487,146 research outputs found
Planetary benchmarks
Design criteria and technology requirements for a system of radar reference devices to be fixed to the surfaces of the inner planets are discussed. Offshoot applications include the use of radar corner reflectors as landing beacons on the planetary surfaces and some deep space applications that may yield a greatly enhanced knowledge of the gravitational and electromagnetic structure of the solar system. Passive retroreflectors with dimensions of about 4 meters and weighing about 10 kg are feasible for use with orbiting radar at Venus and Mars. Earth-based observation of passive reflectors, however, would require very large and complex structures to be delivered to the surfaces. For Earth-based measurements, surface transponders offer a distinct advantage in accuracy over passive reflectors. A conceptual design for a high temperature transponder is presented. The design appears feasible for the Venus surface using existing electronics and power components
Self-interacting Dark Matter Benchmarks
Dark matter self-interactions have important implications for the
distributions of dark matter in the Universe, from dwarf galaxies to galaxy
clusters. We present benchmark models that illustrate characteristic features
of dark matter that is self-interacting through a new light mediator. These
models have self-interactions large enough to change dark matter densities in
the centers of galaxies in accord with observations, while remaining compatible
with large-scale structure data and all astrophysical observations such as halo
shapes and the Bullet Cluster. These observations favor a mediator mass in the
10 - 100 MeV range and large regions of this parameter space are accessible to
direct detection experiments like LUX, SuperCDMS, and XENON1T.Comment: 4 pages, white paper for Snowmass 2013; v2: finalized version,
figures correcte
Evaluating ontology alignment methods
Many different methods have been designed for aligning ontologies.
These methods use such different techniques that they can hardly be
compared theoretically. Hence, it is necessary to compare them on
common tests.
We present two initiatives that led to the definition and the performance of the
evaluation of ontology alignments during 2004.
We draw lessons from these two experiments and discuss future improvements
Handwriting styles: benchmarks and evaluation metrics
Evaluating the style of handwriting generation is a challenging problem,
since it is not well defined. It is a key component in order to develop in
developing systems with more personalized experiences with humans. In this
paper, we propose baseline benchmarks, in order to set anchors to estimate the
relative quality of different handwriting style methods. This will be done
using deep learning techniques, which have shown remarkable results in
different machine learning tasks, learning classification, regression, and most
relevant to our work, generating temporal sequences. We discuss the challenges
associated with evaluating our methods, which is related to evaluation of
generative models in general. We then propose evaluation metrics, which we find
relevant to this problem, and we discuss how we evaluate the evaluation
metrics. In this study, we use IRON-OFF dataset. To the best of our knowledge,
there is no work done before in generating handwriting (either in terms of
methodology or the performance metrics), our in exploring styles using this
dataset.Comment: Submitted to IEEE International Workshop on Deep and Transfer
Learning (DTL 2018
Updated Post-WMAP Benchmarks for Supersymmetry
We update a previously-proposed set of supersymmetric benchmark scenarios,
taking into account the precise constraints on the cold dark matter density
obtained by combining WMAP and other cosmological data, as well as the LEP and
b -> s gamma constraints. We assume that R parity is conserved and work within
the constrained MSSM (CMSSM) with universal soft supersymmetry-breaking scalar
and gaugino masses m_0 and m_1/2. In most cases, the relic density calculated
for the previous benchmarks may be brought within the WMAP range by reducing
slightly m_0, but in two cases more substantial changes in m_0 and m_1/2 are
made. Since the WMAP constraint reduces the effective dimensionality of the
CMSSM parameter space, one may study phenomenology along `WMAP lines' in the
(m_1/2, m_0) plane that have acceptable amounts of dark matter. We discuss the
production, decays and detectability of sparticles along these lines, at the
LHC and at linear e+ e- colliders in the sub- and multi-TeV ranges, stressing
the complementarity of hadron and lepton colliders, and with particular
emphasis on the neutralino sector. Finally, we preview the accuracy with which
one might be able to predict the density of supersymmetric cold dark matter
using collider measurements.Comment: 43 pages LaTeX, 13 eps figure
Efficient Benchmarking of Algorithm Configuration Procedures via Model-Based Surrogates
The optimization of algorithm (hyper-)parameters is crucial for achieving
peak performance across a wide range of domains, ranging from deep neural
networks to solvers for hard combinatorial problems. The resulting algorithm
configuration (AC) problem has attracted much attention from the machine
learning community. However, the proper evaluation of new AC procedures is
hindered by two key hurdles. First, AC benchmarks are hard to set up. Second
and even more significantly, they are computationally expensive: a single run
of an AC procedure involves many costly runs of the target algorithm whose
performance is to be optimized in a given AC benchmark scenario. One common
workaround is to optimize cheap-to-evaluate artificial benchmark functions
(e.g., Branin) instead of actual algorithms; however, these have different
properties than realistic AC problems. Here, we propose an alternative
benchmarking approach that is similarly cheap to evaluate but much closer to
the original AC problem: replacing expensive benchmarks by surrogate benchmarks
constructed from AC benchmarks. These surrogate benchmarks approximate the
response surface corresponding to true target algorithm performance using a
regression model, and the original and surrogate benchmark share the same
(hyper-)parameter space. In our experiments, we construct and evaluate
surrogate benchmarks for hyperparameter optimization as well as for AC problems
that involve performance optimization of solvers for hard combinatorial
problems, drawing training data from the runs of existing AC procedures. We
show that our surrogate benchmarks capture overall important characteristics of
the AC scenarios, such as high- and low-performing regions, from which they
were derived, while being much easier to use and orders of magnitude cheaper to
evaluate
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