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This paper aims to explore the possibility of converting the nitrile butadiene rubber (NBR) water-lubricated bearing material into a self-lubricating bearing material by the action of polytetrafluoroethylene (PTFE) particles and water lubrication.

A group of experimental studies was carried out on a ring-on-block friction test. The physical properties, tribological properties and interface structure of PTFE-NBR self-lubricating composites filled with different percentages of PTFE particles were investigated.

The experimental results indicated that the reduction in friction and wear is a result of the formation of the lubricating film on the surface of the composites. The lubricating film was formed of a large amount of PTFE particles continuously supplied under water lubrication conditions and the PTFE particles here can greatly enhance the load capacity and lubrication performance.

In this study, the tribological properties of PTFE particles added to the NBR water-lubricated bearing materials under water lubrication were investigated experimentally, and the research was carried out by a ring-on-block friction test. It is believed that this study can provide some guidance for the application of PTFE-NBR self-lubricating.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2020-0187/

The purpose of this study is to describe and observe the effect of surface topography associated with arbitrary directions of rolling and sliding velocities on the performance of lubricating films in elliptical contacts.

The most recently published mixed elastohydrodynamic (EHL) model by Pu and Zhu is used. Three different machined rough surfaces are discussed and the correlated inclined angle of surface velocity varies from 0° to 90° in the analyzed cases. These cases are carried out in a wide range of speeds (five orders of magnitude) while the simulated lubrication condition covers full-film and mixed EHL down to the boundary lubrication.

The results indicate that the variation of the average film thickness corresponding to different entrainment angles is distinct from those without considering surface roughness. In addition, the surface topography appears to have an immense effect on the lubrication film thickness in the exceptive situation.

This paper has not been published previously. Surface roughness has attracted much attention for many years owing to the significant influence on lubricating property. However, previous studies mainly focus on the counterformal contact with the same direction between surface velocity and principal axis of the contact zone. Little attention has been paid to the specific condition with the arbitrary direction of rolling and sliding velocities found in hypoid gears and worm, and some other components. The purpose of this study is to describe and observe the effect of surface topography associated with arbitrary directions of rolling and sliding velocities on the performance of lubricating films in elliptical contacts based on the most recently published mixed EHL model by Pu and Zhu.

Users’ active participation in platform value co-creation is the key to the development of crowdsourcing logistics platforms, especially the active participation of the crowdsourcee who provide logistics services. However, driven by self-interest, coupled with loose links among subjects on the platform ecological chain, it is difficult for users to effectively form value co-creation intentions. This study aims to explore how platform governance affects crowdsourcees’ intention to participate in value co-creation on the platform through individual cognition.

Based on social cognitive theory (SCT), this study built a research model and took the crowdsourcee on China’s well-known crowdsourcing logistics platforms as the investigation object, using the collected 302 valid survey data to test the model.

The results showed that platform governance mechanisms have a significant influence on crowdsourcees’ intention to participate in value co-creation on the platform, either directly or through crowdsourcee cognition, and the impact is different. The crowdsourcee cognition plays a mediating role between platform governance mechanisms and crowdsourcees’ intention to participate in value co-creation on the platform, and the mediating effect of value acquisition perception (VAP) is significantly higher than self-efficacy (SE).

The results provided references for crowdsourcing logistics platforms to develop a targeted governance mechanism to promote the platform to achieve value co-creation.

Digital freight platform is an innovation practice of green concept, sharing economy and crowdsourcing concept in China's logistics field. It has many advantages, such as improving the utilization rate of logistics resources, reducing carbon emissions, etc., so it has been highly regarded by the government. This paper systematically studies what types of government supports are available and explores the influence mechanism of these government supports on users' participation intention in digital freight platform.

In total 191 valid questionnaires were collected through a questionnaire survey in China. Then SmartPLS is used to analyze the collected data.

The empirical results show that user subsidies, standardization of tax administration and financial resource support have a significant impact on actual carriers' participation intention in digital freight platform. The impact of standardization of tax administration on actual carriers' participation intention is the most substantial, followed by that of financial resource support, while the user subsidies exert a minimum impact. Moreover, the impact of standardization of tax administration and user subsidies on legitimacy perception is related to enterprise scale.

This study enriches the field of crowdsourcing logistics research and provides referential suggestions for the formulation and implementation of government supports to promote the sustainable development of green crowdsourcing logistics platforms represented by digital freight platform. In addition, in the growth process of new models with strong social benefits, the government can promote its development through a variety of policy tools to improve the accuracy of government policies.

Instant crowdsourcing logistics (ICL) platform is an emerging business model in the field of logistics services. Crowdsourcees’ active participation in platform value co-creation is the key to success for this business model. This study aims to explore the influence of platform governance mechanisms on crowdsourcees’ participation in value co-creation on the platform.

Based on governance theory, this study constructed a model of the influence of platform governance mechanisms on crowdsourcees’ value co-creation intentions and discussed the role of community diversity in this model. The survey data of 319 collected from crowdsourcees on China’s well-known ICL platform were analyzed using a partial least squares structural equation model.

The results showed that platform governance mechanisms have a significant influence on crowdsourcees’ value co-creation intentions. Among them, the impact of the welfare resource support mechanism is the largest, followed by the reputation reward and punishment mechanism, while the price coordination mechanism has the least impact. Community diversity has a significant positive moderating effect on the welfare resource support mechanism and crowdsourcees’ value co-creation intentions, but not between other governance mechanisms and crowdsourcees’ value co-creation intentions.

The results provide references for ICL platform to develop a targeted governance mechanism to enhance the positive role of community diversity and reduce the negative impact.

The most prominent example of scan matching algorithm is the Iterative Closest Point (ICP) algorithm. But the ICP algorithm and its variants excessively depend on the initial pose estimate between two scans. The purpose of this paper is to propose a scan matching algorithm, which is adaptable to big initial pose errors.

The environments are represented by flat units and upright units. The upright units are clustered to represent objects that the robot cannot cross over. The object cluster is further discretized to generate layered model consisting of cross-section ellipses. The layered model provides simplified features that facilitate an object recognition algorithm to discriminate among common objects in outdoor environments. A layered model graph is constructed with the recognized objects as nodes. Based on the similarity of sub-graphs in each scans, the layered model graph-based matching algorithm generates initial pose estimates and uses ICP to refine the scan matching results.

Experimental results indicate that the proposed algorithm can deal with bad initial pose estimates and increase the processing speed. Its computation time is short enough for real-time implementation in robotic applications in outdoor environments.

This paper proposes a bio-inspired scan matching algorithm for mobile robots based on layered model graph in outdoor environments.

The suppliers of experimental resources required in megaprojects are driven by short-term interests, presuming that participation in the digital platform would only increase their inputs and fail to rapidly expand their revenue, resulting in their insufficient motivation to participate. This paper aims to design effective incentives for these suppliers exhibiting the aforementioned behaviour to drive them to participate and actively share their resources on the platform.

This paper develops incentives for applying the digital platform for experimental resource sharing by using a reverse induction approach to model and solve an incomplete information game. It compares the traditional experiment management mode and the new mode of applying the digital platform, taking the degree of sharing experimental resources on the platform as the variable and constructing three incentive models. By analysing these different degrees of sharing and the different experimental and informatisation capabilities of the suppliers, it could obtain the optimal incentive scheme for changes in sharing behaviour.

The results show that the designed incentives could increase the participation of suppliers in the platform and the number of their shared resources and make the benefits of both the supplier and the demand side reach the optimal state of a win-win situation. However, a higher degree of sharing by suppliers does not yield better results. In addition, the incentive coefficients for this degree should be set based on the suppliers’ different experimental and informatisation capabilities and the ratio of input cost-sharing, so as to avoid blind inputs from both supply and demand.

This study fills the research gap regarding incentives of the digital platform of experimental resource-sharing for megaprojects; it contributes to the body of knowledge by providing a quantitative perspective of understanding the experimental resource-sharing behaviour that motivates the usage of the digital platform. Furthermore, it reveals the incentive mechanism for application in different scenarios, and quantitative analysis is conducted to provide practical insights into promoting the new experiment management mode in megaprojects for more effective incentivisation.

The authors address a two-dimensional (both customer acquisition and retention) incentive in a decentralized service chain consisting of a risk-neutral brand and agent (or averse). 

The authors focus on the relationship between acquisition and retention, that is, retained customers (repeated purchases) are based on and come from the acquired (new) customers in the former period. The authors also design a two-period separate incentive on both dimensions.

The authors found that a targeted incentive strategy should be applied for achieving more revenue when the incentive intensities are relatively small. Otherwise, the brand needs to adjust the targeted incentive strategy into incentivizing the opposite dimension, particularly on acquisition. Under the optimal contract, the brand needs to be very careful with deciding the fixed part of the incentive salary and the incentive intensities on both dimensions. For example, the fixed salary initially decreases and then increases in the incentive intensities. For the optimal incentive policies, the brand should incentivize acquisition but outsource retention if the agent is risk-neutral. When the agent is becoming risk-averse, the brand should lower its incentive intensity as the risk degree and variances become larger. Interestingly, the brand may benefit from introducing risks.

The study contributes to the literature by considering the following points. First, the authors extend the principal-agent incentive model by considering two-period decisions of customer acquisition and retention. Second, based on the two-period principal-agent problem, the authors design separate incentive intensities on acquisition and retention, respectively. While, most of the literature focused on acquisition incentives. Third, different from other works focusing on either risk-neutral or risk-averse environments, the authors consider both and compare the cases of risk-neutral and risk-averse to analyze the impact of risk on the optimal decisions and the brand's expected profit.

Crowdsourcing refers to a new business model in which enterprises or individuals publish tasks or problems, attracting freelancers or contributors to participate in solving tasks, submitting bids and allowing task seekers to choose the final solution. How to attract more quantity and quality of contributors to submit their solutions through a crowdsourcing platform has become a vital question.

In this study, the authors use web crawling to obtain 43,265 effective tasks in EPWK website (www.epwk.com) to probe how to elevate the quantity and quality of contributors via task reward design. This study uses the hierarchical linear model to probe the research questions.

Results show that, with the increase of task reward, the quantity of contributors goes up first and then goes down (inverted U shape), whereas the quality of contributors goes down first and then goes up (U sharp). Moreover, the authors investigate the moderating effects of another task design attribute, task duration. This study finds that task duration weakens the effect of task reward on the quantity of contributors while strengthening the effects of task reward on the quality of contributors.

First, this study theoretically probes two key aspects of task performance, namely, the quantity and quality of contributors, which expand the scope of task performance evaluation. Second, this study reconciles previous concern about the relationship of task reward and performance, which is different from previous studies that have paid more attention to the single perspective of their relationship. Finally, the authors investigate the moderating effects of task duration, which further uncover the mechanism behind task reward and performance, that is, the quantity and quality of task contributors.