检索结果-南通市图书馆

Efficient DPCA SAR imaging with fast iterative spectrum reconstruction method

在线全文

学校读者我要写书评

暂无评论

Science china(information sciences) 2012年第8期55卷 1838-1851页

作者： FANG Jian1,ZENG JinShan1,XU ZongBen1&zhao Yao2 1M inistry of Education key Lab for Intelligent Networks and Network security Xi'an Jiaotong {3.,Xi'an 710049,china 2N ational key laboratory of Science and Technology on Microwave Imaging&Institute of Electronics,chinese Academy of sciences,beijing 10004.,china 1. Ministry of Education key Lab for Intelligent Networks and Network security Xi’an Jiaotong university Xi’an 710049 China2. National Key Laboratory of Science and Technology on Microwave Imaging & Institute of Electronics Chinese Academy of Sciences Beijing 100049 China

The displaced phase center antenna(DPCA)technique is an effective strategy to achieve wide-swath synthetic aperture radar(SAR)imaging with high azimuth ***,traditionally,it requires strict limitation of the pulse repetition frequency(PRF)to avoid non-uniform ***,any deviation could bring serious ambiguity if the data are directly processed using a matched *** break this limitation,a recently proposed spectrum reconstruction method is capable of recovering the true spectrum from the nonuniform ***,the performance is sensitive to the selection of the *** regularization based imaging may provide a way to overcome this *** existing time-domain method,however,requires a large-scale observation matrix to be built,which brings a high computational *** this paper,we propose a frequency domain method,called the iterative spectrum reconstruction method,through integration of the sparse regularization technique with spectrum analysis of the DPCA *** approximately expressing the observation in the frequency domain,which is realized via a series of decoupled linear operations,the method performs SAR imaging which is then not directly based on the observation matrix,which reduces the computational cost from O(N2)to O(N log N)(where N is the number of range cells),and is therefore more efficient than the time domain *** sparse regularization scheme,realized via a fast thresholding iteration,has been adopted in this method,which brings the robustness of the imaging process to the PRF *** provide a series of simulations and ground based experiments to demonstrate the high efficiency and robustness of the *** simulations show that the new method is almost as fast as the traditional mono-channel algorithm,and works well almost independently of the PRF ***,the suggested method can be accepted as a practical and efficient wide-swath SAR imaging technique.

关键词： displaced phase center antenna sparse regularization iterative thresholding spectrum reconstruction

A Novel Digital Audio Watermarking Scheme in the Wavelet Domain

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

A Novel Digital Audio Watermarking Scheme in the Wavelet Dom...

All-dielectric terahertz metasurface governed by bound states in the continuum with high-Q factor

The 1st chinese Conference on Trusted Computing and information security

作者： Xiang-yang, YANG Hong-ying, zhao Hong School of Computer and information Technique, Liaoning Normal university, Dalian 116029, Liaoning,{3. state key laboratory of information security, Institute of Software of chinese Academy of sciences, beijing 10003., {3.

＜正＞ We present a novel quantization-based digital audio watermarking scheme in wavelet domain. By quantizing a host audio’ s wavelet coefficients （Integer Lifting Wavelet Transform ） and utilizing the characteristics of human auditory system （HAS）, the gray image is embedded using our watermarking method. Experimental results show that the proposed watermarking scheme is inaudible and robust against various signal processing such as noising adding, lossy compression, low pass filtering, re-sampling, and re-quantifying.

关键词： digital audio watermarking lifting wavelet transform human auditory system chaotic sequence quantization

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

The Journal of china Universities of Posts and Telecommunications 2024年第2期31卷 44-54页

作者： Li Kun zhao Xu Wang Meng Jia Xingning zhao Ruiqi Lu Guizhen School of Integrated Circuit Science and Engineering Tianjin University of TechnologyTianjin 300384China School of Electronic and Electrical Engineering Ningxia UniversityYinchuan 750021China QILU Aerospace information Research Institute Chinese Academy of Sciences(CAS)Jinan 250101China state key laboratory of Media Convergence and Communication Communication University of ChinaBeijing 100024China

The method of terahertz(THz)resonance with a high-quality(high-Q)factor offers a vital physical mechanism for metasurface sensors and other high-Q factor ***,it is challenging to excite the resonance with a high-Q factor in metasurfaces with proper sensitivity as well as figure of merit(FOM)***,an all-dielectric metasurface composed of two asymmetrical rectangular blocks is *** and silicon are the materials applied for the substrate and cuboids *** distinct resonance governed by bound states in the continuum(BIC)is excited by forming an asymmetric cluster by a novel hybrid method of cutting and moving the *** investigation focuses on analyzing the transmission spectra of the metasurface under different variations in structural parameters and the loss of silicon refractive *** the proposed defective metasurface serves as a transmittance sensor,it shows a Q factor of 1.08×10^(4)and achieves an FOM up to 4.8×10^(6),which is obtained under the asymmetric parameter equalling 1μ***,the proposed defective metasurface is sensitive to small changes in refractive *** the thickness of the analyte is 180μm,the sensitivity reaches a maximum value of 578 GHz/***,the proposed defective metasurface exhibits an extensive number of possible applications in the filters,biomedical diagnosis,security screening,and so on.

关键词： terahertz(THz)metasurface high-quality(high-Q)factor bound states in the continuum figure of merit(FOM)

在线全文

学校读者我要写书评

暂无评论

部分Bent函数的密码学性质

通信学报 2002年第5期23卷 113-118页

作者：赵亚群冯登国李世取中国科学院研究生院信息安全国家重点实验室北京100080 郑州信息工程大学信息工程学院信息研究系河南郑州450002

本文讨论了部分Bent函数的若干密码学性质,分别给出了部分Bent函数满足平衡性、相关免疫性和扩散准则的充分必要条件,具体求出了部分Bent函数的非线性度以及部分Bent函数与仿射函数的符合率。

关键词： Bent函数密码学性质保密通信

在线全文

学校读者我要写书评

暂无评论

半Bent函数的密码学特性

山东大学学报（理学版） 2002年第6期37卷 480-483,512页

作者：秦静赵亚群山东大学数学与系统科学学院济南250100 中科院研究生院信息安全国家重点实验室北京100080

给出了半bent函数的定义与Walsh谱特征 ,并讨论了其密码学特性 .

关键词： bent函数半bent函数 Walsh循环谱自相关函数扩散准则

MRm-DLDet:a memory-resident malware detection framework based on memory forensics and deep neural network

在线全文

学校读者我要写书评

暂无评论

Cybersecurity 2024年第1期7卷 88-109页

作者： Jiaxi Liu Yun Feng Xinyu Liu Jianjun zhao Qixu Liu Institute of information Engineering Chinese Academy of SciencesBeijing 100085China School of Cyber security University of Chinese Academy of SciencesBeijing 100049China

Cyber attackers have constantly updated their attack techniques to evade antivirus software detection in recent *** popular evasion method is to execute malicious code and perform malicious actions only in ***-cious programs that use this attack method are called memory-resident malware,with excellent evasion capability,and have posed huge threats to cyber *** static and dynamic methods are not effective in detect-ing memory-resident *** addition,existing memory forensics detection solutions perform unsatisfactorily in detection rate and depend on massive expert knowledge in memory *** paper proposes MRm-DLDet,a state-of-the-art memory-resident malware detection framework,to overcome these ***-DLDet first builds a virtual machine environment and captures memory dumps,then creatively processes the memory dumps into RGB images using a pre-processing technique that combines deduplication and ultra-high resolution image cropping,followed by our neural network MRmNet in MRm-DLDet to fully extract high-dimensional features from memory dump files and detect *** receives the labeled sub-images of the cropped high-resolution RGB images as input of ResNet-18,which extracts the features of the *** trains a network of gated recurrent units with an attention ***,it determines whether a program is memory-resident malware based on the detection results of each sub-image through a specially designed voting *** created a high-quality dataset consisting of 2,060 benign and memory-resident *** other words,the dataset contains 1,287,500 labeled sub-images cut from the MRm-DLDet transformed ultra-high resolution RGB *** implement MRm-DLDet for Windows 10,and it performs better than the latest methods,with a detection accuracy of up to 98.3.%.Moreover,we measured the effects of mimicry and adversarial attacks on MRm-DLDet,and the experimental results demonstrated the robustness

关键词： Memory-resident malware Memory forensics Malware detection Deep learning Ultra-high resolution image

On the use of explainable AI for susceptibility modeling:Examining the spatial pattern of SHAP values

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2024年第4期15卷 14-27页

作者： Nan Wang Hongyan Zhang Ashok Dahal Weiming Cheng Min zhao Luigi Lombardo key laboratory of Geographical Processes and Ecological security in Changbai Mountains Ministry of EducationSchool of Geographical SciencesNortheast Normal UniversityChangchun 130024China state key laboratory of Resources and Environmental {3. Systems Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China university of Twente Faculty of Geo-Information Science and Earth Observation(ITC)PO Box 217EnschedeAE 7500Netherlands university of chinese Academy of sciences Beijing 100049China Jiangsu Center for Collaborative Innovation in Geographic information Resource Development and Application Nanjing 210023China Collaborative Innovation Center of South china Sea Studies Nanjing 210093China state key laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China key laboratory of Environmental Change and Natural Disaster Beijing Normal UniversityBeijing 100875China Center for Geodata and Analysis Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China

Hydro-morphological processes(HMP,any natural phenomenon contained within the spectrum defined between debris flows and flash floods)are globally occurring natural hazards which pose great threats to our society,leading to fatalities and economical *** this reason,understanding the dynamics behind HMPs is needed to aid in hazard and risk *** this work,we take advantage of an explainable deep learning model to extract global and local interpretations of the HMP occurrences across the whole chinese *** use a deep neural network architecture and interpret the model results through the spatial pattern of SHAP *** doing so,we can understand the model prediction on a hierarchical basis,looking at how the predictor set controls the overall susceptibility as well as doing the same at the level of the single mapping *** model accurately predicts HMP occurrences with AUC values measured in a ten-fold cross-validation ranging between 0.83.and *** level of predictive performance attests for an excellent prediction *** main difference with respect to traditional statistical tools is that the latter usually lead to a clear interpretation at the expense of high performance,which is otherwise reached via machine/deep learning solutions,though at the expense of *** recent development of explainable Al is the key to combine both *** this work,we explore this combination in the context of HMP susceptibility ***,we demonstrate the extent to which one can enter a new level of data-driven interpretation,supporting the decision-making process behind disaster risk mitigation and prevention actions.

关键词： Hydro-morphological processes SHAP maps Explainable AI china

Data-enhanced revealing of trends in Geoscience

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Data and information Science 2024年第3期9卷 29-43页

作者： Yu zhao Meng Wang Jiaxin Ding Jiexing Qi Lyuwen Wu Sibo Zhang Luoyi Fu Xinbing Wang Li Cheng School of Earth sciences and Resources China University of GeosciencesBeijing 100083China key laboratory of Ecological security and Sustainable Development of Arid Areas State Key Laboratory of Desert and Oasis EcologyChinese Academy of SciencesUrumqiXinjiang830011China Xinjiang key laboratory of Mineral Resources and Digital Geology Urumqi 830011China Shanghai Jiao Tong university Shanghai 200240China Journal Center China University of GeosciencesBeijing 100083China

Purpose:This article presents an in-depth analysis of global research trends in Geosciences from 2014 to *** integrating bibliometric analysis with expert insights from the Deep-time Digital Earth(DDE)initiative,this article identifies key emerging themes shaping the landscape of Earth sciences①.Design/methodology/approach:The identification process involved a meticulous analysis of over 400,000 papers from 466 Geosciences journals and approximately 5,800 papers from 93.interdisciplinary journals sourced from the Web of Science and Dimensions *** map relationships between articles,citation networks were constructed,and spectral clustering algorithms were then employed to identify groups of related research,resulting in 407 *** research terms were extracted using the Log-Likelihood Ratio(LLR)algorithm,followed by statistical analyses on the volume of papers,average publication year,and average citation count within each ***,expert knowledge from DDE Scientific Committee was utilized to select top 3. trends based on their representation,relevance,and impact within Geosciences,and finalize naming of these top trends with consideration of the content and implications of the associated *** comprehensive approach in systematically delineating and characterizing the trends in a way which is understandable to ***:Thirty significant trends were identified in the field of Geosciences,spanning five domains:deep space,deep time,deep Earth,habitable Earth,and big *** topics reflect the latest trends and advancements in Geosciences and have the potential to address real-world problems that are closely related to society,science,and *** limitations:The analyzed data of this study only contain those were included in the Web of *** implications:This study will strongly support the organizations and individual scientists to understand the modern frontier of earth science,espec

关键词： Geosciences Research trends Bibliometrics Expert knowledge Global voting

基于运动向量修改的保持块间扰动最小的HEVC信息隐藏算法

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

信息安全学报 2024年第4期9卷 139-149页

作者：唐小晶马熠余建昌张弘赵险峰中国科学院信息工程研究所信息安全国家重点实验室北京100195 中国科学院大学网络空间安全学院北京100195 北京信息技术研究所北京100094

高效视频编码(High Efficiency Video Coding, HEVC)标准能够大幅度提升压缩效率,正被广泛应用中。为提高基于运动向量修改的HEVC视频隐写算法的安全性,本文结合了HEVC标准中帧间预测编码的新技术,并利用在运动向量域进行信息嵌入扰动... 详细信息

高效视频编码(High Efficiency Video Coding, HEVC)标准能够大幅度提升压缩效率,正被广泛应用中。为提高基于运动向量修改的HEVC视频隐写算法的安全性,本文结合了HEVC标准中帧间预测编码的新技术,并利用在运动向量域进行信息嵌入扰动较小的优点,提出了一种基于运动向量修改的保持块间扰动最小的HEVC信息隐藏算法。首先,该算法量化了修改运动向量后对当前高级运动向量预测(Advanced Motion Vector Prediction, AMVP)单元和其相邻融合(Merge)模式预测单元产生的扰动代价,将运动向量垂直分量和水平分量之和作为原始载体元素。其次,结合校验网格码(Syndrome Trellis Codes, STC),寻找扰动代价最小的嵌入路径,通过修改运动向量中绝对值较大的分量将信息嵌入在AMVP模式的预测单元运动向量上。此外,为减小对视频质量的影响,利用修改后的运动向量更新运动向量差值。实验结果表明,所提方法对视频序列进行信息嵌入后,由于本文引入的扰动代价判断可以有效控制视频质量变化,对视频序列的峰值信噪比、码率影响较小,所以该方法对视频的扰动很小。而且本文算法不仅在视频质量保护上有良好的性能,还对运动向量域专用隐写分析具有良好的抗检测能力,有利于基于HEVC视频码流的隐蔽通信的进一步发展。

关键词：信息隐藏高效视频编码运动向量高级运动向量预测