With the advancements of software defined network(SDN)and network function virtualization(NFV),service function chain(SFC)placement becomes a crucial enabler for flexible resource scheduling in low earth orbit(LEO)sat...With the advancements of software defined network(SDN)and network function virtualization(NFV),service function chain(SFC)placement becomes a crucial enabler for flexible resource scheduling in low earth orbit(LEO)satellite networks.While due to the scarcity of bandwidth resources and dynamic topology of LEO satellites,the static SFC placement schemes may cause performance degradation,resource waste and even service failure.In this paper,we consider migration and establish an online migration model,especially considering the dynamic topology.Given the scarcity of bandwidth resources,the model aims to maximize the total number of accepted SFCs while incurring as little bandwidth cost of SFC transmission and migration as possible.Due to its NP-hardness,we propose a heuristic minimized dynamic SFC migration(MDSM)algorithm that only triggers the migration procedure when new SFCs are rejected.Simulation results demonstrate that MDSM achieves a performance close to the upper bound with lower complexity.展开更多
BioNetSim,a Petri net-based software for modeling and simulating biochemistry processes,is developed,whose design and implement are presented in this pa-per,including logic construction,real-time access to KEGG(Kyoto ...BioNetSim,a Petri net-based software for modeling and simulating biochemistry processes,is developed,whose design and implement are presented in this pa-per,including logic construction,real-time access to KEGG(Kyoto Encyclopedia of Genes and Genomes),and BioModel database.Furthermore,glycolysis is simulated as an example of its application.BioNetSim is a helpful tool for researchers to download data,model biological network,and simulate complicated biochemistry processes.Gene regulatory networks,metabolic pathways,signaling pathways,and kinetics of cell interaction are all available in BioNetSim,which makes modeling more efficient and effective.Similar to other Petri net-based softwares,BioNetSim does well in graphic application and mathematic construction.Moreover,it shows several powerful predominances.(1)It creates models in database.(2)It realizes the real-time access to KEGG and BioModel and transfers data to Petri net.(3)It provides qualitative analysis,such as computation of constants.(4)It generates graphs for tracing the concentration of every molecule during the simulation processes.展开更多
基金supported in part by the National Natural Science Foundation of China(NSFC)under grant numbers U22A2007 and 62171010the Open project of Satellite Internet Key Laboratory in 2022(Project 3:Research on Spaceborne Lightweight Core Network and Intelligent Collaboration)the Beijing Natural Science Foundation under grant number L212003.
文摘With the advancements of software defined network(SDN)and network function virtualization(NFV),service function chain(SFC)placement becomes a crucial enabler for flexible resource scheduling in low earth orbit(LEO)satellite networks.While due to the scarcity of bandwidth resources and dynamic topology of LEO satellites,the static SFC placement schemes may cause performance degradation,resource waste and even service failure.In this paper,we consider migration and establish an online migration model,especially considering the dynamic topology.Given the scarcity of bandwidth resources,the model aims to maximize the total number of accepted SFCs while incurring as little bandwidth cost of SFC transmission and migration as possible.Due to its NP-hardness,we propose a heuristic minimized dynamic SFC migration(MDSM)algorithm that only triggers the migration procedure when new SFCs are rejected.Simulation results demonstrate that MDSM achieves a performance close to the upper bound with lower complexity.
基金supported by grants from the National Basic Research Program of China(973 Program)(Grant No.2012CB721000)the Key Project of Shanghai Science and Technology Commission(No.11JC1406400)the Research Innovation Project of Shanghai Education Commission(No.09YZ95).
文摘BioNetSim,a Petri net-based software for modeling and simulating biochemistry processes,is developed,whose design and implement are presented in this pa-per,including logic construction,real-time access to KEGG(Kyoto Encyclopedia of Genes and Genomes),and BioModel database.Furthermore,glycolysis is simulated as an example of its application.BioNetSim is a helpful tool for researchers to download data,model biological network,and simulate complicated biochemistry processes.Gene regulatory networks,metabolic pathways,signaling pathways,and kinetics of cell interaction are all available in BioNetSim,which makes modeling more efficient and effective.Similar to other Petri net-based softwares,BioNetSim does well in graphic application and mathematic construction.Moreover,it shows several powerful predominances.(1)It creates models in database.(2)It realizes the real-time access to KEGG and BioModel and transfers data to Petri net.(3)It provides qualitative analysis,such as computation of constants.(4)It generates graphs for tracing the concentration of every molecule during the simulation processes.
