理想格上格基的快速三角化算法研究

为了提高理想格上格基的三角化算法的效率,该文通过研究理想格上的多项式结构提出了一个理想格上格基的快速三角化算法,其时间复杂度为O(n3log₂B),其中n是格基的维数,B是格基的无穷范数。基于该算法,可以得到一个计算理想格上格基Smith标准型的确定算法,且其时间复杂度也比现有的算法要快。更进一步,对于密码学中经常所使用的一类特殊的理想格,可以用更快的算法将三角化矩阵转化为格基的Hermite标准型。     

一种基于约化因子上三角矩阵求逆的FPGA实现方法

矩阵运算广泛应用于实时性要求的各类电路中，其中矩阵求逆运算最难以实现。基于现场可编程门阵列(FPGA)实现矩阵求逆能够充分发挥硬件的速度与并行性优势，加速求逆运算过程。基于改进的脉动阵列的计算架构，采用一种约化因子求逆的优化算法，将任意一个n×n阶上三角矩阵转换成对角线为1的上三角矩阵，使得除法运算与乘加运算分离开来，大大简化矩阵求逆运算过程。以一个4×4阶上三角矩阵求逆为例，在Xilinx ISE平台下，采用Virtex5 FPGA完成算法实现与功能验证，在14个周期内，使用了2个除法器，3个乘法器与4个加法器实现整个矩阵求逆运算。相比于经典的脉动阵列架构，仅占用近一半资源的同时，性能提升了26.43%；相比于集成更多处理单元(PE)的脉动阵列实现方式，在性能近乎不变的情况下，耗费的资源缩减到1/4，大幅度提升了资源利用率。     

T函数Walsh谱值与差分转移概率快速算法

根据T函数自身输入与输出结构特点,结合T函数窄度相关定义,研究了T函数线性性质和差分性质。通过构造马尔可夫链和概率转移矩阵,给出了其Walsh谱值与差分转移概率计算的多项式时间快速算法,时间复杂度为O(n),并将该算法应用于对TSC系列T函数的研究,得到任意输入输出线性组合的Walsh谱值表达式。     

基于IPCT/3-D Tarp的高光谱图像无损压缩

研究了一种将变换矩阵分解为三角元素可逆矩阵(TERM)实现的主成分变换整数近似算法(IPCT).为限制误差和提高计算效率,改进了TERM分解中选择主元的方法.结合可逆整数PCT和三维Tarp编码技术,提出了一种新的高光谱图像无损压缩算法.该算法在进行空间维小波变换以后,利用改进的IPCT去除谱间相关;在编码阶段,新颖的三维Tarp编码器能利用五个简单的递归滤波器进行概率估计,以驱动一个非自适应算术编码器,对变换系数的显著性映射和细化信息进行熵编码.该算法复杂度较低,能够产生嵌入式码流,并且较已有的算法能获得更高的压缩比.     

基于分阶段LFF策略的大规模模块布局方法

提出了一种用于求解大规模VLSI模块布局问题的确定性方法.该方法在"最小自由度优先"原则的基础上,模拟人工布局过程提出了"分阶段布局"的思想.分阶段布局就是将布局过程按照布局完成的比例划分成若干个阶段,再将各种启发式策略适当地应用到各个阶段中,从而改善算法的整体性能.理论上,算法的时间复杂为(N1 N2)O(n2) N3O(n4lgn),其中N1,N2,N3为各个阶段的模块数目,N1 N2 N3=n,且N3＜＜n,比原有的最小自由度优先算法复杂度O(n5lgn)小很多.实验结果也表明该方法很有潜力.     

基于分阶段LFF策略的大规模模块布局方法

提出了一种用于求解大规模VLSI模块布局问题的确定性方法.该方法在"最小自由度优先"原则的基础上,模拟人工布局过程提出了"分阶段布局"的思想.分阶段布局就是将布局过程按照布局完成的比例划分成若干个阶段,再将各种启发式策略适当地应用到各个阶段中,从而改善算法的整体性能.理论上,算法的时间复杂为(N1+N2)O(n2)+N3O(n4lgn),其中N1,N2,N3为各个阶段的模块数目,N1+N2+N3=n,且N3＜＜n,比原有的最小自由度优先算法复杂度O(n5lgn)小很多.实验结果也表明该方法很有潜力.     

精英类克隆选择算法平均收敛速度估计

克隆选择算法收敛速度估计是算法研究的一个难问题,目前还是处于初始的研究阶段。本文对一大类精英保持策略克隆选择算法的收敛速度问题进行了研究。首先利用算法种群中最佳个体的定向转移概率导出最佳个体的转移概率矩阵,针对实际应用中由于算法种群规模过大而导致该矩阵求取较困难的问题,将最佳个体的转移概率矩阵构造成满足一定条件的矩阵范数,从而提出一种更为简单有效的算法平均收敛速度估计的新方法。对不同的精英保持策略克隆选择算法进行了收敛速度估计仿真实验,其结果表明了该估计方法的有效性。     

基于MILP的轻量级密码算法ACE的差分分析

研究了轻量级密码算法ACE的差分性质。首先定义了n维环形与门组合，充分分析了该结构中与门之间的相互关系，仅利用O(n)个表达式给出其精确的MILP差分刻画，将ACE算法中的非线性操作转化为32维环形与门组合，从而给出了ACE算法的MILP差分模型。其次根据MILP模型求解器Gurobi的求解特点，给出了快速求解ACE的MILP差分模型的方法。对于3～6步的ACE置换，得到了最优差分链，利用多差分技术给出了更高概率的差分对应，从而给出了ACE置换为3步的认证加密算法ACE-Aε-128的差分伪造攻击与哈希算法ACE-H-256的差分碰撞攻击，成功概率为2^-90.52，并证明了4步ACE置换达到了128bit的差分安全边界。实际上，n维环形与门组合的MILP差分刻画具有更多的应用场景，可应用于SIMON、Simeck等密码算法的分析中。     

语言计量研究中的上小三角矩阵压缩存储算法

三角矩阵的压缩存储是科学研究和工程计算领域经常遇到的问题。在语言计量研究的实际应用当中,需要用到一类主对角线元素全为零的特殊三角矩阵川、三角矩阵。通过对相关压缩算法的考察,给出了上小三角矩阵中行主顺序压缩存储算法的正向公式和逆向公式,还给出了算法在语言计量研究中的应用。基于算法的后续计量研究将有助于进一步揭示人类语言结构与演化的规律。     

一种新的软输出译码算法

本文在Bahl算法的基础上给出了一种新的软输出译码的矩阵算法。此算法把Bahl算法中求后验概率和转移概率的复杂计算转化成一系列简单的适合于大规模集成电路实现的矩阵运算,把比特错误概率量化成n比特的二进制值与信息比特或分枝码一起输出,从而使运算速度得到提高,并得到适合多级级联译码器中内译码器的软输出算法。     

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.     

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.     

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.     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

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.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.