Scientific Annals of Computer Science
"Alexandru Ioan Cuza" University of Iaşi
Volume X, 2001
Professor Toader Jucan at Age 60.,
pages 1-2
Abstract |
BibTeX
Professor Toader Jucan is one who had great influence on Computer Science Education at the "Alexandru Ioan Cuza" University of Iasi, Romania. He was formed as a mathematician whose work was initially directed on partial differential equations. Later he started teaching formal languages and automata and, gradually, his teaching and research interests have been directed on computer science.
Further Remarks on P Systems with Symport Rules.,
pages 3-18
Andrei PAUN, Gheorghe PAUN, Alfonso RODRIGUEZ-PATON
Abstract |
BibTeX
We continue the study of $P$ systems with symport and antiport rules, a purely
communicative class of $P$ systems which was recently introduced, based on the trans-membrane
transport of couples of chemicals. We consider here the case of symport
(the chemicals pass jointly in the same direction), and we prove that $P$ systems
with five membranes, with symport rules also able to control the permeability of membranes,
can generate all Turing computable sets of numbers. In the case when also rules which change
the objects in the moment of their passing through membranes are used, a similar
characterization is obtained by systems using only three membranes.
Cluster Analysis in Fuzzy Rule Base Reduction.,
pages 19-26
Eugene ROVENTA, Tiberiu SPIRCU
Abstract |
BibTeX
This paper has a strong expository character, presenting a method to reduce a
"large" knowledge base formed of particular fuzzy rules.
The method is based on a clustering procedure and can be combined with reduction
methods based on interpolation.
On the Complexity of Propositional Calculus Formulae.,
pages 27-44
Stefan ANDREI, Gheorghe GRIGORAS, Manfred KUDLEK, Cristian MASALAGIU
Abstract |
BibTeX
In this paper we present some estimations for the number of resolvents
and the number of steps of the classical Resolution Algorithm applied to a
propositional formula $F$ over $n$ variables. This topic may be useful
for generating PROLOG-like interpreters.
The notations and definitions necessary in this paper are
presented in the {sl first section}. Our variant of Resolution
Algorithm (Algorithm 1) is essential for the results obtained
in the next sections.
The {sl second section} is dedicated to the computation of the maximal
number of resolvents. The situations when this number is reached
are also treated. The main result is Theorem ref{t.1.2.}.
The {sl third} and {sl fourth} sections refer to Krom and Horn clauses,
which represent two classes of clauses forming a {sl stable}
part w.r.t. resolution. For each of these two classes we also compute the maximal number of resolvents which may be reached and study the
{sl limit} cases.
For the class of Krom clauses we obtain a polynomial
algorithm (Proposition ref{p.2.3.})
for testing the (un)satisfiability of $F$ together with the
computation of $Res^(F).$ The computation of $Res^(F)$ for a
Horn formula leads to an exponential algorithm (Theorem ref{t.2.4.}).
We also indicate how some of our results may be improved.
Visibility Properties and Forbiden Holes in Graphs.,
pages 45-54
Cornelius CROITORU, Elefterie OLARU, Mihai TALMACIU
Abstract |
BibTeX
The aim of this paper is to point out results of the following type: for $A$ and $B$
disjoint subsets of vertices in a graph, in some structural conditions,
there is a vertex or an edge which sees all the vertices seen by the set $A$ in $B$ .
We shall refer such properties as visibility properties and we shall deduce some applications
of these visibility results in the study of structural properties of some particular classes
of graphs. More precisely we prove that every maximal clique in a triangulated graph is a cutset
or contains a simplicial vertex. Furthermore, a new characterisation of
this class of graphs is given by restricting the wellknown characterisation of Hayward,
Hong and Maffray for weakly triangulated graphs. We characterise the class of ${overline C}_6$-free
graphs without large induced holes and finally we point out some interesting
properties of minimal imperfect $2K_2$-free graphs.
Some Applications of the Minimal Coverability.,
pages 55-78
Cristian VIDRASCU
Abstract |
BibTeX
The goal of this paper is to
point out how the minimal coverability structures
can be used to compute
the superior concurrency-degree of Petri nets
and finite jumping Petri nets.
The obtained algorithms are more
efficient than the previous algorithms from cite{JuV00}.
A Proposal for a Web Structural Search Language Based on XML Technologies.,
pages 79-
Sabin Corneliu BURAGA, Mihaela BRUT
Abstract |
BibTeX
The wide promotion of XML as the standard meta-language used to define markups for Web
documents stimulated multiple researches on possible XML query languages. In this paper
we propose emph{WQGL} (emph{Web Query Graphical Language}),
an extension of WQFL (Web Query Formulating Language) presented in~cite{wqfl1,wqfl2},
which was defined as a textual-based query language for extracting information
from XML documents and for restructuring such information into novel XML documents.
WQFL allows to formulate various textual queries to search hypermedia information.
By combining WQFL and emph{XUL} (emph{Extensible User-interface Language})
facilities, WQGL offers support to build graphical and intuitive Web interfaces
for assisting users to build queries, no matter of their computer skills.
Also, to allow a more flexible way to formulate complex queries, WQGL offers
support for Perl regular expressions.
