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Enhancing Cancer Classification through a Hybrid Bio-Inspired Evolutionary Algorithm for Biomarker Gene Selection
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作者 Hala AlShamlan Halah AlMazrua 《Computers, Materials & Continua》 SCIE EI 2024年第4期675-694,共20页
In this study,our aim is to address the problem of gene selection by proposing a hybrid bio-inspired evolutionary algorithm that combines Grey Wolf Optimization(GWO)with Harris Hawks Optimization(HHO)for feature selec... In this study,our aim is to address the problem of gene selection by proposing a hybrid bio-inspired evolutionary algorithm that combines Grey Wolf Optimization(GWO)with Harris Hawks Optimization(HHO)for feature selection.Themotivation for utilizingGWOandHHOstems fromtheir bio-inspired nature and their demonstrated success in optimization problems.We aimto leverage the strengths of these algorithms to enhance the effectiveness of feature selection in microarray-based cancer classification.We selected leave-one-out cross-validation(LOOCV)to evaluate the performance of both two widely used classifiers,k-nearest neighbors(KNN)and support vector machine(SVM),on high-dimensional cancer microarray data.The proposed method is extensively tested on six publicly available cancer microarray datasets,and a comprehensive comparison with recently published methods is conducted.Our hybrid algorithm demonstrates its effectiveness in improving classification performance,Surpassing alternative approaches in terms of precision.The outcomes confirm the capability of our method to substantially improve both the precision and efficiency of cancer classification,thereby advancing the development ofmore efficient treatment strategies.The proposed hybridmethod offers a promising solution to the gene selection problem in microarray-based cancer classification.It improves the accuracy and efficiency of cancer diagnosis and treatment,and its superior performance compared to other methods highlights its potential applicability in realworld cancer classification tasks.By harnessing the complementary search mechanisms of GWO and HHO,we leverage their bio-inspired behavior to identify informative genes relevant to cancer diagnosis and treatment. 展开更多
关键词 Bio-inspired algorithms BIOINFORMATICS cancer classification evolutionary algorithm feature selection gene expression grey wolf optimizer harris hawks optimization k-nearest neighbor support vector machine
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A Study of EM Algorithm as an Imputation Method: A Model-Based Simulation Study with Application to a Synthetic Compositional Data
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作者 Yisa Adeniyi Abolade Yichuan Zhao 《Open Journal of Modelling and Simulation》 2024年第2期33-42,共10页
Compositional data, such as relative information, is a crucial aspect of machine learning and other related fields. It is typically recorded as closed data or sums to a constant, like 100%. The statistical linear mode... Compositional data, such as relative information, is a crucial aspect of machine learning and other related fields. It is typically recorded as closed data or sums to a constant, like 100%. The statistical linear model is the most used technique for identifying hidden relationships between underlying random variables of interest. However, data quality is a significant challenge in machine learning, especially when missing data is present. The linear regression model is a commonly used statistical modeling technique used in various applications to find relationships between variables of interest. When estimating linear regression parameters which are useful for things like future prediction and partial effects analysis of independent variables, maximum likelihood estimation (MLE) is the method of choice. However, many datasets contain missing observations, which can lead to costly and time-consuming data recovery. To address this issue, the expectation-maximization (EM) algorithm has been suggested as a solution for situations including missing data. The EM algorithm repeatedly finds the best estimates of parameters in statistical models that depend on variables or data that have not been observed. This is called maximum likelihood or maximum a posteriori (MAP). Using the present estimate as input, the expectation (E) step constructs a log-likelihood function. Finding the parameters that maximize the anticipated log-likelihood, as determined in the E step, is the job of the maximization (M) phase. This study looked at how well the EM algorithm worked on a made-up compositional dataset with missing observations. It used both the robust least square version and ordinary least square regression techniques. The efficacy of the EM algorithm was compared with two alternative imputation techniques, k-Nearest Neighbor (k-NN) and mean imputation (), in terms of Aitchison distances and covariance. 展开更多
关键词 Compositional Data Linear Regression Model Least Square Method Robust Least Square Method Synthetic Data Aitchison Distance Maximum Likelihood Estimation Expectation-Maximization algorithm k-nearest neighbor and Mean imputation
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Wireless Communication Signal Strength Prediction Method Based on the K-nearest Neighbor Algorithm
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作者 Zhao Chen Ning Xiong +6 位作者 Yujue Wang Yong Ding Hengkui Xiang Chenjun Tang Lingang Liu Xiuqing Zou Decun Luo 《国际计算机前沿大会会议论文集》 2019年第1期238-240,共3页
Existing interference protection systems lack automatic evaluation methods to provide scientific, objective and accurate assessment results. To address this issue, this paper develops a layout scheme by geometrically ... Existing interference protection systems lack automatic evaluation methods to provide scientific, objective and accurate assessment results. To address this issue, this paper develops a layout scheme by geometrically modeling the actual scene, so that the hand-held full-band spectrum analyzer would be able to collect signal field strength values for indoor complex scenes. An improved prediction algorithm based on the K-nearest neighbor non-parametric kernel regression was proposed to predict the signal field strengths for the whole plane before and after being shield. Then the highest accuracy set of data could be picked out by comparison. The experimental results show that the improved prediction algorithm based on the K-nearest neighbor non-parametric kernel regression can scientifically and objectively predict the indoor complex scenes’ signal strength and evaluate the interference protection with high accuracy. 展开更多
关键词 INTERFERENCE protection k-nearest neighbor algorithm NON-PARAMETRIC KERNEL regression SIGNAL field STRENGTH
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求解带容量约束车辆路径问题的改进遗传算法
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作者 徐伟华 邱龙龙 +1 位作者 张根瑞 魏传祥 《计算机工程与设计》 北大核心 2024年第3期785-792,共8页
为解决传统遗传算法求解带容量约束的车辆路径问题时收敛速度慢和局部搜索能力差的问题,对传统遗传算法提出一种改进策略。使用基于贪婪策略的启发式交叉算子加强算法接近最优解的能力,加快算法收敛速度,在变异操作中,引入最近邻搜索算... 为解决传统遗传算法求解带容量约束的车辆路径问题时收敛速度慢和局部搜索能力差的问题,对传统遗传算法提出一种改进策略。使用基于贪婪策略的启发式交叉算子加强算法接近最优解的能力,加快算法收敛速度,在变异操作中,引入最近邻搜索算子,缩小基因变异范围,使用单点局部插入算子提高算法的局部优化能力。采用精英选择和轮盘赌法结合的选择策略,保持种群多样性以加强算法的全局搜索能力。实例计算测试表明,与传统遗传算法相比,所提算法求解平均偏差降低了70.25%,求解时间减少了87.41%;与ALNS和AGGWOA算法相比,有更高的求解质量和更好的稳定性。 展开更多
关键词 遗传算法 车辆路径问题 贪婪策略 交叉算子 最近邻搜索 局部优化 精英选择
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基于IKNN和LOF的变压器回复电压数据清洗方法研究
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作者 陈啸轩 邹阳 +3 位作者 翁祖辰 林锦茄 林昕亮 张云霄 《电子测量与仪器学报》 CSCD 北大核心 2024年第2期92-100,共9页
基于回复电压极化谱提取特征参量是目前广泛应用的变压器油纸绝缘状态评估方法,但极化谱易受工况干扰、人工失误等因素影响而出现特征数据异常的情况,严重降低评估准确性。针对上述问题,该文提出了一种基于局部离群因子(LOF)和改进K最近... 基于回复电压极化谱提取特征参量是目前广泛应用的变压器油纸绝缘状态评估方法,但极化谱易受工况干扰、人工失误等因素影响而出现特征数据异常的情况,严重降低评估准确性。针对上述问题,该文提出了一种基于局部离群因子(LOF)和改进K最近邻(IKNN)的回复电压数据清洗方法。首先,选取回复电压极化谱的回复电压极大值Urmax、初始斜率Sr与主时间常数tcdom作为老化特征参量,并基于LOF算法对非标准极化谱中的异常特征量数据进行识别与筛除。其次,利用模糊C均值(FCM)聚类算法减小噪声点对KNN算法的干扰,并通过加权欧氏距离标度突出各特征量间的关联性,进而构建出基于IKNN的数据填补模型架构以实现特征缺失数据的填补。最后,代入多组实测数据验证所提数据清洗方法的实效性。结果表明,数据清洗后的状态评估准确率相较于原有数据上升了50%左右,有效提高了变压器回复电压数据质量,为准确感知变压器运行状况奠定坚实的基础。 展开更多
关键词 油纸绝缘 特征数据清洗 局部离群因子算法 回复电压极化谱 改进K最近邻算法
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基于RRT算法的移动机器人安全光滑路径生成
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作者 李文君 李忠伟 罗偲 《电子测量技术》 北大核心 2024年第2期51-60,共10页
在多障碍物复杂工厂环境中,针对快速探索随机树算法(RRT)生成的路径存在冗余点、贴近障碍物且存在锯齿状转折的问题,改进得到了安全-光滑RRT(Safe-SmoothRRT)路径规划算法。首先,引入目标偏置策略;其次,该算法利用融合目标点引力思想的... 在多障碍物复杂工厂环境中,针对快速探索随机树算法(RRT)生成的路径存在冗余点、贴近障碍物且存在锯齿状转折的问题,改进得到了安全-光滑RRT(Safe-SmoothRRT)路径规划算法。首先,引入目标偏置策略;其次,该算法利用融合目标点引力思想的新节点扩展方式以及改进的近邻点度量策略以减少树的盲目扩展,提高生长的目标性;随后,引入节点安全约束,将安全节点加入树中;改进路径简化方法,剔除冗余点的同时兼顾了安全性;最后通过B样条局部平滑来改善路径的平滑性。在MATLAB仿真实验中分别与标准RRT算法、自适应目标偏向性RRT算法和改进RRT算法相比,在平均路径长度方面最大下降了7.1%,在平均有效节点数方面最大下降了64.1%,且所得路径始终与障碍物保持一定的安全距离,结果表明改进算法有效提升了路径的光滑性和安全性。 展开更多
关键词 移动机器人 路径规划 RRT算法 近邻节点度量 节点安全约束 改进路径简化 局部平滑
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一种改进的局部均值伪近邻算法
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作者 李毅 张德生 张晓 《计算机工程与应用》 CSCD 北大核心 2024年第5期88-94,共7页
针对基于局部均值的伪近邻分类算法(LMPNN)易受近邻参数k和噪声点影响的问题,提出了一种改进的局部均值伪近邻分类算法(IPLMPNN)。利用双层搜索规则确定待测样本的最近邻,提高近邻集的选择质量;为了克服主观赋权法的不利影响,并且加强... 针对基于局部均值的伪近邻分类算法(LMPNN)易受近邻参数k和噪声点影响的问题,提出了一种改进的局部均值伪近邻分类算法(IPLMPNN)。利用双层搜索规则确定待测样本的最近邻,提高近邻集的选择质量;为了克服主观赋权法的不利影响,并且加强每个局部均值向量对分类的作用,引入注意力机制计算距离加权系数;使用改进的调和平均距离计算待测样本与局部均值向量之间的加权多调和平均距离,由此查找伪近邻点对待测样本进行分类。利用UCI和KEEL中的多个数据集对IPLMPNN算法进行仿真实验,并与8种相关算法进行比较。实验结果表明,IPLMPNN算法取得了令人满意的分类结果。 展开更多
关键词 局部均值的伪近邻分类算法(LMPNN) 双层搜索 注意力机制 多调和平均距离
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自适应邻域密度聚类及事故黑点识别应用
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作者 刘韡 黄俊龙 +1 位作者 鲁娜 刁麓弘 《黑龙江交通科技》 2024年第6期138-143,150,共7页
聚类作为识别交通事故黑点的主要方法之一,其主要问题是交通事故多发区事先无法确定,即无法提前知道聚类簇数。利用样本点之间的连接概率定义了数据点的局部密度,根据局部密度大小来确定聚类中心和簇数,再对数据点进行聚类。结果表明:... 聚类作为识别交通事故黑点的主要方法之一,其主要问题是交通事故多发区事先无法确定,即无法提前知道聚类簇数。利用样本点之间的连接概率定义了数据点的局部密度,根据局部密度大小来确定聚类中心和簇数,再对数据点进行聚类。结果表明:一是算法对参数不敏感,具有较好的通用性;二是算法能自动确定聚类簇数;三是算法聚类过程只依赖局部密度与邻接点,能够识别噪声点,提升结果的准确性。运用算法在一些真实数据集上进行试验,将聚类结果与其他算法结果利用评价指标ARI(Adjusted Rand Index)和NMI(Normalized Mutual Information)进行比较。最后利用算法对美国6个州的交通事故进行聚类,结果表明算法对交通事故有较好的适应性,能将城市及周边道路上事故密集区域准确识别出来。 展开更多
关键词 交通事故黑点 聚类算法 聚类簇数 自适应邻域聚类 局部密度
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基于WT-kNN的沥青混凝土心墙坝渗流监测数据异常检测
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作者 毛建刚 阿尔娜古丽·艾买提 +1 位作者 颜志光 廖攀 《西北水电》 2024年第3期54-60,共7页
安全监测数据的质量,对沥青混凝土心墙坝安全状况分析具有重要意义。时间效应导致的趋势性问题是渗流监测数据异常检测的难点。模态分解方法能较好地对时间序列的趋势项进行分离,进而识别处异常信号。但是,土石坝渗流监测数据中的异常... 安全监测数据的质量,对沥青混凝土心墙坝安全状况分析具有重要意义。时间效应导致的趋势性问题是渗流监测数据异常检测的难点。模态分解方法能较好地对时间序列的趋势项进行分离,进而识别处异常信号。但是,土石坝渗流监测数据中的异常值和真实信号往往存在模态混叠。为了解决上述问题,通过引入了小波变换结合局部kNN加权回归(WT-kNN)异常检测方法,使用连续小波变换分离趋势项,通过局部kNN加权回归进一步对小波变换的检测结果进行筛选,提高模型的异常检测准确率。工程应用结果表明:对于粗差占比2.5%~10%的监测序列,WT-kNN的召回率均高于95%,误判率低于5%;该模型与WT-MAD方法和SSA-DBSCAN方法对比实验验证了WT-kNN的有效性和优越性。敏感性分析结果表明,提出模型对异常值数量占总数据量比例和异常值波动范围大小敏感性低,可为后续监测数据分析处理及预测预警建立基础。 展开更多
关键词 小波变换 局部K近邻算法 大坝安全监测 异常检测
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A Memetic Algorithm With Competition for the Capacitated Green Vehicle Routing Problem 被引量:8
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作者 Ling Wang Jiawen Lu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第2期516-526,共11页
In this paper, a memetic algorithm with competition(MAC) is proposed to solve the capacitated green vehicle routing problem(CGVRP). Firstly, the permutation array called traveling salesman problem(TSP) route is used t... In this paper, a memetic algorithm with competition(MAC) is proposed to solve the capacitated green vehicle routing problem(CGVRP). Firstly, the permutation array called traveling salesman problem(TSP) route is used to encode the solution, and an effective decoding method to construct the CGVRP route is presented accordingly. Secondly, the k-nearest neighbor(k NN) based initialization is presented to take use of the location information of the customers. Thirdly, according to the characteristics of the CGVRP, the search operators in the variable neighborhood search(VNS) framework and the simulated annealing(SA) strategy are executed on the TSP route for all solutions. Moreover, the customer adjustment operator and the alternative fuel station(AFS) adjustment operator on the CGVRP route are executed for the elite solutions after competition. In addition, the crossover operator is employed to share information among different solutions. The effect of parameter setting is investigated using the Taguchi method of design-ofexperiment to suggest suitable values. Via numerical tests, it demonstrates the effectiveness of both the competitive search and the decoding method. Moreover, extensive comparative results show that the proposed algorithm is more effective and efficient than the existing methods in solving the CGVRP. 展开更多
关键词 Capacitated green VEHICLE ROUTING problem(CGVRP) COMPETITION k-nearest neighbor(kNN) local INTENSIFICATION memetic algorithm
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Automatic Visual Leakage Detection and Localization from Pipelines in Chemical Process Plants Using Machine Vision Techniques 被引量:7
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作者 Mina Fahimipirehgalin Emanuel Trunzer +1 位作者 Matthias Odenweller Birgit Vogel-Heuser 《Engineering》 SCIE EI 2021年第6期758-776,共19页
Liquid leakage from pipelines is a critical issue in large-scale process plants.Damage in pipelines affects the normal operation of the plant and increases maintenance costs.Furthermore,it causes unsafe and hazardous ... Liquid leakage from pipelines is a critical issue in large-scale process plants.Damage in pipelines affects the normal operation of the plant and increases maintenance costs.Furthermore,it causes unsafe and hazardous situations for operators.Therefore,the detection and localization of leakages is a crucial task for maintenance and condition monitoring.Recently,the use of infrared(IR)cameras was found to be a promising approach for leakage detection in large-scale plants.IR cameras can capture leaking liquid if it has a higher(or lower)temperature than its surroundings.In this paper,a method based on IR video data and machine vision techniques is proposed to detect and localize liquid leakages in a chemical process plant.Since the proposed method is a vision-based method and does not consider the physical properties of the leaking liquid,it is applicable for any type of liquid leakage(i.e.,water,oil,etc.).In this method,subsequent frames are subtracted and divided into blocks.Then,principle component analysis is performed in each block to extract features from the blocks.All subtracted frames within the blocks are individually transferred to feature vectors,which are used as a basis for classifying the blocks.The k-nearest neighbor algorithm is used to classify the blocks as normal(without leakage)or anomalous(with leakage).Finally,the positions of the leakages are determined in each anomalous block.In order to evaluate the approach,two datasets with two different formats,consisting of video footage of a laboratory demonstrator plant captured by an IR camera,are considered.The results show that the proposed method is a promising approach to detect and localize leakages from pipelines using IR videos.The proposed method has high accuracy and a reasonable detection time for leakage detection.The possibility of extending the proposed method to a real industrial plant and the limitations of this method are discussed at the end. 展开更多
关键词 Leakage detection and localization Image analysis Image pre-processing Principle component analysis k-nearest neighbor classification
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An Improved Whale Optimization Algorithm for Feature Selection 被引量:4
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作者 Wenyan Guo Ting Liu +1 位作者 Fang Dai Peng Xu 《Computers, Materials & Continua》 SCIE EI 2020年第1期337-354,共18页
Whale optimization algorithm(WOA)is a new population-based meta-heuristic algorithm.WOA uses shrinking encircling mechanism,spiral rise,and random learning strategies to update whale’s positions.WOA has merit in term... Whale optimization algorithm(WOA)is a new population-based meta-heuristic algorithm.WOA uses shrinking encircling mechanism,spiral rise,and random learning strategies to update whale’s positions.WOA has merit in terms of simple calculation and high computational accuracy,but its convergence speed is slow and it is easy to fall into the local optimal solution.In order to overcome the shortcomings,this paper integrates adaptive neighborhood and hybrid mutation strategies into whale optimization algorithms,designs the average distance from itself to other whales as an adaptive neighborhood radius,and chooses to learn from the optimal solution in the neighborhood instead of random learning strategies.The hybrid mutation strategy is used to enhance the ability of algorithm to jump out of the local optimal solution.A new whale optimization algorithm(HMNWOA)is proposed.The proposed algorithm inherits the global search capability of the original algorithm,enhances the exploitation ability,improves the quality of the population,and thus improves the convergence speed of the algorithm.A feature selection algorithm based on binary HMNWOA is proposed.Twelve standard datasets from UCI repository test the validity of the proposed algorithm for feature selection.The experimental results show that HMNWOA is very competitive compared to the other six popular feature selection methods in improving the classification accuracy and reducing the number of features,and ensures that HMNWOA has strong search ability in the search feature space. 展开更多
关键词 Whale optimization algorithm Filter and Wrapper model k-nearest neighbor method Adaptive neighborhood hybrid mutation
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Research on Initialization on EM Algorithm Based on Gaussian Mixture Model 被引量:4
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作者 Ye Li Yiyan Chen 《Journal of Applied Mathematics and Physics》 2018年第1期11-17,共7页
The EM algorithm is a very popular maximum likelihood estimation method, the iterative algorithm for solving the maximum likelihood estimator when the observation data is the incomplete data, but also is very effectiv... The EM algorithm is a very popular maximum likelihood estimation method, the iterative algorithm for solving the maximum likelihood estimator when the observation data is the incomplete data, but also is very effective algorithm to estimate the finite mixture model parameters. However, EM algorithm can not guarantee to find the global optimal solution, and often easy to fall into local optimal solution, so it is sensitive to the determination of initial value to iteration. Traditional EM algorithm select the initial value at random, we propose an improved method of selection of initial value. First, we use the k-nearest-neighbor method to delete outliers. Second, use the k-means to initialize the EM algorithm. Compare this method with the original random initial value method, numerical experiments show that the parameter estimation effect of the initialization of the EM algorithm is significantly better than the effect of the original EM algorithm. 展开更多
关键词 EM algorithm GAUSSIAN MIXTURE Model k-nearest neighbor K-MEANS algorithm INITIALIZATION
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融合最近邻矩阵与局部密度的自适应K-means聚类算法 被引量:3
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作者 艾力米努尔·库尔班 谢娟英 姚若侠 《计算机科学与探索》 CSCD 北大核心 2023年第2期355-366,共12页
针对传统K-means聚类算法对初始聚类中心和离群孤立点敏感的缺陷,以及现有引入密度概念优化的K-means算法均需要设置密度参数或阈值的缺点,提出一种融合最近邻矩阵与局部密度的自适应K-means聚类算法。受最邻近吸收原则与密度峰值原则启... 针对传统K-means聚类算法对初始聚类中心和离群孤立点敏感的缺陷,以及现有引入密度概念优化的K-means算法均需要设置密度参数或阈值的缺点,提出一种融合最近邻矩阵与局部密度的自适应K-means聚类算法。受最邻近吸收原则与密度峰值原则启发,通过引入数据对象间的距离差异值构造邻近矩阵,根据邻近矩阵计算局部密度,不需要任何参数设置,采取最近邻矩阵与局部密度融合策略,自适应确定初始聚类中心数目和位置,同时完成非中心点的初分配。人工数据集和UCI数据集的实验测试,以及与传统K-means算法、基于离群点改进的K-means算法、基于密度改进的K-means算法的实验比较表明,提出的自适应K-means算法对人工数据集的孤立点免疫度较高,对UCI数据集具有更准确的聚类结果。 展开更多
关键词 自适应K-means聚类算法 密度峰值原则 最邻近吸收原则 局部密度
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基于局部敏感哈希的K邻近算法识别垃圾短信
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作者 樊继慧 滕少华 《济南大学学报(自然科学版)》 CAS 北大核心 2023年第6期746-751,共6页
针对目前垃圾短信的识别算法存在的关键字及频次的规则死板,易于被不法分子探测和规避等问题,提出将局部敏感哈希的K邻近算法应用于垃圾短信分类识别;首先定义特征,然后采用局部敏感哈希算法计算向量距离,通过得到的距离衡量矩阵的相似... 针对目前垃圾短信的识别算法存在的关键字及频次的规则死板,易于被不法分子探测和规避等问题,提出将局部敏感哈希的K邻近算法应用于垃圾短信分类识别;首先定义特征,然后采用局部敏感哈希算法计算向量距离,通过得到的距离衡量矩阵的相似性,量化矩阵相似程度,对本文中提出的优化模型进行实现和训练;基于短信文本内容,运用词频-逆向文本频率算法生成矩阵,利用局部敏感哈希算法求解最相似样本,记录样本类别,将训练结果导入K邻近算法分类器得到最优近邻,在测试集或验证集上对优化模型垃圾短信分类识别准确率进行评测。结果表明,经过K邻近算法分类器后,优化模型垃圾短信分类识别准确率达到98.7%。 展开更多
关键词 垃圾短信识别 K邻近算法 局部敏感哈希 矩阵相似性
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融合相对密度和最近邻关系的密度峰值聚类
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作者 王威娜 朱钰 任艳 《计算机科学与探索》 CSCD 北大核心 2023年第8期1879-1892,共14页
密度峰值算法在处理密度不均匀的数据时对中心点的选取不准确,并在样本分配时易产生连带错误,导致聚类效果不佳。针对上述问题,提出一种融合相对局部密度和最近邻关系的密度峰值聚类算法。在局部密度的定义中引入稀疏平和权重,提出相对... 密度峰值算法在处理密度不均匀的数据时对中心点的选取不准确,并在样本分配时易产生连带错误,导致聚类效果不佳。针对上述问题,提出一种融合相对局部密度和最近邻关系的密度峰值聚类算法。在局部密度的定义中引入稀疏平和权重,提出相对局部密度的定义,根据相对局部密度寻找密度峰值,避免稀疏差异较大的数据集在选取密度峰值时出现的错误,确保中心点选择的正确性;针对分配策略,结合最邻近点准则和阈值限制,提出最近邻分配策略,根据阈值条件有效抑制分配连带错误;基于类内距离均值定义距离比例,提出修正分配策略,提升算法对边界点聚类的准确性。在5个合成数据集和5个UCI数据集上,将提出算法与DPC、DPC-MND、FKNN-DPC、DBSCAN、OPTICS、AP、K-means算法进行比较,实验结果表明,所提算法在调整互信息、调整兰德系数和Fowlkes-Mallows指数上均表现出良好的聚类效果,并通过Friedman检验表明该算法具有最优的性能。 展开更多
关键词 聚类算法 密度峰值 相对局部密度 最近邻关系 分配策略
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基于共享近邻和优化关联策略的边界剥离聚类
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作者 冯洁净 侯新民 《计算机系统应用》 2023年第10期147-156,共10页
边界剥离聚类算法(BP)是一种基于密度的聚类算法,它通过逐渐剥离边界点来揭示聚类的潜在核心,已经被证明是一种十分有效的聚类手段.然而,BP算法仍存在一些不足之处:一方面,数据点的局部密度仅考虑了距离特征,使得边界点的确定不够合理;... 边界剥离聚类算法(BP)是一种基于密度的聚类算法,它通过逐渐剥离边界点来揭示聚类的潜在核心,已经被证明是一种十分有效的聚类手段.然而,BP算法仍存在一些不足之处:一方面,数据点的局部密度仅考虑了距离特征,使得边界点的确定不够合理;另一方面,BP算法中的关联策略容易误判异常值,并且在分配边界点时容易产生连带错误.为此,本文提出了一种基于共享近邻和优化关联策略的边界剥离聚类算法(SOBP).该算法使用了基于共享近邻的局部密度函数来更好地探索数据点之间的相似性,同时优化了BP算法中的关联策略,使得每次迭代中边界点不再仅与一个非边界点进行关联,并进一步采用了边界点与非边界点、已剥离边界点之间的双重关联准则.在一些数据集上的测试表明,相较于其他6种经典算法,该算法在评估指标上表现更佳. 展开更多
关键词 边界剥离聚类算法 共享近邻 局部密度 关联策略
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基于局部自适应阈值与K近邻算法的空气滤芯漏粘识别
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作者 高雅昆 高小红 +2 位作者 胡永涛 吴超 郭华 《内燃机与配件》 2023年第23期106-108,共3页
空气滤芯产品生产时如果出现漏粘会导致空气直接进入发动机,过滤失效。针对该情况,设计了基于局部自适应阈值与K近邻算法的空气滤芯漏粘识别算法:首先,利用局部自适应阈值分割算法对滤芯图像分割,并通过区域标号算法定位到粘胶亮孔;然后... 空气滤芯产品生产时如果出现漏粘会导致空气直接进入发动机,过滤失效。针对该情况,设计了基于局部自适应阈值与K近邻算法的空气滤芯漏粘识别算法:首先,利用局部自适应阈值分割算法对滤芯图像分割,并通过区域标号算法定位到粘胶亮孔;然后,利用K近邻算法以每个粘胶亮孔为中心,通过该中心亮孔与周围近邻亮孔的灰度相似性,判断中心孔是否为漏粘孔。实验表明所提算法漏粘识别率达到99%,有效提高滤芯产品合格率。 展开更多
关键词 空气滤芯 局部自适应阈值分割 K邻算法 漏粘识别
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结合局部敏感哈希的k近邻数据填补算法 被引量:4
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作者 郑奇斌 刁兴春 +2 位作者 曹建军 周星 许永平 《计算机应用》 CSCD 北大核心 2016年第2期397-401,共5页
k近邻(kNN)算法是缺失数据填补的常用算法,但由于需要逐个计算所有记录对之间的相似度,因此其填补耗时较高。为提高算法效率,提出结合局部敏感哈希(LSH)的k NN数据填补算法LSH-k NN。首先,对不存在缺失的完整记录进行局部敏感哈希,为之... k近邻(kNN)算法是缺失数据填补的常用算法,但由于需要逐个计算所有记录对之间的相似度,因此其填补耗时较高。为提高算法效率,提出结合局部敏感哈希(LSH)的k NN数据填补算法LSH-k NN。首先,对不存在缺失的完整记录进行局部敏感哈希,为之后查找近似最近邻提供索引;其次,针对枚举型、数值型以及混合型缺失数据分别提出对应的局部敏感哈希方法,对每一条待填补的不完整记录进行局部敏感哈希,按得到的哈希值找到与其疑似相似的候选记录;最后在候选记录中通过逐个计算相似度来找到其中相似程度最高的k条记录,并按照k NN算法对不完整记录进行填补。通过在4个真实数据集上的实验表明,结合局部敏感哈希的k NN填补算法LSH-k NN相对经典的k NN算法能够显著提高填补效率,并且保持准确性基本不变。 展开更多
关键词 数据质量 数据完整性 数据填补 K近邻算法 局部敏感哈希
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一种求解旅行商问题的高效混合遗传算法 被引量:22
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作者 姜昌华 胡幼华 《计算机工程与应用》 CSCD 北大核心 2004年第22期67-70,共4页
旅行商问题(TravellingSalesmanProblemTSP)是一个典型的组合优化难题,论文提出一种求解旅行商问题的高效混合遗传算法。该算法结合遗传算法和2-opt邻域搜索优化技术,并针对旅行商问题的特点,提出K近邻点集以缩减搜索空间从而加快求解... 旅行商问题(TravellingSalesmanProblemTSP)是一个典型的组合优化难题,论文提出一种求解旅行商问题的高效混合遗传算法。该算法结合遗传算法和2-opt邻域搜索优化技术,并针对旅行商问题的特点,提出K近邻点集以缩减搜索空间从而加快求解速度。基于典型实例的仿真结果表明,此算法的求解效率比较高。 展开更多
关键词 TSP 混合遗传算法 2-opt邻域搜索优化 K近邻点集
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