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The purpose of this paper is to design a multi-sensory anthropomorphic prosthetic hand and a grasping controller that can detect the slip and automatically adjust the grasping force to prevent the slip.

To improve the dexterity, sensing, controllability and practicability of a prosthetic hand, a modular and multi-sensory prosthetic hand was presented. In addition, a slip prevention control based on the tactile feedback was proposed to improve the grasp stability. The proposed controller identifies slippages through detecting the high-frequency vibration signal at the sliding surface in real time and the discrete wavelet transform (DWT) was used to extract the eigenvalues to identify slippages. Once the slip is detected, a direct-feedback method of adjusting the grasp force related with the sliding times was used to prevent it. Furthermore, the stiffness of different objects was estimated and used to improve the grasp force control. The performances of the stiffness estimation, slip detection and slip control are experimentally evaluated.

It was found from the experiment of stiffness estimation that the accuracy rate of identification of the hard metal bottle could reach to 90%, while the accuracy rate of identification of the plastic bottles could reach to 80%. There was a small misjudgment rate in the identification of hard and soft plastic bottles. The stiffness of soft plastic bottles, hard plastic bottles and metal bottles were 0.64 N/mm, 1.36 N/mm and 32.55 N/mm, respectively. The results of slip detection and control show that the proposed prosthetic hand with a slip prevention controller can fast and effectively detect and prevent the slip for different disturbances, which has a certain application prospect.

Due to the small size, low weight, high integration and modularity, the prosthetic hand is easily applied to upper-limb amputees. Meanwhile, the method of the slip prevention control can be used for upper-limb amputees to complete more tasks stably in daily lives.

A multi-sensory anthropomorphic prosthetic hand is designed, and a method of stable grasps control based on slip detection by a tactile sensor on the fingertip is proposed. The method combines the stiffness estimation of the object and the real-time slip detection based on DWT with the design of the proportion differentiation robust controller based on a disturbance observer and the force controller to achieve slip prevention and stable grasps. It is verified effectively by the experiments and is easy to be applied to commercial prostheses.

This paper aims to investigate the additive manufacturing (AM) approach of a spatial complex curve feature (SCCF, mapped from two-dimensional nonuniform rational B-splines [2D-NURBS] curve) on a complex surface based on a serial robot using plasma built-up welding, and lays a foundation for plasma AM SCCFs on complex surfaces by combining the NURBS theory with the serial robotic kinematics.

Combining serial robotic kinematics and NURBS theory, a SCCF mapped from a square-like 2D-NURBS curve is prepared on a predefined complex NURBS surface using serial robotic plasma AM. The interpolation points C (ui) on the square-like 2D-NURBS curve are obtained using the equi-chord length interpolation method, and mapped on a predefined NURBS surface to get mapped points S (ui, vj). The homogeneous transformation matrix T = [n o a S (ui, vj)] of the plasma torch is calculated using the mapped points S (ui, vj) and the designated posture [n o a]. Using the inverse kinematics of the serial robot, the joint vector θ of the serial robot can be computed. After that, the AM programs are generated and transferred into the serial robotic controller and carried out by the serial robot of Motoman-UP6. The 2D-NURBS curve (square-like) is considered as AM trajectory planning curve, while its corresponding SCCF mapped from the 2D-NURBS curve as AM trajectory.

Simulation and experiments show that the preparation of SCCF (mapped from 2D-NURBS curve) on complex NURBS surface using robotic plasma AM is feasible and effective.

A SCCF mapped from a 2D-NURBS curve is prepared on a complex NURBS surface using the serial robotic plasma AM for the first time. It provides a theoretical and technical basis for plasma AM to produce SCCFs on complex surfaces. With the increasing demand for surface remanufacturing of complex parts, the serial robotic plasma AM of SCCFs on complex NURBS surfaces has a broad application prospect in aero-engine components, high-speed rail power components, nuclear industry components and complex molds.

This study aims to explore the social networks and network interactions of bed-and-breakfast (B&B) entrepreneurs in rural China. In addition, it evaluates how such network interactions relate to rural resilience.

In-depth interviews were performed in two locations: Ningbo and Dujiangyan, China. Purposive sampling was combined with snowball sampling to select interviewees. The 154 interviews involved 29 B&B owners and relevant social actors. All codes and data were analyzed using the discourse analysis framework.

The B&B owners’ social networks were identified based on strategic goals, revealing a business operation network, business development network and business citizenship network. Challenges in seeking financial support for rural B&Bs during the pandemic were specified along with network interactions. The institutional adaptation approach was used to evaluate network interaction in rural B&B business. It was argued that other networks would react based on primary network members’ goal compatibility and the effectiveness of the primary network in addressing obstacles.

This study indicates that the rural B&B entrepreneurs’ interactions with various networks could influence on business resilience, community resilience as well as rural resilience.

By combining the institutional adaptation typology with social network theory, this study generates a new typology of network interactions for rural B&Bs. The typology helps to explain how and why B&B entrepreneurs make decisions and provides a broader scope of social networks involved in these business operations.

In this study, the authors use the term “e-quality” to refer to information quality, system quality and service quality. This study aims to focus on e-quality, exploring and comparing users' perceptions of digital libraries and virtual communities in the hope that the results of this study can help lead to better understanding of the exact nature of e-quality as perceived by users.

A large-scale survey was conducted for data collection. Data collected from 334 users of digital libraries and virtual communities were used for data analysis.

The study finds that users are likely to perceive a higher level of information quality, system quality and service quality of digital libraries than of virtual communities.

The authors suggest that librarians do not need to have concerns over the challenge brought by virtual communities, which indeed have an increasing impact on the way a lot of people seek and gather information. Instead, they should encourage their users to use both digital libraries and virtual communities. The authors believe that the usage of these two types of information sources by users can efficiently inform each other, thus facilitating the e-quality of both digital libraries and virtual communities to reach excellence.

Building on the information systems (IS) success model, this study explores and compares users' perceptions of digital libraries and virtual communities in terms of e-quality, which the authors think presents a new view for digital library research and practice alike.

The economic law of population distribution and migration has been studied chiefly based on the Chinese situation. The distribution and development of productive forces decide the distribution and migration of population, and in turn, the latter influences the former. The population distributions in three different stages of social development, namely agricultural, industrial and information society, are described. A new concept in population economics is introduced, i.e. population economic density, which is different from the concept of population density. The formula of population economic density is P(population)/R(resources). Many kinds of migration are analysed, and it is believed that the main efficient cause of migration is economy.

The purpose of this paper is to examine how the sentiment of social networking site (SNS)-based brand-related electronic word-of-mouths (eWOMs) influences consumers’ engagement in brand value co-creation and brand trust change, thereby influencing their purchase intention for the brand; and explores a potential moderating effect of mavenism.

A sample of 237 college students participated in an online survey to report brand-related eWOM stories to which they were exposed and the brand trust change, brand value co-creation behavior and attitude and purchase intention in response to this exposure. The eWOM stories were content analyzed into positive vs negative eWOM. Structural equation modeling was used to test all hypotheses.

Participants reported a significantly higher level of brand value co-creation engagement behavior and more positive brand value co-creation engagement attitude and brand trust change after seeing a positive (vs negative) brand-related eWOM on SNSs. Brand trust change and value co-creation engagement attitude positively influenced purchase intention. The moderating effect of mavenism was not significant.

Findings suggest that brand marketers should actively monitor and respond to the sentiment of SNS-based eWOMs and establish strategies to encourage consumers to create and share positive eWOMs on SNSs.

This study contributes to closing the empirical gap in SNS-based eWOM research by providing support for brand-related eWOM sentiment as a significant motivational factor triggering consumers’ engagement in brand value co-creation and brand trust change on SNSs as well as purchase intention.