This paper develops novel stochastic models and associated signal processing algorithms for detecting intent in terms of anomalous trajectory patterns in target tracking. Stochastic context-free grammar models are presented for anomalous trajectories using the concept of tracklets. Bayesian signal processing algorithms for each model are also described to solve the related classification and pr...

The use of the Inside-Outside (IO) algorithm for the estimation of the probability distributions of Stochastic Context-Free Grammars (SCFGs) in Natural-Language processing is restricted due to the time complexity per iteration and the large number of iterations that it needs to converge. Alternatively, an algorithm based on the Viterbi score (VS) is used. This VS algorithm converges more rapidl...

A quasi-polynomial-time algorithm is presented for sampling almost uniformly at random from the n-slice of the language L(G) generated by an arbitrary context-free grammar G. (The n-slice of a language L over an alphabet is the subset L\ n of words of length exactly n.) The time complexity of the algorithm is " ?2 (n jGj) O(log n) , where the parameter " bounds the variation of the output distr...

The finite temperature Casimir free energy is calculated for a dielec-tric ball of radius a embedded in an infinite medium. The condition ǫµ = 1 is assumed for the inside/outside regions. Both the Green function method and the mode summation method are considered, and found to be equivalent. For a dilute medium we find, assuming a simple " square " dispersion relation with an abrupt cutoff at i...

Finding augmenting chains is in the heart of the maximum matching problem, which is equivalent to the maximum stable set problem in the class of line graphs. Due to the celebrated result of Edmonds, augmenting chains can be found in line graphs in polynomial time. Minty and Sbihi generalized this result to claw-free graphs. In this paper we extend it to larger classes. As a particular consequen...

The only available combinatorial algorithm for the minimum weighted clique cover (mwcc) in claw-free perfect graphs is due to Hsu and Nemhauser [10] and dates back to 1984. More recently, Chudnovsky and Seymour [3] introduced a composition operation, strip-composition, in order to define their structural results for claw-free graphs; however, this composition operation is general and applies to...

The application of machine learning techniques to forecast financial time-series is not a recent development, yet it continues to attract considerable attention due to the difficulty of the problem which is compounded by the non-linear and non-stationary nature of the time-series. The choice of an appropriate set of features is crucial to improve forecasting accuracy of machine learning techniq...

The maximum cardinality basis problem in a genoid (i.e. an independence system), although NP-complete in general, is solvable in a polynomial time in the following cases: matchings of a graph [l], intersection of two matroi’ds [2,4] and independent set of vertices in claw-free graphs [S, 71. These three genoi’ds satisfy the continuous cardinal&y of bases for all their minors. The aim of this pa...

The focus of this paper is the family of languages generated by transitional non-cooperative P systems without further ingredients. This family can also be defined by so-called time yields of derivation trees of context-free grammars. In this paper we prove that such languages can be parsed in polynomial time, where the degree of polynomial may depend on the number of rules and on the size of t...