Reformulation of the support set selection problem in the logical analysis of data

The paper is concerned with the problem of binary classification of data records, given an already classified training set of records. Among the various approaches to the problem, the methodology of the logical analysis of data (LAD) is considered. Such approach is based on discrete mathematics, with special emphasis on Boolean functions. With respect to the standard LAD procedure, enhancements based on probability considerations are presented. In particular, the problem of the selection of the optimal support set is formulated as a weighted set covering problem. Testable statistical hypothesis are used. Accuracy of the modified LAD procedure is compared to that of the standard LAD procedure on datasets of the UCI repository. Encouraging results are obtained and discussed.     

On routing in large WDM networks

An important problem in WDM network design is to construct a logical topology and determine an optimal routing over that topology. Mixed Integer Linear Program (MILP) formulations to generate optimal solutions for this problem have been presented. Such formulations are computationally intractable, even for moderate sized networks. A standard approach is to decouple the problem of logical topology design and the problem of routing the traffic on this logical topology. Heuristics for finding the logical topology exist and a straight-forward linear program (LP), based on the node-arc formulation can be used to solve the routing problem over a given logical topology. We have found that such LP formulations become computationally infeasible for large networks. In this paper, we present a new formulation, based on the arc-chain representation, for optimally routing the specified traffic over a given logical topology to minimize the congestion of the network. We have used the revised simplex method incorporating an implicit column generation technique, and exploited the special Generalized Upper Bounding structure as well as the possibility of eta-factorization for efficiently updating the dual variables and finding the solution. Experimental results on a number of networks demonstrate the suitability of this approach.     

基于ForCES协议的软件集群路由器模型研究

文章提出了软件集群路由器的参考模型。且对软件集群路由器模型的物理结构、逻辑结构和流量场景进行了深入的分析。通过一个简单的模型实例，提出了总体设计的方案。     

On the polynomial-space completeness of intuitionistic propositional logic

We present an alternative, purely semantical and relatively simple, proof of the Statman's result that both intuitionistic propositional logic and its implicational fragment are PSPACE-complete.This paper was supported by grant 401/01/0218 of the Grant Agency of the Czech Republic. % Mathematics Subject Classification (2000):     

On a family of connectives for fuzzy sets

In this paper we find the general solution of the functional equation $\text{S}{}^1\text{(T(x, y), T(x, N(y))) = x}$, where $\text{S}{}^1$ is a t-conorm, T is a t-norm and N is a strong negation on the unit interval. In particular the result yields a family of connectives for fuzzy sets.     

Genetic algorithm to design logical topologies in reconfigurable WDM networks

A new method to design logical topologies based on genetic algorithms is presented. Not only does the algorithm determine which nodes should be connected by means of lightpaths with the aim of minimizing congestion, but it also solves the routing and wavelength assignment problem. In this way, the algorithm guarantees that the logical topology obtained can be embedded in the optical network subject to the available set of resources. The algorithm is effective in terms of both congestion and fairness. For instance, when compared with other work, the congestion is significantly reduced (from 20% to 75% depending on the matrix of traffic considered), and the fairness, when evaluated in terms of the Jain index, is generally higher than 0.94. Moreover, the algorithm brings advantages when employed in dynamic scenarios where the logical topology is frequently reconfigured, as it is fast and, in contrast to other algorithms previously proposed, the calculation process can be stopped at any time (if required) in order to give the best virtual topology found up to the moment.

广义部分Bent函数和广义Bent函数的关系

Bent函数是一类特殊的布尔函数,因其非线性性和稳定性在密码学和通信等领域有很重要的应用,但它们数量少,不平衡且无相关免疫性,为了弥补Bent函数的不足,Claud Carlet提出了部分Bent函数的概念,部分Bent函数是包含Bent函数的更大的函数类,后来,人们又将这两种函数概念先后都拓广到了环zm^n(m为正整数）上,分别被称为zm^n上的广义Bent函数和广义部分Bent函数,本文利用zp^n(p为素数）上广义部分Bent函数的Chrestenson循环谱特征讨论了zp^n上的广义部分Bent函数和广义Bent函数之间的关系,给出了这两种函数之间的函数关系式和谱值关系式。     

适用于ASIC的高速低功耗逻辑单元

本文介绍一种ECL电路结构形式的ASIC逻辑单元的设计和应用。该单元使用2.5V的电源,内部开关电流设计为0.5mA,逻辑摆幅设计为340mV,输入输出均采用双向互补信号。它具有信息的基本记忆功能,用它进行多级组合配套设计,可制作不同模数的分频器、寄存器和计数器等。设计灵活,功能强,电路速度快,功耗低,仅为具有相同功能的普通ECL电路的1/30。这些电路可用在通讯机、电子控制系统、电子测量系结中作高速数字锁相环,数字信号处理的专用集成电路。     

Efficient multi-hop scheduling algorithms for packet transmissions in WDM optical star networks

This paper proposes multi-hop scheduling algorithms for the All-to-All Broadcast (AAB) problem in Wavelength Division Multiplexed (WDM) optical star networks. The multi-hop AAB problem can be split into two subproblems: Logical Topologies Construction (LTC) problem, and Transmission Scheduling (TS) problem. For improving the efficiency of multi-hop scheduling, we focus on a new multi-hop transmission model and transfer the LTC problem to a special case of the Round Robin Tournament (RRT) problem. In the proposed logical topologies, our multi-hop scheduling algorithms can easily overlap the tuning latency and reduce the number of tuning operations on each node. We compare our results with previous research in terms of schedule length. Overall results indicate that our multi-hop scheduling algorithms have better performance than previous algorithms.