7,098 research outputs found
Foundations for the Integration of Enterprise Wikis and Specialized Tools for Enterprise Architecture Management
Organizations are challenged with rapidly changing business requirements and an ever-increasing volume respectively variety of information. Enterprise Architecture (EA) and its respective management function are considered as means to overcome these challenges. Appropriate tool support to this end is an elementary success factor to guide the EA management (EAM) initiative. Nevertheless, practitioners perceive currently available tools specialized for EAM as not sufficient in their organizations. Major reasons are inflexible data models as well as missing integration with processes and their focus on expert users. Regarding these limitations Enterprise Wikis provide practice proven solutions already exploited by organizations. These Enterprise Wikis are able to extend the capabilities of existing EA tools to cope with unstructured information and leverage a better utilization of structured EA information. In this paper we present the foundations for an integration of specialized EAM tools and Enterprise Wikis. We elaborate scenarios for both tool species using a practitioner survey and differentiate four integration cases
A Primer on Motion Capture with Deep Learning: Principles, Pitfalls and Perspectives
Extracting behavioral measurements non-invasively from video is stymied by
the fact that it is a hard computational problem. Recent advances in deep
learning have tremendously advanced predicting posture from videos directly,
which quickly impacted neuroscience and biology more broadly. In this primer we
review the budding field of motion capture with deep learning. In particular,
we will discuss the principles of those novel algorithms, highlight their
potential as well as pitfalls for experimentalists, and provide a glimpse into
the future.Comment: Review, 21 pages, 8 figures and 5 boxe
Statistical Computations with AstroGrid and the Grid
We outline our first steps towards marrying two new and emerging
technologies; the Virtual Observatory (e.g, AstroGrid) and the computational
grid. We discuss the construction of VOTechBroker, which is a modular software
tool designed to abstract the tasks of submission and management of a large
number of computational jobs to a distributed computer system. The broker will
also interact with the AstroGrid workflow and MySpace environments. We present
our planned usage of the VOTechBroker in computing a huge number of n-point
correlation functions from the SDSS, as well as fitting over a million CMBfast
models to the WMAP data.Comment: Invited talk to appear in "Proceedings of PHYSTAT05: Statistical
Problems in Particle Physics, Astrophysics and Cosmology
Observing the Symmetry of Attractors
We show how the symmetry of attractors of equivariant dynamical systems can
be observed by equivariant projections of the phase space. Equivariant
projections have long been used, but they can give misleading results if used
improperly and have been considered untrustworthy. We find conditions under
which an equivariant projection generically shows the correct symmetry of the
attractor.Comment: 28 page LaTeX document with 9 ps figures included. Supplementary
color figures available at http://odin.math.nau.edu/~jws
Course Allocation via Stable Matching
The allocation of students to courses is a wide-spread and repeated task in higher education, often accomplished by a simple first-come first-served (FCFS) procedure. FCFS is neither stable nor strategy-proof, however. The Nobel Prize in Economic Sciences was awarded to Al Roth and Lloyd Shapley for theirwork on the theory of stable allocations. This theory was influential in many areas, but found surprisingly little application in course allocation as of yet. In this paper, different approaches for course allocation with a focus on appropriate stablematchingmechanisms are surveyed. Two such mechanisms are discussed in more detail, the Gale- Shapley student optimal stable mechanism (SOSM) and the efficiency adjusted deferred acceptance mechanism (EADAM). EADAM can be seen as a fundamental recent contribution which recovers efficiency losses from SOSM at the expense of strategy-proofness. In addition to these two important mechanisms, a survey of recent extensions with respect to the assignment of schedules of courses rather than individual courses is provided. The survey of the theoretical literature is complemented with results of a field experiment, which help understand the benefits of stable matching mechanisms in course allocation applications
Experimental characterization of frequency dependent squeezed light
We report on the demonstration of broadband squeezed laser beams that show a
frequency dependent orientation of the squeezing ellipse. Carrier frequency as
well as quadrature angle were stably locked to a reference laser beam at
1064nm. This frequency dependent squeezing was characterized in terms of noise
power spectra and contour plots of Wigner functions. The later were measured by
quantum state tomography. Our tomograph allowed a stable lock to a local
oscillator beam for arbitrary quadrature angles with one degree precision.
Frequency dependent orientations of the squeezing ellipse are necessary for
squeezed states of light to provide a broadband sensitivity improvement in
third generation gravitational wave interferometers. We consider the
application of our system to long baseline interferometers such as a future
squeezed light upgraded GEO600 detector.Comment: 8 pages, 8 figure
The Chandra Deep Field North Survey. IX. Extended X-ray Sources
The ~1 Ms Chandra Deep Field North observation is used to study the extended
X-ray sources in the region surrounding the Hubble Deep Field North (HDF-N),
yielding the most sensitive probe of extended X-ray emission at cosmological
distances to date. A total of six such sources are detected, the majority of
which align with small numbers of optically bright galaxies. Their angular
sizes, band ratios, and X-ray luminosities -- assuming they lie at the same
distances as the galaxies coincident with the X-ray emission -- are generally
consistent with the properties found for nearby groups of galaxies. One source
is notably different and is likely to be a poor-to-moderate X-ray cluster at
high redshift (i.e., z > 0.7). We are also able to place strong constraints on
the optically detected cluster of galaxies ClG 1236+6215 at z=0.85 and the
wide-angle-tail radio galaxy VLA J123725.7+621128 at z~1-2. With rest-frame
0.5--2.0 keV X-ray luminosities of <(3-15)e42 ergs s^{-1}, the environments of
both sources are either likely to have a significant deficit of hot
intra-cluster gas compared to local clusters of galaxies, or they are X-ray
groups. We find the surface density of extended X-ray sources in this
observation to be 167 (+97,-67) deg^{-2} at a limiting soft-band flux of
approximately 3e-16 ergs s^{-1} cm^{-2}. No evolution in the X-ray luminosity
function of clusters is needed to explain this value. (Abridged)Comment: 16 pages, 14 figures (8 color), LaTeX emulateapj5.sty, accepted for
publication by the Astronomical Journal. Manuscript with full resolution
embedded images available at
http://www.astro.psu.edu/users/niel/hdf/hdf-chandra.htm
The Chandra Deep Field-North Survey. XIV. X-ray detected Obscured AGNs and Starburst Galaxies in the Bright Submm Source Population
We provide X-ray constraints and perform the first X-ray spectral analyses
for bright (f_850>=5mJy; S/N>=4) SCUBA sources in an 8.4'x8.4' area of the 2 Ms
Chandra Deep Field-North survey containing the Hubble Deep Field-North. X-ray
emission is detected from 7 of the 10 bright submm sources in this region,
corresponding to an X-ray detected submm source density of ~360 deg^-2 (>~36%
of the bright submm source population). Two of the X-ray detected sources have
nearby (within 3") X-ray companions, suggesting merging/interacting sources or
gravitational lensing effects, and 3 lie within the approximate extent of a
proto-cluster candidate. Five of the X-ray detected sources have flat X-ray
spectral slopes, suggesting obscured AGN activity. X-ray spectral analyses
suggest that one of these AGNs may be a Compton-thick source; of the other 4
AGNs, 3 appear to be Compton-thin sources and one has poor constraints. The
rest-frame unabsorbed X-ray luminosities of these AGNs are more consistent with
those of Seyfert galaxies than QSOs. Thus, the low X-ray detection rate of
bright submm sources by moderately deep X-ray surveys appears to be due to the
relatively low luminosities of the AGNs rather than Compton-thick absorption. A
comparison of these sources to the well-studied heavily obscured AGN NGC6240
shows that the average AGN contribution is negligible at submm wavelengths. The
X-ray properties of the other 2 X-ray detected sources are consistent with
those expected from luminous star formation; however, we cannot rule out the
possibility that low-luminosity AGNs are present. The 3 X-ray undetected
sources appear to lie at high redshift (z>4) and could be either AGNs or
starbust galaxies.Comment: AJ in press (February 2003), 16 pages, includes emulateapj5.st
Efficient Photometric Selection of Quasars from the Sloan Digital Sky Survey: 100,000 z<3 Quasars from Data Release One
We present a catalog of 100,563 unresolved, UV-excess (UVX) quasar candidates
to g=21 from 2099 deg^2 of the Sloan Digital Sky Survey (SDSS) Data Release One
(DR1) imaging data. Existing spectra of 22,737 sources reveals that 22,191
(97.6%) are quasars; accounting for the magnitude dependence of this
efficiency, we estimate that 95,502 (95.0%) of the objects in the catalog are
quasars. Such a high efficiency is unprecedented in broad-band surveys of
quasars. This ``proof-of-concept'' sample is designed to be maximally
efficient, but still has 94.7% completeness to unresolved, g<~19.5, UVX quasars
from the DR1 quasar catalog. This efficient and complete selection is the
result of our application of a probability density type analysis to training
sets that describe the 4-D color distribution of stars and spectroscopically
confirmed quasars in the SDSS. Specifically, we use a non-parametric Bayesian
classification, based on kernel density estimation, to parameterize the color
distribution of astronomical sources -- allowing for fast and robust
classification. We further supplement the catalog by providing photometric
redshifts and matches to FIRST/VLA, ROSAT, and USNO-B sources. Future work
needed to extend the this selection algorithm to larger redshifts, fainter
magnitudes, and resolved sources is discussed. Finally, we examine some science
applications of the catalog, particularly a tentative quasar number counts
distribution covering the largest range in magnitude (14.2<g<21.0) ever made
within the framework of a single quasar survey.Comment: 35 pages, 11 figures (3 color), 2 tables, accepted by ApJS; higher
resolution paper and ASCII version of catalog available at
http://sdss.ncsa.uiuc.edu/qso/nbckde
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