4,096 research outputs found
Structured Training for Neural Network Transition-Based Parsing
We present structured perceptron training for neural network transition-based
dependency parsing. We learn the neural network representation using a gold
corpus augmented by a large number of automatically parsed sentences. Given
this fixed network representation, we learn a final layer using the structured
perceptron with beam-search decoding. On the Penn Treebank, our parser reaches
94.26% unlabeled and 92.41% labeled attachment accuracy, which to our knowledge
is the best accuracy on Stanford Dependencies to date. We also provide in-depth
ablative analysis to determine which aspects of our model provide the largest
gains in accuracy
Drinking-driving and social control: An analysis of peer intervention
The present study contends that legislative sanctions, regardless of severity, cannot sufficiently curb the drunken driver unless they are met with the concern of an equally sanctitive public (Formby and Smykla, 1984). The explicit goal of research presented here is to report the extent and power of peer sanction surrounding potential drinking and driving situations. This goal consists of the following components: (1) to discern whether individuals are at all inclined to attempt intervention in situations of potential drunken driving, and if so, to ascertain the types of intervention techniques attempted as well as intervention settings; (2) to determine which intervention techniques tend to produce the best (i.e. most preventive) results; and (3) to establish some demographic and social psychological characteristics of those who do and do not intervene. Data used in discussing these issues are gathered from a questionnaire administered to elements of a population known for frequent drinking practices--college students. (Abstract shortened with permission of author.)
Molecular electrostatic potentials by systematic molecular fragmentation
A simple method is presented for estimating the molecular electrostatic potential in and around molecules using systematic molecular fragmentation. This approach estimates the potential directly from the electron density. The accuracy of the method is established for a set of organic molecules and ions. The utility of the approach is demonstrated by estimating the binding energy of a water molecule in an internal cavity in the protein ubiquitin
Probing the qudit depolarizing channel
For the quantum depolarizing channel with any finite dimension, we compare
three schemes for channel identification: unentangled probes, probes maximally
entangled with an external ancilla, and maximally entangled probe pairs. This
comparison includes cases where the ancilla is itself depolarizing and where
the probe is circulated back through the channel before measurement. Compared
on the basis of (quantum Fisher) information gained per channel use, we find
broadly that entanglement with an ancilla dominates the other two schemes, but
only if entanglement is cheap relative to the cost per channel use and only if
the external ancilla is well shielded from depolarization. We arrive at these
results by a relatively simple analytical means. A separate, more complicated
analysis for partially entangled probes shows for the qudit depolarizing
channel that any amount of probe entanglement is advantageous and that the
greatest advantage comes with maximal entanglement
The Effect of Projection on Derived Mass-Size and Linewidth-Size Relationships
Power law mass-size and linewidth-size correlations, two of "Larson's laws,"
are often studied to assess the dynamical state of clumps within molecular
clouds. Using the result of a hydrodynamic simulation of a molecular cloud, we
investigate how geometric projection may affect the derived Larson
relationships. We find that large scale structures in the column density map
have similar masses and sizes to those in the 3D simulation (PPP). Smaller
scale clumps in the column density map are measured to be more massive than the
PPP clumps, due to the projection of all emitting gas along lines of sight.
Further, due to projection effects, structures in a synthetic spectral
observation (PPV) may not necessarily correlate with physical structures in the
simulation. In considering the turbulent velocities only, the linewidth-size
relationship in the PPV cube is appreciably different from that measured from
the simulation. Including thermal pressure in the simulated linewidths imposes
a minimum linewidth, which results in a better agreement in the slopes of the
linewidth-size relationships, though there are still discrepancies in the
offsets, as well as considerable scatter. Employing commonly used assumptions
in a virial analysis, we find similarities in the computed virial parameters of
the structures in the PPV and PPP cubes. However, due to the discrepancies in
the linewidth- and mass- size relationships in the PPP and PPV cubes, we
caution that applying a virial analysis to observed clouds may be misleading
due to geometric projection effects. We speculate that consideration of
physical processes beyond kinetic and gravitational pressure would be required
for accurately assessing whether complex clouds, such as those with highly
filamentary structure, are bound.Comment: 25 pages, including 7 Figures; Accepted for publication in Ap
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