1,291 research outputs found
Using Cross-Lingual Explicit Semantic Analysis for Improving Ontology Translation
Semantic Web aims to allow machines to make inferences using the explicit conceptualisations contained in ontologies. By pointing to ontologies, Semantic Web-based applications are able to inter-operate and share common information easily. Nevertheless, multilingual semantic applications are still rare, owing to the fact that most online ontologies are monolingual in English. In order to solve this issue, techniques for ontology localisation and translation are needed. However, traditional machine translation is difficult to apply to ontologies, owing to the fact that ontology labels tend to be quite short in length and linguistically different from the free text paradigm. In this paper, we propose an approach to enhance machine translation of ontologies based on exploiting the well-structured concept descriptions contained in the ontology. In particular, our approach leverages the semantics contained in the ontology by using Cross Lingual Explicit Semantic Analysis (CLESA) for context-based disambiguation in phrase-based Statistical Machine Translation (SMT). The presented work is novel in the sense that application of CLESA in SMT has not been performed earlier to the best of our knowledge
Tidally Induced Offset Disks in Magellanic Spiral Galaxies
Magellanic spiral galaxies are a class of one-armed systems that often
exhibit an offset stellar bar, and are rarely found around massive spiral
galaxies. Using a set of N-body and hydrodynamic simulations we consider a
dwarf-dwarf galaxy interaction as the driving mechanism for the formation of
this peculiar class of systems. We investigate here the relation between the
dynamical, stellar and gaseous disk center and the bar. In all our simulations
the bar center always coincides with the dynamical center, while the stellar
disk becomes highly asymmetric during the encounter causing the photometric
center of the Magellanic galaxy disk to become mismatched with both the bar and
the dynamical center. The disk asymmetries persist for almost 2 Gyrs, the time
that it takes for the disk to be re-centered with the bar, and well after the
companion has passed. This explains the nature of the offset bar found in many
Magellanic-type galaxies, including the Large Magellanic Cloud (LMC) and NGC
3906. In particular, these results, once applied to the LMC, suggest that the
dynamical center should reside in the bar center instead of the HI center as
previously assumed, pointing to a variation in the current estimate of the
north component of the LMC proper motion.Comment: 12 pages, 8 figures, corrected for referee comment
Fostering IPv6 Migration Through Network Quality Differentials
Although IPv6 has been the next generation Internet protocol for nearly 15 years, new evidences indicate that transitioning from IPv4 to IPv6 is about to become a more pressing issue. This paper attempts to quantify if and how such a transition may unfold. The focus is on ``connectivity quality,\u27\u27 e.g., as measured by users\u27 experience when accessing content, as a possible incentive (or disincentive) for migrating to IPv6, and on ``translation costs\u27\u27 (between IPv6 and IPv4) that Internet Service Providers will incur during this transition. The paper develops a simple model that captures some of the underlying interactions, and highlights the ambiguous role of translation gateways that can either help or discourage IPv6 adoption. The paper is an initial foray in the complex and often puzzling issue of migrating the current Internet to a new version with which it is incompatible
Entropy measures for complex networks: Toward an information theory of complex topologies
The quantification of the complexity of networks is, today, a fundamental
problem in the physics of complex systems. A possible roadmap to solve the
problem is via extending key concepts of information theory to networks. In
this paper we propose how to define the Shannon entropy of a network ensemble
and how it relates to the Gibbs and von Neumann entropies of network ensembles.
The quantities we introduce here will play a crucial role for the formulation
of null models of networks through maximum-entropy arguments and will
contribute to inference problems emerging in the field of complex networks.Comment: (4 pages, 1 figure
Coupling Transcriptional State to Large-Scale Repeat Expansions in Yeast
SummaryExpansions of simple DNA repeats cause numerous hereditary disorders in humans. Replication, repair, and transcription are implicated in the expansion process, but their relative contributions are yet to be distinguished. To separate the roles of replication and transcription in the expansion of Friedreich’s ataxia (GAA)n repeats, we designed two yeast genetic systems that utilize a galactose-inducible GAL1 promoter but contain these repeats in either the transcribed or nontranscribed region of a selectable cassette. We found that large-scale repeat expansions can occur in the lack of transcription. Induction of transcription strongly elevated the rate of expansions in both systems, indicating that active transcriptional state rather than transcription through the repeat per se affects this process. Furthermore, replication defects increased the rate of repeat expansions irrespective of transcriptional state. We present a model in which transcriptional state, linked to the nucleosomal density of a region, acts as a modulator of large-scale repeat expansions
Photoluminescence measurements of quantum-dot-containing semiconductor microdisk resonators using optical fiber taper waveguides
Fiber taper waveguides are used to improve the efficiency of room temperature
photoluminescence measurements of AlGaAs microdisk resonant cavities with
embedded self-assembled InAs quantum dots. As a near-field collection optic,
the fiber taper improves the collection efficiency from microdisk lasers by a
factor of ~ 15-100 times in comparison to conventional normal incidence
free-space collection techniques. In addition, the fiber taper can serve as a
efficient means for pumping these devices, and initial measurements employing
fiber pumping and collection are presented. Implications of this work towards
chip-based cavity quantum electrodynamics experiments are discussed.Comment: 10 pages, 7 figure
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