Search results for "Peace"
showing 10 items of 705 documents
Deportation, Crisis, and Social Change
2018
In contemporary migration policy and practice across the globe, deportation has emerged as an apparently inevitable response to real, or otherwise perceived, migration crises. A skeptical attitudetoward the analytic use of “crisis” in the context of deportation is called for, as is the need to concentrate on the political genealogy of the term, which culminates in the justification of “emergency” policies and the implementation of new measures of control. Yet, at the same time—when states govern undocumented or unwanted residents through deportation and employ the notion of crisis for justifying irregular and often violent acts towards deportable subjects—a situation emerges that indeed sha…
La respuesta del sistema de Naciones Unidas ante la situación de crisis prolongada en Haití
2016
Haití se ha erigido en un factor de inestabilidad regional que ha derivado en su consideración por parte del Consejo de Seguridad de las Naciones Unidas como una amenaza a la paz y a la seguridad internacionales a lo largo de los últimos 25 años. Este artículo pretende analizar la importancia de la actuación internacional llevada a cabo en Haití, así como si la respuesta del sistema de las Naciones Unidas ante las crisis haitianas ha garantizado unas condiciones de paz y estabilidad que han servido de base para importantes avances en otros ámbitos. Haiti has emerged as a factor of regional instability that led to its consideration by the United Nations Security Council as a threat to peace …
Peace as a Priority
2012
Chapter 9 underlines how since its inception the European Union has presented itself to the world as a great “peace project”. The European project consists in creating a “community of peace and democracy” based on the conviction that peace does not emerge from dissuasion but rather out of cooperation. Europe attempts to remodel the world by realising the Kantian dream of “perpetual peace”, which is not based on the balance of military powers (or the supremacy of one of them) but rather on the universal recognition of the dignity of the human being, on the universal guarantee of human rights, and on sustainable human development, which means superseding the current neoliberal model of global…
Forbidden words in symbolic dynamics
2000
AbstractWe introduce an equivalence relation≃between functions from N to N. By describing a symbolic dynamical system in terms of forbidden words, we prove that the≃-equivalence class of the function that counts the minimal forbidden words of a system is a topological invariant of the system. We show that the new invariant is independent from previous ones, but it is not characteristic. In the case of sofic systems, we prove that the≃-equivalence of the corresponding functions is a decidable question. As a more special application, we show, by using the new invariant, that two systems associated to Sturmian words having “different slope” are not conjugate.
Testing Grammars for Parsability
1990
In the preceding chapters we have studied in detail the major methods of deterministic context-free parsing: strong LL(k) parsing (Chapter 5), simple precedence parsing (Chapter 5), canonical LR(k) parsing, LALR(k) parsing, and SLR(k) parsing (Chapters 6 and 7), and canonical LL(k) parsing (Chapter 8). Each of these methods induces a class of grammars that are “parsable” using that method, that is, a class of grammars for which a deterministic parser employing that method can be constructed. For example, the LL(k) grammars constitute the class of grammars parsable by the LL(k) parsing method. By definition, a context-free grammar is an LL(k) grammar if and only if its canonical LL(k) parser…
Querying the Guarded Fragment with Transitivity
2016
We study the problem of answering a union of Boolean conjunctive queries q against a database Δ, and a logical theory φ which falls in the guarded fragment with transitive guards (GF + TG). We trace the frontier between decidability and undecidability of the problem under consideration. Surprisingly, we show that query answering under GF2 + TG, i.e., the two-variable fragment of GF + TG, is already undecidable (even without equality), whereas its monadic fragment is decidable; in fact, it is 2exptime-complete in combined complexity and coNP-complete in data complexity. We also show that for a restricted class of queries, query answering under GF+TG is decidable. © 2013 Springer-Verlag.
Witness computation for solving geometric constraint systems
2014
International audience; In geometric constraint solving, the constraints are represented with an equation system F(U, X) = 0, where X denotes the unknowns and U denotes a set of parameters. The target solution for X is noted XT. A witness is a couple (U_W, X_W) such that F(U_W, X_W) = 0. The witness is not the target solution, but they share the same combinatorial features, even when the witness and the target lie on two distinct connected components of the solution set of F(U, X) = 0. Thus a witness enables the qualitative study of the system: the detection of over- and under-constrained systems, the decomposition into irreducible subsystems, the computation of subsystems boundaries. This …
On the use of relational expressions in the design of efficient algorithms
2005
Relational expressions have finite binary relations as arguments and the operations are composition (·), closure (*), inverse (−1), and union (U). The efficient computation of the relation denoted by a relational expression is considered, and a tight bound is established on the complexity of the algorithm suggested by Hunt, Szymanski and Ullman. The result implies a unified method for deriving efficient algorithms for many problems in parsing. For example, optimal algorithms are derived for strong LL(1) and strong LL(2) parser construction and an efficient polynomialtime algorithm is derived for determining the inessential error entries in an LR(1) parsing table.
Minimal forbidden words and symbolic dynamics
1996
We introduce a new complexity measure of a factorial formal language L: the growth rate of the set of minimal forbidden words. We prove some combinatorial properties of minimal forbidden words. As main result we prove that the growth rate of the set of minimal forbidden words for L is a topological invariant of the dynamical system defined by L.
Matchings in three Catalan lattices
2003
In this note we consider a series of lattices that are enumerated by the well-known Catalan numbers. For each of these lattices, we exhibit a matching in a constructive way.