Climate Change and Modelling of Extreme Temperatures in Switzerland

This study models maximum temperatures in Switzerland monitored in twelve locations using the Generalised Extreme Value (GEV) distribution. The parameters of the GEV distribution are determined within a Bayesian framework. We find that the parameters of the underlying distribution underwent a substantial change in the beginning of the 1980s. This change is characterised by an increase both in the level and the variability. We assess the likelihood of a heat wave of the Summer of 2003 using the fitted GEV distribution by accounting for the presence of a structural break. The estimation results do suggest that the heat wave of 2003 appears not that statistically improbable event as it is generally accepted in the relevant literature.Climate change, GEV, Bayesian modelling, Great Alpine Heat Wave

Zur Kasuistik des Selbstmordes durch elektrischen Strom

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Climate change and modelling of extreme temperatures in Switzerland

This study models maximum temperatures in Switzerland monitored in twelve locations using the generalised extreme value (GEV) distribution. The parameters of the GEV distribution are determined within a Bayesian framework. We find that the parameters of the underlying distribution underwent a substantial change in the beginning of the 1980s. This change is characterised by an increase both in the level and the variability. We assess the likelihood of the heat wave of the summer 2003 using the fitted GEV distribution by accounting for the presence of a structural break. The estimation results do suggest that the heat wave of 2003 is not that statistically improbable if an appropriate methodology is used for dealing with nonstationarit

Autonomie in IT-Systemen : Ein Konzeptionelles Modell

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Die Erforschung und Anwendung von autonomen Systemen ist momentan in der Informatik ein Themengebiet von wachsendem Interesse. Die Aussicht, mit autonomen Verfahren komplexe Systeme handhabbar zu machen und Kosteneinsparungen bei deren Betrieb zu erzielen, hat bereits die Softwareindustrie auf dieses Thema gelenkt und zu neuartigen Produkten geführt. Andererseits darf die Verlässlichkeit eines Systems nicht aufgrund eines autonomen Verfahrens herabgesetzt werden. Dieses Spannungsfeld ist ein Fokus verschiedener Forschungsbemühungen, um autonome Systeme alltagstauglich zu machen.Beim Gebiet der autonomen Systeme handelt es sich um ein junges Themengebiet, welches noch nicht durch allgemein akzeptierte Definitionen geprägt ist. Dadurch entsteht der Bedarf einer terminologischen Basis, die sich momentan in der Phase der Etablierung befindet. Diese Arbeit beteiligt sich an diesem Prozess und schlägt ein konzeptionelles Modell vor. Dieses Modell benennt die grundlegenden Termini und zeigt deren Zusammenhänge auf. Es beschreibt eine Interpretation der relevanten Begriffe und leitet daraus Relationen ab. Auf diese Weise fördert es das gemeinsame Verständnis und erleichtert die Kommunikation bezüglich spezifischer Fragestellungen innerhalb dieses Gebietes

Onkolojide PET-BT ile multimodal görüntüleme

Pozitron-emisyon tomografi (PET) ile bilgisayarlı tomografinin (BT) birlikte kullanımı (PET-BT) PET'in klinik kullanımını önemli ölçüde artırmıştır. PET-BT, BT'nin yüksek çüzünürlüğünü PET'in yüksek duyarlığıyla birleştirmektedir. PET ve BT sonuçlarının tek incelemede ve aynı cihazla elde edilmesi nedeniyle her iki prosedürün en uygun birleşimi mümkündür. PET ve BT görüntülerinin klasik birleştirilmesine oranla, PET-BT ile PET'in doğruluğu yaklaşık %15 oranında artırılabilir. PET-BT'nin gücünden tam olarak yararlanmak sadece oral veya intravenöz kontrast ajanların kullanılmasıyla mümkündür. BT'nin X- ışını aynı zamanda atenüasyon düzeltmesi için kullanılır. Bu makalede ağırlıklı olarak akciğer kanseri, malign melanom, baş-boyun tümörleri, tiroid tümörleri ve kolorektal kanserler üzerinde durulmuş ve PET-BT'nin görsel gücü olgulara ait görüntüler aracılığıyla ortaya konmuştur.The combination of PET (positron emission tomography) with CT (computed tomography) has considerably enhanced the clinical application of PET. PET-CT combines the high resolution of CT with the high sensitivity of PET. As PET and CT results are obtained with one machine during one investigation, an optimal fusion of both procedures is possible. The accuracy of PET can be increased by about 15% by PET-CT, compared to conventional fusion of PET and CT images. The potential of PET-CT can only be fully used if contrast agents -either orally or intravenously- are applied. The Xrays of CT may also be used for attenuation correction. This article focuses mainly on PET-CT in lung cancer, malignant melanoma, head and neck tumors, thyroid tumors, and colorectal cancer, with illustrations of some cases documenting the potentials of PET-CT

A ``Tetris''-like model for the Compaction of Dry Granular Media

We propose a two-dimensional geometrical model, based on the concept of geometrical frustration, conceived for the study of compaction in granular media. The dynamics exhibits an interesting inverse logarithmic law that is well known from real experiments. Moreover we present a simple dynamical model of $N$ planes exchanging particles with excluded volume problems, which allows to clarify the origin of the logarithmic relaxations and the stationary density distribution. A simple mapping allows us to cast this Tetris-like model in the form of an Ising-like spin systems with vacancies.Comment: 4 pages, Latex including 2 PS figures (reference corrected). Subm. to Phys. Rev. Lett. (1997

Introduction to Stopping Time in Stochastic Finance Theory

SummaryWe start with the definition of stopping time according to [4], p.283. We prove, that different definitions for stopping time can coincide. We give examples of stopping time using constant-functions or functions defined with the operator max or min (defined in [6], pp.37–38). Finally we give an example with some given filtration. Stopping time is very important for stochastic finance. A stopping time is the moment, where a certain event occurs ([7], p.372) and can be used together with stochastic processes ([4], p.283). Look at the following example: we install a function ST: {1,2,3,4} → {0, 1, 2} ∪ {+∞}, we define:a. ST(1)=1, ST(2)=1, ST(3)=2, ST(4)=2.b. The set {0,1,2} consists of time points: 0=now,1=tomorrow,2=the day after tomorrow. We can prove:c. {w, where w is Element of Ω: ST.w=0}=∅ & {w, where w is Element of Ω: ST.w=1}={1,2} & {w, where w is Element of Ω: ST.w=2}={3,4} andST is a stopping time. We use a function Filt as Filtration of {0,1,2}, Σ where Filt(0)=Ωnow, Filt(1)=Ωfut1 and Filt(2)=Ωfut2. From a., b. and c. we know that:d. {w, where w is Element of Ω: ST.w=0} in Ωnow and{w, where w is Element of Ω: ST.w=1} in Ωfut1 and{w, where w is Element of Ω: ST.w=2} in Ωfut2.The sets in d. are events, which occur at the time points 0(=now), 1(=tomorrow) or 2(=the day after tomorrow), see also [7], p.371. Suppose we have ST(1)=+∞, then this means that for 1 the corresponding event never occurs.As an interpretation for our installed functions consider the given adapted stochastic process in the article [5].ST(1)=1 means, that the given element 1 in {1,2,3,4} is stopped in 1 (=tomorrow). That tells us, that we have to look at the value f2(1) which is equal to 80. The same argumentation can be applied for the element 2 in {1,2,3,4}.ST(3)=2 means, that the given element 3 in {1,2,3,4} is stopped in 2 (=the day after tomorrow). That tells us, that we have to look at the value f3(3) which is equal to 100.ST(4)=2 means, that the given element 4 in {1,2,3,4} is stopped in 2 (=the day after tomorrow). That tells us, that we have to look at the value f3(4) which is equal to 120.In the real world, these functions can be used for questions like: when does the share price exceed a certain limit? (see [7], p.372).Siegmund-Schacky-Str. 18a, 80993 Munich, GermanyGrzegorz Bancerek. The fundamental properties of natural numbers. Formalized Mathematics, 1(1):41–46, 1990.Czesław Byliński. Functions and their basic properties. Formalized Mathematics, 1(1): 55–65, 1990.Czesław Byliński. Functions from a set to a set. Formalized Mathematics, 1(1):153–164, 1990.Hans Föllmer and Alexander Schied. Stochastic Finance: An Introduction in Discrete Time, volume 27 of Studies in Mathematics. de Gruyter, Berlin, 2nd edition, 2004.Peter Jaeger. Modelling real world using stochastic processes and filtration. Formalized Mathematics, 24(1):1–16, 2016. doi: 10.1515/forma-2016-0001.Achim Klenke. Wahrscheinlichkeitstheorie. Springer-Verlag, Berlin, Heidelberg, 2006.Jürgen Kremer. Einführung in die diskrete Finanzmathematik. Springer-Verlag, Berlin, Heidelberg, New York, 2006.Andrzej Nędzusiak. σ-fields and probability. Formalized Mathematics, 1(2):401–407, 1990.Andrzej Trybulec. Binary operations applied to functions. Formalized Mathematics, 1(2): 329–334, 1990.25210110

Generation of Porous Particle Structures using the Void Expansion Method

The newly developed "void expansion method" allows for an efficient generation of porous packings of spherical particles over a wide range of volume fractions using the discrete element method. Particles are randomly placed under addition of much smaller "void-particles". Then, the void-particle radius is increased repeatedly, thereby rearranging the structural particles until formation of a dense particle packing. The structural particles' mean coordination number was used to characterize the evolving microstructures. At some void radius, a transition from an initially low to a higher mean coordination number is found, which was used to characterize the influence of the various simulation parameters. For structural and void-particle stiffnesses of the same order of magnitude, the transition is found at constant total volume fraction slightly below the random close packing limit. For decreasing void-particle stiffness the transition is shifted towards a smaller void-particle radius and becomes smoother.Comment: 9 pages, 8 figure

Early detection of Varicella-Zoster Virus (VZV)-specific T-cells before seroconversion in primary varicella infection: case report

Here we report the case of a 54-year old, immunocompetent German patient with primary varicella whose Varicella-Zoster Virus (VZV)-specific T-cell responses could be detected early in infection and before the onset of seroconversion. This case demonstrates that the detection of VZV-specific T-cells may under certain circumstances support the diagnosis of a primary varicella infection, as for example in cases of atypical or subclinical varicella or in the absence of detectable VZV DNA in plasma