A Note on Negligible Functions

In theoretical cryptography, one formalizes the notion of an adversary's success probability being ``too small to matter' by asking that it be a negligible function of the security parameter. We argue that the issue that really arises is what it might mean for a collection of functions to be ``negligible.' We consider (and define) two such notions, and prove them equivalent. Roughly, this enables us to say that any cryptographic primitive has a specific associated ``security level.' In particular we say this for any one-way function. We also reconcile different definitions of negligible error arguments and computational proofs of knowledge that have appeared in the literature. Although the motivation is cryptographic, the main result is purely about negligible functions.     

关于M序列的自相关函数的一点注记

本文讨论了Ｍ序列的自相关性，并证明了：当０＜｜ｔ－２＾ｎ－１｜≤［ｎ－１／２］时，｜ＣＭ（ｔ）｜≤２＾ｎ－１。     

用采样数据进行网络函数有理逼近的一种有效方法

随着集成电路工作频率达到GHz范围和电路朝更大更密集型发展的趋势,互连与封装等寄生效应对电路的影响越来越大,如何准确地对这些效应进行分析模拟,成为当前集成电路CAD中十分重要的任务。在高频率时,互连与封装的特性只能通过测量或电磁场的数值模拟给出的一组不同频率上网络函数的采样值描述。基于这些采样值通过有理插值构造网络函数的近似宏模型是实现这类电路模拟的关键,但这一问题在数值上是高度病态的。本文通过复频率的双线性变换提出了获得稳定有理逼近的一个新方法,可有效克服这一困难。文中给出的例子实现了高达60阶的有理插值。     

Modelling of 2-D Real Rational Reactance Functions. A Parameter-Based Approach

Lossless (reactive) one-ports are of great importance in the field of linear network theory. This statement also applies for the two-dimensional (2-D) case, where the design of corresponding impedance or admittance functions is a much more challenging task. In this paper a model for 2-D real rational reactance functions is introduced which is a rational function in p₁ and p₂ where the coefficients are functions of parameters. The following features make it best suited for the computer based design of lossless one-ports, namely no dependencies between the real valued parameters, coverage of the whole class of 2-D real rational reactance functions, and the coefficients are polynomials in the parameters. The synthesis of 2-D lossless networks and skew symmetric matrices form the basis of our considerations.     

A Note on Symmetric Boolean Functions With Maximum Algebraic Immunity in Odd Number of Variables

In this note, it is proved that for each odd positive integer n there are exactly two n-variable symmetric Boolean functions with maximum algebraic immunity.     

一种PIN开关调制器

介绍了一种用FET作为开关的高性能PIN开关调制器的工作原理和设计方法。给出了实际应用调制器的波形。     

Scattering Domain Passivity Verification and Enforcement of Delayed Rational Functions

This letter introduces new algorithms for passivity verification and compensation of macromodels constructed from delayed rational functions in the scattering domain. For passivity verification, a frequency-dependent generalized eigenvalue is formulated, which is used to accurately determine the regions of passivity violation. For passivity compensation, first order perturbation theory is used to iteratively perturb the residues of the system until passivity is achieved. Numerical results validating the proposed algorithms are presented.     

Realization of Multidimensional Digital Transfer Functions with Separable Numerator or Denominator Polynomials

In this paper a straightforward z-domain procedure for realizing multidimensional transfer functions with either numerator or denominator polynomial separable is presented. This procedure yields structures with minimum number of multipliers. It is shown that the number of delay elements can be reduced by selecting the optimum values for certain parameters. To facilitate this theorems that are applicable for some special cases are presented.     

一种新颖双馈电型PIN开关

微波光电二极管（PIN）开关速度和功率容量是相互矛盾的2个指标,为同时兼顾改善2个指标,结合半导体器件特性,采取PIN管芯两极同时馈电的设计形式（即双馈电型开关）,经过优化设计,研制出2 GHz～6 GHz单刀双掷PIN开关。与传统型开关电路相比,开关速度和功率容量都得到较好提升,为后续的工程应用奠定了基础。     

A Class of Equiripple Functions which Complement the Achieser (or Zolotarev) Polynomials (Correspondence)

A symmetrical cascade of N commensurate transmission lines having equal ripple performance over a passband centered at the quarter-wavelength frequency may be synthesized using Achieser (or Zolotarev) polynomials for N odd. This correspondence identifies the solution of the case where N is even, and a new class of functions which complement these polynomials is identified.     

Compact Macromodeling of High-Speed Circuits via Delayed Rational Functions

This letter introduces a new method for compact macromodeling of high-speed circuits with long delays, characterized by tabulated time-domain data. The algorithm is based on partitioning the response and subsequently approximating each partition with a low-order sum-of-exponentials, delayed in time-domain. This results in a compact low-order macromodel in the form of delayed-differential equations, which can be efficiently analyzed using SPICE like simulators.     

Inverse Laplace Transformation of Rational Functions: Part 2

For pt.I see ibid., vol.9, p.13-15, (2006). In this article the author has listed the basic steps in computing the inverse Laplace transform of a rational function H(s).     

基于空变多项式的高精度重构模型

针对由于合成孔径雷达(SAR)图像几何失真的空变性,传统的多项式模型与距离多普勒模型精度不高的问题,文中提出了结合距离多普勒模型和空变的多项式模型的少量控制点精确重构模型。该模型从距离多普勒方程出发,通过优化地面控制点的方位向分布建立空变的多项式模型,实现SAR图像的高精度重构。实验数据表明:在少量控制点情况下,文中的重构模型精度高于传统的距离多普勒模型和多项式模型。     

Generalized Rational Function Approximation in Finite Intervals Using Zolotarev Functions

The results of Chebyshev in the theory of approximation find wide application in the design of circuits and microwave components. Part of the comparatively unknown work of Zolotarev and Achieser which has found useful applications in the design of certain microwave components, especially of mixed lumped/distributed components, is described. Several new results are presented, including formulas which enable the approximation functions to be computed in a relatively simple manner.     

A Note on Computer Diagnosis

A computer program is described for the preparation of decision tables (based upon observed statistics) for diagnosis. The procedure does not depend upon the assumption that symptoms occur independently. The program is intended for preliminary diagnosis or screening, therefore it should have value as a device of preventive medicine. This program is available from SHARE as HO BC CRIT.     

关于Huffman编码的一个注记

Huffman编码是无损压缩中的重要方法,在数据压缩、音频编码、图像编码中得到广泛的应用.除了压缩效率以外,作为变长码的Huffman编码,还有其他的判断其编码优劣的准则,例如码方差、抗误码的能力等.本文讨论Huffman编码后的码流中0、1码元(二进制情况下)出现的概率问题.研究结果表明,通常的经典Huffman编码的0、1码元出现的概率差最大,在出现概率均衡准则下的性能最劣.文章进行了严格的数学建模,并给出了一种算法,可以使编码后码流中0、1码元的分布概率(趋向)均等;并且,算法可在原Huffman编码中结合进行,所增加的计算量很小.文章最后进行了实验验证.     

A Note on Noise Temperature

The effective noise temperature of the output impedance of a Iossy passive network at an arbitrary noise temperature connected to one or more resistive loads at arbitrary noise temperature lies between the highest and the lowest of these noise temperatures, as determined by the losses between the output terminals and the loads. The determination of the effective noise temperature of a gas-discharge noise generator over a wide frequency range is simplified by the substitution of a loss measurement for the more difficult noise temperature measurement. For minimum-noise radar applications care must be used in considering the excess noise of crystal mixers and gas-discharge duplexers. The influeuce of galactic radiation on a receiving system is such that there is an optimum frequency in the region of 200 to 600 mc for minimum "operating noise figure." Typical examples of radio-astronomy measurements are amenable to analysis of the type given. Finally, several corrections to measured noise figure are analyzed.     

一种正交多项式混沌全局建模方法

本文研究了一种正交多项式混沌全局建模方法 ,所用正交多项式集以吸引子不变测度为核 .通过对H啨ｎｏｎ映射数据和电离层参数实测数据的分析 ,表明在待建模系统不很复杂时 (其内在机理可用较低阶多项式表达 ) ,这种全局建模方法能得到系统动力学特性 .在低噪声情况下模型还能充分精确地重构系统方程式 .在噪声较大或系统内在机理很复杂时建模结果仍可用于一步预测 ,且具有较好效果     

A Family of Binomial Polynomials and Its Applications

Discrete polynomials of special type are widely used in digital filter design, signal processing, image processing, and control systems[1]. Haddad et al. introduced binomial sequences to synthesize digital filters for signal and image processing[2-3]. Aburdene et al. shown a method for computing discrete polynomial (Hermite, binomial and Laguerre) transform representation using binary matrices and flow diagrams[4] and developed a new discrete transforms using Pascal polynomials for applicatio…