Due to the road-constrained data delivery and highly dynamic topology of vehicle nodes in a Vehicular Ad Hoc Network (VANET), it is better to construct routing based on the road-to-road pattern than the traditional no...Due to the road-constrained data delivery and highly dynamic topology of vehicle nodes in a Vehicular Ad Hoc Network (VANET), it is better to construct routing based on the road-to-road pattern than the traditional node-to-node routing pattern in MANETs. However, the challenging issue is the opportunistic forwarding at intersections. Therefore, we propose a novel routing scheme, called Buffer and Switch (BAS). In BAS, each road buffers the data packets with multiple duplicates propagation in order to provide more opportunities for packet switching at intersections. Different from conventional protocols in VANETs, the propagation of duplicates in BAS is bidirectional along the routing path. Moreover, BAS's cost is much lower than other flooding-based protocols due to its spatio-temporally controlled duplicates propagation. Different from recent researches, BAS can deliver packets not only to a stationary node, but also to the stationary or mobile nodes in a specified area. We conduct the extensive simulations to evaluate the performance of BAS based on the road map of a real city collected from Google Earth. The simulation results show that BAS can outperform the existing protocols, especially when the network resources are limited.展开更多
At the base of the reflection developed in this research work, there is the concept of habitat as a system, as an articulated ＂whole＂ that cannot be explained with the simple sum of its parts. The concept of habitat...At the base of the reflection developed in this research work, there is the concept of habitat as a system, as an articulated ＂whole＂ that cannot be explained with the simple sum of its parts. The concept of habitat, in fact, implies issues of dialectic spaces, in other words, those settings that can be defined as relational subsystems within the urban/domestic scale. This essay has its roots in the CIAM （Congr^s International d＇Architecture Moderne （in English： International Congress of Modem Architecture）） of 1953, during which the complementarity of the outside space next to the dwelling and its relevance within the project discipline, have been affirmed. In particular, assimilating the lesson of Aldo van Eyck, this work investigates the deepest issues of the concept of threshold. The analysis makes use of the work-tools of critical reading and comparison between urban and rural habitats, with different density levels, whose relational fabrics have been layering over time permeable ＂thicknesses＂ which articulate complex threshold spatial configurations.展开更多
In this paper, the continuous-time independent edge-Markovian random graph process model is constructed. The authors also define the interval isolated nodes of the random graph process, study the distribution sequence...In this paper, the continuous-time independent edge-Markovian random graph process model is constructed. The authors also define the interval isolated nodes of the random graph process, study the distribution sequence of the number of isolated nodes and the probability of having no isolated nodes when the initial distribution of the random graph process is stationary distribution, derive the lower limit of the probability in which two arbitrary nodes are connected and the random graph is also connected, and prove that the random graph is almost everywhere connected when the number of nodes is sufficiently large.展开更多
基金supported by the National Natural Science Foundation of China under Grants No. 60903155,No. 60903156,No.60903158,No. 61003229the Fundamental Research Funds for the Central Universities under Grants No. ZYGX2009J063, No.ZYGX2010J074
文摘Due to the road-constrained data delivery and highly dynamic topology of vehicle nodes in a Vehicular Ad Hoc Network (VANET), it is better to construct routing based on the road-to-road pattern than the traditional node-to-node routing pattern in MANETs. However, the challenging issue is the opportunistic forwarding at intersections. Therefore, we propose a novel routing scheme, called Buffer and Switch (BAS). In BAS, each road buffers the data packets with multiple duplicates propagation in order to provide more opportunities for packet switching at intersections. Different from conventional protocols in VANETs, the propagation of duplicates in BAS is bidirectional along the routing path. Moreover, BAS's cost is much lower than other flooding-based protocols due to its spatio-temporally controlled duplicates propagation. Different from recent researches, BAS can deliver packets not only to a stationary node, but also to the stationary or mobile nodes in a specified area. We conduct the extensive simulations to evaluate the performance of BAS based on the road map of a real city collected from Google Earth. The simulation results show that BAS can outperform the existing protocols, especially when the network resources are limited.
文摘At the base of the reflection developed in this research work, there is the concept of habitat as a system, as an articulated ＂whole＂ that cannot be explained with the simple sum of its parts. The concept of habitat, in fact, implies issues of dialectic spaces, in other words, those settings that can be defined as relational subsystems within the urban/domestic scale. This essay has its roots in the CIAM （Congr^s International d＇Architecture Moderne （in English： International Congress of Modem Architecture）） of 1953, during which the complementarity of the outside space next to the dwelling and its relevance within the project discipline, have been affirmed. In particular, assimilating the lesson of Aldo van Eyck, this work investigates the deepest issues of the concept of threshold. The analysis makes use of the work-tools of critical reading and comparison between urban and rural habitats, with different density levels, whose relational fabrics have been layering over time permeable ＂thicknesses＂ which articulate complex threshold spatial configurations.
基金supported by the National Natural Science Foundation of China(Nos.60872060,11101265)the Shanghai Natural Science Foundation of China(No.12ZR1421000)the Shanghai Education Commission Innovation Project Fund(Nos.12ZZ193,14YZ152,15ZZ099)
文摘In this paper, the continuous-time independent edge-Markovian random graph process model is constructed. The authors also define the interval isolated nodes of the random graph process, study the distribution sequence of the number of isolated nodes and the probability of having no isolated nodes when the initial distribution of the random graph process is stationary distribution, derive the lower limit of the probability in which two arbitrary nodes are connected and the random graph is also connected, and prove that the random graph is almost everywhere connected when the number of nodes is sufficiently large.
