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Seasonality, Climate Cycles and Body Size Evolution

T. A. Troost, J. A. van Dam, B. W. Kooi, E. Tuenter (2009)

Mathematical Modelling of Natural Phenomena

The seasonality hypothesis states that climates characterized by large annual cycles select for large body sizes. In order to study the effects of seasonality on the evolution of body size, we use a model that is based on physiological rules and first principles. At the ecological time scale, our model results show that both larger productivity and seasonality may lead to larger body sizes. Our model is the first dynamic and process-based model to support the seasonality hypothesis and hence...

Some generalizations in the mathematical developments of the theory of the geodetic overdetermined problems.

F. Sacerdote, F. Sansò (1990)

Revista Matemática de la Universidad Complutense de Madrid

Two particular cases of the overdetermined gravimetry-gradiometry problem are discussed: (i) the case of a latitude-dependant statistical weight for gradiometric data, corresponding to a data distribution coming from satellite polar orbits, (ii) the case of a volume distribution, instead of a surface distribution, for satellite gradiometric data. In both cases a discussion of numerical methods for solving the problem with realistic data is started; for case (i), an analytic solution is found under...

Some properties of forced, dissipative large-scale circulations in a barotropic, non-divergent rotating atmosphere

Laura Gardini, Renzo Lupini, Carlo Pellacani (1983)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

Viene studiata la stabilità dell’atmosfera in un pianeta ruotante, forzata da un agente esterno ed in presenza di dissipazione. Lo studio vien condotto nelle ipotesi barotropiche e riguarda, per l’effetto delle approssimazioni adottate, solamente quei fenomeni caratterizzati da grandi scale spaziali. In particolare viene studiata la stabilità dei flussi zonali che caratterizzano la circolazione dei maggiori pianeti del sistema solare; ne vengono determinate, servendosi della approssimazione di Galerkin,...

Stability and contagion measures for spatial extreme value analyzes

Cecília Fonseca, Helena Ferreira, Luísa Pereira, Ana Paula Martins (2014)

Kybernetika

As part of global climate change an accelerated hydrologic cycle (including an increase in heavy precipitation) is anticipated (Trenberth [20, 21]). So, it is of great importance to be able to quantify high-impact hydrologic relationships, for example, the impact that an extreme precipitation (or temperature) in a location has on a surrounding region. Building on the Multivariate Extreme Value Theory we propose a contagion index and a stability index. The contagion index makes it possible to quantify...

Survival analysis on data streams: Analyzing temporal events in dynamically changing environments

Ammar Shaker, Eyke Hüllermeier (2014)

International Journal of Applied Mathematics and Computer Science

In this paper, we introduce a method for survival analysis on data streams. Survival analysis (also known as event history analysis) is an established statistical method for the study of temporal “events” or, more specifically, questions regarding the temporal distribution of the occurrence of events and their dependence on covariates of the data sources. To make this method applicable in the setting of data streams, we propose an adaptive variant of a model that is closely related to the well-known...

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