Qinjie Yang, Guozhe Shen, Chao Liu, Zheng Wang, Kai Zheng and Rencheng Zheng
Steer-by-wire (SBW) system mainly relies on sensors, controllers and motors to replace the traditionally mechanical transmission mechanism to realize steering functions. However…
Abstract
Purpose
Steer-by-wire (SBW) system mainly relies on sensors, controllers and motors to replace the traditionally mechanical transmission mechanism to realize steering functions. However, the sensors in the SBW system are particularly vulnerable to external influences, which can cause systemic faults, leading to poor steering performance and even system instability. Therefore, this paper aims to adopt a fault-tolerant control method to solve the safety problem of the SBW system caused by sensors failure.
Design/methodology/approach
This paper proposes an active fault-tolerant control framework to deal with sensors failure in the SBW system by hierarchically introducing fault observer, fault estimator, fault reconstructor. Firstly, the fault observer is used to obtain the observation output of the SBW system and then obtain the residual between the observation output and the SBW system output. And then judge whether the SBW system fails according to the residual. Secondly, dependent on the residual obtained by the fault observer, a fault estimator is designed using bounded real lemma and regional pole configuration to estimate the amplitude and time-varying characteristics of the faulty sensor. Eventually, a fault reconstructor is designed based on the estimation value of sensors fault obtained by the fault estimator and SBW system output to tolerate the faulty sensor.
Findings
The numerical analysis shows that the fault observer can be rapidly activated to detect the fault while the sensors fault occurs. Moreover, the estimation accuracy of the fault estimator can reach to 98%, and the fault reconstructor can make the faulty SBW system to retain the steering characteristics, comparing to those of the fault-free SBW system. In addition, it was verified for the feasibility and effectiveness of the proposed control framework.
Research limitations/implications
As the SBW fault diagnosis and fault-tolerant control in this paper only carry out numerical simulation research on sensors faults in matrix and laboratory/Simulink, the subsequent hardware in the loop test is needed for further verification.
Originality/value
Aiming at the SBW system with parameter perturbation and sensors failure, this paper proposes an active fault-tolerant control framework, which integrates fault observer, fault estimator and fault reconstructor so that the steering performance of SBW system with sensors faults is basically consistent with that of the fault-free SBW system.
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Ya-Fei Liu, Yu-Bo Zhu, Hou-Han Wu and Fangxuan (Sam) Li
This study aims to explore the differences in the tourists’ perceived destination image on travel e-commerce platforms (e.g. Ctrip and Fliggy) and social media platforms (e.g…
Abstract
Purpose
This study aims to explore the differences in the tourists’ perceived destination image on travel e-commerce platforms (e.g. Ctrip and Fliggy) and social media platforms (e.g. Xiaohongshu and Weibo).
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I. Martens, H. Verbeek, J. Aarts, W.P.H. Bosems, E. Felix and J. van Hoof
Over 8 per cent of the Dutch nursing home population is bedfast, and this number is slowly increasing. The quality of life (QoL) of this population is lower than that of residents…
Abstract
Purpose
Over 8 per cent of the Dutch nursing home population is bedfast, and this number is slowly increasing. The quality of life (QoL) of this population is lower than that of residents who are still mobile. Little research has been conducted on how to improve the QoL of this bedfast population, particularly through making technological adjustments to the bed and the direct surroundings. The purpose of this paper is to gain insight into the QoL of bedfast residents and how to improve this through technology.
Design/methodology/approach
A mixed-method multi-case study with thematic analysis was conducted in two nursing homes with seven participants based on semi-structured interviews and Short Form-12 questionnaire.
Findings
The major causes of the experienced low QoL were the limited opportunities for engaging in social contacts with others, and coping with the dependency on other people and having limited control. Participants suggested improvements of QoL through the application of modern communication technologies to engage in social contacts and to control the bed itself and environment around the bed.
Practical implications
The results may help improve the design of the bed and the direct environment in order to improve the QoL of bedfast nursing home residents.
Originality/value
The QoL of bedfast nursing home residents has not been studied before in relation to the bed itself and technological solutions that may help improve the QoL and level of control.
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Feng-Ming Tsai and Tat-Dat Bui
This study aims to examine a hierarchical framework for sustainable consumption (SC) for cruise ships and identify the causal relationships and decisive attributes of cruise ship…
Abstract
Purpose
This study aims to examine a hierarchical framework for sustainable consumption (SC) for cruise ships and identify the causal relationships and decisive attributes of cruise ship operation practices that allow cruise organizations to achieve a higher level of sustainable performance.
Design/methodology/approach
This study applies a hybrid of the Delphi method and a fuzzy decision-making trial and evaluation laboratory (DEMATEL). DEMATEL methodology helps to construct complex causal relations through digraphs, which depict interrelationships among attributes. The fuzzy set theory assesses experts’ perceptions of attributes given in linguistic preferences. The Delphi method has been previously used to validate attributes and determine the validity and reliability of the construct from qualitative information.
Findings
A set of three aspects containing 21 criteria were defined based on previous literature and expert consultations. The analysis results show that waste minimization and recycling and recovery are causal aspects that influence efficient resource use. Emission controls on ships, cruise ship alternative energy sources, ballast water treatment systems, water purification systems and nanofiltration systems are also prominent criteria for the improvement of SC during cruise ship operation.
Originality/value
This study contributes to the literature by offering a hierarchical framework for SC literature and confirming the role of this issue in improving the cruise industry sustainability. In practice, as such results provide key attributes for successful performance, the implications are offered for companies developing new activities, either in ensuring compliance with business goals or in decreasing the environmental impact.
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Jiansen Zhao, Xin Ma, Bing Yang, Yanjun Chen, Zhenzhen Zhou and Pangyi Xiao
Since many global path planning algorithms cannot achieve the planned path with both safety and economy, this study aims to propose a path planning method for unmanned vehicles…
Abstract
Purpose
Since many global path planning algorithms cannot achieve the planned path with both safety and economy, this study aims to propose a path planning method for unmanned vehicles with a controllable distance from obstacles.
Design/methodology/approach
First, combining satellite image and the Voronoi field algorithm (VFA) generates rasterized environmental information and establishes navigation area boundary. Second, establishing a hazard function associated with navigation area boundary improves the evaluation function of the A* algorithm and uses the improved A* algorithm for global path planning. Finally, to reduce the number of redundant nodes in the planned path and smooth the path, node optimization and gradient descent method (GDM) are used. Then, a continuous smooth path that meets the actual navigation requirements of unmanned vehicle is obtained.
Findings
The simulation experiment proved that the proposed global path planning method can realize the control of the distance between the planned path and the obstacle by setting different navigation area boundaries. The node reduction rate is between 33.52% and 73.15%, and the smoothness meets the navigation requirements. This method is reasonable and effective in the global path planning process of unmanned vehicle and can provide reference to unmanned vehicles’ autonomous obstacle avoidance decision-making.
Originality/value
This study establishes navigation area boundary for the environment based on the VFA and uses the improved A* algorithm to generate a navigation path that takes into account both safety and economy. This study also proposes a method to solve the redundancy of grid environment path nodes and large-angle steering and to smooth the path to improve the applicability of the proposed global path planning method. The proposed global path planning method solves the requirements of path safety and smoothness.
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Devrim Murat Yazan, Guido van Capelleveen and Luca Fraccascia
The sustainable transition towards the circular economy requires the effective use of artificial intelligence (AI) and information technology (IT) techniques. As the…
Abstract
The sustainable transition towards the circular economy requires the effective use of artificial intelligence (AI) and information technology (IT) techniques. As the sustainability targets for 2030–2050 increasingly become a tougher challenge, society, company managers and policymakers require more support from AI and IT in general. How can the AI-based and IT-based smart decision-support tools help implementation of circular economy principles from micro to macro scales?
This chapter provides a conceptual framework about the current status and future development of smart decision-support tools for facilitating the circular transition of smart industry, focussing on the implementation of the industrial symbiosis (IS) practice. IS, which is aimed at replacing production inputs of one company with wastes generated by a different company, is considered as a promising strategy towards closing the material, energy and waste loops. Based on the principles of a circular economy, the utility of such practices to close resource loops is analyzed from a functional and operational perspective. For each life cycle phase of IS businesses – e.g., opportunity identification for symbiotic business, assessment of the symbiotic business and sustainable operations of the business – the role played by decision-support tools is described and embedding smartness in these tools is discussed.
Based on the review of available tools and theoretical contributions in the field of IS, the characteristics, functionalities and utilities of smart decision-support tools are discussed within a circular economy transition framework. Tools based on recommender algorithms, machine learning techniques, multi-agent systems and life cycle analysis are critically assessed. Potential improvements are suggested for the resilience and sustainability of a smart circular transition.
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This survey overviews the literature on entrepreneurship and self-employment. The author catalogs the main contributions of this body of research and makes a distinction between…
Abstract
This survey overviews the literature on entrepreneurship and self-employment. The author catalogs the main contributions of this body of research and makes a distinction between issues on which there is now widespread agreement and those for which no consensus has yet emerged. This latter set of issues provides fertile ground for further research.
This study clarifies the mediating effects of job satisfaction and knowledge sharing on the relationship between leadership humility and salesperson creativity. It also shows how…
Abstract
Purpose
This study clarifies the mediating effects of job satisfaction and knowledge sharing on the relationship between leadership humility and salesperson creativity. It also shows how job satisfaction mediates between leadership humility and knowledge sharing.
Design/methodology/approach
This study sampled 380 salespeople in Japan’s financial sector to participate in a two-wave online survey. The partial least squares structural equation modeling was applied to test the research hypotheses.
Findings
The results of the partial least squares structural equation modeling showed that the serial mediating effect of leadership humility on salesperson creativity through job satisfaction and knowledge sharing was statistically significant. The supplementary analysis showed that leadership humility had a curvilinear effect on salesperson creativity.
Research limitations/implications
The findings were restricted to salespeople employed in Japan’s financial sector.
Practical implications
Contrary to previous meta-analytic studies, the mere presence of humble leaders is insufficient to induce salesperson creativity.
Originality/value
This study is the first to deeply elucidate the underlying mechanism between leadership humility and salesperson creativity and examine the curvilinear relationship between leadership humility and salesperson creativity.
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Faharuddin Faharuddin, M. Yamin, Andy Mulyana and Y. Yunita
Using cross-sectional household survey data, this paper aims to determine the impact of food price increases on poverty in Indonesia.
Abstract
Purpose
Using cross-sectional household survey data, this paper aims to determine the impact of food price increases on poverty in Indonesia.
Design/methodology/approach
This paper uses the quadratic almost ideal demand system applied to the 2013 Indonesian household survey data. The impact of food price increase on household welfare is calculated using a welfare measure, compensating variation.
Findings
Three food groups with the most outstanding price impact on poverty, rice, vegetables and fish, were studied. The 20% increase in the price of each food group causes an increase in the headcount ratio by 1.360 points (rice), 0.737 points (vegetables) and 0.636 points (fish). Maintaining food price stability for these food groups is very important because the more the price increases, the more the impact on poverty. Food price policies in rural areas are also more critical than in urban areas because the impact of food price increases in rural areas is higher.
Research limitations/implications
This paper does not consider the positive impact of rising food prices on food-producing households.
Practical implications
Implementing appropriate poverty alleviation policies through food policies for main food groups and social protection.
Social implications
Promoting rural development policies and agricultural growth.
Originality/value
This paper contributes to the existing literature by providing empirical results regarding the impact of domestic food prices increase on poverty in Indonesia.