Fundamenta Informaticae - Volume 105, issue 4

Authors: van den Bergh, Frans | Engelbrecht, Andries Petrus

Article Type: Research Article

Abstract: The Particle Swarm Optimiser (PSO) is a population based stochastic optimisation algorithm, empirically shown to be efficient and robust. This paper provides a proof to show that the original PSO does not have guaranteed convergence to a local optimum. A flaw in the original PSO is identified which causes stagnation of the swarm. Correction of this flaw results in a PSO algorithm with guaranteed convergence to a local minimum. Further extensions with provable global convergence are also described. Experimental results are provided to elucidate the behavior of the modified PSO as well as PSO variations with global convergence.

Keywords: Particle swarm optimisation, convergence proofs, stochastic optimisation, local convergence, global convergence

DOI: 10.3233/FI-2010-370

Citation: Fundamenta Informaticae, vol. 105, no. 4, pp. 341-374, 2010

Authors: Ghassemi, Fatemeh | Fokkink, Wan | Movaghar, Ali

Article Type: Research Article

Abstract: We provide an equational theory for Restricted Broadcast Process Theory to reason about ad hoc networks. We exploit an extended algebra called Computed Network Theory to axiomatize restricted broadcast. It allows one to define the behavior of an ad hoc network with respect to the underlying topologies. We give a sound and ground-complete axiomatization for CNT terms with finite-state behavior, modulo what we call rooted branching computed network bisimilarity.

DOI: 10.3233/FI-2010-371

Citation: Fundamenta Informaticae, vol. 105, no. 4, pp. 375-415, 2010

Authors: Grigoryan, Hayk | Shoukourian, Arsen

Article Type: Research Article

Abstract: In this paper, the functional equivalence problem for processes, which is an important constituent of process optimization, is considered in object-oriented environments. Two basic cases are investigated: when the turn of operations execution is not essential for some objects while it is essential for the rest of them. In the first case, those objects are named commutative. Environments with both commutative and non-commutative objects are named partially commutative. It is shown, that the equivalence problem of processes in partially commutative environments that contain two or more commutative objects with more than one operation is unsolvable. The largest class of partially …commutative environments is outlined where the equivalence problem is solvable (decidable). It is shown, that if there is only one object with two or more operations among commutative objects then the equivalence problem is solvable. Show more

Keywords: object-oriented environment, environment model, model equation, process, equivalence of processes, multitape multidimensional automaton, partially commutative, regular expression

DOI: 10.3233/FI-2010-372

Citation: Fundamenta Informaticae, vol. 105, no. 4, pp. 417-434, 2010

Authors: Kenaza, Tayeb | Tabia, Karim | Benferhat, Salem

Article Type: Research Article

Abstract: Bayesian networks are very powerful tools for knowledge representation and reasoning under uncertainty. This paper shows the applicability of naive Bayesian classifiers to two major problems in intrusion detection: the detection of elementary attacks and the detection of coordinated ones. We propose two models starting with stating the problems and defining the variables necessary for model building using naive Bayesian networks. In addition to the fact that the construction of such models is simple and efficient, the performance of naive Bayesian networks on a representative data is competing with the most efficient state of the art classification tools. We show …how the decision rules used in naive Bayesian classifiers can be improved to detect new attacks and new anomalous activities. We experimentally show the effectiveness of these improvements on a recent Web-based traffic. Finally, we propose a naive Bayesian network-based approach especially designed to detect coordinated attacks and provide experimental results showing the effectiveness of this approach. Show more

Keywords: Bayesian networks, classification, naive Bayes classifiers, intrusion detection, coordinated attacks

DOI: 10.3233/FI-2010-373

Citation: Fundamenta Informaticae, vol. 105, no. 4, pp. 435-466, 2010