231 research outputs found
Do Physicians’ Online Activities Impact Outpatient Visits? An Examination of Online Health Communities
The medical service on online health communities (OHCs) has created an additional touch point whereby physicians can interact with patients and extends physicians’ service from hospitals to the online environment. As the supplement and improvement of physicians’ diagnosis and treatment services, online consultation services can make full use of physicians’ spare time. Despite heated debates about the pros and cons of the online services to the traditional services in the hospitals, little empirical work has been conducted to examine it. We seek to understand and measure the impacts of physicians’ various activities online on their outpatient visits in the hospitals. By collecting a panel dataset from an OHC and a hospital in China, we find that participation in the OHCs leads to an increase in outpatient visits. We provide insights for physicians about how to increase patient visits in the emerging era of the Internet medical
The Why of Abandonment: Effects of Team Diversity and Leadership Type on the Disbandment and Stagnation of Online Medical Teams
Medical teams (MTs) online could provide more comprehensive and rapid services to patients through the collaboration among physicians. Numerous doctors have participated, but parts of MTs disband or stagnate after a period, so this pressing issue is in need of relief through exploring the reasons. Effects of team diversity, leadership types and their interaction on the team disbandment and stagnation were studied. This study comprehensively examined a sample of 1,071 MTs online, the total MTs on January 10, 2018, and we crawled the data from a leading OHC in China. Logistic regression was utilized. Results revealed team state would be influenced by team diversity and its interaction with leadership type, so the combination pairwise of the leadership and team diversity could reduce the abandonment possibility. Implications in theory and practice about the dealing with the abandonment crisis in online health community, and limitations are discussed
Multi-Objective Topology Optimization for Curved Arm of Multifunctional Billet Tong Based on Characterization of Working Conditions
A windlass driven heavy duty multifunctional billet tong was designed for large-scale forging and casting to reduce the number of auxiliary material handling devices in manufacturing workshops. To improve its mechanical performance and safety, a novel multi-objective topology optimization method for its curved arm is proposed in this paper. Firstly, the influence of different open angles and working frequencies for the curved arm was simplified to a multi-objective optimization problem. A comprehensive evaluation function was constructed using the compromise programming method, and a mathematical model of multi-objective topology optimization was established. Meanwhile, a radar chart was employed to portray the comparative measures of working conditions, the weight coefficient for each working condition was determined based on the corresponding enclosed areas, combining the stress indices, the displacement indices and the frequency indices of all working conditions. The optimization results showed that the stiffness and strength of the curved arm can be improved while its weight can be reduced by 10.77%, which shows that it is feasible and promising to achieve a lightweight design of the curved arm of a billet tong. The proposed method can be extended to other equipment with complex working conditions
Multi-Objective Topology Optimization for Curved Arm of Multifunctional Billet Tong Based on Characterization of Working Conditions
A windlass driven heavy duty multifunctional billet tong was designed for large-scale forging and casting to reduce the number of auxiliary material handling devices in manufacturing workshops. To improve its mechanical performance and safety, a novel multi-objective topology optimization method for its curved arm is proposed in this paper. Firstly, the influence of different open angles and working frequencies for the curved arm was simplified to a multi-objective optimization problem. A comprehensive evaluation function was constructed using the compromise programming method, and a mathematical model of multi-objective topology optimization was established. Meanwhile, a radar chart was employed to portray the comparative measures of working conditions, the weight coefficient for each working condition was determined based on the corresponding enclosed areas, combining the stress indices, the displacement indices and the frequency indices of all working conditions. The optimization results showed that the stiffness and strength of the curved arm can be improved while its weight can be reduced by 10.77%, which shows that it is feasible and promising to achieve a lightweight design of the curved arm of a billet tong. The proposed method can be extended to other equipment with complex working conditions
AN IMPROVED BARE-BONES PARTICLE SWARM ALGORITHM FOR MULTI-OBJECTIVE OPTIMIZATION WITH APPLICATION TO THE ENGINEERING STRUCTURES
In this paper, an improved bare-bones multi-objective particle swarm algorithm is proposed to solve the multi-objective size optimization problems with non-linearity and constraints in structural design and optimization. Firstly, the development of particle individual guide and the randomness of gravity factor are increased by modifying the updated form of particle position. Then, the combination of spatial grid density and congestion distance ranking is used to maintain the external archive, which is divided into two parts: feasible solution set and infeasible solution set. Next, the global best positions are determined by increasing the probability allocation strategy which varies with time. The algorithmic complexity is given and the performance of solution ability, convergence and constraint processing are analyzed through standard test functions and compared with other algorithms. Next, as a case study, a support frame of triangle track wheel is optimized by the BB-MOPSO and improved BB-MOPSO. The results show that the improved algorithm improves the cross-region exploration, optimal solution distribution and convergence of the bare-bones particle swarm optimization algorithm, which can effectively solve the multi-objective size optimization problem with non-linearity and constraints
DESIGN AND OPTIMIZATION OF THE VARIABLE-DENSITY LATTICE STRUCTURE BASED ON LOAD PATHS
Lattice structure is more and more widely used in engineering by replacing solid structure. But its mechanical performances are constrained by the external shape if the unit cells are directly filled in the design domain, and the traditional topology optimization methods are difficult to give the explicitly mechanical guidance for the distribution of internal unit cells. In this paper, a novel design and optimization method of variable-density lattice structure is proposed in order to simultaneously optimize the external shape and the internal unit cells. First of all, the envelope model of any given structure should be established, and the load paths need to be visualized by the theory of load path. Then, the design criteria of external shape are established based on the principle of smoother load paths in the structure. An index of load flow capacity is defined to indicate the load paths density and to control the density distribution of unit cells, and a detailed optimization strategy is given. Finally, three examples of a cantilever plate, an L-shaped bracket and a classical three-point bending beam are used to verify the method. The results show that the models designed by the proposed method have better mechanical performances, lower material usage and less printing time
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