检索结果-南通市图书馆

Fast uniform content-based satellite image registration using the scale-invariant feature transform descriptor

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Frontiers of Information Technology & Electronic Engineering 2017年第8期18卷 1108-1116页

作者： hamed BOZORGI Ali jafari Electrical Engineering Department University of Guilan Rasht 41635-3756 Iran School of Electrical & Electronic Engineering Malek Ashtar University of Technology Tehran 15875-1774 Iran

基于内容的卫星图像配准是在遥感和图像处理领域的一大难题。受照度、旋转、来源差异的影响,该问题在多源遥感图像匹配中更为突出。尺度不变特征变换(scale-invariant feature transform,SIFT)算法是一种成功应用于卫星图像配准的算法... 详细信息

基于内容的卫星图像配准是在遥感和图像处理领域的一大难题。受照度、旋转、来源差异的影响,该问题在多源遥感图像匹配中更为突出。尺度不变特征变换(scale-invariant feature transform,SIFT)算法是一种成功应用于卫星图像配准的算法。本地SIFT描述符被许多研究者应用于改进图像检索流程。尽管SIFT算法具有良好的稳定性,它在提取多源遥感中本地特征点的质量和数量上仍然具有一定的劣势。另外,SIFT算法提取的本地特征具有较高维度,导致计算过程耗时过长以及对保存相关信息的储存空间要求过高,而这两点也是在基于内容图像检索(content-based image retrieval,CBIR)的相关应用中的重要因素。本文介绍了一种在多源遥感中将本地SIFT特征转变为全局特征的新方法。通过在预处理阶段对图像进行对比度均衡化来提升SIFT本地特征点质量和数量。将参考数据库中每副图像的本地特征单独分为一类后,采用线性判别分析(linear discriminant analysis,LDA)方法将本地SIFT特征转变为全局特征,同时不为降低特征空间的维度。该方法可以显著减少计算时间和所需存储空间。将核函数应用于检定数据并映射,所测试特征点的检索率高达91.67%。

关键词：基于内容的卫星图像配准特征点分布图像配准线性判别准则遥感尺度不变特征变换

Explosive synchronization:From synthetic to real-world networks

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Chinese Physics B 2022年第2期31卷 89-108页

作者： Atiyeh Bayani Sajad jafari hamed Azarnoush Department of Biomedical Engineering Amirkabir University of TechnologyNo.350Hafez Ave.Valiasr SquareTehran 159163-4311Iran Health Technology Research Institute Amirkabir University of TechnologyNo.350Hafez Ave.Valiasr SquareTehran 159163-4311Iran

Synchronization is a widespread phenomenon in both synthetic and real-world networks.This collective behavior of simple and complex systems has been attracting much research during the last decades.Two different routes to synchrony are defined in networks;first-order,characterized as explosive,and second-order,characterized as continuous transition.Although pioneer researches explained that the transition type is a generic feature in the networks,recent studies proposed some frameworks in which different phase and even chaotic oscillators exhibit explosive synchronization.The relationship between the structural properties of the network and the dynamical features of the oscillators is mainly proclaimed because some of these frameworks show abrupt transitions.Despite different theoretical analyses about the appearance of the firstorder transition,studies are limited to the mean-field theory,which cannot be generalized to all networks.There are different real-world and man-made networks whose properties can be characterized in terms of explosive synchronization,e.g.,the transition from unconsciousness to wakefulness in the brain and spontaneous synchronization of power-grid networks.In this review article,explosive synchronization is discussed from two main aspects.First,pioneer articles are categorized from the dynamical-structural framework point of view.Then,articles that considered different oscillators in the explosive synchronization frameworks are studied.In this article,the main focus is on the explosive synchronization in networks with chaotic and neuronal oscillators.Also,efforts have been made to consider the recent articles which proposed new frameworks of explosive synchronization.

关键词： synchronization explosive synchronization Kuramoto oscillator chaotic systems neuronal networks complex network

Epidemiology of animal bite injuries in North of Fars province in Iran

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Journal of Acute Disease 2023年第4期12卷 157-162页

作者： hamed Karami Fatemeh jafari Ali Khani Jeihooni Sanaz Amiri Tahereh Hashemifard Asadollah Niknam Student Research Committee Shiraz University of Medical SciencesShirazIran Nutrition Research Center Department of Public HealthSchool of HealthShiraz University of Medical SciencesShirazIran Department of Epidemiology in Shiraz University of Medical Sciences ShirazIran Department of Health Islamic Azad University of KazerunKazerunIran Department of Communicable Diseases Shiraz University of Medical ScienceShirazIran

Objective:To investigate the epidemiological situation of animal bites in Rostam city of Fars province.Methods:This is a cross-sectional study.Cases of animal bites registered in health centers of Rostam city of Fars province from the beginning of 2014 to 2020 were analyzed using the census method.The tool for collecting information was the portal of the Ministry of Health and the registration offices of people who were referred to the rabies center.Results:A total of 628 cases of animal bites registered in health centers of Rostam city of Fars province from the beginning of 2014 to 2020.The mean age of the injured was(31.3±20.2)years.Of the total injured cases,414(65.9%)were male,and 491(78.2%)lived in villages.Most of the cases were bitten by dogs(n=420,66.8%)and the upper limb was involved in 280(55.2%)cases.In addition,an increasing trend was observed in the incidence of animal bites from 2015 to 2020.Conclusions:The incidence of animal bites in Rostam City is high,and most of the cases occur in rural areas.Considering the injuries caused by animal bites,the risk of rabies transmission,and the high costs of vaccination and serum therapy,it is necessary to hold control,educational,and vaccination programs.

关键词： Injury Animal bites Rabies Incidence Epidemiology Iran

Observation of chimera patterns in a network of symmetric chaotic finance systems

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Communications in Theoretical Physics 2020年第10期72卷 19-28页

作者： Biqun Chen Karthikeyan Rajagopal Fatemeh Parastesh hamed Azarnoush Sajad jafari Iqtadar Hussain School of Electronic Engineering Changzhou College of Information TechnologyChangzhou 213164China Nonlinear Systems and Applications Faculty of Electrical and Electronics EngineeringTon Duc Thang UniversityHo Chi Minh CityVietnam Department of Biomedical Engineering Amirkabir University of TechnologyNo.350Hafez AveValiasr SquareTehran 159163-4311Iran Health Technology Research Institute Amirkabir University of TechnologyNo.350Hafez AveValiasr SquareTehran 159163-4311Iran Department of Mathematics Statistics and PhysicsQatar UniversityDoha 2713Qatar

The economic and financial systems consist of many nonlinear factors that make them behave as the complex systems.Recently many chaotic finance systems have been proposed to study the complex dynamics of finance as a noticeable problem in economics.In fact,the intricate structure between financial institutions can be obtained by using a network of financial systems.Therefore,in this paper,we consider a ring network of coupled symmetric chaotic finance systems,and investigate its behavior by varying the coupling parameters.The results show that the coupling strength and range have significant effects on the behavior of the coupled systems,and various patterns such as the chimera and multi-chimera states are observed.Furthermore,changing the parameters'values,remarkably influences on the oscillators attractors.When several synchronous clusters are formed,the attractors of the synchronized oscillators are symmetric,but different from the single oscillator attractor.

关键词： nance system symmetric attractors chimera state synchronization transitions nonlocally coupled network

Phytochemical studies of various polarities leave crude extracts of Omani Datura metel L.and evaluation of their antimicrobial potential

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Journal of Coastal Life Medicine 2015年第3期3卷 214-219页

作者： Ali Saleh hamed Al-jafari Mohammad Amzad Hossain School of Pharmacy College of Pharmacy and NursingUniversity of NizwaP.O.Box 33Postal Code 616NizwaSultanate of Oman

Objective:To identify the chemical constituents and evaluate antimicrobial potential of various crude extracts from leaves of Datura metel grown in Oman.Methods:The leaf samples were collected from the University of Nizwa and extracted with methanol by using Soxhlet extractor.The isolated crude extract was defatted with distilled water and extracted with solvents of different polarities including hexane,chloroform,ethyl acetate and butanol.Chemical compositions of the crude extracts were analyzed by gas chromatography-mass spectrometer and their antimicrobial potential was evaluated by agar disc diffusion method against one Gram positive bacteria Staphylococcus aureus and two Gram negative bacteria Escherichia coli and Pseudomonus aeruginosa.Results:The crude extracts were composed of different organic compounds such as alkaloids,hydrocarbons,aromatic hydrocarbons,organic acids,terpenoids,vitamin etc.The methanol and its fractionated crude extracts showed antimicrobial potential with inhibition zone in the range of 0-13 mm.Conclusions:The selective crude extract from the leaves of Datura metel could be used as natural antibiotics.

关键词： Datura metel Soxhlet extractor Crude extracts Gas chromatography-mass spectrometry analysis Antimicrobial activity