Computations by fly-automata beyond monadic second-order logic

We present logically based methods for constructing XP and FPT graph algorithms, parametrized by tree-width or clique-width. We will use fly-automata introduced in a previous article. They make possible to check properties that are not monadic second-order expressible because their states may include counters, so that their sets of states may be infinite. We equip these automata with output functions, so that they can compute values associated with terms or graphs. Rather than new algorithmic results we present tools for constructing easily certain dynamic programming algorithms by combining predefined automata for basic functions and properties.Comment: Accepted for publication in Theoretical Computer Scienc

Financial Vulnerability in the Central and Eastern European Countries

In this work we use a panel probit model to analyze the sources of financial vulnerability in four Central and Eastern European countries. The incontestable advantages of applying this method, associated with some elements of the non-parametric approach applied during the initial selection of the used indicators, allow us to accomplish, rather well, this objective.Indeed, the model performs considerably well in the sample and the whole approach can provide useful and supportive instruments for the study of financial vulnerabilities in transition economies.Financial Vulnerability; Panel Probit Model; CEECs

A tool for reasoning about qualitative temporal information: the theory of S-languages with a Lisp implementation

http://www.jucs.org/jucs_14_20/a_tool_for_reasoningInternational audienceReasoning about incomplete qualitative temporal information is an essential topic in many artificial intelligence and natural language processing applications. In the domain of natural language processing for instance, the temporal analysis of a text %provides yields a set of temporal relations between events in a given linguistic theory. The problem is first to express events and any possible temporal relations between them, then to express the qualitative temporal constraints (as subsets of the set of all possible temporal relations) and compute (or count) all possible temporal relations that can be deduced. For this purpose, we propose to use the formalism of S-languages, based on the mathematical notion of S-arrangements with repetitions [schwer:CRM02]. In this paper, we present this formalism in detail and our implementation of it. We explain why Lisp is adequate to implement this theory. Next we describe a Common Lisp system \SLS\ (for S-LanguageS) which implements part of this formalism. A graphical interface written using McCLIM, the free implementation of the CLIM specification, frees the potential user of any Lisp knowledge. Fully developed examples illustrate both the theory and the implementation

Financial Vulnerability in the Central and Eastern European Countries

Working Paper GATE 2009-07In this work we use a panel probit model to analyze the sources of financial vulnerability in four Central and Eastern European countries. The incontestable advantages of applying this method, associated with some elements of the non-parametric approach applied during the initial selection of the used indicators, allow us to accomplish, rather well, this objective.Indeed, the model performs considerably well in the sample and the whole approach can provide useful and supportive instruments for the study of financial vulnerabilities in transition economies

A forewarning indicator system for financial crises: the case of six Central and Eastern European countries

We propose a measure of the probability of crises associated with an aggregate indicator, where the percentage of false alarms and the proportion of missed signals can be combined to give an appreciation of the vulnerability of an economy. In this perspective, the important issue is not only to determine whether a system produces true predictions of a crisis, but also whether there are forewarning signs of a forthcoming crisis prior to its actual occurrence. To this end, we adopt the approach initiated by Kaminsky, Lizondo and Reinhart (1998), analyzing each indicator and calculating each threshold separately. We depart from this approach in that each country is also analyzed separately, permitting the creation of a more “custom-made” early warning system for each one.Currency Crisis; Early Warning System; Composite Indicator; Eastern Europe

On defining linear orders by automata

We define linear orders ≤Z on product sets Z := X1 × X2 × ... × Xn and on subsets Z of X1 × X2 where each composing set Xi is [0, p] or N, and ordered in the natural way. We require that (Z, ≤Z) be isomor-phic to (N, ≤) if it is infinite. We want linear orderings of Z such that, in two consecutive tuples z = (z1, ..., zn) and z = (z 1 , ..., z n), we have |zi − z i | ≤ 1 for each i. Furthermore, we define their distance d(z, z) as the number of indices i such that zi = z i. We will consider orderings where the distance of two consecutive tuples is at most 2. We are interested in algorithms that determine the tuple in Z following z by using local information, where "local" is meant with respect to graphs associated with Z, and that work as well for finite and infinite components Xi, without knowing whether the components Xi are finite or not. We will formalize these algorithms by deterministic graph-walking automata

A forewarning indicator system for financial crises: the case of six Central and Eastern European countries

We propose a measure of the probability of crises associated with an aggregate indicator, where the percentage of false alarms and the proportion of missed signals can be combined to give an appreciation of the vulnerability of an economy. In this perspective, the important issue is not only to determine whether a system produces true predictions of a crisis, but also whether there are forewarning signs of a forthcoming crisis prior to its actual occurrence. To this end, we adopt the approach initiated by Kaminsky, Lizondo and Reinhart (1998), analyzing each indicator and calculating each threshold separately. We depart from this approach in that each country is also analyzed separately, permitting the creation of a more “custom-made” early warning system for each one