Noise recovery for L\'evy-driven CARMA processes and high-frequency behaviour of approximating Riemann sums

We consider high-frequency sampled continuous-time autoregressive moving average (CARMA) models driven by finite-variance zero-mean L\'evy processes. An L^2-consistent estimator for the increments of the driving L\'evy process without order selection in advance is proposed if the CARMA model is invertible. In the second part we analyse the high-frequency behaviour of approximating Riemann sum processes, which represent a natural way to simulate continuous-time moving average processes on a discrete grid. We shall compare their autocovariance structure with the one of sampled CARMA processes, where the rule of integration plays a crucial role. Moreover, new insight into the kernel estimation procedure of Brockwell et al. (2012a) is given.Comment: 26 pages, 2 figure

Diophantine triples in linear recurrence sequences of Pisot type

The study of Diophantine triples taking values in linear recurrence sequences is a variant of a problem going back to Diophantus of Alexandria which has been studied quite a lot in the past. The main questions are, as usual, about existence or finiteness of Diophantine triples in such sequences. Whilst the case of binary recurrence sequences is almost completely solved, not much was known about recurrence sequences of larger order, except for very specialized generalizations of the Fibonacci sequence. Now, we will prove that any linear recurrence sequence with the Pisot property contains only finitely many Diophantine triples, whenever the order is large and a few more not very restrictive conditions are met.Comment: 25 pages. arXiv admin note: text overlap with arXiv:1602.0823

Vibrational phenomena in glasses at low temperatures captured by field theory of disordered harmonic oscillators

We investigate the vibrational properties of topologically disordered materials by analytically studying particles that harmonically oscillate around random positions. Exploiting field theory in the thermodynamic limit at $T=0$, we build up a self-consistent model by analysing the Hessian utilizing Euclidean Random Matrix theory. In accordance with earlier findings [1], we take non-planar diagrams into account to correctly address multiple local scattering events. By doing so, we end up with a first principles theory that can predict the main anomalies of athermal disordered materials, including the boson peak, sound softening, and Rayleigh damping of sound. In the vibrational density of states, the sound modes lead to Debye's law for small frequencies. Additionally, quasi-localised modes (QLMs), cause an excess in the density of states starting as $\omega^4$ in the low frequency limit.Comment: 6 pages, 5 figures; 7 pages of supplemental informatio

Visual Integration of Data and Model Space in Ensemble Learning

Ensembles of classifier models typically deliver superior performance and can outperform single classifier models given a dataset and classification task at hand. However, the gain in performance comes together with the lack in comprehensibility, posing a challenge to understand how each model affects the classification outputs and where the errors come from. We propose a tight visual integration of the data and the model space for exploring and combining classifier models. We introduce a workflow that builds upon the visual integration and enables the effective exploration of classification outputs and models. We then present a use case in which we start with an ensemble automatically selected by a standard ensemble selection algorithm, and show how we can manipulate models and alternative combinations.Comment: 8 pages, 7 picture

Bodennahe Wärmeprozesse und vegetatives Wachstum bei Sonnenblumen

Wärme als qualitativer Naturprozess ist mehr als ein Temperaturzustand. In einem Versuch wurde das Wachstum von Sonnenblumen an zwei unterschiedlich exponierten Standorten mit und ohne Folie untersucht. Ein sensibler Zusammenhang zwischen Wärmeprozessen an der Erdoberfläche und der vegetativen Entwicklungsdynamik wurde festgestellt

A Flux-Scaling Scenario for High-Scale Moduli Stabilization in String Theory

Tree-level moduli stabilization via geometric and non-geometric fluxes in type IIB orientifolds on Calabi-Yau manifolds is investigated. The focus is on stable non-supersymmetric minima, where all moduli are fixed except for some massless axions. The scenario includes the purely axionic orientifold-odd moduli. A set of vacua allowing for parametric control over the moduli vacuum expectation values and their masses is presented, featuring a specific scaling with the fluxes. Uplift mechanisms and supersymmetry breaking soft masses on MSSM-like D7-branes are discussed as well. This scenario provides a complete effective framework for realizing the idea of F-term axion monodromy inflation in string theory. It is argued that, with all masses close to the Planck and GUT scales, one is confronted with working at the threshold of controlling all mass hierarchies.Comment: 74 pages, 3 figure

Simulating Collaborative Mobile Services – An Approach to Evaluate a New Location Enabling Service

Although enthusiasm for the “killer-application” in the mobile sector has decreased, location based services still seem to be valuable mobile services. Today’s location based services are mostly forced to use the proprietary location information provided by mobile network operators. The approach that is discussed here depicts a way of locating a mobile client independently from certain network operators and in heterogeneous networks. The Location Trader system collects and provides location information for users and providers of location based services. The accumulated interaction of each user of the user community enables to generate reliable location information in the Location Trader database. This paper prepares the groundwork for modeling the core principles of unintended value co-production with the Location Trader System. We intend to focus our analysis on the Location Trader System resp. Services, as the phenomenon of value co-production is widespread because of low coordination costs for integration and transactions enabled by immateriality and potential automation of business and transaction processes. The focus of this paper is the simulation of the user integration based on the theoretical basis

Einfluss verschiedener Anbaustrategien auf Ertrag und Pflanzengesundheit von Zwiebeln (Allium cepa L.)

In field experiments in five Bavarian farms three cultivation systems of onion produc-tion were compared: direct sowing, planting of set onions and planting of seedlings with 7 seeds per each tray. In three of five farms the onions yield up to more than 500 dt ha-1and in average the planted seedling yielded higher than the sown ones. In the other farms, where the set onions where included in the trials, the yields were lower depending on the high and early infection with downy mildew. The plant density (90-70 plant m-2) had more effect on the onion size distribution than on the total yield