117,871 research outputs found
An Empirical Approach to Cosmological Galaxy Survey Simulation: Application to SPHEREx Low-Resolution Spectroscopy
Highly accurate models of the galaxy population over cosmological volumes are
necessary in order to predict the performance of upcoming cosmological
missions. We present a data-driven model of the galaxy population constrained
by deep 0.1-8 imaging and spectroscopic data in the COSMOS survey,
with the immediate goal of simulating the spectroscopic redshift performance of
the proposed SPHEREx mission. SPHEREx will obtain over the full-sky
spectrophotometry at moderate spatial resolution () over the wavelength
range 0.75-4.18 and over the wavelength range 4.18-5
. We show that our simulation accurately reproduces a range of known
galaxy properties, encapsulating the full complexity of the galaxy population
and enables realistic, full end-to-end simulations to predict mission
performance. Finally, we discuss potential applications of the simulation
framework to future cosmology missions and give a description of released data
products
A Neural Model for Generating Natural Language Summaries of Program Subroutines
Source code summarization -- creating natural language descriptions of source
code behavior -- is a rapidly-growing research topic with applications to
automatic documentation generation, program comprehension, and software
maintenance. Traditional techniques relied on heuristics and templates built
manually by human experts. Recently, data-driven approaches based on neural
machine translation have largely overtaken template-based systems. But nearly
all of these techniques rely almost entirely on programs having good internal
documentation; without clear identifier names, the models fail to create good
summaries. In this paper, we present a neural model that combines words from
code with code structure from an AST. Unlike previous approaches, our model
processes each data source as a separate input, which allows the model to learn
code structure independent of the text in code. This process helps our approach
provide coherent summaries in many cases even when zero internal documentation
is provided. We evaluate our technique with a dataset we created from 2.1m Java
methods. We find improvement over two baseline techniques from SE literature
and one from NLP literature
Generating collaborative systems for digital libraries: A model-driven approach
This is an open access article shared under a Creative Commons Attribution 3.0 Licence (http://creativecommons.org/licenses/by/3.0/). Copyright @ 2010 The Authors.The design and development of a digital library involves different stakeholders, such as: information architects, librarians, and domain experts, who need to agree on a common language to describe, discuss, and negotiate the services the library has to offer. To this end, high-level, language-neutral models have to be devised. Metamodeling techniques favor the definition of domainspecific visual languages through which stakeholders can share their views and directly manipulate representations of the domain entities. This paper describes CRADLE (Cooperative-Relational Approach to Digital Library Environments), a metamodel-based framework and visual language for the definition of notions and services related to the development of digital libraries. A collection of tools allows the automatic generation of several services, defined with the CRADLE visual language, and of the graphical user interfaces providing access to them for the final user. The effectiveness of the approach is illustrated by presenting digital libraries generated with CRADLE, while the CRADLE environment has been evaluated by using the cognitive dimensions framework
EAD - enabling armchair delivery : approaches to encoding finding aids at the University of Liverpool
EAD is increasingly being selected as the primary data format for constructing archival finding aids in the British Archive Community as the new technologies and know-how required to encode lists are being embraced in many repositories. One major problem facing archivists, though, is how to convert finding aids held in a variety of formats (including databases, word processed documents and paper lists with no machine readable form) into EAD. This article will discuss the methods used in Special Collections and Archives at the University of Liverpool Library in converting finding aids into EAD. Two main examples will be discussed: firstly, designing database output styles which automatically generate EAD tags to wrap around database fields using the ProCite bibliographic database and secondly, offshore keying of paper lists with the addition of basic EAD tags following a rigorous template designed by Special Collections and Archives staff. Both methods have proved effective and have facilitated the generation of EAD encoded lists for a number of our largest collections. Finally, there will be a brief discussion of our use of native EAD generation using AdeptEdit software and our continuing use of conversion methods
The pre-launch Planck Sky Model: a model of sky emission at submillimetre to centimetre wavelengths
We present the Planck Sky Model (PSM), a parametric model for the generation
of all-sky, few arcminute resolution maps of sky emission at submillimetre to
centimetre wavelengths, in both intensity and polarisation. Several options are
implemented to model the cosmic microwave background, Galactic diffuse emission
(synchrotron, free-free, thermal and spinning dust, CO lines), Galactic H-II
regions, extragalactic radio sources, dusty galaxies, and thermal and kinetic
Sunyaev-Zeldovich signals from clusters of galaxies. Each component is
simulated by means of educated interpolations/extrapolations of data sets
available at the time of the launch of the Planck mission, complemented by
state-of-the-art models of the emission. Distinctive features of the
simulations are: spatially varying spectral properties of synchrotron and dust;
different spectral parameters for each point source; modeling of the clustering
properties of extragalactic sources and of the power spectrum of fluctuations
in the cosmic infrared background. The PSM enables the production of random
realizations of the sky emission, constrained to match observational data
within their uncertainties, and is implemented in a software package that is
regularly updated with incoming information from observations. The model is
expected to serve as a useful tool for optimizing planned microwave and
sub-millimetre surveys and to test data processing and analysis pipelines. It
is, in particular, used for the development and validation of data analysis
pipelines within the planck collaboration. A version of the software that can
be used for simulating the observations for a variety of experiments is made
available on a dedicated website.Comment: 35 pages, 31 figure
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