@article{42797, abstract = {{An efficient algorithm to compute automorphism groups and isometries of definite Fq[t]-lattices for odd q is presented. The algorithm requires several square root computations in Fq₂ but no enumeration of orbits having more than eight elements. }}, author = {{Kirschmer, Markus}}, issn = {{0025-5718}}, journal = {{Mathematics of Computation}}, keywords = {{Applied Mathematics, Computational Mathematics, Algebra and Number Theory}}, number = {{279}}, pages = {{1619--1634}}, publisher = {{American Mathematical Society (AMS)}}, title = {{{A normal form for definite quadratic forms over $\mathbb{F}_{q}[t]$}}}, doi = {{10.1090/s0025-5718-2011-02570-6}}, volume = {{81}}, year = {{2012}}, } @article{4708, author = {{Müller-Wienbergen, Felix and Müller, Oliver and Seidel, Stefan and Becker, Jörg}}, isbn = {{1536-9323}}, issn = {{15369323}}, journal = {{Journal of the Association for Information Systems}}, keywords = {{Creativity, Creativity Support Systems, convergent thinking, design theory, divergent thinking}}, number = {{11}}, pages = {{714----740}}, title = {{{Leaving the Beaten Tracks in Creative Work – A Design Theory for Systems that Support Convergent and Divergent Thinking}}}, doi = {{10.1016/S0006-3495(00)76637-9}}, year = {{2011}}, } @article{17233, abstract = {{It has been proposed that the design of robots might benefit from interactions that are similar to caregiver–child interactions, which is tailored to children’s respective capacities to a high degree. However, so far little is known about how people adapt their tutoring behaviour to robots and whether robots can evoke input that is similar to child-directed interaction. The paper presents detailed analyses of speakers’ linguistic and non-linguistic behaviour, such as action demonstration, in two comparable situations: In one experiment, parents described and explained to their nonverbal infants the use of certain everyday objects; in the other experiment, participants tutored a simulated robot on the same objects. The results, which show considerable differences between the two situations on almost all measures, are discussed in the light of the computer-as-social-actor paradigm and the register hypothesis.}}, author = {{Fischer, Kerstin and Foth, Kilian and Rohlfing, Katharina and Wrede, Britta}}, issn = {{1572-0381}}, journal = {{Interaction Studies}}, keywords = {{human–robot interaction (HRI), social communication, register theory, motionese, robotese, child-directed speech (CDS), motherese, mindless transfer, computers-as-social-actors}}, number = {{1}}, pages = {{134--161}}, publisher = {{John Benjamins Publishing Company}}, title = {{{Mindful tutors: Linguistic choice and action demonstration in speech to infants and a simulated robot}}}, doi = {{10.1075/is.12.1.06fis}}, volume = {{12}}, year = {{2011}}, } @article{34846, abstract = {{Given a field extension K/k of degree n we are interested in finding the subfields of K containing k. There can be more than polynomially many subfields. We introduce the notion of generating subfields, a set of up to n subfields whose intersections give the rest. We provide an efficient algorithm which uses linear algebra in k or lattice reduction along with factorization in any extension of K. Implementations show that previously difficult cases can now be handled.}}, author = {{van Hoeij, Mark and Klüners, Jürgen and Novocin, Andrew}}, issn = {{0747-7171}}, journal = {{Journal of Symbolic Computation}}, keywords = {{Computational Mathematics, Algebra and Number Theory}}, pages = {{17--34}}, publisher = {{Elsevier BV}}, title = {{{Generating subfields}}}, doi = {{10.1016/j.jsc.2012.05.010}}, volume = {{52}}, year = {{2011}}, } @article{5195, abstract = {{This article analyses 336 German venture capital transactions from 1990 to 2005 and seeks to determine why selected financial securities differ across deals. We find that a broad array of financial instruments is used, covering straight equity, mezzanine and debt‐like securities. Based on the chosen financial securities’ upside potential and downside protection characteristics, we provide an explanation for the differing use of these securities. Our results show that investors’ deal experience, adverse selection risks and economic prospects in the public equity market influence the selection of financial securities. }}, author = {{Hartmann-Wendels, Thomas and Keienburg, Georg and Sievers, Sönke}}, journal = {{European Financial Management (VHB-JOURQUAL 4 Ranking B)}}, keywords = {{venture capital, capital structure, contract theory, deal experience}}, number = {{3}}, pages = {{464--499}}, publisher = {{Wiley Online Library}}, title = {{{Adverse selection, investor experience and security choice in venture capital finance: evidence from Germany}}}, doi = {{10.1111/j.1468-036X.2010.00568.x}}, volume = {{17}}, year = {{2011}}, } @techreport{4448, abstract = {{"Lernkultur" wird als Begriff häufig gebraucht und fast ebenso häufig definiert  das gilt für den betrieblichen Kontext ebenso wie für die Bereiche der Schul-, Hochschul-, Berufs- und Erwachsenenbildung (z. B. Wulf, Althans, Blaschke, Ferrin, Göhlich, Jörissen, Mattig et al., 2007; Jenert, Zellweger Moser, Dommen & Gebhardt, 2009; Kirchhöfer, 2004; Erpenbeck & Sauer, 2000). Trotz der grossen Aufmerksamkeit, die der Begriff in den letzten zwei Jahrzehnten erfahren hat, kann man nicht von einem in sich geschlossenen Forschungsprogramm sprechen. Die Zugänge zum Phänomenbereich Lernkultur sind ebenso vielfältig wie die hinter einzelnen Ansätzen stehenden Lernkulturkonstrukte. Den Autoren ist keine Publikation bekannt, welche unterschiedliche Ansätze der Lernkulturforschung systematisch aufarbeitet. Eine wichtige Referenzquelle ist der Bericht von Kuh und Whitt (1988) "The Invisible Tapestry: Culture in American Colleges and Universities". Ausgehend von einer fundierten Übersicht zu unterschiedlichen Zugängen zum Kulturbegriff (oft in starker Anlehnung an die Organisationskulturforschung (vgl. Allaire & Firsirotu, 1984)) stellen die Autoren ein Rahmenmodell zur Analyse von Hochschulkulturen vor (Kuh und Whitt, 1988, S. 56). Diese Arbeit erweist sich für ein besseres Verständnis unter-schiedlicher Zugänge zum Lernkulturbegriff als aufschlussreich, weil im Kontext Hoch-schule zwangsweise viele Aspekte des Lernens und Lehrens angesprochen werden. Allerdings fokussiert auch dieser Bericht nicht das Konstrukt der Lernkultur und bietet damit nur einen Ausgangspunkt für die Identifizierung unterschiedlicher Zugänge.}}, author = {{Jenert, Tobias and Gebhardt, Anja}}, keywords = {{Lernkultur, learning culture, culture theory, approaches to learning culture, culture of learning}}, title = {{{Zugänge zum Begriff der Lernkultur: Eine Systematisierung auf Basis kultur-und lerntheoretischer Überlegungen}}}, year = {{2010}}, } @inproceedings{9763, abstract = {{Recent advances in information processing enable new kinds of technical systems, called self-optimizing systems. These systems are able to adapt their objectives and their behavior according to the current situation and influences autonomously. This behavior adaptation is non-deterministic and hence self-optimization is a risk to the system, e.g. if the result of the self-optimization process does not match the suddenly changed situation. In contrary, self-optimization could be used to increase the dependability by pursuing objectives like reliability and availability. In our preceding publications we introduced the so called multi-level dependability concept to cope with this new kind of systems (cf. [6]). This concept comprises the monitoring of the system behavior, the classification of the current situation, and the selection of the appropriate measure, if reliability limits are exceeded. In this paper we present for the first time experimental results. The dependability concept is implemented in the self-optimizing active guidance system of a railway vehicle. The test drives illustrate clearly that the proposed concept is able to cope with, e.g., sensor failures, and is able to increase the reliability and availability of the active guidance module.}}, author = {{Sondermann-Wölke, Christoph and Geisler, Jens and Sextro, Walter}}, booktitle = {{Reliability and Maintainability Symposium (RAMS), 2010 Proceedings - Annual}}, issn = {{0149-144X}}, keywords = {{availability, dependability concept, multilevel dependability concept, railway vehicle, reliability, self optimizing active guidance system, self optimizing railway guidance system, situation classification, system behavior monitoring, optimal control, railways, reliability theory, self-adjusting systems}}, pages = {{1 --6}}, title = {{{Increasing the reliability of a self-optimizing railway guidance system}}}, doi = {{10.1109/RAMS.2010.5448080}}, year = {{2010}}, } @inproceedings{5632, abstract = {{Enduring doubts about the value of IS investments reveal that IS researchers have not fully managed to identify and to explain the economic benefits of IS. Three research tasks are essential requisites on the path towards addressing this criticism: the synthesis of knowledge, the identification of lack of knowledge, and the proposition of paths for closing knowledge gaps. This paper considers each of these tasks by a) synthesizing key research findings based on a comprehensive literature review, b) identifying and unfolding key limitations of current research, and c) applying a decision-theoretic perspective, which opens new horizons to IS business value research and shows paths for overcoming the limitations. The adoption of this perspective results in a decision-theoretic foundation of IS business value research and includes the proposition of a consistent terminology and a research model that frames further research.}}, author = {{Schryen, Guido and Bodenstein, Christian}}, booktitle = {{Proceedings of the 18th European Conference on Information Systems (ECIS 2010)}}, keywords = {{Decision theory, IT value, IS assessment, IS evaluation}}, title = {{{A decision-theoretic foundation of IS business value research}}}, year = {{2010}}, } @inproceedings{5643, abstract = {{Enduring doubts about the value of IS investments reveal that IS researchers have not fully managed to identify and to explain the economic benefits of IS. This paper assumes that literature reviews, which represent a powerful instrument for the identification and synthesis of knowledge, have not tapped their full potential to address this issue due to deficiencies in methodology. The analysis of 18 literature reviews published in pertinent academic outlets during the past 20 years shows such deficiencies. Two of the most critical weaknesses identified are (1) the lack of theory use in most reviews and (2) a weak linkage of reviews, resulting in little progress in theory and framework development. The systematic identification of these weaknesses and the extraction of promising methodological examples from past literature are the main contributions of this work, which supports the composition of more effective literature reviews in future research.}}, author = {{Schryen, Guido}}, booktitle = {{Proceedings of the First Scandinavian Conference on Information Systems (SCIS)}}, keywords = {{Literature review, Business value, Information systems, Methodology, Theory}}, title = {{{An Analysis of Literature Reviews on IS Business Value: How Deficiencies in Methodology and Theory Use Resulted in Limited Effectiveness}}}, year = {{2010}}, } @article{34887, abstract = {{Let d be a nonsquare positive integer. We give the value of the natural probability that the narrow ideal class groups of the quadratic fields ℚ(√d) and ℚ(√−d) have the same 4-ranks. }}, author = {{Fouvry, Étienne and Klüners, Jürgen}}, issn = {{1937-0652}}, journal = {{Algebra & Number Theory}}, keywords = {{Algebra and Number Theory}}, number = {{5}}, pages = {{493--508}}, publisher = {{Mathematical Sciences Publishers}}, title = {{{On the Spiegelungssatz for the 4-rank}}}, doi = {{10.2140/ant.2010.4.493}}, volume = {{4}}, year = {{2010}}, } @article{32519, abstract = {{Im vorliegenden Beitrag wird der Zusammenhang zwischen der Fähigkeit zur Perspektivenübernahme und sinnverstehendem Lesen dargestellt. Auf der Grundlage von Arbeiten zum Textverstehen sowie zu Perspektivenübernahme und Theory of Mind wurde ein positiver Zusammenhang zwischen Perspektivenübernahmefähigkeit und Textverstehensleistung erwartet. Diese Hypothese wurde an zwei Stichproben unterschiedlichen Alters geprüft: In der ersten Studie beantworteten 37 Vorschulkinder Fragen zu vorgelesenen Geschichten sowie Perspektivenübernahme-Aufgaben. Zwischen den Bereichen fand sich eine deutliche positive Korrelation, die bei Kontrolle der Intelligenz erhalten blieb. An der zweiten Studie nahmen 69 Grundschulkinder der dritten Jahrgangsstufe teil, die Texte lasen und Aufgaben dazu wie auch zur Perspektivenübernahme bearbeiteten. In dieser Stichprobe fand sich der erwartete Zusammenhang ausschließlich in der Teilgruppe der guten Leser. Er blieb bei Kontrolle der Intelligenz erhalten. Die Ergebnisse werden auch in Hinblick auf die Förderung der Lesekompetenz diskutiert.}}, author = {{Buhl, Heike M. and Möller, Franziska and Oebser, Manuela and Stein, Freia and Noack, Peter}}, journal = {{Diskurs Kindheits- und Jugendforschung}}, keywords = {{Textverstehen, Lesekompetenz, Perspektivenübernahme, Theory of Mind, Kindesalter}}, pages = {{75 -- 90}}, title = {{{Zusammenhänge zwischen der Fähigkeit zur Perspektivenübernahme und dem Textverstehen im Vor- und Grundschulalter}}}, volume = {{1}}, year = {{2009}}, } @article{34889, abstract = {{We prove that van Hoeij’s original algorithm to factor univariate polynomials over the rationals runs in polynomial time, as well as natural variants. In particular, our approach also yields polynomial time complexity results for bivariate polynomials over a finite field.}}, author = {{Belabas, Karim and van Hoeij, Mark and Klüners, Jürgen and Steel, Allan}}, issn = {{1246-7405}}, journal = {{Journal de Théorie des Nombres de Bordeaux}}, keywords = {{Algebra and Number Theory}}, number = {{1}}, pages = {{15--39}}, publisher = {{Cellule MathDoc/CEDRAM}}, title = {{{Factoring polynomials over global fields}}}, doi = {{10.5802/jtnb.655}}, volume = {{21}}, year = {{2009}}, } @inproceedings{9568, abstract = {{A simple pre-stress estimate method of Langevin transducers is studied. The measurement setup consists of a capacitor, an impedance converter and a voltmeter. Based on the piezoelectric equation and the basic circuit theory, the mathematical expression between the pre-stress and the voltage across the capacitor is derived. The pre-stress level can then be calculated out of the measurement of the capacitor voltage. In order to evaluate the precision of this method, a force washer is used to measure the pre-stress of the Langevin transducer. The result shows the pre-stress level obtained from this method is 30-40\% higher than the pre-stress level measured by the force washer. This method is simple and can be used to estimate the pre-stress of various Langevin transducers. The precision of this method can be raised if d33 is identified under different pre-stress levels.}}, author = {{Bo, Fu and Ting, Li and Hemsel, Tobias}}, booktitle = {{Piezoelectricity, Acoustic Waves, and Device Applications, 2008. SPAWDA 2008. Symposium on}}, keywords = {{capacitors, impedance convertors, piezoelectric transducers, stress analysis, Langevin transducers, basic circuit theory, capacitor, impedance converter, piezoelectric equation, pre-stress estimating method, voltmeter, Capacitors, Educational institutions, Equations, Force measurement, Impedance measurement, Manufacturing, Mechatronics, Piezoelectric transducers, Voltage, Voltmeters, Langevin transducer, capacitor, piezoelectric element, pre-stress}}, pages = {{324--327}}, title = {{{A simple pre-stress estimating method of langevin transducers}}}, doi = {{10.1109/SPAWDA.2008.4775801}}, year = {{2008}}, } @article{4435, abstract = {{Der Beitrag beschreibt die Potenziale informeller Mitarbeiter-Communities für die Innovationsfähigkeit kleiner und mittlerer Unternehmen (KMU). Innovationsmanagement bezieht sich in der Regel auf grosse Unternehmen. Die speziellen Bedürfnisse und Möglichkeiten von KMU werden dabei oftmals vernachlässigt. Auf Basis einer Fallstudie werden daher Gestaltungsmöglichkeiten für innovationsfreundliche Arbeitskontexte in kleinen und mittleren Betrieben herausgearbeitet. Im Mittelpunkt der Analyse stehen Kriterien, die kritisch für die Entstehung und den Fortbestand informeller Innovationsnetzwerke innerhalb formeller Organisationsstrukturen sind. Die Studie greift auf Erkenntnisse der Kreativitäts- und der Lernforschung zurück und bezieht sich explizit auf den Community of Practice-Ansatz. Abschliessend werden die Grenzen eines "Managements" innovativer Mitarbeiternetzwerke diskutiert und Möglichkeiten der Gestaltung von Arbeitskontexten vorgestellt.}}, author = {{Jenert, Tobias}}, issn = {{1615-7729}}, journal = {{Wirtschaftspsychologie}}, keywords = {{Innovation, Community of Practice, KMU}}, number = {{1}}, pages = {{43----48}}, publisher = {{Pabst Publishers}}, title = {{{Kooperation, Kompetenz und Kontinuität: Grundlagen innovativer Fach-Communities im Mittelstand}}}, year = {{2008}}, } @article{45431, author = {{Mahnken, Rolf}}, issn = {{0178-7675}}, journal = {{Computational Mechanics}}, keywords = {{Applied Mathematics, Computational Mathematics, Computational Theory and Mathematics, Mechanical Engineering, Ocean Engineering, Computational Mechanics}}, number = {{5}}, pages = {{408--425}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{A Newton-Multigrid algrithm for elasto-plastic/viscoplastic problems}}}, doi = {{10.1007/bf00350355}}, volume = {{15}}, year = {{2008}}, } @article{39947, author = {{Rösler, Margit}}, issn = {{0010-437X}}, journal = {{Compositio Mathematica}}, keywords = {{Algebra and Number Theory}}, number = {{03}}, pages = {{749--779}}, publisher = {{Wiley}}, title = {{{Bessel convolutions on matrix cones}}}, doi = {{10.1112/s0010437x06002594}}, volume = {{143}}, year = {{2007}}, } @article{34891, abstract = {{We study the asymptotics conjecture of Malle for dihedral groups Dℓ of order 2ℓ, where ℓ is an odd prime. We prove the expected lower bound for those groups. For the upper bounds we show that there is a connection to class groups of quadratic number fields. The asymptotic behavior of those class groups is predicted by the Cohen--Lenstra heuristics. Under the assumption of this heuristic we are able to prove the expected upper bounds. }}, author = {{Klüners, Jürgen}}, issn = {{1246-7405}}, journal = {{Journal de Théorie des Nombres de Bordeaux}}, keywords = {{Algebra and Number Theory}}, number = {{3}}, pages = {{607--615}}, publisher = {{Cellule MathDoc/CEDRAM}}, title = {{{Asymptotics of number fields and the Cohen–Lenstra heuristics}}}, doi = {{10.5802/jtnb.561}}, volume = {{18}}, year = {{2006}}, } @article{34892, abstract = {{We prove that the number of quartic S4--extensions of the rationals of given discriminant d is $O_\eps(d^{1/2+\eps})$ for all $\eps>0$. For a prime number p we derive that the dimension of the space of octahedral modular forms of weight 1 and conductor p or p² is bounded above by O(p¹/²log(p)²). }}, author = {{Klüners, Jürgen}}, issn = {{0065-1036}}, journal = {{Acta Arithmetica}}, keywords = {{Algebra and Number Theory}}, number = {{2}}, pages = {{185--194}}, publisher = {{Institute of Mathematics, Polish Academy of Sciences}}, title = {{{The number of S₄-fields with given discriminant}}}, doi = {{10.4064/aa122-2-3}}, volume = {{122}}, year = {{2006}}, } @article{34893, abstract = {{Let K be a global field and O be an order of K. We develop algorithms for the computation of the unit group of residue class rings for ideals O in . As an application we show how to compute the unit group and the Picard group of O provided that we are able to compute the unit group and class group of the maximal order O of K.}}, author = {{Klüners, Jürgen and Pauli, Sebastian}}, issn = {{0021-8693}}, journal = {{Journal of Algebra}}, keywords = {{Algebra and Number Theory}}, number = {{1}}, pages = {{47--64}}, publisher = {{Elsevier BV}}, title = {{{Computing residue class rings and Picard groups of orders}}}, doi = {{10.1016/j.jalgebra.2005.04.013}}, volume = {{292}}, year = {{2005}}, } @inproceedings{11931, abstract = {{The paper is concerned with binaural signal processing for a bimodal human-robot interface with hearing and vision. The two microphone signals are processed to obtain an enhanced single-channel input signal for the subsequent speech recognizer and to localize the acoustic source, an important information for establishing a natural human-robot communication. We utilize a robust adaptive algorithm for filter-and-sum beamforming (FSB) and extract speaker direction information from the resulting FIR filter coefficients. Further, particle filtering is applied which conducts a nonlinear Bayesian tracking of speaker movement. Good location accuracy can be achieved even in highly reverberant environments. The results obtained outperform the conventional generalized cross correlation (GCC) method.}}, author = {{Warsitz, Ernst and Haeb-Umbach, Reinhold}}, booktitle = {{IEEE Workshop on Multimedia Signal Processing (MMSP 2004)}}, keywords = {{bimodal human-robot interface, binaural signal processing, enhanced single-channel input signal, filter-and-sum beamforming, filtering theory, FIR filter coefficient, generalized cross correlation method, microphones, microphone signal, nonlinear Bayesian tracking, particle filtering, robust adaptive algorithm, robust speaker direction estimation, signal processing, speech enhancement, speech recognition, speech recognizer, user interfaces}}, pages = {{367--370}}, title = {{{Robust speaker direction estimation with particle filtering}}}, doi = {{10.1109/MMSP.2004.1436569}}, year = {{2004}}, }