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This paper aims to present an evaluation method for energy-absorption characteristics of thin-walled composite structures with random uncertain parameters.

The mechanical properties of T700/3234 are obtained by material performance tests and energy-absorption results are obtained by quasi-static crushing tests of thin-walled composite circular tubes. The indicators of triggering specific load (TSL) and specific energy absorption (SEA) are introduced and calculated to determine the energy-absorption characteristics and validate the probability finite element analysis model. The uncertainty in the parameters contain the machining tolerance for the thickness and inner diameter of composite circular tubes and are associated with the composite material system. The Plackett–Burman method is used to choose the measurement parameters. Then, the response surface method is used to build a second-order function of random uncertain parameters versus TSL/SEA, and the Monte Carlo method is finally used to obtain the probabilities of TSL and SEA.

The finite element models can accurately simulate the initial peak load, load-displacement curve and SEA value. The random uncertain parameter method can be used to evaluate the energy-absorption characteristics of thin-walled composite circular tubes.

The presented evaluation method for energy-absorption characteristics of thin-walled composite structures is an approach that considers uncertain parameters to increase the simulation accuracy and decrease the computational burden.

This methodology considers uncertain parameters in evaluating the energy-absorption characteristics of thin-walled composite structures, and this methodology can be applied to other thin-walled composite structures.

This chapter differentiates the effect of solicited credit ratings (SCRs) and unsolicited credit ratings (UCRs) on bank leverage decision before and after the credit rating change. We find that banks with UCRs issue less debt relative to equity when the credit rating changes are approaching. Such findings are also prominent when bank credit rating moves from investment grade to speculative grade. After credit rating upgrades (downgrades), banks with unsolicited (solicited) credit ratings are inclined to issue more (less) debt relative to equity than those with solicited (unsolicited) credit ratings. We conclude that SCR and UCR changes lead to significantly different effects on bank leverage decision.

This research aims to improve the performance of rail fastener defect inspection method for multi railways, to effectively ensure the safety of railway operation.

Firstly, a fastener region location method based on online learning strategy was proposed, which can locate fastener regions according to the prior knowledge of track image and template matching method. Online learning strategy is used to update the template library dynamically, so that the method not only can locate fastener regions in the track images of multi railways, but also can automatically collect and annotate fastener samples. Secondly, a fastener defect recognition method based on deep convolutional neural network was proposed. The structure of recognition network was designed according to the smaller size and the relatively single content of the fastener region. The data augmentation method based on the sample random sorting strategy is adopted to reduce the impact of the imbalance of sample size on recognition performance.

Test verification of the proposed method is conducted based on the rail fastener datasets of multi railways. Specifically, fastener location module has achieved an average detection rate of 99.36%, and fastener defect recognition module has achieved an average precision of 96.82%.

The proposed method can accurately locate fastener regions and identify fastener defect in the track images of different railways, which has high reliability and strong adaptability to multi railways.

Applying resource dependence theory (RDT), this research paper aims to examine the effect of imbalanced trade dependence (ITD) on entry mode choices and how state ownership and marketization each can moderate this effect.

Using data on 1,404 foreign projects made by 493 Chinese listed firms during the 2009–2015 period of time, this study applies logit regression to do the statistical analysis.

It finds that ITD positively affects the choice of wholly-owned subsidiaries. State ownership and marketization each can moderate this influence.

It develops the concept of ITD, applies it to examine entry mode choices and lets us better understand the substitutive or complementary relationship between governments and foreign firms as two sources of resources. It helps us better understand some competitive advantages of emerging market firms (EMFs) and the impacts of the state on EMFs’ outward FDI. It contributes to entry mode research by applying RDT to explain how ITD influences entry mode choices and how state ownership and marketization each can moderate this relationship.

The global prevalence of vaccine misinformation has underscored the crucial necessity to combat false information and explore innovative solutions like chatbots. These artificial intelligence (AI)-powered tools play a pivotal role in disseminating accurate information and mitigating the adverse effects of misinformation. This study aimed to investigate what factors motivated users to combat vaccine misinformation using chatbot tools, and their active communication actions and anti-misinformation behaviors.

Researchers surveyed 612 chatbot users in the United States and utilized structural equation modeling for data analysis.

The findings of this study revealed that both situational and gratification motivations of chatbot users significantly contributed to three essential types of communicative actions: information-seeking, forwarding and forfending. Meanwhile, the data demonstrated that except for information forfending, both information-seeking and forwarding communicative actions could enhance user engagement with anti-misinformation behavior.

The originality of this study lies in its integration of two key motivational frameworks – gratification and situational motivations – within the context of AI-driven tools like chatbots, particularly in combating misinformation. While previous research has explored the use of chatbots or the role of situational motivations in communication separately, this study uniquely combines these concepts to enhance the situational theory of problem-solving (STOPS) model and uses and gratifications (U&G) theory. Additionally, the practical implications for chatbot design and communication strategies targeted at misinformation are a significant contribution, demonstrating how motivation-driven interactions can be used to improve user engagement and public health outcomes.

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.

The precast concrete slab track (PST) has advantages of fewer maintenance frequencies, better smooth rides and structural stability, which has been widely applied in urban rail transit. Precise positioning of precast concrete slab (PCS) is vital for keeping the initial track regularity. However, the cast-in-place process of the self-compacting concrete (SCC) filling layer generally causes a large deformation of PCS due to the water-hammer effect of flowing SCC, even cracking of PCS. Currently, the buoyancy characteristic and influencing factors of PCS during the SCC casting process have not been thoroughly studied in urban rail transit.

In this work, a Computational Fluid Dynamics (CFD) model is established to calculate the buoyancy of PCS caused by the flowing SCC. The main influencing factors, including the inlet speed and flowability of SCC, have been analyzed and discussed. A new structural optimization scheme has been proposed for PST to reduce the buoyancy caused by the flowing SCC.

The simulation and field test results showed that the buoyancy and deformation of PCS decreased obviously after adopting the new scheme.

The findings of this study can provide guidance for the control of the deformation of PCS during the SCC construction process.

This paper aims to comprehensively review the preparation methods of superhydrophobic surfaces (SHPS) for corrosion protection of Mg alloy in recent years.

The preparation methods, wettability and corrosion resistance of SHPS on Mg alloy in the past three years are systematically described in this paper.

Two types of SHPS, including single-layer and multilayer coatings for corrosion protection of Mg alloy are summarized. Preparing multilayered coatings with multifunction is the current trend in developing SHPS on Mg alloy.

This paper reviewed the preparation methods and corrosion resistance of SHPS on Mg alloys. It provides a valuable reference for researchers to develop highly durable SHPS with excellent corrosion resistance for Mg alloys.

Integrating tourism and sustainability in achieving an eco-friendlier industry, this chapter highlights current trends in sustainable tourism, both in hospitality and recreational activities. The chapter describes sustainable, tourism, hospitality, and recreation trends. The research analyzes the origin of these trends, the vast majority motivated by the aftermath of the pandemic.