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Article
Publication date: 8 June 2015

Kai Feng and Xueyuan Zhao

The purpose of this paper is to investigate the effects of misalignment on the static and dynamics characteristics of bump-type foil bearings (BFBs). High-speed and…

Abstract

Purpose

The purpose of this paper is to investigate the effects of misalignment on the static and dynamics characteristics of bump-type foil bearings (BFBs). High-speed and high-temperature oil-free turbomachinery can be realized with the use of gas foil bearings (GFBs). GFBs have a flexible supporting structure; thus, they can tolerate a higher degree of misalignment compared with rolling element bearings.

Design/methodology/approach

A test rig for GFBs has been developed to measure the effects of misalignment on the structure characteristics of bump-type foil bearings. The link-spring model, which is the foil structure model presented previously by the authors, is used as a basis in the present study to predict the static and dynamic performances of the foil structure. In general, predictions of the dynamic characteristics exhibit good agreement with the measurements acquired from the dynamic load tests.

Findings

Results from the static tests show that GFBs develop high stiffness when the misalignment angle increases. Moreover, the dynamic characteristics of GFBs are identified by considering the test bearing supported by a non-rotating shaft as a one-degree-of-freedom system. The results indicate that the dynamic characteristics of GFBs strongly depend on excitation frequency and excitation amplitude because of the variation in the dynamic friction force within the foil structure. The structural stiffness and equivalent viscous damping increase with an increase in the misalignment angle.

Originality/value

The present study focuses on the misalignment of GFBs and investigates experimentally the effects of misalignment on the structure characteristics of GFBs.

Details

Industrial Lubrication and Tribology, vol. 67 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 6 February 2017

Bo Zou, Feng Guo and Michael Song

Although the extant innovation literature has extensively explored the attributes of different types of innovation capability, little is known yet about the common…

Abstract

Purpose

Although the extant innovation literature has extensively explored the attributes of different types of innovation capability, little is known yet about the common phenomenon of the rebound and durableness of innovation capability. Therefore, the purpose of this paper is to address these aspects by introducing the concepts of elastic and plastic innovation capability.

Design/methodology/approach

Based on the behavioral theory of the firm, the authors propose a theoretical model to study the antecedents and outcomes of elastic and plastic innovation capability. An empirical testing involves two data sets that contained 183 companies in three industries. The empirical evidence supports the existence of the concepts of elastic and plastic innovation capability.

Findings

The research findings also demonstrate that a firm’s past performance is positively related to elastic innovation capability. Elastic innovation capability and organizational aspiration are positively related to plastic innovation capability. Both elastic and plastic innovation capability significantly lead to superior performance.

Originality/value

This study makes three main contributions to the existing innovation literature. First, the authors extend existing knowledge on innovation capability by proposing two new types of innovation capability – elastic and plastic innovation capability. Second, the proposed concepts of elastic and plastic innovation capability contribute to the theory of dynamic capability. Finally, this study reveals the micro-mechanism of elastic and plastic innovation capability from the perspective of the behavior theory of the firm and their different effect on firm performance.

Details

Industrial Management & Data Systems, vol. 117 no. 1
Type: Research Article
ISSN: 0263-5577

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Article
Publication date: 2 September 2019

Chunjia Hu, Michael Song and Feng Guo

The purpose of this paper is to employ a quantitative approach to explore the intellectual structure of the market orientation (MO) field over the course of its development.

Abstract

Purpose

The purpose of this paper is to employ a quantitative approach to explore the intellectual structure of the market orientation (MO) field over the course of its development.

Design/methodology/approach

This research was conducted by using the bibliometric techniques of citation and co-citation analyses to investigate 1,892 publications in the MO field from 1990 to 2016, as well as factor analysis and multidimensional scaling to present a clear visual experience of the knowledge structure of the MO filed.

Findings

This study reveals meaningful outputs to assist in: delineating the critical authors, institutions and countries related to the study of MO; identifying the published documents that have had a significant influence on the field; clarifying the subfields that have developed from the MO field; and mapping the intellectual structure of the field in a two-dimensional space that allows for the visual representation of different themes.

Research limitations/implications

Given the sheer volume of works that exist, these bibliometric techniques cannot completely measure, describe and present the entire intellectual structure of the MO field. Instead, co-citation analysis was performed using the data from only the top publications to identify the level of integration of the field, the changes of each knowledge group and the maturity of its evolution.

Originality/value

First, this study extends the approach to identify the subject of MO from a quantitative perspective. Second, our analysis shows the intersection between the marketing discipline and management discipline in the MO literature. Finally, this study reveals the development tendency of the MO field in recent years. The results of this study are valuable to readers interested in MO research, especially those newly interested in this field.

Details

Marketing Intelligence & Planning, vol. 37 no. 6
Type: Research Article
ISSN: 0263-4503

Keywords

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Article
Publication date: 8 August 2016

Jianjun Zhang, Qibo Ni, Jing Wang and Feng Guo

Vibration exists widely in all machineries working under high speed. The unpredictability of vibration and the change of the relative surface speed may result in…

Abstract

Purpose

Vibration exists widely in all machineries working under high speed. The unpredictability of vibration and the change of the relative surface speed may result in difficulties in the elastohydrodynamic lubrication (EHL) analysis. By far, few studies on EHL relating to vibration have been published. The purpose of the present study is to investigate the effect of the vertical vibrations and the influence of temperature on the thermal EHL contacts.

Design/methodology/approach

The lubricant was assumed to be Newtonian fluid. The time-dependent numerical solutions were achieved instant after instant in each period of the vibration. At each instant, the pressure field was solved with a multi-level technique, the surface deformation was solved with a multi-level multi-integration method and the temperature filed was solved with a finite different scheme through a sweeping progress. The periodic error was checked at each end of the vibration period until the responses of pressure, film thickness and temperature were all periodic functions with the frequency of the roller’s vibrations.

Findings

The results reveal that normal vibration produces little drastic change of pressure, film thickness and temperature in EHL. Under some conditions, the vibrations of the roller can produce transient dimples within the contact conjunction. It is also showed that the lubrication in the same sliding is better than the opposite sliding.

Research limitations/implications

For the unpredictability of vibration, it is not easy to do the experiment to realize a real comparison with numerical results. The reach does not show any verification and consider the effect of non-Newtonian fluid.

Originality/value

The effect of the vertical vibrations on the thermal EHL point contact hast been studied. The effects of both the amplitude and the frequency on the predicted load-carrying capacity, minimum film thickness, center pressure and center temperature and the coefficient of friction were investigated. The role of the thermal effect was given.

Details

Industrial Lubrication and Tribology, vol. 68 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 7 August 2017

Zhi-Jin Zhong, Tongchen Wang and Minting Huang

The purpose of this paper is to examine the impact of internet censorship, which is represented by the Great Fire Wall, on Chinese internet users’ self-censorship.

Abstract

Purpose

The purpose of this paper is to examine the impact of internet censorship, which is represented by the Great Fire Wall, on Chinese internet users’ self-censorship.

Design/methodology/approach

A 3×2 factorial experiment (n=315) is designed. Different patterns of censorship (soft censorship, compared censorship, and hard censorship) and the justification of internet regulation are involved in the experiment as two factors. The dependent variable is self-censorship which is measured through the willingness to speak about sensitive issues and the behavior of refusing to sign petitions with true names.

Findings

The results show that perceived internet censorship significantly decreases the willingness to talk about sensitive issues and the likelihood of signing petitions with true names. The justification of censorship significantly decreases self-censorship on the behaviors of petition signing. Although there are different patterns of internet censorship that Chinese netizens may encounter, they do not differ from each other in causing different levels of self-censorship.

Research limitations/implications

The subjects are college students who were born in the early 1990s, and the characteristics of this generation may influence the results of the experiment. The measurement of self-censorship could be refined.

Originality/value

The study contributes to the body of literature about internet regulation because it identifies a causal relationship between the government’s internet censorship system and ordinary people’s reaction to the regulation in an authoritarian regime. Unpacking different patterns of censorship and different dimensions of self-censorship depicts the complexity of censoring and being censored.

Details

Internet Research, vol. 27 no. 4
Type: Research Article
ISSN: 1066-2243

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Article
Publication date: 31 March 2020

Donghua Zhao, Tianqi Li, Beijun Shen, Yicheng Jiang, Weizhong Guo and Feng Gao

The purpose of this paper is to design and develop a rotary three-dimensional (3D) printer for curved layer fused deposition modeling (CLFDM), and discuss some technical…

Abstract

Purpose

The purpose of this paper is to design and develop a rotary three-dimensional (3D) printer for curved layer fused deposition modeling (CLFDM), and discuss some technical challenges in the development.

Design/methodology/approach

Some technical challenges include, but are not limited to, the machine design and control system, motion analysis and simulation, workspace and printing process analysis, curved layer slicing and tool path planning. Moreover, preliminary experiments are carried out to prove the feasibility of the design.

Findings

A rotary 3D printer for CLFDM has been designed and developed. Moreover, this printer can function as a polar 3D printer for flat layer additive manufacturing (AM). Compared with flat layer AM, CLFDM weakens the staircase effect and improves geometrical accuracy and mechanical properties. Hence, CLFDM is more suitable for parts with curved surfaces.

Research limitations/implications

Double extruders have brought improved build speed. However, this paper is restricted to complex process planning and mechanical structures, which may lead to collisions during printing. Meanwhile, the rotation range of the nozzle is limited by mechanical structures, affecting the manufacturing capability of complex curved surfaces.

Originality/value

A novel rotary 3D printer, which has four degrees of freedom and double extruders, has been designed and manufactured. The investigation on the prototype has proved its capability of CLFDM. Besides, this rotary 3D printer has two working modes, which brings the possibility of flat layer AM and CLFDM.

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Article
Publication date: 17 August 2012

Duan Li‐zhong, Duan Gu‐na, Zhai Guang‐Qian, Zhang Ying, Xuan Chun‐Yu and Geng Hao

The purpose of this paper is to strengthen and standardize general hospital use of traditional Chinese medicine, strengthen the inner construction, highlight the…

Abstract

Purpose

The purpose of this paper is to strengthen and standardize general hospital use of traditional Chinese medicine, strengthen the inner construction, highlight the characteristics and advantages of Chinese medicine and improve Chinese medicine services' capacity and competitiveness.

Design/methodology/approach

Through data analysis and face‐to‐face interviews, the influential factors for Chinese medicine use in general hospitals are found and the extent and impact of these factors are researched. Based on survey results, grey relational analysis is used to analyze the actual factors.

Findings

Based on the results of grey relational analysis, a clear order of these factors on the degree of influence is obtained and suggestions are offered which can promote the development of traditional Chinese medicine in general hospitals.

Originality/value

The grey system theory was applied in medical management. The influential factors for Chinese medicine use in general hospitals was analyzed by using grey relational analysis, to offer the relevant departments several operational recommendations which can accelerate the development of general hospital use of traditional Chinese medicine.

Details

Grey Systems: Theory and Application, vol. 2 no. 2
Type: Research Article
ISSN: 2043-9377

Keywords

Abstract

Details

Ethnographies of Law and Social Control
Type: Book
ISBN: 978-0-76231-128-6

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Abstract

Details

The Emerald Handbook of Blockchain for Business
Type: Book
ISBN: 978-1-83982-198-1

Keywords

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Article
Publication date: 1 April 2019

Xiaoyi He, Liping Li, Xiaojian Liu, Yongsheng Wu, Shujiang Mei and Zhen Zhang

Hand, foot and mouth disease (HFMD) is a common infectious disease in infants and children. HFMD has caused millions of cases and a large epidemic worldwide. A number of…

Abstract

Purpose

Hand, foot and mouth disease (HFMD) is a common infectious disease in infants and children. HFMD has caused millions of cases and a large epidemic worldwide. A number of studies have shown that the incidence of HFMD is closely related to various factors such as meteorological factors, environmental air pollution factors and socio-economic factors. However, there are few studies that systematically consider the impact of various factors on the incidence of HFMD. The paper aims to discuss these issues.

Design/methodology/approach

This study used grey correlation analysis and principal component analysis (PCA) method to systematically analyse the impact of meteorological factors, health resource factors, socio-economic factors and environmental air pollution factors on the incidence of HFMD in Shenzhen.

Findings

The incidence of HFMD in Shenzhen was affected by multiple factors. Grey correlation analysis found eight influencing factors which are as follows: volume of industrial waste gas emission; the days of air quality equal to or above grade; the volume of industrial nitrogen oxide emission; precipitation; the mean air temperature; the gross domestic product; the expenditure for medical and health care; and the gross domestic product per capita. PCA found that the gross domestic product, the volume of industrial soot emission, the relative humidity, and the days of air quality equal to or above grade have a higher load value.

Originality/value

This study is the one of the first studies that apply the grey correlation analysis to analyse the influencing factors of HFMD in the English literature, which to some extent fills up the blank in this field.

Details

Grey Systems: Theory and Application, vol. 9 no. 2
Type: Research Article
ISSN: 2043-9377

Keywords

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