检索结果-南通市图书馆

Implementation of Abstract MAC Layer Under Jamming

Tsinghua Science and Technology 2022年第2期27卷 257-269页

作者： Yifei Zou Minghui Xu Dongxiao Yu Liandong Chen Shaoyong Guo Xiaoshuang Xing School of Computer Science and Technology Shandong UniversityQingdao 266237China Information and Telecommunication Branch State Grid Hebei Electric Power Company Ltd.Shijiazhuang 050022China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China School of Computer Science and Engineering Changshu Institute of TechnologyChangshu 215500China

In the past decades,with the widespread implementation of wireless networks,such as the Internet of Things,an enormous demand for designing relative algorithms for various realistic scenarios has ***,with the widening of scales and deepening of network layers,it has become increasingly challenging to design such algorithms when the issues of message dissemination at high levels and the contention management at the physical layer are ***,the abstract medium access control(absMAC)layer,which was proposed in2009,is designed to solve this ***,the absMAC layer consists of two basic operations for network agents:the acknowledgement operation to broadcast messages to all neighbors and the progress operation to receive messages from *** absMAC layer divides the wireless algorithm design into two independent and manageable components,i.e.,to implement the absMAC layer over a physical network and to solve higher-level problems based on the acknowledgement and progress operations provided by the absMAC layer,which makes the algorithm design easier and *** this study,we consider the implementation of the absMAC layer under *** efficient algorithm is proposed to implement the absMAC layer,attached with rigorous theoretical analyses and extensive simulation *** on the implemented absMAC layer,many high-level algorithms in non-jamming cases can be executed in a jamming network.

关键词： abstract MAC layer distributed algorithm Rayleigh-fading model jamming networks

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Power optimization for maximum channel capacity in MIMO relay system

引用

The Journal of China Universities of Posts and telecommunications 2007年第3期14卷 10-15页

作者： WANG Ying SHEN Xiao-dong WU Tong LIU Bao-ling Key Laboratory of Ubiquitous Wireless Communication Ministry ofEducation Beijing University of Posts and TelecommunicationsBeijing 100876 China

Introducing multiple-input multiple-output（MIMO） relay channel could offer significant capacity gain. And it is of great importance to develop effective power allocation strategies to achieve power efficiency and improve channel capacity in amplify-and-forward relay system. This article investigates a two-hop MIMO relay system with multiple antennas in relay node （RN） and receiver （RX）. Maximizing capacity with antenna selection（MCAS） and maximizing capacity with eigen-decomposition （MCED） schemes are proposed to efficiently allocate power among antennas in RN under first and second hop limited scenarios. The analysis and simulation results show that both MCED and MCAS can improve the channel capacity compared with uniform power allocation （UPA） scheme in most of the studied areas. The MCAS bears comparison with MCED with an acceptable capacity loss, but lowers the complexity by saving channel state information （CSI） feedback to the transmitter （TX）. Moreover, when the RN is close to RX, the performance of UPA is also close to the upper bound as the performance of first hop is limited.

关键词： MIMO-relay MCAS MCED UPA maximum channel capacity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Resource optimization in distributed cooperative multi-relay system based on STBC-OFDM

引用

The Journal of China Universities of Posts and telecommunications 2007年第2期14卷 1-6页

作者： WU Tong QU Xin-chun WANG Ying Key laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

On the basis of the amplify-and-forward relaying mode, a two-hop distributed cooperative multi-relay system is proposed combining with the space-time block coding OFDM （STBC-OFDM） technique. Taking the maximum end-to-end data rate as optimization criterion, the signal-to-noise ratio （SNR） of receiving terminal is deduced. On the basis of the water-filling theory, the optimal power allocation （OPA） is achieved for each subcarrier in each antenna and each relay node （RN） of the two-hop, to realize the resource optimization. Monte Carlo method is adopted in simulation. The simulation results show that compared with the uniform resource allocation scheme, the proposed OPA strategy *** the system capacity. And the energy consumption of each transmission bit will be decreased, indicating the improvement of resource efficiency. In the scenario that the total power is limited, the system performance can be enhanced further by the distributed cooperative multi-relay through the diversity gain.

关键词： STBC-OFDM distributed multi-relay water-filling theory OPA Monte Carlo

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Self-adaptive Learning Rate Principle for Stacked Denoising Autoencoders

引用

软件 2015年第9期36卷 82-86页

作者： HAO Qian-qian DING Jin-kou WANG Jian-fei School of Science Beijing University of Posts and Telecommunications State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Zhe Jiang Xinlan Network Media Limited company

Existing research on image classification mainly used the artificial definition as the pre-training of the original image,which cost a lot of time on adjusting ***,the depth of learning algorithm intends to make the computers automatically choose the most suitable features in the training *** substantial of deep learning is to train mass data and obtain an accurate classification or prediction without any artificial work by constructing a multi-hidden-layer ***,current deep learning model has problems of local minimums when choosing a constant learning rate to solve non-convex objective cost function in model *** paper proposes an algorithm based on the Stacked Denoising Autoencoders(SDA)to solve this problem,and gives a contrast of different layer designs to test the performance.A MNIST database of handwritten digits is used to verify the effectiveness of this model..

关键词： Deep learning SDA model Regularization Adaptive le

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

thuraya在北美推出机对机服务和首个终端

引用

电脑与电信 2016年第3期 14-14页

作者： thuraya Satellite telecommunications company thuraya Satellite telecommunications company

阿联酋迪拜2016年3月15日电/--领先的移动卫星服务运营商thuraya telecommunications company（舒拉亚电信公司）今天在其广泛的覆盖区推出专门的机器对机器（M2M）服务与终端,并首次将这项服务推向北美。该公司的设备与应用开发合作伙... 详细信息

阿联酋迪拜2016年3月15日电/--领先的移动卫星服务运营商thuraya telecommunications company（舒拉亚电信公司）今天在其广泛的覆盖区推出专门的机器对机器（M2M）服务与终端,并首次将这项服务推向北美。该公司的设备与应用开发合作伙伴网络目前所提供的M2M解决方案正面临越来越大的市场需求,此次新服务的推出正是为了顺应这一上升势头。

关键词：服务运营商移动卫星舒拉 thuraya 覆盖区阿联酋迪拜卫讯低数据速率客户需要副总裁

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Hierarchy echo state network based service-awareness in 10G-EPON

引用

The Journal of China Universities of Posts and telecommunications 2016年第2期23卷 91-96页

作者： Bai Huifeng Wang Dongshan Wang Licheng Wang Xiang Beijing Smart Chip Microelectronics company Limited Beijing 102200 China

Aimed to enhance the supporting ability for diversified services, this paper proposes a hierarchy echo state network（HESE） based service-awareness（SA）（HESN-SA） mechanism in 10 Gbit/s Ethernet passive optical network（10G-EPON）. In this HESN-SA, hierarchy architecture is adopted to realize echo state network（ESN） classification based SA. According to the network architecture of 10G-EPON, the parent-ESN（p-ESN） module works in the optical line terminal（OLT）, while the sub-ESN（s-ESN） module is embedded in optical network units（ONUs）. Thus, the p-ESN plays the main function of SA with a total view of this system, and s-ESN in each ONU conducts the SA function under the control of p-ESN. Thus, resources allocation and transport policy are both determined by the proposed mechanism through cooperation between OLT and ONUs. Simulation results show that the HESN-SA can improve the supporting ability for multiple services.

关键词： passive optical network service-awareness hierarchy echo state network echo state network

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research on Power Load Forecasting and Visualization Method Based on Deep Neural Network

Research on Power Load Forecasting and Visualization Method ...

引用

第三届材料科学应用与能源材料国际研讨会

作者： Yifei Wang Xian Li Shuang Mo State Grid Jibei Information and Telecommunication company School of Computer Beijing University of Posts and Telecommunications

Short-term load forecasting（STLF） has attracted much attention in the last decade, which uses data from historical power grid operation monitor to forecast future power demand for a few days. Previous works on STLF mainly focus on features, which are widely used to capturing external factors in power system. There are also approaches based on physics, which use linear combination of active and reactive power consumption to model dynamics of power demand. However, in many real-world applications they don’t work well. In the self-service power grid, STLF is a very important part in power scheduling and planning. But STLF is a challenging task for its complex power demand and the effects of weather. In this paper, we study the problem of combination of complex and seasonality of power demand, as well as effect of external weather. Therefore, we come up with an approach, called DNNCast, it’s a model based on deep neural network, which can achieve a good accuracy and fast training speed. In the structure it uses a deep neural network to model various power loads and external weather conditions. Finally, with visualization tools we can wisely make decision about power scheduling and planning. Compared with the current STLF methods, our model has a better prediction effect, and faster in the experiments of the extended experiment on 133 real power datasets.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Traffic-load prediction based on echo state network improved by Bayesian theory in 10G-EPON

引用

The Journal of China Universities of Posts and telecommunications 2015年第2期22卷 69-73页

作者： Bai Huifeng Zhao Xianlong Zhou Hongfeng Zhang Likun Beijing NARI Smart Chip Microelectronics company Limited Translation Department

With the evolution of 10-gigabit Ethemet passive optical network （10G-EPON）, the traffic-load prediction ability is necessary to support soaring services traffic with diversified characteristics and requirements. As a strong candidate to be used for the traffic-load prediction, the echo state network （ESN） may face the pseudo-regression problem and need to be improved for the better traffic-load prediction. To overcome this problem, this paper proposes an ESN based traffic-load prediction scheme using Bayesian theory in 10G-EPON for future-proof. In this proposed approach, Bayesian probability is introduced into the ESN and is used to improve the performance of ESN. According to the architecture between optical line terminal （OLT） and optical network units （ONU） in 10G-EPON, an ESN based on the Bayesian theory （B-ESN） is realized and the B-ESN based traffic load prediction scheme is also developed in OLT. Experiment results show that the proposed scheme can greatly better the accuracy of traffic-load prediction with lower complex degree.

关键词： 10-gigabit passive optical network traffic-load prediction ESN Bayesian theory

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

High throughput route selection in multi-rate wireless mesh networks

引用

The Journal of China Universities of Posts and telecommunications 2008年第3期15卷 13-18页

作者： WEI Yi-fei GUO Xiang-li SONG Mei SONG Jun-de Personal Communication Networks Computer Aided Design Center School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

Most existing Ad-hoc routing protocols use the shortest path algorithm with a hop count metric to select paths. It is appropriate in single-rate wireless networks, but has a tendency to select paths containing long-distance links that have low data rates and reduced reliability in multi-rate networks. This article introduces a high throughput routing algorithm utilizing the multi-rate capability and some mesh characteristics in wireless fidelity （WiFi） mesh networks. It uses the medium access control （MAC） transmission time as the routing metric, which is estimated by the information passed up from the physical layer. When the proposed algorithm is adopted, the Ad-hoc on-demand distance vector （AODV） routing can be improved as high throughput AODV （HT-AODV）. Simulation results show that HT-AODV is capable of establishing a route that has high data-rate, short end-to-end delay and great network throughput.

关键词： wireless mesh networks Ad-hoc AODV routing protocol multi-rate WiFi

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Experiments and SPICE simulations of double MgO-based perpendicular magnetic tunnel junction

引用

Chinese Physics B 2021年第4期30卷 518-525页

作者： Qiuyang Li Penghe Zhang Haotian Li Lina Chen Kaiyuan Zhou Chunjie Yan Liyuan Li Yongbing Xu Weixin Zhang Bo Liu Hao Meng Ronghua Liu Youwei Du China Electric Power Research Institute Beijing 100192China School of Physics Nanjing UniversityNanjing 210093China School of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China School of Electronics Science and Engineering Nanjing UniversityNanjing 210093China State Grid Tianjin Electric Power company Tianjin 300384China Key Laboratory of Spintronics Materials Devices and Systems of Zhejiang ProvinceZhejiang 311300China

We investigate properties of perpendicular anisotropy magnetic tunnel junctions(pMTJs) with a stack structure MgO/CoFeB/Ta/CoFeB/MgO as the free layer(or recording layer),and obtain the necessary device parameters from the tunneling magnetoresistance(TMR) *** loops and current-driven magnetization switching *** on the experimental results and device parameters,we further estimate current-driven switching performance of pMTJ including switching time and power,and their dependence on perpendicular magnetic anisotropy and damping constant of the free layer by SPICE-based circuit *** results show that the pMTJ cells exhibit a less than 1 ns switching time and write energies <1.4 pJ;meanwhile the lower perpendicular magnetic anisotropy(PMA) and damping constant can further reduce the switching time at the studied range of damping constant α <***,our results demonstrate that the pMTJs with the thermal stability factor■73 can be easily transformed into spin-torque nano-oscillators from magnetic memory as microwave sources or detectors for telecommunication devices.

关键词： magnetic tunnel junctions magnetic tunnel junction(MTJ)model switching time spin torque nano-oscillator

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：