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This paper aims to propose a dynamic parameter identification method based on sensitivity analysis for the 5-degree of freedom (DOF) hybrid robots, to solve the problems of too many identification parameters, complex model, difficult convergence of optimization algorithms and easy-to-fall into a locally optimal solution, and improve the efficiency and accuracy of dynamic parameter identification.

First, the dynamic parameter identification model of the 5-DOF hybrid robot was established based on the principle of virtual work. Then, the sensitivity of the parameters to be identified is analyzed by Sobol’s sensitivity method and verified by simulation. Finally, an identification strategy based on sensitivity analysis was designed, experiments were carried out on the real robot and the results were verified.

Compared with the traditional full-parameter identification method, the dynamic parameter identification method based on sensitivity analysis proposed in this paper converges faster when optimized using the genetic algorithm, and the identified dynamic model has higher prediction accuracy for joint drive forces and torques than the full-parameter identification models.

This work analyzes the sensitivity of the parameters to be identified in the dynamic parameter identification model for the first time. Then a parameter identification method is proposed based on the results of the sensitivity analysis, which can effectively reduce the parameters to be identified, simplify the identification model, accelerate the convergence of the optimization algorithm and improve the prediction accuracy of the identified model for the joint driving forces and torques.

The assumption that the family migrates as a unit downplays migrants’ circularity. This chapter focuses on China's rural–urban labor migrants that travel back and forth between the sites of work and home community and between places of work. I argue that migrants and their households pursue work flexibility in order to obtain the best of the urban and rural worlds, by gaining earnings from urban work and at the same time maintaining social and economic security in the countryside. Work flexibility demands flexibility in household organization, in the form of division of labor and collaboration between genders, generations, and households. Based on a study in Sichuan, I examine household biographies and narratives to identify migrants’ work and household strategies.

Migrants change jobs frequently, switch from one type of work to another and one location to another readily, and often return to the home village for months or even years before pursuing migrant work again. Not only are migrants ready to split the household between the city and the countryside, but also they frequently change from one form of division of labor to another. The inside–outside model, where the wife stays in the village and the husband does migrant work, used to be the dominant arrangement. Over time, the outside–outside model, where both the husband and wife migrate to work and leave behind other family members, is increasingly popular. This is facilitated by intergenerational and interhousehold division of labor in the form of assistance by the extended family. Intergenerational division of labor takes place when the second generation is replacing the parents in migrant work. This research's findings support the notion that rural–urban migrants are fast becoming a hybrid segment of Chinese society, playing dual roles of farmers and urban workers and straddling the peasant and urban worlds.

The purpose of this paper is to describe a low‐cost mobile robot localization and navigation system based on wireless sensor network (WSN). This can be used in extreme environments such as mines, hostile areas, and other places where static nodes cannot be deployed directly.

The distance between robot and beacon nodes is estimated by received signal strength indicator (RSSI). The adaptive Kalman filter algorithm is used to eliminate noise from the RSSI signal. Then, the paper gets the mobile robot's status information which includes position, velocity, and acceleration. In order to improve the real‐time performance of systems and reduce the computation overhead of robot's CPU, the paper chooses a beacon node by some certain rules to implement the localization program. The robot and beacon nodes use the CC2430 as the communication and data‐processing unit.

The experiment shows it has the characteristics of good position precision, is easily realized, and inexpensive.

That the system needs so many beacon nodes, is the main limitation.

A very useful and low‐cost method for mobile robot localization and navigation.

The innovative aspect of the paper is that it attempts an analysis of the localization system based on WSN, by attempting to analyze and explain the model of localization system which includes robot and beacon nodes.

Travel companies are increasingly hosting online communities to extend their initiatives of customer relationship management and gain additional insight into their business. While the benefits to companies from hosting online communities are clear, another closely related issue has not been given comparative attention: Why do customers engage voluntarily in online travel communities? The purpose of this paper is to answer the question by developing and testing a conceptual model that exploring the influence of socialization interactions on customer engagement with the community.

Hypotheses were tested by applying structural equation modeling based on survey data collected from an online travel community (n=665).

The results supported the research hypotheses and demonstrated that socialization interactions (i.e. information and social exchange) in the online travel community are important catalysts for customer engagement.

The contribution of this study is twofold. First, from a theoretical perspective, it offers new insights into the conceptualization of customer engagement and its antecedents in the context of the online travel community. Second, from a pragmatic perspective, the conceptual model derived from this research aids practitioners in stimulating customer engagement from the perspective of socialization interactions.

The purpose of this paper is to investigate thermoregulation properties of different composite phase change materials (PCMs), which could be used in the high temperature environmental conditions to protect human body against the extra heat flow.

Three kinds of composite PCM samples were prepared using the selected pure PCMs, including n-hexadecane, n-octadecane and n-eicosane. The DSC experiment was performed to get the samples’ phase change temperature range and enthalpy. The simulated high temperature experiments were performed using human arms in three different high temperature conditions (40°C, 45°C, 50°C), and the skin temperature variation curves varying with time were obtained. Then a comprehensive index TGP was introduced from the curves and calculated to evaluate the thermoregulation properties of different composite PCM samples comprehensively.

Results show that the composite PCM samples could provide much help to the high temperature human body. It could decrease the skin temperature quickly in a short time and it will not cause the over-cooling phenomenon. Comparing with other two composite PCM samples, the thermoregulation properties of the n-hexadecane and n-eicosane composite PCM is the best.

Using the n-hexadecane and n-eicosane composite PCM may provide people with better protection against the high temperature conditions, which is significative for the manufacture of functional thermoregulating textiles, garments or equipments.

The purpose of this paper is to understand the factors influencing content generation and community initiative in PESCs. Taking advantage of an emerging PESC – Xiaohongshu APP, the study identifies three antecedent resources, including customer-owned knowledge, harmonious passion to shopping and perceived information usefulness, that affect content generating and further community initiative.

Based on the service-dominant (S-D) logic model and resource integration related work, the authors proposed a conceptual framework empirically tested using data of a survey and the real content-generating behavior from 347 respondents.

This paper identifies three resource antecedents of content generating behavior with significant influence. Furthermore, there is a moderating effect of perceived information usefulness among these three resources, which echoes the concept of resource integration. Content generating has a significant and positive influence on community initiative.

First, the paper identified customer and platform resources promoting the prosperity of PESCs, enhancing the research on antecedents of community prosperity. Second, the paper empirically quantifies the process and outcome of resource integration conceptual model. Third, it enriches the understanding of C2C interaction by investigating the value creation process on PESCs. Moreover, findings in the study provide insights for community managers to improve the operation of PESCs.

The purpose of this paper is to summarize the advances in grey system theory research and various application achievements in science and engineering. At the same time, it commemorates the 40th anniversary of the birth of grey system theory and the 10th anniversary of Grey Systems–Theory and Application.

Firstly, the innovations of theoretical research in grey system theory were summarized and some of the widely recognized new results are briefly described. By searching and combing the research results of grey system theory in China national knowledge infrastructure (CNKI) database and Web of Science by Institute for Scientific Information (ISI), this paper shows the rapid development trend of grey system theory in the past 40 years, and the successful applications of grey system theory in the fields of social sciences, natural sciences and engineering technologies.

More than 227 thousands literature were found by input 10 phrases such as grey system, grey number and sequence operator etc. in CNKI database. After entering the new century, the number of grey system papers included in CNKI database is increasing rapidly. Since 2008, more than 10 thousands papers have been included per year and more than 15 thousands papers have been included per year since 2014. Grey system method and model are widely used in physics, chemistry, biology and other fields of natural science, as well as transportation, electric power, machinery and other fields of engineering technology, and a large number of valuable results have been achieved.

It can be seen that the grey system theory plays an important role in promoting China’s scientific and technological progress, innovation and development and high-level talent training from tens of thousands of literatures marked with important national science and technology projects and a large number of grey system literatures published by China’s double first-class universities and double first-class discipline construction universities.

Both innovations of theoretical research and practical application play important role in the growth of new theory. The innovations of theoretical research provide methods and tools for practical application, which is conducive to improve application efficiency and broaden application fields. A large number of practical applications needs have become the source of theoretical innovation and the solid background for the birth of theoretical innovation achievements.

As the grey systems theory has been widely used in the field of sustainable development (SD) research, in the following, a short literature overview will be put forward, starting from the usage of these theories in the economic development, social inclusion and environmental protection contributions to the evolving process of SD during 2011–2021. The purpose of this paper is to identify some key studies from all the SD areas in which the grey systems can be used in order to open and to bring the researchers to new domains in which they can reveal their interest and in which they can successfully use the methods offered by the grey systems theory.

Using the search engine offered by the Google Scholar and the Web of Science (WoS), a literature review has been performed for the grey systems applications on SD research on both grey relational analysis (GRA) and grey forecasting. In addition, some grey evaluation theories – clustering evaluation models and grey target decision models – have also been presented.

Many grey models are widely used in the field of SD. Compared with other methods such as grey prediction, grey evaluation and decision-making model, GRA technology is the most used method, and the research using this method is more than three times that of all other methods.

The present paper identifies some of the most representative examples in which the grey system theory (GST) has been used, but, in the same time, there are a lot of studies that have not been mentioned here due to the lack of space.

The present paper focuses on the SD applications in which GST has been successfully used, bringing to the reader a general overview on this field and, in the same time, enables new research perspectives.

After the occurrence of natural disasters, the rapid and accurate delivery of geo-afforestation is the key to emergency rescue and is the fundamental solution to the “last mile” problem. It provides technical support for the territorial rapid and accurate delivery. The paper aims to discuss this issue.

Through literature and theoretical research, combined with the research experience of scholars, the qualitative research method is adopted. The paper establishes a three-dimensional analysis framework, including disaster predictability, resource availability and transport accessibility, and proposes the integrated delivery triangular technical framework, including integrated monitoring analysis, the territorial virtual public storage and transportation.

Based on the analysis of the factors affecting the effectiveness of emergency delivery, the paper establishes a three-dimensional analysis framework, including disaster predictability, resource availability and transport accessibility, and proposes the integrated delivery triangular technical framework, including integrated monitoring analysis, the territorial virtual public storage and transportation. The triangular technical characteristics and functions of emergency delivery are studied, providing theoretical basis and technical support for effective rescue and emergency planning.

The territorial emergency delivery refers to the process of rapid and accurate delivery without relying on external territorial supplies. The paper establishes a three-dimensional analysis framework, including disaster predictability, resource availability and transport accessibility, and proposes the integrated delivery triangular technical framework, including integrated monitoring analysis, the territorial virtual public storage and transportation.

Exploring the intrinsic connection between the ecological environment and the digital economy and empirically testing how the level of digital economic development affects the ecological environment. Using the entropy weighting method to analyze the weights of the indicators in the digital economic development level and ecological environment system to explore the factors that have the greatest impact on the ecological environment in the indicator system of the digital economic development level so as to deepen the theoretical understanding of the relationship between the level of development of the digital economy and the ecological environment. Explore the regional heterogeneity of the level of development of the digital economy to promote the healthy development of China’s ecological environment proving the difference in the level of development of the digital economy in the east west and central regions of China and the difference in the effect on the ecological environment.

Based on the panel data of 30 provinces in China from 2013 to 2021 this paper fits the index system of digital economy development level with three factors. A digital infrastructure digital industry and digital application combines environmental pollution and energy consumption to construct ecological environment indicators and explored the impact of digital economy development level on the ecological environment by using the entropy weight method and the random effect model.

The findings indicate that the degree of digital economic development has a positive and significant impact on promoting the healthy development of the ecological environment, in which the digital industry has the greatest impact on the ecological environment. Meanwhile, the improvement of industrial structure also has a positive effect on the improvement of the ecological environment, whereas the level of human capital inhibits the healthy development of the ecological environment, and the governmental support fails to effectively and significantly promote the improvement of the ecological environment. Furthermore, the empirical research indicates that the level of digital economy development has obvious regional heterogeneity on the healthy development of the ecological environment: the eastern and central regions have a significant effect, while the western region has a less significant effect.

Although domestic and foreign scholars and experts have conducted sufficient studies on the ecological environment and the development level of digital economy respectively, there are few studies on the empirical analysis of the positive significance and regional heterogeneity of the impact of the development level of digital economy on the ecological environment, which can be supplemented and referred to in this study. At the same time, it also provides intellectual support for our country to achieve high-quality development of digital economy and efficient governance of ecological environment.