一种具有低相关特性的分块交织器的设计

Ｔｕｒｂｏｃｏｄｅｓ是近年信道编码理论研究的热点课题。交织器的设计问题是Ｔｕｒｂｏｃｏｄｅｓ研究中的主要问题之一。本文结合Ｔｕｒｂｏｃｏｄｅｓ在个人通信中的应用问题，对分块交织方法进行了研究，给出了一种新的交织器的设计方案，理论分析和计算机仿真证实了此方案在实现上和相关性上都具有良好的性能。同时，本文从理论上解释了在交织长度很大时，交织器的选择对Ｔｕｒｂｏｃｏｄｅｓ译码性能几乎没有影响的原因。     

用多面体测试分度误差研究

采用多面体和光电平行光管测试圆刻机分度误差，比较了１２、３６、７２面体的测试特点，从数据分析中可找到一些造成误差的因素     

Lipschitz局部严格伪压缩映象的迭代逼近

设Ｋ是一致光滑Ｂａｎａｃｈ空间Ｋ的非空子集，Ｔ：Ｋ→Ｘ是Ｌｉｐｓｃｈｉｔｚ局部严格伪压缩映象。本文给出一个迭代序列强收敛到Ｔ的唯一不动点，并给出一个涉及Ｌｉｐｓｃｈｉｔｚ局部强增殖映象Ｔ的非线性方程Ｔｘ＝ｆ的解的迭代逼近。     

Invariant Euler–Lagrange Equations and the Invariant Variational Bicomplex

In this paper, we derive an explicit group-invariant formula for the Euler–Lagrange equations associated with an invariant variational problem. The method relies on a group-invariant version of the variational bicomplex induced by a general equivariant moving frame construction, and is of independent interest.     

广义小波变换及其在人工神经网络中的应用

相应于非线性系统用人工神经网络的逼近问题，本文引入了一种新的小波变换并研究了其性质.作为推论，本文给出了在Lp范数下单个隐层前馈神经网络逼近定理的构造性证明.     

Modelling of pressure-strain correlations for Taylor-Proudman turbulence

The theoretical foundation for the modelling of the turbulent pressure-strain correlations in rotating reference frame is presented. Based on the recently developed materially-frame indifference principle it is observed that most of the existing second-moment closures violate the Taylor-Proudman theorem in the limit of rapid rotation. It is shown that the application of the materially-frame indifference principle gives rise to the formation of a new pressure-strain correlation model which satisfies the Taylor-Proudman theorem. Project supported by thr National Natural Science Foundation of China (Grant No. 19421003), the State Education Commission and Tsinghua University.     

空间l1(Xn)中的弱紧性

本文首先讨论空间l₁(X_n)中的弱收敛性，然后给出了l₁(X_n)中弱紧性的几种等价刻画，同时对l_p(X_n)（１＜ｐ＜∞）中的弱紧性也得到了类似的结果．     

Banach空间X的弱局部Zk性质

本文引入了Ｂａｎａｃｊ空间Ｘ的弱局部Ｚ_k性质和弱Ｚ_k性质，得出了：Ｂａｎａｃｈ空间Ｘ是Ｋ－ＮＵＣ空间的一个充分必要条件和Ｂａｎａｃｈ空间Ｘ是ＬＫ－ＮＵＣ空间的一个充分条件，并指出弱Ｚ_k性质蕴含弱Ｂａｎａｃｈ－Ｓａｋｓ性质．     

UNIFORMLY ASYMPTOTIC STABILITY FOR DIFFERENTIAL EQUATIONS WITH INFINITE DELAY

11血roductlonAssume that BC(H)＝{p:(一 co,0]一R Is continuous and 11 yi 11二sup卜(。)l三 H}and that F:[0;＋比)X BC(H)一 Ris a given cofltiflllollSs＜0function;such that F(·,0)三 0．A＞0 Is a constant．Consider one－dimensionaldel叫dl俭rentlal equationX川＋入X(z)＝*I,X;)．(1〕In addition to the conditions above F also satisfies same conditions such thatthe SOllltiofl Of Eq．(1)x(t)＝x(t; to;i)llllqllely eXIStS Oil壬to;十①)for。11[to;i) E R＋ X BC(H(See [*])．FOr every yi …     

A novel high-resolution interference spectrometer

A novel precision wavemeter is presented with a resolution of better than 0·01 nm. A Sagnac interferometer with two diffraction gratings forms the basis of the instrument. Using spatial heterodyning techniques and a CCD camera/frame grabber data acquisition system allows fast computer control and power spectrum analysis. The mode structure and mode hopping characteristics of a typical laser diode were examined as a function of diode injection current.