Academic literature on the topic 'Estimateur à noya'
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Journal articles on the topic "Estimateur à noya"
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Molod, A., H. Salmun, and M. Dempsey. "Estimating Planetary Boundary Layer Heights from NOAA Profiler Network Wind Profiler Data." Journal of Atmospheric and Oceanic Technology 32, no. 9 (2015): 1545–61. http://dx.doi.org/10.1175/jtech-d-14-00155.1.
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AbstractAn algorithm was developed to estimate planetary boundary layer (PBL) heights from hourly archived wind profiler data from the NOAA Profiler Network (NPN) sites located throughout the central United States. Unlike previous studies, the present algorithm has been applied to a long record of publicly available wind profiler signal backscatter data. Under clear-sky conditions, summertime averaged hourly time series of PBL heights compare well with Richardson number–based estimates at the few NPN stations with hourly temperature measurements. Comparisons with estimates based on clear-sky reanalysis show that the wind profiler (WP) PBL heights are lower by approximately 250–500 m. The geographical distribution of daily maximum PBL heights corresponds well with the expected distribution based on patterns of surface temperature and soil moisture. Wind profiler PBL heights were also estimated under mostly cloudy-sky conditions, and are generally comparable to the Richardson number–based PBL heights and higher than the reanalysis PBL heights. WP PBL heights have a smaller clear–cloudy condition difference than either of the other two. The algorithm presented here is shown to provide a reliable summertime climatology of daytime hourly PBL heights throughout the central United States.
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Cook, Werner E., and J. Scott Greene. "Gridded Monthly Rainfall Estimates Derived from Historical Atoll Observations." Journal of Atmospheric and Oceanic Technology 36, no. 4 (2019): 671–87. http://dx.doi.org/10.1175/jtech-d-18-0140.1.
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AbstractTo provide an analysis tool for areal rainfall estimates, 1° gridded monthly sea level rainfall estimates have been derived from historical atoll rainfall observations contained in the Pacific Rainfall (PACRAIN) database. The PACRAIN database is a searchable repository of in situ rainfall observations initiated and maintained by the University of Oklahoma and supported by a research grant from the National Oceanic and Atmospheric Administration (NOAA)/Climate Program Office/Ocean Observing and Monitoring. The gridding algorithm employs ordinary kriging, a standard geostatistical technique, and selects for nonnegative estimates and for local estimation neighborhoods yielding minimum kriging variance. This methodology facilitates the selection of fixed-size neighborhoods from available stations beyond simply choosing the closest stations, as it accounts for dependence between estimator stations. The number of stations used for estimation is based on bias and standard error exhibited under cross estimation. A cross validation is conducted, comparing estimated and observed rains, as well as theoretical and observed standard errors for the ordinary kriging estimator. The conditional bias of the kriging estimator and the predictive value of kriging standard errors, with respect to observed standard errors, are discussed. Plots of the gridded rainfall estimates are given for sample El Niño and La Niña cases and standardized differences between the estimates produced here and the merged monthly rainfall estimates published by the Global Precipitation Climatology Project (GPCP) are shown and discussed.
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Smak, J. "Dwarf Nova Outbursts and Superoutbursts." International Astronomical Union Colloquium 158 (1996): 45–46. http://dx.doi.org/10.1017/s0252921100038185.
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Dwarf nova outbursts provide an almost unique opportunity of getting an insight into the nature of viscosity in accretion disks or, within the α- disk approach, of putting some constraints on α. In particular, the strong dependence of the viscous time-scale on viscosity itself permits us to estimate a almost directly from the observed time-scales. In the case of the hot branch of the ∑ — Te relation, the most reliable estimates (αhot) are based on the rate of decline following the dwarf nova outburst. From a comparison with model light curves calculated with different αs one gets: αhot ≈ 0.2(e.g. Smak 1984b). An independent, but much cruder, estimate can be obtained from the widths of normal outbursts, by assuming that the duration of an outburst represents the travel time of an instability wave across the disk. The result is similar: αhot ≈ 0.2 (Gicger 1987).
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Della Valle, M., and R. Claudi. "The Galactic Nova Rate." International Astronomical Union Colloquium 122 (1990): 53–54. http://dx.doi.org/10.1017/s0252921100068329.
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AbstractThe recently estabilished values of M31 and M33 nova rate, rM31 = 29 ± 4 novae yr−1 (Capaccioli et al.,1989), rM33 = 4 ± 2 novae yr−1 (Della Valle, 1988), seems to be at variance with the present estimates for the galactic nova rate, r = 260 novae yr−1 (Sharov,1972) and r = 73 ± 24 novae yr−1 (Liller and Meyer,1987), if we take into account the luminosity class and the Hubble type of the Galaxy. Assuming the nova production per unit of B–luminosity about constant for spiral galaxies and adopting the derived values of the nova rate of M31, M33 and LMC as calibrators, we estimate a galactic nova rate of rGal = 15 ± 5 novae yr−1.
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Smith, Barry D. "Comparison of Productivity Estimates for Laminaria in Nova Scotia." Canadian Journal of Fisheries and Aquatic Sciences 45, no. 3 (1988): 557–62. http://dx.doi.org/10.1139/f88-066.
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An estimate of productivity for a southwestern Nova Scotia Laminaria community was obtained using a dynamic simulation model which incorporated data on population recruitment and mortality, lamina growth and attrition, and interspecific competition for L. longicruris and L. digitata. The estimate for the total quantity of particulate material produced by this community at equilibrium is ≈6800 g∙m−2∙yr−1 (wet weight), or ≈408 g C∙m−2∙yr−1. The annual productivity to standing crop ratio (P:S) was determined to be ≈2.1:1. The productivity estimate for this community at equilibrium is considerably lower than a widely cited previous estimate for Laminaria productivity in Nova Scotia, which placed the seaweed zone amongst the most productive plant communities known. An evaluation of the methodology yielding this estimate has indicated that inaccurate estimates of population age structure and mortality have possibly resulted in a significant overestimation of particulate productivity.
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Dobrotka, A., A. Retter, L. Hric, R. Novak, O. Shemmer, and Y. Lipkin. "V1493 AQL an Extremely Distant Nova?" International Astronomical Union Colloquium 194 (2004): 236. http://dx.doi.org/10.1017/s0252921100152819.
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Analysis of CCD photometry performed during 12 nights and the estimate of the distance based on the light curve is presented. The photometric data is modulated with a period of 3.7 h, which we interpret as the orbital period above the period gap distribution of cataclysmic variables. The VSNET light curve combined with data from IAU Circulars suggests a distance of 4.5±0.4 kpc based on t2/t3 time estimates. Two spectra 11 days after the maximum were taken. The expansion velocity of the envelope was derived to be 1658±62 km s–1.
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Munda, Ivka M. "Long-term marine floristic changes around Rovinj (Istrian coast, North Adriatic) estimated on the basis of historical data from Paul Kuckuck’s field diaries from the end of the 19th century." Nova Hedwigia 71, no. 1-2 (2000): 1–36. http://dx.doi.org/10.1127/nova/71/2000/1.
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O'Brien, Brian D., Murray G. Brown, and George Kephart. "Estimation of Hospital Costs for Colorectal Cancer Care for Nova Scotia." Canadian Journal of Gastroenterology 15, no. 1 (2001): 43–47. http://dx.doi.org/10.1155/2001/975208.
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BACKGROUND: Colorectal cancer (CRC) is the second most common invasive cancer in Canada. Estimates of the costs of care allow estimation of the cost effectiveness of screening for premalignant and early disease.OBJECTIVE: To estimate, from administrative data, the hospital costs incurred by a population-based cohort of CRC cases over three years from diagnosis.DESIGN: All Nova Scotia residents with CRC who were diagnosed in 1990 were identified from the Nova Scotia Cancer Registry. These cases were linked to the administrative files of the Nova Scotia Department of Health, which contain information on diagnosis, procedures and length of stay for all admissions and day surgery visits to Nova Scotia hospitals.MEASUREMENTS: The lengths of stay and hospital-specific per diem rates were used as the measures of resource use. The costs were analyzed in terms of the extent of spread at diagnosis; the time period after diagnosis; the time period before death; and, for typical cases, the age and presence of comorbidity identified during the initial surgical admission.RESULTS: The estimated three-year hospital cost for the complete cohort of 593 cases was $9.8 million. This cost was significantly less for cases with local spread, highest in the six months around, and after diagnosis and in the final six months of life, and highest in the typical cases (patients who were older and had significant comorbid conditions).CONCLUSIONS: Hospital-specific per diem rates and lengths of stay are an approximate measure of hospital resource use.
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Rigby, M., R. G. Prinn, S. O'Doherty, et al. "Re-evaluation of the lifetimes of the major CFCs and CH<sub>3</sub>CCl<sub>3</sub> using atmospheric trends." Atmospheric Chemistry and Physics Discussions 12, no. 9 (2012): 24469–99. http://dx.doi.org/10.5194/acpd-12-24469-2012.
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Abstract. Since the Montreal Protocol on substances that deplete the ozone layer and its amendments came into effect, growth rates of the major ozone depleting substances (ODS), particularly CFC-11, -12 and -113 and CH3CCl3, have declined markedly, paving the way for global stratospheric ozone recovery. Emissions have now fallen to relatively low levels, therefore the rate at which this recovery occurs will depend largely on the atmospheric lifetime of these compounds. The first ODS measurements began in the early 1970s along with the first lifetime estimates calculated by considering their atmospheric trends. We now have global mole fraction records spanning multiple decades, prompting this lifetime re-evaluation. Using surface measurements from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the National Oceanic and Atmospheric Administration Global Monitoring Division (NOAA GMD) from 1978 to 2011, we estimated the lifetime of CFC-11, CFC-12, CFC-113 and CH3CCl3 using a multi-species inverse method. The CFC-11 lifetime of 45 yr, currently recommended in the World Meteorological Organisation (WMO) Scientific Assessment of Ozone Depletion, lies at the lower uncertainty bound of our estimates which are 524066 yr (1-sigma uncertainty) when AGAGE data were used, and 504066 yr when the NOAA network data were used. Our derived lifetime for CFC-113 is higher than the WMO estimates of 85 yr (10488123 using AGAGE, 10387122 using NOAA). Our estimates of the lifetime of CFC-12 and CH3CCl3 agree well with other recent estimates being 10885137 and 10484135 yr (CFC-12, AGAGE and NOAA, respectively) and 5.24.85.6 and 5.24.85.7 yr (CH3CCl3, AGAGE and NOAA, respectively).
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Rigby, M., R. G. Prinn, S. O'Doherty, et al. "Re-evaluation of the lifetimes of the major CFCs and CH<sub>3</sub>CCl<sub>3</sub> using atmospheric trends." Atmospheric Chemistry and Physics 13, no. 5 (2013): 2691–702. http://dx.doi.org/10.5194/acp-13-2691-2013.
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Abstract. Since the Montreal Protocol on Substances that Deplete the Ozone Layer and its amendments came into effect, growth rates of the major ozone depleting substances (ODS), particularly CFC-11, -12 and -113 and CH3CCl3, have declined markedly, paving the way for global stratospheric ozone recovery. Emissions have now fallen to relatively low levels, therefore the rate at which this recovery occurs will depend largely on the atmospheric lifetime of these compounds. The first ODS measurements began in the early 1970s along with the first lifetime estimates calculated by considering their atmospheric trends. We now have global mole fraction records spanning multiple decades, prompting this lifetime re-evaluation. Using surface measurements from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the National Oceanic and Atmospheric Administration Global Monitoring Division (NOAA GMD) from 1978 to 2011, we estimated the lifetime of CFC-11, CFC-12, CFC-113 and CH3CCl3 using a multi-species inverse method. A steady-state lifetime of 45 yr for CFC-11, currently recommended in the most recent World Meteorological Organisation (WMO) Scientific Assessments of Ozone Depletion, lies towards the lower uncertainty bound of our estimates, which are 544861 yr (1-sigma uncertainty) when AGAGE data were used and 524561 yr when the NOAA network data were used. Our derived lifetime for CFC-113 is significantly higher than the WMO estimates of 85 yr, being 10999121 (AGAGE) and 10997124 (NOAA). New estimates of the steady-state lifetimes of CFC-12 and CH3CCl3 are consistent with the current WMO recommendations, being 11195132 and 11295136 yr (CFC-12, AGAGE and NOAA respectively) and 5.044.925.20 and 5.044.875.23 yr (CH3CCl3, AGAGE and NOAA respectively).
Dissertations / Theses on the topic "Estimateur à noya"
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Tadj, Amel. "Sur les modèles non paramétriques conditionnels en statistique fonctionnelle." Toulouse 3, 2011. http://thesesups.ups-tlse.fr/1219/.
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La problématique abordée dans cette thèse est l'estimation non paramétrique des modèles conditionnels à variable explicative fonctionnelle en traitant deux cas : le cas où la variable réponse est réelle et le cas d'une variable réponse fonctionnelle. On établit la convergence uniforme presque complète d'estimateurs non paramétriques pour certains modèles conditionnels. Dans un premier temps, nous considérons une suite d'observation si. I. D. Et nous construisons des estimateurs par la méthode du noyau pour la fonction de régression généralisée, la fonction de répartition conditionnelle, la densité conditionnelle, la fonction de hasard conditionnelle et le mode conditionnel. Nous étudions la convergence uniforme presque complète de ces estimateurs en précisant leurs vitesses. A titre illustratif, nous donnons des exemples d'applications sur des données simulées. Dans un second temps, on généralise nos résultats au cas d'une variable réponse fonctionnelle (appartenant à un espace de Banach) et on estime la régression classique. Cette généralisation a été étudiée dans les deux cas : les observations i. I. D. Ainsi que le cas dépendant. Dans ce dernier, nous avons fixé comme objectif la convergence presque complète ponctuelle lorsque les observations sont Béta-mélangeantes. Nos résultats asymptotiques exploitent bien la structure topologique de l'espace fonctionnel de nos observations et le caractère fonctionnel de nos modèles. En effet, toutes nos vitesses de convergence sont quantifiées en fonction de la concentration de la mesure de probabilité de la variable fonctionnelle, de l'entropie de Kolmogorov et du degré de régularité des modèles. Notons également que dans le cas où la variable réponse est aussi fonctionnelle, nos vitesses de convergence contiennent un terme additionnel qui dépend du type de l'espace de Banach de la variable réponse<br>In this thesis, we consider the problem of the nonparametric estimation in the conditional models when the regressor takes its values in infinite dimension space. More precisely, we treated two cases when the response variable is real and functional. One establishes almost complete uniform convergence of nonparametric estimators for certain conditional models. Firstly, we consider a sequence of i. I. D. Observations. In this context, we build kernel estimators of the conditional cumulative distribution, the conditional density, the conditional hazard function and the conditional mode. We give the uniform consistency rate of these estimators. We illustrate our results by giving an application on simulated samples. Secondly, we generalize our results when the response variable is in a Banach space. We estimate the regression function. In this context, we treat both cases : i. I. D and dependent observations. In the last case, we consider that the observations are Béta-mixing and we establishes almost complete pointwise convergence. Our asymptotic results exploit the topological structure of functional space for the observations. Let us note that all the rates of convergence are based on an hypothesis of concentration of the measure of probability of the functional variable on the small balls and also on the Kolmogorov’s entropy which measures the number of the balls necessary to cover some set. Moreover, when the response variable is functional the rate of convergence contains a new term which depends on type of Banach space
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Hodara, Pierre. "Systèmes de neurones en interactions : modélisation probabiliste et estimation." Thesis, Cergy-Pontoise, 2016. http://www.theses.fr/2016CERG0854/document.
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On étudie un système de particules en interactions. Deux types de processus sont utilisés pour modéliser le système. Tout d'abord des processus de Hawkes. On propose deux modèles pour lesquels on obtient l'existence et l'unicité d'une version stationnaire, ainsi qu'une construction graphique de la mesure stationnaire à l'aide d'une décomposition de type Kalikow et d'un algorithme de simulation parfaite.Le deuxième type de processus utilisés est un processus de Markov déterministe par morceaux (PDMP). On montre l'ergodicité de ce processus et propose un estimateur à noyau pour la fonction de taux de saut possédant une vitesse de convergence optimale dans L²<br>We work on interacting particles systems. Two different types of processes are studied. A first model using Hawkes processes, for which we state existence and uniqueness of a stationnary version. We also propose a graphical construction of the stationnary measure by the mean of a Kalikow-type decomposition and a perfect simulation algorithm.The second model deals with Piecewise deterministic Markov processes (PDMP). We state ergodicity and propose a Kernel estimator for the jump rate function having an optimal speed of convergence in L²
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El, Waled Khalil. "Estimations paramétriques et non-paramétriques pour des modèles de diffusions périodiques." Thesis, Rennes 2, 2015. http://www.theses.fr/2015REN20042/document.
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Cette thèse est consacrée au problème d'estimation de la fonction de dérive de certains modèles de processus stochastiques périodiques lorsque la durée d'observation tend vers l'infini. Aucune hypothèse de récurrence n'est posée a priori.Dans un premier temps nous considérons le modèle du type signal plus bruit dζt = f (t, θ)dt + σ(t)dWt,; et puis nous étudions l'estimation du paramètre θ à partir d'une observation continue et puis d'une observation discrète du processus {ζt} sur l'intervalle [0; T]. Les fonctions f (·, ·) et σ(·) sont continues et périodiques en t de même période P > 0, σ(·) > 0 et θ ∈ Θ ⊂R. Nous établissons la convergence en probabilité d'un estimateur du maximum de vraisemblance θˆT , sa normalité asymptotique et son efficacité asymptotique minimax. Lorsque f (t, θ) = θf (t), l'expression de θˆT est explicite et nous obtenons la convergence en moyenne quadratique aussi bien pour le cas d'une observation continue que pour le cas d'une observation discrète. De plus, nous déduisons la convergence presque sûre dans le cas d'une observation continue.Dans la seconde partie nous traitons l'estimation non-paramétrique de la fonction f(_) pour les modèles périodiques du type signal plus bruit et du type Ornstein-Uhlenbeck donnés par dζt = f (t)dt + σ(t)dWt, dξt = f (t)ξtdt + dWt. Pour le premier modèle, un estimateur à noyau périodique est construit, la convergence en moyenne quadratique uniformément sur [0; P] et presque sûre de cet estimateur est établie ainsi que sa normalité asymptotique. Dans le cas du modèle d'Ornstein-Uhlenbeck, la convergence du biais ainsi que la convergence en moyenne quadratique uniformément sur [0; P] sont prouvées, et leurs vitesses de convergence sont étudiées<br>In this thesis, we consider a drift estimation problem of a certain class of stochastic periodic processes when the length of observation goes to infinity. Firstly, we deal with the linear periodic signal plus noise model dζt = f (t, θ)dt + σ(t)dWt, ;and we study the parametric estimation from a continuous and discrete observation of the process f_tg throughout the interval [0; T]. Using the maximum likelihood method we show the existence of an estimator θˆT which is consistent, asymptotically normal and asymptotically efficient in the sens minimax. When f(t; _) = _f(t), the expression of ^_T is explicit and we obtain the mean square convergence in the both continuous and discrete observation cases. In addition, we deduce the strong consistency in the case of continuous observation.Secondly, we consider the nonparametric estimation problem of the function f(_) for the next two periodic models of type signal plus noise and Ornstein-Uhlenbeckd_t = f(t)dt + _(t)dWt; d_t = f(t)_tdt + dWt:For the signal plus noise model, we build a kernel estimator, the convergence in mean square uniformly over [0; P] and almost sure convergence are established, as well as the asymptotic normality. For the Ornstein-Uhlenbeck model, we prove the convergence uniformly over [0; P] of the bias and the mean square convergence. Moreover, we study the speed of these convergences
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Lei, Liangzhen. "Grandes déviations pour les estimateurs à noyau de la densité et étude de l'estimateur de décrément aléatoire." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2005. http://tel.archives-ouvertes.fr/tel-00011959.
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Cette thèse est consacrée à l'étude de deux thèmes : les grandes déviations pour les estimateurs à noyau de la densité $f_n^*$ des processus stochastiques stationnaires et l'estimateur de décrément aléatoire (EDA) pour les processus gaussiens stationnaires.<br /><br /><br />Le premier thème est la partie principale de cette thèse, constituées des quatre premiers chapitres. Dans le chapitre 1, on établit le w*-PGD(principe de grandes déviations) de $f_n^*$ et une inégalité de concentration dans le cas i.i.d.. On démontre dans le chapitre 2 la convergence exponentielle de $f_n^*$ dans $L^1(R^d)$ et une inégalité de concentration pour des suites $\phi$-mélangeants, en se basant sur une inégalité de tranport de Rio. Les chapitre 3 et 4 constituent le coeur de cette thèse : on établit (i) le PGD de $f_n^*$ pour la topologie faible $\sigma(L^1, L^{\infty})$ ; (ii) le w*-PGD de $f_n^*$ dans $L^1$ pour la topologie forte $\vert\cdot\vert_1$ ; (iii) l'estimation de grandes déviations pour l'erreur $D_n^*=\vert f_n^*(x)-f(x) \vert_1$ et (iv) l'optimalité asymptotique de $f_n^*$ au sens de Bahadur. Ces résultats sont prouvés dans le chapitre 3 pour des processus de Markov uniformément ergodiques et dans le chapitre 4 pour des processus de Markov réversibles uniformément intégrables.<br /><br /><br />Le dernier chapitre est consacré au second thème. On démontre la loi des grands nombres et le théorème de limite centrale pour l'EDA à temps discret et on établit pour la première fois l'expression explicite du biais de l'EDA à temps continu.
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Bassene, Aladji. "Contribution à la modélisation spatiale des événements extrêmes." Thesis, Lille 3, 2016. http://www.theses.fr/2016LIL30039/document.
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Dans cette de thèse, nous nous intéressons à la modélisation non paramétrique de données extrêmes spatiales. Nos résultats sont basés sur un cadre principal de la théorie des valeurs extrêmes, permettant ainsi d’englober les lois de type Pareto. Ce cadre permet aujourd’hui d’étendre l’étude des événements extrêmes au cas spatial à condition que les propriétés asymptotiques des estimateurs étudiés vérifient les conditions classiques de la Théorie des Valeurs Extrêmes (TVE) en plus des conditions locales sur la structure des données proprement dites. Dans la littérature, il existe un vaste panorama de modèles d’estimation d’événements extrêmes adaptés aux structures des données pour lesquelles on s’intéresse. Néanmoins, dans le cas de données extrêmes spatiales, hormis les modèles max stables,il n’en existe que peu ou presque pas de modèles qui s’intéressent à l’estimation fonctionnelle de l’indice de queue ou de quantiles extrêmes. Par conséquent, nous étendons les travaux existants sur l’estimation de l’indice de queue et des quantiles dans le cadre de données indépendantes ou temporellement dépendantes. La spécificité des méthodes étudiées réside sur le fait que les résultats asymptotiques des estimateurs prennent en compte la structure de dépendance spatiale des données considérées, ce qui est loin d’être trivial. Cette thèse s’inscrit donc dans le contexte de la statistique spatiale des valeurs extrêmes. Elle y apporte trois contributions principales. • Dans la première contribution de cette thèse permettant d’appréhender l’étude de variables réelles spatiales au cadre des valeurs extrêmes, nous proposons une estimation de l’indice de queue d’une distribution à queue lourde. Notre approche repose sur l’estimateur de Hill (1975). Les propriétés asymptotiques de l’estimateur introduit sont établies lorsque le processus spatial est adéquatement approximé par un processus M−dépendant, linéaire causal ou lorsqu'il satisfait une condition de mélange fort (a-mélange). • Dans la pratique, il est souvent utile de lier la variable d’intérêt Y avec une co-variable X. Dans cette situation, l’indice de queue dépend de la valeur observée x de la co-variable X et sera appelé indice de queue conditionnelle. Dans la plupart des applications, l’indice de queue des valeurs extrêmes n’est pas l’intérêt principal et est utilisé pour estimer par exemple des quantiles extrêmes. La contribution de ce chapitre consiste à adapter l’estimateur de l’indice de queue introduit dans la première partie au cadre conditionnel et d’utiliser ce dernier afin de proposer un estimateur des quantiles conditionnels extrêmes. Nous examinons les modèles dits "à plan fixe" ou "fixed design" qui correspondent à la situation où la variable explicative est déterministe et nous utlisons l’approche de la fenêtre mobile ou "window moving approach" pour capter la co-variable. Nous étudions le comportement asymptotique des estimateurs proposés et donnons des résultats numériques basés sur des données simulées avec le logiciel "R". • Dans la troisième partie de cette thèse, nous étendons les travaux de la deuxième partie au cadre des modèles dits "à plan aléatoire" ou "random design" pour lesquels les données sont des observations spatiales d’un couple (Y,X) de variables aléatoires réelles. Pour ce dernier modèle, nous proposons un estimateur de l’indice de queue lourde en utilisant la méthode des noyaux pour capter la co-variable. Nous utilisons un estimateur de l’indice de queue conditionnelle appartenant à la famille de l’estimateur introduit par Goegebeur et al. (2014b)<br>In this thesis, we investigate nonparametric modeling of spatial extremes. Our resultsare based on the main result of the theory of extreme values, thereby encompass Paretolaws. This framework allows today to extend the study of extreme events in the spatialcase provided if the asymptotic properties of the proposed estimators satisfy the standardconditions of the Extreme Value Theory (EVT) in addition to the local conditions on thedata structure themselves. In the literature, there exists a vast panorama of extreme events models, which are adapted to the structures of the data of interest. However, in the case ofextreme spatial data, except max-stables models, little or almost no models are interestedin non-parametric estimation of the tail index and/or extreme quantiles. Therefore, weextend existing works on estimating the tail index and quantile under independent ortime-dependent data. The specificity of the methods studied resides in the fact that theasymptotic results of the proposed estimators take into account the spatial dependence structure of the relevant data, which is far from trivial. This thesis is then written in thecontext of spatial statistics of extremes. She makes three main contributions.• In the first contribution of this thesis, we propose a new approach of the estimatorof the tail index of a heavy-tailed distribution within the framework of spatial data. This approach relies on the estimator of Hill (1975). The asymptotic properties of the estimator introduced are established when the spatial process is adequately approximated by aspatial M−dependent process, spatial linear causal process or when the process satisfies a strong mixing condition.• In practice, it is often useful to link the variable of interest Y with covariate X. Inthis situation, the tail index depends on the observed value x of the covariate X and theunknown fonction (.) will be called conditional tail index. In most applications, the tailindexof an extreme value is not the main attraction, but it is used to estimate for instance extreme quantiles. The contribution of this chapter is to adapt the estimator of the tail index introduced in the first part in the conditional framework and use it to propose an estimator of conditional extreme quantiles. We examine the models called "fixed design"which corresponds to the situation where the explanatory variable is deterministic. To tackle the covariate, since it is deterministic, we use the window moving approach. Westudy the asymptotic behavior of the estimators proposed and some numerical resultsusing simulated data with the software "R".• In the third part of this thesis, we extend the work of the second part of the framemodels called "random design" for which the data are spatial observations of a pair (Y,X) of real random variables . In this last model, we propose an estimator of heavy tail-indexusing the kernel method to tackle the covariate. We use an estimator of the conditional tail index belonging to the family of the estimators introduced by Goegebeur et al. (2014b)
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Walsh, David J. "Multispectral NOAA Marine Atmospheric Boundary Layer (MABL) estimates during VOCAR." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1994. http://handle.dtic.mil/100.2/ADA283702.
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Amiri, Aboubacar. "Estimateurs fonctionnels récursifs et leurs applications à la prévision." Phd thesis, Université d'Avignon, 2010. http://tel.archives-ouvertes.fr/tel-00565221.
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Nous nous intéressons dans cette thèse aux méthodes d'estimation non paramétriques par noyaux récursifs ainsi qu'à leurs applications à la prévision. Nous introduisons dans un premier chapitre une famille d'estimateurs récursifs de la densité indexée par un paramètre ℓ ∈ [0, 1]. Leur comportement asymptotique en fonction de ℓ va nous amener à introduire des critères de comparaison basés sur les biais, variance et erreur quadratique asymptotiques. Pour ces critères, nous comparons les estimateurs entre eux et aussi comparons notre famille à l'estimateur non récursif de la densité de Parzen-Rosenblatt. Ensuite, nous définissons à partir de notre famille d'estimateurs de la densité, une famille d'estimateurs récursifs à noyau de la fonction de régression. Nous étudions ses propriétés asymptotiques en fonction du paramètre ℓ. Nous utilisons enfin les résultats obtenus sur l'estimation de la régression pour construire un prédicteur non paramétrique par noyau. Nous obtenons ainsi une famille de prédicteurs non paramétriques qui permettent de réduire considérablement le temps de calcul. Des exemples d'application sont donnés pour valider la performance de nos estimateurs
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Dion, Charlotte. "Estimation non-paramétrique de la densité de variables aléatoires cachées." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAM031/document.
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Cette thèse comporte plusieurs procédures d'estimation non-paramétrique de densité de probabilité.Dans chaque cas les variables d'intérêt ne sont pas observées directement, ce qui est une difficulté majeure.La première partie traite un modèle linéaire mixte où des observations répétées sont disponibles.La deuxième partie s'intéresse aux modèles d'équations différentielles stochastiques à effets aléatoires. Plusieurs trajectoires sont observées en temps continu sur un intervalle de temps commun.La troisième partie se place dans un contexte de bruit multiplicatif.Les différentes parties de cette thèse sont reliées par un contexte commun de problème inverse et par une problématique commune: l'estimation de la densité d'une variable cachée. Dans les deux premières parties la densité d'un ou plusieurs effets aléatoires est estimée. Dans la troisième partie il s'agit de reconstruire la densité de la variable d'origine à partir d'observations bruitées.Différentes méthodes d'estimation globale sont utilisées pour construire des estimateurs performants: estimateurs à noyau, estimateurs par projection ou estimateurs construits par déconvolution.La sélection de paramètres mène à des estimateurs adaptatifs et les risques quadratiques intégrés sont majorés grâce à une inégalité de concentration de Talagrand. Une étude sur simulations de chaque estimateur illustre leurs performances. Un jeu de données neuronales est étudié grâce aux procédures mises en place pour les équations différentielles stochastiques<br>This thesis contains several nonparametric estimation procedures of a probability density function.In each case, the main difficulty lies in the fact that the variables of interest are not directly observed.The first part deals with a mixed linear model for which repeated observations are available.The second part focuses on stochastic differential equations with random effects. Many trajectories are observed continuously on the same time interval.The third part is in a full multiplicative noise framework.The parts of the thesis are connected by the same context of inverse problems and by a common problematic: the estimation of the density function of a hidden variable.In the first two parts the density of one or two random effects is estimated. In the third part the goal is to rebuild the density of the original variable from the noisy observations.Different global methods are used and lead to well competitive estimators: kernel estimators, projection estimators or estimators built from deconvolution.Parameter selection gives adaptive estimators and the integrated risks are bounded using a Talagrand concentration inequality.A simulation study for each proposed estimator highlights their performances.A neuronal dataset is investigated with the new procedures for stochastic differential equations developed in this work
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Kabthimer, Getahun Tadesse. "Assessment of spatio-temporal patterns of NDVI in response to precipitation using NOAA-AVHRR rainfall estimate and NDVI data from 1996-2008, Ethiopia." Thesis, Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-78770.
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The role of remote sensing data for monitoring different parameters in the study of ecosystems has been increasing. Particularly the development of different indices has played a great role to study the properties of vegetation and vegetation dynamics in large countries. In addition to this, satellite rainfall estimate data has been used to study the pattern of precipitation in areas where station rain-gauge data is not available. The Normalized Difference Vegetation Index (NDVI) and rainfall estimates data from the National Oceanic and Atmospheric Administration (NOAA) satellites were used to investigate the spatio-tempotal pattern of precipitation and the response of vegetation to precipitation in Ethiopia from 1996 to 2008. The patterns were studied in different land cover classes using data from the Global Land Cover Network (GLCN). The spatial patternof NDVI and precipitation showed that vegetation responded directly to precipitation. The seasonal patterns showed that there was between 0 to 3 months lag between precipitationand vegetation. However it was not possible to draw conclusion regarding the annual trendsof precipitation and NDVI because of the nature of the NDVI data, which was produced using the 10 day maximum composite values.
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Debbarh, Mohammed. "Quelques propriétés asymptotiques dans les modèles additifs de régression." Paris 6, 2006. http://www.theses.fr/2006PA066020.
Full textBooks on the topic "Estimateur à noya"
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Walsh, David J. Multispectral NOAA Marine Atmospheric Boundary Layer (MABL) estimates during VOCAR. Naval Postgraduate School, 1994.
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author, Rajbhandari Rupak, Bajracharya Sagar R. author, and International Centre for Integrated Mountain Development, eds. Validation of NOAA CPC_RFE satellite-based rainfall estimates in the Central Himalayas. International Centre for Integrated Mountain Development, 2013.
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United States. Congress. House. Committee on Merchant Marine and Fisheries. NOAA Fleet Modernization Act: Report (to accompany H.R. 5324) (including cost estimate of the Congressional Budget Office). U.S. G.P.O., 1992.
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United States. Congress. House. Committee on Merchant Marine and Fisheries. NOAA Fleet Modernization Act: Report (to accompany H.R. 5324) (including cost estimate of the Congressional Budget Office). U.S. G.P.O., 1992.
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United States. Congress. House. Committee on Merchant Marine and Fisheries. NOAA Fleet Modernization Act: Report (to accompany H.R. 5324) (including cost estimate of the Congressional Budget Office). U.S. G.P.O., 1992.
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Resources, United States Congress House Committee on. Conveyance of NOAA vessel Whiting: Report (to accompany H.R. 4158) (including cost estimate of the Congressional Budget Office). U.S. G.P.O., 2004.
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Conveyance of a NOAA vessel to Utrok Atoll: Report (to accompany H.R. 2584) (including cost estimate of the Congressional Budget Office). U.S. G.P.O., 2003.
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Availability of NOAA real property on Virginia Key, Florida: Report (to accompany H.R. 4027) (including cost estimate of the Congressional Budget Office). U.S. G.P.O., 2004.
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Treasury, HM. Estimates of the civil establishments abroad: Viz. (1.) Bahamas, Islands, in America (2.) Bermuda or Somers Islands (3.) Dominica (4.) Province of Upper Canada, in America (5.) Province of Nova Scotia (6.) Province of New Brunswick (7.) Island of Cape Breton (8.) Island of St. John, now called Prince Edward Island (9.) Island of Newfoundland (10.) Settlement of Sierra Leone (11.) Civil establishment of New South Wales (12.) Amount of bills drawn or to be drawn from New South Wales, in 1811, for the year 1811. s.n., 2005.
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D, DeMaster, and United States. National Marine Fisheries Service., eds. Recommendations to NOAA fisheries: ESA listing criteria by the quantitative working group 10 June 2004. U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, 2004.
Find full textBook chapters on the topic "Estimateur à noya"
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Seguin, Bernard. "The Use of AVHRR-Derived Land Surface Temparature Estimates for Agricultural Monitoring." In Advances in the Use of NOAA AVHRR Data for Land Applications. Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-0203-9_15.
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"Benthic Habitats and the Effects of Fishing." In Benthic Habitats and the Effects of Fishing, edited by K. A. Madley. American Fisheries Society, 2005. http://dx.doi.org/10.47886/9781888569605.ch29.
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A standard, benthic habitat classification system for Florida does not exist. Over fourteen different classification systems have been used with Florida mapping projects to date. This is problematic for efforts to compile statewide habitat area estimates, produce habitat maps for the entire state, or compare habitats across regions. Implementation of a standardized classification system will be a large step toward more reliable characterization of Florida seafloor habitats. The Florida Marine Research Institute has studied the classification systems used throughout Florida and the tropics and subtropics as well as successful efforts in terrestrial habitat characterization. The goal has been to combine appropriate components of a variety of systems to form a hierarchical classification system to propose as a strawman for further testing in Florida. We have formed this scheme with guidance from the Allee et al. 2000 NOAA Technical Memorandum for the purpose of creating a habitat characterization system compatible with the forthcoming national classification system. The Gulf of Mexico program has interest in eventually expanding the Florida classification system to encompass habitats for all of the Gulf states. The goal would then be to coordinate adoption of this classification system to be used by all mapping agencies involved with Gulf of Mexico habitat classification. This would enhance fishery habitat comparisons among Gulf states thus assisting fishery and habitat resource managers.
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Huenneke, Laura F., and William H. Schlesinger. "Patterns of Net Primary Production in Chihuahuan Desert Ecosystems." In Structure and Function of a Chihuahuan Desert Ecosystem. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195117769.003.0015.
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The Jornada Basin of southern New Mexico has long been an important location for the study of productivity in desert ecosystems. Researchers have studied the magnitude and sustainability of plant production since the founding of the USDA Jornada Experimental Range (JER) in 1912. The consistent administration and research focus of the JER and of the Chihuahuan Desert Rangeland Research Center (CDRRC) have facilitated a number of long-term studies of vegetation dynamics and productivity. These long-term data sets are especially critical for understanding arid ecosystems, where interannual and decadal scale variation in climate is great and plant performance is strongly constrained by the physical environment. Long-term data, including the net primary productivity (NPP) data that are the focus of this chapter, are also essential for understanding the progression or rather, degradation of ecosystem structure that has been called desertification. Through the years a variety of approaches have been used to evaluate plant production in the Jornada Basin. These approaches span the range from applied or management-oriented techniques, focused primarily on assessing patterns of palatable forage production, to more basic empirical studies based on dimension analysis or similar measurements of plant growth, to estimates based on photosynthetic measurements, to remote sensing and modeling approaches. NPP was a particular focus of the work performed during the International Biological Programme or IBP (1970s) and is still a major emphasis in the Long-Term Ecological Research (LTER) era. Thus, the Jornada provides a unique opportunity to compare the strengths and weaknesses of different approaches applied to a complex system. Ecosystem science has provided a set of general hypotheses about the factors regulating NPP in arid and semiarid ecosystems (reviewed by Noy-Meir 1973; Hadley and Szarek 1981; Ludwig 1986, 1987). These premises include the following: 1. Plant productivity is low relative to that of other ecosystems (Lieth 1975). 2. NPP is regulated primarily by localized water availability and hence should be correlated closely with precipitation (Le Houerou 1984; Le Houerou et al. 1988). This premise is related to Noy-Meir’s (1973) definition of deserts as “water-controlled ecosystems with infrequent, discrete, and largely unpredictable water inputs.”
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Schmidt, Steven K., and Ann E. West. "Soil-Atmosphere Gas Exchange." In Structure and Function of an Alpine Ecosystem. Oxford University Press, 2001. http://dx.doi.org/10.1093/oso/9780195117288.003.0020.
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The alpine, while not extensive in global area, has several advantages for trace gas research, particularly the spatial landscape heterogeneity in soil types and plant communities. This variation can be viewed as a “natural experiment,” allowing field measurements under extremes of moisture and temperature. While the atmospheric carbon dioxide (CO2) record at Niwot Ridge extends back to 1968 (chapter 3), and NOAA has done extensive measurements on atmospheric chemistry at the subalpine climate station (e.g., Conway et al. 1994), work on tundra soil-atmosphere interactions were not initiated until recently. In 1992, studies were begun on Niwot Ridge to gain a comprehensive understanding of trace gas fluxes from alpine soils. Our sampling regime was designed to capture the spatial and temporal patterns of trace gas fluxes in the alpine. In addition, we coupled our studies of trace gas fluxes with ongoing studies of nitrogen cycling on Niwot Ridge (Fisk and Schmidt 1995,1996; Fisk et al. 1998; chapter 12). Methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) were studied because of their role in global environmental change and because they could be easily monitored at our remote sites. On a per-molecule basis, CH4 and N2O are much more potent as greenhouse gases than CO2 is (Lashof and Ahuja 1990; Rodhe 1990). In addition, N2O plays a role in ozone depletion in the stratosphere. The global CH4 and N2O budgets are still poorly understood and the relative importance of soils in these budgets is even less clear. For example, estimates of the global soil sink for CH4 range from 9.0 to 55.9 Tg per year (Dörr et al. 1993). This range is large compared with the approximately 30 Tg of excess CH4 that is accumulating in the atmosphere every year. To better assess the role of soil in trace gas budgets, our work focused on investigating landscape patterns of gas fluxes (CH4, N2O, and CO2) and environmental controls on these fluxes.
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Elsner, James B., and Thomas H. Jagger. "Data Sets." In Hurricane Climatology. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199827633.003.0009.
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Hurricane data originate from careful analysis of past storms by operational meteorologists. The data include estimates of the hurricane position and intensity at 6-hourly intervals. Information related to landfall time, local wind speeds, damages, and deaths, as well as cyclone size, are included. The data are archived by season. Some effort is needed to make the data useful for hurricane climate studies. In this chapter, we describe the data sets used throughout this book. We show you a work flow that includes importing, interpolating, smoothing, and adding attributes. We also show you how to create subsets of the data. Code in this chapter is more complicated and it can take longer to run. You can skip this material on first reading and continue with model building in Chapter 7. You can return here when you have an updated version of the data that includes the most recent years. Most statistical models in this book use the best-track data. Here we describe these data and provide original source material. We also explain how to smooth and interpolate them. Interpolations are needed for regional hurricane analyses. The best-track data set contains the 6-hourly center locations and intensities of all known tropical cyclones across the North Atlantic basin, including the Gulf of Mexico and Caribbean Sea. The data set is called HURDAT for HURricane DATa. It is maintained by the U.S. National Oceanic and Atmospheric Administration (NOAA) at the National Hurricane Center (NHC). Center locations are given in geographic coordinates (in tenths of degrees) and the intensities, representing the one-minute near-surface (∼10 m) wind speeds, are given in knots (1 kt = .5144 m s−1) and the minimum central pressures are given in millibars (1 mb = 1 hPa). The data are provided in 6-hourly intervals starting at 00 UTC (Universal Time Coordinate). The version of HURDAT file used here contains cyclones over the period 1851 through 2010 inclusive. Information on the history and origin of these data is found in Jarvinen et al (1984). The file has a logical structure that makes it easy to read with a FORTRAN program. Each cyclone contains a header record, a series of data records, and a trailer record.
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Agterberg, F. P., and G. F. Bonharn-Carter. "Weights Of Evidence Modeling And Weighted Logistic Regression For Mineral Potential Mapping." In Computers in Geology - 25 Years of Progress. Oxford University Press, 1994. http://dx.doi.org/10.1093/oso/9780195085938.003.0007.
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During the past few years, we have developed a method of weights of evidence modeling for mineral potential mapping (cf. Agterberg, 1989; Bonham- Carter et al., 1990). In this paper, weights of evidence modeling and logistic regression are applied to occurrences of hydrothermal vents on the ocean floor, East Pacific Rise near 21° N. For comparison, logistic regression is also applied to occurrences of gold deposits in Meguma Terrane, Nova Scotia. The volcanic, tectonic, and hydrothermal processes along the central axis of the East Pacific Rise at 21° N were originally studied by Ballard et al. (1981). Their maps were previously taken as the starting point for a pilot project on estimation of the probability of occurrence of polymetallic massive sulfide deposits on the ocean floor (Agterberg and Franklin, 1987). In the earlier work, presence or absence of deposits in relatively large square cells was related to explanatory variables quantified for small square cells (pixels) by means of stepwise multiple regression and logistic regression. In this paper, weights of evidence modeling and weighted logistic regression are applied to the same maps but a geographic information system (Intera- TYDAC SPANS, 1991) was used to create polygons for combinations of maps. These polygons can be classified taking the different classes from each map. Probabilities estimated for the resulting "unique conditions" can be classified and displayed. The vents are correlated with only a few patterns and it is relatively easy to interpret the weights and final probability maps in terms of the underlying volcanic, tectonic, and hydrothermal processes. The vents are situated along the central axis of the rise together with the youngest volcanics. They occur at approximately the same depth below sea level, tend to be associated with pillow flows rather than sheet flows, and with absence of fissures which are more prominent in older volcanics. Contrary to weights of evidence modeling, weighted logistic regression (cf. Agterberg, 1992, for discussion of algorithm) can be applied when the explanatory variables are not conditionally independent. This method was previously applied by Reddy et al. (1991) to volcanogenic massive sulfide deposits in the Snow Lake area of Manitoba.
Conference papers on the topic "Estimateur à noya"
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Bonnin, Geoffrey M., Sanja Perica, Deborah Martin, et al. "Updated NOAA Precipitation Frequency Estimates for Hawaii." In World Environmental and Water Resources Congress 2008. American Society of Civil Engineers, 2008. http://dx.doi.org/10.1061/40976(316)586.
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Tian, Xiaoxu, Xiaolei Zou, and N. Sun. "Comparison of RO-Estimated ATMS Biases Between NOAA-20 and S-NPP." In IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium. IEEE, 2018. http://dx.doi.org/10.1109/igarss.2018.8519416.
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Odeyemi, Kehinde O., and Pius A. Owolawi. "Performance Analysis of Cooperative NOMA with Partial Relay Selection under Outdated Channel Estimate." In 2019 IEEE 2nd Wireless Africa Conference (WAC). IEEE, 2019. http://dx.doi.org/10.1109/africa.2019.8843391.
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Nawaz, Syed Junaid, Babar Mansoor, Mohammad N. Patwary, and Mak Sharma. "An Iterative Massive-MIMO NOMA Receiver with Superimposed Pilots based Estimator for Sparse Channels." In 2019 15th International Wireless Communications and Mobile Computing Conference (IWCMC). IEEE, 2019. http://dx.doi.org/10.1109/iwcmc.2019.8766518.
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Ito, Eriko, Makoto Araki, Akihiro Tani, et al. "Leaf-shedding phenology in tropical seasonal forests of Cambodia estimated from NOAA satellite images." In 2007 IEEE International Geoscience and Remote Sensing Symposium. IEEE, 2007. http://dx.doi.org/10.1109/igarss.2007.4423810.
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Li, Xiang, Sundar A. Christopher, Jianglong Zhang, Joyce Chou, and Ronald M. Welch. "Aerosol single-scattering albedo estimated from NOAA-14 AVHRR measurements: case studies over Brazil." In SPIE's International Symposium on Optical Science, Engineering, and Instrumentation, edited by Allen M. Larar. SPIE, 1999. http://dx.doi.org/10.1117/12.366393.
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Sykora, Jan. "Non-Pilot-Aided Phase Estimator for 2-Source BPSK NOMA Channel with Closed-Form Solver." In 2019 22nd International Symposium on Wireless Personal Multimedia Communications (WPMC). IEEE, 2019. http://dx.doi.org/10.1109/wpmc48795.2019.9096099.
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O’Neil, G. D., G. R. Simmonds, D. A. Grivas, and B. C. Schultz. "Rainfall-Ground Movement Modeling for Natural Gas Pipelines Through Landslide Terrain." In 1996 1st International Pipeline Conference. American Society of Mechanical Engineers, 1996. http://dx.doi.org/10.1115/ipc1996-1945.
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Perhaps the greatest challenge to geotechnical engineers is to maintain the integrity of pipelines at river crossings where landslide terrain dominates the approach slopes. The current design process at NOVA Gas Transmission Ltd. (NGTL) has developed to the point where this impact can be reasonably estimated using in-house models of pipeline-soil interaction. To date, there has been no method to estimate ground movements within unexplored slopes at the outset of the design process. To address this problem, rainfall and slope instrumentation data have been processed to derive rainfall-ground movement relationships. Early results indicate that the ground movements exhibit two components: a steady, small rate of movement independent of the rainfall, and; increased rates over short periods of time following heavy amounts of rainfall. Evidence exists of a definite threshold value of rainfall which has to be exceeded before any incremental movement is induced. Additional evidence indicates a one-month lag between rainfall and ground movement. While these models are in the preliminary stage, results indicate a potential to estimate ground movements for both initial design and planned maintenance actions.
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Simos, Alexandre N., Eduardo A. Tannuri, José J. da Cruz, Asdrubal N. Queiroz Filho, Iuri B. da Silva Bispo, and Rafaella C. A. Carvalho. "Development of an On-Board Wave Estimation System Based on the Motions of a Moored FPSO: Commissioning and Preliminary Validation." In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83729.
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This paper addresses the development, installation and initial tests of a system for wave spectra estimation from the measurements of the first order motions of a moored FPSO located in Campos Basin, Brazil. The estimation is based on Bayesian inference algorithms, previously validated by means of numerical and small-scale experimental analysis. A 6-dof inertial measurement unit (IMU) is used for monitoring the motions of the platform, and this information is sent to a remote data-base, also accessed by the wave-estimation system. The algorithm also requires the Response Amplitude Operators (RAOs), and they depend on the loading conditions of the FPSO. A previous analysis considering typical loading configurations of the tanks showed that the wave estimation is mainly dependent on the total displacement of the vessel, and not on the load distribution among the tanks. Hence, the RAOs for the full-range of drafts (or total displacements) were numerically generated, considering a uniform distribution of the load among the tanks. Since the draft of the platform was not directly measured, the loading levels of the tanks are obtained from the automation system of the platform, and the draft is then estimated. Finally, the heading is measured by a gyrocompass, and it is necessary for the definition of the global wave direction. The Bayesian estimation is executed at time-spans of 30min. A parametric optimization algorithm is then applied for the calculation of the wave spectrum parameters from the raw-spectrum obtained by the Bayesian estimation. A user-friendly interface was also developed, with on-line information about platform motions, estimated wave spectrum, peak statistics and data history. Since all information is accessed by network, the wave system can be installed either on-board or in the on-shore monitoring center. The system was commissioned and a partial 3-month validation campaign was executed. The spectrum results were compared to NOAA estimates. As expected, low-period wave components (smaller than 8s) could not be estimated with accuracy, since the FPSO presents small motion response for these components. Swell and high-period wave components estimates presented good qualitative and quantitative agreement with satellite prediction.
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Wang, Lianxi, Xiaoyu Zhang, and Xiaoguang Chen. "Applications of NOAA weather satellite data to the estimates of topographic height and retrieval of soil moisture in Ningxia." In Third International Asia-Pacific Environmental Remote Sensing Remote Sensing of the Atmosphere, Ocean, Environment, and Space, edited by Xiaoling Pan, Wei Gao, Michael H. Glantz, and Yoshiaki Honda. SPIE, 2003. http://dx.doi.org/10.1117/12.466522.
Full textReports on the topic "Estimateur à noya"
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Plueddemann, Albert, Benjamin Pietro, and Emerson Hasbrouck. The Northwest Tropical Atlantic Station (NTAS): NTAS-19 Mooring Turnaround Cruise Report Cruise On Board RV Ronald H. Brown October 14 - November 1, 2020. Woods Hole Oceanographic Institution, 2021. http://dx.doi.org/10.1575/1912/27012.
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The Northwest Tropical Atlantic Station (NTAS) was established to address the need for accurate air-sea flux estimates and upper ocean measurements in a region with strong sea surface temperature anomalies and the likelihood of significant local air–sea interaction on interannual to decadal timescales. The approach is to maintain a surface mooring outfitted for meteorological and oceanographic measurements at a site near 15°N, 51°W by successive mooring turnarounds. These observations will be used to investigate air–sea interaction processes related to climate variability. This report documents recovery of the NTAS-18 mooring and deployment of the NTAS-19 mooring at the same site. Both moorings used Surlyn foam buoys as the surface element. These buoys were outfitted with two Air–Sea Interaction Meteorology (ASIMET) systems. Each system measures, records, and transmits via Argos satellite the surface meteorological variables necessary to compute air–sea fluxes of heat, moisture and momentum. The upper 160 m of the mooring line were outfitted with oceanographic sensors for the measurement of temperature, salinity and velocity. Deep ocean temperature and salinity are measured at approximately 38 m above the bottom. The mooring turnaround was done on the National Oceanic and Atmospheric Administration (NOAA) Ship Ronald H. Brown, Cruise RB-20-06, by the Upper Ocean Processes Group of the Woods Hole Oceanographic Institution. The cruise took place between 14 October and 1 November 2020. The NTAS-19 mooring was deployed on 22 October, with an anchor position of about 14° 49.48° N, 51° 00.96° W in 4985 m of water. A 31-hour intercomparison period followed, during which satellite telemetry data from the NTAS-19 buoy and the ship’s meteorological sensors were monitored. The NTAS-18 buoy, which had gone adrift on 28 April 2020, was recovered on 20 October near 13° 41.96° N, 58° 38.67° W. This report describes these operations, as well as other work done on the cruise and some of the pre-cruise buoy preparations.