TY - JOUR A1 - Grajewski, Matthias A1 - Köster, Michael A1 - Turek, Stefam T1 - Numerical analysis and implementational aspects of a new multilevel grid deformation method JF - Applied Numerical Mathematics N2 - Recently, we introduced and mathematically analysed a new method for grid deformation (Grajewski et al., 2009) [15] we call basic deformation method (BDM) here. It generalises the method proposed by Liao et al. (Bochev et al., 1996; Cai et al., 2004; Liao and Anderson, 1992) [4], [6], [20]. In this article, we employ the BDM as core of a new multilevel deformation method (MDM) which leads to vast improvements regarding robustness, accuracy and speed. We achieve this by splitting up the deformation process in a sequence of easier subproblems and by exploiting grid hierarchy. Being of optimal asymptotic complexity, we experience speed-ups up to a factor of 15 in our test cases compared to the BDM. This gives our MDM the potential for tackling large grids and time-dependent problems, where possibly the grid must be dynamically deformed once per time step according to the user's needs. Moreover, we elaborate on implementational aspects, in particular efficient grid searching, which is a key ingredient of the BDM. Y1 - 2010 U6 - https://doi.org/10.1016/j.apnum.2010.03.017 SN - 0168-9274 VL - 60 IS - 8 SP - 767 EP - 781 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Gronsfeld, Richard A1 - Sparla, Peter A1 - Weinnhold, Wolfgang T1 - Airborne und terrestrisches Laserscanning - neue Tools für den Talsperrenbetreiber? JF - Wasserwirtschaft Y1 - 2010 U6 - https://doi.org/10.1007/BF03241621 SN - 0043-0978 VL - 100 IS - 4 SP - 80 EP - 82 PB - Springer Vieweg CY - Wiesbaden ER - TY - JOUR A1 - Grottke, O. A1 - Braunschweig, T. A1 - Philippen, B. A1 - Gatzweiler, Karl-Heinz A1 - Gronloh, N. A1 - Staat, Manfred A1 - Rossaint, R. A1 - Tolba, R. T1 - A new model for blunt liver injuries in the swine JF - European Surgical Research N2 - Background: To elaborate the impact of new haemostatic agents we developed an instrument for the pressure-controlled induction of blunt liver injuries in a porcine animal model. Materials and Methods: A dilutional coagulopathy of 80% of animal blood volume was induced in 9 anaesthetized pigs. Animals were randomly assigned to be injured with a force of 112 Newton (N) (n = 1), 224 ± 19 N (n = 4) or 355 ± 35 N (n = 4). The impact of injury was measured by blood loss, survival time and coagulation parameters. Liver histology was obtained to evaluate the degree of liver injury. Results: The profound haemodilution resulted in a significant alteration of all coagulation parameters. After inflicting the injury with 355 ± 35 N, both the survival time (30 ± 9 min; p = 0.006) and blood loss (68 ± 16 ml min–1, p = 0.002) were significantly different as compared to injuries with 224 ± 19 N (survival time: 76 ± 20 min, blood loss: 23 ± 4 ml min–1). In contrast, an injury with 112 N led to an insignificant blood loss of only 239 ml. Conclusion: We developed a pressure-controlled clamp that allows for the induction of blunt liver traumas with highly reproducible injuries with a positive correlation with blood loss and survival. Y1 - 2010 U6 - https://doi.org/10.1159/000265053 SN - 1421-9921 VL - 44 IS - 2 SP - 65 EP - 73 PB - Karger CY - Basel ER - TY - CHAP A1 - Gömmel, Andreas A1 - Frauenrath, Tobias A1 - Otten, Mario A1 - Niendorf, Thoralf A1 - Butenweg, Christoph ED - Möser, Michael ED - Schulte-Fortkamp, Brgitte ED - Ochmann, Martin T1 - In-vivo measurements of vocal fold geometry using Magnetic Resonance Imaging T2 - Fortschritte der Akustik - DAGA 2010, 36. Jahrestagung für Akustik Y1 - 2010 SN - 978-3-9808659-8-2 PB - Deutsche Gesellschaft für Akustik CY - Berlin ER - TY - CHAP A1 - Gömmel, Andreas A1 - Niendorf, Thoralf A1 - Frauenrath, Tobias A1 - Otten, Mario A1 - Butenweg, Christoph A1 - Kob, Malte T1 - 3D vocal fold geometry mapping using Magnetic Resonance Imaging T2 - Fortschritte der Akustik : 36. Deutsche Jahrestagung für Akustik, Band 1 Y1 - 2010 SN - 978-3-9808659-8-2 N1 - Fortschritte der Akustik : 36. Deutsche Jahrestagung für Akustik ; 15.-18. März 2010, Berlin SP - 271 EP - 272 PB - Deutsche Gesellschaft für Akustik CY - Berlin ER - TY - JOUR A1 - Göttsche, Joachim A1 - Hoffschmidt, Bernhard A1 - Schmitz, Stefan A1 - Sauerborn, Markus T1 - Solar Concentrating Systems Using Small Mirror Arrays JF - Journal of solar energy engineering N2 - The cost of solar tower power plants is dominated by the heliostat field making up roughly 50% of investment costs. Classical heliostat design is dominated by mirrors brought into position by steel structures and drives that guarantee high accuracies under wind loads and thermal stress situations. A large fraction of costs is caused by the stiffness requirements of the steel structure, typically resulting in ~ 20 kg/m² steel per mirror area. The typical cost figure of heliostats (figure mentioned by Solucar at Solar Paces Conference, Seville, 2006) is currently in the area of 150 €/m² caused by the increasing price of the necessary raw materials. An interesting option to reduce costs lies in a heliostat design where all moving parts are protected from wind loads. In this way, drives and mechanical layout may be kept less robust, thereby reducing material input and costs. In order to keep the heliostat at an appropriate size, small mirrors (around 10x10 cm²) have to be used, which are placed in a box with a transparent cover. Innovative drive systems are developed in order to obtain a cost-effective design. A 0,5x0,5 m² demonstration unit will be constructed. Tests of the unit are carried out with a high-precision artificial sun unit that imitates the sun’s path with an accuracy of less than 0.5 mrad and creates a beam of parallel light with a divergence of less than 4 mrad. Y1 - 2010 U6 - https://doi.org/10.1115/1.4000332 SN - 0199-6231 SN - 1528-8986 (eISSN) VL - 132 IS - 1 PB - ASME CY - New York ER - TY - JOUR A1 - Harms, Alexander A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Schiebahn, Alexander A1 - Thiele, Regina T1 - Herausforderungen an die Fügetechnik: Leichtbau und Kosteneffizienz beim Elektrofahrzeug JF - Elektromobilität made in Aachen. (RWTH-Themen : Berichte aus der Rheinisch-Westfälischen Technischen Hochschule Aachen ; Ausg. 2010, 2) Y1 - 2010 SN - 0179-079X SP - 58 EP - 60 ER - TY - JOUR A1 - Haselgruber, Nikolaus A1 - Mautner, Karin A1 - Thiele, Jan T1 - Usage Space Analysis for Reliability Testing JF - Quality and Reliability Engineering International N2 - During the development process of a complex technical product, one widely used and important technique is accelerated testing where the applied stress on a component is chosen to exceed the reference stress, i.e. the stress encountered in field operation, in order to reduce the time to failure. For that, the reference stress has to be known. Since a complex technical product may fail regarding numerous failure modes, stress in general is highly dimensional rather than scalar. In addition, customers use their products individually, i.e. field operation should be described by a distribution rather than by one scalar stress value. In this paper, a way to span the customer usage space is shown. It allows the identification of worst case reference stress profiles in significantly reduced dimensions with minimal loss of information. The application example shows that even for a complex product like a combustion engine, stress information can be compressed significantly. With low measurement effort it turned out that only three reference stress cycles were sufficient to cover a broad range of customer stress variety. Y1 - 2010 U6 - https://doi.org/10.1002/qre.1155 SN - 1099-1638 N1 - Special Issue: Business and Industrial Statistics: Developments and Industrial Practices in Quality and Reliability VL - 26 IS - 8 SP - 877 EP - 885 PB - Wiley CY - New York ER - TY - CHAP A1 - Havermann, Marc A1 - Seiler, F. A1 - Henning, P. ED - Dillmann, Andreas ED - Heller, Gerd ED - Klaas, Michael ED - Kreplin, Hans-Peter ED - Nitsche, Wolfgang ED - Schröder, Wolfgang T1 - Shock Tunnel Experiments and CFD Simulation of Lateral Jet Interaction in Hypersonic Flows T2 - New Results in Numerical and Experimental Fluid Mechanics VII; Contributions to the 16th STAB/DGLR Symposium Aachen, Germany 2008 Y1 - 2010 SN - 9783642142437 U6 - https://doi.org/10.1007/978-3-642-14243-7_45 N1 - Notes on numerical fluid mechanics and multidisciplinary design 112 SP - 365 EP - 372 PB - Springer CY - Berlin ER - TY - BOOK A1 - Hebel, Christoph T1 - Einsatzmöglichkeiten und Anforderungen von makroskopischen Personenverkehrsnachfragemodellen Y1 - 2010 SN - 978-3-88354-160-0 N1 - Stadt, Region, Land : B, Bericht ; 53 ; Zugl. Aachen, Techn. Hochsch., Diss., 2010 PB - Inst. für Stadtbauwesen und Stadtverkehr, RWTH Aachen CY - Aachen ER -