期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
指数型二系性的粗糙度
1
作者 林发兴 《福建师大福清分校学报》 1995年第2期40-57,共18页
3 粗糙度 本节是讨论指数型二分性的粗糙度问题,即探讨一个具有指数型二分性的线性系统在保持指数型二分性的前提,系数矩阵可扰动的范围。 首先我们用一种简单的方法来证明指数型二分性的粗糙度理论。 指数型二分性粗糙定理:若(4.1)是... 3 粗糙度 本节是讨论指数型二分性的粗糙度问题,即探讨一个具有指数型二分性的线性系统在保持指数型二分性的前提,系数矩阵可扰动的范围。 首先我们用一种简单的方法来证明指数型二分性的粗糙度理论。 指数型二分性粗糙定理:若(4.1)是有界线性系统,且具有指数型二分性,则存在常数δ>0,只要时,线性系统(4.2)也具有指数型二分性。 证明:由定理2.7的必要性,存在有界连续、分段C′的可逆实对称矩阵函数G(t),使得对于任意向量x ∈R^n,在G(t)的C′点满足: 展开更多
关键词 粗糙 指数形二分性 线性系统 系数矩阵 粗糙定理 标准解方程
下载PDF
AN INTRUSION DETECTION SYSTEM BASED ON EVIDENCE THEORY AND ROUGH SET THEORY 被引量:2
2
作者 Ye Qing Wu Xiaoping Zhang Changhong 《Journal of Electronics(China)》 2009年第6期777-781,共5页
In this paper,we propose a novel Intrusion Detection System (IDS) architecture utilizing both the evidence theory and Rough Set Theory (RST). Evidence theory is an effective tool in dealing with uncertainty question. ... In this paper,we propose a novel Intrusion Detection System (IDS) architecture utilizing both the evidence theory and Rough Set Theory (RST). Evidence theory is an effective tool in dealing with uncertainty question. It relies on the expert knowledge to provide evidences,needing the evidences to be independent,and this make it difficult in application. To solve this problem,a hybrid system of rough sets and evidence theory is proposed. Firstly,simplification are made based on Variable Precision Rough Set (VPRS) conditional entropy. Thus,the Basic Belief Assignment (BBA) for all evidences can be calculated. Secondly,Dempster’s rule of combination is used,and a decision-making is given. In the proposed approach,the difficulties in acquiring the BBAs are solved,the correlativity among the evidences is reduced and the subjectivity of evidences is weakened. An illustrative example in an intrusion detection shows that the two theories combination is feasible and effective. 展开更多
关键词 Intrusion Detection System (IDS) Evidence theory Rough Set Theory (RST)
下载PDF
Where do Random Rough Surfaces Fail? Part I: Fracture Loci Safety Envelopes at Early Stages of Degradation
3
作者 Hector Medina Brian Hinderliter 《Journal of Energy and Power Engineering》 2013年第5期907-916,共10页
Damage on surfaces often compromises the efficiency of some types of energy production, the safety and reliability of components, and ultimately increases costs. The environment can degrade the structural integrity of... Damage on surfaces often compromises the efficiency of some types of energy production, the safety and reliability of components, and ultimately increases costs. The environment can degrade the structural integrity of surfaces in service by the accumulation of large numbers of small destructive events, which based on the Central Limit Theorem leads to a Gaussian distribution of pit depth. In order to develop safety envelopes relating fracture loci with topological parameters of a brittle material, scatter plots were obtained and analyzed. Starting with an engineering surface, after 6 to 9 micrometers of average degradation depth, safety envelopes could be developed using average roughness and two other proposed parameters. Interestingly, maximum pit depth showed very low correlation with the location of fracture, at the early stage of degradation studied. This is attributed to relaxation of stress concentration at a given pit location due to the assuaging effect caused by neighboring pits. Additionally, energy at fracture was obtained, and a maximum relaxation region was observed. Analytical and experimental study of this region, as well as ductility effects are currently under research. 展开更多
关键词 Safety envelopes ROUGHNESS surfaces.
下载PDF
Attribute reduction in interval-valued information systems based on information entropies 被引量:9
4
作者 Jian-hua DAI Hu HU +3 位作者 Guo-jie ZHENG Qing-hua HU Hui-feng HAN Hong SHI 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2016年第9期919-928,共10页
Interval-valued data appear as a way to represent the uncertainty affecting the observed values. Dealing with interval-valued information systems is helpful to generalize the applications of rough set theory. Attribut... Interval-valued data appear as a way to represent the uncertainty affecting the observed values. Dealing with interval-valued information systems is helpful to generalize the applications of rough set theory. Attribute reduction is a key issue in analysis of interval-valued data. Existing attribute reduction methods for single-valued data are unsuitable for interval-valued data. So far, there have been few studies on attribute reduction methods for interval-valued data. In this paper, we propose a framework for attribute reduction in interval-valued data from the viewpoint of information theory. Some information theory concepts, including entropy, conditional entropy, and joint entropy, are given in interval-valued information systems. Based on these concepts, we provide an information theory view for attribute reduction in interval-valued information systems. Consequently, attribute reduction algorithms are proposed. Experiments show that the proposed framework is effective for attribute reduction in interval-valued information systems. 展开更多
关键词 Rough set theory Interval-valued data Attribute reduction Entropy
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部