Fast vectorized algorithm for the Monte Carlo simulation of the random field Ising model

An algorithm for the simulation of the 3-dimensional random field Ising model with a binary distribution of the random fields is presented. It uses multi-spin coding and simulates 64 physically different systems simultaneously. On one processor of a Cray YMP it reaches a speed of 184 million spin updates per second. For smaller field strength we present a version of the algorithm that can perform 242 million spin updates per second on the same machine.     

量子Turbo码

量子纠错编码技术在量子通信和量子计算领域起着非常重要的作用.构造量子纠错编码的主要方法是借鉴经典纠错编码技术,目前几乎所有经典纠错编码方案都已经被移植到量子领域中来,然而在经典编码领域纠错性能最杰出的Turbo码却至今没有量子对应.提出了一种利用量子寄存器网络构造量子递归系统卷积码的简单实现方案,同时利用量子SWAP门设计了一种高效的量子交织器门组网络方案.最后仿照经典Turbo码的设计原理提出串行级联的量子Turbo码,同时提出了可行的译码方法.量子Turbo码不仅丰富了量子纠错码研究的领域,同时为解释 关键词： 量子递归系统卷积码 量子Turbo码 量子纠错编码 量子信息     

基于子带位平面容错算法的应用

在研究容错图像编码算法的基础上，针对图像压缩编码中复杂度较大和将图像分成多个小块而带来的图像重建中有分块痕迹等问题，在子带位平面编码（SBC）算法中加入了与图像无关的率失真优化编码并采用虚拟分块的方法，对SBC算法进行了改进，实验结果表明，在相同压缩倍数和相同误码率情况下，本算法与传统的图像压缩算法重建图像的峰值信噪比提高了1．0～1．5dB。     

Probabilistic Coding of Quantum States of Different Dimensions

We investigate the scheme which enables encoding of n qudits whose Hilbert spaces are of different dimensions to one qudit of dimension smaller than that of the Hilbert space of the n qudits and then probabilistically but error-free decoding any subset of k qudits. We also give a formula for calculating the average probability of successful decoding.     

彩色莫尔等高术

本文提出了用棱镜色散产生莫尔等高线条纹假彩色编码的方法.研究了单棱镜和互补双棱镜两种典型系统.给出了实验验证.     

Meshwork multipicture holography

In this paper, a method of meshwork multipicture holography is suggested, which uses spatially coded recording plate with one dimension grating meshwork. The method is simple in coding and easy to realize. The reconstructing images obtained are very clear.     

一种采用JPEG标准的实时视频图像压缩处理系统

本文重点探讨了在设计ＪＰＥＧ视频压缩应用系统时，应着重考虑的几个重要技术问题，并介绍了一种采用以ＰＣ为平台，以ＣＬ５５０视频压缩处理器和８２Ｃ９００１视频窗口控制器为基础的实时视频图像压缩处理系统。描述了该系统总体构成，深入讨论了图像数据缓冲存储和压缩速率控制等关键技术问题。     

A real-time LPC-based vocal tract area display for voice development

This article reports the design and implementation of a graphical display that presents an approximation to vocal tract area in real time for voiced vowel articulation. The acoustic signal is digitally sampled by the system. From these data a set of reflection coefficients is derived using linear predictive coding. A matrix of area coefficients is then determined that approximates the vocal tract area of the user. From this information a graphical display is then generated. The complete cycle of analysis and display is repeated at ≈20 times/s. Synchronised audio and visual sequences can be recorded and used as dynamic targets for articulatory development. Use of the system is illustrated by diagrams of system output for spoken cardinal vowels and for vowels sung in a trained and untrained style     

Gaussian channels and the optimal coding

For the Gaussian channel Y(t) = Φ(ξ(s), Y(s); s ≦ t) + X(t), the mutual information I(ξ, Y) between the message ξ(·) and the output Y(·) is evaluated, where X(·) is a Gaussian noise. Furthermore, the optimal coding under average power constraints is constructed.     

Monte Carlo technique for very large ising models

Rebbi's multispin coding technique is improved and applied to the kinetic Ising model with size 600*600*600. We give the central part of our computer program (for a CDC Cyber 76), which will be helpful also in a simulation of smaller systems, and describe the other tricks necessary to go to large lattices. The magnetizationM atT=1.4*T _c is found to decay asymptotically as exp(-t/2.90) ift is measured in Monte Carlo steps per spin, and M(t = 0) = 1 initially.