新的二元互素序列的迹表示和线性复杂度

利用周期分别为奇素数p 和q的Legendre序列构造大量新的周期为 的二元序列,根据这些序列与Legendre序列在结构上的联系,给出它们的迹表示,依据E.L. Key方法得到其线性复杂度。结果表明该类序列具有良好的符号平衡性和线性复杂度性质,作为密钥流序列可抵抗Berlekamp-Massey算法的攻击。     

Optimal binary codes and binary construction of quantum codes

This paper discusses optimal binary codes and pure binary quantum codes created using Steane construction. First, a local search algorithm for a special subclass of quasi-cyclic codes is proposed, then five binary quasi-cyclic codes are built. Second, three classical construction methods are generalized for new codes from old such that they are suitable for constructing binary self-orthogonal codes, and 62 binary codes and six subcode chains of obtained self-orthogonal codes are designed. Third, six pure binary quantum codes are constructed from the code pairs obtained through Steane construction. There are 66 good binary codes that include 12 optimal linear codes, 45 known optimal linear codes, and nine known optimal self-orthogonal codes. The six pure binary quantum codes all achieve the performance of their additive counterparts constructed by quaternary construction and thus are known optimal codes.     

A novel binary image representation algorithm by using NAM and coordinate encoding procedure and its application to area calculation

We propose a novel binary image representation algorithm using the non-symmetry and anti-packing model and the coordinate encoding procedure （NAMCEP）. By tak- ing some idiomatic standard binary images in the field of image processing as typical test objects, and by comparing our proposed NAMCEP representation with linear quadtree （LQT）, binary tree （Bintree）, non-symmetry and anti-packing model （NAM） with K-lines （NAMK）, and NAM representa- tions, we show that NAMCEP can not only reduce the aver- age node, but also simultaneously improve the average com- pression. We also present a novel NAMCEP-based algorithm for area calculation and show experimentally that our algo- rithm offers significant improvements.     

Multi-Wavelength vs. Binary Code Pattern Unwrapping in Fringe Projection Method

Phase extraction, phase unwrapping and phase to height conversion are consecutive steps within the fringe projection method for reconstruction of 3D objects. The procedure of determining discontinuities on the wrapped phase, resolving them and achieving the unwrapped phase is called phase unwrapping. A software system was developed that provides the ability to create many kinds of patterns with a verity of desirable properties suitable for different demands in fringe projection systems. In our previous work, an experimental study was reported based on a multi-wavelength unwrapping approach. In the following work, we implemented a new method called binary code pattern unwrapping that is based on time analysis. A comparison of the two unwrapping approaches in terms of resolution, quality, noise, depth accuracy, and computational cost is provided.     

Binary Cyclic Codes and Minimal Codewords

Cyclic codes form an important class of codes. They have very interesting algebraic structure. Furthermore, they are equivalent to many important codes, such as binary Hamming codes, Golay codes and BCH codes. Minimal codewords in linear codes are widely used in constructing decoding algorithms and studying linear secret sharing scheme. In this paper, we show that in the binary cyclic code all of the codewords are minimal, except 0 and 1. Then, we obtain a result about the number of minimal codewords in the binary cyclic codes.     

A comparative study of two formal semantics of the SIGNAL language

SIGNAL is a part of the synchronous languages family, which are broadly used in the design of safety-critical real-time systems such as avionics, space systems, and nu- clear power plants. There exist several semantics for SIG- NAL, such as denotational semantics based on traces （called trace semantics）, denotational semantics based on tags （called tagged model semantics）, operational semantics presented by structural style through an inductive definition of the set of possible transitions, operational semantics defined by syn- chronous transition systems （STS）, etc. However, there is lit- tle research about the equivalence between these semantics. In this work, we would like to prove the equivalence be- tween the trace semantics and the tagged model semantics, to get a determined and precise semantics of the SIGNAL language. These two semantics have several different defini- tions respectively, we select appropriate ones and mechanize them in the Coq platform, the Coq expressions of the abstract syntax of SIGNAL and the two semantics domains, i.e., the trace model and the tagged model, are also given. The dis- tance between these two semantics discourages a direct proof of equivalence. Instead, we transform them to an intermediate model, which mixes the features of both the trace semantics and the tagged model semantics. Finally, we get a determined and precise semantics of SIGNAL.     

线性复杂度为2n-2m-1的2n-周期二元序列的k-错线性复杂度*

线性复杂度和k-错线性复杂度是研究流密码稳定性的两个重要概念。当改变序列某几位时不会使得序列的线性复杂度急剧减少,说明该序列的稳定性良好。运用Chan-Games给出了当k=4或5时,F2上固定线性复杂度为2n-2m-1的2n-周期二元序列的k-错线性复杂度所有可能值,LCk(s)=0或LCk(s)=2n-2m-2r+1+c,LCk(s)=2n-2r+1+c。这一结果对流密码稳定性的研究有重要的应用价值。     

Improved Linear Attacks on the Chinese Block Cipher Standard

The block cipher used in the Chinese Wireless LAN Standard （WAPI）, SMS4, was recently renamed as SM4, and became the block cipher standard issued by the Chinese government. This paper gives a method for finding the linear approximations of SMS4. With this method, 19-round one-dimensional approximations are given, which are used to improve the previous linear cryptanalysis of SMS4. The 19-round approximations hold with bias 2-62.27; we use one of them to leverage a linear attack on 23-round SMS4. Our attack improves the previous 23-round attacks by reducing the time complexity. Furthermore, the data complexity of our attack is further improved by the multidimensional linear approach.     

Trace representation of some generalized cyclotomic sequences of length pq

This paper contributes to trace representation of some generalized cyclotomic sequences of length which are defined by Ding and Helleseth. From the relations between these sequences and the Legendre sequence, we firstly confirm the defining pairs of these sequences of arbitrary order. Then, we obtain their trace representation, from which we give their linear complexity using Key’s method. It can be seen that Bai et al.’s conclusion is a special case of our result when the order is two. Finally, an example is given to illustrate the validity of our result.     

A sequential GM-based PHD filter for a linear Gaussian system

The probability hypothesis density(PHD)flter provides an efciently parallel processing method for multi-target tracking.However,measurements have to be gathered for a scan period before the PHD flter can perform a recursion,therefore,signifcant delay may arise if the scan period is long.To reduce the delay in the PHD flter,we propose a sequential PHD flter which updates the posterior intensity whenever a new measurement becomes available.An implementation of the sequential PHD flter for a linear Gaussian system is also developed.The unique characteristic of the proposed flter is that it can retain the useful information of missed targets in the posterior intensity and sequentially handle the received measurements in time.     

Interval Arithmetic and Its Application to Electrical Circuits

Interval arithmetic is an elegant tool for practical work with inequalities, approximate numbers, error bounds, and more generally with certain convex and bounded sets. In this section we give a number of simple examples showing where intervals and ranges of functions over intervals arise naturally. Interval mathematics is a generalization in which interval numbers replace real numbers, interval arithmetic replaces real arithmetic, and interval analysis replaces real analysis. Interval is limited by two bounds： lower bound and upper bound. The present paper introduces some of the basic notions and techniques from interval analysis needed in the sequel for presenting various uses of interval analysis in electric circuit theory and its applications. In this article we address the representation of uncertain and imprecise information, the interval arithmetic and its application to electrical circuits.     

Estimation of Human Movements via Quaternion

This paper presents the authors＇ research results about HRI （human-robot interaction）. The goal is to estimate together the arm position, the anatomical movements of the shoulder and accelerations of the arm with respect to the shoulder and visualizing this movement in a 3-D virtual model to control a Robot. The estimation algorithm makes use of a nonlinear observer and an optimization routine to fuse information from the sensor. The global asymptotic convergence of the nonlinear observer is guaranteed. Extensive tests of the presented methodology with real world data show the effectiveness of the proposed procedure.     

Spectroscopic Multicomponent Analysis Using Multi-objective Optimization for Variable Selection

The multiple determination tasks of chemical properties are a classical problem in analytical chemistry. The major problem is concerned in to find the best subset of variables that better represents the compounds. These variables are obtained by a spectrophotometer device. This device measures hundreds of correlated variables related with physicocbemical properties and that can be used to estimate the component of interest. The problem is the selection of a subset of informative and uncorrelated variables that help the minimization of prediction error. Classical algorithms select a subset of variables for each compound considered. In this work we propose the use of the SPEA-II （strength Pareto evolutionary algorithm II）. We would like to show that the variable selection algorithm can selected just one subset used for multiple determinations using multiple linear regressions. For the case study is used wheat data obtained by NIR （near-infrared spectroscopy） spectrometry where the objective is the determination of a variable subgroup with information about E protein content （%）, test weight （Kg/HI）, WKT （wheat kernel texture） （%） and farinograph water absorption （%）. The results of traditional techniques of multivariate calibration as the SPA （successive projections algorithm）, PLS （partial least square） and mono-objective genetic algorithm are presents for comparisons. For NIR spectral analysis of protein concentration on wheat, the number of variables selected from 775 spectral variables was reduced for just 10 in the SPEA-II algorithm. The prediction error decreased from 0.2 in the classical methods to 0.09 in proposed approach, a reduction of 37%. The model using variables selected by SPEA-II had better prediction performance than classical algorithms and full-spectrum partial least-squares.     

Controller Design for Networked Control System with Uncertain Parameters

This paper deals with the problem of controller design for NCSs （networked control systems） with uncertain parameters and network induced time-delays. In the case of long time delay constraint and data package loss, the closed-loop model of a class of NCSs is presented for controlled objects with uncertain parameters. Based on Lyapunov stability theory combined with LMIs （linear matrix inequalities） techniques, the design method of state feedback controller for NCSs with asymptotic stability is given in the form of LMIs. Numerical example and simulation suggest that the results are effective and are an improvement over previous ones.     

线性复杂度为2n-2m的2n-周期序列的k-错线性复杂度*

线性复杂度和k-错线性复杂度是衡量密钥序列随机性的两个重要标准,运用Chan-Games算法,得到线性复杂度为2n-2m的2n-周期二元序列的k-错线性复杂度的所有可能的值,LCk(s)=0或2n－2m－2r+1+c,2n-2r+1+c。这一结果对于进一步探讨流密码密钥序列的安全性有重要的应用价值。     

Some Notes on Prime-Square Sequences

The well-known binary Legendre sequences possess good autocorrelation functions and high linear complexity, and are just special cases of much larger families of cyclotomic sequences. Prime-square sequences are the generalization of these Legendre sequences, but the ratio of the linear complexity to the least period of these sequences approximates to zero if the prime is infinite. However, a relatively straightforward modification can radically improve this situation. The structure and properties, including linear complexity, minimal polynomial, and autocorrelation function, of these modified prime-square sequences are investigated. The hardware implementation is also considered.     

一种新的灰度图像Legendre矩的快速算法

Legendre正交矩在模式识别和图像分析等领域有着广泛的应用，但由于计算的复杂性，相关的快速算法尚未得到很好的解决，已有方法均局限于二值图像．文章提出了一种灰度图像的Legendre正交矩的快速算法，借助于Legendre多项式的递推公式推导出计算一维Legendre矩的递归公式．利用该关系式，一维Legendre矩Lp可以用一系列初始值L1(a)，a＜p，Lo(a)，a＜p-1来得到．而二维Legendre矩pq可以利用一维算法进行计算,为了降低算法复杂度，文中采用基于Systolic阵列的快速算法进行计算L1(a)，Lo(a),与直接方法相比，快速算法可以大幅度减少乘法的次数，从而达到了降低算法复杂度的目的。     

Representation of ℤ<Subscript>4</Subscript>-Linear Preparata Codes Using Vector Fields

A binary code is called ℤ₄-linear if its quaternary Gray map preimage is linear. We show that the set of all quaternary linear Preparata codes of length n = 2^m, m odd, m ≥ 3, is nothing more than the set of codes of the form with

周期为p 7(mod 8)的一类新六次剩余序列的迹表示

构造了一类新的周期为素数 的六次剩余序列，利用有限域和差集理论给出了该序列在周期为素数 情形下的迹函数表示。新序列的线性复杂度为 ，优于Hall六次剩余序列在相同条件下的线性复杂度。     

Efficient Legendre moment computation for grey level images

Legendre orthogonal moments have been widely used in the field of image analysis. Because their computation by a direct method is very time expensive, recent efforts have been devoted to the reduction of computational complexity. Nevertheless, the existing algorithms are mainly focused on binary images. We propose here a new fast method for computing the Legendre moments, which is not only suitable for binary images but also for grey level images. We first establish a recurrence formula of one-dimensional (1D) Legendre moments by using the recursive property of Legendre polynomials. As a result, the 1D Legendre moments of order p, L_p=L_p(0), can be expressed as a linear combination of L_p-1(1) and L_p-2(0). Based on this relationship, the 1D Legendre moments L_p(0) can thus be obtained from the arrays of L₁(a) and L₀(a), where a is an integer number less than p. To further decrease the computation complexity, an algorithm, in which no multiplication is required, is used to compute these quantities. The method is then extended to the calculation of the two-dimensional Legendre moments L_pq. We show that the proposed method is more efficient than the direct method.