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An Introduction to Information Sets with an Application to Iris Based Authentication 认领
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作者 Madasu Hanmandlu Mamta Bansal Shantaram Vasikarla 《现代物理(英文)》 2020年第1期122-144,共23页
This paper presents the information set which originates from a fuzzy set on applying the Hanman-Anirban entropy function to represent the uncertainty. Each element of the information set is called the information val... This paper presents the information set which originates from a fuzzy set on applying the Hanman-Anirban entropy function to represent the uncertainty. Each element of the information set is called the information value which is a product of the information source value and its membership function value. The Hanman filter that modifies the information set is derived by using a filtering function. Adaptive Hanman-Anirban entropy is formulated and its properties are given. It paves the way for higher form of information sets called Hanman transforms that evaluate the information source based on the information obtained on it. Based on the information set six features, Effective Gaussian Information source value (EGI), Total Effective Gaussian Information (TEGI), Energy Feature (EF), Sigmoid Feature (SF), Hanman transform (HT) and Hanman Filter (HF) features are derived. The performance of the new features is evaluated on CASIA-IRIS-V3-Lamp database using both Inner Product Classifier (IPC) and Support Vector Machine (SVM). To tackle the problem of partially occluded eyes, majority voting method is applied on the iris strips and this enables better performance than that obtained when only a single iris strip is used. 展开更多
关键词 Information Sets Energy FEATURE (EF) SIGMOID FEATURE (SF) Hanman Trans-form (HT) Hanman Filter (HF) Hanman-Anirbanentropy Function
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森林优化特征选择算法的增强与扩展 认领
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作者 刘兆赓 李占山 +2 位作者 王丽 王涛 于海鸿 《软件学报》 EI CSCD 北大核心 2020年第5期1511-1524,共14页
特征选择作为一种重要的数据预处理方法,不但能解决维数灾难问题,还能提高算法的泛化能力.各种各样的方法已被应用于解决特征选择问题,其中,基于演化计算的特征选择算法近年来获得了更多的关注并取得了一些成功.近期研究结果表明,森林... 特征选择作为一种重要的数据预处理方法,不但能解决维数灾难问题,还能提高算法的泛化能力.各种各样的方法已被应用于解决特征选择问题,其中,基于演化计算的特征选择算法近年来获得了更多的关注并取得了一些成功.近期研究结果表明,森林优化特征选择算法具有更好的分类性能及维度缩减能力.然而,初始化阶段的随机性、全局播种阶段的人为参数设定,影响了该算法的准确率和维度缩减能力;同时,算法本身存在着高维数据处理能力不足的本质缺陷.从信息增益率的角度给出了一种初始化策略,在全局播种阶段,借用模拟退火控温函数的思想自动生成参数,并结合维度缩减率给出了适应度函数;同时,针对形成的优质森林采取贪心算法,形成一种特征选择算法EFSFOA(enhanced feature selection using forest optimization algorithm).此外,在面对高维数据的处理时,采用集成特征选择的方案形成了一个适用于EFSFOA的集成特征选择框架,使其能够有效处理高维数据特征选择问题.通过设计对比实验,验证了EFSFOA与FSFOA相比在分类准确率和维度缩减率上均有明显的提高,高维数据处理能力更是提高到了100 000维.将EFSFOA与近年来提出的比较高效的基于演化计算的特征选择方法进行对比,EFSFOA仍具有很强的竞争力. 展开更多
关键词 enhanced feature selection using forest optimization algorithm(EFSFOA) 高维 特征选择 演化计算
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Comparing the Area of Data Mining Algorithms in Network Intrusion Detection 认领
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作者 Yasamin Alagrash Azhar Drebee Nedda Zirjawi 《信息安全(英文)》 2020年第1期1-18,共18页
The network-based intrusion detection has become common to evaluate machine learning algorithms. Although the KDD Cup’99 Dataset has class imbalance over different intrusion classes, still it plays a significant role... The network-based intrusion detection has become common to evaluate machine learning algorithms. Although the KDD Cup’99 Dataset has class imbalance over different intrusion classes, still it plays a significant role to evaluate machine learning algorithms. In this work, we utilize the singular valued decomposition technique for feature dimension reduction. We further reconstruct the features form reduced features and the selected eigenvectors. The reconstruction loss is used to decide the intrusion class for a given network feature. The intrusion class having the smallest reconstruction loss is accepted as the intrusion class in the network for that sample. The proposed system yield 97.90% accuracy on KDD Cup’99 dataset for the stated task. We have also analyzed the system with individual intrusion categories separately. This analysis suggests having a system with the ensemble of multiple classifiers;therefore we also created a random forest classifier. The random forest classifier performs significantly better than the SVD based system. The random forest classifier achieves 99.99% accuracy for intrusion detection on the same training and testing data set. 展开更多
关键词 Feature Reduction SINGULAR Value Decomposition INTRUSION DETECTION Correlation Analysis Association Impact Scale INTRUSION DETECTION System KDD CUP 1999 Random FOREST
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A Multisource Contour Matching Method Considering the Similarity of Geometric Features 认领
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作者 Wenyue GUO Anzhu YU +4 位作者 Qun SUN Shaomei LI Qing XU Bowei WEN Yuanfu LI 《测绘学报:英文版》 2020年第3期76-87,共12页
The existing multi-source contour matching studies have focused on the matching methods with consideration of topological relations and similarity measurement based on spatial Euclidean distance,while it is lack of ta... The existing multi-source contour matching studies have focused on the matching methods with consideration of topological relations and similarity measurement based on spatial Euclidean distance,while it is lack of taking the contour geometric features into account,which may lead to mismatching in map boundaries and areas with intensive contours or extreme terrain changes.In light of this,it is put forward that a matching strategy from coarse to precious based on the contour geometric features.The proposed matching strategy can be described as follows.Firstly,the point sequence is converted to feature sequence according to a feature descriptive function based on curvature and angle of normal vector.Then the level of similarity among multi-source contours is calculated by using the longest common subsequence solution.Accordingly,the identical contours could be matched based on the above calculated results.In the experiment for the proposed method,the reliability and efficiency of the matching method are verified using simulative datasets and real datasets respectively.It has been proved that the proposed contour matching strategy has a high matching precision and good applicability. 展开更多
关键词 multisource contour matching geometric feature similarity measurement longest common subsequence feature descriptor
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Change features of time-series climate variables from 1962 to 2016 in Inner Mongolia,China 认领
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作者 XU Lili YU Guangming +2 位作者 ZHANG Wenjie TU Zhenfa TAN Wenxia 《干旱区科学:英文版》 SCIE CSCD 2020年第1期58-72,共15页
Detecting change features of climate variables in arid/semi-arid areas is essential for understanding related climate change patterns and the driving and evolution mechanism between climate and arid/semi-arid ecosyste... Detecting change features of climate variables in arid/semi-arid areas is essential for understanding related climate change patterns and the driving and evolution mechanism between climate and arid/semi-arid ecosystems. This paper takes Inner Mongolia of China, a unique arid/semi-arid ecosystem, as the study area. We first detected trend features of climate variables using the linear trend analysis method and then detected their trend-shift features using the breaks for additive seasonal and trend method based on the time-series of monthly precipitation and monthly mean temperature datasets from 1962 to 2016. We analyzed the different change features of precipitation and temperature on a regional scale and in different ecological zones to discover the spatial heterogeneity of change features. The results showed that Inner Mongolia has become warmer-wetter during the past 54 years. The regional annual mean temperature increased 0.4°C per decade with a change rate of 56.2%. The regional annual precipitation increased 0.07 mm per decade with a slightly change rate of about 1.7%, but the trend was not statistically significant. The warmer trend was contributed by the same positive trend in each season, while the wetter trend was contributed by the negative trend of the summer precipitation and the positive trend of the other three seasons. The regional monthly precipitation series had a trend-shift pattern with a structural breakpoint in the year 1999, while the regional monthly mean temperature series showed an increasing trend without a periodical trend-shift. After the year 2000, the warmer-wetter trend of the climate in Inner Mongolia was accelerated. The late 20th century was a key period, because the acceleration of the wetter trend in some local zones(Ⅰ and Ⅱ) and the alleviation of the warmer trend in some local zones(Ⅶ, Ⅷ and Ⅸ) occurred simultaneously. Moreover, the change features had a strong spatial heterogeneity, the southeastern and southwestern of Inner Mongolia went through a warmer-drier 展开更多
关键词 temperature precipitation trend FEATURE trend-shift FEATURE arid/semi-arid area
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Association of Elevated Yes-Associated Protein Expression with Gastric Cancer and Its Clinicopathological Features: A Meta-Analysis 认领
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作者 Qian Peng Ting Yuan +4 位作者 Xingmei Duan Jianyou Shi Lan Bai Jiying Yu Lei Zhong 《生物科学与医学(英文)》 2020年第2期96-109,共14页
Objectives: To evaluate the difference of YAP-positive expression between GC and adjacent tissues, as well as the association of elevated YAP expression with clinicopathological features of GC. Methods: PubMed, Embase... Objectives: To evaluate the difference of YAP-positive expression between GC and adjacent tissues, as well as the association of elevated YAP expression with clinicopathological features of GC. Methods: PubMed, Embase, Web of Science databases and the Chinese National Knowledge Infrastructure (CNKI) were searched from inception up to December 2018. The pooled ORs and corresponding 95% CIs were used to assess the strength of association. The heterogeneity among eligible studies was evaluated by the Q-test and I2 values. The sensitivity analysis was performed by sequential omission of individual studies. Moreover, Begg’s test and Egger’s test were used to evaluate publication bias. Results: A total of 2229 patients from 16 studies were included in this meta-analysis. The results showed that positive YAP expression was closely correlated with GC but not adjacent non-tumor tissue (OR = 8.08, 95% CI = 4.41 - 14.80). Additionally, YAP overexpression was found to be associated with more advanced TNM stage (OR = 2.68, 95% CI = 1.61 - 4.48), deeper invasion depth (OR = 2.05, 95% CI = 1.32 - 3.19), and lymph node metastasis (OR = 1.95, 95% CI = 1.29 - 2.96). No significant correlation was observed between YAP overexpression and degree of differentiation (OR = 1.17, 95% CI = 0.63 - 2.16), as well as gender of patients (OR = 1.12, 95% CI = 0.91 - 1.37) or tumor size (OR = 1.11, 95% CI = 0.82 - 1.49) of gastric cancer. Conclusions: This meta-analysis demonstrated that YAP might be a promising diagnostic marker and even a therapeutic target for gastric cancer. 展开更多
关键词 Yes-Associated Protein GASTRIC Cancer CLINICOPATHOLOGICAL FEATURE META-ANALYSIS
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Detection of “Swollen Shoot” Disease in Ivorian Cocoa Trees via Convolutional Neural Networks 认领
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作者 Mamadou Coulibaly Konan Hyacinthe Kouassi +1 位作者 Silue Kolo Olivier Asseu 《工程(英文)(1947-3931)》 2020年第3期166-176,共11页
Recent advances in diagnostics have made image analysis one of the main areas of research and development. Selecting and calculating these characteristics of a disease is a difficult task. Among deep learning techniqu... Recent advances in diagnostics have made image analysis one of the main areas of research and development. Selecting and calculating these characteristics of a disease is a difficult task. Among deep learning techniques, deep convolutional neural networks are actively used for image analysis. This includes areas of application such as segmentation, anomaly detection, disease classification, computer-aided diagnosis. The objective which we aim in this article is to extract information in an effective way for a better diagnosis of the plants attending the disease of “swollen shoot”. 展开更多
关键词 DRONE Convolutional NEURAL Networks Image Recognition FEATURE DETECTION
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An SLGC Model for Asian Food Image Classification 认领
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作者 Ruoqi Wu Shuai Zhao Zhijian Qu 《电脑和通信(英文)》 2020年第4期26-43,共18页
As a fine-grained classification problem, food image classification faces many difficulties in the specific implementation. Different countries and regions have different eating habits. In particular, Asian food image... As a fine-grained classification problem, food image classification faces many difficulties in the specific implementation. Different countries and regions have different eating habits. In particular, Asian food images have a complicated structure, and the related classification methods are still very scarce. There is an urgent need to develop a feature extraction and fusion scheme based on the characteristics of Asian food images. To solve the above problems, we proposed an image classification model SLGC (SURF-Local and Global Color) that combines image segmentation and feature fusion. By studying the unique structure of Asian foods, the color features of the images are merged into the representation vectors in the local and global dimensions, respectively, thereby further enhancing the effect of feature extraction. The experimental results show that the SLGC model can express the intrinsic characteristics of Asian food images more comprehensively and improve classification accuracy. 展开更多
关键词 ASIAN FOOD IMAGE Classification IMAGE SEGMENTATION FEATURE Fusion BAG of Features
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A feature selection method combined with ridge regression and recursive feature elimination in quantitative analysis of laser induced breakdown spectroscopy 认领
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作者 王国栋 孙兰香 +3 位作者 汪为 陈彤 郭美亭 张鹏 《等离子体科学与技术:英文版》 SCIE EI CAS CSCD 2020年第7期11-20,共10页
In the spectral analysis of laser-induced breakdown spectroscopy,abundant characteristic spectral lines and severe interference information exist simultaneously in the original spectral data.Here,a feature selection m... In the spectral analysis of laser-induced breakdown spectroscopy,abundant characteristic spectral lines and severe interference information exist simultaneously in the original spectral data.Here,a feature selection method called recursive feature elimination based on ridge regression(Ridge-RFE)for the original spectral data is recommended to make full use of the valid information of spectra.In the Ridge-RFE method,the absolute value of the ridge regression coefficient was used as a criterion to screen spectral characteristic,the feature with the absolute value of minimum weight in the input subset features was removed by recursive feature elimination(RFE),and the selected features were used as inputs of the partial least squares regression(PLS)model.The Ridge-RFE method based PLS model was used to measure the Fe,Si,Mg,Cu,Zn and Mn for 51 aluminum alloy samples,and the results showed that the root mean square error of prediction decreased greatly compared to the PLS model with full spectrum as input.The overall results demonstrate that the Ridge-RFE method is more efficient to extract the redundant features,make PLS model for better quantitative analysis results and improve model generalization ability. 展开更多
关键词 laser-induced breakdown spectroscopy feature selection ridge regression recursive feature elimination quantitative analysis
特征核查理论及其最新发展 认领
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作者 吴胜伟 《平顶山学院学报》 2020年第4期40-44,共5页
句法操作的最基本单位是特征,从可诠释性角度可分为可解释的特征和不可解释的特征;从强度的角度可分为强势特征和弱势特征。经典的特征核查理论认为:在拼读前进行特征核查并删除不可解释的特征。扩充的特征核查理论认为:a.在拼读前,核... 句法操作的最基本单位是特征,从可诠释性角度可分为可解释的特征和不可解释的特征;从强度的角度可分为强势特征和弱势特征。经典的特征核查理论认为:在拼读前进行特征核查并删除不可解释的特征。扩充的特征核查理论认为:a.在拼读前,核查并删除强势特征;b.在LF接口层,核查并删除不可解释的特征。这更符合Chomsky的最简方案的理论追求,即一切句法推导都是为了满足PF和LF两个表达式条件,都是为了解读的需要。 展开更多
关键词 特征 特征核查 最新发展
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Research on Spatial Pattern and Its Industrial Distribution of Commercial Space in Mianyang Based on POI Data 认领
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作者 Da Zheng Changqi Li 《数据分析和信息处理(英文)》 2020年第1期20-40,共21页
The rational layout of urban commercial space is conducive to optimizing the allocation of commercial resources in the urban interior space. Based on the commercial POI (Point of Interest) data in the central district... The rational layout of urban commercial space is conducive to optimizing the allocation of commercial resources in the urban interior space. Based on the commercial POI (Point of Interest) data in the central district of Mianyang, the characteristics of urban commercial spatial pattern under different scales are analyzed by using Kernel Density Estimation, Getis-Ord , Ripley’s K Function and Location Entropy method, and the spatial agglomeration characteristics of various industries in urban commerce are studied. The results show that: 1) The spatial distribution characteristics of commercial outlets in downtown Mianyang are remarkable, and show a multi-center distribution pattern. The hot area distribution of commercial outlets based on road grid unit is generally consistent with the identified commercial density center distribution. 2) The commercial grade scale structure has been formed in the central urban area as a whole, and the distribution of commercial network hot spots based on road grid unit is generally consistent with the identified commercial density center distribution. 3) From the perspective of commercial industry, the differentiation of urban commercial space “center-periphery” is obvious, and different industries show different spatial agglomeration modes. 4) The multi-scale spatial agglomeration of each industry is different, the spatial scale of location choice of comprehensive retail, household appliances and other industries is larger, and the scale of location choice of textile, clothing, culture and sports is small. 5) There are significant differences in specialized functional areas from the perspective of industry. Mature areas show multi-functional elements, multi-advantage industry agglomeration characteristics, and a small number of developing areas also show multi-advantage industry agglomeration characteristics. 展开更多
关键词 Point of INTEREST (POI) Commercial Space Aggregating FEATURE Industry Dis-tribution Mianyang
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Detection and Classification of Brain Tumor Based on Multilevel Segmentation with Convolutional Neural Network 认领
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作者 Rafiqul Islam Shah Imran +1 位作者 Md. Ashikuzzaman Md. Munim Ali Khan 《生物医学工程(英文)》 2020年第4期45-53,共9页
Magnetic Resonance Imaging (MRI) is an important diagnostic technique for early detection of brain Tumor and the classification of brain Tumor from MRI image is a challenging research work because of its different sha... Magnetic Resonance Imaging (MRI) is an important diagnostic technique for early detection of brain Tumor and the classification of brain Tumor from MRI image is a challenging research work because of its different shapes, location and image intensities. For successful classification, the segmentation method is required to separate Tumor. Then important features are extracted from the segmented Tumor that is used to classify the Tumor. In this work, an efficient multilevel segmentation method is developed combining optimal thresholding and watershed segmentation technique followed by a morphological operation to separate the Tumor. Convolutional Neural Network (CNN) is then applied for feature extraction and finally, the Kernel Support Vector Machine (KSVM) is utilized for resultant classification that is justified by our experimental evaluation. Experimental results show that the proposed method effectively detect and classify the Tumor as cancerous or non-cancerous with promising accuracy. 展开更多
关键词 SEGMENTATION Classification Non-Cancerous TUMOR Cancerous TUMOR FEATURE Extraction Convolutional Neural Network
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Automatic Identification of Clear-Air Echoes Based on Millimeter-wave Cloud Radar Measurements 认领
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作者 Ling YANG Yun WANG +5 位作者 Zhongke WANG Qian YANG Xingang FAN Fa TAO Xiaoqiong ZHEN Zhipeng YANG 《大气科学进展:英文版》 SCIE CAS CSCD 2020年第8期912-924,共13页
Millimeter-wave cloud radar(MMCR)provides the capability of detecting the features of micro particles inside clouds and describing the internal microphysical structure of the clouds.Therefore,MMCR has been widely appl... Millimeter-wave cloud radar(MMCR)provides the capability of detecting the features of micro particles inside clouds and describing the internal microphysical structure of the clouds.Therefore,MMCR has been widely applied in cloud observations.However,due to the influence of non-meteorological factors such as insects,the cloud observations are often contaminated by non-meteorological echoes in the clear air,known as clear-air echoes.It is of great significance to automatically identify the clear-air echoes in order to extract effective meteorological information from the complex weather background.The characteristics of clear-air echoes are studied here by combining data from four devices:an MMCR,a laser-ceilometer,an L-band radiosonde,and an all-sky camera.In addition,a new algorithm,which includes feature extraction,feature selection,and classification,is proposed to achieve the automatic identification of clear-air echoes.The results show that the recognition algorithm is fairly satisfied in both simple and complex weather conditions.The recognition accuracy can reach up to 95.86%for the simple cases when cloud echoes and clear-air echoes are separate,and 88.38%for the complicated cases when low cloud echoes and clear-air echoes are mixed. 展开更多
关键词 millimeter-wave cloud radar clear-air echoes neural network laser ceilometer all-sky camera feature extraction feature selection
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Arabic Speech Recognition System Based on MFCC and HMMs 认领
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作者 Hussien A. Elharati Mohamed Alshaari Veton Z. K?puska 《电脑和通信(英文)》 2020年第3期28-34,共7页
Speech recognition allows the machine to turn the speech signal into text through identification and understanding process. Extract the features, predict the maximum likelihood, and generate the models of the input sp... Speech recognition allows the machine to turn the speech signal into text through identification and understanding process. Extract the features, predict the maximum likelihood, and generate the models of the input speech signal are considered the most important steps to configure the Automatic Speech Recognition System (ASR). In this paper, an automatic Arabic speech recognition system was established using MATLAB and 24 Arabic words Consonant-Vowel Consonant-Vowel Consonant-Vowel (CVCVCV) was recorded from 19 Arabic native speakers, each speaker uttering the same word 3 times (total 1368 words). In order to test the system, 39-features were extracted by partitioning the speech signal into frames ~ 0.25 sec shifted by 0.10 sec. in back-end, the statistical models were generated by separated the features into number of states between 4 to 10, each state has 8-gaussian distributions. The data has 48 k sample rate and 32-bit depth and saved separately in a wave file format. The system was trained in phonetically rich and balanced Arabic speech words list (10 speakers * 3 times * 24 words, total 720 words) and tested using another word list (24 words * 9 speakers * 3 times *, total 648 words). Using different speakers similar words, the system obtained a very good word recognition accuracy results of 92.92% and a Word Error Rate (WER) of 7.08%. 展开更多
关键词 Speech Recognition Feature Extraction Maximum LIKELIHOOD GAUSSIAN Distribution Consonant-Vowel
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按区域自动批量裁剪地理数据的建模方法 认领
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作者 温树栋 吴翁慧 夏高峰 《北京测绘》 2020年第2期143-146,共4页
ArcGIS中文件地理数据库是常用数据格式。经常需要按其所辖单元区域批量裁剪输出地理数据。针对常规的手工操作不仅费时且易出错,本文提出基于ArcGIS ModelBuilder(模型构建器)建立模型工具的方法来实现地理数据库按区域自动批量的裁剪... ArcGIS中文件地理数据库是常用数据格式。经常需要按其所辖单元区域批量裁剪输出地理数据。针对常规的手工操作不仅费时且易出错,本文提出基于ArcGIS ModelBuilder(模型构建器)建立模型工具的方法来实现地理数据库按区域自动批量的裁剪输出。该方法使用模型工具嵌套的方式,利用迭代要素类建立裁剪子模型工具对地理数据库中全部要素类依次进行裁剪,再将裁剪子模型工具嵌套到主模型工具中,使用迭代要素选择按区域逐个选择裁剪要素,直至完成所有区域对地理数据的裁剪输出。 展开更多
关键词 模型构建器 地理数据库 迭代器 子模型工具 裁剪 要素 要素类
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现代韪书影响的拓展及其主要特征 认领
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作者 王明贵 《贵州工程应用技术学院学报》 2020年第2期40-44,共5页
现代时期韪书的影响,已经从传统的彝族地区、彝族基层群众特别是彝族传统知识分子毕摩阶层,向汉族地区和外国延展。现代韪书向外延展的主要表现,是在高层知识分子的推动下取得的,同时也是在外国传教者在中国与外国之间的活动,和彝族精... 现代时期韪书的影响,已经从传统的彝族地区、彝族基层群众特别是彝族传统知识分子毕摩阶层,向汉族地区和外国延展。现代韪书向外延展的主要表现,是在高层知识分子的推动下取得的,同时也是在外国传教者在中国与外国之间的活动,和彝族精英人物借助现代时期的媒体而达到的。这个动向,打破了韪书千百年来仅仅局限在西南彝族地区和彝族人民内部传承的格局,使韪书向更宽广的地域、更高级的层次和更专业的学者流播。 展开更多
关键词 民国韪书 影响 拓展 特征
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“老三届”散文家的创作特点、贡献及局限 认领
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作者 周纪鸿 《石家庄学院学报》 2020年第4期150-156,共7页
“老三届”散文家先写小说、诗歌,后写散文,他们具有深刻的生活意蕴,酿造人生苦旅后的锦绣华章;品味叙写特殊境遇下的酸甜苦辣,深刻体验和理解人间真情;关心国家民族命运,关注社会民俗风情,执笔秉持“为天地立心,为生民立命,为往圣继绝... “老三届”散文家先写小说、诗歌,后写散文,他们具有深刻的生活意蕴,酿造人生苦旅后的锦绣华章;品味叙写特殊境遇下的酸甜苦辣,深刻体验和理解人间真情;关心国家民族命运,关注社会民俗风情,执笔秉持“为天地立心,为生民立命,为往圣继绝学,为万世开太平”的精神信念。对当代散文,他们有着独特的贡献:创作持续的时间长、跨度大,作品数量多、质量高;用生命写作,很多是一种无法命名的生命绝唱;文体上不断追求创新。由于时代的局限和影响,部分“老三届”散文家的文化积淀不够厚实,对散文理论的开掘和创新不够多。 展开更多
关键词 “老三届”散文家 特点 贡献 局限
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集成设计参数和制造参数的车削工件机加工能耗预测方法 认领
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作者 何彦 陈文奇 +3 位作者 王禹林 岳冠楠 李育锋 田小成 《计算机集成制造系统》 EI CSCD 北大核心 2020年第9期2355-2366,共12页
为从工件设计和制造协同的角度出发,促进制造企业节能,提出了一种集成设计参数和制造参数的车削工件机加工能耗预测方法。基于STEP AP224协议对车削工件进行特征识别,并将工件设计参数以特征字典的形式保存。对车削工件进行基于特征的... 为从工件设计和制造协同的角度出发,促进制造企业节能,提出了一种集成设计参数和制造参数的车削工件机加工能耗预测方法。基于STEP AP224协议对车削工件进行特征识别,并将工件设计参数以特征字典的形式保存。对车削工件进行基于特征的工艺规划后考虑工序加工顺序对刀具路径的影响,生成各加工工序的刀具路径,利用token文件实现对工件各加工工序加工参数和刀具路径等制造参数的集成。通过分层面向对象的Petri网构建了工件机加工过程动态能耗模型,利用token文件驱动能耗模型对工件机加工能耗进行预测。以盘类及轴类工件为例,通过比较工件机加工过程能耗的测量值和预测值验证了该方法的有效性和准确性。 展开更多
关键词 特征 工件机加工能耗 分层面向对象的Petri网 设计参数 制造参数 数控机床
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Breast non-mass-like lesions on contrast-enhanced ultrasonography:Feature analysis,breast image reporting and data system classification assessment 认领
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作者 Ping Xu Min Yang +3 位作者 Yong Liu Yan-Ping Li Hong Zhang Guang-Rui Shao 《世界临床病例杂志》 SCIE 2020年第4期700-712,共13页
BACKGROUND Breast non-mass-like lesions(NMLs)account for 9.2%of all breast lesions.The specificity of the ultrasound diagnosis of NMLs is low,and it cannot be objectively classified according to the 5th Edition of the... BACKGROUND Breast non-mass-like lesions(NMLs)account for 9.2%of all breast lesions.The specificity of the ultrasound diagnosis of NMLs is low,and it cannot be objectively classified according to the 5th Edition of the Breast Imaging Reporting and Data System(BI-RADS).Contrast-enhanced ultrasound(CEUS)can help to differentiate and classify breast lesions but there are few studies on NMLs alone.AIM To analyze the features of benign and malignant breast NMLs in grayscale ultrasonography(US),color Doppler flow imaging(CDFI)and CEUS,and to explore the efficacy of the combined diagnosis of NMLs and the effect of CEUS on the BI-RADS classification of NMLs.METHODS A total of 51 breast NMLs verified by pathology were analyzed in our hospital from January 2017 to April 2019.All lesions were examined by US,CDFI and CEUS,and their features from those examinations were analyzed.With pathology as the gold standard,binary logic regression was used to analyze the independent risk factors for malignant breast NMLs,and a regression equation was established to calculate the efficiency of combined diagnosis.Based on the regression equation,the combined diagnostic efficiency of US combined with CEUS(US+CEUS)was determined.The initial BI-RADS-US classification of NMLs was adjusted according to the independent risk factors identified by CEUS,and the diagnostic efficiency of CEUS combined with BI-RADS(CEUS+BI-RADS)was calculated based on the results.ROC curves were drawn to compare the diagnostic values of the three methods,including US,US+CEUS,and CEUS+BI-RADS,for benign and malignant NMLs.RESULTS Microcalcification,enhancement time,enhancement intensity,lesion scope,and peripheral blood vessels were significantly different between benign and malignant NMLs.Among these features,microcalcification,higher enhancement,and lesion scope were identified as independent risk factors for malignant breast NMLs.When US,US+CEUS,and CEUS+BI-RADS were used to identify the benign and malignant breast NMLs,their sensitivity rates were 82.6%,91.3%,and 展开更多
关键词 BREAST tumor Ultrasonography Contrast agents Feature exploration Diagnosis Non-mass-like LESIONS
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Object tracking method based on joint global and local feature descriptor of 3D LIDAR point cloud 认领
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作者 钱其姝 胡以华 +3 位作者 赵楠翔 李敏乐 邵福才 张鑫源 《中国光学快报:英文版》 SCIE EI CAS CSCD 2020年第6期24-29,共6页
To fully describe the structure information of the point cloud when the LIDAR-object distance is long,a joint global and local feature(JGLF)descriptor is constructed.Compared with five typical descriptors,the object r... To fully describe the structure information of the point cloud when the LIDAR-object distance is long,a joint global and local feature(JGLF)descriptor is constructed.Compared with five typical descriptors,the object recognition rate of JGLF is higher when the LIDAR-object distances change.Under the situation that airborne LIDAR is getting close to the object,the particle filtering(PF)algorithm is used as the tracking frame.Particle weight is updated by comparing the difference between JGLFs to track the object.It is verified that the proposed algorithm performs 13.95%more accurately and stably than the basic PF algorithm. 展开更多
关键词 object tracking LIDAR global and local feature descriptor point cloud
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