1,367 research outputs found
Mexitl: Multimedia in Executable Interval Temporal Logic
This paper explores a formalism for describing a wide class of multimedia document constraints, based on an interval temporal logic. We describe the requirements on temporal logic specification that arise from the multimedia documents application area. In particular, we highlight a canonical specification example. Then we present the temporal logic formalism that we use. This extends existing interval temporal logic with a number of new features: actions, framing of actions, past operators, a projection-like operator called filter and a new handling of interval length. A model theory, logic and satisfaction relation are defined for the notation, a specification of the canonical example is presented, and a proof system for the logic is introduced
Nanoporous biocarbon as a storage system for methane
Abstract only availableActivated carbon produced from waste corn cobs have recently been developed as an efficient and economical form of gas storage. With rising gas prices and concerns of global warming, natural gas has been brought to attention as an alternative to gas and diesel. Activated carbons are capable of storing natural gas at low pressures and safe lengths of time via gas adsorption. Van der Waals interactions between methane gas molecules and the carbon solid forces the methane into a supercritical fluid that adsorbs onto surface of the solid. Methane uptake is assessed gravimetrically with steel sample cells. Masses are calibrated to correct for the effects due to air buoyancy. Data collected through methane isotherms, techniques of solid state NMR, and small-angle scattering reveal the pore structures and distribution of various carbon samples. The optimal pore size can be determined by executing methane isotherms at varying pressures between 25 and 500 psi. Ultimately, the same advances will be performed with hydrogen gas in exploring solutions and improvements to the gas crisis.U.S. Department of Energy Alliance for Collaborative Research in Alternative Fuel Technolog
Impact of stout-link smearing in lattice fermion actions
The impact of stout-link smearing in lattice fermion actions is examined
through the consideration of the mass and renormalization functions of the
overlap quark propagator over a variety of smeared configurations. Up to six
sweeps of stout-link smearing are investigated. For heavy quark masses, the
quark propagator is strongly affected by the smearing procedure. For moderate
masses, the effect appears to be negligible. A small effect is seen for light
quark masses, where dynamical mass generation is suppressed through the
smearing procedure.Comment: 7 pages, 3 figures, presented at the XXVII International Symposium on
Lattice Field Theory - LAT2009, July 26-31 2009, Peking University, Beijing,
Chin
Stout-link smearing in lattice fermion actions
The properties of the momentum space quark propagator in Landau gauge are
studied for the overlap quark action in quenched lattice QCD. Numerical
calculations are performed over four ensembles of gauge configurations, where
three are smeared using either 1, 3, or 6 sweeps of stout-link smearing. We
calculate the non-perturbative wave function renormalization function
and the non-perturbative mass function for a variety of bare quark
masses. We find that the wave-function renormalization function is slightly
sensitive to the number of stout-link smearing sweeps. For the mass function we
find the effect of the stout-link smearing algorithm to be small for moderate
to light bare quark masses. For a heavy bare quark mass we find a strong
dependence on the number of smearing sweeps.Comment: 8 pages, 4 figure
An End of Term Exam: October Term 2003 at the Supreme Court of the United States
The goal of this Essay is to provide a resource of digestible proportions that any Court watcher (judge, lawyer, professor, student) can use to inform himself or herself about current developments at the Court. While the Essay discusses how the current Term compares to past ones, it does not do so simply as an exercise in dry social science. Instead, it highlights those trends of interest to both the scholar and the practitioner. Likewise, while the Essay discusses particular cases, it does not simply summarize facts and holdings. Instead, it places those doctrinal developments in a larger context, analyzes them, and critiques them.
This Essay proceeds in two parts. The first part provides the broad overview of October Term 2003. It analyzes current statistics in the size and composition of the Court\u27s caseload and compares those figures to past terms. It also considers the justices\u27 voting patterns and which justices proved to be the “swing” votes, both generally and in particular fields. The second part focuses on the key cases of the Term. It addresses both what the Court decided and what it failed to decide. It critiques those decisions and considers their implications for future doctrinal developments. The Court Consensus offers some closing lessons to be drawn from the Term
Cardiac SNARE expression in health and disease
SNARE proteins are integral to intracellular vesicular trafficking, which in turn is the process underlying the regulated expression of substrate transporters such as the glucose transporter GLUT4 at the cell surface of insulin target tissues. Impaired insulin stimulated GLUT4 trafficking is associated with reduced cardiac function in many disease states, most notably diabetes. Despite this, our understanding of the expression and regulation of SNARE proteins in cardiac tissue and how these may change in diabetes is limited. Here we characterize the array of SNARE proteins expressed in cardiac tissue, and quantify the levels of expression of VAMP2, SNAP23, and Syntaxin4—key proteins involved in insulin-stimulated GLUT4 translocation. We examined SNARE protein levels in cardiac tissue from two rodent models of insulin resistance, db/db mice and high-fat fed mice, and show alterations in patterns of expression are evident. Such changes may have implications for cardiac function
A Technique for Foreground Subtraction in Redshifted 21 cm Observations
One of the main challenges for future 21 cm observations is to remove
foregrounds which are several orders of magnitude more intense than the HI
signal. We propose a new technique for removing foregrounds of the redshifted
21 cm observations. We consider multi-frequency interferometer observations. We
assume that the 21 cm signals in different frequency channels are uncorrelated
and the foreground signals change slowly as a function of frequency. When we
add the visibilities of all channels, the foreground signals increase roughly
by a factor of ~N because they are highly correlated. However, the 21 cm
signals increase by a factor of ~\sqrt{N} because the signals in different
channels contribute randomly. This enables us to obtain an accurate shape of
the foreground angular power spectrum. Then, we obtain the 21-cm power spectrum
by subtracting the foreground power spectrum obtained this way. We describe how
to obtain the average power spectrum of the 21 cm signal.Comment: 5 pages, 1 figure; To appear on the Astrophysical Journa
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