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Logarithmic Components of the Vacant Set for Random Walk on a Discrete Torus
(2008)Electronic Journal of ProbabilityThis work continues the investigation, initiated in a recent work by Benjamini and Sznitman, of percolative properties of the set of points not visited by a random walk on the discrete torus (Z/NZ)d up to time uNd in high dimension d. If u>0 is chosen sufficiently small it has been shown that with overwhelming probability this vacant set contains a unique giant component containing segments of length c0logN for some constant c0>0, and ...Journal Article -
Correlations between total cell concentration, total adenosine tri-phosphate concentration and heterotrophic plate counts during microbial monitoring of drinking water
(2008)Drinking Water Engineering and ScienceThe general microbial quality of drinking water is normally monitored by heterotrophic plate counts (HPC). This method has been used for more than 100 years and is recommended in drinking water guidelines. However, the HPC method is handicapped because it is time-consuming and restricted to culturable bacteria. Recently, rapid and accurate detection methods have emerged, such as adenosine tri-phosphate (ATP) measurements to assess microbial ...Journal Article -
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A combined particle trap/HTDMA hygroscopicity study of mixed inorganic/organic aerosol particles
(2008)Atmospheric Chemistry and PhysicsAtmospheric aerosols are often mixtures of inorganic and organic material. Organics can represent a large fraction of the total aerosol mass and are comprised of water-soluble and insoluble compounds. Increasing attention was paid in the last decade to the capability of mixed inorganic/organic aerosol particles to take up water (hygroscopicity). We performed hygroscopicity measurements of internally mixed particles containing ammonium ...Journal Article -
Nonparametric Econometrics: The np Package
(2008)Journal of Statistical SoftwareWe describe the R np package via a series of applications that may be of interest to applied econometricians. The np package implements a variety of nonparametric and semiparametric kernel-based estimators that are popular among econometricians. There are also procedures for nonparametric tests of significance and consistent model specification tests for parametric mean regression models and parametric quantile regression models, among ...Journal Article -
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Reconstruction of the solar spectral UV irradiance for nowcasting of the middle atmosphere state on the basis of LYRA measurements
(2008)Atmospheric Chemistry and PhysicsThe LYRA instrument onboard ESA PROBA2 satellite will provide 6-hourly solar irradiance at the Lyman-alpha (121.6 nm) and the Herzberg continuum (~200–220 nm wavelength range). Because the nowcasting of the neutral and ionic state of the middle atmosphere requires the solar irradiance for the wide spectral range (120–680 nm) we have developed the statistical tool for the reconstruction of the full spectrum from the LYRA measurements. The ...Journal Article -
Receptor modeling of C2-C7 hydrocarbon sources at an urban background site in Zurich, Switzerland
(2008)Atmospheric Chemistry and PhysicsHourly measurements of 13 volatile hydrocarbons (C2–C7) were performed at an urban background site in Zurich (Switzerland) in the years 1993–1994 and again in 2005–2006. For the separation of the volatile organic compounds by gas-chromatography (GC), an identical chromatographic column was used in both campaigns. Changes in hydrocarbon profiles and source strengths were recovered by positive matrix factorization (PMF). Eight and six factors ...Journal Article -
Reconstruction of erythemal UV-doses for two stations in Austria: A comparison between alpine and urban regions
(2008)Atmospheric Chemistry and PhysicsThe aim of this study is the reconstruction of past UV-doses for two stations in Austria, Hoher Sonnblick and Vienna, using a physical radiation transfer model. The method uses the modeled UV-dose under clear-sky conditions, cloud modification factors and a correction factor as input variables. To identify the influence of temporal resolution of input data and modification factors, an ensemble of four different modelling approaches was ...Journal Article -
Measurements of UV irradiance within the area of one satellite pixel
(2008)Atmospheric Chemistry and PhysicsA measurement campaign was performed in the region of Vienna and its surroundings from May to July 2007. Within the scope of this campaign erythemal UV was measured at six ground stations within a radius of 30 km. First, the homogeneity of the UV levels within the area of one satellite pixel was studied. Second, the ground UV was compared to ground UV retrieved by the ozone monitoring instrument (OMI) onboard the NASA EOS Aura Spacecraft. ...Journal Article