TWT GmbH Science and Innovation

Neuhausen, Germany

TWT GmbH Science and Innovation

Neuhausen, Germany
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Hagemeyer J.,Bielefeld University | Hilgenstein A.,Bielefeld University | Jungewelter D.,Bielefeld University | Cozzi D.,Bielefeld University | And 11 more authors.
Proceedings of the 2012 NASA/ESA Conference on Adaptive Hardware and Systems, AHS 2012 | Year: 2012

Reconfigurable hardware is gaining a steadily growing interest in the domain of space applications. The ability to reconfigure the information processing infrastructure at runtime together with the high computational power of today's FPGA architectures at relatively low power makes these devices interesting candidates for data processing in space applications. Partial dynamic reconfiguration of FPGAs enables maximum flexibility and can be utilized for performance increase, for improving energy efficiency, and for enhanced fault tolerance. To be able to prove the effectiveness of these novel approaches for satellite payload processing, a highly scalable prototyping environment has been developed, combining dynamically reconfigurable FPGAs with the required interfaces such as SpaceWire, MIL-STD-1553B, and SpaceFibre. Up to 30 SpaceWire interfaces, 5 copper-based SpaceFibre interfaces, and 270 GPIOs can be realized and combined with one to five dynamically reconfigurable Xilinx FPGAs and up to 20 GByte of working memory. The implemented approach for dynamic reconfiguration enables partial reconfiguration at 400 MByte/s. Blind and readback scrubbing is supported and the scrub rate can be adapted individually for different parts of the design. © 2012 IEEE.

Sievers K.,Leibniz Institute For Wissensmedien Knowledge Media Research Center | Wodzicki K.,Leibniz Institute For Wissensmedien Knowledge Media Research Center | Aberle I.,TWT GmbH Science and Innovation | Keckeisen M.,TWT GmbH Science and Innovation | Cress U.,Leibniz Institute For Wissensmedien Knowledge Media Research Center
Computers in Human Behavior | Year: 2015

Online professional networks become more and more important for professional self-presentation, for recruitment processes, and job hunting. While previous studies determine that individuals present themselves authentically on rather privately used social networks, self-presentation on online professional networks is still unexplored. This study examines how validly individuals present themselves on professional networks. It investigates whether an individual's online self-presentation is idealized or rather authentic. 63 owners of a profile on the German professional network XING had to describe themselves twice - first authentically and then idealistically. Both self-descriptions were compared with the ratings of five independent observers who received the participants' XING profiles. Results reveal that observer ratings correlated significantly with some of the profile owners' authentic personality and job-relevant characteristics, but none of them correlated significantly with the idealized self-descriptions of the profile owners. This shows that individuals present themselves rather authentically on XING. © 2015 Elsevier Ltd. All rights reserved.

Gulan S.,TWT GmbH Science and Innovation | Johr S.,TWT GmbH Science and Innovation | Kretschmer R.,TWT GmbH Science and Innovation | Rieger S.,TWT GmbH Science and Innovation | Ditze M.,TWT GmbH Science and Innovation
IEEE International Conference on Industrial Informatics (INDIN) | Year: 2013

The graphical modelling languages UML and SysML, nowadays widely used in industry, integrate different modelling concepts and notations in one standardised framework. However, they lack a clearly defined, unambiguous semantics and thus their formal verification represents a challenge. On the other hand, current safety standards, including ISO 26262, demand such verification especially for safety-relevant systems. The literature proposes a plethora of different semantics and formalisms for UML/SysML. In this paper we compare and summarise existing work on the formalisation of behavioural UML and SysML models and their verification. Our goal is to foster a better understanding of the problems related to UML/SysML formalisation, and to aid people bridging the gap from high level graphical modelling to formal verification techniques. © 2013 IEEE.

Gulan S.,TWT GmbH Science and Innovation | Harnisch J.,Infineon Technologies | Johr S.,TWT GmbH Science and Innovation | Kretschmer R.,TWT GmbH Science and Innovation | And 2 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

Safety-relevant software developed within the automotive domain is subject to the safety standard ISO 26262. In particular, a supplier must show that implemented safety mechanisms sufficiently address relevant failure modes. This involves complex and costly testing procedures. We introduce an early analysis approach for safety mechanisms implemented in safety-relevant software by combining model checking and model-based testing. Model checking is applied to verify the correctness of an abstract a model of the system under test. The verified model is then used to automatically generate tests for the verification of the implemented Safety Elements. The approach has been evaluated in an industrial case study, addressing Analogue Digital Converters as part of the motor control within a hybrid electric vehicle. The results suggest that our approach allows to create high quality test suites. In addition, the test model helps to reduce misunderstandings due to imprecise specification of safety mechanisms. © Springer International Publishing Switzerland 2015.

Vartziotis D.,National Technical University of Athens | Vartziotis D.,NIKI Ltd. Digital Engineering | Vartziotis D.,TWT GmbH Science and Innovation | Wipper J.,TWT GmbH Science and Innovation
Computer Methods in Applied Mechanics and Engineering | Year: 2011

Due to their increased complexity hexahedral elements are more challenging with respect to mesh generation and mesh improvement techniques than tetrahedral elements. In particular, there is a lack of geometry-based all-hexahedral smoothing methods for mesh quality improvement being easy to implement, practicable, and efficient. The recently introduced geometric element transformation method represents a new promising element oriented smoothing concept to resolve this deficiency. By giving a dual octahedron based regularizing transformation this new approach is adapted in order to smooth all-hexahedral meshes. First numerical tests indicate that the resulting smoothing method yields high quality results at least comparable to those of a state of the art global optimization-based approach while being significantly faster. © 2010 Elsevier B.V.

Hudert S.,TWT Science and Innovation GmbH | Ditze M.,TWT Science and Innovation GmbH | Konig S.,Fiducia IT AG | Fassler V.,TWT Science and Innovation GmbH
IEEE International Conference on Emerging Technologies and Factory Automation, ETFA | Year: 2012

Smart connected electromobility will leverage the cross-domain cooperation along a new value chain of stakeholders from the automotive and energy industry. Intelligent charge management, i.e. charging the electric vehicle as a tradeoff between charging costs and personal or operational constraints, represents an important service in an electronic service market for electromobility. The market features the energy supplier as a service provider, the electric vehicle as a service consumer along with intermediate brokers in between. All of them continuously interact to exchange data, thus implementing the vision of an open and global Internet of Services in an electromobile ecosystem. A joint service life cycle management which considers both, the build-time and the runtime view of a service, is essential for such a service market. It allows the service provider to design, implement and deploy services while investigating systems of deployed services and their on-demand consumption at run-time. In this paper we present such an integrated service life cycle model for electronic electromobility market places. The life cycle model will be elaborated by means of an intelligent charge management use case. © 2012 IEEE.

Vartziotis D.,National Technical University of Athens | Vartziotis D.,NIKI Ltd. Digital Engineering | Vartziotis D.,TWT GmbH Science and Innovation | Papadrakakis M.,National Technical University of Athens
Computer Assisted Mechanics and Engineering Sciences | Year: 2013

Mesh smoothing improves mesh quality by node relocation without altering mesh topology. Such methods play a vital role in finite element mesh improvement with a direct consequence on the quality of the discretized solution. In this work, an improved version of the recently proposed geometric element trans- formation method (GETMe) for mesh smoothing is presented. Key feature is the introduction of adaptive concepts, which improve the resulting mesh quality, reduce the number of parameters, and enhance the parallelization capabilities. Implementational aspects are discussed and results of a more efficient version are presented, which demonstrate that GETMe adaptive smoothing yields high quality meshes, is par- ticularly fast, and has a comparably low memory profile. Furthermore, results are compared to those of other state of the art smoothing methods. Copyright © 2013 by Institute of Fundamental Technological Research, Polish Academy of Sciences.

Vartziotis D.,National Technical University of Athens | Vartziotis D.,NIKI Ltd. Digital Engineering | Vartziotis D.,TWT GmbH Science and Innovation | Wipper J.,TWT GmbH Science and Innovation | Papadrakakis M.,National Technical University of Athens
Finite Elements in Analysis and Design | Year: 2013

Mesh quality plays an essential role in finite element applications, since it affects the efficiency of the simulation with respect to solution accuracy and computational effort. Therefore, mesh smoothing techniques are often applied for improving mesh quality while preserving mesh topology. One of these methods is the recently proposed geometric element transformation method (GETMe), which is based on regularizing element transformations. It will be shown numerically that this smoothing method is particularly suitable, from an applicational point of view, since it leads to a significant reduction of discretization errors within the first few smoothing steps requiring only little computational effort. Furthermore, due to reduced condition numbers of the stiffness matrices the performance of iterative solvers of the resulting finite element equations is improved. This is demonstrated for the Poisson equation with a number of meshes of different complexity and type as well as for piecewise linear and quadratic finite element basis functions. Results are compared to those obtained by two variants of Laplacian smoothing and a state of the art global optimization-based approach. © 2012 Elsevier B.V.

Hetterich J.,Lüneburg University | Bonnemeier S.,TWT GmbH Science and Innovation | Pritzke M.,Institute of Business Administration | Georgiadis A.,Lüneburg University
Journal of Environmental Planning and Management | Year: 2012

There are several motives for the adoption of 'green' or sustainable materials for car interiors, for example, the shortage of fossil resources and the resulting oil-price increase, new legal requirements (regulations and laws) which penalise environmental pollution and the changing behaviour patterns of consumers. The latter was the subject of an empirical study involving 106 potential car buyers, who were asked about their attitude to sustainable materials in a car interior. Furthermore, consumers' willingness to pay a premium price for a vehicle interior made of renewable resources was also analysed. The main conclusion is that more than 66% of the respondents would accept green car components for a moderate price increase. The relevance and pressure to substitute fossil materials with renewable ones can be expected to increase. This increase will not only be due to the potential decline of resources, but more notably as a result of consumer demand. © 2012 Copyright Taylor and Francis Group, LLC.

Muller A.,TWT GmbH Science and Innovation | Hudert S.,TWT GmbH Science and Innovation | Fassler V.,TWT GmbH Science and Innovation
Lecture Notes in Informatics (LNI), Proceedings - Series of the Gesellschaft fur Informatik (GI) | Year: 2014

Today's cloud infrastructure platforms such as Amazon Web Services (AWS) allow to deploy and run complex services without having to worry about scalability, reliability and general maintenance tasks. However, with distributed services running on multiple instances and on potentially untrusted nodes, the protection of data and in particular the preservation of privacy has become a huge challenge: On the one hand, data storage must be achieved in a way that an attacker with access to the file system, or in some use cases also the cloud operator, is not able to retrieve critical information such as personal data. On the other hand, the combination of individual data chunks to privacy critical information at runtime must be prevented when creating distributed applications. For example, a commercial location-based service needs information about the location of a device, as well as personal data of the owner for billing issues. Today, both of these details (location and personal data) are kept at the service although a combination of the two is not necessarily needed: a location-based service can operate without knowledge about personal data of the owner and a related billing service without the exact location. This talk focuses on such scenarios and presents ongoing work that is carried out in the BMWi-funded research project Shared EFleet.

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