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This study aims to explore the impact of key parameters of brake pads on the dynamic characteristics of the braking system.

This study conducted experimental research based on a friction testing machine with a slider-disc structure. The experiment studied the impact of key parameters of brake pads (rotation speed, pressure, mass, braking radius, etc.) and the braking environment (dry friction, wetness, sand, etc.) on the stability of the braking system. At the same time, a dynamic model of the brake pad braking system was established and compared with experimental results using the mathematical tool of autocorrelation coefficient.

The key parameters of brake pads have a significant impact on the dynamic characteristics of the braking system; under different conditions of brake pad mass, tribological parameters, brake pad radius and braking environment, the chaotic characteristics of the braking friction force signal show a trend of expansion or contraction, which can be suppressed by adjusting the key parameters of brake pads.

This study can provide a reference for optimizing the braking strategy and reducing noise and vibration in brake pad systems.

The literature review aims to facilitate a broader understanding of on-demand service platform operations management and proposes potential research directions for scholars.

This study searches four databases for relevant literature on on-demand service platform operations management and selects 72 papers for this review. According to the research context, the literature can be divided into research on “a single platform” and research on “multiple platforms”. According to the research methods, the literature can be classified into “Mathematical Models”, “Empirical Studies”, “Multiple Methods” and “Literature Review”. Through comparative analysis, we identify research gaps and propose five future research agendas.

This paper proposes five research agendas for future research on on-demand service platform operations management. First, research can be done to combine classic research problems in the field of operations management with platform characteristics. Second, both the dynamic and steady-state issues of on-demand service platforms can be further explored. Third, research employing mathematical models and empirical analysis simultaneously can be more fruitful. Fourth, more research efforts on the various interactions among two or more platforms can be pursued. Last but not least, it is worthwhile to examine new models and paths that have emerged during the latest development of the platform economy.

Through categorizing the literature into two research contexts as well as classifying it according to four research methods, this article clearly shows the research progresses made so far in on-demand service platform operations management and provides future research directions.

A dynamic model of the brake system considering the tangential and radial motion of the pad, and the torsion and wobbling motion of the disk is established in this paper. The influence of radial stiffness on the brake system is investigated under different tribological conditions. This paper aims to prove that sufficient radial stiffness is indispensable in the design of the brake system with good tribological performance.

By using the lumped mass method, a dynamic model of the brake system is established. A Stribeck-type friction model is applied to this model to correlate the frictional velocity, pressure and friction force. The stability of pad vibration is analysed by analysis methods. A new stability evaluation parameter is proposed to study the influence of radial stiffness on stability of pad vibration in a certain friction coefficient brake pressure range.

The findings show that the tangential vibration of the pad transits from periodic motion to quasi-periodic motion under a low tangential stiffness. The influence of radial stiffness on motion stability is stronger under a low nominal brake radius. The stability of the brake system can be ensured when the brake radius and radial stiffness are sufficient.

The influence of tangential stiffness of pad on stability of the brake system has been researched for decades. The insufficiency of stiffness in radial direction may also generate certain levels of instabilities but has not been fully investigated by modelling approach. This paper reveals that this parameter is also strongly correlated to nonlinear vibration of the brake pad.

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.

A finite element method (FEM) model of the frictional behavior of two rough surfaces with a group of third-body particles confined by the surface asperities is established. By monitoring the stress distribution, friction force and the displacement of the surfaces, how the frictional instability is induced by these particles is studied. This modeling job aims to explore the relation between the meso-scale behavior and the macro-scale frictional behavior of these particles.

By using FEM, a 2D model of two frictional rough surfaces with a group of elastic or elasto-plastic particles confined by surface asperities is established. The Mises stress, macro friction force and displacements of elements are monitored during compressing and shearing steps.

The macro friction coefficient is more stable under higher pressure and smaller under higher shearing speed. The dilatancy of the interface is caused by the elevation effect of the particles sheared on the peak of the lower surface, particles collision and third body supporting. The combined effect of particles motion and surface–surface contact will induce high-frequency displacements of surface units in restricted direction.

Previous studies about third-body tribology are mainly concentrated on the frictional behavior with large number of particles distributed homogeneously across the interface, but this paper focuses on the behavior of third-body particles confined by surface asperities.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2019-0544/

The purpose of this study is to examine the impact of the implementation of supply chain strategic collaboration (SCSC) on companies’ operating performance.

Based on 181 SCSC announcements of listed companies in China, this study analyzes changes in the operating performance of the sample companies in the 20 quarters after the announcement. The changes in different operating performance metrics for the sample firms are compared against their metrics before the announcement. This study uses a self-control model based on historical performance and uses a combination of adjustment percentage changes and adjustment level changes to measure performance changes.

SCSC helps to improve firm operating performance, although this effect is only evident after two years. Companies that collaborate on product development have better performance improvements than do companies that implement market collaboration. The operating performance of buyer companies is better than that of supplier companies. Finally, strategic collaboration in the service supply chain improves performance more than that in the manufacturing supply chain.

The finding that company performance varies in different situations can help managers better understand and manage SCSC.

This study newly uses secondary data to assess changes in companies’ operating performance brought about by the implementation of SCSC.

The paper proposes a research method to verify the perception bias of consumers on the freshness preservation effects of vacuum packaging (VP) and modified atmosphere packaging (MAP) chilled pork packages, the influence of “sensory experience” on correcting consumers' perception bias of packaging performance and willingness-to-pay (WTP) enhancement channels.

Using data from 458 and 188 participants who completed the contingent valuation method (CVM) and auction experiment, respectively, the study aimed to uncover consumers' packing quality perception bias and WTP, and investigated the societal factors that contribute to variations in WTP.

The CVM experiment revealed that although consumers' high perception bias rate toward MAP to maintain freshness, as compared to lab test results, came along with low WTP premium to cost rate with sensory experience in the auction experiment, the proportion of consumers with quality perception bias decreased from 49.85% to 34.46%, while the WTP premium to cost rate for MAP increased largely by 36.7%. Perceptive embedding has a positive effect on chilled pork packaging WTP, while normative embedding decreases WTP.

The findings emphasize the need of public policies to promote positive consumption attitudes, while whittling the negative consumption norms, to increase the WTP for packaged child pork and promote the chilled pork market formation.

Frontline employees (FLEs) play a pivotal role in service delivery. Beyond their expected in-role behaviors, FLEs often have to perform extra-role behaviors such as providing additional help to customers. The purpose of this study is to investigate how customers’ power distance belief (PDB) influences their perceptions of FLEs’ warmth and competence when FLEs perform extra-role helping behaviors.

Four experiments were conducted to test the hypotheses. The first three experiments used a one factor two-level (PDB: low vs high) between-participants design. The fourth one used a 2 (PDB: low vs high) × 2 (firm reputation: low vs high) between-participants design.

The results indicate that, compared to high-PDB customers, low-PDB customers perceive greater warmth in FLEs’ extra-role helping behaviors but no significant difference in FLEs’ perceived competence. Importantly, these effects are mediated by customer gratitude. Moreover, these effects are moderated by firm reputation such that customers’ perceptions of FLEs’ warmth and competence are both enhanced when the firm has a favorable reputation.

To the best of the authors’ knowledge, the study is the first to identify the differential effects of PDB on customer perceptions of FLEs’ warmth and competence in the context of FLEs’ extra-role helping behaviors and to reveal the mediating role of gratitude. These findings contribute to the literatures on FLEs’ extra-role behaviors and social perceptions of both warmth and competence.

As an increasing number of users have acquired information across the web and mobile platforms for social question and answering (Q&A), it is of interest to explore whether there are differences in social Q&A usages between the two platforms. The purpose of this paper is to compare web and mobile platforms of a social Q&A service from the user’s perspective in terms of three dimensions, namely, demographics, individual-based constructs, and information-based constructs.

Because Zhihu.com is one of the most popular social Q&A sites in China, the authors used online questionnaires to investigate its users’ perceptions of these three dimensions. From January to March 2016, the authors obtained 278 valid responses in total through snowball and convenient sampling. Collected data are analyzed through descriptive statistics and inferential statistics.

The results indicate that there exist significant differences between web users and mobile users on Zhihu.com in terms of gender, affinity, and information seeking. More specifically, compared to the male users, more female users rely on the mobile platform to access the information service; mobile users perceive higher affinity with Zhihu.com than web users; and mobile users perceive higher information-seeking intention than web users do.

Regarding the theoretical aspect, this study proposes a conceptual framework for comparison between the web and mobile platforms of social Q&A from the user’s perspective. Regarding the practical aspect, the comparative results of this study could give social Q&A service providers useful information about users’ differences between web and mobile platforms of social Q&A services.