@article{ReindlZhengSchwarzetal., author = {Reindl, Klaus and Zheng, Yuanhang and Schwarz, Andreas and Meier, Stefan and Maas, Roland and Sehr, Armin and Kellermann, Walter}, title = {A stereophonic acoustic signal extraction scheme for noisy and reverberant environments}, series = {Computer Speech and Language}, volume = {27}, journal = {Computer Speech and Language}, number = {3}, publisher = {Elsevier}, doi = {10.1016/j.csl.2012.07.011}, pages = {726 -- 745}, abstract = {In this contribution, a novel two-channel acoustic front-end for robust automatic speech recognition in adverse acoustic environments with nonstationary interference and reverberation is proposed. From a MISO system perspective, a statistically optimum source signal extraction scheme based on the multichannel Wiener filter (MWF) is discussed for application in noisy and underdetermined scenarios. For free-field and diffuse noise conditions, this optimum scheme reduces to a Delay \& Sum beamformer followed by a single-channel Wiener postfilter. Scenarios with multiple simultaneously interfering sources and background noise are usually modeled by a diffuse noise field. However, in reality, the free-field assumption is very weak because of the reverberant nature of acoustic environments. Therefore, we propose to estimate this simplified MWF solution in each frequency bin separately to cope with reverberation. We show that this approach can very efficiently be realized by the combination of a blocking matrix based on semi-blind source separation ('directional BSS'), which provides a continuously updated reference of all undesired noise and interference components separated from the desired source and its reflections, and a single-channel Wiener postfilter. Moreover, it is shown, how the obtained reference signal of all undesired components can efficiently be used to realize the Wiener postfilter, and at the same time, generalizes well-known postfilter realizations. The proposed front-end and its integration into an automatic speech recognition (ASR) system are analyzed and evaluated in noisy living-room-like environments according to the PASCAL CHiME challenge. A comparison to a simplified front-end based on a free-field assumption shows that the introduced system substantially improves the speech quality and the recognition performance under the considered adverse conditions.}, language = {de} } @inproceedings{RuehrupSchindelhauerVolbert, author = {R{\"u}hrup, Stefan and Schindelhauer, Christian and Volbert, Klaus}, title = {Performance analysis of the hierarchical layer graph for wireless networks}, series = {4th International Conference, ADHOC-NOW 2005, Cancun, Mexico, October 6-8, 2005}, booktitle = {4th International Conference, ADHOC-NOW 2005, Cancun, Mexico, October 6-8, 2005}, publisher = {Springer}, address = {Berlin ; Heidelberg}, isbn = {978-3-540-29132-9}, doi = {10.1007/11561354_21}, pages = {244 -- 257}, abstract = {The Hierarchical Layer Graph (HL graph) is a promising network topology for wireless networks with variable transmission ranges. It was introduced and analyzed by Meyer auf der Heide et al. 2004. In this paper we present a distributed, localized and resource-efficient algorithm for constructing this graph. The qualtiy of the HL graph depends on the domination radius and the publication radius, which affect the amount of interference in the network. These parameters also determine whether the HL graph is a c-spanner, which implies an energy-efficient topology. We investigate the performance on randomly distributed node sets and show that the restrictions on these parameters derived from a worst case analysis are not so tight using realistic settings. Here, we present the results of our extensive experimental evaluation, measuring congestion, dilation and energy. Congestion includes the load that is induced by interfering edges. We distinguish between congestion and realistic congestion where we also take the signal-to-interference ratio into account. Our experiments show that the HL graph contains energy-efficient paths as well as paths with a few number of hops while preserving a low congestion.}, language = {en} } @inproceedings{SchildgenDessloch, author = {Schildgen, Johannes and Deßloch, Stefan}, title = {NotaQL is not a query language! It's for data transformation on wide-column stores}, series = {Data Science : 30th British International Conference on Databases, BICOD 2015 Edingburgh, UK, July 6-8, 2015, Proceedings}, volume = {9147}, booktitle = {Data Science : 30th British International Conference on Databases, BICOD 2015 Edingburgh, UK, July 6-8, 2015, Proceedings}, editor = {Maneth, Sebastian}, publisher = {Springer Nature}, isbn = {978-3-319-20423-9}, issn = {1611-3349}, doi = {10.1007/978-3-319-20424-6_14}, pages = {139 -- 151}, abstract = {It is simple to query a relational database because all columns of the tables are known and the language SQL is easily applicable. In NoSQL, there usually is no fixed schema and no query language. In this article, we present NotaQL, a data-transformation language for wide-column stores. NotaQL is easy to use and powerful. Many MapReduce algorithms like filtering, grouping, aggregation and even breadth-first-search, PageRank and other graph and text algorithms can be expressed in two or three short lines of code.}, language = {en} } @inproceedings{SchildgenLottermannDessloch, author = {Schildgen, Johannes and Lottermann, Thomas and Deßloch, Stefan}, title = {Cross-system NoSQL data transformations with NotaQL}, series = {BeyondMR '16: Proceedings of the 3rd ACM SIGMOD Workshop on Algorithms and Systems for MapReduce and BeyondJune 2016}, booktitle = {BeyondMR '16: Proceedings of the 3rd ACM SIGMOD Workshop on Algorithms and Systems for MapReduce and BeyondJune 2016}, publisher = {ACM}, doi = {10.1145/2926534.2926535}, pages = {1 -- 10}, abstract = {The rising adoption of NoSQL technology in enterprises causes a heterogeneous landscape of different data stores. Different stores provide distinct advantages and disadvantages, making it necessary for enterprises to facilitate multiple systems for specific purposes. This resulting polyglot persistence is difficult to handle for developers since some data needs to be replicated and aggregated between different and within the same stores. Currently, there are no uniform tools to perform these data transformations since all stores feature different APIs and data models. In this paper, we present the transformation language NotaQL that allows cross-system data transformations. These transformations are output-oriented, meaning that the structure of a transformation script is similar to that of the output. Besides, we provide an aggregation-centric approach, which makes aggregation operations as easy as possible.}, language = {en} } @article{SchildgenJoergDossingeretal., author = {Schildgen, Johannes and J{\"o}rg, Thomas and Dossinger, Manuel and Deßloch, Stefan}, title = {Marimba: A framework for making MapReduce jobs incremental}, series = {Proceedings - 2014 IEEE International Congress on Big Data, BigData Congress 2014, 27 June 2014 - 02 July 2014, Anchorage, AK, USA}, journal = {Proceedings - 2014 IEEE International Congress on Big Data, BigData Congress 2014, 27 June 2014 - 02 July 2014, Anchorage, AK, USA}, publisher = {IEEE}, doi = {10.1109/BigData.Congress.2014.27}, abstract = {Many MapReduce jobs for analyzing Big Data require many hours and have to be repeated again and again because the base data changes continuously. In this paper we propose Marimba, a framework for making MapReduce jobs incremental. Thus, a recomputation of a job only needs to process the changes since the last computation. This accelerates the execution and enables more frequent recomputations, which leads to results which are more up-to-date. Our approach is based on concepts that are popular in the area of materialized views in relational database systems where a view can be updated only by aggregating changes in base data upon the previous result.}, language = {en} } @article{SchindelhauerVolbertZiegler, author = {Schindelhauer, Christian and Volbert, Klaus and Ziegler, Martin}, title = {Geometric spanners with applications in wireless networks}, series = {Computational Geometry: Theory and Applications}, volume = {36}, journal = {Computational Geometry: Theory and Applications}, number = {3}, doi = {10.1016/j.comgeo.2006.02.001}, pages = {197 -- 214}, abstract = {In this paper we investigate the relations between spanners, weak spanners, and power spanners in for any dimension and apply our results to topology control in wireless networks. For , a c-spanner is a subgraph of the complete Euclidean graph satisfying the condition that between any two vertices there exists a path of length at most c-times their Euclidean distance. Based on this ability to approximate the complete Euclidean graph, sparse spanners have found many applications, e.g., in FPTAS, geometric searching, and radio networks. In a weak c-spanner, this path may be arbitrarily long, but must remain within a disk or sphere of radius c-times the Euclidean distance between the vertices. Finally in a c-power spanner, the total energy consumed on such a path, where the energy is given by the sum of the squares of the edge lengths on this path, must be at most c-times the square of the Euclidean distance of the direct edge or communication link. While it is known that any c-spanner is also both a weak -spanner and a -power spanner for appropriate , depending only on c but not on the graph under consideration, we show that the converse is not true: there exists a family of -power spanners that are not weak C-spanners and also a family of weak -spanners that are not C-spanners for any fixed C. However a main result of this paper reveals that any weak c-spanner is also a C-power spanner for an appropriate constant C. We further generalize the latter notion by considering -power spanners where the sum of the δth powers of the lengths has to be bounded; so ()-power spanners coincide with the usual power spanners and ()-power spanners are classical spanners. Interestingly, these ()-power spanners form a strict hierarchy where the above results still hold for any some even hold for while counter-examples exist for . We show that every self-similar curve of fractal dimension is not a -power spanner for any fixed C, in general. Finally, we consider the sparsified Yao-graph (SparsY-graph or YY) that is a well-known sparse topology for wireless networks. We prove that all SparsY-graphs are weak c-spanners for a constant c and hence they allow us to approximate energy-optimal wireless networks by a constant factor.}, language = {en} } @article{SehrBarfussHofmannetal., author = {Sehr, Armin and Barfuss, Hendrik and Hofmann, Christian and Maas, Roland and Kellermann, Walter}, title = {Efficient training of acoustic models for reverberation-robust medium-vocabulary automatic speech recognition}, series = {2014 4th Joint Workshop on Hands-Free Speech Communication and Microphone Arrays, HSCMA, 12-14 May 2014, Villers-les-Nancy, France}, journal = {2014 4th Joint Workshop on Hands-Free Speech Communication and Microphone Arrays, HSCMA, 12-14 May 2014, Villers-les-Nancy, France}, publisher = {IEEE}, doi = {10.1109/HSCMA.2014.6843275}, pages = {177 -- 181}, abstract = {A recently proposed concept for training reverberation-robust acoustic models for automatic speech recognition using pairs of clean and reverberant data is extended from word models to tied-state triphone models in this paper. The key idea of the concept, termed ICEWIND, is to use the clean data for the temporal alignment and the reverberant data for the estimation of the emission densities. Experiments with the 5000-word Wall Street Journal corpus confirm the benefits of ICEWIND with tied-state triphones: While the training time is reduced by more than 90\%, the word accuracy is improved at the same time, both for room-specific and multi-style hidden Markov models. Since the acoustic models trained with ICEWIND need less Gaussian components for the emission densities to achieve comparable recognition rates as Baum-Welch acoustic models, ICEWIND also allows for a reduced decoding complexity.}, language = {en} } @inproceedings{MeierReindlWetzeletal., author = {Meier, Hans and Reindl, Andrea and Wetzel, Daniel and Niemetz, Michael}, title = {Comparative Analysis of CAN, CAN FD and Ethernet for Networked Control Systems}, series = {Embedded World 2021 Exhibition \& Conference: 1.-5.3.2021, digital, conference proceedings}, booktitle = {Embedded World 2021 Exhibition \& Conference: 1.-5.3.2021, digital, conference proceedings}, publisher = {WEKA Fachmedien}, abstract = {Networked control systems as e.g., battery management systems, smart grids or vehicular systems, consist of sensors, actuators and controllers with a communication network in the control loop. The data rate and the reliability of the underlying communication network are key factors since delays or message losses directly affect the system control. In addition, the processor load caused by the communication is significant as it influences the calculation of system states and the setting of control parameters. The power consumption of the communication network has a further impact on the energy efficiency of the respective application. In this paper, the communication technologies Controller Area Network (CAN), Controller Area Network Flexible Data-rate (CAN FD) and Ethernet are compared in the context of networked control systems with focus on a decentralized battery management system. First, the message processing time and the processor load are measured. With regard to energy efficiency, the maximum power consumption is determined. The Bit Error Rates (BER) and the Residual Error Rates (RER) are calculated to evaluate the reliability. Finally, the receive FIFO load under high traffic conditions is examined. Index Terms—Networked control systems, decentralized battery management system, microcontrollers, communication systems, Ethernet, Controller Area Network (CAN), Controller Area Network Flexible Data-rate (CAN FD) energy efficiency, energy consumption, bit error rate, residual error rate, processor load.}, language = {en} } @inproceedings{WetzelReindlMeieretal., author = {Wetzel, Daniel and Reindl, Andrea and Meier, Hans and Niemetz, Michael and Farmbauer, Michael}, title = {A Customized Python Interface for Windows OS for a Low Budget USB-to-CAN-Adapter}, series = {International Conference on Electrical, Computer and Energy Technologies (ICECET 2022): 20-22 July 2022, Prague, Czech Republic}, booktitle = {International Conference on Electrical, Computer and Energy Technologies (ICECET 2022): 20-22 July 2022, Prague, Czech Republic}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, isbn = {978-1-66547-087-2}, doi = {10.1109/ICECET55527.2022.9872574}, pages = {5}, abstract = {Over the last three decades, the Controller Area Network (CAN) has become the dominant communication in embedded systems. Especially for automotive systems it offers advantages including high robustness, low error rate and high reliability combined with low power consumption. Therefore, learning the basics of this bus system is substantial in this field. Nowadays, various media about the functionality and use of CAN exist which make it easy to read into the topic. But often, theory alone is not sufficient. To deepen the understanding, practical implementation contributes significantly. However, affordable and easy-to-use CAN devices for training purposes are scarce. Existing equipment can be divided into expensive professional devices, which have many functions and inexpensive ones for hobbyists, which require difficult configurations. Therefore, a practical solution is a low-budget device equipped with an overlay which deals with the time consuming configurations. This paper covers the development of a python interface for a purchasable cost effective CAN device for Windows OS. The intention is to create an easy-to-use program that enables beginners to get in touch with CAN and collect practical experience. At the start, a brief explanation of the CAN functionality is given. After that, we introduce the hardware used in this project. Next, the software part covers the development of the interface and the integration of this interface into python-can. Furthermore, a virtual playground is introduced for testing purposes. Also, to demonstrate the functionality of the interface, a test program is executed in conjunction with a logic analyzer.}, language = {en} } @techreport{GoeppelFrikelHaltmeier, author = {G{\"o}ppel, Simon and Frikel, J{\"u}rgen and Haltmeier, Markus}, title = {Translation invariant diagonal frame decomposition of inverse problems and their regularization}, doi = {10.48550/arXiv.2208.08500}, abstract = {Solving inverse problems is central to a variety of important applications, such as biomedical image reconstruction and non-destructive testing. These problems are characterized by the sensitivity of direct solution methods with respect to data perturbations. To stabilize the reconstruction process, regularization methods have to be employed. Well-known regularization methods are based on frame expansions, such as the wavelet-vaguelette (WVD) decomposition, which are well adapted to the underlying signal class and the forward model and allow efficient implementation. However, it is well known that the lack of translational invariance of wavelets and related systems leads to specific artifacts in the reconstruction. To overcome this problem, in this paper we introduce and analyze the concept of translation invariant diagonal frame decomposition (TI-DFD) of linear operators. We prove that a TI-DFD combined with a regularizing filter leads to a convergent regularization method with optimal convergence rates. As illustrative example, we construct a wavelet-based TI-DFD for one-dimensional integration, where we also investigate our approach numerically. The results indicate that filtered TI-DFDs eliminate the typical wavelet artifacts when using standard wavelets and provide a fast, accurate, and stable solution scheme for inverse problems.}, language = {en} } @inproceedings{FrauenschlaegerMottok, author = {Frauenschl{\"a}ger, Tobias and Mottok, J{\"u}rgen}, title = {Security-Gateway for SCADA-Systems in Critical Infrastructures}, series = {27th International Conference on Applied Electronics (AE): 06-07 September 2022, Pilsen, CZ}, booktitle = {27th International Conference on Applied Electronics (AE): 06-07 September 2022, Pilsen, CZ}, publisher = {IEEE}, doi = {10.1109/AE54730.2022.9920070}, pages = {6}, abstract = {Supervisory Control and Data Acquisition (SCADA) systems are used to control and monitor components within the energy grid, playing a significant role in the stability of the system. As a part of critical infrastructures, components in these systems have to fulfill a variety of different requirements regarding their dependability and must also undergo strict audit procedures in order to comply with all relevant standards. This results in a slow adoption of new functionalities. Due to the emerged threat of cyberattacks against critical infrastructures, extensive security measures are needed within these systems to protect them from adversaries and ensure a stable operation. In this work, a solution is proposed to integrate extensive security measures into current systems. By deploying additional security-gateways into the communication path between two nodes, security features can be integrated transparently for the existing components. The developed security-gateway is compliant to all regulatory requirements and features an internal architecture based on the separation-of-concerns principle to increase its security and longevity. The viability of the proposed solution has been verified in different scenarios, consisting of realistic field tests, security penetration tests and various performance evaluations.}, language = {en} } @inproceedings{SchmidMottok, author = {Schmid, Michael and Mottok, J{\"u}rgen}, title = {Investigation of Scheduling Algorithms for DAG. Tasks through Simulations}, series = {ERTS 2022, 11th European Congress Embedded Real Time Systems: 1-2 June, Toulouse, France}, booktitle = {ERTS 2022, 11th European Congress Embedded Real Time Systems: 1-2 June, Toulouse, France}, pages = {9}, abstract = {In the real-time systems sector, various task models and corresponding tests exist to model and verify the schedulability of task sets on the system at hand. While those models and schedulability tests have intensively been studied from a theoretical point of view, it is hard to ma e use of them to compare the actual execution behavior of scheduling algorithms on a real system. In contrast to schedulability tests, simulators can help to investigate the performance of specific scheduling algorithms. One of the most generalized task models to describe parallel tasks is the Directed Acyclic Graph model that allows to represent tasks as a series of subtasks that depict the potentially parallel computations and precedence constraints that denote the order in which the subtasks are allowed to execute. In this paper, we investigate various scheduling algorithms for the Directed Acyclic Graph model. For that, we first recapitulate the examined scheduling algorithms in detail and point out relevant differences. Subsequently, we present the evaluation of different global and federated scheduling algorithms using fine-grained parallel tasks. To this end, we generate random Directed Acyclic Graph tasks and simulate their execution on multiprocessor systems using scheduling algorithms such as global rate-monotonic and semi-federated scheduling as well as global scheduling policies using the thread pool model.}, language = {en} } @misc{RennerPozzobonMottok, author = {Renner, Sebastian and Pozzobon, Enrico and Mottok, J{\"u}rgen}, title = {3rd Round Ciphers Evaluation on Microcontrollers}, series = {Lightweight Cryptography Workshop (virtual): May 9-11 2022}, journal = {Lightweight Cryptography Workshop (virtual): May 9-11 2022}, publisher = {National Institute of Standards and Technology (NIST)}, address = {Gaithersburg}, language = {en} } @inproceedings{DeNiklasRooneyetal., author = {De, Sangita and Niklas, Michael and Rooney, Brian and Mottok, J{\"u}rgen and Brada, Premek}, title = {Towards Semantic model-to-model Mapping of Cross-Domain Component Interfaces for Interoperability of Vehicle Applications : An Approach towards Synergy Exploration}, series = {MDE4IoT \& ModComp 2019: Model-Driven Engineering for the Internet of Things (MDE4IoT) \& Interplay of Model-Driven and Component-Based Software Engineering (ModComp); joint proceedings of the Workshop on Model-Driven Engineering for the Internet of Things (MDE4IoT) \& of the Workshop on Interplay of Model-Driven and Component-Based Software Engineering (ModComp); co-located with the IEEE/ACM 22nd International Conference on Model Driven Engineering Languages and Systems (MODELS 2019), Munich, Germany, September 15 and 17, 2019}, booktitle = {MDE4IoT \& ModComp 2019: Model-Driven Engineering for the Internet of Things (MDE4IoT) \& Interplay of Model-Driven and Component-Based Software Engineering (ModComp); joint proceedings of the Workshop on Model-Driven Engineering for the Internet of Things (MDE4IoT) \& of the Workshop on Interplay of Model-Driven and Component-Based Software Engineering (ModComp); co-located with the IEEE/ACM 22nd International Conference on Model Driven Engineering Languages and Systems (MODELS 2019), Munich, Germany, September 15 and 17, 2019}, publisher = {RWTH Aachen}, address = {Aachen}, doi = {10.13140/RG.2.2.28765.15840}, abstract = {With the increase in demand of services in the automotive industry, automotive enterprises prefer to collaborate with other qualified cross-domain partners to provide complex automotive functions (or services), such as autonomous driving, OTA (Over The Air) vehicle update, V2X (Vehicle-to-Vehicle communication), etc. One key element in cross-domain enterprise collaboration is the mutual agreement between interfaces of software components. In this context, model-to-model mappings of software component models of heterogeneous frameworks for automotive services and to explore the synergies in their interface semantics, have become an essential factor in improving the interoperability among the automotive and other cross-domain enterprises. However, one of the challenges in achieving cross-domain component interface model-to-model mappings at an application level lies in detecting the interface semantics and the semantic relations that are conveyed in different component models in different frameworks. This paper addresses this challenge using a Model Driven Architecture (MDA) based analytical approach to explore interface semantic synergies in the cross-domain component meta-models that are used for automotive services. The approach applies manual semantic checking measurements at an application interface level to understand the meanings and relations between the different meta-model entities of cross-domain framework software components. In this research, we attempt to ensure that interface description models of software components from heterogeneous frameworks can be compared, correlated and re-used for automotive services based on semantic synergies. We have demonstrated our approach using component meta-models from cross-domain enterprises, that are used for the automotive application domain.}, language = {en} } @article{Frikel, author = {Frikel, J{\"u}rgen}, title = {A measurement-based model for image reconstruction in MPI using a FFL}, series = {Proceedings of the 20th International Conference of Numerical Analysis and Applied Mathematics (ICNAAM-2022), 2022, Heraklion (Crete, Greece)}, journal = {Proceedings of the 20th International Conference of Numerical Analysis and Applied Mathematics (ICNAAM-2022), 2022, Heraklion (Crete, Greece)}, publisher = {AIP Publishing}, abstract = {Most of the common model-based reconstruction schemes in magnetic particle imaging (MPI) use idealized assumptions, e.g., of an ideal field-free-line (FFL) topology. However, the magnetic fields that are generated in real MPI scanners have distortions and, therefore, model-based approaches often lead to inaccurate reconstructions and may contain artifacts. In order to improve the reconstruction quality in MPI, more realistic MPI models need to be derived. In the present work, we address this problem and present a hybrid model for MPI that allows us to incorporates real measurements of the applied magnetic fields. We will explain that the measurements, that are needed to setup a model for the magnetic fields, can be obtained in a novel calibration procedure that is independent of the resolution and which is much less time-consuming than the one employed in measurement-based MPI reconstructions.We will also present a discretization strategy for this model, that can be used in context of algebraic reconstructions. The presented approach was validated on simulated data in [1], however, its evaluation on real data is a topic for future research.}, language = {en} } @article{GoeppelFrikelHaltmeier, author = {G{\"o}ppel, Simon and Frikel, J{\"u}rgen and Haltmeier, Markus}, title = {Regularization of Inverse Problems with Translation Invariant Frames}, series = {Proceedings of the 20th International Conference of Numerical Analysis and Applied Mathematics (ICNAAM-2022), 2022, Heraklion (Crete, Greece)}, journal = {Proceedings of the 20th International Conference of Numerical Analysis and Applied Mathematics (ICNAAM-2022), 2022, Heraklion (Crete, Greece)}, publisher = {AIP Publishing}, abstract = {In various fields of applications, inverse problems are characterized by their sensitivity to data perturbations which can cause severe reconstruction errors. Hence, regularization procedures are employed in order to ensure stability and reconstruction quality. To overcome limitations of classical approaches such as the filtered singular value decomposition (SVD), frame based diagonalization methods have been studied in the recent years, e.g., wavelet-vagulette (WVD) decomposition. While these methods can be well adapted to the problem at hand, it is well-known, that the lack of translation invariance in multiscale systems can cause specific artifacts in the recovered object. Thus, to overcome these drawbacks we use the translation invariant diagonal frame decomposition (TI-DFD) of linear operators. For illustration, we construct a TI-WVD for one-dimensional integration operator, and confirm our theoretical findings by numerical simulations.}, language = {en} } @article{LukyanetsSnarskiiShamoninChamonineetal., author = {Lukyanets, S. and Snarskii, Andrei A. and Shamonin (Chamonine), Mikhail and Bakaev, V. V.}, title = {Calculation of magnetic leakage field from a surface defect in a linear ferromagnetic material: an analytical approach}, series = {NDT \& E International}, volume = {36}, journal = {NDT \& E International}, number = {1}, publisher = {Elsevier}, doi = {10.1016/s0963-8695(02)00071-3}, pages = {51 -- 55}, abstract = {A novel analytical approach for calculating the magnetic leakage field from surface defects is proposed and demonstrated for the case of a linear ferromagnetic material. The novelty of the theory is that it relates the distribution of induced magnetic charges to the surface shape. An excellent agreement between the analytical and numerical results is shown. The functional relations between different magnetic field components are discussed.}, language = {en} } @article{BakaevSnarskiiShamoninChamonine, author = {Bakaev, V. V. and Snarskii, Andrei A. and Shamonin (Chamonine), Mikhail}, title = {The permeability and remanent magnetization of a randomly inhomogeneous two-phase medium}, series = {Technical Physics}, volume = {47}, journal = {Technical Physics}, number = {1}, publisher = {Springer}, doi = {10.1134/1.1435901}, pages = {125 -- 128}, abstract = {A randomly inhomogeneous composite consisting of two, ferromagnetic and nonmagnetic (para-or diamagnetic), phases is considered. The dependence of the effective permeability of the composite on the concentration of the ferromagnetic phase and on the applied magnetic field is found for the case of the negligible hysteresis loop. When the hysteresis loop is appreciable, the remanent magnetization as a function of the ferromagnet concentration is calculated.}, language = {en} } @article{BakaevSnarskiiShamoninChamonine, author = {Bakaev, V. V. and Snarskii, Andrei A. and Shamonin (Chamonine), Mikhail}, title = {The effective magnetic permeability of a two-phase fibred ferromagnetic composite}, series = {Technical Physics}, volume = {46}, journal = {Technical Physics}, number = {12}, publisher = {Springer}, doi = {10.1134/1.1427995}, pages = {1571 -- 1574}, language = {en} } @inproceedings{DeMottokBrada, author = {De, Sangita and Mottok, J{\"u}rgen and Brada, Premek}, title = {Evaluation of Semantic Interoperability of Automotive Service API Models Based on Metamodels Similarity Metrics Using a Semi-automated Approach}, series = {iCETiC 2022 : 5th International Conference on Emerging Technologies in Computing 2022: Aug 15, 2022 - Aug 16, 2022, Chester, UK}, booktitle = {iCETiC 2022 : 5th International Conference on Emerging Technologies in Computing 2022: Aug 15, 2022 - Aug 16, 2022, Chester, UK}, editor = {Miraz, M.H. and Southall, G. and Ali, Maaruf and Ware, A.}, publisher = {Springer}, address = {Cham}, doi = {10.1007/978-3-031-25161-0_2}, pages = {14 -- 28}, abstract = {In recent years, mapping of application software components' ontologies semantically emerged as a big research challenge in automotive application domain that manipulates several cross-enterprise synergy knowledge application frameworks. The same knowledge formalized by different experts in different vehicle application frameworks leads to heterogeneous representations of components' interface data. Consequently, this causes the most daunting impediment in semantic interoperability between the service components in cooperative automotive systems. From a modeling perspective, in the absence of standardized domain-based unified modeling techniques, the orchestration and resolution of semantic data interoperability between various vehicle application frameworks' components' interface models remain a challenge. However, this challenge could be addressed using ontological metamodeling by specifying semantic associations between components' interface model concepts based on the domain knowledge. Apart from the semantic mapping of interface ontological metamodels, this work also defines quality metrics to determine the degree of semantic alignment achieved between the various interface ontologies. Additionally, to reduce development time and cost towards semantic interoperability, this work proposes a semi-automated plugin tool for the applicability of the evaluated quality metrics to semantic mapping of real-world components' interface models.}, language = {en} } @inproceedings{RaspSahinbasReisingeretal., author = {Rasp, Franziska and Sahinbas, Burak and Reisinger, Thomas and Hipp, Susanne and Leitgeb, Erich}, title = {From Ray Tracing to Channel Impulse Responses: A Review on the Description of Polarimetric Time-Invariant SISO Channels}, series = {2024 International Conference on Broadband Communications for Next Generation Networks and Multimedia Applications (CoBCom), 09-11 July 2024, Graz, Austria}, booktitle = {2024 International Conference on Broadband Communications for Next Generation Networks and Multimedia Applications (CoBCom), 09-11 July 2024, Graz, Austria}, publisher = {IEEE}, isbn = {979-8-3503-8845-9}, issn = {2834-8265}, doi = {10.1109/CoBCom62281.2024.10631174}, pages = {1 -- 8}, abstract = {One key enabler of autonomous driving is vehicle-to-everything (V2X) communication and positioning using cellular technologies. To design a vehicular localization system, the understanding and modeling of the physical radio channel (RC) is crucial. Polarization is an important yet often overlooked parameter of the RC. The combined polarization of the transmitting and receiving antennas, along with the environment, significantly affects the Channel Impulse Response (CIR) and localization performance. This paper aims to provide a deterministic description of the time-invariant Single-Input Single-Output (SISO) RC with focus on its polarimetric properties. The aim is to link the understanding of physical wave propagation directly to the conventional CIR descriptions used in localization and signal processing. The focus is on SISO RC modeling for arbitrary antennas, including Line-of-Sight (LoS) and multiple reflections. This study intentionally excludes diffraction, diffuse scattering, and bandwidth limitations, yet establishes a foundational frame-work for future multi-antenna systems with full polarimetric capabilities. The paper describes wave propagation using the Jones Calculus to separate polarimetric wave components, and models the polarimetric reception typical of RC modeling methods in positioning. This approach allows for the calculation of received signal at the antenna feed point. The application context of this research is in ranging or positioning within the V2X framework.}, language = {en} } @inproceedings{RaspEberleinPerneretal., author = {Rasp, Franziska and Eberlein, Ernst and Perner, Bastian and Roth-Mandutz, Elke and Hipp, Susanne}, title = {Enhanced 5G Sidelink Ranging Based on Carrier Aggregation}, series = {2023 13th International Conference on Indoor Positioning and Indoor Navigation (IPIN), Nuremberg, Germany, 25-28 September 2023}, booktitle = {2023 13th International Conference on Indoor Positioning and Indoor Navigation (IPIN), Nuremberg, Germany, 25-28 September 2023}, publisher = {IEEE}, isbn = {9798350320114}, doi = {10.1109/IPIN57070.2023.10332548}, pages = {1 -- 6}, abstract = {Radio access network based positioning and ranging technologies become more and more important for autonomous driving. Positioning on the 5G Sidelink (SL) is discussed in Release 18 (2022-2024) of the Third Generation Partnership Project. For accurate timing-based ranging, a high temporal and spatial resolution is fundamental. The bandwidth for 5G SL positioning is limited due to sharing the existing SL resources with communication. Therefore, we send the positioning reference signal on two separate Component Carriers, i.e. we use a fragmented spectrum. We introduce a two step algorithm for estimating the time of arrival using the inflection point method. We proved a fragmented spectrum can achieve the same accuracy as a continuous spectrum.}, language = {en} } @misc{BaumannGeiserMenzeletal., author = {Baumann, Timo and Geiser, Dorothee and Menzel, Wolfgang and Mohr, Mario and Neef, Svenja and Nykamp, S{\"o}ren and Rokita, Nils}, title = {Concurrent Sub-turn Interaction Specification and Dialogue Management with an Application to Interactive Storytelling}, series = {GSCL Workshop Gesprochene Sprache und Sprachverarbeitung (GSS), Darmstadt, Germany, 2013}, journal = {GSCL Workshop Gesprochene Sprache und Sprachverarbeitung (GSS), Darmstadt, Germany, 2013}, address = {Darmstadt, Germany}, abstract = {Conventional dialogue management centers around an interaction style that is best described as a ping-pong game, with full turns being the units at which speech is delivered (and expected) by the system, which greatly simplifies the interaction management, delivery and understanding components of the system. While the resulting mode of interaction works well for task-based systems, it is insufficient for more conversational interaction styles, where content is delivered and grounded in units finer than full turns (Poesio and Traum 1997) and where turns are delivered concurrently by both interlocutors and hence overlap more frequently. One domain with particularly frequent overlapping contributions is interactive storytelling: a storyteller that is responsive to listeners will integrate their feedback immediately while still speaking a current contribution, and listener's remarks or propositions regarding the story will typically be uttered immediately when the related content is delivered. We present our work on a dialogue manager that leverages recent advances in incremental speech delivery and reception (Baumann 2013) to provide for an interactive and concurrent storytelling experience. Our system uses an interaction graph, which uses a word-by-word granularity and allows to specify for individual stretches of speech where (and with what content) users may interrupt/comment, how this is interpreted, and how it is integrated into the storytelling process, thus providing for in-utterance alternatives to be spoken even without audibly interrupting the system's ongoing utterance. The system's interaction graph is specified in an XML language and may be hand-crafted by a story designer but can also be automatically generated. In our current system, speech recognition results are interpreted only when the user utterance is finished; however, we plan to integrate incremental speech recognition and understanding capabilities, and to immediately react to the start of user contributions.}, language = {en} } @article{ReschkeNeumannBerlitz, author = {Reschke, Johannes and Neumann, Cornelius and Berlitz, Stephan}, title = {Personalised neural networks for a driver intention prediction: communication as enabler for automated driving}, series = {Advanced Optical Technologies}, volume = {9}, journal = {Advanced Optical Technologies}, number = {6}, publisher = {De Gruyter}, doi = {10.1515/aot-2020-0035}, pages = {357 -- 364}, abstract = {In everyday traffic, pedestrians rely on informal communication with other road users. In case of auto� mated vehicles, this communication can be replaced by light signals, which need to be learned beforehand. Prior to an extensive introduction of automated vehicles, a learning phase for these light signals can be set up in manual driving with help of a driver intention prediction. Therefore, a three-staged algorithm consisting of a neural network, a random forest and a conditional stage, is implemented. Using this algorithm, a true-positive rate (TPR) of 94.0\% for a 5.0\% false-positive rate (FPR) can be achieved. To improve this process, a personalization pro� cedure is implemented, using driver-specific behaviours, resulting in TPRs ranging from 91.5 to 96.6\% for a FPR of 5.0\%. Transfer learning of neural networks improves the prediction accuracy of almost all drivers. In order to introduce the implemented algorithm in today's traffic, especially the FPR has to be improved considerably.}, language = {en} } @inproceedings{NunesVolbert, author = {Nunes, Danilo Weber and Volbert, Klaus}, title = {A Wireless Low-power System for Digital Identification of Examinees (Including Covid-19 Checks)}, series = {Proceedings of the 11th International Conference on Sensor Networks (SENSORNETS), 07.02.2022 - 08.02.2022}, booktitle = {Proceedings of the 11th International Conference on Sensor Networks (SENSORNETS), 07.02.2022 - 08.02.2022}, publisher = {SCITEPRESS - Science and Technology Publications}, isbn = {978-989-758-551-7}, doi = {10.5220/0010912800003118}, pages = {51 -- 59}, abstract = {Indoor localization has been, for the past decade, a subject under intense development. There is, however, no currently available solution that covers all possible scenarios. Received Signal Strength Indicator (RSSI) based methods, although the most widely researched, still suffer from problems due to environment noise. In this paper, we present a system using Bluetooth Low Energy (BLE) beacons attached to the desks to localize students in exam rooms and, at the same time, automatically register them for the given exam. By using Kalman Filters (KFs) and discretizing the location task, the presented solution is capable of achieving 100\% accuracy within a distance of 45cm from the center of the desk. As the pandemic gets more controlled, with our lives slowly transitioning back to normal, there are still sanitary measures being applied. An example being the necessity to show a certification of vaccination or previous disease. Those certifications need to be manually checked for everyone entering the university's building, which requires time and staff. With that in mind, the automatic check for Covid certificates feature is also built into our system.}, language = {en} } @inproceedings{SchenkeBaumann, author = {Schenke, Diana Marie and Baumann, Timo}, title = {Controlled Diversity: Length-optimized Natural Language Generation}, series = {Proceedings of the ISCA/ITG Workshop on Diversity in Large Speech and Language Models, February 20, 2025 in Berlin, Germany}, booktitle = {Proceedings of the ISCA/ITG Workshop on Diversity in Large Speech and Language Models, February 20, 2025 in Berlin, Germany}, editor = {M{\"o}ller, Sebastian and Knoeferle, Pia and Schulte, Britta and Feldhus, Nils}, doi = {10.48550/arXiv.2502.19347}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-80534}, pages = {8}, abstract = {LLMs are not generally able to adjust the length of their outputs based on strict length requirements, a capability that would improve their usefulness in applications that require adherence to diverse user and system requirements. We present an approach to train LLMs to acquire this capability by augmenting existing data and applying existing fine-tuning techniques, which we compare based on the trained models' adherence to the length requirement and overall response quality relative to the baseline model. Our results demonstrate that these techniques can be successfully applied to train LLMs to adhere to length requirements, with the trained models generating texts which better align to the length requirements. Our results indicate that our method may change the response quality when using training data that was not generated by the baseline model. This allows simultaneous alignment to another training objective in certain scenarios, but is undesirable otherwise. Training on a dataset containing the model's own responses eliminates this issue.}, language = {en} } @unpublished{AmanpourBaumannHofmann, author = {Amanpour, Ali and Baumann, Timo and Hofmann, Ulrich G.}, title = {Optimizing Neural Data Analysis: Determining Minimum Recording Length for Unambigous Signal Processing}, doi = {10.35096/othr/pub-8060}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-80606}, pages = {5}, abstract = {Advanced silicon electrode arrays facilitate the recording of thousands of neurons, generating extensive neural data that imposes a significant burden on researchers and processing algorithms. Thus, real-time analysis pipelines are gaining increasing value, while at the same time having to deal with non-stationary and noisy data. We intend to apply Machine Learning (ML) algorithms to a dense set of recordings from rat brains in order to prepare a functional atlas, correlating neuronal signals with anatomical position. While doing so, we needed to decide on a rational way which recording snippet length would best represent the original, longer source sequence and thus suffices to be further processed for anatomical correlation. We implemented an algorithm to evaluate the spectral information of systematically length varied records based on similarity to the original record. For our dataset a recording duration of 3 seconds satisfied moderate requirements across all channels, thus allowing us to reduce computational load for ongoing ML classification of microprobe sourced electrophysiologic signals.}, language = {en} } @inproceedings{ReusnerPoehnerBresinsky, author = {Reusner, Florian and P{\"o}hner, Miriam and Bresinsky, Markus}, title = {The Joint Effort Workshop as a tool for Knowledge Management and competence development}, series = {5th International Conference on Higher Education Advances (HEAd'19): 26.06.2019 - 28.06.2019, Valencia}, booktitle = {5th International Conference on Higher Education Advances (HEAd'19): 26.06.2019 - 28.06.2019, Valencia}, publisher = {Universitat Polit{\`e}cnica Val{\`e}ncia}, address = {Valencia}, isbn = {9788490486610}, doi = {10.4995/head19.2019.9305}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-26973}, abstract = {Cybersecurity is a complex global phenomenon where the risk for individuals, organisation and the society at large are at risk. These risks need to be in focus and solutions for the prevention and developing countermeasures. In this paper, we describe the Joint Effort Workshop as an approach to raise awareness to these threads and the possibility to generate and exchange knowledge between students and experts. We conclude that mechanisms for systematic response to attacks need the developed technical requirements, but foremost human behaviour, knowledge and resilience to response to risks, which can be experienced through the collaborative environment of the Joint Effort Workshop}, language = {en} } @incollection{MoralesBaumannPerezetal., author = {Morales, Juan A. and Baumann, Timo and P{\´e}rez, Jos{\´e} L. and Peinado, Antonio M. and G{\´o}mez, {\´A}ngel M.}, title = {Implementaci{\`o}n de un reconocedor distribuido de voz en tiempo real sobre IP}, series = {Actas de las IV Jornadas en Tecnolog{\´i}as del Habla}, booktitle = {Actas de las IV Jornadas en Tecnolog{\´i}as del Habla}, abstract = {En este trabajo se presenta una implementaci{\´o}n de unsistema de reconocimiento distribuido del habla en tiem-po real para su aplicaci{\´o}n en un entorno de Internet. Desa-rrollado como una aplicaci{\´o}n cliente-servidor, el clien-te hace uso del front-end est{\´a}ndar definido por la ETSI.Incluye un detector de voz para s{\´o}lo enviar informaci{\´o}ncuando el locutor habla y la transmisi{\´o}n de la informaci{\´o}nse hace de acuerdo al RFC 3557. El servidor realiza el re-conocimiento utilizando programaci{\´o}n din{\´a}mica, incluyea su vez un detector de voz y utiliza la t{\´e}cnica de mitiga-ci{\´o}n de p{\´e}rdida de paquetes propuesta en el est{\´a}ndar de laETSI. La modularidad del dise{\~n}o permite la utilizaci{\´o}n decualquier otro reconocedor sin que por ello se vean afec-tados los clientes. Las pruebas reales de funcionamientopara la aplicaci{\´o}n particular desarrollada han demostradouna alta fiabilidad en varias condiciones de transmisi{\´o}n.}, language = {es} } @article{NigelGWardVegaBaumann, author = {Nigel G. Ward, and Vega, Alejandro and Baumann, Timo}, title = {Prosodic and Temporal Features for Language Modeling for Dialog}, series = {Speech Communication}, volume = {54}, journal = {Speech Communication}, number = {2}, publisher = {ELSEVIER}, doi = {10.1016/j.specom.2011.07.009}, pages = {161 -- 174}, abstract = {If we can model the cognitive and communicative processes underlying speech, we should be able to better predict what a speaker will do. With this idea as inspiration, we examine a number of prosodic and timing features as potential sources of information on what words the speaker is likely to say next. In spontaneous dialog we find that word probabilities do vary with such features. Using perplexity as the metric, the most informative of these included recent speaking rate, volume, and pitch, and time until end of utterance. Using simple combinations of such features to augment trigram language models gave up to a 8.4\% perplexity benefit on the Switchboard corpus, and up to a 1.0\% relative reduction in word error rate (0.3\% absolute) on the Verbmobil II corpus.}, language = {en} } @incollection{LohmannEichhornBaumann, author = {Lohmann, Kris and Eichhorn, Ole and Baumann, Timo}, title = {Generating Situated Assisting Utterances to Facilitate Tactile-Map Understanding: A Prototype System}, series = {Proceedings of the Third Workshop on Speech and Language Processing for Assistive Technologies (SLPAT), Montreal, Canada, June 7-8, 2012}, booktitle = {Proceedings of the Third Workshop on Speech and Language Processing for Assistive Technologies (SLPAT), Montreal, Canada, June 7-8, 2012}, publisher = {Association for Computational Linguistics}, pages = {56 -- 65}, abstract = {Tactile maps are important substitutes for visual maps for blind and visually impaired people and the efficiency of tactile-map reading can largely be improved by giving assisting utterances that make use of spatial language. In this paper, we elaborate earlier ideas for a system that generates such utterances and present a prototype implementation based on a semantic conceptualization of the movements that the map user performs. A worked example shows the plausibility of the solution and the output that the prototype generates given input derived from experimental data.}, language = {en} } @article{VoglLauxBialasetal., author = {Vogl, Stefanie and Laux, Patrick and Bialas, Joachim and Reifenberger, Christian}, title = {Modelling Precipitation Intensities from X-Band Radar Measurements Using Artificial Neural Networks—A Feasibility Study for the Bavarian Oberland Region}, series = {water}, volume = {14}, journal = {water}, number = {3}, publisher = {MDPI}, doi = {10.3390/w14030276}, pages = {1 -- 17}, abstract = {Radar data may potentially provide valuable information for precipitation quantification, especially in regions with a sparse network of in situ observations or in regions with complex topography. Therefore, our aim is to conduct a feasibility study to quantify precipitation intensities based on radar measurements and additional meteorological variables. Beyond the well-established Z-R relationship for the quantification, this study employs Artificial Neural Networks (ANNs) in different settings and analyses their performance. For this purpose, the radar data of a station in Upper Bavaria (Germany) is used and analysed for its performance in quantifying in situ observations. More specifically, the effects of time resolution, time offsets in the input data, and meteorological factors on the performance of the ANNs are investigated. It is found that ANNs that use actual reflectivity as only input are outperforming the standard Z-R relationship in reproducing ground precipitation. This is reflected by an increase in correlation between modelled and observed data from 0.67 (Z-R) to 0.78 (ANN) for hourly and 0.61 to 0.86, respectively, for 10 min time resolution. However, the focus of this study was to investigate if model accuracy benefits from additional input features. It is shown that an expansion of the input feature space by using time-lagged reflectivity with lags up to two and additional meteorological variables such as temperature, relative humidity, and sunshine duration significantly increases model performance. Thus, overall, it is shown that a systematic predictor screening and the correspondent extension of the input feature space substantially improves the performance of a simple Neural Network model. For instance, air temperature and relative humidity provide valuable additional input information. It is concluded that model performance is dependent on all three ingredients: time resolution, time lagged information, and additional meteorological input features. Taking all of these into account, the model performance can be optimized to a correlation of 0.9 and minimum model bias of 0.002 between observed and modelled precipitation data even with a simple ANN architecture.}, language = {en} } @inproceedings{Baumann, author = {Baumann, Timo}, title = {Feedback in Adaptive Interactive Storytelling}, series = {13th annual conference of the International Speech Communication Association 2012 (INTERSPEECH 2012): Portland, Oregon, USA, 9 - 13 September 2012, Interdisciplinary Workshop on Feedback Behaviors in Dialog}, booktitle = {13th annual conference of the International Speech Communication Association 2012 (INTERSPEECH 2012): Portland, Oregon, USA, 9 - 13 September 2012, Interdisciplinary Workshop on Feedback Behaviors in Dialog}, address = {Stevenson, USA}, isbn = {978-1-62276-759-5}, abstract = {Telling stories is different from reading out text: a speakerreponds to the listener's feedback and incorporates thisinto the ongoing talk. However, current computer sys-tems are unable to do this and instead just non-attentivelyread out a text, disregarding all feedback (or the absencethereof). I propose and discuss an idea for a small researchproject and a plan for how an attentive listening storytellercan be built.}, language = {en} } @inproceedings{Baumann, author = {Baumann, Timo}, title = {Integrating Prosodic Modelling with Incremental Speech Recognition}, series = {Proceedings of DiaHolmia, the 13th International Workshop on the Semantics and Pragmatics of Dialogue (SEMDIAL 2009), 24-26 JUNE, 2009, Sttockhom, Sweden}, booktitle = {Proceedings of DiaHolmia, the 13th International Workshop on the Semantics and Pragmatics of Dialogue (SEMDIAL 2009), 24-26 JUNE, 2009, Sttockhom, Sweden}, publisher = {Royal Institute of Technology}, pages = {143 -- 144}, abstract = {We describe ongoing and proposed work concerning incremental prosody extraction and classification for a spoken dialogue system. The system described will be tightly integrated with the SDS's speech recogntion which also works incrementally. The proposed architecture should allow for more control over the user interaction experience, for example allowing more precise and timely end-of-utterance vs. hesitation distinction, and auditive or visual back-channel generation.}, language = {en} } @masterthesis{Baumann, type = {Bachelor Thesis}, author = {Baumann, Timo}, title = {Automatische Erkennung von Akzentuierungen und Phrasierungen in Sprachsynthesekorpora}, address = {Hamburg}, language = {de} } @inproceedings{RiegervandeParRabletal., author = {Rieger, Anna and van de Par, Steven and Rabl, Hans-Peter and Oetjen, Arne}, title = {Ein Ton macht noch keine Harmonie - Der Einfluss von Tonhaltigkeit und Dissonanz auf Pr{\"a}ferenzurteile}, series = {Fortschritte der Akustik - DAGA 2023, 49. Jahrestagung f{\"u}r Akustik, 06.-09. M{\"a}rz 2023 in Hamburg}, booktitle = {Fortschritte der Akustik - DAGA 2023, 49. Jahrestagung f{\"u}r Akustik, 06.-09. M{\"a}rz 2023 in Hamburg}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik e.V. (DAGA)}, address = {Berlin}, isbn = {978-3-939296-21-8}, pages = {1167 -- 1170}, abstract = {Produkt- bzw. Maschinenger{\"a}usche mit deutlich h{\"o}rbaren tonalen Komponenten werden h{\"a}ufig als l{\"a}stig empfunden. Wenn zus{\"a}tzlich eine Interaktion mehrerer tonaler Komponenten in Ger{\"a}uschen stattfindet, was in realen Szenarien beispielsweise durch die {\"U}berlagerung tonaler Komponenten durch verschiedene Aggregate, wie Motoren und Getrieben, stattfindet, dann k{\"o}nnen Ger{\"a}usche unterschiedlich tonal, aber auch unterschiedlich konsonant und dissonant wahrgenommen werden. Vorangehende H{\"o}rexperimente haben gezeigt, dass die Dissonanz bei {\"a}hnlicher Tonhaltigkeit der Ger{\"a}usche einen großen Einfluss auf die Pr{\"a}ferenzurteile hat. Des Weiteren konnte bereits ein grundlegendes Empfindungsmodell f{\"u}r die "Dissonanz" sowie ein Pr{\"a}ferenz-Pr{\"a}diktor entwickelt werden, die die Subjektivdaten in hoher G{\"u}te vorhersagen konnten. In den hier vorgestellten Versuchen wurde das Zusammenspiel zwischen der empfundenen Tonhaltigkeit und der sich aus mehreren Tonkomponenten ergebenden Dissonanz auf die Pr{\"a}ferenzurteile untersucht. In der Analyse wird aufgezeigt, auf welche Weise und in welchem Umfang die wahrgenommene Ausgepr{\"a}gtheit der Tonhaltigkeit durch Interaktion mehrerer Tonkomponenten die allgemeine Ger{\"a}uschqualit{\"a}t beeinflusst. Da verschiedene Grade der Dissonanz nur durch die gleichzeitige Anwesenheit tonaler Komponenten entstehen k{\"o}nnen, ist das Zusammenspiel beider Gr{\"o}ßen bei der Bildung eines Pr{\"a}ferenzurteils von einer speziellen Natur. Dies wird sowohl bei der Modellierung der Interaktion beider Gr{\"o}ßen als auch im Vorhersagemodell der Dissonanz ber{\"u}cksichtigt.}, language = {de} } @article{KratzerWestnerStrahringer, author = {Kratzer, Simon and Westner, Markus and Strahringer, Susanne}, title = {Four Decades of Chief Information Officer Research}, series = {ACM SIGMIS Database: the DATABASE for Advances in Information Systems}, volume = {54}, journal = {ACM SIGMIS Database: the DATABASE for Advances in Information Systems}, number = {3}, publisher = {ACM}, doi = {10.1145/3614178.3614182}, pages = {37 -- 74}, abstract = {Despite the relevance and maturity of the Chief Information Officer (CIO) research field, no studies exist that exhaustively summarize the current body of knowledge, focusing on the development of the field over its entire timespan. The paper at hand addresses this research gap and presents an exhaustive literature review on the CIO research field using main path analysis. We identify the central papers in CIO research and eight main research streams by quantitatively and qualitatively analyzing 466 papers. We find that established research streams, e.g., 'Evolving role of the CIO' and 'CIO hierarchical position and relationships' as well as recently emerging research streams, e.g., 'CIO as business enabler' and 'CIOs and IT security,' draw growing attention. Based on our findings, we develop promising further avenues for research in the CIO field.}, subject = {Informationsmanager}, language = {en} } @article{JohnsonAnwerXuetal., author = {Johnson, Ebin M. and Anwer, Shakil and Xu, Yongchao and Fuhrmann, Thomas and Mandl, Roland}, title = {Contactless Low-Cost Position Sensor using a D-Shaped Polymer Optical Fiber}, series = {IEEE Sensors Journal}, journal = {IEEE Sensors Journal}, publisher = {IEEE}, doi = {10.1109/JSEN.2023.3348127}, abstract = {This article describes a contactless fiber-optic position sensor. It comprises a Polymer Optical Fiber that is grinded to form a D-shaped cross-section with an exposed fiber core. This sensor has two photodiodes at both fiber ends to measure the emitted light intensity. Light is coupled using a red LED at the side face into the exposed core of the fiber at a defined position. The position of the LED at the length of the fiber is measured by calculating the optical power quotient measured by both photodiodes. To test this sensor, Polymer Optical Fibers with different side surface roughness are produced and qualified. Measurements show that the optical power quotient is reproducible and nearly linear over the length of the fiber. It is also seen that the fiber attenuation increases when grinding the fiber side-face with rougher sandpaper. Position measurements show an absolute position error of this sensor in the range of a few millimeters. Microscope images show surface defects along the polished side face of the fiber that are expected to lead to a nonuniform attenuation along the fiber and cause the position errors. Overall, it is proven that this sensor principle works as a contactless low-cost position sensor for short distances with an absolute position standard deviation error lower than 1 mm.}, language = {en} } @inproceedings{PenzkoferBaumann, author = {Penzkofer, Vinzent and Baumann, Timo}, title = {Evaluating and Fine-Tuning Retrieval-Augmented Language Models to Generate Text With Accurate Citations}, series = {Proceedings of the 20th Conference on Natural Language Processing (KONVENS 2024), September 10-13, 2024, Vienna, Austria}, booktitle = {Proceedings of the 20th Conference on Natural Language Processing (KONVENS 2024), September 10-13, 2024, Vienna, Austria}, publisher = {Association for Computational Linguistics}, organization = {Austrian Research Institute for Artificial Intelligence}, pages = {57 -- 64}, abstract = {Retrieval Augmented Generation (RAG) is becoming an essential tool for easily accessing large amounts of textual information. However, it is often challenging to determine whether the information in a given response originates from the retrieved context, the training, or is a result of hallucination. Our contribution in this area is twofold. Firstly, we demonstrate how existing datasets for information retrieval evaluation can be used to assess the ability of Large Language Models (LLMs) to correctly identify relevantsources. Our findings indicate that there are notable discrepancies in the performance of different current LLMs in this task. Secondly, we utilise the datasets and metrics for citation evaluation to enhance the citation quality of small open-weight LLMs through fine-tuning. We achieve significant performance gains in this task, matching the results of much larger models.}, language = {en} } @inproceedings{BaumannEllerGagarina, author = {Baumann, Timo and Eller, Korbinian and Gagarina, Natalia}, title = {BERT-based Annotation of Oral Texts Elicited via Multilingual Assessment Instrument for Narratives}, series = {Proceedings of the the 6th Workshop on Narrative Understanding (WNU), November 12th to November 16th 2024, Miami, Florida, USA}, booktitle = {Proceedings of the the 6th Workshop on Narrative Understanding (WNU), November 12th to November 16th 2024, Miami, Florida, USA}, editor = {Lal, Yash Kumar and Clark, Elizabeth and Iyyer, Mohit and Chaturvedi, Snigdha and Brei, Anneliese and Brahman, Faeze and Chandu, Khyathi Raghavi}, publisher = {Association for Computational Linguistics}, address = {Stroudsburg, PA, USA}, doi = {10.18653/v1/2024.wnu-1.16}, pages = {99 -- 104}, abstract = {We investigate how NLP can help annotate the structure and complexity of oral narrative texts elicited via the Multilingual Assessment Instrument for Narratives (MAIN). MAIN is a theory-based tool designed to evaluate the narrative abilities of children who are learning one or more languages from birth or early in their development. It provides a standardized way to measure how well children can comprehend and produce stories across different languages and referential norms for children between 3 and 12 years old. MAIN has been adapted to over ninety languages and is used in over 65 countries. The MAIN analysis focuses on story structure and story complexity which are typically evaluated manually based on scoring sheets. We here investigate the automation of this process using BERT-based classification which already yields promising results.}, language = {en} } @inproceedings{Fuhrmann, author = {Fuhrmann, Thomas}, title = {Teaching Digital Electronics Principles by Connecting Diverse Technologies}, series = {2024 IEEE International Conference on Teaching, Assessment and Learning for Engineering (TALE), 09-12 December 2024, Bengaluru, India}, booktitle = {2024 IEEE International Conference on Teaching, Assessment and Learning for Engineering (TALE), 09-12 December 2024, Bengaluru, India}, publisher = {IEEE}, isbn = {979-8-3503-7623-4}, doi = {10.1109/TALE62452.2024.10834379}, pages = {1 -- 5}, abstract = {A lab course for digital electronics is developed and implemented in the second semester of a bachelor of engineering study program. This lab course runs parallel to a lecture about the basics of digital electronics. The goal of this lab course is that students should acquire the competence to develop digital circuits, no matter which design technique or circuit technology they use. Therefore, students have to learn abstract thinking without sticking to a certain digital design technique or circuit technology. For this reason, digital circuits with identical functions are developed by students, using different digital design techniques. A SPICE simulation software, the Analog Discovery board, VHDL simulation and implementation using an FPGA board are used for the five experiments with increasing complexity that are carried out during this lab course. The last task is a small project where students can carry out own ideas. The lecturer sees that students are very engaged during this lab course and also their feedback is very positive. They answered that the time frame and complexity of the course was appropriate, the usage of the Analog Discovery board was very instructive, and they learned much. In sum, the students are very satisfied with the course. This success is encouraging to retain the overall structure of this lab course and develop the details further.}, language = {en} } @masterthesis{Semmelmann, type = {Bachelor Thesis}, author = {Semmelmann, Ernst}, title = {Einsatz eines optischen Lesers zum Auslesen von Stromz{\"a}hlerdaten}, doi = {10.35096/othr/pub-8031}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-80318}, school = {Ostbayerische Technische Hochschule Regensburg}, pages = {78}, abstract = {An der Ostbayerischen Technischen Hochschule Regensburg existiert ein Forschungsprojekt f{\"u}r energieoptimiertes Wohnen. Im Zuge dessen werden im genossenschaftlichen Wohnquartier Margaretenau in Regensburg bereits Daten zum Stromverbrauch erfasst. Daf{\"u}r wird ein separater Dreiphasenz{\"a}hler verwendet, f{\"u}r dessen Installation jedoch eine Fachkraft notwendig ist. Eine Alternative stellen die bereits verbauten Stromz{\"a}hler dar, die f{\"u}r die Stromabrechnung verwendet werden. Diese besitzen eine optische Schnittstelle, {\"u}ber die ermittelte Messgr{\"o}ßen ausgegeben werden k{\"o}nnen. Die Arbeit behandelt die Entwicklung eines Verfahrens, in dem diese Daten ausgelesen und zur Analyse abgespeichert werden. Daf{\"u}r wird ein optischer Lesekopf verwendet, der die extrahierten Messwerte an einen Datenaggregator weiterleitet. Dieser wird durch einen Raspberry Pi realisiert, der die Daten aller Lesek{\"o}pfe aufbereitet und anschließend an die zentrale Sammelstelle versendet, die an der Hochschule betrieben wird und bereits die Datens{\"a}tze der externen Dreiphasenz{\"a}hler verarbeitet. Diese f{\"u}gt die Messwerte schließlich in eine Datenbank ein, damit sie f{\"u}r eine nachfolgende Analyse weiterverwendet werden k{\"o}nnen. In der Arbeit werden zuerst die theoretischen Grundlagen erl{\"a}utert, was die Analyse der verwendeten Protokolle und das Funktionsprinzip des optischen Lesekopfs beinhaltet. Anschließend wird das entwickelte Verfahren beschrieben und die Konfiguration der eingesetzten Komponenten erl{\"a}utert. Schließlich erfolgt die Evaluation der umgesetzten Methode im Hinblick auf die Datenkonsistenz und die Plausibilit{\"a}t der ausgelesenen Messwerte.}, subject = {Elektrizit{\"a}tsz{\"a}hler}, language = {de} } @inproceedings{FuxenHackenbergHeinletal., author = {Fuxen, Philipp and Hackenberg, Rudolf and Heinl, M. P. and Schunck, C. H. and Yahalom, R.}, title = {MANTRA: A Graph-based Unified Information Aggregation Foundation for Enhancing Cybersecurity Management in Critical Infrastructures // Aufsatznr.: P-335}, series = {Lecture Notes in Informatics (LNI), Proceedings - Series of the Gesellschaft fur Informatik (GI),}, booktitle = {Lecture Notes in Informatics (LNI), Proceedings - Series of the Gesellschaft fur Informatik (GI),}, doi = {10.18420/OID2023_10}, pages = {123 -- 128}, abstract = {The digitization of almost all sectors of life and the quickly growing complexity of interrelationships between actors in this digital world leads to a dramatically increasing attack surface regarding both direct and also indirect attacks over the supply chain. These supply chain attacks can have different characters, e.g., vulnerabilities and backdoors in hardware and software, illegitimate access by compromised service providers, or trust relationships to suppliers and customers exploited in the course of business email compromise. To address this challenge and create visibility along these supply chains, threat-related data needs to be rapidly exchanged and correlated over organizational borders. The publicly funded project MANTRA is meant to create a secure and resilient framework for real-time exchange of cyberattack patterns and automated, contextualized risk management. The novel graph-based approach provides benefits for automation regarding cybersecurity management, especially when it comes to prioriization of measures for risk reduction and during active defense against cyberattacks. In this paper, we outline MANTRA's scope, objectives, envisioned scientific approach, and challenges.}, language = {en} } @inproceedings{RaspSahinbasReisingeretal., author = {Rasp, Franziska and Sahinbas, Burak and Reisinger, Thomas and Hipp, Susanne and Leitgeb, Erich}, title = {Experimental Validation of a Full Polarimetric Channel Model with Frequency-Dependent Antenna Gain for Polarization Diversity Studies}, series = {2025 19th European Conference on Antennas and Propagation (EuCAP), 30. March-04. April 2025, Stockholm}, booktitle = {2025 19th European Conference on Antennas and Propagation (EuCAP), 30. March-04. April 2025, Stockholm}, publisher = {IEEE}, isbn = {978-88-31299-10-7}, doi = {10.23919/EuCAP63536.2025.10999403}, pages = {5}, abstract = {Autonomous driving, child presence detection, and digital car keys rely on precise localization. Therefore, accurate simulation environments are essential for designing radio systems and optimizing their positioning algorithms. A critical aspect of developing a reliable localization system is modeling the physical radio channel, which includes the transmitting antenna, the propagation medium, and the receiving antenna. However, existing channel models often overlook important physical effects of antennas, such as frequency dependence and polarization, leading to discrepancies between simulations and real-world measurements. To address this, the paper enhances full polarimetric channel models by incorporating the frequency dependence of both antennas and propagation channels. The theoretical model is validated through Vector Network Analyzer channel sounding measurements using reference antennas. This approach provides a foundation for polarization-based post-processing, ultimately improving positioning accuracy.}, language = {en} } @inproceedings{HolthausHagedornKlanketal., author = {Holthaus, Carsten and Hagedorn, Oliver and Klank, Michael and Shamonin (Chamonine), Mikhail and Trifonov, A. and D{\"o}tsch, Horst}, title = {Preparation and Characterization of Sensitive Magnetic Garnet Films for MOI Applications}, series = {Magneto-Optical Imaging. Proceedings of the NATO Advanced Research Workshop on Magneto-Optical Imaging, {\O}ystese, Norway, 28 - 30 August 2003}, booktitle = {Magneto-Optical Imaging. Proceedings of the NATO Advanced Research Workshop on Magneto-Optical Imaging, {\O}ystese, Norway, 28 - 30 August 2003}, publisher = {Kluwer}, address = {Dodrecht}, doi = {10.1007/978-94-007-1007-8_42}, pages = {329 -- 336}, abstract = {Magnetic garnet films prepared by liquid phase epitaxy on paramagnetic substrates of gadolinium gallium garnet are currently used for the imaging of magnetic field distributions. This application is based on the Faraday rotation which can be strongly enhanced by bismuth incorporation. For gray scale imaging the plane of the sensor film should be an easy plane of magnetization so that no domains nucleate. However, incorporation of bismuth induces a strong positive uniaxial anisotropy perpendicular to the film plane, especially if films of [111] orientation are used. To counteract this unwanted behavior neodymium and/or praseodymium are substituted in addition to bismuth. These two elements cause a very strong negative anisotropy. This is tested experimentally by growing series of garnet films with gradually changing composition and growth parameters.}, language = {en} } @article{ShamoninChamonineKlankHagedornetal., author = {Shamonin (Chamonine), Mikhail and Klank, Michael and Hagedorn, Oliver and D{\"o}tsch, Horst}, title = {Magneto-optical visualization of metal-loss defects in a ferromagnetic plate: experimental verification of theoretical modeling}, series = {Applied optics}, volume = {40}, journal = {Applied optics}, number = {19}, publisher = {Optica Publishing Group}, doi = {10.1364/ao.40.003182}, pages = {3182 -- 3189}, abstract = {Rare-earth iron garnet films with in-plane magnetic anisotropy grown on [111]-oriented substrates are promising for the visualization of magnetic leakage fields in nondestructive evaluation. Such magneto-optical films have to be specifically engineered, and we give an example of this technology. To assess the validity and accuracy of finite-element calculations of a magnetization assembly combined with the physical modeling of the image formation, comparisons between calculated and experimentally obtained magneto-optical images of metal-loss defects have been made. A convincing quantitative agreement is demonstrated. It is shown that both physical and computer modeling techniques allow for a predictive engineering design of the prospective applications and provide greater insight into the method.}, language = {en} } @article{KapsLehrerLepeniesetal., author = {Kaps, Arne and Lehrer, Tobias and Lepenies, Ingolf and Wagner, Marcus and Duddeck, Fabian}, title = {Multi-fidelity optimization of metal sheets concerning manufacturability in deep-drawing processes}, series = {Structural and Multidisciplinary Optimization}, volume = {66}, journal = {Structural and Multidisciplinary Optimization}, publisher = {Springer Nature}, doi = {10.1007/s00158-023-03631-8}, abstract = {Multi-fidelity optimization, which complements an expensive high-fidelity function with cheaper low-fidelity functions, has been successfully applied in many fields of structural optimization. In the present work, an exemplary cross-die deep-drawing optimization problem is investigated to compare different objective functions and to assess the performance of a multi-fidelity efficient global optimization technique. To that end, hierarchical kriging is combined with an infill criterion called variable-fidelity expected improvement. Findings depend significantly on the choice of objective function, highlighting the importance of careful consideration when defining an objective function. We show that one function based on the share of bad elements in a forming limit diagram is not well suited to optimize the example problem. In contrast, two other definitions of objective functions, the average sheet thickness reduction and an averaged limit violation in the forming limit diagram, confirm the potential of a multi-fidelity approach. They significantly reduce computational cost at comparable result quality or even improve result quality compared to a single-fidelity optimization.}, language = {en} } @inproceedings{DoetschKlankHagedornetal., author = {D{\"o}tsch, Horst and Klank, Michael and Hagedorn, Oliver and Holthaus, Carsten and Shamonin (Chamonine), Mikhail and Trifonov, A.}, title = {Optimization of Magnetic Garnet Films for Magneto-Optical Imaging of Magnetic Field Distributions}, series = {Magneto-Optical Imaging. Proceedings of the NATO Advanced Research Workshop on Magneto-Optical Imaging, {\O}ystese, Norway, 28 - 30 August 2003}, booktitle = {Magneto-Optical Imaging. Proceedings of the NATO Advanced Research Workshop on Magneto-Optical Imaging, {\O}ystese, Norway, 28 - 30 August 2003}, publisher = {KLuwer}, address = {Dodrecht}, doi = {10.1007/978-94-007-1007-8_39}, pages = {301 -- 309}, abstract = {Rare-earth iron garnet films are currently applied for magneto-optical imaging of magnetic field distributions. The physical properties of the films can be controlled by the chemical composition, the growth conditions and the crystallographic orientation. The sensor properties must be optimized according to the application desired. A new optimization method is introduced based on the swing of the photoresponse. An application example is presented. Furthermore, the sensitivity can be strongly enhanced using specific crystallographic orientations which induce an easy plane of magnetization being tilted with respect to the film plane. Experimental results of a [112] oriented garnet film are in good agreement with calculations. The influence of the cubic anisotropy on the sensor performance is discussed. Finally, it is shown that also domain films can be applied for magneto-optical imaging.}, language = {en} } @inproceedings{KlotzWestnerStrahringer, author = {Klotz, Stefan and Westner, Markus and Strahringer, Susanne}, title = {From Shadow IT to Business-managed IT and Back Again}, series = {Pacific Asia Conference on Information Systems (PACIS): 2020, Dubai}, booktitle = {Pacific Asia Conference on Information Systems (PACIS): 2020, Dubai}, pages = {14}, abstract = {Today, information technology (IT) is not anymore solely deployed and maintained by the IT organization, but also by business units. IT deployed or managed by business units is called Shadow IT (without alignment with the IT organization) or Business-managed IT (in alignment or a split responsibility model with the IT organization), contrasting "classical" IT. However, the responsibility for deployed IT might change over time. Therefore, this paper conceptualizes the progression of the responsibility for IT as a trajectory through initialization, potential transitions, and discontinuance. The paper illustrates this conceptual framework using four exemplary case vignettes of IT instances. Empirical findings of the case vignettes determine indications when employees initialize an IT instance as Shadow IT, Business-managed IT, or IT-managed systems and reasons why the responsibility for an IT instance changes over time. The results suggest that scholars and practitioners should add a temporal dimension to the governance of IT instances.}, subject = {IT-Governance}, language = {en} } @article{ShamoninChamonineBeukerRosenetal., author = {Shamonin (Chamonine), Mikhail and Beuker, T. and Rosen, P. and Klank, Michael and Hagedorn, Oliver and D{\"o}tsch, Horst}, title = {Feasibility of magneto-optic flaw visualization using thin garnet films}, series = {NDT \& E International}, volume = {33}, journal = {NDT \& E International}, number = {8}, publisher = {Elsevier}, doi = {10.1016/s0963-8695(00)00028-1}, pages = {547 -- 553}, abstract = {We investigate the feasibility of using rare-earth iron garnet films grown on (111)-oriented substrates as magneto-optic indicator films for the visualization of magnetic leakage fields in non-destructive evaluation. In most cases the leakage field of the defect has a strong component in the film plane. The influence of this in-plane dc magnetic field on the image formation is investigated. It is shown that the presence of a strong in-plane magnetic field allows one to extend the dynamic range of the out-of-plane field imposed by the uniaxial anisotropy field HA. On the other hand, an in-plane field reduces the sensitivity. The guidelines for selecting parameters of magneto-optic indicator films are given.}, language = {en} } @inproceedings{FrikelBorgJorgensenetal., author = {Frikel, J{\"u}rgen and Borg, Leise and J{\o}rgensen, Jakob Sauer and Quinto, Eric Todd}, title = {Singular artifacts in incomplete data x-ray tomography}, series = {Tomographic Inverse Problems: Theory and Applications; 27.01. - 02.02.2019}, booktitle = {Tomographic Inverse Problems: Theory and Applications; 27.01. - 02.02.2019}, editor = {Burger, Martin and Hahn, Bernadette and Quinto, Eric Todd}, issn = {1660-8941}, doi = {10.4171/OWR/2019/4}, pages = {295 -- 297}, language = {en} }