A new paradigm of scalable routing for ICN is to combine a geometric routing scheme with a Distributed Hash Table. However, for most routing schemes in this paradigm, when a node joins or leaves, large numbers of node...A new paradigm of scalable routing for ICN is to combine a geometric routing scheme with a Distributed Hash Table. However, for most routing schemes in this paradigm, when a node joins or leaves, large numbers of nodes, even the whole topology, need to be re-embedded, and a great number of contents need to be re-registered. In this paper, we propose D-Griffin, a geometric routing scheme on flat names for dynamic topologies. D-Griffin provides two advantages. First, it avoids re-embedding the topology by using an online greedy embedding scheme and a void handling greedy forwarding scheme. Second, it decreases the number of re-registrations by using a name mapping scheme with a tradeoff between topology independence and load balancing. Theoretical and experimental analyses show that D-Griffin provides guaranteed content lookup, low description complexity, low path stretch, scalable routing update, and acceptable load balancing.展开更多
The key problem in unstructured P2P system is how to control "Flood".Some studies focus on constructing more efficient topology while others focus on better query algorithms.This paper presents HICUS(Hierarc...The key problem in unstructured P2P system is how to control "Flood".Some studies focus on constructing more efficient topology while others focus on better query algorithms.This paper presents HICUS(Hierarchical Interest-driven Community-based Unstructured System) motivated by a basic thought-whether the resources correlate with topology distinguishes structured and unstruc-tured P2P essentially.By introducing hierarchical "interest",HICUS organizes a quasi-structured topology through a pure distributed way,and provides a new platform for query algorithms.We study the procedure and performance of topology organization,and the simulations show that HICUS forms a small-world which can significantly improve the routing efficiency.展开更多
The phenomenon of data explosion represents a severe challenge for the upcoming big data era.However,the current Internet architecture is insufficient for dealing with a huge amount of traffic owing to an increase in ...The phenomenon of data explosion represents a severe challenge for the upcoming big data era.However,the current Internet architecture is insufficient for dealing with a huge amount of traffic owing to an increase in redundant content transmission and the end-point-based communication model.Information-centric networking(ICN)is a paradigm for the future Internet that can be utilized to resolve the data explosion problem.In this paper,we focus on content-centric networking(CCN),one of the key candidate ICN architectures.CCN has been studied in various network environments with the aim of relieving network and server burden,especially in name-based forwarding and in-network caching functionalities.This paper studies the effect of several caching strategies in the CCN domain from the perspective of network and server overhead.Thus,we comprehensively analyze the in-network caching performance of CCN under several popular cache replication methods(i.e.,cache placement).We evaluate the performance with respect to wellknown Internet traffic patterns that follow certain probabilistic distributions,such as the Zipf/Mandelbrot–Zipf distributions,and flashcrowds.For the experiments,we developed an OPNET-based CCN simulator with a realistic Internet-like topology.展开更多
This paper proposes a simple and efficient distributed algorithm for calculating minimal dominating set in wireless sensor network. This method can avoid maintaining the connectivities between backbone hosts. Consider...This paper proposes a simple and efficient distributed algorithm for calculating minimal dominating set in wireless sensor network. This method can avoid maintaining the connectivities between backbone hosts. Considering that the hosts in mobile networks have different characteristics, this paper proposes a method of calculating minimal dominating set with weight. The nodes can be chosen to form a minimal dominating set when the network topology changes. For the host switch on/off operation, the updating algorithm was provided. The change in the status of a hostaffects only the status of hosts in the restricted vicinity. Simulation results show that the proposed method can ensure fewer dominators but with higher weight to form the minimal dominating set and the nodes can be adaptive to the changes of network topology.展开更多
Communication bandwidth and network topology are two important factors that affect performance of distributed consensus in multi-agent systems.The available works about quantized average consensus assume that the adja...Communication bandwidth and network topology are two important factors that affect performance of distributed consensus in multi-agent systems.The available works about quantized average consensus assume that the adjacency matrices associated with the digraphs are doubly stochastic,which amounts to that the digital networks are balanced.However,this assumption may be unrealistic in practice.In this paper,without assuming double stochasticity,the authors revisit an existing quantized average consensus protocol with the logarithmic quantization scheme,and investigate the quantized consensus problem in general directed digital networks that are strongly connected but not necessarily balanced.The authors first derive an achievable upper bound of the quantization precision parameter to design suitable logarithmic quantizer,and this bound explicitly depends on network topology.Subsequently,by means of the matrix transformation and the Lyapunov techniques,the authors provide a testable condition under which the weighted average consensus can be achieved with the proposed quantized protocol.展开更多
This paper addresses the distributed attitude synchronization problem of multiple spacecraft with unknown inertia matrices. Two distributed adaptive controllers are proposed for the cases with and without a virtual le...This paper addresses the distributed attitude synchronization problem of multiple spacecraft with unknown inertia matrices. Two distributed adaptive controllers are proposed for the cases with and without a virtual leader to which a time-varying reference attitude is assigned. The first controller achieves attitude synchronization for a group of spacecraft with a leaderless communication topology having a directed spanning tree. The second controller guarantees that all spacecraft track the reference attitude if the virtual leader has a directed path to all other spacecraft. Simulation examples are presented to illustrate the effectiveness of the results.展开更多
This paper addresses attitude synchronization problems for systems of multiple rigid-body agents with directed interconnection topologies.Two scenarios which differ in available information are considered.In the first...This paper addresses attitude synchronization problems for systems of multiple rigid-body agents with directed interconnection topologies.Two scenarios which differ in available information are considered.In the first scenario the agents can obtain their rotations and angular velocities relative to an inertial reference frame and transmit these information to their neighbors,while in the second scenario the agents can only obtain their own angular velocities and measure the relative rotations and relative angular velocities of their neighbors.By using rotation vectors and the high gain control,the authors provide torque control laws asymptotically synchronizing the rotations of the system almost globally for the first scenario and with initial rotations of the agents contained in a convex ball of SO(3)for the second scenario.An illustrative example is provided to show the synchronization results for both scenarios.展开更多
基金supported in part by the National Key Basic Research Program of China(973 Program) under Grant No. 2011CB302605,2013CB329602the National Natural Science Foundation of China under Grant No.61202457,61402149
文摘A new paradigm of scalable routing for ICN is to combine a geometric routing scheme with a Distributed Hash Table. However, for most routing schemes in this paradigm, when a node joins or leaves, large numbers of nodes, even the whole topology, need to be re-embedded, and a great number of contents need to be re-registered. In this paper, we propose D-Griffin, a geometric routing scheme on flat names for dynamic topologies. D-Griffin provides two advantages. First, it avoids re-embedding the topology by using an online greedy embedding scheme and a void handling greedy forwarding scheme. Second, it decreases the number of re-registrations by using a name mapping scheme with a tradeoff between topology independence and load balancing. Theoretical and experimental analyses show that D-Griffin provides guaranteed content lookup, low description complexity, low path stretch, scalable routing update, and acceptable load balancing.
基金Supported by the National Natural Science Foundation of China (No.60602018 and 60772033)
文摘The key problem in unstructured P2P system is how to control "Flood".Some studies focus on constructing more efficient topology while others focus on better query algorithms.This paper presents HICUS(Hierarchical Interest-driven Community-based Unstructured System) motivated by a basic thought-whether the resources correlate with topology distinguishes structured and unstruc-tured P2P essentially.By introducing hierarchical "interest",HICUS organizes a quasi-structured topology through a pure distributed way,and provides a new platform for query algorithms.We study the procedure and performance of topology organization,and the simulations show that HICUS forms a small-world which can significantly improve the routing efficiency.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2014R1A1A2057796)and(2015R1D1A1A01059049)
文摘The phenomenon of data explosion represents a severe challenge for the upcoming big data era.However,the current Internet architecture is insufficient for dealing with a huge amount of traffic owing to an increase in redundant content transmission and the end-point-based communication model.Information-centric networking(ICN)is a paradigm for the future Internet that can be utilized to resolve the data explosion problem.In this paper,we focus on content-centric networking(CCN),one of the key candidate ICN architectures.CCN has been studied in various network environments with the aim of relieving network and server burden,especially in name-based forwarding and in-network caching functionalities.This paper studies the effect of several caching strategies in the CCN domain from the perspective of network and server overhead.Thus,we comprehensively analyze the in-network caching performance of CCN under several popular cache replication methods(i.e.,cache placement).We evaluate the performance with respect to wellknown Internet traffic patterns that follow certain probabilistic distributions,such as the Zipf/Mandelbrot–Zipf distributions,and flashcrowds.For the experiments,we developed an OPNET-based CCN simulator with a realistic Internet-like topology.
基金Supported by National Natural Science Foundation of China (No.60973141)Natural Science Foundation of Tianjin (No.09JCYBJC00300)
文摘This paper proposes a simple and efficient distributed algorithm for calculating minimal dominating set in wireless sensor network. This method can avoid maintaining the connectivities between backbone hosts. Considering that the hosts in mobile networks have different characteristics, this paper proposes a method of calculating minimal dominating set with weight. The nodes can be chosen to form a minimal dominating set when the network topology changes. For the host switch on/off operation, the updating algorithm was provided. The change in the status of a hostaffects only the status of hosts in the restricted vicinity. Simulation results show that the proposed method can ensure fewer dominators but with higher weight to form the minimal dominating set and the nodes can be adaptive to the changes of network topology.
基金supported by the Major State Basic Research Development Program of China(973 Program)under Grant No.2010CB731400the Natural Science Foundation of China under Grant Nos.61074125,61073102,61170059,61170172,61272153Anhui Provincial Natural Science Foundation under Grant No.090412251
文摘Communication bandwidth and network topology are two important factors that affect performance of distributed consensus in multi-agent systems.The available works about quantized average consensus assume that the adjacency matrices associated with the digraphs are doubly stochastic,which amounts to that the digital networks are balanced.However,this assumption may be unrealistic in practice.In this paper,without assuming double stochasticity,the authors revisit an existing quantized average consensus protocol with the logarithmic quantization scheme,and investigate the quantized consensus problem in general directed digital networks that are strongly connected but not necessarily balanced.The authors first derive an achievable upper bound of the quantization precision parameter to design suitable logarithmic quantizer,and this bound explicitly depends on network topology.Subsequently,by means of the matrix transformation and the Lyapunov techniques,the authors provide a testable condition under which the weighted average consensus can be achieved with the proposed quantized protocol.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10832006, 60974078)China Postdoctoral Science Foundation (Grant No. 20100480211)
文摘This paper addresses the distributed attitude synchronization problem of multiple spacecraft with unknown inertia matrices. Two distributed adaptive controllers are proposed for the cases with and without a virtual leader to which a time-varying reference attitude is assigned. The first controller achieves attitude synchronization for a group of spacecraft with a leaderless communication topology having a directed spanning tree. The second controller guarantees that all spacecraft track the reference attitude if the virtual leader has a directed path to all other spacecraft. Simulation examples are presented to illustrate the effectiveness of the results.
基金supported by Beijing Natural Science Foundation under Grant No.4152057973 program(2014CB845301/2/3)
文摘This paper addresses attitude synchronization problems for systems of multiple rigid-body agents with directed interconnection topologies.Two scenarios which differ in available information are considered.In the first scenario the agents can obtain their rotations and angular velocities relative to an inertial reference frame and transmit these information to their neighbors,while in the second scenario the agents can only obtain their own angular velocities and measure the relative rotations and relative angular velocities of their neighbors.By using rotation vectors and the high gain control,the authors provide torque control laws asymptotically synchronizing the rotations of the system almost globally for the first scenario and with initial rotations of the agents contained in a convex ball of SO(3)for the second scenario.An illustrative example is provided to show the synchronization results for both scenarios.
