@phdthesis{Abedjan2014, author = {Abedjan, Ziawasch}, title = {Improving RDF data with data mining}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71334}, school = {Universit{\"a}t Potsdam}, year = {2014}, abstract = {Linked Open Data (LOD) comprises very many and often large public data sets and knowledge bases. Those datasets are mostly presented in the RDF triple structure of subject, predicate, and object, where each triple represents a statement or fact. Unfortunately, the heterogeneity of available open data requires significant integration steps before it can be used in applications. Meta information, such as ontological definitions and exact range definitions of predicates, are desirable and ideally provided by an ontology. However in the context of LOD, ontologies are often incomplete or simply not available. Thus, it is useful to automatically generate meta information, such as ontological dependencies, range definitions, and topical classifications. Association rule mining, which was originally applied for sales analysis on transactional databases, is a promising and novel technique to explore such data. We designed an adaptation of this technique for min-ing Rdf data and introduce the concept of "mining configurations", which allows us to mine RDF data sets in various ways. Different configurations enable us to identify schema and value dependencies that in combination result in interesting use cases. To this end, we present rule-based approaches for auto-completion, data enrichment, ontology improvement, and query relaxation. Auto-completion remedies the problem of inconsistent ontology usage, providing an editing user with a sorted list of commonly used predicates. A combination of different configurations step extends this approach to create completely new facts for a knowledge base. We present two approaches for fact generation, a user-based approach where a user selects the entity to be amended with new facts and a data-driven approach where an algorithm discovers entities that have to be amended with missing facts. As knowledge bases constantly grow and evolve, another approach to improve the usage of RDF data is to improve existing ontologies. Here, we present an association rule based approach to reconcile ontology and data. Interlacing different mining configurations, we infer an algorithm to discover synonymously used predicates. Those predicates can be used to expand query results and to support users during query formulation. We provide a wide range of experiments on real world datasets for each use case. The experiments and evaluations show the added value of association rule mining for the integration and usability of RDF data and confirm the appropriateness of our mining configuration methodology.}, language = {en} } @article{Abramowicz2014, author = {Abramowicz, Isidoro}, title = {Das Jahreskaddisch in der Frankfurter Melodiengestaltung}, series = {PaRDeS : Zeitschrift der Vereinigung f{\"u}r J{\"u}dische Studien e.V.}, volume = {20}, journal = {PaRDeS : Zeitschrift der Vereinigung f{\"u}r J{\"u}dische Studien e.V.}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1614-6492}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71661}, pages = {75 -- 86}, year = {2014}, abstract = {Das Jahreskaddisch ist ein Spezifikum der westaschkenasischen Liturgie. Es wird am Abend und am Morgen des Simchat-Tora-Festes vorgetragen und ist aus den wichtigsten musikalischen Motiven des Kaddisch-Gebetes innerhalb des gesamten j{\"u}dischen Jahreszyklus zusammengesetzt. Anhand von Tonaufnahmen wurde das Jahreskaddisch der Frankfurter Tradition transkribiert und seine einzelnen melodischen Bestandteile identifiziert. Die vorgestellte Kaddischmelodie wird im heutigen Gottesdienst in Frankfurt a. M. nicht mehr vorgetragen.}, language = {de} } @misc{AbramowiczArnoldDrorietal.2014, author = {Abramowicz, Isidoro and Arnold, Rafael and Drori, Itamar and Haußig, Hans-Michael and Huber, Jasmina and Katz, Daniel S. and Keßler, Katrin and Kleinecke, Ulrike and Knufinke, Ulrich and Przystawik, Mirko and Nemtsov, Jascha and Rebiger, Bill and Ries, Rotraud and Salzer, Dorothea M. and Schirrmeister, Sebastian and Stellmacher, Martha}, title = {PaRDeS : Zeitschrift der Vereinigung f{\"u}r J{\"u}dische Studien e.V. = 'Ein Gebet ohne Gesang ist wie ein K{\"o}rper ohne Seele.' : Aspekte der synagogalen Musik}, number = {20}, editor = {Denz, Rebekka and Salzer, Dorothea M.}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-290-2}, issn = {1614-6492}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70306}, year = {2014}, abstract = {Die Zeitschrift m{\"o}chte die fruchtbare und facettenreiche Kultur des Judentums sowie seine Ber{\"u}hrungspunkte zur Umwelt in den unterschiedlichen Bereichen dokumentieren. Daneben dient die Zeitschrift als Forum zur Positionierung der F{\"a}cher J{\"u}dische Studien und Judaistik innerhalb des wissenschaftlichen Diskurses sowie zur Diskussion ihrer historischen und gesellschaftlichen Verantwortung.}, language = {de} } @misc{AdaniForgiariniGuastietal.2014, author = {Adani, Flavia and Forgiarini, Matteo and Guasti, Maria Teresa and Van der Lely, Heather K. J.}, title = {Number dissimilarities facilitate the comprehension of relative clauses in children with (Grammatical) Specific Language Impairment}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {525}, issn = {1866-8364}, doi = {10.25932/publishup-41545}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-415453}, pages = {811 -- 841}, year = {2014}, abstract = {This study investigates whether number dissimilarities on subject and object DPs facilitate the comprehension of subject-and object-extracted centre-embedded relative clauses in children with Grammatical Specific Language Impairment (G-SLI). We compared the performance of a group of English-speaking children with G-SLI (mean age: 12; 11) with that of two groups of younger typically developing (TD) children, matched on grammar and receptive vocabulary, respectively. All groups were more accurate on subject-extracted relative clauses than object-extracted ones and, crucially, they all showed greater accuracy for sentences with dissimilar number features (i.e., one singular, one plural) on the head noun and the embedded DP. These findings are interpreted in the light of current psycholinguistic models of sentence comprehension in TD children and provide further insight into the linguistic nature of G-SLI.}, language = {en} } @book{Adelmann2014, author = {Adelmann, Dieter}, title = {Die Tr{\"a}nen des Henri Quatre}, series = {Schriften aus dem Nachlass von Dieter Adelmann}, journal = {Schriften aus dem Nachlass von Dieter Adelmann}, number = {2}, editor = {Hasselhoff, G{\"o}rge K.}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-288-9}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70346}, publisher = {Universit{\"a}t Potsdam}, pages = {112}, year = {2014}, abstract = {Der vorliegende zweite Band mit Texten aus dem Nachlass von Dieter Adelmann (1936-2008) macht eine der letzten Arbeiten, die ihr Verfasser anl{\"a}sslich seines 70. Geburtstags aus der Hand gegeben hat, f{\"u}r ein breites Publikum zug{\"a}nglich. Der Essay bildet dabei einen Abschluss von Adelmanns ersten, im weitesten Sinne philosophischen Publikationen, die nach der Doktorarbeit (Bd. 1 der Nachlasspublikationen) entstanden sind. Ausgehend von einer Beobachtung in Heinrich Manns epochaler Doppelromanbiografie des navarresisch-franz{\"o}sischen protestantischen K{\"o}nigs Henri IV. untersucht Adelmann die Tr{\"a}nen- und Todesmetaphorik in dem Romanwerk aus den 1930er Jahren. Von hier aus wird eine Br{\"u}cke zur literaturwissenschaftlichen {\"A}sthetik und Erkenntnistheorie Walter Benjamins geschlagen, mit der sich Adelmann bereits in seinen Arbeiten zur Politkunst Klaus Staecks besch{\"a}ftigt hatte. Dabei deckt der Verfasser Fehlinterpretationen der Benjaminschen Theorien durch dessen Freund und Nachlassverwalter Theodor W. Adorno auf.}, language = {de} } @phdthesis{Ahmad2014, author = {Ahmad, Nadeem}, title = {People centered HMI's for deaf and functionally illiterate users}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70391}, school = {Universit{\"a}t Potsdam}, year = {2014}, abstract = {The objective and motivation behind this research is to provide applications with easy-to-use interfaces to communities of deaf and functionally illiterate users, which enables them to work without any human assistance. Although recent years have witnessed technological advancements, the availability of technology does not ensure accessibility to information and communication technologies (ICT). Extensive use of text from menus to document contents means that deaf or functionally illiterate can not access services implemented on most computer software. Consequently, most existing computer applications pose an accessibility barrier to those who are unable to read fluently. Online technologies intended for such groups should be developed in continuous partnership with primary users and include a thorough investigation into their limitations, requirements and usability barriers. In this research, I investigated existing tools in voice, web and other multimedia technologies to identify learning gaps and explored ways to enhance the information literacy for deaf and functionally illiterate users. I worked on the development of user-centered interfaces to increase the capabilities of deaf and low literacy users by enhancing lexical resources and by evaluating several multimedia interfaces for them. The interface of the platform-independent Italian Sign Language (LIS) Dictionary has been developed to enhance the lexical resources for deaf users. The Sign Language Dictionary accepts Italian lemmas as input and provides their representation in the Italian Sign Language as output. The Sign Language dictionary has 3082 signs as set of Avatar animations in which each sign is linked to a corresponding Italian lemma. I integrated the LIS lexical resources with MultiWordNet (MWN) database to form the first LIS MultiWordNet(LMWN). LMWN contains information about lexical relations between words, semantic relations between lexical concepts (synsets), correspondences between Italian and sign language lexical concepts and semantic fields (domains). The approach enhances the deaf users' understanding of written Italian language and shows that a relatively small set of lexicon can cover a significant portion of MWN. Integration of LIS signs with MWN made it useful tool for computational linguistics and natural language processing. The rule-based translation process from written Italian text to LIS has been transformed into service-oriented system. The translation process is composed of various modules including parser, semantic interpreter, generator, and spatial allocation planner. This translation procedure has been implemented in the Java Application Building Center (jABC), which is a framework for extreme model driven design (XMDD). The XMDD approach focuses on bringing software development closer to conceptual design, so that the functionality of a software solution could be understood by someone who is unfamiliar with programming concepts. The transformation addresses the heterogeneity challenge and enhances the re-usability of the system. For enhancing the e-participation of functionally illiterate users, two detailed studies were conducted in the Republic of Rwanda. In the first study, the traditional (textual) interface was compared with the virtual character-based interactive interface. The study helped to identify usability barriers and users evaluated these interfaces according to three fundamental areas of usability, i.e. effectiveness, efficiency and satisfaction. In another study, we developed four different interfaces to analyze the usability and effects of online assistance (consistent help) for functionally illiterate users and compared different help modes including textual, vocal and virtual character on the performance of semi-literate users. In our newly designed interfaces the instructions were automatically translated in Swahili language. All the interfaces were evaluated on the basis of task accomplishment, time consumption, System Usability Scale (SUS) rating and number of times the help was acquired. The results show that the performance of semi-literate users improved significantly when using the online assistance. The dissertation thus introduces a new development approach in which virtual characters are used as additional support for barely literate or naturally challenged users. Such components enhanced the application utility by offering a variety of services like translating contents in local language, providing additional vocal information, and performing automatic translation from text to sign language. Obviously, there is no such thing as one design solution that fits for all in the underlying domain. Context sensitivity, literacy and mental abilities are key factors on which I concentrated and the results emphasize that computer interfaces must be based on a thoughtful definition of target groups, purposes and objectives.}, language = {en} } @unpublished{AizenbergTarkhanov2014, author = {Aizenberg, Lev A. and Tarkhanov, Nikolai Nikolaevich}, title = {An integral formula for the number of lattice points in a domain}, volume = {3}, number = {3}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {2193-6943}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70453}, pages = {7}, year = {2014}, abstract = {Using the multidimensional logarithmic residue we show a simple formula for the difference between the number of integer points in a bounded domain of R^n and the volume of this domain. The difference proves to be the integral of an explicit differential form over the boundary of the domain.}, language = {en} } @phdthesis{Albrecht2014, author = {Albrecht, Steve}, title = {Generation, recombination and extraction of charges in polymer}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-72285}, school = {Universit{\"a}t Potsdam}, pages = {144}, year = {2014}, abstract = {A dramatic efficiency improvement of bulk heterojunction solar cells based on electron-donating conjugated polymers in combination with soluble fullerene derivatives has been achieved over the past years. Certified and reported power conversion efficiencies now reach over 9\% for single junctions and exceed the 10\% benchmark for tandem solar cells. This trend brightens the vision of organic photovoltaics becoming competitive with inorganic solar cells including the realization of low-cost and large-area organic photovoltaics. For the best performing organic materials systems, the yield of charge generation can be very efficient. However, a detailed understanding of the free charge carrier generation mechanisms at the donor acceptor interface and the energy loss associated with it needs to be established. Moreover, organic solar cells are limited by the competition between charge extraction and free charge recombination, accounting for further efficiency losses. A conclusive picture and the development of precise methodologies for investigating the fundamental processes in organic solar cells are crucial for future material design, efficiency optimization, and the implementation of organic solar cells into commercial products. In order to advance the development of organic photovoltaics, my thesis focuses on the comprehensive understanding of charge generation, recombination and extraction in organic bulk heterojunction solar cells summarized in 6 chapters on the cumulative basis of 7 individual publications. The general motivation guiding this work was the realization of an efficient hybrid inorganic/organic tandem solar cell with sub-cells made from amorphous hydrogenated silicon and organic bulk heterojunctions. To realize this project aim, the focus was directed to the low band-gap copolymer PCPDTBT and its derivatives, resulting in the examination of the charge carrier dynamics in PCPDTBT:PC70BM blends in relation to by the blend morphology. The phase separation in this blend can be controlled by the processing additive diiodooctane, enhancing domain purity and size. The quantitative investigation of the free charge formation was realized by utilizing and improving the time delayed collection field technique. Interestingly, a pronounced field dependence of the free carrier generation for all blends is found, with the field dependence being stronger without the additive. Also, the bimolecular recombination coefficient for both blends is rather high and increases with decreasing internal field which we suggest to be caused by a negative field dependence of mobility. The additive speeds up charge extraction which is rationalized by the threefold increase in mobility. By fluorine attachment within the electron deficient subunit of PCPDTBT, a new polymer F-PCPDTBT is designed. This new material is characterized by a stronger tendency to aggregate as compared to non-fluorinated PCPDTBT. Our measurements show that for F-PCPDTBT:PCBM blends the charge carrier generation becomes more efficient and the field-dependence of free charge carrier generation is weakened. The stronger tendency to aggregate induced by the fluorination also leads to increased polymer rich domains, accompanied in a threefold reduction in the non-geminate recombination coefficient at conditions of open circuit. The size of the polymer domains is nicely correlated to the field-dependence of charge generation and the Langevin reduction factor, which highlights the importance of the domain size and domain purity for efficient charge carrier generation. In total, fluorination of PCPDTBT causes the PCE to increase from 3.6 to 6.1\% due to enhanced fill factor, short circuit current and open circuit voltage. Further optimization of the blend ratio, active layer thickness, and polymer molecular weight resulted in 6.6\% efficiency for F-PCPDTBT:PC70BM solar cells. Interestingly, the double fluorinated version 2F-PCPDTBT exhibited poorer FF despite a further reduction of geminate and non-geminate recombination losses. To further analyze this finding, a new technique is developed that measures the effective extraction mobility under charge carrier densities and electrical fields comparable to solar cell operation conditions. This method involves the bias enhanced charge extraction technique. With the knowledge of the carrier density under different electrical field and illumination conditions, a conclusive picture of the changes in charge carrier dynamics leading to differences in the fill factor upon fluorination of PCPDTBT is attained. The more efficient charge generation and reduced recombination with fluorination is counterbalanced by a decreased extraction mobility. Thus, the highest fill factor of 60\% and efficiency of 6.6\% is reached for F-PCPDTBT blends, while 2F-PCPDTBT blends have only moderate fill factors of 54\% caused by the lower effective extraction mobility, limiting the efficiency to 6.5\%. To understand the details of the charge generation mechanism and the related losses, we evaluated the yield and field-dependence of free charge generation using time delayed collection field in combination with sensitive measurements of the external quantum efficiency and absorption coefficients for a variety of blends. Importantly, both the yield and field-dependence of free charge generation is found to be unaffected by excitation energy, including direct charge transfer excitation below the optical band gap. To access the non-detectable absorption at energies of the relaxed charge transfer emission, the absorption was reconstructed from the CT emission, induced via the recombination of thermalized charges in electroluminescence. For a variety of blends, the quantum yield at energies of charge transfer emission was identical to excitations with energies well above the optical band-gap. Thus, the generation proceeds via the split-up of the thermalized charge transfer states in working solar cells. Further measurements were conducted on blends with fine-tuned energy levels and similar blend morphologies by using different fullerene derivatives. A direct correlation between the efficiency of free carrier generation and the energy difference of the relaxed charge transfer state relative to the energy of the charge separated state is found. These findings open up new guidelines for future material design as new high efficiency materials require a minimum energetic offset between charge transfer and the charge separated state while keeping the HOMO level (and LUMO level) difference between donor and acceptor as small as possible.}, language = {en} } @article{Amschler2014, author = {Amschler, Helmut}, title = {„NEW" - Neue Energien West eG und B{\"u}rger-Energiegenossenschaft West eG}, series = {KWI-Schriften}, journal = {KWI-Schriften}, number = {8}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1867-951X}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71037}, pages = {57 -- 62}, year = {2014}, abstract = {Helmut Amschler, Vorstand der Stadtwerke Grafenw{\"o}hr, stellt in seinem Beitrag 2 konkrete Genossenschaften - die Neue Energien West eG und die B{\"u}rger-Energiegenossenschaft West eG vor. Dabei diskutiert er u. a. Kriterien wie B{\"u}rgerbeteiligung und Transparenz.}, language = {de} } @phdthesis{Andree2014, author = {Andree, Kai}, title = {Horizontale Fusionen bei r{\"a}umlichem Wettbewerb}, series = {Potsdamer Schriften zur Raumwirtschaft}, journal = {Potsdamer Schriften zur Raumwirtschaft}, number = {6}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-279-7}, issn = {2190-8702}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69209}, school = {Universit{\"a}t Potsdam}, pages = {xi, 227}, year = {2014}, abstract = {Fusionen stellen einen zentralen Baustein der Industrie{\"o}konomik dar. In diesem Buch wird der Frage nachgegangen, welchen Einfluss die r{\"a}umliche Dimension auf eine Fusion aus{\"u}bt. Dabei wird ein Grundmodell entwickelt und {\"u}ber dieses hinaus eine Vielzahl Erweiterungen pr{\"a}sentiert. Der Leser erh{\"a}lt somit die M{\"o}glichkeit ein tiefes Verst{\"a}ndnis f{\"u}r Fusionen bei r{\"a}umlichem Wettbewerb zu erlangen.}, language = {de} }