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1
Großmann, Knut. "Tradition und Gegenwart bei der Analyse des thermischen Verhaltens spanender Werkzeugmaschinen: Tagungsband 16. Dresdner Werkzeugmaschinen-Fachseminar, 21. und 22. März 2013 Dresden: Gewidmet dem 100. Geburtstag von Prof. Dr.-Ing. habil. Dr. h.c. Horst Berthold." Technische Universität Dresden, 2013. https://tud.qucosa.de/id/qucosa%3A27057.
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Die Dresdner Werkzeugmaschinen-Fachseminare sind ein Forum zu ausgewählten Spezialthemen der Entwicklung und Nutzung von Werkzeugmaschinen.
Das 16. WZM-Fachseminar berichtetet inhaltlich detailliert von aktuellen Arbeiten im Rahmen des DFG-Sonderforschungsbereiches "Thermo-Energetische Gestaltung von Werkzeugmaschinen" (SFB/TR 96) an den Standorten Dresden, Aachen und Chemnitz.
Die Fachbeiträge berichten über experimentelle und modellgestützte Analyse von Wärmequellen und -übertragung in spanenden Werkzeugmaschinen sowie zu Lösungsansätzen zur Korrektur und Kompensation der thermo-elastischen Verlagerungen.:H. P. Schossig DMG, Pfronten: Thermik-Forschung und die Umsetzung der Erkenntnisse in Maschinenkonzepten bei DMG
K. Großmann Sprecher des DFG-SFB Transregio 96 IWM, TU Dresden: Thermo-Energetische Gestaltung von Werkzeugmaschinen
F. Klocke; M. Brockmann WZL, RWTH Aachen, K. Großmann; Ch. Städel IWM, TU Dresden: Untersuchungen des Zerspanungsprozesses hinsichtlich auftretender Wärmeströme und Temperaturen
R. Werner; St. Winkler EWA, TU Chemnitz, Ch. Brecher; D. Haber WZL, RWTH Aachen: Verlustleistungen in einer Vorschubachse und die daraus resultierende Temperaturverteilung
R. Kneer; S. Vieler WSA, RWTH Aachen, K. Großmann; St. Schroeder IWM, TU Dresden: Messungen des Wärmeübergangs an Fugenkontakten von Werkzeugmaschinen
J. Weber; Jul. Weber IFD, TU Dresden, G. Schmidt; U. Semmler Fraunhofer IWU, Chemnitz: Fluidische Kühlung von Motorspindeln und Werkzeugen
W.-G. Drossel; St. Ihlenfeldt; C. Zwingenberger Fraunhofer IWU, Chemnitz, K. Großmann; St. Schroeder IWM, TU Dresden: Modellierung des Wärmeaustauschs Maschine-Umgebung
A. Voigt; J. Wensch; A. Naumann IWR, TU Dresden: Defektkorrektur bei Mittelungsverfahren in der Zeitintegration des Temperaturverhaltens
K. Großmann; A. Galant IWM, TU Dresden, M. Beitelschmidt; M. Partzsch IFKM, TU Dresden: Strukturveränderlichkeit in FEM und Blocksimulation bei der Berechnung von Temperaturfeldern
K. Großmann; M. Merx IWM, TU Dresden: Thermografie und Nahbereichs-Fotogrammetrie zur Erfassung von Temperatur- u. Verlagerungsfeldern
Ch. Brecher; M. Wennemer WZL, RWTH Aachen: Eigenschaftsmodellbasierter Ansatz zur Korrektur thermo-elastischer Verlagerungen
K. Großmann; Ch. Städel IWM, TU Dresden: Simulative Erweiterung der Datenbasis zur korrelativen Korrektur thermo-elastischer Verlagerungen
W.-G. Drossel; Ch. Ohsenbrügge Fraunhofer IWU, Chemnitz: Materialeffekte und Funktionsmechanismen zur Wärmefluss-Steuerung
2
Vorländer, Hans. "Transzendenz und Gemeinsinn: Themen und Perspektiven des Dresdner Sonderforschungsbereichs 804." Technische Universität Dresden, 2011. https://tud.qucosa.de/id/qucosa%3A26300.
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VORWORT: Ikonisch verdichtet sich auf dem Umschlag dieser Broschüre das Selbstbild Dresdens. Von der Brühlschen Terrasse, „Balkon Europas“ genannt, geht der Blick auf die Kunstakademie, mit der gläsernen Kuppel des Kunstvereins, die mit einer eigenartigen Figur an ihrer Spitze besetzt ist, die sich beim näheren Hinsehen als Chimäre aus Nike und Fama zu erkennen gibt. Auf dem Sockel in der Bildmitte steht Gottfried Semper, der jene Oper baute, die heute medial auch als „das schönste Brauhaus Deutschlands“ bekannt ist. Und am hinteren Bildrand werden das neu errichtete Coselpalais, benannt nach der berühmten Mätresse August des Starken, und die wiedererrichtete Frauenkirche sichtbar. Sie ist das Stein gewordene Symbol für die Rekonstruktion des „alten“ Dresden und zugleich Objekt eines neu-alten Bürgerstolzes.
Betrachtet man dieses Bild, mag es verständlich erscheinen, dass manche sagen, Dresden sei gar keine Stadt, sondern ein Mythos. Indes, so wäre zu entgegnen, macht der Mythos erst die Stadt. „Elbflorenz“ – das ist die Erzählung von barocker Schönheit, Liebe zur Kunst und Prunk der alten Residenz. Es ist ein Erinnerungsmythos, zugleich aber auch ein Mythos der Wiederbegründung. Zwischen beide schiebt sich der Mythos des Opfers: die Zerstörung Dresdens am 13. und 14. Februar 1945.
In den Konflikten um die Kirchen- und die Stadtrekonstruktion, um die Restituierung von räumlicher Mitte und urbaner Identität, hat sich eine die Bürgerschaft mobilisierende Energie zu erkennen gegeben. Sie hat es vermocht, dass mehr als drei Viertel der Kosten für den Wiederaufbau der Kirche von privaten Geldgebern gespendet wurde. Zugleich hat diese gemeinsinnige Kraft aber auch bei der Bebauung der die Frauenkirche umgebenden Brachen zu einer Emphase historistischer Rekonstruktionstreue auf dem Neumarkt geführt. In der Erzählung von Zerstörung und Wiederauferstehung verschränken sich mithin mythische Eigentranszendierung der Stadt und aktuelle Gemeinsinnsbehauptungen in einer höchst spannungsvollen Weise.
Dresden illustriert die Fragestellung des Sonderforschungsbereichs, der in dieser Stadt auch seinen Sitz hat. Der Sonderforschungsbereich 804 „Transzendenz und Gemeinsinn“ wurde im Mai 2009 von der Deutschen Forschungsgemeinschaft bewilligt und besteht seit dem 1. Juli 2009 an der Technischen Universität Dresden. Er umfasst 20 Teilprojekte aus drei Fakultäten und neun Instituten der TU Dresden sowie von Partnern der italienischen Universitäten Turin und Matera und der Universität Zürich, Schweiz. Zudem besitzt der SFB 804 ein Integriertes Graduiertenkolleg zur Ausbildung von Doktoranden und internationalen Stipendiaten. Das Forschungsprogramm sieht vor, jenseits herkömmlicher Epocheneinteilungen Ordnungsformationen wie Stadt, Republik, Demokratie, Nation, bürgerliche Gesellschaft, Adel und Hof, religiöse und nicht-religiöse Gemeinschaften miteinander zu vergleichen. Stets geht es um die Analyse des spannungsvollen Zusammenspiels von Transzendenzformen und Gemeinsinnsvorstellungen bei Entstehung, Stabilisierung und Scheitern von vormodernen und modernen sozialen und politischen Ordnungen. Mit dieser interdisziplinär und international vernetzten Fragestellung setzt der SFB 804 die erfolgreiche Grundlagenforschung der Dresdner Geistes-, Sozial- und Kulturwissenschaften fort, die in der zweiten Hälfte der 1990er Jahre mit dem Sonderforschungsbereich 537 „Institutionalität und Geschichtlichkeit“ und einem Internationalen Graduiertenkolleg begonnen hat.
Die folgenden Seiten beabsichtigen, den gemeinsamen Forschungsansatz und die Ziele der einzelnen Projekte des SFB 804 der wissenschaftlichen und interessierten Öffentlichkeit vorzustellen. Sie möchten auch zu Anregung und Auseinandersetzung einladen.:6 Hans Vorländer: Einleitung
16 Maria Häusl: Trennung und Öffnung. Alttestamentarische Diskurse um die Konstituierung des nachexilischen Israel
22 Matthias Klinghardt: Mahl und Kanon. Gemeinschaftsbildung im frühen Christentum
28 Martin Jehne: Die Investition eigener Ressourcen in die Gemeinschaft von der mittleren Republik bis in die hohe Kaiserzeit
34 Fritz-Heiner Mutschler: Tradition, Vernunft, Gott. Zur wechselnden Fundierung gemeinsinnigen Handelns vom Ausgang der Republik bis in die Umbruchphase des 3. Jahrhunderts
40 Cristina Andenna/Gert Melville: Dynastie, Idoneität und Transzendenz. Vergleichende Untersuchungen zum hohen und späten Mittelalter
46 Bruno Klein: Die Kirche als Baustelle. Großstädtische Sakralbauten im Mittelalter
52 Jürgen Müller: Das subversive Bild. Religiöse und profane Deutungsmuster in der Kunst der Frühen Neuzeit
58 Gerd Schwerhoff: Gottlosigkeit und Eigensinn. Religiöse Devianz in der Frühen Neuzeit
64 Winfried Müller: Gemeinsinnsdiskurse und religiöse Prägung zwischen Spätaufklärung und Vormärz (ca. 1770 - ca. 1848)
70 Hans Vorländer: Demokratische Ordnung zwischen Transzendenz und Gemeinsinn
76 Werner J. Patzelt: Transzendenz und Gemeinsinn als Ressourcen politischer Ordnungskonstruktion
82 Karl-Siegbert Rehberg: Kunstsakralisierung und Gemeinsinn
88 Hans-Georg Lippert: Das Planbare und das Unverfügbare. Modelle von Transzendenz und Gemeinsinn in Architektur und Städtebau im 20. Jahrhundert
94 Thomas Hänseroth: Das Fortschrittsversprechen von Technik und die Altruismusbehauptung der Ingenieure in der technokratischen Hochmoderne (ca. 1880 - 1970)
100 Christian Schwarke: Konstruktionen von Transzendenz und Gemeinsinn in Technik und Theologie
106 Karl Lenz: Transzendenz und Gemeinsinn in privaten Lebensformen
112 Thomas Rentsch: Transzendenz und Gemeinsinn in Geschichte und Gegenwart der Philosophie
118 Pier Paolo Portinaro: Die Sakralisierung der Kulturnation im italienischen Risorgimento
124 Georg Kohler: Die Kontingenz des Unverfügbaren - Die „Willensnation Schweiz“
130 Marina Münkler: Das Ethos der Freundschaft
136 Gerd Schwerhoff: Integriertes Graduiertenkolleg
138 Kontakt und Impressum
3
Großmann, Knut. "Thermo-Energetische Gestaltung von Werkzeugmaschinen: Modellierung und Simulation: 2. Kolloquium zum SFB/TR 96: 24./25.10.2012 in Chemnitz." Technische Universität Dresden, 2012. https://tud.qucosa.de/id/qucosa%3A28098.
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Der Beitrag "Voraussetzungen und Grenzen einer eigenschaftsmodellbasierten Korrektur St. Bäumler, C. Brecher, M. Wennemer; RWTH Aachen, Lehrstuhl für Werkzeugmaschinen" ist in dieser Version nicht enthalten, bitte nutzen Sie die Version unter oben angegebenen Link (Nachfolger).<br>Im Mittelpunkt der 2. Tagung des Sonderforschungsbereichs Transregio 96 „Thermo-energetische Gestaltung von Werkzeugmaschinen standen erste Ergebnisse zur Modellierung und Simulation von Komponenten und Baugruppen von Werkzeugmaschinen im Mittelpunkt. An den drei Standorten Aachen, Chemnitz und Dresden werden unterschiedliche Lösungsansätze für die steuerungsintegrierte Korrektur thermischer bedingter Strukturverformungen in spanenden Werkzeugmaschinen verfolgt. Von diesen wird eine unterschiedliche Wirksamkeit bzw. Eignung für verschiedene Einsatzfälle erwartet.
Bevor diese in der Praxis umgesetzt werden können, müssen Fragen zur Beschreibung der Wärmequellen und zur Wärmeübertragung beantwortet werden. Außerdem bedarf die Umsetzung der Konzepte in den CNC-Steuerungen effizienter Verfahren zur Modellierung und Simulation der thermisch bedingten Strukturverformung. Für die Entwicklung und Bewertung der Korrekturverfahren sowie zur Berechnung der notwendigen Achs-Korrekturen ist die Systemsimulation u. a. an einem prozessaktuelle Werkzeugmaschinenabbild erforderlich. Für die Bewertung ihrer Praxisrelevanz werden die Einzellösungen nach und nach in ein betriebswirtschaftlich orientiertes Gesamtmodell integriert.
4
Großmann, Knut. "Thermo-Energetische Gestaltung von Werkzeugmaschinen: Experimentelle Methodik: 3. Kolloquium zum SFB/TR 96: 29./30.10.2013 in Aachen." Prof. Dr.-Ing. habil. Knut Großmann, 2013. https://tud.qucosa.de/id/qucosa%3A28099.
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Im Mittelpunkt der 3. Tagung des Sonderforschungsbereichs Transregio 96 am 29. und 30.Oktober 2013 am Werkzeugmaschinenlabor der RWTH Aachen standen die verschiedenen Lösungsansätze der einzelnen Teilprojekte bei der Durchführung der experimentellen Untersuchungen zur Verifizierung von Simulationsergebnissen bzw. zur Ableitung von Modellparametern.
Es wurden vier Themenblöcke behandelt:
• Ermittlung von thermisch relevanten Prozessparametern
• Experimentelle Methodik zur Analyse von Teilsystemen in Werkzeugmaschinen
• Methodische Rahmenbedingungen bei der Ermittlung von thermisch relevanten Parametern
• Verfahren zur Verformungs- und Verlagerungsmessung
5
Keyserlingk, Linda von. "Akademische Forschung und universitäre Sammlungen." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-111314.
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Die zweite Sektion begann am 4. Oktober mit einem einführenden Vortrag von Klaus Mauersberger über die Entwicklung, die Bewahrung und die Spezifik der Sammlungen der TU Dresden. Mauersberger, langjähriger Mitarbeiter am Zentrum für Geschichte der Technikwissenschaften und seit 1993 Leiter der Kustodie der TU Dresden, gab einen Überblick über die Anfänge, die Aufgaben sowie den Umfang und die Diversität der Dresdner Universitätssammlungen. (...)
6
Küster, Kerstin, and Felicitas von Mallinckrodt. "Exkursion ins Museum der deutschsprachigen Bewohner der böhmischen Länder in Ústí nad Labem (Aussig)." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-111350.
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Werden normalerweise neue Museen für bereits bestehende Sammlungen gebaut, so verkehrt sich in Ústí nad Labem dieses Prinzip ins Gegenteil. Auf Initiative des Collegium Bohemicum und unterstützt von der Jan Evangelista Purkyně-Universität Ústí nad Labem wurde 2006 das „Museum für die deutschsprachigen Bewohner der böhmischen Länder“ ins Leben gerufen. Das im Aufbau befindliche Museum hat sich zum Ziel gesetzt, das Wirken und den Beitrag der deutschsprachigen Bewohner in den böhmischen Ländern aus tschechischer Perspektive, aber in europäische Zusammenhänge eingebettet darzustellen und zu vermitteln. (...)
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Kolb, Lisa Christina. "Kulturelle Gedächtnisinstitutionen und ihre digitale Zukunft." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-111305.
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Bereits seit einiger Zeit ist von Seiten kulturgutverwahrender Institutionen ein Aufbruch in Richtung der digitalen Welt zu konstatieren. Eine steigende Anzahl von Tagungen, Publikationen und kulturwissenschaftlichen Studien zu diesem Thema belegt dies.1 Doch welche Umbrüche in den Strukturen, im Denken und in den Strategien sind notwendig, um die digitale Zukunft erfolgreich zu beschreiten? (...)
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Kern, Lisa. "Datenbanken, Inventarisierung, Provenienzforschung." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-111327.
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Die dritte Sektion der Dresden Summer School behandelte die für die wissenschaftliche Arbeit am Museum zentralen Aspekte Datenbanken, Inventarisierung und Provenienzforschung. Alle diese Punkte sind eng mit dem Thema Digitalisierung verbunden, greifen die genannten Arbeitsbereiche doch mittlerweile standardmäßig auf Datenbanken und elektronische Systeme zur Erfassung, Dokumentation und Erforschung der musealen Bestände zurück. (...)
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Popplow, Laura. "Nur Mut zum Prozess! Oder: Wie kann zeitgemäße, mediale Ausstellungsgestaltung gelingen?" Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-111345.
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Der Besuch des im Bau befindlichen Staatlichen Museums für Archäologie Chemnitz bot den Teilnehmerinnen und Teilnehmern der Dresden Summer School 2012 die Möglichkeit, die Planung eines von Grund auf neuen Museums mit einer sehr modernen Ausstellungsarchitektur und Medieninszenierung durch die Mitarbeiter und den leitenden Ausstellungsgestalter kennenzulernen. (...)
10
Ostendorf-Rupp, Sonja. "Kulturelle Bildung und Social Media." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-111333.
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Facebook, Twitter, YouTube – die Namen dieser Plattformen sozialer Medien sind in aller Munde, doch was steckt hinter diesen Medienformen und wie lassen sie sich sinnvoll in die Arbeit von Kultureinrichtungen integrieren? Welche Potentiale der Besucheransprache bieten sie? Das waren die Leitfragen der vierten und letzten Sektion der Dresden Summer School. Eingebettet in Besichtigungen des Militärhistorischen Museums der Bundeswehr (MHM) und des Deutschen Hygiene-Museums Dresden (DHMD), erhielten die Teilnehmer und Teilnehmerinnen eine Einführung zu diesem Thema, die durch Best-Practice-Beispiele von Museen und Ausstellungsplanern ergänzt wurden. (...)
11
Fraunholz, Uwe, Sebastian Beese, and Ralf Pulla. "Ein Funken Wahrheit." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-139092.
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Knaus, Gudrun. "Ich sammle." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-111384.
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Ob Kunstmuseum oder ethnographische Sammlung, ob Militärhistorisches Museum oder Münzkabinett: In einem vielfältigen Angebotsspektrum ringen große und kleine Museen um die Gunst der Besucher. Die Struktur des Zielpublikums ist dabei in der Regel sehr weit gefasst, da im Sinne des Bildungsauftrags möglichst viele soziale Milieus oder Altersgruppen angesprochen werden sollen. Das Informationsmaterial zur Vermittlung der Ausstellungsinhalte, wie Ausstellungskataloge, Audioguides, Flyer oder der Internetauftritt der jeweiligen Institutionen, enthält eine Vielzahl von weiterführenden Informationen, die in der Regel nur teilweise zielgruppenspezifisch aufbereitet werden, da die Adressaten jeweils nur schwer eingegrenzt werden können. (...)
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Fraunholz, Uwe, Sebastian Beese, and Ralf Pulla. "Ein Funken Wahrheit: Energievisionen in der technokratischen Hochmoderne." Technische Universität Dresden, 2011. https://tud.qucosa.de/id/qucosa%3A27808.
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Vorländer, Hans, Felicitas von Mallinckrodt, and Kerstin Küster. "Dresden Summer School 2012 - Dokumentation: Von der Vitrine zum Web 2.0 - Museen, Bibliotheken und Archive im digitalen Zeitalter." Technische Universität Dresden, 2013. https://tud.qucosa.de/id/qucosa%3A26840.
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Die Dresden Summer School 2012 gliedert sich in vier aufeinander folgende Sektionen. Diese bestehen aus Vorträgen, Diskussionen, Workshops, Kuratorengesprächen und Führungen. Die Kooperation der fünf renommierten Dresdner Kunst-und Kulturstätten bietet den TeilnehmerInnen ein vielfältiges inhaltliches Angebot und einen Ideen- und Erfahrungsaustausch in verschiedenen Fachbereichen.
Die Sektionen der Dresden Summer School 2012:
1. Digitalisierung in Museen und Bibliotheken. Erfahrungen, Methoden, Strategien.
2. Akademische Forschung und universitäre Sammlungen im digitalen Zeitalter.
3. Virtuelle Inventarisierung – Potentiale der Provenienzforschung.
4. Kulturelle Bildung und Social Media.:EINLEITUNG S. 9
SEKTIONEN S. 15
Kulturelle Gedächtnisinstitutionen und ihre digitale Zukunft - Sächsische Landesbibliothek – Staats- und Universitätsbibliothek Dresden S. 17
Akademische Forschung und universitäre Sammlungen - Technische Universität Dresden S. 25
Datenbanken, Inventarisierung, Provenienzforschung - Staatliche Kunstsammlungen Dresden S. 31
Kulturelle Bildung und Social Media - Deutsches Hygiene-Museum Dresden / Militärhistorisches Museum der Bundeswehr S. 41
EXKURSIONEN S. 47
Nur Mut zum Prozess! Oder: Wie kann zeitgemäße, mediale Ausstellungsgestaltung gelingen? Exkursion in das Staatliche Museum für Archäologie Chemnitz S. 48
Exkursion ins Museum der deutschsprachigen Bewohner der böhmischen Länder in Ústí nad Labem (Aussig) S. 58
PRÄSENTATIONEN S. 63
Speicherchip der Vergangenheit S. 65
Der Maya-Countdown 21/12 S. 73
Ich sammle S. 81
Steuerung Alt Entfernen / Re-boot Science S. 87
BIOGRAPHIEN S. 95
Teilnehmer S. 96
Referenten S. 102
INSTITUTIONEN S. 112
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Becker, Claudia. "Steuerung Alt Entfernen / Re-boot Science." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-101879.
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Am Ende der Dresden Summer School 2012 haben die Teilnehmerinnen und Teilnehmer eigene Ideen und Impulse zur Zukunft der Vernetzung von Kultur- und Wissenschaftseinrichtungen vorgestellt. Claudia Becker, wissenschaftliche Mitarbeiterin am Vilém Flusser Archiv der Universität der Künste Berlin, ist an neuen Wegen der Wissens- und Kulturvermittlung mit digitalen Technologien interessiert.
Wissen, Wissenssammlungen und Wissensordnungen haben sich im Laufe der Jahre verändert, ebenso wie die Wissensproduktion, die Schaffung neuen Wissens, die Wissenschaft selbst. Der Baum des Wissens, „arbor porphyriana“ oder auch „arbor scientiae“ war seit der Antike eine gültige Metapher und das Klassifikationsschema für die Struktur des Wissen, die epistemologische Ordnung. So lehnte auch Denis Diderot die Ordnung seiner berühmten Enzyklopädie an die Baumstruktur des Wissens von Francis Bacon an. Wohl wissend, dass Wissen Macht ist, widmeten Diderot und seine Enzyklopädisten einen großen Teil ihrer Lebenszeit, um das Wissen aus allen Bereichen der Welt zu sammeln und aller Welt zugänglich zu machen. Diderot nutzte somit damals schon die Intelligenz des Schwarmes, seine Enzyklopädie ist ein Produkt des „Crowd Sourcing“, eines kollektiven Verbundes mehrerer Autoren, die gemeinsam an einem Werk schreiben, um Wissen im Namen der Aufklärung den Herrschenden zu entreißen und möglichst vielen zugänglich zu machen. Die Parallelen zu einem der heutigen größten und bedeutendsten Wissensprojekte – der Internet-Enzyklopädie Wikipedia – sind unverkennbar.
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16
Van, Slingerland Krista. "Design, Implementation, and Evaluation of a Sport-Focused Mental Health Service Delivery Model Within a Canadian Centre for Mental Health and Sport." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42792.
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The overall aim of this Participatory Action Research (PAR; Chevalier & Buckles, 2013; Lewin, 1946) project was to design, implement, and evaluate a specialized sport-focused mental health service delivery model for competitive and high-performance athletes, integrated within a broader Canadian Centre for Mental Health and Sport (CCMHS). A transformative mixed methods research design (Cresswell, 2014) guided by the PAR approach was employed across three phases during which (a) a sport-specific mental health service delivery model for competitive and high-performance athletes was collaboratively designed by stakeholders (Design Phase [Study 1]), (b) the model was pilot-tested within the CCMHS (Implementation Phase [Study 2]), and (c) the model was evaluated to understand whether practitioners and service-users perceived the care delivered / received within the model to be acceptable and appropriate (Evaluation Phase [Study 3]). Design Phase (Study 1). The purpose of study 1 was to (a) perform an environmental scan of the Canadian mental health care and sport contexts, and (b) design a sport-focused mental health service delivery model for competitive and high-performance athletes within a broader CCMHS. To meet these objectives, 20 stakeholders from the sport and mental health sectors explored (a) the availability and effectiveness of mental health care for competitive and high-performance Canadian athletes, and (b) the strengths, weaknesses, opportunities and threats associated with creating a CCMHS, via two iterations of stakeholder-led focus groups (Rio-Roberts, 2011). The resulting data informed a subsequent Group Concept Mapping (GCM; Burke et al., 2005; Kane & Trochim, 2007; Rosas & Kane, 2012) activity undertaken by stakeholders, which produced an actionable framework (i.e., concept map) organized into six clusters that visually represented the elements (e.g., services, personnel, organizational structures) that stakeholders deemed important to include in the sport-focused mental health care model (e.g., bilingual services, a triage system, sport-specialized practitioners). In addition, the results revealed that misconceptions about the competitive and high-performance population’s mental health and experience of mental illness were widespread and required clarification before significant advances could be made. This led the group to develop six principles designed to establish a common language and understanding upon which to build effective models of mental health care, improved programming, and strategic education for Canada’s competitive and high-performance athletes, coaches, and organizations (Article 1). The framework that emerged from the GCM activity served to guide the remainder of the project, and supported actions (e.g., develop eligibility criteria to access services, hire a team of mental health practitioners with sport competencies [i.e., CCMHS Care Team]) to build the CCMHS and test the model during the Implementation Phase (Article 2). Implementation Phase (Study 2). The purpose of study 2 was to pilot test the mental health service delivery model designed during the first phase of the research project. To do so, an illustrative case study (Keegan et al., 2017; Stake, 1995, 2005) was carried out to demonstrate how (i.e., intake, referral, and service delivery processes) the CCMHS Care Team provided mental health care to a high-performance athlete, and what outcomes resulted from this process. Data to inform the case study was gathered through a review of the service-user’s clinical documents (e.g., intake summary, session notes), and qualitative interviews (n = 2) with the athlete’s Collaborative Care Team lead and the CCMHS Care Coordinator. Document analysis (Bowen, 2009) was used to organize the details of the case found within clinical documents under the categories of the case study framework (i.e., intake and referral process, service-user description, integrated care plan, and outcomes), while a conventional descriptive content analysis (Hsieh & Shannon, 2005) served to extract salient data from the interviews to further build out the case study. Results revealed that sport significantly influenced the onset and experience of mental illness for the athlete service-user. The lead practitioner’s sport-specific knowledge played a significant role in the diagnosis, treatment and recovery of this athlete given the nature of the athlete’s concerns and high athletic identity. Findings support the notion that specialized mental health care models and teams are necessary to address sport-related factors that can pose unique threats to the diagnosis and treatment of mental illness in athletes (Article 3). Implementation Phase (Study 3). The purpose of study 3 was to evaluate the acceptability and appropriateness of the mental health service delivery model designed during Phase 1 and implemented during Phase 2. Qualitative data from three sources (CCMHS practitioners, CCMHS service-users, and CCMHS stakeholders) were collected and analyzed using a multi-step, multi-method process, including16 one-on-one semi-structured interviews with CCMHS practitioners (n = 10) and service-users (n = 6), and a meeting with CCMHS stakeholders (captured via meeting minutes). In addition, 47 documents (e.g., clinical, procedural) created during the implementation phase of the project by CCMHS team members (i.e., practitioners, stakeholders, members of the board of directors) were used to triangulate the other data (Carter, Bryant-Lukosius, DiCenso, Blythe, and Neville, 2014). The Framework Method (Gale et al., 2013; Ritchie and Spencer, 1994) was used to analyze, synthesize, integrate, and interpret the dataset. The deductive data analysis approach taken was guided by the seven components of acceptability developed by Sekhon and colleagues (2017), and the Canadian Medical Association’s definition of appropriate care. Findings showed that the care provided and received within the CCMHS service delivery model was perceived to be acceptable and appropriate, and each component of the model uniquely contributed to practitioner and service-user experiences. For example, the collaborative interdisciplinary approach contributed to the ethicality of the model, promoted the professional development of team members, and enabled Pan-Canadian service provision. The sport-centered nature of care was perceived to enhance the ethicality of services delivered, effectiveness of care, and affective experience of service-users. Implications for further research and practice were discussed in light of areas of the model that emerged as needing improvement (e.g., prohibitive cost of care, practitioner burden from collaborative processes and procedures). Overall, the findings of the research project demonstrate that collaborative approaches to inquiry and practice can be successfully applied in sport to guide stakeholders in developing and testing novel models to improve the health outcomes of sport participants. The research also shows that an interdisciplinary team of practitioners can successfully deliver sport-focused mental health care that is acceptable and appropriate to service-users. Lastly, the project provides data on the first known empirical project to design, implement and evaluate a specialized mental health service delivery model applied nationwide in person and virtually with competitive and high-performance athletes experiencing mental health challenges and symptoms of mental illness.
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Kissinger, Thomas, Benjamin Schlegel, Dirk Habich, and Wolfgang Lehner. "QPPT: Query Processing on Prefix Trees." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-113269.
Full textAbstract:
Modern database systems have to process huge amounts of data and should provide results with low latency at the same time. To achieve this, data is nowadays typically hold completely in main memory, to benefit of its high bandwidth and low access latency that could never be reached with disks. Current in-memory databases are usually columnstores that exchange columns or vectors between operators and suffer from a high tuple reconstruction overhead. In this paper, we present the indexed table-at-a-time processing model that makes indexes the first-class citizen of the database system. The processing model comprises the concepts of intermediate indexed tables and cooperative operators, which make indexes the common data exchange format between plan operators. To keep the intermediate index materialization costs low, we employ optimized prefix trees that offer a balanced read/write performance. The indexed tableat-a-time processing model allows the efficient construction of composed operators like the multi-way-select-join-group. Such operators speed up the processing of complex OLAP queries so that our approach outperforms state-of-the-art in-memory databases.
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Baier, Christel, Benjamin Engel, Sascha Klüppelholz, Steffen Märcker, Hendrik Tews, and Marcus Völp. "A Probabilistic Quantitative Analysis of Probabilistic-Write/Copy-Select." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-129917.
Full textAbstract:
Probabilistic-Write/Copy-Select (PWCS) is a novel synchronization scheme suggested by Nicholas Mc Guire which avoids expensive atomic operations for synchronizing access to shared objects. Instead, PWCS makes inconsistencies detectable and recoverable. It builds on the assumption that, for typical workloads, the probability for data races is very small. Mc Guire describes PWCS for multiple readers but only one writer of a shared data structure. In this paper, we report on the formal analysis of the PWCS protocol using a continuous-time Markov chain model and probabilistic model checking techniques. Besides the original PWCS protocol, we also considered a variant with multiple writers. The results were obtained by the model checker PRISM and served to identify scenarios in which the use of the PWCS protocol is justified by guarantees on the probability of data races. Moreover, the analysis showed several other quantitative properties of the PWCS protocol.
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Pfennig, Stefan, and Elke Franz. "Secure Network Coding: Dependency of Efficiency on Network Topology." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-128456.
Full textAbstract:
Network Coding is a new possibility to transmit data through a network. By combining different packets instead of simply forwarding, network coding offers the opportunity to reach the Min-Cut/Max-Flow capacity in multicast data transmissions. However, the basic schemes are vulnerable to so-called pollution attacks, where an attacker can jam large parts of the transmission by infiltrating only one bogus message. In the literature we found several approaches which aim at handling this kind of attack with different amounts of overhead. Though, the cost for a specific secure network coding scheme highly depends on the underlying network. The goal of this paper is on the one hand to describe which network parameters influence the efficiency of a certain scheme and on the other hand to provide concrete suggestions for selecting the most efficient secure network coding scheme considering a given network. We will illustrate that there does not exist “the best” secure network scheme concerning efficiency, but all selected schemes are more or less suited under certain network topologies.
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Hähnel, Marcus, Björn Döbel, Marcus Völp, and Hermann Härtig. "Measuring energy consumption for short code paths using RAPL." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-113258.
Full textAbstract:
Measuring the energy consumption of software components is a major building block for generating models that allow for energy-aware scheduling, accounting and budgeting. Current measurement techniques focus on coarse-grained measurements of application or system events. However, fine grain adjustments in particular in the operating-system kernel and in application-level servers require power profiles at the level of a single software function. Until recently, this appeared to be impossible due to the lacking fine grain resolution and high costs of measurement equipment. In this paper we report on our experience in using the Running Average Power Limit (RAPL) energy sensors available in recent Intel CPUs for measuring energy consumption of short code paths. We investigate the granularity at which RAPL measurements can be performed and discuss practical obstacles that occur when performing these measurements on complex modern CPUs. Furthermore, we demonstrate how to use the RAPL infrastructure to characterize the energy costs for decoding video slices.
21
Engelmann, Sabrina, Zuleita K. M. Ho, and Eduard A. Jorswieck. "Interference Leakage Neutralization in Two-Hop Wiretap Channels with Partial CSI." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-128438.
Full textAbstract:
In this paper, we analyze the four-node relay wiretap channel, where the relay performs amplify-and-forward. There is no direct link between transmitter and receiver available. The transmitter has multiple antennas, which assist in securing the transmission over both phases. In case of full channel state information (CSI), the transmitter can apply information leakage neutralization in order to prevent the eavesdropper from obtaining any information about the signal sent. This gets more challenging, if the transmitter has only an outdated estimate of the channel from the relay to the eavesdropper. For this case, we optimize the worst case secrecy rate by choosing intelligently the beamforming vectors and the power allocation at the transmitter and the relay.
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Lehner, Wolfgang. "Energy-Efficient In-Memory Database Computing." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-115547.
Full textAbstract:
The efficient and flexible management of large datasets is one of the core requirements of modern business applications. Having access to consistent and up-to-date information is the foundation for operational, tactical, and strategic decision making. Within the last few years, the database community sparked a large number of extremely innovative research projects to push the envelope in the context of modern database system architectures. In this paper, we outline requirements and influencing factors to identify some of the hot research topics in database management systems. We argue that—even after 30 years of active database research—the time is right to rethink some of the core architectural principles and come up with novel approaches to meet the requirements of the next decades in data management. The sheer number of diverse and novel (e.g., scientific) application areas, the existence of modern hardware capabilities, and the need of large data centers to become more energy-efficient will be the drivers for database research in the years to come.
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Fettweis, Gerhard P., Hassan Najeeb ul, Lukas Landau, and Erik Fischer. "Wireless Interconnect for Board and Chip Level." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-118302.
Full textAbstract:
Electronic systems of the future require a very high bandwidth communications infrastructure within the system. This way the massive amount of compute power which will be available can be inter-connected to realize future powerful advanced electronic systems. Today, electronic inter-connects between 3D chip-stacks, as well as intra-connects within 3D chip-stacks are approaching data rates of 100 Gbit/s soon. Hence, the question to be answered is how to efficiently design the communications infrastructure which will be within electronic systems. Within this paper approaches and results for building this infrastructure for future electronics are addressed.
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Pfennig, Stefan, and Elke Franz. "Comparison of Different Secure Network Coding Paradigms Concerning Transmission Efficiency." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-145096.
Full textAbstract:
Preventing the success of active attacks is of essential importance for network coding since even the infiltration of one single corrupted data packet can jam large parts of the network. The existing approaches for network coding schemes preventing such pollution attacks can be divided into two categories: utilize cryptographic approaches or utilize redundancy similar to error correction coding. Within this paper, we compared both paradigms concerning efficiency of data transmission under various circumstances. Particularly, we considered an attacker of a certain strength as well as the influence of the generation size. The results are helpful for selecting a suitable approach for network coding taking into account both security against pollution attacks and efficiency.
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Baier, Christel, Marcus Daum, Benjamin Engel, et al. "Chiefly Symmetric: Results on the Scalability of Probabilistic Model Checking for Operating-System Code." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-121319.
Full textAbstract:
Reliability in terms of functional properties from the safety-liveness spectrum is an indispensable requirement of low-level operating-system (OS) code. However, with evermore complex and thus less predictable hardware, quantitative and probabilistic guarantees become more and more important. Probabilistic model checking is one technique to automatically obtain these guarantees. First experiences with the automated quantitative analysis of low-level operating-system code confirm the expectation that the naive probabilistic model checking approach rapidly reaches its limits when increasing the numbers of processes. This paper reports on our work-in-progress to tackle the state explosion problem for low-level OS-code caused by the exponential blow-up of the model size when the number of processes grows. We studied the symmetry reduction approach and carried out our experiments with a simple test-and-test-and-set lock case study as a representative example for a wide range of protocols with natural inter-process dependencies and long-run properties. We quickly see a state-space explosion for scenarios where inter-process dependencies are insignificant. However, once inter-process dependencies dominate the picture models with hundred and more processes can be constructed and analysed.
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Pfennig, Stefan, and Elke Franz. "Comparison of Different Secure Network Coding Paradigms Concerning Transmission Efficiency." Technische Universität Dresden, 2013. https://tud.qucosa.de/id/qucosa%3A28134.
Full textAbstract:
Preventing the success of active attacks is of essential importance for network coding since even the infiltration of one single corrupted data packet can jam large parts of the network. The existing approaches for network coding schemes preventing such pollution attacks can be divided into two categories: utilize cryptographic approaches or utilize redundancy similar to error correction coding. Within this paper, we compared both paradigms concerning efficiency of data transmission under various circumstances. Particularly, we considered an attacker of a certain strength as well as the influence of the generation size. The results are helpful for selecting a suitable approach for network coding taking into account both security against pollution attacks and efficiency.
27
Kissinger, Thomas, Benjamin Schlegel, Matthias Böhm, Dirk Habich, and Wolfgang Lehner. "A high-throughput in-memory index, durable on flash-based SSD." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-105947.
Full textAbstract:
Growing memory capacities and the increasing number of cores on modern hardware enforces the design of new in-memory indexing structures that reduce the number of memory transfers and minimizes the need for locking to allow massive parallel access. However, most applications depend on hard durability constraints requiring a persistent medium like SSDs, which shorten the latency and throughput gap between main memory and hard disks. In this paper, we present our winning solution of the SIGMOD Programming Contest 2011. It consists of an in-memory indexing structure that provides a balanced read/write performance as well as non-blocking reads and single-lock writes. Complementary to this index, we describe an SSD-optimized logging approach to fit hard durability requirements at a high throughput rate.
28
Baier, Christel, Marcus Daum, Benjamin Engel, et al. "Chiefly Symmetric: Results on the Scalability of Probabilistic Model Checking for Operating-System Code." Technische Universität Dresden, 2012. https://tud.qucosa.de/id/qucosa%3A27132.
Full textAbstract:
Reliability in terms of functional properties from the safety-liveness spectrum is an indispensable requirement of low-level operating-system (OS) code. However, with evermore complex and thus less predictable hardware, quantitative and probabilistic guarantees become more and more important. Probabilistic model checking is one technique to automatically obtain these guarantees. First experiences with the automated quantitative analysis of low-level operating-system code confirm the expectation that the naive probabilistic model checking approach rapidly reaches its limits when increasing the numbers of processes. This paper reports on our work-in-progress to tackle the state explosion problem for low-level OS-code caused by the exponential blow-up of the model size when the number of processes grows. We studied the symmetry reduction approach and carried out our experiments with a simple test-and-test-and-set lock case study as a representative example for a wide range of protocols with natural inter-process dependencies and long-run properties. We quickly see a state-space explosion for scenarios where inter-process dependencies are insignificant. However, once inter-process dependencies dominate the picture models with hundred and more processes can be constructed and analysed.
29
Hassan, Najeeb ul, Ali E. Pusane, Michael Lentmaier, Gerhard P. Fettweis, and Daniel J. Costello. "Reduced Complexity Window Decoding Schedules for Coupled LDPC Codes." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-105936.
Full textAbstract:
Window decoding schedules are very attractive for message passing decoding of spatially coupled LDPC codes. They take advantage of the inherent convolutional code structure and allow continuous transmission with low decoding latency and complexity. In this paper we show that the decoding complexity can be further reduced if suitable message passing schedules are applied within the decoding window. An improvement based schedule is presented that easily adapts to different ensemble structures, window sizes, and channel parameters. Its combination with a serial (on-demand) schedule is also considered. Results from a computer search based schedule are shown for comparison.
30
Richter, Johannes, Elke Franz, Sabrina Engelmann, Stefan Pfennig, and Eduard A. Jorswieck. "Physical Layer Security vs. Network Layer Secrecy: Who Wins on the Untrusted Two-Way Relay Channel?" Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-145086.
Full textAbstract:
We consider the problem of secure communications in a Gaussian two-way relay network where two nodes exchange confidential messages only via an untrusted relay. The relay is assumed to be honest but curious, i.e., an eavesdropper that conforms to the system rules and applies the intended relaying scheme. We analyze the achievable secrecy rates by applying network coding on the physical layer or the network layer and compare the results in terms of complexity, overhead, and efficiency. Further, we discuss the advantages and disadvantages of the respective approaches.
31
Kissinger, Thomas, Benjamin Schlegel, Matthias Böhm, Dirk Habich, and Wolfgang Lehner. "A high-throughput in-memory index, durable on flash-based SSD: Insights into the winning solution of the SIGMOD programming contest 2011." Technische Universität Dresden, 2012. https://tud.qucosa.de/id/qucosa%3A26635.
Full textAbstract:
Growing memory capacities and the increasing number of cores on modern hardware enforces the design of new in-memory indexing structures that reduce the number of memory transfers and minimizes the need for locking to allow massive parallel access. However, most applications depend on hard durability constraints requiring a persistent medium like SSDs, which shorten the latency and throughput gap between main memory and hard disks. In this paper, we present our winning solution of the SIGMOD Programming Contest 2011. It consists of an in-memory indexing structure that provides a balanced read/write performance as well as non-blocking reads and single-lock writes. Complementary to this index, we describe an SSD-optimized logging approach to fit hard durability requirements at a high throughput rate.
32
Krone, Stefan, and Gerhard Fettweis. "Capacity of Communications Channels with 1-Bit Quantization and Oversampling at the Receiver." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-101462.
Full textAbstract:
Communications receivers that rely on 1-bit analogto-digital conversion are advantageous in terms of hardware complexity and power dissipation. Performance limitations due to the 1-bit quantization can be tackled with oversampling. This paper considers the oversampling gain from an information-theoretic perspective by analyzing the channel capacity with 1-bit quantization and oversampling at the receiver for the particular case of AWGN channels. This includes a numerical computation of the capacity and optimal transmit symbol constellations, as well as the derivation of closed-form expressions for large oversampling ratios and for high signal-to-noise ratios of the channel.
33
Baier, Christel, Marcus Daum, Benjamin Engel, et al. "Waiting for Locks: How Long Does It Usually Take?" Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-121259.
Full textAbstract:
Reliability of low-level operating-system (OS) code is an indispensable requirement. This includes functional properties from the safety-liveness spectrum, but also quantitative properties stating, e.g., that the average waiting time on locks is sufficiently small or that the energy requirement of a certain system call is below a given threshold with a high probability. This paper reports on our experiences made in a running project where the goal is to apply probabilistic model checking techniques and to align the results of the model checker with measurements to predict quantitative properties of low-level OS code.
34
Richter, Johannes, Elke Franz, Sabrina Engelmann, Stefan Pfennig, and Eduard A. Jorswieck. "Physical Layer Security vs. Network Layer Secrecy: Who Wins on the Untrusted Two-Way Relay Channel?" Technische Universität Dresden, 2013. https://tud.qucosa.de/id/qucosa%3A28133.
Full textAbstract:
We consider the problem of secure communications in a Gaussian two-way relay network where two nodes exchange confidential messages only via an untrusted relay. The relay is assumed to be honest but curious, i.e., an eavesdropper that conforms to the system rules and applies the intended relaying scheme. We analyze the achievable secrecy rates by applying network coding on the physical layer or the network layer and compare the results in terms of complexity, overhead, and efficiency. Further, we discuss the advantages and disadvantages of the respective approaches.
35
Ho, Zuleita K. M., and Eduard Jorswieck. "Secure degrees of freedom on widely linear instantaneous relay-assisted interference channel." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-128420.
Full textAbstract:
The number of secure data streams a relay-assisted interference channel can support has been an intriguing problem. The problem is not solved even for a fundamental scenario with a single antenna at each transmitter, receiver and relay. In this paper, we study the achievable secure degrees of freedom of instantaneous relay-assisted interference channels with real and complex coefficients. The study of secure degrees of freedom with complex coefficients is not a trivial multiuser extension of the scenarios with real channel coefficients as in the case for the degrees of freedom, due to secrecy constraints. We tackle this challenge by jointly designing the improper transmit signals and widely-linear relay processing strategies.
36
Jorswieck, Eduard A., Anne Wolf, and Sabrina Engelmann. "Secret key generation from reciprocal spatially correlated MIMO channels." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-143998.
Full textAbstract:
Secret key generation from reciprocal multi-antenna channels is an interesting alternative to cryptographic key management in wireless systems without infrastructure access. In this work, we study the secret key rate for the basic source model with a MIMO channel. First, we derive an expression for the secret key rate under spatial correlation modelled by the Kronecker model and with spatial precoding at both communication nodes. Next, we analyze the result for uncorrelated antennas to understand the optimal precoding for this special case, which is equal power allocation. Then, the impact of correlation is characterized using Majorization theory. Surprisingly for small SNR, spatial correlation increases the secret key rate. For high SNR, the maximum secret key rate is achieved for uncorrelated antennas. The results indicate that a solid system design for reciprocal MIMO key generation is required to establish the secret key rate gains.
37
Baier, Christel, Marcus Daum, Benjamin Engel, et al. "Waiting for Locks: How Long Does It Usually Take?" Technische Universität Dresden, 2012. https://tud.qucosa.de/id/qucosa%3A27128.
Full textAbstract:
Reliability of low-level operating-system (OS) code is an indispensable requirement. This includes functional properties from the safety-liveness spectrum, but also quantitative properties stating, e.g., that the average waiting time on locks is sufficiently small or that the energy requirement of a certain system call is below a given threshold with a high probability. This paper reports on our experiences made in a running project where the goal is to apply probabilistic model checking techniques and to align the results of the model checker with measurements to predict quantitative properties of low-level OS code.
38
Ho, Zuleita K. M., Eduard A. Jorswieck, and Sabrina Engelmann. "Efficient information leakage neutralization on a relay-assisted multi-carrier interference channel." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-128447.
Full textAbstract:
In heterogeneous dense networks where spectrum is shared, users privacy remains one of the major challenges. When the receivers are not only interested in their own signals but also in eavesdropping other users' signals, the cross talk becomes information leakage.We propose a novel and efficient secrecy rate enhancing relay strategy EFFIN for information leakage neutralization. The relay matrix is chosen such that the effective leakage channel (spectral and spatial) is zero. Thus, it ensures secrecy regardless of receive processing employed at eavesdroppers and does not rely on wiretaps codes to ensure secrecy, unlike other physical layer security techniques such as artificial noise. EFFIN achieves a higher sum secrecy rate over several state-of-the-art baseline methods.
39
Krone, Stefan, and Gerhard Fettweis. "Communications with 1-Bit Quantization and Oversampling at the Receiver: Benefiting from Inter-Symbol-Interference." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-101473.
Full textAbstract:
1-bit analog-to-digital conversion is very attractive for low-complexity communications receivers. A major drawback is, however, the small spectral efficiency when sampling at symbol rate. This can be improved through oversampling by exploiting the signal distortion caused by the transmission channel. This paper analyzes the achievable data rate of band-limited communications channels that are subject to additive noise and inter-symbol-interference with 1-bit quantization and oversampling at the receiver. It is shown that not only the channel noise but also the inter-symbol-interference can be exploited to benefit from oversampling.
40
Hassan, Najeeb ul, Ali E. Pusane, Michael Lentmaier, Gerhard P. Fettweis, and Daniel J. Costello. "Reduced Complexity Window Decoding Schedules for Coupled LDPC Codes." Technische Universität Dresden, 2012. https://tud.qucosa.de/id/qucosa%3A26634.
Full textAbstract:
Window decoding schedules are very attractive for message passing decoding of spatially coupled LDPC codes. They take advantage of the inherent convolutional code structure and allow continuous transmission with low decoding latency and complexity. In this paper we show that the decoding complexity can be further reduced if suitable message passing schedules are applied within the decoding window. An improvement based schedule is presented that easily adapts to different ensemble structures, window sizes, and channel parameters. Its combination with a serial (on-demand) schedule is also considered. Results from a computer search based schedule are shown for comparison.
41
Fernández-Díaz, Álvaro, Christel Baier, Clara Benac-Earle, and Lars-Åke Fredlund. "Static Partial Order Reduction for Probabilistic Concurrent Systems." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-121261.
Full textAbstract:
Sound criteria for partial order reduction for probabilistic concurrent systems have been presented in the literature. Their realization relies on a depth-first search-based approach for generating the reduced model. The drawback of this dynamic approach is that it can hardly be combined with other techniques to tackle the state explosion problem, e.g., symbolic probabilistic model checking with multi-terminal variants of binary decision diagrams. Following the approach presented by Kurshan et al. for non-probabilistic systems, we study partial order reduction techniques for probabilistic concurrent systems that can be realized by a static analysis. The idea is to inject the reduction criteria into the control flow graphs of the processes of the system to be analyzed. We provide the theoretical foundations of static partial order reduction for probabilistic concurrent systems and present algorithms to realize them. Finally, we report on some experimental results.
42
Jorswieck, Eduard A., Anne Wolf, and Sabrina Engelmann. "Secret key generation from reciprocal spatially correlated MIMO channels." Technische Universität Dresden, 2013. https://tud.qucosa.de/id/qucosa%3A28101.
Full textAbstract:
Secret key generation from reciprocal multi-antenna channels is an interesting alternative to cryptographic key management in wireless systems without infrastructure access. In this work, we study the secret key rate for the basic source model with a MIMO channel. First, we derive an expression for the secret key rate under spatial correlation modelled by the Kronecker model and with spatial precoding at both communication nodes. Next, we analyze the result for uncorrelated antennas to understand the optimal precoding for this special case, which is equal power allocation. Then, the impact of correlation is characterized using Majorization theory. Surprisingly for small SNR, spatial correlation increases the secret key rate. For high SNR, the maximum secret key rate is achieved for uncorrelated antennas. The results indicate that a solid system design for reciprocal MIMO key generation is required to establish the secret key rate gains.
43
Gerbracht, Sabrina, Eduard A. Jorswieck, Gan Zheng, and Björn Ottersten. "Non-regenerative Two-Hop Wiretap Channels using Interference Neutralization." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-113245.
Full textAbstract:
In this paper, we analyze the achievable secrecy rates in the two-hop wiretap channel with four nodes, where the transmitter and the receiver have multiple antennas while the relay and the eavesdropper have only a single antenna each. The relay is operating in amplify-and-forward mode and all the channels between the nodes are known perfectly by the transmitter. We discuss different transmission and protection schemes like artificial noise (AN). Furthermore, we introduce interference neutralization (IN) as a new protection scheme. We compare the different schemes regarding the high-SNR slope and the high-SNR power offset and illustrate the performance by simulation results. It is shown analytically as well as by numerical simulations that the high SNR performance of the proposed IN scheme is better than the one of AN.
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Krone, Stefan, and Gerhard Fettweis. "Capacity of Communications Channels with 1-Bit Quantization and Oversampling at the Receiver." Technische Universität Dresden, 2012. https://tud.qucosa.de/id/qucosa%3A26361.
Full textAbstract:
Communications receivers that rely on 1-bit analogto-digital conversion are advantageous in terms of hardware complexity and power dissipation. Performance limitations due to the 1-bit quantization can be tackled with oversampling. This paper considers the oversampling gain from an information-theoretic perspective by analyzing the channel capacity with 1-bit quantization and oversampling at the receiver for the particular case of AWGN channels. This includes a numerical computation of the capacity and optimal transmit symbol constellations, as well as the derivation of closed-form expressions for large oversampling ratios and for high signal-to-noise ratios of the channel.
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Fernández-Díaz, Álvaro, Christel Baier, Clara Benac-Earle, and Lars-Åke Fredlund. "Static Partial Order Reduction for Probabilistic Concurrent Systems." Technische Universität Dresden, 2012. https://tud.qucosa.de/id/qucosa%3A26083.
Full textAbstract:
Sound criteria for partial order reduction for probabilistic concurrent systems have been presented in the literature. Their realization relies on a depth-first search-based approach for generating the reduced model. The drawback of this dynamic approach is that it can hardly be combined with other techniques to tackle the state explosion problem, e.g., symbolic probabilistic model checking with multi-terminal variants of binary decision diagrams. Following the approach presented by Kurshan et al. for non-probabilistic systems, we study partial order reduction techniques for probabilistic concurrent systems that can be realized by a static analysis. The idea is to inject the reduction criteria into the control flow graphs of the processes of the system to be analyzed. We provide the theoretical foundations of static partial order reduction for probabilistic concurrent systems and present algorithms to realize them. Finally, we report on some experimental results.
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Hassan, Najeeb ul, Michael Lentmaier, and Gerhard P. Fettweis. "Comparison of LDPC Block and LDPC Convolutional Codes based on their Decoding Latency." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-101450.
Full textAbstract:
We compare LDPC block and LDPC convolutional codes with respect to their decoding performance under low decoding latencies. Protograph based regular LDPC codes are considered with rather small lifting factors. LDPC block and convolutional codes are decoded using belief propagation. For LDPC convolutional codes, a sliding window decoder with different window sizes is applied to continuously decode the input symbols. We show the required Eb/N0 to achieve a bit error rate of 10 -5 for the LDPC block and LDPC convolutional codes for the decoding latency of up to approximately 550 information bits. It has been observed that LDPC convolutional codes perform better than the block codes from which they are derived even at low latency. We demonstrate the trade off between complexity and performance in terms of lifting factor and window size for a fixed value of latency. Furthermore, the two codes are also compared in terms of their complexity as a function of Eb/N0. Convolutional codes with Viterbi decoding are also compared with the two above mentioned codes.
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Krone, Stefan, and Gerhard Fettweis. "Communications with 1-Bit Quantization and Oversampling at the Receiver: Benefiting from Inter-Symbol-Interference." Technische Universität Dresden, 2012. https://tud.qucosa.de/id/qucosa%3A26362.
Full textAbstract:
1-bit analog-to-digital conversion is very attractive for low-complexity communications receivers. A major drawback is, however, the small spectral efficiency when sampling at symbol rate. This can be improved through oversampling by exploiting the signal distortion caused by the transmission channel. This paper analyzes the achievable data rate of band-limited communications channels that are subject to additive noise and inter-symbol-interference with 1-bit quantization and oversampling at the receiver. It is shown that not only the channel noise but also the inter-symbol-interference can be exploited to benefit from oversampling.
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Gerbracht, Sabrina, Eduard A. Jorswieck, Gan Zheng, and Björn Ottersten. "Non-regenerative Two-Hop Wiretap Channels using Interference Neutralization." Technische Universität Dresden, 2012. https://tud.qucosa.de/id/qucosa%3A26894.
Full textAbstract:
In this paper, we analyze the achievable secrecy rates in the two-hop wiretap channel with four nodes, where the transmitter and the receiver have multiple antennas while the relay and the eavesdropper have only a single antenna each. The relay is operating in amplify-and-forward mode and all the channels between the nodes are known perfectly by the transmitter. We discuss different transmission and protection schemes like artificial noise (AN). Furthermore, we introduce interference neutralization (IN) as a new protection scheme. We compare the different schemes regarding the high-SNR slope and the high-SNR power offset and illustrate the performance by simulation results. It is shown analytically as well as by numerical simulations that the high SNR performance of the proposed IN scheme is better than the one of AN.
49
Hassan, Najeeb ul, Michael Lentmaier, and Gerhard P. Fettweis. "Comparison of LDPC Block and LDPC Convolutional Codes based on their Decoding Latency." Technische Universität Dresden, 2012. https://tud.qucosa.de/id/qucosa%3A26359.
Full textAbstract:
We compare LDPC block and LDPC convolutional codes with respect to their decoding performance under low decoding latencies. Protograph based regular LDPC codes are considered with rather small lifting factors. LDPC block and convolutional codes are decoded using belief propagation. For LDPC convolutional codes, a sliding window decoder with different window sizes is applied to continuously decode the input symbols. We show the required Eb/N0 to achieve a bit error rate of 10 -5 for the LDPC block and LDPC convolutional codes for the decoding latency of up to approximately 550 information bits. It has been observed that LDPC convolutional codes perform better than the block codes from which they are derived even at low latency. We demonstrate the trade off between complexity and performance in terms of lifting factor and window size for a fixed value of latency. Furthermore, the two codes are also compared in terms of their complexity as a function of Eb/N0. Convolutional codes with Viterbi decoding are also compared with the two above mentioned codes.
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Ho, Zuleita, Eduard Jorswieck, and Sabrina Engelmann. "Information Leakage Neutralization for the Multi-Antenna Non-Regenerative Relay-Assisted Multi-Carrier Interference Channel." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-121245.
Full textAbstract:
In heterogeneous dense networks where spectrum is shared, users' privacy remains one of the major challenges. On a multi-antenna relay-assisted multi-carrier interference channel, each user shares the spectral and spatial resources with all other users. When the receivers are not only interested in their own signals but also in eavesdropping other users' signals, the cross talk on the spectral and spatial channels becomes information leakage. In this paper, we propose a novel secrecy rate enhancing relay strategy that utilizes both spectral and spatial resources, termed as information leakage neutralization. To this end, the relay matrix is chosen such that the effective channel from the transmitter to the colluding eavesdropper is equal to the negative of the effective channel over the relay to the colluding eavesdropper and thus the information leakage to zero. Interestingly, the optimal relay matrix in general is not block-diagonal which encourages users' encoding over the frequency channels. We proposed two information leakage neutralization strategies, namely efficient information leakage neutralization (EFFIN) and local-optimized information leakage neutralization (LOPTIN). EFFIN provides a simple and efficient design of relay processing matrix and precoding matrices at the transmitters in the scenario of limited power and computational resources. LOPTIN, despite its higher complexity, provides a better sum secrecy rate performance by optimizing the relay processing matrix and the precoding matrices jointly. The proposed methods are shown to improve the sum secrecy rates over several state-of-the-art baseline methods.