Comparing selected sub-GHz transceivers : results from the field

Various chip vendors are offering proprietary Sub-1 GHz RF transceivers with an attractive balance between long communication range and low-power consumption. While datasheets reveal many interesting parameters, it is difficult for users to assess performance, robustness and power consumption of such transceivers for a specific application. Furthermore, it is a challenge to determine the appropriate parameter settings for each of the chips. The paper presents measurement results from a several months long field trial featuring selected transceivers from five different chip vendors

Measurement of Galactic Logarithmic Spiral Arm Pitch Angle Using Two-Dimensional Fast Fourier Transform Decomposition

A logarithmic spiral is a prominent feature appearing in a majority of observed galaxies. This feature has long been associated with the traditional Hubble classification scheme, but historical quotes of pitch angle of spiral galaxies have been almost exclusively qualitative. We have developed a methodology, utilizing two-dimensional fast Fourier transformations of images of spiral galaxies, in order to isolate and measure the pitch angles of their spiral arms. Our technique provides a quantitative way to measure this morphological feature. This will allow comparison of spiral galaxy pitch angle to other galactic parameters and test spiral arm genesis theories. In this work, we detail our image processing and analysis of spiral galaxy images and discuss the robustness of our analysis techniques.Comment: 23 pages, 22 figures, and 3 Tables; published in ApJS 199, 33 http://iopscience.iop.org/0067-0049/199/2/33/; software available for download at http://dafix.uark.edu/~ages/downloads.html and http://astro.host.ualr.edu/2DFFT

Gene x Gene Interactions Highlight the Role of Incretin Resistance for Insulin Secretion

Introduction: Genetic polymorphisms in TCF7L2 are the strongest common risk variants for type 2 diabetes mellitus (T2D). We and others have shown that genetic variation in TCF7L2 and WFS1 affect incretin-stimulated insulin secretion. A recent genome-wide association study discovered genetic variants associated with incretin levels. We hypothesized that these SNPs (single nucleotide polymorphisms) interact with the well-known TCF7L2 variant rs7903146 on insulin secretion due to their incretin altering effect.Methods: In this retrospective analysis, we used data from the cross-sectional TUEF-cohort (n = 2929) and a hyperglycemic clamp study using additional GLP-1 infusion at the end of the clamp (n = 76). Insulin secretion was measured by evaluating OGTT-derived indexes of insulin secretion and insulin/C-peptide levels during clamp. We genotyped rs7903146 in TCF7L2, rs10010131 in WFS1, and six SNPs associated with GLP-1 and GIP levels.Results: One of the six incretin-associated SNPs, rs17681684 in GLP2R, exhibited significant SNP x SNP interactions with rs7903146 in TCF7L2 on insulin secretion (p = 0.0024) after correction for multiple testing. Three further SNP‘s showed nominally significant interactions (p < 0.05). In the hyperglycemic clamp study, rs7903146 in TCF7L2 also interacted with rs17681684 on AUC C-peptide during the GLP-1 stimulation phase, thereby replicating the above finding.Conclusion: The findings exemplify the role of SNP x SNP interactions in the genetics of type 2 diabetes mellitus and corroborate the existence of clinically relevant differences in incretin sensitivity

Flickering AGN can explain the strong circumgalactic O VI observed by COS-Halos

Proximity zone fossils (PZFs) are ionization signatures around recently active galactic nuclei (AGNs) where metal species in the circumgalactic medium remain overionized after the AGNs have shut off due to their long recombination time scales. We explore cosmological zoom hydrodynamic simulations, using the EAGLE (Evolution and Assembly of GaLaxies and their Environments) model paired with a non-equilibrium ionization and cooling module including time-variable AGN radiation to model PZFs around star-forming disc galaxies in the z ∼ 0.2 Universe. Previous simulations typically underestimated the O VI content of galactic haloes, but we show that plausible PZF models increase O VI column densities by 2 − 3 × to achieve the levels observed around COS-Halos star-forming galaxies out to 150 kpc. Models with AGN bolometric luminosities 1043.6erg s−1, duty cycle fractions 10 per cent, and AGN lifetimes 106 yr are the most promising, because their supermassive black holes grow at the cosmologically expected rate and they mostly appear as inactive AGN, consistent with COS-Halos. The central requirement is that the typical star-forming galaxy hosted an active AGN within a time-scale comparable to the recombination time of a high metal ion, which for circumgalactic O VI is ≈107 yr. H I, by contrast, returns to equilibrium much more rapidly due to its low neutral fraction and does not show a significant PZF effect. O VI absorption features originating from PZFs appear narrow, indicating photoionization, and are often well aligned with lower metal ion species. PZFs are highly likely to affect the physical interpretation of circumgalactic high ionization metal lines if, as expected, normal galaxies host flickering AGN

CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey

The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) is designed to document the first third of galactic evolution, over the approximate redshift (z) range 8--1.5. It will image >250,000 distant galaxies using three separate cameras on the Hubble Space Telescope, from the mid-ultraviolet to the near-infrared, and will find and measure Type Ia supernovae at z>1.5 to test their accuracy as standardizable candles for cosmology. Five premier multi-wavelength sky regions are selected, each with extensive ancillary data. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies down to a stellar mass of 10^9 M_\odot to z \approx 2, reaching the knee of the ultraviolet luminosity function (UVLF) of galaxies to z \approx 8. The survey covers approximately 800 arcmin^2 and is divided into two parts. The CANDELS/Deep survey (5\sigma\ point-source limit H=27.7 mag) covers \sim 125 arcmin^2 within GOODS-N and GOODS-S. The CANDELS/Wide survey includes GOODS and three additional fields (EGS, COSMOS, and UDS) and covers the full area to a 5\sigma\ point-source limit of H \gtrsim 27.0 mag. Together with the Hubble Ultra Deep Fields, the strategy creates a three-tiered "wedding cake" approach that has proven efficient for extragalactic surveys. Data from the survey are nonproprietary and are useful for a wide variety of science investigations. In this paper, we describe the basic motivations for the survey, the CANDELS team science goals and the resulting observational requirements, the field selection and geometry, and the observing design. The Hubble data processing and products are described in a companion paper.Comment: Submitted to Astrophysical Journal Supplement Series; Revised version, subsequent to referee repor

Internet-of-Things : Digitalisierung zum Anfassen

Drahtlose Embedded-Systeme vernetzen eine grosse Anzahl von Sensoren. Diese Vernetzung von meist energieautarken Knoten steigert den Nutzen und damit den Wert der einzelnen Objekte. Entscheidend für einen erfolgreichen  Business Case sind aber neben der Wahl der optimalen Übertragungstechnologie eine gezielte Speicherung, Verdichtung und Auswertung der gemessenen Daten. Auf Basis der analysierten Messdaten werden Abläufe in Echtzeit dynamisch optimiert und individualisiert. Dadurch werden innovative Geschäftsmodelle und Produkte mit echtem Mehrwert realisiert. Die ZHAW zeigt die Möglichkeiten der Vernetzung zur Umsetzung eines Business Cases live auf der ECC. In den Räumlichkeiten verteilte und drahtlos vernetzte Sensoren erfassen die Schallpegel. Die gezielte Datenanalyse erlaubt Rückschlüsse auf die Besucherbewegungen: Wo ist auf der Konferenz im Moment am meisten los? Ein Bildschirm visualisiert die erfassten Daten und ein Industrieroboter zeigt am Stand den Weg zur momentan interessantesten Stelle der Konferenz. Das Referat beschreibt die technische Umsetzung des drahtlosen Netzwerkes basierend auf LoRaWAN und die verwendeten Verfahren für die Datenanalyse

Towards a novel and applicable approach for Resilience Engineering

Resilience Engineering can provide society and its critical infrastructure and systems with means, methods and technologies to overcome disruptions with as less harm as possible. In this context it is of utmost importance to identify ways to strengthen the adaptive capacity of up to complex socio technical systems. We try to establish Resilience Engineering as away of thinking that enables engineers to use their scientific expertise, creative ingenuity and help society to develop tools to handle all kinds of adverse events properly - from critical system disruptions, natural disasters, global terrorism to large-scale infrastructure failure. For that purpose, we suggest to deliberately limit the scope of Resilience Engineering towards engineering, i.e. mainly technological solutions, in contrast to the main body of Resilience Engineering literature. By that we try to pave the way for the next generation of engineers dealing with the extension from risk analysis and management towards resilience thinking. In short, Resilience Engineering means preserving critical functionality, ensuring graceful degradation and enabling fast recovery of systems with the help of engineered generic capabilities as well as customized technological solutions when the systems witness problems, unexpected disruptions or unexampled events. One central aspect of Resilience Engineering is the ability to quantify and measure resilience. Only adequate and valid indicators will give us the chance for comparatively and absolutely analyzing various systems with respect to their specific resilience. Finally, we need to be able to develop advanced methods for modelling and simulating, in particular for complex systems and their resilience towards adverse events. The presentation will hint at opportunities and research necessities for developing a new and integrated approach to model, simulate and improve the resilience of complex, interdependent, sociotechnical systems

Bluetooth low energy everywhere : using the audio interface to bring Ble features to any smart phone

The integration of Bluetooth Smart Ready in many new smart phones allows them to communicate with low energy sensors, opening new opportunities for interaction with many useful devices. However, there are millions of smart phones in use (or on the market) that do not sport Bluetooth Low Energy. In order to allow owners of such phones to benefit (at least in part) from the services associated with the new Ble interface, a concept allowing the interface of a Ble module to a smart phone through the audio interface has been developed. The audio link is the common denominator to all mobile phones. Appropriate hardware and software was built and successfully tested on Android platforms. A variation of the concept also allows powering the module via the audio interface