LT348电路的研制

本文介绍了ＬＴ３４８的电路、版图和工艺设计。ＬＴ３４８是由四个功能和７４１组件等同而又各自独立的高增益、内补偿、低功耗运放器组成，并且它的电源电流可以和单个的７４１典型运放器相比拟。此外，它还具有比标准７４正低得多的输入失调电流和输入偏流的特征。     

一类三元线性分组码的译码

Ｐｌｅｓｓ［１］证明了三元（１２，６，６）Ｇｏｌａｙ码具有一种双层结构，并据此给出了该码的快速硬判决译码算法。本文推广了Ｇｏｌａｙ码的Ｐｌｅｓｓ结构，给出了由三元（ｎ，ｋ，ｄ）线性分组码构造的三元（３，ｎ＋ｋ，≥ｍｉｎ（ｎ，２ｄ，６））线性分组码，其中包括（１２，６，６）Ｇｏｌａｙ码和（１８，９，６）码，并以三元（１８，９，６）码为例给出了这类码的最大似然软判决译码算法。     

一种分布式喷泉码在协作通信中的应用

为了减少基于数字喷泉码的协作传输系统中的计算复杂度和传输延迟,提出了一种基于分布式喷泉码的协作通信传输方案,给出了两层数字喷泉编码的度分布函数的设计过程;以各链路的丢包率为参量分析了系统传输时延,并与其他数字喷泉码传输方案进行了比较.理论分析和仿真结果表明,在各链路丢包率较大时采用这种分布式喷泉码的协作传输机制能在传输时延上显著改善系统性能,而且各链路删除概率越大时优势越明显.     

Verification of Euler/Navier–Stokes codes using the method of manufactured solutions

The method of manufactured solutions is used to verify the order of accuracy of two finite‐volume Euler and Navier–Stokes codes. The Premo code employs a node‐centred approach using unstructured meshes, while the Wind code employs a similar scheme on structured meshes. Both codes use Roe's upwind method with MUSCL extrapolation for the convective terms and central differences for the diffusion terms, thus yielding a numerical scheme that is formally second‐order accurate. The method of manufactured solutions is employed to generate exact solutions to the governing Euler and Navier–Stokes equations in two dimensions along with additional source terms. These exact solutions are then used to accurately evaluate the discretization error in the numerical solutions. Through global discretization error analyses, the spatial order of accuracy is observed to be second order for both codes, thus giving a high degree of confidence that the two codes are free from coding mistakes in the options exercised. Examples of coding mistakes discovered using the method are also given. Copyright © 2004 John Wiley & Sons, Ltd.     

Hydrodynamic Model and Its Computational Code for Thermal Self-focusing

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｒｅａｒｅｖｅｒｙｓｔｒｏｎｇｎｏｎｌｉｎｅａｒｏｐｔｉｃａｌｅｆｅｃｔｓｄｕｅｔｏｔｈｅｈｉｇｈｐｏｗｅｒｄｅｎｓｉｔｙｏｆｔｈｅｏｕｔｐｕｔｏｆｌａｒｇｅｌａｓｅｒｓｙｓｔｅｍｓａｎｄｐａｒｔｉｃｕｌａｒｌｙｔｈｅ...     

Binary caps with many free pairs of points

We introduce the following new viewpoint in the study of caps in PG(m,q). The objective is to maximize, among all caps of given cardinality in a given projective space, the number of free pairs of points, which we define as pairs of points not participating in any coplanar quadruple of points of the cap. We survey the known results (which were motivated by an application in statistical experiment design) and then we improve the known lower bound on the number of free pairs of points for q = 2 and the smallest cap sizes for which the maximization problem is non‐trivial. © 2006 Wiley Periodicals, Inc. J Combin Designs 14: 490–499, 2006     

Using the Simplex Code to Construct Relative Difference Sets in 2-groups

Relative Difference Sets with the parameters (2a, 2b, 2a, 2a-b) have been constructed many ways (see davis, EB, jung, maschmidt, and pottsurvey for examples). This paper modifies an example found in arasusehgal to construct a family of relative difference sets in 2-groups that gives examples for b = 2 and b = 3 that have a lower rank than previous examples. The Simplex code is used in the construction.     

Prove the Minimal Delay of Complex Orthogonal Space-Time Block Code by Hadamard Matrix

1IntroductionWith the development of mobile communications inthe world Space-Ti me Block Code(STBC)fromcom-plex orthogonal designs have received extensive interestin Code Division Multiple Access(CDMA)system de-sign recently,see for example[1~3].Since the…     

Optimal binary covering codes of length 2j

The minimum size of a binary covering code of length n and covering radius r is denoted by K(n,r), and codes of this length are called optimal. For j > 0 and n = 2^j, it is known that K(n,1) = 2 · K(n?1,1) = 2^{n ? j}. Say that two binary words of length n form a duo if the Hamming distance between them is 1 or 2. In this paper, it is shown that each optimal binary covering code of length n = 2^j, j > 0, and covering radius 1 is the union of duos in just one way, and that the closed neighborhoods of the duos form a tiling of the set of binary words of length n. Methods of constructing such optimal codes from optimal covering codes of length n ? 1 (that is, perfect single‐error‐correcting codes) are discussed. The paper ends with the construction of an optimal covering code of length 16 that does not contain an extension of any optimal covering code of length 15. © 2005 Wiley Periodicals, Inc. J Combin Designs     

二维磁流体力学程序MFCGⅢ计算结果与测试结果的对比分析

 根据磁场、流函数和感应电流的解析公式，研制了间接馈电爆磁压缩发生器充电和爆磁压缩过程计算程序MFCGⅢ。用MFCGⅢ计算了实验模型，其结果与测试结果符合较好。因此MFCGⅢ可对实验提供优化设计，并且可分析、解释MFCG实验中有关的物理问题。