基于函数复杂度的自适应模拟退火和禁忌搜索新算法

在求解多峰复杂函数的过程中,传统的模拟退火算法和禁忌搜索算法经常出现算法快速收敛于局部最优解、后期收敛速度变慢和搜索能力变差等问题.为解决这些问题,本文给出函数复杂度的定义,并提出基于函数复杂度的自适应模拟退火和禁忌搜索算法.该算法首先根据函数复杂度自适应调整步长控制参数,然后根据调整后步长求得函数的粗糙解,在此基础上再使用初始步长求得全局最优解.实验表明,该算法不仅可以跳出局部最优解的限制,并且减少了迭代次数,有效地提高了全局和局部搜索能力.     

基于凸松弛全局优化算法的视觉测量位姿估计

针对参考点存在较大噪声时基于光束法平差的视觉测量位姿估计无法确保目标函数在全局极小处收敛,本文提出利用凸松弛（LMI）全局优化算法进行视觉测量全局最优位姿估计。利用归一化图像点和摄像机光心组成的正交投影矩阵,构造以旋转矩阵四元数为参数的物空间误差目标非凸多项式函数。对非凸多项式进行LMI,可以逼近其全局极小值,进而求解...     

禁忌粒子群算法在几何约束求解中的应用

约束问题可以转化为优化问题,针对粒子群优化算法在算法的后期易陷入局部最优的缺点,提出TPSO(禁忌粒子群优化算法),在算法的前期采用粒子群算法快速产生全局最优解信息素的初始分布,后期引入禁忌搜索算法,记录已经达到的局部最优解,在下一次搜索中,不再或者有选择地搜索这些点,从而跳出局部最优点,并且在搜索过程中允许接受劣解,充分利用禁忌搜索的记忆能力及较强的爬山能力,大大提高了获得全局最优解的概率.该算法综合了粒子群优化算法的快速性,随机性和全局收敛性以及禁忌搜索局部寻优的能力.在确保全局收敛性的基础上,能够快速搜索到高质量的优化解.该方法用于几何约束求解的性能明显高于标准粒子群算法,算法具有良好的优化性能和时间性能.     

一种基于禁忌搜索的全局最优化模糊聚类算法

模糊C均值（FCM）算法是一种基于贪心思想的迭代算法,算法沿迭代序列收敛到一个极小值,但存在搜索能力弱、易陷入局部最优的缺点.本文提出了一种基于禁忌搜索的模糊聚类算法,该算法在一个解的邻域内使用禁忌搜索,并采用了基于FCM局部收敛性质的长期表禁忌策略,保证在不断移动搜索起点的同时避免重复搜索;其次使用混沌优化思想与动态步长策略来提升算法的全局搜索能力,以达到获取全局最优解的目的.实验结果表明,改进算法极大地提高了聚类准确率,并具有良好的稳定性,与群智算法和遗传算法的优化相比也具有一定的优势.     

一种网络时延矩阵分布式自适应重建算法

该文基于互联网时延矩阵的近似稀疏性,通过给定重建矩阵的零范数先验估计,讨论了不完整时延矩阵在完全去中心化环境下的填充问题。首先,将该问题转化为一对耦合凸优化问题,并进行轮转求解;然后,针对次梯度下降求解算法中存在的计算代价过高与泛化能力不足的问题,提出了搜索上界倍增的自适应分布式矩阵重建(ADMC)算法,并引入不同的损失函数作为重建误差评价准则,以提升算法的适应能力。实验证明,在不增加测量与通信负载的前提下,ADMC能够在不损失精度的情况下显著降低计算代价,同时,多种损失函数的引入也提升了算法的鲁棒性。     

基于Q学习算术优化算法的无人机三维航迹规划

针对传统方法求解无人机三维航迹规划易导致规划代价高、精度差和容易陷入局部最优的不足,提出基于Q学习算术优化算法的无人机三维航迹规划算法。为了提升算术优化算法的寻优精度,引入Circle混沌映射提高初始种群多样性和分布均匀性,引入Q学习根据个体状态自适应调整数学优化加速函数更新,均衡算法全局搜索与局部开发,设计最优解邻域扰动优化全局搜索能力。通过建立无人机三维航迹规划模型,将航迹规划转化为多目标函数优化问题,并利用改进算法求解无人机三维航迹规划,以综合考虑航迹代价、地形代价和边界代价的目标函数评估粒子适应度,对航迹规划迭代寻优。仿真实验结果表明,所提算法规划的航迹具有更低的总代价和适应不同复杂地形环境的稳定性。     

基于网格爬山法的最大似然DOA估计算法

最大似然波达方向（DOA）估计具有最优的理论性能,但是存在计算量过大的问题。为了降低最大似然DOA估计的计算量,将参数估计转化为高维非线性函数的优化问题,并提出了一种新的优化算法。首先利用波束形成法对空间谱进行预估计并根据空间谱信息构造一组满足“预估分布”的初始解,这组初始解以较大概率落在全局最优解的局部吸引域中。然后将其中适应度最大的一个初始解作为局部搜索的起点。网格爬山法是一种以网格为单元的局部搜索方法,比传统爬山法更加高效和稳定,因此采用该方法获取全局最优解。新算法不仅能够得到精确的参数估计,同时具有较高的计算效率,计算机仿真显示新算法的计算效率高于基于粒子群优化的最大似然DOA估计算法。      

OFDM系统中基于压缩传感理论的信道估计算法

信道估计是OFDM系统中的一项关键技术,信道估计质量的好坏对整个系统的性能有重要的影响。传统的最小均方算法对稀疏信道进行估计时存在精确性差的缺陷。本文利用信道冲激响应的稀疏性,提出了一种基于近似l₀范数的信道估计算法。该算法用三种函数逼近l₀范数,应用梯度下降法和梯度投影算法获得代价函数的最优解,从而得到信道的最稀疏解。仿真实验结果表明:在相同条件下,与基于l₁范数的信道估计算法比较,本文算法的收敛速度快,估计值信噪比高,且均方误差小。      

基于多目标禁忌搜索算法的认知无线电频谱分配

针对认知无线电动态频谱分配问题,建立图着色频谱分配模型,将模型中的分配矩阵和禁忌搜索算法中的可行解相对应,提出基于禁忌搜索的智能求解算法。同时将高斯柯西算子引入到禁忌搜索的更新策略当中,改善了算法的收敛速度和爬坡能力。在最大化认知无线电网络效益和最大化公平效益准则下建立多目标评价函数,将禁忌搜索算法和粒子群算法在图着色频谱分配模型基础上进行性能比较,结果表明在不同权重的评价函数下,禁忌搜索算法找到的理想最优解都要优于粒子群算法。     

基于多智能体粒子群算法的盲均衡技术研究

在解决盲均衡的问题中,当前主要采用梯度搜索的方法,这种方法的优点在于局部最优解收敛,降低通信性能。本文根据粒子群算法,设计了各种算子,提出了用粒子群算法的快速搜索全局最优解的性能来优化盲均衡算法的代价函数,从而提出了一种新的基于粒子群算法的盲均衡算法。仿真结果表明,所提出的算法在较少的迭代次数情况下,能够快速收敛,具有较优的性能。     

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.     

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.