Search results

1 – 10 of over 4000
Per page
102050
Citations:
Loading...
Available. Open Access. Open Access
Article
Publication date: 29 August 2023

Yangsheng Ye, Degou Cai, Qianli Zhang, Shaowei Wei, Hongye Yan and Lin Geng

This method will become a new development trend in subgrade structure design for high speed railways.

570

Abstract

Purpose

This method will become a new development trend in subgrade structure design for high speed railways.

Design/methodology/approach

This paper summarizes the structural types and design methods of subgrade bed for high speed railways in China, Japan, France, Germany, the United States and other countries based on the study and analysis of existing literature and combined with the research results and practices of high speed railway subgrade engineering at home and abroad.

Findings

It is found that in foreign countries, the layered reinforced structure is generally adopted for the subgrade bed of high speed railways, and the unified double-layer or multi-layer structure is adopted for the surface layer of subgrade bed, while the simple structure is adopted in China; in foreign countries, different inspection parameters are adopted to evaluate the compaction state of fillers according to their respective understanding and practice, while in China, compaction coefficient, subsoil coefficient and dynamic deformation modulus are adopted for such evaluation; in foreign countries, the subgrade top deformation control method, the subgrade bottom deformation control method, the subsurface fill strength control method are mainly adopted in subgrade bed structure design of high speed railways, while in China, dynamic deformation control of subgrade surface and dynamic strain control of subgrade bed bottom layer is adopted in the design. However, the cumulative deformation of subgrade caused by train cyclic vibration load is not considered in the existing design methods.

Originality/value

This paper introduces a new subgrade structure design method based on whole-process dynamics analysis that meets subgrade functional requirements and is established on the basis of the existing research at home and abroad on prediction methods for cumulative deformation of subgrade soil.

Details

Railway Sciences, vol. 2 no. 3
Type: Research Article
ISSN: 2755-0907

Keywords

Access Restricted. View access options
Article
Publication date: 8 January 2018

Ye Zhou, Degong Chang and Songmei Li

This paper aims to improve the grease thermal elastohydrodynamic lubrication (TEHL) properties of the tripod sliding universal coupling (TSUC) under automotive practical…

89

Abstract

Purpose

This paper aims to improve the grease thermal elastohydrodynamic lubrication (TEHL) properties of the tripod sliding universal coupling (TSUC) under automotive practical conditions. For this purpose, the effect of effective radius was theoretically investigated.

Design/methodology/approach

Based on the simplified geometric model, the effect of effective radius on the pressure distribution, film thickness and temperature distribution of the TSUC was theoretically investigated using the multigrid and stepping methods. The TEHL properties were compared with the results obtained using the isothermal calculation method.

Findings

The results show that the thermal effect has a great impact on the film thickness and the pressure distribution of grease lubrication properties. Moreover, larger effective radius results in a wider but lower pressure distribution, a wider and thicker lubricating film and a lower temperature distribution.

Originality/value

The TSUC can be widely used in the front drive automotive transmission because it can transmit larger torque than before. The effect of effective radius on the thermal grease lubrication properties under automotive practical conditions provides a new direction for designing it.

Details

Industrial Lubrication and Tribology, vol. 70 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Access Restricted. View access options
Article
Publication date: 10 July 2017

Ye Zhou, Degong Chang and Songmei Li

This paper aims to investigate the grease isothermal lubrication properties of the tripod sliding universal coupling (TSUC) in automotive transmission shaft and study its impact…

110

Abstract

Purpose

This paper aims to investigate the grease isothermal lubrication properties of the tripod sliding universal coupling (TSUC) in automotive transmission shaft and study its impact on a variety of factors to improve its grease lubrication properties.

Design/methodology/approach

Based on the simplified geometrical model, the research of grease lubrication properties of the TSUC was analyzed, and compared with oil lubrication in same parameters. Then the effects of effective radius, frequency (vehicle speed) and amplitude (angle between intermediate shaft and input shaft) on grease isothermal lubrication properties are theoretically investigated by using multigrid methods.

Findings

The results indicate that the grease isothermal elastohydrodynamic lubrication (EHL) film thickness shape and pressure distribution shape of the TSUC are similar to the oil lubrication, but the film thickness of grease lubrication is less than that of oil lubrication. Higher effective radius results in a wider pressure distribution, a lower center pressure and a thicker lubricating film. Higher frequency (vehicle speed) results in a remarkable second pressure peak and a thicker lubricating film. The effects of amplitude (angle between intermediate shaft and input shaft) and frequency have similar tendencies.

Originality/value

The numerical analysis research on grease lubrication properties of the TSUC is significant because the automotive transmission shaft is widely used. And it provides a new direction in designing TSUCs.

Details

Industrial Lubrication and Tribology, vol. 69 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

Access Restricted. View access options
Article
Publication date: 12 October 2018

Jiaolin Wang, Ye Zhou and Qi-Hong Deng

The purpose of this study is to investigate the flow interaction between the cavities and its impact on heat transfer. The role of the openings is examined and three strategies…

111

Abstract

Purpose

The purpose of this study is to investigate the flow interaction between the cavities and its impact on heat transfer. The role of the openings is examined and three strategies are considered: one opening, two openings on single side and two openings on double sides.

Design/methodology/approach

A two-dimensional laminar natural convection heat transfer in multilayered open cavities was numerically investigated. The governing equations in primitive variables were discretized by the finite volume method and solved by SIMPLE algorithm.

Findings

The results show that for the cavities with one opening, the flow in the cavities is connected with each other. The exhaust hot fluid from the lower cavity was entrained into the upper cavities by thermal buoyancy and hence the heat transfer in the upper cavities was decreased because of thermal accumulation. Two openings on the single side could strengthen the flow interaction between the cavities and then enhance the heat transfer. However, the double-sided openings eliminated the flow interaction between the cavities and thus the fluid flow and heat transfer characteristics in all cavities are independent. It was concluded that the flow interaction between the multilayered open cavities has an importance effect on the heat transfer in the cavities.

Originality/value

The flow interaction between the multilayered open cavities was illustrated. The effect of flow interaction on the heat transfer in the cavities was investigated. The role of openings in the flow interaction and heat transfer in cavities was explored. The cavity below affects above cavity for the openings on single side. No interaction exists between the cavities with openings on double sides.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 28 no. 8
Type: Research Article
ISSN: 0961-5539

Keywords

Access Restricted. View access options
Article
Publication date: 8 January 2018

Ye Zhou, Caichao Zhu, Huaiju Liu, Chaosheng Song and Zufeng Li

Coatings are widely used in gears to keep interface from wearing excessively. The purpose of this paper is to study the effect of coating properties and working conditions on the…

365

Abstract

Purpose

Coatings are widely used in gears to keep interface from wearing excessively. The purpose of this paper is to study the effect of coating properties and working conditions on the pressure, the shear traction, stresses as well as the fatigue life of spur gear.

Design/methodology/approach

A numerical contact fatigue life model of a coated spur gear pair under elastohydrodynamic lubrication (EHL) is developed based on the characteristics of gear geometry and kinematics, lubrication conditions and material properties. Frequency response functions and the discrete convolute and fast Fourier transform (DC-FFT) algorithm are applied to obtain elastic deformation and stress. Mutil-axial fatigue criteria are used to evaluate the contact fatigue life based upon the predicted time-varying stress fields of coated bodies.

Findings

The maximum Mises stress decreases while the fatigue life increases as the coating modulus decreases. A thinner coating leads to a longer life and a smaller maximum Mises stress for hard coatings. The load has more significant effect on the contact fatigue life of soft coatings.

Originality/value

The developed model can be used to evaluate the contact fatigue life of coated gear under EHL and help designers analyze the effect of coating elastic modulus and thickness on the contact pressure, film thickness and stress.

Details

Industrial Lubrication and Tribology, vol. 70 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Access Restricted. View access options
Article
Publication date: 24 July 2024

Ulpiana Kocollari, Andrea Girardi, Maddalena Cavicchioli and Alessia Pedrazzoli

This study analyses how different forms of online accountability – hierarchical/individualising, hierarchical/calculative and socialising accountability – influence online…

77

Abstract

Purpose

This study analyses how different forms of online accountability – hierarchical/individualising, hierarchical/calculative and socialising accountability – influence online financing success of non-profit organisations (NPOs).

Design/methodology/approach

The study is based on 797 NPOs’ projects listed on three international crowdfunding platforms providing space for NPOs to present, account for and fund social projects.

Findings

Results show that accountability forms developed online play significantly different roles in NPOs’ financing. While online hierarchical/individualising and socialising accountability enhance NPO funding, hierarchical/calculative accountability reduces financing success.

Research limitations/implications

The empirical analysis is limited to the specific research context. However, the research provides theoretical and practical insights for the accounting literature.

Practical implications

The paper recommends that NPOs invest more in explaining their past and future activities rather than reporting on pure financial performances, as this may lead to stakeholders’ perception of mission drift and reduce financing success.

Originality/value

This research enhances the understanding of online accountability and its significance in securing financial resources for NPOs by highlighting the necessity of examining various accountability forms individually, as they may serve distinct functions in the financial sustenance of NPOs.

Details

Journal of Applied Accounting Research, vol. 26 no. 1
Type: Research Article
ISSN: 0967-5426

Keywords

Access Restricted. View access options
Article
Publication date: 14 November 2022

Ruichen Ge, Sha Zhang and Hong Zhao

Extant research shows mixed results on the impact of expressed negative emotions on donations in online charitable crowdfunding. This study solves the puzzle by examining how…

779

Abstract

Purpose

Extant research shows mixed results on the impact of expressed negative emotions on donations in online charitable crowdfunding. This study solves the puzzle by examining how different types of negative emotions (i.e. sadness, anxiety and fear) expressed in crowdfunding project descriptions affect donations.

Design/methodology/approach

Data on 15,653 projects across four categories (medical assistance, education assistance, disaster assistance and poverty assistance) from September 2013 to May 2019 come from a leading online crowdfunding platform in China. Text analysis and regression models serve to test the hypotheses.

Findings

In the medical assistance category, the expression of sadness has an inverted U-shaped effect on donations, while the expression of anxiety has a negative effect. An appropriate number of sadness words is helpful but should not exceed five times. In the education assistance and disaster assistance categories, the expression of sadness has a positive effect on donations, but disclosure of anxiety and fear has no influence on donations. Expressions of sadness, anxiety and fear have no impact on donations in the poverty assistance category.

Research limitations/implications

This work has important implications for fundraisers on how to regulate the fundraisers' expressions of negative emotions in a project's description to attract donations. These insights are also relevant for online crowdfunding platforms.

Originality/value

Online crowdfunding research often studies negative emotions as a whole and does not differentiate project types. The current work contributes by empirically testing the impact of three types of negative emotions on donations across four major online crowdfunding categories.

Details

Information Technology & People, vol. 36 no. 7
Type: Research Article
ISSN: 0959-3845

Keywords

Access Restricted. View access options
Book part
Publication date: 12 September 2017

Yu-Ling Hsiao and Lucy E. Bailey

This chapter draws from a three-year ethnographic study focused on the educational and community interactions among working- and middle-class ethnic Chinese immigrants in a…

Abstract

This chapter draws from a three-year ethnographic study focused on the educational and community interactions among working- and middle-class ethnic Chinese immigrants in a mid-western town in the United States. Aihwa Ong (1999) argues that “Chineseness” is a fluid, cultural practice manifested within the Chinese diaspora in particular ways that relate to globalization in late modernity, immigrants’ cultural background, their place in the social structure in their home society, and their new social class status in the context they enter. The study extends research focused on the complexities of social reproduction within larger global flows of Chinese immigrants. First, we describe how Chinese immigrants’ social status in their countries of origin in part shapes middle and working-class group’s access to cultural capital and positions in the social structure of their post-migration context. Second, we trace groups’ negotiation of their relational race and class positioning in the new context (Ong, 1999) that is often invisible in the processes of social reproduction. Third, we describe how both groups must negotiate national, community, and schooling conceptions of the model minority concept (Lee, 1996) that shapes Asian-American’s lived realities in the United States; yet the continuing salience of their immigrant experience, home culture, and access to cultural capital (Bourdieu, 2007) means that they enact the “model minority” concept differently. The findings suggest the complexity of Chinese immigrants’ accommodation of and resistance to normative ideologies and local structures that cumulatively contribute to social reproduction on the basis of class.

Details

The Power of Resistance
Type: Book
ISBN: 978-1-78350-462-6

Keywords

Access Restricted. View access options
Book part
Publication date: 28 December 2016

Marios Sotiriadis and Ciná van Zyl

The aim of this chapter is twofold: (i) to perform a synthesis of the academic research regarding the changes of tourist consumer behavior brought about by social media; and (ii…

Abstract

Purpose

The aim of this chapter is twofold: (i) to perform a synthesis of the academic research regarding the changes of tourist consumer behavior brought about by social media; and (ii) to suggest a set of strategies for tourism businesses to address resulting challenges.

Methodology/approach

Extensive literature reviews have been executed on the motivating factors and the effects of online reviews.

Findings

This analysis of the related research identified three main topics, namely: (1) the antecedents, the factors motivating tourists to write online reviews; (2) the impact of eWOM on providers of tourism services (business perspective); and (3) the influence of online reviews on consumers’ behavior (demand perspective). This chapter focuses on the impact of online reviews on tourism businesses and suggests suitable strategies.

Research limitations/implications

This study is based on a literature review and implications indicated by previous studies; hence the suggestions are indicative rather than conclusive. A need exists for empirical studies to fully validate the chapter’s suggestions.

Practical implications

This chapter outlines a series of adequate strategies formulated for business practitioners divided into two fields, namely managerial and marketing activities.

Originality/value

This study provides practical recommendations/suggestions for tourism businesses in addressing the challenges and opportunities raised within the online context.

Details

The Handbook of Managing and Marketing Tourism Experiences
Type: Book
ISBN: 978-1-78635-289-7

Keywords

Access Restricted. View access options
Article
Publication date: 17 September 2020

Elise Wong, S. Mostafa Rasoolimanesh and Saeed Pahlevan Sharif

This study aims to investigate the relationships between service quality, perceived value and hotel guest satisfaction, drawing upon data from TripAdvisor – an online travel agent…

2430

Abstract

Purpose

This study aims to investigate the relationships between service quality, perceived value and hotel guest satisfaction, drawing upon data from TripAdvisor – an online travel agent (OTA) platform. The study also investigates the mediating role of perceived value on the relationship between service quality and satisfaction, as well as the moderating role of hotel star ratings on all direct and indirect relationships.

Design/methodology/approach

Data for this study were collected via Web scraping from August–October 2018. Data were collected from 192 three- to five star-rated hotels in Kuala Lumpur, Malaysia. Partial least squares – structural equation modeling was used for data analysis. Furthermore, importance-performance map analysis (IPMA) was performed to identify the most important items of service quality and perceived value in improving customer satisfaction.

Findings

The findings of this study provide support for all direct and indirect relationships for three-star and four- and five-star hotels. Moreover, the results indicate that perceived value mediates the relationship between service quality and customer satisfaction. These results support the moderating role of hotel star ratings for the relationship between service quality and perceived value. The results also show that after perceived value, three-star hotels looking to improve customer satisfaction should prioritize improving the quality of their services, sleep quality, cleanliness and rooms. Four- and five-star hotels, on the other hand, should prioritize service, cleanliness, room and sleep quality.

Originality/value

OTA platforms collect a wealth of data pertaining to large number of hotels; nevertheless, few studies to date have drawn on this data to examine a pre-determined conceptual framework developed based on the literature. As such, this study makes a valuable methodological contribution to the tourism and hospitality literature. In terms of theoretical contributions, this study examines the mediating role of perceived value between service quality and satisfaction using OTA data. In addition, this study assesses the moderating role of hotel star ratings for the direct and indirect effects of service quality on satisfaction. Using IPMA, this study compares the importance and performance of service quality indicators to generate satisfaction between three-star and four- and five-star hotels.

研究目的

本论文检测了服务质量、价值感知、和酒店顾客满意度之间的关系, 使用TripAdvisor的数据—OTA。本论文还检测了价值感知对服务质量和满意度之间的中介作用, 以及酒店星级评价对其中直接和间接关系的调节作用。.

研究设计/方法/途径

本论文采样通过网络爬虫技术, 截取了2018年八月至十月之间的数据。研究样本为192家马来西亚Kuala Lumpur地区的三星-五星酒店。样本分析方法为PLS-SEM。此外, 本论文采样IPMA分析法来找出提高顾客满意度中的服务质量和价值感知中最重要的因子。.

研究结果

研究结果指出了三星、四星、五星酒店的直接和间接关系。此外, 研究还显示了服务质量和顾客满意度关系的价值感知中介作用。研究结果还指出了酒店星级评价对服务质量和价值感知关系的调节作用。此外, 研究还指出, 除了价值感知, 如果三星酒店想提高顾客满意度, 那么他们应该优先提高其服务质量、睡眠质量、清洁度、和房间。另一方面, 四星和五星酒店应该优先提高其服务质量、清洁度、房间、和睡眠质量。.

研究原创性/价值

OTA平台搜集大量酒店数据, 但是很少作品研究这些数据, 以检测根据文献提出的理论模型。因此, 本论文在方法论上对旅游酒店文献做出宝贵贡献。理论贡献而言, 本论文使用OTA数据检测了价值感知对服务质量和满意度关系之间的中介作用。此外, 本论文检测了酒店星级评价对服务质量和满意度之间直接和间接关系的调节作用。本论文使用IPMA方法, 比较各种服务质量指标的重要性对在三星、四星、五星酒店的提高满意度的不同作用。.

Details

Journal of Hospitality and Tourism Technology, vol. 11 no. 3
Type: Research Article
ISSN: 1757-9880

Keywords

1 – 10 of over 4000
Per page
102050