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Infrared and Visible Image Fusion Based on Res2Net-Transformer Automatic Encoding and Decoding 被引量:1
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作者 Chunming Wu Wukai Liu Xin Ma 《Computers, Materials & Continua》 SCIE EI 2024年第4期1441-1461,共21页
A novel image fusion network framework with an autonomous encoder and decoder is suggested to increase thevisual impression of fused images by improving the quality of infrared and visible light picture fusion. The ne... A novel image fusion network framework with an autonomous encoder and decoder is suggested to increase thevisual impression of fused images by improving the quality of infrared and visible light picture fusion. The networkcomprises an encoder module, fusion layer, decoder module, and edge improvementmodule. The encoder moduleutilizes an enhanced Inception module for shallow feature extraction, then combines Res2Net and Transformerto achieve deep-level co-extraction of local and global features from the original picture. An edge enhancementmodule (EEM) is created to extract significant edge features. A modal maximum difference fusion strategy isintroduced to enhance the adaptive representation of information in various regions of the source image, therebyenhancing the contrast of the fused image. The encoder and the EEM module extract features, which are thencombined in the fusion layer to create a fused picture using the decoder. Three datasets were chosen to test thealgorithmproposed in this paper. The results of the experiments demonstrate that the network effectively preservesbackground and detail information in both infrared and visible images, yielding superior outcomes in subjectiveand objective evaluations. 展开更多
关键词 image fusion Res2Net-Transformer infrared image visible image
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A color image encryption scheme based on a 2D coupled chaotic system and diagonal scrambling algorithm
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作者 苏静明 方士辉 +1 位作者 洪炎 温言 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期233-243,共11页
A novel color image encryption scheme is developed to enhance the security of encryption without increasing the complexity. Firstly, the plain color image is decomposed into three grayscale plain images, which are con... A novel color image encryption scheme is developed to enhance the security of encryption without increasing the complexity. Firstly, the plain color image is decomposed into three grayscale plain images, which are converted into the frequency domain coefficient matrices(FDCM) with discrete cosine transform(DCT) operation. After that, a twodimensional(2D) coupled chaotic system is developed and used to generate one group of embedded matrices and another group of encryption matrices, respectively. The embedded matrices are integrated with the FDCM to fulfill the frequency domain encryption, and then the inverse DCT processing is implemented to recover the spatial domain signal. Eventually,under the function of the encryption matrices and the proposed diagonal scrambling algorithm, the final color ciphertext is obtained. The experimental results show that the proposed method can not only ensure efficient encryption but also satisfy various sizes of image encryption. Besides, it has better performance than other similar techniques in statistical feature analysis, such as key space, key sensitivity, anti-differential attack, information entropy, noise attack, etc. 展开更多
关键词 color image encryption discrete cosine transform two-dimensional(2D)coupled chaotic system diagonal scrambling
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联合多时相GF-6 WFV和Sentinel-2的森林类型识别 被引量:1
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作者 叶青龙 欧阳勋志 +2 位作者 黄诚 李坚锋 潘萍 《江西农业大学学报》 CAS CSCD 北大核心 2024年第2期389-400,共12页
【目的】我国南方地区多云雨,地型较破碎,森林类型精细识别较为困难,探讨联合多源、多时相的遥感数据对森林类型识别具有重要意义。【方法】以江西省信丰县为研究区,基于2019年森林资源二类调查数据,将森林划分为松林、杉木林、阔叶林... 【目的】我国南方地区多云雨,地型较破碎,森林类型精细识别较为困难,探讨联合多源、多时相的遥感数据对森林类型识别具有重要意义。【方法】以江西省信丰县为研究区,基于2019年森林资源二类调查数据,将森林划分为松林、杉木林、阔叶林、针叶混交林、针阔混交林、竹林、灌木林和其他林地等8种类型,利用随机森林算法比较GF-6 WFV和Sentinel-2最佳时相相同波段(紫/深蓝、蓝、绿、红、近红外、红边)和不同波段(黄边、短波红外)的森林类型识别能力,构建联合光谱特征集。联合多时相GF-6 WFV和Sentinel-2,构建多时相植被指数特征集,结合联合光谱特征集、纹理特征和地形特征,通过随机森林和递归消除法构建特征变量优选数据集进行森林类型识别,利用混淆矩阵和森林类型的实际分布对识别结果进行精度验证。【结果】(1)GF-6 WFV蓝、绿和红波段组合的总体精度为58.31%,分别加入紫、近红外、红边、黄边和Sentinel-2短波红外波段后,其总体精度分别提高1.99%、8.90%、10.71%、1.50%和14.10%;Sentinel-2蓝、绿和红波段组合的总体精度为54.68%,分别加入深蓝、近红外、红边、短波红外和GF-6 WFV黄边波段后,其总体精度分别提高3.30%、10.82%、12.92%、17.31%和3.97%。(2)特征变量优选数据集的总体精度和Kappa系数为80.80%和75.56%,贡献程度大小依次为GF-6 WFV多时相植被指数、Sentinel-2多时相植被指数、GF-6 WFV光谱特征、Sentinel-2光谱特征、地形特征和纹理特征,贡献率分别为40.44%、23.23%、18.12%、10.21%、4.61%和3.39%。(3)松林、杉木林、阔叶林、针叶混交林、针阔混交林、竹林、灌木林和其他林地的制图精度分别为86.97%、85.60%、88.61%、9.43%、19.01%、53.60%、86.90%和82.56%,用户精度分别为81.42%、79.79%、77.57%、71.43%、81.82%、67.00%、87.74%和82.88%,识别结果与研究区实际森林类型分布较吻合。【结论】联合多时相GF-6 WFV和Sentinel-2可以综合多时相、多源影像的优点,能够有效提高森林类型的识别精度。 展开更多
关键词 gf-6 WFV Sentinel-2 森林类型识别 随机森林
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基于GF-1卫星遥感反演排水河沟水体溶存N_(2)O浓度模型对比研究
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作者 嵇晶晶 白立影 +3 位作者 佘冬立 管伟 阿力木·阿布来提 潘永春 《水土保持研究》 CSCD 北大核心 2024年第5期257-264,共8页
[目的]探究利用GF-1卫星数据反演水体溶存氧化亚氮(N_(2)O)浓度的可行性,为实现低成本、高效率的水质实时监测提供有效途径。[方法]以宁夏青铜峡灌区第1和第5排水河沟为研究对象,选取与排水河沟水体溶存N_(2)O浓度相关性高的GF-1卫星影... [目的]探究利用GF-1卫星数据反演水体溶存氧化亚氮(N_(2)O)浓度的可行性,为实现低成本、高效率的水质实时监测提供有效途径。[方法]以宁夏青铜峡灌区第1和第5排水河沟为研究对象,选取与排水河沟水体溶存N_(2)O浓度相关性高的GF-1卫星影像波段反射率和水质参数作为自变量,通过最优子集筛选法确定最优自变量组合,分别构建了多元线性回归、BP神经网络和支持向量机模型,对水体溶存N_(2)O浓度进行预测对比。[结果]水温(T)、溶解性有机碳(DOC)等是影响水体溶存N_(2)O浓度的主要因素,同时近红外(NIR)等卫星波段与水体溶存N_(2)O浓度变化趋势显著相关。当自变量包括T,NIR等7个因素时,模型预测效果最佳。在3种模型中,BP神经网络模型验证结果R^(2)为0.64,具有最高预测精度。[结论]GF-1卫星数据以及水质参数与水体溶存N_(2)O浓度存在复杂的相关性关系,且BP神经网络能够实现利用GF-1卫星数据较高精度地反演水体溶存N_(2)O浓度。 展开更多
关键词 N_(2)O浓度 gf-1卫星 反演 机器学习
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级联语义分割和边缘检测的GF-2影像耕地提取
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作者 尚华胜 甘淑 +2 位作者 袁希平 朱智富 李绕波 《遥感信息》 CSCD 北大核心 2024年第4期134-143,共10页
针对山地丘陵区的坡耕地和小面积耕地碎片边界模糊不清、分类提取困难的问题,以GF-2影像为数据源,提出了一种级联语义分割和边缘检测模型的遥感影像耕地信息提取方法。首先,针对不同类型耕地的特点选择级联方式;其次,将耕地边缘作为独... 针对山地丘陵区的坡耕地和小面积耕地碎片边界模糊不清、分类提取困难的问题,以GF-2影像为数据源,提出了一种级联语义分割和边缘检测模型的遥感影像耕地信息提取方法。首先,针对不同类型耕地的特点选择级联方式;其次,将耕地边缘作为独立的特征类别,结合改进U-Net、DeeplabV3+和DexiNed模型,融合面特征和线特征,使得耕地边缘特征与语义特征能够进行互补,从而提高耕地提取的准确性,实现对复杂地形背景噪声的抑制和不同类型耕地的提取。实验结果表明,对比单一模型DeeplabV3+和U-Net,级联模型的耕地信息提取的总体精度、Kappa系数和F1值均有大幅度提升,针对不同类型耕地级联模型提取的耕地结果更接近真实耕地标注,漏提、误提区域远低于单一模型。 展开更多
关键词 耕地信息 语义分割 边缘检测 gf-2影像 丘陵山区
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基于GF-2遥感影像和改进后PSPNet模型的丘陵地区耕地图斑提取方法
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作者 颜玲 李少达 +6 位作者 李彩瑛 陈薇 刘林 宋承远 杨莉 吴若楚 冉培廉 《成都理工大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第2期269-280,共12页
针对丘陵地区耕地地块具有边界模糊、覆盖物种类多样、大小和空间位置分布不规则等特点,传统分类方法难以快速准确提取耕地信息的问题,本文以四川省金堂县竹篙镇和高板镇为研究区域,利用高分二号卫星影像和改进后的PSPNet语义分割网络... 针对丘陵地区耕地地块具有边界模糊、覆盖物种类多样、大小和空间位置分布不规则等特点,传统分类方法难以快速准确提取耕地信息的问题,本文以四川省金堂县竹篙镇和高板镇为研究区域,利用高分二号卫星影像和改进后的PSPNet语义分割网络模型进行耕地图斑提取研究。在模型训练中,引入CBAM注意力模块以提高整个网络的特征提取和表达能力,采用余弦退火学习率以加快模型的收敛速度。结果表明,改进后的PSPNet模型在丘陵地区耕地提取精度方面取得了显著提高,耕地识别精度达到了95.69%,比标准PSPNet模型提高了1.07%,比Unet++,DeepLabv3+和支持向量机方法方法提高了1.32%,1.75%和6.33%。基于改进后的PSPNet模型具有更强的特征提取和表达能力,可以更准确地提取丘陵地区的耕地信息,为农业决策提供更准确的数据支持,促进农业智能化和精准化,提高农作物产量和质量,推动农业现代化进程。 展开更多
关键词 丘陵耕地 PSPNet模型 CBAM注意力模块 余弦退火学习率 gf-2遥感影像
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基于GF-2和ASTER数据青海德龙地区构造蚀变信息提取及找矿预测 被引量:1
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作者 王艺龙 王然 +3 位作者 严子清 张新铭 李笑龙 徐崇文 《自然资源遥感》 CSCD 北大核心 2024年第1期217-226,共10页
德龙地区位于青海东昆仑金及多金属成矿带东段,是该成矿带内极具勘查潜力区域之一,受限于偏远的地理位置和崎岖的地形条件,大比例尺地球化学勘查及常规地质调查工作难以直接开展。为此,基于ASTER和GF-2数据,通过分析不同空间分辨率遥感... 德龙地区位于青海东昆仑金及多金属成矿带东段,是该成矿带内极具勘查潜力区域之一,受限于偏远的地理位置和崎岖的地形条件,大比例尺地球化学勘查及常规地质调查工作难以直接开展。为此,基于ASTER和GF-2数据,通过分析不同空间分辨率遥感影像的色调、几何结构和纹理特征进行线性和环形构造识别;同时,根据主要蚀变矿物光谱特征分析,利用ASTER可见光—近红外波段和短波红外波段,采用“掩模+主成分分析”方法提取铁化、Al-OH和Mg-OH蚀变信息;在此基础上,结合多元地学信息及野外调查结果,综合分析遥感解译构造蚀变信息与研究区金矿化的内在联系,建立基于区内金矿床的遥感找矿预测模型,并以此为依据划分出找矿远景区3处。通过野外查证,在德龙找矿远景区新发现金矿体多条。研究结果表明,融合遥感数据和地理信息系统技术可有效识别地表热液蚀变和构造空间结构特征,能够为该地区进一步找矿预测提供参考和依据。 展开更多
关键词 gf-2 ASTER 主成分分析 找矿预测 德龙地区
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基于GF-2影像的武汉市九峰山国家森林公园地上碳储量估算 被引量:1
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作者 韩云亭 李思悦 罗协 《地质通报》 CAS CSCD 北大核心 2024年第4期611-619,共9页
探究国产高分辨率数据在森林碳储量估算研究中的潜力,为构建森林碳储量估算模型提供新思路。选取武汉市九峰山国家森林公园为研究对象,以GF-2遥感影像为数据源,结合地面实测信息,对研究区森林地上碳储量进行估算,共提取6个植被指数、4... 探究国产高分辨率数据在森林碳储量估算研究中的潜力,为构建森林碳储量估算模型提供新思路。选取武汉市九峰山国家森林公园为研究对象,以GF-2遥感影像为数据源,结合地面实测信息,对研究区森林地上碳储量进行估算,共提取6个植被指数、4个波段值、8种纹理特征,筛选出9个与实测碳储量相关的遥感变量,运用线性与非线性方程对单个高相关变量和多个相关变量进行建模,选出最优模型,为进一步提高预测精度,将模型代入4种纹理窗口(3×3、5×5、7×7、9×9)。结果表明:通过遥感图像提取的植被指数之间,具有较强的共线性,单变量建立的模型精度低于多变量模型;利用均方根误差RMSE与决定系数R^(2)对4个窗口下模型的预测精度进行评价,模型在5×5窗口下预测效果最好(R^(2)=0.73,RMSE=0.5),3×3窗口下预测效果最差(R^(2)=0.64,RMSE=0.8),将所有估测模型进行比较,在纹理窗口下模型精度提高了0.11。利用5×5窗口下构建的多变量模型对研究区碳储量进行估算,九峰山国家森林公园碳储总量为1.06×10^(4) t,总体平均碳密度为84.59 t/hm^(2),具有一定的固碳作用。选用国产高分辨率影像GF-2数据对武汉市九峰山森林公园进行反演研究,能很好地运用在森林植被碳储量定量与生长状况领域。研究结果对“双碳”目标下森林生态系统碳汇监测与管理具有重要科学意义。 展开更多
关键词 gf-2 地上碳储量 遥感反演 森林碳汇 湖北
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T2-weighted imaging-based radiomic-clinical machine learning model for predicting the differentiation of colorectal adenocarcinoma 被引量:1
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作者 Hui-Da Zheng Qiao-Yi Huang +4 位作者 Qi-Ming Huang Xiao-Ting Ke Kai Ye Shu Lin Jian-Hua Xu 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第3期819-832,共14页
BACKGROUND The study on predicting the differentiation grade of colorectal cancer(CRC)based on magnetic resonance imaging(MRI)has not been reported yet.Developing a non-invasive model to predict the differentiation gr... BACKGROUND The study on predicting the differentiation grade of colorectal cancer(CRC)based on magnetic resonance imaging(MRI)has not been reported yet.Developing a non-invasive model to predict the differentiation grade of CRC is of great value.AIM To develop and validate machine learning-based models for predicting the differ-entiation grade of CRC based on T2-weighted images(T2WI).METHODS We retrospectively collected the preoperative imaging and clinical data of 315 patients with CRC who underwent surgery from March 2018 to July 2023.Patients were randomly assigned to a training cohort(n=220)or a validation cohort(n=95)at a 7:3 ratio.Lesions were delineated layer by layer on high-resolution T2WI.Least absolute shrinkage and selection operator regression was applied to screen for radiomic features.Radiomics and clinical models were constructed using the multilayer perceptron(MLP)algorithm.These radiomic features and clinically relevant variables(selected based on a significance level of P<0.05 in the training set)were used to construct radiomics-clinical models.The performance of the three models(clinical,radiomic,and radiomic-clinical model)were evaluated using the area under the curve(AUC),calibration curve and decision curve analysis(DCA).RESULTS After feature selection,eight radiomic features were retained from the initial 1781 features to construct the radiomic model.Eight different classifiers,including logistic regression,support vector machine,k-nearest neighbours,random forest,extreme trees,extreme gradient boosting,light gradient boosting machine,and MLP,were used to construct the model,with MLP demonstrating the best diagnostic performance.The AUC of the radiomic-clinical model was 0.862(95%CI:0.796-0.927)in the training cohort and 0.761(95%CI:0.635-0.887)in the validation cohort.The AUC for the radiomic model was 0.796(95%CI:0.723-0.869)in the training cohort and 0.735(95%CI:0.604-0.866)in the validation cohort.The clinical model achieved an AUC of 0.751(95%CI:0.661-0.842)in the training cohort and 0.676(95%CI:0.525-0.827)in the validation cohort.All three models demonstrated good accuracy.In the training cohort,the AUC of the radiomic-clinical model was significantly greater than that of the clinical model(P=0.005)and the radiomic model(P=0.016).DCA confirmed the clinical practicality of incorporating radiomic features into the diagnostic process.CONCLUSION In this study,we successfully developed and validated a T2WI-based machine learning model as an auxiliary tool for the preoperative differentiation between well/moderately and poorly differentiated CRC.This novel approach may assist clinicians in personalizing treatment strategies for patients and improving treatment efficacy. 展开更多
关键词 Radiomics Colorectal cancer Differentiation grade Machine learning T2-weighted imaging
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血清TGF-β1、Nesfatin-1、SFRP5与2型糖尿病胰岛素抵抗关系探究
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作者 孟祥雨 徐云 +1 位作者 陈雪辉 白立炜 《医学检验与临床》 2024年第2期52-55,共4页
目的:探讨血清转化生长因子-β1(TGF-β1)、Nesfatin-1、分泌型卷曲相关蛋白-5(SFRP5)与2型糖尿病胰岛素抵抗的关系。方法:选取我院2021年4月-2023年4月收治的148例2型糖尿病患者为研究对象,根据稳态模型胰岛素抵抗指数(HOMA-IR)检测结... 目的:探讨血清转化生长因子-β1(TGF-β1)、Nesfatin-1、分泌型卷曲相关蛋白-5(SFRP5)与2型糖尿病胰岛素抵抗的关系。方法:选取我院2021年4月-2023年4月收治的148例2型糖尿病患者为研究对象,根据稳态模型胰岛素抵抗指数(HOMA-IR)检测结果将患者分为轻度胰岛素抵抗组(91例,HOMA-IR<2.5)和中重度胰岛素抵抗组(57例,HOMA-IR≥2.5)。比较两组入院时血清TGF-β1、Nesfatin-1、SFRP5水平,分析入院时血清TGF-β1、Nesfatin-1、SFRP5水平与HOMA-IR的相关性,分析发生中重度胰岛素抵抗的影响因素、联合检测的诊断价值及危险度。结果:入院时,中重度胰岛素抵抗组血清TGF-β1、Nesfatin-1水平高于轻度胰岛素抵抗组,SFRP5水平低于轻度胰岛素抵抗组(P<0.05);入院时,HOMA-IR与血清TGF-β1、Nesfatin-1水平呈正相关,与SFRP5水平呈负相关(P<0.05);入院时,血清TGF-β1、Nesfatin-1、SFRP5水平为2型糖尿病患者发生中重度胰岛素抵抗的影响因素(P<0.05);入院时血清TGF-β1、Nesfatin-1、SFRP5水平联合诊断中重度胰岛素抵抗的AUC为0.808,最佳诊断敏感度为91.23%,特异度为70.33%;入院时血清TGF-β1、Nesfatin-1、SFRP5高水平患者发生中重度胰岛素抵抗的危险度是低水平的3.560、2.134、0.341倍(P<0.05)。结论:血清TGF-β1、Nesfatin-1、SFRP5水平与2型糖尿病胰岛素抵抗密切相关,可作为临床诊断病情的参考依据。 展开更多
关键词 2型糖尿病 胰岛素抵抗 gf-β1 NESFATIN-1 SFRP5
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Sentiment Analysis Using E-Commerce Review Keyword-Generated Image with a Hybrid Machine Learning-Based Model
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作者 Jiawen Li Yuesheng Huang +3 位作者 Yayi Lu Leijun Wang Yongqi Ren Rongjun Chen 《Computers, Materials & Continua》 SCIE EI 2024年第7期1581-1599,共19页
In the context of the accelerated pace of daily life and the development of e-commerce,online shopping is a mainstreamway for consumers to access products and services.To understand their emotional expressions in faci... In the context of the accelerated pace of daily life and the development of e-commerce,online shopping is a mainstreamway for consumers to access products and services.To understand their emotional expressions in facing different shopping experience scenarios,this paper presents a sentiment analysis method that combines the ecommerce reviewkeyword-generated imagewith a hybrid machine learning-basedmodel,inwhich theWord2Vec-TextRank is used to extract keywords that act as the inputs for generating the related images by generative Artificial Intelligence(AI).Subsequently,a hybrid Convolutional Neural Network and Support Vector Machine(CNNSVM)model is applied for sentiment classification of those keyword-generated images.For method validation,the data randomly comprised of 5000 reviews from Amazon have been analyzed.With superior keyword extraction capability,the proposedmethod achieves impressive results on sentiment classification with a remarkable accuracy of up to 97.13%.Such performance demonstrates its advantages by using the text-to-image approach,providing a unique perspective for sentiment analysis in the e-commerce review data compared to the existing works.Thus,the proposed method enhances the reliability and insights of customer feedback surveys,which would also establish a novel direction in similar cases,such as social media monitoring and market trend research. 展开更多
关键词 Sentiment analysis keyword-generated image machine learning Word2Vec-TextRank CNN-SVM
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Mapping soil organic matter in cultivated land based on multi-year composite images on monthly time scales
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作者 Jie Song Dongsheng Yu +4 位作者 Siwei Wang Yanhe Zhao Xin Wang Lixia Ma Jiangang Li 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第4期1393-1408,共16页
Rapid and accurate acquisition of soil organic matter(SOM)information in cultivated land is important for sustainable agricultural development and carbon balance management.This study proposed a novel approach to pred... Rapid and accurate acquisition of soil organic matter(SOM)information in cultivated land is important for sustainable agricultural development and carbon balance management.This study proposed a novel approach to predict SOM with high accuracy using multiyear synthetic remote sensing variables on a monthly scale.We obtained 12 monthly synthetic Sentinel-2 images covering the study area from 2016 to 2021 through the Google Earth Engine(GEE)platform,and reflectance bands and vegetation indices were extracted from these composite images.Then the random forest(RF),support vector machine(SVM)and gradient boosting regression tree(GBRT)models were tested to investigate the difference in SOM prediction accuracy under different combinations of monthly synthetic variables.Results showed that firstly,all monthly synthetic spectral bands of Sentinel-2 showed a significant correlation with SOM(P<0.05)for the months of January,March,April,October,and November.Secondly,in terms of single-monthly composite variables,the prediction accuracy was relatively poor,with the highest R^(2)value of 0.36 being observed in January.When monthly synthetic environmental variables were grouped in accordance with the four quarters of the year,the first quarter and the fourth quarter showed good performance,and any combination of three quarters was similar in estimation accuracy.The overall best performance was observed when all monthly synthetic variables were incorporated into the models.Thirdly,among the three models compared,the RF model was consistently more accurate than the SVM and GBRT models,achieving an R^(2)value of 0.56.Except for band 12 in December,the importance of the remaining bands did not exhibit significant differences.This research offers a new attempt to map SOM with high accuracy and fine spatial resolution based on monthly synthetic Sentinel-2 images. 展开更多
关键词 soil organic matter Sentinel-2 monthly synthetic images machine learning model spatial prediction
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GF-2正射影像融合方法的比较与分析
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作者 邱承兴 《低碳世界》 2024年第6期193-195,共3页
基于高分二号卫星(GF-2)多光谱影像和全色影像,采用5 m数字高程模型(digital elevation model,DEM)影像进行正射校正,选用无波段限制的7种影像融合方法对正射影像进行融合,通过定性和定量分析,探究不同影像融合结果的差异性。结果表明,... 基于高分二号卫星(GF-2)多光谱影像和全色影像,采用5 m数字高程模型(digital elevation model,DEM)影像进行正射校正,选用无波段限制的7种影像融合方法对正射影像进行融合,通过定性和定量分析,探究不同影像融合结果的差异性。结果表明,施密特全色锐化(GramˉSchmidt pan sharpening, GS)融合方法能够较为真实地反映原有地物信息,地物细节处理效果比其他影像融合方法好;小波变换(wavelet transform, WT)和最近邻扩散(nearest neighbor diffusion, NND)方法对植被的区分度较差;不同的影像融合方法有其各自的特性,在实际应用中,应根据不同的需求,选择适宜的影像融合方法。 展开更多
关键词 gf-2 正射影像 影像融合 质量评价
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A Novel 2D Hyperchaotic with a Complex Dynamic Behavior for Color Image Encryption 被引量:1
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作者 Yongsheng Hu Liyong Nan 《Computers, Materials & Continua》 SCIE EI 2023年第3期6555-6571,共17页
The generation method of the key stream and the structure of the algorithm determine the security of the cryptosystem.The classical chaotic map has simple dynamic behavior and few control parameters,so it is not suita... The generation method of the key stream and the structure of the algorithm determine the security of the cryptosystem.The classical chaotic map has simple dynamic behavior and few control parameters,so it is not suitable for modern cryptography.In this paper,we design a new 2D hyperchaotic system called 2D simple structure and complex dynamic behavior map(2D-SSCDB).The 2D-SSCDB has a simple structure but has complex dynamic behavior.The Lyapunov exponent verifies that the 2D-SSCDB has hyperchaotic behavior,and the parameter space in the hyperchaotic state is extensive and continuous.Trajectory analysis and some randomness tests verify that the 2D-SSCDB can generate random sequences with good performance.Next,to verify the excellent performance of the 2D-SSCDB,we use the 2D-SSCDB to generate a keystream for color image encryption.In the encryption algorithm,the encryption algorithm scrambles and diffuses simultaneously,increasing the cryptographic system’s security.The horizontal correlation,vertical correlation,and diagonal correlation of ciphertext are−0.0004,−0.0004 and 0.0007,respectively.The average information entropy of the ciphertext is 7.9993.In addition,the designed encryption algorithm reduces the correlation between the three channels of the color image.Security analysis shows that the color image encryption algorithm designed using 2DSSCDB has good security,can resist standard attack methods,and has high efficiency. 展开更多
关键词 Chaos theory 2D-SSCDB CRYPTOGRAPHY image encryption
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Image to Image Translation Based on Differential Image Pix2Pix Model 被引量:1
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作者 Xi Zhao Haizheng Yu Hong Bian 《Computers, Materials & Continua》 SCIE EI 2023年第10期181-198,共18页
In recent years,Pix2Pix,a model within the domain of GANs,has found widespread application in the field of image-to-image translation.However,traditional Pix2Pix models suffer from significant drawbacks in image gener... In recent years,Pix2Pix,a model within the domain of GANs,has found widespread application in the field of image-to-image translation.However,traditional Pix2Pix models suffer from significant drawbacks in image generation,such as the loss of important information features during the encoding and decoding processes,as well as a lack of constraints during the training process.To address these issues and improve the quality of Pix2Pixgenerated images,this paper introduces two key enhancements.Firstly,to reduce information loss during encoding and decoding,we utilize the U-Net++network as the generator for the Pix2Pix model,incorporating denser skip-connection to minimize information loss.Secondly,to enhance constraints during image generation,we introduce a specialized discriminator designed to distinguish differential images,further enhancing the quality of the generated images.We conducted experiments on the facades dataset and the sketch portrait dataset from the Chinese University of Hong Kong to validate our proposed model.The experimental results demonstrate that our improved Pix2Pix model significantly enhances image quality and outperforms other models in the selected metrics.Notably,the Pix2Pix model incorporating the differential image discriminator exhibits the most substantial improvements across all metrics.An analysis of the experimental results reveals that the use of the U-Net++generator effectively reduces information feature loss,while the Pix2Pix model incorporating the differential image discriminator enhances the supervision of the generator during training.Both of these enhancements collectively improve the quality of Pix2Pix-generated images. 展开更多
关键词 image-to-image translation generative adversarial networks U-Net++ differential image Pix2Pix
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Retrieving chlorophyll content and equivalent water thickness of Moso bamboo(Phyllostachys pubescens) forests under Pantana phyllostachysae Chao-induced stress from Sentinel-2A/B images in a multiple LUTs-based PROSAIL framework 被引量:1
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作者 Zhanghua Xu Anqi He +10 位作者 Yiwei Zhang Zhenbang Hao Yifan Li Songyang Xiang Bin Li Lingyan Chen Hui Yu Wanling Shen Xuying Huang Xiaoyu Guo Zenglu Li 《Forest Ecosystems》 SCIE CSCD 2023年第2期252-267,共16页
Biochemical components of Moso bamboo(Phyllostachys pubescens)are critical to physiological and ecological processes and play an important role in the material and energy cycles of the ecosystem.The coupled PROSPECT w... Biochemical components of Moso bamboo(Phyllostachys pubescens)are critical to physiological and ecological processes and play an important role in the material and energy cycles of the ecosystem.The coupled PROSPECT with SAIL(PROSAIL)radiative transfer model is widely used for vegetation biochemical component content inversion.However,the presence of leaf-eating pests,such as Pantana phyllostachysae Chao(PPC),weakens the performance of the model for estimating biochemical components of Moso bamboo and thus must be considered.Therefore,this study considered pest-induced stress signals associated with Sentinel-2A/B images and field data and established multiple sets of biochemical canopy reflectance look-up tables(LUTs)based on the PROSAIL framework by setting different parameter ranges according to infestation levels.Quantitative inversions of leaf area index(LAI),leaf chlorophyll content(LCC),and leaf equivalent water thickness(LEWT)were derived.The scale conversions from LCC to canopy chlorophyll content(CCC)and LEWT to canopy equivalent water thickness(CEWT)were calculated.The results showed that LAI,CCC,and CEWT were inversely related with PPC-induced stress.When applying multiple LUTs,the p-values were<0.01;the R2 values for LAI,CCC,and CEWT were 0.71,0.68,and 0.65 with root mean square error(RMSE)(normalized RMSE,NRMSE)values of 0.38(0.16),17.56μg cm-2(0.20),and 0.02 cm(0.51),respectively.Compared to the values obtained for the traditional PROSAIL model,for October,R2 values increased by 0.05 and 0.10 and NRMSE decreased by 0.09 and 0.02 for CCC and CEWT,respectively and RMSE decreased by 0.35μg cm-2 for CCC.The feasibility of the inverse strategy for integrating pest-induced stress factors into the PROSAIL model,while establishing multiple LUTs under different pest-induced damage levels,was successfully demonstrated and can potentially enhance future vegetation parameter inversion and monitoring of bamboo forest health and ecosystems. 展开更多
关键词 Moso bamboo Chlorophyll content Equivalent water thickness PROSAIL model Multiple LUTs Pantana phyllostachysae Chao Sentinel-2A/B images
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基于GF-2影像的德阳城市黑臭水体遥感监测研究
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作者 宋蒙蒙 王春艳 +2 位作者 黄樯 秦欢 黄御书 《皮革制作与环保科技》 2024年第11期78-80,共3页
黑臭水体地面监测覆盖范围有限,受人为因素影响较大,监测结果具有局限性。以德阳市城市建成区内主要黑臭水体为研究对象,采用2017~2022年4幅高质量的GF-2遥感影像,通过ENVI 5.3对GF-2遥感影像进行正射校正、影像融合、辐射定标、图像裁... 黑臭水体地面监测覆盖范围有限,受人为因素影响较大,监测结果具有局限性。以德阳市城市建成区内主要黑臭水体为研究对象,采用2017~2022年4幅高质量的GF-2遥感影像,通过ENVI 5.3对GF-2遥感影像进行正射校正、影像融合、辐射定标、图像裁剪、几何校正等预处理后进行遥感监测研究。分析了黑臭水体与一般水体的光谱特征,发现不同波段黑臭水体反射率与一般水体反射率变化差异明显。基于这一特点提出了取不同波段斜率比值作为遥感识别指数。采用水体清洁指数模型,识别黑臭水体与具有黑臭风险的水体。本文基于德阳黑臭水体的光谱特征提出的WCI,仅对德阳市丁家堰进行了验证,还需扩大范围检测其适用性。 展开更多
关键词 黑臭水体 遥感监测 gf-2 水体清洁指数 WCI
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基于GF-2面向对象土地利用分类研究
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作者 郝旋捷 冯晓天 +1 位作者 赵燕伶 张巧玲 《山西建筑》 2024年第7期171-174,共4页
高分辨率遥感技术发展迅速,传统技术已经无法满足信息提取的要求,严重影响提取精度和效率。以秦岭北麓长安区与鄠邑区交界处北部部分区域为实验区,高分二号影像为数据源,采用面向对象分类法进行土地利用分类研究,并进行监督分类做对比... 高分辨率遥感技术发展迅速,传统技术已经无法满足信息提取的要求,严重影响提取精度和效率。以秦岭北麓长安区与鄠邑区交界处北部部分区域为实验区,高分二号影像为数据源,采用面向对象分类法进行土地利用分类研究,并进行监督分类做对比实验。结果表明,采用面向对象分类法分类结果总体精度为90.05%,Kappa系数为0.857,比监督分类方法精度高出14.55%,Kappa系数高出0.288。面向对象分类方法总体分类效果较好,有效提高了分类精度。 展开更多
关键词 高分二号影像 面向对象分类 秦岭北麓 ECOGNITION 土地利用
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MRI T_2 star mapping、T_1 images与3D DESS融合图在隐匿性膝关节软骨损伤中的应用 被引量:4
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作者 范伟雄 杨志企 +3 位作者 程凤燕 黄健 于昭 侯文忠 《临床医学工程》 2017年第4期437-439,共3页
目的探讨T_2 star mapping、T_1 images与3D DESS融合伪彩图在关节软骨损伤中的诊断价值。方法对26例关节软骨损伤患者行T_2 star mapping、T_1 images和3D DESS扫描,并将T_1 images、T_2 star mapping与3D DESS图像融合,评价患者股骨... 目的探讨T_2 star mapping、T_1 images与3D DESS融合伪彩图在关节软骨损伤中的诊断价值。方法对26例关节软骨损伤患者行T_2 star mapping、T_1 images和3D DESS扫描,并将T_1 images、T_2 star mapping与3D DESS图像融合,评价患者股骨、胫骨、髌骨关节软骨损伤程度并与关节镜结果对比,计算融合伪彩图诊断软骨损伤的特异性、敏感性及与关节镜诊断结果一致性。结果 T_1 images-3D DESS融合伪彩图诊断关节软骨损伤的敏感度、特异度及Kappa值分别为92.8%、93.0%、0.769,T_2 star mapping-3D DESS融合伪彩图诊断关节软骨损伤的敏感度、特异度及Kappa值分别为91.4%、94.2%、0.787。结论 T_2 star mapping、T_1 images与3D DESS融合伪彩图在关节软骨早期损伤评价上优于关节镜。 展开更多
关键词 膝关节 关节软骨 磁共振成像 T2 star mapping T1 imageS 3D DESS
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2型糖尿病患者骨骼肌厚度和弹性变化及其影响因素
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作者 冯晓蕾 黄丽丽 +1 位作者 周琦 李苗 《中国医学影像技术》 CSCD 北大核心 2024年第2期270-274,共5页
目的观察2型糖尿病患者骨骼肌厚度和弹性变化及其影响因素。方法前瞻性招募62例2型糖尿病患者(T2DM组)及60名健康成年人(HC组),以剪切波弹性成像(SWE)技术检测其放松及收缩状态下腹直肌和腓肠肌最大杨氏模量(E_(max)),比较组间2种状态... 目的观察2型糖尿病患者骨骼肌厚度和弹性变化及其影响因素。方法前瞻性招募62例2型糖尿病患者(T2DM组)及60名健康成年人(HC组),以剪切波弹性成像(SWE)技术检测其放松及收缩状态下腹直肌和腓肠肌最大杨氏模量(E_(max)),比较组间2种状态下骨骼肌厚度及弹性模量,并采用多重线性回归分析影响腹直肌和腓肠肌弹性模量的因素。结果组间放松及收缩状态下腹直肌和腓肠肌厚度差异均无统计学意义(P均>0.05);T2DM组放松及收缩状态下腹直肌及腓肠肌Emax均低于HC组(P均<0.05)。多重线性回归分析显示,T2DM组放松及收缩状态下腹直肌及腓肠肌弹性模量均随病程、空腹血糖(FBG)及糖化血红蛋白(HbA1c)而呈线性降低(P均<0.05)。结论2型糖尿病患者骨骼肌弹性模量降低,且随病程、FBG及HbA1c而呈线性下降。 展开更多
关键词 糖尿病 2 骨骼 弹性成像技术 前瞻性研究
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