Systematic Approaches to Advanced Information Flow Analysis – and Applications to Software Security

In dieser Arbeit berichte ich über Anwendungen von Slicing und Programmabhängigkeitsgraphen (PAG) in der Softwaresicherheit. Außerdem schlage ich ein Analyse-Rahmenwerk vor, welches Datenflussanalyse auf Kontrollflussgraphen und Slicing auf Programmabhängigkeitsgraphen verallgemeinert. Mit einem solchen Rahmenwerk lassen sich neue PAG-basierte Analysen systematisch ableiten, die über Slicing hinausgehen. Die Hauptthesen meiner Arbeit lauten wie folgt: (1) PAG-basierte Informationsflusskontrolle ist nützlich, praktisch anwendbar und relevant. (2) Datenflussanalyse kann systematisch auf Programmabhängigkeitsgraphen angewendet werden. (3) Datenflussanalyse auf Programmabhängigkeitsgraphen ist praktisch durchführbar

Detection and Removal of Artifacts in Astronomical Images

Astronomical images from optical photometric surveys are typically contaminated with transient artifacts such as cosmic rays, satellite trails and scattered light. We have developed and tested an algorithm that removes these artifacts using a deep, artifact free, static sky coadd image built up through the median combination of point spread function (PSF) homogenized, overlapping single epoch images. Transient artifacts are detected and masked in each single epoch image through comparison with an artifact free, PSF-matched simulated image that is constructed using the PSF-corrected, model fitting catalog from the artifact free coadd image together with the position variable PSF model of the single epoch image. This approach works well not only for cleaning single epoch images with worse seeing than the PSF homogenized coadd, but also the traditionally much more challenging problem of cleaning single epoch images with better seeing. In addition to masking transient artifacts, we have developed an interpolation approach that uses the local PSF and performs well in removing artifacts whose widths are smaller than the PSF full width at half maximum, including cosmic rays, the peaks of saturated stars and bleed trails. We have tested this algorithm on Dark Energy Survey Science Verification data and present performance metrics. More generally, our algorithm can be applied to any survey which images the same part of the sky multiple times.Comment: 17 pages, 6 figures. Accepted for publication in Astronomy and Computin

Integration and Development in Schizotypy Research: An Introduction to the Special Supplement

In its fifth decade of existence, the construct of schizotypy is recapturing the early scientific interest it attracted when Paul E. Meehl (1920-2003), who coined the term, pioneered the field of schizotypy research. The International Lemanic Workshop on Schizotypy, hosted at the University of Geneva in December 2013, recently offered an opportunity to address some of the fundamental questions in contemporary schizotypy research and situate the construct in the greater scheme of future scientific projects on schizophrenia and psychological health research. What kind of knowledge has schizotypy research provided in furthering our understanding of schizophrenia? What types of questions can schizotypy research tackle, and which are the conceptual and methodological frameworks to address them? How will schizotypy research contribute to future scientific endeavors? The International Lemanic Workshop brought together leading experts in the field around the tasks of articulating the essential findings in schizotypy research, as well as providing some key insights and guidance to face scientific challenges of the future. The current supplement contains 8 position articles, 4 research articles, and 1 invited commentary that outline the state of the art in schizotypy research toda

Temperature development in the leakage flow of screw extruders

Temperature distribution at the exit of the leakage gap is of interest for a number of problems. For the calculation of temperatures, the leakage flow may be considered to be a pure drag flow to a good approximation. In the Newtonian case, thermal development length may be expressed in terms of gap height as L ≈ 3/8Pe ·δ ;usually this is less than the available gap length. Pe is the Peclet number and δ the height of leakage gap. Therefore the existing flow may be considered fully developed. For power law fluids, numerical calculations lead to results of the same order. Martin's results therefore may be applied to the flow at the exit of the leakage gap

A unified survey of Si-H and H-H bond activation catalysed by electron-deficient boranes

The bond activation chemistry of B(C6F5)(3) and related electron-deficient boranes is currently experiencing a renaissance due to the fascinating development of frustrated Lewis pairs (FLPs). B(C6F5)(3)'s ability to catalytically activate Si-H bonds through eta(1) coordination opened the door to several unique reduction processes. The ground-breaking finding that the same family of fully or partially fluorinated boron Lewis acids allows for the related H-H bond activation, either alone or as a component of an FLP, brought considerable momentum into the area of transition-metal-free hydrogenation and, likewise, hydrosilylation. This review comprehensively summarises synthetic methods involving borane-catalysed Si-H and H-H bond activation. Systems corresponding to an FLP-type situation are not covered. Aside from the broad manifold of C=X bond reductions and C=X/C-X defunctionalisations, dehydrogenative (oxidative) Si-H couplings are also included.DFG, EXC 314, Unifying Concepts in Catalysi

A Regression Model for Plasma Reaction Kinetics

Machine learning (ML) is used to provide reactions rates appropriate for models of low temperature plasmas with a focus on A + B $\rightarrow$ C + D binary chemical reactions. The regression model is trained on data extracted from the QBD, KIDA, NFRI and UfDA databases. The regression model used a variety of data on the reactant and product species, some of which also had to be estimated using ML. The final model is a voting regressor comprising three distinct optimized regression models: a support vector regressor, random forest regressor and a gradient-boosted trees regressor model; this model is made freely available via a GitHub repository. As a sample use case, the ML results are used to augment the chemistry of a BCl3/H2 gas mixture

Anisotropic Acoustic Plasmons in Black Phosphorus

Recently, it was demonstrated that a graphene/dielectric/metal configuration can support acoustic plasmons, which exhibit extreme plasmon confinement an order of magnitude higher than that of conventional graphene plasmons. Here, we investigate acoustic plasmons supported in a monolayer and multilayers of black phosphorus (BP) placed just a few nanometers above a conducting plate. In the presence of a conducting plate, the acoustic plasmon dispersion for the armchair direction is found to exhibit the characteristic linear scaling in the mid- and far-infrared regime while it largely deviates from that in the long wavelength limit and near-infrared regime. For the zigzag direction, such scaling behavior is not evident due to relatively tighter plasmon confinement. Further, we demonstrate a new design for an acoustic plasmon resonator that exhibits higher plasmon confinement and resonance efficiency than BP ribbon resonators in the mid-infrared and longer wavelength regime. Theoretical framework and new resonator design studied here provide a practical route toward the experimental verification of the acoustic plasmons in BP and open up the possibility to develop novel plasmonic and optoelectronic devices that can leverage its strong in-plane anisotropy and thickness-dependent band gap

Investigations of Inducers Operating with High Rotational Speed

International audienceSuction performance, pressure rise and efficiency for four different inducers are examined with CFD simulations and experiments performed with 18000rpm and 24000rpm. The studies originate from a research project which includes the design of a new test bench in order to judge the design of the different inducers. This test bench allows to perform experiments with a rotational speed of up to 40000rpm and high pressure ranges with water as working fluid. Experimental results are used to evaluate the accuracy of the simulations and to gain a be er understanding of the design parameter. The influence of increasing the rotating speed from 18000rpm to 24000rpm on the performance is also shown