Min Zhang, Dongming Guo and Zhuji Jin
Cu‐ZrB2 shell electrodes were fabricated by composite electroforming to improve the spark‐resistance of the electrical discharge machining (EDM) electrodes made by rapid tooling.
Abstract
Purpose
Cu‐ZrB2 shell electrodes were fabricated by composite electroforming to improve the spark‐resistance of the electrical discharge machining (EDM) electrodes made by rapid tooling.
Design/methodology/approach
Cu‐ZrB2 shell electrodes were fabricated using composite electroforming, separating and backing. EDM performance evaluation of the Cu‐ZrB2 shell electrodes is performed using tool steel as the cathode workpiece and the Cu‐ZrB2 composite as the anode tool. The effects of ZrB2 content on the electrode and workpiece removal rate, wear ratio of the electrode to workpiece, and surface quality of workpiece and electrode were studied.
Findings
Compared with the conventional electroformed copper tools, Cu‐ZrB2 shell electrodes yield higher workpiece removal rate and lower tool wear ratio. Scanning electron microscopy (SEM) and electron microprobe analysis reveal that, due to the large difference between the melting point of ZrB2 and copper, the heat generated by the sparks is conducted mainly through the copper matrix, reducing the erosion of ZrB2 particles. The refractory ZrB2 particles then act as barriers to the flowing and outburst of melted copper and enhance the resistance to erosion of the electrodes.
Originality/value
The use of Cu‐ZrB2 shell electrodes improves the anti‐erosion properties of the EDM electrodes made by rapid tooling, especially in finish machining conditions. Such electrodes will not only reduce the failure of the EDM electrodes but also improve the machining precision due to the less dimension loss of the electrodes during machining.
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Drawing on the stress and coping theory, conservation of resources (COR) theory and social role theory, this study aims to investigate the impact of social media overload on…
Abstract
Purpose
Drawing on the stress and coping theory, conservation of resources (COR) theory and social role theory, this study aims to investigate the impact of social media overload on knowledge withholding behavior and examine the gender differences in social media overload, engendering knowledge withholding.
Design/methodology/approach
By hiring a professional online survey company, this study collected valid responses from 325 general social media users. The structural equation modeling (SEM) technique, bootstrapping method and multi-group analysis were used to test the proposed theoretical model.
Findings
The empirical results reveal that three types of social media overload positively affect users' knowledge withholding behavior and that emotional exhaustion significantly mediates the above relationships. The multi-group analysis demonstrates that gender differences do exist in the decision-making process of knowledge withholding; for example, females are more likely than males to become emotionally exhausted from social media overload, while males are more likely than females to engage in knowledge withholding behavior in the case of emotional exhaustion.
Originality/value
This study contributes to the existing body of knowledge by examining the relationship between social media overload and knowledge withholding, verifying the mediating role of emotional exhaustion as the key mechanism linking them, and narrowing the research gap of lacking gender differences research in knowledge withholding literature.
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Xi Zhang, Xuyan Wang, Fangqing Tian, Dongming Xu and Longwei Fan
Feedback-seeking behavior is an important way for individuals to actively seek information feedback to achieve individuals' goals. In the environment driven by contactless digital…
Abstract
Purpose
Feedback-seeking behavior is an important way for individuals to actively seek information feedback to achieve individuals' goals. In the environment driven by contactless digital technologies, the way of individual feedback-seeking behavior through monitoring indirectly becomes obvious, especially for people who complete the work online in digital collaboration. However, previous empirical research on feedback-seeking behavior mainly focused on direct inquiry. The purpose of this paper is to verify the impact of individual learning goal orientation and the digital feedback environment on individuals' feedback-seeking behaviors through inquiry and monitoring approaches. And the moderating effect of time pressure on these relationships was also investigated.
Design/methodology/approach
Based on socio-technical system theory, this study proposes a model to describe the formation of the two approaches of feedback-seeking behaviors (inquiry and monitoring). The hypotheses were examined with the structural equation model method and data were collected from 152 graduate students who completed online surveys.
Findings
The results show that both the digital feedback environment and learning goal orientation can promote individual inquiry and monitoring approaches of feedback-seeking. Furthermore, time pressure moderates the relationship between the digital feedback environment and feedback monitoring negatively.
Originality/value
This study establishes an antecedent model that influences the choice of feedback-seeking approaches in digital environments from the perspective of a socio-technical system. The empirical results supplement the explanation of the influence of both technical and social factors on individual feedback-seeking behavior in digital environments.
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Xi Zhang, Yihang Cheng, Juan Liu, Hongke Zhao, Dongming Xu and Yulong Li
Prosocial lending in online crowdfunding has flourished in recent years, and it has become a new way to fundraise for philanthropy. However, there is almost a 70% user attrition…
Abstract
Purpose
Prosocial lending in online crowdfunding has flourished in recent years, and it has become a new way to fundraise for philanthropy. However, there is almost a 70% user attrition rate in crowdfunding. The purpose of this study is to understand what the lender’s lending experience and social connection influence lender retention of online prosocial lending from a self-determination perspective.
Design/methodology/approach
Drawing on self-determination theory (SDT), this research utilizes a quantifiable method for factors of the lender's lending experience and social connection. Additionally, the research constructs economic models to explore the impacts of these factors acting as the necessary conditions for basic psychological needs on lender retention, using a large-scale sample of over 380,000 lenders from Kiva.
Findings
The results indicate that, from the lender's lending experience aspect, the loan narratives with more profit language in the last lending and the failure of past participation are negatively related to lender retention. Regarding the lender's social connection aspect, their friends or small lending teams are positively related to lender retention, while whether they are invited and lending team size show negative influence. Furthermore, results indicate the moderating effects of the disclosure of lending motivation.
Originality/value
This research explores the mechanism of lender retention of online prosocial lending, providing a self-determination perspective about how previous experience influences long-term lending behavior. The study offers significant implications for the literature on online philanthropy, SDT and user retention of online platforms. At the same time, the study provides an understanding of the effects of different aspects of SDT.
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Rensheng Wang, Cong Sun, Shichao Xiu, Dongming Liang and Bo Li
This paper aims to analyze the significance of machining parameters (workpiece’s rotational speed, magnet coil current and working gap) on final Ra (surface roughness) and…
Abstract
Purpose
This paper aims to analyze the significance of machining parameters (workpiece’s rotational speed, magnet coil current and working gap) on final Ra (surface roughness) and material removal rate (MRR) of workpiece in reciprocating magnetorheological polishing (RMRP) process.
Design/methodology/approach
The research is planned to analyze, model and predict the optimum machining parameters to anticipate final Ra and MRR by applying response surface methodology (RSM) and multiresponse optimization (desirability function approach). The experiments have been planned by design of experiments (DOE). Analysis of variance (ANOVA) is applied to determine the significances of machining parameters on RMRP performance characteristics.
Findings
Response surface plots for final Ra and MRR by RSM show that machining parameters are significant for the responses. The optimum machining parameters obtained are optimized by desirability function approach (DFA), and the optimum parametric combination has been validated by confirmatory experiments. The experimental results of the final Ra and MRR are deviated by 5.12% and 2.31% from the response results under the same optimization conditions, respectively.
Originality/value
In this study, the RMRP responses (final Ra and MRR) are improved at predicted input machining parameters condition obtained by RSM and DFA approach. Furthermore, the research results provide a reference for experimental design and optimization of MRP process.
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Yong-Hua Li, Ziqiang Sheng, Pengpeng Zhi and Dongming Li
How to get a lighter and stronger anti-rolling torsion bar has become a barrier for the development of high-speed railway vehicles. The purpose of this paper is to realize the…
Abstract
Purpose
How to get a lighter and stronger anti-rolling torsion bar has become a barrier for the development of high-speed railway vehicles. The purpose of this paper is to realize the multi-objective optimization of an anti-rolling torsion bar with a Modified Non-dominated Sorting Genetic Algorithm III (MNSGA-III), which aims to obtain a better design scheme of an anti-rolling torsion bar device.
Design/methodology/approach
First, the Non-dominated Sorting Genetic Algorithm III (NSGA-III) uses a simulated binary crossover (SBX) operator and a polynomial mutation operator, while the MNSGA-III algorithm proposed in this paper introduces an arithmetic crossover and an adaptive mutation operator to change the crossover and mutate operator in NSGA-III. Second, two algorithms are tested by ZDT3, ZDT4 functions. Both algorithms set the same population size and evolutionary generation, and then compare the results of NSGA-III and MNSGA-III. Finally, MNSGA-III is applied to the multi-objective model of an anti-rolling torsion bar which is established by taking the mass and stiffness of the torsion bar as the optimization object. After that, it obtains the Pareto solution set by solving the multi-objective model with MNSGA-III. The only optimal solution selected from the Pareto solution set is compared with the traditional design scheme of an anti-rolling torsion bar.
Findings
The MNSGA-III converges faster than NSGA-III. Besides, MNSGA-III has better diversity of Pareto solutions than NSGA-III and is closer to the ideal Pareto frontier. Comparing with the results before the optimization, it shows that the volume of the anti-rolling torsion bar reduces by 1.6 percent and the stiffness increases by 3.3 percent. The optimized data verifies the effectiveness of this method proposed in this paper.
Originality/value
The simulated binary crossover operator and polynomial mutation operator of NSGA-III are changed into an arithmetic crossover operator and an adaptive mutation operator, respectively, which improves the optimization performance of the algorithm.
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Rensheng Wang, Cong Sun, Shichao Xiu, Qi Wang, Dongming Liang and Qi Zhao
This paper aims to study the effects of the processing parameters in the reciprocating magnetorheological polishing (RMRP) on abrasive particle trajectory by the simulation…
Abstract
Purpose
This paper aims to study the effects of the processing parameters in the reciprocating magnetorheological polishing (RMRP) on abrasive particle trajectory by the simulation analysis, which provides a basis for the machining uniformity of the workpiece.
Design/methodology/approach
The principle of the RMRP method is discussed, and a series of simulation analysis of the abrasive particle trajectory are performed to evaluate the effects of the workpiece’s rotational speed, the eccentric wheel’s rotational speed, the eccentricity and the frame gap on abrasive particle trajectory by using the RMRP method.
Findings
The processing parameters have a significant influence on the abrasive particle trajectory, and then the machining uniformity of the workpiece is affected. Under certain experimental conditions, the height difference of workpiece measuring points varies between 4 and 11 µm, and the height difference of equal radial measuring points is less than 1.5 µm by optimizing processing parameters.
Originality/value
In this study, the optimal processing parameters can be obtained by the simulation analysis of abrasive particle trajectory, which can replace the experimental methods to obtain the reasonable processing parameters for the machining uniformity of the workpiece. It provides references for the selection of processing parameter values in magnetorheological polishing process.
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Zhaohui Wu, Hong Li, Guoqing Yang, Zhigang Gao and Pan Lv
The purpose of this paper is to focus on the method to improve real‐time property of real‐time operating system (RTOS), one of the most essential problems in RTOS studies.
Abstract
Purpose
The purpose of this paper is to focus on the method to improve real‐time property of real‐time operating system (RTOS), one of the most essential problems in RTOS studies.
Design/methodology/approach
Improved task models are proposed based on the basic task and extended task models of OSEK operating system (OSEK OS). According to different task states, optimized scheduling algorithm was put forward. Some examples in a practical environment are described that illustrate the value of the method.
Findings
This method has been successfully implemented and evaluated in an OSEK compatible operating system, SmartOSEK OS. The time cost of context switching is decreased and the efficiency is enhanced.
Research limitations/implications
The improvement gained depends on the ratio of each strategy applied. In case the strategy D is applied too many times, the performance will be lead to a depressing result. For real‐time system, a long‐lived process that maybe increase the ratio of strategy D is not the optimal selection.
Originality/value
Dividing the ready state of task into intermediate state and initial state, can optimize the process of task context switching for OSEK OS. The method has proven to be useful in improving the real‐time property of RTOS.
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Dongming Ma, Anping Cheng and Hao Qian
The purpose of the study is to examine the impact of augmented reality (AR) on users' tour experience and psychological well-being in museums. The study utilizes the Information…
Abstract
Purpose
The purpose of the study is to examine the impact of augmented reality (AR) on users' tour experience and psychological well-being in museums. The study utilizes the Information System (IS) Success Model and the Perceived Value Theory to investigate the relationships between AR quality, content quality, system quality, vividness, utilitarian value, hedonic value, tour experience, and psychological well-being.
Design/methodology/approach
The study adopts a quantitative research approach and surveys 286 visitors at the Wuhan Natural History Museum. The collected data is analyzed using PLS-SEM to test the proposed model.
Findings
The study finds that content quality, system quality, and vividness significantly influence utilitarian and hedonic value. Utilitarian and hedonic values mediate the relationship between AR quality and tour experience and psychological well-being, with hedonic value having a greater impact. Utilitarian value positively influences customers' hedonic value, while tour experience positively influences customers' psychological well-being.
Originality/value
This study contributes to the existing literature by applying the Information System Success Model and Perceived Value Theory to explore the impact of AR on users' tour experience and psychological well-being in museums. It provides empirical evidence supporting the importance of content quality and perceived value in promoting AR adoption and use. The findings add value to the field of augmented reality research and offer practical implications for AR service providers.
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The purpose of this paper is to test a catering theory by examining impacts of minority shareholders’ pressures on earnings management (EM), and attempt to answer: what is the…
Abstract
Purpose
The purpose of this paper is to test a catering theory by examining impacts of minority shareholders’ pressures on earnings management (EM), and attempt to answer: what is the role of minority shareholders participation (MSP) in corporate governance? and does MSP serve as an external monitor to managers, or does it put excessive pressure on them?
Design/methodology/approach
Using a novel online voting data set in China’s stock market, the author constructs the measure of MSP, and regress the EM on MSP. To address the endogeneity, the author introduces propensity score matching and difference-in-difference methods, instrumental variables, and Heckman estimation to show that the results are robust to different specifications and alternative measures.
Findings
The author documents that: MSP plays limited role in external monitoring; and firms facing high MSP levels tend to manage earnings more actively. In addition, information asymmetry, proposals’ importance, managerial incentives, and CEO financial expertise significantly affect firms’ catering behaviors.
Originality/value
This paper contributes to different strands of the literature. First, the finding significantly supports the catering hypothesis from a new perspective of EM. Second, the author contributes to a hotly debated issue in corporate governance: whether minority shareholders should be granted increased participation in corporate decisions? The results also provide timely empirical evidence for government regulators who are concerned about the costs and benefits of granting minority shareholders direct control over corporate decisions.