Wen Liu, Shuangchao Huang, Hongfeng Qi, Xin Zhao, Shulin Liang and Xuesong Jin
Dynamic low adhesion (DLA) has become an urgent problem for the high-speed wheel-rail system because of continuous decrease of adhesion redundancy in the past decades. This…
Abstract
Purpose
Dynamic low adhesion (DLA) has become an urgent problem for the high-speed wheel-rail system because of continuous decrease of adhesion redundancy in the past decades. This article aims to provide a simulation method to reveal the mechanism of DLA under high-frequency vibrations.
Design/methodology/approach
A transient wheel-rail rolling contact model is developed for a typical Chinese high-speed railway system using the explicit finite element (FE) method. Instantaneous adhesion exploitation levels are studied in the time domain, for which driving cases over corrugated rails are taken as an example. A speed up to 500 km/h is considered together with different traction coefficients and corrugation dimensions. DLA is expected when the instantaneous adhesion exploitation level reaches 1.0, that is adhesion saturates and full sliding contact occurs.
Findings
The instantaneous adhesion exploitation level can be very high in the presence of corrugation, even at low traction coefficients. DLA is found to occur as great vertical unloading takes place and causes a significant increase of creepage. An approach is further developed to determine the critical depth of corrugation over which DLA occurs.
Originality/value
This study employs the transient wheel-rail rolling contact model to predict the instantaneous adhesion exploitation level under high-frequency vibrations. The presented results reveal a mechanism of DLA being beneficial to guidelines for future railway practice.
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This study investigates the impact of smart city construction (SCC) on urban energy consumption.
Abstract
Purpose
This study investigates the impact of smart city construction (SCC) on urban energy consumption.
Design/methodology/approach
The focus is on a panel of 285 prefecture level cities in China from 2010 to 2021. The empirical evidence is based on the difference-in-difference (DID) method. We uses per capita coal consumption as a proxy variable to measure urban energy consumption energy consumption. We set the SCC as a policy dummy variable, with pilot cities set to 1 and non-pilot cities set to 0. We also selected a series of control variables that affect urban energy consumption, such as urbanization rate, labor force, road density, number of college students per 10000 people, regional economic development level and so on.
Findings
(1) SCC significantly reduces urban energy consumption, and the conclusion still holds after conducting robustness testing; (2) SCC reduces urban energy consumption is mainly effective in those cities with larger scale, stronger human capital, larger financial services and better information infrastructure construction; (3) The technological innovation and industrial structure upgrading are the main mechanisms for the SSC policy to reduce urban energy consumption.
Originality/value
The results in this study provide evidence for achieving an environmentally friendly society.
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Hongji Xie, Shulin Xu and Zefeng Tong
This study examines the effect of local government debt (LGD) on corporate earnings management using 25,624 firm-year observations from 2007 to 2019.
Abstract
Purpose
This study examines the effect of local government debt (LGD) on corporate earnings management using 25,624 firm-year observations from 2007 to 2019.
Design/methodology/approach
Pooled ordinary least squares (OLS) regression is used to examine the impact of LGD on earnings management. A difference-in-differences (DID) method is also used to alleviate potential endogeneity.
Findings
Results show that LGD motivates firms to increase earnings management, especially income-decreasing earnings management. Findings are robust to DID method and robustness tests. Heterogeneity analyses show that the positive effect of LGD on earnings management is pronounced in firms with political dependence and moderated by external governance mechanisms. Further discussions indicate that tax enforcement is an underlying channel for LGD to affect earnings management. Firms engage in downward real earnings management by increasing their abnormal discretionary expenditures and higher LGD leads to a greater book-tax difference in those firms that manipulate income-decreasing earnings management.
Originality/value
This study contributes towards examining the political costs hypothesis, the microeconomic effects of LGD and the determinants of earnings management.
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Xu Yuhui, Liang Chengcheng and Wu Yue
To solve several “inorganic” problems generated recently by community development in China (e.g., waste of social resources, environmental pollution, and decreased economic energy…
Abstract
To solve several “inorganic” problems generated recently by community development in China (e.g., waste of social resources, environmental pollution, and decreased economic energy efficiency), focus should be on improving the community traffic organic micro-circulation system. As a historic and mixed functional urban community, the micro-circulation system of Xi'an Railway Bureau exhibits representativeness and complexity. Based on existing research results and years of follow-up investigations, which concentrate on circulation patterns and inherent organic development requirements of the community traffic micro-circulation system, this paper builds an evaluation index system. Value function method was used to implement the index factor quantitative analysis and comprehensive evaluation. Several related strategies were proposed to improve the organic micro-circulation system of the community, which is based on the analysis of the evaluation, in order to adopt the trend in both increasing urban development and stock updating. The analysis results demonstrate that it is necessary to present guiding renewal strategies on community land, road, people, and the environment for those mixed functional communities which use progressive renewed mode. It compensates the problems of overly strong export-oriented system, which is caused by the lack of organic traffic micro-circulation, so as to achieve the selective opening of community external. The study mainly highlights the significance of the systematic analysis of evaluation in influencing strategies on community renewal.
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Ju-Young M. Kang, Jae-Eun Kim, Ji Young Lee and Shu Hwa Lin
The purpose of the study was to identify (1) whether aspects of expectancy-value judgments (EVJ) of uses and gratifications, such as novelty, fashion/status, sociability and…
Abstract
Purpose
The purpose of the study was to identify (1) whether aspects of expectancy-value judgments (EVJ) of uses and gratifications, such as novelty, fashion/status, sociability and relaxation, influenced trust in augmented reality (AR) apps; (2) whether trust in AR apps influenced usage intention toward AR apps and online/offline store patronage intention and (3) the moderating effect of consumer self-determination.
Design/methodology/approach
Mobile users (n = 630) were drawn from a USA market research company. The proposed model was tested by structural equation modeling with maximum likelihood estimation.
Findings
The study found that trust in AR apps was a determinant of usage intention toward AR apps and online/offline store patronage intention. Novelty and fashion/status for EVJs of uses and gratifications affected trust in AR apps. Sociability for EVJs of uses and gratifications negatively affected trust in AR apps. Users' self-determination moderated the influence of users' trust in AR apps on usage intention toward AR apps and online/offline store patronage intention.
Originality/value
First, the study elaborates on the impacts of the underlying aspects of an EVJ model of uses and gratifications regarding AR apps on trust in AR apps and EVJ model's influence on usage intention toward AR apps and online/offline store patronage intention. Second, the results of the study suggest useful strategies involved in the development of consumer-driven AR apps that satisfy users' needs and desires.
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Dangshu Wang, Xuan Deng, Zhimin Guan, Shulin Liu, Yaqiang Yang and Xinxia Wang
To simplify the circuit design and control complexity of the magnetic coupling resonant wireless charging system, the radio energy transmission constant current and constant…
Abstract
Purpose
To simplify the circuit design and control complexity of the magnetic coupling resonant wireless charging system, the radio energy transmission constant current and constant voltage charging is realized.
Design/methodology/approach
The purpose of this study is to simplify the circuit design and control complexity of the magnetic coupling resonance wireless charging system, in order to achieve constant current and constant voltage charging for wireless energy transmission. First, the principle of LCC/S-S compensation structure is analyzed, and the equivalent mathematical model is established; then, the system characteristics under constant current and constant voltage mode are analyzed, and the design method of system parameters is given; finally, a simulation and experimental system is built to verify the correctness and feasibility of the theoretical analysis.
Findings
The results show that the proposed hybrid topology can achieve a constant current output of 2 A and a constant voltage output of 30 V under variable load conditions, and effectively suppress the current distortion problem under light load conditions. The waveform distortion rate of the inverter current is reduced from 33.97% to 10.45%.
Originality/value
By changing the high-order impedance characteristics of the compensation structure, the distortion of the current waveform under light load is suppressed, and the overall stability and efficiency of the system are improved.
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With the analysis of the causes of corruption, this study aims to investigate specific anti-corruption measures that can be implemented to reform the political system and the…
Abstract
Purpose
With the analysis of the causes of corruption, this study aims to investigate specific anti-corruption measures that can be implemented to reform the political system and the social climate of China.
Design/methodology/approach
This study examines 97 severe corruption cases of high-ranking officials in China, which occurred between 2012 and 2015. As this insinuates that both institutional and social corruption are major problems in China, the analysis delves into multiple facts of corruption, including different types, four primary underlying causes, and suggestions regarding the implementation of three significant governmental shifts that focus on investigation, prevention tactics and legal regulations.
Findings
China’s corruption is not only individual-based but also it has developed into institutional corruption and social corruption. Besides human nature and instinct, the causes of corruption can be organised into four categories, namely, social customs, social transitions, institutional designs and institutional operations. For the removed high-ranking officials, the formation of interest chains was an important underlying cause behind their corruption.
Originality/value
This study makes a significant contribution to the literature because this study provides a well-rounded approach to a complex issue by highlighting the significance of democracy and the rule of law as ways to regulate human behaviour to combat future corruption.
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Shulin Lan, Hao Zhang, Ray Y. Zhong and G.Q. Huang
As the modern manufacturing twining seamlessly with logistics operations for value adding services, logistics service is becoming more and more significant. Under this research…
Abstract
Purpose
As the modern manufacturing twining seamlessly with logistics operations for value adding services, logistics service is becoming more and more significant. Under this research background, the purpose of this paper is to introduce an innovative evaluation model for customer satisfaction using fuzzy analytic hierarchy process (FAHP).
Design/methodology/approach
This model uses triangular fuzzy concept to determine the weight of each index so that subjective or objective weighting is addressed. A case study from two large express companies in China is used to demonstrate the feasibility and practicality of the proposed model for examining customer satisfaction.
Findings
One of the key findings is that Company B has higher customer satisfaction than Company A due to its quick response and flexible logistics strategy. This paper has several contributions. First, A FAHP-based customer satisfaction evaluation model is proposed for the logistics service. Second, the triangular fuzzy concept is introduced to determine the weight of each index so as to addresses the limitation of subjective or objective weighting method. Third, a case study demonstrates the implementation of the model.
Research limitations/implications
First, this paper considers the fuzzy AHP for the customer satisfaction evaluation. Comparing with other multi-criteria decision-making methods like data envelopment analysis, evidential reasoning approach, and multi-attribute value theory will be carried out in the near future. Second, the manufacturing modes like make-to-order, make-to-stock, and mass-customized production may have different logistics support so that the final products may reach the final targets quickly. How to evaluate various mode-based logistics and their customer satisfactions have great significance. Finally, Big Data-enabled customer satisfaction evaluation approaches may be a possible solution.
Practical implications
Based on the data from questionnaire, it is found that, in practical applications, manufacturing enterprises should amend the index system according to the specific business scope and the production characteristics. Manufacturing enterprises need to collect large amounts of data through market research and conduct the measurement on the related coefficient between the measurement indicators and customer satisfaction degree. After that, they can make sorting and filtering on the measurement index according to the measurement results.
Social implications
Customer satisfaction is very important to manufacturing and logistics enterprises due to its time constraints. The physical products with services like logistics are paid close attention to by the final customers.
Originality/value
The contribution of this paper is as follows: a FAHP-based customer satisfaction evaluation model is proposed for the logistics service; triangular fuzzy concept is introduced to determine the weight of each index so as to addresses the limitation of subjective or objective weighting method; a case study was used to demonstrate the implementation of the model. One of the key findings is that Company B has higher customer satisfaction than Company B due to its quick response and flexible logistics strategy.
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Peixin Liang, Yulong Pei, Feng Chai and Shukang Cheng
For high torque-density permanent magnet synchronous in-wheel motor, service life and electromagnetic performance are related directly to winding temperature. The purpose of this…
Abstract
Purpose
For high torque-density permanent magnet synchronous in-wheel motor, service life and electromagnetic performance are related directly to winding temperature. The purpose of this paper is to investigate the equivalent stator slot model to calculate the temperature of winding accurately.
Design/methodology/approach
This paper analyzes the the law of heat flux transfer in slot, which points the main influence factors of equivalent stator slot model. Thermal network model is used to investigate the drawbacks of conventional equivalent model. Based on the law of heat transfer in stator slot, a new layered winding model is put forward. According to winding type and property of impregnations, detailed method and equivalent principle of the new model are presented. The accuracy of this new method has been verified experimentally.
Findings
An accurate equivalent stator slot model should be built according to the low of heat transfer. According to theory analysis, the drawbacks of conventional equivalent stator slot model are pointed: it cannot reflect the temperature gradient of winding; the maximum and the average temperature of winding are much higher than actual value. For the new layered model, equivalent principle is related to winding type and property of impregnations, which makes the new model widely used.
Originality/value
This paper presents a new layered model, and shows detailed method, which is more meaningful for designers. The new layered model takes winding type and property of impregnations into account, which makes the new model widely used. It is verified experimentally that layered model is applicable to not only steady-state temperature field but also transient temperature field.