8,635 research outputs found
The evolution of free wave packets
We discuss four general features of force-free evolution: (1) The spatial
spread of any packet changes with time in a very simple way. (2) Over
sufficiently short periods of time (whose duration is related to the spread in
momentum of the packet) the probability distribution moves but there is little
change in shape. (3) After a sufficiently long period (related to the initial
spatial spread) the packet settles into a simple form simply related to the
momentum distribution in the packet. In this asymptotic regime, the shape of
the probability distribution no longer changes except for its scale, which
increases linearly with the time. (4) There is an infinite denumerable set of
simple wave packets (the Hermite-Gauss packets) that do not change shape as
they evolve.Comment: 6 pages, 4 figures, didactic pape
Online Self-Indexed Grammar Compression
Although several grammar-based self-indexes have been proposed thus far,
their applicability is limited to offline settings where whole input texts are
prepared, thus requiring to rebuild index structures for given additional
inputs, which is often the case in the big data era. In this paper, we present
the first online self-indexed grammar compression named OESP-index that can
gradually build the index structure by reading input characters one-by-one.
Such a property is another advantage which enables saving a working space for
construction, because we do not need to store input texts in memory. We
experimentally test OESP-index on the ability to build index structures and
search query texts, and we show OESP-index's efficiency, especially
space-efficiency for building index structures.Comment: To appear in the Proceedings of the 22nd edition of the International
Symposium on String Processing and Information Retrieval (SPIRE2015
Equitable Conversion: Its Application to Contracts for the Sale of Land in Montana
Equitable Conversion: Its Application to Contracts for the Sale of Land in Montan
Advice for Young Communicators
Carroll P. Streeter, former editor of Farm Journal, and a recipient of the ACE Reuben Brigham Award, used to say: When you want to find out something, go ask the customer
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