133 research outputs found
Low Space External Memory Construction of the Succinct Permuted Longest Common Prefix Array
The longest common prefix (LCP) array is a versatile auxiliary data structure
in indexed string matching. It can be used to speed up searching using the
suffix array (SA) and provides an implicit representation of the topology of an
underlying suffix tree. The LCP array of a string of length can be
represented as an array of length words, or, in the presence of the SA, as
a bit vector of bits plus asymptotically negligible support data
structures. External memory construction algorithms for the LCP array have been
proposed, but those proposed so far have a space requirement of words
(i.e. bits) in external memory. This space requirement is in some
practical cases prohibitively expensive. We present an external memory
algorithm for constructing the bit version of the LCP array which uses
bits of additional space in external memory when given a
(compressed) BWT with alphabet size and a sampled inverse suffix array
at sampling rate . This is often a significant space gain in
practice where is usually much smaller than or even constant. We
also consider the case of computing succinct LCP arrays for circular strings
Wave Energy: a Pacific Perspective
This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by The Royal Society and can be found at: http://rsta.royalsocietypublishing.org/.This paper illustrates the status of wave energy development in Pacific Rim countries by characterizing the available resource and introducing the region‟s current and potential future leaders in wave energy converter development. It also describes the existing licensing and permitting process as well as potential environmental concerns. Capabilities of Pacific Ocean testing facilities are described in addition to the region‟s vision of the future of wave energy
Lattice Artefacts In The Non-Abelian Debye Screening Mass In One Loop Order
We compute the electric screening mass in lattice QCD with Wilson fermions at
finite temperature and chemical potential to one-loop order, and show that
lattice artefacts arising from a finite lattice spacing result in an
enhancement of the screening mass as compared to the continuum. We discuss the
magnitude of this enhancement as a function of the temperature and chemical
potential for lattices with different number of lattice sites in the temporal
direction that can be implemented in lattice simulations. Most of the
enhancement is found to be due to the fermion loop contribution.Comment: 23 pages, 8 figures, LaTe
Lightweight Lempel-Ziv Parsing
We introduce a new approach to LZ77 factorization that uses O(n/d) words of
working space and O(dn) time for any d >= 1 (for polylogarithmic alphabet
sizes). We also describe carefully engineered implementations of alternative
approaches to lightweight LZ77 factorization. Extensive experiments show that
the new algorithm is superior in most cases, particularly at the lowest memory
levels and for highly repetitive data. As a part of the algorithm, we describe
new methods for computing matching statistics which may be of independent
interest.Comment: 12 page
Gauged Yukawa Matrix Models and 2-Dimensional Lattice Theories
We argue that chiral symmetry breaking in three dimensional QCD can be
identified with N\'eel order in 2-dimensional quantum antiferromagnets. When
operators which drive the chiral transition are added to these theories, we
postulate that the resulting quantum critical behavior is in the universality
class of gauged Yukawa matrix models. As a consequence, the chiral transition
is typically of first order, although for a limited class of parameters it can
be second order with computable critical exponents.Comment: LaTeX, 11 page
On finding minimal absent words
<p>Abstract</p> <p>Background</p> <p>The problem of finding the shortest absent words in DNA data has been recently addressed, and algorithms for its solution have been described. It has been noted that longer absent words might also be of interest, but the existing algorithms only provide generic absent words by trivially extending the shortest ones.</p> <p>Results</p> <p>We show how absent words relate to the repetitions and structure of the data, and define a new and larger class of absent words, called minimal absent words, that still captures the essential properties of the shortest absent words introduced in recent works. The words of this new class are minimal in the sense that if their leftmost or rightmost character is removed, then the resulting word is no longer an absent word. We describe an algorithm for generating minimal absent words that, in practice, runs in approximately linear time. An implementation of this algorithm is publicly available at <url>ftp://www.ieeta.pt/~ap/maws</url>.</p> <p>Conclusion</p> <p>Because the set of minimal absent words that we propose is much larger than the set of the shortest absent words, it is potentially more useful for applications that require a richer variety of absent words. Nevertheless, the number of minimal absent words is still manageable since it grows at most linearly with the string size, unlike generic absent words that grow exponentially. Both the algorithm and the concepts upon which it depends shed additional light on the structure of absent words and complement the existing studies on the topic.</p
Heavy Quark Potentials in Quenched QCD at High Temperature
Heavy quark potentials are investigated at high temperatures. The temperature
range covered by the analysis extends from values just below the
deconfinement temperature up to about in the deconfined phase. We
simulated the pure gauge sector of QCD on lattices with temporal extents of 4,
6 and 8 with spatial volumes of . On the smallest lattice a tree level
improved action was employed while in the other two cases the standard Wilson
action was used. Below we find a temperature dependent logarithmic term
contributing to the confinement potential and observe a string tension which
decreases with rising temperature but retains a finite value at the
deconfinement transition. Above the potential is Debye-screened, however
simple perturbative predictions do not apply.Comment: 20 pages, 9 figure
A representation of a compressed de Bruijn graph for pan-genome analysis that enables search
Supporting Communication and Decision Making in Finnish Intensive Care with Language Technology
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