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Multi-well hydrofracturing is a key technology in engineering, and the evaluation, control and optimization of the fracturing network determine the recovery rate of unconventional oil and gas production. In engineering terms, altering well spacing and perforation initiation sequences changes fracture propagation behavior. Fracture propagation can result in fracture-to-fracture and well-to-well interactions. This may be attributed to the interference between fractures caused by squeezing of the reservoir strata. Meanwhile, the stratal movement caused by the propagation of the fractures may lead to either the secondary fracturing of wells with primary fractures or perforation to begin fracturing. Besides, the stratal compression and squeeze of multi-well hydrofracturing will cause earthquakes; the fracture size is different owing to the different fracturing scenarios, and the occurrence of induced microseismic events is still unknown; microseismic events also affect fracture orientation and deflection. If the mechanism of the above mechanical behavior cannot be clarified, optimizing the fracture network and reduce the induced microseismic disaster becomes difficult.

In this study, combined finite element-discrete element models were used to simulate the multi-well hydrofracturing. Numerical cases compared the fracture network, dynamic stratal movement and microseismic events at 50, 75 and 100 m well spacings, respectively, and varying initiation sequence of multiple horizontal wells.

From the results, fracture propagation in multi-well hydrofracturing may simulate the propagation and deflection of adjacent fractures and induce fracture-to-fracture and well-to-well interactions. As the well spacing increases, the effect of fracturing-induced stratal movement and squeezing deformation decrease. In alternate fracturing, starting from a well located in the middle can effectively reduce the influence of stratal movement on fracturing, and the fracturing scenario with cross-perforation can minimize the influence of stratal movement. The stratal movement between multiple wells is positively correlated to microseismic events, which behaviors can be effectively weakened by reducing the strata movement.

The fracture network, thermal-hydro-mechanical coupling, fracturing-induced stratal movement and microseismic events were analyzed. This study analyzed the intersection and propagation behavior of fractures in multi-well hydrofracturing, which can be used to evaluate and study the mechanism of hydrofracturing fracture network propagation in multiple horizontal wells and conduct fracture optimization research to form an optimized hydrofracturing scheme by reasonably arranging the spacing between wells and initiation sequences of perforation clusters.

This study aims to develop an adaptive finite element method for structural eigenproblems of cracked Euler–Bernoulli beams via the superconvergent patch recovery displacement technique. This research comprises the numerical algorithm and experimental results for free vibration problems (forward eigenproblems) and damage detection problems (inverse eigenproblems).

The weakened properties analogy is used to describe cracks in this model. The adaptive strategy proposed in this paper provides accurate, efficient and reliable eigensolutions of frequency and mode (i.e. eigenpairs as eigenvalue and eigenfunction) for Euler–Bernoulli beams with multiple cracks. Based on the frequency measurement method for damage detection, using the difference between the actual and computed frequencies of cracked beams, the inverse eigenproblems are solved iteratively for identifying the residuals of locations and sizes of the cracks by the Newton–Raphson iteration technique. In the crack detection, the estimated residuals are added to obtain reliable results, which is an iteration process that will be expedited by more accurate frequency solutions based on the proposed method for free vibration problems.

Numerical results are presented for free vibration problems and damage detection problems of representative non-uniform and geometrically stepped Euler–Bernoulli beams with multiple cracks to demonstrate the effectiveness, efficiency, accuracy and reliability of the proposed method.

The proposed combination of methodologies described in the paper leads to a very powerful approach for free vibration and damage detection of beams with cracks, introducing the mesh refinement, that can be extended to deal with the damage detection of frame structures.

Public libraries are incubators for collective action in the knowledge economy. As three case studies from the United States and Singapore demonstrate, public libraries can serve as influential champions that garner financial resources, communicate an urgent need for change, and respond to the unmet information and economic needs of marginalized individuals and communities. In the Raise Up Radio (RUR) case, public librarians engaged schools, museums, youth, and families in rural communities to develop and deliver STEM (science, technology, engineering, and math) content over local radio stations. In collaboration with organizational partners, RUR librarians created a model for library-community-radio projects for the rural United States. In the What Health Looks Like (WHLL) case, public librarians engaged senior citizens in discussions of health and the creation of health comics. In partnership with an interdisciplinary health research team, WHLL librarians developed a pilot for library-community-public health projects aimed at information dissemination and health narrative generation. In the Singapore shopping mall libraries case, the National Library Board (NLB) created public libraries in commercial spaces serving working families, senior citizens, and the Chinese community. The NLB developed an exportable model for locating information centers in convenient, popular, and useful business spaces. These case studies demonstrate how libraries are nodes in the knowledge economy, providing vital services such as preservation of cultural heritage, technology education, community outreach, information access, and services to working families, small- and medium-size businesses, and other patrons. In the years to come, public libraries will be called upon to respond to shifting social norms, inequitable opportunities, emergencies and disasters, and information asymmetries. As the cases of RUR, WHLL, and the shopping mall libraries show, public librarians have the vision and capacities to serve as influential champions for collective action to solve complex problems and foster sustainable development and equitable participation in the knowledge economy.

This paper aims to present a natural human–robot teleoperation system, which capitalizes on the latest advancements of monocular human pose estimation to simplify scenario requirements on heterogeneous robot arm teleoperation.

Several optimizations in the joint extraction process are carried on to better balance the performance of the pose estimation network. To bridge the gap between human joint pose in Cartesian space and heterogeneous robot joint angle pose in Radian space, a routinized mapping procedure is proposed.

The effectiveness of the developed methods on joint extraction is verified via qualitative and quantitative experiments. The teleoperation experiments on different robots validate the feasibility of the system controlling.

The proposed system provides an intuitive and efficient human–robot teleoperation method with low-cost devices. It also enhances the controllability and flexibility of robot arms by releasing human operator from motion constraints, paving a new way for effective robot teleoperation.

Despite the prevalent use of professional status and service feedback in online healthcare markets, the potential interaction relationship between two types of information is still unknown. This study used the signaling theory to examine the substitute relationship between professional status and service feedback in patients' doctor choice, as well as the moderating effect of illness severity.

To test the paper's hypotheses, we constructed a panel data model using 418 doctors' data collected over a period of six months from an online healthcare market in China. Then, according to the results of the Hausman test, we estimated a fixed-effects model of patients' choice in online healthcare markets.

The empirical results showed that the effect of a doctor's professional status and service feedback on a patient's doctor choice was substitutable. Moreover, patients' illness severity played a moderating role, in that the influence of professional status on a patient with high-severity illness was higher than that on a patient with low-severity illness, whereas the influence of service feedback on a patient with low-severity illness was higher than that of a patient with high-severity illness. In addition, we found that illness severity negatively moderated the substitute relationship between professional status and service feedback on a patient's choice.

These findings not only contribute to signaling theory and research on online healthcare markets, but also help us understand the importance of professional status and service feedback on a patient's choice when seeking a doctor online.

Prior studies on the impact of incentives on physicians’ online participation mainly focused on different incentives while ignoring the difficulty of setting monetary incentives efficiently. Based on goal-setting theory, the current research examines the relationship between incentives with goals of varying difficulty and professional health knowledge sharing (PHKS) in online health knowledge-sharing platforms (OHKSPs).

Four field experiments with different monetary incentives were conducted by one of China’s largest OHKSPs, with whom the researchers cooperated in data collection. Monthly panel data on 10,584 physicians were collected from September 2018 to December 2019. There were 9,376 physicians in the treatment group and 1,208 in the control group. The authors used a difference-in-difference (DID) model to explore the research question based on the same control group and the Chow test with seemingly unrelated estimation (sureg) to compare regression coefficients between four groups. Several robustness checks were performed to validate the main results, including a relative time model, multiple falsification tests and a DID estimation using the propensity score matching method.

The results show that the monetary incentive significantly positively affected the volume of physicians’ PHKS directly with negative spillover to the duration of physicians’ PHKS. Moreover, the positive effect of incentives with higher difficulty on the volume of physicians’ PHKS was significantly smaller than that of incentives with low difficulty. Finally, professional title had a positive moderating effect on the volume of goal difficulty setting and did not significantly moderate the effect on the duration of physicians’ PHKS.

Some limitations of this study are: firstly, because the field experiments were enterprise benefit oriented, the treatment and control groups were not balanced. Secondly, the experiments for different incentive measures were relatively similar, making it challenging to validate a causal effect. Finally, more consideration should be given to the strategy for setting hierarchical incentives in future research.

The research indicates that monetary incentives have a bilateral effect on PHKS, i.e. a positive direct effect on the volume of physicians’ contributions and a negative spillover effect on the duration of physicians’ PHKS. The professional titles of physicians also moderate such bilateral switches of PHKS. Furthermore, when a physician’s energy is limited, the goal difficulty setting of the incentive mechanism tends to be low. The more difficult the incentives are, the more inefficient the effects on physicians’ PHKS will be.

Social media facilitates the communication and the relationship between healthcare professionals and patients. However, limited research has examined the role of social media in a physicians' online return. This study, therefore, investigates physicians' online economic and social capital return in relation to physicians' use of social media and consumer engagement.

Using ordinary least squares (OLS) regression with fixed effects (FE) and panel data collected from Sina Weibo and Sina Health, this study analyzes the impact of physicians' social media use and consumer engagement on physicians' online return and the moderation effect of professional seniority.

The results reveal that physicians' use of social media and consumer sharing behavior positively affect physicians' online economic return. In contrast, consumer engagement positively impacts physicians' online social capital return. While professional seniority enhances the effect of physicians' social media use on online economic return, professional seniority only enhances the relationship between consumers' sharing behavior to the posts and physicians' online social capital return when professional seniority comes to consumer engagement.

This study reveals the different roles of social media use and consumer engagement in physicians' online return. The results also extend and examine the social media affordances theory in online healthcare communities and social media platforms.

This study aims to investigate the dual effects of commitment-based governance on the relationship between formal control and public–private partnership (PPP) project performance. Formal control and relationship governance are two primary forms of inter-organizational governance that affect project performance. However, little is known about the interplay between formal control and commitment and its effect on PPP projects. More specifically, previous studies have failed to distinguish the function routes of relationship governance resulting from different types of formal control (process and outcome control).

This study adopts a questionnaire survey to empirically investigate the mechanism that commitment-based governance influences the relationship between formal control and PPP performance. After collecting data from public and private sector professionals involved in 101 Chinese PPP projects, the theoretical framework proposed in this paper is verified by the empirical results of the hierarchical multiple regression analysis.

The results show that process control has an inverted U-shaped effect and outcome control has a significant positive influence on PPP project performance. Furthermore, commitment moderates the effect of formal control on PPP project performance by increasing the relevance of outcome control and mediates the inverted U-shaped relationship between process control and PPP project performance.

Managers should recognize that process control is a double-edged sword and prevent the overuse of process control. Managers should direct their attention toward efforts to improve the commitment, which allows for the effectiveness of outcome control strategies. Additionally, this study new measurement method for relationship governance suggests that managers should be aware of the difference in parties' perceptions of the relationship.

This study allows for a comprehensive understanding of the relationship governance-control nexus from a commitment perspective. The authors bring into light the dual role of commitment-based governance in the relationship between the two types of formal control and PPP project performance. Moreover, the new approach to measure relationship governance offers valuable insight into the measurement of variables about individual's perception.

Various individual and environmental factors influencing employees’ online knowledge sharing have been identified, but the understanding regarding these has been mostly limited because of their independent and direct effects our understanding has been mostly limited to their independent and direct effects. This study aims to propose that the fit between employees and their environments (PE fit) matters. A model explaining how PE fit and misfit affect employees’ knowledge sharing behavior through influencing their affective commitment is developed and assessed.

The proposed model was assessed with data collected in a survey of 218 employees.

Results indicate that PE fit in the norm of collaboration, innovativeness and skill variety leads to the development of stronger affective commitment and, therefore, more knowledge sharing behavior than when they are in shortfall or excess in the environment (i.e. PE misfit).

The findings indicate a new direction for knowledge sharing research that focuses on PE fit and suggest that knowledge sharing can be improved more proactively in practice by assessing PE fit during recruitment.

In keystroke‐based authentication systems, an input device to enter a password is needed. Users are verified by checking the validity of the password and typing characteristics. However, some devices have no standard desktop keyboard such as personal digital assistants and mobile phones. With these types of electronics, the system cannot successfully work in the authentication phase while the registration process is implemented based on a computer keyboard. This results in a reduction of system portability. The purpose of this paper is to employ the rhythm clicked by a mouse as another identifiable factor to authenticate a user's identity.

Mouse click can be replaced by a stylus and fingers on touch screens or numeral buttons on mobile phones. A total of 25 users participated and the click data are based on time instances of pressing and releasing the mouse button, which are captured while the user clicks a rhythm. Three features are calculated using these click data, and a reasonable amount of results with neural networks and other classifiers shows the click characteristics are able to function as another identifiable factor.

A reasonable amount of results with neural networks and other classifiers shows the click characteristics are able to function as another identifiable factor.

The paper presents a personalized rhythm click‐based authentication system.