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1 – 10 of over 3000Xingwen Wu, Zhenxian Zhang, Wubin Cai, Ningrui Yang, Xuesong Jin, Ping Wang, Zefeng Wen, Maoru Chi, Shuling Liang and Yunhua Huang
This review aims to give a critical view of the wheel/rail high frequency vibration-induced vibration fatigue in railway bogie.
Abstract
Purpose
This review aims to give a critical view of the wheel/rail high frequency vibration-induced vibration fatigue in railway bogie.
Design/methodology/approach
Vibration fatigue of railway bogie arising from the wheel/rail high frequency vibration has become the main concern of railway operators. Previous reviews usually focused on the formation mechanism of wheel/rail high frequency vibration. This paper thus gives a critical review of the vibration fatigue of railway bogie owing to the short-pitch irregularities-induced high frequency vibration, including a brief introduction of short-pitch irregularities, associated high frequency vibration in railway bogie, typical vibration fatigue failure cases of railway bogie and methodologies used for the assessment of vibration fatigue and research gaps.
Findings
The results showed that the resulting excitation frequencies of short-pitch irregularity vary substantially due to different track types and formation mechanisms. The axle box-mounted components are much more vulnerable to vibration fatigue compared with other components. The wheel polygonal wear and rail corrugation-induced high frequency vibration is the main driving force of fatigue failure, and the fatigue crack usually initiates from the defect of the weld seam. Vibration spectrum for attachments of railway bogie defined in the standard underestimates the vibration level arising from the short-pitch irregularities. The current investigations on vibration fatigue mainly focus on the methods to improve the accuracy of fatigue damage assessment, and a systematical design method for vibration fatigue remains a huge gap to improve the survival probability when the rail vehicle is subjected to vibration fatigue.
Originality/value
The research can facilitate the development of a new methodology to improve the fatigue life of railway vehicles when subjected to wheel/rail high frequency vibration.
Details
Keywords
Intuitionistic linguistic fuzzy information (ILFI), characterized by linguistic terms and intuitionistic fuzzy sets (IFSs), can easily express the fuzzy information in the process…
Abstract
Purpose
Intuitionistic linguistic fuzzy information (ILFI), characterized by linguistic terms and intuitionistic fuzzy sets (IFSs), can easily express the fuzzy information in the process of muticriteria decision making (MCDM) and muticriteria group decision making (MCGDM) problems. The purpose of this paper is to provide an overview of aggregation operators (AOs) and applications of ILFI.
Design/methodology/approach
First, some meaningful AOs for ILFI are summarized, and some extended MCDM approaches for intuitionistic uncertain linguistic variables (IULVs), such as extended TOPSIS, extended TODIM, extended VIKOR, are discussed. Then, the authors summarize and analyze the applications about the AOs of IULVs.
Findings
IULVs, characterized by linguistic terms and IFSs, can more detailed and comprehensively express the criteria values in the process of MCDM and MCGDM. Therefore, lots of researchers pay more and more attention to the MCDM or MCGDM methods with IULVs.
Originality/value
The authors summarize and analyze the applications about the AOs of IULVs Finally, the authors point out some possible directions for future research.
Details
Keywords
Wenzhen Yang, Johan K. Crone, Claus R. Lønkjær, Macarena Mendez Ribo, Shuo Shan, Flavia Dalia Frumosu, Dimitrios Papageorgiou, Yu Liu, Lazaros Nalpantidis and Yang Zhang
This study aims to present a vision-guided robotic system design for application in vat photopolymerization additive manufacturing (AM), enabling vat photopolymerization AM hybrid…
Abstract
Purpose
This study aims to present a vision-guided robotic system design for application in vat photopolymerization additive manufacturing (AM), enabling vat photopolymerization AM hybrid with injection molding process.
Design/methodology/approach
In the system, a robot equipped with a camera and a custom-made gripper as well as driven by a visual servoing (VS) controller is expected to perceive objective, handle variation, connect multi-process steps in soft tooling process and realize automation of vat photopolymerization AM. Meanwhile, the vat photopolymerization AM printer is customized in both hardware and software to interact with the robotic system.
Findings
By ArUco marker-based vision-guided robotic system, the printing platform can be manipulated in arbitrary initial position quickly and robustly, which constitutes the first step in exploring automation of vat photopolymerization AM hybrid with soft tooling process.
Originality/value
The vision-guided robotic system monitors and controls vat photopolymerization AM process, which has potential for vat photopolymerization AM hybrid with other mass production methods, for instance, injection molding.
Details
Keywords
Li Xuemei, Yun Cao, Junjie Wang, Yaoguo Dang and Yin Kedong
Research on grey systems is becoming more sophisticated, and grey relational and prediction analyses are receiving close review worldwide. Particularly, the application of grey…
Abstract
Purpose
Research on grey systems is becoming more sophisticated, and grey relational and prediction analyses are receiving close review worldwide. Particularly, the application of grey systems in marine economics is gaining importance. The purpose of this paper is to summarize and review literature on grey models, providing new directions in their application in the marine economy.
Design/methodology/approach
This paper organized seminal studies on grey systems published by Chinese core journal database – CNKI, Web of Science and Elsevier from 1982 to 2018. After searching the aforementioned database for the said duration, the authors used the CiteSpace visualization tools to analyze them.
Findings
The authors sorted the studies according to their countries/regions, institutions, keywords and categories using the CiteSpace tool; analyzed current research characteristics on grey models; and discussed their possible applications in marine businesses, economy, scientific research and education, marine environment and disasters. Finally, the authors pointed out the development trend of grey models.
Originality/value
Although researches are combining grey theory with fractals, neural networks, fuzzy theory and other methods, the applications, in terms of scope, have still not met the demand. With the increasingly in-depth research in marine economics and management, international marine economic research has entered a new period of development. Grey theory will certainly attract scholars’ attention, and its role in marine economy and management will gain considerable significance.
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Keywords
Jian Liu, Mengyao Xu, Wenxiong Xi, Jiawen Song, Shibin Luo and Bengt Ake Sunden
Endwall film cooling protects vane endwall by coolant coverage, especially at the leading edge (LE) region and vane-pressure side (PS) junction region. Strong flow impingement and…
Abstract
Purpose
Endwall film cooling protects vane endwall by coolant coverage, especially at the leading edge (LE) region and vane-pressure side (PS) junction region. Strong flow impingement and complex vortexaa structures on the vane endwall cause difficulties for coolant flows to cover properly. This work aims at a full-scale arrangement of film cooling holes on the endwall which improves coolant efficiency in the LE region and vane-PS junction region.
Design/methodology/approach
The endwall film holes are grouped in four-holes constructal patterns. Three ways of arranging the groups are studied: based on the pressure field, the streamlines or the heat transfer field. The computational analysis is done with the k-ω SST model after validating the turbulence model properly.
Findings
By clustering the film cooling holes in four-holes patterns, the ejection of the coolant flow is stronger. The four-holes constructal patterns also improve the local coolant coverage in the “tough” regions, such as the junction region of the PS and the endwall. The arrangement based on streamlines distribution can effectively improve the coolant coverage and the arrangement based on the heat transfer distribution (HTD) has benefits by reducing high-temperature regions on the endwall.
Originality/value
A full-scale endwall film cooling design is presented considering interactions of different film cooling holes. A comprehensive model validation and mesh independence study are provided. The cooling holes pattern on the endwall is designed as four-holes constructal patterns combined with several arrangement choices, i.e. by pressure, by heat transfer and by streamline distributions.
Details
Keywords
Weihua Liu, Di Wang, Shangsong Long, Xinran Shen and Victor Shi
The purpose of this paper is to provide an overview of the evolution of service supply chain management from a behavioural operations perspective, pointing out future research…
Abstract
Purpose
The purpose of this paper is to provide an overview of the evolution of service supply chain management from a behavioural operations perspective, pointing out future research directions for scholars.
Design/methodology/approach
This study searched five databases for relevant literature published between 2009 and 2018, selecting 64 papers for this review. The selected literature was categorised according to two dimensions: a service supply chain link perspective and a behavioural factor perspective. Comparative analysis was used to identify gaps in the literature, and five future research agendas were proposed.
Findings
In terms of the perspective of service supply chain link, extant literature primarily focuses on service supply and service co-ordination management, and less on service demand and integration management. In terms of the behavioural factor’s perspective, most focus on classic behaviour factors, with less attention paid to emerging behaviour factors. This paper thus proposes five research agendas: demand-oriented management and integrated supply chain-oriented behavioural research; broadening the understanding of the scope of behavioural operations; integrating the latest backgrounds and trends of service industry into the research; greater attention to behavioural operations in service sub-industries; and multimethod combination is encouraged to be used to dig into the interesting research problems.
Originality/value
This study constitutes the first systematic review of service supply chain research from a behavioural perspective. By categorising the literature into two dimensions, the state of existing research is evaluated with an eye towards future research avenues.
Details
Keywords
Yuhan Liu, Linhong Wang, Ziling Zeng and Yiming Bie
The purpose of this study is to develop an optimization method for charging plans with the implementation of time-of-day (TOD) electricity tariff, to reduce electricity bill.
Abstract
Purpose
The purpose of this study is to develop an optimization method for charging plans with the implementation of time-of-day (TOD) electricity tariff, to reduce electricity bill.
Design/methodology/approach
Two optimization models for charging plans respectively with fixed and stochastic trip travel times are developed, to minimize the electricity costs of daily operation of an electric bus. The charging time is taken as the optimization variable. The TOD electricity tariff is considered, and the energy consumption model is developed based on real operation data. An optimal charging plan provides charging times at bus idle times in operation hours during the whole day (charging time is 0 if the bus is not get charged at idle time) which ensure the regular operation of every trip served by this bus.
Findings
The electricity costs of the bus route can be reduced by applying the optimal charging plans.
Originality/value
This paper produces a viable option for transit agencies to reduce their operation costs.
Details
Keywords
Claudia Aguirre, Salvador Ruiz de Maya, Mariola Palazón Vidal and Augusto Rodríguez
This study aims to analyze consumer motivations to share information about corporate social responsibility (CSR) activities through electronic word of mouth. It examines the roles…
Abstract
Purpose
This study aims to analyze consumer motivations to share information about corporate social responsibility (CSR) activities through electronic word of mouth. It examines the roles of self-enhancement, identity signaling and social bonding as antecedents of consumers’ CSR engagement on social media.
Design/methodology/approach
A quantitative approach is used with a single-factor between-subjects experimental design in which the presence vs absence of CSR information on a company website is manipulated. The hypotheses are tested through structural equation modeling.
Findings
Results show that after viewing the company’s CSR message on its website, consumers who generated more CSR associations were more motivated to engage with the CSR information to satisfy fundamental personality traits (need for self-enhancement) and social relationship motivations (social bonding), which increased their intention to share the information.
Research limitations/implications
This study is restricted to CSR information on websites. Further research should consider what happens if such information is shared on social media, as consumers are more likely to spread CSR messages when they are shared by other public social network sites.
Practical implications
The study highlights the relevance of including CSR information on websites and offers insights into the importance of considering consumers in disseminating CSR information. Consumers share information when they have personal motivation for doing so.
Social implications
This study put the focus on the role of consumers in the diffusion of corporate information.
Originality/value
The results show the importance of personal motivations such as self-enhancement and social bonding in sharing CSR information on social media.
Propósito
El estudio analiza las motivaciones que tiene el consumidor para compartir información sobre acciones de responsabilidad social corporativa (RSC) a través de boca oído electrónico (eWOM). En particular, las motivaciones de mejora del auto-concepto, necesidad de mostrar una identidad deseada y la vinculación social.
Metodología
Se utiliza un diseño experimental entre sujetos donde se manipuló la presencia vs ausencia de información sobre la RSC de la empresa. Las hipótesis se contrastaron mediante un modelo de ecuaciones estructurales.
Resultados
Los resultados muestran que los consumidores con más asociaciones de RSC comparten más la información de RSC motivados por satisfacer la mejora del auto-concepto y vinculación social.
Implicaciones prácticas
El estudio destaca la importancia de generar contenido de RSC en el sitio web de la empresa, y la importancia de los consumidores en la difusión de información de dicha información.
Limitaciones
El estudio está restringido a la presencia de información de RSC en el sitio web de la empresa. Sería interesante evaluar lo que sucede si dicha información se comparte en redes sociales, en la medida en que los consumidores tienen mayor tendencia a compartir la información procedente de redes sociales.
Originalidad
Los resultados muestran la importancia de las motivaciones personales como la mejora del auto-concepto y la vinculación social a la hora compartir información de RSC en las redes sociales.
目的
本研究分析了消费者通过电子口碑分享企业社会责任(CSR)活动信息的动机。它研究了自我提升、身份信号和社会联系作为消费者在社交媒体上参与企业社会责任的前因的作用。
方法
采用单因素主体间实验设计的定量方法, 对公司网站上企业社会责任信息的存在与否进行操纵。假设通过使用R软件包lavaan的结构方程模型进行检验。
研究结果
结果显示, 在观看公司网站上的企业社会责任信息后, 产生更多企业社会责任联想的消费者更有动力参与到企业社会责任信息中, 以满足基本的人格特征(自我提升的需要)和社会关系动机(社会纽带), 这增加了他们分享信息的意向。
实践意义
该研究强调了将企业社会责任信息纳入网站的相关性, 并对在传播企业社会责任信息时考虑消费者的重要性提出了见解。消费者在有个人动机的情况下会分享信息。
研究局限性
本研究仅限于网站上的企业社会责任信息。进一步的研究应该考虑到社交媒体, 因为当消费者在其他公共社交网站上分享企业社会责任信息时, 他们更有可能进行传播。
原创性
研究结果表明, 在社交媒体上分享企业社会责任信息时, 自我提升和社会联系等个人动机的重要性。
Details
Keywords
- Corporate social responsibility
- CSR communication
- CSR engagement
- Self-enhancement
- Identity signaling
- Social bonding
- Responsabilidad social corporativa
- Comunicación de la RSC
- Asociaciones de RSC
- Compromiso con la RSC
- Mejora del auto-concepto
- Mostrar una identidad deseada
- Vinculación social
- 企业社会责任
- 企业社会责任传播
- 企业社会责任参与
- 自我提升
- 身份信号
- 社会纽带