针对低功耗有损网络中采用博弈论的网络拥塞控制(game theory based network congestion control protocol,GTNCC)路由算法在路由构建过程中仅仅考虑无线链路质量不能使网络拓扑最优,以及在拥塞控制过程中由拥塞节点的子节点判断是否切...针对低功耗有损网络中采用博弈论的网络拥塞控制(game theory based network congestion control protocol,GTNCC)路由算法在路由构建过程中仅仅考虑无线链路质量不能使网络拓扑最优,以及在拥塞控制过程中由拥塞节点的子节点判断是否切换父节点不能快速高效地缓解网络拥塞等问题,提出一种基于多维度量结合的集中式网络拥塞控制(centralized network congestion control based on multi-metrics combination,CNCCMC)路由协议。首先,为了降低网络拥塞发生的概率,CNCCMC路由协议综合考虑了节点剩余能量、缓存占用率、无线链路质量和中继节点当前子节点个数等多维度量完成路由构建;其次,当检测到网络拥塞时,CNCCMC路由协议依据网络拥塞节点进行流量分析和判断的结果采取集中式的方式控制其子节点的切换;最后,在网络拥塞缓解过程中,提出一种"乒乓效应"避免机制。理论分析和仿真结果表明,与GTNCC路由算法相比,CNCCMC路由协议在降低网络拥塞发生的概率、延长网络平均生存寿命和提高网络吞吐量等方面的性能得到了有效提升。展开更多
针对低功耗有损网络(low power and lossy networks,LLN)中现有路由修复算法存在控制开销冗余、修复时延较大和路由环路等问题,提出一种LLN中基于环路避免的高效路由修复算法(highly-efficient loop-free based repair routing protocol...针对低功耗有损网络(low power and lossy networks,LLN)中现有路由修复算法存在控制开销冗余、修复时延较大和路由环路等问题,提出一种LLN中基于环路避免的高效路由修复算法(highly-efficient loop-free based repair routing protocol for LLN,HLR-RPL)。该算法提出了3个优化思路:首先,采用一种修正后的面向目的地的有向无循环图(destination oriented directed acyclic graph,DODAG)信息请求消息(DODAG information solicitation amend,DIS-A),使得链路中断通告过程和寻路过程同时进行;其次,提出一种减少控制消息回复机制,避免所有接收到DIS-A消息的节点均回复DODAG信息对象消息;最后,提出一种链路中断节点的子节点切换机制,从而优化了网络拓扑。仿真结果表明,HLR-RPL算法在控制开销和路由修复时延等性能方面优于现有的路由修复算法,且能够彻底避免路由环路的产生。展开更多
Owing to the unreliability of wireless link and the resource constraints of embedded devices in terms of energy, processing power, and memory size in low power and lossy networks （LLNs）, network congestion may occur...Owing to the unreliability of wireless link and the resource constraints of embedded devices in terms of energy, processing power, and memory size in low power and lossy networks （LLNs）, network congestion may occur in an emergency and lead to significant packet loss and end-to-end delay. To mitigate the effect of network congestion, this paper proposes a centralized congestion control routing protocol based on multi-metrics （CCRPM）. It combines the residual energy of a node, buffer occupancy rate, wireless link quality, and the current number of sub-nodes for the candidate parent to reduce the probability of network congestion in the process of network construction. In addition, it adopts a centralized way to determine whether the sub-nodes of the congested node need to be switched based on the traffic analysis when network congestion occurs. Theoretical analysis and extensive simulation results show that compared with the existing routing protocol, the performance of CCRPM is improved significantly in reducing the probability of network congestion, prolonging average network lifetime, increasing network throughput, and decreasing end-to-end delay.展开更多
Objective Non-motor symptoms are important prodromal characteristics of Parkinson's disease(PD).The siblings and the spouses of PD patients do not have classic motor symptoms.This study aimed to investigate if the...Objective Non-motor symptoms are important prodromal characteristics of Parkinson's disease(PD).The siblings and the spouses of PD patients do not have classic motor symptoms.This study aimed to investigate if they have PD prodromal symptoms.Methods A total of 98 PD patients from the Affiliated Hospital of Yangzhou University were recruited between January 2015 and August 2017;256 siblings of these patients were included in a siblings group,87 spouses of PD patients were included in a spouses group and 250 healthy individuals were included in a control group.Various scales were used to assess non-motor symptoms,including depression,anxiety,cognitive function,sleep status,constipation,daytime sleepiness,subjective olfactory disorder,rapid-eye-movement sleep behavior disorder(RBD),and restless legs syndrome(RLS).Results The incidence of anxiety(OR=3.06,95% CI 1.86-5.05,P<0.01),depression(OR=2.16,95% CI 1.16-4.04,P=0.01),RBD(OR=3.83,95% CI 1.79-8.19,P<0.01)and subjective olfactory disorder(OR=4.48,95% CI 2.02-9.90,P<0.01)was higher in the siblings group than in the control group.There were no statistically significant differences in constipation,cognitive impairment,sleep disorder,daytime sleepiness,and RLS between the two groups.There were no statistically significant differences in non-motor symptoms between the spouses group and the control group,except that the mild depression(OR=2.58,95% CI 1.07-6.20,P=0.03)in the spouses group was more obvious.Conclusion The siblings of PD patients are more likely to have PD prodromal symptoms compared with those without PD family history,perhaps because PD patients and their siblings have common pathogenic genetic factors and early living environment for neurode-generation.There are no obvious non-motor symptoms in the spouses of PD patients.It can be concluded that the onset of PD is not related to the family life environment in adulthood.展开更多
文摘针对低功耗有损网络中采用博弈论的网络拥塞控制(game theory based network congestion control protocol,GTNCC)路由算法在路由构建过程中仅仅考虑无线链路质量不能使网络拓扑最优,以及在拥塞控制过程中由拥塞节点的子节点判断是否切换父节点不能快速高效地缓解网络拥塞等问题,提出一种基于多维度量结合的集中式网络拥塞控制(centralized network congestion control based on multi-metrics combination,CNCCMC)路由协议。首先,为了降低网络拥塞发生的概率,CNCCMC路由协议综合考虑了节点剩余能量、缓存占用率、无线链路质量和中继节点当前子节点个数等多维度量完成路由构建;其次,当检测到网络拥塞时,CNCCMC路由协议依据网络拥塞节点进行流量分析和判断的结果采取集中式的方式控制其子节点的切换;最后,在网络拥塞缓解过程中,提出一种"乒乓效应"避免机制。理论分析和仿真结果表明,与GTNCC路由算法相比,CNCCMC路由协议在降低网络拥塞发生的概率、延长网络平均生存寿命和提高网络吞吐量等方面的性能得到了有效提升。
文摘针对低功耗有损网络(low power and lossy networks,LLN)中现有路由修复算法存在控制开销冗余、修复时延较大和路由环路等问题,提出一种LLN中基于环路避免的高效路由修复算法(highly-efficient loop-free based repair routing protocol for LLN,HLR-RPL)。该算法提出了3个优化思路:首先,采用一种修正后的面向目的地的有向无循环图(destination oriented directed acyclic graph,DODAG)信息请求消息(DODAG information solicitation amend,DIS-A),使得链路中断通告过程和寻路过程同时进行;其次,提出一种减少控制消息回复机制,避免所有接收到DIS-A消息的节点均回复DODAG信息对象消息;最后,提出一种链路中断节点的子节点切换机制,从而优化了网络拓扑。仿真结果表明,HLR-RPL算法在控制开销和路由修复时延等性能方面优于现有的路由修复算法,且能够彻底避免路由环路的产生。
基金supported by the National Natural Science Foundation of China (61379159)the Foundation and Frontier Research Project of Chongqing (cstc2015jcyjBX0085)
文摘Owing to the unreliability of wireless link and the resource constraints of embedded devices in terms of energy, processing power, and memory size in low power and lossy networks （LLNs）, network congestion may occur in an emergency and lead to significant packet loss and end-to-end delay. To mitigate the effect of network congestion, this paper proposes a centralized congestion control routing protocol based on multi-metrics （CCRPM）. It combines the residual energy of a node, buffer occupancy rate, wireless link quality, and the current number of sub-nodes for the candidate parent to reduce the probability of network congestion in the process of network construction. In addition, it adopts a centralized way to determine whether the sub-nodes of the congested node need to be switched based on the traffic analysis when network congestion occurs. Theoretical analysis and extensive simulation results show that compared with the existing routing protocol, the performance of CCRPM is improved significantly in reducing the probability of network congestion, prolonging average network lifetime, increasing network throughput, and decreasing end-to-end delay.
文摘Objective Non-motor symptoms are important prodromal characteristics of Parkinson's disease(PD).The siblings and the spouses of PD patients do not have classic motor symptoms.This study aimed to investigate if they have PD prodromal symptoms.Methods A total of 98 PD patients from the Affiliated Hospital of Yangzhou University were recruited between January 2015 and August 2017;256 siblings of these patients were included in a siblings group,87 spouses of PD patients were included in a spouses group and 250 healthy individuals were included in a control group.Various scales were used to assess non-motor symptoms,including depression,anxiety,cognitive function,sleep status,constipation,daytime sleepiness,subjective olfactory disorder,rapid-eye-movement sleep behavior disorder(RBD),and restless legs syndrome(RLS).Results The incidence of anxiety(OR=3.06,95% CI 1.86-5.05,P<0.01),depression(OR=2.16,95% CI 1.16-4.04,P=0.01),RBD(OR=3.83,95% CI 1.79-8.19,P<0.01)and subjective olfactory disorder(OR=4.48,95% CI 2.02-9.90,P<0.01)was higher in the siblings group than in the control group.There were no statistically significant differences in constipation,cognitive impairment,sleep disorder,daytime sleepiness,and RLS between the two groups.There were no statistically significant differences in non-motor symptoms between the spouses group and the control group,except that the mild depression(OR=2.58,95% CI 1.07-6.20,P=0.03)in the spouses group was more obvious.Conclusion The siblings of PD patients are more likely to have PD prodromal symptoms compared with those without PD family history,perhaps because PD patients and their siblings have common pathogenic genetic factors and early living environment for neurode-generation.There are no obvious non-motor symptoms in the spouses of PD patients.It can be concluded that the onset of PD is not related to the family life environment in adulthood.
