Characterizations of regular ordered semigroups in terms of (α, β)-fuzzy generalized bi-ideals

In this paper, the concept of an (α, β)-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.     

A new generalised α scale spaces quadrature filters

The α   scale spaces is a recent theory that open new possibilities of phase-based image processing. It is a parameterised class (α∈]0,1])$(\alpha \in ]0,1\left]\right)$ of linear scale space representations, which allows a continuous connection beyond the well-known Gaussian scale space (α=1$\alpha =1$). In this paper, we make use of this unified representation to derive new families of band pass quadrature filters, built from derivatives and difference of the α scale space generating kernels. This construction leads to generalised α kernel filters including the commonly known families derived from the Gaussian and the Poisson kernels. The properties of each family are first studied and then experiments on one- and two-dimensional signals are shown to exemplify how the suggested filters can be used for edge detection. This work is complemented by an experimental evaluation, which demonstrates that the new proposed filters are a good alternative to the commonly used Log-Gabor filter.     

Studies of angular correlations in the decays Bs→J/ψφ by using the SIMUB generator

The performance of the method of angular moments on the ΔΓ_s 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 ΔΓ_s and is found to be an efficient and flexible tool for the quantitative investigation of the B⁰_s→J/ψφ decay. The statistical error of the ratio ΔΓ_s/Γ_s 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.     

A simpler linear time 2/3−ε approximation for maximum weight matching

We present two approximation algorithms for the maximum weight matching problem that run in time . We give a simple and practical randomized algorithm and a somewhat more complicated deterministic algorithm. Both algorithms are exponentially faster in terms of ε than a recent algorithm by Drake and Hougardy. We also show that our algorithms can be generalized to find a 1−ε approximation to the maximum weight matching, for any ε>0.     

不确定数据的最优?? 近邻和局部密度聚类算法

传统聚类算法一般针对的是确定数据, 无法解决不确定数据的聚类问题; 现有基于密度的不确定数据聚类算法存在参数敏感且计算率低的问题. 对此, 在引进新的不确定数据相异度函数、最优?? 近邻、局部密度和互包含概念的基础上, 提出解决不确定数据聚类问题的不确定数据的最优?? 近邻和局部密度聚类(OLUC) 算法. 该算法不仅能降低参数敏感性, 提高计算效率, 而且具有动态自适应优化?? 近邻, 快速发现聚类中心和除噪优化的能力. 实验结果表明, 所提出的算法对无论是否存在噪声的不确定数据集都效果良好.

     

Vertex fault tolerance of optimal-κ graphs and super-κ graphs

A connected graph G is optimal-κ if κ(G)=δ(G). It is super-κ if every minimum vertex cut isolates a vertex. An optimal-κ graph G is m-optimal-κ if for any vertex set S⊆V(G) with |S|?m, G−S is still optimal-κ. We define the vertex fault tolerance with respect to optimal-κ, denoted by Oκ(G), as the maximum integer m such that G is m-optimal-κ. The concept of vertex fault tolerance with respect to super-κ, denoted by Sκ(G), is defined in a similar way. In this paper, we show that min{κ₁(G)−δ(G),δ(G)−1}?Oκ(G)?δ(G)−1 and min{κ₁(G)−δ(G)−1,δ(G)−1}?Sκ(G)?δ(G)−1, where κ₁(G) is the 1-extra connectivity of G. Furthermore, when the graph is triangle free, more refined lower bound can be derived for Oκ(G).     

Evolutionary bi-objective optimization of a semi-arid vegetation dynamics model with NDVI and σ satellite data

Satellite radar backscattering coefficient σ⁰ data from ENVISAT-ASAR and Normalized Difference Vegetation Index (NDVI) data from SPOT-VEGETATION are assimilated in the STEP model of vegetation dynamics. The STEP model is coupled with a radiative transfer model of the radar backscattering and NDVI signatures of the soil and herbaceous vegetation. These models are driven by field data (rainfall time series, soil properties, etc.). While some model parameters have fixed values, some other parameters have target values to be optimized. The study focuses on a well documented 1 km² homogeneous area in a semi-arid region (Gourma, Mali).We here investigate whether departures between model predictions and the corresponding data result from field data errors, in situ data lack of representativeness or some model shortcomings. For this purpose we introduce an evolutionary strategy (ES) approach relying on a bi-objective function to be minimized in the data assimilation/inversion process. Several numerical experiments are conducted, in various mono-objective and bi-objective modes, and the performances of the model predictions compared in terms of NDVI, backscattering coefficient, leaf area index (LAI) and biomass.It is shown that the bi-objective ES leads to improved model predictions and also to a better readability of the results by exploring the Pareto front of optimal and admissible solutions. It is also shown that the information brought from the optical sensor and the radar is coherent; that the corresponding radiative transfer models are also coherent; that the representativeness of in situ data can be compared to satellite data through the modeling process. However some systematic biases on the biomass predictions (errors in the range 140 to 300 kg ha^− 1) are observed. Thanks to the bi-objective ES, we are able to identify some likely shortcoming in the vegetation dynamics model relating the LAI to the biomass variables.     

A ν-twin support vector machine (ν-TSVM) classifier and its geometric algorithms

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.     

基于多尺度H/A/α分解的全极化HRRP特征提取

针对现有基于H/A/α 分解的全极化高分辨率距离像(HRRP) 特征提取方法没有考虑度量尺度对特征性能的影响问题, 引入动态互信息思想设计了度量尺度评价准则, 并提出了基于平均度量尺度、不定度量尺度和金字塔型度量尺度3 种特征提取方法. 采用两类飞机目标全极化HRRP 数据对提取的特征子集进行了有效性分析, 并通过识别多类飞机目标验证了3 种方法提取的特征子集具有良好的类别可分性和稳定性.     

Extending ?-diversity to generalize sensitive data

Generalization is an important technique for protecting privacy in data dissemination. In the framework of generalization, ?-diversity is a strong notion of privacy. However, since existing ?-diversity measures are defined in terms of the most specific (rather than general) sensitive attribute (SA) values, algorithms based on these measures can have narrow eligible ranges for data that has a heavily skewed distribution of SA values and produce anonymous data that has a low utility. In this paper, we propose a new ?-diversity measure called the functional (τ, ?)-diversity, which extends ?-diversity by using a simple function to constrain frequencies of base SA values that are induced by general SA values. As a result, algorithms based on (τ, ?)-diversity may generalize SA values, thus are much less constrained by skew SA distributions. We show that (τ, ?)-diversity is more flexible and elaborate than existing ?-diversity measures. We present an efficient heuristic algorithm that uses a novel order of quasi-identifier (QI) values to achieve (τ, ?)-diversity. We compare our algorithm with two state-of-the-art algorithms that are based on existing ?-diversity measures. Our preliminary experimental results indicate that our algorithm not only provides a stronger privacy protection but also results in better utility of anonymous data.     

Improving the efficiency of ?-dominance based grids

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.     

The general α-decomposition problem of fuzzy relations

This paper deals with a general α-decomposition problem of fuzzy relations, which can be stated as follows: given a fuzzy relation R∈F(X×Y), determine two fuzzy relations Q∈F(X×Z) and T∈F(Z×Y) such that , where X (resp. Y) is a finite set. Firstly we point out that every fuzzy relation R is always generally α-decomposable, and give an algorithm to construct Q and T with for a given R. Secondly, we show that the general content ρ(R) with is equal to the chromatic number of the simple graph F_R generated by R. Therefore, finding an exact algorithm for calculating ρ(R) is an NP-complete problem.     

Robust skeletonization using the discrete λ-medial axis

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.     

A simple proof of the necessity of the failure detector Σ to implement an atomic register in asynchronous message-passing systems

This paper presents a simple proof that shows that the quorum failure detector class (denoted Σ) is the weakest failure detector class required to implement an atomic read/write register in an asynchronous message-passing system prone to an arbitrary number of process crashes. This proof is based on a new reduction algorithm in which all the variables are bounded.     

On λ-statistical convergence of difference sequences of fuzzy numbers

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.     

On the privacy offered by (k, δ)-anonymity

The widespread deployment of technologies with tracking capabilities, like GPS, GSM, RFID and on-line social networks, allows mass collection of spatio-temporal data about their users. As a consequence, several methods aimed at anonymizing spatio-temporal data before their publication have been proposed in recent years. Such methods are based on a number of underlying privacy models. Among these models, (k,δ)-anonymity$(k,\delta )\mathrm{-}\mathrm{anonymity}$ claims to extend the widely used k  -anonymity concept by exploiting the spatial uncertainty δ≥0$\delta \ge 0$ in the trajectory recording process. In this paper, we prove that, for any δ>0$\delta >0$ (that is, whenever there is actual uncertainty), (k,δ)-anonymity$(k,\delta )\mathrm{-}\mathrm{anonymity}$ does not offer trajectory k-anonymity, that is, it does not hide an original trajectory in a set of k   indistinguishable anonymized trajectories. Hence, the methods based on (k,δ)-anonymity$(k,\delta )\mathrm{-}\mathrm{anonymity}$, like Never Walk Alone (NWA) and Wait For Me (W4M) can offer trajectory k  -anonymity only when δ=0$\delta =0$ (no uncertainty). Thus, the idea of exploiting the recording uncertainty δ$\delta$ to achieve trajectory k  -anonymity with information loss inversely proportional to δ$\delta$ turns out to be flawed.     

极小-极大-加系统(F,G,H)的能达能观性

在数字电路中"两个时间信号通过逻辑电路的"与"门相当于极大运算,"或"门相当于极小运算.因此,极小-极大-加系统可用于数字电路的时间分析.对于非线性极强的极小-极大-加系统(F,G,H)引入了分别能达和上限能观的概念.利用图论的方法给出了极小-极大-加系统(F,G,H)的状态变量x_t为分别能达分量的充要条件,同时,还得到了x_t为上限能观分量的充要条件.

     

A saturation method for the modal μ-calculus over pushdown systems

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.