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1.
Wireless sensor networks (WSNs) are used for many real‐time applications. User authentication is an important security service for WSNs to ensure only legitimate users can access the sensor data within the network. In 2012, Yoo and others proposed a security‐performance‐balanced user authentication scheme for WSNs, which is an enhancement of existing schemes. In this paper, we show that Yoo and others' scheme has security flaws, and it is not efficient for real WSNs. In addition, this paper proposes a new strong authentication scheme with user privacy for WSNs. The proposed scheme not only achieves end‐party mutual authentication (that is, between the user and the sensor node) but also establishes a dynamic session key. The proposed scheme preserves the security features of Yoo and others' scheme and other existing schemes and provides more practical security services. Additionally, the efficiency of the proposed scheme is more appropriate for real‐world WSNs applications.  相似文献   

2.

A huge torrent of data traffic is generated from various heterogeneous applications and services at the Internet backbone. In general, at the backbone, all such applications and services are allocated spectral resources under a shared spectrum environment within elastic optical networks (EONs). In such a fully shared environment, connection requests (CRs) belonging to different traffic profiles compete for spectral resources. Hence, it is very challenging for network operators to resolve resource conflict that occur at the time of provisioning resources to such CRs. The heterogeneous traffic profile (HTP) considered in this work includes permanent lightpath demands (PLDs) and scheduled lightpath demands (SLDs). We propose various distance adaptive routing and spectrum assignment (DA-RSA) heuristics to resolve resource conflict among these two traffic profiles in EONs under a full sharing environment. Conventionally, preemption was the only technique to resolve such resource conflict among HTPs. Since preemption involves the overhead of selecting CRs to be preempted and then deallocating the resources given to those CRs, excessive preemption adversely affects the performance of the network. Therefore, in this work, we utilized bandwidth splitting as a solution to resolve resource conflict among HTPs under such a shared environment in EONs. Moreover, an integrated solution consisting of splitting and preemption is also proposed. We refer to this new integration as flow-based preemption. Our simulation results demonstrate that bandwidth splitting-based heuristics yield significant improvement in terms of the amount of bandwidth accepted in the network, link and node utilization ratio, number of transponders utilized and the amount of bandwidth dropped due to preemption. Moreover, the flow-based preemption approach is proved to be superior in performance amongst all proposed strategies.

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3.
针对大量电动汽车充电给电网带来较大影响的问题,进行了研究和分析。首先从电动汽车的普及程度、类型、充电时间、充电方式以及充电特性等角度,阐述了其对电网产生的影响。接着对电动汽车充电对输电网、配电网的影响进行了详细分析,对不同的影响因素提出了应对策略。最后对充电站的谐波污染治理和布局规划进行了研究,并讨论了未来的研究方向。  相似文献   

4.
针对当前无线可充电传感器网络(WRSNs)一对一移动充电方式存在充电效率低、定向充电模型缺乏问题,该文提出了一种基于充电效用最大化(MUC)的一对多有向充电调度方案.方案首先筛选网络中充电增益最大的有向覆盖子集;然后根据有向覆盖子集确定充电锚点,并进而规划充电器的移动路径;最后在满足移动充电器能量和充电周期约束条件下优化移动充电器的充电时间.实验结果表明,该方案与平均能量充电(AEC)、固定能量充电(FEC)相比,充电效率分别提高了13.7%和32.7%;与最多节点覆盖(MNC)、最大平均增益覆盖(MAGC)子集筛选方案相比,充电效率分别提高了4.4%和35.9%;同时在网络饿死节点数目上与MNC, MAGC方案相比也显著降低.  相似文献   

5.
针对当前无线可充电传感器网络(WRSNs)一对一移动充电方式存在充电效率低、定向充电模型缺乏问题,该文提出了一种基于充电效用最大化(MUC)的一对多有向充电调度方案。方案首先筛选网络中充电增益最大的有向覆盖子集;然后根据有向覆盖子集确定充电锚点,并进而规划充电器的移动路径;最后在满足移动充电器能量和充电周期约束条件下优...  相似文献   

6.
保护隐私的数字产品网上交易方案   总被引:3,自引:0,他引:3       下载免费PDF全文
毛剑  杨波  王育民 《电子学报》2005,33(6):1053-1055
电子商务中需要尽可能地保护用户隐私,而密码技术则是这一需求的重要保障.在安全的1/2不经意传输存在这一假设下,本文提出了一个安全且具隐私保护的数字产品网上交易方案.方案很好的考虑了实际交易中可能出现的情况,并针对可能出现的种种欺诈行为(如:商家以次充好,买家一次消费多次交易等问题)给予了有效的解决.同时结合匿名支付和匿名通信技术保证了用户交易的匿名性.  相似文献   

7.
This paper presents the wireless power transfer (WPT) technology based on inductive coupling and the design challenges of a hybrid energy harvester (EH) circuit as a promising solution to promote the energy efficiency of the electric vehicles (EVs). The design methodologies of ultra-low power (ULP) electronic module based on low leakage conditioning and processing device are detailed based on nanoscale transistor technology so that the WPT and hybrid EH can be implemented for self-powered devices in EVs. Moreover, in-vehicle network design verification based on a new power-aware behavioral model formulation and extraction for high-speed and ULP transceivers that enables the transient prediction of power and ground currents and voltages when multiple drivers are simultaneously switching for signal-power integrity evaluation. The derivation of the proposed model is based on the analysis and extension of the input/output buffer information specification (IBIS). The analysis of the previous IBIS and Mpilog modeling approaches is followed by a new model formulation along with a well-designed characterization and parametric extraction procedure.  相似文献   

8.
一种新型的无线光通信调制方法   总被引:1,自引:0,他引:1  
程刚  王红星  孙晓明  张铁英 《中国激光》2008,35(12):1914-1918
针对脉冲位置调制(PPM)和数字脉冲间隔调制(DPIM)等方法存在的问题,提出了一种新的双宽脉冲位置调制(DD-PPM)方式.在给出其符号结构的基础上,分析了带宽需求、传输容量和平均功率,推导出弱湍流信道下的误包率模型,并将其与开关键控调制(OOK),PPM和DPIM等典型调制方式进行了比较.理论分析和仿真结果表明,DD-PPM不仅比OOK具有更高的功率利用率和更好的差错性能,比PPM具有更高的带宽效率和传输容量,比DPIM具有相近甚至略好的差错性能,而且因符号长度固定,解调时不存在等待或缓存器溢出等问题,较DPIM更易工程实现.因而作为一种折中的调制方式,DD-PPM在无线光通信中有一定的应用场合.  相似文献   

9.
This paper proposes a new automatic repeat request (ARQ) scheme for reliable broadcasting in distributed wireless LANs. Unlike traditional ARQ schemes for reliable broadcasting, the proposed scheme is highly efficient in its ARQ control information delivery and only introduces light control overhead in the network. Our simulation results show that as compared with traditional ARQ schemes, the proposed scheme improves the LAN throughput by from several tens to more than one hundred percent, depending on the number of nodes in the LAN.  相似文献   

10.
Incorporating electric vehicles into smart grid,vehicle-to-Grid(V2G) makes it feasible to charge for large-scale electric vehicles,and in turn support electric vehicles,as mobile and distributed storage units,to discharge to smart grid.In order to provide reliable and efficient services,the operator of V2 G networks needs to monitor realtime status of every plug-in electric vehicle(PEV) and then evaluate current electricity storage capability.Anonymity,aggregation and dynamic management are three basic but crucial characteristics of which the services of V2 G networks should be.However,few of existing authentication schemes for V2 G networks could satisfy them simultaneously.In this paper,we propose a secure and efficient authentication scheme with privacy-preserving for V2 G networks.The scheme makes the charging/discharging station authenticate PEVs anonymously and manage them dynamically.Moreover,the monitoring data collected by the charging/discharging station could be sent to a local aggregator(LAG)in batch mode.In particular,time overheads during verification stage are independent with the number of involved PEVs,and there is no need to update the membership certificate and key pair before PEV logs out.  相似文献   

11.
12.
Lei  Zhang  Lili  Yu  Bin  Wang  Xingchao  Bian 《Wireless Personal Communications》2019,109(4):2411-2425
Wireless Personal Communications - With the development of iris technology, iris identification has been widely used in various domains, as an efficient security authentication pattern. However, as...  相似文献   

13.
Many schemes to reduce the inter-cluster handoff delay in wireless ATMnetworks have been proposed, but the previous schemes waste relativelylarge network resources to decrease the path rerouting delay. In thispaper, we propose the 2-layered cluster concept, where the seamlessinter-cluster handoff can be supported regardless of path reroutingtime. As a result, the waste of wired resources and the rate of theinter-cluster handoff can be reduced. From the performance analysisand simulation, the inter-cluster handoff rate for non-real-timetraffic is only about 1/3 of the conventional result. Suchadvantageous features of the proposed scheme neither incur anyincrease of the total handoff rate nor require additional ATMswitches.  相似文献   

14.
In commercial unmanned aerial vehicle(UAV) applications, one of the main restrictions is UAVs’ limited battery endurance when executing persistent tasks. With the mature of wireless power transfer(WPT) technologies, by leveraging ground vehicles mounted with WPT facilities on their proofs, we propose a mobile and collaborative recharging scheme for UAVs in an on-demand manner. Specifically,we first present a novel air-ground cooperative UAV recharging framework, where ground vehicles cooperative...  相似文献   

15.
频谱共享是认知无线网络关键技术之一。为消除认知无线网络中频率选择性信道下授权主用户与认知用户间的相互干扰,本文提出了一种新的频谱共享方法。该方法充分利用了无线通信系统中由信道的频率选择性衰落导致的不同用户信道的不相关性,通过求解矩阵方程获得预处理矩阵的通解,并在主用户和认知用户发射端分别进行预处理。从而实现认知系统中主用户与认知用户之间的相互零干扰,并使每个用户都可有效地传输数据。理论推导及系统仿真均表明,新方法可以有效地消除授权主用户与认知用户之间的双向干扰,实现不同用户平等地共享无线频谱资源。新方法可以提高频谱的利用率,一定程度上缓解无线频谱资源在当前及未来无线通信领域日益紧缺的矛盾。而且新方法也同样适用于不同认知用户之间共享频谱。   相似文献   

16.
现将文献[1]所提出的异步电机定子电阻在线自校正技术用于电动车辆VVVF异步电机变频调速器的起动和运行,从而获得了高转矩一电流比的优良性能,本文示出了一些重要的仿真结果,并对其进行了评述。  相似文献   

17.
随着政府对电动汽车的重视,电动汽车规模日益增大,电动汽车的充放电有序控制不仅减小对电网的负面影响,还能将其应用于系统的调峰,调频,事故备用等方面。本文介绍了电动汽车充电对电网影响的研究方向,从时间维度和空间维度两方面总结了目前采用的研究方法和存在的问题,并总结了常用的优化方法、目标函数和重要的约束条件。指出完善电价激励机制,实现智能充电导航,开发便捷友好的控制终端是有序充电控制未来的研究方向。  相似文献   

18.
本文开发了基于磁耦合谐振式的微型无线充电实验系统,并将其应用于本科实验教学.由于实验系统涵盖了无线电能传输理论与技术,以及电路、电磁场、模拟与数字电路和射频功率器件等理论与知识,通过本实验系统的教学,既提高了本科生综合应用基础理论知识解决实际问题的能力,又加深了他们对新知识和新原理的理解.  相似文献   

19.
We propose a new coded cooperation scheme for wireless communications to obtain transmit diversity in the scenarios that agents such as mobile handsets, sensor network nodes and etc., due to size, power or other constraints, cannot utilize multiple antennas. New scheme supports more than two cooperative users with a relatively low cooperation level. We evaluate the performance of the proposed scheme in a frequency nonselective slow fading channel. For two cooperative users, we provide the exact analytical analysis. However, for more than two users, as the analytical analysis is very complicated, our performance evaluation is based on computer simulations. Our numerical results show that each of the N cooperative users obtains a full diversity order of N at moderate to high signal to noise ratio regimes. In addition, the results indicate that the new coded cooperation scheme can achieve a noticeable gain over the non-cooperative scheme. Further, the simulation results confirm the analytical derivations derived for two cooperative users.
Masoumeh Nasiri-KenariEmail:

Azizollah Jamshidi   (IEEE’s 2006) received the B.S. degree (with honors) in Electrical Engineering from Shiraz University, Shiraz, Iran, in 1997, and the M.S. degree in Electrical Engineering from Sharif University of Technology, Tehran, Iran in 1999. He is currently working toward the Ph.D. degree in Electrical Engineering in Sharif University of Technology, Tehran, Iran. Since February 2003, he has been a member of Wireless Research Laboratory of the Electrical Engineering Department in Sharif University. His research interests include multi-user detection in CDMA systems, cooperative diversity, cognitive radio, channel coding and information theory. Masoumeh Nasiri-Kenari   received the B.S and M.S. degrees in Electrical Engineering from Isfahan University of Technology, Isfahan, Iran, in 1986 and 1987, respectively, and the Ph.D. degree in Electrical Engineering from the University of Utah, Salt Lake City, in 1993. From 1987 to 1988, she was a Technical Instructor and Research Assistant at Isfahan University of Technology. Since 1994, she has been with the Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran, where she is now a Professor. Professor Nasiri-Kenari is also the Director of Wireless Research Laboratory of the Electrical Engineering Department. From 1999 to 2001, She was a Co-Director of the Advanced Communication Science Research Laboratory, Iran Telecommunication Research Center, Tehran, Iran. Her current research interests are in wireless communication systems, error correcting codes, and optical communication systems.  相似文献   

20.
This paper proposes a new approach to avoiding collisions for broadcast packets in distributed wireless LANs. The basic idea is to use in-band pulses to convey the medium access control information for broadcast packets. The new approach extends the basic functionality of the IEEE 802.11 distributed coordination function (DCF) from the unicast case to the broadcast case and significantly improves the broadcasting efficiency in wireless LANs.  相似文献   

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