41,025 research outputs found
Renormalisation group evolution for the effective Hamiltonian with
We discuss the renormalisation group (RG) evolution for the
operators in unquenched QCD with () or, more generally,
() flavors. In particular, we focus on the
specific problem of how to treat the singularities which show up only for
or in the original solution of Buras {\it et al.} for the
RG evolution matrix at next-to-leading order. On top of Buras {\it et al.}'s
original treatment, we use a new method of analytic continuation to obtain the
correct solution in this case. It is free of singularities and can therefore be
used in numerical analysis of data sets calculated in lattice QCD.Comment: 7 pages, minor revisions, to appear in PR
Information logistics: A production-line approach to information services
Logistics can be defined as the process of strategically managing the acquisition, movement, and storage of materials, parts, and finished inventory (and the related information flow) through the organization and its marketing channels in a cost effective manner. It is concerned with delivering the right product to the right customer in the right place at the right time. The logistics function is composed of inventory management, facilities management, communications unitization, transportation, materials management, and production scheduling. The relationship between logistics and information systems is clear. Systems such as Electronic Data Interchange (EDI), Point of Sale (POS) systems, and Just in Time (JIT) inventory management systems are important elements in the management of product development and delivery. With improved access to market demand figures, logisticians can decrease inventory sizes and better service customer demand. However, without accurate, timely information, little, if any, of this would be feasible in today's global markets. Information systems specialists can learn from logisticians. In a manner similar to logistics management, information logistics is concerned with the delivery of the right data, to the ring customer, at the right time. As such, information systems are integral components of the information logistics system charged with providing customers with accurate, timely, cost-effective, and useful information. Information logistics is a management style and is composed of elements similar to those associated with the traditional logistics activity: inventory management (data resource management), facilities management (distributed, centralized and decentralized information systems), communications (participative design and joint application development methodologies), unitization (input/output system design, i.e., packaging or formatting of the information), transportations (voice, data, image, and video communication systems), materials management (data acquisition, e.g., EDI, POS, external data bases, data entry) and production scheduling (job, staff, and project scheduling)
Learning to Skim Text
Recurrent Neural Networks are showing much promise in many sub-areas of
natural language processing, ranging from document classification to machine
translation to automatic question answering. Despite their promise, many
recurrent models have to read the whole text word by word, making it slow to
handle long documents. For example, it is difficult to use a recurrent network
to read a book and answer questions about it. In this paper, we present an
approach of reading text while skipping irrelevant information if needed. The
underlying model is a recurrent network that learns how far to jump after
reading a few words of the input text. We employ a standard policy gradient
method to train the model to make discrete jumping decisions. In our benchmarks
on four different tasks, including number prediction, sentiment analysis, news
article classification and automatic Q\&A, our proposed model, a modified LSTM
with jumping, is up to 6 times faster than the standard sequential LSTM, while
maintaining the same or even better accuracy
Bioeconomic Modeling of the Invasive Aquatic Plants Hydrilla verticillata (hydrilla), Eichhornia crassipes (water hyacinth), and Pistia stratiotes (water lettuce) and their impacts on angler effort on Florida lakes
The invasive aquatic plants Hydrilla verticillata (hydrilla), Eichhornia crassipes (water hyacinth), and Pistia stratiotes (water lettuce) have the potential to negatively impact recreational use of Florida lakes if consistent, adequate control expenditures are not made. In the mid-1990's, Florida significantly reduced its spending on invasive aquatic plant control measures, which resulted in a significant increase in needed control expenditures in subsequent years. This paper attempts to formalize a relationship between coverage of these invasive aquatic plants and angler effort on Florida lakes using data on 38 lakes over 20 years. Estimated regression coefficients are used to simulate control alternatives, and expenditure cost-benefit comparisons are made.Hydrilla, water hyacinth, water lettuce, bioeconomic, invasive, control, Resource /Energy Economics and Policy,
Glassy slowdown and replica-symmetry-breaking instantons
Glass-forming liquids exhibit a dramatic dynamical slowdown as the
temperature is lowered. This can be attributed to relaxation proceeding via
large structural rearrangements whose characteristic size increases as the
system cools. These cooperative rearrangements are well modeled by instantons
in a replica effective field theory, with the size of the dominant instanton
encoding the liquid's cavity point-to-set correlation length. Varying the
parameters of the effective theory corresponds to varying the statistics of the
underlying free-energy landscape. We demonstrate that, for a wide range of
parameters, replica-symmetry-breaking instantons dominate. The detailed
structure of the dominant instanton provides a rich window into point-to-set
correlations and glassy dynamics.Comment: 6 pages, 3 figures; v2: narrative revised to clarify our
effective-theoretic viewpoint, results unchanged, added reference
Evaluating the Potential for Technology Adoption in Mitigating Invasive Species Damage and Risk: Application to Zebra Mussels
Research and Development/Tech Change/Emerging Technologies, Resource /Energy Economics and Policy,
Experimental demonstration of stimulated polarization wave in a chain of nuclear spins
A stimulated wave of polarization, which implements a simple mechanism of
quantum amplification, is experimentally demonstrated in a chain of four
J-coupled nuclear spins, irradiated by a weak radio-frequency transverse field.
The "quantum domino" dynamics, a wave of flipped spins triggered by a flip of
the first spin, has been observed in fully C-labeled sodium butyrate.Comment: 8 pages including 3 figure
Structure of logarithmically divergent one-loop lattice Feynman integrals
For logarithmically divergent one-loop lattice Feynman integrals I(p,a),
subject to mild general conditions, we prove the following expected and crucial
structural result: I(p,a) = f(p)log(aM)+g(p)+h(p,M) up to terms which vanish
for lattice spacing a -> 0. Here p denotes collectively the external momenta
and M is a mass scale which may be chosen arbitrarily. The f(p) and h(p,M) are
shown to be universal and coincide with analogous quantities in the
corresponding continuum integral when the latter is regularized either by
momentum cut-off or dimensional regularization. The non-universal term g(p) is
shown to be a homogeneous polynomial in p of the same degree as f(p). This
structure is essential for consistency between renormalized lattice and
continuum formulations of QCD at one loop.Comment: 26 pages (after reformatting using revtex); typos corrected; to
appear in Phys.Rev.
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