基于量子粒子群优化算法的光纤光栅参数重构

提出了一种基于量子粒子群优化算法的光纤光栅参数重构方法。该方法通过传输矩阵法得到优化目标函数,并将待优化的光纤光栅参数以粒子表示,再让粒子在解空间模拟量子行为进行搜索。以均匀布拉格光栅和线性啁啾光纤光栅为例,分别采用遗传算法(GA)、经典粒子群优化(PSO)算法以及量子粒子群优化(QPSO)算法对其进行参数重构。与传统粒子群算法及遗传算法相比,该方法借鉴了量子行为,具有更好的收敛性能和稳态性能。数值结果表明,种群规模为40时,针对均匀和非均匀光栅分别进化100代和200代得到的重构参数误差均小于0.5%。     

基于改进协同量子粒子群的小波去噪分析研究

小波阈值函数中,因信号之间的不连续性及小波估计系数与原信号的小波系数存在误差等原因,图像无法得到最优还原.为此提出一种基于改进协同量子粒子群算法优化小波函数的去噪方法.该方法在协同量子粒子群优化(CQPSO)算法的基础上引入了自适应收缩扩张因子,用改进的协同量子粒子群算法优化小波阈值函数中的调节因子和阈值.仿真图像和数...     

基于量子粒子群算法的PID参数自整定方法

PID控制在工业生产中应用非常广泛.以直流电机模型为被控对象,提出了基于量子粒子群算法的PID参数自动整定方法.应用经典的Ziegler-Nichols方法整定PID参数,被控对象性超调大往往难以满足要求.粒子群算法是通过模拟鸟群觅食过程中的迁徙和群聚行为而提出的一种基于群体智能的全局随机搜索算法.将量子粒子群算法用于优化PID参数,并与Z-N法整定的PID控制器性能进行对比.仿真结果发现,与Z-N法相比,基于粒子群算法优化的PID控制器,系统超调明显减小.除QPSO-PID(ITSE)对应的系统具有较长调节时间外,虽然应用不同优化目标优化后的PID参数不同,控制对象的响应性能却非常相似.     

基于遗传 PSO 的无线传感网络覆盖优化算法研究

针对基于标准粒子群算法的网络覆盖存在收敛速度慢、易早熟等问题,提出一种基于遗传 PSO 的无线传感网络覆盖优化算法.以无线传感器最大覆盖率为目标函数,通过运用加入自适应交叉变异因子的遗传算法搜索解空间,利用 PSO 粒子群强大的全局搜索能力加大搜索范围,使粒子覆盖更有效率,加强算法的寻优能力,提高节点的覆盖率,解决早熟问题.仿真实验表明,与传统遗传算法、新量子遗传算法相比,其覆盖率分别提高了2.28%和0.65%,收敛速度也有所提高,因此该方法能有效地实现无线传感网络覆盖优化.     

基于干扰因子的QPSO算法改进

具有量子行为的粒子群优化算法(Quantum-Behaved Particle Swarm Optimization,QPSO)是一种新的基于群体智能的优化方法.与粒子群算法(Particle Swarm Optimization,PSO)相比,QPSO的全局收敛性能更好.但与其他进化算法一样,QPSO仍然不可避免地遇到早熟收敛的问题.因此在QPSO算法的基础上,引入干扰因子以避免算法的早熟现象.实验结果表明,改进后的QPSO算法具有更好的收敛性能.     

基于改进QPSO算法的阵列天线方向图综合

 针对传统智能方法在方向图综合中易于早熟和局部寻优能力不足等缺陷,在基于量子位概率幅编码的量子粒子群优化算法(QPSO)的基础上,设计一种进行收敛停滞检测,并对粒子选择性变异的新量子粒子群算法,然后将其应用于阵列天线方向图综合.仿真结果表明,在多零点和低旁瓣约束情况下新算法均可以取得良好的优化效果,而且该算法相对于近邻粒子群算法(NPSO)和免疫克隆选择算法(ICSA)来说,在方向图综合中精度更高,速度更快,具有很好的推广能力.     

基于量子粒子群优化算法的图像分割方法

利用量子粒子群优化算法(QPSO)对二维Fisher准则图像分割评价函数进行了全局优化,提高了分割阈值的求解速度。并针对量子粒子群优化算法存在收敛性差、易早熟的问题,提出了量子粒子群优化算法和邻域搜索双重寻优的改进算法。实验结果表明,改进后的分割方法具有良好的分割效果和求解速度。寻找到的最佳阈值与二维Fisher准则函数算法完全相同,而阈值求解时间只有二维Fisher准则函数算法的1/3。     

基于进化计算的二元序列优化算法研究

具有良好非周期自相关特性二元序列在通信同步、雷达等领域具有广泛的应用。通过对遗传算法、粒子群算法与量子粒子群算法三种进化算法进行对比分析,设计了具有良好非周期自相关特性的二元序列的搜索算法。研究结果表明,粒子群算法的搜索能力优于遗传算法,而量子粒子群算法具有参数少,易于控制的优点,取得了较好的优化结果。     

基于量子粒子群优化算法的图像矢量量化码书设计

鉴于经典的LBG码书设计算法易陷入局部最优解,将量子粒子群优化算法应用到图像矢量量化码书设计中,提出一种基于量子粒子群的矢量量化码书设计算法(QPSO-VQ)。在该算法中,用粒子表示码书,用峰值信噪比(PSNR)作为算法的适应度函数,通过量子粒子群算法的更新公式来更新码书。实验结果表明,与经典的LBG码书设计算法和粒子群矢量量化码书设计算法相比,QPSO-VQ在解码图像的PSNR值和算法的稳定度等方面有比较明显的优势,可以获得性能较好的码书。     

基于量子粒子群算法的QoS组播路由问题研究

对具有带宽、延时、延时抖动约束的最小代价的QoS组播路由问题进行研究,提出了一种收敛速度快、全局性能好、不易陷入局部最优的智能迭代算法--量子粒子群算法来实现对该问题的求解.该算法采用整数编码方式,将路由优化问题转化成准连续优化,并采用惩罚函数处理约束条件.最后通过具体算例,对该算法进行了仿真验证,结果表明,在求解QoS组播路由问题时,量子粒子群算法要优于遗传算法、基本微粒群算法,从而验证了该算法的可行性和有效性.     

面向全变分图像复原的增广拉格朗日方法综述

图像复原旨在根据退化图像重建高品质原始图像,其复原的质量和速度问题一直都是图像处理领域研究的重要方向。由于其图像边缘保持特性,全变分(TV)最小化模型在图像复原领域取得了很大的成功。然而,全变分图像复原是一个典型的非光滑优化问题,需要发展相应的快速优化算法,而增广拉格朗日方法(ALM)则是近年来发展起来的一类代表性方法。结合相关进展,综述了全变分图像复原模型,变量分裂(VS)法和典型ALM算法,并通过实验从CPU运行时间、峰值信噪比(PSNR)和品质评价等方面分析了不同的变量分裂和ALM方法对图像复原性能的影响。     

应用双稀疏模型和ADMM优化的图像复原

基于稀疏表示的图像复原算法大都只利用了图像整体稀疏性和局部稀疏性中的一种,未充分利用图像的先验知识,基于此,本文在稀疏表示框架下,同时引入Cosparse解析模型及平移不变小波变换两种稀疏模型,前者对每个图像块进行稀疏表示,后者对整幅图像进行稀疏表示,从而提出一种新的图像复原算法。该算法将图像复原问题归结为双稀疏正则化问题。为求解复杂的双稀疏优化问题,本文运用交替方向乘子法 (ADMM, Alternating Direction Method of Multipliers)算法将该约束优化问题分解为若干子问题,通过交替迭代求解获得复原图像。实验中对不同类型的模糊图像进行了复原,其结果表明该算法对于各类模糊图像的复原比现有复原算法效果更好,从而验证了算法的有效性。      

基于模糊和遗传算法的阈值分割方法

提出了一种阈值分割方法。本算法将模糊集理论和遗传算法有机地结合起来,它是一种有监督的分割方法,首先确定图像阈值的数目,然后将灰度图像模糊化,确定准则函数,采用遗传算法求得意了优解,最后经过后处理得到最终分割结果。实验表明该方法运算速度快,且对噪声不敏感,具有较高的鲁棒性。     

Convergence properties of Gauss-Newton iterative algorithms in nonlinear image restoration

Nonlinear image restoration is a complicated problem that is receiving increasing attention. Since every image formation system involves a built-in nonlinearity, nonlinear image restoration finds applications in a wide variety of research areas. Iterative algorithms have been well established in the corresponding linear restoration problem. In this paper, a generalized analysis regarding the convergence properties of nonlinear iterative algorithms is introduced. Moreover, the applications of the iterative Gauss-Newton (GN) algorithm in nonlinear image restoration are considered. The convergence properties of a general class of nonlinear iterative algorithms are rigorously studied through the Global Convergence Theorem (GCT). The derivation of the convergence properties is based on the eigen-analysis, rather than on the norm analysis. This approach offers a global picture of the evolution and the convergence properties of an iterative algorithm. Moreover, the generalized convergence-analysis introduced may be interpreted as a link towards the integration of minimization and projection algorithms. The iterative GN algorithm for the solution of the least-squares optimization problem is introduced. The computational complexity of this algorithm is enormous, making its implementation very difficult in practical applications. Structural modifications are introduced, which drastically reduce the computational complexity while preserving the convergence rate of the GN algorithm. With the structural modifications, the GN algorithm becomes particularly useful in nonlinear optimization problems. The convergence properties of the algorithms introduced are readily derived, on the basis of the generalized analysis through the GCT. The application of these algorithms on practical problems, is demonstrated through several examples.     

On the computational aspects of Gibbs-Markov random field modelingof missing-data in image sequences

Gibbs-Markov random field (GMRF) modeling has been shown to be a robust method in the detection of missing-data in image sequences for a video restoration application. However, the maximum a posteriori probability (MAP) estimation of the GMRF model requires computationally expensive optimization algorithms in order to achieve an optimal solution. The continuous relaxation labeling (RL) is explored in this paper as an efficient approach for solving the optimization problem. The conversion of the original combinatorial optimization into a continuous RL formulation is presented. The performance of the RL formulation is analyzed and compared with that of other optimization methods such as stochastic simulated annealing, iterated conditional modes, and mean field annealing. The results show that RL holds out promise as an optimization algorithm for problems in image sequence processing.     

Restoration of blurred star field images by maximally sparseoptimization

The problem of removing blur from, or sharpening, astronomical star field intensity images is discussed. An approach to image restoration that recovers image detail using a constrained optimization theoretic approach is introduced. Ideal star images may be modeled as a few point sources in a uniform background. It is argued that a direct measure of image sparseness is the appropriate optimization criterion for deconvolving the image blurring function. A sparseness criterion based on the l(p) is presented, and candidate algorithms for solving the ensuing nonlinear constrained optimization problem are presented and reviewed. Synthetic and actual star image reconstruction examples are presented to demonstrate the method's superior performance as compared with several image deconvolution methods.     

基于TwIST-TV 约束的图像去模糊方法

传统的基于频域和小波域的去模糊算法所得的复原图像总是存在比较明显的边缘振铃及模糊效应,而较为有效的空域迭代优化去模糊算法速度通常比较慢。为了解决上述问题,提出了基于二步迭代阈值收缩（TwIST）与总变分（TV）约束相结合的图像去模糊算法（TwIST-TV）。首先在去模糊目标函数中加入对图像的TV 正则化约束,其次在对图像小波系数的每次二步迭代之前,加入对图像的TV 优化去噪约束,最后迭代获取去模糊图像。实验结果表明:相对于基于频域和小波域的模糊图像恢复算法,TwIST-TV 能有效抑制边缘模糊和振铃效应,复原图像的信噪比（SNR）、峰值信噪比（PSNR）高出1~7 dB,平均结构相似度指标（MSSIM）可高出0.05,相对于空域解卷积算法在保证求解精度相当的情况下具备6 倍以上的速度优势。     

基于CSD编码遗传算法的FIR滤波器优化设计

本文主要研究了采用CSD(canonic signed digit)编码的遗传算法对FIR(Finite Impulse Response)滤波器系数进行的有限精度优化,并对传统的CSD编码方法进行了改进,使之能够更快地收敛到最优解.针对CSD编码经过交叉、变异后可能出现的问题,提出了解码替代的解决方法.在级联滤波器的设计中,采用了波纹互相抵消技术使设计的级联滤波器通带内纹波大大降低.     

Nonlocal Joint Regularizations Framework with Application to Image Denoising

Low-rank (LR) representation and the nonlocal model (NLM) are important techniques in the field of image restoration, offering significant improvements over many current recovery algorithms. Natural images contain global and local redundancy, and this can be utilized to enhance the restoration performance. Thus, we propose a novel optimization framework that incorporates the benefits of LR and NLM. First, NLM is employed to search for similar patches to reduce the global redundancy. An LR model is then exploited as the prior knowledge needed to constrain the low-rank property of the searched patches. We also use a 3D sparse model to constrain the local sparsity of these patches, thus preserving their underlying structure more effectively. To solve the minimization problem within our novel framework, we describe an iterative scenario that uses an alternating optimization method based on the improved split Bregman technique. Experimental results demonstrate that our proposed method outperforms several state-of-the-art algorithms.     

Image restoration using a conjugate gradient-based adaptive filtering algorithm

A new two-dimensional (2D) sample-based conjugate gradient (SCG) algorithm is developed for adaptive filtering. This algorithm is based on the conjugate gradient method of optimization and therefore has a fast convergence characteristic. The SCG is computationally simpler than the recursive least squares (RLS) algorithm. The SCG algorithm with the equation-error and output-error methods is investigated for application in image restoration. Simulation results show that the new algorithm significantly outperforms existing algorithms in the restoration of noisy images.This work was supported in part by a grant from the Colorado Advanced Software Institute.