Value Constraints in the CLP Scheme

We define value constraints, a method for incorporating constraint propagation into logic programming. It is a subscheme of the CLP scheme and is applicable wherever one has an efficient method for representing sets of possible values. As examples we present: small finite sets, sets of ground instances of a term, and intervals of reals with floating-point numbers as bounds. Value constraints are defined by distinguishing two storage management strategies in the CLP scheme. In value constraints the infer step of the CLP scheme is implemented by Waltz filtering. We give a semantics for value constraints in terms of set algebra that gives algebraic characterizations of local and global consistency. The existing extremal fixpoint characterization of chaotic iteration is shown to be applicable to prove convergence of Waltz filtering.     

Interval Arithmetic for Input-output Models with Inexact Data

Input-output models are subject to uncertainty. If these models are solved without regard to the effects of the uncertainty the solutions can be substantially in error. Interval arithmetic offers a means by which the effects of this uncertainty can be assessed. They also offer a means of evaluating changes in the technical coefficients and a means of determining inverse important coefficients.     

The adjustment of prediction intervals to account for errors in parameter estimation

Abstract.  Standard approximate 1 −  α prediction intervals (PIs) need to be adjusted to take account of the error in estimating the parameters. This adjustment may be aimed at setting the (unconditional) probability that the PI includes the value being predicted equal to 1 −  α . Alternatively, this adjustment may be aimed at setting the probability that the PI includes the value being predicted equal to 1 −  α , conditional on an appropriate statistic T . For an autoregressive process of order p , it has been suggested that T consist of the last p observations. We provide a new criterion by which both forms of adjustment can be compared on an equal footing. This new criterion of performance is the closeness of the coverage probability, conditional on all of the data, of the adjusted PI and 1 −  α . In this paper, we measure this closeness by the mean square of the difference between this conditional coverage probability and 1 −  α . We illustrate the application of this new criterion to a Gaussian zero-mean autoregressive process of order 1 and one-step-ahead prediction. For this example, this comparison shows that the adjustment which is aimed at setting the coverage probability equal to 1 −  α conditional on the last observation is the better of the two adjustments.     

Sufficient stability conditions for the weighted minimum uncertainty prediction controller

Sufficient BIBO-stability conditions are provided for the weighted minimum uncertainty prediction controller. This controller minimizes a cost functional which penalizes the predicted output uncertainty, the control effort, and the tracking error. The BIBO-stability is addressed by examining the worst case time-variant interval matrix representation of the closed loop system.     

数据库中一种挖掘数值属性关联规则的方法

提出了一个新的数值属性关联规则的挖掘算法,即先找出其他属性的频繁项集,再在数值属性上找出最佳的数值区间,挖掘出易于理解的关联规则.     

A Kharitonov-like theorem for interval polynomial matrices

As an extension of Kharitonov's theorem, robust stability of interval polynomial matrices is studied. Here a polynomial matrix is said to be stable if its determinant has all roots with negative real parts. The present paper shows that the robust stability of interval polynomial matrices is equivalent to that of the subclasses where each row (column) has only one element that involves Kharitonov edge polynomials and all the other elements take on one of the four Kharitonov vertex polynomials.     

一种格形VSAT网络多址协议分析

主要讨论了格形ＶＳＡＴ网络多址协议的选择，利用排队和仿真的方法分析了ＭＦ－ＴＤＭＡ多频时分多址）的吞吐量和延时性能，并和ＴＤＭＡ多址方式进行了比较，旨在多用户、稀业务量的情况下ＭＦ－ＴＤＭＡ比ＴＤＭＡ具有更好的性能。     

长途高速通信主干线的技术考虑

阐述我国长距离，高速率通信主干线在设计时应行考虑的主要技术问题，包括工作波长的选择，单模光纤的新设计，光纤放大器的应用，密集波分多路系统的应用，对光子器件和光子集成的要求，文末附带提及越洋海底光缆的技术趋向。     

一种快变信道中的正交频分复用系统均衡算法

当信道参数随时间的快速变化时,正交频分复用通信系统(OFDM)子载波间的正交性遭到破坏,出现了载波间的相互干扰(ICI),传统的单抽头频域均衡不再适用。虽然可采用最小均方误差(MMSE)均衡来补偿信道失真,但其计算量太大。为此,常用的方法是:先对接收信号进行ICI消除,恢复载波间的正交性,然后再进行单抽头频域或均衡。现有文献对ICI的分析均在频域进行,在此基础上提出的ICI消除与均衡算法存在计算量大或频谱利用率低的缺点。本文对ICI的产生机理和性质进行了时域和频域两方面的分析,利用现有OFDM标准中的空闲子载波信息,提出了一种ICI消除与均衡算法。理论分析和计算机仿真结果表明:该算法具有ICI消除效果好、计算量小和频谱利用率高等优点。     

企业集团财务管理实行财务平衡控制模式的构想

通过分析集权和分权财务管理的优缺点，并结合我国目前企业集团财务管理中存在的问题，提出了集权模式下适当分权的财务平衡控制构想。