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The pulsed plasma thruster (PPT) is one sort of promising electric thrusters, but the low efficiency is always a big problem for PPT. Many researches have been working on solving this problem. However, there is still no significant breakthrough. This paper aimed to discuss some methods for improving the PPT's efficiency.

The causes for the low efficiency by analyzing the theoretical models of PPT are discussed, and the influences on PPT's performance investigated in terms of the structural or electrical parameters.

The change of structural or electrical parameters which influence the thrust efficiency significantly are taken into account. In the process of designing PPT, optimized structural and electrical parameters should be chosen to attain a better performance.

This analysis is mainly based on the parallel‐rail PPT.

The result of analysis is adopted, the higher thrust efficiency of PPT is expectable.

By introducing theoretical models and analyzing results of some researcher's experiments, this paper offers a method of designing PPT and attempts to help designer to choose appropriate structural and electrical parameters.

The purpose of this paper is to propose and assess the possibility of using ceramic coating layer as a heat‐resistant material in micro solid propellant thruster.

A ceramic layer is coated on the inner surface of the combustor of a micro thruster by applying micro‐arc oxidation (MAO) technology. The thermal property of the coating is analyzed with laser pulse method. To evaluate the heat‐resistant performance of the coating, the temperature history of the micro thruster inner surface is experimentally tested and recorded in a water thermostat bath. A numerical simulation of the thruster working condition is also carried out.

Both experimental and simulation results reveal that the heat‐resistant ability of the coating processed by MAO is proven to be effective.

This paper attempts to help designers choose material processing technology to improve micro solid propellant thruster heat‐resistant ability.

The paper shows that with a ceramic coating layer processed with MAO, aluminium can sustain higher temperature and it can be used as the structural material for short‐time‐work micro thruster.

Field emission electric propulsion (FEEP) thruster is a type of electric propulsion based on space‐proven indium liquid metal ion sources. The lifetime of FEEP thruster limits its application in space. A better method to improve its lifetime is the reduction of emission current. This paper aims to discuss the minimum emission current of operating FEEP thrusters.

In this work, theoretical models, including fluid‐flow model and ion formation model, are analyzed. Current densities of these models are discussed and the minimum emission current is calculated.

There are few equilibrium states under low emission current conditions. However, the minimum emission current is the only stable state at which the FEEP thruster can operate.

This analysis is mainly based on the needle indium FEEP, which is compared indirectly with experiments of gallium.

This paper attempts to help designers choose appropriate electric parameters to improve the lifetime of FEEP.

By introducing and analyzing theoretical models, this paper calculates the minimum emission current for stable operation of FEEP.

Ethical decision making, business ethics.

This case is applicable to MBA, EDP and EMBA courses.

TOREAD, a professional provider of outdoor equipment in China, started in business by producing and selling tents. To meet market demand, TOREAD expanded its product line which ranges from outdoor durable tent products to “pan-outdoor” products including footwear and clothing. During the critical expansion phase, TOREAD was challenged by a quality problem in a batch of outsourced sandals that had been manufactured by a contracted supplier. By researching different options and going through an ethical decision making process, TOREAD made the choice of destroying all “problem sandals”. Since then, TOREAD has focused development on product quality improvement and product innovation to establish a sustainable brand image and generate social benefits. TOREAD's decision making in the critical development phase helped it to become the leader in the outdoor product industry in China.

This case may be used for courses such as business ethics and strategy. By learning this case, students can understand the process of making ethical decisions when facing moral dilemmas among corporate decision makers, employees and relevant interested parties, and learn how to make strategic decisions to balance company profit growth and social benefits in critical development phases.

Teaching notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes.

Employee engagement serves as a critical strategy for tourism and hospitality organizations to support their employees and fight adversity. This study aims to investigate the antecedents and effects of employee engagement and examine innovative behavior as a linchpin mechanism for the relationship between organizational engagement culture and organizational performance.

This study analyzed the antecedents and effects of employee engagement through a hierarchical linear model that considers both organizational- and individual-level factors. The data was collected through a questionnaire survey from employees of 39 hotels in Guangzhou, China.

The results confirmed the significant positive effect of organizational empowerment, leadership and collaboration atmosphere on employment engagement. An individual’s perception of rewards and recognition, distributive justice and procedural justice significantly affected employee engagement. It was also confirmed that employee engagement ultimately improved performance outcomes at the individual and organizational levels. Additionally, the mediation effect of organizational innovation culture on the relationship between organizational employee engagement and organizational performance was confirmed.

Organizations can improve their performance by enhancing employee engagement, which in turn, can be encouraged by empowering leadership and organizational collaboration culture. Organizations can also improve their performance by providing rewards and recognition appreciated by employees and ensuring justice to them.

This research contributes to the literature on employee engagement in the hospitality industry by demonstrating how organizational performance can be improved through employee engagement using a multilevel model. The findings highlight that organizations with engaged employees are more likely to achieve an innovative culture, which in turn, leads to organizational success. This study also confirmed that empowerment, leadership and collaboration culture help improve organizational performance in the hospitality industry.

The purpose of this paper is to provide a critical synthesis of research conducted within the hospitality and tourism industries in response to the impact of the COVID-19 pandemic, identify key perspectives and themes relating to the recovery and resilience of the two sectors and put forward recommendations that help address organizational and consumer behavior changes produced by the pandemic.

This study adopted a critical reflection approach to identify, select and synthesize relevant research based on which recommendations are drawn.

This study offers a contemporary framework discussing three distinct themes that emerged from existing research regarding the impact of COVID-19 on the hospitality and tourism industries: management, marketing and consumer behavior.

This study offers operational, practical and actionable recommendations for organizations about how to adapt and recover from the impact of the COVID-19 pandemic by guiding the industry in sustaining long-term resilience.

This study provides a critical and current synthesis of selected literature and theory that discuss key implications of the COVID-19 pandemic for the recovery and resilience-building of the hospitality and tourism sectors.

Examines the fifteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

This paper aims to study the tribological behavior of the WS2/oil-impregnated porous polyimide (PPI) solid/liquid composite system, in which both PFPE (perfluoropolyether) and SiCH (silahydrocarbons) oils with different hydrocarbon chains were used, respectively. Lubricating mechanism of the composite system was also explored.

The tribological behaviors of the WS2 films against the PPI cylindrical pins before and after immersing oil were evaluated under different loads by a reciprocating-type ball-on-disc tribometer.

The composite system exhibited the low and stable friction coefficient after the running-in stage, and the lubricant oil played a positive effect. It was found that the WS2/PFPE composite system exhibited more excellent lubricating property, although sole SiCH far exceeds PFPE in lubrication. The abnormal phenomenon mainly resulted from the influence of the oil amount. XRD results on the wear track surfaces indicated that PFPE and SiCH oils with different hydrocarbon chains were likely to preferentially adsorb to the edge plane and basal plane of the WS2 crystals, respectively.

In previous studies, liquid lubricants were directly dripped or spin-coated on the solid lubricant surface. Based on its potential advantage in application, the tribological behavior and mechanism of the solid lubricating film/oil-impregnated PPI composite system were investigated in this study.

The purpose of this study is to explore the potential of trainable activation functions to enhance the performance of deep neural networks, specifically ResNet architectures, in the task of image classification. By introducing activation functions that adapt during training, the authors aim to determine whether such flexibility can lead to improved learning outcomes and generalization capabilities compared to static activation functions like ReLU. This research seeks to provide insights into how dynamic nonlinearities might influence deep learning models' efficiency and accuracy in handling complex image data sets.

This research integrates three novel trainable activation functions – CosLU, DELU and ReLUN – into various ResNet-n architectures, where “n” denotes the number of convolutional layers. Using CIFAR-10 and CIFAR-100 data sets, the authors conducted a comparative study to assess the impact of these functions on image classification accuracy. The approach included modifying the traditional ResNet models by replacing their static activation functions with the trainable variants, allowing for dynamic adaptation during training. The performance was evaluated based on accuracy metrics and loss profiles across different network depths.

The findings indicate that trainable activation functions, particularly CosLU, can significantly enhance the performance of deep learning models, outperforming the traditional ReLU in deeper network configurations on the CIFAR-10 data set. CosLU showed the highest improvement in accuracy, whereas DELU and ReLUN offered varying levels of performance enhancements. These functions also demonstrated potential in reducing overfitting and improving model generalization across more complex data sets like CIFAR-100, suggesting that the adaptability of activation functions plays a crucial role in the training dynamics of deep neural networks.

This study contributes to the field of deep learning by introducing and evaluating the impact of three novel trainable activation functions within widely used ResNet architectures. Unlike previous works that primarily focused on static activation functions, this research demonstrates that incorporating trainable nonlinearities can lead to significant improvements in model performance and adaptability. The introduction of CosLU, DELU and ReLUN provides a new pathway for enhancing the flexibility and efficiency of neural networks, potentially setting a new standard for future deep learning applications in image classification and beyond.

Human group behavior is the driving force behind many complex social and economic phenomena. Few studies have integrated multi-dimensional travel patterns and city interest points to construct urban security risk indicators. This paper combines traffic data and urban alarm data to analyze the safe travel characteristics of the urban population. The research results are helpful to explore the diversity of human group behavior, grasp the temporal and spatial laws and reveal regional security risks. It provides a reference for optimizing resource deployment and group intelligence analysis in emergency management.

Based on the dynamics index of group behavior, this paper mines the data of large shared bikes and ride-hailing in a big city of China. We integrate the urban interest points and travel dynamic characteristics, construct the urban traffic safety index based on alarm behavior and further calculate the urban safety index.

This study found significant differences in the travel power index among ride-sharing users. There is a positive correlation between user shared bike trips and the power-law bimodal phenomenon in the logarithmic coordinate system. It is closely related to the urban public security index.

Based on group-shared dynamic index integrated alarm, we innovatively constructed an urban public safety index and analyzed the correlation of travel alarm behavior. The research results fully reveal the internal mechanism of the group behavior safety index and provide a valuable supplement for the police intelligence analysis.