A load-balancing scheme for IEEE 802.11 WLANs based on cooperative game theory is presented.A coalition among the access points（APs） with overlapping coverage is formed to share the network load through a game.First...A load-balancing scheme for IEEE 802.11 WLANs based on cooperative game theory is presented.A coalition among the access points（APs） with overlapping coverage is formed to share the network load through a game.Firstly, the candidate APs submit their load-competing strategies（i.e., the amount of user traffic they can admit in an AC/game period） to the control AP.Secondly, the control AP solves the game by the method of shapley value, which is the maximum traffic allocated to each AP in an AC/game period.Finally, the game is repeated periodically to distribute the traffic load among the APs.Simulation results show that the proposed game can balance the network load effectively compared with the IEEE 802.11 standard balancing solution.展开更多
目的研究视觉对人体姿势控制影响及其脑功能网络连接机制。方法以15名健康青年为研究对象,要求受试者分别进行30 s睁眼、闭眼的双腿站立平衡,采集平衡过程中身体压力中心(center of pressure,COP)和脑电。对COP进行样本熵(SampleEn)计算...目的研究视觉对人体姿势控制影响及其脑功能网络连接机制。方法以15名健康青年为研究对象,要求受试者分别进行30 s睁眼、闭眼的双腿站立平衡,采集平衡过程中身体压力中心(center of pressure,COP)和脑电。对COP进行样本熵(SampleEn)计算;对脑电θ、α和β频段,计算相位滞后指数(phase lag index,PLI)构建大脑功能网络,并基于图论计算集聚系数(C)、特征路径长度(L)及小世界网络属性(σ)。结果人体在双腿站立平衡过程中,闭眼COPY样本熵显著高于睁眼(P<0.05)。闭眼α频段PLI平均值显著高于睁眼(P<0.05);闭眼α频段C、σ显著高于睁眼,L显著低于睁眼(P<0.05)。闭眼时α频段额区-中央区-顶区之间的网络连接以及中央区和顶区内连接强度显著高于睁眼(P<0.05)。闭眼时α频段PLI平均值以及C值与COPY样本熵中度呈中度负相关(P<0.05)。睁眼时左前额区、左顶区、左枕区α频段PLI平均值与COPY样本熵呈中度负相关;闭眼时左中央区、右枕区α频段PLI平均值则与COPY样本熵呈中度负相关。结论人体在站立平衡时,当没有视觉信息输入时,身体平衡稳定性下降,同时伴随着脑电α频段的脑网络连接增强以及大脑处理信息的效率需提升。人体在不同的视觉条件下进行姿势控制时,大脑会采用不同的神经策略。展开更多
目的浅析椎动脉型颈椎病(cervical spondylotic vertebral arteriopathy,CSA)患者实施基于“筋骨平衡”理论针刺推拿疗法对其中医症状积分、颈性眩晕症状与功能评估量表(cervical vertigo symptom and function assessment scale,ESCV)...目的浅析椎动脉型颈椎病(cervical spondylotic vertebral arteriopathy,CSA)患者实施基于“筋骨平衡”理论针刺推拿疗法对其中医症状积分、颈性眩晕症状与功能评估量表(cervical vertigo symptom and function assessment scale,ESCV)评分、颈椎曲度及脑血流参数的影响。方法选择该院2019年12月—2021年12月就诊的CSA患者86例实施研究,随机数字表法分作观察组与对照组,各43例;其中对照组脱落2例,剔除1例,共完成40例;观察组脱落1例,剔除1例,共完成41例;对照组予以常规牵引疗法,观察组予以基于“筋骨平衡”理论针刺推拿疗法;比较两组治疗前与治疗后中医症状积分、ESCV评分、颈椎曲度及脑血流参数的变化,并对比两组疗效。结果治疗后,观察组中医症状积分皆显著低于对照组(P<0.05)。治疗后,观察组ESCV评分和颈椎曲度皆明显高于对照组(P<0.05)。治疗后,观察组椎底动脉及左、右椎动脉的Vs与Vd水平均显著高于对照组(P<0.05)。观察组总有效率显著高于对照组[95.12%(39/41)vs 80.00%(32/40),P<0.05]。结论基于“筋骨平衡”理论针刺推拿疗法对CSA患者疗效显著,有效改善中医症状积分、ESCV评分以及颈椎曲度,增强脑血流参数。展开更多
基金supported by the Aviation Science Fund (20080196005)
文摘A load-balancing scheme for IEEE 802.11 WLANs based on cooperative game theory is presented.A coalition among the access points（APs） with overlapping coverage is formed to share the network load through a game.Firstly, the candidate APs submit their load-competing strategies（i.e., the amount of user traffic they can admit in an AC/game period） to the control AP.Secondly, the control AP solves the game by the method of shapley value, which is the maximum traffic allocated to each AP in an AC/game period.Finally, the game is repeated periodically to distribute the traffic load among the APs.Simulation results show that the proposed game can balance the network load effectively compared with the IEEE 802.11 standard balancing solution.
文摘目的研究视觉对人体姿势控制影响及其脑功能网络连接机制。方法以15名健康青年为研究对象,要求受试者分别进行30 s睁眼、闭眼的双腿站立平衡,采集平衡过程中身体压力中心(center of pressure,COP)和脑电。对COP进行样本熵(SampleEn)计算;对脑电θ、α和β频段,计算相位滞后指数(phase lag index,PLI)构建大脑功能网络,并基于图论计算集聚系数(C)、特征路径长度(L)及小世界网络属性(σ)。结果人体在双腿站立平衡过程中,闭眼COPY样本熵显著高于睁眼(P<0.05)。闭眼α频段PLI平均值显著高于睁眼(P<0.05);闭眼α频段C、σ显著高于睁眼,L显著低于睁眼(P<0.05)。闭眼时α频段额区-中央区-顶区之间的网络连接以及中央区和顶区内连接强度显著高于睁眼(P<0.05)。闭眼时α频段PLI平均值以及C值与COPY样本熵中度呈中度负相关(P<0.05)。睁眼时左前额区、左顶区、左枕区α频段PLI平均值与COPY样本熵呈中度负相关;闭眼时左中央区、右枕区α频段PLI平均值则与COPY样本熵呈中度负相关。结论人体在站立平衡时,当没有视觉信息输入时,身体平衡稳定性下降,同时伴随着脑电α频段的脑网络连接增强以及大脑处理信息的效率需提升。人体在不同的视觉条件下进行姿势控制时,大脑会采用不同的神经策略。
