It is well known that the pushdown store language P (M) of a pushdown automaton (PDA) M — i.e., the language consisting of words occurring on the pushdown along accepting computations of M — is a regular language. Here, we design succinct nondeterministic finite automata (NFA) accepting P (M). In detail, an upper bound on the size of an NFA for P (M) is obtained, which is quadratic in the numbe...

air defense is a crucial area for all naval combat systems. in this study, we consider a warship equipped with an air-defense weapon that targets incoming threats using surface-to-air missiles. we define the weapon scheduling problem as the optimal scheduling of a set of surface-to-air missiles of a warship to a set of attacking air threats. the optimal scheduling of the weapon results in an in...

We present a hybrid text understanding methodology for the resolution of textual ellipsis. It integrates language-independent conceptual criteria and language-dependent functional constraints. The methodological framework for text ellipsis resolution is the centering model that has been adapted to constraints reflecting the functional information structure within utterances, i.e., the distincti...

Generalised Łukasiewicz languages are simply described languages having good information-theoretic properties. An especially desirable property is the one of being a prefix code. This paper addresses the question under which conditions a generalised Łukasiewicz language is a prefix code. Moreover, an upper bound on the delay of decipherability of a generalised Łukasiewicz language is derived.

We consider combinatorial and algebraic properties of the language of factors of the in+nite sequence on the three-letter alphabet built by S.E. Arshon in 1930s. This sequence never contains two successive equal words, i. e., avoids the number 2. The notion of avoidability is extended from integers to rational numbers. It is shown that the avoidability bound for the considered language is 4 . T...

The CD complexity of a stringx is the length of the shortest polynomial time program which accepts only the string x. The language compression problem consists of giving an upper bound on the CDA n complexity of all strings x in some set A. The best known upper bound for this problem is 2 log(jjA njj) + O(log(n)), due to Buhrman and Fortnow. We show that the constant factor 2 in this bound is o...

In this article, applying different types of boundary conditions; Dirichlet, Neumann, or Mixed, on open strings we realize various new brane bound states in string theory. Calculating their interactions with other D-branes, we find their charge densities and their tension. A novel feature of (p− 2, p) brane bound state is its ”non-commutative” nature which is manifestly seen both in the open st...

Some lower bound results are presented that separate the language classes accepted by certain types of nonforgetting restarting automata or CD-systems of restarting automata from each other.