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Pipeline maintenance technology using smart isolation tool is becoming more widely used in the global scope. This paper aims to investigate the effects of parameters on the frictional resistance between the slip and pipeline and the frictional characteristics under different lubrication films.

An experimental platform consisting of slip, pipeline and data acquisition system was developed, wherein the slip slips on the pipeline under different normal forces and velocities. In addition, three lubrication conditions, namely, dry wall, oil liquid and black powder on the wall, were investigated to study the effects of lubrications on the frictional coefficient and characteristics.

Research results indicate that the frictional force and coefficient were sensitive to normal force. The crude oil affected the frictional coefficient within a certain range of normal force, and the black powder enhanced the surface roughness in the natural gas pipeline. However, velocity had no effect on them. In addition, different contact behaviors could be observed from the frictional coefficient curves.

In this paper, the effects of normal force and velocity on frictional resistance of sliding slip during decelerating process in pipeline were investigated, and the effects of lubrication films on frictional characteristics were also revealed. The research results are of great value to improve the prediction accuracy of smart isolation tool, and also provide a guiding significance for the development of maintenance operation in pipelines.

With many countries having reached universal primary and secondary education, parents are increasingly investing in private tutoring as a means of ensuring that their children attend the best schools and universities. However, unlike the returns to years of schooling and effects of school quality on student achievement, the effects of spending on private tutoring have received limited attention. This chapter studies the impact of tutoring on higher educational outcomes using exogenous variation in tutoring expenditure caused by the imposition of a curfew on the operating hours of tutoring institutes in Korea. The estimated effects of the curfew highlight the severity of the college entrance rat race, with a 10 p.m. curfew constraining tutoring expenditure and increasing sleeping hours. I find diminishing marginal effects of tutoring on college entrance and positive effects on degree completion while the impact on college major followed varies across disciplines.

Research and development (R&D) projects are often pursued through a project portfolio (PP). R&D PPs involve many stakeholders, and without proactive management, their interactions may lead to conflict risks. These conflict risks change dynamically with different stages of the PP life cycle, increasing the challenge of PP risk management. Existing conflict risk research mainly focuses on source identification but lacks risk assessment work. To better manage the stakeholder conflict risks (SCRs) of R&D PPs, this study employs the dynamic Bayesian network (DBN) to construct its dynamic assessment model.

This study constructs a DBN model to assess the SCRs in R&D PP. First, an indicator system of SCRs is constructed from the life cycle perspective. Then, the risk relationships within each R&D PPs life cycle stage are identified via interpretative structural modeling (ISM). The prior and conditional probabilities of risks are obtained by expert judgment and Monte Carlo simulation (MCS). Finally, crucial SCRs at each stage are identified utilizing propagation analysis, and the corresponding risk responses are proposed.

The results of the study identify the crucial risks at each stage. Also, for the crucial risks, this study suggests appropriate risk response strategies to help managers better perform risk response activities.

This study dynamically assesses the stakeholder conflict risks in R&D PPs from a life-cycle perspective, extending the stakeholder risk management research. Meanwhile, the crucial risks are identified at each stage accordingly, providing managerial insights for R&D PPs.

This study aimed to examine beliefs in repressed memory and dissociative amnesia from a cross-cultural perspective.

Chinese (n = 123) and Belgian student participants (n = 270) received several statements tapping into various dimensions of repressed memory and dissociative amnesia. Participants provided belief ratings for each of these statements. Because the field of psychoanalysis is less well developed in China, it was expected that Chinese participants would believe less in repressed memory and dissociative amnesia than their Belgian counterparts.

Overall, beliefs in repressed memory and dissociative amnesia were high among all participants. Although confirmatory analyses revealed that most belief ratings concerning statements did not statistically significantly differ between the two samples, Chinese participants did statistically believe less that therapy can recover lost traumatic memories than Belgian participants. Also, exploratory analyses showed that Chinese participants were more critical towards the idea that traumatic memories can be unconsciously repressed and that these memories can be accurately retrieved in therapy than Belgian participants. Many participants also confused repressed memory with plausible memory mechanisms such as ordinary forgetting.

The current study extends previous surveys on repressed memory and dissociative amnesia by comparing their beliefs in different cultures.

This study aims to present a novel topology optimization method for effectively minimizing the frequency response over a given frequency interval considering anisotropic features and fiber angles simultaneously.

The variable thickness sheet (VTS) method is used to obtain a free material distribution under the specified volume constraint. The anisotropic equivalent stiffness matrix based on the material fiber angles is considered in the orthotropic material properties model, which ensures a sufficiently large design space to minimize the frequency response. To lessen the computational burden, the quasi-static Ritz vector (QSRV) method is integrated to approximate the structural response.

Compared to considering only one element, the optimization process simultaneously considers the spatially-varying fiber angles and the material distribution, allowing for a broader design space to minimize the frequency response of additive manufacturing (AM) structures. The orthotropic properties play an important role in determining optimal material distribution of the structure. Moreover, the QSRV method makes the frequency response analysis more efficient.

The anisotropic stiffness and spatially-varying angles of the fiber materials induced by the layer-by-layer printing process of carbon fiber reinforced plastics (CFRP) are simultaneously considered to further minimize the frequency response of AM structures, which improves the performance of AM-CFRP structures.

Considering that the historic city of Yazd was registered as a UNESCO World Heritage Site, and given the necessity of improving the environmental qualities due to the increased number of domestic and foreign tourists, the concept of acoustic comfort seems to be of considerable importance. In this regard, the purpose of this paper is to identify and evaluate the role of sound space components affecting acoustic comfort in the historic urban spaces of the City of Yazd and its two historic squares named Khan Square and Fahadan Square.

Accordingly, a total of 632 foreign tourists visiting these squares were asked to enumerate different sounds they could hear in the square and identify their relation with acoustic comfort. In terms of the objectives, this is an applied research using survey and correlation methods. In addition, ANOVA and multiple regression analysis were used to analyze the data.

The results of this study indicated that motorcycle and automobile noises were considered as the most important sounds disturbing the acoustic comfort, and sounds of children’s play, water, talking and businesses were the most important factors promoting the acoustic comfort in the historic squares.

The paper highlights the soundscape and acoustic conditions that affect the tourisms in the traditional and tourism square in historical context of Yazd city.

The differential magnetic gradient tensor system is usually constructed from the three-axis magnetic sensor array. While the effects of measurement error, sensor performance and baseline distance on localization performance of such systems have been widely reported, the research about the effect of spatial design of sensor array is less presented. This paper aims to provide a spatial design method of sensor array and corresponding optimization strategy to localization based on magnetic tensor gradient to get the optimum design of the sensor array. Based on the results of simulation, magnetic localization systems constructed from the proposed array and the traditional array have been built to carry out a localization experiment. The results of experiment have verified the effectiveness of magnetic localization based on the proposed array.

The authors focus on the localization of the magnetic target based on magnetic gradient by using three-axis magnetic sensor array and combine a design method with corresponding optimization strategy to get the optimum design of the sensor array.

This paper provides an array design and optimization method for magnetic target localization based on magnetic gradient to improve the localization performance.

In this paper, the authors focus on the magnetic localization based on magnetic gradient by using three-axis magnetic sensors and study the effect of the spatial design of sensor array on localization performance.

This paper aims to reveal the tribochemical reaction mechanism on the nano-cutting interface between HMX crystal and diamond tool.

Molecular dynamics simulation of HMX crystal nano-cutting by the reactive force field is carried out in this paper. The affinity of activated atoms and friction damage at the different interface have been well identified by comparing two cutting systems with diamond tool or indenter. The analyses of reaction kinetics, decomposition products and reaction pathways are performed to reveal the underlying atomistic origins of tribocatalytic reaction on the nano-cutting interface.

The HMX crystals only undergo damage and removal in the indenter cutting, while they appear to accelerate thermal decomposition in the diamond cutting. the C-O affinity is proved to be the intrinsic reason of the tribocatalytic reaction of the HMX-diamond cutting system. The reaction activation energy of the HMX crystals in the diamond cutting system is lower, resulting in a rapid increase in the decomposition degree. The free O atoms can induce the asymmetric ring-opening mode and change the decomposition pathways, which is the underlying atomistic origins of the thermal stability of the HMX-diamond cutting system.

This paper describes a method for analyzing the tribochemical behavior of HMX and diamond, which is beneficial to study the thermal stability in the nano-cutting of HMX.

The cable inspection robot is essential in maintaining bridge cables. The purpose of this paper is to summarize the maintenance methods of bridge cables. It summarizes the advantages and disadvantages of the critical structures of the external overall frame, intermediate adhesion device, attachment mechanism and driving method of the cable inspection robot. Finally, it discusses the challenges the cable inspection robot faces and the direction of future research.

This paper summarizes the research progress of the cable inspection robot and details the advantages and disadvantages of critical structures such as the external frame, intermediate adhesion device, attachment mechanism, driving method and safe return device of the robot. Finally, it points out the future direction of cable inspection robots, including lightweight design, hybrid design, multi-robot cooperative work, multi-technology integration and intelligent cable inspection digital twin model.

The cables are the main load-bearing components of a bridge, and their safety is crucial. However, subjected to varying loads and environmental influences over a long period, cables are prone to damage, threatening the bridge’s stability. Cable inspection robots can comprehensively detect and repair cable damage, significantly improving efficiency and safety.

This paper provides a comprehensive review of the current research on cable inspection robots, enabling readers to have a comprehensive and systematic understanding of the critical structures and key technologies of cable inspection robots and providing scientific references for researchers working on cable inspection robots.

This paper aims to explore the impact of business environment on high-quality economic development (HQED) and clarify the role of technological innovation and government intervention in this relationship.

Based on China’s provincial panel data from 2010 to 2019, this paper adopts the system generalized method of moments to empirically analyze the influential mechanism and heterogeneity of the business environment on HQED. Furthermore, the authors construct a dynamic panel threshold model to test the threshold effect of government intervention.

The results indicate that optimizing the business environment can significantly promote HQED, technological innovation plays a partial mediating role in the impact of business environment on HQED, mainly by enhancing the intensity of innovation input and increasing innovation output to facilitate HQED. Government intervention can regulate the impact of business environment on HQED, and there is a double threshold effect, and it possesses an inverted U-shaped feature of first promoting and then inhibiting.

This paper examines the influence path of business environment on HQED from the perspective of technological innovation and government intervention, filling the gap in the study of provincial business environment. Moreover, the conclusions furnish a theoretical basis for optimizing the business environment and facilitating the HQED in China.