Neural network guided adjoint computations in dual weighted residual error estimation

In this work, we are concerned with neural network guided goal-oriented a posteriori error estimation and adaptivity using the dual weighted residual method. The primal problem is solved using classical Galerkin finite elements. The adjoint problem is solved in strong form with a feedforward neural network using two or three hidden layers. The main objective of our approach is to explore alternatives for solving the adjoint problem with greater potential of a numerical cost reduction. The proposed algorithm is based on the general goal-oriented error estimation theorem including both linear and nonlinear stationary partial differential equations and goal functionals. Our developments are substantiated with some numerical experiments that include comparisons of neural network computed adjoints and classical finite element solutions of the adjoints. In the programming software, the open-source library deal.II is successfully coupled with LibTorch, the PyTorch C++ application programming interface

First year of practical experiences of the new Arctic AWIPEV-COSYNA cabled Underwater Observatory in Kongsfjorden, Spitsbergen

A combined year-round assessment of selected oceanographic data and a macrobiotic community assess- ment was performed from October 2013 to November 2014 in the littoral zone of the Kongsfjorden polar fjord system on the western coast of Svalbard (Norway). State of the art remote controlled cabled underwater observatory technology was used for daily vertical profiles of temperature, salinity, and turbidity together with a stereo-optical assessment of the macrobiotic community, including fish. The results reveal a distinct seasonal cycle in total species abundances, with a significantly higher total abundance and species richness dur- ing the polar winter when no light is available underwater compared to the summer months when 24 h light is available. During the winter months, a temporally highly segmented community was observed with respect to species occurrence, with single species dominating the winter community for re- stricted times. In contrast, the summer community showed an overall lower total abundance as well as a significantly lower number of species. The study clearly demonstrates the high potential of cable connected remote controlled digital sampling devices, especially in remote areas, such as po- lar fjord systems, with harsh environmental conditions and limited accessibility. A smart combination of such new dig- ital “sampling” methods with classic sampling procedures can provide a possibility to significantly extend the sampling time and frequency, especially in remote and difficult to access areas. This can help to provide a sufficient data density and therefore statistical power for a sound scientific analysis without increasing the invasive sampling pressure in ecolog- ically sensitive environments

Möglichkeiten und Maßnahmen zur Wahrung und Steigerung der Wettbewerbsfähigkeit der Baden-Württembergischen Wertpapierbörse zu Stuttgart

Die Börsenstrukturen befinden sich international in einer Phase dynamischer Veränderungen. Der härter gewordene Wettbewerb hinterläßt bei den großen nationalen Börsen tiefe Spuren und führt zu Anpassungsmaßnahmen, die vor allem in der technischen Neuorganisation des Börsenhandels und in der Erweiterung der Produktpalette ihren Ausdruck finden. Regionalbörsen wie die Baden-Württembergische Wertpapierbörse zu Stuttgart sind dabei einem noch stärkeren Wettbewerbsdruck ausgesetzt, da neben die internationale Konkurrenz noch die Konkurrenz der deutschen Börsen untereinander tritt. Das vorliegende Gutachten, das vom Staatsministerium Baden-Württemberg in Auftrag gegeben wurde, widmet sich speziell der Erarbeitung von Vorschlägen, die der Wahrung und Steigerung der Wettbewerbsfähigkeit der Stuttgarter Wertpapierbörse dienen

Möglichkeiten und Maßnahmen zur Wahrung und Steigerung der Wettbewerbsfähigkeit der Baden-Württembergischen Wertpapierbörse zu Stuttgart

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Tomographic analysis of jammed ellipsoid packings

Disordered packings of ellipsoidal particles are an important model for disordered granular matter. Here we report a way to determine the average contact number of ellipsoid packings from tomographic analysis. Tomographic images of jammed ellipsoid packings prepared by vertical shaking of loose configurations are recorded and the positions and orientations of the ellipsoids are reconstructed. The average contact number can be extracted from a contact number scaling (CNS) function. The size of the particles, that may vary due to production inaccuracies, can also be determined by this method

Challenges in Annotation of useR Data for UbiquitOUs Systems: Results from the 1st ARDUOUS Workshop

Labelling user data is a central part of the design and evaluation of pervasive systems that aim to support the user through situation-aware reasoning. It is essential both in designing and training the system to recognise and reason about the situation, either through the definition of a suitable situation model in knowledge-driven applications, or through the preparation of training data for learning tasks in data-driven models. Hence, the quality of annotations can have a significant impact on the performance of the derived systems. Labelling is also vital for validating and quantifying the performance of applications. In particular, comparative evaluations require the production of benchmark datasets based on high-quality and consistent annotations. With pervasive systems relying increasingly on large datasets for designing and testing models of users' activities, the process of data labelling is becoming a major concern for the community. In this work we present a qualitative and quantitative analysis of the challenges associated with annotation of user data and possible strategies towards addressing these challenges. The analysis was based on the data gathered during the 1st International Workshop on Annotation of useR Data for UbiquitOUs Systems (ARDUOUS) and consisted of brainstorming as well as annotation and questionnaire data gathered during the talks, poster session, live annotation session, and discussion session