We deal with a consensus control problem for a group of third order agents which are networked by digraphs.Assuming that the control input of each agent is constructed based on weighted difference between its states a...We deal with a consensus control problem for a group of third order agents which are networked by digraphs.Assuming that the control input of each agent is constructed based on weighted difference between its states and those of its neighbor agents, we aim to propose an algorithm on computing the weighting coefficients in the control input. The problem is reduced to designing Hurwitz polynomials with real or complex coefficients. We show that by using Hurwitz polynomials with complex coefficients, a necessary and sufficient condition can be obtained for designing the consensus algorithm. Since the condition is both necessary and sufficient, we provide a kind of parametrization for all the weighting coefficients achieving consensus. Moreover, the condition is a natural extension to second order consensus, and is reasonable and practical due to its comparatively decreased computation burden. The result is also extended to the case where communication delay exists in the control input.展开更多
The complex relationship between structural connectivity(SC) and functional connectivity(FC) of human brain networks is still a critical problem in neuroscience. In order to investigate the role of SC in shaping resti...The complex relationship between structural connectivity(SC) and functional connectivity(FC) of human brain networks is still a critical problem in neuroscience. In order to investigate the role of SC in shaping resting-state FC, numerous models have been proposed. Here, we use a simple dynamic model based on the susceptible-infected-susceptible(SIS) model along the shortest paths to predict FC from SC. Unlike the previous dynamic model based on SIS theory, we focus on the shortest paths as the principal routes to transmit signals rather than the empirical structural brain network. We first simplify the structurally connected network into an efficient propagation network according to the shortest paths and then combine SIS infection theory with the efficient network to simulate the dynamic process of human brain activity. Finally, we perform an extensive comparison study between the dynamic models embedded in the efficient network, the dynamic model embedded in the structurally connected network and dynamic mean field(DMF) model predicting FC from SC. Extensive experiments on two different resolution datasets indicate that i) the dynamic model simulated on the shortest paths can predict FC among both structurally connected and unconnected node pairs; ii) though there are fewer links in the efficient propagation network, the predictive power of FC derived from the efficient propagation network is better than the dynamic model simulated on a structural brain network; iii) in comparison with the DMF model,the dynamic model embedded in the shortest paths is found to perform better to predict FC.展开更多
Background： A positive association between fundamental movement skills （FMS） and physical activity （PA） has been shown in previous research of children with and without disability. This pilot study explored a cau...Background： A positive association between fundamental movement skills （FMS） and physical activity （PA） has been shown in previous research of children with and without disability. This pilot study explored a causal mechanism for such relationship, and hypothesized that when FMS proficiency is improved, enhanced PA uptake will be found in children with and without disability. It was further hypothesized that improving FMS proficiency will have a greater impact on children with disability than those without disability. Methods： Participants include typically developing （TD） children without disability and children with cerebral palsy （CP）, who were allocated to FMS training groups （CP-FMS n = 12, TD-FMS n = 13） and control groups （CP-C n = 12, TD-C n = 13）. Training groups practiced five FMS （run, jump, kick, throw, catch） in weekly 45-min sessions for 4 weeks. Control groups had their regular physiotherapy （CP） or physical education （TD） sessions. FMS were evaluated using process- and product-oriented measures, and PA was measured using accelerometers, before and after training. Results： It was verified that training groups gained improvements in FMS while control groups did not. No significant changes in weekday PA were found. Increased weekend moderate to vigorous physical activity （MVPA） was found in the CP-FMS group, while decreased weekend sedentary time was found in the CP-FMS and TD-FMS groups. The percentages of participants who exceeded the minimum detectable change （MDC9o） in MVPA and sedentary time were larger in children with CP than in children without disability. Conclusion： The findings suggest that improved FMS proficiency could potentially contribute to heightened PA and decreased sedentary time during weekends for children. Such effect of improved FMS proficiency on PA appears to be greater in those with physical disability than in those without disability. It is recommended that the findings of this pilot study should be further examined in future research.展开更多
基金supported by Japan Ministry of Education,Sciences and Culture(C21560471)the National Natural Science Foundation of China(61603268)+1 种基金the Research Project Supported by Shanxi Scholarship Council of China(2015-044)the Fundamental Research Project of Shanxi Province(2015021085)
文摘We deal with a consensus control problem for a group of third order agents which are networked by digraphs.Assuming that the control input of each agent is constructed based on weighted difference between its states and those of its neighbor agents, we aim to propose an algorithm on computing the weighting coefficients in the control input. The problem is reduced to designing Hurwitz polynomials with real or complex coefficients. We show that by using Hurwitz polynomials with complex coefficients, a necessary and sufficient condition can be obtained for designing the consensus algorithm. Since the condition is both necessary and sufficient, we provide a kind of parametrization for all the weighting coefficients achieving consensus. Moreover, the condition is a natural extension to second order consensus, and is reasonable and practical due to its comparatively decreased computation burden. The result is also extended to the case where communication delay exists in the control input.
基金supported by China Scholarship Council(201306455001)the National Natural Science Foundation of China(61271407)the Fundamental Research Funds for the Central Universities(16CX06050A)
文摘The complex relationship between structural connectivity(SC) and functional connectivity(FC) of human brain networks is still a critical problem in neuroscience. In order to investigate the role of SC in shaping resting-state FC, numerous models have been proposed. Here, we use a simple dynamic model based on the susceptible-infected-susceptible(SIS) model along the shortest paths to predict FC from SC. Unlike the previous dynamic model based on SIS theory, we focus on the shortest paths as the principal routes to transmit signals rather than the empirical structural brain network. We first simplify the structurally connected network into an efficient propagation network according to the shortest paths and then combine SIS infection theory with the efficient network to simulate the dynamic process of human brain activity. Finally, we perform an extensive comparison study between the dynamic models embedded in the efficient network, the dynamic model embedded in the structurally connected network and dynamic mean field(DMF) model predicting FC from SC. Extensive experiments on two different resolution datasets indicate that i) the dynamic model simulated on the shortest paths can predict FC among both structurally connected and unconnected node pairs; ii) though there are fewer links in the efficient propagation network, the predictive power of FC derived from the efficient propagation network is better than the dynamic model simulated on a structural brain network; iii) in comparison with the DMF model,the dynamic model embedded in the shortest paths is found to perform better to predict FC.
基金supported by the Sciences of Learning Strategic Research Theme of the University of Hong Kong
文摘Background： A positive association between fundamental movement skills （FMS） and physical activity （PA） has been shown in previous research of children with and without disability. This pilot study explored a causal mechanism for such relationship, and hypothesized that when FMS proficiency is improved, enhanced PA uptake will be found in children with and without disability. It was further hypothesized that improving FMS proficiency will have a greater impact on children with disability than those without disability. Methods： Participants include typically developing （TD） children without disability and children with cerebral palsy （CP）, who were allocated to FMS training groups （CP-FMS n = 12, TD-FMS n = 13） and control groups （CP-C n = 12, TD-C n = 13）. Training groups practiced five FMS （run, jump, kick, throw, catch） in weekly 45-min sessions for 4 weeks. Control groups had their regular physiotherapy （CP） or physical education （TD） sessions. FMS were evaluated using process- and product-oriented measures, and PA was measured using accelerometers, before and after training. Results： It was verified that training groups gained improvements in FMS while control groups did not. No significant changes in weekday PA were found. Increased weekend moderate to vigorous physical activity （MVPA） was found in the CP-FMS group, while decreased weekend sedentary time was found in the CP-FMS and TD-FMS groups. The percentages of participants who exceeded the minimum detectable change （MDC9o） in MVPA and sedentary time were larger in children with CP than in children without disability. Conclusion： The findings suggest that improved FMS proficiency could potentially contribute to heightened PA and decreased sedentary time during weekends for children. Such effect of improved FMS proficiency on PA appears to be greater in those with physical disability than in those without disability. It is recommended that the findings of this pilot study should be further examined in future research.
