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云环境下基于函数编码的移动应用克隆检测
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作者 杨佳 付才 +2 位作者 韩兰胜 鲁宏伟 刘京亮 《通信学报》 EI CSCD 北大核心 2019年第8期60-71,共12页
提出了一种云环境下基于汇编函数层编码的App克隆检测方法,实现了Android应用克隆检测原型系统Pentagon。首先,针对App执行文件代码设计了二进制函数基本代码块特征提取方法;其次,提出了一种对二进制函数进行单调编码的算法,基于图形嵌... 提出了一种云环境下基于汇编函数层编码的App克隆检测方法,实现了Android应用克隆检测原型系统Pentagon。首先,针对App执行文件代码设计了二进制函数基本代码块特征提取方法;其次,提出了一种对二进制函数进行单调编码的算法,基于图形嵌入原理,融合执行流程图与函数代码基本块特征,形成每个函数代码的投影特征;最后,提出了一种高效的第三方库函数过滤方法,进一步提升了克隆检测效果。实验证明,所提方法具有97.6%的准确率,在实验条件下判定一个App克隆对只需要79 ms,能够支撑云环境下应用市场级别的大规模克隆检测。 展开更多
关键词 克隆检测 函数编码 控制流程图 知识产权保护
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不对称分数傅里叶变换计算全息 被引量:6
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作者 盛兆玄 王红霞 +2 位作者 何俊发 王君 赵玮 《激光技术》 CAS CSCD 北大核心 2005年第3期295-296,303,共3页
提出了不对称分数傅里叶变换计算全息,并给出了相应算法。将输入图像信息分别经过x,y不同方向实施不同级次的分数傅里叶变换,采用迂回位相法对其分数域谱编码,绘出计算全息图。再现时需用两个特定的柱面透镜才能再现出所记录的图像信息... 提出了不对称分数傅里叶变换计算全息,并给出了相应算法。将输入图像信息分别经过x,y不同方向实施不同级次的分数傅里叶变换,采用迂回位相法对其分数域谱编码,绘出计算全息图。再现时需用两个特定的柱面透镜才能再现出所记录的图像信息,利用其再现方式的特殊性可制成一种安全认证系统,计算机上模拟演示结果表明,利用该方法进行安全认证,在防伪力度提高的同时,实际应用也更为方便,具有很高的安全性。 展开更多
关键词 计算全息 分数傅里叶变换 迂回位相法 编码函数 光学安全
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双通道无透镜Fourier变换计算机全息图
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作者 纪宪明 韩良恺 《光电工程》 CAS CSCD 1999年第4期49-52,共4页
介绍一种制作双通道无透镜Fourier变换计算机全息图的新方法,用这种方法不仅可以把两个物图象重叠记录在同一张全息图上,而且再现时可省去一个Fourier变换透镜,制作时不需要增加绘图仪的单元数目和尺寸,方法简便。
关键词 计算机全息图 傅里叶变换 双通道 编码函数
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加密汉字字符数据在数据库中的存储与查询
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作者 李迎斌 《信息技术》 2015年第1期65-68,共4页
汉字字符数据加密后的查询方法少有研究,针对该问题,提出一个基于对偶编码函数的密文过滤方法,并利用C#语言将该密文过滤方法在SQL Server 2008数据库中进行了实现,实验证实了此方法对密文数据操作的有效性。
关键词 数据库加密 加密存储与查询 对偶编码函数 过滤效率 密文过滤 SQL SERVER数据库
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PERFORMANCE ANALYSIS FOR THE RECEIVER WITH ISI
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作者 仰枫帆 毕光国 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1995年第2期212-217,共6页
In this paper we use trellis coded amplitude modulation (TC-AM) as models to analyze the receivers with intersymbol interference (ISI) under BPSK and π/4-QPSK modulations.Using the modified generating function and th... In this paper we use trellis coded amplitude modulation (TC-AM) as models to analyze the receivers with intersymbol interference (ISI) under BPSK and π/4-QPSK modulations.Using the modified generating function and the weight profile function of the TC-AM,the bit error probability for both cases is evaluated in the sense of maximum likelihood decoding.The numerical result is given. 展开更多
关键词 intersymbol interferences maximum-likelihood decoding generating functions weight profile functions trellis coded modulation
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A Novel High Spectral Efficiency Waveform Coding-OVFDM 被引量:2
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作者 LI Daoben 《China Communications》 SCIE CSCD 2015年第2期61-73,共13页
Based on the Overlapped Multiplexing Principle[12],a frequency domain OVFDM(Overlapped Frequency Domain Multiplexing) Coding is proposed.By the data weighted shift overlapped version of any band-limited Multiplexing T... Based on the Overlapped Multiplexing Principle[12],a frequency domain OVFDM(Overlapped Frequency Domain Multiplexing) Coding is proposed.By the data weighted shift overlapped version of any band-limited Multiplexing Transfer Function H(f) the coding gain and spectral efficiency are both achieved.The heavier the overlap of the data weighted Multiplexing Transfer Function H(f),the higher the coding gain and spectral efficiency as well as the closer the output to the optimum complex Gaussian distribution.The bit error probability performance is estimated.The time domain OVTDM(Overlapped Time Domain Multiplexing) Coding,the dual of OVFDM in time domain is incidentally proposed as well.Both theoretical analysis and testified simulations show that OVFDM(OVTDM) is suitable for high spectral efficiency application and its spectral efficiency is only roughly linear to SNR rather than the well-known logarithm to SNR. 展开更多
关键词 overlapped multiplexing principle frequency domain coding waveform coding spectral efficiency shannon capacity dual relation OVFDM OVTDM
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Source extension based on ε-entropy 被引量:3
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作者 张剑 《Journal of Chongqing University》 CAS 2005年第2期102-106,共5页
It is known by entropy theory that image is a source correlated with a certain characteristic of probability. The entropy rate of the source and ε- entropy (rate-distortion function theory) are the information conten... It is known by entropy theory that image is a source correlated with a certain characteristic of probability. The entropy rate of the source and ε- entropy (rate-distortion function theory) are the information content to identify the characteristics of video images, and hence are essentially related with video image compression. They are fundamental theories of great significance to image compression, though impossible to be directly turned into a compression method. Based on the entropy theory and the image compression theory, by the application of the rate-distortion feature mathematical model and Lagrange multipliers to some theoretical problems in the H.264 standard, this paper presents a new the algorithm model of coding rate-distortion. This model is introduced into complete test on the capability of the test model of JM61e (JUT Test Model). The result shows that the speed of coding increases without significant reduction of the rate-distortion performance of the coder. 展开更多
关键词 Rate-Distortion function LAGRANGIAN source extension Theory of information video coding image compression
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CONSTRUCTIONOFACLASSOFPNSEQUENCESWITHPRIMENUMBERPERIODSOF4t+1FORM
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作者 Yang Fengfan Bi Guangguo Department of Radio Engineering,Southeast UniversityNanjing 210096,P.R.China 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1996年第1期118-120,共3页
A class of new PN sequence with prime number periods of 4t +1 form (t is an integer)is constructed.The advantage of these PN sequencs over the m(M) sequence is their large number of alternative periods.They hav... A class of new PN sequence with prime number periods of 4t +1 form (t is an integer)is constructed.The advantage of these PN sequencs over the m(M) sequence is their large number of alternative periods.They have good pseudo random characteristics demonstrated by the expression of periodic autocorrelation function found out in this paper. 展开更多
关键词 CODING autocorrelation function MATRIX PN sequences quadratic element finite field
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