Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Untersuchung der Porenfüllung von Nanoporösem Aluminiumoxid durch thermoresponsive PNIPAM-Polymer mittels SAXS-Experiment

In this thesis we aim to determine the filling status and thermoresponsive behavior of polymer in the confinement of nanopores of aluminum oxide. The anodic aluminum oxide (AAO) nanopores are obtained by the anodization of the aluminum under certain conditions. The right choice of anodization condition enables us to achieve well-ordered hexagonal arrangement of circular pores. The AAO nanopores are then filled by thermoresponsive poly(N-isopropyl acrylamide) polymers (PNIPAM) with different percentages of solution concentration. The X-ray reflectivity (XRR) from polymers which are wetting on silicon substrates with various solution concentrations is used to determine their wetting and scattering properties. Samples with empty and filled pores are carefully calibrated and examined by small angle X-ray scattering (SAXS). The in-situ SAXS experiment at filled samples is performed at temperatures above and below the lower critical solution temperature (LCST) with the purpose to find differences of the effective pore diameter caused by different wetting behaviors at the pores inner surfaces. The 2D scattering pattern is converted to line profiles which contains the structural information of the sample. An analytical model of SAXS intensity taken from the sample system is adapted to describe the scattering properties of samples under investigation. The parameters of the model are obtained by fitting to the experimental data employing a Monte-Carlo algorithm. It is shown that the developed mathematical model describes the structural parameters of the AAO in reasonable agreement and are in good agreement with previous works. Particular details of the scattering pattern for the different measurements are found qualitatively with the help of a toy model. This model is built up by an analytical solution of the 2D gratings problem containing circular pinholes. The differences in samples with varied polymer solution concentrations as well as the differences for the measurements at various temperatures are estimated with the use of this model. More accurate model that can provide detailed and quantitative analysis of samples differences is explained. In this approach, the accuracy of the sample identification is a question of higher resolution of the measured data which can be gained by a different experimental setup

Mobile app development : challenges and opportunities for automated support

Mobile app development is a relatively new phenomenon that is increasing rapidly due to the ubiquity and popularity of smartphones among end-users. As with any new domain, mobile app development has its own set of new challenges. The work presented in this dissertation has focused on improving the state-of-the-art by understanding the current practices and challenges in mobile app development as well as proposing a new set of techniques and tools based on the identified challenges. To understand the current practices, real challenges and issues in mobile development, we first conducted an explorative field study, in which we interviewed 12 senior mobile developers from nine different companies, followed by a semi-structured survey, with 188 respondents from the mobile development community. Next, we mined and quantitatively and qualitatively analyzed 32K non-reproducible bug reports in one industrial and five open-source bug repositories. Then, we performed a large-scale comparative study of 80K iOS and Android app-pairs and 1.7M reviews by mining the Google Play and Apple app stores. Based on the identified challenges, we first proposed a reverse engineering technique that automatically analyzes a given iOS mobile app and generates a state model of the app. Finally, we proposed an automated technique for detecting inconsistencies in the same mobile app implemented for iOS and Android platforms. To measure the effectiveness of the proposed techniques, we evaluated our methods using various industrial and open-source mobile apps. The evaluation results point to the effectiveness of the proposed model generation and mapping techniques in terms of accuracy and inconsistency detection capability.Applied Science, Faculty ofElectrical and Computer Engineering, Department ofGraduat

The effect of previous gaming experience on game play performance

In this thesis, I looked at how the skills/knowledge gained from playing games from different genres can influence players’ gameplay performance when playing a new game; this is critical as different genres provide players with different abilities. Although understanding players’ gameplay behaviours and performance abilities is one of the growing areas of research, none of the previous research within this area has deeply investigated players’ behaviours and its relation to knowledge/skills gained by playing specific genres. Knowing the details of the skills gained and their influence on performance of target audience’s playing habits plays an important role in making informed decisions about game design. Since many game genres exist, to narrow it down I explored the influence of prior gaming experience, specifically with Role Playing and First Person Shooter games on players’ ability to navigate and solve spatial puzzles in 3D games

Reverse Engineering iOS Mobile Applications

As a result of the ubiquity and popularity of smartphones, the number of third party mobile applications is explosively growing. With the increasing demands of users for new dependable applications, novel software engineering tech-niques and tools geared towards the mobile platform are required to support developers in their program compre-hension and analysis tasks. In this paper, we propose a reverse engineering technique that automatically (1) hooks into, dynamically runs, and analyzes a given iOS mobile application, (2) exercises its user interface to cover the interaction state space and extracts information about the runtime behaviour, and (3) generates a state model of the given application, capturing the user interface states and transitions between them. Our technique is implemented i