一种适用于任意峰度非高斯信号的多目标盲波束形成方法

该文提出了一种新的适用于任意峰度非高斯信号的多目标盲波束形成算法。该方法在最大峰度算法(KMA)的基础上,引入信号的互相关约束定义了一种新的代价函数。通过对该代价函数的最大化,来盲估计波束形成器的权向量,从而完成对多目标的分离和定向。由于波束形成过程不需要正交化处理,避免了波束形成器锁定噪声的可能性。同时,采用一种复数编码的遗传算法来求解权向量,不但可避免陷入局部极值的可能性,而且还能有效提高运行速度。仿真实验验证了该算法的有效性和正确性。     

有线网络行业垄断性的改变及竞争形势分析

有线网络行业既具有自然垄断性,又具有行政垄断性.但随技术进步和国家政策的调整,其自然垄断性被削弱,行政垄断也被打破.在位的有线网络企业面临着两个层面的竞争：一是基于不同视频传输方式的竞争,二是同为有线网络传输方式的竞争,而后者是直接的竞争.对有线网络行业的竞争进行了SWOT分析.最后讨论了竞争形势下在位的有线网络运营商的应对思路.     

江西电视台数字硬盘播出系统的设计与应用

本文从江西电视台数字硬盘播出系统的设计和技术方案谈到整个系统的构成及其特点,从系统的构建谈到系统的使用维护体会、硬盘播出与传统播出方式的不同及其优点。     

光学和电子束曝光系统之间的匹配与混合光刻技术

介绍如何实现光学和电子束曝光系统之间的匹配和混合光刻的技术，包括：(1）光学曝光系统与电子束曝光系统的匹配技术；(2）投影光刻和JBX-5000LS混合曝光技术；(3）接触式光刻机和JBX-5000LS混合曝光技术；(4）大小束流混合曝光技术或大小光阑混合曝光技术；(5）电子束与光学曝光系统混合光刻对准标记制作技术. 该技术已成功地应用于纳米器件和集成电路的研制工作，实现了20nm线条曝光，研制成功了27nm CMOS器件；进行了50nm单电子器件的演试；并广泛地用于100nm化合物器件和其他微/纳米结构的制造.     

基于BiCMOS技术的高速数字/模拟转换器

基于BiCMOS技术，进行了高速数字/模拟转换器研究. 以并行输入类型，电流工作模式的16位D/A转换器为载体，进行了电路设计、工艺制作和测试. 在±5.0V工作电压下，测试得到转换速率≥30MSPS，建立时间为50ns，增益误差为±8% FSR，积分非线性误差为1/2 LSB，功耗为500mW.     

Performance characterization of the dynamic programming obstacle detection algorithm.

A computer vision-based system using images from an airborne aircraft can increase flight safety by aiding the pilot to detect obstacles in the flight path so as to avoid mid-air collisions. Such a system fits naturally with the development of an external vision system proposed by NASA for use in high-speed civil transport aircraft with limited cockpit visibility. The detection techniques should provide high detection probability for obstacles that can vary from subpixels to a few pixels in size, while maintaining a low false alarm probability in the presence of noise and severe background clutter. Furthermore, the detection algorithms must be able to report such obstacles in a timely fashion, imposing severe constraints on their execution time. For this purpose, we have implemented a number of algorithms to detect airborne obstacles using image sequences obtained from a camera mounted on an aircraft. This paper describes the methodology used for characterizing the performance of the dynamic programming obstacle detection algorithm and its special cases. The experimental results were obtained using several types of image sequences, with simulated and real backgrounds. The approximate performance of the algorithm is also theoretically derived using principles of statistical analysis in terms of the signal-to-noise ration (SNR) required for the probabilities of false alarms and misdetections to be lower than prespecified values. The theoretical and experimental performance are compared in terms of the required SNR.     

Quality-aware images.

We propose the concept of quality-aware image, in which certain extracted features of the original (high-quality) image are embedded into the image data as invisible hidden messages. When a distorted version of such an image is received, users can decode the hidden messages and use them to provide an objective measure of the quality of the distorted image. To demonstrate the idea, we build a practical quality-aware image encoding, decoding and quality analysis system, which employs: 1) a novel reduced-reference image quality assessment algorithm based on a statistical model of natural images and 2) a previously developed quantization watermarking-based data hiding technique in the wavelet transform domain.     

基于精简标准单元库的OPC复用技术

提出了一种对标准单元的光学邻近效应校正结果进行复用的方法,并通过将传统标准单元中的所有核心逻辑通过反相器和二选一多路选择器的组合来实现,得到了一套可制造性强的精简标准单元库,从而使OPC复用技术得以有效实施,并将在很大程度上提高芯片生产效率和降低掩模数据存储量.精简标准单元库中单元的电气仿真结果表明其在面积、速度、功耗方面与传统标准单元库相比性能损失很小.     

Nanoporous Copper with Tunable Nanoporosity for SERS Applications

Nanostructured materials with designable microstructure and controllable physical and chemical properties are highly desired for practical applications in nanotechnology. In this article, it is reported that nanoporous copper with a tunable nanopore size can be fabricated by controlling the dealloying process. The influence of acid concentration and etching potential on the formation of nanoprosity is systematically investigated. With optimal etching conditions, the nanopore sizes can be tailored from ～15 to ～120 nm by controlling the dealloying time. It is found that the tunable nanoporosity leads to significant improvements in surface‐enhanced Raman scattering (SERS) of nanoporous copper and peak values of SERS enhancements for both rhodamine 6G and crystal violet 10B molecules are observed at a pore size of ～30–50 nm. This study underscores the effect of complex three‐dimensional nanostructures on physical and chemical properties and is helpful in developing inexpensive SERS substrates for sensitive instrumentations in molecular diagnostics.     

Magnetic Field‐Induced Phase Transformation in NiMnCoIn Magnetic Shape‐Memory Alloys—A New Actuation Mechanism with Large Work Output

Magnetic shape memory alloys (MSMAs) have recently been developed into a new class of functional materials that are capable of magnetic‐field‐induced actuation, mechanical sensing, magnetic refrigeration, and energy harvesting. In the present work, the magnetic &!hyphen;field‐induced martensitic phase transformation (FIPT) in Ni₄₅Mn_36.5Co₅In_13.5 MSMA single crystals is characterized as a new actuation mechanism with potential to result in ultra‐high actuation work outputs. The effects of the applied magnetic field on the transformation temperatures, magnetization, and superelastic response are investigated. The magnetic work output of NiMnCoIn alloys is determined to be more than 1 MJ m^?3 per Tesla, which is one order of magnitude higher than that of the most well‐known MSMAs, i.e., NiMnGa alloys. In addition, the work output of NiMnCoIn alloys is orientation independent, potentially surpassing the need for single crystals, and not limited by a saturation magnetic field, as opposed to NiMnGa MSMAs. Experimental and theoretical transformation strains and magnetostress levels are determined as a function of crystal orientation. It is found that [111]‐oriented crystals can demonstrate a magnetostress level of 140 MPa T^?1 with 1.2% axial strain under compression. These field‐induced stress and strain levels are significantly higher than those from existing piezoelectric and magnetostrictive actuators. A thermodynamical framework is introduced to comprehend the magnetic energy contributions during FIPT. The present work reveals that the magnetic FIPT mechanism is promising for magnetic actuation applications and provides new opportunities for applications requiring high actuation work‐outputs with relatively large actuation frequencies. One potential issue is the requirement for relatively high critical magnetic fields and field intervals (1.5–3 T) for the onset of FIPT and for reversible FIPT, respectively.