TY - JOUR A1 - Conzen, Catharina A1 - Albanna, Walid A1 - Weiss, Miriam A1 - Kürten, David A1 - Vilser, Walthard A1 - Kotliar, Konstantin A1 - Zäske, Charlotte A1 - Clusmann, Hans A1 - Schubert, Gerrit Alexander T1 - Vasoconstriction and Impairment of Neurovascular Coupling after Subarachnoid Hemorrhage: a Descriptive Analysis of Retinal Changes JF - Translational Stroke Research N2 - Impaired cerebral autoregulation and neurovascular coupling (NVC) contribute to delayed cerebral ischemia after subarachnoid hemorrhage (SAH). Retinal vessel analysis (RVA) allows non-invasive assessment of vessel dimension and NVC hereby demonstrating a predictive value in the context of various neurovascular diseases. Using RVA as a translational approach, we aimed to assess the retinal vessels in patients with SAH. RVA was performed prospectively in 24 patients with acute SAH (group A: day 5–14), in 11 patients 3 months after ictus (group B: day 90 ± 35), and in 35 age-matched healthy controls (group C). Data was acquired using a Retinal Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and NVC using flicker-light excitation. Diameter of retinal vessels—central retinal arteriolar and venular equivalent—was significantly reduced in the acute phase (p < 0.001) with gradual improvement in group B (p < 0.05). Arterial NVC of group A was significantly impaired with diminished dilatation (p < 0.001) and reduced area under the curve (p < 0.01) when compared to group C. Group B showed persistent prolonged latency of arterial dilation (p < 0.05). Venous NVC was significantly delayed after SAH compared to group C (A p < 0.001; B p < 0.05). To our knowledge, this is the first clinical study to document retinal vasoconstriction and impairment of NVC in patients with SAH. Using non-invasive RVA as a translational approach, characteristic patterns of compromise were detected for the arterial and venous compartment of the neurovascular unit in a time-dependent fashion. Recruitment will continue to facilitate a correlation analysis with clinical course and outcome. Y1 - 2018 U6 - https://doi.org/10.1007/s12975-017-0585-8 SN - 1868-601X IS - 9 SP - 284 EP - 293 PB - Springer Nature CY - Cham ER - TY - RPRT A1 - Conan, Yulian A1 - D'Haeyer, R. A1 - Béguin, P. A1 - Döring, Bernd A1 - Kuhnhenne, Markus A1 - Bayo, E. T1 - Steel in low-rise building : a symbiosis of cold formed sections and light rolled profiles : final report. Contract-No. 7215-PP/070. EUR 22080 en Y1 - 2006 SN - 92-79-02082-X PB - Office for Official Publications of the European Communities CY - Luxembourg ER - TY - JOUR A1 - Colombo, Daniele A1 - Drira, Slah A1 - Frotscher, Ralf A1 - Staat, Manfred T1 - An element-based formulation for ES-FEM and FS-FEM models for implementation in standard solid mechanics finite element codes for 2D and 3D static analysis JF - International Journal for Numerical Methods in Engineering N2 - Edge-based and face-based smoothed finite element methods (ES-FEM and FS-FEM, respectively) are modified versions of the finite element method allowing to achieve more accurate results and to reduce sensitivity to mesh distortion, at least for linear elements. These properties make the two methods very attractive. However, their implementation in a standard finite element code is nontrivial because it requires heavy and extensive modifications to the code architecture. In this article, we present an element-based formulation of ES-FEM and FS-FEM methods allowing to implement the two methods in a standard finite element code with no modifications to its architecture. Moreover, the element-based formulation permits to easily manage any type of element, especially in 3D models where, to the best of the authors' knowledge, only tetrahedral elements are used in FS-FEM applications found in the literature. Shape functions for non-simplex 3D elements are proposed in order to apply FS-FEM to any standard finite element. KW - distorted element KW - ES-FEM KW - FS-FEM KW - non-simplex S-FEM elements KW - S-FEM Y1 - 2022 U6 - https://doi.org/10.1002/nme.7126 SN - 1097-0207 VL - 124 IS - 2 SP - 402 EP - 433 PB - Wiley CY - Chichester ER - TY - JOUR A1 - Coll-Perales, Baldomero A1 - Schulte-Tigges, Joschua A1 - Rondinone, Michele A1 - Gozalvez, Javier A1 - Reke, Michael A1 - Matheis, Dominik A1 - Walter, Thomas T1 - Prototyping and evaluation of infrastructure-assisted transition of control for cooperative automated vehicles JF - IEEE Transactions on Intelligent Transportation Systems N2 - Automated driving is now possible in diverse road and traffic conditions. However, there are still situations that automated vehicles cannot handle safely and efficiently. In this case, a Transition of Control (ToC) is necessary so that the driver takes control of the driving. Executing a ToC requires the driver to get full situation awareness of the driving environment. If the driver fails to get back the control in a limited time, a Minimum Risk Maneuver (MRM) is executed to bring the vehicle into a safe state (e.g., decelerating to full stop). The execution of ToCs requires some time and can cause traffic disruption and safety risks that increase if several vehicles execute ToCs/MRMs at similar times and in the same area. This study proposes to use novel C-ITS traffic management measures where the infrastructure exploits V2X communications to assist Connected and Automated Vehicles (CAVs) in the execution of ToCs. The infrastructure can suggest a spatial distribution of ToCs, and inform vehicles of the locations where they could execute a safe stop in case of MRM. This paper reports the first field operational tests that validate the feasibility and quantify the benefits of the proposed infrastructure-assisted ToC and MRM management. The paper also presents the CAV and roadside infrastructure prototypes implemented and used in the trials. The conducted field trials demonstrate that infrastructure-assisted traffic management solutions can reduce safety risks and traffic disruptions. KW - Automated driving KW - automated vehicles KW - connected automated vehicles KW - CAV KW - experimental evaluation Y1 - 2021 U6 - https://doi.org/10.1109/TITS.2021.3061085 SN - 1524-9050 (Print) SN - 1558-0016 (Online) VL - 23 IS - 7 SP - 6720 EP - 6736 PB - IEEE ER - TY - CHAP A1 - Claßen, R. A1 - Dören, Horst-Peter A1 - Codani, L. A1 - Watermeyer, Klaus T1 - Begleitende Untersuchungen beim Löten mit vorübergehend flüssiger Phase (TL PB) einschließlich Aktivkomponente an Verbindungen verschiedener Kupfer- und Kohlenstoffwerkstoffe (CFC). T2 - Fortschritte in der Metallographie. Vortragstexte der 33. Metallographie-Tagung, 15.-17. September 1999 in Rostock. Hrsg. Gerhard Schneider... Praktische Metallographie. Sonderband 31. Y1 - 2013 SP - 97 EP - 104 PB - Werkstoff-Informationsgesellschaft CY - Frankfurt ER - TY - JOUR A1 - Clausnitzer, Julian A1 - Kleefeld, Andreas T1 - A spectral Galerkin exponential Euler time-stepping scheme for parabolic SPDEs on two-dimensional domains with a C² boundary JF - Discrete and Continuous Dynamical Systems - Series B N2 - We consider the numerical approximation of second-order semi-linear parabolic stochastic partial differential equations interpreted in the mild sense which we solve on general two-dimensional domains with a C² boundary with homogeneous Dirichlet boundary conditions. The equations are driven by Gaussian additive noise, and several Lipschitz-like conditions are imposed on the nonlinear function. We discretize in space with a spectral Galerkin method and in time using an explicit Euler-like scheme. For irregular shapes, the necessary Dirichlet eigenvalues and eigenfunctions are obtained from a boundary integral equation method. This yields a nonlinear eigenvalue problem, which is discretized using a boundary element collocation method and is solved with the Beyn contour integral algorithm. We present an error analysis as well as numerical results on an exemplary asymmetric shape, and point out limitations of the approach. KW - Nonlinear eigenvalue problems KW - Boundary integral equations, KW - Exponential Euler scheme, KW - Parabolic SPDEs Y1 - 2024 U6 - https://doi.org/10.3934/dcdsb.2023148 SN - 1531-3492 SN - 1553-524X (eISSN) VL - 29 IS - 4 SP - 1624 EP - 1651 PB - AIMS CY - Springfield ER - TY - JOUR A1 - Claessens, J. A1 - Fuchsberger, A. A1 - Günther, C. A1 - Horn, G. A1 - Howker, K. A1 - Hulsebosch, R.J. A1 - Mitchell, C. A1 - Paterson, K. A1 - Preneel, B. A1 - Schellekens, D. A1 - Schuba, Marko T1 - Pioneering Advanced Mobile Privacy and Security Y1 - 2003 N1 - electronic proceedings of the 18th IFIP International Information Security Conference, Athens, Greece, May 2003 SP - 1 EP - 17 ER - TY - JOUR A1 - Claessen, O. A1 - Grefen, Dana A1 - Mang, Thomas A1 - Dikland, H. G. A1 - Dikland, H. G. A1 - Duin, M. van T1 - Helle Fensterprofilmaterialien : Alterungsverhalten auf Basis von peroxidisch vernetztem EPDM JF - Kautschuk, Gummi, Kunststoffe : KGK Y1 - 2010 SN - 0948-3276 VL - 63 IS - 9 SP - 350 EP - 360 ER - TY - JOUR A1 - Claer, Mario A1 - Ferrein, Alexander A1 - Schiffer, Stefan T1 - Calibration of a Rotating or Revolving Platform with a LiDAR Sensor JF - Applied Sciences Y1 - 2019 U6 - https://doi.org/10.3390/app9112238 SN - 2076-3417 VL - Volume 9 IS - issue 11, 2238 PB - MDPI CY - Basel ER - TY - JOUR A1 - Ciritsis, Alexander A1 - Horbach, Andreas A1 - Staat, Manfred A1 - Kuhl, Christiane K. A1 - Kraemer, Nils Andreas T1 - Porosity and tissue integration of elastic mesh implants evaluated in vitro and in vivo JF - Journal of Biomedical Materials Research: Part B: Applied Biomaterials N2 - Purpose In vivo, a loss of mesh porosity triggers scar tissue formation and restricts functionality. The purpose of this study was to evaluate the properties and configuration changes as mesh deformation and mesh shrinkage of a soft mesh implant compared with a conventional stiff mesh implant in vitro and in a porcine model. Material and Methods Tensile tests and digital image correlation were used to determine the textile porosity for both mesh types in vitro. A group of three pigs each were treated with magnetic resonance imaging (MRI) visible conventional stiff polyvinylidene fluoride meshes (PVDF) or with soft thermoplastic polyurethane meshes (TPU) (FEG Textiltechnik mbH, Aachen, Germany), respectively. MRI was performed with a pneumoperitoneum at a pressure of 0 and 15 mmHg, which resulted in bulging of the abdomen. The mesh-induced signal voids were semiautomatically segmented and the mesh areas were determined. With the deformations assessed in both mesh types at both pressure conditions, the porosity change of the meshes after 8 weeks of ingrowth was calculated as an indicator of preserved elastic properties. The explanted specimens were examined histologically for the maturity of the scar (collagen I/III ratio). Results In TPU, the in vitro porosity increased constantly, in PVDF, a loss of porosity was observed under mild stresses. In vivo, the mean mesh areas of TPU were 206.8 cm2 (± 5.7 cm2) at 0 mmHg pneumoperitoneum and 274.6 cm2 (± 5.2 cm2) at 15 mmHg; for PVDF the mean areas were 205.5 cm2 (± 8.8 cm2) and 221.5 cm2 (± 11.8 cm2), respectively. The pneumoperitoneum-induced pressure increase resulted in a calculated porosity increase of 8.4% for TPU and of 1.2% for PVDF. The mean collagen I/III ratio was 8.7 (± 0.5) for TPU and 4.7 (± 0.7) for PVDF. Conclusion The elastic properties of TPU mesh implants result in improved tissue integration compared to conventional PVDF meshes, and they adapt more efficiently to the abdominal wall. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 827–833, 2018. Y1 - 2018 U6 - https://doi.org/10.1002/jbm.b.33877 SN - 1552-4981 VL - 106 IS - 2 SP - 827 EP - 833 PB - Wiley CY - New York, NY ER - TY - JOUR A1 - Ciobanu, Octavian A1 - Staat, Manfred A1 - Rahimi, Alireza T1 - The use of open source software in biomechanical finite element analysis JF - Buletinul Institutului Politehnic din Iaşi / Universitatea Tehnică Gh. Asachi, Iaşi Secţia 5, Construcţii de maşini = Machine construction = Bulletin of the Polytechnic Institute of Jassy = Izvestija Jasskogo Politechničeskogo Instituta Y1 - 2008 SN - 1011-2855 VL - 54 IS - 7/8 SP - 213 EP - 220 ER - TY - JOUR A1 - Chwallek, Constanze A1 - Schuh, Günther A1 - Lorscheider, Bernd T1 - Die virtuelle Fabrik Rhein-Ruhr / Schuh, Günther ; Lorscheider, Bernd ; Chwallek, Constanze JF - Ingenieur-Forum Westfalen-Ruhr (2001) Y1 - 2001 SP - 7 EP - 7 ER - TY - RPRT A1 - Chwallek, Constanze A1 - Radach, Karina A1 - Schieferdecker, Richard T1 - Innovation im Mittelstand : Studie zur Innovationsfähigkeit kleiner und mittlerer Unternehmen in der Region Aachen Y1 - 2015 ER - TY - JOUR A1 - Chwallek, Constanze A1 - Nawrath, Lara A1 - Krastina, Anzelika A1 - Bruksle, Ieva T1 - Supportive research on sustainable entrepreneurship and business practices JF - SECA Sustainable Entrepreneurship for Climate Action Y1 - 2024 SN - 978-952-316-514-4 (pdf) SN - 2954-1654 (on-line publication) IS - 3 PB - Lapland University of Applied Sciences Ltd CY - Rovaniemi ER - TY - CHAP A1 - Chwallek, Constanze A1 - Gölzer, Kaan A1 - Reichert, Walter T1 - Faymonville – Wachstum als Komplexitätstreiber T2 - Fallstudienkompendium Hidden Champions - Innovationen für den Weltmarkt N2 - Die Fallstudie FAYMONVILLE beschäftigt sich damit, wie es dem Familienunternehmen Faymonville aus Ostbelgien gelungen ist, sich zu einem der führenden Hersteller in seiner Branche zu entwickeln. Die gezielte Identifizierung neuer Märkte, die Fokussierung auf die relevanten Kundenbedürfnisse und eine konsistente Produktpolitik mit einem abgestimmten Fertigungskonzept legen die Grundsteine für den Erfolg. Das vorliegende Fallbeispiel zeigt anschaulich, wie es gelingen kann, den prinzipiellen Widerspruch zwischen wirtschaftlicher und kundenindividueller Fertigung erfolgreich aufzulösen. Y1 - 2018 SN - 978-3-658-17829-1 U6 - https://doi.org/10.1007/978-3-658-17829-1_18 SP - 299 EP - 312 PB - Springer Gabler ER - TY - JOUR A1 - Chwallek, Constanze A1 - Frohn, Sandra T1 - Den Mitarbeitern den Rücken stärken JF - Personalwirtschaft N2 - Ein Drittel der Mitarbeiter der Saint-Gobain Glass Deutschland GmbH hat drei Jahre lang regelmäßig seinen Rücken trainiert. Mit Erfolg, wie eine abschließende Evaluation in Zusammenarbeit mit der FH Aachen zeigt. Die Fehltage der Trainingsteilnehmer sind enorm zurückgegangen, während die untrainierten Kollegen weiterhin unter Rückenbeschwerden leiden. Y1 - 2016 SN - 0341-4698 IS - 5 SP - 46 EP - 48 PB - F.A.Z. Business Media CY - Frankfurt a.M. ER - TY - JOUR A1 - Chwallek, Constanze A1 - Felden, Brigit T1 - Wachstumsfinanzierung in der Nachgründungsphase / Chwallek, Constanze ; Felden, Birgit JF - Finanz-Betrieb : FB ; Zeitschrift für Unternehmensfinanzierung und Finanzmanagement. 8 (2006), H. 10 Y1 - 2006 SN - 1437-8981 SP - 664 EP - 675 ER - TY - JOUR A1 - Chwallek, Constanze A1 - Felden, Birgit T1 - Existenzgründung durch Übernahme / Felden, Birgit ; Chwallek, Constanze JF - Finanz-Betrieb : FB ; Zeitschrift für Unternehmensfinanzierung und Finanzmanagement. 8 (2006), H. 6 Y1 - 2006 SN - 1437-8981 SP - 409 EP - 418 ER - TY - BOOK A1 - Chwallek, Constanze A1 - Felden, Birgit T1 - RatingCheck : Wertschöpfungskette / Chwallek, Constanze ; Felden, Birgit Y1 - 2006 PB - Deutscher Sparkassen Verlag CY - Stuttgart ER - TY - JOUR A1 - Chwallek, Constanze A1 - Farzi, T. A1 - Winkelmann, K. A1 - Killich, S. T1 - Etablierung der Dienstleistung Wissensmanagement in vernetzten Organisationsstrukturen / Farzi, T. ; Winkelmann, K. ; Killich, S. ; Hutterer, P. ; Chwallek, C. JF - Kooperation und Arbeit in vernetzten Welten - Tagungsband der GFA Herbstkonferenz 2003 Aachen, 29.September - 01. Oktober 2003, Hrsg.: Luczak, H. Y1 - 2003 SP - 261 EP - 265 PB - Ergonomia Verl. CY - Stuttgart ER -