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Article
Publication date: 4 April 2020

Pan-Pan Li, Feng Gao, Yan Li and Bo Yang

The serious friction caused by the fluctuation of friction occurs when start-up and will reduce the positioning accuracy of the servo axes of high precision machine tools, the…

Abstract

Purpose

The serious friction caused by the fluctuation of friction occurs when start-up and will reduce the positioning accuracy of the servo axes of high precision machine tools, the purpose of this paper is to study the friction fluctuation characteristics of friction coefficients between interfaces under different working conditions.

Design/methodology/approach

HT200 and 45# materials were experimentally studied by friction and wear testing machine UMT-3, the variation of friction coefficient under different working conditions (different start-up conditions, the variation of lubrication state area and different roughness) were measured.

Findings

The results show that the larger start-up acceleration shortens the pre-sliding time of the interface friction, makes the friction coefficient decrease faster, reduces the mixed lubrication area of the contact surface and makes the contact surface reach the stable lubrication state quickly. It can be concluded that the larger roughness surface will lead to the larger mixed lubrication area, the larger static friction coefficient and the larger drop between static and dynamic friction coefficient and easy to cause friction vibration.

Originality/value

The results reveal the friction fluctuation rule of the metal interface during the different start-up process, which is of guiding significance to reveal the lubrication principle and mechanism of the mechanical interface.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2019-0482/

Details

Industrial Lubrication and Tribology, vol. 72 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 21 October 2021

Feng Gao, Pan-Pan Li and Yan Li

For ball screw feed system, a sudden start or stop has a great influence on the transmission stiffness, so the axial stiffness mutation of feed system will occur. The purpose of…

Abstract

Purpose

For ball screw feed system, a sudden start or stop has a great influence on the transmission stiffness, so the axial stiffness mutation of feed system will occur. The purpose of this paper is to study the influence of acceleration on the transmission stiffness and dynamic characteristics of the ball screw feed system.

Design/methodology/approach

Taking the ball screw feed system as a research object, on the basis of the Hertz contact theory and the mixed element method, axial stiffness model and dynamic model are established. And the system stability was analyzed by the time history diagram and Phase-plane portrait diagram. The feed system was analyzed theoretically and experimentally, the experimental results are in good agreement with the model results.

Findings

Lead screw lead angle, preload, load and start acceleration affected ball-screw pair, bearing and transmission stiffness. And the load, nut contact stiffness, bearing contact stiffness, preload have a large effect on the transmission stiffness. The results show that a certain acceleration value will make the axial stiffness abrupt change.

Originality/value

This research provides a useful theoretical support for ensuring a good dynamic for the ball screw feed system.

Details

Industrial Lubrication and Tribology, vol. 73 no. 10
Type: Research Article
ISSN: 0036-8792

Keywords

Open Access
Article
Publication date: 29 March 2024

Runze Ling, Ailing Pan and Lei Xu

This study examines the impact of China’s mixed-ownership reform on the innovation of non-state-owned acquirers, with a particular focus on the impact on firms with high financing…

Abstract

Purpose

This study examines the impact of China’s mixed-ownership reform on the innovation of non-state-owned acquirers, with a particular focus on the impact on firms with high financing constraints, low-quality accounting information or less tangible assets.

Design/methodology/approach

We use a proprietary dataset of firms listed on the Shanghai and Shenzhen Stock Exchanges to investigate the impact of mixed ownership reform on non-state-owned enterprise (non-SOE) innovation. We employ regression analysis to examine the association between mixed ownership reform and firm innovation.

Findings

The study finds that non-state-owned firms can improve innovation by acquiring equity in state-owned enterprises (SOEs) under the reform. Eased financing constraints, lowered financing costs, better access to tax incentives or government subsidies, lowered agency costs, better accounting information quality and more credit loans are underlying the impact. Additionally, cross-ownership connections amongst non-SOE executives and government intervention strengthen the impact, whilst regional marketisation weakens it.

Originality/value

This study adds to the literature on the association between mixed ownership reform and firm innovation by focussing on the conditions under which this impact is stronger. It also sheds light on the policy implications for SOE reforms in emerging economies.

Details

China Accounting and Finance Review, vol. 26 no. 2
Type: Research Article
ISSN: 1029-807X

Keywords

Article
Publication date: 4 October 2019

Xiongfeng Pan, Yang Ming, Mengna Li, Shucen Guo and Cuicui Han

The purpose of this paper is to find out the characteristics and evolutionary trends of China’s inter-regional innovation correlation network, the status and roles of each…

Abstract

Purpose

The purpose of this paper is to find out the characteristics and evolutionary trends of China’s inter-regional innovation correlation network, the status and roles of each province in China’s inter-regional innovation correlation network and the influencing factors of China’s inter-regional innovation correlation effect.

Design/methodology/approach

Based on the patent data of 30 provinces (autonomous regions and municipalities) in China from 1991 to 2017, social network analysis was used to find out the characteristics and evolutionary trends of China’s inter-regional innovation correlation network and the status and roles of each province in China’s inter-regional innovation correlation network. Furthermore, the QAP method was used to find out the influencing factors of China’s inter-regional innovation correlation effect.

Findings

China’s inter-regional innovation correlation is becoming increasingly close and inter-regional innovation correlation network is becoming increasingly stable. Jiangsu, Zhejiang, Beijing, Shanghai, Guangdong and other eastern coastal provinces are at the core in the inter-regional innovation correlation network, while the western regions are marginal actors. China’s regional innovation development territory can be divided into four blocks, namely, “bidirectional spillover block,” “net spillover block,” “main beneficial block” and “net beneficial block,” and gradient transfer mechanism is obvious between the blocks. The geographical adjacency and similarity in regional industrial structure, urbanization level and government attention degree have significant positive effect on China’s inter-regional innovation correlation effects.

Research limitations/implications

This paper only uses patent application as a measure of regional innovation level to analyze inter-regional innovation correlation effect. Meanwhile, this paper carries out an empirical study only from the provincial level and not from the city level.

Practical implications

This paper provides the practical basis for further promoting the coordinated development of regional innovation and promoting the construction of regional innovation systems with different characteristics.

Originality/value

This paper contributes to understand the status and role of each province in inter-regional innovation correlation network. Meanwhile, this paper also helps to understand the influence of the proximity and external environmental factors on inter-regional innovation correlation effect.

Details

Business Process Management Journal, vol. 26 no. 4
Type: Research Article
ISSN: 1463-7154

Keywords

Article
Publication date: 4 October 2018

Hong wei Li, Hairong Zhu and Li Pan

To realize the operation optimizing of today’s distribution power system (DPS), like economic dispatch, contingency analysis, and reliability and security assessment etc., it is…

Abstract

Purpose

To realize the operation optimizing of today’s distribution power system (DPS), like economic dispatch, contingency analysis, and reliability and security assessment etc., it is beneficial and indispensable that a faster linear load flow method is adopted with a reasonable accuracy. Considering the high R/X branch ratios and unbalanced features of DPS, the purpose of this paper is to propose a faster and non-iterative linear load flow solution for DPS.

Design/methodology/approach

Based on complex function theory, the derivations of the injection current linear approximation have been proposed for the balanced and the single-, double- and three-phase unbalanced loads of DPS on complex plane. Then, a simple and direct linear load flow has been developed with loop-analysis theory and node-branch incidence matrix.

Findings

The methodology is appropriate for balanced and single-, double- and three-phase hybrid distribution system with different load models. It provides a fast and robust load flow method with a satisfactory accuracy to handle the problems of DPS whenever the load flow solutions are required.

Research limitations/implications

The distributed generators (DGs) with unity or fixed power factors can be easily included. But the power and voltage nodes cannot be dealt with directly and need to be further studied.

Originality/value

By combining the current linear approximation with the loop theory-based method, a new linear load flow method for DPS has been proposed. The method is valid and acute enough for balanced and unbalanced systems and has no convergent problems.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 38 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 10 June 2021

Michael S. Lin, Yun Liang, Joanne X. Xue, Bing Pan and Ashley Schroeder

Recent tourism research has adopted social media analytics (SMA) to examine tourism destination image (TDI) and gain timely insights for marketing purposes. Comparing the…

2095

Abstract

Purpose

Recent tourism research has adopted social media analytics (SMA) to examine tourism destination image (TDI) and gain timely insights for marketing purposes. Comparing the methodologies of SMA and intercept surveys would provide a more in-depth understanding of both methodologies and a more holistic understanding of TDI than each method on their own. This study aims to investigate the unique merits and biases of SMA and a traditional visitor intercept survey.

Design/methodology/approach

This study collected and compared data for the same tourism destination from two sources: responses from a visitor intercept survey (n = 1,336) and Flickr social media photos and metadata (n = 11,775). Content analysis, machine learning and text analysis techniques were used to analyze and compare the destination image represented from both methods.

Findings

The results indicated that the survey data and social media data shared major similarities in the identified key image phrases. Social media data revealed more diverse and more specific aspects of the destination, whereas survey data provided more insights in specific local landmarks. Survey data also included additional subjective judgment and attachment towards the destination. Together, the data suggested that social media data should serve as an additional and complementary source of information to traditional survey data.

Originality/value

This study fills a research gap by comparing two methodologies in obtaining TDI: SMA and a traditional visitor intercept survey. Furthermore, within SMA, photo and metadata are compared to offer additional awareness of social media data’s underlying complexity. The results showed the limitations of text-based image questions in surveys. The findings provide meaningful insights for tourism marketers by having a more holistic understanding of TDI through multiple data sources.

Details

International Journal of Contemporary Hospitality Management, vol. 33 no. 6
Type: Research Article
ISSN: 0959-6119

Keywords

Article
Publication date: 30 October 2019

Wei Lu, Yuwei Zhou, Li Sunny Pan and Yuhao Zhao

People often need to make intertemporal choices in their daily life, such as savings and spending, but their decisions are not always entirely rational. The purpose of this paper…

Abstract

Purpose

People often need to make intertemporal choices in their daily life, such as savings and spending, but their decisions are not always entirely rational. The purpose of this paper is to study the effect of hunger on intertemporal choices and the moderating effect of sensitivity to reward.

Design/methodology/approach

Two studies verified these two hypotheses. The first study confirmed the existence of the main effect by manipulating food aroma. In the second study, by manipulating hunger with images, the authors increased external validity of the study and confirmed the regulation of the sensitivity of rewards.

Findings

The authors found that hungry people prefer to reap the benefits as early as possible in an intertemporal choice; this effect is significant only for those people who are sensitive to reward.

Practical implications

The research contributes to understand more about which factors will influence Chinese residents’ decisions on savings and spending. It also has practical implication for government policy, for example, proposing new ideas for reducing household savings rate and stimulating consumption.

Originality/value

The results confirmed that hunger significantly affects consumers’ intertemporal choices, which broadened the scope of researches on the factors that influence intertemporal choice, and advanced the study on the influence of individual’s physiological state on intertemporal choices. This study filled the gaps in previous researches, and opened up new research ideas for interdisciplinary study.

Details

Journal of Contemporary Marketing Science, vol. 2 no. 3
Type: Research Article
ISSN: 2516-7480

Keywords

Book part
Publication date: 19 July 2023

Thai-Ha Le, Manh-Tien Bui and Duc Manh Chu

The research analyzes the convergence of several socioeconomic indicators in a sample of 137 countries over the period 1990–2019. Applying log t-convergence tests, it finds that…

Abstract

The research analyzes the convergence of several socioeconomic indicators in a sample of 137 countries over the period 1990–2019. Applying log t-convergence tests, it finds that socioeconomic indicators’ convergence is divergent. Measuring seven different indicators, there are only two indicators of life expectancy and access to the internet converging at the global level, while the remaining indicators of gross domestic product per capita (GDPP), foreign direct investment (FDI) inflow, urbanization, fertility, and CO2 emissions do not. An extension to sub-sample analysis by levels of income and clustering convergence clubs is employed to confirm the heterogeneity and complexity of development pathways among countries. There are several insights for researchers and governments regarding future research and policies, especially for the development of developing countries.

Details

Inclusive Developments Through Socio-economic Indicators: New Theoretical and Empirical Insights
Type: Book
ISBN: 978-1-80455-554-5

Keywords

Book part
Publication date: 25 January 2023

Joseph Deutsch, Pundarik Mukhopadhaya, Jacques Silber and Jing Yang

To explore income inequality in urban China, this paper investigates disparities between- and within-urban locals and rural migrants from 2002 to 2013, using three waves of the…

Abstract

To explore income inequality in urban China, this paper investigates disparities between- and within-urban locals and rural migrants from 2002 to 2013, using three waves of the China Household Income Project (CHIP) data. While the existing literature concentrates on the wage disparity between these two groups, our results show that the Gini among the migrants increased by 17.86% between 2007 and 2013 and that among the locals increased by 15.54% from 2002 to 2007. The urban–migrant average income gap decreased during the whole period mainly due to higher growth in migrants’ average income. Estimates based on Mincerian earnings functions for both groups reveal the significant role of the education, occupation and type of contract in determining the within-group inequality. In addition, using a recentred influence function (RIF), we observe that short-term and other types of contracts, duration of the job, in-system ownership, marriage and skill have inequality-enhancing effects for migrants. The variation of skills has a larger impact on the income disparity among migrants than on that among urban locals. The RIF-based Blinder–Oaxaca decomposition of the mean difference of incomes shows that labour market discrimination between the two groups is not significant; however, both pure explained and unexplained differences are significant when applying the RIF decomposition to the variance of the logarithms of incomes. While the type of contract significantly reduces the pure explained difference between migrants and urban locals, occupation has a positive impact on this difference between these two groups. The heterogenity analysis shows that the factors influencing incomes in these two groups are different. We recommend labour market intervention to reduce unreasonable occupational and sectoral disparities, especially in the net inflow provinces, to mitigate urban inequality in China effectively.

Details

Mobility and Inequality Trends
Type: Book
ISBN: 978-1-80382-901-2

Keywords

Open Access
Article
Publication date: 6 March 2017

Jiaqi Lu, Shijun Liu, Lizhen Cui, Li Pan and Lei Wu

A fundamental problem for intelligent manufacturing is to equip the agents with the ability to automatically make judgments and decisions. This paper aims to introduce the basic…

1774

Abstract

Purpose

A fundamental problem for intelligent manufacturing is to equip the agents with the ability to automatically make judgments and decisions. This paper aims to introduce the basic principle for intelligent crowds in an attempt to show that crowd wisdom could help in making accurate judgments and proper decisions. This further shows the positive effects that crowd wisdom could bring to the entire manufacturing process.

Design/methodology/approach

Efforts to support the critical role of crowd wisdom in intelligent manufacturing involve theoretical explanation, including a discussion of several prevailing concepts, such as consumer-to-business (C2B), crowdfunding and an interpretation of the contemporary Big Data mania. In addition, an empirical study with three business cases was conducted to prove the conclusion that our ideas could well explain the current business phenomena and guide the future of manufacturing.

Findings

This paper shows that crowd wisdom could help make accurate judgments and proper decisions. It further shows the positive effects that crowd wisdom could bring to the entire manufacturing process.

Originality/value

The paper highlights the importance of crowd wisdom in manufacturing with sufficient theoretical and empirical analysis, potentially providing a guideline for future industry.

Details

International Journal of Crowd Science, vol. 1 no. 1
Type: Research Article
ISSN: 2398-7294

Keywords

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