A modified ant system to achieve better balance between intensification and diversification for the traveling salesman problem

This paper presents a new variant of Ant Colony Optimization (ACO) for the Traveling Salesman Problem (TSP). ACO has been successfully used in many combinatorial optimization problems. However, ACO has a problem in reaching the global optimal solutions for TSPs, and the algorithmic performance of ACO tends to deteriorate significantly as the problem size increases. In the proposed modification, adaptive tour construction and pheromone updating strategies are embedded into the conventional Ant System (AS), to achieve better balance between intensification and diversification in the search process. The performance of the proposed algorithm is tested on randomly generated data and well-known existing data. The computational results indicate the proposed modification is effective and efficient for the TSP and competitive with Ant Colony System (ACS), Max-Min Ant System (MMAS), and Artificial Bee Colony (ABC) Meta-Heuristic.     

自适应模糊蚁群系统

针对蚁群系统（Ant Colony System，ACS）容易陷入局部最优和收敛速度较慢的不足，提出了自适应模糊蚁群系统（AF-ACS）用于旅行商问题（TSP）。该算法的核心是引入模糊隶属度和信息熵的概念，AF-ACS将以信息熵为概率，自适应地对ACS引入模糊隶属度，以平衡算法的种群多样性与收敛速度之间的关系。算法早期引入模糊隶属度的概率较小，保证算法的多样性；算法后期引入模糊隶属度的概率较大，提高算法的收敛速度。通过与ACS和ECACS（Entropy-based Adaptive Chaotic Ant Colony Algorithm）进行14种不同规模的TSP测试集实验对比，AF-ACS以较少的迭代次数取得最优解或较优解。从而证明了AF-ACS的可行性与高效性。     

Exchange strategies for multiple Ant Colony System

In this paper we apply the concept of parallel processing to enhance the performance of the Ant Colony System algorithm. New exchange strategies based on a weighting scheme are introduced under three different types of interactions. A search assessment technique based on a team consensus methodology is developed to study the influence of these strategies on the search behavior. This technique demonstrates the influence of these strategies in terms of search diversity. The performance of the Multiple Ant Colony System algorithm, applied to the Vehicle Routing Problem with Time Windows as well as the Traveling Salesman Problem, is investigated and evaluated with respect to solution quality and computational effort. The experimental studies demonstrate that the Multiple Ant Colony System outperforms the sequential Ant Colony System. The studies also indicate that the weighting scheme improves performance, particularly in strategies that share pheromone information among all colonies. A considerable improvement is also obtained by combining the Multiple Ant Colony System with a local search procedure.     

基于图像处理的变电站中隔离开关的状态研究

随着图像处理技术的不断发展,本文利用图像处理技术分析变电站中隔离开关的状态。蚁群算法(Ant Colony Algorithm,ACA)使用的广泛性,很多学者将其应用到图像处理中。本文将蚁群算法应用于变电站设备区域图像分割中,从某个或某些像素点出发,提取出变电站的隔离开关信息,然后对其进一步的图像处理,分析隔离开关的状态。但是,蚁群算法在运算过程中,易出现过早收敛于局部最优解及运算时间过长的缺点。为了使蚁群算法收敛于全局最优解及加快收敛速度,本文针对传统的蚁群算法模型对其信息浓度更新规则改进及参数的改进。通过仿真对比分析改进后的蚁群算法对于图像分割效果更好。     

基于人工免疫算法和蚁群算法求解旅行商问题

人工免疫算法具有快速随机的全局搜索能力,但对于系统中的反馈信息利用不足,往往做大量无为的冗余迭代,求解效率低。蚁群算法具有分布式并行全局搜索能力,通过信息素的积累和更新收敛于最优路径上,但初期信息素匮乏,求解速度慢。该文提出一种基于人工免疫算法和蚁群算法的混合算法,采用人工免疫算法生成信息素分布,利用蚁群算法求优化解。将该算法用于求解旅行商问题进行计算机仿真,结果表明,该算法是一种收敛速度和寻优能力都比较好的优化方法。     

非参数曲线识别方法研究

图像分割后的二值图像中,难免会有噪声和断点,这对后期的分类等处理带来了很大困难。针对二值图像中含有噪声、断点,蚁群算法没有充分利用非参数曲线的特征,随机初始化搜索位置,搜索范围大、路径选择计算量大等,提出了免疫蚁群算法（ACSI）。它融合了免疫算法和蚁群算法的优势,从免疫算子开始搜索,同时采用局部搜索策略。实验证明,该算法在求解效果和效率两方面都取得了理想效果。     

– Ant System

Ant System, the first Ant Colony Optimization algorithm, showed to be a viable method for attacking hard combinatorial optimization problems. Yet, its performance, when compared to more fine-tuned algorithms, was rather poor for large instances of traditional benchmark problems like the Traveling Salesman Problem. To show that Ant Colony Optimization algorithms could be good alternatives to existing algorithms for hard combinatorial optimization problems, recent research in this area has mainly focused on the development of algorithmic variants which achieve better performance than Ant System.In this paper, we present – Ant System ( ), an Ant Colony Optimization algorithm derived from Ant System. differs from Ant System in several important aspects, whose usefulness we demonstrate by means of an experimental study. Additionally, we relate one of the characteristics specific to — that of using a greedier search than Ant System — to results from the search space analysis of the combinatorial optimization problems attacked in this paper. Our computational results on the Traveling Salesman Problem and the Quadratic Assignment Problem show that is currently among the best performing algorithms for these problems.     

基于人工蚁群优化算法的遥感图像自动分类

将人工蚁群优化算法(AACO)尝试性地引入遥感图像分类,并进行了探索性研究。作为计算智能新的分支,人工蚁群优化算法具有很强的自组织性和自适应性。因此,自然成为科学工程领域一种强有力的信息处理和解决问题的手段;AACO算法利用蚂蚁的生物特性来实现遥感图像分类等非线性操作,具有并行性、鲁棒性。初步试验分析,此方法用于遥感图像分类是有效的,在一定程度上克服传统统计分类方法与ANN方法的某些不足。本文也推动人类利用群智能在遥感图像处理及相关领域的深入研究。     

改进的求解TSP问题文化蚁群优化方法

在文化算法基础上提出了一种改进的用于求解TSP问题的蚁群优化算法。改进算法采用新的双层进化机制对文化算法的种群空间与信念空间进行了重新设计,用最大最小蚁群系统（MMAS）构建种群空间,在信念空间中对当前最优解进行改进的3-OPT交叉变换操作,由于采用了这种双层进化机制,种群空间获得了更高的进化效率。通过仿真实验结果表明,改进算法比传统的蚁群算法（ACO）、文化蚁群算法（CACS）效果更好,收敛速度更快,精确度更高。     

基于人眼视觉特性的多尺度彩色图象增强算法

图象增强技术主要是通过调整图象的参数来改善图象质量,以获得更佳的视觉效果．为了获得色彩更加鲜艳,细节更加清晰的彩色图象,因而根据人眼视觉对亮度和颜色不同的敏感特性,按照视觉心理选择了HSV彩色空间,并在此空间中,提出了一种基于小波变换的彩色图象增强算法．该算法首先进行了自适应亮度动态调节,同时对图象的饱和度分量也进行了处理．实验证明,和目前存在的灰度图象增强算法相比,用该算法增强后的彩色图象不仅更加清晰,同时更加生动,鲜艳,达到了预期的目的．     

蚁群系统(ACS)及其收敛性证明

蚁群系统(ACS)是解决旅行商问题(TSP)的最好方法之一,它是在蚂蚁系统的基础上作了许多改进之后得到的一种优化算法。这些改进在一定程度上避免了过早停滞现象的发生,是一种较好的协作式搜索算法。通过与蚂蚁系统的比较,系统地介绍了蚁群系统(ACS)所作出的种种改进,并且在理论上证明了该算法的收敛性。     

Using Ant Colony Optimization algorithm for solving project management problems

Network analysis provides an effective practical system for planning and controlling large projects in construction and many other fields. Ant Colony System is a recent approach used for solving path minimization problems. This paper presents the use of Ant Colony Optimization (ACO) system for solving and calculating both deterministic and probabilistic CPM/PERT networks. The proposed method is investigated for a selected case study in construction management. The results demonstrate that – compared to conventional methods – ACO can produce good optimal and suboptimal solutions.     

场景化立体空间色彩饱和度动态修正仿真研究

当前立体空间色彩饱和度修正方法,受到噪声干扰导致图像空间的光照信息计算失准,造成低动态范围图像空间色彩饱和度失衡,从而需要二次修正,存在修正耗时较长、成本较高、且图像细节信息模糊的问题。据此提出场景化立体空间色彩饱和度动态修正方法,采用Retinex图像增强算法加入全局自适应亮度调节以及去噪环节,对图像亮度分量进行增强处理,在求解反射分量的过程中,保留场景化立体空间中的光照信息,以完成图像的预处理。将经过预处理的彩色图像压缩到普通显示器能够显示的范围内,采用阶跃方程对低动态范围内场景化立体空间色彩饱和度进行动态调整,实现场景化立体空间色彩饱和度动态修正。仿真结果表明,所提方法修正耗时较短、成本较低,并且能够更好的保存图像的细节信息。     

基于栅格空间V图的无人机路径规划

在进行无人机低空飞行的路径规划时,障碍物已不能简单的简化为点状;针对该问题,首先将带有面状障碍物的图片格式地图以像素为单位进行栅格划分,在定义了栅格距离后,进行距离变换,并运用边界跟踪方法生成栅格空间V图;其次,将A-Star算法的启发思想引入到蚁群算法中,并修改了启发信息计算公式以使蚁群算法更适合于栅格空间优化;最后,以栅格空间V图为初始路径,运用改进的蚁群算法进行优化选择,得到了满意的路径规划结果。     

Salient Region Detection by Modeling Distributions of Color and Orientation

We present a robust salient region detection framework based on the color and orientation distribution in images. The proposed framework consists of a color saliency framework and an orientation saliency framework. The color saliency framework detects salient regions based on the spatial distribution of the component colors in the image space and their remoteness in the color space. The dominant hues in the image are used to initialize an expectation-maximization (EM) algorithm to fit a Gaussian mixture model in the hue-saturation (H-S) space. The mixture of Gaussians framework in H-S space is used to compute the inter-cluster distance in the H-S domain as well as the relative spread among the corresponding colors in the spatial domain. Orientation saliency framework detects salient regions in images based on the global and local behavior of different orientations in the image. The oriented spectral information from the Fourier transform of the local patches in the image is used to obtain the local orientation histogram of the image. Salient regions are further detected by identifying spatially confined orientations and with the local patches that possess high orientation entropy contrast. The final saliency map is selected as either color saliency map or orientation saliency map by automatically identifying which of the maps leads to the correct identification of the salient region. The experiments are carried out on a large image database annotated with ldquoground-truthrdquo salient regions, provided by Microsoft Research Asia, which enables us to conduct robust objective level comparisons with other salient region detection algorithms.     

变异蚁群优化算法在流水作业排序中的应用

在采用蚁群算法求解流水作业排序中,针对蚁群算法存在的时间过长及过早收敛问题,使用解锁素及信息素挥发率作为启发式信息并引入局部优化,对蚁群系统加以改进。计算机仿真结果表明,改进后的蚁群系统对流水作业优化调度有较好的效果。     

An adaptive unsupervised approach toward pixel clustering and color image segmentation

This paper proposes an adaptive unsupervised scheme that could find diverse applications in pattern recognition as well as in computer vision, particularly in color image segmentation. The algorithm, named Ant Colony-Fuzzy C-means Hybrid Algorithm (AFHA), adaptively clusters image pixels viewed as three dimensional data pieces in the RGB color space. The Ant System (AS) algorithm is applied for intelligent initialization of cluster centroids, which endows clustering with adaptivity. Considering algorithmic efficiency, an ant subsampling step is performed to reduce computational complexity while keeping the clustering performance close to original one. Experimental results have demonstrated AFHA clustering's advantage of smaller distortion and more balanced cluster centroid distribution over FCM with random and uniform initialization. Quantitative comparisons with the X-means algorithm also show that AFHA makes a better pre-segmentation scheme over X-means. We further extend its application to natural image segmentation, taking into account the spatial information and conducting merging steps in the image space. Extensive tests were taken to examine the performance of the proposed scheme. Results indicate that compared with classical segmentation algorithms such as mean shift and normalized cut, our method could generate reasonably good or better image partitioning, which illustrates the method's practical value.     

基于蚁群优化算法的图像边缘检测

图像边缘携带了图像的大部分主要信息。通过对图像进行边缘检测不仅能有效地提取图像信息降低计算的复杂度而且是图像测量、图像分割、图像压缩、模式识别等图像处理的基础。本文尝试将蚁群优化算法（Ant Colony Optimization, ACO）用于图像边缘检测,通过选取经典house图像和SAR机场图像设置阈值进行自适应边缘提取,实现了边缘的精确检测。实验结果显示,该算法能够有效地提取图像目标的轮廓信息,很好保持图像纹理,具有理想的抗干扰性能,保证了检测结果的准确性。