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Automatic modulation recognition of radiation source signals based on two-dimensional data matrix and improved residual neural network
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作者 Guanghua Yi Xinhong Hao +3 位作者 Xiaopeng Yan Jian Dai Yangtian Liu Yanwen Han 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期364-373,共10页
Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the ... Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the AMR method of radiation source signals based on two-dimensional data matrix and improved residual neural network is proposed in this paper.First,the time series of the radiation source signals are reconstructed into two-dimensional data matrix,which greatly simplifies the signal preprocessing process.Second,the depthwise convolution and large-size convolutional kernels based residual neural network(DLRNet)is proposed to improve the feature extraction capability of the AMR model.Finally,the model performs feature extraction and classification on the two-dimensional data matrix to obtain the recognition vector that represents the signal modulation type.Theoretical analysis and simulation results show that the AMR method based on two-dimensional data matrix and improved residual network can significantly improve the accuracy of the AMR method.The recognition accuracy of the proposed method maintains a high level greater than 90% even at -14 dB SNR. 展开更多
关键词 Automatic modulation recognition Radiation source signals Two-dimensional data matrix Residual neural network Depthwise convolution
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Corrigendum to“Atomic-scale electromagnetic theory bridging optics in microscopic world and macroscopic world”
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作者 李志远 陈剑锋 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期586-586,共1页
The signs of the electric field markers in Figs.2 and 4 of the paper[Chin.Phys.B 32104211(2023)]have been corrected.These modifications do not affect the results derived in the paper.
关键词 CORRIGENDUM atomic-scale electromagnetic theory two-dimensional materials transfer matrix method
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Single-cell manipulation by two-dimensional micropatterning
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作者 Xuehe Ma Haimei Zhang +7 位作者 Shiyu Deng Qiushuo Sun Qingsong Hu Yuhang Pan Fen Hu Imshik Lee Fulin Xing Leiting Pan 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2024年第1期45-59,共15页
Cells are highly sensitive to their geometrical and mechanical microenvironment that directly regulate cell shape,cytoskeleton and organelle,as well as the nucleus morphology and genetic expression.The emerging two-di... Cells are highly sensitive to their geometrical and mechanical microenvironment that directly regulate cell shape,cytoskeleton and organelle,as well as the nucleus morphology and genetic expression.The emerging two-dimensional micropatterning techniques offer powerful tools to construct controllable and well-organized microenvironment for single-cell level investigations with qualitative analysis,cellular standardization,and in vivo environment mimicking.Here,we provide an overview of the basic principle and characteristics of the two most widely-used micropatterning techniques,including photolithographic micropatterning and soft lithography micropatterning.Moreover,we summarize the application of micropatterning technique in controlling cytoskeleton,cell migration,nucleus and gene expression,as well as intercellular communication. 展开更多
关键词 Two-dimensional micropatterning CYTOSKELETON cell migration extracellular matrix intercellular communication gene expression
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CHANGES OF NUCLEAR MATRIX PROTEIN AND ITS RELATIONSHIP WITH c-erbB-2 IN HUMAN COLON ADENOCARCINOMA
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作者 王娅兰 高静 李圆圆 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2005年第4期255-259,共5页
Objective: Nuclear matrix protein is tissue, cell-type specific, and tumor-relative. It plays an important role in the regulation of intranuclear processes. Some researches also showed that a c-erbB-2 promoter-specif... Objective: Nuclear matrix protein is tissue, cell-type specific, and tumor-relative. It plays an important role in the regulation of intranuclear processes. Some researches also showed that a c-erbB-2 promoter-specific DNA-binding nuclear matrix protein is present only in malignant human breast tissues and induces mitogenesis and cell surface expression of the c-erbB-2 protein in resting NIH/3T3 cells. But it is not clear that how it in colon adenocarcinomas. Methods: Two-dimensional gel electrophoretic method was used for NMP identification and immunohistochemistry was used for c-erbB-2 detection in 12 cases of colon adenocarcinomas and matched adjacent normal colon tissues. Results: 5 different nuclear matrix proteins (named C1-C5) were identified in 12 colon adenocarcinoma specimens, but not in the matched adjacent normal colon tissues; 3 nuclear matrix proteins (named N1-N3) were identified in all 12 matched adjacent normal colon tissues, but not in colon adenocarcinoma specimens. A nuclear matrix protein (named N4) was detected in all of 9 moderated-well differentiated adenocarcinomas and all 12 matched adjacent normal colon tissues, but not in 3 poor-differentiated adenocarcinomas. All of the 10 colon adenocarcinomas which had the nuclear matrix protein C4 were c-erbB-2 expression positive. Conclusion: The data suggest that there are specific nuclear matrix proteins in colon adenocarcinomas and its subtypes, which maybe valuable to serve as markers of colon adenocarcinomas in future. Nuclear matrix protein C4 probably is a c-erbB-2 promotor-specific nuclear matrix protein in colon adenocarcinomas, and may induce the expression of c-erbB-2. 展开更多
关键词 Colon adenocarcinoma Nuclear matrix protein C-ERBB-2 Two-dimensional gel electrophoresis
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Eigenfunction expansion method of upper triangular operator matrixand application to two-dimensional elasticity problems based onstress formulation
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作者 额布日力吐 阿拉坦仓 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2012年第2期223-232,共10页
This paper studies the eigenfunction expansion method to solve the two dimensional (2D) elasticity problems based on the stress formulation. The fundamental system of partial differential equations of the 2D problem... This paper studies the eigenfunction expansion method to solve the two dimensional (2D) elasticity problems based on the stress formulation. The fundamental system of partial differential equations of the 2D problems is rewritten as an upper tri angular differential system based on the known results, and then the associated upper triangular operator matrix matrix is obtained. By further research, the two simpler com plete orthogonal systems of eigenfunctions in some space are obtained, which belong to the two block operators arising in the operator matrix. Then, a more simple and conve nient general solution to the 2D problem is given by the eigenfunction expansion method. Furthermore, the boundary conditions for the 2D problem, which can be solved by this method, are indicated. Finally, the validity of the obtained results is verified by a specific example. 展开更多
关键词 eigenfunction expansion method two-dimensional (2D) elasticity problem upper triangular operator matrix general solution
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Atomic-scale electromagnetic theory bridging optics in microscopic world and macroscopic world
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作者 李志远 陈剑锋 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第10期483-502,共20页
Atoms in the microscopic world are the basic building blocks of the macroscopic world. In this work, we construct an atomic-scale electromagnetic theory that bridges optics in the microscopic and macroscopic worlds. A... Atoms in the microscopic world are the basic building blocks of the macroscopic world. In this work, we construct an atomic-scale electromagnetic theory that bridges optics in the microscopic and macroscopic worlds. As the building block of the theory, we use the microscopic polarizability to describe the optical response of a single atom, solve the transport of electromagnetic wave through a single atomic layer under arbitrary incident angle and polarization of the light beam, construct the single atomic layer transfer matrix for light transport across the atomic layer. Based on this transfer matrix, we get the analytical form of the dispersion relation, refractive index, and transmission/reflection coefficient of the macroscopic medium. The developed theory can handle single-layer and few-layers of homogeneous and heterogeneous 2D materials, investigate homogeneous 2D materials with various vacancies or insertion atomic-layer defects, study compound 2D materials with a unit cell composed of several elements in both the lateral and parallel directions with respect to the light transport. 展开更多
关键词 atomic-scale electromagnetic theory two-dimensional materials transfer matrix method
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Identification of differentially expressed proteins in poplar leaves in-duced by Marssonina brunnea f. sp. Multigermtubi 被引量:6
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作者 Kun Yuan Bo Zhang +3 位作者 Yanmei Zhang Qiang Cheng Mingxiu Wang Minren Huang 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2008年第1期49-60,共12页
Black spot disease in poplar is a disease of the leaf caused by fungus. The major pathogen is Marssonina brunnea f. sp. multigermtubi. To date, little is known about the molecular mechanism of poplar (M. brunnea) in... Black spot disease in poplar is a disease of the leaf caused by fungus. The major pathogen is Marssonina brunnea f. sp. multigermtubi. To date, little is known about the molecular mechanism of poplar (M. brunnea) interaction. In order to identify the proteins related to disease resistance and understand its molecular basis, the clone "NL895" (P. euramericana CL"NL895"), which is highly resistant to M. brunnea f. sp. multigermtubi, was used in this study. We used two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) to identify the proteins in poplar leaves that were differentially expressed in response to black spot disease pathogen, M. brunnea f. sp. multigermtubi. Proteins extracted from poplar leaves at 0, 12, 24, 48, and 72 h after pathogen-inoculation were separated by 2-DE, About 500 reproducible protein spots were detected, of which 40 protein spots displayed differential expression in levels and were subjected to Matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) followed by database searching. According to the function, the identified proteins were sorted into five categories, that is, protein synthesis, metabolism, defense response and unclassified proteins. 展开更多
关键词 black spot disease defense response two-dimensional gel electrophoresis (2-DE) matrix assisted laser desorption/ionization time of flightmass spectrometry (MALDI-TOF MS) POPLAR
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Design of Discrete-time Repetitive Control System Based on Two-dimensional Model 被引量:1
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作者 Song-Gui Yuan Min Wu +1 位作者 Bao-Gang Xu Rui-Juan Liu 《International Journal of Automation and computing》 EI 2012年第2期165-170,共6页
This paper presents a novel design method for discrete-time repetitive control systems (RCS) based on two-dimensional (2D) discrete-time model. Firstly, the 2D model of an RCS is established by considering both th... This paper presents a novel design method for discrete-time repetitive control systems (RCS) based on two-dimensional (2D) discrete-time model. Firstly, the 2D model of an RCS is established by considering both the control action and the learning action in RCS. Then, through constructing a 2D state feedback controller, the design problem of the RCS is converted to the design problem of a 2D system. Then, using 2D system theory and linear matrix inequality (LMI) method, stability criterion is derived for the system without and with uncertainties, respectively. Parameters of the system can be determined by solving the LMI of the stability criterion. Finally, numerical simulations validate the effectiveness of the proposed method. 展开更多
关键词 Linear systems learning control discrete-time repetitive control two-dimensional (2D) systems linear matrix inequality.
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Establishment and Preliminary Application of Two dimensional Electrophoresis and Mass Spectrometry in Ovary Study 被引量:1
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作者 XiangMA Ye-feiZHU +2 位作者 Jia-haoSHA Zuo-minZHOU Jia-yinLIU 《Journal of Reproduction and Contraception》 CAS 2003年第4期209-216,共8页
Objective To apply two-dimensional electrophoresis and mass spectrometry in the ovary proteome researchMethods Protein extractions from mouse ovaries were run in IPGphor isoelectric focus system with 11 cm and 24 cm I... Objective To apply two-dimensional electrophoresis and mass spectrometry in the ovary proteome researchMethods Protein extractions from mouse ovaries were run in IPGphor isoelectric focus system with 11 cm and 24 cm IPG strips respectively (pH 3~10, 0.3 mm thick), then the protein spots were identified by mass spectrometry.Results The ovary protein exactions separated by two-dimensional electrophoresis have got high resolution, and identifing protein by mass spectrometry was highly efficient and facilitly. These two techniques should facilitate further investigation of female reproduction proteome research.Conclusion These two rapid high resolutions and efficient techniques have a variety of applications foreground in female reproduction proteome pattern research. 展开更多
关键词 PROTEOME two-dimensional electrophoresis matrix assisted laser desorption/ ionization time of flight mass spectrometry (MALDITOF MS) OVARY
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Further studies on stability analysis of nonlinear Roesser-type two-dimensional systems
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作者 代小林 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第4期191-197,共7页
This paper is concerned with further relaxations of the stability analysis of nonlinear Roesser-type two-dimensional (2D) systems in the Takagi-Sugeno fuzzy form. To achieve the goal, a novel slack matrix variable t... This paper is concerned with further relaxations of the stability analysis of nonlinear Roesser-type two-dimensional (2D) systems in the Takagi-Sugeno fuzzy form. To achieve the goal, a novel slack matrix variable technique, which is homogenous polynomially parameter-dependent on the normalized fuzzy weighting functions with arbitrary degree, is developed and the algebraic properties of the normalized fuzzy weighting functions are collected into a set of augmented matrices. Consequently, more information about the normalized fuzzy weighting functions is involved and the relaxation quality of the stability analysis is significantly improved. Moreover, the obtained result is formulated in the form of linear matrix inequalities, which can be easily solved via standard numerical software. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed result. 展开更多
关键词 stability analysis Roesser-type two-dimensional system slack matrix variable reducing conser-vatism
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RF-PSSM:A Combination of Rotation Forest Algorithm and Position-Specific Scoring Matrix for Improved Prediction of Protein-Protein Interactions Between Hepatitis C Virus and Human
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作者 Xin Liu Yaping Lu +3 位作者 Liang Wang Wei Geng Xinyi Shi Xiao Zhang 《Big Data Mining and Analytics》 EI CSCD 2023年第1期21-31,共11页
The identification of hepatitis C virus(HCV)virus-human protein interactions will not only help us understand the molecular mechanisms of related diseases but also be conductive to discovering new drug targets.An incr... The identification of hepatitis C virus(HCV)virus-human protein interactions will not only help us understand the molecular mechanisms of related diseases but also be conductive to discovering new drug targets.An increasing number of clinically and experimentally validated interactions between HCV and human proteins have been documented in public databases,facilitating studies based on computational methods.In this study,we proposed a new computational approach,rotation forest position-specific scoring matrix(RF-PSSM),to predict the interactions among HCV and human proteins.In particular,PSSM was used to characterize each protein,two-dimensional principal component analysis(2DPCA)was then adopted for feature extraction of PSSM.Finally,rotation forest(RF)was used to implement classification.The results of various ablation experiments show that on independent datasets,the accuracy and area under curve(AUC)value of RF-PSSM can reach 93.74% and 94.29%,respectively,outperforming almost all cutting-edge research.In addition,we used RF-PSSM to predict 9 human proteins that may interact with HCV protein E1,which can provide theoretical guidance for future experimental studies. 展开更多
关键词 protein-protein interactions hepatitis C virus position specific scoring matrix two-dimensional principal component analysis rotation forest
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Investigation on surface roughness,residual stress and fatigue property of milling in-situ TiB_2/7050Al metal matrix composites 被引量:6
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作者 Yifeng XIONG Wenhu WANG +4 位作者 Yaoyao SHI Ruisong JIANG Chenwei SHAN Xiaofen LIU Kunyang LIN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2021年第4期451-464,共14页
For higher efficiency and precision manufacturing,more and more attentions are focused on the surface roughness and residual stress of machined parts to obtain a good fatigue life.At present,the in-situ TiB_2/7050 Al ... For higher efficiency and precision manufacturing,more and more attentions are focused on the surface roughness and residual stress of machined parts to obtain a good fatigue life.At present,the in-situ TiB_2/7050 Al metal matrix composites are widely researched due to its attractive properties such as low density,good wear resistance and improved strength.It is of great significance to investigate the machined surface roughness,residual stress and fatigue life for higher efficiency and precision manufacturing of this new kind material.In this study,the surface roughness including two-dimensional and three-dimensional roughness,residual stress and fatigue life of milling in-situ TiB_2/7050 Al metal matrix composites were analyzed.It was found from comparative investigation that the three-dimensional surface roughness would be more appropriate to represent the machined surface profile of milling particle reinforced metal matrix composites.The cutting temperature played a great role on the residual stress.However,the effect of increasing cutting force could slow down the transformation from compressive stress to tensile stress under 270°C.An exponential relationship between three-dimensional roughness and fatigue life was established and the main fracture mechanism was brittle fracture with observation of obvious shellfish veins,river pattern veins and wave shaped veins in fracture surface. 展开更多
关键词 Fatigue life Metal matrix composite Residual stress Three-dimensional surface roughness TiB_2 particle Two-dimensional surface roughness
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Two-dimensional van der Waals thin film transistors as active matrix for spatially resolved pressure sensing 被引量:3
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作者 Chao Ma Dong Xu +7 位作者 Peiqi Wang Zhaoyang Lin Jingyuan Zhou Chuancheng Jia Jin Huang Shengtao Li Yu Huang Xiangfeng Duan 《Nano Research》 SCIE EI CSCD 2021年第10期3395-3401,共7页
The development of pressure sensor arrays capable of distinguishing the shape and texture details of objects is of considerable interest in the emerging fields of smart robots,prostheses,human-machine interfaces,and a... The development of pressure sensor arrays capable of distinguishing the shape and texture details of objects is of considerable interest in the emerging fields of smart robots,prostheses,human-machine interfaces,and artificial intelligence(AI).Here we report an integrated pressure sensor array,by combining solution-processed two-dimensional(2D)MoS2 van der Waals(vdW)thin film transistor(TFT)active matrix and conductive micropyramidal pressure-sensitive rubber(PSR)electrodes made of polydimethylsiloxane/carbon nanotube composites,to achieve spatially revolved pressure mapping with excellent contrast and low power consumption.We demonstrate a 10×10 active matrix by using the 2D MoS2 vdW-TFTs with high on-off ratio>10^(6),minimal hysteresis,and excellent device-to-device uniformity.The combination of the vdW-TFT active matrix with the highly uniform micropyramidal PSR electrodes creates an integrated pressure sensing array for spatially resolved pressure mapping.This study demonstrates that the solution-processed 2D vdW-TFTs offer a solution for active-matrix control of pressure sensor arrays,and could be extended for other active-matrix arrays of electronic or optoelectronic devices. 展开更多
关键词 pressure sensor array van der Waals thin film transistor two-dimensional material active matrix micropyramids
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Real-time SERS monitoring anticancer drug release along with SERS/MR imaging for pH-sensitive chemo-phototherapy
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作者 Xueqin Huang Bingbing Sheng +10 位作者 Hemi Tian Qiuxia Chen Yingqi Yang Brian Bui Jiang Pi Huaihong Cai Shanze Chen Jianglin Zhang Wei Chen Haibo Zhou Pinghua Sun 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2023年第3期1303-1317,共15页
In situ and real-time monitoring of responsive drug release is critical for the assessment of pharmacodynamics in chemotherapy.In this study,a novel pH-responsive nanosystem is proposed for real-time monitoring of dru... In situ and real-time monitoring of responsive drug release is critical for the assessment of pharmacodynamics in chemotherapy.In this study,a novel pH-responsive nanosystem is proposed for real-time monitoring of drug release and chemo-phototherapy by surface-enhanced Raman spectroscopy(SERS).The Fe3O4@Au@Ag nanoparticles(NPs)deposited graphene oxide(GO)nanocomposites with a high SERS activity and stability are synthesized and labeled with a Raman reporter 4-mercaptophenylboronic acid(4-MPBA)to form SERS probes(GO-Fe3O4@Au@Ag-MPBA).Furthermore,doxorubicin(DOX)is attached to SERS probes through a pH-responsive linker boronic ester(GO-Fe3O4@Au@Ag-MPBA-DOX),accompanying the 4-MPBA signal change in SERS.After the entry into tumor,the breakage of boronic ester in the acidic environment gives rise to the release of DOX and the recovery of 4-MPBA SERS signal.Thus,the DOX dynamic release can be monitored by the real-time changes of 4-MPBA SERS spectra.Additionally,the strong T2 magnetic resonance(MR)signal and NIR photothermal transduction efficiency of the nanocomposites make it available for MR imaging and photothermal therapy(PTT).Altogether,this GO-Fe3O4@Au@Ag-MPBA-DOX can simultaneously fulfill the synergistic combination of cancer cell targeting,pH-sensitive drug release,SERS-traceable detection and MR imaging,endowing it great potential for SERS/MR imaging-guided efficient chemo-phototherapy on cancer treatment. 展开更多
关键词 Surface-enhanced Raman spectroscopyp H-sensitive nanoparticles Real-time monitoring Chemo-phototherapy Drug delivery systems Anti-cancer nanotechnology Two-dimensional matrix Cancer cell targeting MR imaging
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Hurricane eye morphology extraction from SAR images by texture analysis 被引量:3
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作者 Weicheng NI Ad STOFFELEN Kaijun REN 《Frontiers of Earth Science》 SCIE CSCD 2022年第1期190-205,共16页
Tropical hurricanes are among the most devastating hazards on Earth.Knowledge about its intense inner-core structure and dynamics will improve hurricane forecasts and advisories.The precise morphological parameters ex... Tropical hurricanes are among the most devastating hazards on Earth.Knowledge about its intense inner-core structure and dynamics will improve hurricane forecasts and advisories.The precise morphological parameters extracted from high-resolution spaceborne Synthetic Aperture Radar(SAR)images,can play an essential role in further exploring and monitoring hurricane dynamics,especially when hurricanes undergo amplification,shearing,eyewall replacements and so forth.Moreover,these parameters can help to build guidelines for wind calibration of the more abundant,but lower resolution scatterometer wind data,thus better linking scatterometer wind fields to hurricane categories.In this paper,we develop a new method for automatically extracting the hurricane eyes from C-band SAR data by constructing Gray Level-Gradient Co-occurrence Matrices(GLGCMs).The hurricane eyewall is determined with a two-dimensional vector,generated by maximizing the class entropy of the hurricane eye region in GLGCM.The results indicate that when the hurricane is weak,or the eyewall is not closed,the hurricane eye extracted with this automatic method still agrees with what is observed visually,and it preserves the texture characteristics of the original image.As compared to Du’s wavelet analysis method and other morphological analysis methods,the approach developed here has reduced artefacts due to factors like hurricane size and has lower programming complexity.In summary,the proposed method provides a new and elegant choice for hurricane eye morphology extraction. 展开更多
关键词 hurricane eyewall morphological parameter texture analysis Gray Level-Gradient Co-occurrence matrix Two-dimensional Entropy Maximization
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Gene Expression Profile Changes in Germinating Rice 被引量:3
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作者 Dongli He Chao Han Pingfang Yang 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2011年第10期835-844,共10页
Water absorption is a prerequisite for seed germination. During imbibition, water influx causes the resumption of many physiological and metabolic processes in growing seed. In order to obtain more complete knowledge ... Water absorption is a prerequisite for seed germination. During imbibition, water influx causes the resumption of many physiological and metabolic processes in growing seed. In order to obtain more complete knowledge about the mechanism of seed germination, two-dimensional gel electrophoresis was applied to investigate the protein profile changes of rice seed during the first 48 h of imbibition. Thirty- nine differentially expressed proteins were identified, including 19 down-regulated and 20 up-regulated proteins. Storage proteins and some seed development- and desiccation-associated proteins were down regulated. The changed patterns of these proteins indicated extensive mobilization of seed reserves. By contrast, catabolism-associated proteins were up regulated upon imbibition. Semi-quantitative real time polymerase chain reaction analysis showed that most of the genes encoding the down- or up- regulated proteins were also down or up regulated at mRNA level. The expression of these genes was largely consistent at mRNA and protein levels. In providing additional information concerning gene regulation in early plant life, this study will facilitate understanding of the molecular mechanisms of seed germination. 展开更多
关键词 rice seed two-dimensional gel electrophoresis matrix assisted baser desorption ionization-time of flight semi-quantitative real timepolymerase chain reaction GERMINATION proteomics imbibition.
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Computationally efficient 2-D DOA estimation for non-uniform two-L-shaped array 被引量:1
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作者 Yang Jinsheng Xiang Yang +1 位作者 Chen Weigang Dong Yangyang 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2018年第6期81-89,共9页
A two-dimensional direction-of-arrival(DOA) estimation method for non-uniform two-L-shaped array is presented in which the element spacing is larger than half-wavelength. To extract automatically paired low-variance c... A two-dimensional direction-of-arrival(DOA) estimation method for non-uniform two-L-shaped array is presented in which the element spacing is larger than half-wavelength. To extract automatically paired low-variance cyclically ambiguous direction cosines and high-variance unambiguous direction cosines from the sub-blocks, the proposed method constructs and partitions the cross-correlation matrices. Then, the low-variance unambiguous direction cosines are obtained using the ambiguity resolved technique. Simulation results demonstrate that the proposed method has lower computation complexity and higher resolution than the existing methods especially when the elevation angles are between 70 and 90 degrees. 展开更多
关键词 aperture extension two-dimensional DOA estimation cross-correlation matrix ambiguity resolved
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Design of a Discrete-time Output-feedback Based Repetitive-control System 被引量:1
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作者 Lan Zhou Jin-Hua She Min Wu 《International Journal of Automation and computing》 EI CSCD 2013年第4期343-349,共7页
This paper deals with the problem of designing a robust discrete output-feedback based repetitive-control system for a class of linear plants with periodic uncertainties. The periodicity of the repetitive-control syst... This paper deals with the problem of designing a robust discrete output-feedback based repetitive-control system for a class of linear plants with periodic uncertainties. The periodicity of the repetitive-control system is exploited to establish a two-dimensional (2D) model that converts the design problem into a robust stabilization problem for a discrete 2D system. By employing Lyapunov stability theory and the singular-value decomposition of the output matrix, a linear-matrix-inequality (LMI) based stability condition is derived. The condition can be used directly to design the gains of the repetitive controller. Two tuning parameters in the LMI enable the preferential adjustment of control and learning. A numerical example illustrates the design procedure and demonstrates the validity of the method. 展开更多
关键词 Repetitive control discrete two-dimensional system singular-value decomposition output feedback linear matrix in- equality (LMI).
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Guided Wave Propagation in Multilayered Two-dimensional Quasicrystal Plates with Imperfect Interfaces
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作者 Xin Feng Liangliang Zhang +2 位作者 Zhiming Hu Han Zhang Yang Gao 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2022年第4期694-704,共11页
An analytical solution of the guided wave propagation in a multilayered twodimensional decagonal quasicrystal plate with imperfect interfaces is derived.According to the elastodynamic equations of quasicrystals(QCs),t... An analytical solution of the guided wave propagation in a multilayered twodimensional decagonal quasicrystal plate with imperfect interfaces is derived.According to the elastodynamic equations of quasicrystals(QCs),the wave propagating problem in the plate is converted into a linear control system by employing the state-vector approach,from which the general solutions of the extended displacements and stresses can be obtained,These solutions along the thickness direction are utilized to derive the propagator matrix which connects the physical variables on the lower and upper interfaces of each layer.The special spring model,which describes the discontinuity of the physical quantities across the interface,is introduced into the propagator relationship of the multilayered structure.The total propagator matrix can be used to propagate the solutions in each interface and each layer about the multilayered plate.In addition,the traction-free boundary condition on the top and bottom surfaces of the laminate is considered to obtain the dispersion equation of wave propagation,Finally,typical numerical examples are presented to illustrate the marked influences of stacking sequence and interface coeficients on the dispersion curves and displacement mode shapes of the QC laminates. 展开更多
关键词 Two-dimensional QC materials Wave propagation Dispersion curve State vector approach Propagator matrix Imperfect interface
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