In recent years, realising a "clean- state" design for the future Internet has become an important research focus. An architecture com- bining an Information-Centric Network (ICN) and Sottware-Defmed Network (SDN...In recent years, realising a "clean- state" design for the future Internet has become an important research focus. An architecture com- bining an Information-Centric Network (ICN) and Sottware-Defmed Network (SDN) (IC-SDN) has gradually attracted more attention. How- ever, the existing studies regarding IC-SDN still lack support in terms of the "network status awareness" function, resulting in unreasonable resource allocation. In this paper, we propose a new status-aware resource adaptation sche- me, i.e. a status-aware module is embedded into basic elements (Forwarding Node (FN) and Resource adaption Manager (RM)). The FNs collect the network status dynamically for the controller to reallocate network resources accor- ding to the fluctuations in environmental con- ditions. Simulation results show that, compared with the existing IC-SDN mechanism, the pro- posed scheme reduced the link bandwidth var- iance by 56% and the content delivery latency by 40%. The proof-of-concept implementation demonstrates the feasibility of our proposed sc- heme for small-scale deployment.展开更多
The paper follows possible specification of a control algorithm of a WS (water management system) during floods using the procedures of AI (artificial intelligence). The issue of minimizing negative impacts of flo...The paper follows possible specification of a control algorithm of a WS (water management system) during floods using the procedures of AI (artificial intelligence). The issue of minimizing negative impacts of floods represents influencing and controlling a dynamic process of the system where the main regulation elements are water reservoirs. Control of water outflow from reservoirs is implicitly based on the used model (titled BW) based on FR (fuzzy regulation). Specification of a control algorithm means dealing with the issue of preparing a knowledge base for the process of tuning fuzzy regulators based on an I/O (input/output) matrix obtained by optimization of the target behaviour of WS. Partial results can be compared with the regulation outputs when specialized tuning was used for the fuzzy regulator of the control algorithm. Basic approaches follow from the narrow relation on BW model use to simulate floods, without any connection to real water management system. A generally introduced model allows description of an outflow dynamic system with stochastic inputs using submodels of robust regression in the outflow module. The submodels are constructed on data of historical FS (flood situations).展开更多
Water management is of great importance to maintain performance and durability of proton exchange membrane fuel cells. This paper presents a novel proton exchange membrane (PEM) fuel cell with a humidification zone in...Water management is of great importance to maintain performance and durability of proton exchange membrane fuel cells. This paper presents a novel proton exchange membrane (PEM) fuel cell with a humidification zone in the membrane electrode assembly (MEA) of each cell, in which the moisture of the cathode exhaust gas could transfer through the membrane to humidify anode or cathode dry gas. With a simple model, the relative humidity (RH) of the dry air exhaust from a membrane humidifier with 100% RH stream as a counter flow is calculated to be 60.0%, which is very close to the experimental result (62.2%). Fuel cell performances with hydrogen humidifying, air humidifying and no humidifying are compared at 50, 60 and 70°C and the results indicate that humidifying is necessary and the novel design with humidifying zone in MEA is effective to humidify dry reactants. The hydrogen humidifying shows better performance in short term, while water recovered is limited and the stability is not as good as air humidifying. It is recommended that both air and hydrogen should be humidified with proper design of the humidifying zones in MEA and plates.展开更多
The CME’s structure of solar wind(interplanetary magnetic field)is different from CIR’s.The two processes in which plasma and solar wind energy are injected into the Earth’s inner magnetosphere are not the same.So,...The CME’s structure of solar wind(interplanetary magnetic field)is different from CIR’s.The two processes in which plasma and solar wind energy are injected into the Earth’s inner magnetosphere are not the same.So,the variations of energetic elec- trons flux in the radiation belts are different between the storms associated with CMEs and CIRs.By using data from SAMPEX(Solar,Anomalous,and Magnetospheric Particle Explorer)satellite,we have investigated the dynamic variations of the outer radiation belt for 1.5–6.0 MeV electrons during 54 CME-driven storms and 26 CIR-driven recurrent storms.According to the superposed epoch analysis,for CME-and CIR-driven storms,when the Dst index reaches the minimum,the locations of the outer boundary move to L=4 and L=5.5,respectively.In the recovery phases,the locations of the outer boundary of the outer radiation belt are generally lower than and slightly higher than those before CME-and CIR-driven storms,respectively.We have found that the logarithmically decaying 1/e cut-off L-shell is a satisfying indicator of the outer boundary of the outer radiation belt.Furthermore,our study shows that the logarithmically decaying 1/e cut-off latitude is dependent on the Kp index in the main phases of CME-and CIR-driven storms,while in the recovery phases,there is no obvious correlation.In ad- dition,it has been shown that the locations of the peak electron flux are controlled by the minimum Dst index in the main phases of CME-driven storms.The influences of multiple storms on the electron flux of outer radiation belt have also been in- vestigated.展开更多
基金supported in part by the National Basic Research Program of China(973 Program)under Grant No.2013CB329100the National Natural Science Foundation of China under Grants No.61232017,No.61271200the Fundamental Research Funds for the Central Universities under Grant No.2013YJS007
文摘In recent years, realising a "clean- state" design for the future Internet has become an important research focus. An architecture com- bining an Information-Centric Network (ICN) and Sottware-Defmed Network (SDN) (IC-SDN) has gradually attracted more attention. How- ever, the existing studies regarding IC-SDN still lack support in terms of the "network status awareness" function, resulting in unreasonable resource allocation. In this paper, we propose a new status-aware resource adaptation sche- me, i.e. a status-aware module is embedded into basic elements (Forwarding Node (FN) and Resource adaption Manager (RM)). The FNs collect the network status dynamically for the controller to reallocate network resources accor- ding to the fluctuations in environmental con- ditions. Simulation results show that, compared with the existing IC-SDN mechanism, the pro- posed scheme reduced the link bandwidth var- iance by 56% and the content delivery latency by 40%. The proof-of-concept implementation demonstrates the feasibility of our proposed sc- heme for small-scale deployment.
文摘The paper follows possible specification of a control algorithm of a WS (water management system) during floods using the procedures of AI (artificial intelligence). The issue of minimizing negative impacts of floods represents influencing and controlling a dynamic process of the system where the main regulation elements are water reservoirs. Control of water outflow from reservoirs is implicitly based on the used model (titled BW) based on FR (fuzzy regulation). Specification of a control algorithm means dealing with the issue of preparing a knowledge base for the process of tuning fuzzy regulators based on an I/O (input/output) matrix obtained by optimization of the target behaviour of WS. Partial results can be compared with the regulation outputs when specialized tuning was used for the fuzzy regulator of the control algorithm. Basic approaches follow from the narrow relation on BW model use to simulate floods, without any connection to real water management system. A generally introduced model allows description of an outflow dynamic system with stochastic inputs using submodels of robust regression in the outflow module. The submodels are constructed on data of historical FS (flood situations).
基金Supported by the National High Technology Research and Development Program of China (2008AA05Z104)
文摘Water management is of great importance to maintain performance and durability of proton exchange membrane fuel cells. This paper presents a novel proton exchange membrane (PEM) fuel cell with a humidification zone in the membrane electrode assembly (MEA) of each cell, in which the moisture of the cathode exhaust gas could transfer through the membrane to humidify anode or cathode dry gas. With a simple model, the relative humidity (RH) of the dry air exhaust from a membrane humidifier with 100% RH stream as a counter flow is calculated to be 60.0%, which is very close to the experimental result (62.2%). Fuel cell performances with hydrogen humidifying, air humidifying and no humidifying are compared at 50, 60 and 70°C and the results indicate that humidifying is necessary and the novel design with humidifying zone in MEA is effective to humidify dry reactants. The hydrogen humidifying shows better performance in short term, while water recovered is limited and the stability is not as good as air humidifying. It is recommended that both air and hydrogen should be humidified with proper design of the humidifying zones in MEA and plates.
基金supported by the National Natural Science Foundation of China(Grant Nos.40831061,41074117)the Specialized Research Fund for State Key Laboratories
文摘The CME’s structure of solar wind(interplanetary magnetic field)is different from CIR’s.The two processes in which plasma and solar wind energy are injected into the Earth’s inner magnetosphere are not the same.So,the variations of energetic elec- trons flux in the radiation belts are different between the storms associated with CMEs and CIRs.By using data from SAMPEX(Solar,Anomalous,and Magnetospheric Particle Explorer)satellite,we have investigated the dynamic variations of the outer radiation belt for 1.5–6.0 MeV electrons during 54 CME-driven storms and 26 CIR-driven recurrent storms.According to the superposed epoch analysis,for CME-and CIR-driven storms,when the Dst index reaches the minimum,the locations of the outer boundary move to L=4 and L=5.5,respectively.In the recovery phases,the locations of the outer boundary of the outer radiation belt are generally lower than and slightly higher than those before CME-and CIR-driven storms,respectively.We have found that the logarithmically decaying 1/e cut-off L-shell is a satisfying indicator of the outer boundary of the outer radiation belt.Furthermore,our study shows that the logarithmically decaying 1/e cut-off latitude is dependent on the Kp index in the main phases of CME-and CIR-driven storms,while in the recovery phases,there is no obvious correlation.In ad- dition,it has been shown that the locations of the peak electron flux are controlled by the minimum Dst index in the main phases of CME-driven storms.The influences of multiple storms on the electron flux of outer radiation belt have also been in- vestigated.