无线传感器网络密钥建立协议的能耗分析

从密钥存储量负载、通信负载和节点能耗等方面,对三个具有代表性的密钥建立协议SPINS、Random Key Scheme和PeerSiz进行了能耗测试和分析,结果表明:尽管基于对称密码体制的密钥建立协议的能耗远小于基于公钥体制的协议,但是如果选择部署了合适的密码算法,如ECC-160,基于公钥体制的密钥建立协议也能够较好地适应无线传感器网络环境。     

高能激光武器及其技术发展

本文综述了高能激光武器的分类、组成、基本工作原理,以美、俄等世界军事大国特别是以美国为例介绍了当今世界高能激光武器的发展现状,归纳总结了高能激光武器的未来研究,分析提出了我国在高能激光武器方面应重点研究和发展的关键技术.     

基于EPON智能电能表光通信模块的设计与实现

智能电能表光通信模块的研究,在智能电网建设中发挥着重要作用。通过对EPON(以太网无源光网络)、PLC(电力载波通信)和WiMAX(全球微波互联接入)技术的对比分析,选择EPON作为智能电能表通信接入网技术,并设计了通信流程。基于QCA8829嵌入式芯片,在Redhat Linux 2.6.x开发平台上采用可接入EPON系统的光纤接口技术,实现了智能电能表主站与从站的通信系统。经测试表明,基于EPON智能电表光通信模块实现了智能电网配电侧信息全采集、全覆盖,并使远程电费控制及负载控制到户。     

一种基于多跳光旁路的IP over WDM节能网络设计方法

针对IP over WDM网络,基于多跳光旁路和流量疏导,以减少能耗为目标对网络链路配置进行设计;考虑多跳光旁路会增大业务传输距离的问题,分析了光路建立顺序对业务传输距离的影响;通过优先路由短距离业务和限制最大传输跳数来减少业务的平均传输跳数。仿真结果表明,优先建立短距离光路的启发式算法与Dijkstra算法相比可以减少25%～55%的能耗,业务平均物理跳数与Dijkstra算法相差在1跳之内。     

太阳能电池在偏远基站的应用

太阳能供电系统由太阳能电池板、太阳能控制器、蓄电池、备用发电机组及开关电源等组成,其供电可靠、长期成本低、维护量少,且能耗极低,符合国家节能减排政策。在没有市电供应的海岛基站或市电供应十分困难的偏远基站,太阳能供电系统是一种很好的供电方式。     

基于分布式检测和协作的自适应频谱感知机制

对当前备受关注的认知无线电多点协作频谱感知技术进行了系统归纳与总结.对频谱感知基本问题进行研究,指出了低信噪比情况下单节点检测存在的局限性;接着着重对基于能量检测的多点协作检测技术和多种数据合并算法等最新的研究情况进行了介绍和评价;最后提出了一种具有自适应优化功能的协作频谱感知机制,对控制信道和检测判决信道采用两种控制方式,采用较为稳健的拓扑控制方式,提高了检测网络的稳定性和运作效率.     

Energy efficiency of TCP: An analytical model and its application to reduce energy consumption of the most diffused transport protocol

Energy efficient communications become a challenge for both industries and researchers. Incorporating energy efficiency into the design of network protocols and architectures represents a relevant issue in networking research. Currently, very few works address energy efficiency as a fundamental feature of network protocols. This paper benchmarks energy efficiency of TCP to understand the parameters and operational mechanics that determine and contribute to energy consumption. We propose an analytical model with energy consumption to protocol operation cycles and novel optimization techniques for reducing energy consumption of TCP. The evaluation results, obtained from NS2 simulations, demonstrate that even minor modifications of the protocol behavior can bring significant savings of energy. Copyright © 2015 John Wiley & Sons, Ltd.     

Coexisting with the dynamic PU,the effect of PU‐returns on a secondary network

Coexisting with a dynamic primary user network is a challenge in cognitive radio networks, since the rate at which primary user reoccupies the spectrum is high. Therefore, it is important to investigate deeply the effect of primary traffic dynamics on secondary network performance metrics. To do that, interference due to both sensing error and primary user re‐occupancy must be formulated and considered in throughput and collision probability. Besides them, secondary packet retransmissions due to such interference should be considered in metrics such as average energy consumption and average packet delay. In this study, we formulate the mentioned secondary network metrics regarding to such kinds of interference and secondary packet retransmission. Numerical results along with discussions are given to clarify derived expressions. Simulations are also performed to justify the theoretical results, and optimum operating point for secondary network settings is derived by genetic algorithm.     

航天器低功耗电源控制器测控单元设计

本文针对航天器电源控制器智能化、低功耗等方面的设计需求,对电源控制器遥测遥控接口单元采用智能化控制设计,依托微处理器内部软件来执行电源系统全任务周期的控制和管理,提高电源系统的效率、可靠性、自主管理能力,并降低系统的静态功耗.     

Modification of Energy Level Alignment for Boosting Carbon-Based CsPbI2Br Solar Cells with 14% Certified Efficiency

Hole transfer material (HTM)-free, carbon-based all-inorganic perovskite solar cells (C-PSCs) are promising alternatives to conventional organic–inorganic hybrid PSCs in addressing thermal and moisture instability issues. However, the energy level mismatch between the inorganic perovskite and carbon electrode coupled, together with the incapability of the carbon electrode to reflect incident light for reabsorption, limits the power conversion efficiency (PCE) of C-PSCs. To address these issues, herein, a new strategy of a hexyltrimethylammonium bromide (HTAB)-modified CsPbI₂Br perovskite surface is devised to reduce this energy offset from 0.70 to 0.32 eV and increase the built-in potential by 70 mV for the final devices. Additionally, a CsPbI₂Br perovskite film with a thickness of up to 800 nm is realized via a hot-flow-assisted spin coating approach in an ambient atmosphere with humidity of less than 80%. Reduced energy offset coupled with suppressed charge recombination and thick perovskite layer boosts the champion PCE of CsPbI₂Br C-PSCs to 14.3% (J_sc = 14.1 mA cm⁻², V_oc = 1.26 V, and fill factor = 0.806), and the average PCE to 13.9% under one sun illumination. A new certified efficiency record of 14.0% is obtained for HTM-free inorganic C-PSCs. Meanwhile, the moisture-resistant barrier from the alkyl chain in HTAB improves the stability of the final devices.