期刊文献+
共找到5,422篇文章
< 1 2 250 >
每页显示 20 50 100
一种多优先级的自适应太赫兹无线局域网定向MAC协议
1
作者 任智 张伟业 +1 位作者 祁君易 吕玉超 《电讯技术》 北大核心 2025年第10期1650-1656,共7页
针对太赫兹无线局域网定向网络中重要信息传输优先级不足以及时隙请求帧碰撞的问题,提出了一种多优先级的自适应太赫兹无线局域网定向MAC(Medium Access Control)协议——PA-MAC(Priority-based Adaptive Time Slot Request MAC)。PA-MA... 针对太赫兹无线局域网定向网络中重要信息传输优先级不足以及时隙请求帧碰撞的问题,提出了一种多优先级的自适应太赫兹无线局域网定向MAC(Medium Access Control)协议——PA-MAC(Priority-based Adaptive Time Slot Request MAC)。PA-MAC协议采用基于数据业务类型的优先级划分机制,为不同优先级节点赋予不同的退避窗口大小,确保重要信息优先传输;采用基于优先级的新型CAP(Contention Access Period)时段划分机制,降低了碰撞概率;采用基于节点状态的自适应申请时隙机制,提高了时隙利用率。与现有相关协议相比,PA-MAC协议使节点申请到更多的剩余时隙资源,使时隙利用率最大提升了5.89%,网络吞吐量提高了5.86%,数据传输成功率最大提升了6.23%。 展开更多
关键词 太赫兹无线局域网 优先级划分 定向通信 mac协议
在线阅读 下载PDF
Effects of acupuncture in treating insomnia due to spleen-stomach disharmony syndrome and its influence on intestinal microbiome: Study protocol for a randomized controlled trial 被引量:19
2
作者 Ya-ru Huangfu Wei Peng +5 位作者 Bao-jun Guo Zhi-fu Shen Li Li Shi-wei Liu Hui Zheng You-ping Hu 《Journal of Integrative Medicine》 SCIE CAS CSCD 2019年第3期161-166,共6页
Background: Insomnia is a common complaint that is closely related to gastrointestinal symptoms, which is consistent with the traditional Chinese medicine classical theory of ‘‘stomach disharmony leading to restless... Background: Insomnia is a common complaint that is closely related to gastrointestinal symptoms, which is consistent with the traditional Chinese medicine classical theory of ‘‘stomach disharmony leading to restless sleep." Acupuncture is an effective complementary and alternative medicine therapy to improve gastrointestinal function and restore the normal sleep-wake cycle. However, studies on the effectiveness of acupuncture for insomnia due to spleen-stomach disharmony syndrome are limited to case reports and few randomized controlled trials; deeper research on its mechanism is still lacking. This randomized controlled trial aims to assess the treatment efficacy of ‘‘harmonizing stomach to tranquilize mind"acupuncture for insomnia and its influence on the intestinal microbiome.Methods/design: This is a randomized, single-blind, parallel-group study. Sixty eligible patients with insomnia due to spleen-stomach disharmony syndrome will be randomly divided into two groups(1:1 allocation ratio). The intervention group will use ‘‘harmonizing stomach to tranquilize mind"acupuncture, and the control group will receive sham acupuncture. Participants will receive 5 acupuncture treatment sessions per week for 4 consecutive weeks. The Pittsburgh Sleep Quality Index will be used to evaluate the clinical efficacy of acupuncture treatment by making assessments at baseline, the end of treatment and the end of the follow-up. High-throughput 16 S ribosomal ribonucleic acid gene sequencing will be performed to detect changes in the intestinal microbial composition before and after treatment.Discussion: The results of this trial are expected to confirm that ‘‘harmonizing stomach to tranquilize mind" acupuncture can effectively relieve insomnia and alter the intestinal microbiome. 展开更多
关键词 INSOMNIA Gastrointestinal SYMPTOMS ACUPUNCTURE INTESTINAL MICROBIOME Randomized controlled trial Study protocol
原文传递
基于改进Transformer模型的Ad Hoc网络MAC协议识别技术
3
作者 何文雯 李盛祥 +3 位作者 王莉 李浩 李盈达 马鹏飞 《电讯技术》 北大核心 2025年第8期1240-1247,共8页
针对现有的媒体访问控制(Media Access Control,MAC)协议识别模型存在特征数据选取不完善和只关注局部特征的问题,首先,基于Transformer模型提出了Conv-Transformer模型。该模型将卷积操作引入到模型中,对卷积后特征图中的特征值进行分... 针对现有的媒体访问控制(Media Access Control,MAC)协议识别模型存在特征数据选取不完善和只关注局部特征的问题,首先,基于Transformer模型提出了Conv-Transformer模型。该模型将卷积操作引入到模型中,对卷积后特征图中的特征值进行分割拼接,并添加类别信息编码。其次,基于Exata平台搭建不同拓扑结构的Ad Hoc网络仿真场景,收集所有物理层的数据对Conv-Transformer模型进行训练和测试。测试结果表明,在Ad Hoc网络中对ALOHA、CSMA/CA、MACA和TDMA 4种MAC协议的识别任务上,提出的模型与经典深度学习模型递归神经网络(Recurrent Neural Network,RNN)、卷积神经网络(Convolutional Neural Network,CNN)和Transformer相比,比RNN模型的准确率提高了20.8%,比CNN模型的准确率提高了14.6%,比Transformer模型的准确率提高了68.8%。 展开更多
关键词 Ad Hoc网络 mac协议识别 深度学习 Transformer模型
在线阅读 下载PDF
Priority Based Energy Efficient MAC Protocol by Varying Data Ratefor Wireless Body Area Network
4
作者 R.Sangeetha Usha Devi Gandhi 《Computer Systems Science & Engineering》 2024年第2期395-411,共17页
Wireless Body Area Network(WBAN)is a cutting-edge technology that is being used in healthcare applications to monitor critical events in the human body.WBAN is a collection of in-body and on-body sensors that monitor ... Wireless Body Area Network(WBAN)is a cutting-edge technology that is being used in healthcare applications to monitor critical events in the human body.WBAN is a collection of in-body and on-body sensors that monitor human physical parameters such as temperature,blood pressure,pulse rate,oxygen level,body motion,and so on.They sense the data and communicate it to the Body Area Network(BAN)Coordinator.The main challenge for the WBAN is energy consumption.These issues can be addressed by implementing an effective Medium Access Control(MAC)protocol that reduces energy consumption and increases network lifetime.The purpose of the study is to minimize the energy consumption and minimize the delay using IEEE 802.15.4 standard.In our proposed work,if any critical events have occurred the proposed work is to classify and prioritize the data.We gave priority to the highly critical data to get the Guarantee Tine Slots(GTS)in IEEE 802.15.4 standard superframe to achieve greater energy efficiency.The proposed MAC provides higher data rates for critical data based on the history and current condition and also provides the best reliable service to high critical data and critical data by predicting node similarity.As an outcome,we proposed a MAC protocol for Variable Data Rates(MVDR).When compared to existing MAC protocols,the MVDR performed very well with low energy intake,less interruption,and an enhanced packet-sharing ratio. 展开更多
关键词 Wireless Body Area Network(WBAN) IEEE 802.15.4 energy efficiency mac protocol ZIGBEE
在线阅读 下载PDF
基于MAC的PTP同步优化设计与实现
5
作者 修相宇 王康 武建锋 《时间频率学报》 2025年第2期101-108,共8页
针对PTP(precise time protocol)协议在应用层获取软件时间戳导致时钟同步精度下降的问题,提出一种基于MAC(media access control)层获取硬件时间戳的PTP同步优化方案。设计了以STM32F407微处理器为核心的PTP时钟应用平台,在MAC层实现... 针对PTP(precise time protocol)协议在应用层获取软件时间戳导致时钟同步精度下降的问题,提出一种基于MAC(media access control)层获取硬件时间戳的PTP同步优化方案。设计了以STM32F407微处理器为核心的PTP时钟应用平台,在MAC层实现了硬件时间戳获取,避免了由于协议栈软件处理延时产生的不确定性;针对PTP时钟晶振老化导致的时间同步偏差及网络延迟抖动问题,采用迭代方法优化了本地时钟频率调节算法,提高了频率校正精度。经实际测试,主从时钟偏差的RMS(root mean square)优于20 ns,提升了时钟同步精度。 展开更多
关键词 PTP协议 mac 滤波 时钟同步 时间戳
在线阅读 下载PDF
A Quantitative Security Metric Model for Security Controls:Secure Virtual Machine Migration Protocol as Target of Assessment 被引量:1
6
作者 Tayyaba Zeb Muhammad Yousaf +1 位作者 Humaira Afzal Muhammad Rafiq Mufti 《China Communications》 SCIE CSCD 2018年第8期126-140,共15页
Quantitative security metrics are desirable for measuring the performance of information security controls. Security metrics help to make functional and business decisions for improving the performance and cost of the... Quantitative security metrics are desirable for measuring the performance of information security controls. Security metrics help to make functional and business decisions for improving the performance and cost of the security controls. However, defining enterprise-level security metrics has already been listed as one of the hard problems in the Info Sec Research Council's hard problems list. Almost all the efforts in defining absolute security metrics for the enterprise security have not been proved fruitful. At the same time, with the maturity of the security industry, there has been a continuous emphasis from the regulatory bodies on establishing measurable security metrics. This paper addresses this need and proposes a relative security metric model that derives three quantitative security metrics named Attack Resiliency Measure(ARM), Performance Improvement Factor(PIF), and Cost/Benefit Measure(CBM) for measuring the performance of the security controls. For the effectiveness evaluation of the proposed security metrics, we took the secure virtual machine(VM) migration protocol as the target of assessment. The virtual-ization technologies are rapidly changing the landscape of the computing world. Devising security metrics for virtualized environment is even more challenging. As secure virtual machine migration is an evolving area and no standard protocol is available specifically for secure VM migration. This paper took the secure virtual machine migration protocol as the target of assessment and applied the proposed relative security metric model for measuring the Attack Resiliency Measure, Performance Improvement Factor, and Cost/Benefit Measure of the secure VM migration protocol. 展开更多
关键词 attack resiliency measure cost-benefit measure performance improvement factor security assessment formal verification security controls security metrics virtual machine migration protocol
在线阅读 下载PDF
基于Q-learning的广域物联网热点地区MAC层机制设计
7
作者 雷迪 刘向 +4 位作者 孙文彬 杨欣 许茜 陈丽丽 易波 《移动通信》 2025年第8期90-95,共6页
在广域物联网应用中,热点地区由于终端密集接入、业务负载波动大,存在接入冲突频发、信道资源利用率低下等问题。作为共享无线信道管理重要一环,MAC层协议在提升系统吞吐量与接入效率方面发挥着核心作用。分析了热点地区MAC层协议所需特... 在广域物联网应用中,热点地区由于终端密集接入、业务负载波动大,存在接入冲突频发、信道资源利用率低下等问题。作为共享无线信道管理重要一环,MAC层协议在提升系统吞吐量与接入效率方面发挥着核心作用。分析了热点地区MAC层协议所需特征,提出基于Q-learning算法的优化方案,在节点侧引入强化学习模型以实现参数自适应调整。在传统CSMA/CA协议基础上,设计了结合动态RTS/CTS机制与动态退避窗口的接入机制。仿真结果表明,所提出的优化方案在系统吞吐量、平衡信道冲突率与利用率方面有一定提升。 展开更多
关键词 物联网 mac层协议 CSMA/CA Q-LEARNING
在线阅读 下载PDF
A DUAL RESERVATION CDMA-BASED MAC PROTOCOL WITH POWER CONTROL FOR AD HOC NETWORKS
8
作者 Jia Min Chen Huimin Yuan Yuhua 《Journal of Electronics(China)》 2007年第1期64-68,共5页
This paper proposes a new multi-channel Medium Access Control (MAC) protocol named as Dual Reservation Code Division Multiple Access (CDMA) based MAC protocol with Power Control (DRCPC). The code channel is divided in... This paper proposes a new multi-channel Medium Access Control (MAC) protocol named as Dual Reservation Code Division Multiple Access (CDMA) based MAC protocol with Power Control (DRCPC). The code channel is divided into common channel,broadcast channel and several data chan-nels. And dynamic power control mechanism is implemented to reduce near-far interference. Compared with IEEE 802.11 Distributed Coordination Function (DCF) protocol,the results show that the pro-posed mechanism improves the average throughput and limits the transmission delay efficiently. 展开更多
关键词 Ad hoc networks Medium Access control mac protocol MULTICHANNEL Code Division Multiple Access (CDMA) Power control
在线阅读 下载PDF
基于BTMA的LoRa网络隐藏终端MAC协议研究
9
作者 汪浩 蔡宇航 +1 位作者 陈国杰 王璐 《计算机科学》 北大核心 2025年第3期318-325,共8页
低功耗广域网(Low Power Wide Area Network,LPWAN)技术的出现,能够在保证更远距离的通信传输的同时,最大限度地降低功耗,节约传输成本。LoRa(Long Range)技术作为其中的佼佼者,凭借其远距离、低功耗、大容量、强抗干扰、高接收灵敏度... 低功耗广域网(Low Power Wide Area Network,LPWAN)技术的出现,能够在保证更远距离的通信传输的同时,最大限度地降低功耗,节约传输成本。LoRa(Long Range)技术作为其中的佼佼者,凭借其远距离、低功耗、大容量、强抗干扰、高接收灵敏度的特点,备受工业界和学术界的青睐。针对目前工业中主流使用的基于ALOHA的LoRaWAN协议无法很好地解决海量终端设备接入LoRa网络后所带来的严重数据包冲突以及LoRa CAD(Channel Activity Detection)功能带来的隐藏终端问题,提出了一种基于BTMA(Busy Tone Multiple Access)的LoRa网络MAC协议——BT-MAC协议。该协议利用了LoRa高接收灵敏度的特性,网关利用“忙音”信标来通知各个节点网关的工作情况,减少了无效包的发送。同时,节点端通过记录有“忙音”信息和本地信息的逻辑信道矩阵,结合最优信道选择算法,选出最优逻辑信道进行发送,降低了端节点上行数据包之间的冲突,有效缓解了LoRa网络中的隐藏终端问题以及阻塞问题。此外,搭建了LoRa网络MAC协议测试平台,并测试了BT-MAC的有效性,完成了室内和室外环境大规模的并发实验和能耗检测实验。实验结果表明,BT-MAC协议的吞吐量是LMAC-2协议的1.6倍,是ALOHA协议的5.1倍;同时其包接收率达到LMAC-2协议的1.53倍,ALOHA协议的17.2倍;其包接收平均能耗约为LMAC-2协议的64.1%,为ALOHA协议的14.2%。 展开更多
关键词 LoRa mac协议 BTMA 隐藏终端 CAD
在线阅读 下载PDF
Hybrid bidirectional quantum communication with different levels of control with simulation
10
作者 Plaban Saha Manoj Kumar Mandal +1 位作者 Binayak S Choudhury Soumen Samanta 《Communications in Theoretical Physics》 2025年第1期65-91,共27页
In this paper,we develop a quantum communication protocol for the simultaneous preparation of a two-qubit and a three-qubit state at the positions of two different parties situated spatially apart.For one party,Alice,... In this paper,we develop a quantum communication protocol for the simultaneous preparation of a two-qubit and a three-qubit state at the positions of two different parties situated spatially apart.For one party,Alice,it is a remote state preparation of a known two-qubit state while for the other party,Bob,it is a joint remote state preparation with the help of a third party,Eve.The protocol is executed in a hybrid form bi-directionally in the presence of two controllers,Charlie and David.There is a hierarchy in the process through different levels of control under which the actions by Alice and Bob are performed.There is a need for a ten-qubit entangled channel connecting the five parties.The generation of this channel through a circuit is discussed.The protocol is executed on the IBM Quantum platform.We also study the effect of noise on our protocol.Here,amplitude-damping,bit-flip and phase-flip noisy environments are considered and the corresponding variations of fidelity are theoretically and numerically analyzed. 展开更多
关键词 remote state preparation joint remote state preparation HIERARCHY entangled state quantum circuit controlled protocol
原文传递
无人机Ad Hoc网络MAC协议比较
11
作者 傅伟 逄珂 李英棣 《科学与信息化》 2025年第1期105-107,共3页
Ad Hoc网络无中心、自组织、动态拓扑且支持多路径通信,适合无人机组网。传统单信道MAC协议难以解决Ad Hoc网络中的隐藏终端和暴露终端问题,影响数据传输。本文探讨多信道MAC协议原理及其优劣性,通过OPNET平台对多信道MMAC协议和单信道I... Ad Hoc网络无中心、自组织、动态拓扑且支持多路径通信,适合无人机组网。传统单信道MAC协议难以解决Ad Hoc网络中的隐藏终端和暴露终端问题,影响数据传输。本文探讨多信道MAC协议原理及其优劣性,通过OPNET平台对多信道MMAC协议和单信道IEEE 802.11DCF协议进行仿真。实验显示,MMAC协议在解决隐藏终端和暴露终端问题上表现卓越,且在吞吐量和丢包率等网络性能指标上优于单信道IEEE802.11协议。 展开更多
关键词 Ad Hoc网络 mac协议 单信道 多信道
在线阅读 下载PDF
基于深度强化学习的认知水声网络MAC协议
12
作者 柏然 张育芝 +2 位作者 韩翔 常嘉政 张舒敏 《计算机与数字工程》 2025年第7期1947-1953,共7页
针对长传输时延下多信道认知水声网络中信道利用率和网络吞吐量低的问题,提出了一种用于认知节点的基于深度强化学习算法自适应MAC协议,称为MDMA。认知节点自主选择被主节点以一定协议模式占用信道的空闲时隙传输数据包,目标是优化最大... 针对长传输时延下多信道认知水声网络中信道利用率和网络吞吐量低的问题,提出了一种用于认知节点的基于深度强化学习算法自适应MAC协议,称为MDMA。认知节点自主选择被主节点以一定协议模式占用信道的空闲时隙传输数据包,目标是优化最大化网络吞吐量的接入策略。同时,为了减少由部分可观性带来的决策偏差,提出了LSTM改进的MDMA神经网络模型。仿真结果表明MDMA-LSTM的提升吞吐量性能优于FC和随机策略,验证了所提方案的有效性。 展开更多
关键词 深度强化学习算法 多信道 认知水声网络 mac协议 长传输时延
在线阅读 下载PDF
移动Ad Hoc网络语音多跳通信MAC层协议设计
13
作者 李红卫 《移动通信》 2025年第5期128-134,共7页
媒体接入控制(MAC)协议的设计是实现Ad Hoc网络语音多跳通信的一个关键点所在。分析了无线网络中影响语音质量的因素及保障语音传输质量的QoS方案,为达到在MAC层减小语音传输时延和时延抖动目的,根据移动Ad Hoc网络的分布式应用、动态... 媒体接入控制(MAC)协议的设计是实现Ad Hoc网络语音多跳通信的一个关键点所在。分析了无线网络中影响语音质量的因素及保障语音传输质量的QoS方案,为达到在MAC层减小语音传输时延和时延抖动目的,根据移动Ad Hoc网络的分布式应用、动态拓扑、多跳通信等特性和语音通信的实时性要求等特点,分析传统多跳网络的MAC协议难以满足语音多跳通信需求的原因,进而提出采用调度机制的TDMA协议,并进行恰当的改进,设计基于优先级的空分时分复用P-STDMA接入协议,给出P-STDMA接入协议的详细设计方案并分析协议的技术特性及适用范围。利用软件仿真分析P-STDMA接入协议算法的接入延迟性能,证明该协议具有较高的时隙利用率,可有效减小接入延迟和语音传输时延,降低时延抖动。 展开更多
关键词 移动Ad Hoc通信网络 语音多跳通信 mac协议 基于优先级的空分时分复用
在线阅读 下载PDF
OFDM-PON MAC协议设计与实现
14
作者 杨鸣 《工业控制计算机》 2025年第8期29-31,共3页
近年来,接入网的带宽需求呈指数上涨的趋势,现有的TDM-PON由于其技术缺陷很难向更高速发展。在GPON的基础上,针对OFDM-PON的特点,提出了一种适用于OFDM-PON的媒质接入控制协议。所提出的协议设计了一种三层报头的帧结构,并引入了信道探... 近年来,接入网的带宽需求呈指数上涨的趋势,现有的TDM-PON由于其技术缺陷很难向更高速发展。在GPON的基础上,针对OFDM-PON的特点,提出了一种适用于OFDM-PON的媒质接入控制协议。所提出的协议设计了一种三层报头的帧结构,并引入了信道探测过程的交互控制消息,确保了系统数据传输的准确性和可靠性。在FPGA平台上,开发并实现了OLT和ONU的关键模块,对搭建的系统进行了功能的仿真验证和灵活速率传输特性的板级验证,结果表明发送数据在采用不同调制格式的情况下能够实现10.4 Gbps到46.6 Gbps范围的传输速率动态调整,为基于OFDM-PON系统的进一步研究提供了测试平台。 展开更多
关键词 OFDM-PON 媒质接入控制协议 FPGA 灵活速率
在线阅读 下载PDF
QoS-based MAC protocol for cognitive radio networks 被引量:2
15
作者 胡静 沈连丰 宋铁成 《Journal of Southeast University(English Edition)》 EI CAS 2012年第4期375-379,共5页
In order to improve the throughput performance of the secondary users (SUs) in the cognitive radio (CR) environment, a quality of service (QoS) based media access control (MAC) protocol is proposed. In this pr... In order to improve the throughput performance of the secondary users (SUs) in the cognitive radio (CR) environment, a quality of service (QoS) based media access control (MAC) protocol is proposed. In this protocol, the CR node maps the channel state as a vector, and the transmitter and the receiver obtain the final channel map through an AND operation to prepare for an optional channel set. Data from the upper application layer are classified into two priority levels according to the QoS requirement. The data of each level relate to different contention windows so that the priority of real time data can be guaranteed. A two-dimensional discrete-time Markov chain is utilized to evaluate the system performance, and mathematical expressions of the system throughput are derived. Simulation results show that compared with the IEEE 802. 11 distributed coordination function (DCF), the proposed MAC protocol can achieve higher throughput. 展开更多
关键词 quality of service (QoS) cognitive radio media access control mac channel map Markov chain
在线阅读 下载PDF
高效低时延分级多PAN太赫兹无线网络MAC层优化协议 被引量:3
16
作者 刘洋 任智 +1 位作者 古金东 周逊 《小型微型计算机系统》 CSCD 北大核心 2024年第8期1966-1971,共6页
针对现有分级多PAN太赫兹无线网络MAC(Medium Access Control)协议中存在的子网形成方案不合理以及私有CTA(Channel Time Allocation)与子网内实际负载不匹配等问题,提出了一种高效低时延的MAC层优化协议.该协议采用基于泛听的按需形成... 针对现有分级多PAN太赫兹无线网络MAC(Medium Access Control)协议中存在的子网形成方案不合理以及私有CTA(Channel Time Allocation)与子网内实际负载不匹配等问题,提出了一种高效低时延的MAC层优化协议.该协议采用基于泛听的按需形成子网机制避免了子网分布不均匀以及因子网形成后没有节点加入而造成的私有CTA资源浪费的问题.在子网形成后,子微微网协调器(Piconet Coordinator,PNC)根据子网内实际负载情况自适应选择私有CTA时隙资源优化机制,让有数据传输需求的节点及时将数据发出.仿真结果表明,所提出的方案能有效地降低数据帧平均接入时延,提高吞吐量以及数据帧的传输成功率. 展开更多
关键词 太赫兹 分级 多PAN 无线网络 媒体访问控制协议 低时延
在线阅读 下载PDF
无人机群自组网MAC协议综述 被引量:3
17
作者 周艳红 宁进 +1 位作者 丁志恒 多滨 《无线电工程》 2024年第8期1917-1927,共11页
近年来,无人机群自组网(UAV Swarm Ad Hoc Network,UAVSNet)的单个UAV不断自主化与智能化,但UAV之间的协同通信仍存在挑战。媒体接入控制(Media Access Control,MAC)协议是其关键技术之一,并成为了新的研究热点。通过概述MAC协议的分类... 近年来,无人机群自组网(UAV Swarm Ad Hoc Network,UAVSNet)的单个UAV不断自主化与智能化,但UAV之间的协同通信仍存在挑战。媒体接入控制(Media Access Control,MAC)协议是其关键技术之一,并成为了新的研究热点。通过概述MAC协议的分类及设计要点,对竞争类MAC协议、非竞争类MAC协议以及混合类MAC协议接入机制、性能表现及不足进行详细综述并提出展望。为UAVSNet的MAC协议的研究和应用提供了理论支持。 展开更多
关键词 无人机群 媒体接入控制协议 接入机制 自组网
在线阅读 下载PDF
一种移动感知的太赫兹无线局域网定向MAC协议
18
作者 任智 陈春宇 +1 位作者 古金东 姚毅 《电讯技术》 北大核心 2024年第5期725-731,共7页
现有太赫兹无线局域网定向MAC(Medium Access Control)协议中,节点移动情况下PNC(PicoNet)发送beacon帧时存在部分控制字段浪费、CTAP(Channel Time Allocation Period)中PNC与DEV(Device)进行波束赋形开销偏大等问题。为此,提出了一种... 现有太赫兹无线局域网定向MAC(Medium Access Control)协议中,节点移动情况下PNC(PicoNet)发送beacon帧时存在部分控制字段浪费、CTAP(Channel Time Allocation Period)中PNC与DEV(Device)进行波束赋形开销偏大等问题。为此,提出了一种移动感知的太赫兹无线局域网定向MAC(Mobility-aware Directional MAC,MA-MAC)协议。该协议采用基于卡尔曼算法的节点扇区预测机制对移动节点的扇区范围进行迭代预测,采用基于DEV扇区预测的beacon帧内容填充机制对beacon帧中时隙分配字段进行填充,采用基于节点扇区预测的快速波束赋形机制使得PNC与DEV之间波束赋形操作简化。通过仿真验证,与基于IEEE 802.15.3c的太赫兹无线局域网定向MAC协议和现有协议进行对比,MA-MAC协议下网络吞吐量得到了提升,网络平均时延、网络整体控制开销得到了改善。 展开更多
关键词 太赫兹无线局域网 定向通信 mac协议 移动感知
在线阅读 下载PDF
Fire-needle acupuncture for upper limb spastic paralysis after stroke:Study protocol for a randomized controlled trial 被引量:12
19
作者 Xin-yu Yue Zhuo-qi Feng +3 位作者 Xi-yi Yu Jia-min Hu Xiao-Jing He Shi Shu 《Journal of Integrative Medicine》 SCIE CAS CSCD 2019年第3期167-172,共6页
Background: Fire-needle acupuncture, an important kind of acupuncture therapy, has been clinically used to treat upper limb spastic paralysis(ULSP) after stroke. Clinical experience has indicated that fire-needle acup... Background: Fire-needle acupuncture, an important kind of acupuncture therapy, has been clinically used to treat upper limb spastic paralysis(ULSP) after stroke. Clinical experience has indicated that fire-needle acupuncture treatment takes less time, requires fewer visits, and has more rapid results and fewer side effects compared to chemical medicine alternatives. This study will evaluate the effects of fire-needle acupuncture for ULSP in the context of standardized clinical research and provide high-quality data to inform clinical procedures and future study design.Methods/Design: A randomized controlled trial will be carried out to evaluate the effects of fire-needle acupuncture therapy in patients with ULSP from stroke. ULSP patients(n = 120) will be recruited at Changhai Hospital in Shanghai, China. Patients will be randomly divided into three groups, including fire-needle acupuncture group(FAG), filiform-needle acupuncture group(FFAG) and rehabilitation treatment group(RTG). During the 3-week treatment, the FAG will be treated every two days, while FFAG and RTG will be treated 5 d in a row and then rest for 2 d. The Simplified Fugl-Meyer Motor Function Scale and Modified Ashworth Scale will be used as the primary outcome measures. Statistical analysis will be conducted by an independent statistician.Discussion: Through this study, the utility of fire-needle acupuncture in treating ULSP after stroke will be tested, and some specific claims of fire-needle acupuncture therapy will be evaluated, such as relieving spasm and muscular tension, improving activities of daily living, rapidity of response and less frequency of treatment compared with other treatments. 展开更多
关键词 Fire-needle ACUPUNCTURE Upper limb SPASTIC PARALYSIS STROKE Randomized controlled trial Study protocol
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部