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基于(α, λ)联系度容差关系的变精度粗糙集模型   总被引:1,自引:1,他引:1  
徐怡  李龙澍 《自动化学报》2011,37(3):303-308
基于传统粗糙集理论的方法不能有效地处理含噪音的不完备信息系统. 根据集对分析理论, 提出(α, λ)联系度容差关系. 将(α, λ)联系度容差关系与Ziarko提出的多数包含关系相结合, 提出变精度(α, λ)联系度粗糙集模型. 给出了该模型下基于正域相似度的启发式属性约简算法, 分析了算法的时间复杂度, 通过仿真实验验证了所提方法处理含噪音的不完备信息系统的有效性.  相似文献   

3.
In this study, we develop a MATLAB simulation of area search with acoustic sensors modeled by the Poisson Scan model and the Lambda–Sigma (λσ) model. Detection time results are compared to those given by the much simpler Random Search formula. Random Search was found to closely approximate the more complex models if detection range was selected correctly. Guidelines for selecting the Random Search detection range were developed.  相似文献   

4.
Xinjun Peng 《Information Sciences》2010,180(20):3863-3980
In this paper, a ν-twin support vector machine (ν-TSVM) is presented, improving upon the recently proposed twin support vector machine (TSVM). This ν-TSVM introduces a pair of parameters (ν) to control the bounds of the fractions of the support vectors and the error margins. The theoretical analysis shows that this ν-TSVM can be interpreted as a pair of minimum generalized Mahalanobis-norm problems on two reduced convex hulls (RCHs). Based on the well-known Gilbert’s algorithm, a geometric algorithm for TSVM (GA-TSVM) and its probabilistic speed-up version, named PGA-TSVM, are presented. Computational results on several synthetic as well as benchmark datasets demonstrate the significant advantages of the proposed algorithms in terms of both computation complexity and classification accuracy.  相似文献   

5.
In this paper, an approach to the performance analysis of dual-branch switch-and-stay combining (SSC) diversity receiver, operating over correlated α-μ fading channels in the presence of co-channel interference (CCI), is presented. Very useful novel infinite series expressions are obtained for the probability density function (PDF) and cumulative distribution function (CDF) of the SSC output signal-to-interference ratio (SIR). Capitalizing on these, performance analysis is performed based on standard criterion measures, such as the outage probability (OP) and average bit error probability (ABEP). Obtained results are graphically presented to show the effects of various parameters such as the fading severity, propagation environment non-linearity and level of correlation on the overall system’s performance.  相似文献   

6.
In this paper, the concept of an (αβ)-fuzzy generalized bi-ideal in an ordered semigroup is introduced, which is a generalization of the concept of a fuzzy generalized bi-ideal in an ordered semigroup. Using this concept, some characterization theorems are provided. The upper/lower parts of an (∈, ∈ ∨ q)-fuzzy generalized bi-ideal are introduced and some characterizations of regular ordered semigroups are given. Also, we consider the concept of implication-based fuzzy generalized bi-ideals in an ordered semigroup. In particular, the implication operators in Lukasiewicz system of continuous-valued logic are discussed.  相似文献   

7.
In this paper the concept of strongly -Cesàro summability of a sequence of fuzzy numbers is introduced. Also some inclusion relations between the set of strongly -Cesàro convergent and -statistically convergent sequences of fuzzy numbers are given.  相似文献   

8.
The aim of the paper is to investigate the known classical problem of a partition of a semigroup into a family of groups in the lattice-valued (fuzzy) framework. For that purpose, a fuzzy subgroup of a fuzzy subsemigroup is introduced and characterized by cuts, using the cutworthy approach. As a main result it is proved that a fuzzy subsemigroup can be partitioned (using special type of fuzzy partitions) into a family of fuzzy ε-subgroups if and only if it is fuzzy completely regular.  相似文献   

9.
In this paper, we deal with the problem of handling solutions in an external archive with the use of a relaxed form of Pareto dominance called ?-dominance and a variation of it called pa?-dominance. These two relaxed forms of Pareto dominance have been used as archiving strategies in some multi-objective evolutionary algorithms (MOEAs). The main objective of this work is to improve the ?-dominance based schemes to handle nondominated solutions, or to retain nondominated solutions in an external archive. Thus, our main contribution is to add an extra objective function only at the time of accepting a nondominated solution into the external archive, in order to preserve some solutions which are normally lost when using any of the aforementioned relaxed forms of Pareto dominance. Such a proposal is inexpensive (computationally speaking) and quite effective, since it is able to produce Pareto fronts of much better quality than the aforementioned archiving techniques.  相似文献   

10.
Medial axes and skeletons are notoriously sensitive to contour irregularities. This lack of stability is a serious problem for applications in e.g. shape analysis and recognition. In 2005, Chazal and Lieutier introduced the λ-medial axis as a new concept for computing the medial axis of a shape subject to single parameter filtering. The λ-medial axis is stable under small shape perturbations, as proved by these authors. In this article, a discrete λ-medial axis (DLMA) is introduced and compared with the recently introduced integer medial axis (GIMA). We show that DLMA provides measurably better results than GIMA, with regard to stability and sensibility to rotations. We give efficient algorithms to compute the DLMA, and we also introduce a variant of the DLMA which may be computed in linear-time.  相似文献   

11.
On the measurement of privacy as an attacker’s estimation error   总被引:1,自引:0,他引:1  
A wide variety of privacy metrics have been proposed in the literature to evaluate the level of protection offered by privacy-enhancing technologies. Most of these metrics are specific to concrete systems and adversarial models and are difficult to generalize or translate to other contexts. Furthermore, a better understanding of the relationships between the different privacy metrics is needed to enable more grounded and systematic approach to measuring privacy, as well as to assist system designers in selecting the most appropriate metric for a given application. In this work, we propose a theoretical framework for privacy-preserving systems, endowed with a general definition of privacy in terms of the estimation error incurred by an attacker who aims to disclose the private information that the system is designed to conceal. We show that our framework permits interpreting and comparing a number of well-known metrics under a common perspective. The arguments behind these interpretations are based on fundamental results related to the theories of information, probability, and Bayes decision.  相似文献   

12.
The performance of the method of angular moments on the ΔΓs determination from analysis of untagged decays is examined by using the SIMUB generator. The results of Monte Carlo studies with evaluation of measurement errors are presented. The method of angular moments gives stable results for the estimate of ΔΓs and is found to be an efficient and flexible tool for the quantitative investigation of the B0sJ/ψφ decay. The statistical error of the ratio ΔΓs/Γs for values of this ratio in the interval [0.03,0.3] was found to be independent on this value, being 0.015 for 105 events.  相似文献   

13.
This paper investigates how personal privacy behavior and confidence differ by gender, focusing on the dimensions of online privacy data protection and release. A hierarchical regression analysis of cross-sectional survey of a national sample (n = 419) revealed that men and women differed on the level of privacy protection; however, gender had no direct effect on the extent to which data release was exercised. Additionally, gender had a positive association with confidence in privacy protection, but not in the dimension of release. Our study suggests that the gender may affect subjective well-being of online privacy and potentially exacerbate the disparity rooted in socialization of gender. Implications of the findings are discussed in light of Internet access, skill and effort required for building and maintaining privacy, and the important role played by gender in indicating the need for gender-sensitive policy awareness.  相似文献   

14.
Yang Xu  Da Ruan 《Information Sciences》2011,181(10):1836-1862
Key issues for resolution-based automated reasoning in lattice-valued first-order logic LF(X) are investigated with truth-values in a lattice-valued logical algebraic structure-lattice implication algebra (LIA). The determination of resolution at a certain truth-value level (called α-resolution) in LF(X) is proved to be equivalently transformed into the determination of α-resolution in lattice-valued propositional logic LP(X) based on LIA. The determination of α-resolution of any quasi-regular generalized literals and constants under various cases in LP(X) is further analyzed, specified, and subsequently verified. Hence the determination of α-resolution in LF(X) can be accordingly solved to a very broad extent, which not only lays a foundation for the practical implementation of automated reasoning algorithms in LF(X), but also provides a key support for α-resolution-based automated reasoning approaches and algorithms in LIA based linguistic truth-valued logics.  相似文献   

15.
A new algorithm to calculate Coulomb wave functions with all of its arguments complex is proposed. For that purpose, standard methods such as continued fractions and power/asymptotic series are combined with direct integrations of the Schrödinger equation in order to provide very stable calculations, even for large values of |η| or |ℑ(?)|. Moreover, a simple analytic continuation for is introduced, so that this zone of the complex z-plane does not pose any problem. This code is particularly well suited for low-energy calculations and the calculation of resonances with extremely small widths. Numerical instabilities appear, however, when both |η| and |ℑ(?)| are large and comparable or smaller than |ℑ(?)|.

Program summary

Title of program: cwfcomplexCatalogue number:ADYO_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADYO_v1_0Program obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandLicensing provisions: noneComputers on which the program has been tested: DELL GX400Operating systems: Linux, WindowsProgramming language used: C++No. of bits in a word: 64No. of processors used: 1Has the code been vectorized?: noNo. of bytes in distributed program, including test data, etc.: 33 092No. of lines in distributed program, including test data, etc.: 3210Distribution format:tar.gzNature of physical problem: The calculation of Coulomb wave functions with all of their arguments complex is revisited. The new methods introduced allow to greatly augment the range of accessible ?, η, and z.Method of solution: Power/asymptotic series and continued fractions are supplemented with direct integrations of the Coulomb Schrödinger equation. Analytic continuation for is also precisely computed using linear combinations of the functions provided by standard methods, which do not follow the branch cut requirements demanded for Coulomb wave functions.Typical running time: N/AUnusual features of the program: none  相似文献   

16.
The δ-matching problem is a special version of approximate pattern-matching, motivated by applications in musical information retrieval, where the alphabet Σ is an interval of integers. We investigate relations between δ-matching and pattern-matching with don't care symbol ∗ (a symbol matching every symbol, including itself). We show that the δ-matching is reducible to k instances of pattern-matching with don't cares. We investigate how the numbers δ and k are related by introducing δ-distinguishing families of morphisms. The size of corresponds to k. We show that for minimal families we have .  相似文献   

17.
§0 什么是LR(k)文法 本文建立在文[2]上,因此要求读者具备有文[2]的有关知识,此外,需明白下面二个定义的确切含义:  相似文献   

18.
We present an extension of standard coalgebraic specification techniques for state based systems which allows us to integrate constants and n-ary operations in a smooth way and, moreover, leads to a simplification of the coalgebraic structure of the models of a specification. The framework of (Ω;,Ξ)-logic can be considered as the result of a translation of concepts of observational logic (cf. [9]) into the coalgebraic world. As a particular outcome we obtain the notion of an (Ω, Ξ)-structure and a sound and complete proof system for (first-order) observational properties of specifications.  相似文献   

19.
We present an algorithm for computing directly the denotation of a μ-calculus formula χ over the configuration graph of a pushdown system. Our method gives the first extension of the saturation technique to the full μ-calculus. Finite word automata are used to represent sets of pushdown configurations. Starting from an initial automaton, we perform a series of automaton manipulations which compute the denotation by recursion over the structure of the formula. We introduce notions of under-approximation (soundness) and over-approximation (completeness) that apply to automaton transitions rather than runs. Our algorithm is relatively simple and direct, and avoids an immediate exponential blow up. Finally, we show experimentally that the direct algorithm is more efficient than via a reduction to parity games.  相似文献   

20.
A simple and general proof is given for the information theoretic (unconditional) security of the Kirchhoff-law–Johnson-noise key exchange system under practical conditions. The unconditional security for ideal circumstances, which is based on the second law of thermodynamics, is found to prevail even under slightly non-ideal conditions. This security level is guaranteed by the continuity of functions describing classical physical linear, as well as stable non-linear, systems. Even without privacy amplification, Eve’s probability for successful bit guessing is found to converge toward 0.5—i.e., the perfect security level—when ideal conditions are approached.  相似文献   

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