Estimation adaptative d'une fonction de transfert à deux termes avec erreurs sur les entrées

On établit un algorithme adaptatif d'estimation d'une fonction de transfert à deux termes lorsque les entrées comportent des erreurs, cas présumé fréquent sur des pluies servant à calculer un débit. On développe pour cela les dérivées des paramètres par rapport aux fonctions d'autocorrélation et d'autocorrélation croisée des variables. L'estimateur est testé par une méthode de Monte Carlo contre une régression multiple récursive, lorsque le vrai modèle est l'un ou l'autre. On montre sur un exemple que l'erreur d'hypothèse de modélisation des erreurs augmente le risque de mauvaise prévision sans trop affecter la qualité moyenne des résultats. (Résumé d'auteur

Introduction

This introduction to Lawrence's three books on Italy - Twilight in Italy, Sea and Sardinia and Etruscan Places - seeks to explain the importance of Italy in the development of Lawrence's themes and style, in particular his obsession with confronting worlds that were new to them and overcoming his fear of whatever at first seemed alien. Considering the different moments of his career in which the three books were written the piece shows how they are emblematic of the styles of those periods and how each connects to the other as Lawrence finally identifies in death both the ultimate 'exoticism' the last fear to overcome. In particular, the essay seeks to show how the need to step outside convention in order to adopt a proper response to 'the other' is reflected in a non-conventional use of of English

Aggregate and fractal tessellations

Consider a sequence of stationary tessellations {‹n}, n=0,1,..., of  d consisting of cells {Cn(xin)}with the nuclei {xin}. An aggregate cell of level one, C01(xi0), is the result of merging the cells of ‹1 whose nuclei lie in C0(xi0). An aggregate tessellation ‹0n consists of the aggregate cells of level n, C0n(xi0), defined recursively by merging those cells of ‹n whose nuclei lie in Cnm1(xi0). We find an expression for the probability for a point to belong to atypical aggregate cell, and obtain bounds for the rate of itsexpansion. We give necessary conditions for the limittessellation to exist as nMX and provide upperbounds for the Hausdorff dimension of its fractal boundary and forthe spherical contact distribution function in the case ofPoisson-Voronoi tessellations {‹n}

Strategic behavior and efficiency in a groundwater pumping differential game

In this paper socially optimal and private exploitation of a common property aquifer are compared. Open-loop and feedback equilibria in nonlinear strategies have been computed to characterize the private solution. The use of these two equilibrium concepts aIlows us to distinguish between cost and strategic externalities. The open-Loop solution captures only the cost externality, whereas the feedback solution captures both externalities. The results show that strategic behavior increases the overexploitation of the aquifer compared to the open-loop solution. However, if the groundwater storage capacity is large, the difference between the socIally optImal and private exploitation, characterized by a feedback equilibrium, is negligible and can be ignored for practical purposes. En este trabajo se comparan la explotación privada y socialmente óptima de un acuífero de propiedad común. Para caracterizar la solución privada se han calculado los equilibrios' openloop' y 'feedback' en estrategias no lineales. El uso de estos dos conceptos de equilibrio nos ha permitido distinguir entre efectos externos estratégicos y de coste. La solución 'open-loop' captura solamente el efecto externo de los costes mientras que la SolucIón 'feedback' captura ambos efectos externos. Los resultados muestran que el comportamiento estratégico aumenta la sobreexplotación del acuífero comparado con la solución 'open-loop' o Sin embargo, si la capacidad de almacenamiento del acuífero es grande, la diferencia entre la explotación privada y la socialmente óptima, caracterizada por un equilibrio 'feedback', es despreciable y puede Ignorarse para propósitos prácticos.Explotación de aguas subterráneas, recursos de propiedad común, efecto externo estratégico, juegos diferenciales, solución 'feedback', estrategias no lineales Groundwater exploitation, common property resources, strategic externality, differential games, feedback solution, nonlinear strategies

Mechanism of proton exchange: guided ion beam studies of the reactions, H(H2O)n+ (n=1-4) + D2O and D(D 2O)n+ (n=1-4) + H2O

Journal ArticleReactions of protonated water clusters, H(H2O)n+ (n=1-4) with D2O and their "mirror" reactions, D(D2O)n+ (n=1-4) with H2O, are are studied using guided-ion beam mass spectrometry. Absolute reaction cross sections are determined as a function of collision energy from thermal energy to over 10 eV

Stochastic Methods for Sequential Data Assimilation in Strongly Nonlinear Systems

This paper considers several filtering methods of stochastic nature based on Monte-Carlo drawings, in view of the sequential data assimilation in non linear models. They include some known methods such as the particle filter and the ensemble Kalman filters and some other introduced by us: the second order particle filters and the singular evolutive interpolated filter. The aim is to study their behaviour in the simple non linear chaotic Lorenz system, in the hope of getting some insight on more complex models. It is seen that these filters perform satisfactory but our filters have the clear advantage in term of cost. This is achieved through the concept of second order exact drawing and the selective error correction parallel to the tangent space of the attractor of the system (which is of low dimension- ). We have also introduced the use of the forgetting factor, which could enhance significantly the filter stability in this nonlinear context

Fahrtbericht der "Poseidon"-Reise 111/3 [POS111/3] vom 26.8. - 23.9.84

Der dritte und letzte Abschnitt der "Poseidon"-Reise 111 fand, wie die ersten beiden Abschnitte, im Nordatlantik statt. Es wurden Schnitte mit dem "Sea-Rover-System" zwischen den Azoren, Neufundland und den Britischen Inseln gefahren, siehe Abbildung 1.1 und Tabelle 1. Während dieser Reise wurden mittels des Schleppfisches Temperatur, Salzgehalt, die abwärtsgerichte Strahlung und auch die Fluoreszenz gemessen. Strömungen an der Oberfläche und in der Tiefe wurden mit dem EM-Log und mit dem Doppler-Stromprofiler gemessen. Es war ursprünglich geplant, den Schnitt von St. John' s nach Europa über OWS 'L' und Fair Isle zu führen. Da aber das Wetter in diesem Gebiet sich sehr verschlechterte, mußte der Schnitt über 25°W, 49° N und Scilly gefahren werden

PENETAPAN KADAR CAMPURAN PARASETAMOL DAN KOFEIN DALAM SEDIAAN TABLET YANG BEREDAR DENGAN METODA SPEKTROFOTOMETRI UV MULTIKOMPONEN

Telah dilakukan penelitian tentang penetapan kadar campuran parasetamol dan kofein dalam sediaan tablet yang beredar dengan metoda spektrofotometri UV multikomponen. Spektrum dari kedua zat ini saling tumpang tindih satu sama lain sehingga dapat diukur dalam bentuk campuran dengan mengeliminasi dua persamaan. Penelitian dilakukan dengan mengukur kadar zat dalam tablet, kemudian dilanjutkan dengan validasi metoda dimana pada tablet ditambahkan bahan baku tiap-tiap zat. Penambahan bahan baku dilakukan terhadap tiga konsentrasi, yaitu 80%, 100%, dan 120%

Angiotensin II: A Potential Link Between Inflammation and Hypertension in SLE

The disease Systemic Lupus Erythematosus is a chronic inflammatory, autoimmune disorder that primarily affects women during their reproductive years. Women with SLE are at a greater risk of developing hypertension, which increases their risk of mortality from a cardiac related event. A proposed mechanism for SLE hypertension suggests that inflammation in the kidneys causes renal dysfunction, presumably resulting in less water excretion, increased plasma volume, and thus high blood pressure. This experiment tests the hypothesis that the T-cells from a mouse model of SLE hyper secrete the inflammatory cytokines IL-17, IL-10, and IFN- y, and are more sensitive to the cytokine-stimulating hormone angiotensin II (ANGII). To test this hypothesis, T lymphocytes were isolated from control and SLE mice, and cytokine secretion into the culture media was determined in the presence or absence of ANG II. Thymocytes from SLE mice secreted greater levels of all three inflammatory cytokines, although excess IL-17 secretion occurred only after the onset of renal damage. Angiotensin II increased production of IFN- y, but there was no major difference between the SLE and Control groups. These results indicate that hyper secretion of IL-17, IL-10, and IFN- y by SLE T-cells may be contributing to renal inflammation, kidney damage, and therefore SLE hypertension. T-cell hypersensitivity to ANG II could not account for the hypertension, suggesting that these cells are excessively sensitive to another factor (that is present in the culture media) or have an innately higher secretion rate

Boletín oficial de la provincia de León: Boletín oficial de la provincia de León: Número 135 - 1952 junio 16 (16/06/1952)

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2011-201