17,879 research outputs found
The Astro-WISE approach to quality control for astronomical data
We present a novel approach to quality control during the processing of
astronomical data. Quality control in the Astro-WISE Information System is
integral to all aspects of data handing and provides transparent access to
quality estimators for all stages of data reduction from the raw image to the
final catalog. The implementation of quality control mechanisms relies on the
core features in this Astro-WISE Environment (AWE): an object-oriented
framework, full data lineage, and both forward and backward chaining. Quality
control information can be accessed via the command-line awe-prompt and the
web-based Quality-WISE service. The quality control system is described and
qualified using archive data from the 8-CCD Wide Field Imager (WFI) instrument
(http://www.eso.org/lasilla/instruments/wfi/) on the 2.2-m MPG/ESO telescope at
La Silla and (pre-)survey data from the 32-CCD OmegaCAM instrument
(http://www.astro-wise.org/~omegacam/) on the VST telescope at Paranal.Comment: Accepted for publication in topical issue of Experimental Astronomy
on Astro-WISE information syste
Evaluating Knowledge Representation and Reasoning Capabilites of Ontology Specification Languages
The interchange of ontologies across the World Wide Web (WWW) and the cooperation among heterogeneous agents placed on it is the main reason for the development of a new set of ontology specification languages, based on new web standards such as XML or RDF. These languages (SHOE, XOL, RDF, OIL, etc) aim to represent the knowledge contained in an ontology in a simple and human-readable way, as well as allow for the interchange of ontologies across the web. In this paper, we establish a common framework to compare the expressiveness of "traditional" ontology languages (Ontolingua, OKBC, OCML, FLogic, LOOM) and "web-based" ontology languages. As a result of this study, we conclude that different needs in KR and reasoning may exist in the building of an ontology-based application, and these needs must be evaluated in order to choose the most suitable ontology language(s)
Reason Maintenance - Conceptual Framework
This paper describes the conceptual framework for reason maintenance developed as part of
WP2
A Potpourri of Reason Maintenance Methods
We present novel methods to compute changes to materialized
views in logic databases like those used by rule-based reasoners.
Such reasoners have to address the problem of changing axioms in the
presence of materializations of derived atoms. Existing approaches have
drawbacks: some require to generate and evaluate large transformed programs
that are in Datalog - while the source program is in Datalog and
significantly smaller; some recompute the whole extension of a predicate
even if only a small part of this extension is affected by the change.
The methods presented in this article overcome these drawbacks and derive
additional information useful also for explanation, at the price of an
adaptation of the semi-naive forward chaining
Horn Binary Serialization Analysis
A bit layout is a sequence of fields of certain bit lengths that specifies
how to interpret a serial stream, e.g., the MP3 audio format. A layout with
variable length fields needs to include meta-information to help the parser
interpret unambiguously the rest of the stream; e.g. a field providing the
length of a following variable length field. If no such information is
available, then the layout is ambiguous. I present a linear-time algorithm to
determine whether a layout is ambiguous or not by modelling the behaviour of a
serial parser reading the stream as forward chaining reasoning on a collection
of Horn clauses.Comment: In Proceedings HCVS2016, arXiv:1607.0403
Focusing and Polarization in Intuitionistic Logic
A focused proof system provides a normal form to cut-free proofs that
structures the application of invertible and non-invertible inference rules.
The focused proof system of Andreoli for linear logic has been applied to both
the proof search and the proof normalization approaches to computation. Various
proof systems in literature exhibit characteristics of focusing to one degree
or another. We present a new, focused proof system for intuitionistic logic,
called LJF, and show how other proof systems can be mapped into the new system
by inserting logical connectives that prematurely stop focusing. We also use
LJF to design a focused proof system for classical logic. Our approach to the
design and analysis of these systems is based on the completeness of focusing
in linear logic and on the notion of polarity that appears in Girard's LC and
LU proof systems
Semantic Storage: Overview and Assessment
The Semantic Web has a great deal of momentum behind it. The promise of a ‘better web’, where information is given well defined meaning and computers are better able to work with it has captured the imagination of a significant number of people, particularly in academia. Language standards such as RDF and OWL have appeared with remarkable speed, and development continues apace. To back up this development, there is a requirement for ‘semantic databases’, where this data can be conveniently stored, operated upon, and retrieved. These already exist in the form of triple stores, but do not yet fulfil all the requirements that may be made of them, particularly in the area of performing inference using OWL. This paper analyses the current stores along with forthcoming technology, and finds that it is unlikely that a combination of speed, scalability, and complex inferencing will be practical in the immediate future. It concludes by suggesting alternative development routes
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