Quantum protocol for millionaire problem

We present a quantum protocol for the solution of a two-party comparison task with the help of a semi-honest third party, which can be used to solve the millionaire problem. The secrets are coded into the phases of d-level entangled states by local operations and read by the third party's collective measurements. The two parties can deduce the results of comparisons based on the secret bits shared between them beforehand and the announcement of the third party. Moreover, others will learn no information of the comparison results, even the third party. Our scheme is private and fair, and the security has also been discussed.     

Diffraction errors in micromirror-array based wavefront generation

Using Laser-based Speckle-Interferometers, the shape of optically rough surfaces can be measured precisely and contactlessly from variable measuring distances even in regions of difficult access. This work is concerned with the integration of a micromirror array (MMA) into an electronic Speckle-Pattern-Interferometer. With the adaptive optics, it is intended to adapt the phasefront of a reference wave to critical surface areas of the measurement object. Yet, due to the topography of the MMA, diffraction effects occur which affect the phase and intensity of the generated wavefront. We demonstrate how these diffraction effects can be efficiently modelled by a Fraunhofer diffraction method. We compare the results of this model to theoretical data obtained by a numerical Fresnel diffraction model and to measurement data obtained from a measurement setup incorporating a multi mirror array.     

结构光测量相位波动误差补偿方法研究

在计算机仿真分析投影仪伽马非线性特性对包裹相位波动误差影响的基础上,提出一种面向相移结构光测量的相位波动误差补偿方法.该方法采用二次多项式最小二乘拟合的方法近似输出条纹光强分布,实现包裹相位波动误差的补偿,减小投影仪非线性导致的系统测量误差.此方法简单,运算量小,不依赖环境光源及投影仪、摄像机具体参数,具有很强的通用性...     

Speckle interferometry for measurement of continuous deformations

Improvements of a method for measurement of continuous displacements and deformations with digital phase shifting speckle pattern interferometry are presented. The method is based on an algorithm that, with the knowledge of the initial phase, only needs one image at a time to evaluate continuos phase changes due to object deformations. In the improved method, the initial random phase of the speckle pattern is evaluated using a number of phase-shifted images before the deformation under study. This is used for increasing the accuracy of the initial phase estimation and reducing influences from image noise and other measurement disturbances. The phase-shifted speckle patterns are used as references for comparison with the speckle patterns of the deformed object, thereby increasing the reliability and accuracy of the phase estimations of the deformed patterns. The technique can be used for measuring deformations such as transients and other dynamic events, heat expansion as well as other phenomena where it is difficult to accomplish phase shifting during deformation.     

DDS调制芯片AD7008的原理及应用

基于DDS(直接数字频率合成)专用芯片得到广泛应用,使得信号的产生与调制变得更为简单。介绍了DDS芯片AD7008的内部结构与工作原理,分析了采用AD7008实现正弦信号发生器、调幅、调频的方法,给出了基于89C51单片机与AD7008的软硬件设计方案。     

A New Algorithm for Solving the Word Problem in Braid Groups

One of the most interesting questions about a group is whether its word problem can be solved and how. The word problem in the braid group is of particular interest to topologists, algebraists, and geometers, and is the target of intensive current research. We look at the braid group from a topological point of view (rather than a geometric one). The braid group is defined by the action of diffeomorphisms on the fundamental group of a punctured disk. We exploit the topological definition in order to give a new approach for solving its word problem. Our algorithm, although not better in complexity, is faster in comparison with known algorithms for short braid words, and it is almost independent of the number of strings in the braids. Moreover, the algorithm is based on a new computer presentation of the elements of the fundamental group of a punctured disk. This presentation can be used also for other algorithms.     

字定理在Heegaard分解方面的一个应用

The word theorem states that x can be denoted as a rotation inserting word of A if x is in the normal closure of A in F(X). As an application of the theorem, in this note a condition that guarantees reducing the genus of Heegaard splitting of 3-manifolds is given. This leads Poincare conjecture to a new formulation.     

HMM关键词检出系统专

关键词检出(keywordspottin)g也称词检出(wordspottin)g,是近年来语音识别中颇受重视的研究领域,可广泛应用于电话的自动接听和对话监听、语音的录入和检索等方面。文中首先介绍了关键词检出的HMM方案及其研究成果,并对其进行了仿真实验,最后指出了关键词检出尚待解决的一些问题及研究方向。     

Uniqueness and stability of slowly oscillating periodic solutions of delay equations with bounded nonlinearity

We study slowly oscillating periodic solutions of delay equations with small parameters. When the nonlinearity has finite and nonzero limits at infinities, the appearance of these solutions and their periods can be found though asymptotic analysis. Under further natural assumptions on the nonlinearity, we prove that slowly oscillating periodic solutions are unique and asymptotically stable when parameters are sufficiently small.