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Tomato Growth Height Prediction Method by Phenotypic Feature Extraction Using Multi-modal Data
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作者 GONG Yu WANG Ling +3 位作者 ZHAO Rongqiang YOU Haibo ZHOU Mo LIU Jie 《智慧农业(中英文)》 2025年第1期97-110,共14页
[Objective]Accurate prediction of tomato growth height is crucial for optimizing production environments in smart farming.However,current prediction methods predominantly rely on empirical,mechanistic,or learning-base... [Objective]Accurate prediction of tomato growth height is crucial for optimizing production environments in smart farming.However,current prediction methods predominantly rely on empirical,mechanistic,or learning-based models that utilize either images data or environmental data.These methods fail to fully leverage multi-modal data to capture the diverse aspects of plant growth comprehensively.[Methods]To address this limitation,a two-stage phenotypic feature extraction(PFE)model based on deep learning algorithm of recurrent neural network(RNN)and long short-term memory(LSTM)was developed.The model integrated environment and plant information to provide a holistic understanding of the growth process,emploied phenotypic and temporal feature extractors to comprehensively capture both types of features,enabled a deeper understanding of the interaction between tomato plants and their environment,ultimately leading to highly accurate predictions of growth height.[Results and Discussions]The experimental results showed the model's ef‐fectiveness:When predicting the next two days based on the past five days,the PFE-based RNN and LSTM models achieved mean absolute percentage error(MAPE)of 0.81%and 0.40%,respectively,which were significantly lower than the 8.00%MAPE of the large language model(LLM)and 6.72%MAPE of the Transformer-based model.In longer-term predictions,the 10-day prediction for 4 days ahead and the 30-day prediction for 12 days ahead,the PFE-RNN model continued to outperform the other two baseline models,with MAPE of 2.66%and 14.05%,respectively.[Conclusions]The proposed method,which leverages phenotypic-temporal collaboration,shows great potential for intelligent,data-driven management of tomato cultivation,making it a promising approach for enhancing the efficiency and precision of smart tomato planting management. 展开更多
关键词 tomato growth prediction deep learning phenotypic feature extraction multi-modal data recurrent neural net‐work long short-term memory large language model
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Test method of laser paint removal based on multi-modal feature fusion 被引量:1
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作者 HUANG Hai-peng HAO Ben-tian +2 位作者 YE De-jun GAO Hao LI Liang 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第10期3385-3398,共14页
Laser cleaning is a highly nonlinear physical process for solving poor single-modal(e.g., acoustic or vision)detection performance and low inter-information utilization. In this study, a multi-modal feature fusion net... Laser cleaning is a highly nonlinear physical process for solving poor single-modal(e.g., acoustic or vision)detection performance and low inter-information utilization. In this study, a multi-modal feature fusion network model was constructed based on a laser paint removal experiment. The alignment of heterogeneous data under different modals was solved by combining the piecewise aggregate approximation and gramian angular field. Moreover, the attention mechanism was introduced to optimize the dual-path network and dense connection network, enabling the sampling characteristics to be extracted and integrated. Consequently, the multi-modal discriminant detection of laser paint removal was realized. According to the experimental results, the verification accuracy of the constructed model on the experimental dataset was 99.17%, which is 5.77% higher than the optimal single-modal detection results of the laser paint removal. The feature extraction network was optimized by the attention mechanism, and the model accuracy was increased by 3.3%. Results verify the improved classification performance of the constructed multi-modal feature fusion model in detecting laser paint removal, the effective integration of acoustic data and visual image data, and the accurate detection of laser paint removal. 展开更多
关键词 laser cleaning multi-modal fusion image processing deep learning
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BDMFuse:Multi-scale network fusion for infrared and visible images based on base and detail features
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作者 SI Hai-Ping ZHAO Wen-Rui +4 位作者 LI Ting-Ting LI Fei-Tao Fernando Bacao SUN Chang-Xia LI Yan-Ling 《红外与毫米波学报》 北大核心 2025年第2期289-298,共10页
The fusion of infrared and visible images should emphasize the salient targets in the infrared image while preserving the textural details of the visible images.To meet these requirements,an autoencoder-based method f... The fusion of infrared and visible images should emphasize the salient targets in the infrared image while preserving the textural details of the visible images.To meet these requirements,an autoencoder-based method for infrared and visible image fusion is proposed.The encoder designed according to the optimization objective consists of a base encoder and a detail encoder,which is used to extract low-frequency and high-frequency information from the image.This extraction may lead to some information not being captured,so a compensation encoder is proposed to supplement the missing information.Multi-scale decomposition is also employed to extract image features more comprehensively.The decoder combines low-frequency,high-frequency and supplementary information to obtain multi-scale features.Subsequently,the attention strategy and fusion module are introduced to perform multi-scale fusion for image reconstruction.Experimental results on three datasets show that the fused images generated by this network effectively retain salient targets while being more consistent with human visual perception. 展开更多
关键词 infrared image visible image image fusion encoder-decoder multi-scale features
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Unraveling Single-Cell Metabolic Features in Breast Cancer Drug Resistance Using Mass Spectrometry
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作者 LIU Chun-yan CHEN Hao-ran +3 位作者 WANG Yan WU Xian-zhe FANG Dan-jun CHEN Yun 《质谱学报》 北大核心 2025年第6期826-837,I0005,共13页
Drug resistance remains a major challenge in breast cancer chemotherapy,yet the metabolic alterations underlying this phenomenon are not fully understood.There is much evidence indicating the cellular heterogeneity am... Drug resistance remains a major challenge in breast cancer chemotherapy,yet the metabolic alterations underlying this phenomenon are not fully understood.There is much evidence indicating the cellular heterogeneity among cancer cells,which exhibit varying degrees of metabolic reprogramming and thus may result in differential contributions to drug resistance.A home-built single-cell quantitative mass spectrometry(MS)platform,which integrates micromanipulation and electro-osmotic sampling,was developed to quantitatively profile the tricarboxylic acid(TCA)cycle metabolites at the single-cell level.Using this platform,the metabolic profiles of drug-sensitive MCF-7 breast cancer cells and their drug-resistant derivative MCF-7/ADR cells were compared.This results revealed a selective upregulation of downstream TCA cycle metabolites includingα-ketoglutarate,succinate,fumarate,and malate in drug-resistant cancer cells,while early TCA metabolites remained largely unchanged.Furthermore,notable variations in the abundance of the metabolites were observed in individual cells.The comparative analysis also revealed that not all MCF-7/ADR cells exhibit the same degree of metabolic deviation from the parental line in the metabolites during resistance acquisition.The observed metabolic profiles indicate enhanced glutaminolysis,altered mitochondrial electron transport chain activity,and increased metabolic flexibility in drug-resistant cancer cells that support their survival under chemotherapeutic stress.The findings further suggest the potential for incorporating cellular metabolic heterogeneity into future drug resistance studies. 展开更多
关键词 mass spectrometry single-cell metabolic features breast cancer drug resistance tricarboxylic acid(TCA)cycle
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Seismic features of vibration induced by train 被引量:16
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作者 陈棋福 李丽 +5 位作者 李纲 陈凌 彭文涛 汤毅 陈颙 王夫运 《地震学报》 CSCD 北大核心 2004年第6期651-659,共9页
Based on schematically formulation of the vibrations induced by moving trains, this paper analyses the waveforms along the Datong-Qinhuangdao railroad in Northern China recorded in the suburban Huairou district of Bei... Based on schematically formulation of the vibrations induced by moving trains, this paper analyses the waveforms along the Datong-Qinhuangdao railroad in Northern China recorded in the suburban Huairou district of Beijing on March 8, 2003. It is illustrated that vibrations induced by train, except traditional recognized noises and interfer- ence effects, could be used as a seismic source to detect crustal structures with its advantage of abundant frequency spectrum, repeatability and no additional harm to the environment. It will bring lights to the traditional exploration seismology with the further studies of signal processing and interpretation methods, and related models and new observing systems. 展开更多
关键词 列车振动 多点运动源 记录特征
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Probing the Linguistic and Rhetorical Features of English Speeches 被引量:1
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作者 李庆明 《西安理工大学学报》 CAS 2004年第3期327-331,共5页
English speech is a discourse delivered at an assembly or on formal occasions. As a variety of the English language, English speech has a unique presentation of its own. This paper, as its title indicates, is to analy... English speech is a discourse delivered at an assembly or on formal occasions. As a variety of the English language, English speech has a unique presentation of its own. This paper, as its title indicates, is to analyze and probe the linguistic and rhetorical features of famous English speeches with a view to improving the ability to appreciate English speeches on the part of Chinese learners of English. 展开更多
关键词 英语演讲 语言学 修辞特征 句型
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Mechanical properties and deformation features of AZ31-0.84%Sb alloy 被引量:3
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作者 田素贵 SOHN Keun-yong KIM Kyung-hyun 《材料与冶金学报》 CAS 2005年第2期138-141,共4页
The mechanical properties and deformation features of AZ31-0.84% Sb alloy have been studied by means of the measurement of the properties and morphology observation. Results show that UTS of AZ31-0.84% Sb alloy at roo... The mechanical properties and deformation features of AZ31-0.84% Sb alloy have been studied by means of the measurement of the properties and morphology observation. Results show that UTS of AZ31-0.84% Sb alloy at room temperature is 297MPa, a higher value of UTS is still maintained up to 189MPa as temperature elevated to 200℃. One of the main reasons for enhancing UTS of the alloy is attributed to the high volume fraction of the precipitates dispersed in the matrix, including Mg3Sb2 phase, which effectively hindered the movement of dislocations during the elevated temperature deformation. The deformation mechanisms of AZ31-0.84% Sb alloy are the twins and dislocations activated on basal and non-basal planes. a+c dislocations may be activated on the basal and non-basal planes in twins regions, and some of the thinner twins may shear through the dense dislocations within the thicker twins. 展开更多
关键词 机械性能 变形特征 AZ31合金 显微结构
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The Lexis Features of Advertisement English
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作者 张高锋 田建国 《陕西师范大学学报(哲学社会科学版)》 CSSCI 北大核心 2004年第S2期401-404,共4页
This paper is going to focus on the lexis characteristics of the advertisement English in stylistics. The lexis characteristics of advertisement include using the new form of the spelling of a word to attract the cons... This paper is going to focus on the lexis characteristics of the advertisement English in stylistics. The lexis characteristics of advertisement include using the new form of the spelling of a word to attract the consumers’ attention; using the borrowed words to enhance the transmission effect of the advertisements; Frequent use of some verbs, adjectives to express the information and enhance the effect of language expression; Using the compounds in flexibility. Meanwhile, we could find out that some specific terms are used and the word used in advertisements show the gender. 展开更多
关键词 ADVERTISEMENT ENGLISH lexis featurE LANGUAGE EXPRESSION
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The Detecting System of Image Forgeries with Noise Features and EXIF Information 被引量:5
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作者 SUN Xiaoting LI Yezhou +1 位作者 NIU Shaozhang HUANG Yanli 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第5期1164-1176,共13页
Recently, the digital image blind forensics technology has received an increasing attention in academic community. This paper aims at developing a new identification approach based on the statistical noise and exchang... Recently, the digital image blind forensics technology has received an increasing attention in academic community. This paper aims at developing a new identification approach based on the statistical noise and exchangeable image file format (EXIF) information of image for images authen- tication. In particular, the authors can identify whether the current image has been modified or not by utilizing the relevance between noise and EXIF parameters and comparing the real values with the estimated values of the EXIF parameters. Experimental results validate the proposed method. That is, the detecting system can identify the doctored image effectively. 展开更多
关键词 Blind forensics doctored image EXIF parameters noise features
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Texture features analysis on micro-structure of paste backfill based on image analysis technology 被引量:8
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作者 YIN Sheng-hua SHAO Ya-jian +2 位作者 WU Ai-xiang WANG Yi-ming GAO Zhi-yong 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第10期2360-2372,共13页
The strength of cement-based materials,such as mortar,concrete and cement paste backfill(CPB),depends on its microstructures(e.g.pore structure and arrangement of particles and skeleton).Numerous studies on the relati... The strength of cement-based materials,such as mortar,concrete and cement paste backfill(CPB),depends on its microstructures(e.g.pore structure and arrangement of particles and skeleton).Numerous studies on the relationship between strength and pore structure(e.g.,pore size and its distribution)were performed,but the micro-morphology characteristics have been rarely concerned.Texture describing the surface properties of the sample is a global feature,which is an effective way to quantify the micro-morphological properties.In statistical analysis,GLCM features and Tamura texture are the most representative methods for characterizing the texture features.The mechanical strength and section image of the backfill sample prepared from three different solid concentrations of paste were obtained by uniaxial compressive strength test and scanning electron microscope,respectively.The texture features of different SEM images were calculated based on image analysis technology,and then the correlation between these parameters and the strength was analyzed.It was proved that the method is effective in the quantitative analysis on the micro-morphology characteristics of CPB.There is a significant correlation between the texture features and the unconfined compressive strength,and the prediction of strength is feasible using texture parameters of the CPB microstructure. 展开更多
关键词 microstructure texture feature Tamura texture GLCM feature unconfined compressive strength quantitative analysis cement paste backfill
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Pulse-to-pulse periodic signal sorting features and feature extraction in radar emitter pulse sequences 被引量:5
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作者 Qiang Guo Zhenshen Qu Changhong Wang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第3期382-389,共8页
A novel class of periodically changing features hidden in radar pulse sequence environment,named G features,is proposed.Combining fractal theory and Hilbert-Huang transform,the features are extracted using changing ch... A novel class of periodically changing features hidden in radar pulse sequence environment,named G features,is proposed.Combining fractal theory and Hilbert-Huang transform,the features are extracted using changing characteristics of pulse parameters in radar emitter signals.The features can be applied in modern complex electronic warfare environment to address the issue of signal sorting when radar emitter pulse signal parameters severely or even completely overlap.Experiment results show that the proposed feature class and feature extraction method can discriminate periodically changing pulse sequence signal sorting features from radar pulse signal flow with complex variant features,therefore provide a new methodology for signal sorting. 展开更多
关键词 signal sorting fractal geometry Hilbert-Huang transform(HHT) G feature extraction.
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Elitism-based immune genetic algorithm and its application to optimization of complex multi-modal functions 被引量:4
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作者 谭冠政 周代明 +1 位作者 江斌 DIOUBATE Mamady I 《Journal of Central South University of Technology》 EI 2008年第6期845-852,共8页
A novel immune genetic algorithm with the elitist selection and elitist crossover was proposed, which is called the immune genetic algorithm with the elitism (IGAE). In IGAE, the new methods for computing antibody s... A novel immune genetic algorithm with the elitist selection and elitist crossover was proposed, which is called the immune genetic algorithm with the elitism (IGAE). In IGAE, the new methods for computing antibody similarity, expected reproduction probability, and clonal selection probability were given. IGAE has three features. The first is that the similarities of two antibodies in structure and quality are all defined in the form of percentage, which helps to describe the similarity of two antibodies more accurately and to reduce the computational burden effectively. The second is that with the elitist selection and elitist crossover strategy IGAE is able to find the globally optimal solution of a given problem. The third is that the formula of expected reproduction probability of antibody can be adjusted through a parameter r, which helps to balance the population diversity and the convergence speed of IGAE so that IGAE can find the globally optimal solution of a given problem more rapidly. Two different complex multi-modal functions were selected to test the validity of IGAE. The experimental results show that IGAE can find the globally maximum/minimum values of the two functions rapidly. The experimental results also confirm that IGAE is of better performance in convergence speed, solution variation behavior, and computational efficiency compared with the canonical genetic algorithm with the elitism and the immune genetic algorithm with the information entropy and elitism. 展开更多
关键词 immune genetic algorithm multi-modal function optimization evolutionary computation elitist selection elitist crossover
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Densification,microstructural features and tensile properties of selective laser melted AlMgSiScZr alloy from single track to block specimen 被引量:6
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作者 BI Jiang CHEN Yan-bin +2 位作者 CHEN Xi STAROSTENKOV M D DONG Guo-jiang 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第4期1129-1143,共15页
The selective laser melting(SLM)processed aluminum alloys have already aroused researchers’attention in aerospace,rail transport and petrochemical engineering due to the comprehensive advantages of low density,good c... The selective laser melting(SLM)processed aluminum alloys have already aroused researchers’attention in aerospace,rail transport and petrochemical engineering due to the comprehensive advantages of low density,good corrosion resistance and high mechanical performance.In this paper,an Al-14.1Mg-0.47Si-0.31Sc-0.17Zr alloy was fabricated via SLM.The characteristics of single track at different process parameters,and the influence of hatch spacing on densification,microstructural features and tensile properties of block specimens were systematically studied.The hatch spacing has an influence on the overlap ratio of single track,and further affects the internal forming quality of printed specimen.At a laser power of 160 W and scanning speed of 400 mm/s,the densification of block specimen increased first and then decreased with the increase of hatch spacing.The nearly full dense specimen(98.7%)with a tensile strength of 452 MPa was fabricated at a hatch spacing of 80μm.Typical characteristics of dimple and cleavage on the tensile fracture of the AlMgSiScZr alloy showed the mixed fracture of ductility and brittleness. 展开更多
关键词 selective laser melting aluminum alloy hatch spacing microstructural feature tensile properties
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Face recognition using SIFT features under 3D meshes 被引量:1
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作者 张诚 谷宇章 +1 位作者 胡珂立 王营冠 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第5期1817-1825,共9页
Expression, occlusion, and pose variations are three main challenges for 3D face recognition. A novel method is presented to address 3D face recognition using scale-invariant feature transform(SIFT) features on 3D mes... Expression, occlusion, and pose variations are three main challenges for 3D face recognition. A novel method is presented to address 3D face recognition using scale-invariant feature transform(SIFT) features on 3D meshes. After preprocessing, shape index extrema on the 3D facial surface are selected as keypoints in the difference scale space and the unstable keypoints are removed after two screening steps. Then, a local coordinate system for each keypoint is established by principal component analysis(PCA).Next, two local geometric features are extracted around each keypoint through the local coordinate system. Additionally, the features are augmented by the symmetrization according to the approximate left-right symmetry in human face. The proposed method is evaluated on the Bosphorus, BU-3DFE, and Gavab databases, respectively. Good results are achieved on these three datasets. As a result, the proposed method proves robust to facial expression variations, partial external occlusions and large pose changes. 展开更多
关键词 3D face recognition seale-invariant feature transform (SIFT) expression OCCLUSION large pose changes 3D meshes
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Detection of artificial pornographic pictures based on multiple features and tree mode 被引量:3
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作者 MAO Xing-liang LI Fang-fang +1 位作者 LIU Xi-yao ZOU Bei-ji 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第7期1651-1664,共14页
It is easy for teenagers to view pornographic pictures on social networks. Many researchers have studied the detection of real pornographic pictures, but there are few studies on those that are artificial. In this wor... It is easy for teenagers to view pornographic pictures on social networks. Many researchers have studied the detection of real pornographic pictures, but there are few studies on those that are artificial. In this work, we studied how to detect artificial pornographic pictures, especially when they are on social networks. The whole detection process can be divided into two stages: feature selection and picture detection. In the feature selection stage, seven types of features that favour picture detection were selected. In the picture detection stage, three steps were included. 1) In order to alleviate the imbalance in the number of artificial pornographic pictures and normal ones, the training dataset of artificial pornographic pictures was expanded. Therefore, the features which were extracted from the training dataset can also be expanded too. 2) In order to reduce the time of feature extraction, a fast method which extracted features based on the proportionally scaled picture rather than the original one was proposed. 3) Three tree models were compared and a gradient boost decision tree (GBDT) was selected for the final picture detection. Three sets of experimental results show that the proposed method can achieve better recognition precision and drastically reduce the time cost of the method. 展开更多
关键词 multiple feature artificial pornographic pictures picture detection gradient boost decision tree
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Multi-modality liver image registration based on multilevel B-splines free-form deformation and L-BFGS optimal algorithm 被引量:1
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作者 宋红 李佳佳 +1 位作者 王树良 马婧婷 《Journal of Central South University》 SCIE EI CAS 2014年第1期287-292,共6页
A new coarse-to-fine strategy was proposed for nonrigid registration of computed tomography(CT) and magnetic resonance(MR) images of a liver.This hierarchical framework consisted of an affine transformation and a B-sp... A new coarse-to-fine strategy was proposed for nonrigid registration of computed tomography(CT) and magnetic resonance(MR) images of a liver.This hierarchical framework consisted of an affine transformation and a B-splines free-form deformation(FFD).The affine transformation performed a rough registration targeting the mismatch between the CT and MR images.The B-splines FFD transformation performed a finer registration by correcting local motion deformation.In the registration algorithm,the normalized mutual information(NMI) was used as similarity measure,and the limited memory Broyden-Fletcher- Goldfarb-Shannon(L-BFGS) optimization method was applied for optimization process.The algorithm was applied to the fully automated registration of liver CT and MR images in three subjects.The results demonstrate that the proposed method not only significantly improves the registration accuracy but also reduces the running time,which is effective and efficient for nonrigid registration. 展开更多
关键词 multi-modal image registration affine transformation B-splines free-form deformation (FFD) L-BFGS
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基于Bag of Features的手势识别 被引量:4
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作者 陈小波 谢伙生 《计算机工程与设计》 CSCD 北大核心 2013年第3期983-988,共6页
基于视觉的手势识别中,手势的识别效果易受手势旋转,光照亮度的影响,针对该问题,借鉴了目标识别和图像检索领域的Bag of Features(特征袋)算法,将Bag of Features算法应用到手势识别领域。通过SURF(加速鲁棒性特征)算法提取手势图像的... 基于视觉的手势识别中,手势的识别效果易受手势旋转,光照亮度的影响,针对该问题,借鉴了目标识别和图像检索领域的Bag of Features(特征袋)算法,将Bag of Features算法应用到手势识别领域。通过SURF(加速鲁棒性特征)算法提取手势图像的特征描述符,使手势对尺度、旋转、光照具有很强的适应力,再应用Bag of Features算法把SURF特征描述符映射到一个统一维度的向量,即Bag of Features特征向量,再用支持向量机对图像得到的特征向量进行训练分类。实验结果表示,该方法不仅具有较高的时间效率,满足手势识别的实时性,而且即使在很大角度的旋转以及亮度的变化下,仍能达到较高的识别率。 展开更多
关键词 手势识别 特征袋 加速鲁棒性特征 向量量化 支持向量机
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The 3D Face Recognition Algorithm Fusing Multi-geometry Features 被引量:3
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作者 SUN Yan-Feng TANG Heng-Liang YIN Bao-Cai 《自动化学报》 EI CSCD 北大核心 2008年第12期1483-1489,共7页
因为它的 insensitivity, 3D 脸识别吸引越来越多的注意到照明和姿势的变化。有在这个话题要解决的许多关键问题,例如 3D 脸表示和有效多特征熔化。在这份报纸,一个新奇 3D 脸识别算法被建议,它的性能在 BJUT-3D 脸数据库上被表明... 因为它的 insensitivity, 3D 脸识别吸引越来越多的注意到照明和姿势的变化。有在这个话题要解决的许多关键问题,例如 3D 脸表示和有效多特征熔化。在这份报纸,一个新奇 3D 脸识别算法被建议,它的性能在 BJUT-3D 脸数据库上被表明。这个算法选择脸表面性质和相对关系矩阵的原则部件为脸表示特征。为每个特征的类似公制被定义。特征熔化策略被建议。它基于菲希尔是线性加权的策略线性判别式分析。最后,介绍算法在 BJUT-3D 脸数据库上被测试。算法和熔化策略的表演是令人满意的,这被结束。 展开更多
关键词 三维系统 人脸识别系统 计算方法 几何特征
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Spectroscopic Features and Coloration of Gem-Quality Green Tsavorite in Major International Deposits and China
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作者 L Linsu ZHANG Yong +3 位作者 LI Hongbo LU Taijin MAO Bing CHEN Hua 《矿物学报》 CAS CSCD 北大核心 2013年第S1期63-63,共1页
Tsavorite green colored by Cr3+/V3+ has been traditionally found and mined in Tanzania, Kenya and Madagascar in the Neoproterozoic Mozambique metamorphic belt (NMMB), and recently be found in Sanjiang, Litang, Sichuan... Tsavorite green colored by Cr3+/V3+ has been traditionally found and mined in Tanzania, Kenya and Madagascar in the Neoproterozoic Mozambique metamorphic belt (NMMB), and recently be found in Sanjiang, Litang, Sichuan, China. The differences of the chemical formula, spectroscopic features, as well as the concentrations of the V2O3 and Cr2O3 in the tsavorite crystals collected from major international deposits and Sanjiang, China have been investigated using EPMA, XRF, UV-VIS spectrometers, FTIR, Raman scattering microscopy, DiamondView TM techniques. It was found that the chemical formulas of African tsavorite and Chinese tsavorite are Ca3(Al,V)2[SiO4]3 and Ca3(Al,Cr)2[SiO4]3, respectively, indicating that tsavorite is a solid solution between dominant grossular and minor goldmanite and uvarovite. Two broad bands centered at 430 nm and 605 nm were the main absorption features in the tsavorite samples, which attribute to the absorption of Cr3+ and/or V3+ ions in the lattice. The green coloration is caused by Cr3+ and/or V3+ ions resulting in the absorption of purple and red components of the visible light. Absorptions caused of Fe3+ and Fe2+ ions could add the bluish color component in some of tsavorite samples. The intensity of green color is proportional to the concentrations of V2O3 and Cr2O3. The basic gemological properties, such as refractive index in the investigated samples were presented, and the definition and chemical and spectroscopic properties of tsavorite are discussed. 展开更多
关键词 tsavorite SPECTROSCOPIC feature COLORATION China EAST AFRICA
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A Study on the Mineralogical Features of the Oxidation-reduction of Graphite Deposit in Pingdu, Shandong
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作者 QIN Lang CHUAN Xiu-yun 《矿物学报》 CAS CSCD 北大核心 2013年第S1期76-76,共1页
The mineralogical features of the oxidation-reduction of graphite deposit in pingdu, Shandong province were studied by field search, polarization microscope, X-ray diffraction (XRD) and SEM. The results show that, the... The mineralogical features of the oxidation-reduction of graphite deposit in pingdu, Shandong province were studied by field search, polarization microscope, X-ray diffraction (XRD) and SEM. The results show that, the major rocks of the reduction graphite zone are graphite-quartz anorthosite, gabbro. The major rocks of the oxidation graphite zone are marble with graphite, biotite granite, monzogranite. The main minerals of the reduction zone are plagioclase, pyroxene, quartz, pyrite. The graphite is aphanitic graphite appearing as dense massive, layered, spherical aggregates. The main minerals of the oxidation zone are calcite, quartz, K-feldspar, biotite, amphibole, chlorite. The graphite is flake graphite uniformly dispersed in the loose, and strongly erosion rocks. A large number of rocks in the area have been suffered chloritization, regional metamorphism, indicating that the formation of the graphite deposit should be related with gabbro melting. The carbon source in the lower part was taken into the mine, and then experienced regional metamorphism. 展开更多
关键词 GRAPHITE oxidation-reduction DEPOSIT MINERALOGICAL feature Pingdu SHANDONG
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