The long authentication handover delay is the greatest challenge in multi-domain SDN environment. In order to solve this problem, an authentication handover mechanism under multi-SDN domain(AHMMD) is proposed in this ...The long authentication handover delay is the greatest challenge in multi-domain SDN environment. In order to solve this problem, an authentication handover mechanism under multi-SDN domain(AHMMD) is proposed in this paper. In AHMMD, firstly, when the mobility entity accesses the network for the first time, its identity and service attributes are authenticated by the flow authentication protocol, which is designed based on the asymmetric encryption key; secondly, when the mobility entity moves to the neighbor domain, the authentication information will be delivered from the current controller to the neighborhood controller through a security communication channel. In order to promote the efficiency, a handover time prediction algorithm is adopted in AHMMD. Experimental results based on our AHMMD prototype have shown that the handover delay decreases by 50% while the handover cost decreases by 60%.展开更多
Exhaust thermal management is essential to allow engines to meet the Euro VI emissions standards and reducing nitrogen oxide emissions is one of the most important targets being pursued nowadays.Along these lines,in t...Exhaust thermal management is essential to allow engines to meet the Euro VI emissions standards and reducing nitrogen oxide emissions is one of the most important targets being pursued nowadays.Along these lines,in the present study,engine’s thermal performances have been evaluated on the basis of a WHTC test,namely a transient engine dynamometer schedule defined by the global technical regulation(GTR)developed by the UN ECE GRPE group(the GTR is covering a world-wide harmonized heavy-duty certification(WHDC)procedure for engine exhaust emissions).The influence of thermal management on fuel consumption,intake,and tailpipe NO_(x) have been quantitatively analyzed for the overrun state.The results have shown that there can be a strong influence on the after-treatment temperatures and tailpipe NO_(x).In particular,the average temperature upstream of the diesel oxidation catalyst(DOC)has been found to increase from 245°C to 254°C,the average temperature of the selective catalytic reduction(SCR)to increase from 248°C to 253°C,the SCR’s minimum temperature to increase from 196°C to 204°C,and the peak value of the NO_(x) emissions in the low-temperature region to decrease from 73 to 51 mg/s.However,the influence of the overrun state’s thermal management strategy on the fuel consumption,the air intake,the ammonia storage,the NO_(2)/NO_(x) ratio,and the urea consumption has been observed to be relatively limited.展开更多
Accurately simulating large-scale user behavior is important to improve the similarity between the cyber range and the real network environment. The Linux Container provides a method to simulate the behavior of large-...Accurately simulating large-scale user behavior is important to improve the similarity between the cyber range and the real network environment. The Linux Container provides a method to simulate the behavior of large-scale users under the constraints of limited physical resources. In a container-based virtualization environment, container networking is an important component. To evaluate the impact of different networking methods between the containers on the simulation performance, the typical container networking methods such as none, bridge, macvlan were analyzed, and the performance of different networking methods was evaluated according to the throughput and latency metrics. The experiments show that under the same physical resource constraints, the macvlan networking method has the best network performance, while the bridge method has the worst performance. This result provides a reference for selecting the appropriate networking method in the user behavior simulation process.展开更多
基金supported in part by the National Natural Science Foundation of China under Grant No.61402521Jiangsu Province Natural Science Foundation of China under Grant No.BK20140068
文摘The long authentication handover delay is the greatest challenge in multi-domain SDN environment. In order to solve this problem, an authentication handover mechanism under multi-SDN domain(AHMMD) is proposed in this paper. In AHMMD, firstly, when the mobility entity accesses the network for the first time, its identity and service attributes are authenticated by the flow authentication protocol, which is designed based on the asymmetric encryption key; secondly, when the mobility entity moves to the neighbor domain, the authentication information will be delivered from the current controller to the neighborhood controller through a security communication channel. In order to promote the efficiency, a handover time prediction algorithm is adopted in AHMMD. Experimental results based on our AHMMD prototype have shown that the handover delay decreases by 50% while the handover cost decreases by 60%.
基金This work was supported by the Natural Science Foundation Project of Shandong Provincial(Grant No.ZR2019MEE041)the open funds of National Engineering Laboratory of Mobile Source Emission Control Technology(Grant No.NELMS2019A01)。
文摘Exhaust thermal management is essential to allow engines to meet the Euro VI emissions standards and reducing nitrogen oxide emissions is one of the most important targets being pursued nowadays.Along these lines,in the present study,engine’s thermal performances have been evaluated on the basis of a WHTC test,namely a transient engine dynamometer schedule defined by the global technical regulation(GTR)developed by the UN ECE GRPE group(the GTR is covering a world-wide harmonized heavy-duty certification(WHDC)procedure for engine exhaust emissions).The influence of thermal management on fuel consumption,intake,and tailpipe NO_(x) have been quantitatively analyzed for the overrun state.The results have shown that there can be a strong influence on the after-treatment temperatures and tailpipe NO_(x).In particular,the average temperature upstream of the diesel oxidation catalyst(DOC)has been found to increase from 245°C to 254°C,the average temperature of the selective catalytic reduction(SCR)to increase from 248°C to 253°C,the SCR’s minimum temperature to increase from 196°C to 204°C,and the peak value of the NO_(x) emissions in the low-temperature region to decrease from 73 to 51 mg/s.However,the influence of the overrun state’s thermal management strategy on the fuel consumption,the air intake,the ammonia storage,the NO_(2)/NO_(x) ratio,and the urea consumption has been observed to be relatively limited.
文摘Accurately simulating large-scale user behavior is important to improve the similarity between the cyber range and the real network environment. The Linux Container provides a method to simulate the behavior of large-scale users under the constraints of limited physical resources. In a container-based virtualization environment, container networking is an important component. To evaluate the impact of different networking methods between the containers on the simulation performance, the typical container networking methods such as none, bridge, macvlan were analyzed, and the performance of different networking methods was evaluated according to the throughput and latency metrics. The experiments show that under the same physical resource constraints, the macvlan networking method has the best network performance, while the bridge method has the worst performance. This result provides a reference for selecting the appropriate networking method in the user behavior simulation process.
