Search results for " Coherence"
showing 10 items of 429 documents
Emergence of long-range phase coherence in nonlocal nonlinear media
2017
The emergence of long range phase coherence among random nonlinear waves is a fascinating effect that characterizes many fundamental phenomena. For instance, the condensation of classical waves [1,2] is an important example of self-organization process that generates lot of interest as a classical analogue of quantum Bose-Einstein condensation. Wave condensation is known to be characterized by the emergence of long-range order and phase-coherence, in the sense that the correlation function of the wave amplitude does not decay at infinity. This property of long range phase coherence is fundamental, for instance for the manifestation of superfluid behaviors, or the generation of Bogoliubov so…
On general conditional prevision assessments
2009
In this paper we consider general conditional random quantities of the kind $X|Y$, where $X$ and $Y$ are finite discrete random quantities. Then, we introduce the notion of coherence for conditional prevision assessments on finite families of general conditional random quantities. Moreover, we give a compound prevision theorem and we examine the relation between the previsions of $X|Y$ and $Y|X$. Then, we give some results on random gains and, by a suitable alternative theorem, we obtain a characterization of coherence. We also propose an algorithm for the checking of coherence. Finally, we briefly examine the case of imprecise conditional prevision assessments by introducing the notions of…
El sistema de continuidad como proceso unificador
2007
El sistema de continuidad es un procedimiento de construcción de relatos audiovisuales que tiene como fundamento la causalidad narrativa y un conjunto de normas de elaboración, especialmente en el montaje, cuya finalidad es mostrar al espectador un desarrollo argumental lógico que se desarrolla en un espacio-tiempo diegético coherente. La continuidad, está sometida a un modelo ideológico de representación que condiciona la percepción. La continuidad no es, por lo tanto, un concepto absoluto, sino que evoluciona a lo largo del tiempo. Sin embargo, el sistema de continuidad permanece vigente porque garantiza el predominio de la cadena causal y la inmersión del espectador en el universo diegét…
Response by Meneveau and Ecarnot to Letter Regarding Article, “Optical Coherence Tomography to Optimize Results of Percutaneous Coronary Intervention…
2017
We read with interest the letters by Vallurupalli and Uretsky and also Dr Nadir relating to the results of the DOCTORS study (Does Optical Coherence Tomography Optimize Results of Stenting).1 We thank the authors for their insightful remarks. Vallurupalli and Uretsky raise an interesting point when they underline that a prolonged inflation time is superior to a rapid inflation/deflation technique in terms of both stent expansion and apposition. We acknowledge that we did not take stent inflation time into account in the case report form of the DOCTORS study. The arguments put forward by Vallurupalli and Uretsky suggest that this variable should be systematically recorded and reported. Howev…
The stability of sense of coherence: comparing two age groups in a 5-year follow-up study
2003
In the original theoretical formulation, Antonovsky (1987a) proposed that sense of coherence is a developmental construct that becomes stabilized at the age of 30. The present 5-year follow-up study was designed to test this hypothesis by investigating the differences in stability in sense of coherence among two age groups the younger group of which consisted of individuals under and the older group of individuals over 30 years of age. The participants were Finnish technical designers (N=352) of whom 40% (n=141) comprised the younger age group (25–29 years) and 60% (n=211) the older age group (35–40 years). The 13-item Orientation to Life Questionnaire (Antonovsky, 1987a) was used to measur…
Application of time-resolved spectroscopy to concentration measurements in gas mixtures
2001
1296-2147; Concentration measurements using femtosecond Raman Induced Polarization Spectroscopy (RIPS) are performed in binary gas mixtures CO2-N2 and CO2-N2O at room temperature. The principle of these measurements is based on the nonlinear rotational time response of each molecular component of the mixture, The general form of this molecular response is a series of periodic transients with a period related to the rotational constant Be The relative strength of the individual responses allows an accurate determination of the concentration. Two techniques are presented using either two pulses (one pump and one probe) or three pulses (two pumps and one probe). (C) 2001 Academie des sciences/…
Probabilistic Logic under Coherence‚ Model−Theoretic Probabilistic Logic‚ and Default Reasoning in System P
2016
We study probabilistic logic under the viewpoint of the coherence principle of de Finetti. In detail, we explore how probabilistic reasoning under coherence is related to model-theoretic probabilistic reasoning and to default reasoning in System P. In particular, we show that the notions of g-coherence and of g-coherent entailment can be expressed by combining notions in model-theoretic probabilistic logic with concepts from default reasoning. Moreover, we show that probabilistic reasoning under coherence is a generalization of default reasoning in System P. That is, we provide a new probabilistic semantics for System P, which neither uses infinitesimal probabilities nor atomic bound (or bi…
Probabilistic Logic under Coherence, Model-Theoretic Probabilistic Logic, and Default Reasoning
2001
We study probabilistic logic under the viewpoint of the coherence principle of de Finetti. In detail, we explore the relationship between coherence-based and model-theoretic probabilistic logic. Interestingly, we show that the notions of g-coherence and of g-coherent entailment can be expressed by combining notions in model-theoretic probabilistic logic with concepts from default reasoning. Crucially, we even show that probabilistic reasoning under coherence is a probabilistic generalization of default reasoning in system P. That is, we provide a new probabilistic semantics for system P, which is neither based on infinitesimal probabilities nor on atomic-bound (or also big-stepped) probabil…
New imaging techniques and opportunities in endoscopy.
2011
Gastrointestinal endoscopy is undergoing major improvements, which are driven by new available technologies and substantial refinements of optical features. In this Review, we summarize available and evolving imaging technologies that could influence the clinical algorithm of endoscopic diagnosis. Detection, characterization and confirmation are essential steps required for proper endoscopic diagnosis. Optical and nonoptical methods can help to improve each step; these improvements are likely to increase the detection rate of neoplasias and reduce unnecessary endoscopic treatments. Furthermore, functional and molecular imaging are emerging as new diagnostic tools that could provide an oppor…
Degree of coherence: a lensless measuring technique.
2009
We present a technique for measuring the degree of coherence that is based on the self-imaging phenomenon. The technique is lensless, has multiplexing capabilities, and can work with high light throughput. Experimental verifications are given.