random forest classifier

随机森林分类器
  • 文章类型: Journal Article
    森林冠层覆盖(FCC)在森林评估和管理中至关重要,影响生态系统服务,如碳封存,野生动物栖息地,和水的调节。准确有效地映射和提取FCC信息的技术的不断进步需要对其有效性和可靠性进行全面评估。本研究的主要目标是:(1)创建具有1米空间分辨率的大规模森林FCC数据集,(2)在区域尺度上评估FCC的区域空间分布,和(3)调查全球森林变化中FCC区域的差异(Hansen等人。,2013)和阿肯色州各种空间尺度的美国森林服务树冠覆盖产品(即,县级和市级)。这项研究利用了高分辨率的航空图像和机器学习算法,使用GoogleEarthEngine云计算平台进行了处理和分析,以生成FCC数据集。使用从全球森林变化中获得的参考位置的三分之一验证了该数据集的准确性(Hansen等人。,2013)数据集和国家农业图像计划(NAIP)航空图像,空间分辨率为0.6米。结果表明,该数据集在研究区域中以1-m的分辨率成功识别了FCC,总体准确率在每个县83.31%至94.35%之间。产生的FCC数据集和Hansen等人之间的空间比较结果。,2013年和USFS产品显示出强正相关,县级和市级的R2值在0.94到0.98之间。该数据集为监测提供了有价值的信息,预测,和管理阿肯色州及其他地区的森林资源。本研究采用的方法提高效率,成本效益,和可扩展性,因为它可以在基于云的环境中处理具有高计算要求的大规模数据集。它还证明了机器学习和云计算技术可以生成高分辨率的森林覆盖数据集,这可能对世界其他地区有所帮助。
    Forest canopy cover (FCC) is essential in forest assessment and management, affecting ecosystem services such as carbon sequestration, wildlife habitat, and water regulation. Ongoing advancements in techniques for accurately and efficiently mapping and extracting FCC information require a thorough evaluation of their validity and reliability. The primary objectives of this study are to: (1) create a large-scale forest FCC dataset with a 1-meter spatial resolution, (2) assess the regional spatial distribution of FCC at a regional scale, and (3) investigate differences in FCC areas among the Global Forest Change (Hansen et al., 2013) and U.S. Forest Service Tree Canopy Cover products at various spatial scales in Arkansas (i.e., county and city levels). This study utilized high-resolution aerial imagery and a machine learning algorithm processed and analyzed using the Google Earth Engine cloud computing platform to produce the FCC dataset. The accuracy of this dataset was validated using one-third of the reference locations obtained from the Global Forest Change (Hansen et al., 2013) dataset and the National Agriculture Imagery Program (NAIP) aerial imagery with a 0.6-m spatial resolution. The results showed that the dataset successfully identified FCC at a 1-m resolution in the study area, with overall accuracy ranging between 83.31% and 94.35% per county. Spatial comparison results between the produced FCC dataset and the Hansen et al., 2013 and USFS products indicated a strong positive correlation, with R2 values ranging between 0.94 and 0.98 for county and city levels. This dataset provides valuable information for monitoring, forecasting, and managing forest resources in Arkansas and beyond. The methodology followed in this study enhances efficiency, cost-effectiveness, and scalability, as it enables the processing of large-scale datasets with high computational demands in a cloud-based environment. It also demonstrates that machine learning and cloud computing technologies can generate high-resolution forest cover datasets, which might be helpful in other regions of the world.
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  • 文章类型: Journal Article
    Production plantation forestry has many economic benefits but can also have negative environmental impacts such as the spreading of invasive pines to native forest habitats. Monitoring forest for the presence of invasive pines helps with the management of this issue. However, detection of vegetation change over a large time period is difficult due to changes in image quality and sensor types, and by the spectral similarity of evergreen species and frequent cloud cover in the study area. The costs of high-resolution images are also prohibitive for routine monitoring in resource-constrained countries. This research investigated the use of remote sensing to identify the spread of Pinus caribaea over a 21-year period (2000 to 2021) in Belihuloya, Sri Lanka, using Landsat images. It applied a range of techniques to produce cloud free images, extract vegetation features, and improve vegetation classification accuracy, followed by the use of Geographical Information System to spatially analyze the spread of invasive pines. The results showed most invading pines were found within 100 m of the pine plantations\' borders where broadleaved forests and grasslands are vulnerable to invasion. However, the extent of invasive pine had an overall decline of 4 ha over the 21 years. The study confirmed that remote sensing combined with spatial analysis are effective tools for monitoring invasive pines in countries with limited resources. This study also provides information to conservationists and forest managers to conduct strategic planning for sustainable forest management and conservation in Sri Lanka.
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  • 文章类型: Journal Article
    未经证实:心房颤动(AF)是最常见的心血管疾病之一,其无症状趋势使房颤检测具有挑战性。机器和深度学习方法通常用于AF检测。
    UNASSIGNED:这项研究的目的是评估卷积神经网络(CNN)和随机森林(RF)机器学习模型提供的信息,以进行AF分类。
    UNASSIGNED:我们手动提取了166个时频域以及线性和非线性特征,将单导联心电图(ECG)分类为正常,AF,other,或嘈杂的窦性心律。我们使用射频模型中使用的遗传算法选择了56个鲁棒特征的子集。在另一项研究中,一维,在原始ECG节律上设计了12层CNN。来自CNN的输出层的四个特征和来自完全连接层的128个特征被独立地探索用于分类。这些模型在8,528个ECG上进行了训练和内部验证,并在包含3,658个ECG的隐藏数据集上进行了外部验证。接下来,我们分析了工程和CNN学习特征之间的相关性.
    UNASSIGNED:使用56个工程特征训练的RF分类器对于正常,F1得分为0.91、0.78和0.72,AF,和其他节奏,分别。然而,支持向量机和CNN模型的集合分别导致F1得分为0.92、0.87和0.80。
    UNASSIGNED:我们探索了各种功能和机器学习模型,以使用短(9-61秒)单导联ECG记录来识别AF节律。我们的结果表明,提出的CNN模型为AF分类提取了独特的特征。
    UNASSIGNED: Atrial fibrillation (AF) is one of the most common cardiovascular problems, and its asymptomatic tendency makes AF detection challenging. Machine and deep learning methods are commonly used in AF detection.
    UNASSIGNED: The purpose of this study was to evaluate the information provided by convolutional neural network (CNN) and random forest (RF) machine learning models for AF classification.
    UNASSIGNED: We manually extracted 166 time-frequency domains and linear and nonlinear features to classify single-lead electrocardiograms (ECGs) as normal, AF, other, or noisy sinus rhythms. We selected a subset of 56 robust features using a genetic algorithm that was used in the RF model. In a separate study, a 1-dimensional, 12-layer CNN was designed on the raw ECG rhythms. Four features from the output layer and 128 features from the fully connected layer of CNN were explored independently for classification. The models were trained and internally validated on 8,528 ECGs and externally validated on a hidden dataset containing 3,658 ECGs. Next,we analyzed the correlation between engineered and CNN-learned features.
    UNASSIGNED: An RF classifier trained with 56-engineered features resulted in an F1 score of 0.91, 0.78, and 0.72 for normal, AF, and other rhythms, respectively. However, an ensemble of support vector machine and the CNN model resulted in an F1 score of 0.92, 0.87, and 0.80, respectively.
    UNASSIGNED: We explored various features and machine learning models to identify AF rhythms using short (9-61 seconds) single-lead ECG recordings. Our results showed that the proposed CNN model abstracted distinctive features for AF classification.
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