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This review aims to give a critical view of the wheel/rail high frequency vibration-induced vibration fatigue in railway bogie.

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.

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.

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.

This paper aims to give an overview about the state of wireless passive surface acoustic wave (SAW) gas sensor used in the detection of chemical vapor. It also discusses a variety of different architectures including delay line and array sensor for gas detection, and it is considered that this technology has a good application prospect.

The authors state the most of the wireless passive SAW methods used in gas sensing, such as CO2, CO, CH4, C2H4, NH3, NO2, et al., the sensor principles, design procedures and technological issues are discussed in detail; their advantages and disadvantages are also summarized. In conclusion, it gives a prospect of wireless passive SAW sensor applications and proposes the future research field might lie in the studying of many kinds of harmful gases.

In this paper, the authors will try to cover most of the important methods used in gas sensing and their recent developments. Although wireless passive SAW sensors have been used successfully in harsh environments for the monitoring of temperature or pressure, the using in chemical gases are seldom reported. This review paper gives a survey of the present state of wireless passive SAW sensor in gas detection and suggests new and exciting perspectives of wireless passive SAW gas sensor technology.

The authors will review most of the methods used in wireless passive SAW sensor and discuss the current research status and development trend; the potential application in future is also forecasted.

The authors will review most of the methods used in wireless passive SAW sensor and discuss the current research status and development trend; the potential application in future is also forecasted.

This study aims to establish a comprehensive model integrating variables from the updated unified theory of acceptance and use of technology (UTAUT), expectation-confirmation model (ECM) and trust to determine what factors influence consumers’ decision to continue using food delivery apps (FDA) after the COVID-19 outbreak in Taiwan.

Data was collected from 350 respondents living in Taiwan via Line using a Google Forms link. A total of 333 valid responses were analyzed after 17 invalid questionnaires were eliminated. To test the suggested study paradigm, partial least squares-structural equation modeling was used as the data analysis approach.

The results indicate FDA users’ continuance intention (CI) is directly significantly affected by performance expectancy, satisfaction and habit. All the constructs of the updated UTAUT theory, confirmation and trust significantly influence the satisfaction of FDA, and users’ satisfaction significantly positively impacts users’ CI.

Although consumers’ intentions toward FDA have previously been the topic of research, there is a paucity of literature that discusses the connections between the variables that influence FDA users’ CI after the COVID-19 pandemic in Taiwan. By focusing on the relationships between the multiple antecedents of FDA users’ CI, this study contributes to reducing the existing literature gap. Explanation surrounding the elements influencing FDA users’ CI is provided by examining several aspects of FDA usage, including technological and psychological postadoption issues.

本研究试图建立一个综合模型, 整合了来自统一接受和使用科技理论（UTAUT）、期望-确认模型（ECM）和信任等变量, 以确定影响消费者在COVID-19疫情爆发后继续使用食品外卖应用(FDA)的因素。

本研究针对台湾的居民通过Line平台使用Google Forms链接收集了350份问卷数据, 经过筛选后得到333份有效回复。为了验证所提出的研究范式, 本研究采用了PLS-SEM作为数据分析方法。

结果表明, FDA用户的继续使用意图受到性能预期、满意度和习惯的直接显著影响。UTAUT理论、期望确认和信任显著影响FDA用户的满意度, 而用户的满意度对用户的继续使用意图产生积极影响。

尽管消费者对FDA的意向不是新的研究的主题, 但在讨论COVID-19疫情后影响FDA用户继续使用意图的变量之间的关系方面, 文献中存在不足。通过探索FDA用户继续使用意图的多个前因关系, 本研究有助于弥补现有文献的空白。通过考察FDA使用的技术和心理因素等多个方面, 本研究提供了解释影响FDA用户继续使用意图的论述。

This research proposes an innovative fault-tolerant media content list management technology applied to the smart robot domain.

A fault tolerant Content List Management Unit (CLMU) for real-time streaming systems focusing on smart robot claw machines is proposed to synchronize and manage the hyperlink stored on media servers. The fault-tolerant mechanism is realized by the self-healing method. A media server allows exchanging the hyperlink within the network through the CLMU mechanism.

Internet users can access the current multimedia information, and the multimedia information list can be rearranged appropriately. Furthermore, the service of the proposed multimedia system should be uninterrupted even when the master media server fails. Therefore, one of the slave media servers enables the Content List Service (CLS) of the proposed CLMU and replaces the defunct master media server.

The recovery time is less than 1.5 seconds. The multimedia transmission is not interrupted while any one of the media servers keeps functioning. The proposed method can serve to stabilize the system of media servers in a smart robot domain.

This paper aims to apply vector space model (VSM)-PCR model to compute the similarity of Fault zone ontology semantics, which verified the feasibility and effectiveness of the application of VSM-PCR method in uncertainty mapping of ontologies.

The authors first define the concept of uncertainty ontology and then propose the method of ontology mapping. The proposed method fully considers the properties of ontology in measuring the similarity of concept. It expands the single VSM of concept meaning or instance set to the “meaning, properties, instance” three-dimensional VSM and uses membership degree or correlation to express the level of uncertainty.

It provides a relatively better accuracy which verified the feasibility and effectiveness of VSM-PCR method in treating the uncertainty mapping of ontology.

The future work will focus on exploring the similarity measure and combinational methods in every dimension.

This paper presents an uncertain mapping method of ontology concept based on three-dimensional combination weighted VSM, namely, VSM-PCR. It expands the single VSM of concept meaning or instance set to the “meaning, properties, instance” three-dimensional VSM. The model uses membership degree or correlation which is used to express the degree of uncertainty; as a result, a three-dimensional VSM is obtained. The authors finally provide an example to verify the feasibility and effectiveness of VSM-PCR method in treating the uncertainty mapping of ontology.

This study examines potential ways to break the inequality reproduction circle faced by ethnic minority health workers and sustained by key performance indicators (KPIs)-centred management in the National Health Service (NHS) in England. It does so through the lens of signalling theory.

Three years panel data for 2018–2020 covering 207 hospitals was compiled from the annual NHS staff survey and matched with relevant administrative records. Structural equation modelling was used to test the proposed hypotheses at the organisational level.

The moderated mediating model reveals that persistent racial discrimination by managers and coworkers can disadvantage the career progression of ethnic minority health workers, which in turn reinforces and reproduces economic and health inequalities among them. More importantly, we show how the collective agreement that the senior management team acts (SMTA) on staff feedback can break this vicious circle.

While our research focuses on the not-for-profit health care sector, it opens important opportunities to extend the proposed model to understand organisational inequality and how to address it.

Perceived SMTA can send strong signals to reduce deep-rooted discrimination (race, gender, age, etc.) through resource allocations and instrumental functions. This is also a way to address the current staff burnout and shortage issues in the healthcare sector.

This article reveals why the purpose of organisations that provide public service to reduce social inequality was comprised during their business-like operations and more importantly, how to reflect their foundational purpose through management practice.

This study offers a way forward to resolve one of the unintended consequences of KPI-centred management in the not-for-profit sector through unpacking the process of inequality reproduction and, more importantly, how it is possible to break this vicious circle.

A self-adaptive piston is designed for the compressional gas cushion press nanoimprint lithography system. It avoids the lube pollution and high wear of traditional piston.

The self-adaptive piston device consists of symmetrical piston bodies, piston rings and other parts. The two piston bodies are linked by a ball-screw. The locking nut adjusts the distance between two piston bodies to avoid the piston rings from being stuck. The piston rings are placed between two piston bodies.

The simulation results based on COMSOL indicate that cylinder vibration caused by self-adaptive piston is 15.9 times smaller than the one caused by a traditional piston.

The self-adaptive piston is superior to the traditional piston in decreasing cylinder vibration.

The explosion of data due to the sophistication of information and communication technology makes it simple for prospective tourists to learn about previous hotel guests' experiences. They prioritize the rating score when selecting a hotel. However, rating scores are less reliable for suggesting a personalized preference for each aspect, especially when they are in a limited number. This study aims to recommend ratings and personalized preference hotels using cross-domain and aspect-based features.

We propose an aspect-based cross-domain personalized recommendation (AsCDPR), a novel framework for rating prediction and personalized customer preference recommendations. We incorporate a cross-domain personalized approach and aspect-based features of items from the review text. We extracted aspect-based feature vectors from two domains using bidirectional long short-term memory and then mapped them by a multilayer perceptron (MLP). The cross-domain recommendation module trains MLP to analyze sentiment and predict item ratings and the polarities of the aspect based on user preferences.

Expanded by its synonyms, aspect-based features significantly improve the performance of sentiment analysis on accuracy and the F1-score matrix. With relatively low mean absolute error and root mean square error values, AsCDPR outperforms matrix factorization, collaborative matrix factorization, EMCDPR and Personalized transfer of user preferences for cross-domain recommendation. These values are 1.3657 and 1.6682, respectively.

This study assists users in recommending hotels based on their priority preferences. Users do not need to read other people's reviews to capture the key aspects of items. This model could enhance system reliability in the hospitality industry by providing personalized recommendations.

This study introduces a new approach that embeds aspect-based features of items in a cross-domain personalized recommendation. AsCDPR predicts ratings and provides recommendations based on priority aspects of each user's preferences.

The purpose of this paper is not only to investigate the impact of self-determined motivation on counterproductive work behaviors (CWBs), but also to examine the moderating role of perceived job insecurity in CWB.

This study utilized Partial Least Squares analysis to examine the data. In total, 292 private bank employees that experienced bank mergers and acquisitions before were invited to participate in this study.

The study findings have indicated that perceived autonomy will be positively linked to perceived competence and relatedness, and perceived competence and relatedness will be negatively associated with organizational and interpersonal CWB. Moreover, it has been found that perceived job insecurity could play a key role in moderating the link between self-determined motivation and CWB.

Although several researchers have highly focused on the critical roles of self-determined motivation and perceived job insecurity in organizational competitiveness, little is known about whether perceived job insecurity could play a key role in moderating the relationship between self-determined motivation and CWBs.

Based on laser-range-finder (LRF) sensing, the control design of location and orientation stabilization for the mobile robot is investigated. However, the practical limitation of the LRF sensing is usually ignored in the control design, which leads to incorrect localization and unexpected control results. The purpose of this study is to design the fuzzy controller subject to the practical limitation on the LRF-based localization for a differentially driven wheeled mobile robot.

First, the Takagi–Sugeno (T-S) fuzzy model is derived from the polar kinematic model of a differentially driven mobile robot. Then, the fuzzy controller is designed to the derived T-S fuzzy kinematic model in accordance with the Lyapunov stabilization theorem. The derived Lyapunov stabilization conditions for the fuzzy control design are expressed as the linear matrix inequality (LMI) form and effectively solved by LMI tools. The practical limitation on the LRF-based localization is also expressed as the LMI form and simultaneously solved with the control design.

The location and posture stabilization experiments are carried out on a mobile robot with LRF-based localization to prove the effectiveness of the proposed T-S fuzzy model-based control design. Furthermore, the ground truth experiment evaluates the accuracy of LRF-based localization.

The contribution of this study is to develop the fuzzy control law for a differentially driven wheeled mobile robot under the practical limitation on LRF-based localization. The proposed control design can be applied to other robots with practical limitations on the sensors.