The growing trend of network virtualization results in a widespread adoption of virtual switches in virtualized environments. However, virtual switching is confronted with great performance challenges regarding packet...The growing trend of network virtualization results in a widespread adoption of virtual switches in virtualized environments. However, virtual switching is confronted with great performance challenges regarding packet classification especially in Open Flow-based software defined networks. This paper first takes an insight into packet classification in virtual Open Flow switching, and points out that its performance bottleneck is dominated by flow table traversals of multiple failed mask probing for each arrived packet. Then we are motivated to propose an efficient packet classification algorithm based on counting bloom filters. In particular, counting bloom filters are applied to predict the failures of flow table lookups with great possibilities, and bypass flow table traversals for failed mask probing. Finally, our proposed packet classification algorithm is evaluated with real network traffic traces by experiments. The experimental results indicate that our proposed algorithm outperforms the classical one in Open v Switch in terms of average search length, and contributes to promote virtual Open Flow switching performance.展开更多
Essential oil from clove buds Syzygium aromaticum L. Merr. ＆ Perry （Myrtaceae） was extracted using petroleum ether in Soxhlet apparatus. The resultant oil contained eugenol （48.92%）, caryophyllene （18.55%）, α-...Essential oil from clove buds Syzygium aromaticum L. Merr. ＆ Perry （Myrtaceae） was extracted using petroleum ether in Soxhlet apparatus. The resultant oil contained eugenol （48.92%）, caryophyllene （18.55%）, α-caryophyllene （3.25%）, eugenol acetate （23%）, cis-13-docosenamide （3.2 1%）, presenting more than 96% of the oil. This oil was examined as a fumigant and repellent agent against adults of the red flour beetle, Tribolium castaneum. Data showed that various concentrations of the oil have revealed dramatic repellent activity against the tested insect, where it gave 100% repellency by 1.0, 0.8, and 0.2% clove oil at 4, 8, 10 min, respectively. The RTs0 and RT95 were 1.1 and 8.0 min at 0.2% and 0.4, 2.6 min at 0.8%, respectively. In addition, fumigation assay has also exhibited strong fumigant activity toward the adults of T. castaneum. At 100 μL oil/L air, mortality was 75, 80 and 100% after 6, 7, and 8 days exposure period with LCs0 and LC95 17 and 70 μL/L air, respectively. The utilization of clove oil for its potential effects against stored product insect is discussed.展开更多
基金supported in part by National Natural Science Foundation of China(61272148,61572525,61502056,and 61602525)Hunan Provincial Natural Science Foundation of China(2015JJ3010)Scientific Research Fund of Hunan Provincial Education Department(15B009,14C0285)
文摘The growing trend of network virtualization results in a widespread adoption of virtual switches in virtualized environments. However, virtual switching is confronted with great performance challenges regarding packet classification especially in Open Flow-based software defined networks. This paper first takes an insight into packet classification in virtual Open Flow switching, and points out that its performance bottleneck is dominated by flow table traversals of multiple failed mask probing for each arrived packet. Then we are motivated to propose an efficient packet classification algorithm based on counting bloom filters. In particular, counting bloom filters are applied to predict the failures of flow table lookups with great possibilities, and bypass flow table traversals for failed mask probing. Finally, our proposed packet classification algorithm is evaluated with real network traffic traces by experiments. The experimental results indicate that our proposed algorithm outperforms the classical one in Open v Switch in terms of average search length, and contributes to promote virtual Open Flow switching performance.
文摘Essential oil from clove buds Syzygium aromaticum L. Merr. ＆ Perry （Myrtaceae） was extracted using petroleum ether in Soxhlet apparatus. The resultant oil contained eugenol （48.92%）, caryophyllene （18.55%）, α-caryophyllene （3.25%）, eugenol acetate （23%）, cis-13-docosenamide （3.2 1%）, presenting more than 96% of the oil. This oil was examined as a fumigant and repellent agent against adults of the red flour beetle, Tribolium castaneum. Data showed that various concentrations of the oil have revealed dramatic repellent activity against the tested insect, where it gave 100% repellency by 1.0, 0.8, and 0.2% clove oil at 4, 8, 10 min, respectively. The RTs0 and RT95 were 1.1 and 8.0 min at 0.2% and 0.4, 2.6 min at 0.8%, respectively. In addition, fumigation assay has also exhibited strong fumigant activity toward the adults of T. castaneum. At 100 μL oil/L air, mortality was 75, 80 and 100% after 6, 7, and 8 days exposure period with LCs0 and LC95 17 and 70 μL/L air, respectively. The utilization of clove oil for its potential effects against stored product insect is discussed.
