Limit theorems for nondegenerate U-statistics of continuous semimartingales

This paper presents the asymptotic theory for nondegenerate $U$-statistics of high frequency observations of continuous It\^{o} semimartingales. We prove uniform convergence in probability and show a functional stable central limit theorem for the standardized version of the $U$-statistic. The limiting process in the central limit theorem turns out to be conditionally Gaussian with mean zero. Finally, we indicate potential statistical applications of our probabilistic results.Comment: Published in at http://dx.doi.org/10.1214/13-AAP983 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

Same, Different or Diverse? An Analysis of the European Union´s Gender Mainstreaming Policies- A Critical Comment

This paper examines the adoption of the EU´s gender mainstreaming policies. More specifically, the purpose of this paper is to explore how gender equality has been constructed and what this implies in terms of representations of gender and possibilities of transformation. By using discourse theory drawing mainly on Laclau and Mouffe, the policy document 'A Roadmap for Equality between women and men 2006-2010' is analyzed. In this respect the discourse theoretical framework functions both as theory and method. In order to structure the analysis, Laclau and Mouffe´s theoretical tools are combined with Judith Squire´s theories on 'feminist political strategies'. Concepts such as inclusion, reversal and displacement are applied to the empirical material. The paper argues that the construction of gender equality is articulated around narrow representations of gender drawing upon notions of 'sameness' and 'difference' but concludes that there are elements aspiring to 'move beyond gender' too. Key words: gender mainstreaming, the EU, gender equality, discourse theory,representations

Data Mining und wissenschaftliche Forschung – de lege lata und de lege ferenda

Der Vorentwurf zum neuen Urheberrechtsgesetz enthält mit Art. 24d E-URG eine Bestimmung, welche die Verwendung von Werken zu wissenschaftlichen Zwecken regelt. So soll die Vervielfältigung und Bearbeitung von urheberrechtlich geschützten Werken künftig zulässig sein, sofern dies durch die Anwendung eines technischen Verfahrens bedingt ist. Die neue Bestimmung zielt auf Fälle des so genannten Text and Data Mining ab, d.h. der computergestützten Suche, Analyse und Vernetzung von Daten mit dem Ziel, neue Erkenntnisse und Zusammenhänge zu erhalten. Es stellt sich die Frage, ob die in Art. 24d E-URG genannten Werknutzungen nicht bereits nach geltendem Recht zulässig sind. Der vorliegende Beitrag beschreibt zunächst den Vorgang des Text und Data Mining (I.) und dessen urheberrechtliche Relevanz (II.), bevor die möglicherweise einschlägigen Schranken des Urheberrechts untersucht werden (III.). Schliesslich wird auf die neue Bestimmung Art. 24d E-URG eingegangen (IV.)

Der Kosovo vor unsicherer Zukunft

Syftet med undersökningen har varit att få en bild av hur kristendomen som religion samt hur kristna identiteter framställs i svensk press. Undersökningen är en textanalys av ett antal artiklar där jag har undersökt vilka olika, eller lika, bilder som dags- och kvällstidningar ger av kristendomen och kristna i Sverige idag. Utifrån teorier om ”den andre” har jag undersökt om artiklarna framställer någon form av ”vi”- och ”de”- perspektiv mellan kristna och “icke-kristna”. Syftet har också varit att försöka utskilja vilka retoriska grepp som används i framställningen av kristendomen och kristna. Undersökningens frågeställningar är: Hur framställs kristendomen i artiklarna? Hur konstrueras kristna identiteter i artiklarna? Hur ser relationen ut mellan skribent och läsare? Vilka retoriska grepp används i framställningen av kristendom och kristna

Visual Analytics for Understanding Draco's Knowledge Base

Draco has been developed as an automated visualization recommendation system formalizing design knowledge as logical constraints in ASP (Answer-Set Programming). With an increasing set of constraints and incorporated design knowledge, even visualization experts lose overview in Draco and struggle to retrace the automated recommendation decisions made by the system. Our paper proposes an Visual Analytics (VA) approach to visualize and analyze Draco's constraints. Our VA approach is supposed to enable visualization experts to accomplish identified tasks regarding the knowledge base and support them in better understanding Draco. We extend the existing data extraction strategy of Draco with a data processing architecture capable of extracting features of interest from the knowledge base. A revised version of the ASP grammar provides the basis for this data processing strategy. The resulting incorporated and shared features of the constraints are then visualized using a hypergraph structure inside the radial-arranged constraints of the elaborated visualization. The hierarchical categories of the constraints are indicated by arcs surrounding the constraints. Our approach is supposed to enable visualization experts to interactively explore the design rules' violations based on highlighting respective constraints or recommendations. A qualitative and quantitative evaluation of the prototype confirms the prototype's effectiveness and value in acquiring insights into Draco's recommendation process and design constraints.Comment: To be presented at VIS 202

Low-temperature DC conductivity of LiNbO 3 single crystals

We report on conductivity measurements of LiNbO3 single crystals with congruent composition in ambient atmosphere between 449 and 727 K which include the lowest temperatures covered so far. The ionic DC conductivity observed along the c-axis at, e. g., 650 K is 6.7 × 10-9 S/cm and shows an activation energy of 1.33 eV. The corresponding Li+ diffusion coefficients range between 2.5 × 10-22 and 1.4 × 10-16 m2/s. These results are perfectly consistent with our conductivity results in the high-temperature regime as well as SIMS measurements published recently (Rahn et al., Phys. Chem. Chem. Phys. 14 (2012) 2427). From the Li+ diffusion coefficients obtained here a Haven ratio of 0.7(2) can be deduced. © by Oldenbourg Wissenschaftsverlag, München

Lithium Diffusion in Ion-Beam Sputtered Amorphous LiAlO2

We investigated lithium self-diffusion in amorphous lithium aluminate (LiAlO2) layers between room temperature and 473 K. For the experiments, amorphous 6LiAlO2 (30 nm)/7LiAlO2 (1200 nm) isotope hetero-structures were deposited by ion-beam sputtering on sapphire substrates. Diffusion profiles were analysed by secondary ion mass spectrometry (SIMS). The results show that the diffusivities obey the Arrhenius law with an activation enthalpy of (0.94 ± 0.02) eV. This is not much different to the activation enthalpy of 1.14 eV found for LiAlO2 single crystals by impedance spectroscopy. It rationalizes the only modest enhancement of diffusivities in amorphous lithium aluminate compared to single crystals of three to five orders of magnitude in the temperature range studied, when compared with, e.g., lithium niobate. © 2015 Walter de Gruyter

Lithography-based additive manufacturing of ceramics from siloxane preceramic polymers

Additive manufacturing is a fabrication approach which offers the possibility to build complex 3D structures from a virtual model without requiring moulds or costly post-processing steps to accom-plish the final structures. Digital Light Processing (DLP) and 2-Photon-Lithography (2PL), two lithog-raphy-based techniques, represent additive manufacturing processes, which offer the highest de-gree of achievable complexity and resolution in their printed structures. Both techniques print their 3D structures by using light to polymerise photosensitive materials. Photocurable preceramic poly-mer resins offer the possibility to be shaped by both DLP and 2PL printing and are subsequently transformed into ceramic material through pyrolysis, while maintaining their predetermined printed structure. This work is divided into four parts and presents complementary approaches at the material and production level to build highly complex 3D ceramic macro- and micro-structures, all based on the printing of a photosensitive siloxane preceramic polymer. In the first part the photosensitive polysiloxane is blended with other preceramic siloxane resins, of-fering no photosensitivity but a high ceramic yield upon pyrolysis. Complicated structures with cm-sized dimensions and resolution as low as 30 µm are shaped via DLP printing and turned into SiOC macro-structures with complete shape maintenance. The blending of two siloxanes offers the pos-sibility to control and alter the ceramic yield, shrinkage, resolution and free-carbon content of the structures, while at the same time exhibiting no diminished printing capability. Detailed sinter- and mechanical properties of one of the blends was investigated in detail and at all scales and demon-strated that, while the overall shape of ceramic structures are preserved during pyrolysis, different shrinkages as well as a change in aspect ratio depending on the structural configuration can occur and has to be taken into consideration. The photosensitive polysiloxane, already used for macro-fabrication to gain SiOC structures, was al-so used in 2PL printing to fabricate structures of the same complexity at the microscale. SiOC ce-ramics with homogenous shrinkage and feature sizes as low as 800 nm were built with the help of a new printing configuration and printed support structures. The third part of this work describes a complementary approach at the processing level, when SiOC ceramic structures are fabricated with a new hybrid additive manufacturing approach, combining DLP and 2PL printing. The advantages of DLP, the free standing and easy handling of macro-dimensional structures, are joined with the resolution capability of 2PL printing. Precisely positioned 3D structures with sub-µm sized features on top of cm-sized structured components were printed. In the final part the polymer processing capability of preceramic polymers and their transformation into a reactive ceramic phase upon pyrolysis is exploited. Instead of producing pure SiOC ceramics, the photocurable siloxane preceramic polymer is combined with alumina powders to develop a new ceramic phase, mullite, upon sintering. The phase transformation at low sintering temperatures de-veloped the new mullite phase within the 3D structure, fabricated due to the photosensitive capabil-ities of the siloxane via DLP printing. Due to the complementary approach in this work, 3D ceramic structures have been fabricated at the macroscale (DLP), microscale (2PL) and multi-scale (Hybrid additive manufacturing; DLP + 2PL) on basis of a photosensitive preceramic polymer. Different ceramic materials, SiOC and mullite, have been produced from the polysiloxane thanks to its transformation capability into SiOC ceramic and reactive SiO2 phase at high temperatures. Through the addition of passive and active fillers complex, dense, pore- and crack-free ceramic structures with no sign of delamination and complete mainte-nance of shape have been developed with varying properties