K-nearest neighbours

k - 最近的邻居
  • 文章类型: Journal Article
    呼吸是人体最基本的功能之一,呼吸异常可能表明潜在的心肺问题。监测呼吸异常可以帮助早期发现并降低心肺疾病的风险。在这项研究中,使用77GHz调频连续波(FMCW)毫米波(mmWave)雷达以非接触方式检测来自人体的不同类型的呼吸信号,以进行呼吸监测(RM)。为解决日常环境中噪声干扰对不同呼吸模式的识别问题,该系统利用毫米波雷达捕获的呼吸信号。首先,我们使用信号叠加方法滤除了大部分静态噪声,并设计了一个椭圆滤波器,以获得0.1Hz至0.5Hz之间更准确的呼吸波形图像。其次,结合方向梯度直方图(HOG)特征提取算法,K-最近邻(KNN),卷积神经网络(CNN)和HOG支持向量机(G-SVM)对四种呼吸模式进行分类,即,正常呼吸,缓慢而深呼吸,快速呼吸,和脑膜炎呼吸。整体精度达到94.75%。因此,这项研究有效地支持日常医疗监测。
    Breathing is one of the body\'s most basic functions and abnormal breathing can indicate underlying cardiopulmonary problems. Monitoring respiratory abnormalities can help with early detection and reduce the risk of cardiopulmonary diseases. In this study, a 77 GHz frequency-modulated continuous wave (FMCW) millimetre-wave (mmWave) radar was used to detect different types of respiratory signals from the human body in a non-contact manner for respiratory monitoring (RM). To solve the problem of noise interference in the daily environment on the recognition of different breathing patterns, the system utilised breathing signals captured by the millimetre-wave radar. Firstly, we filtered out most of the static noise using a signal superposition method and designed an elliptical filter to obtain a more accurate image of the breathing waveforms between 0.1 Hz and 0.5 Hz. Secondly, combined with the histogram of oriented gradient (HOG) feature extraction algorithm, K-nearest neighbours (KNN), convolutional neural network (CNN), and HOG support vector machine (G-SVM) were used to classify four breathing modes, namely, normal breathing, slow and deep breathing, quick breathing, and meningitic breathing. The overall accuracy reached up to 94.75%. Therefore, this study effectively supports daily medical monitoring.
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  • 文章类型: Journal Article
    ASD(自闭症谱系障碍)是一种复杂的发育和神经障碍,通过干扰受影响者的互动和沟通能力来影响他们的社交生活。因为它是一种行为障碍,早期治疗可提高ASD患者的生活质量。传统的筛查是通过训练有素的医生进行行为评估,这是昂贵和耗时的。要解决问题,几种常规方法努力实现有效的ASD识别系统,但由于处理大型数据集而受到限制,准确度,和速度。因此,所提出的识别系统采用了基于人工神经网络(ANN)的MBA(改进的蝙蝠)算法,改进的人工神经网络(改进的人工神经网络),DT(决策树),和KNN(k-最近的邻居)用于对儿童和青少年的ASD进行分类。BA(蝙蝠算法)用于自动缩放能力,通过在识别系统中出色地找到解决方案,提高了系统的效率。相反,BA在鉴定中有效,它仍然有一些缺点,如速度,准确度,并陷入局部极值。因此,所提出的识别系统通过趋势和最佳方向的随机扰动来修改BA优化。在相应模型中使用的数据集是Q-chat-10数据集。该数据集包含四个年龄段的数据,例如幼儿,孩子们,青少年,和成年人。为了分析数据集的质量,数据集评估机制,如卡方统计和p值,在各自的研究中使用。评估表示数据集相对于所提出的模型的关系。Further,所提出的检测系统的性能检查与某些性能指标,以计算其效率。结果表明,与其他最先进的方法相比,改进的ANN分类器模型的准确性为1.00,确保了性能的提高。因此,该模型旨在帮助医师和研究人员加强ASD的诊断,从而改善ASD患者的生活水平.
    ASD (autism spectrum disorder) is a complex developmental and neurological disorder that impacts the social life of the affected person by disturbing their capability for interaction and communication. As it is a behavioural disorder, early treatment will improve the quality of life of ASD patients. Traditional screening is carried out with behavioural assessment through trained physicians, which is expensive and time-consuming. To resolve the issue, several conventional methods strive to achieve an effective ASD identification system, but are limited by handling large data sets, accuracy, and speed. Therefore, the proposed identification system employed the MBA (modified bat) algorithm based on ANN (artificial neural networks), modified ANN (modified artificial neural networks), DT (decision tree), and KNN (k-nearest neighbours) for the classification of ASD in children and adolescents. A BA (bat algorithm) is utilised for the automatic zooming capability, which improves the system\'s efficacy by excellently finding the solutions in the identification system. Conversely, BA is effective in the identification, it still has certain drawbacks like speed, accuracy, and falls into local extremum. Therefore, the proposed identification system modifies the BA optimisation with random perturbation of trends and optimal orientation. The dataset utilised in the respective model is the Q-chat-10 dataset. This dataset contains data of four stages of age groups such as toddlers, children, adolescents, and adults. To analyse the quality of the dataset, dataset evaluation mechanism, such as the Chi-Squared Statistic and p-value, are used in the respective research. The evaluation signifies the relation of the dataset with respect to the proposed model. Further, the performance of the proposed detection system is examined with certain performance metrics to calculate its efficiency. The outcome revealed that the modified ANN classifier model attained an accuracy of 1.00, ensuring improved performance when compared with other state-of-the-art methods. Thus, the proposed model was intended to assist physicians and researchers in enhancing the diagnosis of ASD to improve the standard of life of ASD patients.
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  • 文章类型: Journal Article
    在医院进行的活动会产生几种类型的风险。因此,进行风险评估是医疗保健行业质量改进的关键之一。出于这个原因,医疗保健管理者需要设计和执行有效的风险评估流程。失效模式和影响分析(FMEA)是最常用的风险评估方法之一。FMEA是一种主动技术,包括使用三个因素评估与研究过程相关的故障模式:发生,不检测,和严重性,为了使用模糊逻辑方法和机器学习算法获得风险优先级数,即支持向量机和k近邻。所提出的模型适用于三级国家牙科治疗参考中心的中央灭菌单元,与经典方法相比,对其效率进行了评估。这些比较基于专家建议和机器学习性能指标。我们开发的模型在专家投票结果中证明了很高的有效性(她同意96%的模糊FMEA结果,而经典的FMEA结果为6%)。此外,机器学习指标在训练数据(最佳率为96%)和测试数据(90%)中都显示出很高的准确性。这项研究是第一项旨在在摩洛哥医疗保健部门执行人工智能方法进行风险管理的研究。本研究旨在促进人工智能在摩洛哥健康管理中的应用,特别是在质量和安全管理领域。
    Activities practiced in the hospital generate several types of risks. Therefore, performing the risk assessment is one of the quality improvement keys in the healthcare sector. For this reason, healthcare managers need to design and perform efficient risk assessment processes. Failure modes and effects analysis (FMEA) is one of the most used risk assessment methods. The FMEA is a proactive technique consisting of the evaluation of failure modes associated with a studied process using three factors: occurrence, non-detection, and severity, in order to obtain the risk priority number using fuzzy logic approach and machine learning algorithms, namely the support vector machine and the k-nearest neighbours. The proposed model is applied in the case of the central sterilization unit of a tertiary national reference centre of dental treatment, where its efficiency is evaluated compared to the classical approach. These comparisons are based on expert advice and machine learning performance metrics. Our developed model proved high effectiveness throughout the results of the expert\'s vote (she agrees with 96% fuzzy-FMEA results against 6% with classical FMEA results). Furthermore, the machine learning metrics show a high level of accuracy in both training data (best rate is 96%) and testing data (90%). This study represents the first study that aims to perform artificial intelligence approach to risk management in the Moroccan healthcare sector. The perspective of this study is to promote the application of the artificial intelligence in Moroccan health management, especially in the field of quality and safety management.
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  • 文章类型: Journal Article
    一项重要但具有挑战性的任务是在没有人工干预的情况下自动诊断注意力缺陷/多动障碍(ADHD)。本研究强调利用结构MRI和个人特征(PC)数据来开发用于ADHD分类的自动诊断系统。这里,一个年龄平衡的数据集316ADHD和316个典型发育儿童(TDC)从公开可用的数据集制备.我们使用Destrieux图谱从由自动解剖标记(AAL3)图谱和基于皮质厚度(CT)特征定义的大脑区域的灰质(GM)体积中提取体积特征。使用最小冗余和最大相关性(mRMR)和集成特征选择(EFS)方法独立选择一组显着的特征。使用五个众所周知的分类器训练决策模型:K-近邻,逻辑回归,线性支持向量机(SVM)径向基支持向量机(RBSVM),和随机森林。使用准确性评估了拟议系统的性能,召回,和特异性,十次运行十次交叉验证方案。我们通过考虑特征的不同组合来运行七个实验。用CT和PC特征用RBSVM和SVM用EFS获得75%的最大分类准确率。观察到15个大脑区域的GM体积增加,而27个大脑区域的皮质厚度减少。
    An essential yet challenging task is an automatic diagnosis of attention-deficit/hyperactivity disorder (ADHD) without manual intervention. The present study emphasises utilizing structural MRI and personal characteristic (PC) data for developing an automated diagnostic system for ADHD classification. Here, an age-balanced dataset of 316 ADHD and 316 Typically Developing Children (TDC) was prepared from the publicly available dataset. We extracted volumetric features from gray matter (GM) volumes from brain regions defined by Automated Anatomical Labelling (AAL3) atlas and cortical thickness-based (CT) features using the Destrieux atlas. A set of salient features were selected independently using minimum redundancy and maximum relevance (mRMR) and ensemble feature selection (EFS) methods. Decision models were trained using five well-known classifiers: K-nearest neighbours, logistic regression, linear Support Vector Machine (SVM), radial-based SVM (RBSVM), and Random Forest. The performance of the proposed system was evaluated using accuracy, recall, and specificity with ten runs of a ten-fold cross-validation scheme. We run seven experiments by considering different combinations of features. The maximum classification accuracy of 75% was obtained with CT and PC features with RBSVM and SVM with the EFS. An increase in GM volume in fifteen brain regions and loss of cortical thickness in twenty-seven brain regions were observed.
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  • 文章类型: Journal Article
    精油在各个行业都很有价值,但它们容易掺假会对健康造成不良影响。电子鼻传感器为掺假检测提供了解决方案。本文提出了一种基于低成本传感器网络和机器学习技术的表征精油的新系统。所使用的传感器属于MQ家族(MQ-2、MQ-3、MQ-4、MQ-5、MQ-6、MQ-7和MQ-8)。使用了六种精油,包括CistusLadanifer,Pinuspinaster,和掺有松果的天麻油,互花千层,茶树,红色水果总共包括7100次测量,超过118小时的33个不同的参数的测量。这些数据用于训练和比较五种机器学习算法:判别分析,支持向量机,k-最近的邻居,神经网络,当单独使用数据或包括小时平均值时,以及天真的贝叶斯。为了评估包含的机器学习算法的性能,准确度,精度,召回,并考虑了F1评分。研究发现,使用k最近的邻居,准确度,召回,F1分数,和精度值分别为1、0.99、0.99和1。对于平均数据仅使用2个参数或单个数据使用15个参数的k个最近邻居,准确度达到100%。
    Essential oils are valuable in various industries, but their easy adulteration can cause adverse health effects. Electronic nasal sensors offer a solution for adulteration detection. This article proposes a new system for characterising essential oils based on low-cost sensor networks and machine learning techniques. The sensors used belong to the MQ family (MQ-2, MQ-3, MQ-4, MQ-5, MQ-6, MQ-7, and MQ-8). Six essential oils were used, including Cistus ladanifer, Pinus pinaster, and Cistus ladanifer oil adulterated with Pinus pinaster, Melaleuca alternifolia, tea tree, and red fruits. A total of up to 7100 measurements were included, with more than 118 h of measurements of 33 different parameters. These data were used to train and compare five machine learning algorithms: discriminant analysis, support vector machine, k-nearest neighbours, neural network, and naive Bayesian when the data were used individually or when hourly mean values were included. To evaluate the performance of the included machine learning algorithms, accuracy, precision, recall, and F1-score were considered. The study found that using k-nearest neighbours, accuracy, recall, F1-score, and precision values were 1, 0.99, 0.99, and 1, respectively. The accuracy reached 100% with k-nearest neighbours using only 2 parameters for averaged data or 15 parameters for individual data.
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  • 文章类型: Journal Article
    本文提出了一种高效快速的方法,通过微波成像系统为应用于脑卒中分类的机器学习算法创建大型数据集。所提出的方法基于失真玻恩近似和散射算子的线性化,以最大限度地减少生成训练机器学习算法所需的大型数据集的时间。然后将该方法应用于微波成像系统,它由24个与头部上部共形的天线组成,用三维拟人化多组织模型实现。每个天线充当发射器和接收器,工作频率为1GHz。数据详细阐述了三种机器学习算法:支持向量机,多层感知器,和k最近的邻居,比较他们的表现。所有分类器都可以识别中风的存在或不存在,中风的种类(出血性或缺血性),以及它在大脑中的位置。使用通过整个系统的全波模拟生成的数据集对训练后的算法进行了测试,还考虑稍微修改的天线和限制数据采集的幅度只有。所获得的结果对于可能的实时脑中风分类是有希望的。
    This paper proposes an efficient and fast method to create large datasets for machine learning algorithms applied to brain stroke classification via microwave imaging systems. The proposed method is based on the distorted Born approximation and linearization of the scattering operator, in order to minimize the time to generate the large datasets needed to train the machine learning algorithms. The method is then applied to a microwave imaging system, which consists of twenty-four antennas conformal to the upper part of the head, realized with a 3D anthropomorphic multi-tissue model. Each antenna acts as a transmitter and receiver, and the working frequency is 1 GHz. The data are elaborated with three machine learning algorithms: support vector machine, multilayer perceptron, and k-nearest neighbours, comparing their performance. All classifiers can identify the presence or absence of the stroke, the kind of stroke (haemorrhagic or ischemic), and its position within the brain. The trained algorithms were tested with datasets generated via full-wave simulations of the overall system, considering also slightly modified antennas and limiting the data acquisition to amplitude only. The obtained results are promising for a possible real-time brain stroke classification.
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  • 文章类型: Journal Article
    脑电图是用于提取有关脑部状况的信息的最常用方法之一,可用于诊断癫痫。脑电图信号的波形包含有关大脑状态的重要信息,这对人类观察者的分析和解释来说可能是具有挑战性的。此外,癫痫的特征波形(尖锐的波,尖峰)可以随时间随机发生。考虑到上述所有原因,使用计算机自动提取和分析脑电信号可以显着影响癫痫的成功诊断。本研究使用四种机器学习分类器探讨了不同窗口大小对脑电信号分类精度的影响。机器学习方法包括具有使用三种不同训练算法和k最近邻分类器训练的十个隐藏节点的神经网络。神经网络训练方法包括Broyden-Fletcher-Goldfarb-Shanno算法,全局优化问题的多起点方法,和遗传算法。当前的研究利用了波恩大学包含EEG数据的数据集,划分为具有50%重叠的时期和范围从1到24s的窗口长度。然后,统计和光谱特征被提取并用于训练上述四个分类器。上述实验的结果表明,长度约为21s的大窗口大小可能会对比较方法之间的分类准确性产生积极影响。
    Electroencephalography is one of the most commonly used methods for extracting information about the brain\'s condition and can be used for diagnosing epilepsy. The EEG signal\'s wave shape contains vital information about the brain\'s state, which can be challenging to analyse and interpret by a human observer. Moreover, the characteristic waveforms of epilepsy (sharp waves, spikes) can occur randomly through time. Considering all the above reasons, automatic EEG signal extraction and analysis using computers can significantly impact the successful diagnosis of epilepsy. This research explores the impact of different window sizes on EEG signals\' classification accuracy using four machine learning classifiers. The machine learning methods included a neural network with ten hidden nodes trained using three different training algorithms and the k-nearest neighbours classifier. The neural network training methods included the Broyden-Fletcher-Goldfarb-Shanno algorithm, the multistart method for global optimization problems, and a genetic algorithm. The current research utilized the University of Bonn dataset containing EEG data, divided into epochs having 50% overlap and window lengths ranging from 1 to 24 s. Then, statistical and spectral features were extracted and used to train the above four classifiers. The outcome from the above experiments showed that large window sizes with a length of about 21 s could positively impact the classification accuracy between the compared methods.
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  • 文章类型: Journal Article
    季节性变化(SV)影响人口密度(PD),命运,以及环境水资源中病原体的适应性和公共卫生影响。因此,这项研究旨在应用机器学习智能(MLI)来预测在水生环境中SVs对志贺氏菌种群密度(PDP)的影响。通过标准微生物和仪器技术跨季节获得的三条河流的物理化学事件(PE)和PDP适用于MLI算法(线性回归(LR),多元线性回归(MR),随机森林(RF),梯度增压机(GBM),神经网络(NN),K-最近邻(KNN),增强回归树(BRT),极端梯度增强(XGB)回归,支持向量回归(SVR),决策树回归(DTR),M5修剪回归(M5P),人工神经网络(ANN)回归(具有一个10节点隐藏层(ANN10),两个6节点和4节点隐藏层(ANN64),和两个5节点和5节点隐藏层(ANN55),和弹性净回归(ENR))来评估PE的SV对水生PDP的影响。结果表明,SVs显著影响水中的PDP和PE(p<0.0001),展示特定地点的模式。虽然MLI算法预测PDP的贡献变量具有不同的绝对通量大小,DTR预测最高PDP值为1.707对数单位,其次是XGB(1.637对数单位),但是XGB(均方误差(MSE)=0.0025;均方根误差(RMSE)=0.0501;R2=0.998;中等绝对偏差(MAD)=0.0275)在回归指标方面优于其他模型。温度和总悬浮固体(TSS)在预测PDP的53.3%(8/15)和40%(6/15)中排名第一和第二,是重要因素。分别,的模型,基于排列后的RMSE损失。此外,赛季在7个模特中排名第三,浊度(TBS)排名第四,为26.7%(4/15),作为预测水生环境中PDP的主要重要因素。这项调查的结果表明,MLI预测建模技术可以有望用于补充对PDP和其他病原体的重复实验室监测。尤其是在低资源环境中,响应季节性通量,并可以提供对新出现的病原体和TSS污染的潜在公共卫生风险的见解(例如,纳米颗粒和微米和纳米塑料)在水生环境中。该模型输出提供低成本和有效的预警信息,以协助流域管理者和养鱼户就水资源保护做出适当的决策,水产养殖管理,和可持续的公共卫生保护。
    Seasonal variations (SVs) affect the population density (PD), fate, and fitness of pathogens in environmental water resources and the public health impacts. Therefore, this study is aimed at applying machine learning intelligence (MLI) to predict the impacts of SVs on P. shigelloides population density (PDP) in the aquatic milieu. Physicochemical events (PEs) and PDP from three rivers acquired via standard microbiological and instrumental techniques across seasons were fitted to MLI algorithms (linear regression (LR), multiple linear regression (MR), random forest (RF), gradient boosted machine (GBM), neural network (NN), K-nearest neighbour (KNN), boosted regression tree (BRT), extreme gradient boosting (XGB) regression, support vector regression (SVR), decision tree regression (DTR), M5 pruned regression (M5P), artificial neural network (ANN) regression (with one 10-node hidden layer (ANN10), two 6- and 4-node hidden layers (ANN64), and two 5- and 5-node hidden layers (ANN55)), and elastic net regression (ENR)) to assess the implications of the SVs of PEs on aquatic PDP. The results showed that SVs significantly influenced PDP and PEs in the water (p < 0.0001), exhibiting a site-specific pattern. While MLI algorithms predicted PDP with differing absolute flux magnitudes for the contributing variables, DTR predicted the highest PDP value of 1.707 log unit, followed by XGB (1.637 log unit), but XGB (mean-squared-error (MSE) = 0.0025; root-mean-squared-error (RMSE) = 0.0501; R2 =0.998; medium absolute deviation (MAD) = 0.0275) outperformed other models in terms of regression metrics. Temperature and total suspended solids (TSS) ranked first and second as significant factors in predicting PDP in 53.3% (8/15) and 40% (6/15), respectively, of the models, based on the RMSE loss after permutations. Additionally, season ranked third among the 7 models, and turbidity (TBS) ranked fourth at 26.7% (4/15), as the primary significant factor for predicting PDP in the aquatic milieu. The results of this investigation demonstrated that MLI predictive modelling techniques can promisingly be exploited to complement the repetitive laboratory-based monitoring of PDP and other pathogens, especially in low-resource settings, in response to seasonal fluxes and can provide insights into the potential public health risks of emerging pathogens and TSS pollution (e.g., nanoparticles and micro- and nanoplastics) in the aquatic milieu. The model outputs provide low-cost and effective early warning information to assist watershed managers and fish farmers in making appropriate decisions about water resource protection, aquaculture management, and sustainable public health protection.
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  • 文章类型: Journal Article
    预测城市固体废物(MSW)的产生和组成在有效的废物管理中起着至关重要的作用。政策决策和城市生活垃圾处理过程。智能预测系统可用于短期和长期废物处理,确保循环经济和资源的可持续利用。这项研究通过提出一种混合k-近邻(H-kNN)方法来预测城市固体废物及其在经历数据不完整和无法访问的地区的组成,从而为该领域做出了贡献。立陶宛和其他许多国家也是如此。为此,邻近城市的平均MSW产生,作为地理因素,用于估算缺失值,和社会经济因素以及影响城市废物收集的人口指标被确定和量化使用相关性分析。其中,影响最大的因素,比如人口密度,人均GDP,私有财产,人均外国投资,和旅游业,然后将其纳入H-kNN方法的层次结构设置中。结果表明,在预测MSW产生时,H-kNN实现了11.05%的MAPE,平均而言,包括立陶宛所有城市,这比使用kNN获得的低7.17个百分点。这意味着通过在市政一级找到相关因素,我们可以弥补数据的不完整性,提高城市生活垃圾产生和组成的预测结果。
    Forecasting municipal solid waste (MSW) generation and composition plays an essential role in effective waste management, policy decision-making and the MSW treatment process. An intelligent forecasting system could be used for short-term and long-term waste handling, ensuring a circular economy and a sustainable use of resources. This study contributes to the field by proposing a hybrid k-nearest neighbours (H-kNN) approach to forecasting municipal solid waste and its composition in the regions that experience data incompleteness and inaccessibility, as is the case for Lithuania and many other countries. For this purpose, the average MSW generation of neighbouring municipalities, as a geographical factor, was used to impute missing values, and socioeconomic factors together with demographic indicator affecting waste collected in municipalities were identified and quantified using correlation analysis. Among them, the most influential factors, such as population density, GDP per capita, private property, foreign investment per capita, and tourism, were then incorporated in the hierarchical setting of the H-kNN approach. The results showed that, in forecasting MSW generation, H-kNN achieved MAPE of 11.05%, on average, including all Lithuanian municipalities, which is by 7.17 percentage points lower than obtained using kNN. This implies that by finding relevant factors at the municipal level, we can compensate for the data incompleteness and enhance the forecasting results of MSW generation and composition.
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  • 文章类型: Journal Article
    This paper presents a learning system with a K-nearest neighbour classifier to classify the wear condition of a multi-piston positive displacement pump. The first part reviews current built diagnostic methods and describes typical failures of multi-piston positive displacement pumps and their causes. Next is a description of a diagnostic experiment conducted to acquire a matrix of vibration signals from selected locations in the pump body. The measured signals were subjected to time-frequency analysis. The signal features calculated in the time and frequency domain were grouped in a table according to the wear condition of the pump. The next step was to create classification models of a pump wear condition and assess their accuracy. The selected model, which best met the set criteria for accuracy assessment, was verified with new measurement data. The article ends with a summary.
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