Compton M.,CSIRO |
Barnaghi P.,University of Surrey |
Bermudez L.,Open Geospatial Consortium |
Garcia-Castro R.,Technical University of Madrid |
And 18 more authors.
Journal of Web Semantics | Year: 2012
The W3C Semantic Sensor Network Incubator group (the SSN-XG) produced an OWL 2 ontology to describe sensors and observations - the SSN ontology, available at http://purl.oclc.org/NET/ssnx/ssn. The SSN ontology can describe sensors in terms of capabilities, measurement processes, observations and deployments. This article describes the SSN ontology. It further gives an example and describes the use of the ontology in recent research projects. © 2012 Elsevier B.V. All rights reserved.
Calabrese F.,Fraunhofer Gesellschaft
SAE International Journal of Passenger Cars - Mechanical Systems | Year: 2015
Currently used tire models have shown a certain lack of accuracy in some advanced handling applications. This lack of accuracy is believed to be partly due to thermal effects. In reality, the tire rubber temperature is not constant during the normal operating conditions and it's really well known that the tire friction coefficient strongly depends on the temperature level. The temperature generation, propagation and evolution are the result of a dynamic energy equilibrium between phenomena of different natures. Various mechanisms create a non-uniform temperature distribution in various parts of the tire structure: heat is generated in zones with large cyclic deformations due to the energy dissipated from the rubber strains and in the sliding part of the contact patch due to friction. The rubber cools down because the heat energy transferred to the air (internally and externally) and to the asphalt in the stick zone of the contact patch. The presented thermodynamic tire model allows for the simulation of all these local thermal phenomena and the thermal energy equilibrium is described by the Fourier diffusion equation solved with a finite volume approach. Furthermore the described thermal model is coupled with the structural MBD tire model ‘CDTire/3D’ and with an enhanced magic formula (MF) formulation. The coupling strategy naturally incorporates the structural tire model, while in the case of the MF model some empirical adaptations are needed. Both tire models' behavior is influenced by the local calculated temperature, e.g. by modifying the local friction of the tread/asphalt contact. One result the model clearly shows is the variation of the road holding performance as a consequence of the temperature evolution. The capabilities of the overall model are demonstrated and validated in some illustrative scenarios by using measured date from motorsport applications. Copyright © 2015 SAE International.
Hoyer P.,Fraunhofer Gesellschaft |
Matthaus G.,Friedrich - Schiller University of Jena |
Blumroder U.,Friedrich - Schiller University of Jena |
Fuchsel K.,Friedrich - Schiller University of Jena |
Nolte S.,Friedrich - Schiller University of Jena
Applied Physics Letters | Year: 2011
A nondestructive and contact free method for the characterization of semiconductor devices is presented using stimulated terahertz (THz) emission. For demonstration purposes, nanostructured semiconductor-insulator-semiconductor solar cells are investigated. These solar cells are based on indium tin oxide (ITO) upon black silicon (BS). During illumination with fs laser pulses, free charge carriers are generated at the junction between ITO and BS yielding the emission of broadband THz radiation. Since the THz field strength depends on the acceleration characteristics of the photoinduced charge carriers, phase sensitive detection of the emitted THz signal reflects the existing electric field distribution at the boundary zone. In contrast to existing methods where the sample is illuminated by an additional THz generator, here, the THz emission itself characterizes the sample. Moreover, only the region of THz generation is probed yielding a depth-resolved measurement setup that can be applied for the investigation of semiconductor multilayer systems in general as far as THz generation is supported. © 2011 American Institute of Physics.
Neugebauer R.,Fraunhofer Gesellschaft |
Krausel V.,TU Chemnitz |
Barthel T.,Fraunhofer Institute for Machine Tools and Forming Technology |
Jesche F.,Fraunhofer Institute for Machine Tools and Forming Technology |
Schonherr J.,Fraunhofer Institute for Machine Tools and Forming Technology
CIRP Annals - Manufacturing Technology | Year: 2013
Precision cutting is a single stroke shear cutting process to achieve a flush-cut amount between 60 and 90% of the sheet thickness by using a single-acting standard press. This paper presents a method to quantify the amount of required compression stresses based on theoretical and experimental precision cutting tests in which the stress state is overlaid by an additional radial pre-load on the strip. It was found that even a minimal pre-load of 30% of the yield stress can move the stress level to a state with lower tensile stress. © 2013 CIRP.
Kaiser L.,Fraunhofer Gesellschaft
ICMIT 2014 - 2014 IEEE International Conference on Management of Innovation and Technology | Year: 2014
A safe intellectual property rights (IPR) basis often becomes the decisive competitive advantage in the commercialization of research and development (R&D) results. But many actors in the markets of innovative products claim the lack of transparency in dealing with immaterial goods, especially patents. In this respect the internationalization of R&D adds difficulties, but also chances. This paper tries to categorize the historical and contemporary forces to homogenize the heterogeneous fields of IPR. This includes the question whether an intellectual property (IP) economy exists, is imaginable or only utopian in a worldwide dimension. Which factors play a role? © 2014 IEEE.