Search results for "INDUCTION"

Discovering the Senses of an Ambiguous Word by Clustering its Local Contexts

2005

As has been shown recently, it is possible to automatically discover the senses of an ambiguous word by statistically analyzing its contextual behavior in a large text corpus. However, this kind of research is still at an early stage. The results need to be improved and there is considerable disagreement on methodological issues. For example, although most researchers use clustering approaches for word sense induction, it is not clear what statistical features the clustering should be based on. Whereas so far most researchers cluster global co-occurrence vectors that reflect the overall behavior of a word in a corpus, in this paper we argue that it is more appropriate to use local context v…

Gl-learning

2016

In this paper, we present a new open-source software library, Gl-learning, for grammatical inference. The rise of new application scenarios in recent years has required optimized methods to address knowledge extraction from huge amounts of data and to model highly complex systems. Our library implements the main state-of-the-art algorithms in the grammatical inference field (RPNI, EDSM, L*), redesigned through the OpenMP library for a parallel execution that drastically decreases execution times. To our best knowledge, it is also the first comprehensive library including a noise tolerance learning algorithm, such as Blue*, that significantly broadens the range of the potential application s…

A note on beliefs formation in signalling games

1994

Abstract We present a new criterion, called incentive dominance, for belief formation in signalling games, which subsumes refinements criteria such as equilibrium dominance and divinity. It captures the principle of forward induction through explicitly modelling the player's thought process when forming preliminary beliefs.

Surface and bulk changes of a Pt 1%/Ce0.6Zr0.4O2 catalyst during CO oxidation in the absence of O2

2004

The reduction of a Pt 1%/Ce0.6Zr0.4O2 catalyst by CO in the absence of gaseous oxygen was studied by transient reactivity tests, temperature programmed surface reaction with CO, flow thermogravimetric tests and DRIFTS experiments, in order to obtain information generally on the OSC properties and, specifically, on the mechanism of CO oxidation over both, Pt catalyst and support-only sample (Ce0.6Zr0.4O2). The results of thermogravimetric experiments showed the presence of an induction time in the weight change % of the catalyst, depending on the CO concentration in the gas flow. This induction time could be related to the presence of two oxygen reactive sites. The first one leads to strongl…

Co-regulation between cyclo-oxygenase-2 and inducible nitric oxide synthase expression in the time-course of murine inflammation.

2000

Many in vitro studies have used cell cultures to focus on the relationships between cyclo-oxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) isoforms. We have investigated the time-course of regulation and the role of COX-2 and iNOS in a model of experimental inflammation in mice, the air pouch injected with zymosan. This study demonstrates that there is an early acute phase (4 h) mediated mainly by eicosanoids, with high levels of prostaglandin E2 (PGE2) produced by cyclo-oxygenase-1. In addition, in the later phase (from 12 h) there is a participation of nitric oxide (NO) and PGE2 accompanied by co-induction of both iNOS and COX-2. These enzymes were detected in migrating leuk…

Impact on Immune Tolerance induced by Medullary Thymic Epithelial Cells and Limbal Stem Cells

Pharmacological preconditioning in global cerebral ischemia

2004

Single dose 3-nitropropionic acid (3-NPA) 24 hr before global ischemia improves neuronal survival in both, neocortex and hippocampus (‘chemical preconditioning’). Neuronal survival after transient global ischemia requires new protein synthesis during recovery, especially of those with anti-apoptotic function. Bcl-2-protein is expressed in neurons that survive cerebral ischemia and may parallel the time course of tolerance after ischemic preconditioning. With this study we examined whether differences in bcl-2-protein expression compared to baseline may be involved in the induction of ischemic tolerance using 3-NPA.

RELEVANCE OF MESENCHYMAL THYMUS CELLS (MC) FOR ACCEPTANCE OF ALLOGENEIC MATURE THYMUS GRAFTS AND INDUCTION OF ALLOTOLERANCE IN NUDE MICE

1984

Allogeneic thymus (aTh) from an adult immunocompetent donor cannot be transplanted successfully in thymusless nude mice even if the graft is irradiated. The graft is destroyed for unknown reasons and no immunocompetence is achieved in the host. Two approaches were established to achieve acceptance of aTh. In experiment 1, mature aTh was transplanted in nude mice, after specific tolerance to the recipient was induced in the donor during the neonatal period. This resulted in acceptance of the aTh, immunological reconstitution and tolerance to the donor's and recipient's MHC-haplotype as proved by skin-grafts and MLC. In experiment 2, neonatal thymus was grafted into allogeneic nude mice and r…

The Measurement of Reactive Energy in Polluted Distribution Power Systems: An Analysis of the Performance of Commercial Static Meters

2008

This paper presents a comparative analysis of the performances of both a traditional induction meter and various types of commercial static meters for reactive energy in the presence of harmonic distortion. This is a topical issue, since there are several types of static meters on the market, based on different principles of construction. In accordance with current standards, these meters are designed to operate in sinusoidal conditions and their performance is not tested in the presence of harmonic distortion. However, with the increase of pollution levels in power systems, the meters may be used even in the presence of distorted voltages and/or currents; in such cases, their accuracy may …

Learning the structure of HMM's through grammatical inference techniques

2002

A technique is described in which all the components of a hidden Markov model are learnt from training speech data. The structure or topology of the model (i.e. the number of states and the actual transitions) is obtained by means of an error-correcting grammatical inference algorithm (ECGI). This structure is then reduced by using an appropriate state pruning criterion. The statistical parameters that are associated with the obtained topology are estimated from the same training data by means of the standard Baum-Welch algorithm. Experimental results showing the applicability of this technique to speech recognition are presented. >