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In this paper it is shown that Winograd’s algorithm for computing convolutions and a fast, prime factor, discrete Fourier transform (DFT) algorithm can be modified to compute Fourier-like transforms of long sequences of 2m − 1 points over GF(2m), for 8 ? m ? 10. These new transform techniques can be used to decode Reed-Solomon (RS) codes of block length 2m − 1. The complexity of this new transform algorithm is reduced substantially from more conventional methods. A computer simulation verifies these new results.  相似文献   

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一种新的基于Radon变换的车牌倾斜校正方法   总被引:5,自引:1,他引:4       下载免费PDF全文
车牌的倾斜给车牌字符分割与识别带来不利的影响。基于Radon变换,提出了一种新的车牌倾斜校正方法。对车牌图像在[-20°,20°]范围内进行Radon变换,并对变换后的结果求一阶导数绝对值的累加和,将累加和的最大值所对应的Radon变换的角度作为倾斜角度。对水平倾斜的车牌进行双线性插值旋转校正,对垂直倾斜的车牌进行双线性插值错位偏移校正。实验结果证明,该方法简单实用,对光照、污迹等不敏感,抗干扰能力强。  相似文献   

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W.A.  H.J. 《Pattern recognition》1995,28(12):1985-1992
A fast digital Radon transform based on recursively defined digital straight lines is described, which has the sequential complexity of N2 log N additions for an N × N image. This transform can be used to evaluate the Hough transform to detect straight lines in a digital image. Whilst a parallel implementation of the Hough transform algorithm is difficult because of global memory access requirements, the fast digital Radon transform is vectorizable and therefore well suited for parallel computation. The structure of the fast algorithm is shown to be quite similar to the FFT algorithm for decimation in frequency. It is demonstrated that even for sequential computation the fast Radon transform is an attractive alternative to the classical Hough transform algorithm.  相似文献   

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为了准确估计运动模糊图像的方向,在理论推导部分,以定积分、Fourier 变换和 Sinc 函数的性质为依据,得出了运动模糊方向、图像尺寸和频谱图像平行条纹方向三者的关系。在算法优化部分,系统分析了Radon 变换法、Gabor 变换法和频谱分块法的原理和不足,并提出了基于频谱边缘检测和Radon 变换的改进算法。在数值实验部分,编写Matlab 程序对几种方法进行了测试和比较,结果表明,该方法的估计精度最高,更适用于估计运动模糊图像的方向。  相似文献   

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基于主导边界Radon变换的SAR目标方位角估计方法   总被引:1,自引:0,他引:1  
黄嘉辛  陆军  赵凌君 《计算机应用》2011,31(9):2473-2476
针对仅利用主导边界估计带来的目标垂直与水平方位的模糊问题,提出一种基于主导边界Radon变换的合成孔径雷达(SAR)图像目标方位角估计方法。该方法基于分割图像中目标主导边界长度的判别准则进行解模糊,同时引入目标主导边界Radon变换的估计算法,解决了传统主导边界算法中长、短主导边界不易分离的问题。MSTAR实测数据的实验结果表明提出的算法具有良好的精确度和适应性。  相似文献   

7.
Radon transform has been widely used in content-based image representation due to its excellent geometric properties. In this paper, we propose a family of geometric invariant features based on Radon transform for near-duplicate image detection. According to the theoretical analysis between geometric operations (translation, scaling, and rotation) and Radon transform, we present a geometric invariant feature model. Based on the feature model, we developed four kinds of geometric invariant features. In addition, a uniform sampling technique is introduced to combine different features. The comprehensive performance of the combined feature is better than that of a single one. Extensive experiments show that the proposed features are robust, not only to rotation and scaling, but also to other operations, such as compression, noise contamination, blurring, illumination modification, cropping, etc., and achieve strong competitive performance compared with the state-of-the-art image features.  相似文献   

8.
This paper considers an economic lot sizing model with constant capacity, non-increasing setup cost, and convex inventory cost function. Algorithms with computational time of O(N×TDN)have been developed for solving the model, where N is the number of planning periods and TDN is the total demand. This study partially characterizes the optimal planning structure of the model. A new efficient algorithm with computational time of O(N log N) has also been developed based on the partial optimal structure. Moreover, computational study demonstrates that the new algorithm is efficient.  相似文献   

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As a generalization of the precise and pessimistic diagnosis strategies of system-level diagnosis of multicomputers, the t/k diagnosis strategy can significantly improve the self-diagnosing capability of a system at the expense of no more than k fault-free processors (nodes) being mistakenly diagnosed as faulty. In the case k ? 2, to our knowledge, there is no known t/k diagnosis algorithm for general diagnosable system or for any specific system. Hypercube is a popular topology for interconnecting processors of multicomputers. It is known that an n-dimensional cube is (4n − 9)/3-diagnosable. This paper addresses the (4n − 9)/3 diagnosis of n-dimensional cube. By exploring the relationship between a largest connected component of the 0-test subgraph of a faulty hypercube and the distribution of the faulty nodes over the network, the fault diagnosis of an n-dimensional cube can be reduced to those of two constituent (n − 1)-dimensional cubes. On this basis, a diagnosis algorithm is presented. Given that there are no more than 4n − 9 faulty nodes, this algorithm can isolate all faulty nodes to within a set in which at most three nodes are fault-free. The proposed algorithm can operate in O(N log2 N) time, where N = 2n is the total number of nodes of the hypercube. The work of this paper provides insight into developing efficient t/k diagnosis algorithms for larger k value and for other types of interconnection networks.  相似文献   

11.
一种结合DWT和DFT的彩色图像盲水印方案   总被引:1,自引:0,他引:1       下载免费PDF全文
为了扩大数字水印的适用范围,提出了一种彩色图像盲水印算法。在嵌入过程中,将宿主图像从RGB空间转换到YIQ空间,对其进行小波分解后再进行分块DFT变换,结合一个嵌入模板矩阵和两个伪随机序列,将Arnold置乱以后的二值图像水印嵌入到宿主图像中;在提取过程中,根据嵌入模板矩阵提取出嵌入到每一图像小块的序列,分别计算该序列和两个伪随机序列的相关性,根据相关性的大小关系恢复水印信息。实验结果表明,算法具有良好的不可见性和鲁棒性。  相似文献   

12.
Indium oxide (In2O3) doped with 0.5-5 at.% of Ba was examined for their response towards trace levels of NOx in the ambient. Crystallographic phase studies, electrical conductivity and sensor studies for NOx with cross interference for hydrogen, petroleum gas (PG) and ammonia were carried out. Bulk compositions with x ≤ 1 at.% of Ba exhibited high response towards NOx with extremely low cross interference for hydrogen, PG and ammonia, offering high selectivity. Thin films of 0.5 at.% Ba doped In2O3 were deposited using pulsed laser deposition technique using an excimer laser (KrF) operating at a wavelength of (λ) 248 nm with a fluence of ∼3 J/cm2 and pulsed at 10 Hz. Thin film sensors exhibited better response towards 3 ppm NOx quite reliably and reproducibly and offer the potential to develop NOx sensors (Threshold limit value of NO2 and NO is 3 and 25 ppm, respectively).  相似文献   

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介绍一种基于LabWindows/CVI的光谱测量数据采集系统,利用LabWindows/CVI的编程优势,提高了编程效率与光谱仪数据分析的处理能力.给出了傅里叶变换光谱测量方法的设计原理、硬件系统构成以及LabWindows/CVI软件数据采集系统,包括实现干涉图数据采集、实时显示、数据分析处理和光谱分辨率的精确计算等功能.实验结果证明该系统满足设计需求.  相似文献   

14.
The paper deals with quadrature and cubature formulas, optimal and nearly optimal in accuracy, used to evaluate integrals of quickly oscillating functions in a class of bounded functions with piecewise continuous first derivatives bounded by a constant in one-and multidimensional cases. Optimal estimates for the numerical integration error and upper bounds are obtained for these integrals in case of strong oscillation of subintegral functions. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 5, pp. 144–164, September–October 2007.  相似文献   

15.
For over 40 years, system response time has been a topic of interest and controversy in computer science. Since the late 1960s, the field has seen numerous studies conducted and articles written addressing the issue. Many factors were measured in these studies including: users’ accuracy and error rates with different levels of system response time, user performance speed and the efficiency of the commands used, how user interactions with the computer changed as a result of changes in system response time, how their bodies reacted physiologically to those same changes and even how happy, satisfied, anxious or annoyed they were as system response times changed.In this paper, we summarize the major issues in system response time research and look at what can be concluded from them. Generally, researchers have suggested specific response-time guidelines based on the complexity of the task or the type of interaction with the computer. We suggest that rather than system response time being task- or expectation-focused, instead interactions with a computer fall into two categories: control tasks and conversational tasks. For control tasks, immediate response times are necessary for optimal user performance whereas for conversational tasks, some delays may be necessary to maintain the optimal pacing of the on-going conversation. The location and duration of these delays will depend on both task complexity and user expectations. Future system response time research is needed to further quantify limits of delay detection, and the location and duration of inter-task delays to optimize user performance and satisfaction with computers.  相似文献   

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In this paper, we consider a ring as a universal set and study (?T)-fuzzy rough approximation operators with respect to a TL-fuzzy ideal of a ring. First, some new properties of generalized (?T)-fuzzy rough approximation operators are obtained. Then, a new fuzzy algebraic structure - TL-fuzzy rough ideal is defined and its properties investigated. And finally, the homomorphism of (?T)-fuzzy rough approximation operators is studied.  相似文献   

17.
This paper submits a comprehensive report of the use of order statistics (OS) for parametric pattern recognition (PR) for various distributions within the exponential family. Although the field of parametric PR has been thoroughly studied for over five decades, the use of the OS of the distributions to achieve this has not been reported. The pioneering work on using OS for classification was presented earlier for the uniform distribution and for some members of the exponential family, where it was shown that optimal PR can be achieved in a counter-intuitive manner, diametrically opposed to the Bayesian paradigm, i.e., by comparing the testing sample to a few samples distant from the mean. Apart from the results for the Gaussian and doubly exponential which are merely cited here, our new results include the Rayleigh, Gamma and certain Beta distributions. The new scheme, referred to as classification by moments of order statistics (CMOS), has an accuracy that attains Bayes' bound for symmetric distributions, and is, otherwise, very close to the optimal Bayes' bound, as has been shown both theoretically and by rigorous experimental testing. The results here also give a theoretical foundation for the families of border identification (BI) algorithms reported in the literature.  相似文献   

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在提出的符号序列的高维数字表达以及高维傅里叶变换概念的基础上,提出了蛋白质比较的新方法——高维共鸣识别。将两种蛋白质对应的氨基酸序列转化为向量序列,分别计算它们对应的向量序列的离散傅里叶变换。据此,定义两个蛋白质序列所对应的交叉谱函数,考查交叉谱函数的信噪比,判断两种蛋白质序列的相似性或差异性。计算结果显示它是蛋白质比对的又一个有效方法,是Cosic一维共鸣识别的拓展。  相似文献   

19.
To maximize the total cost of savings, a mixed-integer programming model for remanufacturing proposed by Kim et al. [Kim, K., Song, I., Kim, J., & Jeong, B. (2006). Supply planning model for remanufacturing system in reverse logistics environment. Computers & Industrial Engineering, 51, 279–287] was published in Computers & Industrial Engineering journal to decide optimally the quantity of parts to be processed at each remanufacturing facilities, the number of purchased parts from subcontractor. In this work, comments and suggestions are given to the published model of Kim, Song, Kim, and Jeong (2006). Comments like partial and complete disassembly, disassembly cost, optimum level of disassembly and finally, the modification of constraints are suggested in this work.  相似文献   

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