3,456 research outputs found

    Transient interference of transmission and incidence

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    Due to a transient quantum interference during a wavepacket collision with a potential barrier, a particular momentum, that depends on the potential parameters but is close to the initial average momentum, becomes suppressed. The hole left pushes the momentum distribution outwards leading to a significant constructive enhancement of lower and higher momenta. This is explained in the momentum complex-plane language in terms of a saddle point and two contiguous ``structural'' poles, which are not associated with resonances but with incident and transmitted components of the wavefunction.Comment: 4 pages of text, 6 postscript figures, revte

    Tensile effective stresses in hydrocarbon storage caverns

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    The "no-tensile effective stress" criterion is discussed. It is proven that effective tensile stresses can be generated at a cavern wall after a rapid increase or decrease in pressure. The Etzel K-102 test, performed in Germany more than 20 years ago, is revisited using the notion of effective tensile stresses

    Work Absenteeism Due to a Chronic Disease

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    Research on health-related work absenteeism focuses primarily on moral hazard issues but seldom discriminates between the types of illnesses that prompt workers to stay home or seek care. This paper focuses on chronic migraine, a common and acute illness that can prove to be relatively debilitating. Our analysis is based upon the absenteeism of workers employed in a large Fortune-100 manufacturing firm in the United States. We model their daily transitions between work and absence spells between January 1996 up until December 1998. Only absences due to migraine and depression, its main comorbidity, are taken into account. Our results show that there is considerable correlation between the different states we consider. In addition, workers who are covered by the Blue Preferred Provided Organization tend to have shorter employment spells but also shorter migraine spells.migraine, absenteeism, insurance policies, transition models, unobserved heterogeneity

    Graphic Symbol Recognition using Graph Based Signature and Bayesian Network Classifier

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    We present a new approach for recognition of complex graphic symbols in technical documents. Graphic symbol recognition is a well known challenge in the field of document image analysis and is at heart of most graphic recognition systems. Our method uses structural approach for symbol representation and statistical classifier for symbol recognition. In our system we represent symbols by their graph based signatures: a graphic symbol is vectorized and is converted to an attributed relational graph, which is used for computing a feature vector for the symbol. This signature corresponds to geometry and topology of the symbol. We learn a Bayesian network to encode joint probability distribution of symbol signatures and use it in a supervised learning scenario for graphic symbol recognition. We have evaluated our method on synthetically deformed and degraded images of pre-segmented 2D architectural and electronic symbols from GREC databases and have obtained encouraging recognition rates.Comment: 5 pages, 8 figures, Tenth International Conference on Document Analysis and Recognition (ICDAR), IEEE Computer Society, 2009, volume 10, 1325-132

    Work Absenteeism Due to a Chronic Disease

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    Research on health-related work absenteeism focuses primarily on moral hazard issues but seldom discriminates between the types of illnesses that prompt workers to stay home or seek care. This paper focuses on chronic migraine, a common and acute illness that can prove to be relatively debilitating. Our analysis is based upon the absenteeism of workers employed in a large Fortune-100 manufacturing firm in the United States. We model their daily transitions between work and absence spells between January 1996 up until December 1998. Only absence due to migraine and depression, its main comorbidity, are taken into account. Our results show that there is considerable correlation between the different states we consider. In addition, workers who are covered by the Blue Preferred Provided Organization tend to have shorter employment spells but also shorter migraine spells.Migraine, absenteeism, insurance policies, transition models, unobserved heterogeneity

    CLIPS at TREC-11: Experiments in Filtering

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    International audienceAt the TREC9 conference, we presented a new adaptive filtering system called RELIEFS. This system which is based on the idea of resonance, combines for each term t, the relative frequency of relevance knowing t and the relative frequency of t kwowing relevance. On the basis of other experiments, several changes have been made. We improved our threshold adaption, we slightly changed our relevance evaluation function and we gave up the use of conjunctions and thesaurus. The system is now focusing more exclusively on the combination of both reverse frequencies that we believe to represent the fundamental aspects of relevance estimation. This year we used the system in its new version and we tested it on the Reuters corpus. Focusing on the combination of the two frequencies, we varied their relative importance. The results show globally a good effectiveness especially when both frequencies are balanced

    Professional prejudice: Are psychology and psychiatry helping or hindering our understanding of sexualities and gender?

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    [BOOK REVIEW]Tosh, Jemma (2015) Perverse psychology: The pathologization of sexual violence and transgenderism. London & New York: Routledge. ISBN 978-1-84872-173-9 pbk. Pages xiv + 146. South Africa is grappling with high levels of gender based violence and rape, some of it extreme in the lengths to which perpetrators go to assert dominance, mostly over women. Who can forget the horrific crime of rape, robbery and murder which took place at Rhodes Park in Johannesburg in October 2015, resulting in the recent sentencing of the perpetrators, all men? Please note this is a trigger warning for the next paragraph. &nbsp

    RELIEFS : un système d'inspiration cognitive pour le filtrage adaptatif de documents textuels

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    International audienceL'objet de cet article est la présentation d'un nouveau système nommé RELIEFS (pour RELevance Information Extraction Fuzzy System) pour le filtrage adaptatif de documents textuels. Les grands principes de fonctionnement de ce système s'inspirent de mécanismes cognitifs intervenant dans les processus de sélection de l'information. Plus précisément, notre recherche part de l'analyse de modèles de la mémoire sémantique (accès et organisation des connaissances en mémoire) et de modèles qui rendent compte de phénomènes attentionnels (sélection des informations provenant de l'environnement). Des liens forts sont tissés entre ces modèles et des modèles traditionnellement utilisés en RI. Une nouvelle interprétation de la notion de pertinence est proposée. L'analyse nous conduit à extraire un ensemble de mécanismes de base renvoyant aux notions d'activation et de propagation d'activation pour la sélection d'information " pertinentes ". Ces mécanismes sont implémentés et testés avec succès dans la tâche de filtrage adaptatif de TREC9
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