Multilevel Methods for Uncertainty Quantification of Elliptic PDEs with Random Anisotropic Diffusion

We consider elliptic diffusion problems with a random anisotropic diffusion coefficient, where, in a notable direction given by a random vector field, the diffusion strength differs from the diffusion strength perpendicular to this notable direction. The Karhunen-Lo\`eve expansion then yields a parametrisation of the random vector field and, therefore, also of the solution of the elliptic diffusion problem. We show that, given regularity of the elliptic diffusion problem, the decay of the Karhunen-Lo\`eve expansion entirely determines the regularity of the solution's dependence on the random parameter, also when considering this higher spatial regularity. This result then implies that multilevel collocation and multilevel quadrature methods may be used to lessen the computation complexity when approximating quantities of interest, like the solution's mean or its second moment, while still yielding the expected rates of convergence. Numerical examples in three spatial dimensions are provided to validate the presented theory

Multilevel quadrature for elliptic problems on random domains by the coupling of FEM and BEM

Elliptic boundary value problems which are posed on a random domain can be mapped to a fixed, nominal domain. The randomness is thus transferred to the diffusion matrix and the loading. While this domain mapping method is quite efficient for theory and practice, since only a single domain discretisation is needed, it also requires the knowledge of the domain mapping. However, in certain applications, the random domain is only described by its random boundary, while the quantity of interest is defined on a fixed, deterministic subdomain. In this setting, it thus becomes necessary to compute a random domain mapping on the whole domain, such that the domain mapping is the identity on the fixed subdomain and maps the boundary of the chosen fixed, nominal domain on to the random boundary. To overcome the necessity of computing such a mapping, we therefore couple the finite element method on the fixed subdomain with the boundary element method on the random boundary. We verify the required regularity of the solution with respect to the random domain mapping for the use of multilevel quadrature, derive the coupling formulation, and show by numerical results that the approach is feasible

Satellite/radiosonde comparison

Collocated measurements of radiosonde and TIROS Operational Vertical Sounder (TOVS) data are compared to determine whether significant latitudinal, seasonal, or instrumental biases exist. Long-wave structure determined by each system is being examined for correlation. Because U.S. radiosonde data are archived uncorrected, an effort to correct the measurements is being considered. These corrections will be applied to 7 years of measurements. New comparisons will then be made using corrected radiosonde and TOVS data. A regression method is used to retrieve temperatures, and radiosonde zonal means are used to update the regression coefficients. Preliminary results of auto-correlation analysis indicate that detection of long-wave structure in each set of data is slightly different with some levels and locations experiencing different wave periods or amplitudes. Scatter diagrams and linear regression for each layer show bias in the mean temperatures. Winter-time measurements show poorer correlations due to noisy measurements

Electrodynamics, wind and temperature

This RTOP provides for correlative meteorological wind and temperature measurements with atmospheric electrodynamic measurements. Meteorological rocketsondes were launched as part of a number of electrodynamic investigations in Alaska, Norway, Peru, Sweden, and at the Wallops Flight Facility, Wallops Island, Virginia. Measurements obtained as part of the MAC/Epsilon campaign during October 1987 from Andoya, Norway, were in conjunction with electric field, ion mobility, conductivity, and energy deposition studies. The measurements obtained between 30 and 90 km are to evaluate and correlate changes in the atmospheric electrical structure caused by the neutral wind and temperature, or changes in the neutral atmosphere resulting from electrical anomalies

Names as legacy: Catalogue of taxa described by and for Michel Brancucci (1950-2012)

This article provides a compilation of the taxa introduced to science by the late Dr. MichelBrancucci, Basel, and of the taxa named in honour of him. We provide details of nomenclatorial value such asholotype depository (for species described by Michel Brancucci), page number of the original description andtype locality. References of the original descriptions are given in full and the actual publication dates werethoroughly checked. Indices to all taxa complete this article and make it a searchable catalogue

Nierentrauma: Behandlungsstrategien und Operationsindikationen

Zusammenfassung: Nierenverletzungen werden meist durch stumpfe Krafteinwirkungen als Folge von Verkehrs- und Sportunfällen verursacht, die vorwiegend junge Patienten betreffen. Beim stabilen Patienten ist die Computertomographie (CT) die Standardabklärung, die beim stumpfen Trauma im Falle einer makroskopischen Hämaturie durchgeführt werden sollte. Beim offenen Trauma muss jede Form von Hämaturie sowie der alleinige klinische Verdacht aufgrund der Wundlokalisation radiologisch abgeklärt werden. Nierenverletzungen werden in 5Schweregrade eingeteilt und stellen in der Mehrheit leichte Verletzungsformen dar. Die Behandlung ist heutzutage meist konservativ. Absolute Operationsindikationen bestehen bei lebensbedrohender Blutung, Nierengefäßstielabrissen sowie bei einem expandierenden retroperitonealen Hämatom. Große Parenchymdefekte mit Harnaustritt sowie begleitenden Abdominalverletzungen des Pankreas und des Kolons stellen relative Operationsindikationen dar. Chirurgische Revisionen werden häufiger bei offenen Verletzungen durchgeführt. Bei chirurgischer Revision ermöglicht die Kontrolle der Nierengefäße vor Eröffnung der Nierenloge eine signifikante Reduktion der Nephrektomierat