Fundamenta Informaticae - Volume 133, issue 4

Authors: Bernardinello, Luca | Ferigato, Carlo | Haar, Stefan | Pomello, Lucia

Article Type: Research Article

Abstract: The semantics of concurrent processes can be defined in terms of partially ordered sets. Occurrence nets, which belong to the family of Petri nets, model concurrent processes as partially ordered sets of occurrences of local states and local events. On the basis of the associated concurrency relation, a closure operator can be defined, giving rise to a lattice of closed sets. Extending previous results along this line, the present paper studies occurrence nets with forward conflicts, modelling families of processes. It is shown that the lattice of closed sets is orthomodular, and the relations between closed sets and some particular …substructures of an occurrence net are studied. In particular, the paper deals with runs, modelling concurrent histories, and trails, corresponding to possible histories of sequential components. A second closure operator is then defined by means of an iterative procedure. The corresponding closed sets, here called ‘dynamically closed’, are shown to form a complete lattice, which in general is not orthocomplemented. Finally, it is shown that, if an occurrence net satisfies a property called B-density, which essentially says that any antichain meets any trail, then the two notions of closed set coincide, and they form a complete, algebraic orthomodular lattice. Show more

Keywords: Concurrency theory, partial order semantics, closure operators, orthomodular lattices

DOI: 10.3233/FI-2014-1079

Citation: Fundamenta Informaticae, vol. 133, no. 4, pp. 323-344, 2014

Authors: Chang, Bae-Muu

Article Type: Research Article

Abstract: A novel character recognition method, called a Neuro-Fuzzy system combined with Particle swarm optimization for Handwritten Character Recognition (NFPHCR), is proposed in this paper. The NFPHCR method integrates Recurrent Neural Network (RNN), Fuzzy Inference System (FIS), and Particle Swarm Optimization (PSO) algorithm to recognize handwritten characters. It employs the RNN to effectively extract oriented features of handwritten characters, and then, these features are applied to create the FIS. Finally, the FIS combined with the PSO algorithm can powerfully estimate similarity ratings between the recognized character and sampling characters in the character database. Experimental results demonstrate that the NFPHCR method achieves …a satisfying recognition performance and outperforms other existing methods under considerations. Show more

Keywords: Neuro-fuzzy system, Recurrent neural network, Fuzzy inference system, Particle swarm optimization, Handwritten character recognition

DOI: 10.3233/FI-2014-1080

Citation: Fundamenta Informaticae, vol. 133, no. 4, pp. 345-366, 2014

Authors: Kułakowski, Konrad

Article Type: Research Article

Abstract: The Heuristic Ratio Estimation (HRE) approach proposes a new way of using the pairwise comparisons matrix. It allows the assumption that the weights of some alternatives (herein referred to as concepts) are known and fixed, hence the weight vector needs to be estimated only for the other unknown values. The main purpose of this paper is to extend the previously proposed iterative HRE algorithm and present all the heuristics that create a generalized approach. Theoretical considerations are accompanied by a few numerical examples demonstrating how the selected heuristics can be used in practice.

DOI: 10.3233/FI-2014-1081

Citation: Fundamenta Informaticae, vol. 133, no. 4, pp. 367-386, 2014

Authors: Lim, Seongan | Lee, Hyang-Sook | Choi, Mijin

Article Type: Research Article

Abstract: The McEliece cryptosystem is defined using a Goppa code, and decoding the Goppa code is a crucial step of its decryption. Patterson's decoding algorithm is the best known algorithm for decoding Goppa codes. Currently, the most efficient implementation of Patterson's algorithm uses a precomputation. In this paper, we modify Patterson's decoding algorithm so that one can remove the precomputation part while sustaining the best efficiency. Precomputations yield additional storage requirement to store the precomputed value which increases as the security level increases in McEliece cryptosystem. In the original decoding algorithm of Patterson, computing square root in a quotient field of …polynomial ring over a finite field is necessary. In our modification, the computations are involved only in the arithmetics of polynomial ring over a finite field, not in the quotient field. This achieves better efficiency because one can remove polynomial reductions in the computations of quotient field. Show more

Keywords: McEliece Cryptosystem, Goppa code, Patterson's algorithm, square roots

DOI: 10.3233/FI-2014-1082

Citation: Fundamenta Informaticae, vol. 133, no. 4, pp. 387-397, 2014

Authors: Mráz, František | Otto, Friedrich | Plátek, Martin

Article Type: Research Article

Abstract: In natural languages with a high degree of word-order freedom, syntactic phenomena like dependencies (subordinations) or valences do not depend on the word-order (or on the individual positions of the individual words). This means that some permutations of sentences of these languages are in some (important) sense syntactically equivalent. Here we study this phenomenon in a formal way. Various types of j-monotonicity for restarting automata can serve as parameters for the degree of word-order freedom and for the complexity of word-order in sentences (languages). Here we combine two types of parameters on computations of restarting automata: the degree of j-monotonicity, …and the number of rewrites per cycle. We study these notions formally in order to obtain an adequate tool for modelling and comparing formal descriptions of (natural) languages with different degrees of word-order freedom and word-order complexity. Show more

Keywords: Restarting automaton, word-order freedom, word-order complexity

DOI: 10.3233/FI-2014-1083

Citation: Fundamenta Informaticae, vol. 133, no. 4, pp. 399-419, 2014

Authors: Narayanamoorthy, S. | Murugan, K.

Article Type: Research Article

Abstract: In this paper, we present an algorithmic form of the variational iteration method (VIM) to handle both linear and nonlinear higher order fuzzy integro-differential equations. Using parametric form of fuzzy numbers to convert higher order fuzzy integro-differential equation to a system of higher order integro-differential equations in crisp case. By using the variational integration method we find the approximate solution of this system and consequently we obtain an approximation for fuzzy solution of the higher order fuzzy integro-differential equations. The numerical results are examined.

Keywords: numerical algorithm, fuzzy number, fuzzy integro-differential equations, variational iteration method, convergence

DOI: 10.3233/FI-2014-1084

Citation: Fundamenta Informaticae, vol. 133, no. 4, pp. 421-431, 2014

Authors: Öztürk, Mehmet Ali | Uçkun, Mustafa | İnan, Ebubekir

Article Type: Research Article

Abstract: In this paper, we consider the problem of how to establish algebraic structures of near sets on nearness approximation spaces. Essentially, our approach is define the near group of all weak cosets by considering an operation on the set of all weak cosets. Afterwards, our aim is to study near homomorphism theorems on near groups, and investigate some properties of near groups.

Keywords: Near set, near group, weak coset, near homomorphism

DOI: 10.3233/FI-2014-1085

Citation: Fundamenta Informaticae, vol. 133, no. 4, pp. 433-448, 2014

Article Type: Other

Citation: Fundamenta Informaticae, vol. 133, no. 4, pp. 449-450, 2014