基于调幅—线性调频信号参数估计的机动目标成像方法

逆合成孔径雷达（ISAR）机动目标成像受到了研究者的广泛重视。在已有的机动目标成像算法中,通常假设在综合孔径处理期间,各距离单元内各散射回波是等幅线性调频信号。在实际中,以上假设仅是近似成立,基于此假设的机动成像算法难以得到较高质量的目标图像。本文采用更精确的信号模型－多分量调幅－线性调频（AM－LFM）信号表示实际机动目标的各距离单元回波,并提出一种AM－LFM信号参数估计方法以及快速算法,通过估计信号的时变振幅、调频率和初相等参数,得到了更高质量的机动目标的动态ISAR像序列,以利于目标识别,而且运算量比已有算法要小。     

HomePNA通信中的技术与应用

正如局域网 (LAN)是为了满足企业内多用户互连和资源共享 ,为满足家庭中多种数字设备互连和资源共享 ,家庭电话线网设备 (HomePNA)应运而生。文章叙述了HomePNA通信中所需的技术与应用。     

基于宽谱光源OFDM信号传输技术

提出了一种新型的基于ASE宽谱光源的OFDM传输技术,该技术实现了3.0 GHz带宽、1 GHz带宽、16QAM、512个载波、速率2 Gbit/s的OFDM信号20 km以内无误码传输。对系统的矢量信号特性EVM和系统工作点的关系也进行了讨论。     

基于Intel VT-d技术的虚拟机安全隔离研究

资源隔离是计算机安全的一个重要手段,良好的安全隔离使得虚拟机技术成为近年来学术界和工业界的热点。在深入分析Linux环境下Xen完全虚拟化技术理论的基础上,设计了一个基于IntelVT技术的虚拟机安全隔离设计方案。该方案通过安全内存管理（SMM）和安全I/O管理（SIOM）两种手段进行保护,完善了Xen宿主机系统与虚拟机系统之间的安全隔离,为Xen虚拟机在实际的安全隔离环境中的应用提供了较高的安全保障。     

磷酸铁锂电池在宽带大提速中的应用

宽带大提速是中国电信实现企业转型和"三网合一"战略的重要举措,随着宽带大提速业务的不断推进,近几年来以FTTN为接入方式的室外机柜大规模建设。文章主要介绍了磷酸铁锂电池在室外机柜中使用的优良特性及其应用前景,并通过实验证明了磷酸铁锂电池能够满足通信后备电源保障需求,作为新型节能环保电池,将逐步代替传统的铅酸蓄电池。     

Augmentation of XNAV System to an Ultraviolet Sensor-Based Satellite Navigation System

X-ray pulsar-based navigation (XNAV) using one X-ray detector is investigated as an augmentation to the capability of an ultraviolet (UV) sensor-based satellite autonomous navigation system. The satellite state dynamics are analyzed to establish the dynamical equations of the satellite autonomous navigation system. A time transformation equation that accounts for relativistic effects is presented and the measurement model of the XNAV system is derived using pulse phase information from only one pulsar. The measurement model of the UV sensor-based satellite navigation system is presented using the Earth image information from the UV sensor. In order to integrate the measurements from the X-ray sensor and the UV sensor, a federated filter is developed to provide the optimal simultaneous estimation of position and velocity of the satellite. The concept is demonstrated on a GPS orbit and a geosynchronous orbit and it is found that the performance of the integrated satellite navigation system is improved with respect to that of the UV sensor-based satellite navigation system.     

Timing and hamming weight attacks on minimal cost encryption scheme

The timing and Hamming weight attacks on the data encryption standard (DES) cryptosystem for minimal cost encryption scheme is presented in this article. In the attack, timing information on encryption processing is used to select and collect effective plaintexts for attack. Then the collected plaintexts are utilized to infer the expanded key differences of the secret key, from which most bits of the expanded secret key are recovered. The remaining bits of the expanded secret key are deduced by the correlations between Hamming weight values of the input of the S-boxes in the first-round. Finally, from the linear relation of the encryption time and the secret key's Hamming weight, the entire 56 bits of the secret key are thoroughly recovered. Using the attack, the minimal cost encryption scheme can be broken with 223 known plaintexts and about 221 calculations at a success rate a＞99%. The attack has lower computing complexity, and the method is more effective than other previous methods.     

利用光纤拉曼散射温度传感系统的电力电缆温度在线监测

电力电缆线路运行温度在线检测技术是目前及时发现电力电缆线路局部过热点位置、检测运行线路的绝缘状态和计算导体载流量的首选技术措施。分布式光纤拉曼测温技术是利用激光在光纤中的传播特性,实现实时测量空间温度场分布的新技术,可以对光纤沿线的温度场进行分布式的连续检测。介绍了光纤拉曼传感技术的测温原理,以及基于此技术的电力电缆温度在线监测系统在实际中的应用,获得了一些仿真结果,并同传统的测温技术进行了详细的比较,说明分布式光纤拉曼测温系统应用于电力电缆在线监测的优势,适合于推广使用。     

Printed stretchable circuit on soft elastic substrate for wearable application

In this paper,a flexible and stretchable circuit has been fabricated by the printing method based on Ag NWs/PDMS composite.The randomly oriented Ag NWs were buried in PDMS to form a conductive and stretchable electrode.Stable conductivity was achieved with a large range of tensile strain (0-50％) after the initial stretching/releasing cycle.The stable electrical response is due to the buckling of the Ag NWs/PDMS composite layer.Furthermore,printed stretchable circuits integrated with commercial ICs have been demonstrated for wearable applications.     

光分组交换节点技术

文章首先介绍了光分组交换网络的分类和光分组交换节点的基本结构,接着详细讨论了全光分组交换节点设计和实现中的关键问题:交换结构的设计、光存储的实现以及分组拥塞问题的解决方案。