期刊文献+
共找到1,514篇文章
< 1 2 76 >
每页显示 20 50 100
Automated Classification of Lung Diseases in Computed Tomography Images Using a Wavelet Based Convolutional Neural Network 被引量:2
1
作者 Eri Matsuyama Du-Yih Tsai 《Journal of Biomedical Science and Engineering》 2018年第10期263-274,共12页
Recently, convolutional neural networks (CNNs) have been utilized in medical imaging research field and have successfully shown their ability in image classification and detection. In this paper we used a CNN combined... Recently, convolutional neural networks (CNNs) have been utilized in medical imaging research field and have successfully shown their ability in image classification and detection. In this paper we used a CNN combined with a wavelet transform approach for classifying a dataset of 448 lung CT images into 4 categories, e.g. lung adenocarcinoma, lung squamous cell carcinoma, metastatic lung cancer, and normal. The key difference between the commonly-used CNNs and the presented method is that in this method, we adopt the use of redundant wavelet coefficients at level 1 as inputs to the CNN, instead of using original images. One of the main advantages of the proposed method is that it is not necessary to extract regions of interest from original images. The wavelet coefficients of the entire image are used as inputs to the CNN. We compare the classification performance of the proposed method to that of an existing CNN classifier and a CNN-based support vector machine classifier. The experimental results show that the proposed method outperforms the other two methods and achieve the highest overall accuracy of 91.9%. It demonstrates the potential for use in classification of lung diseases in CT images. 展开更多
关键词 Convolutional neural networks wavelet Transforms classification LUNG DISEASES CT Imaging
下载PDF
An Ensemble of Convolutional Neural Networks Using Wavelets for Image Classification 被引量:3
2
作者 Travis Williams Robert Li 《Journal of Software Engineering and Applications》 2018年第2期69-88,共20页
Machine learning is an integral technology many people utilize in all areas of human life. It is pervasive in modern living worldwide, and has multiple usages. One application is image classification, embraced across ... Machine learning is an integral technology many people utilize in all areas of human life. It is pervasive in modern living worldwide, and has multiple usages. One application is image classification, embraced across many spheres of influence such as business, finance, medicine, etc. to enhance produces, causes, efficiency, etc. This need for more accurate, detail-oriented classification increases the need for modifications, adaptations, and innovations to Deep Learning Algorithms. This article used Convolutional Neural Networks (CNN) to classify scenes in the CIFAR-10 database, and detect emotions in the KDEF database. The proposed method converted the data to the wavelet domain to attain greater accuracy and comparable efficiency to the spatial domain processing. By dividing image data into subbands, important feature learning occurred over differing low to high frequencies. The combination of the learned low and high frequency features, and processing the fused feature mapping resulted in an advance in the detection accuracy. Comparing the proposed methods to spatial domain CNN and Stacked Denoising Autoencoder (SDA), experimental findings revealed a substantial increase in accuracy. 展开更多
关键词 CNN SDA neural network Deep LEARNING wavelet classification Fusion Machine LEARNING Object Recognition
下载PDF
Study on Ecological Change Remote Sensing Monitoring Method Based on Elman Dynamic Recurrent Neural Network
3
作者 Zhen Chen Yiyang Zheng 《Journal of Geoscience and Environment Protection》 2024年第4期31-44,共14页
In this paper, Hailin City of Heilongjiang Province, China is taken as the research area. As an important city in Heilongjiang Province, China, the sustainable development of its ecological environment is related to t... In this paper, Hailin City of Heilongjiang Province, China is taken as the research area. As an important city in Heilongjiang Province, China, the sustainable development of its ecological environment is related to the opening up, economic prosperity and social stability of Northeast China. In this paper, the remote sensing ecological index (RSEI) of Hailin City in recent 20 years was calculated by using Landsat 5/8/9 series satellite images, and the temporal and spatial changes of the ecological environment in Hailin City were further analyzed and the influencing factors were discussed. From 2003 to 2023, the mean value of RSEI in Hailin City decreased and increased, and the ecological environment decreased slightly as a whole. RSEI declined most significantly from 2003 to 2008, and it increased from 2008 to 2013, decreased from 2013 to 2018, and increased from 2018 to 2023 again, with higher RSEI value in the south and lower RSEI value in the northwest. It is suggested to appropriately increase vegetation coverage in the northwest to improve ecological quality. As a result, the predicted value of Elman dynamic recurrent neural network model is consistent with the change trend of the mean value, and the prediction error converges quickly, which can accurately predict the ecological environment quality in the future study area. 展开更多
关键词 remote sensing Ecological Index Long Time Series Space-Time Change Elman Dynamic Recurrent neural network
下载PDF
Optimal Deep Convolutional Neural Network for Vehicle Detection in Remote Sensing Images
4
作者 Saeed Masoud Alshahrani Saud S.Alotaibi +5 位作者 Shaha Al-Otaibi Mohamed Mousa Anwer Mustafa Hilal Amgad Atta Abdelmageed Abdelwahed Motwakel Mohamed I.Eldesouki 《Computers, Materials & Continua》 SCIE EI 2023年第2期3117-3131,共15页
Object detection(OD)in remote sensing images(RSI)acts as a vital part in numerous civilian and military application areas,like urban planning,geographic information system(GIS),and search and rescue functions.Vehicle ... Object detection(OD)in remote sensing images(RSI)acts as a vital part in numerous civilian and military application areas,like urban planning,geographic information system(GIS),and search and rescue functions.Vehicle recognition from RSIs remained a challenging process because of the difficulty of background data and the redundancy of recognition regions.The latest advancements in deep learning(DL)approaches permit the design of effectual OD approaches.This study develops an Artificial Ecosystem Optimizer with Deep Convolutional Neural Network for Vehicle Detection(AEODCNN-VD)model on Remote Sensing Images.The proposed AEODCNN-VD model focuses on the identification of vehicles accurately and rapidly.To detect vehicles,the presented AEODCNN-VD model employs single shot detector(SSD)with Inception network as a baseline model.In addition,Multiway Feature Pyramid Network(MFPN)is used for handling objects of varying sizes in RSIs.The features from the Inception model are passed into theMFPNformultiway andmultiscale feature fusion.Finally,the fused features are passed into bounding box and class prediction networks.For enhancing the detection efficiency of the AEODCNN-VD approach,AEO based hyperparameter optimizer is used,which is stimulated by the energy transfer strategies such as production,consumption,and decomposition in an ecosystem.The performance validation of the presentedmethod on benchmark datasets showed promising performance over recent DL models. 展开更多
关键词 Object detection remote sensing vehicle detection artificial ecosystem optimizer convolutional neural network
下载PDF
A Novel Lung Cancer Detection Method Using Wavelet Decomposition and Convolutional Neural Network
5
作者 Ahmad M. Sarhan 《Journal of Biomedical Science and Engineering》 2020年第5期81-92,共12页
Computerized tomography (CT) scan is the only screening test recommended by doctors to look for lung cancer. Convolutional neural networks (CNNs) have recently proven their ability to successfully classify medical ima... Computerized tomography (CT) scan is the only screening test recommended by doctors to look for lung cancer. Convolutional neural networks (CNNs) have recently proven their ability to successfully classify medical images. Due to its strong compactness property, the Discrete Wavelet transform (DWT) has been commonly used in image feature extraction applications. This paper presents a novel technique for the classification of Lung cancer in Computerized Tomography (CT) scans using Wavelets to find discriminative features in the CT images and CNN to classify the extracted features. Experimental results prove that the proposed approach outperforms other commonly used methods and gives an overall accuracy of 99.5%. 展开更多
关键词 Convolutional neural network CNN) wavelet TRANSFORM Image classification LUNG Cancer COMPUTERIZED TOMOGRAPHY (CT)
下载PDF
A Review on Back-Propagation Neural Networks in the Application of Remote Sensing Image Classification 被引量:2
6
作者 Alaeldin Suliman Yun Zhang 《Journal of Earth Science and Engineering》 2015年第1期52-65,共14页
关键词 BP神经网络 遥感图像分类 应用 人工神经网络 网络设计 评论 遥感图像处理 上下文信息
下载PDF
MOVING TARGETS PATTERN RECOGNITION BASED ON THE WAVELET NEURAL NETWORK
7
作者 GeGuangying ChenLili XuJianjian 《Journal of Electronics(China)》 2005年第3期321-328,共8页
Based on pattern recognition theory and neural network technology, moving objects automatic detection and classification method integrating advanced wavelet analysis are discussed in detail. An algorithm of moving tar... Based on pattern recognition theory and neural network technology, moving objects automatic detection and classification method integrating advanced wavelet analysis are discussed in detail. An algorithm of moving targets pattern recognition on the combination of inter-frame difference and wavelet neural network is presented. The experimental results indicate that the designed BP wavelet network using this algorithm can recognize and classify moving targets rapidly and effectively. 展开更多
关键词 移动目标检测 模式识别 微波神经网络 目标分类
下载PDF
Artificial neural network model for identifying taxi gross emitter from remote sensing data of vehicle emission 被引量:10
8
作者 ZENG Jun GUO Hua-fang HU Yue-ming 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第4期427-431,共5页
Vehicle emission has been the major source of air pollution in urban areas in the past two decades. This article proposes an artificial neural network model for identifying the taxi gross emitters based on the remote ... Vehicle emission has been the major source of air pollution in urban areas in the past two decades. This article proposes an artificial neural network model for identifying the taxi gross emitters based on the remote sensing data. After carrying out the field test in Guangzhou and analyzing various factors from the emission data, the artificial neural network modeling was proved to be an advisable method of identifying the gross emitters. On the basis of the principal component analysis and the selection of algorithm and architecture, the Back-Propagation neural network model with 8-17-1 architecture was established as the optimal approach for this purpose. It gave a percentage of hits of 93%. Our previous research result and the result from aggression analysis were compared, and they provided respectively the percentage of hits of 81.63% and 75%. This comparison demonstrates the potentiality and validity of the proposed method in the identification of taxi gross emitters. 展开更多
关键词 vehicle emission remote sensing neural network principal component analysis regression analysis
下载PDF
Effective distributed convolutional neural network architecture for remote sensing images target classification with a pre-training approach 被引量:3
9
作者 LI Binquan HU Xiaohui 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第2期238-244,共7页
How to recognize targets with similar appearances from remote sensing images(RSIs) effectively and efficiently has become a big challenge. Recently, convolutional neural network(CNN) is preferred in the target classif... How to recognize targets with similar appearances from remote sensing images(RSIs) effectively and efficiently has become a big challenge. Recently, convolutional neural network(CNN) is preferred in the target classification due to the powerful feature representation ability and better performance. However,the training and testing of CNN mainly rely on single machine.Single machine has its natural limitation and bottleneck in processing RSIs due to limited hardware resources and huge time consuming. Besides, overfitting is a challenge for the CNN model due to the unbalance between RSIs data and the model structure.When a model is complex or the training data is relatively small,overfitting occurs and leads to a poor predictive performance. To address these problems, a distributed CNN architecture for RSIs target classification is proposed, which dramatically increases the training speed of CNN and system scalability. It improves the storage ability and processing efficiency of RSIs. Furthermore,Bayesian regularization approach is utilized in order to initialize the weights of the CNN extractor, which increases the robustness and flexibility of the CNN model. It helps prevent the overfitting and avoid the local optima caused by limited RSI training images or the inappropriate CNN structure. In addition, considering the efficiency of the Na¨?ve Bayes classifier, a distributed Na¨?ve Bayes classifier is designed to reduce the training cost. Compared with other algorithms, the proposed system and method perform the best and increase the recognition accuracy. The results show that the distributed system framework and the proposed algorithms are suitable for RSIs target classification tasks. 展开更多
关键词 convolutional neural network (CNN) DISTRIBUTED architecture remote sensing images (RSIs) TARGET classification pre-training
下载PDF
Estimation of Poverty Based on Remote Sensing Image and Convolutional Neural Network 被引量:1
10
作者 Peng Wu Yumin Tan 《Advances in Remote Sensing》 2019年第4期89-98,共10页
Poverty has always been one of the topics concerned by governments and researchers all over the world, especially in developing countries. Remote sensing image is widely used in poverty estimation because of its large... Poverty has always been one of the topics concerned by governments and researchers all over the world, especially in developing countries. Remote sensing image is widely used in poverty estimation because of its large area observation, timeliness and periodicity. In this study, we explore the applicability of convolution neural network (CNN) combined with remote sensing image in regional poverty estimation. In the 2016 economic indicators estimation of Guizhou Province, China, the Pearson coefficient of per capita GDP (PCGDP) reached 0.76, which means that the image features extracted by CNN can explain the change of PCGDP of county level economic indicators up to 76%. Compared with other methods, our method still has high precision. Based on these results, we found that convolutional neural network combined with remote sensing image can be used in regional poverty estimation. 展开更多
关键词 POVERTY CONVOLUTION neural network remote sensing Image ECONOMIC INDICATORS GUIZHOU PCGDP
下载PDF
Estimation of vegetation biophysical parameters by remote sensing using radial basis function neural network 被引量:2
11
作者 YANG Xiao-hua HUANG Jing-feng +2 位作者 WANG Jian-wen WANG Xiu-zhen LIU Zhan-yu 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第6期883-895,共13页
Hyperspectral reflectance (350~2500 nm) data were recorded at two different sites of rice in two experiment fields including two cultivars, and three levels of nitrogen (N) application. Twenty-five Vegetation Indices ... Hyperspectral reflectance (350~2500 nm) data were recorded at two different sites of rice in two experiment fields including two cultivars, and three levels of nitrogen (N) application. Twenty-five Vegetation Indices (VIs) were used to predict the rice agronomic parameters including Leaf Area Index (LAI, m2 green leaf/m2 soil) and Green Leaf Chlorophyll Density (GLCD, mg chlorophyll/m2 soil) by the traditional regression models and Radial Basis Function Neural Network (RBF). RBF emerged as a variant of Artificial Neural Networks (ANNs) in the late 1980’s. A large variety of training algorithms has been tested for training RBF networks. In this study, Original RBF (ORBF), Gradient Descent RBF (GDRBF), and Generalized Regression Neural Network (GRNN) were employed. Results showed that green waveband Normalized Difference Vegetation Index (NDVIgreen) and TCARI/OSAVI have the best prediction power for LAI by exponent model and ORBF respectively, and that TCARI/OSAVI has the best prediction power for GLCD by exponent model and GDRBF. The best performances of RBF are compared with the traditional models, showing that the relationship between VIs and agronomic variables are further improved when RBF is used. Compared with the best traditional models, ORBF using TCARI/OSAVI improves the prediction power for LAI by lowering the Root Mean Square Error (RMSE) for 0.1119, and GDRBF using TCARI/OSAVI improves the prediction power for GLCD by lowering the RMSE for 26.7853. It is concluded that RBF provides a useful exploratory and predictive tool when applied to the sensitive VIs. 展开更多
关键词 径向基函数 神经网络 遥感 植被 生物物理参数 估计
下载PDF
Remote sensing image classification based on BP neural network model
12
作者 ZHENG Yong-guo, WANG Ping, MA Jing, ZHANG Hong-bo (Shandong University of Science and Technology, Tai’an 271019, China) 《中国有色金属学会会刊:英文版》 CSCD 2005年第S1期240-243,共4页
Aiming at the characteristics of remote sensing image classification, the mixed pixel problem is one of the main factors that affect the improvement of classifying precision in remote sensing classification. A BP neur... Aiming at the characteristics of remote sensing image classification, the mixed pixel problem is one of the main factors that affect the improvement of classifying precision in remote sensing classification. A BP neural network was established to solve mixed pixel classifying problems. The aim of our work is to improve the BP network algorithm and set the intensity of training, which changes with training process, because the BP algorithm converyging speed of learning algorithm is rather slow, it is possible to fall into the local minimum, and because the algorithm makes the learning result poor, the global minimum value can’t be reached. The results show that this method effectively solves mixed pixel classifying problem, improves learning speed and classification accuracy of BP network classifier,so it is one kind of effective remote sensing imagery classifying method. 展开更多
关键词 remote sensing IMAGE classification neural network TRAINING INTENSITY
下载PDF
Using Neural Networks to Combine Multiple Features in Remote Sensing Image Classification
13
作者 俞璐 谢钧 张艳艳 《Journal of Donghua University(English Edition)》 EI CAS 2015年第2期225-228,共4页
Remote sensing image classification is the basis of remote sensing image analysis and understanding.It aims to assign each pixel an object class label.To achieve satisfactory classification accuracy,single feature is ... Remote sensing image classification is the basis of remote sensing image analysis and understanding.It aims to assign each pixel an object class label.To achieve satisfactory classification accuracy,single feature is not enough.Multiple features are usually integrated in remote sensing image classification.In this paper,a method based on neural network to combine multiple features was proposed.A single network was used to perform the task instead of ensemble of neural networks.A special architecture of network was designed to fit the task.The method effectively avoids the problems in direct conjunction of multiple features.Experiments on Indian93 data set show that the method has obvious advantages over conjunction of features on both recognition rate and training time. 展开更多
关键词 neural network remote sensing image image classification multiple features
下载PDF
The Monitoring of Red Tides Based on Modular Neural Networks Using Airborne Hyperspectral Remote Sensing
14
作者 JI Guangrong SUN Jie +1 位作者 ZHAO Wencang ZHANG Hande 《Journal of Ocean University of China》 SCIE CAS 2006年第2期169-173,共5页
这篇论文建议基于聚类和模块化的神经网络监视方法的红潮。从天线的一个团获得红潮的特征遥远的 sensinghyperspectral 数据,首先,日志剩余修正(纵向冗余码校验) 被用来使数据,然后聚类的分析正常化被采用为神经网络选择并且形成训... 这篇论文建议基于聚类和模块化的神经网络监视方法的红潮。从天线的一个团获得红潮的特征遥远的 sensinghyperspectral 数据,首先,日志剩余修正(纵向冗余码校验) 被用来使数据,然后聚类的分析正常化被采用为神经网络选择并且形成训练样本。监视的 Forrapid,辨别者由模块化的神经网络组成,其结构和学习参数被一个适应基因算法(统帅) 决定。实验证明这个方法罐头很快并且有效地监视红潮。 展开更多
关键词 遥感技术 光谱数据 空气传播 人工神经网络 赤潮 海洋污染
下载PDF
Self-organizing feature map neural network classification of the ASTER data based on wavelet fusion 被引量:7
15
作者 HASI Bagan MA Jianwen LI Qiqing HAN Xiuzhen LIU Zhili 《Science China Earth Sciences》 SCIE EI CAS 2004年第7期651-658,共8页
Most methods for classification of remote sensing data are based on the statistical parameter evaluation with the assumption that the samples obey the normal distribution. How-ever, more accurate classification result... Most methods for classification of remote sensing data are based on the statistical parameter evaluation with the assumption that the samples obey the normal distribution. How-ever, more accurate classification results can be obtained with the neural network method through getting knowledge from environments and adjusting the parameter (or weight) step by step by a specific measurement. This paper focuses on the double-layer structured Kohonen self-organizing feature map (SOFM), for which all neurons within the two layers are linked one another and those of the competition layers are linked as well along the sides. Therefore, the self-adapting learning ability is improved due to the effective competition and suppression in this method. The SOFM has become a hot topic in the research area of remote sensing data classi-fication. The Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) is a new satellite-borne remote sensing instrument with three 15-m resolution bands and three 30-m resolution bands at the near infrared. The ASTER data of Dagang district, Tianjin Munici-pality is used as the test data in this study. At first, the wavelet fusion is carried out to make the spatial resolutions of the ASTER data identical; then, the SOFM method is applied to classifying the land cover types. The classification results are compared with those of the maximum likeli-hood method (MLH). As a consequence, the classification accuracy of SOFM increases about by 7% in general and, in particular, it is almost as twice as that of the MLH method in the town. 展开更多
关键词 classification wavelet fusion SELF-ORGANIZING neural network FEATURE map (SofM) ASTER data.
原文传递
A Novel Remote Sensing Signal De-noising Algorithm based on Neural Networks and Tensor Analysis
16
作者 Wang Wei 《International Journal of Technology Management》 2016年第9期26-28,共3页
关键词 神经网络 去噪算法 噪声信号 张量分析 遥感 无监督学习 阈值函数 小波系数
下载PDF
Meta-Heuristic Optimized Hybrid Wavelet Features for Arrhythmia Classification
17
作者 S.R.Deepa M.Subramoniam +2 位作者 R.Swarnalatha S.Poornapushpakala S.Barani 《Intelligent Automation & Soft Computing》 SCIE 2023年第7期745-761,共17页
The non-invasive evaluation of the heart through EectroCardioG-raphy(ECG)has played a key role in detecting heart disease.The analysis of ECG signals requires years of learning and experience to interpret and extract ... The non-invasive evaluation of the heart through EectroCardioG-raphy(ECG)has played a key role in detecting heart disease.The analysis of ECG signals requires years of learning and experience to interpret and extract useful information from them.Thus,a computerized system is needed to classify ECG signals with more accurate results effectively.Abnormal heart rhythms are called arrhythmias and cause sudden cardiac deaths.In this work,a Computerized Abnormal Heart Rhythms Detection(CAHRD)system is developed using ECG signals.It consists of four stages;preprocessing,feature extraction,feature optimization and classifier.At first,Pan and Tompkins algorithm is employed to detect the envelope of Q,R and S waves in the preprocessing stage.It uses a recursive filter to eliminate muscle noise,T-wave interference and baseline wander.As the analysis of ECG signal in the spatial domain does not provide a complete description of the signal,the feature extraction involves using frequency contents obtained from multiple wavelet filters;bi-orthogonal,Symlet and Daubechies at different resolution levels in the feature extraction stage.Then,Black Widow Optimization(BWO)is applied to optimize the hybrid wavelet features in the feature optimization stage.Finally,a kernel based Support Vector Machine(SVM)is employed to classify heartbeats into five classes.In SVM,Radial Basis Function(RBF),polynomial and linear kernels are used.A total of∼15000 ECG signals are obtained from the Massachusetts Institute of Technology-Beth Israel Hospital(MIT-BIH)arrhythmia database for performance evaluation of the proposed CAHRD system.Results show that the proposed CAHRD system proved to be a powerful tool for ECG analysis.It correctly classifies five classes of heartbeats with 99.91%accuracy using an RBF kernel with 2nd level wavelet coefficients.The CAHRD system achieves an improvement of∼6%over random projections with the ensemble SVM approach and∼2%over morphological and ECG segment based features with the RBF classifier. 展开更多
关键词 Arrhythmia classification abnormal heartbeats waveletS meta-heuristics algorithm neural network signal classification
下载PDF
Estimating Monthly Surface Air Temperature Using MODIS LST Data and an Artificial Neural Network in the Loess Plateau, China
18
作者 HE Tian LIU Fuyuan +1 位作者 WANG Ao FEI Zhanbo 《Chinese Geographical Science》 SCIE CSCD 2023年第4期751-763,共13页
Air temperature(Ta)datasets with high spatial and temporal resolutions are needed in a wide range of applications,such as hydrology,ecology,agriculture,and climate change studies.Nonetheless,the density of weather sta... Air temperature(Ta)datasets with high spatial and temporal resolutions are needed in a wide range of applications,such as hydrology,ecology,agriculture,and climate change studies.Nonetheless,the density of weather station networks is insufficient,especially in sparsely populated regions,greatly limiting the accuracy of estimates of spatially distributed Ta.Due to their continuous spatial coverage,remotely sensed land surface temperature(LST)data provide the possibility of exploring spatial estimates of Ta.However,because of the complex interaction of land and climate,retrieval of Ta from the LST is still far from straightforward.The estimation accuracy varies greatly depending on the model,particularly for maximum Ta.This study estimated monthly average daily minimum temperature(Tmin),average daily maximum temperature(Tmax)and average daily mean temperature(Tmean)over the Loess Plateau in China based on Moderate Resolution Imaging Spectroradiometer(MODIS)LST data(MYD11A2)and some auxiliary data using an artificial neural network(ANN)model.The data from 2003 to 2010 were used to train the ANN models,while 2011 to 2012 weather station temperatures were used to test the trained model.The results showed that the nighttime LST and mean LST provide good estimates of Tmin and Tmean,with root mean square errors(RMSEs)of 1.04℃ and 1.01℃,respectively.Moreover,the best RMSE of Tmax estimation was 1.27℃.Compared with the other two published Ta gridded datasets,the produced 1 km×1 km dataset accurately captured both the temporal and spatial patterns of Ta.The RMSE of Tmin estimation was more sensitive to elevation,while that of Tmax was more sensitive to month.Except for land cover type as the input variable,which reduced the RMSE by approximately 0.01℃,the other vegetation-related variables did not improve the performance of the model.The results of this study indicated that ANN,a type of machine learning method,is effective for long-term and large-scale Ta estimation. 展开更多
关键词 air temperature land surface temperature(LST) artificial neural network(ANN) remote sensing climate change Loess Plateau China
下载PDF
Estimating Fraction of Photosynthetically Active Radiation of Corn with Vegetation Indices and Neural Network from Hyperspectral Data 被引量:2
19
作者 YANG Fei ZHU Yunqiang +1 位作者 ZHANG Jiahua YAO Zuofang 《Chinese Geographical Science》 SCIE CSCD 2012年第1期63-74,共12页
The fraction of photosynthetically active radiation(FPAR) is a key variable in the assessment of vegetation productivity and land ecosystem carbon cycles.Based on ground-measured corn hyperspectral reflectance and FPA... The fraction of photosynthetically active radiation(FPAR) is a key variable in the assessment of vegetation productivity and land ecosystem carbon cycles.Based on ground-measured corn hyperspectral reflectance and FPAR data over Northeast China,the correlations between corn-canopy FPAR and hyperspectral reflectance were analyzed,and the FPAR estimation performances using vegetation index(VI) and neural network(NN) methods with different two-band-combination hyperspectral reflectance were investigated.The results indicated that the corncanopy FPAR retained almost a constant value in an entire day.The negative correlations between FPAR and visible and shortwave infrared reflectance(SWIR) bands are stronger than the positive correlations between FPAR and near-infrared band reflectance(NIR).For the six VIs,the normalized difference vegetation index(NDVI) and simple ratio(SR) performed best for estimating corn FPAR(the maximum R2 of 0.8849 and 0.8852,respectively).However,the NN method esti-mated results(the maximum R2 is 0.9417) were obviously better than all of the VIs.For NN method,the two-band combinations showing the best corn FPAR estimation performances were from the NIR and visible bands;for VIs,however,they were from the SWIR and NIR bands.As for both the methods,the SWIR band performed exceptionally well for corn FPAR estimation.This may be attributable to the fact that the reflectance of the SWIR band were strongly controlled by leaf water content,which is a key component of corn photosynthesis and greatly affects the absorption of photosynthetically active radiation(APAR),and makes further impact on corn-canopy FPAR. 展开更多
关键词 高光谱反射率 光合有效辐射 神经网络方法 玉米冠层 植被生产力 数据估算 归一化差异植被指数 指数和
下载PDF
Brain Tumor Classification in Magnetic Resonance Images Using Deep Learning and Wavelet Transform
20
作者 Ahmad M. Sarhan 《Journal of Biomedical Science and Engineering》 2020年第6期102-112,共11页
A brain tumor is a mass of abnormal cells in the brain. Brain tumors can be benign (noncancerous) or malignant (cancerous). Conventional diagnosis of a brain tumor by the radiologist is done by examining a set of imag... A brain tumor is a mass of abnormal cells in the brain. Brain tumors can be benign (noncancerous) or malignant (cancerous). Conventional diagnosis of a brain tumor by the radiologist is done by examining a set of images produced by magnetic resonance imaging (MRI). Many computer-aided detection (CAD) systems have been developed in order to help the radiologists reach their goal of correctly classifying the MRI image. Convolutional neural networks (CNNs) have been widely used in the classification of medical images. This paper presents a novel CAD technique for the classification of brain tumors in MRI images. The proposed system extracts features from the brain MRI images by utilizing the strong energy compactness property exhibited by the Discrete Wavelet Transform (DWT). The Wavelet features are then applied to a CNN to classify the input MRI image. Experimental results indicate that the proposed approach outperforms other commonly used methods and gives an overall accuracy of 99.3%. 展开更多
关键词 Convolutional neural network CNN) wavelet Transform Image classification Brain Cancer Magnetic Resonance Imaging (MRI)
下载PDF
上一页 1 2 76 下一页 到第
使用帮助 返回顶部