PU- and P*U*-equivalent parallel mechanisms (PMs) are critical families of PMs with one translational and two rotational (1T2R) degree of freedoms and have always been a research hotspot among lower mobility PMs. However, researches on these two families of PMs remain to be inadequate, and existing types are few and uncomprehensive. In this study, first, general wrench systems of PU-equivalent are derived based on virtual-chain approach and screw theory, revealing its constraint characteristics under general configuration. Cause of one parasitic motion is put forward and general wrench systems of P*U*-equivalent PMs with one parasitic motion are obtained. In addition, constraint analysis has been carried out to figure out constraint characteristics of P*U*-equivalent PMs with three parasitic motions. Second, branch chains are divided by generating constraints, and their structures are synthesized based on the presented rules. Then, the process for type synthesis of PU-equivalent PMs and P*U*-equivalent PMs and a series of novel 1T2R PMs are attained based on this. Finally, a novel PU-equivalent PM, 2PRU-PRUPc, and a novel P*U*-equivalent PM with one parasitic motion, 2PRU-PUU PM, are analyzed, demonstrating the effectiveness of the proposed type synthesis method.
Abstract-Virtual learning community, as a new model of network education, is widely used in the process of learning. But this kind of way is not gradually satisfying people's needs for more intelligent and personalized. Teaching strategy in virtual learning community is an important research direction of intelligent reasoning and it is the key to realize intelligent which has great role in promoting for it. In this paper, the fuzzy cmeans clustering algorithm is applied to analysis of the characteristics of learning and grouped from the perspective of teaching strategy and reasoning in virtual learning community. And the model of teaching strategy reasoning mechanism based on learning characteristics is designed which use the cosine similarity and grouping clustering center vector and teaching part of the matching degree of policy rule conditions by setting the threshold of matching processing. Formulate specific feasible learning tasks and teaching strategies will be made for the learners. Through the simulation experiments it is found that the teaching strategy reasoning algorithm is feasible and it has achieved good results.Keywords-virtual learning community; the fuzzy c-means clustering algorithm; learning characteristic; teaching strategy reasoning mechanism.
In recent years, with the development of the Internet and network learning community rapid development, information technology is changing people's ways of e-learning with amazing speed. At the same time, learning trek, knowledge overload problems gradually emerged. Personalized learning recommendation has gradually become an important means for people to quickly learn and master the knowledge, but also reflects the people-oriented personalized learning mode. However, recommendation algorithm based on collaborative filtering still faces problems such as sparsity, scalability, cold start and precision. In this paper, a multi Agent collaborative filtering model based on double layer behavior is proposed for the problem of data sparsity and accuracy. Using social network relationship and dynamic agent perception and the ability to interact with learning, combined with individual behavior to measure the degree of interest, group behavior measure of trust and influence of learning resources for collaborative forecasting scale, reduce the score prediction error and the problem of learning trek.
Based on some features of supply chain, game theory is utilized to analyze the behaviors of nodal enterprises in supply chain. the results of analysis show that the process of games among nodal enterprises belongs to non-zero-sum cooperative games, dynamic games and incomplete information games. Then, for the nodal enterprises in supply chain, the model of non-zero-sum cooperative and dynamic games is established. Furthermore, the core method is improved by introducing a subsidy variable. Solution of model by applying the improved core method and the Shapley value method combined with cooperative game theory is used as the criterion of payoff allocation for nodal enterprises. Finally, researching potentials and suggestions about supply chain coordination and incentive are proposed. The work of this paper provides the theory basis and the direction of further research for the coordination mechanism and the incentive mechanism among nodal enterprises.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.