TY - JOUR A1 - Lehmann, Matthias A1 - Wittpahl, Christian A1 - Zakour, Hatem Ben A1 - Braun, Alexander T1 - Modeling realistic optical aberrations to reuse existing drive scene recordings for autonomous driving validation JF - Journal of Electronic Imaging N2 - Training autonomous vehicles requires lots of driving sequences in all situations. Collecting and labeling these drive scenes is a very time-consuming and expensive process. Currently, it is not possible to reuse these drive scenes with different optical properties, because there exists no numerically efficient model for the transfer function of the optical system. We present a numerical model for the point spread function (PSF) of an optical system that can efficiently model both experimental measurements and lens design simulations of the PSF. The numerical basis for this model is a nonlinear regression of the PSF with an artificial neural network. The novelty lies in the portability and the parameterization of this model. We present a lens measurement series, yielding a numerical function for the PSF that depends only on the parameters defocus, field, and azimuth. By convolving existing images and videos with this PSF, we generate images as if seen through the measured lens. The methodology applies to any optical scenario, but we focus on the context of autonomous driving, where the quality of the detection algorithms depends directly on the optical quality of the used camera system. With this model, it is possible to reuse existing recordings, with the potential to avoid millions of test drive miles. The parameterization of the optical model allows for a method to validate the functional and safety limits of camera-based advanced driver assistance systems based on the real, measured lens actually used in the product. Y1 - 2019 U6 - https://doi.org/10.1117/1.JEI.28.1.013005 SN - 1560-229X VL - 28 IS - 1 SP - 013005 PB - SPIE ER - TY - JOUR A1 - Leadbetter, S. J. A1 - Hort, M. C. A1 - von Löwis, S. A1 - Weber, Konradin A1 - Witham, C. S. T1 - Modeling the resuspension of ash deposited during the eruption of Eyjafjallajökull in spring 2010 JF - Journal of Geophysical Research: Atmospheres N2 - Eyjafjallajökull, a volcano in southern Iceland, erupted explosively in April and May 2010 depositing ash over a region of more than 3000 km2 to the east and southeast of the volcano. This deposited ash has been frequently remobilized by the wind causing concern for the health of Icelanders living in the region. An investigation was carried out to determine whether it would be possible to produce forecasts of days when high airborne ash concentrations were likely to occur. Information about the spatially varying surface characteristics of the region of deposited ash is not available so in the modeling approach adopted here ash is released from the surface at a rate proportional to the cube of the excess friction velocity (local friction velocity minus a threshold) only when the friction velocity exceeds a threshold. Movement of the resuspended ash is then modeled in a Lagrangian dispersion model. Modeled ash concentrations are compared to observed concentrations from two periods; PM10 observations between 23 May and 2 July 2010 and airborne particle counts between 21 September 2010 and 16 February 2011. More than 66% of the resuspension episodes between May and July are captured by the model and the relative magnitudes of the modeled episodes in this period are in good agreement with the observations. 66% of episodes between October and February are also captured by the model although there is an increase in the false alarm rate which appears to be due to the influence of precipitation. KW - Luftreinhaltung Y1 - 2012 U6 - https://doi.org/10.1029/2011JD016802 SN - 0148-0227 VL - 117 IS - D20 PB - American Geophysical Union (AGU) ER - TY - JOUR A1 - Versümer, Siegbert A1 - Steffens, Jochen A1 - Blättermann, Patrick A1 - Becker-Schweitzer, Jörg T1 - Modelling evaluations of low-level sounds in everyday situations using linear machine learning for variable selection JF - Frontiers in Psychology KW - DOAJ Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-23779 SN - 1664-1078 N1 - Supplementary Material The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fpsyg.2020.570761/full#supplementary-material VL - 11 PB - Frontiers ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Epple, B. A1 - Krohmer, B. T1 - Modelling of pulverised coal combustion by a Eulerian-Eulerian two-phase flow formulation JF - Progress in Computational Fluid Dynamics, An International Journal Y1 - 2005 U6 - https://doi.org/10.1504/pcfd.2005.007067 VL - 5 IS - 6 PB - inderscience ER - TY - CHAP A1 - Jürjens, Jan A1 - Ochoa, Martín A1 - Schmidt, Holger A1 - Marchal, Loïc A1 - Houmb, Siv Hilde A1 - Islam, Shareeful ED - Bernardo, Marco ED - Issarny, Valérie T1 - Modelling Secure Systems Evolution: Abstract and Concrete Change Specifications T2 - Formal Methods for Eternal Networked Software Systems: 11th International School on Formal Methods for the Design of Computer, Communication and Software Systems, SFM 2011, Bertinoro, Italy, June 13-18, 2011. Advanced Lectures N2 - Developing security-critical systems is difficult, and there are many well-known examples of vulnerabilities exploited in practice. In fact, there has recently been a lot of work on methods, techniques, and tools to improve this situation already at the system specification and design. However, security-critical systems are increasingly long-living and undergo evolution throughout their lifetime. Therefore, a secure software development approach that supports maintaining the needed levels of security even through later software evolution is highly desirable. In this chapter, we recall the UMLsec approach to model-based security and discuss on tools and techniques to model and verify evolution of UMLsec models. KW - software evolution KW - UMLsec KW - UMLseCH KW - security Y1 - 2011 UR - https://link.springer.com/chapter/10.1007/978-3-642-21455-4_15 SN - 978-3-642-21455-4 U6 - https://doi.org/10.1007/978-3-642-21455-4_15 VL - LNCS, 6659 SP - 504 EP - 526 PB - Springer CY - Berlin, Heidelberg ER - TY - CHAP A1 - Echternacht, David A1 - Stagge, Hanno A1 - Priebe, Jens A1 - Wiernes, Pablo Ezequiel A1 - Jagielski, Kai A1 - Petri, Anne-Kathrin A1 - Drießen, Sarah A1 - Trevisan, Bianka A1 - Digmayer, Claas A1 - Oberst, Christian A. A1 - Keysselitz, Bärbel A1 - Kremer, Martin A1 - Sieber, Sandra A1 - Krapp, Stefan A1 - Jakobs, Eva-Maria A1 - Frenz, Martin A1 - Lohrberg, Frank A1 - Wachten, Kunibert A1 - Moser, Albert T1 - Modelling, Planning, Design and Evaluation of DC-Distribution Grids T2 - International ETG Congress 2015 : die Energiewende ; blueprints for the new energy age ; proceedings ; November 17 - 18, 2015, World Conference Center, Bonn Y1 - 2015 UR - http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7388494 SP - 289 EP - 295 PB - VDE-Verl. CY - Bonn ER - TY - GEN A1 - Mehlhorn, Nils T1 - Modern Cross-Platform Development for Mobile Applications N2 - While developing for multiple platforms at once seems like a convenient solution, there are several challenges arising when trying to abstract the entire mobile development. This paper is meant to evaluate current cross-platform development for mobile applications. The background for its necessity, its conceptual approach and the problems to face when developing cross-platform were determined and explained in detail. Afterwards, certain solutions were evaluated against the former insights. Based on the results, an informed discussion and conclusion was performed. The mobile environment consist of only two big players by now, Android and iOS. These operating systems differ in architecture, design and consequently in the way applications are developed for each of them. Therefore, high demands are made towards cross-platform solutions. Tools which allow for the creation of applications for multiple platforms at once have to match native applications in regard to user experience and performance. At the same time they need to be able to optimize developments with the goal of being cost efficient. Apache Cordova, Xamarin and NativeScript were selected for evaluation in regard to their ability to meet these requirements. Cordova acts as the comparison group of cross-platform tools. It is the big player in the field and there are reasons for this. However, aspiring solutions with higher nativity and ambitious approaches are emerging. Xamarin and NativeScript deliver top quality results while offering loosely coupled developments. Therefore it is possible to develop high quality applications and still benefit from the advantages of platform-independent solutions. As a consequence mobile development is about to change in the foreseeable future. More sophisticated approaches may lead to a higher number of developments done cross-platform, and rightfully so. KW - cross-plattform KW - mobile KW - Entwicklung KW - cross-platform KW - mobile KW - development KW - M Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-11276 CY - Düsseldorf ER - TY - CHAP A1 - Hurd, Paul A1 - Truckenmueller, Frank A1 - Thamm, Norbert A1 - Pollak, Helmut A1 - Neef, Matthias A1 - Deckers, Mathias T1 - Modern Reaction HP/IP Turbine Technology Advances and Experiences T2 - Proceedings of the ASME Power Conference - 2005 : includes papers from the 2005 International Conference on Power Engineering (ICOPE) ; presented at the 2005 ASME Power Conference, April 5 - 7, 2005, Chicago, Illinois, USA Y1 - 2005 UR - https://asmedigitalcollection.asme.org/POWER/proceedings/POWER2005/41820/425/311927 SN - 0-7918-4182-0 U6 - https://doi.org/10.1115/PWR2005-50085 SP - 425 EP - 435 PB - ASME CY - New York ER - TY - JOUR A1 - Elíasson, Jónas A1 - Palsson, Asgeir A1 - Weber, Konradin T1 - Monitoring ash clouds for aviation JF - Nature KW - Luftreinhaltung Y1 - 2011 U6 - https://doi.org/10.1038/475455b VL - 475 IS - 7357 PB - Springer Nature ER - TY - JOUR A1 - Galban, Craig A1 - Maderwald, Stefan A1 - Eggebrecht, Holger A1 - Grote, Wolfgang A1 - de Greiff, A. A1 - Uffmann, K. A1 - Ladd, M. E. T1 - Monitoring the Effects of Chronic Obstructive Pulmonary Disease on Muscle Elasticity by MR Elastography JF - Proc. Intl. Soc. Mag. Reson. Med. N2 - Men afflicted with chronic obstructive pulmonary disease (COPD) show signs of muscle dysfunction, such as increased muscle fatigue and acidosis during exercise. We hypothesize that muscle elasticity of the lower extremities differs between patients with COPD and age-related controls. The shear modulus of the soleus muscle was measured non-invasively using MR elastography (MRE) at 0%, 5%, 10%, 15%, and 20% of the subject’s maximum applied force. The results from this study showed statistical differences between the patients and controls, even though there were no statistical differences in the maximum applied force. Y1 - 2005 UR - https://cds.ismrm.org/protected/05MProceedings/PDFfiles/02015.pdf VL - 13 SP - 2015 ER -