Because the node of vehicular ad-hoc networks has the characteristics of high mobility and encounter temporary, a trust management between the nodes in the routing process becomes more difficult. To solve this problem...Because the node of vehicular ad-hoc networks has the characteristics of high mobility and encounter temporary, a trust management between the nodes in the routing process becomes more difficult. To solve this problem, this paper proposes a new trusted routing protocol in VANET based on GeoDTN＋Nav by using trust management model of Bayesian and the three opportunistic routing forwarding models, which includes four steps of the routing initialization, the routing discovery, the trusted routing establishment and the routing deletion. The proposed protocol not only improves the security of routing, but also has the lower time complexity. Besides, experimental results and analysis show that the protocol has achieved good performance in the removal ratio of malicious nodes, correct reception ratio of packet and the message payload.展开更多
In this paper, we propose a Packet Cache-Forward(PCF) method based on improved Bayesian outlier detection to eliminate out-of-order packets caused by transmission path drastically degradation during handover events in...In this paper, we propose a Packet Cache-Forward(PCF) method based on improved Bayesian outlier detection to eliminate out-of-order packets caused by transmission path drastically degradation during handover events in the moving satellite networks, for improving the performance of TCP. The proposed method uses an access node satellite to cache all received packets in a short time when handover occurs and forward them out in order. To calculate the cache time accurately, this paper establishes the Bayesian based mixture model for detecting delay outliers of the entire handover scheme. In view of the outliers' misjudgment, an updated classification threshold and the sliding window has been suggested to correct category collections and model parameters for the purpose of quickly identifying exact compensation delay in the varied network load statuses. Simulation shows that, comparing to average processing delay detection method, the average accuracy rate was scaled up by about 4.0%, and there is about 5.5% cut in error rate in the meantime. It also behaves well even though testing with big dataset. Benefiting from the advantage of the proposed scheme in terms of performance, comparing to conventional independent handover and network controlled synchronizedhandover in simulated LEO satellite networks, the proposed independent handover with PCF eliminates packet out-of-order issue to get better improvement on congestion window. Eventually the average delay decreases more than 70% and TCP performance has improved more than 300%.展开更多
It is controversial whether steroid therapy should be continued to prevent the recurrence of autoimmune hepatitis （AIH） in patients who have undergone liver transplantation （LTx） due to AIH. We report a case of re...It is controversial whether steroid therapy should be continued to prevent the recurrence of autoimmune hepatitis （AIH） in patients who have undergone liver transplantation （LTx） due to AIH. We report a case of recurrent autoimmune hepatitis after LTx despite a persistently normal range of alanine aminotransferase （ALT）. A S0-year-old woman was admitted to our hospital because of jaundice and severe liver dysfunction, where she was diagnosed with liver failure due to AIH. Steroid therapy was not effective enough and the patient received living-donor LTx in 1999. Following the operation, the level of ALT was maintained within a normal range and anti-nuclear antibody （ANA） became negative, however, the serum level of IgG gradually elevated and ANA became positive, while platelets decreased. A liver biopsy performed 6 years after LTx showed histological findings of AIH and she was diagnosed with recurrent AIH. A recurrence of AIH may occur after LTx even if the level of ALT remains within a normal range. We consider that a protocol liver biopsy should be performed in patients who undergo LTx due to AIH to decide the indication for steroid therapy.展开更多
A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer e...A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer experiments of thin film were conducted in a designed diffusion cell including vacuum and feeding system. In this study,acetone was used as the volatile organic compound(VOC) and syrup as the highly viscous media.The thickness of thin film was changed by using different liquid distributor.It was found that bubbling played an important role in the devolatilization.The correlation of diffusion coefficient of acetone in highly viscous dilute solution was proposed.The relative error between predicted and experimental data was within the range of ± 30% for diffusion coefficient of acetone in syrup.A comparison of experimental data of RPB with model indicated that the relative error was within ± 30% for efficiency of acetone removal.展开更多
Delay-Tolerant Networks (DTNs) are wireless networks that often experience temporary, even long-duration partitioning. Current DTN researches mainly focus on pure delay-tolerant networks that are extreme environments ...Delay-Tolerant Networks (DTNs) are wireless networks that often experience temporary, even long-duration partitioning. Current DTN researches mainly focus on pure delay-tolerant networks that are extreme environments within a limited application scope. It motivates the identification of a more reasonable and valuable DTN architecture, which can be applied in a wider range of environments to achieve interoperability between some networks suffering from frequent network partitioning, and other networks provided with stable and high speed Internet access. Such hybrid delay-tolerant networks have a lot of applications in real world. A novel and practical Cache-Assign-Forward (CAF) architecture is proposed as an appropriate approach to tie together such hybrid networks to achieve an efficient and flexible data communication. Based on CAF, we enhance the existing DTN routing protocols and apply them to complex hybrid delay-tolerant networks. Simulations show that CAF can improve DTN routing performance significantly in hybrid DTN environments.展开更多
A transfer-reaction experiment of ~9Be(~9Be,^(10)Be)~8Be was performed at a beam energy of 45 Me V.Excited states in ^(10)Be up to 18.80 Me V are produced using missing mass and invariant mass methods.Most of the obse...A transfer-reaction experiment of ~9Be(~9Be,^(10)Be)~8Be was performed at a beam energy of 45 Me V.Excited states in ^(10)Be up to 18.80 Me V are produced using missing mass and invariant mass methods.Most of the observed high-lying resonant states,reconstructed from theα+~6He and t+~7Li decay channels,agree with the previously reported results.In addition,two new resonances at 15.6 and 18.8 Me V are identified from the present measurement.The 18.55 Me V state is found to decay into both the t + ~7Lig:s: and t + ~7Li?(0.478 MeV) channels, with a relative branching ratio of 0:93 ± 0:33. Further theoretical investigations are encouraged to interpret this new information on cluster structure in neutron-rich light nuclei.展开更多
文摘Because the node of vehicular ad-hoc networks has the characteristics of high mobility and encounter temporary, a trust management between the nodes in the routing process becomes more difficult. To solve this problem, this paper proposes a new trusted routing protocol in VANET based on GeoDTN＋Nav by using trust management model of Bayesian and the three opportunistic routing forwarding models, which includes four steps of the routing initialization, the routing discovery, the trusted routing establishment and the routing deletion. The proposed protocol not only improves the security of routing, but also has the lower time complexity. Besides, experimental results and analysis show that the protocol has achieved good performance in the removal ratio of malicious nodes, correct reception ratio of packet and the message payload.
基金supported by National High Technology Research and Development Program of China(863 Program,No.2014AA7011005)National Nature Science Foundation of China(No.91438120)
文摘In this paper, we propose a Packet Cache-Forward(PCF) method based on improved Bayesian outlier detection to eliminate out-of-order packets caused by transmission path drastically degradation during handover events in the moving satellite networks, for improving the performance of TCP. The proposed method uses an access node satellite to cache all received packets in a short time when handover occurs and forward them out in order. To calculate the cache time accurately, this paper establishes the Bayesian based mixture model for detecting delay outliers of the entire handover scheme. In view of the outliers' misjudgment, an updated classification threshold and the sliding window has been suggested to correct category collections and model parameters for the purpose of quickly identifying exact compensation delay in the varied network load statuses. Simulation shows that, comparing to average processing delay detection method, the average accuracy rate was scaled up by about 4.0%, and there is about 5.5% cut in error rate in the meantime. It also behaves well even though testing with big dataset. Benefiting from the advantage of the proposed scheme in terms of performance, comparing to conventional independent handover and network controlled synchronizedhandover in simulated LEO satellite networks, the proposed independent handover with PCF eliminates packet out-of-order issue to get better improvement on congestion window. Eventually the average delay decreases more than 70% and TCP performance has improved more than 300%.
文摘It is controversial whether steroid therapy should be continued to prevent the recurrence of autoimmune hepatitis （AIH） in patients who have undergone liver transplantation （LTx） due to AIH. We report a case of recurrent autoimmune hepatitis after LTx despite a persistently normal range of alanine aminotransferase （ALT）. A S0-year-old woman was admitted to our hospital because of jaundice and severe liver dysfunction, where she was diagnosed with liver failure due to AIH. Steroid therapy was not effective enough and the patient received living-donor LTx in 1999. Following the operation, the level of ALT was maintained within a normal range and anti-nuclear antibody （ANA） became negative, however, the serum level of IgG gradually elevated and ANA became positive, while platelets decreased. A liver biopsy performed 6 years after LTx showed histological findings of AIH and she was diagnosed with recurrent AIH. A recurrence of AIH may occur after LTx even if the level of ALT remains within a normal range. We consider that a protocol liver biopsy should be performed in patients who undergo LTx due to AIH to decide the indication for steroid therapy.
基金Supported by the National Natural Science Foundation of China（20821004 20990221） the National High Technology Research and Development Program of China（2006AA030202）+1 种基金 the Program for New Century Excellent Talents in University of China（NCET-07-0053） the National Basic Research Program of China（2009CB219903）
文摘A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer experiments of thin film were conducted in a designed diffusion cell including vacuum and feeding system. In this study,acetone was used as the volatile organic compound(VOC) and syrup as the highly viscous media.The thickness of thin film was changed by using different liquid distributor.It was found that bubbling played an important role in the devolatilization.The correlation of diffusion coefficient of acetone in highly viscous dilute solution was proposed.The relative error between predicted and experimental data was within the range of ± 30% for diffusion coefficient of acetone in syrup.A comparison of experimental data of RPB with model indicated that the relative error was within ± 30% for efficiency of acetone removal.
基金The authors would like to thank Prof. Xu Zhiwei and the re- viewers for their detailed reviews and constructive comments, which have helped improve the quality of this paper. This work was supported by the National Key Basic Research Program of China under Grant No. 2011CB302702 the Na- tional Natural Science Foundation of China under Grants No. 61132001, No. 61120106008, No. 61070187, No. 60970133, No. 61003225 the Beijing Nova Program.
文摘Delay-Tolerant Networks (DTNs) are wireless networks that often experience temporary, even long-duration partitioning. Current DTN researches mainly focus on pure delay-tolerant networks that are extreme environments within a limited application scope. It motivates the identification of a more reasonable and valuable DTN architecture, which can be applied in a wider range of environments to achieve interoperability between some networks suffering from frequent network partitioning, and other networks provided with stable and high speed Internet access. Such hybrid delay-tolerant networks have a lot of applications in real world. A novel and practical Cache-Assign-Forward (CAF) architecture is proposed as an appropriate approach to tie together such hybrid networks to achieve an efficient and flexible data communication. Based on CAF, we enhance the existing DTN routing protocols and apply them to complex hybrid delay-tolerant networks. Simulations show that CAF can improve DTN routing performance significantly in hybrid DTN environments.
基金supported by the National Basic Research Program of China (Grant No. 2013CB834402)the National Natural Science Foundation of China (Grant Nos. 11535004, 11275011, 11375017, and 11275001)
文摘A transfer-reaction experiment of ~9Be(~9Be,^(10)Be)~8Be was performed at a beam energy of 45 Me V.Excited states in ^(10)Be up to 18.80 Me V are produced using missing mass and invariant mass methods.Most of the observed high-lying resonant states,reconstructed from theα+~6He and t+~7Li decay channels,agree with the previously reported results.In addition,two new resonances at 15.6 and 18.8 Me V are identified from the present measurement.The 18.55 Me V state is found to decay into both the t + ~7Lig:s: and t + ~7Li?(0.478 MeV) channels, with a relative branching ratio of 0:93 ± 0:33. Further theoretical investigations are encouraged to interpret this new information on cluster structure in neutron-rich light nuclei.
