迫零对Turbo码的性能影响

从距离谱的角度对迫零在Turbo码中的作用进行了理论分析。通过仿真，研究了迫零对Turbo码性能的影响。仿真结果表明，Turbo码编码器迫零处理有助于改善Turbo码的性能。     

Construction of Improved Geometric Goppa Codes from Klein Curves and Klein-like Curves

Linear error-correcting codes, especially Reed-Solomon codes, find applications in communication and computer memory systems, to enhance their reliability and data integrity. In this paper, we present Improved Geometric Goppa (IGG) codes, a new class of error-correcting codes, based on the principles of algebraic-geometry. We also give a reasonably low complexity procedure for the construction of these IGG codes from Klein curves and Klein-like curves, in plane and high-dimensional spaces. These codes have good code parameters like minimum distance rate and information rate, and have the potential to replace the conventional Reed-Solomon codes in most practical applications. Based on the approach discussed in this paper, it might be possible to construct a class of codes whose performance exceeds the Gilbert-Varshamov bound. Received: November 14, 1995; revised version: November 22, 1999     

Gröbner basis approach to list decoding of algebraic geometry codes

We show how our Gröbner basis algorithm, which was previously applied to list decoding of Reed Solomon codes, can be used in the hard and soft decision list decoding of Algebraic Geometry codes. In addition, we present a linear functional version of our Gröbner basis algorithm in order to facilitate comparisons with methods based on duality.     

The virtues of laziness: Complexity of the Tangent Cone Algorithm

The Tangent Cone Algorithm is a variant of Buchberger Algorithm, to compute standard bases with respect to orderings which are not well-orderings, which is useful in computational local algebra. We show here that its complexity is the same as the one of Buchberger Algorithm.     

Computing the irreducible real factors and components of an algebraic curve

We present algorithms that decompose an algebraic curve with rational coefficients in its defining bivariate equation into its irreducible real factors and its non-empty irreducible real components. We show that our algorithms are of polynomial bit complexity in the degree of the equation and the size of its coefficients. Our construction is based on computing the irreducible complex factors and then investigating high precision complex floating point coefficients of these factors and the complex norms.This material is based on work supported by the National Science Foundation under Grant No. CCR-87-05363 and under Grant No. CDA-8805910. A preliminary version of this paper appears in the Proceedings of the 5th Annual Symposium on Computational Geometry, ACM Press, pp. 79–87 (1989)     

从复杂性看科学发展观

发展观指人们对社会发展的目标、动力、模式、规律等的根本看法，其复杂性涉及四个层面：在对象层面上，发展观的复杂性源于社会是特殊的开放复杂巨系统；在认知层面上，认知过程的复杂性源于思维巨系统的复杂性与习以为常的还原论和非系统思维带来的曲解；在实践层面上，落实发展观的复杂性源于现实的利益格局、现行体制中的不完善、国际关系的复杂性等因素；在哲学层面上，发展观的复杂性源于发展过程包含的大量对立统一，只有对它们统筹兼顾，确保矛盾各方全面协调发展，才是科学的。     

On the Equivalence of Codes over Finite Rings

It is known that if a finite ring R is Frobenius then equivalences of linear codes over R are always monomial transformations. Among other results, in this paper we show that the converse of this result holds for finite local and homogeneous semilocal rings. Namely, it is shown that for every finite ring R which is a direct sum of local and homogeneous semilocal subrings, if every Hamming-weight preserving R-linear transformation of a codeC₁ onto a code C₂ is a monomial transformation then R is a Frobenius ring.Partially supported by Center of Ring Theory and Applications, Ohio University.     

试析战略创新的复杂性

指明了战略创新研究属于复杂性科学,依据系统学原理诠释创新概念;论述了战略创新的复杂性在 于它自身内含的对立统一;论证了国家战略创新是开放复杂巨系统,并指出驾驭这种复杂性需要建设创新型 国家。     

任意随机序列关于广义几何分布的一类强偏差定理

本文引进对数似然比作为任意随机变量序列相对于服从广义几何分布的随机变量序列的偏差的一种度量,给出样本空间的一个子集。在该子集上通过构造非负上鞅和纯分析运算得到了任意随机变量序列关于广义几何分布的一类用不等式表示的强极限定理,即强偏差定理。作为推论得到了已有的随机变量序列关于几何分布的强偏差定理以及服从广义几何分布的任意随机变量序列的一类强大数定律。     

面向物联网的信息家电设计之繁与简

针对信息家电与传统家电相比之下存在的特点和优势,结合物联网技术的发展和应用,提出了新技术环境下信息家电数字化、智能化的未来发展方向。根据信息家电功能、形态、情感因素的设计,阐述了其设计的复杂性与简洁性之间需要制约和平衡,以达到满足消费者物质和精神双层需要的目的,从而建立一种超智能家居环境,并提高人们的生活质量。     

样条有限条法分析板的几何非线性振动特性

本文利用样条有限条法分析矩形板的几何非线性振动特性问题,指出了试函数的选取方法,并利用B样条函数的特点得出了精确地求非线性刚度矩阵的一种方法.该方法具有占计算机内存少、计算速度快、收敛快、精度高的特点.该方法还适用于响应分析.     

SiC/Fe界面固相反应模型

使用XRD、EPMA和SEM等研究了SiC/Fe界面固相反应产物的相组成、反应区的显微结构以及反应区中反应物原子的浓度分布。SiC/Fe界面固相反应形成Fe₃Si、Fe(Si)和石墨态C沉积物,Fe₃Si的形成为该反应提供了足够的热力学驱动力。1100°×3h热处理后,反应区由调整的C沉积物区/均匀的C沉积物区/无C沉积物区(从SiC侧至Fe侧)构成。建立SiC/Fe界面固相反应模型以解释SiC/Fe界面固相反应的微观机理。在SiC/Fe界面固相反应过程中,SiC分解是不连续的,从而在SiC界面前沿形成调整的C沉积物区独特结构。     

Equation of State for Substances that Satisfy the Corresponding States Law

Universal expressions for the free energy of substances that satisfy the law of corresponding states are obtained. The equation of state is constructed using an interpolation between the high temperature Debye approximation and the ideal-gas one. Missing data needed for calculations have been found from the comparison of calculated and tabulated values of entropy and pressure along the phase coexistence curves. The thermodynamics of corresponding states, constructed in this way, allows one to find the triple- and critical-point parameters, as well as the phase coexistence curves with an accuracy that does not exceed the accuracy of the law of corresponding states itself.     

Prediction of Critical Properties of Binary Mixtures Using the PRSV-2 Equation of State

The aim of this work is to test the value of the Peng–Robinson–Stryjek–Vera (PRSV-2) equation of state for predicting the critical behavior of binary mixtures. A procedure adopted by Heidemann and Khalil, based on the Helmholtz free energy, has been followed. The resulting two complex nonlinear equations have been solved simultaneously for the critical temperature and volume, while the critical pressure is calculated from the PRSV-2 equation of state itself. Three forms of binary-interaction parameters have been tried: the zero-type, conventional one-parameter type, and Margules two-parameter type. The optimum values of the binary interaction parameters, based on minimizing the sum of the squares of the relative errors between predicted and experimental critical temperatures, have been calculated for 20 polar and nonpolar systems. The Margules two-parameter type gives the best results, but its mathematical derivation is cumbersome and it requires more computation time. The standard and the average of the absolute relative deviations in critical properties are included. The predicted critical temperatures and pressures agree well with the experimental results, and are always better than those predicted by the group-contribution method. The deviations in the predicted critical volumes using any of the tested binary-interaction parameter types are relatively large compared to those using the group-contribution method.     

标准化与法治国家治理关系的研究

本文从标准化和法治国家治理的关系的角度出发,分别从经济层面、生态文明建设、社会管理、政府管理4个方面进行阐述标准化如何推进法治国家治理,进而论证标准化对法治国家治理的重要意义。     

Predictions of the Joule–Thomson inversion curves for polar and non-polar fluids from the SAFT-CP equation of state

In this work, we calculate the Joule–Thomson inversion curves of some non-polar fluids, including argon, nitrogen, oxygen, carbon dioxide, n-alkanes (C₁–C₄), ethene, acetylene, benzene and toluene and some polar fluids, including hydrogen sulfide, ammonia, acetone and ethyl ether from the SAFT-CP equation of state. Comparisons with correlated experimental data and reference equation of state indicate that this molecular based equation of state gives good prediction for non-polar fluids. For polar fluids, the predictions of the low-temperature branch are satisfied; but, unfortunately, due to lack of isenthalpic data for high-pressure–high-temperature gas condensate, the reliability of model predictions could not be completely verified. In this work, the performance of some cubic equations of state in predicting the Joule–Thomson inversion curves is also compared with SAFT-CP equation of state.     

风机盘管新风终状态点的处理分析

从新风处理过程中的焓差和需要的泠水温度两个方面来分析风机盘管新风系统的处理终态点，通过比较和分析几个有代表性的状态点，从中得出在实际过程中最佳的一种终态处理点，以供设计工作中参考和借鉴。     

3种典型面心立方金属的超声物态方程比较研究

旨在通过对各种解析物态方程的对比研究,试图寻找一种可以利用较低压力下的超声测量数据建立在较宽广的压力范围内适用于简单面心立方金属的等温物态方程模型。对于Al、Cu、Ag3种面心立方金属,结合实测DAC实验数据对比研究了基于较低压力下的超声测量数据计算的各种解析状态方程适用的压力范围,发现目前尚不存在一种完全适用于材料从低压段到极高压力区的物态方程模型,而从较低压力下得到的超声测量数据出发,选取Vinet等温物态方程模型,可以在相当高的压力范围内(对铝约200GPa,对于铜和银约100GPa)很好地描述几种面心立方金属的压缩性。