Artificial neural networks

人工神经网络
  • 文章类型: Journal Article
    野火在全球范围内构成重大威胁,需要准确的预测来缓解。这项研究使用机器学习技术来预测上Colorado河流域的野火严重程度。使用了1984年至2019年的数据集以及天气条件和土地利用等关键指标。随机森林优于人工神经网络,达到72%的准确率。有影响的预测因素包括气温,蒸气压力不足,NDVI,和燃料水分。太阳辐射,SPEI,降水,蒸散量也有很大贡献。对2016年至2019年实际严重程度的验证显示,平均预测误差为11.2%,确认模型的可靠性。这些结果突出了机器学习在理解野火严重性方面的功效。特别是在脆弱地区。
    Wildfires pose significant threats worldwide, requiring accurate prediction for mitigation. This study uses machine learning techniques to forecast wildfire severity in the Upper Colorado River basin. Datasets from 1984 to 2019 and key indicators like weather conditions and land use were employed. Random Forest outperformed Artificial Neural Network, achieving 72 % accuracy. Influential predictors include air temperature, vapor pressure deficit, NDVI, and fuel moisture. Solar radiation, SPEI, precipitation, and evapotranspiration also contribute significantly. Validation against actual severities from 2016 to 2019 showed mean prediction errors of 11.2 %, affirming the model\'s reliability. These results highlight the efficacy of machine learning in understanding wildfire severity, especially in vulnerable regions.
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  • 文章类型: Journal Article
    人工神经网络(ANN)是能够在没有先验知识的情况下进行学习的多功能工具。这项研究旨在评估ANN是否可以使用来自代谢性酸中毒动物模型的数据进行训练后计算自主呼吸期间的分钟体积。数据是从十例麻醉中收集的,自主呼吸猪随机分为两组,在实验开始时,一个没有死空间,另一个有死空间。通过连续输注乳酸,每组都经历了两个相等的pH降低序列,并具有预定的目标。人工神经网络的输入是pH,ΔPaCO2(CO2的动脉分压的变化),从动物模型取样的PaO2和血液温度。输出为Δ分钟体积(ΔVM),(与动物在实验开始时具有的分钟体积相比,分钟体积的变化)。使用均方误差(MSE)分析了神经网络性能,线性回归,和Bland-Altman(B-A)方法。动物实验提供了必要的数据来训练ANN。ANN的最佳结构有17个中间神经元;最终训练的ANN的最佳性能具有线性回归,R2为0.99,MSE为0.001[L/min]。B-A分析,偏差±标准偏差为0.006±0.039[L/min]。ANN可以使用到达呼吸中心的相同信息来准确地估计ΔVM。这种性能使它们成为闭环人工呼吸机未来发展的有希望的组成部分。
    Artificial neural networks (ANNs) are versatile tools capable of learning without prior knowledge. This study aims to evaluate whether ANN can calculate minute volume during spontaneous breathing after being trained using data from an animal model of metabolic acidosis. Data was collected from ten anesthetized, spontaneously breathing pigs divided randomly into two groups, one without dead space and the other with dead space at the beginning of the experiment. Each group underwent two equal sequences of pH lowering with pre-defined targets by continuous infusion of lactic acid. The inputs to ANNs were pH, ΔPaCO2 (variation of the arterial partial pressure of CO2), PaO2, and blood temperature which were sampled from the animal model. The output was the delta minute volume (ΔVM), (the change of minute volume as compared to the minute volume the animal had at the beginning of the experiment). The ANN performance was analyzed using mean squared error (MSE), linear regression, and the Bland-Altman (B-A) method. The animal experiment provided the necessary data to train the ANN. The best architecture of ANN had 17 intermediate neurons; the best performance of the finally trained ANN had a linear regression with R2 of 0.99, an MSE of 0.001 [L/min], a B-A analysis with bias ± standard deviation of 0.006 ± 0.039 [L/min]. ANNs can accurately estimate ΔVM using the same information that arrives at the respiratory centers. This performance makes them a promising component for the future development of closed-loop artificial ventilators.
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  • 文章类型: Journal Article
    背景:肥胖的全球患病率不断上升,需要探索新的诊断方法。最近的科学调查表明,与肥胖相关的语音特征可能发生变化,提示使用语音作为肥胖检测的非侵入性生物标志物的可行性。
    目的:本研究旨在通过对短录音的分析,使用深度神经网络来预测肥胖状态,研究声乐特征与肥胖的关系。
    方法:对696名参与者进行了一项初步研究,使用自我报告的BMI将个体分为肥胖和非肥胖组。参与者阅读简短脚本的录音被转换为频谱图,并使用改编的YOLOv8模型(Ultralytics)进行分析。使用准确性对模型性能进行了评估,召回,精度,和F1分数。
    结果:适应的YOLOv8模型显示出0.70的全局准确性和0.65的宏F1评分。在识别非肥胖(F1评分为0.77)方面比肥胖(F1评分为0.53)更有效。这种中等水平的准确性凸显了使用声乐生物标志物进行肥胖检测的潜力和挑战。
    结论:虽然该研究在基于语音的肥胖医学诊断领域显示出希望,它面临着一些限制,比如依赖自我报告的BMI数据,均匀的样本量。这些因素,再加上录音质量的可变性,需要使用更强大的方法和不同的样本进行进一步的研究,以增强这种新颖方法的有效性。这些发现为将来使用语音作为肥胖检测的非侵入性生物标志物的研究奠定了基础。
    BACKGROUND: The escalating global prevalence of obesity has necessitated the exploration of novel diagnostic approaches. Recent scientific inquiries have indicated potential alterations in voice characteristics associated with obesity, suggesting the feasibility of using voice as a noninvasive biomarker for obesity detection.
    OBJECTIVE: This study aims to use deep neural networks to predict obesity status through the analysis of short audio recordings, investigating the relationship between vocal characteristics and obesity.
    METHODS: A pilot study was conducted with 696 participants, using self-reported BMI to classify individuals into obesity and nonobesity groups. Audio recordings of participants reading a short script were transformed into spectrograms and analyzed using an adapted YOLOv8 model (Ultralytics). The model performance was evaluated using accuracy, recall, precision, and F1-scores.
    RESULTS: The adapted YOLOv8 model demonstrated a global accuracy of 0.70 and a macro F1-score of 0.65. It was more effective in identifying nonobesity (F1-score of 0.77) than obesity (F1-score of 0.53). This moderate level of accuracy highlights the potential and challenges in using vocal biomarkers for obesity detection.
    CONCLUSIONS: While the study shows promise in the field of voice-based medical diagnostics for obesity, it faces limitations such as reliance on self-reported BMI data and a small, homogenous sample size. These factors, coupled with variability in recording quality, necessitate further research with more robust methodologies and diverse samples to enhance the validity of this novel approach. The findings lay a foundational step for future investigations in using voice as a noninvasive biomarker for obesity detection.
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  • 文章类型: Journal Article
    急性腹痛(AAP)是急诊科(ED)的常见症状,客观准确的分诊至关重要。本研究旨在开发一种基于机器学习的AAP分诊预测模型。目标是确定危重病人的分诊指标,并确保及时提供诊断和治疗资源。
    在这项研究中,我们对2019年武汉普仁医院ED收治的急性腹痛患者的病历资料进行回顾性分析.为了识别高风险因素,采用31个预测变量进行单变量和多变量逻辑回归分析.使用测试和验证队列对八个机器学习分诊预测模型进行评估,以优化AAP分诊预测模型。
    确定了11项具有统计学意义(p<0.05)的临床指标,发现它们与急性腹痛的严重程度有关。在从训练和测试队列构建的八个机器学习模型中,基于人工神经网络(ANN)的模型表现出最佳性能,达到0.9792的精度和0.9972的曲线下面积(AUC)。进一步的优化结果表明,通过仅纳入七个变量,ANN模型的AUC值可以达到0.9832:糖尿病史,中风史,脉搏,血压,苍白的外观,肠鸣音,和疼痛的位置。
    ANN模型在预测AAP的分诊方面最有效。此外,当只考虑七个变量时,包括糖尿病史,等。,该模型仍然显示出良好的预测性能。这有助于AAP患者的快速临床分诊和医疗资源的分配。
    UNASSIGNED: Acute abdominal pain (AAP) is a common symptom presented in the emergency department (ED), and it is crucial to have objective and accurate triage. This study aims to develop a machine learning-based prediction model for AAP triage. The goal is to identify triage indicators for critically ill patients and ensure the prompt availability of diagnostic and treatment resources.
    UNASSIGNED: In this study, we conducted a retrospective analysis of the medical records of patients admitted to the ED of Wuhan Puren Hospital with acute abdominal pain in 2019. To identify high-risk factors, univariate and multivariate logistic regression analyses were used with thirty-one predictor variables. Evaluation of eight machine learning triage prediction models was conducted using both test and validation cohorts to optimize the AAP triage prediction model.
    UNASSIGNED: Eleven clinical indicators with statistical significance (p < 0.05) were identified, and they were found to be associated with the severity of acute abdominal pain. Among the eight machine learning models constructed from the training and test cohorts, the model based on the artificial neural network (ANN) demonstrated the best performance, achieving an accuracy of 0.9792 and an area under the curve (AUC) of 0.9972. Further optimization results indicate that the AUC value of the ANN model could reach 0.9832 by incorporating only seven variables: history of diabetes, history of stroke, pulse, blood pressure, pale appearance, bowel sounds, and location of the pain.
    UNASSIGNED: The ANN model is the most effective in predicting the triage of AAP. Furthermore, when only seven variables are considered, including history of diabetes, etc., the model still shows good predictive performance. This is helpful for the rapid clinical triage of AAP patients and the allocation of medical resources.
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  • 文章类型: Journal Article
    人工神经网络为评估和理解重金属的存在和浓度提供了可行的途径,这些重金属可能在生态系统可持续性的水质预测的更广泛背景下引起危险的并发症。为了估算伊兹尼克湖的重金属浓度,是周边社区的重要水源,表征数据来自2015年至2021年流入湖泊的五种不同水源。使用IBMSPSSStatistics23软件评估这些表征结果,随着湖泊水质系统的加入。为此,在卡拉苏测量和监测了七个不同的物理化学参数,克兰德尔,Olukdere和Sölöz水源流入湖中,作为输入数据。源自湖泊的Karsak流中15种不同重金属的浓度水平作为输出。具体来说,Sn代表Karasu(0.999),Sb代表Kºrandere(1.000),Olukdere的Cr(1.000)和Sölöz的Pb和Se(0.995)表明参数估计R2系数接近1.000。Sn是具有最佳估算前景的常见重金属参数。鉴于自变量在估计重金属污染中的重要性,电导率,COD,CODCOD和温度是Karasu最有效的参数,Olukdere,克兰德尔和索洛兹,分别。ANN模型是一种很好的预测工具,可以有效地用于确定湖泊中的重金属污染,作为保护伊兹尼克湖的水收支和消除现有污染的努力的一部分。
    Artificial neural networks offer a viable route in assessing and understanding the presence and concentration of heavy metals that can cause dangerous complications in the wider context of water quality prediction for the sustainability of the ecosystem. In order to estimate the heavy metal concentrations in Iznik Lake, which is an important water source for the surrounding communities, characterization data were taken from five different water sources flowing into the lake between 2015 and 2021. These characterization results were evaluated with IBM SPSS Statistics 23 software, with the addition of the lake water quality system. For this purpose, seven distinct physicochemical parameters were measured and monitored in Karasu, Kırandere, Olukdere and Sölöz water sources flowing into the lake, to serve as input data. Concentration levels of 15 distinct heavy metals in Karsak Stream originating from the lake were as the output. Specifically, Sn for Karasu (0.999), Sb for Kırandere (1.000), Cr for Olukdere (1.000) and Pb and Se for Sölöz (0.995) indicate parameter estimation R2 coefficients close to 1.000. Sn stands out as the common heavy metal parameter with best estimation prospects. Given the importance of the independent variable in estimating heavy metal pollution, conductivity, COD, COD and temperature stood out as the most effective parameters for Karasu, Olukdere, Kırandere and Sölöz, respectively. The ANN model emerges as a good prediction tool that can be used effectively in determining the heavy metal pollution in the lake as part of the efforts to protect the water budget of Lake Iznik and to eliminate the existing pollution.
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  • 文章类型: Journal Article
    与常规有机溶剂相比,天然深共熔溶剂(NaDES)对于中药的成分提取是环保且高效的。在这项研究中,筛选并采用NaDES提取丹参葛根(DG),并通过响应面法(RSM)和人工神经网络(ANN)模型对提取过程进行了优化。此外,在PC12细胞中评价DG提取物的体外安全性。因此,筛选甜菜碱-尿素(Bet-Ur)作为提取溶剂,在优化提取参数方面,ANN模型比RSM模型更准确。通过ANN优化的提取工艺如下:70%的NaDES浓度,80mg/mL固液比,超声温度67°C,和33分钟的超声时间。提取率的综合值为0.7251±0.84%。Bet-Ur的IC50,NaDESDG提取物和水性DG提取物为0.15%,0.3%和10%(v/v)。
    Natural deep eutectic solvents (NaDESs) are environmentally friendly and efficient for the componential extraction of traditional Chinese medicine compared to conventional organic solvents. In this study, NaDES was screened and employed to extract Danshen-Gegen (DG), and the extraction process was optimised by response surface methodology (RSM) and artificial neural networks (ANN) model. Besides, the in vitro security of extracts of DG were evaluated in PC12 cells. As a result, Betaine-Urea (Bet-Ur) was screened as extraction solvent and ANN model was more accurate than RSM model in optimising the extraction parameter. The extraction process optimised by ANN was as follows: 70% NaDES concentration, 80 mg/mL solid to liquid ratio, 67 °C ultrasonic temperature, and 33 min of ultrasonic time. The comprehensive value of extraction yield was 0.7251 ± 0.84%. IC50 of Bet-Ur, NaDES DG extract and aqueous DG extract were 0.15%, 0.3% and 10% (v/v).
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  • 文章类型: Journal Article
    目的:本研究评估了语音分析结合机器学习(ML)技术在帕金森病(PD)诊断中的功效。
    方法:语音数据,元音\“a”的发声,“从三个不同的数据集(两个来自加州大学欧文分校ML存储库,一个来自无花果)对432名参与者(278名PD患者)进行了分析。我们采用了四种机器学习模型-人工神经网络,随机森林,梯度提升(GB),和支持向量机(SVM)-以及两种集成方法(软投票分类器-集成投票分类器和堆叠方法-集成堆叠模型(ESM))。这些模型经历了50次迭代评估,涉及各种数据分割和10倍交叉验证。使用单向方差分析进行比较分析,然后进行Bonferronipostthoc校正。
    结果:ESM,SVM,GB模型成为表现最好的,展示跨指标的卓越性能,包括准确性,灵敏度,特异性,精度,F1得分,和受试者工作特征曲线下面积(ROCAUC)。尽管数据异质性和变量选择限制,模型对所有指标都显示出较高的值.
    结论:ML与语音分析的集成,主要通过ESM,SVM,GB,对早期PD诊断很有希望。使用多源数据和大样本量提高了我们的发现的有效性,可靠性,和普适性。
    结论:将先进的ML技术与语音分析相结合,显示出改善早期PD检测的巨大潜力,为语言病理学家(SLP)提供有价值的工具。这些发现提供了临床相关的见解,可以在SLP实践的范围内应用,以完善诊断过程并促进早期干预。
    OBJECTIVE: This study evaluates the efficacy of voice analysis combined with machine learning (ML) techniques in enabling the diagnosis of Parkinson\'s disease (PD).
    METHODS: Voice data, phonation of the vowel \"a,\" from three distinct datasets (two from the University of California Irvine ML Repository and one from figshare) for 432 participants (278 PD patients) were analyzed. We employed four ML models-Artificial Neural Networks, Random Forest, Gradient Boosting (GB), and Support Vector Machine (SVM)-alongside two ensemble methods (soft voting classifier-Ensemble Voting Classifier and stacking method-Ensemble Stacking Model (ESM)). The models underwent 50 iterations of evaluation, involving various data splits and 10-fold cross-validation. Comparative analysis was done using one-way Analysis of Variance followed by Bonferroni posthoc corrections.
    RESULTS: The ESM, SVM, and GB models emerged as the top performers, demonstrating superior performance across metrics, including accuracy, sensitivity, specificity, precision, F1 score, and area under the receiver operating characteristic curve (ROC AUC). Despite data heterogeneity and variable selection limitations, the models showed high values for all metrics.
    CONCLUSIONS: ML integration with voice analysis, mainly through ESM, SVM, and GB, is promising for early PD diagnosis. Using multi-source data and a large sample size enhances our findings\' validity, reliability, and generalizability.
    CONCLUSIONS: Integrating advanced ML techniques with voice analysis demonstrates substantial potential for improving early PD detection, offering valuable tools for speech-language pathologists (SLPs). These findings provide clinically relevant insights that can be applied within the scope of SLP practice to refine diagnostic processes and facilitate early intervention.
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  • 文章类型: Journal Article
    本文介绍了在与机器学习算法集成的周期性边界条件下,利用多尺度建模方法对介孔二氧化硅进行的全面研究。该研究从分子动力学(MD)模拟开始,以提取纳米尺度的二氧化硅的弹性特性和热导率,利用泰索夫的潜力。随后,将衍生的材料特性应用于一系列生成的多孔代表性体积元素(RVE)。该阶段涉及孔隙度和孔隙形状对二氧化硅热性能和机械性能的影响的探索,考虑沿X轴的不均匀性分布和三维空间内孔细胞的随机分散。此外,通过定义开放和封闭细胞模型来检查孔隙形状的影响,包含球形和椭圆形空隙,纵横比为2和4。为了预测多孔二氧化硅的性质,部署了浅层人工神经网络(ANN),利用RVE和孔隙率的几何参数。随后,揭示了二氧化硅的热和力学行为与孔隙几何形状有关,分布,和孔隙度模型。最后,将多孔二氧化硅的行为分为三类,准各向同性,正交各向异性,横向各向同性,决策树方法的三种方法,K-近邻(KNN)算法,和支持向量机(SVM)被采用。其中,采用二次核函数的SVM在对多孔二氧化硅的热和机械行为进行分类方面表现出强大的性能。
    This paper presents a comprehensive investigation of mesoporous Silica utilizing a multi-scale modeling approach under periodic boundary conditions integrated with machine learning algorithms. The study begins with Molecular Dynamics (MD) simulations to extract Silica\'s elastic properties and thermal conductivity at the nano-scale, employing the Tersoff potential. Subsequently, the derived material characteristics are applied to a series of generated porous Representative Volume Elements (RVEs) at the microscale. This phase involves the exploration of porosity and void shape effects on Silica\'s thermal and mechanical properties, considering inhomogeneities\' distributions along the X-axis and random dispersion of pore cells within a three-dimensional space. Furthermore, the influence of pore shape is examined by defining open and closed-cell models, encompassing spherical and ellipsoidal voids with aspect ratios of 2 and 4. To predict the properties of porous Silica, a shallow Artificial Neural Network (ANN) is deployed, utilizing geometric parameters of the RVEs and porosity. Subsequently, it is revealed that Silica\'s thermal and mechanical behavior is linked to pore geometry, distribution, and porosity model. Finally, to classify the behavior of porous Silica into three categories, quasi-isotropic, orthotropic, and transversely-isotropic, three methodologies of decision tree approach, K-Nearest Neighbors (KNN) algorithm, and Support Vector Machines (SVMs) are employed. Among these, SVMs employing a quadratic kernel function demonstrate robust performance in categorizing the thermal and mechanical behavior of porous Silica.
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  • 文章类型: Journal Article
    侧流测定法已广泛用于检测2019年冠状病毒病(COVID-19)。侧流测定由硝化纤维素(NC)膜组成,必须具有特定的侧向流速才能使蛋白质发生反应。芯吸速率通常用作评估膜中横向流动的方法。我们使用多元回归和人工神经网络(ANN)根据膜配方数据预测NC膜的芯吸速率。开发的ANN以均方误差0.059预测芯吸率,而多元回归的平方误差为0.503。该研究还通过从扫描电子显微镜获得的图像强调了水含量对芯吸速率的显着影响。这项研究的发现可以显着降低具有特定芯吸率的新型NC膜的研发成本,因为该算法可以根据膜配方预测芯吸速率。
    Lateral flow assays have been widely used for detecting coronavirus disease 2019 (COVID-19). A lateral flow assay consists of a Nitrocellulose (NC) membrane, which must have a specific lateral flow rate for the proteins to react. The wicking rate is conventionally used as a method to assess the lateral flow in membranes. We used multiple regression and artificial neural networks (ANN) to predict the wicking rate of NC membranes based on membrane recipe data. The developed ANN predicted the wicking rate with a mean square error of 0.059, whereas the multiple regression had a square error of 0.503. This research also highlighted the significant impact of the water content on the wicking rate through images obtained from scanning electron microscopy. The findings of this research can cut down the research and development costs of novel NC membranes with a specific wicking rate significantly, as the algorithm can predict the wicking rate based on the membrane recipe.
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  • 文章类型: Journal Article
    装配线效率是决定制造企业整体效率的重要参数之一。产品在最佳条件下的生产是由一个平衡的组件保证。有了平衡的装配线,机械,材料和劳动力成本降低。在本研究范围内,获取了一家生产紧急灯具的公司的日常生产能力和装配线效率的真实数据,用4种不同的启发式ALB方法对同一装配线进行平衡,并对结果进行了比较。根据获得的结果,使用霍夫曼实现了93.955%的高生产线效率,Comsoal和Moodie&Young(M&Y)方法,用排名位置权重(RPW)方法获得84.414%。因此,据观察,日生产能力从250台增加到375台。作为研究的结果,据透露,现有装配线的效率和相应的日常生产能力增加。此外,该装配线的研究结果被教授给人工神经网络模型进行训练,并获得了不同装配线的工作站结果,精度为99.940。在这种情况下,已经发现,除了使用启发式方法外,还可以使用人工神经网络方法来解决ALB问题。
    Assembly line efficiency is one of the most important parameters that determine the overall efficiency of a manufacturing company. The production of a product under optimum conditions is ensured by a balanced assembly. With a balanced assembly line, machinery, material and labour costs are reduced. Within the scope of this research, real data about the daily production capacity and assembly line efficiency of a company producing Emergency Luminaire were taken, the same assembly line was balanced with 4 different Heuristic ALB methods and the results were compared. According to the results obtained, a high line efficiency of 93.955% was achieved using the Hoffman, Comsoal and Moodie&Young (M&Y) methods, and 84.414% was achieved with the Ranked Positional Weight (RPW) method. As a result of this, it was observed that the daily production capacity increased from 250 units to 375 units. As a result of the study, it was revealed that the efficiency of the existing assembly line and accordingly the daily production capacity increased. In addition, the study results of this assembly line were taught to an artificial neural network model for training purposes, and the work station results of the operations of a different assembly line were obtained with 99.940 accuracy. In this context, it has been revealed that the artificial neural networks method can be used in addition to the use of the heuristic method in the solution of ALB problems.
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