4,654 research outputs found
The Treatment of Ties in AP Correlation
No full textThe Kendall tau and AP correlation coefficients are very commonly use to compare two rankings over the same set of items. Even though Kendall tau was originally defined assuming that there are no ties in the rankings, two alternative versions were soon developed to account for ties in two different scenarios: measure the accuracy of an observer with respect to a true and objective ranking, and measure the agreement between two observers in the absence of a true ranking. These two variants prove useful in cases where ties are possible in either ranking, and may indeed result in very different scores. AP correlation was devised to incorporate a top-heaviness component into Kendall tau, penalizing more heavily if differences occur between items at the top of the rankings, making it a very compelling coefficient in Information Retrieval settings. However, the treatment of ties in AP correlation remains an open problem. In this paper we fill this gap, providing closed analytical formulations of AP correlation under the two scenarios of ties contemplated in Kendall tau. In addition,we developed an R package that implements these coefficients.Best Short Paper Accepted author manuscriptMultimedia ComputingWeb Information System
L’image numérique au service de l’histoire et du patrimoine : de la maquette de Paul Bigot à une Rome virtuelle
No full textRéalisée de 1904 à 1942 par l’architecte Paul Bigot, Grand Prix de Rome en 1900, la maquette de Rome antique à l’université de Caen offre une vision aérienne de la capitale au IVe siècle ap. J.-C., à son apogée monumental. Dans un projet original, Paul Bigot s’était posé la question de l’image de la ville à partir des fragments de la Forma urbis sévérienne, faisant des choix esthétiques en tant qu’architecte, mais surtout des choix scientifiques en tant que chercheur passionné d’histoire. Son plan-relief, exposé à Rome, puis en France, en Belgique et aux USA, suscita en Italie l’émulation d’Itali Gismondi, auteur du Plastico du museo della Civilità romana. Objets figés et datés, ces plans appartiennent désormais au patrimoine des musées. Aujourd’hui, la maquette numérique en trois dimensions peut donner aux monuments même disparus une gamme d’échelles et de points de vue permettant, grâce à la navigation virtuelle, de restituer l’espace de Rome dans les conditions « réelles » d’autrefois.Lecocq Françoise. L’image numérique au service de l’histoire et du patrimoine : de la maquette de Paul Bigot à une Rome virtuelle. In: Images et relevés archéologiques : de la preuve à la démonstration. Actes du 132e Congrès national des sociétés historiques et scientifiques, « Images et imagerie », Arles, 2007. Paris : Editions du CTHS, 2008. pp. 47-54. (Actes des congrès nationaux des sociétés historiques et scientifiques, 132-1
Estrelas magnéticas quimicamente peculiares: Evolução, oscilações e Imageamento Doppler
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas - Programa de Pós-Graduação em Física.Apresentamos nesta tese os resultados de três estudos observacionais relacionados com as estrelas Ap, assim como a sub-classe das estrelas rapidamente oscilantes (roAp). No primeiro estudo, investigamos o estado evolutivo das estrelas Ap visando responder a seguinte pergunta: as estrelas nascem peculiares, ou desenvolvem suas peculiaridades ao longo de sua vida na seqüência principal? Para isso, observamos e classificamos 470 estrelas pertencentes a 18 aglomerados com idades entre 6.9 < log t < 8.1 e estudamos a freqüência de ocorrência de estrelas Ap em função da idade dos aglomerados
Delamination Analysis of A Class of AP-PLY Composite Laminates
No full textA recently developed fiber placement architecture, AP-PLY, has been shown to give significantly improved damage tolerance characteristics of composite structures. The behavior of delaminations resulting from low speed impact damage is of particular concern. Major attention has been paid to expand current knowledge on the delamination response of simple AP-PLY composite structure and move towards in-depth understanding of the failure mechanisms behind the damage tolerance. This thesis presents the approaches to predict delamination onset and analyze delamination growth, in support of the search of the optimum woven pattern for AP-PLY composite laminates. The recovered interlaminar stress between layers combined with the maximum stress criterion determined the delamination onset of simple AP-PLY composite laminate under out-of-plane loads. 2D finite element models with cohesive elements inserted in the interfaces of woven layers have been built to evaluate the delamination initiation and propagation in the different woven patterns of simple AP-PLY composite beams. The parameters of the woven pattern, such as the woven angle, the number of woven plies, the number of straight filled plies, and the location of the woven patterns in through the thickness direction, were investigated and shown to have a significant effect on delamination creation and growth. An energy method based on beam theory was proposed to analyze the strain energy release rate (SERR) of an existing crack in an AP-PLY beam structure. The developed analytical method was implemented in isotropic materials and the obtained SERR of a crack was validated by reference results and finite element solutions. The general behavior of crack growth on the left or right crack tip was evaluated and basic trends leading to crack propagation on one side of the crack were established. A correction factor was introduced to improve the accuracy of the SERR of a small crack through the numerical calculation. The singularity of crack tip caused by dissimilar materials was investigated and was found that the inclusion of the singularity effect could increase the accuracy for small cracks. It has been shown that the neutral axis needs to be relocated to decouple the bending and membrane behavior of unsymmetrical composite laminates, thus to meet the requirement of minimizing the strain energy of the delaminated beam to calculate the SERR of a delaminated composite beam. The calculated SERR of a crack in a composite beam has been verified by comparing with a finite element model. The woven plies in AP-PLY composite laminate altered the layup and two conventional laminates with different stacking sequences were identified in an AP-PLY composite laminate based on the assumption that the resin areas were ignored. A step by step approach was developed to obtain the SERR of a crack that goes across different materials. The analytical SERR determined when two materials are used in sequence, sets the stage for optimization of AP-PLY composite laminates without taking account of the effect of the resin area. The procedure of optimization of simple AP-PLY pattern was proposed and industry may benefit for many applications. An equivalent stiffness approach was used to model regions containing resin pockets and straight or inclined composite layers. A series of three point bending tests was carried out where the failure process and loading capacity were evaluated. The methodology, procedure of optimization, philosophy outlined in this thesis might also be applied to the more complicated fully woven AP-PLY composite laminates. The work in this thesis contributes to the understanding of the behavior of AP-PLY composite laminates with delaminations
Structure function analysis of blazars AP Librae and 3c279
No full textHighest Honors in AstronomyBlazars AP Librae and 3c279 are analyzed for microvariability using a technique known as structure function analysis. AP Librae was observed in April
of 2005 and 3c279 was observed in April of 2007. The data for AP Librae was
previously reduced by Andrew Collazzi and the author reduced the data for
3c279. Both sets of data were reduced using Robert Knop's data reduction
program.
The author ran structure function analysis on both sets of data. Structure function analysis is a statistical analysis run on data that is suppose to
nd timescales of variability, periodicity, and the noise type of data. Previous analysis of AP Librae confirmed mircrovariability, which also shows up in
the structure function of AP Librae. Blazar 3c279 was much quieter than AP
Librae and showed no microvariability durning any of the nights.College of Arts and ScienceDepartment of Physics and Astronom
AP-based wireless intrusion detection systems
No full textThis thesis was scanned from the print manuscript for digital preservation and is copyright the author.
Researchers can access this thesis by asking their local university, institution or public library to
make a request on their behalf. Monash staff and postgraduate students can use the link in the References field
Étude préliminaire des amphores gauloises des fouilles de l’épave Arles-Rhône 3 (Arles, B.-du-Rh.) (2e moitié du Ier s. – 1ère moitié du IIe s. ap. J.‑C)
No full textUnderwater excavations carried out prior to the raising of the ancient barge Arles-Rhône 3 have uncovered numerous ceramics and amphorae dating to between 60 and 140 C. E. Amphorae play the most important role in this assemblage, and almost half of these are locally produced Gallic amphorae. This proportion reflects the importance of wine from Narbonensis in this period in trade with both Rome and towards the Germanic limes, and confirms the important position of Arles with respect to the distribution of this product. The excellent state of preservation of the amphorae, a number of which are intact, allows for consideration of commercial networks between the last quarter of the 1st century and the mid-2nd century C. E., as well as for morphological and volumetric studies.Les fouilles subaquatiques, réalisées préalablement à l’opération de levage du chaland antique Arles-Rhône 3, ont permis de mettre au jour de très nombreuses céramiques et d’amphores datées entre les années 60 ap. J. ‑C. et 140 ap. J. ‑C. Les amphores occupent la place la plus importante au sein de ce dépotoir portuaire. Parmi celles-ci, près de la moitié est gauloise (de provenance régionale). Cette proportion témoigne, pour cette période, de l’importance du vin de Narbonnaise dans le grand commerce aussi bien vers Rome qu’en direction du limes germanique et confirme la place centrale occupée par Arles pour la distribution de cette denrée. L’excellent état de conservation des amphores dont plusieurs sont entières, permet également une réflexion sur les modèles commercialisés entre le dernier quart du Ier s. ap. J. ‑C. et le milieu du IIe s. ap. J. ‑C., ainsi qu’une étude morphologique et volumétrique.Bigot Fabrice, Djaoui David. Étude préliminaire des amphores gauloises des fouilles de l’épave Arles-Rhône 3 (Arles, B.-du-Rh.) (2e moitié du Ier s. – 1ère moitié du IIe s. ap. J.‑C). In: Revue archéologique de Narbonnaise, tome 46, 2013. pp. 375-393
Environmental toxicity, redox signaling and lung inflammation:the role of glutathione
No full textGlutathione (gamma-glutamyl-cysteinyl-glycine, GSH) is the most abundant intracellular antioxidant thiol and is central to redox defense during oxidative stress. GSH metabolism is tightly regulated and has been implicated in redox signaling and also in protection against environmental oxidant-mediated injury. Changes in the ratio of the reduced and disulfide form (GSH/GSSG) can affect signaling pathways that participate in a broad array of physiological responses from cell proliferation, autophagy and apoptosis to gene expression that involve H(2)O(2) as a second messenger. Oxidative stress due to oxidant/antioxidant imbalance and also due to environmental oxidants is an important component during inflammation and respiratory diseases such as chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, acute respiratory distress syndrome, and asthma. It is known to activate multiple stress kinase pathways and redox-sensitive transcription factors such as Nrf2, NF-kappaB and AP-1, which differentially regulate the genes for pro-inflammatory cytokines as well as the protective antioxidant genes. Understanding the regulatory mechanisms for the induction of antioxidants, such as GSH, versus pro-inflammatory mediators at sites of oxidant-directed injuries may allow for the development of novel therapies which will allow pharmacological manipulation of GSH synthesis during inflammation and oxidative injury. This article features the current knowledge about the role of GSH in redox signaling, GSH biosynthesis and particularly the regulation of transcription factor Nrf2 by GSH and downstream signaling during oxidative stress and inflammation in various pulmonary diseases. We also discussed the current therapeutic clinical trials using GSH and other thiol compounds, such as N-acetyl-l-cysteine, fudosteine, carbocysteine, erdosteine in environment-induced airways disease
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