共查询到20条相似文献，搜索用时 109 毫秒
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本文采用基于新息准则的快速子空间跟踪算法解决了直接序列扩频(DS/SS)信号的扩频码盲估计问题.该方法具有较高的运算效率,克服了传统方法在PN码盲恢复时实时处理上的困难,理论分析和数值仿真结果表明,该方法在较低的输入信噪比下能够完成对PN码的正确估计,与特征值分解、神经网络等算法相比具有更好的性能. 相似文献
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Gram-Schmidt正交化算法是数值线性代数中的基本算法之一,主要用于计算矩阵QR分解.经典和修正Gram-Schmidt正交化算法基于level 1/2 BLAS运算,低级BLAS运算对cache的利用率比较低,从而限制了算法性能.提出一种新的分块Gram-Schmidt正交化算法.新算法通过重正交保证产生矩阵 Q 的正交性达到机器精度,并且利用level 3 BLAS运算提高了算法性能.数值试验表明,新算法能使得矩阵 Q 的正交性达到机器精度,并且新算法使得性能得到显著提高. 相似文献
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文章提出一种快速的基于遗传匹配追踪（MP）的甚低码率视频编码算法,同时结合MP特征,用排序差分法对稀疏分解结果进行编码。仿真实验证明,在甚低码率下该算法与H-264编码算法相比,减少了块效应,提高了视频的主观质量和PNSR;与同类型算法相比,该算法速度更快,编码效率更高。 相似文献
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压缩感知理论是利用信号的稀疏性,采用重构算法通过少量的观测值就可以实现对该信号的精确重构。SL0（Smoothed l0）算法是基于l0范数的稀疏信号重构算法,通过控制参数逐步逼近最优解。针对平滑函数的选取问题,文章提出一种新的平滑函数序列近似l0范数,实现稀疏信号的精确重构。仿真结果表明,在相同实验条件下文章算法较传统算法有着较高的重构概率。 相似文献
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在高动态、弱信号等工作环境下,载体在飞行过程中可能面临GNSS信号失锁等情况,从而使超紧组合导航系统无法正常工作。为改善组合导航系统性能,本文在一般的惯性信息辅助捕获算法基础上,设计了一种基于IMU辅助的多通道快速捕获算法,同时针对信号捕获后组合导航系统基带信号处理时间过长的问题,在多通道辅助捕获的基础上增加了惯性信息辅助快速帧同步,从而实现信号失锁后的快速重定位。最后通过半实物仿真试验对算法的有效性进行验证,结果表明基于IMU辅助的多通道捕获及快速帧同步算法对重定位时间有较大改善。 相似文献
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抛物线法是数值分析中在实数范围内方程求根的一种快速迭代算法,针对Julia集的绘图原理,给出了一种利用此方法绘图的改进算法。算法的基本思想是首先将图片的坐标分别转换成不同的复数初值,然后利用抛物线法在复数范围内进行反复迭代运算,最后将运算的结果绘成分形图形。绘出的分形图优美而玄妙,几何意义明显。在此基础上加入逃逸时间算法的思想,进一步扩展了它的使用范围,绘出更加丰富的图形。 相似文献
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时滞相关Logistic函数浮点数据模糊加密稀疏集构造 总被引：1，自引：0，他引：1
提出一种基于时滞相关Logistic函数线性调频采样的浮点数据模糊加密算法优化技术,给出时滞相关Logistic函数及相关定义,研究了浮点数据的模糊编码算法,设计实时交互网络的浮点数据模糊加密方案,实现密钥稀疏集构造,采用基于稀疏矩阵的存储格式下的时滞相关Logistic函数浮点数据加密运算,构造密钥稀疏集,优化了算法性能。仿真结果表明,算法数据加密和解密性能较好,具有较高的数据吞吐量,能实现对大数据库的数据加密,提高了密文的不可预测性。 相似文献
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课程管理系统中设计了一个矩阵运算系统,该矩阵运算系统具有普通矩阵相加、相减、相乘及稀疏矩阵转置等功能。运算系统以MicrosoftVisualC＋＋6．0作为系统开发工具,采用算数表达式处理算法来实现矩阵的加、减、乘等混合运算和稀疏矩阵的转置矩阵运算。系统操作简单、界面清晰,便于用户使用。 相似文献
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Zhenzhen Yang Lu Fan Yongpeng Yang Zhen Yang Guan Gui 《Journal of The Franklin Institute》2019,356(16):10138-10154
Moving object detection is one of the most challenging tasks in computer vision and many other fields, which is the basis for high-level processing. Low-rank and sparse decomposition (LRSD) is widely used in moving object detection. The existing methods primarily address the LRSD problem by exploiting the approximation of rank functions and sparse constraints. Conventional methods usually consider the nuclear norm as the approximation of the low-rank matrix. However, the actual results show that the nuclear norm is not the best approximation of the rank function since it simultaneously minimize all the singular values. In this paper, we exploit a novel nonconvex surrogate function to approximate the low-rank matrix and propose a generalized formulation for nonconvex low-rank and sparse decomposition based on the generalized singular value thresholding (GSVT) operator. And then, we solve the proposed nonconvex problem via the alternating direction method of multipliers (ADMM), and also analyze its convergence. Finally, we give numerical results to validate the proposed algorithm on both synthetic data and real-life image data. The results demonstrate that our model has superior performance. And we use the proposed nonconvex model for moving objects detection, and provide the experimental results. The results show that the proposed method is more effective than representative LRSD based moving objects detection algorithms. 相似文献
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基于极化干涉互相关矩阵的林高估计方法 总被引：1，自引：0，他引：1
基于噪声影响较小的极化干涉数据的互相关矩阵,提出了一种新的林高估计方法.该方法使用互相关矩阵的奇异值分解代替ESPRIT方法中相干矩阵的特征分解,获取森林散射中心的干涉相位信息,再由森林散射中心的干涉相位差估计森林高度.该方法不但能抑制噪声对森林散射中心干涉相位估计的影响,还提高了运算效率.L波段松树林极化干涉仿真数据验证该方法的有效性. 相似文献
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多尺度几何分析方法用于图像去噪已经成为图像处理方向的研究的一个热点。简要介绍和分析了几种常用于去噪的多尺度几何分析方法(曲波变换、轮廓波变换、剪切波变换),其中剪切波能提供了更稀疏的表示,图像实现最优逼近。实验结果也证明,剪切波变换阈值去噪在主观视觉上与峰值信噪比优于其他多尺度分析方法。 相似文献
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对计算水平分层介质响应正交归一化法的改进 总被引：1，自引：0，他引：1
汪荣江提出一个简单的正交归一化技术来克服经典的Thomson-Haskell传播矩阵方法中存在的数值不稳定问题.为了进一步提高计算效率,给出该方法的2种改进.一种改进方法是将传播矩阵中与频率无关的部分分离出来,对于某一固定的水平慢度,这些矩阵只需计算一次;另一个改进是利用Langer块对角化的技术,将传播矩阵分解为几个稀疏矩阵的乘积.我们将改进之后的算法应用于计算水平分层模型中的广义反射系数.较之原有方案,提出的改进能节省一半计算时间. 相似文献
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本文提出了利用灰度图像的梯度信息直接进行HOUGH变换以检测直线的方法；文中简述了传统HOUGH变换检测直线和直接HOUGH变换检测直线的原理和方法；通过编程对不加噪声和加了GAUSE噪声图像中单根直线和多根直线进行了检测，并且获取了理想的实验效果文中最后还对实际数字图像中条纹轮廓进行了检测，也获得了理想效果。实验证明，直接HOUGH变换的方法具有计算量小、运算速度快和抗噪能力强的特点。 相似文献
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Jian-Chen Liu 《Journal of The Franklin Institute》2018,355(3):1373-1393
Based on the generalized probability-interval-decomposition approach, the delay-dependent stability analysis for a class of T-S fuzzy systems with stochastic delays is investigated. The information of the probability distribution of stochastic delay is fully exploited and a series of sufficient stability criteria are obtained. A rigorous mathematical proof is provided that the conservatism of the proposed stability criteria can be reduced progressively by increasing the number of the probability interval. Based on this, a novel hierarchy of LMI conditions is established. It is rigorously proved that with the same decomposition of probability interval, the conservatism of the proposed stability criteria is less than the one obtained by time-varying delay decomposition approach. The computation burden of the proposed method is analyzed and compared with one of the time-varying delay decomposition approach. Finally, a numerical example is given to illustrate the validness and effectiveness of the proposed approach. 相似文献
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Semiconductors, a significant type of material in the information era, are becoming more and more powerful in the field of quantum information. In recent decades, semiconductor quantum computation was investigated thoroughly across the world and developed with a dramatically fast speed. The research varied from initialization, control and readout of qubits, to the architecture of fault-tolerant quantum computing. Here, we first introduce the basic ideas for quantum computing, and then discuss the developments of single- and two-qubit gate control in semiconductors. Up to now, the qubit initialization, control and readout can be realized with relatively high fidelity and a programmable two-qubit quantum processor has even been demonstrated. However, to further improve the qubit quality and scale it up, there are still some challenges to resolve such as the improvement of the readout method, material development and scalable designs. We discuss these issues and introduce the forefronts of progress. Finally, considering the positive trend of the research on semiconductor quantum devices and recent theoretical work on the applications of quantum computation, we anticipate that semiconductor quantum computation may develop fast and will have a huge impact on our lives in the near future. 相似文献
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Pa-Yee Tsai 《Journal of The Franklin Institute》2010,347(10):1850-1862
In this paper, a hybrid method which combines the Adomian decomposition method (ADM), the Laplace transform algorithm and the Padé approximant is introduced to solve the approximate analytic solutions of the nonlinear Riccati differential equations. This hybrid method demonstrates accurate and reliable results, and has a great improvement in the ADM truncated series solution which diverges rapidly as the applicable domain increases. Three examples herein are given to demonstrate good accuracy and fast convergence in comparison with the exact solution. 相似文献
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《Information processing & management》2022,59(2):102870
In recent times, exploration of multimedia required ever increasing demand and application for intelligent video retrieval from repositories. This paper presents an efficient video retrieval framework by employing the effective singular value decomposition and computationally low complex ordered dither block truncation coding to extract simple, compact, and well discriminative Color Co-occurrence Feature (CCF). In this context, the occurrence probability of a video frame pixel in the neighborhood is employed to formulate this specific and distinct feature. Moreover, we applied a new adaptive low rank thresholding based on energy concentricity, transposition, and replacement invariance characteristics to formulate a unified fast shot boundary detection approach to solve the protuberant bottleneck problem for real-time cut and gradual transition that eventually contributes for effective keyframes extraction. Therefore, we can assert that the keyframes are distinct and discriminative to represent the whole video content. For effective indexing and retrieval, it is imperative to formulate similarity score evaluator for the encapsulated contextual video information with substantial temporal consistency, least computation, and post-processing. Therefore, we introduced graph-based pattern matching for video retrieval with an aim to sustain temporal consistency, accuracy and time overhead. Experimental results signify that the proposed method on average provides 7.40% and 17.91% better retrieval accuracy and 23.21% and 20.44% faster than the recent state-of-the-art methods for UCF11 and HMDB51 standard video dataset, respectively. 相似文献
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大数据技术的快速发展与应用,加快了可视媒体大数据的传播与利用。可视媒体数据的特点与广泛应用也带来了一些新的可视媒体大数据安全性问题。构建网络环境可视媒体大数据版权保护模式,可为数字图书馆可视媒体应用服务提供安全保障,增强图书馆数字资源综合服务能力。充分挖掘可视媒体价值稀疏性与视觉稀疏性,提取可视媒体稀疏特征,建立可视媒体大数据稀疏感知计算模型,从可视媒体稀疏特性角度给出可视媒体大数据版权加密、版权认证、版权告示与版权审计追踪方案设计思路,构建可视媒体大数据版权保护应用新模式。结合数字图书馆应用实践验证了该版权保护模式的有效性,该版权保护模式可较好维护数字图书馆中可视媒体大数据机密性、完整性、可用性、可审计性,切实提升大数据环境数字图书馆可视媒体内容服务能力。 相似文献