非高斯背景下高分辨雷达CFAR检测器

本文讨论了球不变随机过程（ＳＩＲＰ）非高斯杂波背景下高分辨雷达距离扩展目标检测问题。文中提出了ＣＡ—ＣＦＡＲ、ＯＳ—ＣＦＡＲ两种距离扩展目标检测器。文中证明了它们的形状因子和尺度因子未知的情形下具有恒虚警性,即双参数恒虚警性,并分析了这两种检测器的检测性能。这两种检测器亦可用作ＳＩＲＰ杂波背景下低分辨雷达检测器。     

一种具有自动筛选技术的恒虚警检测器及其在多目标情况下的性能

提出一种新的基于有序统计的恒虚警检测器和一种新的自动筛选技术。这种新的检测器是广义有序统计单元平均（ＧＯＳＣＡ）恒虚警算法。对这种新的恒虚警算法在斯威林２型目标假设下，我们获得了虚警概率、探测概率和度量ＡＤＴ的解析表达式。在均匀背景和强干扰存在的情况下，分析了它的探测性能，并把它与ＯＳ－ＣＦＡＲ进行了比较。分析结果表明，ＧＯＳＣＡ－ＣＦＡＲ在均匀干扰背景和多目标情况下均具有较好的探测性能，而ＧＯＳ     

K分布杂波背景下次序统计恒虚警检测器的性能

本文证明了在形状因子已知条件下次序统计恒虚警（ＯＳ－ＣＦＡＲ）检测器在Ｋ分布杂波背景下能保持恒虚警的特性，分析了均匀Ｋ分布杂波背景下检测器的性能，研究了不同参考单元数的信杂比损失，对于未知形状因子，本文提出了一种有效的估计方法。     

两种具有自动筛选技术的广义有序统计恒虚警检测器及其在多目标…

本文提出两种广义修正的有序统计恒虚警（ＯＳ－ＣＦＡＲ）检测器和一种自动筛选技术。对这两种新的ＯＳ－ＣＦＡＲ检测器，在Ｓｗｅｒｌｉｎｇ ２型目标假设下我们推出了虚警和检测概率及度量平均判决门限的解析表达式。在均匀背景和强干扰目标情况下，文中分析了它们的检测性能，并把它们与几个以前提出的恒虚警处理器进行了比较。     

基于准最佳加权有序统计的最大选择CFAR检测算法

为了提高恒虚警检测器在均匀背景中的检测性能及增强对干扰的鲁棒性，本文提出了一种准最佳加权（ＱＢＷ）有序统计方法．基于这种方法，还提出了准最佳加权最大选择恒虚警检测器（ＱＢＷＧＯ－ＣＦＡＲ），它的前、后沿滑窗均采用ＱＢＷ方法来产生局部估计，将局部估计中的最大值作为检测器对杂波功率水平的估计，设置自适应检测门限，应用文献［３］提出的自动筛选技术在ＳｗｅｒｌｉｎｇⅡ型目标及瑞利杂波假设下，推导出了它的Ｐｆａ、Ｐｄ、ＡＤＴ及杂波边缘虚警尖峰的数学解析表达式分析结果表明，它在均匀背景及多目标和杂波边缘引起的非均匀背景中的性能，均比ＧＯＳＧＯ或ＯＳＧＯ获得了改善．在特殊情况下，ＱＢＷＧＯ退化为ＧＯ和ＭＸ－ＣＭＬＤ     

一种基于排序和平均的新恒虚警检测器

基于有序统计和单元平均方法及文献中的自动筛选技术，提出了一种新的恒虚警检测器，它被称作排序与平衡均值（ＭＯＳＣＡ）处理器。对这种新的恒虚检测器，在ＳｗｅｒｌｉｎｇⅡ型目标假设下，我们获得了虚警和检测概率及度量ＡＤＴ的解析表达式。在均匀背景和存在强干扰目标的情况下，分析了它的检测性能，并将其与ＣＡ和ＯＳ－ＣＦＡＲ进行了比较。结果表明ＭＯＳＣＡＣＦＡＲ在均匀干扰背景中的性能位于ＣＡ和ＯＳ之间，在多目标     

OSGO-和OSSO-CFAR在K分布杂波背景下的性能分析

该文证明了形状因子已知条件下OSGO-CFAR和OSSO-CFAR检测器在均匀统计独立的K分布杂波背景下具有恒虚警性能,分析了两种检测器在均匀杂波背景、杂波边缘和存在强干扰目标情况下的检测性能。并与OS-CFAR进行了比较,结果表明OSGO-CFAR在均匀杂波背景和存在强干扰目标情况下带来的附加检测损失很小, 在杂波边缘具有更好的虚警控制能力。所以,OSGO-CFAR是K分布杂波背景下一种性能比较好的恒虚警检测器。     

一种基于检测统计量的SOSGO-CFAR 检测算法

提出了一种新的恒虚警检测算法SOSGO-CFAR.该算法应用检测单元采样作为选择参考单元的依据,使用了基于转换恒虚警(S-CFAR)和排序选大恒虚警(OSGO-CFAR)的复合算法.文章给出了该算法在均匀背景中的数学分析.并在均匀背景、杂波边缘和多目标情况下,用MonteCarlo方法进行了仿真分析.结果表明,该检测器既具有均匀背景下和CA-CFAR相近的良好性能,在杂波边缘环境中,具有接近OSGO-CFAR的性能,且在多目标环境中,其性能明显好于S-CFAR.     

基于异常单元删除的改进CFAR检测器

雷达在大入射余角海杂波下进行检测时易受到功率突然增大的杂波异常单元影响,虚警率及误检率较高。为解决此问题,提出具有杂波抑制模块与恒虚警模块的二级检测器。杂波抑制模块通过参考单元的协方差矩阵构造正定矩阵,求解其矩阵范数用以估计杂波功率水平,根据功率水平设置一个动态门限,剔除异常单元后的杂波作为待检测信号输入恒虚警模块,恒虚警模块使用基于有序数据可变性的自动删除平均（ACCA-ODV-）CFAR检测器来改进传统变化指数恒虚警（VI-CFAR）检测器。仿真结果表明,新检测器在均匀杂波环境中检测性能与单元平均恒虚警(CA-CFAR)检测器几乎相同,在多目标环境中检测性能远远优于最大选择恒虚警(GO-CFAR)检测器、最小选择恒虚警(SO-CFAR)检测器、CA-CFAR检测器及VI-CFAR检测器,在杂波边缘环境中虚警控制能力仅次于VI-CFAR检测器与GO-CFAR检测器。综合考虑实测数据中各个检测器的检测结果,改进后的检测器在高分辨率大入射余角情况下具有最优的检测性能。     

OSCA-CFAR在K分布杂波背景下的性能分析

本文证明了形状因子已知条件下有序统计平均（OSCA）恒虚警检测器在K分布杂波背景下具有恒虚警性能，分析了均匀K分布杂波背景和多目标情况下该检测器的性能，并与OS和OSGO-CFAR进行了比较，仿真结果表明OSCA在两种环境下均具有最好的检测性能。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.