基于转台的线阵激光雷达地面检校方法研究

介绍了一种基于转台的线阵激光雷达地面检校方法,该方法通过布设物方检校控制场,使用指示激光器建立激光测距值与物方控制点之间的对应关系并引入激光测距的加/乘常数与外方位元素一并作为检校参数,通过坐标转换列出误差方程式;最后使用最小二乘平差解算所有的检校参数。文中给出了实测数据的实验结果分析及精度评定,验证了本文方法的可行性。     

Sparse polynomial division using a heap

In 1974, Johnson showed how to multiply and divide sparse polynomials using a binary heap. This paper introduces a new algorithm that uses a heap to divide with the same complexity as multiplication. It is a fraction-free method that also reduces the number of integer operations for divisions of polynomials with integer coefficients over the rationals. Heap-based algorithms use very little memory and do not generate garbage. They can run in the CPU cache and achieve high performance. We compare our C implementation of sparse polynomial multiplication and division with integer coefficients to the routines of the Magma, Maple, Pari, Singular and Trip computer algebra systems.     

基于MapReduce的增量矩阵乘法设计

矩阵乘法是许多应用中的核心计算,在这些应用中只是少量矩阵元素发生改变,如果全量重新计算则工作量很大,因此增量计算是解决该问题的有效手段. 本文提出了一种基于MapReudce模型的增量矩阵乘法计算方法,以及计算矩阵中变化元素的高效识别方法,通过利用矩阵元素的摘要信息快速计算出变化元素,然后将矩阵乘法计算过程转换为一系列等价的连接问题,实现了一种有效的矩阵乘法增量计算. 对于矩阵元素变化率较小的情形,计算实验表明提出的方法计算时间上明显优于全量重新计算方法.     

抵抗SPA攻击的分段Montgomery标量乘算法

基于Akishita在Montgomery形式椭圆曲线上计算双标量乘kP+lQ的思想,提出了一种计算三标量乘kP+lQ+tR的新算法,使运算量减少了约23%。在上述算法基础上提出一种椭圆曲线上分段计算标量乘bP的方法,通过预计算少量点,将计算bP转化为计算kP+lQ或kP+lQ+tR,并使用边信道原子化的方法使其可以抵抗简单能量分析(SPA)攻击。最后使用Magma在二进制域上对分段算法仿真,结果显示二分段算法计算速度最快,三分段算法其次,在效率上均比原始Montgomery算法提升很大。     

First-order side channel attacks on Zhang’s countermeasures

Zhang’s three countermeasures are known to be secure against certain first-order side channel attacks such as differential power analysis and correlation power analysis. This security comes from the countermeasures’ use of random points to blind the message and random integers to blind the secret scalar. In this paper, we propose first-order side channel attack methods that can perfectly break these three countermeasures. Even though Zhang’s countermeasures use random points and random integers our attacks are made possible by the fact that intermediate values computed by these countermeasures are dependent on specific values that we can guess. The experimental results verify that the proposed attack methods can successfully break existing countermeasures.     

Processor Efficient Parallel Matching

In this paper we consider the problem of finding perfect matchings in parallel. We present a RNC algorithm with almost optimal work with respect to sequential algorithms, i.e., it uses O(n ^ω ) processors, where ω is the matrix multiplication exponent. Our algorithm is based on an RNC algorithm for computing determinant of a degree one polynomial matrix which is of independent interest. Research supported by KBN grant 1P03A01830.     

Non-Linear Scale-Spaces Isomorphic to the Linear Case with Applications to Scalar,Vector and Multispectral Images

A basic requirement of scale-space representations in general is that of scale causality, which states that local extrema in the image should not be enhanced when resolution is diminished. We consider a special class of nonlinear scale-spaces consistent with this constraint, which can be linearised by a suitable isomorphism in the grey-scale domain so as to reproduce the familiar Gaussian scale-space. We consider instances in which nonlinear representations may be the preferred choice, as well as instances in which they enter by necessity. We also establish their relation to morphological scale-space representations based on a quadratic structuring function.     

图象小波分解方式的改进及应用

在传统图象小波分解方式的基础上,提出一种改进的图象小波分解方法,并将它应用到图象压缩编码方案中去减少了运算杂度,实验结果也表明,该方案在不影响图象质量的前提下提高了压缩比,具有广阔的应用前景。     

高速可配RSA加速器设计与实现

为实现高速可配RSA硬件加速器,提出了一种基于基—64蒙哥马利算法的模乘器流水线架构及其对应的可配置存储结构。通过五级流水线的并行运算和存储器的灵活配置,可以高效地实现256位到2048位的RSA运算。实验结果表明:与其他相关工作比较,提出的流水线架构能够取得较好的性能和资源消耗比,加速器在模乘器性能和数据吞吐率方面有明显提高。在73 k门硬件资源下,在1024位RSA运算情况下,实现了333 kbps的数据吞吐率。     

扩散硅压力传感器的高精度误差补偿算法

扩散硅压力传感器的传输特性受温度影响较大,必须采用某种手段将传感器的输入压力与温度进行解耦,从而实现对压力传感器输出的有效补偿,进而得到准确可靠的压力测量值.文中分析了一般扩散硅压力传感器的误差组成,针对误差提出了一个简单而又高精度的补偿模型,建立了有效算式,最后通过实例验证了算法的正确性,其精度可达到0.1％FS以下.