@phdthesis{42237, abstract = {{In dieser Arbeit wird gezeigt, wie optimale Trajektorien für ein unteraktuiertes mechanisches System - das Doppel- bzw. Dreifachpendel auf einem Wagen - mittels optimaler Steuerung bestimmt werden können. Dabei werden neuartige mathematische Methoden verwendet und deren Vorteile in der Anwendung aufgezeigt. Es werden sowohl die theoretischen Ergebnisse analysiert als auch die praktische Umsetzung in Simulationen und am Prüfstand untersucht. Das Manöver, welches hier hauptsächlich betrachtet wird, ist der Aufschwung des Pendels aus der stabilen unteren Ruhelage in die instabile obere Ruhelage. Dabei werden mit Hilfe von Methoden der Mehrzieloptimierung viele Varianten von Lösungen berechnet, die die zwei gegenläufigen Zielgrößen Dauer des Manövers und Steueraufwand unterschiedlich stark berücksichtigen. So ist es möglich eine komplexe Bibliothek von optimalen Lösungen zu erhalten und diese weitergehend bezüglich des Gesamtsystemverhaltens zu analysieren. Ein weiterer Ansatz ist die Entwicklung von Strategien für eine optimale Steuerung auf Mannigfaltigkeiten, die besondere dynamische Strukturen des Pendelsystems für einen optimalen Aufschwung nutzen. Auf der stabilen Mannigfaltigkeit kann sich das dynamische System kostenlos in die Ruhelage bewegen. Dies ist somit ein besonderer physikalisch motivierter Ansatz, um optimale Manöver zu finden.}}, author = {{Timmermann, Julia}}, title = {{{Optimale Steuerung und Mehrzieloptimierung von dynamischen Systemen untersucht am Beispiel des Mehrfachpendels}}}, year = {{2014}}, } @article{8171, abstract = {{The polynomial hierarchy plays a central role in classical complexity theory. Here, we define a quantum generalization of the polynomial hierarchy, and initiate its study. We show that not only are there natural complete problems for the second level of this quantum hierarchy, but that these problems are in fact hard to approximate. Using the same techniques, we also obtain hardness of approximation for the class QCMA. Our approach is based on the use of dispersers, and is inspired by the classical results of Umans regarding hardness of approximation for the second level of the classical polynomial hierarchy [Umans, FOCS 1999]. The problems for which we prove hardness of approximation for include, among others, a quantum version of the Succinct Set Cover problem, and a variant of the local Hamiltonian problem with hybrid classical-quantum ground states.}}, author = {{Gharibian, Sevag and Kempe, Julia}}, journal = {{Quantum Information & Computation}}, keywords = {{Hardness of approximation, polynomial time hierarchy, succinct set cover, quantum complexity}}, number = {{5-6}}, pages = {{517--540}}, title = {{{Hardness of approximation for quantum problems}}}, volume = {{14}}, year = {{2014}}, } @article{8172, abstract = {{We show how to efficiently simulate continuous-time quantum query algorithms that run in time T in a manner that preserves the query complexity (within a polylogarithmic factor) while also incurring a small overhead cost in the total number of gates between queries. By small overhead, we mean T within a factor that is polylogarithmic in terms of T and a cost measure that reflects the cost of computing the driving Hamiltonian. This permits any continuous-time quantum algorithm based on an efficiently computable driving Hamiltonian to be converted into a gate-efficient algorithm with similar running time.}}, author = {{W. Berry, Dominic and Cleve, Richard and Gharibian, Sevag}}, journal = {{Quantum Information & Computation}}, number = {{1-2}}, pages = {{1--30}}, title = {{{Gate-efficient discrete simulations of continuous-time quantum query algorithms}}}, volume = {{14}}, year = {{2014}}, } @article{41438, author = {{Fuchs, Christian and Sandoval, Marisol and Prodnik, Jernej A. and Sevignani, Sebastian and Allmer, Thomas}}, journal = {{tripleC: Communication, Capitalism & Critique}}, number = {{2}}, pages = {{464--801}}, title = {{{Special Issue: Philosophers of the World Unite! Theorising Digital Labour and Virtual Work - Definitions, Dimensions and Forms}}}, doi = {{https://doi.org/10.31269/triplec.v12i2.631}}, volume = {{12}}, year = {{2014}}, } @article{41580, author = {{Fuchs, Christian}}, journal = {{International Journal of Communication}}, pages = {{2718--2732}}, title = {{{WikiLeaks and the Critique of the Political Economy}}}, volume = {{8}}, year = {{2014}}, } @article{28149, abstract = {{ Purpose – Ubiquitous computing and “big data” have been widely recognized as requiring new concepts of privacy and new mechanisms to protect it. While improved concepts of privacy have been suggested, the paper aims to argue that people acting in full conformity to those privacy norms still can infringe the privacy of others in the context of ubiquitous computing and “big data”. Design/methodology/approach – New threats to privacy are described. Helen Nissenbaum's concept of “privacy as contextual integrity” is reviewed concerning its capability to grasp these problems. The argument is based on the assumption that the technologies work, persons are fully informed and capable of deciding according to advanced privacy considerations. Findings – Big data and ubiquitous computing enable privacy threats for persons whose data are only indirectly involved and even for persons about whom no data have been collected and processed. Those new problems are intrinsic to the functionality of these new technologies and need to be addressed on a social and political level. Furthermore, a concept of data minimization in terms of the quality of the data is proposed. Originality/value – The use of personal data as a threat to the privacy of others is established. This new perspective is used to reassess and recontextualize Helen Nissenbaum's concept of privacy. Data minimization in terms of quality of data is proposed as a new concept. }}, author = {{Matzner, Tobias}}, issn = {{1477-996X}}, journal = {{Journal of Information, Communication and Ethics in Society}}, number = {{2}}, pages = {{93--106}}, title = {{{Why privacy is not enough privacy in the context of “ubiquitous computing” and “big data”}}}, doi = {{https://doi.org/10.1108/jices-08-2013-0030}}, volume = {{12}}, year = {{2014}}, } @article{41582, author = {{Fuchs, Christian and Sandoval, Marisol}}, journal = {{tripleC: Communication, Capitalism & Critique}}, number = {{2}}, pages = {{486--563}}, title = {{{Digital Workers of the World Unite! A Framework for Critically Theorising and Analysing Digital Labour. In Special Issue: Philosophers of the World Unite! Theorising Digital Labour and Virtual Work - Definitions, Dimensions and Forms, eds. Marisol Sandoval, Christian Fuchs, Jernej A. Prodnik, Sebastian Sevignani and Thomas Allmer}}}, doi = {{https://doi.org/10.31269/triplec.v12i2.549}}, volume = {{12}}, year = {{2014}}, } @article{41585, author = {{Fuchs, Christian and Sandoval, Marisol and Prodnik, Jernej A. and Sevignani, Sebastian and Allmer, Thomas}}, journal = {{tripleC: Communication, Capitalism & Critique}}, number = {{2}}, pages = {{464--467}}, title = {{{Introduction: Philosophers of the World Unite! Theorising Digital Labour and Virtual Work — Definitions, Dimensions, and Forms}}}, doi = {{https://doi.org/10.31269/triplec.v12i2.622}}, volume = {{12}}, year = {{2014}}, } @article{41587, author = {{Fuchs, Christian}}, journal = {{TELOS. Revista de Estudios Interdisciplinarios en Ciencias Sociales}}, number = {{3}}, pages = {{495--535}}, title = {{{Karl Marx y el estudio de los medios y la cultura hoy (Spanish translation by Roy Alfaro Vargas)}}}, volume = {{16}}, year = {{2014}}, } @article{41586, author = {{Fuchs, Christian}}, journal = {{Culture Unbound}}, number = {{3}}, pages = {{39--76}}, title = {{{Karl Marx and the Study of Media and Culture Today}}}, doi = {{https://doi.org/10.3384/cu.2000.1525.14639}}, volume = {{6}}, year = {{2014}}, } @article{42592, author = {{Fuchs, Christian}}, journal = {{tripleC: Communication, Capitalism & Critique}}, number = {{2}}, pages = {{848--875}}, title = {{{The Dialectic: Not Just the Absolute Recoil, but the World’s Living Fire that Extinguishes and Kindles Itself. Reflections on Slavoj Žižek’s Version of Dialectical Philosophy in “Absolute Recoil. Towards a New Foundation of Dialectical Materialism“}}}, doi = {{https://doi.org/10.31269/triplec.v12i2.640}}, volume = {{12}}, year = {{2014}}, } @article{42595, author = {{Fuchs, Christian}}, journal = {{tripleC: Communication, Capitalism & Critique}}, number = {{1}}, pages = {{413--430}}, title = {{{Thomas Piketty’s Book “Capital in the Twenty-First Century”, Karl Marx and the Political Economy of the Internet}}}, doi = {{https://doi.org/10.31269/triplec.v12i1.575}}, volume = {{12}}, year = {{2014}}, } @article{42597, author = {{Fuchs, Christian and Garnham, Nicholas}}, journal = {{tripleC: Communication, Capitalism & Critique}}, number = {{1}}, pages = {{102--141}}, title = {{{Revisiting the Political Economy of Communication}}}, doi = {{https://doi.org/10.31269/triplec.v12i1.553}}, volume = {{12}}, year = {{2014}}, } @article{42594, author = {{Fuchs, Christian}}, journal = {{Telos – Revista de Pensamiento sobre Comunicación, Tecnología y Sociedad}}, pages = {{71--82}}, title = {{{Medios sociales y esfera pública [in Spanish; Social media and the public sphere]}}}, volume = {{98}}, year = {{2014}}, } @article{42598, author = {{Fuchs, Christian}}, journal = {{tripleC: Communication, Capitalism & Critique}}, number = {{1}}, pages = {{57--101}}, title = {{{Social Media and the Public Sphere [Inaugural Lecture]}}}, doi = {{https://doi.org/10.31269/triplec.v12i1.552}}, volume = {{12}}, year = {{2014}}, } @misc{42593, author = {{Fuchs, Christian and Wilding, Adrian and Smith, R.C. and Gunn, Richard and Ott, Michael}}, booktitle = {{Heathwood Press Online}}, title = {{{Occupy and prefiguration. A roundtable discussion}}}, year = {{2014}}, } @techreport{42596, author = {{Fuchs, Christian}}, title = {{{QTube – Citizen-generated videos for Questions to the Prime Minister. Submission to the House of Commons’-Speaker’s Commission on Digital Democracy. May 19, 2014}}}, year = {{2014}}, } @article{35167, abstract = {{Die Politiken bebilderter Berichterstattung und die Temporalität unserer gegenwärtigen Aufmerksamkeitsökonomie betrachtend, wird den Fragen nachgegangen, wieso die Reaktionen auf die NSA-Affäre so oft von Zynismus oder Resignation gekennzeichnet sind oder sogar ganz ausbleiben, und wer eigentlich betroffen ist und reagieren sollte. Die Überlegungen sind der Versuch, die NSA-Affäre im Spannungsfeld von Technikverliebtheit und Blackboxing, den Bedingungen von Medienereignissen und Geheimdienstpraktiken, der Krise des Journalismus sowie unseren Gewohnheiten im Umgang mit der uns umgebenden rechnenden Umwelt zu situieren.}}, author = {{Shnayien, Mary}}, journal = {{onlinejournal kultur & geschlecht}}, number = {{13}}, pages = {{1–18}}, title = {{{Der rosafarbene Elefant im Raum. Überlegungen zur fehlenden Wut über die NSA-Affäre}}}, year = {{2014}}, } @inproceedings{36533, author = {{Bruns, Julia and Eichen, Lars}}, booktitle = {{Beiträge zum Mathematikunterricht 2014}}, editor = {{Roth, Jürgen and Ames, Judith}}, location = {{Koblenz}}, pages = {{277--280}}, publisher = {{WTM-Verlag}}, title = {{{Adaptive mathematische Förderung im Elementarbereich - Empirische Ergebnisse zum didaktischen Handeln von Erzieherinnen}}}, doi = {{10.17877/DE290R-5105}}, year = {{2014}}, } @phdthesis{64753, author = {{Walter, Boris}}, title = {{{Weighted diffeomorphism groups of Banach spaces and non-compact manifolds and weighted mapping groups}}}, year = {{2014}}, }