@article{BrosigStrahringerWestner, author = {Brosig, Christoph and Strahringer, Susanne and Westner, Markus}, title = {From selling machinery to hybrid offerings}, series = {International Journal of Information Systems and Project Management}, volume = {10}, journal = {International Journal of Information Systems and Project Management}, number = {3}, publisher = {SciKA}, issn = {2182-7788}, doi = {10.12821/ijispm100301}, pages = {5 -- 27}, abstract = {The transition towards services has been imperative for manufacturing firms for years. The change from a productoriented to a more service-dominant business model affects the organizational structure of firms. However, literature provides limited insights into how manufacturing firms organize themselves in this transition. Even though digital technologies are critical for the transition, it is unclear how to orchestrate digital and traditional Information Technology (IT) resources in manufacturing firms accordingly. We analyze the case of a typical manufacturing firm that has adjusted its structure to reorganize for solution offerings based on product, service, and digital components. Our results describe a hybrid organizational structure that splits front- and back-end units. The back-end units are split along solution components. Digital IT resources are internalized and governed decentrally, with traditional IT resources being outsourced and steered centrally. Our findings contribute to digital servitization research by clarifying the overarching as well as the digital and traditional IT-related organization for manufacturing firms.}, language = {en} } @inproceedings{SchindlerSkornia, author = {Schindler, Timo and Skornia, Christoph}, title = {Secure Parallel Processing of Big Data Using Order-Preserving Encryption on Google BigQuery}, series = {INFORMATIK 2016, Jahrestagung der Gesellschaft f{\"u}r Informatik e.V., 2016 Proceedings}, volume = {259}, booktitle = {INFORMATIK 2016, Jahrestagung der Gesellschaft f{\"u}r Informatik e.V., 2016 Proceedings}, publisher = {Gesellschaft f{\"u}r Informatik}, address = {Bonn}, isbn = {978-3-88579-653-4}, doi = {10.48550/arXiv.1608.07981}, pages = {343 -- 352}, abstract = {With the increase of centralization of resources in IT-infrastructure and the growing amount of cloud services, database management systems (DBMS) will be more and more outsourced to Infrastructure-as-a-Service (IaaS) providers. The outsourcing of entire databases, or the computation power for processing Big Data to an external provider also means that the provider has full access to the information contained in the database. In this article we propose a feasible solution with Order-Preserving Encryption (OPE) and further, state of the art, encryption methods to sort and process Big Data on external resources without exposing the unencrypted data to the IaaS provider. We also introduce a proof-of-concept client for Google BigQuery as example IaaS Provider.}, language = {en} } @inproceedings{JohannssenBiemannRemusetal., author = {Johannßen, Dirk and Biemann, Chris and Remus, Steffen and Baumann, Timo and Scheffer, David}, title = {GermEval 2020 Task 1 on the Classification and Regression of Cognitive and Motivational style from Text}, series = {Proceedings of the 5th SwissText \& 16th KONVENS Joint Conference 2020}, booktitle = {Proceedings of the 5th SwissText \& 16th KONVENS Joint Conference 2020}, address = {Zurich, Switzerland}, pages = {1 -- 10}, abstract = {This paper describes the tasks, databases, baseline systems, and summarizes submissions and results for the GermEval 2020 Shared Task 1 on the Classification and Regression of Cognitive and Motivational Style from Text. This shared task is divided into two subtasks, a regression task, and a classification task. Subtask 1 asks participants to reproduce a ranking of students based on average aptitude indicators such as different high school grades and different IQ scores. The second subtask aims to classify so-called implicit motives, which are projective testing procedures that can reveal unconscious desires. Besides five implicit motives, the target labels of Subtask 2 also contain one of six levels that describe the type of self-regulation when acting out a motive, which makes this task a multiclass-classification with 30 target labels. 3 participants submitted multiple systems. Subtask 1 was solved (best r = .3701) mainly with non-neural systems and statistical language representations, submissions for Subtask 2 utilized neural approaches and word embeddings (best macro F1 = 70.40). Not only were the tasks solvable, analyses by the participants even showed connections to the implicit psychometrics theory and behavioral observations made by psychologists. This paper describes the tasks, databases, baseline systems, and summarizes submissions and results for the GermEval 2020 Shared Task 1 on the Classification and Regression of Cognitive and Motivational Style from Text. This shared task is divided into two subtasks, a regression task, and a classification task. Subtask 1 asks participants to reproduce a ranking of students based on average aptitude indicators such as different high school grades and different IQ scores. The second subtask aims to classify so-called implicit motives, which are projective testing procedures that can reveal unconscious desires. Besides five implicit motives, the target labels of Subtask 2 also contain one of six levels that describe the type of self-regulation when acting out a motive, which makes this task a multiclass-classification with 30 target labels. 3 participants submitted multiple systems. Subtask 1 was solved (best r =.3701) mainly with non-neural systems and statistical language representations, submissions for Subtask 2 utilized neural approaches and word embeddings (best macro F1 = 70.40). Not only were the tasks solvable, analyses by the participants even showed connections to the implicit psychometrics theory and behavioral observations made by psychologists.}, language = {en} } @article{GegenfurtnerBoucheixGruberetal., author = {Gegenfurtner, Andreas and Boucheix, Jean-Michel and Gruber, Hans and Hauser, Florian and Lehtinen, Erno and Lowe, Richard K.}, title = {The gaze relational index as a measure of visual expertise}, series = {Journal of Expertise}, volume = {3}, journal = {Journal of Expertise}, number = {March}, publisher = {Michigan State University}, issn = {2573-2773}, pages = {32 -- 40}, abstract = {Eye tracking is a powerful technique that helps reveal how people process visual information. This paper discusses a novel metric for indicating expertise in visual information processing. Named the Gaze Relational Index (GRI), this metric is defined as the ratio of mean fixation duration to fixation count. Data from two eye-tracking studies of professional vision and visual expertise in using 3D dynamic medical visualizations are presented as cases to illustrate the suitability and additional benefits of the GRI. Calculated values of the GRI were higher for novices than for experts, and higher in non-representative, semi-familiar / unfamiliar task conditions than in domain-representative familiar tasks. These differences in GRI suggest that, compared to novices, experts engaged in more knowledge-driven, top-down processing that was characterized by quick, exploratory visual search. We discuss future research aiming to replicate the GRI in professional domains with complex visual stimuli and to identify the moderating role of cognitive ability on GRI estimates.}, language = {en} } @inproceedings{HusseinMeyerSickendiekBaumann, author = {Hussein, Hussein and Meyer-Sickendiek, Burkhard and Baumann, Timo}, title = {Free Verse and Beyond: How to Classify Post-modern Spoken Poetry}, series = {Proceedings of Speech Prosody: Tokyo, Japan, 25-28 May 2020}, booktitle = {Proceedings of Speech Prosody: Tokyo, Japan, 25-28 May 2020}, publisher = {ISCA}, doi = {10.21437/SpeechProsody.2020-141}, pages = {690 -- 694}, abstract = {This paper presents the classification of rhythmical patterns detected in post-modern spoken poetry by means of machine learning algorithms that use manually engineered features or automatically learnt representations. We used the world's largest corpus of spoken poetry from our partner lyrikline. We identified nine rhythmical patterns within a spectrum raging from a more fluent to a more disfluent poetic style. The text data analyzed by a statistical parser. Prosodic features of rhythmical patterns are identified by using the parser information. For the classification of rhythmical patterns, we used a neural networks-based approach which use text, audio, and pause information between poetic lines as features. Different combinations of features as well as the integration of feature engineering in the neural networks-based approach are tested. We compared the performance of both approaches (feature-based and neural network-based) using combinations of different features. The results show - by using the weighted average of f-measure for the evaluation - that the neural networks-based approach performed much better in classification of rhythmical patterns. The important improvement of the classification results lies in the use of the audio information. The integration of feature engineering in the neural networks-based approach yielded a very small result improvement.}, language = {en} } @inproceedings{BaumannMeyerSickendiek, author = {Baumann, Timo and Meyer-Sickendiek, Burkhard}, title = {Deep Learning meets Post-modern Poetry}, series = {TwinTalks 2020: Understanding and Facilitating Collaboration in Digital Humanities 2020, proceedings of the Twin Talks 2 and 3 workshops at DHN 2020 and DH 2020, Ottawa Canada and Riga Latvia, July 23 and October 20, 2020}, booktitle = {TwinTalks 2020: Understanding and Facilitating Collaboration in Digital Humanities 2020, proceedings of the Twin Talks 2 and 3 workshops at DHN 2020 and DH 2020, Ottawa Canada and Riga Latvia, July 23 and October 20, 2020}, editor = {Krauwer, Steven and Fišer, Darja}, publisher = {RWTH Aachen}, issn = {1613-0073}, pages = {30 -- 36}, abstract = {We summarize our project Rhythmicalizer in which we analyze a corpus of post-modern poetry in a combination of qualitative hermeneutical and computational methods, as we have run the project over the course of the past three years (and preparing it for some time before that). Interdisciplinary work is always challenging and we here focus on some of the highlights of our collaboration.}, language = {en} } @inproceedings{Baumann, author = {Baumann, Timo}, title = {How a Listener Influences the Speaker}, series = {Proceedings of Speech Prosody: Tokyo, Japan, 25-28 May 2020}, booktitle = {Proceedings of Speech Prosody: Tokyo, Japan, 25-28 May 2020}, publisher = {ISCA}, doi = {10.21437/SpeechProsody.2020-198}, pages = {970 -- 974}, abstract = {Listeners typically provide feedback while listening to a speaker in conversation and thereby engage in the co-construction of the interaction. We analyze the influence of the listener on the speaker by investigating how her verbal feedback signals help in modeling the speaker's language. We find that feedback from the listener may help in modeling the speaker's language, whether through the listener's feedback as transcribed, or the acoustic signal directly. We find the largest positive effects for end of sentence as well as for pauses mid-utterance, but also effects that indicate we successfully model elaborations of ongoing utterances that may result from the presence or absence of listener feedback.}, language = {en} } @article{BaumannKoehnHennig, author = {Baumann, Timo and K{\"o}hn, Arne and Hennig, Felix}, title = {The Spoken Wikipedia Corpus collection: Harvesting, alignment and an application to hyperlistening}, series = {Language Resources and Evaluation}, volume = {53}, journal = {Language Resources and Evaluation}, number = {2}, publisher = {Springer Nature}, doi = {10.1007/s10579-017-9410-y}, pages = {303 -- 329}, abstract = {Spoken corpora are important for speech research, but are expensive to create and do not necessarily reflect (read or spontaneous) speech 'in the wild'. We report on our conversion of the preexisting and freely available Spoken Wikipedia into a speech resource. The Spoken Wikipedia project unites volunteer readers of Wikipedia articles. There are initiatives to create and sustain Spoken Wikipedia versions in many languages and hence the available data grows over time. Thousands of spoken articles are available to users who prefer a spoken over the written version. We turn these semi-structured collections into structured and time-aligned corpora, keeping the exact correspondence with the original hypertext as well as all available metadata. Thus, we make the Spoken Wikipedia accessible for sustainable research. We present our open-source software pipeline that downloads, extracts, normalizes and text-speech aligns the Spoken Wikipedia. Additional language versions can be exploited by adapting configuration files or extending the software if necessary for language peculiarities. We also present and analyze the resulting corpora for German, English, and Dutch, which presently total 1005 h and grow at an estimated 87 h per year. The corpora, together with our software, are available via http://islrn.org/resources/684-927-624-257-3/. As a prototype usage of the time-aligned corpus, we describe an experiment about the preferred modalities for interacting with information-rich read-out hypertext. We find alignments to help improve user experience and factual information access by enabling targeted interaction.}, language = {en} } @inproceedings{SabooBaumann, author = {Saboo, Ashutosh and Baumann, Timo}, title = {Integration of Dubbing Constraints into Machine Translation}, series = {Proceedings of the Fourth Conference on Machine Translation, Volume 1: Research Papers}, booktitle = {Proceedings of the Fourth Conference on Machine Translation, Volume 1: Research Papers}, editor = {Bojar, Ondřej and Chatterjee, Rajen and Federmann, Christian and Fishel, Mark and Graham, Yvette and Haddow, Barry and Huck, Matthias and Yepes, Antonio Jimeno and Koehn, Philipp and Martins, Andr{\´e} and Monz, Christof and Negri, Matteo and N{\´e}v{\´e}ol, Aur{\´e}lie and Neves, Mariana and Post, Matt and Turchi, Marco and Verspoor, Karin}, publisher = {Association for Computational Linguistics}, address = {Stroudsburg, PA, USA}, doi = {10.18653/v1/W19-5210}, pages = {94 -- 101}, abstract = {Translation systems aim to perform a meaning-preserving conversion of linguistic material (typically text but also speech) from a source to a target language (and, to a lesser degree, the corresponding socio-cultural contexts). Dubbing, i.e., the lip-synchronous translation and revoicing of speech adds to this constraints about the close matching of phonetic and resulting visemic synchrony characteristics of source and target material. There is an inherent conflict between a translation's meaning preservation and 'dubbability' and the resulting trade-off can be controlled by weighing the synchrony constraints. We introduce our work, which to the best of our knowledge is the first of its kind, on integrating synchrony constraints into the machine translation paradigm. We present first results for the integration of synchrony constraints into encoder decoder-based neural machine translation and show that considerably more 'dubbable' translations can be achieved with only a small impact on BLEU score, and dubbability improves more steeply than BLEU degrades.}, language = {en} } @inproceedings{BrunthalerWaasKucera, author = {Brunthaler, Sebastian and Waas, Thomas and Kucera, Markus}, title = {On Verify and Validate a Next Generation Automotive Communication Network}, series = {Proceedings of the 9th International Conference on Pervasive and Embedded Computing and Communication Systems - PECCS, 121-127, 2019, Vienna, Austria}, booktitle = {Proceedings of the 9th International Conference on Pervasive and Embedded Computing and Communication Systems - PECCS, 121-127, 2019, Vienna, Austria}, publisher = {SCITEPRESS - Science and Technology Publications}, isbn = {978-989-758-385-8}, doi = {10.5220/0008191601210127}, pages = {121 -- 127}, abstract = {As a result of the enormous growth in data traffic for autonomous driving, the conventional in-vehicle network is no longer sufficient and requires new types of network concepts in a vehicle. This part of the automobile is known as the next generation communication network. Since the new car-systems can be extended by various services at any time, the network must adapt dynamically to new requirements wherever possible. For example, data flow must be configured dynamically between new services. Also data rates will be much higher in the future than today. This is one of the main reasons why we need to search for new technologies for data transfer in vehicles. This is based on an in-vehicle ethernet network. The process of configuring networks automatically has been discussed several times in recent years. One of the next steps is verifying and validating the automatic configuration process during the development of the new communication network. This research paper identifies several ways to ensure the automatically generated network configuration leads to a secure system. To achieve that, other parts of the company's enterprise IT architecture and network technologies, the conventional vehicle network and other options for verification and validation are analysed}, language = {en} } @inproceedings{HusseinMeyerSickendiekBaumann, author = {Hussein, Hussein and Meyer-Sickendiek, Burkhard and Baumann, Timo}, title = {Identification of Concrete Poetry within a Modern-Poetry Corpus using Neural Networks}, series = {Proceedings of the Quantitative Approaches to Versification Conference}, booktitle = {Proceedings of the Quantitative Approaches to Versification Conference}, address = {Prague, Czech Republic}, pages = {95 -- 104}, abstract = {This work aims to discern the poetics of concrete poetry by using a corpus-based classification focusing on the two most important techniques used within concrete poetry: semantic decomposition and syntactic permutation. We demonstrate how to identify concrete poetry in modern and postmodern free verse. A class contrasting to concrete poetry is defined on the basis of poems with complete and correct sentences. We used the data from lyrikline, which contain both the written as well as the spoken form of poems as read by the original author. We explored two approaches for the identification of concrete poetry. The first is based on the definition of concrete poetry in literary theory by the extraction of various types of features derived from a parser, such as verb, noun, comma, sentence ending, conjunction, and asemantic material. The second is a neural network-based approach, which is theoretically less informed by human insight, as it does not have access to features established by scholars. This approach used the following inputs: textual information and the spoken recitation of poetic lines as well as information about pauses between lines. The results based on the neural network are more accurate than the feature-based approach. The best results, calculated by the weighted F-measure, for the classification of concrete poetry vis-{\`a}-vis the contrasting class is 0.96}, language = {en} } @incollection{Baumann, author = {Baumann, Timo}, title = {Ranking and Comparing Speakers Based on Crowdsourced Pairwise Listener Ratings}, series = {Voice attractiveness: Studies on Sexy, Likable, and Charismatic Speakers}, booktitle = {Voice attractiveness: Studies on Sexy, Likable, and Charismatic Speakers}, editor = {Weiss, Benjamin and Trouvain, J{\"u}rgen and Barkat-Defradas, M{\´e}lissa and Ohala, John J.}, publisher = {Springer}, address = {Singapore}, isbn = {978-981-15-6626-4}, doi = {10.1007/978-981-15-6627-1_14}, pages = {263 -- 279}, abstract = {Speech quality and likability is a multi-faceted phenomenon consisting of a combination of perceptory features that cannot easily be computed nor weighed automatically. Yet, it is often easy to decide which of two voices one likes better, even though it would be hard to describe why, or to name the underlying basic perceptory features. Although likability is inherently subjective and individual preferences differ, generalizations are useful and there is often a broad intersubjective consensus about whether one speaker is more likeable than another. We present a methodology to efficiently create a likability ranking for many speakers from crowdsourced pairwise likability ratings which focuses manual rating effort on pairs of similar quality using an active sampling technique. Using this methodology, we collected pairwise likability ratings for many speakers (>220) from many raters (>160). We analyze listener preferences by correlating the resulting ranking with various acoustic and prosodic features. We also present a neural network that is able to model the complexity of listener preferences and the underlying temporal evolution of features. The recurrent neural network achieves remarkably high performance in estimating the pairwise decisions and an ablation study points toward the criticality of modeling temporal aspects in speech quality assessment.}, language = {en} } @inproceedings{TsaiBaumannPecuneetal., author = {Tsai, Vivian and Baumann, Timo and Pecune, Florian and Cassell, Justine}, title = {Faster Responses Are Better Responses: Introducing Incrementality into Sociable Virtual Personal Assistants}, series = {9th International Workshop on Spoken Dialogue System Technology}, volume = {579}, booktitle = {9th International Workshop on Spoken Dialogue System Technology}, editor = {D'Haro, Luis Fernando and Banchs, Rafael E. and Li, Haizhou}, publisher = {Springer Singapore}, address = {Singapore}, isbn = {978-981-13-9442-3}, issn = {1876-1119}, doi = {10.1007/978-981-13-9443-0_10}, pages = {111 -- 118}, abstract = {Speech-based interactive systems, such as virtual personal assistants, inevitably use complex architectures, with a multitude of modules working in series (or less often in parallel) to perform a task (e.g., giving personalized movie recommendations via dialog). Add modules for evoking and sustaining sociability with the user and the accumulation of processing latencies through the modules results in considerable turn-taking delays. We introduce incremental speech processing into the generation pipeline of the system to overcome this challenge with only minimal changes to the system architecture, through partial underspecification that is resolved as necessary. A user study with a sociable movie recommendation agent objectively diminishes turn-taking delays; furthermore, users not only rate the incremental system as more responsive, but also rate its recommendation performance as higher.}, language = {en} } @inproceedings{NayakBaumannBhattacharyaetal., author = {Nayak, Shravan and Baumann, Timo and Bhattacharya, Supratik and Karakanta, Alina and Negri, Matteo and Turchi, Marco}, title = {See me Speaking? Differentiating on Whether Words are Spoken On Screen or Off to Optimize Machine Dubbing}, series = {ICMI '20 Companion: Companion Publication of the 2020 International Conference on Multimodal Interaction, 25.10.2020 - 29.10.2020; Virtual Event Netherlands}, booktitle = {ICMI '20 Companion: Companion Publication of the 2020 International Conference on Multimodal Interaction, 25.10.2020 - 29.10.2020; Virtual Event Netherlands}, editor = {Truong, Khiet}, publisher = {Association for Computing Machinery}, address = {New York,NY,United States}, isbn = {9781450380027}, doi = {10.1145/3395035.3425640}, pages = {130 -- 134}, abstract = {Dubbing is the art of finding a translation from a source into a target language that can be lip-synchronously revoiced, i. e., that makes the target language speech appear as if it was spoken by the very actors all along. Lip synchrony is essential for the full-fledged reception of foreign audiovisual media, such as movies and series, as violated constraints of synchrony between video (lips) and audio (speech) lead to cognitive dissonance and reduce the perceptual quality. Of course, synchrony constraints only apply to the translation when the speaker's lips are visible on screen. Therefore, deciding whether to apply synchrony constraints requires an automatic method for detecting whether an actor's lips are visible on screen for a given stretch of speech or not. In this paper, we attempt, for the first time, to classify on- from off-screen speech based on a corpus of real-world television material that has been annotated word-by-word for the visibility of talking lips on screen. We present classification experiments in which we classify}, language = {en} } @inproceedings{GeislingerMildeBaumannetal., author = {Geislinger, Robert and Milde, Benjamin and Baumann, Timo and Biemann, Chris}, title = {Live Subtitling for BigBlueButton with Open-Source Software}, series = {INTERSPEECH 2021: (Show \& Tell Contribution), 30 August - 3 September, 2021, Brno, Czechia}, booktitle = {INTERSPEECH 2021: (Show \& Tell Contribution), 30 August - 3 September, 2021, Brno, Czechia}, address = {Brno, Czechia}, pages = {3319 -- 3320}, abstract = {We present an open source plugin for live subtitling in the popular open source video conferencing software BigBlueBut-ton. Our plugin decodes each speaker's audio stream separately and in parallel, thereby obliviating the need for speaker di-arization and seamlessly handling overlapped talk. Any Kaldi-compatible nnet3 model can be used with our plugin and we demonstrate it using freely available TDNN-HMM-based ASR models for English and German. Our subtitles can be used as they are (e.g., in loud environments) or can form the basis for further NLP processes. Our tool can also simplify the collection of remotely recorded multi-party dialogue corpora.}, language = {en} } @inproceedings{BaumannHusseinMeyerSickendieketal., author = {Baumann, Timo and Hussein, Hussein and Meyer-Sickendiek, Burkhard and Elbeshausen, Jasper}, title = {A Tool for Human-in-the-Loop Analysis and Exploration of (not only) Prosodic Classifications for Post-modern Poetry}, series = {Informatik 2019 : 50 Jahre Gesellschaft f{\"u}r Informatik Workshop-Beitr{\"a}ge Fachtagung vom 23.-26. September 2019 in Kassel}, booktitle = {Informatik 2019 : 50 Jahre Gesellschaft f{\"u}r Informatik Workshop-Beitr{\"a}ge Fachtagung vom 23.-26. September 2019 in Kassel}, editor = {Draude, Claude and Lange, Martin and Sick, Bernhard}, publisher = {Gesellschaft f{\"u}r Informatik}, address = {Bonn}, isbn = {978-3-88579-689-3}, pages = {151 -- 156}, abstract = {Data-based analyses are becoming more and more common in the Digital Humanities and tools are needed that focus human efforts on the most interesting and important aspects of exploration, analysis and annotation by using active machine learning techniques. We present our ongoing work on a tool that supports classification tasks for spoken documents (in our case: read-out post-modern poetry) using a neural networks-based classification backend and a web-based exploration and classification environment.}, language = {en} } @inproceedings{KarakantaBhattacharyaNayaketal., author = {Karakanta, Alina and Bhattacharya, Supratik and Nayak, Shravan and Baumann, Timo and Negri, Matteo and Turchi, Marco}, title = {The Two Shades of Dubbing in Neural Machine Translation}, series = {Proceedings of the 28th International Conference on Computational Linguistics (COLING 2020): Barcelona, Spain (Online)}, booktitle = {Proceedings of the 28th International Conference on Computational Linguistics (COLING 2020): Barcelona, Spain (Online)}, editor = {Scott, Donia and Bel, Nuria and Zong, Chengqing}, publisher = {International Committee on Computational Linguistics}, address = {Stroudsburg, PA, USA}, doi = {10.18653/v1/2020.coling-main.382}, pages = {4327 -- 4333}, abstract = {Dubbing has two shades; synchronisation constraints are applied only when the actor's mouth is visible on screen, while the translation is unconstrained for off-screen dubbing. Consequently, different synchronisation requirements, and therefore translation strategies, are applied depending on the type of dubbing. In this work, we manually annotate an existing dubbing corpus (Heroes) for this dichotomy. We show that, even though we did not observe distinctive features between on- and off-screen dubbing at the textual level, on-screen dubbing is more difficult for MT (-4 BLEU points). Moreover, synchronisation constraints dramatically decrease translation quality for off-screen dubbing. We conclude that, distinguishing between on-screen and off-screen dubbing is necessary for determining successful strategies for dubbing-customised Machine Translation.}, language = {en} } @inproceedings{FischerNaikLangedijketal., author = {Fischer, Kerstin and Naik, Lakshadeep and Langedijk, Rosalyn Melissa and Baumann, Timo and Jel{\´i}nek, Matouš and Palinko, Oskar}, title = {Initiating Human-Robot Interactions Using Incremental Speech Adaptation}, series = {HRI '21 Companion, Companion of the 2021 ACM/IEEE International Conference on Human-Robot Interaction: March 8 - 11, 2021, Boulder CO, USA}, booktitle = {HRI '21 Companion, Companion of the 2021 ACM/IEEE International Conference on Human-Robot Interaction: March 8 - 11, 2021, Boulder CO, USA}, editor = {Bethel, Cindy and Paiva, Ana}, publisher = {Association for Computing Machinery}, address = {New York, NY}, isbn = {9781450382908}, doi = {10.1145/3434074.3447205}, pages = {421 -- 425}, abstract = {In this paper, we present a study in which a robot initiates interactions with people passing by in an in-the-wild scenario. The robot adapts the loudness of its voice dynamically to the distance of the respective person approached, thus indicating who it is talking to. It furthermore tracks people based on information on body orientation and eye gaze and adapts the text produced based on people's distance autonomously. Our study shows that the adaptation of the loudness of its voice is perceived as personalization by the participants and that the likelihood that they stop by and interact with the robot increases when the robot incrementally adjusts its behavior.}, language = {en} } @article{GoeppelFrikelHaltmeier, author = {G{\"o}ppel, Simon and Frikel, J{\"u}rgen and Haltmeier, Markus}, title = {Feature Reconstruction from Incomplete Tomographic Data without Detour}, series = {Mathematics}, volume = {10}, journal = {Mathematics}, number = {8}, publisher = {MDPI}, doi = {10.3390/math10081318}, abstract = {In this paper, we consider the problem of feature reconstruction from incomplete X-ray CT data. Such incomplete data problems occur when the number of measured X-rays is restricted either due to limit radiation exposure or due to practical constraints, making the detection of certain rays challenging. Since image reconstruction from incomplete data is a severely ill-posed (unstable) problem, the reconstructed images may suffer from characteristic artefacts or missing features, thus significantly complicating subsequent image processing tasks (e.g., edge detection or segmentation). In this paper, we introduce a framework for the robust reconstruction of convolutional image features directly from CT data without the need of computing a reconstructed image first. Within our framework, we use non-linear variational regularization methods that can be adapted to a variety of feature reconstruction tasks and to several limited data situations. The proposed variational regularization method minimizes an energy functional being the sum of a feature dependent datafitting term and an additional penalty accounting for specific properties of the features. In our numerical experiments, we consider instances of edge reconstructions from angular under-sampled data and show that our approach is able to reliably reconstruct feature maps in this case.}, language = {en} } @inproceedings{BlankBrunnerFuhrmannetal., author = {Blank, M. and Brunner, Stefan and Fuhrmann, Thomas and Meier, Hans and Niemetz, Michael}, title = {Embedded Linux in engineering education}, series = {2015 IEEE Global Engineering Education Conference (EDUCON), 18-20 March 2015, Tallinn, Estonia}, booktitle = {2015 IEEE Global Engineering Education Conference (EDUCON), 18-20 March 2015, Tallinn, Estonia}, publisher = {IEEE}, doi = {10.1109/EDUCON.2015.7095964}, pages = {145 -- 150}, abstract = {With the availability of cost effective embedded Linux solutions and the increasing complexity of embedded devices because of growing calculation power and communication demand, Linux is getting increasingly interesting as an operating system for the design of embedded control solutions. This is the case for almost all technical applications in electrical engineering like energy distribution systems, high level communication, signal processing or industrial automation. In the engineering master courses at the OTH Regensburg, a lecture is offered introducing students to Linux with a strong focus on embedded applications. This paper describes the concept of the lecture including the laboratory set up and gives some examples of embedded Linux projects performed by students.}, language = {en} } @inproceedings{StudtWeissMottoketal., author = {Studt, Reimer and Weiß, Florian and Mottok, J{\"u}rgen and Weiss, Florian and Mottok, J{\"u}rgen}, title = {An engineering approach to developing lecture material for new study courses}, series = {2014 IEEE Global Engineering Education Conference (EDUCON), 3-5 April 2014, Istanbul, Turkey}, booktitle = {2014 IEEE Global Engineering Education Conference (EDUCON), 3-5 April 2014, Istanbul, Turkey}, publisher = {IEEE}, doi = {10.1109/EDUCON.2014.6826153}, pages = {592 -- 597}, abstract = {Professional software development is a complex task with many inputs and a complex output. In order to handle complex topics as software or complex engineering projects, structured processes as the V-model or iterative development processes exist. Similarly, the development of a software engineering lecture is a task with many inputs, and a complex output. A structured and methodological approach to the development of a lecture is presented, which applies the same principles as used in the development of software.}, language = {en} } @inproceedings{SchiekSetzpfandtBaronio, author = {Schiek, Roland and Setzpfandt, Frank and Baronio, Fabio}, title = {Akhmediev Breathers and Modulation Instability's Growth-Decay Cycle in Slab Waveguides}, series = {Nonlinear Optics : 15-19 July 2019, Waikoloa Beach, Hawaii, United States}, booktitle = {Nonlinear Optics : 15-19 July 2019, Waikoloa Beach, Hawaii, United States}, publisher = {OSA}, address = {Washington, D.C.}, isbn = {978-1-943580-62-0}, doi = {10.1364/nlo.2019.ntu2a.2}, abstract = {Optical film waveguides served as new platform for investigating Akhmediev Breathers. Using the interplay between third-order and cascaded second-order optical nonlinearities breathers and modulation instability cycles in a wide nonlinear regime were characterized.}, language = {en} } @misc{Schiek, author = {Schiek, Roland}, title = {On the experimental ex citation of modulation instability and Akhmediev breathers}, series = {CHAOS 2020, Proceedings, 13th Chaotic Modeling and Simulation, International Conference, 9 - 12 June, 2020, Florence, Italy,}, journal = {CHAOS 2020, Proceedings, 13th Chaotic Modeling and Simulation, International Conference, 9 - 12 June, 2020, Florence, Italy,}, language = {en} } @article{Groeger, author = {Gr{\"o}ger, Detlef}, title = {Construction of Locally Compact Near-Fields from p-Adic Division Algebras}, series = {Results in Mathematics}, volume = {75}, journal = {Results in Mathematics}, number = {4}, publisher = {Springer Nature}, doi = {10.1007/s00025-020-01290-5}, abstract = {The aim of this work is the construction of a new class of disconnected locally compact near-fields. They are all Dickson near-fields and derived from finite-dimensional division algebras over local fields by means of strong couplings with a finite Abelian Dickson group consisting of inner automorphisms.}, language = {en} } @article{Stein, author = {Stein, Oliver}, title = {Analytic properties of eisenstein series and standard L-Functions}, series = {Nagoya mathematical Journal}, volume = {244}, journal = {Nagoya mathematical Journal}, publisher = {CAMBRIDGE UNIV PRESS}, doi = {10.1017/nmj.2020.11}, pages = {168 -- 203}, abstract = {We prove a functional equation for a vector valued real analytic Eisenstein series transforming with the Weil representation of Sp(n, Z) on C[(L'/L)(n)]. By relating such an Eisenstein series with a real analytic Jacobi Eisenstein series of degree n, a functional equation for such an Eisenstein series is proved. Employing a doubling method for Jacobi forms of higher degree established by Arakawa, we transfer the aforementioned functional equation to a zeta function defined by the eigenvalues of a Jacobi eigenform. Finally, we obtain the analytic continuation and a functional equation of the standard L-function attached to a Jacobi eigenform, which was already proved by Murase, however in a different way.}, language = {en} } @article{BauerLauf, author = {Bauer, Ulrich and Lauf, Wolfgang}, title = {Conformal Mapping onto a Doubly Connected Circular Arc Polygonal Domain}, series = {Computational Methods and Function Theory}, volume = {19}, journal = {Computational Methods and Function Theory}, publisher = {Springer Nature}, doi = {10.1007/s40315-018-0256-0}, pages = {77 -- 96}, abstract = {This paper presents a construction principle for the Schwarzian derivative of conformal mappings from an annulus onto doubly connected domains bounded by polygons of circular arcs.}, language = {en} } @inproceedings{KaessGodefroidBorghoffetal., author = {K{\"a}ss, Sebastian and Godefroid, Marie and Borghoff, Vincent and Strahringer, Susanne and Westner, Markus and Plattfaut, Ralf}, title = {Towards a taxonomy of concepts describing IT outside the IT department}, series = {Australasian Conference on Information Systems 2021, Sydney}, booktitle = {Australasian Conference on Information Systems 2021, Sydney}, abstract = {Due to technological advances, IT is increasingly introduced and managed outside of (or even hidden from) an organisation's IT department. As a result, researchers and practitioners have created multiple concepts describing different facets and trends of this development. While the individual concepts typically focus on different aspects, there are overlaps between these concepts. This effect hampers research progress as it creates redundancies and separate streams of knowledge development. We propose a taxonomy of the concepts Lightweight IT, IT Consumerisation, Bring Your Own Device, Shadow IT, and Business-Managed IT to solve this research problem based on a systematic literature review. For this purpose, we derive characterising dimensions of each concept from existing studies and analyse literature according to the usage of terms. As a result, we can describe and delineate the concepts. Thus, we contribute a taxonomy of IT outside the IT department to improve the transfer of research results between research streams.}, language = {en} } @inproceedings{Schiek, author = {Schiek, Roland}, title = {Parameter Scans for Characterization of Nonlinear Beam Propagation}, series = {Proceedings OSA Nonlinear Optics 2021: 9-13 August 2021, Washington, DC, United States}, booktitle = {Proceedings OSA Nonlinear Optics 2021: 9-13 August 2021, Washington, DC, United States}, publisher = {Optica Publishing Group, OSA}, address = {Washington, D.C.}, isbn = {978-1-943580-97-2}, doi = {10.1364/nlo.2021.ntu1b.5}, abstract = {Intensity-dependent beam propagation inside nonlinear media is difficult to characterize without cutting back — and destroying — the sample. Observing the output dependent on system parameters can provide information on the beam dynamics along the path.}, language = {en} } @article{DrechslerKieslMeinfelderetal., author = {Drechsler, J{\"o}rg and Kiesl, Hans and Meinfelder, Florian and Raghunathan, Trivellore E. and Rubin, Donald B. and Schenker, Nathaniel and Zell, Elizabeth R.}, title = {In Memory of Professor Susanne R{\"a}ssler}, series = {Journal of Official Statistics}, volume = {35}, journal = {Journal of Official Statistics}, number = {1}, publisher = {de Gruyter}, doi = {10.2478/jos-2019-0013}, pages = {285 -- 286}, language = {en} } @article{SetzpfandtSohlerSchieketal., author = {Setzpfandt, Frank and Sohler, Wolfgang and Schiek, Roland and Pertsch, Thomas}, title = {Nonlinear coupling in discrete optical waveguide arrays with quadratic nonlinearity}, series = {Physical Review A}, volume = {92}, journal = {Physical Review A}, number = {4}, publisher = {American Physical Society}, doi = {10.1103/PhysRevA.92.043832}, abstract = {We demonstrate nonlinear coupling in a discrete optical system. This is achieved in waveguide arrays with quadratic nonlinearity, where the symmetries of the nonlinearly interacting waveguide modes are used to suppress the usually dominating nonlinear effects within individual waveguides. We derive a mathematical model to describe the nonlinear coupling in such waveguide arrays and show experimentally the profound effects of this nonlinear coupling mechanism on second-harmonic generation.}, language = {en} } @article{FreilingGrimmGrosspietschetal., author = {Freiling, Felix and Grimm, R{\"u}diger and Großpietsch, Karl-Erwin and Keller, Hubert B. and Mottok, J{\"u}rgen and M{\"u}nch, Isabel and Rannenberg, Kai and Saglietti, Francesca}, title = {Technische Sicherheit und Informationssicherheit. Unterschiede und Gemeinsamkeiten}, series = {Informatik-Spektrum}, volume = {37}, journal = {Informatik-Spektrum}, number = {1}, publisher = {Springer}, doi = {10.1007/s00287-013-0748-2}, pages = {14 -- 24}, language = {de} } @article{YuanGeisslerShaoetal., author = {Yuan, Jing and Geissler, Christian and Shao, Weijia and Lommatzsch, Andreas and Jain, Brijnesh}, title = {When algorithm selection meets Bi-linear Learning to Rank: accuracy and inference time trade off with candidates expansion}, series = {International Journal of Data Science and Analytics}, journal = {International Journal of Data Science and Analytics}, publisher = {Springer Nature}, doi = {10.1007/s41060-020-00229-x}, pages = {17}, abstract = {Algorithm selection (AS) tasks are dedicated to find the optimal algorithm for an unseen problem instance. With the knowledge of problem instances' meta-features and algorithms' landmark performances, Machine Learning (ML) approaches are applied to solve AS problems. However, the standard training process of benchmark ML approaches in AS either needs to train the models specifically for every algorithm or relies on the sparse one-hot encoding as the algorithms' representation. To escape these intermediate steps and form the mapping function directly, we borrow the learning to rank framework from Recommender System (RS) and embed the bi-linear factorization to model the algorithms' performances in AS. This Bi-linear Learning to Rank (BLR) has proven to work with competence in some AS scenarios and thus is also proposed as a benchmark approach. Thinking from the evaluation perspective in the modern AS challenges, precisely predicting the performance is usually the measuring goal. Though approaches' inference time also needs to be counted for the running time cost calculation, it's always overlooked in the evaluation process. The multi-objective evaluation metric Adjusted Ratio of Root Ratios (A3R) is therefore advocated in this paper to balance the trade-off between the accuracy and inference time in AS. Concerning A3R, BLR outperforms other benchmarks when expanding the candidates range to TOP3. The better effect of this candidates expansion results from the cumulative optimum performance during the AS process. We take the further step in the experimentation to represent the advantage of such TOPK expansion, and illustrate that such expansion can be considered as the supplement for the convention of TOP1 selection during the evaluation process.}, language = {en} } @article{Jain, author = {Jain, Brijnesh}, title = {Sufficient conditions for the existence of a sample mean of time series under dynamic time warping}, series = {Annals of Mathematics and Artificial Intelligence}, volume = {88}, journal = {Annals of Mathematics and Artificial Intelligence}, publisher = {Springer Nature}, doi = {10.1007/s10472-019-09682-2}, pages = {313 -- 346}, abstract = {Time series averaging is an important subroutine for several time series data mining tasks. The most successful approaches formulate the problem of time series averaging as an optimization problem based on the dynamic time warping (DTW) distance. The existence of an optimal solution, called sample mean, is an open problem for more than four decades. Its existence is a necessary prerequisite to formulate exact algorithms, to derive complexity results, and to study statistical consistency. In this article, we propose sufficient conditions for the existence of a sample mean. A key result for deriving the proposed sufficient conditions is the Reduction Theorem that provides an upper bound for the minimum length of a sample mean.}, language = {en} } @article{BrillFluschnikFroeseetal., author = {Brill, Markus and Fluschnik, Till and Froese, Vincent and Jain, Brijnesh and Niedermeier, Rolf and Schultz, David}, title = {Exact mean computation in dynamic time warping spaces}, series = {Data Mining and Knowledge Discovery}, volume = {33}, journal = {Data Mining and Knowledge Discovery}, publisher = {Springer Nature}, doi = {10.1007/s10618-018-0604-8}, pages = {252 -- 291}, abstract = {Averaging time series under dynamic time warping is an important tool for improving nearest-neighbor classifiers and formulating centroid-based clustering. The most promising approach poses time series averaging as the problem of minimizing a Fr{\´e}chet function. Minimizing the Fr{\´e}chet function is NP-hard and so far solved by several heuristics and inexact strategies. Our contributions are as follows: we first discuss some inaccuracies in the literature on exact mean computation in dynamic time warping spaces. Then we propose an exponential-time dynamic program for computing a global minimum of the Fr{\´e}chet function. The proposed algorithm is useful for benchmarking and evaluating known heuristics. In addition, we present an exact polynomial-time algorithm for the special case of binary time series. Based on the proposed exponential-time dynamic program, we empirically study properties like uniqueness and length of a mean, which are of interest for devising better heuristics. Experimental evaluations indicate substantial deficits of state-of-the-art heuristics in terms of their output quality.}, language = {en} } @article{Stein, author = {Stein, Oliver}, title = {The Fourier expansion of Hecke operators for vector-valued modular forms}, series = {Functiones et Approximatio Commentarii Mathematici}, volume = {52}, journal = {Functiones et Approximatio Commentarii Mathematici}, number = {2}, publisher = {Adam Mickiewicz University, Faculty of Mathematics and Computer Science}, address = {Poznań}, issn = {2080-9433}, doi = {10.7169/facm/2015.52.2.4}, pages = {229 -- 252}, abstract = {We compute the Fourier expansion of Hecke operators on vector-valued modular forms for the Weil representation associated to a lattice L. The Hecke operators considered in this paper include operators T(p^2l) where p is a prime dividing the level of the lattice L. Additionally, an explicit formula for a general type of Gauss sum associated to a lattice L drops out as a by-product.}, language = {en} } @inproceedings{HeldWestner, author = {Held, Tobias and Westner, Markus}, title = {IT Business Value Measurement and Communication among German CIOs: A Conceptual Framework}, series = {2022 IEEE 24th Conference on Business Informatics (CBI): 15-17 June 2022, Amsterdam, Netherlands}, booktitle = {2022 IEEE 24th Conference on Business Informatics (CBI): 15-17 June 2022, Amsterdam, Netherlands}, publisher = {IEEE}, doi = {10.1109/CBI54897.2022.00023}, pages = {146 -- 155}, abstract = {This paper applies design science research methodology to iteratively develop a framework for measuring and communicating IT business value from a CIO perspective. The framework design is based on analysis and integration of literature combined with empirical findings. The framework was evaluated by CIO interviews and a practical feasibility study. The results show that IT business value can be measured and communicated using our framework by applying six consecutive process steps. Thereby, IT business value is not a single number but a set of quantitative and qualitative metrics relevant to stakeholders. Our framework represents a novel and integrated approach on how CIOs can select appropriate metrics, measure, and communicate IT business value to stakeholders. In addition, the paper provides insights for CIOs on how to be successful in IT business value management.}, language = {en} } @inproceedings{SchildgenKrueckDessloch, author = {Schildgen, Johannes and Kr{\"u}ck, Yannick and Deßloch, Stefan}, title = {Transformations on Graph Databases for Polyglot Persistence with NotaQL}, series = {Datenbanksysteme f{\"u}r Business, Technologie und Web, 17. Fachtagung des GI-Fachbereichs "Datenbanken und Informationssyteme" (DBIS) : 06.-10.03.2017 in Stuttgart, Deutschland (BTW 2017)}, booktitle = {Datenbanksysteme f{\"u}r Business, Technologie und Web, 17. Fachtagung des GI-Fachbereichs "Datenbanken und Informationssyteme" (DBIS) : 06.-10.03.2017 in Stuttgart, Deutschland (BTW 2017)}, number = {CD-ROM}, editor = {Mitschang, Bernhard and Nicklas, Daniela and Leymann, Frank and Sch{\"o}ning, Harald and Herschel, Melanie and Teubner, Jens and H{\"a}rder, Theo and Kopp, Oliver and Wieland, Matthias}, publisher = {Gesellschaft f{\"u}r Informatik, Bonn}, pages = {83 -- 102}, language = {en} } @article{SchleglRobatzekKuceraetal., author = {Schlegl, Peter and Robatzek, Patrick and Kucera, Markus and Volbert, Klaus and Waas, Thomas}, title = {Performance analysis of mobile radio for automatic control in smart grids}, series = {International Journal of Advancements in Electronics and Electrical Engineering}, volume = {4}, journal = {International Journal of Advancements in Electronics and Electrical Engineering}, number = {1}, issn = {2319-7498}, pages = {69 -- 75}, abstract = {In the context of a "Smart Grid" research project, together with industrial partners, the OTH-Regensburg realized an intelligent medium-voltage grid in the local area. Goal was to improve the current voltage regulation and to counter the problems with inconsistent energy feed-in of decentralized renewable energy producers. In this paper we discuss the possibilities of using 3rd generation (3G) cellular networks (UMTS) as basic technology to communicate the voltage-levels within a medium-voltage grid. We build an experimental hardware setup to generate data-traffic as specified for the smart grid. By analyzing the performance of 3G cellular networks in terms of transmission latency and rate of failure, we tried to evaluate the usability of this technology for such critical data exchange. Though mobile communication in its structure is not specified for the use of transmitting such infrastructure critical data, the results show a promising high reliability with low transmission latency. The experiments served just to test a fragment of the conditions of use in a real scenario. An expanded test scope is needed to further analyze the performance of mobile radio for automatic control in smart grids. In the end the results discussed in this paper led to a successful prototype of an intelligent medium-voltage grid with mobile radio as communication technology}, language = {en} } @inproceedings{BaumannSchlangen, author = {Baumann, Timo and Schlangen, David}, title = {The INPROTK 2012 release}, series = {Sprachkommunikation 2012 : Beitr{\"a}ge zur 10. ITG-Fachtagung vom 26. bis 28. September 2012 in Braunschweig}, booktitle = {Sprachkommunikation 2012 : Beitr{\"a}ge zur 10. ITG-Fachtagung vom 26. bis 28. September 2012 in Braunschweig}, editor = {Fingscheidt, T.}, publisher = {VDE-Verl}, address = {Berlin ; Offenbach}, isbn = {978-3-8007-3455-9}, pages = {147 -- 150}, abstract = {We describe the 2012 release of INPROTK1, our "Incremental Processing Toolkit" which combines a powerful and extensible architecture for incremental processing with components for incremental speech recognition and, new to this release, incremental speech synthesis. These components work domainindependently; we also provide example implementations of higher-level components such as natural language understanding and dialogue management that are somewhat more tied to a particular domain. The toolkit is accompanied by evaluation tools for analysing timing behaviour, and we highlight some timing results on conversational speech input in this paper. We offer our toolkit to foster research in this new and exciting area, which promises to help increase the naturalness of behaviours that can be modelled in such systems.}, language = {en} } @inproceedings{DuennweberGorlatchParlavantzasetal., author = {D{\"u}nnweber, Jan and Gorlatch, Sergei and Parlavantzas, Nikos and Baude, Francoise and Legrand, Virginie}, title = {Towards automatic creation of web services for grid component composition}, series = {Integrated Research in GRID Computing : CoreGRID Integration Workshop 2005 (Selected Papers), November 28-30, Pisa, Italy}, booktitle = {Integrated Research in GRID Computing : CoreGRID Integration Workshop 2005 (Selected Papers), November 28-30, Pisa, Italy}, publisher = {Springer Science+Business Media}, address = {Boston, MA}, isbn = {978-0-387-47658-2}, doi = {10.1007/978-0-387-47658-2_3}, pages = {31 -- 42}, abstract = {While high-level software components simplify the programming of grid applications and Web services increase their interoperability, developing such components and configuring the interconnecting services is a demanding task. In this paper, we consider the combination of Higher-Order Components (HOCs) with the Fractal component model and the ProActive library. HOCs are parallel programming components, made accessible on the grid via Web services that use a special class loader enabling code mobility: executable code can be uploaded to a HOC, allowing one to customize the HOC. Fractal simplifies the composition of components and the ProActive library offers a generator for automatically creating Web services from components composed with Fractal, as long as all the parameters of these services have primitive types. Taking all the advantages of HOCs, ProActive and Fractal together, the obvious conclusion is that composing HOCs using Fractal and automatically exposing them as Web services on the grid via ProActive minimizes the required efforts for building complex grid systems. In this context, we solved the problem of exchanging code-carrying parameters in automatically generated Web services by integrating the HOC class loading mechanism into the ProActive library.}, language = {en} } @article{HecknerSchworm, author = {Heckner, Markus and Schworm, Silke}, title = {The tagblog: Exploring social web user contribution to encourage students to actively engage in learning content}, series = {International Journal of Web Based Communities}, volume = {5}, journal = {International Journal of Web Based Communities}, number = {4}, publisher = {Inderscience Enterprises}, address = {Olney}, issn = {1741-8216}, doi = {10.1504/IJWBC.2009.028088}, pages = {528 -- 542}, abstract = {After leaving the lecture hall, students hardly reflect about the lesson's contents. To foster learning, the lesson content should be reorganised, elaborated and critically reflected. Tagging and blogging offer the opportunity to actively engage students in follow-up course work. This paper presents the results of a case study exploring the use of a social web application to encourage student contributions within the context of an undergraduate university seminar. The tagblog combines blogging, tagging and rating as three forms of online user contribution on Web 2.0 to develop a shared, emergent group knowledge repository. Blog posts, tags and comments are analysed to examine how user contributions reflect the active processing of learning content.}, language = {en} } @article{HecknerWolff, author = {Heckner, Markus and Wolff, Christian}, title = {Wissensmanagement mit Social Software [Editorial]}, series = {Information - Wissenschaft und Praxis : IWP}, volume = {60}, journal = {Information - Wissenschaft und Praxis : IWP}, number = {4}, publisher = {DGI ; De Gruyter}, address = {Frankfurt, Main ; Berlin ; New York}, organization = {Deutsche Gesellschaft f{\"u}r Information und Wissen e.V. (DGI)}, issn = {1619-4292}, pages = {185 -- 187}, language = {de} } @inproceedings{BraunSchildgenDessloch, author = {Braun, Stefan and Schildgen, Johannes and Deßloch, Stefan}, title = {Visualization of NoSQL transformations using sampling techniques | Visualisierung von NoSQL-Transformationen unter der Verwendung von Sampling-Techniken}, series = {Proceedings of the LWA 2015 workshops: KDML, FGWM, IR, and FGDB : Trier, Germany, October 7-9, 2015}, booktitle = {Proceedings of the LWA 2015 workshops: KDML, FGWM, IR, and FGDB : Trier, Germany, October 7-9, 2015}, publisher = {RWTH Aachen}, address = {Aachen}, pages = {427 -- 438}, abstract = {Analysen auf NoSQL-Datenbanken sind oft langdauernd und die Ergebnisse fur den Benutzer haufig schwer verst ̈andlich. Wir prasentieren eine M{\"o}glichkeit, Datenmengen aus Wide-Column Stores mittels der Transformationssprache NotaQL zu transformieren sowie zu aggregieren und die Ergebnisse in Form von Diagrammen dem Benutzer darzustellen. Dabei kommen Sampling-Techniken zum Einsatz, um die Berechnung auf Kosten der Genauigkeit zu beschleunigen. Das von uns verwendete iterative Samplingverfahren sorgt fur eine kontinuierliche Verbesserung der Berechnungsgenauigkeit und bietet zudem M{\"o}glichkeiten zur Genauigkeitsabsch{\"a}tzung, die in Form von Konfidenzintervallen in den Diagrammen dargestellt werden kann.}, language = {en} } @article{aufderHeideSchindelhauerVolbertetal., author = {auf der Heide, Friedhelm Meyer and Schindelhauer, Christian and Volbert, Klaus and Gr{\"u}newald, Matthias}, title = {Congestion, dilation, and energy in radio networks}, series = {Theory of Computing Systems}, volume = {37}, journal = {Theory of Computing Systems}, number = {3}, publisher = {Springer Nature}, doi = {10.1007/s00224-004-1124-z}, pages = {343 -- 370}, abstract = {We investigate the problem of path selection in radio networks for a given static set of n sites in two- and three-dimensional space. For static point-to-point communication we define measures for congestion, dilation, and energy consumption that take interferences among communication links into account. We show that energy-optimal path selection for radio networks can be computed in polynomial time. Then we introduce the diversity g(V) of a set V ⫅ ℝd for any constant d. It can be used to upper bound the number of interfering edges. For real-world applications it can be regarded as Θ(log n). A main result is that a c-spanner construction as a communication network allows one to approximate the congestion-optimal path system by a factor of O(g(V)2). Furthermore, we show that there are vertex sets where only one of the performance parameters congestion, dilation, and energy can be optimized at a time. We show trade-offs lower bounding congestion × dilation and dilation × energy. The trade-off between congestion and dilation increases with switching from two-dimensional to three-dimensional space. For congestion and energy the situation is even worse. It is only possible to find a reasonable approximation for either congestion or energy minimization, while the other parameter is at least a polynomial factor worse than in the optimal network.}, language = {en} } @article{HecknerMuehlbacherWolff, author = {Heckner, Markus and M{\"u}hlbacher, Susanne and Wolff, Christian}, title = {Tagging tagging. Analysing user keywords in scientific bibliography management systems}, series = {Journal of Digital Information}, volume = {9}, journal = {Journal of Digital Information}, number = {2}, publisher = {Multimedia Research Group}, pages = {19}, abstract = {In this paper, an empirical study of tagging behaviour in web-based bibliographic annotation systems is presented. Starting from an initial category finding phase in which tags attributed to selected articles from Connotea were classified we have set up a category model for linguistic and functional aspects of tag usage as well as for the relationship between tags and document full text. In a second phase this model is applied to approx. 500 tagged articles from the information and computer technology domain randomly selected from Connotea. Our findings show significant differences to other tagging research which was primarily conducted using popular (non-scientific) tagging platforms like Flickr or Delicious. We observe a great overlap of tag material and document text and rather few non-content related tags. The comparison of user tags with author keywords shows that users tend to use less and more general tags. Finally, system functionality seems to play a role for users' tagging behaviour.}, language = {en} } @article{HagerFinkeSeitzetal., author = {Hager, Markus and Finke, Thomas and Seitz, Jochen and Waas, Thomas}, title = {Software-based management for Ethernet networks}, series = {Wireless Personal Communications}, volume = {74}, journal = {Wireless Personal Communications}, number = {3}, publisher = {Springer Nature}, doi = {10.1007/s11277-013-1341-3}, pages = {1021 -- 1032}, abstract = {An adequate network management is an essential part for each network permitting to keep the network performance at a suitable level. In this paper, we present our work focusing on an Ethernet network which is used as background interconnection technology for a smart home system in large buildings like tenements or an office block. In this case the network is larger and especially the applications are quite heterogeneous as compared to a private smart home system. Therefore, it is hard to supply a fair and quality of service aware network meeting all the demands. This is especially challenging in the case of an Ethernet network because this technology was intended to use it as a transparent connection system without the feature to support hard quality of service. We present how this problem could be solved by a middleware which best meets the special requirement of the mentioned use case. Finally, we discuss possible design improvements of this solution and present the recent Ethernet standards that could help solve this problem in an alternative way.}, language = {en} } @article{HecknerNeubauerWolff, author = {Heckner, Markus and Neubauer, Tanja and Wolff, Christian}, title = {Tree, funny, to-read, google: What are tags supposed to achieve?: A comparative analysis of user keywords for different digital resource types}, series = {Proceedings of the 2008 ACM workshop on Search in social media (SSM '08), Napa Valley California, USA, 30 October 2008}, journal = {Proceedings of the 2008 ACM workshop on Search in social media (SSM '08), Napa Valley California, USA, 30 October 2008}, publisher = {ACM}, doi = {10.1145/1458583.1458589}, pages = {3 -- 10}, abstract = {Social tagging systems have become increasingly popular over the past years. Users' tagging practices have been little studied and understood so far. However, understanding tagging behaviour can contribute towards a thorough understanding of the tagging phenomenon from multiple perspectives. In the present paper, results of a comparative analysis of tag characteristics on the tagging platforms connotea.org (scientific articles), del.icio.us (bookmarks), flickr.com (photos), and youtube.com (videos) are presented. Results show that differences in tagging behaviour can be observed for different digital resource types. Finally, a short discussion of the possible implications of the results for the design of future tagging systems is presented.}, language = {en} } @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} }