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Article
Publication date: 8 May 2018

Aibin Zhu, Hongling Wu, Yulei Yang and Shengli He

Because of the various geometric descriptions of different bearing types, performance calculation of journal bearing is complicated, and is difficult in traditional model…

Abstract

Purpose

Because of the various geometric descriptions of different bearing types, performance calculation of journal bearing is complicated, and is difficult in traditional model. This paper aims to simplify the calculation of the journal bearing performance, and to reduce the workload.

Design/methodology/approach

On the basis of previous research, a general performance calculation model of journal bearing is proposed in this paper. Eccentricity ratio and attitude angle of axis to each pad are calculated by coordinates of spindle center and each pad center by establishing the unified coordinate system. The surface deformation of journal bearing is taken into consideration, and a correction value is added to the dimensionless oil film thickness.

Findings

The performance calculation results of various fix-pad and tilting-pad journal bearings match the results of the existing references very well, revealing the validity of the model. The general model can greatly reduce programming workload, and increase adaptability to different bearings.

Originality/value

Geometric descriptions of both fix-pad and tilting-pad journal bearings are unified in this model, which can be applied to both standard and non-standard journal bearings with different preload ratios. In addition, due to the unification of different bearings types, this model is more conducive to performance comparison among different bearing types, and promotes the development of new structural forms for journal bearings.

Details

Industrial Lubrication and Tribology, vol. 70 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 7 December 2018

Haitao Wang, Jiayu Shen and Da Gao

Abutment damage in liquefied ground is an important form of seismic damage of bridge structure. This paper aims to further research the effect of beam restriction on…

Abstract

Purpose

Abutment damage in liquefied ground is an important form of seismic damage of bridge structure. This paper aims to further research the effect of beam restriction on seismic damage mode of abutment in liquefied ground.

Design/methodology/approach

Based on the investigation of the seismic damage of Shengli Bridge in Tangshan earthquake, the finite element software dynamic effective stress analysis for ground (UWLC) is used to simulate the seismic damage of Shengli Bridge, and the results were compared with the actual seismic damage results. Then, the influences of the horizontal binding force of the beam, the liquefaction layer thickness, the top weight of the abutment, the peak acceleration, the liquefaction layer buried depth and the type of the foundation soil on the abutment seismic damage model are studied.

Findings

The results show that numerical simulation results are consistent with the actual seismic damage, and it is feasible to use UWLC software to simulate seismic damage. The results show that the seismic failure mode of the gravity abutment in liquefied ground is slip–rotation coupling type, not single slip type or rotation type. The large deformation of abutment bottom layer, horizontal binding force of the beam and post-stage soil pressure are the main reasons for abutment rotation or even destruction.

Research limitations/implications

A series of basic assumptions are used in the calculation process in this paper. The gravity abutment is defined as the elastic body and neglects its local deformation. The soil layer is a homogeneous isotropic. The consolidation process and the drainage boundary problem are not considered in the calculation process. Therefore, the paper may have some limitations.

Originality/value

To further research the seismic damage mode and influencing factors of abutment in liquefied ground, in this paper, based on the investigation of the seismic damage of Shengli Bridge in Tangshan earthquake, the finite element software UWLC is used to simulate the seismic damage of Shengli Bridge, and the results were compared with the actual seismic damage results. The seismic damage mode and influencing factors of gravity abutment in liquefied ground have been studied.

Details

Journal of Engineering, Design and Technology, vol. 17 no. 1
Type: Research Article
ISSN: 1726-0531

Keywords

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Article
Publication date: 20 March 2018

Xiaoyu Chen, Alton Y.K. Chua and Shengli Deng

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…

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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.

Originality/value

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.

Details

Aslib Journal of Information Management, vol. 70 no. 2
Type: Research Article
ISSN: 2050-3806

Keywords

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Article
Publication date: 3 April 2019

Shengli Tian, Xiaoan Chen, Tianchi Chen and Ye He

The purpose of this study is to investigate accurate and effective experimental methods for measuring the frictional loss of bearings (FLB) in mechanical systems and to…

Abstract

Purpose

The purpose of this study is to investigate accurate and effective experimental methods for measuring the frictional loss of bearings (FLB) in mechanical systems and to measure the effect of various operating parameters on the frictional loss of high-speed mechanical systems.

Design/methodology/approach

Two novel methods were studied in this paper to measure the FLB: the free-deceleration method and the energy-balance method. A special high-speed motorised spindle and a friction loss test rig were designed and built to measure the effects of rotational speed, lubrication, preload and operating temperature on the FLB.

Findings

The experimental results showed that the frictional torque of bearings increases initially but then decreases with an increase in rotational speed. Similarly, the FLB decreases initially and then increases with an increase in temperature because of the influence of the viscosity–temperature relationship of the lubricant and the thermomechanical coupling factor. The optimal lubricant flow was determined, and the effectiveness of a novel preload online adjusting device was verified through experiments.

Originality/value

The research results of this paper provide the basis and methods for the measurement, reduction and prediction of the FLB in mechanical systems.

Details

Industrial Lubrication and Tribology, vol. 71 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

Content available
Article
Publication date: 1 August 2001

Abstract

Details

Disaster Prevention and Management: An International Journal, vol. 10 no. 3
Type: Research Article
ISSN: 0965-3562

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Article
Publication date: 3 July 2017

Shengli Yu and Anna Lee Rowe

The purpose of this paper is to explore the motivations underpinning recent evolving corporate social and environmental reporting (CSER) among enterprises in China through…

Abstract

Purpose

The purpose of this paper is to explore the motivations underpinning recent evolving corporate social and environmental reporting (CSER) among enterprises in China through the lenses of senior managers.

Design/methodology/approach

Using the interpretive tenets of engagement research, semi-structured in-depth interviews were adopted to explore the perceptions of senior managers from 21 large companies in various industries. The aim is to make sense of the emerging CSER phenomenon occurring in the field through engagement, observation and penetrating interviews.

Findings

The findings identify the main enablers driving CSER in China as: regulations and government influence; management awareness; benefits to company image; peer pressure/reporting by peers and public pressure on controversial companies. Guided by a system-based theoretical framework in terms of motivations for CSER, this study offers insights into the effectiveness of using widely adopted Western-based theoretical approaches in a Chinese context where companies operate against a different socio-economic, political, regulatory and cultural backdrop.

Research limitations/implications

The deep-rooted face (Mianzi) culture has the potential to influence managers to portray a positive image about their companies and themselves.

Originality/value

This engagement-based study is one of the few initiatives exploring managerial perceptions of CSER in China that adds to the scant literature pertaining to rich “emic” data in accounting, encompassing cultural influence by applying systems-oriented theoretical framework. The stimulus for CSER identified are useful for regulators and organizations to better comprehend how to set effective policies that promote CSER and fit the distinctive institutional characteristics of China.

Details

Sustainability Accounting, Management and Policy Journal, vol. 8 no. 3
Type: Research Article
ISSN: 2040-8021

Keywords

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Article
Publication date: 23 July 2020

Yang Xiao

The purpose of this paper is to investigate regime-switching and single-regime GARCH models for the extreme risk forecast of the developed and the emerging crude oil markets.

Abstract

Purpose

The purpose of this paper is to investigate regime-switching and single-regime GARCH models for the extreme risk forecast of the developed and the emerging crude oil markets.

Design/methodology/approach

The regime-switching GARCH-type models and their single-regime counterparts are used in risk forecast of crude oil.

Findings

The author finds that the regime-switching GARCH-type models are suitable for the developed and the emerging crude oil markets in that they effectively measure the extreme risk of crude oil in different cases. Meanwhile, the model with switching regimes captures dynamic structures in financial markets, and these models are just only better than the corresponding single-regime in terms of long position risk forecast, instead of short position. That is, it just outperforms the single-regime on the downside risk forecast.

Originality/value

This study comprehensively compares risk forecast of crude oil in different situations through the competitive models. The obtained findings have strong implications to investors and policymakers for selecting a suitable model to forecast extreme risk of crude oil when they are faced with portfolio selection, asset allocation and risk management.

Details

International Journal of Emerging Markets, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1746-8809

Keywords

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Abstract

Subject area

Strategic management

Study Level/applicability

Undergraduate/postgraduate modules in strategic management.

Case overview

The case portrays a Chinese surrogate manufacturer – Cool-Comfort Shoes International Co. Ltd. (CCS) – which attempted to build its own brand, Ace-of-Biz (AoB). The surrogate manufacturing business had accumulated the funds needed to develop its AoB brand for sale in the domestic market. The 2007 world financial crisis and subsequent world recession caused exports and, thus, surrogate manufacturing to plummet. CCS was hoping that their loss in export of surrogate products would be more than compensated for by the gain in the domestic sales of AoB. However, despite 10 years of commitment, AoB's sales still had not grown sufficiently to counter the slowdown in exports, and the leaders at CCS were wondering what the future would hold for the company and its AoB brand.

Expected Learning Outcomes

This case study provides students with an ideal context to develop an appreciation of how changes in the domestic and international business environment affect the corporate and business strategies of a small- to medium-sized enterprise and the differences between corporate and business strategies, and to demonstrate their ability to apply a number of strategic management tools and techniques for the critical appraisal of a strategic situation and justify their recommended course of action.

Supplementary Materials

Teaching notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes.

Details

Emerald Emerging Markets Case Studies, vol. 5 no. 5
Type: Case Study
ISSN: 2045-0621

Keywords

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Article
Publication date: 3 June 2019

Shengli Deng, Anqi Zhao, Ruhua Huang and Haiping Zhao

This study aims to examine why users search for images, how users describe their image needs and what the images are used for by analysing questions obtained from two…

Abstract

Purpose

This study aims to examine why users search for images, how users describe their image needs and what the images are used for by analysing questions obtained from two Chinese social Q&A sites, Zhihu and Baidu Zhidao.

Design/methodology/approach

A total of 1,402 image questions were collected from Zhihu and Baidu Zhidao. Both quantitative analysis and qualitative content analysis were performed to identify user image needs and the potential differences on the two social Q&A sites.

Findings

Question-asker’s intention varies in different platforms. Zhihu users asked questions mainly aiming at a promotion of subsequent discussion, whereas users of Baidu Zhidao often did so to seek information. Syntactic attributes were not frequently used in both two sites. Zhihu users were more likely to express subjective evaluations on images (concept, emotion, theme and style) in their questions than users of Baidu Zhidao. In contrast, questions from Baidu Zhidao showed a tendency to more frequently include descriptive metadata (rights, format, size, quality and authenticity) and semantic attributes (generic activity, specific people, fashion and text) of the images than questions from Zhihu. Learning was an important use on social Q&A sites, especially on Baidu Zhidao. In addition, the images were primarily used to trigger emotion or served a persuasive purpose in Zhihu.

Practical implications

This study contributes to a better understanding of user image search behaviour, and the findings could be used to develop better image services on social Q&A sites. Meanwhile, the image attributes extracted from the questions are conducive to the improvement of image retrieval systems.

Originality/value

This study explored the features of image needs on social Q&A sites, especially considering image use specified in the question. The difference of image needs between two Chinese social Q&A sites (Zhihu and Baidu Zhidao) was identified.

Details

The Electronic Library , vol. 37 no. 3
Type: Research Article
ISSN: 0264-0473

Keywords

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Article
Publication date: 27 September 2011

Shengli Deng, Yong Liu and Yuanyuan Qi

The purpose of this paper is to identify the driving factors of web based question‐answer services (WBQAS) adoption. As an emerging knowledge acquisition method and…

Abstract

Purpose

The purpose of this paper is to identify the driving factors of web based question‐answer services (WBQAS) adoption. As an emerging knowledge acquisition method and service there are currently few studies addressing the antecedents of the service's acceptance, in particular concerning Chinese users.

Design/methodology/approach

This paper employs the unified theory of acceptance and use of technology as its theoretical background and applies it to the field of WBQAS. A survey was conducted.

Findings

Based on 169 useful questionnaires the results show that both performance expectancy and effort expectancy are significant predictors of the intention to use WBQAS. Additionally behavioural intention, together with facilitating intention, significantly influences the actual use of WBQAS. Social influence has no significant impact on the intention to use the service.

Originality/value

As research on WBQAS is in its infancy this paper is among the first in the field, in particular regarding Chinese users. In addition the research applied the unified theory of acceptance and use of technology model to the context of WBQAS and validated the adoption model using structural equation modelling.

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