@inbook{33813, abstract = {{Today, mobile and embedded real-time systems have to cope with the migration and allocation of multiple software tasks running on top of a real-time operating system (RTOS) residing on one or several system processors. Each RTOS has to be configured towards the individual needs of the application and environment. For this, different scheduling strategies and task priorities have to be evaluated in order to keep execution and response times for a given task set. Abstract RTOS simulation is applied to analyze different parameters in early design phases. This chapter presents a SystemC RTOS library for abstract yet accurate RTOS sim- ulation, supporting modeling of preemption in the presence of prioritized and nested interrupts. After introducing basic principles of abstract RTOS simula- tion, we present our SystemC library in detail. Thereafter, we discuss related approaches and close with applications in electronic automotive systems design and some evaluations.}}, author = {{Zabel, Henning and Müller, Wolfgang and Gerstlauer, Andreas}}, booktitle = {{Hardware Dependent Software - Principles and Practice}}, editor = {{Ecker, Wolfgang and Müller, Wolfgang and Dömer, Rainer}}, isbn = {{978-1-4020-9435-4}}, keywords = {{RTOS Modelling, RTOS Simulation, SystemC, Task Scheduling, Interrupt Analysis}}, pages = {{233--260}}, publisher = {{Springer Verlag}}, title = {{{Accurate RTOS Modelling and Analysis with SystemC}}}, doi = {{10.1007/978-1-4020-9436-1_9}}, year = {{2009}}, } @inproceedings{11806, abstract = {{Microphone arrays represent the basis for many challenging acoustic sensing tasks. The accuracy of techniques like beamforming directly depends on a precise knowledge of the relative positions of the sensors used. Unfortunately, for certain use cases manually measuring the geometry of an array is not feasible due to practical constraints. In this paper we present an approach to unsupervised shape calibration of microphone array networks. We developed a hierarchical procedure that first performs local shape calibration based on coherence analysis and then employs SRP-PHAT in a network calibration method. Practical experiments demonstrate the effectiveness of our approach especially for highly reverberant acoustic environments.}}, author = {{Hennecke, Marius and Ploetz, Thomas and Fink, Gernot A. and Schmalenstroeer, Joerg and Haeb-Umbach, Reinhold}}, booktitle = {{IEEE/SP 15th Workshop on Statistical Signal Processing (SSP 2009)}}, keywords = {{acoustic sensing tasks, array geometry, calibration, coherence analysis, hierarchical procedure, local shape calibration, microphone array networks, microphone arrays, network calibration method, sensor arrays, SRP-PHAT, unsupervised shape calibration}}, pages = {{257--260}}, title = {{{A hierarchical approach to unsupervised shape calibration of microphone array networks}}}, doi = {{10.1109/SSP.2009.5278589}}, year = {{2009}}, } @inproceedings{37066, abstract = {{Today, mobile and embedded real-time systems have to cope with the migration and allocation of multiple software tasks running on top of a real-time operating system (RTOS) residing on one or multiple system processors. Abstract RTOS simulations and timing analysis applies for fast and early estimation to configure it towards the individual needs of the application and environment. In this context, a high accuracy of the simulation compared to an instruction set simulation (ISS) is of key importance. In this paper, we investigate the accuracy of abstract RTOS simulation and compare it to ISS and the behavior of the physical system. We show that we can reach an increased accuracy of the simulation when we inject noise into the time model. Our results indicate that it is sufficient to inject uniformly distributed random time values to the RTOS real-time clock.}}, author = {{Zabel, Henning and Müller, Wolfgang}}, booktitle = {{Proceedings of DATE'09}}, isbn = {{978-1-4244-3781-8}}, keywords = {{Timing, Analytical models, Clocks, Performance analysis, Scheduling, Operating systems, Delay, Real time systems, Application software, Context modeling}}, title = {{{Increased Accuracy through Noise Injection in Abstract RTOS Simulation}}}, doi = {{10.1109/DATE.2009.5090925}}, year = {{2009}}, } @inproceedings{17272, abstract = {{In developmental research, tutoring behavior has been identified as scaffolding infants' learning processes. It has been defined in terms of child-directed speech (Motherese), child-directed motion (Motionese), and contingency. In the field of developmental robotics, research often assumes that in human-robot interaction (HRI), robots are treated similar to infants, because their immature cognitive capabilities benefit from this behavior. However, according to our knowledge, it has barely been studied whether this is true and how exactly humans alter their behavior towards a robotic interaction partner. In this paper, we present results concerning the acceptance of a robotic agent in a social learning scenario obtained via comparison to adults and 8-11 months old infants in equal conditions. These results constitute an important empirical basis for making use of tutoring behavior in social robotics. In our study, we performed a detailed multimodal analysis of HRI in a tutoring situation using the example of a robot simulation equipped with a bottom-up saliency-based attention model. Our results reveal significant differences in hand movement velocity, motion pauses, range of motion, and eye gaze suggesting that for example adults decrease their hand movement velocity in an Adult-Child Interaction (ACI), opposed to an Adult-Adult Interaction (AAI) and this decrease is even higher in the Adult-Robot Interaction (ARI). We also found important differences between ACI and ARI in how the behavior is modified over time as the interaction unfolds. These findings indicate the necessity of integrating top-down feedback structures into a bottom-up system for robots to be fully accepted as interaction partners.}}, author = {{Vollmer, Anna-Lisa and Lohan, Katrin Solveig and Fischer, Kerstin and Nagai, Yukie and Pitsch, Karola and Fritsch, Jannik and Rohlfing, Katharina and Wrede, Britta}}, booktitle = {{Development and Learning, 2009. ICDL 2009. IEEE 8th International Conference on Development and Learning}}, keywords = {{robot simulation, hand movement velocity, robotic interaction partner, robotic agent, robot-directed interaction, multimodal analysis, Motionese, Motherese, intelligent tutoring systems, immature cognitive capability, human computer interaction, eye gaze, child-directed speech, child-directed motion, bottom-up system, bottom-up saliency-based attention model, adult-robot interaction, adult-child interaction, adult-adult interaction, human-robot interaction, action learning, social learning scenario, social robotics, software agents, top-down feedback structures, tutoring behavior}}, pages = {{1--6}}, publisher = {{IEEE}}, title = {{{People modify their tutoring behavior in robot-directed interaction for action learning}}}, doi = {{10.1109/DEVLRN.2009.5175516}}, year = {{2009}}, } @inproceedings{9568, abstract = {{A simple pre-stress estimate method of Langevin transducers is studied. The measurement setup consists of a capacitor, an impedance converter and a voltmeter. Based on the piezoelectric equation and the basic circuit theory, the mathematical expression between the pre-stress and the voltage across the capacitor is derived. The pre-stress level can then be calculated out of the measurement of the capacitor voltage. In order to evaluate the precision of this method, a force washer is used to measure the pre-stress of the Langevin transducer. The result shows the pre-stress level obtained from this method is 30-40\% higher than the pre-stress level measured by the force washer. This method is simple and can be used to estimate the pre-stress of various Langevin transducers. The precision of this method can be raised if d33 is identified under different pre-stress levels.}}, author = {{Bo, Fu and Ting, Li and Hemsel, Tobias}}, booktitle = {{Piezoelectricity, Acoustic Waves, and Device Applications, 2008. SPAWDA 2008. Symposium on}}, keywords = {{capacitors, impedance convertors, piezoelectric transducers, stress analysis, Langevin transducers, basic circuit theory, capacitor, impedance converter, piezoelectric equation, pre-stress estimating method, voltmeter, Capacitors, Educational institutions, Equations, Force measurement, Impedance measurement, Manufacturing, Mechatronics, Piezoelectric transducers, Voltage, Voltmeters, Langevin transducer, capacitor, piezoelectric element, pre-stress}}, pages = {{324--327}}, title = {{{A simple pre-stress estimating method of langevin transducers}}}, doi = {{10.1109/SPAWDA.2008.4775801}}, year = {{2008}}, } @article{39941, author = {{Rösler, Margit and Voit, Michael}}, issn = {{1815-0659}}, journal = {{Symmetry, Integrability and Geometry: Methods and Applications}}, keywords = {{Geometry and Topology, Mathematical Physics, Analysis}}, number = {{083}}, pages = {{9pp}}, publisher = {{SIGMA (Symmetry, Integrability and Geometry: Methods and Application)}}, title = {{{A Limit Relation for Dunkl-Bessel Functions of Type A and B}}}, doi = {{10.3842/sigma.2008.083}}, volume = {{4}}, year = {{2008}}, } @article{5658, abstract = {{Email communication is encumbered with a mass of email messages which their recipients have neither requested nor require. Even worse, the impacts of these messages are far from being simply an annoyance, as they also involve economic damage. This manuscript examines the resource ?email addresses?, which is vital for any potential bulk mailer and spammer. Both a methodology and a honeypot conceptualization for implementing an empirical analysis of the usage of email addresses placed on the Internet are proposed here. Their objective is to assess, on a quantitative basis, the extent of the current harassment and its development over time. This ?framework? is intended to be extensible to measuring the effectiveness of address-obscuring techniques. The implementation of a pilot honeypot is described, which led to key findings, some of them being: (1) Web placements attract more than two-thirds (70\%) of all honeypot spam emails, followed by newsgroup placements (28.6\%) and newsletter subscriptions (1.4\%), (2) the proportions of spam relating to the email addresses? top-level domain can be statistically assumed to be uniformly distributed, (3) More than 43\% of addresses on the web have been abused, whereas about 27\% was the case for addresses on newsgroups and only about 4\% was the case for addresses used for a newsletter subscription, (4) Regarding the development of email addresses? attractiveness for spammers over time, the service ?web sites? features a negative linear relationship, whereas the service ?Usenet? hows a negative exponential relationship. (5) Only 1.54\% of the spam emails showed an interrelation between the topic of the spam email and that of the location where the recipient?s address was placed, so that spammers are assumed to send their emails in a ?context insensitive? manner. The results of the empirical analysis motivate the need for the protection of email addresses through obscuration. We analyze this need by formulating requirements for address obscuring techniques and we reveal to which extent today?s most relevant approaches fulfill these requirements.}}, author = {{Schryen, Guido}}, journal = {{Computers & Security}}, keywords = {{Address-obfuscating techniques, email, empirical analysis, honeypot, security by design, security by obscurity, spam}}, number = {{5}}, pages = {{361--372}}, publisher = {{Elsevier}}, title = {{{The Impact that Placing Email Addresses on the Internet has on the Receipt of Spam ? An Empirical Analysis}}}, volume = {{2}}, year = {{2007}}, } @article{10646, author = {{Danne, Klaus and Mühlenbernd, Roland and Platzner, Marco}}, issn = {{1751-8601}}, journal = {{IET Computers Digital Techniques}}, keywords = {{reconfigurable architectures, resource allocation, device reconfiguration time, dynamic hardware reconfiguration, dynamically reconfigurable hardware, light-weight runtime system, merge server distribute load, periodic real-time tasks, runtime system overheads, schedulability analysis, scheduling technique, server-based execution, synthesis tool flow}}, number = {{4}}, pages = {{295--302}}, title = {{{Server-based execution of periodic tasks on dynamically reconfigurable hardware}}}, doi = {{10.1049/iet-cdt:20060186}}, volume = {{1}}, year = {{2007}}, } @inproceedings{11785, abstract = {{In this paper we present a novel channel impulse response estimation technique for block-oriented OFDM transmission based on combining estimators: the estimates provided by a Kalman filter operating in the time domain and a Wiener filter in the frequency domain are optimally combined by taking into account their estimated error covariances. The resulting estimator turns out to be identical to the MAP estimator of correlated jointly Gaussian mean vectors. Different variants of the proposed scheme are experimentally investigated in an EEEE 802.11a-like system setup. They compare favourably with known approaches from the literature resulting in reduced mean square estimation error and bit error rate. Further, robustness and complexity issues are discussed}}, author = {{Haeb-Umbach, Reinhold and Bevermeier, Maik}}, booktitle = {{IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2007)}}, keywords = {{bit error rate, block-oriented OFDM transmission, channel estimation, channel impulse response estimation, combining estimators, error statistics, frequency domain estimation, Gaussian mean vectors, Gaussian processes, Kalman filter, Kalman filters, MAP estimator, maximum likelihood estimation, OFDM channel estimation, OFDM modulation, time domain estimation, time-frequency analysis, Wiener filter, Wiener filters}}, pages = {{III--277--III--280}}, title = {{{OFDM Channel Estimation Based on Combined Estimation in Time and Frequency Domain}}}, doi = {{10.1109/ICASSP.2007.366526}}, volume = {{3}}, year = {{2007}}, } @inproceedings{11883, abstract = {{In this paper, we experimentally evaluate algorithms for velocity estimation of a GSM 900 mobile terminal which are based on the analysis of the statistical properties of the fast fading process. It is shown how theses statistics can be obtained from the training sequences present in downlink transmission bursts without establishing an active connection. Realistic simulations of a GSM channel according to the COST 207 channel models have been conducted. These models incorporate effects like multipath propagation, fading, cochannel interference and additive noise. It is shown that velocity estimation by searching for the maximum slope of the power density spectrum of the fast fading performs best.}}, author = {{Peschke, Sven and Haeb-Umbach, Reinhold}}, booktitle = {{4th Workshop on Positioning Navigation and Communication (WPNC 2007)}}, keywords = {{additive noise, cellular radio, channel estimation, cochannel interference, COST 207 channel models, downlink transmission bursts, fading channels, fading process, GSM downlink signalling, mobile terminals, multipath channels, multipath propagation, power density spectrum, statistical analysis, statistical properties, telecommunication links, telecommunication terminals, velocity estimation}}, pages = {{217--222}}, title = {{{Velocity Estimation of Mobile Terminals by Exploiting GSM Downlink Signalling}}}, doi = {{10.1109/WPNC.2007.353637}}, year = {{2007}}, } @inproceedings{38784, abstract = {{This article presents the classification tree method for functional verification to close the gap from the specification of a test plan to SystemVerilog (Chandra and Chakrabarty, 2001) test bench generation. Our method supports the systematic development of test configurations and is based on the classification tree method for embedded systems (CTM/ES) (Chakrabarty et al., 2000) extending CTM/ES for random test generation as well as for functional coverage and property specification}}, author = {{Krupp, Alexander and Müller, Wolfgang}}, booktitle = {{Proceedings of the Design Automation & Test in Europe Conference}}, isbn = {{3-9810801-1-4}}, keywords = {{Classification tree analysis, System testing, Embedded system, Safety, Automatic testing, Automation}}, publisher = {{IEEE}}, title = {{{Classification Trees for Functional Coverage and Random Test Generation}}}, doi = {{10.1109/DATE.2006.243902}}, year = {{2006}}, } @inproceedings{11930, abstract = {{For human-machine interfaces in distant-talking environments multichannel signal processing is often employed to obtain an enhanced signal for subsequent processing. In this paper we propose a novel adaptation algorithm for a filter-and-sum beamformer to adjust the coefficients of FIR filters to changing acoustic room impulses, e.g. due to speaker movement. A deterministic and a stochastic gradient ascent algorithm are derived from a constrained optimization problem, which iteratively estimates the eigenvector corresponding to the largest eigenvalue of the cross power spectral density of the microphone signals. The method does not require an explicit estimation of the speaker location. The experimental results show fast adaptation and excellent robustness of the proposed algorithm.}}, author = {{Warsitz, Ernst and Haeb-Umbach, Reinhold}}, booktitle = {{IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2005)}}, keywords = {{acoustic filter-and-sum beamforming, acoustic room impulses, acoustic signal processing, adaptive principal component analysis, adaptive signal processing, architectural acoustics, constrained optimization problem, cross power spectral density, deterministic algorithm, deterministic algorithms, distant-talking environments, eigenvalues and eigenfunctions, eigenvector, enhanced signal, filter-and-sum beamformer, FIR filter coefficients, FIR filter coefficients, FIR filters, gradient methods, human-machine interfaces, iterative estimation, iterative methods, largest eigenvalue, microphone signals, multichannel signal processing, optimisation, principal component analysis, spectral analysis, stochastic gradient ascent algorithm, stochastic processes}}, pages = {{iv/797--iv/800 Vol. 4}}, title = {{{Acoustic filter-and-sum beamforming by adaptive principal component analysis}}}, doi = {{10.1109/ICASSP.2005.1416129}}, volume = {{4}}, year = {{2005}}, } @article{39951, author = {{Rösler, Margit and Rauhut, Holger}}, issn = {{0176-4276}}, journal = {{Constructive Approximation}}, keywords = {{Computational Mathematics, General Mathematics, Analysis}}, number = {{2}}, pages = {{193--218}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Radial Multiresolution in Dimension Three}}}, doi = {{10.1007/s00365-004-0587-0}}, volume = {{22}}, year = {{2005}}, } @article{45416, author = {{Mahnken, Rolf}}, issn = {{0029-5981}}, journal = {{International Journal for Numerical Methods in Engineering}}, keywords = {{Applied Mathematics, General Engineering, Numerical Analysis}}, number = {{7}}, pages = {{1015--1036}}, publisher = {{Wiley}}, title = {{{An inverse finite-element algorithm for parameter identification of thermoelastic damage models}}}, doi = {{10.1002/(sici)1097-0207(20000710)48:7<1015::aid-nme912>3.0.co;2-4}}, volume = {{48}}, year = {{2005}}, } @article{45433, author = {{Mahnken, Rolf and Stein, E. and Bischoff, D.}}, issn = {{0029-5981}}, journal = {{International Journal for Numerical Methods in Engineering}}, keywords = {{Applied Mathematics, General Engineering, Numerical Analysis}}, number = {{5}}, pages = {{1015--1029}}, publisher = {{Wiley}}, title = {{{A stabilization procedure by line-search computation for first order approximation strategies in structural optimization}}}, doi = {{10.1002/nme.1620350505}}, volume = {{35}}, year = {{2005}}, } @article{45435, author = {{Mahnken, Rolf and Stein, Erwin}}, issn = {{0029-5981}}, journal = {{International Journal for Numerical Methods in Engineering}}, keywords = {{Applied Mathematics, General Engineering, Numerical Analysis}}, number = {{7}}, pages = {{1619--1633}}, publisher = {{Wiley}}, title = {{{Adaptive time-step control in creep analysis}}}, doi = {{10.1002/nme.1620280711}}, volume = {{28}}, year = {{2005}}, } @article{6078, abstract = {{Four experiments investigated the influence of a metacontrast-masked prime on temporal order judgments. The main results were (1) that a masked prime reduced the latency of the mask's conscious perception (perceptual latency priming), (2) that this effect was independent of whether the prime suffered strong or weak masking, (3) that it was unaffected by the degree of visual similarity between the prime and the mask, and that (4) there was no difference between congruent and incongruent primes. Finding (1) suggests that location cueing affects not only response times but also the latency of conscious perception. (2) The finding that priming was unaffected by the prime's detectability argues against a response bias interpretation of this effect. (3) Since visual similarity had no effect on the prime's efficiency, it is unlikely that sensory priming was involved. (4) The lack of a divergence between the effects of congruent and incongruent primes implies a functional difference between t}}, author = {{Scharlau, Ingrid and Neumann, Odmar}}, issn = {{0340-0727}}, journal = {{Psychological Research}}, keywords = {{perceptual latency priming, temporal order judgments, masked stimuli, unmasked stimuli, attentional interpretation, response times, location cueing, visual perception, Adult, Attention, Female, Humans, Male, Models, Psychological, Perceptual Masking, Psychometrics, Reaction Time, Task Performance and Analysis, Time Perception, Masking, Reaction Time, Response Latency, Stimulus Parameters, Visual Contrast, Attention, Cues, Priming, Temporal Frequency, Temporal Order (Judgment)}}, number = {{3}}, pages = {{184 -- 196}}, title = {{{Perceptual latency priming by masked and unmasked stimuli: Evidence for an attentional interpretation.}}}, volume = {{67}}, year = {{2003}}, } @article{39959, author = {{Rösler, Margit and de Jeu, Marcel}}, issn = {{0021-9045}}, journal = {{Journal of Approximation Theory}}, keywords = {{Applied Mathematics, General Mathematics, Numerical Analysis, Analysis}}, number = {{1}}, pages = {{110--126}}, publisher = {{Elsevier BV}}, title = {{{Asymptotic Analysis for the Dunkl Kernel}}}, doi = {{10.1006/jath.2002.3722}}, volume = {{119}}, year = {{2002}}, } @article{45425, author = {{Johansson, Magnus and Mahnken, Rolf and Runesson, Kenneth}}, issn = {{0029-5981}}, journal = {{International Journal for Numerical Methods in Engineering}}, keywords = {{Applied Mathematics, General Engineering, Numerical Analysis}}, number = {{11}}, pages = {{1727--1747}}, publisher = {{Wiley}}, title = {{{Efficient integration technique for generalized viscoplasticity coupled to damage}}}, doi = {{10.1002/(sici)1097-0207(19990420)44:11<1727::aid-nme568>3.0.co;2-p}}, volume = {{44}}, year = {{2002}}, } @article{11778, abstract = {{In this paper, it is shown that a correlation criterion is the appropriate criterion for bottom-up clustering to obtain broad phonetic class regression trees for maximum likelihood linear regression (MLLR)-based speaker adaptation. The correlation structure among speech units is estimated on the speaker-independent training data. In adaptation experiments the tree outperformed a regression tree obtained from clustering according to closeness in acoustic space and achieved results comparable with those of a manually designed broad phonetic class tree}}, author = {{Haeb-Umbach, Reinhold}}, journal = {{IEEE Transactions on Speech and Audio Processing}}, keywords = {{acoustic space, adaptation experiments, automatic generation, bottom-up clustering, broad phonetic class regression trees, correlation criterion, correlation methods, maximum likelihood estimation, maximum likelihood linear regression based speaker adaptation, MLLR adaptation, pattern clustering, phonetic regression class trees, speaker-independent training data, speech recognition, speech units, statistical analysis, trees (mathematics)}}, number = {{3}}, pages = {{299--302}}, title = {{{Automatic generation of phonetic regression class trees for MLLR adaptation}}}, doi = {{10.1109/89.906003}}, volume = {{9}}, year = {{2001}}, }