How to test for partially predictable chaos

For a chaotic system pairs of initially close-by trajectories become eventually fully uncorrelated on the attracting set. This process of decorrelation may split into an initial exponential decrease, characterized by the maximal Lyapunov exponent, and a subsequent diffusive process on the chaotic attractor causing the final loss of predictability. The time scales of both processes can be either of the same or of very different orders of magnitude. In the latter case the two trajectories linger within a finite but small distance (with respect to the overall extent of the attractor) for exceedingly long times and therefore remain partially predictable. Tests for distinguishing chaos from laminar flow widely use the time evolution of inter-orbital correlations as an indicator. Standard tests however yield mostly ambiguous results when it comes to distinguish partially predictable chaos and laminar flow, which are characterized respectively by attractors of fractally broadened braids and limit cycles. For a resolution we introduce a novel 0-1 indicator for chaos based on the cross-distance scaling of pairs of initially close trajectories, showing that this test robustly discriminates chaos, including partially predictable chaos, from laminar flow. One can use furthermore the finite time cross-correlation of pairs of initially close trajectories to distinguish, for a complete classification, also between strong and partially predictable chaos. We are thus able to identify laminar flow as well as strong and partially predictable chaos in a 0-1 manner solely from the properties of pairs of trajectories.Comment: 14 pages, 9 figure

Characterization of an in-vacuum PILATUS 1M detector

A dedicated in-vacuum X-ray detector based on the hybrid pixel PILATUS 1M detector has been installed at the four-crystal monochromator beamline of PTB at the electron storage ring BESSY II in Berlin. Due to its windowless operation, the detector can be used in the entire photon energy range of the beamline from 10 keV down to 1.75 keV for small-angle X-ray scattering (SAXS) experiments and anomalous SAXS (ASAXS) at absorption edges of light elements. The radiometric and geometric properties of the detector like quantum efficiency, pixel pitch and module alignment have been determined with low uncertainties. The first grazing incidence SAXS (GISAXS) results demonstrate the superior resolution in momentum transfer achievable at low photon energies.Comment: accepted by Journal of Synchrotron Radiatio

Rhetorics of Cancer in America

This dissertation examines the constitutive functions of multimodal cancer rhetoric in America and critiques the resulting ideological consequences. This study locates the multimodal manifestations of American cancer rhetoric within three realms – textual/oral, visual/material, and bodily/performative. Beginning in the discursive realm, it traces the metaphoric evolution of the “War on Cancer” and the “Cancer Moonshot Initiative” in presidential rhetoric before then moving to an analysis of artifacts from American cancer rhetoric’s nondiscursive formations. For the visual/material modality, this study analyzes the pink breast cancer “awareness” ribbon and the yellow Livestrong cancer “support” bracelet; for the bodily/performative modality, it then considers two portrayals of cancered bodies in popular media – Walter White from the television series Breaking Bad and the featured childhood cancer patients from St. Jude Children’s Research Hospital. To better understand the ongoing identification processes within and among the various modalities of American cancer rhetoric, this dissertation expands upon several theories of constitutive rhetoric. First, it utilizes an extended concept of constitutive metaphors to properly ascertain the identification and ideological power of the martial and space exploration metaphoric frameworks underlying the “War on Cancer” and the “Cancer Moonshot Initiative.” Second, it positions the pink ribbon and yellow bracelet of American cancer culture as iconic objects and locates their identificatory and ideological impact as emanating from their constitutive materiality. Finally, this study advances a narrative-based framework for understanding the constitutive corporality of cancered bodies in media. By attending to the physical contours of cancered bodies, this study effectively demonstrates the identity and ideological force of such bodies. Overarchingly, however, this dissertation contributes to a more nuanced understanding of constitutive theory through its focus upon cancer’s paradoxical status as an “invisible illness.” That is, although initially invisible, cancer transforms into a highly visible disease when medically treated – and this tension between what is visible and what is not, and its impact on processes of identification – demonstrates the latent power of invisibility in constitutive rhetorics

Correlated Diffuse X-ray Scattering from Periodically Nano-Structured Surfaces

Laterally periodic nanostructures were investigated with grazing incidence small angle X-ray scattering. To support an improved reconstruction of nanostructured surface geometries, we investigated the origin of the contributions to the diffuse scattering pattern which is correlated to the surface roughness. Resonant diffuse scattering leads to a palm-like structure of intensity sheets. Dynamic scattering generates the so-called Yoneda band caused by a resonant scatter enhancement at the critical angle of total reflection and higher-order Yoneda bands originating from a subsequent diffraction of the Yoneda enhanced scattering at the grating. Our explanations are supported by modelling using a solver for the time-harmonic Maxwell's equations based on the finite-element method

Traceable GISAXS measurements for pitch determination of a 25 nm self-assembled polymer grating

The feature sizes of only a few nanometers in modern nanotechnology and next-generation microelectronics continually increase the demand for suitable nanometrology tools. Grazing incidence small-angle X-ray scattering (GISAXS) is a versatile technique to measure lateral and vertical sizes in the nm-range, but the traceability of the obtained parameters, which is a prerequisite for any metrological measurement, has not been demonstrated so far. In this work, the first traceable GISAXS measurements, demonstrated with a self-assembled block copolymer grating structure with a nominal pitch of 25 nm, are reported. The different uncertainty contributions to the obtained pitch value of 24.83(9) nm are discussed individually. The main uncertainty contribution results from the sample-detector distance and the pixel size measurement, whereas the intrinsic asymmetry of the scattering features is of minor relevance for the investigated grating structure. The uncertainty analysis provides a basis for the evaluation of the uncertainty of GISAXS data in a more general context, for example in numerical data modeling.Comment: 9 pages, 6 figures; submitted to Journal of Applied Crystallograph

Content-based Publish/Subscribe in Software-defined Networks

With SDN, content-based publish/subscribe can be implemented on the network layer instead of using an application layer broker network. We present two methods realizing notification distribution with OpenFlow and P4, respectively

From Maya Pyramids to Paleoindian Projectile Points: the Importance of Public Outreach in Archaeology

Public outreach in archaeology can have a valuable impact on education, culture, society and even on the economy. However, it should not be relegated to the addendum of our research projects. Here we present two case studies that the authors have been actively involved in where outreach was a central part of the investigations. Following this, we outline a basic framework for conducting outreach in both the short- and long-term. While these are not perfect examples, they are intended to get archaeologists, as a community, thinking about the real and practical implications of conducting public outreach. Beyond the educational value, it is important to recognize the economic implication of our work to local communities. If we do not communicate the value of our research, then we have only ourselves to blame