Traditional loss-based transports cannot meet the strict requirements of low latency and high throughput in data center networks(DCNs).Thus data center transmission control protocol(DCTCP)is proposed to better manage ...Traditional loss-based transports cannot meet the strict requirements of low latency and high throughput in data center networks(DCNs).Thus data center transmission control protocol(DCTCP)is proposed to better manage the congestion control in DCNs.To provide insight into improving the stability of the DCN,this paper focuses on the Hopf bifurcation analysis of a fluid model of DCTCP,and investigates the stability of the network.The round-trip time(RTT),being an effective congestion signal,is selected as the bifurcation parameter.And the network turns unstable and generates periodic solutions when the parameter is larger than the given critical value,which is given by explicit algorithms.The analytical results reveal the existence of Hopf bifurcation.Numerical simulations are performed to make a comparative analysis between the fluid model and the simplified model of DCTCP.The influence of other parameters on the DCN stability is also discussed.展开更多
One of the fundamental problems in pinning control of complex networks is selecting appropriate pinning nodes, such that the whole system is controlled. This is particularly useful for complex networks with huge numbe...One of the fundamental problems in pinning control of complex networks is selecting appropriate pinning nodes, such that the whole system is controlled. This is particularly useful for complex networks with huge numbers of nodes. Recent research has yielded several pinning node selection strategies, which may be efficient. However, selecting a set of pinning nodes and identifying the nodes that should be selected first remain challenging problems. In this paper, we present a network control strategy based on left Perron vector. For directed networks where nodes have the same in-and out-degrees, there has so far been no effective pinning node selection strategy, but our method can find suitable nodes. Likewise, our method also performs well for undirected networks where the nodes have the same degree. In addition, we can derive the minimum set of pinning nodes and the order in which they should be selected for given coupling strengths. Our proofs of these results depend on the properties of non-negative matrices and M-matrices. Several examples show that this strategy can effectively select appropriate pinning nodes, and that it can achieve better results for both directed and undirected networks.展开更多
In this paper, we address the problem of bifurcation control for a delayed neuron system. By introducing a new fractional-order Proportional-Derivative(PD) feedback controller, this paper aims to control the stability...In this paper, we address the problem of bifurcation control for a delayed neuron system. By introducing a new fractional-order Proportional-Derivative(PD) feedback controller, this paper aims to control the stability and Hopf bifurcation through adjusting the control gain parameters. The order chosen in PD controller is different with that of the integer-order neuron system. Sufficient conditions for guaranteeing the stability and generating Hopf bifurcation are constructed for the controlled neuron system. Finally,numerical simulation results are illustrated to verify our theoretical derivations and the relationships between the onset of the Hopf bifurcation and the gain parameters are obtained.展开更多
基金supported by the Natural Science Foundation of Shandong Province of China(ZR2020MF080)。
文摘Traditional loss-based transports cannot meet the strict requirements of low latency and high throughput in data center networks(DCNs).Thus data center transmission control protocol(DCTCP)is proposed to better manage the congestion control in DCNs.To provide insight into improving the stability of the DCN,this paper focuses on the Hopf bifurcation analysis of a fluid model of DCTCP,and investigates the stability of the network.The round-trip time(RTT),being an effective congestion signal,is selected as the bifurcation parameter.And the network turns unstable and generates periodic solutions when the parameter is larger than the given critical value,which is given by explicit algorithms.The analytical results reveal the existence of Hopf bifurcation.Numerical simulations are performed to make a comparative analysis between the fluid model and the simplified model of DCTCP.The influence of other parameters on the DCN stability is also discussed.
基金supported by the National Natural Science Foundation of China(Grant Nos.61573096,61374011,61833005)the China Postdoctoral Science Foundation(Grant No.2014M561557)+1 种基金the Shandong Province University Scientific Research Project of China(Grant No.J15LI12)the Postdoctoral Science Foundation of Jiangsu Province of China(Grant No.1402040B)
文摘One of the fundamental problems in pinning control of complex networks is selecting appropriate pinning nodes, such that the whole system is controlled. This is particularly useful for complex networks with huge numbers of nodes. Recent research has yielded several pinning node selection strategies, which may be efficient. However, selecting a set of pinning nodes and identifying the nodes that should be selected first remain challenging problems. In this paper, we present a network control strategy based on left Perron vector. For directed networks where nodes have the same in-and out-degrees, there has so far been no effective pinning node selection strategy, but our method can find suitable nodes. Likewise, our method also performs well for undirected networks where the nodes have the same degree. In addition, we can derive the minimum set of pinning nodes and the order in which they should be selected for given coupling strengths. Our proofs of these results depend on the properties of non-negative matrices and M-matrices. Several examples show that this strategy can effectively select appropriate pinning nodes, and that it can achieve better results for both directed and undirected networks.
基金supported by the National Natural Science Foundation of China(Grant Nos. 61573194, 51775284)the Natural Science Foundation of Jiangsu Province of China(Grant Nos. BK20181389, BK20171441)+1 种基金the Key Project of Philosophy and Social Science Research in Colleges and Universities in Jiangsu Province(Grant No. 2018SJZDI142)the Australian Research Council(Grant No. DP120104986)
文摘In this paper, we address the problem of bifurcation control for a delayed neuron system. By introducing a new fractional-order Proportional-Derivative(PD) feedback controller, this paper aims to control the stability and Hopf bifurcation through adjusting the control gain parameters. The order chosen in PD controller is different with that of the integer-order neuron system. Sufficient conditions for guaranteeing the stability and generating Hopf bifurcation are constructed for the controlled neuron system. Finally,numerical simulation results are illustrated to verify our theoretical derivations and the relationships between the onset of the Hopf bifurcation and the gain parameters are obtained.