Supervised hybrid feature selection based on PSO and rough sets for medical diagnosis

Medical datasets are often classified by a large number of disease measurements and a relatively small number of patient records. All these measurements (features) are not important or irrelevant/noisy. These features may be especially harmful in the case of relatively small training sets, where this irrelevancy and redundancy is harder to evaluate. On the other hand, this extreme number of features carries the problem of memory usage in order to represent the dataset. Feature Selection (FS) is a solution that involves finding a subset of prominent features to improve predictive accuracy and to remove the redundant features. Thus, the learning model receives a concise structure without forfeiting the predictive accuracy built by using only the selected prominent features. Therefore, nowadays, FS is an essential part of knowledge discovery. In this study, new supervised feature selection methods based on hybridization of Particle Swarm Optimization (PSO), PSO based Relative Reduct (PSO-RR) and PSO based Quick Reduct (PSO-QR) are presented for the diseases diagnosis. The experimental result on several standard medical datasets proves the efficiency of the proposed technique as well as enhancements over the existing feature selection techniques.     

A note on the learning automata based algorithms for adaptive parameter selection in PSO

PSO, like many stochastic search methods, is very sensitive to efficient parameter setting such that modifying a single parameter may cause a considerable change in the result. In this paper, we study the ability of learning automata for adaptive PSO parameter selection. We introduced two classes of learning automata based algorithms for adaptive selection of value for inertia weight and acceleration coefficients. In the first class, particles of a swarm use the same parameter values adjusted by learning automata. In the second class, each particle has its own characteristics and sets its parameter values individually. In addition, for both classed of proposed algorithms, two approaches for changing value of the parameters has been applied. In first approach, named adventurous, value of a parameter is selected from a finite set while in the second approach, named conservative, value of a parameter either changes by a fixed amount or remains unchanged. Experimental results show that proposed learning automata based algorithms compared to other schemes such as SPSO, PSOIW, PSO-TVAC, PSOLP, DAPSO, GPSO, and DCPSO have the same or even higher ability to find better solutions. In addition, proposed algorithms converge to stopping criteria for some of the highly multi modal functions significantly faster.     

Recommendation using a clustering algorithm based on a hybrid features selection method

The cold start problem is a potentiel problem in Recommender Systems (RSs). It concerns the inability of the system to infer recommendaation for new users or new items about wich it has not enough iformation. Specifically, when an item is new, the system may fail to perform well due to the insufficiency of available information for this item. The most common solution addressed in the literature consists in combining the content and collaborative information under a single RS. However these hybrid solutions inherit the classical problems of natural language ambiguity and don’t exploit semantic knowledge in their items representations. In this paper, we propose a hybrid RS composed of three modules to surpass those weaknesses. The first one is rested on a powerful content clustering algorithm; which uses a Hybrid Features Selection Method (HFSM). It combines statistical and semantic relevant features to get the maximum profit from the content of items. The second module is the Collaborative Filtering (CF) one, which depends only on users’ ratings. The third one combines the previous modules to solve the problem of missing values in CF approach and to handle new-item issue. The proposed hybrid Recommender is evaluated against traditional item-based CF in different settings: no cold-start situation and a simulation of a new-item scenario (an item with few/ no ratings). The conducted experiments show the ability of the proposed hybrid recommender to deliver more accurate predictions for any item and its outperformance on the classical CF approach, which fails in cold-start situations.     

基于混合粒子群算法的保障资源优化研究

针对目前我军在武器保障过程中人力资源的过载问题,提出了应用混合粒子群算法求解资源约束项目调度问题的实现方法.分析了网络计划中工序逻辑关系特点,采用工期指标建立优化模型.在算法设计中,使用遗传算法的交叉和变异操作替代粒子速度和位置的更新,并采用修复算子,以保证个体生成的合法性.对某型武器装备保障进行了优化分析,结果表明方法具有很强的寻优能力,对于促进保障单位合理利用资源、科学安排工程调度具有重要的现实意义.     

基于词典和遗传算法的文本特征获取方法

Web文本特征获取是Web挖掘中重要而关键的前提工作,传统文本特征获取方法由于在确定文本词条的权重方面做得不够准确,从而直接影响了文本分类算法的精确度.为此,提出一种基于主题词典和遗传算法的文本特征获取方法(dic.tionary and GA-based feature selection algorithms,DGFSA),利用主题词典来调整词条权重,从而获取文本特征向量.实验结果表明,DGFSA比传统算法在文本分类的准确率和特征词的约简率方面分别提高了28.4%和16.3%.     

一种基于决策矩阵的属性约简及规则提取算法

研究了Rough集理论中属性约简和值约简问题,扩展了决策矩阵的定义,提出了一种基于决策矩阵的完备属性约简算法,该算法利用决策属性把论域划分成多个等价类,然后利用每个等价类对应的决策矩阵计算属性约简。与区分矩阵相比,采用决策矩阵可以有效地减少存储空间,提高约简算法效率。同时,借助决策矩阵进行值约简,提出了一种新的规则提取算法,使最终得到的决策规则更加简洁。实验结果表明,本文提出的属性约简和值约简算法是正确、有效、可行的。     

Applying a selection method to choose Quality Attribute Techniques

ContextSoftware products have requirements on software quality attributes such as safety and performance. Development teams use various specific techniques to achieve these quality requirements. We call these “Quality Attribute Techniques” (QATs). QATs are used to identify, analyse and control potential product quality problems. Although QATs are widely used in practice, there is no systematic approach to represent, select, and integrate them in existing approaches to software process modelling and tailoring.ObjectiveThis research aims to provide a systematic approach to better select and integrate QATs into tailored software process models for projects that develop products with specific product quality requirements.MethodA selection method is developed to support the choice of appropriate techniques for any quality attribute, across the lifecycle. The selection method is based on three perspectives: (1) risk management; (2) process integration; and (3) cost/benefit using Analytic Hierarchy Process (AHP). An industry case study is used to validate the feasibility and effectiveness of applying the selection method.ResultsThe case study demonstrates that the selection method provides a more methodological and effective approach to choose QATs for projects that target a specific quality attribute, compared to the ad hoc selection performed by development teams.ConclusionThe proposed selection method can be used to systematically choose QATs for projects to target specific product qualities throughout the software development lifecycle.     

基于一种改进粒子群算法的SVM参数选取

支持向量机作为一个新兴的数学建模工具已经被广泛地应用到很多工业控制领域中,其良好的泛化能力和预测精度在很大程度上受到其参数选取的影响.根据智能群体进化模式改进粒子群优化算法.利用模糊C均值聚类算法分类粒子群体,并用子群体最优点取代速度更新公式中的个体历史最优点,并利用该算法搜索支持向量机的最优参数组合.对比仿真实验表明:所提优化算法是支持向量机参数选取的有效算法,在非线性函数估计中体现出优良的性能.     

基于PSO的多约束QoS网格资源选择模型

现有的网格资源选择算法中,只考虑到资源的可利用率,忽略了网络因素的影响,为此提出了一种基于粒子群优化算法的、带网络QoS约束的三层资源选择模型,并对该模型的算法进行了设计.该模型综合考虑了资源利用率和网络因素对网格资源选择的影响,过滤掉一些资源利用率很高但网络通信能力很低,甚至网络无法连通的结点,减轻了资源调度的负担.给出了一个仿真实例,以说明该模型和算法的有效性.     

A powerful hybrid clustering method based on modified stem cells and Fuzzy C-means algorithms

One of the simple techniques for Data Clustering is based on Fuzzy C-means (FCM) clustering which describes the belongingness of each data to a cluster by a fuzzy membership function instead of a crisp value. However, the results of fuzzy clustering depend highly on the initial state selection and there is also a high risk for getting the best results when the datasets are large. In this paper, we present a hybrid algorithm based on FCM and modified stem cells algorithms, we called it SC-FCM algorithm, for optimum clustering of a dataset into K clusters. The experimental results obtained by using the new algorithm on different well-known datasets compared with those obtained by K-means algorithm, FCM, Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Ant Colony Optimization (ACO), Artificial Bee Colony (ABC) Algorithm demonstrate the better performance of the new algorithm.     

A hybrid clustering algorithm based on PSO with dynamic crossover

In order to overcome the premature convergence in particle swarm optimization (PSO), we introduce dynamical crossover, a crossover operator with variable lengths and positions, to PSO, which is briefly denoted as CPSO. To get rid of the drawbacks of only finding the convex clusters and being sensitive to the initial points in $k$ -means algorithm, a hybrid clustering algorithm based on CPSO is proposed. The difference between the work and the existing ones lies in that CPSO is firstly introduced into $k$ -means. Experimental results performing on several data sets illustrate that the proposed clustering algorithm can get completely rid of the shortcomings of $k$ -means algorithms, and acquire correct clustering results. The application in image segmentation illustrates that the proposed algorithm gains good performance.     

基于过滤微粒群优化算法的虚拟企业伙伴选择

提出了一种过滤微粒群优化算法并应用于虚拟企业的伙伴选择问题.该算法以优良适应值微粒取代部分不良适应值微粒,使算法具有过滤能力,加快了搜索速度,并保证收敛于全局最优解.仿真实验及与基本PSO算法的对比分析表明了FPSO算法的有效性.     

基于粒子群算法的弹道导弹设计方法研究

弹道导弹初步设计的主要任务就是寻优选择导弹的设计参数,从而使导弹满足战术指标和限制条件.针对惩罚函数法在弹道导弹设计中计算时间长,计算效果差的缺点,采用柱子群优.化算法进行弹道导弹优化设计,该方法能够提高计算效率,得到更好的弹道导弹设计参数,并通过仿真试验证明了该方法的有效性.     

Software effort estimation using ensemble of hybrid search-based algorithms based on metaheuristic algorithms

Innovations in Systems and Software Engineering - Software effort estimation is an essential task for software organizations to allocate resources efficiently during the development of software and...     

A DE and PSO based hybrid algorithm for dynamic optimization problems

Many real world optimization problems are dynamic in which the fitness landscape is time dependent and the optima change over time. Such problems challenge traditional optimization algorithms. For such problems, optimization algorithms not only have to find the global optimum but also need to closely track its trajectory. In this paper, a new hybrid algorithm integrating a differential evolution (DE) and a particle swarm optimization (PSO) is proposed for dynamic optimization problems. Multi-population strategy is adopted to enhance the diversity and try to keep each subpopulation on a different peak in the fitness landscape. A hybrid operator combining DE and PSO is designed, in which each individual is sequentially carried out DE and PSO operations. An exclusion scheme is proposed that integrates the distance based exclusion scheme with the hill-valley function to track the adjacent peaks. The algorithm is applied to the set of benchmark functions used in CEC 2009 competition for dynamic environment. Experimental results show that it is more effective in terms of overall performance than other comparative algorithms.     

基于粒子群算法的神经网络短期降水预报建模研究

用多样性粒子群算法优化神经网络的网络结构和连接权，获得神经网络集成个体；进一步用二次规划方法，计算各集成个体的最优非负权系数进行组合集成，生成神经网络集成的输出结论，进行短期降水预报建模研究．以广西全区的月降水量实例分析，结果表明该方法能有效提高系统的泛化能力．     

基于PSO神经网络的故障诊断方法研究

将粒子群优化算法和BP算法相结合,提出了一种基于粒子群神经网络的故障诊断方法.该方法分阶段实施神经网络的训练,有效地加强了算法的全局搜索能力,采用PSO优化了传播中的权值、阈值以及网络结构.这不仅弥补了BP算法的不足,而且删除了冗余连接,提高了故障模式识别的能力.仿真结果表明该方法加快了神经网络的学习收敛速度,提高了故障模式的识别正确率,可以有效地应用于设备的故障诊断.     

A novel hybrid method based on fuzzy cognitive maps and fuzzy clustering algorithms for grading celiac disease

This paper presents a new method based on fuzzy cognitive map (FCM) and possibilistic fuzzy c-means (PFCM) clustering algorithm for categorizing celiac disease (CD). CD is a complex disorder whose development is affected by genetics (HLA alleles) and gluten ingestion. The celiac patients who are not treated are at a high risk of cancer, malignant lymphoma, and small bowel neoplasia. Therefore, CD diagnosis and grading are of paramount importance. The proposed FCM models human thinking for the purpose of classifying patients suffering from CD. We used the latest grading method where three grades A, B1, and B2 are used. To improve FCM efficiency and classification capability, a nonlinear Hebbian learning algorithm is applied for adjusting the FCM weights. To this end, 89 cases are studied. Three experts extracted seven main determinant characteristics of CD which were considered as FCM concepts. The mutual effects of these concepts on one another and on the final concept were expressed in the form of fuzzy rules and linguistic variables. Using the center of gravity defuzzifier, we obtained the numerical values of these weights and obtained the total weight matrix. Ultimately, combining the FCM model with PFCM algorithm, we obtained the grades A, B1, and B2 accuracies as 88, 90, and 91%, respectively. The main advantage of the proposed FCM is the good transparency and interpretability in the decision-making procedure, which make it a suitable tool for daily usage in the clinical practice.

     

基于粒子群算法和拥塞控制的移动路由选择方案

基于不同的业务类型对QoS性能有不同的要求的特点,设计了一种基于粒子群算法和拥塞控制的移动路由选择方案。仿真实验表明,该方案可以实现移动路由最优路径选择,同时降低网络中的拥塞概率,保证业务QoS。