A language is k-piecewise testable if it is a finite boolean combination of languages of the form Σa1Σ · · ·ΣanΣ, where ai ∈ Σ and 0 ≤ n ≤ k. We investigate the problem, given a minimal DFA recognizing a piecewise testable language, what is the minimal k for which the language is k-piecewise testable? It was shown by Klı́ma and Polák that such a k is bounded by the depth of the minimal DFA. We f...

This study evaluated clams as bioindicators of fecal protozoan contamination using three approaches: (i) clam tissue spiking experiments to compare several detection techniques; (ii) clam tank exposure experiments to evaluate clams that had filtered Cryptosporidium oocysts from inoculated water under a range of simulated environmental conditions; (iii) sentinel clam outplanting to assess the di...

DFA minimization is an important problem in algorithm design and is based on the notion of DFA equivalence: Two DFA’s are equivalent if and only if they accept the same set of strings. In this paper, we propose a new notion of DFA equivalence (that we call weak-equivalence): We say that two DFA’s are weakly equivalent if they both accept the same number of strings of length k for every k. The m...

The Debye screening mass for a quark-gluon plasma at high temperature is calculated to next-to-leading order in the QCD coupling constant from the correlator of two Polyakov loops. The result agrees with the screening mass defined by the location of the pole in the gluon propagator as calculated by Rebhan. It is logarithmically sensitive to nonperturbative effects associated with the screening ...

Using multi-fractal detrended fluctuation analysis (MF-DFA), the scaling features of wind speed time series (WSTS) could be explored. In this paper, we discuss the influence of sub-daily variation, which is a natural feature of wind, in MF-DFA of WSTS. First, the choice of the lower bound of the segment length, a significant parameter of MF-DFA, was studied. The results of expanding the lower b...

Given a regular expression R and a string T the regular expression matching problem is to determine if T matches any string in the language generated by R. The best known solution to the problem uses linear space and O ( nm log logn log3/2 n +n+m ) time in the worst-case [2], where m and n are the lengths of R and T , respectively. A common misconception is that we can solve the problem efficie...

A study was conducted to ascertain the taxonomic validity of endangered taxon Echinocactus horizonthalonius var. nicholii and whether there may be other groups populations worthy subspecies status within range species. To test hypothesis that individuals E. are morphologically distinct from those typical variety, a multivariate analysis done compare degree morphological variation or phenotypic ...