spherical effects. Besides, the classical contact model, the linear-spring-damping model, is used in DEM, so the plastic deformation cannot be considered.

The DEM and the LBM are well combined to study the compaction effects on permeability of spherical packing. Two simple expressions of the spherical packing structure with uniform diameter distribution are given for the first time.

Propose a more comprehensive explanation on the determinants and fluctuations of China’s exchange rate policy in the past decade (2005–2015).

Case study on China’s exchange rate policies in three respective stages since 2005 and then a comparative study on these three stages.

Put forward a two-pronged explanation on the determinants and fluctuations of China’s exchange rate policy in the past decade and arrive at three specific conclusions. First, external pressure is only one factor among many influencing the formation of China’s national interests (Guojia Liyi in Chinese) and the decision-making process on exchange rate policy. Second, national interest is the fundamental driving force and substratum for making China’s exchange rate policy. Third, in the short term, the specific exchange rate policies in different periods were not always in accordance to the national interests (or Guojia Liyi), due to the influences of some factors on the decision-making environment.

The comprehensive view is conducive to better explaining the formation and fluctuations of China’s exchange rate policy and consequently contributes to understanding and even predicting future policies.

Due to the increasing size and complexity of construction projects, construction engineering and management involves the coordination of many complex and dynamic processes and relies on the analysis of uncertain, imprecise and incomplete information, including subjective and linguistically expressed information. Various modelling and computing techniques have been used by construction researchers and applied to practical construction problems in order to overcome these challenges, including fuzzy hybrid techniques. Fuzzy hybrid techniques combine the human-like reasoning capabilities of fuzzy logic with the capabilities of other techniques, such as optimization, machine learning, multi-criteria decision-making (MCDM) and simulation, to capitalise on their strengths and overcome their limitations. Based on a review of construction literature, this chapter identifies the most common types of fuzzy hybrid techniques applied to construction problems and reviews selected papers in each category of fuzzy hybrid technique to illustrate their capabilities for addressing construction challenges. Finally, this chapter discusses areas for future development of fuzzy hybrid techniques that will increase their capabilities for solving construction-related problems. The contributions of this chapter are threefold: (1) the limitations of some standard techniques for solving construction problems are discussed, as are the ways that fuzzy methods have been hybridized with these techniques in order to address their limitations; (2) a review of existing applications of fuzzy hybrid techniques in construction is provided in order to illustrate the capabilities of these techniques for solving a variety of construction problems and (3) potential improvements in each category of fuzzy hybrid technique in construction are provided, as areas for future research.

The purpose of this paper is to review systematically the research of grey relation analysis (GRA) models.

Three different approaches, the springboard to build a GRA model, the angle of view in modelling, and the dimension of objects, are analysed, respectively.

The GRA models developed from the models based on relation coefficients of each point in the sequences in early days to the generalized GRA models based on integral or overall perspective. It evolved from the GRA models which measure similarity based on nearness, into the models which consider similarity and nearness, respectively. The objects of the research advanced from the analysis of relationship among curves to that among curved surfaces, and further to the analysis of relationship in three‐dimensional space and even the relationship among super surfaces in n‐dimensional space.

The further research on GRA models is proposed. One is about the property of GRA model. An in‐depth knowledge about the properties of GRA model will help people to understand its function, applicable area and requirements for modelling. The other one is about the extension of research object system. The object to be analysed should be extended from the common sequence of real numbers to grey numbers, vectors, matrices, and even multi‐dimensional matrices, etc.

Abnormal behaviors such as rework, backlog, changes and claims generated by project organizations are unavoidable in complex projects. When abnormal behaviors emerge, the previously normal state of interactions between organizations will be altered to some extent. However, previous studies have ignored the associations and interactions between organizations in the context of abnormal organizational behaviors (AOBs), making this challenging to cope with AOBs. As a result, the objective of this paper is to explore how to reduce AOBs in complex projects at the organizational level from a network perspective.

To overcome the inherent limitations of a single case study, this research integrated two data collection methods: questionnaire survey and expert scoring method. The questionnaire survey captured the universal data on the influence possibility of AOBs between complex project organizations and the expert scoring method got the influence probability scores of AOBs between organizations in the case. Using these data, four organizational influence network models of AOBs based on a case were developed to demonstrate how to destroy AOBs networks in complex projects using network attack theory (NAT).

First, the findings show that controlling AOBs generated by key organizations preferentially and improving the ability of key organizations can weaken AOBs network, enabling more effective coping strategies. Second, the owners, government, material suppliers and designers are identified as key organizations across all four influence networks of AOBs. Third, change and claim behaviors are more manageable from the organizational level.

Project managers can target specific organizations for intervention, weaken the AOBs network by applying NAT and achieve better project outcomes through coping strategies. Additionally, by taking a network perspective, this research provides a novel approach to comprehending the associations and interactions between organizations in the context of complex projects.

This paper proposes a new approach to investigating AOBs in complex projects by simultaneously examining rework, backlog, change and claim. Leveraging NAT as a novel tool for managing the harmful effects of influence networks, this study extends the knowledge body in the field of organizational behavior (OB) management and complex project management.

The climate change and related impacts are experienced around the world. There arise different triggering factors to climate change and impact. The purpose of this study is to figure out how changes in vegetation cover may or may not have an impact to climate change. The research will produce ideas for vegetation preservation and replant.

The investigation was probed for 34 years’ time period starting from the year 1981 to 2015. After testing and checking for serial autocorrelation in the vegetation data series, Mann–Kendal nonparametric statistical evaluation was carried out to investigate vegetation cover trends. Sen’s method was deployed to investigate the magnitude of vegetation cover change in natural differential vegetation index (NDVI) unit per year. Furthermore, the ArcGIS spatial analysis tools were used for the calculation of mean NDVI distribution and also for carrying out the spatial investigation of trends at each specific location within the study region.

The yearly mean NDVI during the study period was observed to have a decreasing trend. The mean NDVI value ranges between 0.32 and 0.98 NDVI unit, and hence, this means from less or poor vegetated zones to higher or healthier vegetated zones. The mean NDVI value was seen decreasing toward the highlands regions. The NDVI-rainfall correlation was observed to be stronger than the NDVI-temperature correlation. The % area coverage of NDVI-rainfall positive correlation was higher than the negative correlation. The % area coverage of NDVI-temperature negative correlation was higher than the positive correlation within the study region. Rainfall is seen as a highly influencing climatic factor for vegetation growth than the temperature within the study region.

This study in this country is a new approach for climate change monitoring and planning for the survival of the people of Papua New Guinea, especially for the farmer and those who is living in the coastal area.

The innovation process demands an interaction between environment agents, knowledge generators and policies of incentive for innovation and not only development by companies. Universities have gradually become the core of the knowledge production system and, therefore, their role regarding innovation has become more important and diversified. This study is aimed at identifying the mechanisms of university–industry (U–I) collaboration, as well as the operationalization steps of the U–I collaboration process.

This study is aimed at identifying, based on a systematic literature review, the mechanisms of university–industry (U–I) collaboration, as well as the operationalization steps of the U–I collaboration process.

The analysis of the 72 selected articles enabled identifying 15 mechanisms of U–I collaboration, proposing a new classification for such mechanisms and developing a framework presenting the operationalization steps of the interaction process.

In this paper, the authors screened nearly 1,500 papers and analyzed in detail 86 papers addressing U–I collaboration, mechanisms of U–I collaboration and operationalization steps of the U–I collaboration process. This paper provides a new classification for such mechanisms and developing a framework presenting the operationalization steps of the interaction process. This research contributes to both theory and practice by highlighting managerial aspects and stimulating academic research on such timely topic.