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1 – 10 of 103Chongyi Chang, Yuanwu Cai, Bo Chen, Qiuze Li and Pengfei Lin
In service, the periodic clashes of wheel flat against the rail result in large wheel/rail impact force and high-frequency vibration, leading to severe damage on the wheelset…
Abstract
Purpose
In service, the periodic clashes of wheel flat against the rail result in large wheel/rail impact force and high-frequency vibration, leading to severe damage on the wheelset, rail and track structure. This study aims to analyze characteristics and dynamic impact law of wheel and rail caused by wheel flat of high-speed trains.
Design/methodology/approach
A full-scale high-speed wheel/rail interface test rig was used for the test of the dynamic impact of wheel/rail caused by wheel flat of high-speed train. With wheel flats of different lengths, widths and depths manually set around the rolling circle of the wheel tread, and wheel/rail dynamic impact tests to the flats in the speed range of 0–400 km/h on the rig were conducted.
Findings
As the speed goes up, the flat induced the maximum of the wheel/rail dynamic impact force increases rapidly before it reaches its limit at the speed of around 35 km/h. It then goes down gradually as the speed continues to grow. The impact of flat wheel on rail leads to 100–500 Hz middle-frequency vibration, and around 2,000 Hz and 6,000 Hz high-frequency vibration. In case of any wheel flat found during operation, the train speed shall be controlled according to the status of the flat and avoid the running speed of 20 km/h–80 km/h as much as possible.
Originality/value
The research can provide a new method to obtain the dynamic impact of wheel/rail caused by wheel flat by a full-scale high-speed wheel/rail interface test rig. The relations among the flat size, the running speed and the dynamic impact are hopefully of reference to the building of speed limits for HSR wheel flat of different degrees.
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Xuemei Li, Shiwei Zhou, Kedong Yin and Huichao Liu
The purpose of this paper is to measure the high-quality development level of China's marine economy and analyze corresponding spatial and temporal distribution characteristic.
Abstract
Purpose
The purpose of this paper is to measure the high-quality development level of China's marine economy and analyze corresponding spatial and temporal distribution characteristic.
Design/methodology/approach
Design and optimize the index system of high-quality development level of marine economy and use entropy and TOPSIS method for comprehensive evaluation.
Findings
The research finds that from 2017 to 2019, the high-quality development tendency of China's marine economy is on the rise, but the overall level is still low. The level of each subsystem has different distribution characteristics in different provinces and cities. Guangdong, Shandong and Shanghai have a high comprehensive level. According to the comprehensive level of high-quality development of marine economy, 11 coastal provinces are divided into three types: leading, general and backward.
Research limitations/implications
This paper clarifies the temporal and spatial distribution law of high-quality development level of China's marine economy, providing basis for promoting comprehensive and coordinated improvement of coastal provinces and cities.
Originality/value
An indicator system for the high-quality development level of the marine economy has been established, including social development guarantee, marine economic foundation, marine science and technology drive and green marine sustainability.
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Liyao Song, Bai Chen, Bo Li, Rupeng Zhu and Dan Wang
The supercritical design of tail rotor drive shaft has attracted more attention in helicopter design due to its high power–weight ratio and low maintenance cost. However, there…
Abstract
Purpose
The supercritical design of tail rotor drive shaft has attracted more attention in helicopter design due to its high power–weight ratio and low maintenance cost. However, there exists excessive vibration when the shaft passes through the critical frequency. Dry friction damper is the equipment applied to the drive shaft to suppress the excessive vibration. In order to figure out the damping mechanism of the dry friction damper and improve the damping efficiency, the dynamic model of the shaft/damper system is established based on the Jeffcott rotor model.
Design/methodology/approach
The typical frequency response of the system is studied through bifurcation diagrams, amplitude-frequency characteristic curves and waterfall frequency response spectrum. The typical transient responses under frequency sweeps are also obtained.
Findings
The results show that the response of the system changes from periodic no-rub motion to quasi-periodic rub-impact motion, and then to synchronous full annular rub-impact, and finally, back to periodic no-rub motion. The slip of the rub-impact ring improves the stability of the system. Besides, the effects of the system parameters including critical dry friction force, rub-impact friction coefficient, initial clearance on the stability and the vibration damping capacity are studied. It is observed that the stability changes significantly varying the three parameters respectively. The vibration damping capacity is mainly affected by the critical dry friction force and the initial clearance.
Originality/value
Presented results provide guidance for the design of the dry friction damper.
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Mauro Dini, Ilaria Curina, Barbara Francioni, Sabrina Hegner and Marco Cioppi
The study aims to analyze the relationship between tourists' satisfaction and their sense of belonging in a specific cultural destination by also investigating the moderating role…
Abstract
Purpose
The study aims to analyze the relationship between tourists' satisfaction and their sense of belonging in a specific cultural destination by also investigating the moderating role of their on-site involvement, both offline (on-site activities at the destination) and online (social media activities). A further objective lies in exploring the relationship between tourists' sense of belonging and their adoption of environmentally responsible behavior while at the destination. Finally, the paper attempts to determine whether said behavior can predict tourists' pro-environmental behavior and recommendation intention.
Design/methodology/approach
To reach these objectives, a survey and a structural equation model, based on a sample of 647 visitors of an important world Heritage site UNESCO (i.e. Urbino), have been adopted.
Findings
Findings reveal a positive influence of sense of belonging on satisfaction and environmentally responsible behavior, which, in turn, influences pro-environmental behavior and Recommendation intention, thus triggering a virtuous process in the tourists' formation as responsible and loyal travelers. Moreover, results underline how the relationship between satisfaction and sense of belonging is significantly strengthened when tourists' on-site activity involvement increases. Conversely, the moderating role of social media involvement is not supported.
Practical implications
The present study offers important implications for different actors in the tourism sector, such as policy makers, destination marketing organizations (DMOs) and tourism operators.
Social implications
The present study explores the role of social media involvement, specifically during the tourist's holiday.
Originality/value
This study enriches the empirical evidence in the cultural tourism through an analysis focused on the tourists' perspective, especially by investigating the relationship between satisfaction and emotional constructs (i.e. sense of belonging) that are able to bring environmental and loyalty benefits to the destination. Moreover, although existing research has highlighted the positive influence of the tourists' involvement on their experience, there is a paucity of studies jointly analyzing the on-site and online activities in the sustainability field.
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Mauro Dini and Tonino Pencarelli
The purpose of this paper is to conceptually examine the phenomenon of wellness tourism under a holistic and systemic lens, focusing on the offer system and the main components…
Abstract
Purpose
The purpose of this paper is to conceptually examine the phenomenon of wellness tourism under a holistic and systemic lens, focusing on the offer system and the main components necessary for the staging of wellness experiences. This approach to holistic wellbeing within the tourism sector has led to a broadening of the type of services and experiences that make up the value propositions that can positively contribute to people’s wellbeing.
Design/methodology/approach
This study identifies and defines the components of wellness tourism (including sectors not traditionally associated with it) through a review and analysis of the extant literature on “wellness tourism” and “wellbeing tourism” of the past two decades; the components were classified through an open coding process.
Findings
Wellness tourism, as a broad multidimensional concept, is composed by ten different components of the offer system: hot springs, spas, medical tourism, care of the body and mind, enogastronomy, sports, nature and environment, culture, spirituality and events. Each of these categories may represent a single touristic offer targeted to specific market segments, but they may also be one of several components within an integrated mix of tourism products proposed.
Originality/value
A holistic view of wellness tourism has implications for strategic marketing processes. Destination Management Organizations and company managers should segment their demand according to more innovative criteria than what has traditionally been adopted for wellness in terms of health care and medical procedures. Value propositions for tourists should be wellness-driven to satisfy the growing demand for wellness/well-being and should involve the participation of all the various actors and producers within the wellness tourism offer system at wellness destinations.
康养旅游及其组成元素:一个全方位的视角
目的
此一论文会以全面和有系统的目光, 谈及康养旅游的现象, 并集中于康养旅游的供应系统和主要组成元素。此一以全面身心健康为目的的旅游行业, 使不同服务的覆盖范围和经验得以扩而充之, 提供有利条件正面地影响着人们的身心健康。
研究方法
本研究会分辨和定义康养旅游的组成元素(以及其他在传统定义上被排除的行业), 透过重新审视和分析近20年有关于康养旅游(Wellness tourism)和健康旅游(Wellbeing tourism)的现存文献。同时, 所有元素会以开放式译码 (open coding)来分类。
成果
康养旅游, 作为一个多元概念, 基本上与十个不同的供应行业相关:温泉, 水療, 医疗旅游, 身心护理, 饮食, 运动, 自然环境, 文化, 灵修和特办活动。不同类别的行业可以在代表市场上不同供需关系的同时, 也可以代表供应上可以有一种混合套餐供应。
研究建议
以全面的目光去看康养旅游可以为市场策略定下基础。目的地管理公司(DMO)和不同的公司经理应该在分辨服务需求的时候, 多采用新颖的标准, 摒弃只包括医疗的传统健康观念。为游客订立的价值主张(Value propositions)应以全面身心健康为主导, 以满足对康养(Wellness)和健康(Wellbeing)不断上升的需求; 亦应大力度地提升所有安康旅游工作人员与顾客的互动和参与。
El turismo de bienestar y los componentes de su sistema de oferta: una perspectiva holística
Propósito
Este artículo examina conceptualmente el fenómeno del turismo de bienestar desde una perspectiva holística y sistémica, centrándose en el sistema de oferta y los principales componentes necesarios para la puesta en escena de experiencias de bienestar. Este enfoque de bienestar integral dentro del sector turístico ha propiciado una ampliación del tipo de servicios y experiencias que integran las propuestas de valor que pueden contribuir positivamente al bienestar de las personas.
Diseño/metodología/enfoque
Este estudio identifica y define los componentes del turismo de bienestar (incluidos los sectores no asociados tradicionalmente con él), a través de una revisión y análisis de la literatura existente sobre “turismo de bienestar” de las dos últimas décadas; los componentes se han clasificado mediante un proceso de codificación abierto.
Conclusiones
El turismo de bienestar está compuesto conceptualmente por diez componentes diferentes de ofertas: aguas termales, spas, turismo sanitario, cuidado de cuerpo y mente, enogastronomía, deportes, naturaleza y medio ambiente, cultura, espiritualidad y eventos. Cada una de estas categorías puede representar una única oferta turística para segmentos de mercado específicos, pero también pueden ser uno de los varios componentes de una combinación integrada de productos turísticos.
Originalidad/valor
Esta concepción holística del bienestar sugiere que, en el contexto de los procesos de marketing estratégico, las DMO y los gerentes de negocio deben segmentar la demanda con criterios innovadores respecto a los tradicionales de salud y médicos. Además, deben formular propuestas de turismo orientado al bienestar, valorizando los componentes de la oferta capaces de interceptar la creciente demanda de bienestar e implicando a los distintos productores del sistema de oferta de wellness que operan en los destinos de bienestar
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Xiaolin Sun, Jiawen Zhu, Huigang Liang, Yajiong Xue and Bo Yao
As after-hours technology-mediated work (ATW) becomes common in organizations, the increased workload and interference to life caused by ATW has induced employee turnover. This…
Abstract
Purpose
As after-hours technology-mediated work (ATW) becomes common in organizations, the increased workload and interference to life caused by ATW has induced employee turnover. This research develops a mediated moderation model to explain how employees' intrinsic and extrinsic motivations for ATW affect their turnover intention through work–life conflict.
Design/methodology/approach
A survey was conducted to collect data of 484 employees from Chinese companies. Partial Least Square was used to perform data analysis.
Findings
The results show that intrinsic motivation for ATW has an indirect negative impact on turnover intention via work–life conflict, whereas extrinsic motivation for ATW has both a positive direct impact and a positive indirect impact (via work–life conflict) on turnover intention. This study also helps find that time spent on ATW can strengthen the positive impact of extrinsic motivation for ATW on turnover intention but has no moderation effect on the impact of intrinsic motivation for ATW. Furthermore, this study reveals that the interaction effect of time spent on ATW and extrinsic motivation on turnover intention is mediated by employees' perceived work–life conflict.
Originality/value
By discovering the distinct impact of employees' intrinsic and extrinsic motivations for ATW on turnover intention, this research provides a contingent view regarding the impact of ATW and offers guidance to managers regarding how to mitigate ATW-induced turnover intention through fostering different motivations.
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V. Chowdary Boppana and Fahraz Ali
This paper presents an experimental investigation in establishing the relationship between FDM process parameters and tensile strength of polycarbonate (PC) samples using the…
Abstract
Purpose
This paper presents an experimental investigation in establishing the relationship between FDM process parameters and tensile strength of polycarbonate (PC) samples using the I-Optimal design.
Design/methodology/approach
I-optimal design methodology is used to plan the experiments by means of Minitab-17.1 software. Samples are manufactured using Stratsys FDM 400mc and tested as per ISO standards. Additionally, an artificial neural network model was developed and compared to the regression model in order to select an appropriate model for optimisation. Finally, the genetic algorithm (GA) solver is executed for improvement of tensile strength of FDM built PC components.
Findings
This study demonstrates that the selected process parameters (raster angle, raster to raster air gap, build orientation about Y axis and the number of contours) had significant effect on tensile strength with raster angle being the most influential factor. Increasing the build orientation about Y axis produced specimens with compact structures that resulted in improved fracture resistance.
Research limitations/implications
The fitted regression model has a p-value less than 0.05 which suggests that the model terms significantly represent the tensile strength of PC samples. Further, from the normal probability plot it was found that the residuals follow a straight line, thus the developed model provides adequate predictions. Furthermore, from the validation runs, a close agreement between the predicted and actual values was seen along the reference line which further supports satisfactory model predictions.
Practical implications
This study successfully investigated the effects of the selected process parameters - raster angle, raster to raster air gap, build orientation about Y axis and the number of contours - on tensile strength of PC samples utilising the I-optimal design and ANOVA. In addition, for prediction of the part strength, regression and ANN models were developed. The selected ANN model was optimised using the GA-solver for determination of optimal parameter settings.
Originality/value
The proposed ANN-GA approach is more appropriate to establish the non-linear relationship between the selected process parameters and tensile strength. Further, the proposed ANN-GA methodology can assist in manufacture of various industrial products with Nylon, polyethylene terephthalate glycol (PETG) and PET as new 3DP materials.
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Tiina Tuominen, Bo Edvardsson and Javier Reynoso
This study aims to understand and explain how institutional change occurs at the level of value co-creation practices in service ecosystems. Despite the centrality of collective…
Abstract
Purpose
This study aims to understand and explain how institutional change occurs at the level of value co-creation practices in service ecosystems. Despite the centrality of collective practices to the service ecosystems perspective, theoretically grounded explanations of how practices change and become institutionalized remain underdeveloped. Applying the theory of routine dynamics, this paper addresses two questions as follows: what does the institutional change mean at the level of value co-creation practices and what processes underlie these changes?
Design/methodology/approach
The study develops a conceptual framework that characterizes value co-creation practices as routines involving three aspects, namely, ostensive, performative and artifactual. As a key element in institutional change, the interplay between these informs an account of institutional change processes in service ecosystems.
Findings
The proposed conceptual framework specifies the conditions for institutional change in terms of value co-creation routines. First, any such change is seen to be grounded in alignment between changing institutional rules and the ostensive, performative and artifactual aspects of routines. Second, this alignment is seen to emerge through a dialectics of planned and practice-based activities during institutional change. An empirical research agenda is proposed for the analysis of institutional change processes in different service ecosystems.
Originality/value
This conceptual framework extends existing accounts of how service ecosystems change through the contributions of multiple actors at the level of value co-creation practices.
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Junru Zhang, Yumeng Liu and Bo Yan
This study aims to research the large cross-section tunnel stability evaluation method corrected after considering the thickness-span ratio.
Abstract
Purpose
This study aims to research the large cross-section tunnel stability evaluation method corrected after considering the thickness-span ratio.
Design/methodology/approach
First, taking the Liuyuan Tunnel of Huanggang-Huangmei High-Speed Railway as an example and taking deflection of the third principal stress of the surrounding rock at a vault after tunnel excavation as the criterion, the critical buried depth of the large section tunnel was determined. Then, the strength reduction method was employed to calculate the tunnel safety factor under different rock classes and thickness-span ratios, and mathematical statistics was conducted to identify the relationships of the tunnel safety factor with the thickness-span ratio and the basic quality (BQ) index of the rock for different rock classes. Finally, the influences of thickness-span ratio, groundwater, initial stress of rock and structural attitude factors were considered to obtain the corrected BQ, based on which the stability of a large cross-section tunnel with a depth of more than 100 m during mechanized operation was analyzed. This evaluation method was then applied to Liuyuan Tunnel and Cimushan No. 2 Tunnel of Chongqing Urban Expressway for verification.
Findings
This study shows that under different rock classes, the tunnel safety factor is a strict power function of the thickness-span ratio, while a linear function of the BQ to some extent. It is more suitable to use the corrected BQ as a quantitative index to evaluate tunnel stability according to the actual conditions of the site.
Originality/value
The existing industry standards do not consider the influence of buried depth and span in the evaluation of tunnel stability. The stability evaluation method of large section tunnel considering the correction of overburden span ratio proposed in this paper achieves higher accuracy for the stability evaluation of surrounding rock in a full or large-section mechanized excavation of double line high-speed railway tunnels.
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Siyao Li, Bo Yuan, Yun Bai and Jianfeng Liu
To address the problem that the current train operation mode that train selects one of several offline pre-generated control schemes before the departure and operates following…
Abstract
Purpose
To address the problem that the current train operation mode that train selects one of several offline pre-generated control schemes before the departure and operates following the scheme after the departure, energy-saving performance of the whole metro system cannot be guaranteed.
Design/methodology/approach
A cooperative train control framework is formulated to regulate a novel train operation mode. The classic train four-phase control strategy is improved for generating specific energy-efficient control schemes for each train. An improved brute force (BF) algorithm with a two-layer searching idea is designed to solve the optimisation model of energy-efficient train control schemes.
Findings
Case studies on the actual metro line in Guangzhou, China verify the effectiveness of the proposed train control methods compared with four-phase control strategy under different kinds of train operation scenarios and calculation parameters. The verification on the computation efficiency as well as accuracy of the proposed algorithm indicates that it meets the requirement of online optimisation.
Originality/value
Most existing studies optimised energy-efficient train timetable or train control strategies through an offline process, which has a defect in coping with the disturbance or delays effectively and promptly during real-time train operation. This paper studies an online optimisation of cooperative train control based on the rolling optimisation idea, where energy-efficient train operation can be realised once train running time is determined, thus mitigating the impact of unpredictable operation situations on the energy-saving performance of trains.
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