@article{HeierliPurvesFelberetal.2004, author = {Heierli, Joachim and Purves, Ross S. and Felber, Andreas and Kowalski, Julia}, title = {Verification of nearest-neighbours interpretations in avalanche forecasting}, series = {Annals of Glaciology}, volume = {38}, journal = {Annals of Glaciology}, number = {1}, isbn = {1727-5644}, pages = {84 -- 88}, year = {2004}, abstract = {This paper examines the positive and negative aspects of a range of interpretations of nearest-neighbours models. Measures-oriented and distributionoriented verification methods are applied to categorial, probabilistic and descriptive interpretations of nearest neighbours used operationally in avalanche forecasting in Scotland and Switzerland. The dependence of skill and accuracy measures on base rate is illustrated. The purpose of the forecast and the definition of events are important variables in determining the quality of the forecast. A discussion of the application of different interpretations in operational avalanche forecasting is presented.}, language = {en} } @article{Heuermann2006, author = {Heuermann, Holger}, title = {Verringerung des Phasenrauschens von Oszillatoren durch Dual-Mode-Resonatoren}, series = {HF-Report. 20 (2006), H. 5-6}, journal = {HF-Report. 20 (2006), H. 5-6}, isbn = {1431-827X}, pages = {43 -- 48}, year = {2006}, language = {en} } @article{FoersterMalzerHeberetal.1998, author = {F{\"o}rster, Arnold and Malzer, S. and Heber, J. and Peter, M.}, title = {Vertical transport and relaxation mechanisms in d-doping superlattices. Malzer, S.; Heber, J.; Peter, M.; Eckl, S.; Elpelt, R.; Doehler, G. H.; F{\"o}rster, A.; L{\"u}th, H.}, series = {Physica E: Low-dimensional Systems and Nanostructures. 2 (1998), H. 1-4}, journal = {Physica E: Low-dimensional Systems and Nanostructures. 2 (1998), H. 1-4}, isbn = {1386-9477}, pages = {349 -- 352}, year = {1998}, language = {en} } @article{VogtMottaghyRathetal.2014, author = {Vogt, C. and Mottaghy, Darius and Rath, V. and Marquart, G. and Dijkshoorn, L. and Wolf, A. and Clauser, C.}, title = {Vertical variation in heat flow on the Kola Peninsula: palaeoclimate or fluid flow?}, series = {Geophysical Journal International}, volume = {199}, journal = {Geophysical Journal International}, number = {2}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1365-246X}, doi = {10.1093/gji/ggu282}, pages = {829 -- 843}, year = {2014}, abstract = {Following earlier studies, we present forward and inverse simulations of heat and fluid transport of the upper crust using a local 3-D model of the Kola area. We provide best estimates for palaeotemperatures and permeabilities, their errors and their dependencies. Our results allow discriminating between the two mentioned processes to a certain extent, partly resolving the non-uniqueness of the problem. We find clear indications for a significant contribution of advective heat transport, which, in turn, imply only slightly lower ground surface temperatures during the last glacial maximum relative to the present value. These findings are consistent with the general background knowledge of (i) the fracture zones and the corresponding fluid movements in the bedrock and (ii) the glacial history of the Kola area.}, language = {en} } @article{HoskensTolstikhinFoersteretal.2000, author = {Hoskens, R. C. P. and Tolstikhin, V.I. and F{\"o}rster, Arnold and Roer, T.G. van de}, title = {Vertically integrated transistor-laser structure, take 2}, series = {WOCSDICE 2000, 24th Workshop on Compound Semiconductor Devices and Integrated Circuits held in Europe : May 29 - June 02, 2000, Aegean Sea, Greece.}, journal = {WOCSDICE 2000, 24th Workshop on Compound Semiconductor Devices and Integrated Circuits held in Europe : May 29 - June 02, 2000, Aegean Sea, Greece.}, publisher = {Univ. of Michigan}, address = {Ann Arbor, Mich.}, isbn = {0970311109}, pages = {Getr. Z{\"a}hlung [ca. 200 S.]}, year = {2000}, language = {en} } @article{TheysohnKraffEilersetal.2014, author = {Theysohn, Jens M. and Kraff, Oliver and Eilers, Kristina and Andrade, Dorian and Gerwig, Marcus and Timmann, Dagmar and Schmitt, Franz and Ladd, Mark E. and Ladd, Susanne C. and Bitz, Andreas}, title = {Vestibular effects of a 7 Tesla MRI examination compared to 1.5 T and 0 T in healthy volunteers}, series = {PLoS one}, volume = {9}, journal = {PLoS one}, number = {3}, publisher = {PLOS}, address = {San Francisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0092104}, pages = {e92104}, year = {2014}, abstract = {Ultra-high-field MRI (7 Tesla (T) and above) elicits more temporary side-effects compared to 1.5 T and 3 T, e.g. dizziness or "postural instability" even after exiting the scanner. The current study aims to assess quantitatively vestibular performance before and after exposure to different MRI scenarios at 7 T, 1.5 T and 0 T. Sway path and body axis rotation (Unterberger's stepping test) were quantitatively recorded in a total of 46 volunteers before, 2 minutes after, and 15 minutes after different exposure scenarios: 7 T head MRI (n = 27), 7 T no RF (n = 22), 7 T only B₀ (n = 20), 7 T in \& out B₀ (n = 20), 1.5 T no RF (n = 20), 0 T (n = 15). All exposure scenarios lasted 30 minutes except for brief one minute exposure in 7 T in \& out B₀. Both measures were documented utilizing a 3D ultrasound system. During sway path evaluation, the experiment was repeated with eyes both open and closed. Sway paths for all long-lasting 7 T scenarios (normal, no RF, only B₀) with eyes closed were significantly prolonged 2 minutes after exiting the scanner, normalizing after 15 minutes. Brief exposure to 7 T B₀ or 30 minutes exposure to 1.5 T or 0 T did not show significant changes. End positions after Unterberger's stepping test were significantly changed counter-clockwise after all 7 T scenarios, including the brief in \& out B₀ exposure. Shorter exposure resulted in a smaller alteration angle. In contrast to sway path, reversal of changes in body axis rotation was incomplete after 15 minutes. 1.5 T caused no rotational changes. The results show that exposure to the 7 Tesla static magnetic field causes only a temporary dysfunction or "over-compensation" of the vestibular system not measurable at 1.5 or 0 Tesla. Radiofrequency fields, gradient switching, and orthostatic dysregulation do not seem to play a role.}, language = {en} } @inproceedings{AltayButenwegKlinkel2013, author = {Altay, Okyay and Butenweg, Christoph and Klinkel, Sven}, title = {Vibration control of slender structures by semi-active tuned liquid column dampers}, series = {Conference of the ASCE Engineering Mechanics Institute , Evanston, IL , USA , EMI 2013 , 2013-08-04 - 2013-08-07}, booktitle = {Conference of the ASCE Engineering Mechanics Institute , Evanston, IL , USA , EMI 2013 , 2013-08-04 - 2013-08-07}, pages = {1 Seite}, year = {2013}, language = {en} } @inproceedings{AltayButenwegKlinkel2014, author = {Altay, Okyay and Butenweg, Christoph and Klinkel, Sven}, title = {Vibration mitigation of wind turbine towers by a new semiactive Tuned Liquid Column Damper}, series = {6. Word Congress on Structural Control and Monitoring, 15 - 17 July, 2014 Barcelona,Spain}, booktitle = {6. Word Congress on Structural Control and Monitoring, 15 - 17 July, 2014 Barcelona,Spain}, year = {2014}, language = {en} } @inproceedings{AltayButenwegKlinkeletal.2014, author = {Altay, Okyay and Butenweg, Christoph and Klinkel, Sven and Taddei, Francesca}, title = {Vibration mitigation of wind turbine towers by tuned liquid column dampers}, series = {Proceedings of the 9th European Conference on Structural Dynamics, EURODYN 2014 Porto, Portugal, 30 June - 2 July 2014 / A. Cunha, E. Caetano, .... (eds.)}, booktitle = {Proceedings of the 9th European Conference on Structural Dynamics, EURODYN 2014 Porto, Portugal, 30 June - 2 July 2014 / A. Cunha, E. Caetano, .... (eds.)}, address = {Porto}, organization = {European Conference on Structural Dynamics, EURODYN <9, 2014, Porto>}, isbn = {978-972-752-165-4}, pages = {1531 -- 1538}, year = {2014}, language = {en} } @incollection{AltayTaddeiButenwegetal.2014, author = {Altay, Okyay and Taddei, Francesca and Butenweg, Christoph and Klinkel, Sven}, title = {Vibration mitigation of wind turbine towers with tuned mass dampers}, series = {Wind turbine control and monitoring. (Advances in industrial control)}, booktitle = {Wind turbine control and monitoring. (Advances in industrial control)}, publisher = {Springer}, address = {Cham ; Heidelberg ; New York ; Dordrecht ; London}, isbn = {978-3-319-08412-1 (Print) ; 978-3-319-08413-8 (E-Book)}, doi = {10.1007/978-3-319-08413-8_12}, pages = {337 -- 373}, year = {2014}, abstract = {Because of its minor environmental impact, electricity generation using wind power is getting remarkable. The further growth of the wind industry depends on technological solutions to the challenges in production and construction of the turbines. Wind turbine tower vibrations, which limit power generation efficiency and cause fatigue problems with high maintenance costs, count as one of the main structural difficulties in the wind energy sector. To mitigate tower vibrations auxiliary measures are necessary. The effectiveness of tuned mass damper is verified by means of a numeric study on a 5 MW onshore reference wind turbine. Hereby, also seismic-induced vibrations and soil-structure interaction are considered. Acquired results show that tuned mass damper can effectively reduce resonant tower vibrations and improve the fatigue life of wind turbines. This chapter is also concerned with tuned liquid column damper and a semiactive application of it. Due to its geometric versatility and low prime costs, tuned liquid column dampers are a good alternative to other damping measures, in particular for slender structures like wind turbines.}, language = {en} } @article{MathiakWillneckerPlescher2005, author = {Mathiak, Gerhard and Willnecker, Rainer and Plescher, Engelbert}, title = {Vibrational effects on diffusion experiments}, series = {Microgravity science and technology : international journal for microgravity research and applications}, volume = {Vol. 15}, journal = {Microgravity science and technology : international journal for microgravity research and applications}, number = {No. 1}, issn = {0938-0108}, pages = {295 -- 300}, year = {2005}, language = {en} } @inproceedings{AhlbrinkAlexopoulosAnderssonetal.2009, author = {Ahlbrink, N. and Alexopoulos, Spiros and Andersson, J. and Belhomme, B. and Teixeira Boura, Cristiano Jos{\´e} and Gall, J. and Hirsch, T.}, title = {viCERP - the Virtual Institute of Central Receiver Power Plant}, series = {MATHMOD 2009 - 6th Vienna International Conference on Mathematical Modelling : February 11 - 13, 2009, Vienna, Austria. ARGESIM Report. No. 35}, booktitle = {MATHMOD 2009 - 6th Vienna International Conference on Mathematical Modelling : February 11 - 13, 2009, Vienna, Austria. ARGESIM Report. No. 35}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-3-901608-35-3}, year = {2009}, language = {en} } @incollection{GollandOhrtmann2020, author = {Golland, Alexander and Ohrtmann, Jan-Peter}, title = {Video surveillance: The supervisory authorities' view andrecent case law}, series = {Turning Point in Data Protection Law}, booktitle = {Turning Point in Data Protection Law}, publisher = {Nomos}, address = {Baden-Baden}, isbn = {978-3-8487-6909-4}, doi = {10.5771/9783748921561-175}, pages = {175 -- 178}, year = {2020}, language = {en} } @inproceedings{GaldiHartungDugelay2017, author = {Galdi, Chiara and Hartung, Frank and Dugelay, Jean-Luc}, title = {Videos versus still images: Asymmetric sensor pattern noise comparison on mobile phones}, series = {Electronic Imaging}, booktitle = {Electronic Imaging}, publisher = {Society for Imaging Science and Technology}, address = {Springfield, Virginia}, issn = {2470-1173}, doi = {10.2352/ISSN.2470-1173.2017.7.MWSF-331}, pages = {100 -- 103}, year = {2017}, abstract = {Nowadays, the most employed devices for recoding videos or capturing images are undoubtedly the smartphones. Our work investigates the application of source camera identification on mobile phones. We present a dataset entirely collected by mobile phones. The dataset contains both still images and videos collected by 67 different smartphones. Part of the images consists in photos of uniform backgrounds, especially collected for the computation of the RSPN. Identifying the source camera given a video is particularly challenging due to the strong video compression. The experiments reported in this paper, show the large variation in performance when testing an highly accurate technique on still images and videos.}, language = {en} } @inproceedings{BaaderReiswichBartschetal.2018, author = {Baader, Fabian and Reiswich, M. and Bartsch, M. and Keller, D. and Tiede, E. and Keck, G. and Demircian, A. and Friedrich, M. and Dachwald, Bernd and Sch{\"u}ller, K. and Lehmann, R. and Chojetzki, R. and Durand, C. and Rapp, L. and Kowalski, Julia and F{\"o}rstner, R.}, title = {VIPER - Student research on extraterrestrical ice penetration technology}, series = {Proceedings of the 2nd Symposium on Space Educational Activities}, booktitle = {Proceedings of the 2nd Symposium on Space Educational Activities}, pages = {1 -- 6}, year = {2018}, abstract = {Recent analysis of scientific data from Cassini and earth-based observations gave evidence for a global ocean under a surrounding solid ice shell on Saturn's moon Enceladus. Images of Enceladus' South Pole showed several fissures in the ice shell with plumes constantly exhausting frozen water particles, building up the E-Ring, one of the outer rings of Saturn. In this southern region of Enceladus, the ice shell is considered to be as thin as 2 km, about an order of magnitude thinner than on the rest of the moon. Under the ice shell, there is a global ocean consisting of liquid water. Scientists are discussing different approaches the possibilities of taking samples of water, i.e. by melting through the ice using a melting probe. FH Aachen UAS developed a prototype of maneuverable melting probe which can navigate through the ice that has already been tested successfully in a terrestrial environment. This means no atmosphere and or ambient pressure, low ice temperatures of around 100 to 150K (near the South Pole) and a very low gravity of 0,114 m/s^2 or 1100 μg. Two of these influencing measures are about to be investigated at FH Aachen UAS in 2017, low ice temperature and low ambient pressure below the triple point of water. Low gravity cannot be easily simulated inside a large experiment chamber, though. Numerical simulations of the melting process at RWTH Aachen however are showing a gravity dependence of melting behavior. Considering this aspect, VIPER provides a link between large-scale experimental simulations at FH Aachen UAS and numerical simulations at RWTH Aachen. To analyze the melting process, about 90 seconds of experiment time in reduced gravity and low ambient pressure is provided by the REXUS rocket. In this time frame, the melting speed and contact force between ice and probes are measured, as well as heating power and a two-dimensional array of ice temperatures. Additionally, visual and infrared cameras are used to observe the melting process.}, language = {en} } @article{BhattaraiHorbachStaatetal.2022, author = {Bhattarai, Aroj and Horbach, Andreas and Staat, Manfred and Kowalczyk, Wojciech and Tran, Thanh Ngoc}, title = {Virgin passive colon biomechanics and a literature review of active contraction constitutive models}, series = {Biomechanics}, volume = {2}, journal = {Biomechanics}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2673-7078}, doi = {10.3390/biomechanics2020013}, pages = {138 -- 157}, year = {2022}, abstract = {The objective of this paper is to present our findings on the biomechanical aspects of the virgin passive anisotropic hyperelasticity of the porcine colon based on equibiaxial tensile experiments. Firstly, the characterization of the intestine tissues is discussed for a nearly incompressible hyperelastic fiber-reinforced Holzapfel-Gasser-Ogden constitutive model in virgin passive loading conditions. The stability of the evaluated material parameters is checked for the polyconvexity of the adopted strain energy function using positive eigenvalue constraints of the Hessian matrix with MATLAB. The constitutive material description of the intestine with two collagen fibers in the submucosal and muscular layer each has been implemented in the FORTRAN platform of the commercial finite element software LS-DYNA, and two equibiaxial tensile simulations are presented to validate the results with the optical strain images obtained from the experiments. Furthermore, this paper also reviews the existing models of the active smooth muscle cells, but these models have not been computationally studied here. The review part shows that the constitutive models originally developed for the active contraction of skeletal muscle based on Hill's three-element model, Murphy's four-state cross-bridge chemical kinetic model and Huxley's sliding-filament hypothesis, which are mainly used for arteries, are appropriate for numerical contraction numerical analysis of the large intestine.}, language = {en} } @article{UllrichGrottkeRossaintetal.2010, author = {Ullrich, Sebastian and Grottke, Oliver and Rossaint, Rolf and Staat, Manfred and Deserno, Thomas M. and Kuhlen, Torsten}, title = {Virtual Needle Simulation with Haptics for Regional Anaesthesia}, pages = {1 -- 3}, year = {2010}, language = {en} } @article{BartellaKamalScholletal.2019, author = {Bartella, Alexander K. and Kamal, Mohammad and Scholl, Ingrid and Schiffer, Stefan and Steegmann, Julius and Ketelsen, Dominik and H{\"o}lzle, Frank W. and Lethaus, Bernd}, title = {Virtual reality in preoperative imaging in maxillofacial surgery: implementation of "the next level"?}, series = {British Journal of Oral and Maxillofacial Surgery}, volume = {57}, journal = {British Journal of Oral and Maxillofacial Surgery}, number = {7}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0266-4356}, doi = {10.1016/j.bjoms.2019.02.014}, pages = {644 -- 648}, year = {2019}, language = {en} } @inproceedings{MertenConradKaemperetal.2006, author = {Merten, Sabine and Conrad, Thorsten and K{\"a}mper, Klaus-Peter and Picard, Antoni and Sch{\"u}tze, Andreas}, title = {Virtual Technology Labs - an efficient tool for the preparation of hands-on-MEMS-courses in training foundries}, year = {2006}, abstract = {Hands-on-training in high technology areas is usually limited due to the high cost for lab infrastructure and equipment. One specific example is the field of MEMS, where investment and upkeep of clean rooms with microtechnology equipment is either financed by production or R\&D projects greatly reducing the availability for education purposes. For efficient hands-on-courses a MEMS training foundry, currently used jointly by six higher education institutions, was established at FH Kaiserslautern. In a typical one week course, students manufacture a micromachined pressure sensor including all lithography, thin film and packaging steps. This compact and yet complete program is only possible because participants learn to use the different complex machines in advance via a Virtual Training Lab (VTL). In this paper we present the concept of the MEMS training foundry and the VTL preparation together with results from a scientific evaluation of the VTL over the last three years.}, subject = {Virtuelles Laboratorium}, language = {en} } @article{ReisgenSchleserMokrovetal.2011, author = {Reisgen, Uwe and Schleser, Markus and Mokrov, Oleg and Zabirov, Alexander}, title = {Virtual welding equipment for simulation of GMAW processes with integration of power source regulation}, series = {Frontiers of materials science}, volume = {Vol. 5}, journal = {Frontiers of materials science}, number = {Iss. 2}, publisher = {Springer}, address = {Berlin}, issn = {2095-0268 (E-Journal); 2095-025X (Print)}, pages = {79 -- 89}, year = {2011}, language = {en} }