Entropy of unimodular Lattice Triangulations

Triangulations are important objects of study in combinatorics, finite element simulations and quantum gravity, where its entropy is crucial for many physical properties. Due to their inherent complex topological structure even the number of possible triangulations is unknown for large systems. We present a novel algorithm for an approximate enumeration which is based on calculations of the density of states using the Wang-Landau flat histogram sampling. For triangulations on two-dimensional integer lattices we achive excellent agreement with known exact numbers of small triangulations as well as an improvement of analytical calculated asymptotics. The entropy density is $C=2.196(3)$ consistent with rigorous upper and lower bounds. The presented numerical scheme can easily be applied to other counting and optimization problems.Comment: 6 pages, 7 figure

Poroelastic effects in reservoir modelling

The influence of fluid injection and depletion of reservoirs on pore pressure and the stress state is investigated. This is done analytically as well as by 4D geomechanical poroelastic numerical modelling. The results demonstrate the importance of the orientation of the stress field, and show their relevance for rock stability

Development of an RF IV waveform based stress test procedure for use on GaN HFETs

This paper reports on the development of an RF IV waveform based stress test procedure. DC and low-voltage RF characterisation was carried out before and after high power RF stress. RF waveform measurements showed that the exact change in the RF load line induced during RF degradation cannot be directly inferred from the DC or low power RF measurement. The RF degradation takes the form of a knee-walkout, a small pinch-off shift consistent with charge trapping and defect generation, and in addition gate leakage occurs once the RF voltage exceeds a critical voltage

Investigating inefficiencies of bookmaker odds in football using machine learning

[EN] The efficient-market hypothesis states that it is impossible to beat the market, as the price reflects all available information. Applied to bookmaker odds for football games, there should not be a systematic way of winning money on the long run.However, we show that by using simple machine learning models we can systematically outperform the markets belief manifested through the bookmakers odds. The effect of this inefficiency is diminishing over time, which indicates that the knowledge that has been derived from and the pure amount of the data is also reflected in the odds in recent times.We give some insights how this effect differs across major football leagues in Europe, which algorithms are performing best and statistics on the ROI using machine learning in football betting. Additionally, we share how the simulation study has been designed in more detail.Mangold, B.; Stübinger, J. (2020). Investigating inefficiencies of bookmaker odds in football using machine learning. Editorial Universitat Politècnica de València. 173-179. https://doi.org/10.4995/CARMA2020.2020.11619OCS17317

Regenerative potential of human adipose-derived stromal cells of various origins

AbstractIn regenerative concepts, the potential of adult stem cells holds great promise concerning an individualized therapeutic approach. These cells provide renewable progenitor cells to replace aged tissue, and play a significant role in tissue repair and regeneration.In this investigation, the characteristics of different types of adipose tissue are analysed systematically with special attention to their proliferation and differentiation potential concerning the angiogenic and osteogenic lineage. Tissue samples from subcutaneous, visceral, and omental fat were processed according to standard procedures. The cells were characterized and cultivated under suitable conditions for osteogenic and angiogenic cell culture. The development of the different cell cultures as well as their differentiation were analysed morphologically and immunohistochemically from cell passages P1 to P12. Harvesting and isolation of multipotent cells from all three tissue types could be performed reproducibly. The cultivation of these cells under osteogenic conditions led to a morphological and immunohistochemical differentiation; mineralization could be detected. The most stable results were observed for the cells of subcutaneous origin. An osteogenic differentiation from adipose-derived cells from all analysed fatty tissues can be achieved easily and reproducibly. In therapeutic concepts including angiogenic regeneration, adipose-derived cells from subcutaneous tissue provide the optimal cellular base

Machine Learning in Football Betting: Prediction of Match Results Based on Player Characteristics

In recent times, football (soccer) has aroused an increasing amount of attention across continents and entered unexpected dimensions. In this course, the number of bookmakers, who offer the opportunity to bet on the outcome of football games, expanded enormously, which was further strengthened by the development of the world wide web. In this context, one could generate positive returns over time by betting based on a strategy which successfully identifies overvalued betting odds. Due to the large number of matches around the globe, football matches in particular have great potential for such a betting strategy. This paper utilizes machine learning to forecast the outcome of football games based on match and player attributes. A simulation study which includes all matches of the five greatest European football leagues and the corresponding second leagues between 2006 and 2018 revealed that an ensemble strategy achieves statistically and economically significant returns of 1.58% per match. Furthermore, the combination of different machine learning algorithms could neither be outperformed by the individual machine learning approaches nor by a linear regression model or naive betting strategies, such as always betting on the victory of the home team

Spectral representation of Matsubara n-point functions: Exact kernel functions and applications

In the field of quantum many-body physics, the spectral (or Lehmann) representation simplifies the calculation of Matsubara n-point correlation functions if the eigensystem of a Hamiltonian is known. It is expressed via a universal kernel function and a system- and correlator-specific product of matrix elements. Here we provide the kernel functions in full generality, for arbitrary n, arbitrary combinations of bosonic or fermionic operators and an arbitrary number of anomalous terms. As an application, we consider bosonic 3- and 4-point correlation functions for the fermionic Hubbard atom and a free spin, respectively.Comment: 13 pages, 1 figure, comments welcome

МОНИТОРИНГ И УПРАВЛЕНИЕ УДАЛЕННЫМИ ОБЪЕКТАМИ

Система контроля удаленных объектов предназначена для мониторинга состояния и работоспособности оборудования без постоянного присутствия обслуживающего персонала. Не внося функциональных изменений в систему управления, она обеспечивает круглосуточное наблюдение за состоянием объектов, что позволяет своевременно реагировать на события и оперативно устранять причины неполадок

Below ground efficiency of a parasitic wasp for Drosophila suzukii biocontrol in different soil types

The parasitoid wasp Trichopria drosophilae is promising as a biocontrol agent for controlling the ubiquitous pest Drosophila suzukii (Matsumura). Crucial for the successful implementation of any biocontrol agent is a high parasitisation rate by the parasitoid. Most studies investigating the parasitisation rate of D. suzukii pupae have focused on parasitisation in the fruit or in a petri dish. However, the predominant pupation site of D. suzukii in the field is the soil. Unfortunately, little is known on how well parasitoid wasps can detect and parasitise pupae of D. suzukii buried in the soil. Therefore, we conducted soil parasitisation experiments of T. drosophilae on D. suzukii pupae using two pupation depths in three different soil types (loamy sand, loam, and clay). In all three soil types, we found generally low D. suzukii pupae parasitisation rate by T. drosophilae, independent of the pupation depth. The pupation behaviour of D. suzukii and the parasitisation behaviour of T. drosophilae are discussed in detail. For pest control in most soil types, our results mean that the number of D. suzukii larvae pupating in the soil should be reduced, e.g., by adding a layer of sandy soil or covering the soil with plastic mulch. This might increase the probability of success when using T. drosophilae as a biocontrol agent