Hao Li, Peng Hai Geng and Hao Lin
The normal operation of a rotor system is generally vulnerable to misalignment between gas foil bearing (GFB) and rotor. However, most theoretical and experimental researches…
Abstract
Purpose
The normal operation of a rotor system is generally vulnerable to misalignment between gas foil bearing (GFB) and rotor. However, most theoretical and experimental researches about the characteristics of GFBs have ignored this phenomenon. Therefore, the main purpose of this paper is to evaluate the static and dynamic performance of GFBs considering misalignment.
Design/methodology/approach
The shaft is allowed to misalign in two directions. Then the variations of bearing load, friction force, restoring moment, stiffness and damping coefficients are thoroughly explored. The hydrodynamic pressure on the gas film is modeled with compressible Reynolds equation, and the deformation of the flexible bearing is calculated with finite element method. Small perturbation method is used to obtain the displacement and moment dynamic coefficients.
Findings
The film thickness and pressure distribution distort when misalignments appear. The inclination of GFBs can enhance the restoring moment to withstand the imposed misalignment. Furthermore, the simulation phenomenon demonstrates the misalignment around load direction should be avoided as much as possible, while a small value misalignment around another direction is allowed.
Originality/value
The value of this paper is the exploration of the influence of misalignments on the static and dynamic performance of the Generation II journal GFB.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0418/
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Daniel Amos, Zairul Nisham Musa and Cheong Peng Au-Yong
The purpose of this paper is to explore and establish key performance indicators that could be considered towards improving the delivery of waste management (WM) services in…
Abstract
Purpose
The purpose of this paper is to explore and establish key performance indicators that could be considered towards improving the delivery of waste management (WM) services in public hospitals.
Design/methodology/approach
An exploratory sequential mixed-methods approach was adopted for this study. This involved two phases of data collection and analysis. Specifically, interviews in selected case studies hospitals and a general questionnaire survey. Partial least squares structural equation modelling was used to model the relationships among the performance variables. An expanded balanced scorecard typology was used to categorize performance variables.
Findings
The results demonstrate that quality and internal business strategic indicators have a significant influence on WM performance. By implication, public hospital managers would be well advised to invest resources in improving internal business operations, learning and growths, as well as prioritizing finance in the process of managing healthcare waste.
Practical implications
The developed WM structural model can be used to identify performance indicators that can be incorporated into public hospitals’ WM strategy to improve performance leading to a decent healthcare environment.
Originality/value
The majority of studies have centered on the knowledge and practices of healthcare WM. This study extends the knowledge of healthcare WM literature from the perspective of FM performance measurement. The developed model of the study is invaluable to many developing countries that are faced with the challenge of improving WM practices.
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Zheng Xu, Yihai Fang, Nan Zheng and Hai L. Vu
With the aid of naturalistic simulations, this paper aims to investigate human behavior during manual and autonomous driving modes in complex scenarios.
Abstract
Purpose
With the aid of naturalistic simulations, this paper aims to investigate human behavior during manual and autonomous driving modes in complex scenarios.
Design/methodology/approach
The simulation environment is established by integrating virtual reality interface with a micro-simulation model. In the simulation, the vehicle autonomy is developed by a framework that integrates artificial neural networks and genetic algorithms. Human-subject experiments are carried, and participants are asked to virtually sit in the developed autonomous vehicle (AV) that allows for both human driving and autopilot functions within a mixed traffic environment.
Findings
Not surprisingly, the inconsistency is identified between two driving modes, in which the AV’s driving maneuver causes the cognitive bias and makes participants feel unsafe. Even though only a shallow portion of the cases that the AV ended up with an accident during the testing stage, participants still frequently intervened during the AV operation. On a similar note, even though the statistical results reflect that the AV drives under perceived high-risk conditions, rarely an actual crash can happen. This suggests that the classic safety surrogate measurement, e.g. time-to-collision, may require adjustment for the mixed traffic flow.
Research limitations/implications
Understanding the behavior of AVs and the behavioral difference between AVs and human drivers are important, where the developed platform is only the first effort to identify the critical scenarios where the AVs might fail to react.
Practical implications
This paper attempts to fill the existing research gap in preparing close-to-reality tools for AV experience and further understanding human behavior during high-level autonomous driving.
Social implications
This work aims to systematically analyze the inconsistency in driving patterns between manual and autopilot modes in various driving scenarios (i.e. multiple scenes and various traffic conditions) to facilitate user acceptance of AV technology.
Originality/value
A close-to-reality tool for AV experience and AV-related behavioral study. A systematic analysis in relation to the inconsistency in driving patterns between manual and autonomous driving. A foundation for identifying the critical scenarios where the AVs might fail to react.
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Seyed Abbas Rajaei, Afshin Mottaghi, Hussein Elhaei Sahar and Behnaz Bahadori
This study aims to investigate the spatial distribution of housing prices and identify the affecting factors (independent variable) on the cost of residential units (dependent…
Abstract
Purpose
This study aims to investigate the spatial distribution of housing prices and identify the affecting factors (independent variable) on the cost of residential units (dependent variable).
Design/methodology/approach
The method of the present study is descriptive-analytical and has an applied purpose. The used statistical population in this study is the residential units’ price in Tehran in 2021. For this purpose, the average per square meter of residential units in the city neighborhoods was entered in the geographical information system. Two techniques of ordinary least squares regression and geographically weighted regression have been used to analyze housing prices and modeling. Then, the results of the ordinary least squares regression and geographically weighted regression models were compared by using the housing price interpolation map predicted in each model and the accurate housing price interpolation map.
Findings
Based on the results, the ordinary least squares regression model has poorly modeled housing prices in the study area. The results of the geographically weighted regression model show that the variables (access rate to sports fields, distance from gas station and water station) have a direct and significant effect. Still, the variable (distance from fault) has a non-significant impact on increasing housing prices at a city level. In addition, to identify the affecting variables of housing prices, the results confirm the desirability of the geographically weighted regression technique in terms of accuracy compared to the ordinary least squares regression technique in explaining housing prices. The results of this study indicate that the housing prices in Tehran are affected by the access level to urban services and facilities.
Originality/value
Identifying factors affecting housing prices helps create sustainable housing in Tehran. Building sustainable housing represents spending less energy during the construction process together with the utilization phase, which ultimately provides housing at an acceptable price for all income deciles. In housing construction, the more you consider the sustainable housing principles, the more sustainable housing you provide and you take a step toward sustainable development. Therefore, sustainable housing is an important planning factor for local authorities and developers. As a result, it is necessary to institutionalize an integrated vision based on the concepts of sustainable development in the field of housing in the Tehran metropolis.
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This study longitudinally investigated the predictors and mediators of adolescent smartphone addiction by examining the impact of parental smartphone addiction at T1 on adolescent…
Abstract
Purpose
This study longitudinally investigated the predictors and mediators of adolescent smartphone addiction by examining the impact of parental smartphone addiction at T1 on adolescent smartphone addiction at T3, as well as the separate and sequential role of adolescent self-esteem and depression at T2 as mediating factors.
Design/methodology/approach
This study used a hierarchical regression and the PROCESS macro (Model 6) to investigate research model by collecting 3,904 parent-adolescent pairs. Panel data were collected from three waves of the Korean Children and Youth Panel Survey (KCYPS).
Findings
First, the result showed that parental smartphone addiction at T1 significantly and positively predicted adolescent smartphone addiction at T3. Second, the serial mediation analysis revealed that the impact of parental smartphone addiction at T1 on adolescent smartphone addiction at T3 was mediated by adolescent self-esteem and depression at T2 independently and serially.
Originality/value
The findings enhance our comprehension of the impact of parental smartphone addiction, adolescent self-esteem and depression, on adolescent smartphone addiction.
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Katarzyna Piwowar-Sulej and Qaisar Iqbal
Drawing on social exchange and social comparison theories, the current work aims to examine the direct and indirect effect of sustainable leadership (SL) on employees’…
Abstract
Purpose
Drawing on social exchange and social comparison theories, the current work aims to examine the direct and indirect effect of sustainable leadership (SL) on employees’ change-oriented organizational citizenship behavior (OCB) through workplace envy (WE).
Design/methodology/approach
The authors collected data from multiple sources (311 employees and respective supervisors) of small and medium-sized enterprises (SMEs) in Saudi Arabia. Partial least square-structural equation modeling (PLS-SEM) analysis was conducted to verify the proposed hypotheses.
Findings
The current empirical results confirmed that SL positively influences change-oriented OCB – both directly and indirectly (through WE). The negative impact of WE on change-oriented OCB is also concluded in this study.
Originality/value
To the best of authors’ knowledge, this is among pioneer studies which introduced inhibitor as a mediator in the “SL-employee behavioral outcomes” relationship. Limitations and implications have been elaborated at the end of the study.
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Yang Li, Zhicheng Zheng, Yaochen Qin, Haifeng Tian, Zhixiang Xie and Peijun Rong
Drought is the primary disaster that negatively impacts agricultural and animal husbandry production. It can lead to crop reduction and even pose a threat to human survival in…
Abstract
Purpose
Drought is the primary disaster that negatively impacts agricultural and animal husbandry production. It can lead to crop reduction and even pose a threat to human survival in environmentally sensitive areas of China (ESAC). However, the phases and periodicity of drought changes in the ESAC remain largely unknown. Thus, this paper aims to identify the periodic characteristics of meteorological drought changes.
Design/methodology/approach
The potential evapotranspiration was calculated using the Penman–Monteith formula recommended by the Food and Agriculture Organization of the United Nations, whereas the standardized precipitation evaporation index (SPEI) of drought was simulated by coupling precipitation data. Subsequently, the Bernaola-Galvan segmentation algorithm was proposed to divide the periods of drought change and the newly developed extreme-point symmetric mode decomposition to analyze the periodic drought patterns.
Findings
The findings reveal a significant increase in SPEI in the ESAC, with the rate of decline in drought events higher in the ESAC than in China, indicating a more pronounced wetting trend in the study area. Spatially, the northeast region showed an evident drying trend, whereas the southwest region showed a wetting trend. Two abrupt changes in the drought pattern were observed during the study period, namely, in 1965 and 1983. The spatial instability of moderate or severe drought frequency and intensity on a seasonal scale was more consistent during 1966–1983 and 1984–2018, compared to 1961–1965. Drought variation was predominantly influenced by interannual oscillations, with the periods of the components of intrinsic mode functions 1 (IMF1) and 2 (IMF2) being 3.1 and 7.3 years, respectively. Their cumulative variance contribution rate reached 70.22%.
Research limitations/implications
The trend decomposition and periods of droughts in the study area were analyzed, which may provide an important scientific reference for water resource management and agricultural production activities in the ESAC. However, several problems remain unaddressed. First, the SPEI considers only precipitation and evapotranspiration, making it extremely sensitive to temperature increases. It also ignores the nonstationary nature of the hydrometeorological water process; therefore, it is prone to bias in drought detection and may overestimate the intensity and duration of droughts. Therefore, further studies on the application and comparison of various drought indices should be conducted to develop a more effective meteorological drought index. Second, the local water budget is mainly affected by surface evapotranspiration and precipitation. Evapotranspiration is calculated by various methods that provide different results. Therefore, future studies need to explore both the advantages and disadvantages of various evapotranspiration calculation methods (e.g. Hargreaves, Thornthwaite and Penman–Monteith) and their application scenarios. Third, this study focused on the temporal and spatial evolution and periodic characteristics of droughts, without considering the driving mechanisms behind them and their impact on the ecosystem. In future, it will be necessary to focus on a sensitivity analysis of drought indices with regard to climate change. Finally, although this study calculated the SPEI using meteorological data provided by China’s high-density observatory network, deviations and uncertainties were inevitable in the point-to-grid spatialization process. This shortcoming may be avoided by using satellite remote sensing data with high spatiotemporal resolution in the future, which can allow pixel-scale monitoring and simulation of meteorological drought evolution.
Practical implications
Under the background of continuous global warming, the climate in arid and semiarid areas of China has shown a trend of warming and wetting. It means that the plant environment in this region is getting better. In the future, the project of afforestation and returning farmland to forest and grassland in this region can increase the planting proportion of water-loving tree species to obtain better ecological benefits. Meanwhile, this study found that in the relatively water-scarce regions of China, drought duration was dominated by interannual oscillations (3.1a and 7.3a). This suggests that governments and nongovernmental organizations in the region should pay attention to the short drought period in the ESAC when they carry out ecological restoration and protection projects such as the construction of forest reserves and high-quality farmland.
Originality/value
The findings enhance the understanding of the phasic and periodic characteristics of drought changes in the ESAC. Future studies on the stress effects of drought on crop yield may consider these effects to better reflect the agricultural response to meteorological drought and thus effectively improve the tolerance of agricultural activities to drought events.
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Kedong Yin, Yun Cao, Shiwei Zhou and Xinman Lv
The purposes of this research are to study the theory and method of multi-attribute index system design and establish a set of systematic, standardized, scientific index systems…
Abstract
Purpose
The purposes of this research are to study the theory and method of multi-attribute index system design and establish a set of systematic, standardized, scientific index systems for the design optimization and inspection process. The research may form the basis for a rational, comprehensive evaluation and provide the most effective way of improving the quality of management decision-making. It is of practical significance to improve the rationality and reliability of the index system and provide standardized, scientific reference standards and theoretical guidance for the design and construction of the index system.
Design/methodology/approach
Using modern methods such as complex networks and machine learning, a system for the quality diagnosis of index data and the classification and stratification of index systems is designed. This guarantees the quality of the index data, realizes the scientific classification and stratification of the index system, reduces the subjectivity and randomness of the design of the index system, enhances its objectivity and rationality and lays a solid foundation for the optimal design of the index system.
Findings
Based on the ideas of statistics, system theory, machine learning and data mining, the focus in the present research is on “data quality diagnosis” and “index classification and stratification” and clarifying the classification standards and data quality characteristics of index data; a data-quality diagnosis system of “data review – data cleaning – data conversion – data inspection” is established. Using a decision tree, explanatory structural model, cluster analysis, K-means clustering and other methods, classification and hierarchical method system of indicators is designed to reduce the redundancy of indicator data and improve the quality of the data used. Finally, the scientific and standardized classification and hierarchical design of the index system can be realized.
Originality/value
The innovative contributions and research value of the paper are reflected in three aspects. First, a method system for index data quality diagnosis is designed, and multi-source data fusion technology is adopted to ensure the quality of multi-source, heterogeneous and mixed-frequency data of the index system. The second is to design a systematic quality-inspection process for missing data based on the systematic thinking of the whole and the individual. Aiming at the accuracy, reliability, and feasibility of the patched data, a quality-inspection method of patched data based on inversion thought and a unified representation method of data fusion based on a tensor model are proposed. The third is to use the modern method of unsupervised learning to classify and stratify the index system, which reduces the subjectivity and randomness of the design of the index system and enhances its objectivity and rationality.
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Qiang Wang, Hongliang Zhang, Da Quan Zhang, Hongai Zheng and Lixin Gao
The purpose of this paper is to study the effect of vapor assembly sequence and assembly temperature on the corrosion protection of the complex silane films Al alloy. The…
Abstract
Purpose
The purpose of this paper is to study the effect of vapor assembly sequence and assembly temperature on the corrosion protection of the complex silane films Al alloy. The performance and application range of silane films are enhanced.
Design/methodology/approach
The complex silane films were successfully prepared on the surface of aluminum alloy using via vapor phase assembly of 1,2,3-benzotriazole (BTA) and dodecyltrimethoxysilanes (DTMS). The protection of the assembly films against corrosion of Al alloy is investigated by the electrochemical measurements and the alkaline solution accelerated corrosion test. Thickness and hydrophobicity of the complex films are studied using ellipsometric spectroscopy and contact angle tests.
Findings
It shows that the anti-corrosion ability of the complex films is overall superior to that of the single-component assembled films. DTMS-BTA films have larger thickness and best anti-corrosion ability. The alkyl chains in DTMS have better compatibility with BTA molecules. The rigid BTA molecule can permeate into the long alkyl chain of DTMS as fillers and improve the barrier properties of the complex films.
Originality/value
In this paper, a green and efficient method of vapor phase assembly is proposed to rust prevention during manufacture of Al alloy workpiece.
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This study motivated by humanistic care aims to identify hospitality frontline employees’ alienation in Taiwan during the COVID-19 pandemic, and based on the job demands-resources…
Abstract
Purpose
This study motivated by humanistic care aims to identify hospitality frontline employees’ alienation in Taiwan during the COVID-19 pandemic, and based on the job demands-resources (JD-R) model, the mediating role of alienation between job characteristics and organizational citizenship behavior (OCB) is discussed.
Design/methodology/approach
The authors drew on the JD-R model to delineate the mechanisms by which job demands (including emotional dissonance and work–home conflict) and job resources (including job support, training and possibility for career development) affect OCB through employees’ alienation. This study adopted snowball sampling and purposive sampling to conduct a questionnaire survey aimed at Taiwanese hospitality frontline employees. A total of 373 valid questionnaires were retained, and structural equation model was used to test the research hypotheses.
Findings
The results revealed that job demands of emotional dissonance and work–family conflict positively affect alienation; job resources of job support, training and possibility for career development negatively affect alienation; alienation negatively affects OCB; and alienation mediates the relationship between job characteristics and OCB fully.
Research limitations/implications
Considering that alienation plays a full mediating role between job characteristics and organizational outcomes, this study put forward specific suggestions on how to increase job resources and reduce job demands to weaken alienation and further improve organizational performance in management practices. And practical implications were provided to help hospitality human resource management deal with the issue of talents retention. In addition, “work authenticity” should be introduced as a mediator in the future research. “Work authenticity” reflects employees’ positive working life state and is the opposite of “alienation.” The effectiveness of employees’ positive and negative working life state in communicating job characteristics and organizational outcomes can be compared.
Originality/value
The specific alienation experience of hospitality frontline employees is defined. Moreover, by introducing the alienation theory, this study demonstrates the health impairment path of JD-R model and suggests that job characteristics affect OCB through the full mediation of alienation.
研究目的
本研究以人文关怀为动机, 明确了COVID-19疫情期间台湾酒店一线员工的异化状态, 并基于工作需求-资源理论模型, 探讨了异化在工作特性与组织公民行为之间发挥的中介作用。
研究设计/研究方法/研究路径
笔者运用工作需求-资源模型以阐释工作需求(包括情绪失调和工作-家庭冲突)和工作资源(包括工作支持、培训和职业发展潜能)透过员工的异化影响组织公民行为的机制。本研究采用滚雪球抽样和目的性抽样的抽样方式, 对台湾酒店一线员工开展问卷调查; 留存有效问卷373份, 并采用结构方程模型对研究假设进行检验。
研究发现
本研究揭示了情绪失调和工作-家庭冲突的工作需求正向影响异化; 工作支持、培训和职业发展潜能的工作资源对异化产生负面影响; 异化对组织公民行为产生负面影响; 异化在工作特性与组织公民行为的关系中起完全中介作用。
研究限制∕意涵
综合异化在工作特性与组织成果之间起着完全的中介作用, 本研究就管理实践中如何增加工作资源和减少工作需求以减弱异化并进一步提高组织绩效提出了具体建议, 以此帮助酒店人力资源管理部门处理留住人才的问题。此外, 应引入反映员工积极工作状态的“工作真实性”(即“异化”的对立面)作为中介, 比较员工积极和消极工作状态在沟通工作特性和组织成果上的有效性。
原创性
本研究明确了酒店一线员工具体的异化体验。此外, 透过引入异化理论, 本研究实证了工作需求-资源模型的健康损害路径, 并揭示了工作特性通过异化的完全中介作用影响组织公民行为。
Objetivoo
Este estudio motivado por la atención humanística identificó la alienación de los empleados de primera línea de la hostelería en Taiwán durante la pandemia de COVID-19 y, basándose en el modelo de exigencias laborales-recursos (JD-R), se analizó el papel mediador de la alienación entre las características laborales y el comportamiento de ciudadanía organizacional fue discutido.
Diseño/metodología/enfoque
Nos basamos en el modelo JD-R para delinear los mecanismos por los que las exigencias del puesto de trabajo (incluida la disonancia emocional y el conflicto entre el trabajo y el hogar) y los recursos del puesto de trabajo (incluido el apoyo laboral, la formación y la posibilidad de desarrollo profesional) afectan a la organización. Del comportamiento ciudadano (OCB) a través de la alienación de los empleados. Este estudio adoptó el muestreo de bola de nieve y el muestreo intencional para realizar una encuesta por cuestionario dirigida a los empleados de primera línea de la hostelería taiwanesa. Se obtuvieron 373 cuestionarios válidos y se utilizó un modelo de ecuaciones estructurales para probar las hipótesis de la investigación.
Resultados
Los resultados revelaron que las demandas laborales de disonancia emocional y conflicto trabajo-familia afectan positivamente a la alienación; los recursos laborales de apoyo al trabajo, formación y posibilidad de desarrollo profesional afectan negativamente a la alienación; la alienación afecta negativamente al comportamiento de ciudadanía organizacional; la alienación media totalmente la relación entre las características laborales y el comportamiento de ciudadanía organizacional.
Limitaciones/implicaciones de la investigación
Teniendo en cuenta que la alienación desempeña un papel mediador total entre las características del puesto de trabajo y los resultados organizativos, este estudio presentó sugerencias específicas sobre cómo aumentar los recursos del puesto de trabajo y reducir las exigencias del mismo para debilitar la alienación y mejorar aún más el desempeño organizacional en las prácticas de gestión. Y se aportaron implicaciones prácticas para ayudar a abordar la cuestión de retención de talentos en la gestión de los recursos humanos en la hostelería. Además, la “autenticidad del trabajo” debería introducirse como mediador en la investigación futura. La “autenticidad laboral” refleja el estado de vida laboral positivo de los empleados y es lo contrario de la “alienación”. Se puede comparar la eficacia del estado de vida laboral positivo y negativo de los empleados en la comunicación de las características del trabajo y los resultados organizacionales.
Originalidad/valor
Se define la experiencia específica de alienación de los empleados de primera línea de la hostelería. Además, mediante la introducción de la teoría de la alienación, este estudio demuestra la trayectoria de deterioro de la salud del modelo JD-R, y sugiere que las características del puesto de trabajo afectan al comportamiento de ciudadanía organizacional a través de la mediación total de la alienación.