TY - CHAP
A1 - Curzon, Paul
A1 - Kalas, Ivan
A1 - Schubert, Sigrid
A1 - Schaper, Niclas
A1 - Barnes, Jan
A1 - Kennewell, Steve
A1 - Bröker, Kathrin
A1 - Kastens, Uwe
A1 - Magenheim, Johannes
A1 - Dagiene, Valentina
A1 - Stupuriene, Gabriele
A1 - Ellis, Jason Brent
A1 - Abreu-Ellis, Carla Reis
A1 - Grillenberger, Andreas
A1 - Romeike, Ralf
A1 - Haugsbakken, Halvdan
A1 - Jones, Anthony
A1 - Lewin, Cathy
A1 - McNicol, Sarah
A1 - Nelles, Wolfgang
A1 - Neugebauer, Jonas
A1 - Ohrndorf, Laura
A1 - Schaper, Niclas
A1 - Schubert, Sigrid
A1 - Opel, Simone
A1 - Kramer, Matthias
A1 - Trommen, Michael
A1 - Pottbäcker, Florian
A1 - Ilaghef, Youssef
A1 - Passig, David
A1 - Tzuriel, David
A1 - Kedmi, Ganit Eshel
A1 - Saito, Toshinori
A1 - Webb, Mary
A1 - Weigend, Michael
A1 - Bottino, Rosa
A1 - Chioccariello, Augusto
A1 - Christensen, Rhonda
A1 - Knezek, Gerald
A1 - Gioko, Anthony Maina
A1 - Angondi, Enos Kiforo
A1 - Waga, Rosemary
A1 - Ohrndorf, Laura
A1 - Or-Bach, Rachel
A1 - Preston, Christina
A1 - Younie, Sarah
A1 - Przybylla, Mareen
A1 - Romeike, Ralf
A1 - Reynolds, Nicholas
A1 - Swainston, Andrew
A1 - Bendrups, Faye
A1 - Sysło, Maciej M.
A1 - Kwiatkowska, Anna Beata
A1 - Zieris, Holger
A1 - Gerstberger, Herbert
A1 - Müller, Wolfgang
A1 - Büchner, Steffen
A1 - Opel, Simone
A1 - Schiller, Thomas
A1 - Wegner, Christian
A1 - Zender, Raphael
A1 - Lucke, Ulrike
A1 - Diethelm, Ira
A1 - Syrbe, Jörn
A1 - Lai, Kwok-Wing
A1 - Davis, Niki
A1 - Eickelmann, Birgit
A1 - Erstad, Ola
A1 - Fisser, Petra
A1 - Gibson, David
A1 - Khaddage, Ferial
A1 - Knezek, Gerald
A1 - Micheuz, Peter
A1 - Kloos, Carlos Delgado
ED - Brinda, Torsten
ED - Reynolds, Nicholas
ED - Romeike, Ralf
ED - Schwill, Andreas
T1 - KEYCIT 2014
BT - key competencies in informatics and ICT
N2 - In our rapidly changing world it is increasingly important not only to be an expert in a chosen field of study but also to be able to respond to developments, master new approaches to solving problems, and fulfil changing requirements in the modern world and in the job market. In response to these needs key competencies in understanding, developing and using new digital technologies are being brought into focus in school and university programmes. The IFIP TC3 conference "KEYCIT – Key Competences in Informatics and ICT (KEYCIT 2014)" was held at the University of Potsdam in Germany from July 1st to 4th, 2014 and addressed the combination of key competencies, Informatics and ICT in detail. The conference was organized into strands focusing on secondary education, university education and teacher education (organized by IFIP WGs 3.1 and 3.3) and provided a forum to present and to discuss research, case studies, positions, and national perspectives in this field.
T3 - Commentarii informaticae didacticae (CID) - 7
KW - Schlüsselkompetenzen
KW - Informatik
KW - Bildung
KW - ICT
KW - Informatikdidaktik
KW - Key Competencies
KW - Informatics
KW - education
KW - ICT
KW - Computer Science Education
Y1 - 2015
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-70325
SN - 978-3-86956-292-6
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - CHAP
A1 - Reimer, O.
A1 - Aharonian, Felix A.
A1 - Hinton, J.
A1 - Hofmann, W.
A1 - Hoppe, S.
A1 - Raue, M.
A1 - Reimer, A.
T1 - VHE gamma-rays from Westerlund 2 and implications for the inferred energetics
N2 - The H.E.S.S. collaboration recently reported the discovery of VHE γ-ray emission coincident with the young stellar cluster Westerlund 2. This system is known to host a population of hot, massive stars, and, most particularly, the WR binary WR 20a. Particle acceleration to TeV energies in Westerlund 2 can be accomplished in several alternative scenarios, therefore we only discuss energetic constraints based on the total available kinetic energy in the system, the actual mass loss rates of respective cluster members, and implied gamma-ray production from processes such as inverse Compton scattering or neutral pion decay. From the inferred gammaray luminosity of the order of 1035erg/s, implications for the efficiency of converting available kinetic energy into non-thermal radiation associated with stellar winds in the Westerlund 2 cluster are discussed under consideration of either the presence or absence of wind clumping.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18172
ER -
TY - CHAP
A1 - Banda, Gourinath
A1 - Gallagher, John P.
T1 - Constraint-based abstraction of a model checker for infinite state systems
N2 - Abstract interpretation-based model checking provides an approach to verifying properties of infinite-state systems. In practice, most previous work on abstract model checking is either restricted to verifying universal properties, or develops special techniques for temporal logics such as modal transition systems or other dual transition systems. By contrast we apply completely standard techniques for constructing abstract interpretations to the abstraction of a CTL semantic function, without restricting the kind of properties that can be verified. Furthermore we show that this leads directly to implementation of abstract model checking algorithms for abstract domains based on constraints, making use of an SMT solver.
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41516
ER -
TY - CHAP
A1 - Bischof, Ulrike
T1 - Nachlasserschließung im Goethe- und Schiller-Archiv
N2 - Beiträge zum Thema "Nachlässe an Universitäts- und Hochschularchiven sowie Archiven wissenschaftlicher Institutionen" im Rahmen der Frühjahrstagung der Fachgruppe 8: "Archivare an Hochschularchiven und Archiven wissenschaftlicher Institutionen" am 16./17. Juni an der Universität Potsdam.
KW - Archiv
KW - Nachlass
Y1 - 2005
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-6081
ER -
TY - CHAP
A1 - Wiemers, Gerald
T1 - Der Nachlass des Erziehungswissenschaftlers und Philosophen Theodor Litt in seiner öffentlichen Wirkung
N2 - Beiträge zum Thema "Nachlässe an Universitäts- und Hochschularchiven sowie Archiven wissenschaftlicher Institutionen" im Rahmen der Frühjahrstagung der Fachgruppe 8: "Archivare an Hochschularchiven und Archiven wissenschaftlicher Institutionen" am 16./17. Juni an der Universität Potsdam.
KW - Archiv
KW - Universitätsarchiv
KW - Nachlass
Y1 - 2005
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-6113
ER -
TY - CHAP
A1 - Schultze, Winfried
T1 - Zufall – Wunsch – Planung : die Erwerbung von Nachlässen zur Bestandsergänzung
N2 - Nachlässe sind persönliches Eigentum und unterliegen deshalb keiner Abgabepflicht. Der Wunsch des Nachlassers bezüglich der weiteren Aufbewahrung seines schriftlichen Erbes ist demzufolge primär gegenüber allen unseren Wünschen. Wir können nicht fordern, sondern nur bitten, uns durch eigene Leistungen anbieten und die zukünftigen Nachlassenden oder deren Erben überzeugen. Die nicht vorhandene institutionelle Zuständigkeit für die Übernahme von Nachlässen erzeugt die Reibungspunkte zwischen den Einrichtungen, die sich um den Erwerb von Nachlässen bemühen: Archive – Bibliotheken – Museen - Sammlungen. Die Wünsche zum Erwerb des Nachlasses einer bestimmten Person – egal ob Wissenschaftler, Künstler oder Politiker – sind demzufolge immer an verschiedenen Orten gleichzeitig vorhanden. Der Zufall entscheidet dann leider meist darüber, an welcher Stelle der Nachlass zukünftig verwahrt und wissenschaftlich genutzt wird. Es stellt sich die Frage, ob wir auf solche Zufälle hoffen und warten sollen, oder ob wir nicht eher eine engagierte – gemeinsam zwischen den Archiven abgestimmte - Erwerbspolitik betrieben sollten. ------------ Beiträge zum Thema "Nachlässe an Universitäts- und Hochschularchiven sowie Archiven wissenschaftlicher Institutionen" im Rahmen der Frühjahrstagung der Fachgruppe 8: "Archivare an Hochschularchiven und Archiven wissenschaftlicher Institutionen" am 16./17. Juni an der Universität Potsdam.
KW - Archiv
KW - Nachlass
Y1 - 2005
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-6098
ER -
TY - CHAP
A1 - Arnold, Gabriele
T1 - Beiträge zur spektralen Fernerkundung fester planetarer Oberflächen
N2 - Dr. Gabriele Arnold ist Leiterin des Bereichs Optische Informationssyteme am Institut für Planetenforschung des Deutschen Zentrums für Luft- und Raumfahrt (DLR) in Berlin-Adlershof
Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7235
N1 - [Poster]
ER -
TY - CHAP
A1 - Doktor, Daniel
A1 - Badeck, Franz-Werner
A1 - Bondeau, Alberte
A1 - Koslowsky, Dirk
A1 - Schaber, Jörg
A1 - McAllister, Murdock
T1 - Using satellite imagery and ground observations to quantify the effect of intra-annually changing temperature patterns on spring time phenology
N2 - Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7244
N1 - [Poster]
ER -
TY - CHAP
A1 - Domsch, Horst
T1 - Prägnante räumlich-zeitliche Muster einer landwirtschaftlich genutzten Fläche
N2 - In ihrem Bemühen, landwirtschaftliche Flächen standortgerecht zu bewirtschaften, sammelt eine zunehmende Anzahl landwirtschaftlicher Betriebe Informationen über die räumlich-zeitliche Verteilung von Boden- und Pflanzenmerkmalen auf ihren Schlägen. Diese Informationen dienen unmittelbar (Echtzeitansatz) oder mittelbar (Kartenansatz) zur Dosierung von Dünge- und Pflanzenschutzmitteln (Präzise Landbewirtschaftung). Zur Datensammlung werden vorrangig fahrzeuggestützte Sensoren und VIS- und NIR-Luftbilder, aufgenommen aus Sportflugzeugen, verwendet. Erste Betriebe erwerben von Dienstleistungsunternehmen aufbereitete Satelliten-Fernerkundungsdaten. Die landwirtschaftliche und agrartechnische Forschung ist bestrebt, die grundlegenden Muster (z.B. des Ertragspotentials) zu erkennen und damit den Aufwand der Betriebe für eine regelmäßige Informationserfassung gering zu halten.
Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7257
N1 - [Poster]
ER -
TY - CHAP
A1 - Kühling, Matthias
A1 - Märker, Michael
A1 - Zehe, Erwin
ED - Gzik, Axel
ED - Hochschild, Volker
ED - Schneider, Ingo
ED - Schröder, Boris
T1 - Musterdynamik und Fernerkundung in der Döberitzer Heide : [Poster]
N2 - Mit der politischen Wende in den Staaten des ehemaligen Ostblockes wurde für viele militärisch genutzte Flächen ein tiefgreifender Nutzungswandel eingeleitet. Truppenübungsplätze als stark gestörte Bestandteile unserer Kulturlandschaft weisen auf großen Flächen naturschutzfachlich wertvolle Habitatmosaike mit speziellen Lebensgemeinschaften auf. Der Nutzungswandel ist mit einer Veränderung der Vegetationsstrukturen (Sukzession) und weiteren landschaftsökologischen Prozessen verbunden. Der ehemalige Truppenübungsplatz Döberitz im Norden der Landeshauptstadt Potsdam kann auf eine lange militärische Nutzungsgeschichte verweisen (erste Manöver des Soldatenkönigs im Jahr 1713). Nach 1992 wurden das NSG Döberitzer Heide (3.415 ha) und das NSG Ferbitzer Bruch (1.155 ha) ausgewiesen. Als Schutzgebiete nach der Vogelschutzrichtlinie sind sie Bestandteile des kohärenten Schutzgebietssystems Natura 2000 der europäischen Gemeinschaft. Trotz des Schutzstatus und der militärischen Altlasten unterliegt das Gebiet als größte zusammenhängende Naturfläche im engeren Verflechtungsraum des Landes Brandenburg einem hohen Nutzungsdruck.
Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7277
ER -
TY - CHAP
A1 - Märker, Michael
A1 - Schröder-Esselbach, Boris
A1 - Capolongo, Domenico
A1 - Bentivenga, Mario
T1 - Geomorphological and pedological processes in badland areas of Southern Italy and their interaction with Mediterranean vegetation
N2 - Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7288
N1 - [Poster]
ER -
TY - CHAP
A1 - Hirschi, Raphael
T1 - The impact of reduced mass loss rates on the evolution of massive stars
N2 - Mass loss is a very important aspect of the life of massive stars. After briefly reviewing its importance, we discuss the impact of the recently proposed downward revision of mass loss rates due to clumping (difficulty to form Wolf-Rayet stars and production of critically rotating stars). Although a small reduction might be allowed, large reduction factors around ten are disfavoured. We then discuss the possibility of significant mass loss at very low metallicity due to stars reaching break-up velocities and especially due to the metal enrichment of the surface of the star via rotational and convective mixing. This significant mass loss may help the first very massive stars avoid the fate of pair-creation supernova, the chemical signature of which is not observed in extremely metal poor stars. The chemical composition of the very low metallicity winds is very similar to that of the most metal poor star known to date, HE1327-2326 and offer an interesting explanation for the origin of the metals in this star. We also discuss the importance of mass loss in the context of long and soft gamma-ray bursts and pair-creation supernovae. Finally, we would like to stress that mass loss in cooler parts of the HR-diagram (luminous blue variable and yellow and red supergiant stages) are much more uncertain than in the hot part. More work needs to be done in these areas to better constrain the evolution of the most massive stars.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17616
ER -
TY - CHAP
A1 - Fullerton, A. W.
A1 - Massa, D. L.
A1 - Prinja, R. K.
T1 - Revised mass-loss rates for O stars from the Pv resonance line
N2 - The P v λλ1118, 1128 resonance doublet is an extraordinarily useful diagnostic of O-star winds, because it bypasses the traditional problems associated with determining mass-loss rates from UV resonance lines. We discuss critically the assumptions and uncertainties involved with using P v to diagnose mass-loss rates, and conclude that the large discrepancies between massloss rates determined from P v and the rates determined from “density squared” emission processes pose a significant challenge to the “standard model” of hot-star winds. The disparate measurements can be reconciled if the winds of O-type stars are strongly clumped on small spatial scales, which in turn implies that mass-loss rates based on Hα or radio emission are too large by up to an order of magnitude.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17647
ER -
TY - CHAP
A1 - Bouret, J.-C.
A1 - Lanz, T.
A1 - Hillier, D. J.
A1 - Foellmi, C.
T1 - Clumping in O-type Supergiants
N2 - We have analyzed the spectra of seven Galactic O4 supergiants, with the NLTE wind code CMFGEN. For all stars, we have found that clumped wind models match well lines from different species spanning a wavelength range from FUV to optical, and remain consistent with Hα data. We have achieved an excellent match of the P V λλ1118, 1128 resonance doublet and N IV λ1718, as well as He II λ4686 suggesting that our physical description of clumping is adequate. We find very small volume filling factors and that clumping starts deep in the wind, near the sonic point. The most crucial consequence of our analysis is that the mass loss rates of O stars need to be revised downward significantly, by a factor of 3 and more compared to those obtained from smooth-wind models.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17662
ER -
TY - CHAP
A1 - Gull, T. R.
T1 - Eta Carinae viewed from different vantages
N2 - The spatially-resolved winds of the massive binary, Eta Carinae, extend an arcsecond on the sky, well beyond the 10 to 20 milliarcsecond binary orbital dimension. Stellar wind line profiles, observed at very different angular resolutions of VLTI/AMBER, HST/STIS and VLT/UVES, provide spatial information on the extended wind interaction structure as it changes with orbital phase. These same wind lines, observable in the starlight scattered off the foreground lobe of the dusty Homunculus, provide time-variant line profiles viewed from significantly different angles. Comparisons of direct and scattered wind profiles observed in the same epoch and at different orbital phases provide insight on the extended wind structure and promise the potential for three-dimensional imaging of the outer wind structures. Massive, long-lasting clumps, including the nebularWeigelt blobs, originated during the two historical ejection events. Wind interactions with these clumps are quite noticeable in spatially-resolved spectroscopy. As the 2009.0 minimum approaches, analysis of existing spectra and 3-D modeling are providing bases for key observations to gain further understanding of this complex massive binary.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18200
ER -
TY - CHAP
A1 - Reimer, A.
T1 - Clumping effects on non-thermal particle spectra in massive star systems
N2 - Observational evidence exists that winds of massive stars are clumped. Many massive star systems are known as non-thermal particle production sites, as indicated by their synchrotron emission in the radio band. As a consequence they are also considered as candidate sites for non-thermal high-energy photon production up to gamma-ray energies. The present work considers the effects of wind clumpiness expected on the emitting relativistic particle spectrum in colliding wind systems, built up from the pool of thermal wind particles through diffusive particle acceleration, and taking into account inverse Compton and synchrotron losses. In comparison to a homogeneous wind, a clumpy wind causes flux variations of the emitting particle spectrum when the clump enters the wind collision region. It is found that the spectral features associated with this variability moves temporally from low to high energy bands with the time shift between any two spectral bands being dependent on clump size, filling factor, and the energy-dependence of particle energy gains and losses.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18246
ER -
TY - CHAP
A1 - Schnurr, O.
A1 - Crowther, P. A.
T1 - Mid-IR observations of WC stars, and the connection to wind clumping
N2 - We present preliminary results of a tailored atmosphere analysis of six Galactic WC stars using UV, optical, and mid-infrared Spitzer IRS data. With these data, we are able to sample regions from 10 to 10³ stellar radii, thus to determine wind clumping in different parts of the wind. Ultimately, derived wind parameters will be used to accuratelymeasure neon abundances, and to so test predicted nuclear-reaction rates.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17884
ER -
TY - CHAP
A1 - Vink, J. S.
A1 - Benaglia, P.
A1 - Davies, B.
A1 - de Koter, A.
A1 - Oudmaijer, R. D.
T1 - Advances in mass-loss predictions
N2 - We present the results of Monte Carlo mass-loss predictions for massive stars covering a wide range of stellar parameters. We critically test our predictions against a range of observed massloss rates – in light of the recent discussions on wind clumping. We also present a model to compute the clumping-induced polarimetric variability of hot stars and we compare this with observations of Luminous Blue Variables, for which polarimetric variability is larger than for O and Wolf-Rayet stars. Luminous Blue Variables comprise an ideal testbed for studies of wind clumping and wind geometry, as well as for wind strength calculations, and we propose they may be direct supernova progenitors.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17948
ER -
TY - CHAP
A1 - Moffat, Anthony F. J.
A1 - Hillier, D. J.
A1 - Hamann, Wolf-Rainer
A1 - Owocki, S. P.
T1 - General Discussion
N2 - Clumping in hot-star winds : proceedings of an international workshop held in Potsdam, Germany, 18. - 22. June 2007
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17953
ER -
TY - CHAP
A1 - Sonneborn, G.
T1 - Imaging and spectroscopy with the James Webb Space Telescope
N2 - The James Webb Space Telescope (JWST) is a large, infrared-optimized space telescope scheduled for launch in 2013. JWST will find the first stars and galaxies that formed in the early universe, connecting the Big Bang to our own Milky Way galaxy. JWST will peer through dusty clouds to see stars forming planetary systems, connecting the MilkyWay to our own Solar System. JWST’s instruments are designed to work primarily in the infrared range of 1 - 28 μm, with some capability in the visible range. JWST will have a large mirror, 6.5 m in diameter, and will be diffraction-limited at 2 μm (0.1 arcsec resolution). JWST will be placed in an L2 orbit about 1.5 million km from the Earth. The instruments will provide imaging, coronography, and multi-object and integral-field spectroscopy across the 1 - 28 μm wavelength range. The breakthrough capabilities of JWST will enable new studies of massive star winds from the Milky Way to the early universe.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17983
ER -
TY - CHAP
A1 - Owocki, S. P.
T1 - Dynamical simulation of the “velocity-porosity” reduction in observed strength of stellar wind lines
N2 - I use dynamical simulations of the line-driven instability to examine the potential role of the resulting flow structure in reducing the observed strength of wind absorption lines. Instead of the porosity length formalism used to model effects on continuum absorption, I suggest reductions in line strength can be better characterized in terms of a velocity clumping factor that is insensitive to spatial scales. Examples of dynamic spectra computed directly from instability simulations do exhibit a net reduction in absorption, but only at a modest 10-20% level that is well short of the ca. factor 10 required by recent analyses of PV lines.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17992
ER -
TY - CHAP
A1 - Blomme, R.
T1 - Corotating Interaction Regions and clumping
N2 - We present hydrodynamical models for Corotating Interaction Regions, which were used by Lobel (2007) to model the Discrete Absorption Components in HD 64760. We also discuss our failure to model the rotational modulations seen in the same star.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18100
ER -
TY - CHAP
A1 - Kholtygin, A. F.
T1 - Wavelets for looking for clumping in the wind of OB stars
N2 - Clumping in hot-star winds : proceedings of an international workshop held in Potsdam, Germany, 18. - 22. June 2007
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17796
ER -
TY - CHAP
A1 - Urbaneja, M. A.
A1 - Kudritzki, R.-P.
A1 - Puls, Joachim
T1 - Clumping in the winds of O-type CSPNs
N2 - Recent studies of massive O-type stars present clear evidences of inhomogeneous and clumped winds. O-type (H-rich) central stars of planetary nebulae (CSPNs) are in some ways the low mass–low luminosity analogous of those massive stars. In this contribution, we present preliminary results of our on-going multi-wavelength (FUV, UV and optical) study of the winds of Galactic CSPNs. Particular emphasis will be given to the clumping factors derived by means of optical lines (Hα and Heii 4686) and “classic” FUV (and UV) lines.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17801
ER -
TY - CHAP
A1 - de Koter, A.
A1 - Vink, J. S.
A1 - Muijres, L.
T1 - Constraints on wind clumping from the empirical mass-loss vs. metallicity relation for early-type stars
N2 - We present the latest results on the observational dependence of the mass-loss rate in stellar winds of O and early-B stars on the metal content of their atmospheres, and compare these with predictions. Absolute empirical rates for the mass loss of stars brighter than 10$^{5.2} L_{\odot}$, based on H$\alpha$ and ultraviolet (UV) wind lines, are found to be about a factor of two higher than predictions. If this difference is attributed to inhomogeneities in the wind this would imply that luminous O and early-B stars have clumping factors in their H$\alpha$ and UV line forming regime of about a factor of 3--5. The investigated stars cover a metallicity range $Z$ from 0.2 to 1 $Z_{\odot}$. We find a hint towards smaller clumping factors for lower $Z$. The derived clumping factors, however, presuppose that clumping does not impact the predictions of the mass-loss rate. We discuss this assumption and explain how we intend to investigate its validity in more detail.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17736
ER -
TY - CHAP
A1 - Reyes-Iturbide, J.
A1 - Velázquez, P.
A1 - Rosado, M.
T1 - 3D numerical model for an asymmetrical superbubble
N2 - Massive stars usually form groups such as OB associations. Their fast stellar winds sweep up collectively the surrounding insterstellar medium (ISM) to generate superbubbles. Observations suggest that superbubble evolution on the surrounding ISM can be very irregular. Numerical simulations considering these conditions could help to understand the evolution of these superbubbles and to clarify the dynamics of these objects as well as the difference between observed X-ray luminosities and the predicted ones by the standard model (Weaver et al. 1977).
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17724
ER -
TY - CHAP
A1 - Groh, J. H.
A1 - Hillier, D. J.
A1 - Damineli, A.
T1 - Mass-loss rate and clumping in LBV stars : the impact of time-dependent effects
N2 - This paper outlines a newly-developed method to include the effects of time variability in the radiative transfer code CMFGEN. It is shown that the flow timescale is often large compared to the variability timescale of LBVs. Thus, time-dependent effects significantly change the velocity law and density structure of the wind, affecting the derivation of the mass-loss rate, volume filling factor, wind terminal velocity, and luminosity. The results of this work are directly applicable to all active LBVs in the Galaxy and in the LMC, such as AG Car, HR Car, S Dor and R 127, and could result in a revision of stellar and wind parameters. The massloss rate evolution of AG Car during the last 20 years is presented, highlighting the need for time-dependent models to correctly interpret the evolution of LBVs.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17773
ER -
TY - CHAP
A1 - Piskorski, Jakub
T1 - ExPRESS : extraction pattern recognition engine and specification suite
N2 - The emergence of information extraction (IE) oriented pattern engines has been observed during the last decade. Most of them exploit heavily finite-state devices. This paper introduces ExPRESS – a new extraction pattern engine, whose rules are regular expressions over flat feature structures. The underlying pattern language is a blend of two previously introduced IE oriented pattern formalisms, namely, JAPE, used in the widely known GATE system, and the unificationbased XTDL formalism used in SProUT. A brief and technical overview of ExPRESS, its pattern language and the pool of its native linguistic components is given. Furthermore, the implementation of the grammar interpreter is addressed too.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27227
ER -
TY - CHAP
ED - Kurths, Jürgen
ED - Fradkov, Alexander
ED - Chen, Guanrong
T1 - The 3rd international IEEE scientific conference on physics and control (PhysCon 2007) : September 3rd-7th 2007 at the University of Potsdam
N2 - During the last few years there was a tremendous growth of scientific activities in the fields related to both Physics and Control theory: nonlinear dynamics, micro- and nanotechnologies, self-organization and complexity, etc. New horizons were opened and new exciting applications emerged. Experts with different backgrounds starting to work together need more opportunities for information exchange to improve mutual understanding and cooperation. The Conference "Physics and Control 2007" is the third international conference focusing on the borderland between Physics and Control with emphasis on both theory and applications. With its 2007 address at Potsdam, Germany, the conference is located for the first time outside of Russia. The major goal of the Conference is to bring together researchers from different scientific communities and to gain some general and unified perspectives in the studies of controlled systems in physics, engineering, chemistry, biology and other natural sciences. We hope that the Conference helps experts in control theory to get acquainted with new interesting problems, and helps experts in physics and related fields to know more about ideas and tools from the modern control theory.
KW - nonlinear dynamics
KW - micro- and nanotechnologies
KW - self-organization
KW - complexity
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-15228
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - CHAP
A1 - Watson, Bruce W.
T1 - Advances in automata implementation techniques (Abstract)
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27094
ER -
TY - CHAP
A1 - Barthélemy, François
T1 - Finite-state compilation of feature structures for two-level morphology
N2 - This paper describes a two-level formalism where feature structures are used in contextual rules. Whereas usual two-level grammars describe rational sets over symbol pairs, this new formalism uses tree structured regular expressions. They allow an explicit and precise definition of the scope of feature structures. A given surface form may be described using several feature structures. Feature unification is expressed in contextual rules using variables, like in a unification grammar. Grammars are compiled in finite state multi-tape transducers.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27120
ER -
TY - CHAP
A1 - Blanc, Olivier
A1 - Constant, Matthieu
A1 - Watrin, Patrick
T1 - Segmentation in super-chunks with a finite-state approach
N2 - Since Harris’ parser in the late 50s, multiword units have been progressively integrated in parsers. Nevertheless, in the most part, they are still restricted to compound words, that are more stable and less numerous. Actually, language is full of semi-fixed expressions that also form basic semantic units: semi-fixed adverbial expressions (e.g. time), collocations. Like compounds, the identification of these structures limits the combinatorial complexity induced by lexical ambiguity. In this paper, we detail an experiment that largely integrates these notions in a finite-state procedure of segmentation into super-chunks, preliminary to a parser.We show that the chunker, developped for French, reaches 92.9% precision and 98.7% recall. Moreover, multiword units realize 36.6% of the attachments within nominal and prepositional phrases.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27133
ER -
TY - CHAP
A1 - Bonfante, Guillaume
A1 - Le Roux, Joseph
T1 - Intersection optimization is NP-complete
N2 - Finite state methods for natural language processing often require the construction and the intersection of several automata. In this paper, we investigate the question of determining the best order in which these intersections should be performed. We take as an example lexical disambiguation in polarity grammars. We show that there is no efficient way to minimize the state complexity of these intersections.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27146
ER -
TY - CHAP
A1 - Daciuk, Jan
T1 - Perfect hashing tree automata
N2 - We present an algorithm that computes a function that assigns consecutive integers to trees recognized by a deterministic, acyclic, finite-state, bottom-up tree automaton. Such function is called minimal perfect hashing. It can be used to identify trees recognized by the automaton. Its value may be seen as an index in some other data structures. We also present an algorithm for inverted hashing.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27163
ER -
TY - CHAP
A1 - Padró, Muntsa
A1 - Padró, Lluís
T1 - ME-CSSR : an extension of CSSR using maximum entropy models
N2 - In this work an extension of CSSR algorithm using Maximum Entropy Models is introduced. Preliminary experiments to perform Named Entity Recognition with this new system are presented.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27210
ER -
TY - CHAP
A1 - Arlettaz, Jordane
A1 - Badó, Attila
A1 - Bakos-Kovács, Kitti
A1 - Bató, Szilvia
A1 - Bóka, János
A1 - Congnard, Laureline
A1 - Csatlós, Erzsébet
A1 - Gedeon, Magdolna
A1 - Guemar, Carine
A1 - Hajdú, Dóra
A1 - Jacsó, Judit
A1 - Kelemen, Katalin
A1 - Fekete, Balázs
A1 - Kruzslicz, Péter
A1 - Mezei, Péter
A1 - Szűcs, Tünde
A1 - Zoltán, Péteri
A1 - Szabó, Béla P.
ED - Badó, Attila
ED - Belling, Detlev W.
ED - Bóka, János
ED - Mezei, Péter
T1 - Internationale Konferenz zum zehnjährigen Bestehen des Instituts für Rechtsvergleichung der Universität Szeged
T1 - International conference for the 10th anniversary of the Institute of Comparative Law of the University of Szeged
T1 - Conférence internationale au 10ème anniversaire de l‘Institut de droit comparé de l‘Université de Szeged
N2 - Die Konferenz „International Conference for the 10th Anniversary of the Institute of Comparative Law” hat am 24. Mai 2013 in Szeged stattgefunden. Im Rahmen der viersprachigen Konferenz haben mehr als dreißig Teilnehmer ihre Forschungsergebnisse präsentiert. Der Essay von Zoltán Péteri blickt auf die Disziplin aus der Perspektive der Wissenschaftsgeschichte. Katalin Kelemen und Balázs Fekete gehen in ihrem Aufsatz der Frage nach, welchen Weg die Versuche der Klassifikation der Rechtssysteme von Osteuropa in der späten Phase der Umbrüche der 1980/90er Jahren genommen haben. Die historische Betrachtungsweise mit Bezug auf Rechtsgeschichte und Rechtsvergleichung spiegelt sich auch in anderen Essays wider, vor allem in den Aufsätzen von Szilvia Bató, Magdolna Gedeon und Béla Szabó P. sowie auch in den Aufsätzen von Péter Mezei und Tünde Szűcs. Attila Badó analysiert die Rechtsvergleichung aus der Sicht des Rechts, der Soziologie und der Politikwissenschaft anhand von Untersuchungen über das Sanktionsystem der Richter in den USA. Diese politikwissenschaftliche Seite wird auch in den Aufsätzen über die aktuellen Fragen der europäischen Integration von Carine Guemar und Laureline Congnard betont. Eine Reihe von Aufsätzen behandeln die konventionelle normative Komparatistik auf dem Gebiet des Verfassungsrechts (Jordane Arlettaz und Péter Kruzslicz), Gesellschaftsrechts (Kitti Bakos-Kovács), Urheberrechts (Dóra Hajdú) und Steuerrechts (Judit Jacsó). Daneben bilden eine weitere Gruppe die Aufsätze von János Bóka und Erzsébet Csatlós, die die Verwendung der vergleichenden Methode in der Praxis der Rechtsprechung untersuchen. Die Rechtsvergleichung ist eine sich dynamisch entwickelnde Disziplin. Die Konferenz und dieser Band dienen nicht nur der Würdigung der bisherigen Arbeit des Instituts für Rechtsvergleichung, sondern zeigen gleichzeitig neue Ziele auf. Die wichtigsten Grundsätze bleiben aber fest verankert auch in einem sich stets verändernden rechtlichen und geistigen Umfeld. Das Motto des Instituts lautet „instruere et docere omnes qui edoceri desiderant“ – „alle lehren, die lernen wollen.“ Auch in den folgenden Jahrzehnten werden uns der Wille des Lernens und Lehrens, die Freiheit der Forschung sowie die Übertragung und Weiterentwicklung der ungarischen wie globalen Rechtskultur leiten.
T3 - Acta Iuridica Universitatis Potsdamiensis - 1
KW - Rechtsvergleichung
KW - Rechtsgeschichte
KW - Verfassungsrecht
KW - Gesellschaftrecht
KW - Urheberrecht
KW - comparative law
KW - legal history
KW - constitutional law
KW - company law
KW - copyright law
Y1 - 2014
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-72039
SN - 978-3-86956-308-4
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - CHAP
A1 - Goltz, Hans-Joachim
A1 - Pieth, Norbert
T1 - A tool for generating partition schedules of multiprocessor systems
N2 - A deterministic cycle scheduling of partitions at the operating system level is supposed for a multiprocessor system. In this paper, we propose a tool for generating such schedules. We use constraint based programming and develop methods and concepts for a combined interactive and automatic partition scheduling system. This paper is also devoted to basic methods and techniques for modeling and solving this partition scheduling problem. Initial application of our partition scheduling tool has proved successful and demonstrated the suitability of the methods used.
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41556
ER -
TY - CHAP
A1 - Schrijvers, Tom
T1 - Overview of the monadic constraint programming framework
N2 - A constraint programming system combines two essential components: a constraint solver and a search engine. The constraint solver reasons about satisfiability of conjunctions of constraints, and the search engine controls the search for solutions by iteratively exploring a disjunctive search tree defined by the constraint program. The Monadic Constraint Programming framework gives a monadic definition of constraint programming where the solver is defined as a monad threaded through the monadic search tree. Search and search strategies can then be defined as firstclass objects that can themselves be built or extended by composable search transformers. Search transformers give a powerful and unifying approach to viewing search in constraint programming, and the resulting constraint programming system is first class and extremely flexible.
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41411
ER -
TY - CHAP
A1 - Bergmann, Kirsten
A1 - Kopp, Stefan
T1 - Verbal or visual? : How information is distributed across speech and gesture in spatial dialog
N2 - In spatial dialog like in direction giving humans make frequent use of speechaccompanying gestures. Some gestures convey largely the same information as speech while others complement speech. This paper reports a study on how speakers distribute meaning across speech and gesture, and depending on what factors. Utterance meaning and the wider dialog context were tested by statistically analyzing a corpus of direction-giving dialogs. Problems of speech production (as indicated by discourse markers and disfluencies), the communicative goals, and the information status were found to be influential, while feedback signals by the addressee do not have any influence.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10375
ER -
TY - CHAP
A1 - Diderichsen, Philip
T1 - Cross recurrence quantification analysis of indefinite anaphora in Swedish dialog : an eye-tracking pilot experiment
N2 - A new method is used in an eye-tracking pilot experiment which shows that it is possible to detect differences in common ground associated with the use of minimally different types of indefinite anaphora. Following Richardson and Dale (2005), cross recurrence quantification analysis (CRQA) was used to show that the tandem eye movements of two Swedish-speaking interlocutors are slightly more coupled when they are using fully anaphoric indefinite expressions than when they are using less anaphoric indefinites. This shows the potential of CRQA to detect even subtle processing differences in ongoing discourse.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10388
ER -
TY - CHAP
A1 - Lücking, Andy
A1 - Rieser, Hannes
A1 - Staudacher, Marc
T1 - Multi-modal integration for gesture and speech
N2 - Demonstratives, in particular gestures that "only" accompany speech, are not a big issue in current theories of grammar. If we deal with gestures, fixing their function is one big problem, the other one is how to integrate the representations originating from different channels and, ultimately, how to determine their composite meanings. The growing interest in multi-modal settings, computer simulations, human-machine interfaces and VRapplications increases the need for theories ofmultimodal structures and events. In our workshopcontribution we focus on the integration of multimodal contents and investigate different approaches dealing with this problem such as Johnston et al. (1997) and Johnston (1998), Johnston and Bangalore (2000), Chierchia (1995), Asher (2005), and Rieser (2005).
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10393
ER -
TY - CHAP
A1 - Saget, Sylvie
A1 - Guyomard, Marc
T1 - Goal-oriented dialog as a collaborative subordinated activity involving collective acceptance
N2 - Modeling dialog as a collaborative activity consists notably in specifying the contain of the Conversational Common Ground and the kind of social mental state involved. In previous work (Saget, 2006), we claim that Collective Acceptance is the proper social attitude for modeling Conversational Common Ground in the particular case of goal-oriented dialog. We provide a formalization of Collective Acceptance, besides elements in order to integrate this attitude in a rational model of dialog are provided; and finally, a model of referential acts as being part of a collaborative activity is provided. The particular case of reference has been chosen in order to exemplify our claims.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10420
ER -
TY - CHAP
A1 - DeVault, David
A1 - Stone, Matthew
T1 - Scorekeeping in an uncertain language game
N2 - Received views of utterance context in pragmatic theory characterize the occurrent subjective states of interlocutors using notions like common knowledge or mutual belief. We argue that these views are not compatible with the uncertainty and robustness of context-dependence in humanhuman dialogue. We present an alternative characterization of utterance context as objective and normative. This view reconciles the need for uncertainty with received intuitions about coordination and meaning in context, and can directly inform computational approaches to dialogue.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10448
ER -
TY - CHAP
A1 - Schmid, Gerhard
T1 - Archivarische und bibliothekarische Verfahren der Nachlassbearbeitung
N2 - Beiträge zum Thema "Nachlässe an Universitäts- und Hochschularchiven sowie Archiven wissenschaftlicher Institutionen" im Rahmen der Frühjahrstagung der Fachgruppe 8: "Archivare an Hochschularchiven und Archiven wissenschaftlicher Institutionen" am 16./17. Juni an der Universität Potsdam.
KW - Archiv
KW - Universitätsarchiv
KW - Nachlass
Y1 - 2005
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-6228
ER -
TY - CHAP
A1 - Kaufmann, Hermann
T1 - Abbildende Spektrometrie
BT - [Die neuen diagnostischen Möglichkeiten der Programme ARES und ENMAP bei der Erfassung von Oberflächenprozessen]
N2 - Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7104
ER -
TY - CHAP
A1 - Sommer, Michael
T1 - Nicht-invasive Methoden in der Bodenlandschaftsforschung
BT - Konzeption und Projekte
N2 - Der Referent ist Leiter des Institutes für Bodenlandschaftsforschung am Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e. V. in Müncheberg.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7117
N1 - Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006
ER -
TY - CHAP
A1 - Zehe, Erwin
A1 - Bronstert, Axel
A1 - Itzerott, Sibylle
A1 - Bárdossy, András
A1 - Ihringer, Jürgen
T1 - Hochwasservorhersage, Großhangbewegungen, Schadstofftransport
BT - IMAF-relevante Projektbeispiele und Vorhaben am Institut für Geoökologie
N2 - Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7128
ER -
TY - CHAP
A1 - Kuhnert, Matthias
A1 - Güntner, Andreas
A1 - Klann, Mechthild
A1 - Martin Garrido, F.
A1 - Zillgens, Birgit
T1 - Methods for spatial pattern comparison in distributed hydrological modelling : [Poster]
N2 - The rigorous development, application and validation of distributed hydrological models obligates to evaluate data in a spatially distributed way. In particular, spatial model predictions such as the distribution of soil moisture, runoff generating areas or nutrient-contributing areas or erosion rates, are to be assessed against spatially distributed observations. Also model inputs, such as the distribution of modelling units derived by GIS and remote sensing analyses, should be evaluated against groundbased observations of landscape characteristics. So far, however, quantitative methods of spatial field comparison have rarely been used in hydrology. In this paper, we present algorithms that allow to compare observed and simulated spatial hydrological data. The methods can be applied for binary and categorical data on regular grids. They comprise cell-by-cell algorithms, cell-neighbourhood approaches that account for fuzziness of location, and multi-scale algorithms that evaluate the similarity of spatial fields with changing resolution. All methods provide a quantitative measure of the similarity of two maps. The comparison methods are applied in two mountainous catchments in southern Germany (Brugga, 40 km2) and Austria (Löhnersbach, 16 km2). As an example of binary hydrological data, the distribution of saturated areas is analyzed in both catchments. For categorical data, vegetation zones that are associated with different runoff generation mechanisms are analyzed in the Löhnersbach. Mapped spatial patterns are compared to simulated patterns from terrain index calculations and from satellite image analysis. It is discussed how particular features of visual similarity between the spatial fields are captured by the quantitative measures, leading to recommendations on suitable algorithms in the context of evaluating distributed hydrological models.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7160
N1 - Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006
ER -
TY - CHAP
A1 - Wegehenkel, Martin
T1 - Die Nutzung von Fernerkundungsdaten in der Wasserhaushaltsmodellierung
BT - ein Review
N2 - Die Präsentation gibt zuerst einen Überblick über mögliche Parameter für die Wasserhaushaltsmodellierung, die aus Fernerkundungs(FE)-daten generell abgeleitet werden können. Bei der Beschreibung der Ableitungsverfahren dieser Parameter aus (FE)-Daten wird auf die Landnutzung, Vegetationsindices und die reale Evapotranspiration (ETr) fokussiert. Die Verfahren zur Bestimmung der ETr aus optischen FE-Daten lassen grob wie folgt gliedern : • Direkte Ableitung der Evapotranspiration aus radiometrisch bestimmten Oberflächen-temperaturen • Ableitung von Modellinputdaten wie z.B. Globalstrahlung, Albedo, Blattflächeniondex LAI und NDVI aus FE-Daten zur Anwendung von SoilVegetation-AtmosphereTransfer- und Energiebilanzmodellen wie z.B. SEBAL (Bastiaansen et al . 1998) • Kombinierte Anwendung verschiedenster Sensoren wie SAR-ERS1, LANDSAT-TM, NOAA-AHVRR mit SVAT-Modellen und hydrologischen Einzugsgebietsmodellen Die Validierung dieser Methoden wurde in verschiedenen Messkampagnen wie z.B. Lo-trex10E-HIBE, FIFE oder HAPEX-Sahel durchgeführt. Dabei wurde die aus dem entspre-chenden Sensor abgeleitete ETr mit gemessenen ETr-Raten von Ankerstationen innerhalb eines definierten Gebietes verglichen. Diese Ankerstationen leiteten die ETr aus Profil-, Ed-dy-Flux-, oder Szintillometermessungen ab. Durchgängige längere Zeitreihen der ETr sind nur mit FE-Daten mit hoher Wiederholungsrate wie z.B. NOAA-AVHRR, MODIS hoher Zeitauflösung möglich Mit Landsat-TM z.B. ergeben sich dagegen nur „Snap Shots“ der ETr von einzelnen Tagen. Daher wurden oftmals Multisensorverfahren d.h. Kombination von z.B. Landsat-TM mit NOAA-AVHRR eingesetzt oder die FE-Daten nur für die Erhebung zeitin-varianter Eingangsdaten (z.B. Landnutzung) und zur raumbezogenen Validierung der ETr-Berechnungen von hydrologischen Modellen verwendet. Im zweiten Teil des Vortrags wird ein Anwendungsbeispiel für den Versuch einer räumliche Validierung eines Wasserhaus-haltsmodells über NDVI-ETr-Datenprodukte aus Landsat-TM5-Daten für das Stobbergebiet. Ein weiteres Anwendungsbeispiel für die Einbindung von Landnutzungsdatenprodukten aus Landsat-TM5-Daten in die Wasserhaushaltmodellierung für das Ucker-Einzugsgebiet schliesst den Vortrag ab.
Dokument 1: Foliensatz | Dokument 2: Abstract
Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7050
ER -
TY - CHAP
A1 - Schulz, Karsten
T1 - Die Bedeutung räumlicher Strukturen und Muster für das hydrologische Prozessgeschehen
N2 - Der Referent ist stellvertretender Leiter des Departments Angewandte Landschaftsökologie des UFZ - Umweltforschungszentrum Leipzig-Halle am Fachbereich Umweltsystemmodellierung
Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 20066
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7087
ER -
TY - CHAP
A1 - Wolska, Magdalena
A1 - Kruijff-Korbayová, Ivana
T1 - Modeling anaphora in informal mathematical dialogue
N2 - We analyze anaphoric phenomena in the context of building an input understanding component for a conversational system for tutoring mathematics. In this paper, we report the results of data analysis of two sets of corpora of dialogs on mathematical theorem proving. We exemplify anaphoric phenomena, identify factors relevant to anaphora resolution in our domain and extensions to the input interpretation component to support it.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10455
ER -
TY - CHAP
A1 - Kempson, Ruth
A1 - Cann, Ronnie
T1 - Dialogue pressures and syntactic change
N2 - On the basis of the Dynamic Syntax framework, this paper argues that the production pressures in dialogue determining alignment effects and given versus new informational effects also drive the shift from case-rich free word order systems without clitic pronouns into systems with clitic pronouns with rigid relative ordering. The paper introduces assumptions of Dynamic Syntax, in particular the building up of interpretation through structural underspecification and update, sketches the attendant account of production with close coordination of parsing and production strategies, and shows how what was at the Latin stage a purely pragmatic, production-driven decision about linear ordering becomes encoded in the clitics in theMedieval Spanish system which then through successive steps of routinization yield the modern systems with immediately pre-verbal fixed clitic templates.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10469
ER -
TY - CHAP
A1 - Vlugter, Peter
A1 - Knott, Alistair
T1 - A multi-speaker dialogue system for computer-aided language learning
N2 - The main topic of this paper is how to configure a dialogue system to support computer-aided language learning. The paper also serves to introduce our new multi-speaker dialogue system, and highlight some of its novel features.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10208
ER -
TY - CHAP
A1 - Karagjosova, Elena
T1 - Correction and acceptance by contrastive focus
N2 - An account is presented of the focus properties, common ground effect and dialogue behaviour of the accented German discourse marker "doch" and the accented sentence negation "nicht". It is argued that "doch" and "nicht" evoke as a focus alternative the logical complement of the proposition expressed by the sentence in which they occur, and that an analysis in terms of contrastive focus accounts for their effect on the common ground and their function in dialogue.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10258
ER -
TY - CHAP
A1 - Macura, Zoran
A1 - Ginzburg, Jonathan
T1 - Acquiring words across generations : introspectively or interactively?
N2 - How does a shared lexicon arise in population of agents with differing lexicons, and how can this shared lexicon be maintained over multiple generations? In order to get some insight into these questions we present an ALife model in which the lexicon dynamics of populations that possess and lack metacommunicative interaction (MCI) capabilities are compared. We ran a series of experiments on multi-generational populations whose initial state involved agents possessing distinct lexicons. These experiments reveal some clear differences in the lexicon dynamics of populations that acquire words solely by introspection contrasted with populations that learn using MCI or using a mixed strategy of introspection and MCI. The lexicon diverges at a faster rate for an introspective population, eventually collapsing to one single form which is associated with all meanings. This contrasts sharply with MCI capable populations in which a lexicon is maintained, where every meaning is associated with a unique word. We also investigated the effect of increasing the meaning space and showed that it speeds up the lexicon divergence for all populations irrespective of their acquisition method.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10408
ER -
TY - CHAP
A1 - Thomas, Kavita E.
T1 - Modelling Correction Signalled by "But" in Dialogue
N2 - Claiming that cross-speaker "but" can signal correction in dialogue, we start by describing the types of corrections "but" can communicate by focusing on the Speech Act (SA) communicated in the previous turn and address the ways in which "but" can correct what is communicated. We address whether "but" corrects the proposition, the direct SA or the discourse relation communicated in the previous turn. We will also briefly address other relations signalled by cross-turn "but". After presenting a typology of the situations "but" can correct, we will address how these corrections can be modelled in the Information State model of dialogue, motivating this work by showing how it can be used to potentially avoid misunderstandings. We wrap up by showing how the model presented here updates beliefs in the Information State representation of the dialogue and can be used to facilitate response deliberation.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10308
ER -
TY - CHAP
A1 - Beyssade, Claire
A1 - Marandin, Jean-Marie
T1 - From complex to simple speech acts : a bidimensional analysis of illocutionary
N2 - We present a new analysis of illocutionary forces in dialogue. We analyze them as complex conversational moves involving two dimensions: what Speaker commits herself to and what she calls on Addressee to perform. We start from the analysis of speech acts such as confirmation requests or whimperatives, and extend the analysis to seemingly simple speech acts, such as statements and queries. Then, we show how to integrate our proposal in the framework of the Grammar for Conversation (Ginzburg, to app.), which is adequate for modelling agents' information states and how they get updated.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10319
ER -
TY - CHAP
A1 - Hara, Yurie
T1 - Question intonation and lexicalized bias expression
N2 - This paper examines the interaction between different utterance types and the Japanese modal particle darou, and proposes that the decision-theoretic semantics accounts for the interaction among darou, sentence types and intonation.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10323
ER -
TY - CHAP
A1 - Artstein, Ron
A1 - Poesio, Massimo
T1 - Identifying reference to abstract objects in dialogue
N2 - In two experiments, many annotators marked antecedents for discourse deixis as unconstrained regions of text. The experiments show that annotators do converge on the identity of these text regions, though much of what they do can be captured by a simple model. Demonstrative pronouns are more likely than definite descriptions to be marked with discourse antecedents. We suggest that our methodology is suitable for the systematic study of discourse deixis.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10357
ER -
TY - CHAP
A1 - Lascarides, Alex
A1 - Stone, Matthew
T1 - Formal semantics for iconic gesture
N2 - We present a formal analysis of iconic coverbal gesture. Our model describes the incomplete meaning of gesture that’s derivable from its form, and the pragmatic reasoning that yields a more specific interpretation. Our formalism builds on established models of discourse interpretation to capture key insights from the descriptive literature on gesture: synchronous speech and gesture express a single thought, but while the form of iconic gesture is an important clue to its interpretation, the content of gesture can be resolved only by linking it to its context.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10330
ER -
TY - CHAP
A1 - Lücking, Andy
A1 - Rieser, Hannes
A1 - Staudacher, Marc
T1 - SDRT and multi-modal situated communication
N2 - Classical SDRT (Asher and Lascarides, 2003) discussed essential features of dialogue like adjacency pairs or corrections and up-dating. Recent work in SDRT (Asher, 2002, 2005) aims at the description of natural dialogue. We use this work to model situated communication, i.e. dialogue, in which sub-sentential utterances and gestures (pointing and grasping) are used as conventional modes of communication. We show that in addition to cognitive modelling in SDRT, capturing mental states and speech-act related goals, special postulates are needed to extract meaning out of contexts. Gestural meaning anchors Discourse Referents in contextually given domains. Both sorts of meaning are fused with the meaning of fragments to get at fully developed dialogue moves. This task accomplished, the standard SDRT machinery, tagged SDRSs, rhetorical relations, the up-date mechanism, and the Maximize Discourse Coherence constraint generate coherent structures. In sum, meanings from different verbal and non-verbal sources are assembled using extended SDRT to form coherent wholes.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10348
ER -
TY - CHAP
A1 - Kranstedt, Alfred
A1 - Lücking, Andy
A1 - Pfeiffer, Thies
A1 - Rieser, Hannes
A1 - Staudacher, Marc
T1 - Measuring and reconstructing pointing in visual contexts
N2 - We describe an experiment to gather original data on geometrical aspects of pointing. In particular, we are focusing upon the concept of the pointing cone, a geometrical model of a pointing’s extension. In our setting we employed methodological and technical procedures of a new type to integrate data from annotations as well as from tracker recordings. We combined exact information on position and orientation with rater’s classifications. Our first results seem to challenge classical linguistic and philosophical theories of demonstration in that they advise to separate pointings from reference.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10362
ER -
TY - CHAP
A1 - Mills, Gregory J.
A1 - Healey, Patrick G. T.
T1 - Clarifying spatial descriptions : local and global effects on semantic co-ordination
N2 - A key problem for models of dialogue is to explain the mechanisms involved in generating and responding to clarification requests. We report a 'Maze task' experiment that investigates the effect of 'spoof' clarification requests on the development of semantic co-ordination. The results provide evidence of both local and global semantic co-ordination phenomena that are not captured by existing dialogue co-ordination models.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10414
ER -
TY - CHAP
A1 - Dzikovska, Myroslava O.
A1 - Callaway, Charles B.
A1 - Stone, Matthew
A1 - Moore, Johanna D.
T1 - Understanding student input for tutorial dialogue in procedural domains
N2 - We present an analysis of student language input in a corpus of tutoring dialogue in the domain of symbolic differentiation. Our focus on procedural tutoring makes the dialogue comparable to collaborative problem-solving (CPS). Existing CPS models describe the process of negotiating plans and goals, which also fits procedural tutoring. However, we provide a classification of student utterances and corpus annotation which shows that approximately 28% of non-trivial student language in this corpus is not accounted for by existing models, and addresses other functions, such as evaluating past actions or correcting mistakes. Our analysis can be used as a foundation for improving models of tutoring dialogue.
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-10193
ER -
TY - CHAP
A1 - Hofuku, Yayoi
A1 - Cho, Shinya
A1 - Nishida, Tomohiro
A1 - Kanemune, Susumu
A1 - Linck, Barbara
A1 - Kim, Seungyon
A1 - Park, Seongbin
A1 - Vaníček, Jiří
A1 - Gujberová, Monika
A1 - Tomcsányi, Peter
A1 - Dagiene, Valentina
A1 - Jevsikova, Tatjana
A1 - Schulte, Carsten
A1 - Sentance, Sue
A1 - Thota, Neena
A1 - Gülbahar, Yasemin
A1 - İlkhan, Mustafa
A1 - Kilis, Selcan
A1 - Arslan, Okan
A1 - Nakano, Yoshiaki
A1 - Izutsu, Katsunobu
A1 - Lessner, Daniel
A1 - Reffay, Christophe
A1 - Miled, Mahdi
A1 - Ortiz, Pascal
A1 - Février, Loïc
A1 - Grgurina, Nataša
A1 - Weise, Martin
A1 - Bellettini, Carlo
A1 - Lonati, Violetta
A1 - Malchiodi, Dario
A1 - Monga, Mattia
A1 - Morpurgo, Anna
A1 - Torelli, Mauro
A1 - Planteu, Lukas
A1 - Standl, Bernhard
A1 - Grossmann, Wilfried
A1 - Neuwirth, Erich
A1 - Benacka, Jan
A1 - Ragonis, Noa
A1 - Hodges, Steve
A1 - Berry, Carol
A1 - Kusterer, Peter
ED - Diethelm, Ira
ED - Arndt, Jannik
ED - Dünnebier, Malte
ED - Syrbe, Jörn
T1 - Informatics in schools : local proceedings of the 6th International Conference ISSEP 2013 ; selected papers ; Oldenburg, Germany, February 26–March 2, 2013
N2 - The International Conference on Informatics in Schools: Situation, Evolution and Perspectives – ISSEP – is a forum for researchers and practitioners in the area of Informatics education, both in primary and secondary schools. It provides an opportunity for educators to reflect upon the goals and objectives of this subject, its curricula and various teaching/learning paradigms and topics, possible connections to everyday life and various ways of establishing Informatics Education in schools. This conference also cares about teaching/learning materials, various forms of assessment, traditional and innovative educational research designs, Informatics’ contribution to the preparation of children for the 21st century, motivating competitions, projects and activities supporting informatics education in school.
T3 - Commentarii informaticae didacticae (CID) - 6
KW - ISSEP
KW - Informatics Education
Y1 - 2013
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-63688
SN - 978-3-86956-222-3
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - CHAP
A1 - Bögel, Tina
A1 - Butt, Miriam
A1 - Hautli, Annette
A1 - Sulger, Sebastian
T1 - Developing a finite-state morphological analyzer for Urdu and Hindi
N2 - We introduce and discuss a number of issues that arise in the process of building a finite-state morphological analyzer for Urdu, in particular issues with potential ambiguity and non-concatenative morphology. Our approach allows for an underlyingly similar treatment of both Urdu and Hindi via a cascade of finite-state transducers that transliterates the very different scripts into a common ASCII transcription system. As this transliteration system is based on the XFST tools that the Urdu/Hindi common morphological analyzer is also implemented in, no compatibility problems arise.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27155
ER -
TY - CHAP
A1 - Yli-Jyrä, Anssi
T1 - Applications of diamonded double negation
N2 - Nested complementation plays an important role in expressing counter- i.e. star-free and first-order definable languages and their hierarchies. In addition, methods that compile phonological rules into finite-state networks use double-nested complementation or “double negation”. This paper reviews how the double-nested complementation extends to a relatively new operation, generalized restriction (GR), coined by the author (Yli-Jyrä and Koskenniemi 2004). This operation encapsulates a double-nested complementation and elimination of a concatenation marker, diamond, whose finite occurrences align concatenations in the arguments of the operation. The paper demonstrates that the GR operation has an interesting potential in expressing regular languages, various kinds of grammars, bimorphisms and relations. This motivates a further study of optimized implementation of the operator.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27109
ER -
TY - CHAP
A1 - Barbaiani, Mădălina
A1 - Cancedda, Nicola
A1 - Dance, Chris
A1 - Fazekas, Szilárd
A1 - Gaál, Tamás
A1 - Gaussier, Éric
T1 - Asymmetric term alignment with selective contiguity constraints by multi-tape automata
N2 - This article describes a HMM-based word-alignment method that can selectively enforce a contiguity constraint. This method has a direct application in the extraction of a bilingual terminological lexicon from a parallel corpus, but can also be used as a preliminary step for the extraction of phrase pairs in a Phrase-Based Statistical Machine Translation system. Contiguous source words composing terms are aligned to contiguous target language words. The HMM is transformed into a Weighted Finite State Transducer (WFST) and contiguity constraints are enforced by specific multi-tape WFSTs. The proposed method is especially suited when basic linguistic resources (morphological analyzer, part-of-speech taggers and term extractors) are available for the source language only.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27115
ER -
TY - CHAP
A1 - Karttunen, Lauri
T1 - New features in PARC finite state toolkits (Abstract)
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27085
ER -
TY - CHAP
A1 - Yli-Jyrä, Anssi
T1 - Transducers from parallel replace rules and modes with generalized lenient composition
N2 - Generalized Two-Level Grammar (GTWOL) provides a new method for compilation of parallel replacement rules into transducers. The current paper identifies the role of generalized lenient composition (GLC) in this method. Thanks to the GLC operation, the compilation method becomes bipartite and easily extendible to capture various application modes. In the light of three notions of obligatoriness, a modification to the compilation method is proposed. We argue that the bipartite design makes implementation of parallel obligatoriness, directionality, length and rank based application modes extremely easy, which is the main result of the paper.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27246
ER -
TY - CHAP
A1 - Saléschus, Dirk
T1 - On resolving long distance dependencies in Russian verbs
N2 - Morphological analyses based on word syntax approaches can encounter difficulties with long distance dependencies. The reason is that in some cases an affix has to have access to the inner structure of the form with which it combines. One solution is the percolation of features from ther inner morphemes to the outer morphemes with some process of feature unification. However, the obstacle of percolation constraints or stipulated features has lead some linguists to argue in favour of other frameworks such as, e.g., realizational morphology or parallel approaches like optimality theory. This paper proposes a linguistic analysis of two long distance dependencies in the morphology of Russian verbs, namely secondary imperfectivization and deverbal nominalization.We show how these processes can be reanalysed as local dependencies. Although finitestate frameworks are not bound by such linguistically motivated considerations, we present an implementation of our analysis as proposed in [1] that does not complicate the grammar or enlarge the network unproportionally.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27235
ER -
TY - CHAP
A1 - Ilarraza, Arantza Díaz de
A1 - Gojenola, Koldo
A1 - Oronoz, Maite
A1 - Otaegi, Maialen
A1 - Alegria, Iñaki
T1 - Syntactic error detection and correction in date expressions using finite-state transducers
N2 - This paper presents a system for the detection and correction of syntactic errors. It combines a robust morphosyntactic analyser and two groups of finite-state transducers specified using the Xerox Finite State Tool (xfst). One of the groups is used for the description of syntactic error patterns while the second one is used for the correction of the detected errors. The system has been tested on a corpus of real texts, containing both correct and incorrect sentences, with good results.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27180
ER -
TY - CHAP
A1 - Fernando, Tim
T1 - Temporal propositions as regular languages
N2 - Temporal propositions are mapped to sets of strings that witness (in a precise sense) the propositions over discrete linear Kripke frames. The strings are collected into regular languages to ensure the decidability of entailments given by inclusions between languages. (Various notions of bounded entailment are shown to be expressible as language inclusions.) The languages unwind computations implicit in the logical (and temporal) connectives via a system of finite-state constraints adapted from finite-state morphology. Applications to Hybrid Logic and non-monotonic inertial reasoning are briefly considered.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27194
ER -
TY - CHAP
A1 - Didakowski, Jörg
T1 - SynCoP : combining syntactic tagging with chunking using weighted finite state transducers
N2 - This paper describes the key aspects of the system SynCoP (Syntactic Constraint Parser) developed at the Berlin-Brandenburgische Akademie der Wissenschaften. The parser allows to combine syntactic tagging and chunking by means of constraint grammar using weighted finite state transducers (WFST). Chunks are interpreted as local dependency structures within syntactic tagging. The linguistic theories are formulated by criteria which are formalized by a semiring; these criteria allow structural preferences and gradual grammaticality. The parser is essentially a cascade of WFSTs. To find the most likely syntactic readings a best-path search is used.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27172
ER -
TY - CHAP
A1 - Zarrieß, Sina
A1 - Seeker, Wolfgang
T1 - Finite-state rule deduction for parsing non-constituent coordination
N2 - In this paper, we present a finite-state approach to constituency and therewith an analysis of coordination phenomena involving so-called non-constituents. We show that non-constituents can be seen as parts of fully-fledged constituents and therefore be coordinated in the same way. We have implemented an algorithm based on finite state automata that generates an LFG grammar assigning valid analyses to non-constituent coordination structures in the German language.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27254
ER -
TY - CHAP
A1 - González, Jorge
A1 - Casacuberta, Francisco
T1 - Phrase-based finite state models
N2 - In the last years, statistical machine translation has already demonstrated its usefulness within a wide variety of translation applications. In this line, phrase-based alignment models have become the reference to follow in order to build competitive systems. Finite state models are always an interesting framework because there are well-known efficient algorithms for their representation and manipulation. This document is a contribution to the evolution of finite state models towards a phrase-based approach. The inference of stochastic transducers that are based on bilingual phrases is carefully analysed from a finite state point of view. Indeed, the algorithmic phenomena that have to be taken into account in order to deal with such phrase-based finite state models when in decoding time are also in-depth detailed.
Y1 - 2008
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-27209
ER -
TY - CHAP
A1 - Herre, Heinrich
A1 - Hummel, Axel
T1 - Stationary generated models of generalized logic programs
N2 - The interest in extensions of the logic programming paradigm beyond the class of normal logic programs is motivated by the need of an adequate representation and processing of knowledge. One of the most difficult problems in this area is to find an adequate declarative semantics for logic programs. In the present paper a general preference criterion is proposed that selects the ‘intended’ partial models of generalized logic programs which is a conservative extension of the stationary semantics for normal logic programs of [Prz91]. The presented preference criterion defines a partial model of a generalized logic program as intended if it is generated by a stationary chain. It turns out that the stationary generated models coincide with the stationary models on the class of normal logic programs. The general wellfounded semantics of such a program is defined as the set-theoretical intersection of its stationary generated models. For normal logic programs the general wellfounded semantics equals the wellfounded semantics.
KW - extensions of logic programs
KW - semantics
KW - knowledge representation
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41501
ER -
TY - CHAP
A1 - Abdennadher, Slim
A1 - Ismail, Haythem
A1 - Khoury, Frederick
T1 - Transforming imperative algorithms to constraint handling rules
N2 - Different properties of programs, implemented in Constraint Handling Rules (CHR), have already been investigated. Proving these properties in CHR is fairly simpler than proving them in any type of imperative programming language, which triggered the proposal of a methodology to map imperative programs into equivalent CHR. The equivalence of both programs implies that if a property is satisfied for one, then it is satisfied for the other. The mapping methodology could be put to other beneficial uses. One such use is the automatic generation of global constraints, at an attempt to demonstrate the benefits of having a rule-based implementation for constraint solvers.
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41533
ER -
TY - CHAP
A1 - Betz, Hariolf
A1 - Raiser, Frank
A1 - Frühwirth, Thom
T1 - Persistent constraints in constraint handling rules
N2 - In the most abstract definition of its operational semantics, the declarative and concurrent programming language CHR is trivially non-terminating for a significant class of programs. Common refinements of this definition, in closing the gap to real-world implementations, compromise on declarativity and/or concurrency. Building on recent work and the notion of persistent constraints, we introduce an operational semantics avoiding trivial non-termination without compromising on its essential features.
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41547
ER -
TY - CHAP
A1 - Gebser, Martin
A1 - Hinrichs, Henrik
A1 - Schaub, Torsten H.
A1 - Thiele, Sven
T1 - xpanda: a (simple) preprocessor for adding multi-valued propositions to ASP
N2 - We introduce a simple approach extending the input language of Answer Set Programming (ASP) systems by multi-valued propositions. Our approach is implemented as a (prototypical) preprocessor translating logic programs with multi-valued propositions into logic programs with Boolean propositions only. Our translation is modular and heavily benefits from the expressive input language of ASP. The resulting approach, along with its implementation, allows for solving interesting constraint satisfaction problems in ASP, showing a good performance.
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41466
ER -
TY - CHAP
A1 - Oetsch, Johannes
A1 - Schwengerer, Martin
A1 - Tompits, Hans
T1 - Kato: a plagiarism-detection tool for answer-set programs
N2 - We present the tool Kato which is, to the best of our knowledge, the first tool for plagiarism detection that is directly tailored for answer-set programming (ASP). Kato aims at finding similarities between (segments of) logic programs to help detecting cases of plagiarism. Currently, the tool is realised for DLV programs but it is designed to handle various logic-programming syntax versions. We review basic features and the underlying methodology of the tool.
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41485
ER -
TY - CHAP
A1 - Zhou, Neng-Fa
T1 - What I have learned from all these solver competitions
N2 - In this talk, I would like to share my experiences gained from participating in four CSP solver competitions and the second ASP solver competition. In particular, I’ll talk about how various programming techniques can make huge differences in solving some of the benchmark problems used in the competitions. These techniques include global constraints, table constraints, and problem-specific propagators and labeling strategies for selecting variables and values. I’ll present these techniques with experimental results from B-Prolog and other CLP(FD) systems.
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41431
ER -
TY - CHAP
A1 - Hanus, Michael
A1 - Koschnicke, Sven
T1 - An ER-based framework for declarative web programming
N2 - We describe a framework to support the implementation of web-based systems to manipulate data stored in relational databases. Since the conceptual model of a relational database is often specified as an entity-relationship (ER) model, we propose to use the ER model to generate a complete implementation in the declarative programming language Curry. This implementation contains operations to create and manipulate entities of the data model, supports authentication, authorization, session handling, and the composition of individual operations to user processes. Furthermore and most important, the implementation ensures the consistency of the database w.r.t. the data dependencies specified in the ER model, i.e., updates initiated by the user cannot lead to an inconsistent state of the database. In order to generate a high-level declarative implementation that can be easily adapted to individual customer requirements, the framework exploits previous works on declarative database programming and web user interface construction in Curry.
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41447
ER -
TY - CHAP
A1 - Puls, Joachim
T1 - Discussion : X-rays
N2 - Clumping in hot-star winds : proceedings of an international workshop held in Potsdam, Germany, 18. - 22. June 2007
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18000
ER -
TY - CHAP
A1 - Szeifert, T.
T1 - Wind variabilities and asymmetries in Luminous Blue Variables
N2 - Luminous Blue Variables show strong changes in their stellar wind on time scales of typically years to decades when they expand and contract radially at approximately constant luminosity. Micro-variability on shorter time scales and amplitudes can be observed superimposed to the larger scale radial changes. I will show long-term time series of high resolution spectra which we have collected in the past 20 years for many of the well known LBVs together with a few time series of weekly sampling (HR Car, R40, R71, R110, R127, S Dor) covering a time windows of up to a few months. Wind variability is seen on short and intermediate time scales with the line profiles changing from P Cygni to inverse P Cygni and double peeked profiles sometimes for the same star and spectral line. On longer time scales the ionisation levels for all chemical elements change drastically due to the strong change of the temperature on the stellar surface. While on the long term the characteristic radial changes may have impact on the over all mass loss rates, the variabilities and asymmetries on short and intermediate time scales may cause false estimates of the mass loss rates when confronting models with the observed line profiles
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18146
ER -
TY - CHAP
A1 - Moffat, Anthony F. J.
T1 - Observational overview of clumping in hot stellar winds
N2 - In the old days (pre ∼1990) hot stellar winds were assumed to be smooth, which made life fairly easy and bothered no one. Then after suspicious behaviour had been revealed, e.g. stochastic temporal variability in broadband polarimetry of single hot stars, it took the emerging CCD technology developed in the preceding decades (∼1970-80’s) to reveal that these winds were far from smooth. It was mainly high-S/N, time-dependent spectroscopy of strong optical recombination emission lines in WR, and also a few OB and other stars with strong hot winds, that indicated all hot stellar winds likely to be pervaded by thousands of multiscale (compressible supersonic turbulent?) structures, whose driver is probably some kind of radiative instability. Quantitative estimates of clumping-independent mass-loss rates came from various fronts, mainly dependent directly on density (e.g. electron-scattering wings of emission lines, UV spectroscopy of weak resonance lines, and binary-star properties including orbital-period changes, electron-scattering, and X-ray fluxes from colliding winds) rather than the more common, easier-to-obtain but clumping-dependent density-squared diagnostics (e.g. free-free emission in the IR/radio and recombination lines, of which the favourite has always been Hα). Many big questions still remain, such as: What do the clumps really look like? Do clumping properties change as one recedes from the mother star? Is clumping universal? Does the relative clumping correction depend on $\dot{M}$ itself?
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17633
ER -
TY - CHAP
A1 - Puls, Joachim
A1 - Markova, N.
A1 - Najarro, F.
A1 - Hanson, M. M.
T1 - Clumping in O-star winds
N2 - We review various diagnostics of clumping in O-star winds, with special emphasis on its radial stratification. Implications and problems are discussed, and promising NIR methods are presented.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17683
ER -
TY - CHAP
A1 - St-Louis, N.
A1 - Moffat, Anthony F. J.
T1 - Do clumping corrections increase with decreasing mass-loss rates?
N2 - We report on new mass-loss rate estimates for O stars in six massive binaries using the amplitude of orbital-phase dependent, linear-polarimetric variability caused by electron scattering off free electrons in the winds. Our estimated mass-loss rates for luminous O stars are independent of clumping. They suggest similar clumping corrections as for WR stars and do not support the recently proposed reduction in mass-loss rates of O stars by one or two orders of magnitude.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17696
ER -
TY - CHAP
A1 - Smith, Nathan
T1 - Independent signs of lower mass-loss rates for O-type stars
N2 - I discuss observational evidence – independent of the direct spectral diagnostics of stellar winds themselves – suggesting that mass-loss rates for O stars need to be revised downward by roughly a factor of three or more, in line with recent observed mass-loss rates for clumped winds. These independent constraints include the large observed mass-loss rates in LBV eruptions, the large masses of evolved massive stars like LBVs and WNH stars, WR stars in lower metallicity environments, observed rotation rates of massive stars at different metallicity, supernovae that seem to defy expectations of high mass-loss rates in stellar evolution, and other clues. I pay particular attention to the role of feedback that would result from higher mass-loss rates, driving the star to the Eddington limit too soon, and therefore making higher rates appear highly implausible. Some of these arguments by themselves may have more than one interpretation, but together they paint a consistent picture that steady line-driven winds of O-type stars have lower mass-loss rates and are significantly clumped.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17659
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TY - CHAP
A1 - Votruba, V.
A1 - Feldmeier, Achim
A1 - Kubát, Jiří
A1 - Rätzel, D.
T1 - Multicomponent stellar wind of hot stars
N2 - We developed a time-dependent multicomponent hydrodynamical code for simulation of the stellar wind from hot stars and applied it to stars with high and low density winds.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17677
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TY - CHAP
A1 - Lobel, A.
T1 - Modeling DACs in UV lines of massive hot stars
N2 - We apply the 3-dimensional radiative transport codeWind3D to 3D hydrodynamic models of Corotating Interaction Regions to fit the detailed variability of Discrete Absorption Components observed in Si iv UV resonance lines of HD 64760 (B0.5 Ib). We discuss important effects of the hydrodynamic input parameters on these large-scale equatorial wind structures that determine the detailed morphology of the DACs computed with 3D transfer. The best fit model reveals that the CIR in HD 64760 is produced by a source at the base of the wind that lags behind the stellar surface rotation. The non-corotating coherent wind structure is an extended density wave produced by a local increase of only 0.6% in the smooth symmetric wind mass-loss rate.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17856
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TY - CHAP
A1 - Prinja, R. K.
A1 - Hodges, S. E.
A1 - Massa, D. L.
A1 - Fullerton, A. W.
A1 - Burnley, A. W.
T1 - Structure in the fast wind of NGC6543
N2 - We exploit time-series $FUSE$ spectroscopy to {\it uniquely} probe spatial structure and clumping in the fast wind of the central star of the H-rich planetary nebula NGC~6543 (HD~164963). Episodic and recurrent optical depth enhancements are discovered in the P{\sc v} absorption troughs, with some evidence for a $\sim$ 0.17-day modulation time-scale. The characteristics of these features are essentially identical to the discrete absorption components' (DACs) commonly seen in the UV lines of massive OB stars, suggesting the temporal structures seen in NGC~6543 likely have a physical origin that is similar to that operating in massive, luminous stars. The mechanism for forming coherent perturbations in the outflows is therefore apparently operating equally in the radiation-pressure-driven winds of widely differing momenta ($\mdot$$v_\infty$$R_\star^{0.5}$) and flow times, as represented by OB stars and CSPN.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17788
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TY - CHAP
A1 - Marchenko, S. V.
T1 - Wind inhomogeneities in low-Z environment : observations
N2 - We discuss the results of time-resolved spectroscopy of three presumably single Population I Wolf-Rayet stars in the Small Magellanic Cloud, where the ambient metallicity is $\sim 1/5 Z_\odot$. We were able to detect and follow numerous small-scale wind-embedded inhomogeneities in all observed stars. The general properties of the moving features, such as their velocity dispersions, emissivities and average accelerations, closely match the corresponding characteristics of small-scale inhomogeneities in the winds of Galactic Wolf-Rayet stars.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17769
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TY - CHAP
A1 - Najarro, F.
A1 - Puls, Joachim
A1 - Herrero, A.
A1 - Hanson, M. M.
A1 - Martín-Pintado, J.
A1 - Hillier, D. J.
T1 - Tracking the Clumping in OB Stars from UV to radio
N2 - We review different line and continua diagnostics from the UV to radio, which can be utilized to simultaneously constrain the clumping structure throughout the stellar wind of massive OB stars.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17701
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TY - CHAP
A1 - Massa, D. L.
T1 - Discussion: Spectroscopy and Mass-Loss Diagnostics
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17821
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TY - CHAP
A1 - Liermann, A.
A1 - Hamann, Wolf-Rainer
T1 - Clumping in Galactic WN stars : a comparison of mass loss rates from UV/optical & radio diagnostics
N2 - The mass loss rates and other parameters for a large sample of Galactic WN stars have been revised by Hamann et al. (2006), using the most up-to date Potsdam Wolf-Rayet (PoWR) model atmospheres. For a sub-sample of these stars exist measurements of their radio free-free emission. After harmonizing the adopted distance and terminal wind velocities, we compare the mass loss rates obtained from the two diagnostics. The differences are discussed as a possible consequence of different clumping contrast in the line-forming and radio-emitting regions.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17816
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TY - CHAP
A1 - Raassen, A. J. J.
A1 - Hucht, K. A. van der
A1 - Miller, N. A.
A1 - Cassinelli, Joseph P.
T1 - XMM-Newton observations of zeta Orionis (O9.7 Ib) : a collisional ionization equilibrium model
N2 - We present the analysis of XMM-Newton observations of ζ Orionis. The analysis is based on fitting to the total spectrum as well as diagnostics of individual line.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17747
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TY - CHAP
A1 - Ignace, R.
A1 - Gayley, K. G.
T1 - Circumstellar Magnetic Field Diagnostics from Line Polarization
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18066
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TY - CHAP
A1 - Walter, R.
A1 - Zurita-Heras, J.
A1 - Leyder, J.-C.
T1 - Probing clumpy stellar winds with a neutron star
N2 - INTEGRAL tripled the number of super-giant high-mass X-ray binaries (sgHMXB) known in the Galaxy by revealing absorbed and fast transient (SFXT) systems. Quantitative constraints on the wind clumping of massive stars can be obtained from the study of the hard X-ray variability of SFXT. A large fraction of the hard X-ray emission is emitted in the form of flares with a typical duration of 3 ksec, frequency of 7 days and luminosity of $10^{36}$ erg/s. Such flares are most probably emitted by the interaction of a compact object orbiting at $\sim10~R_*$ with wind clumps ($10^{22 ... 23}$ g) representing a large fraction of the stellar mass-loss rate. The density ratio between the clumps and the inter-clump medium is $10^{2 ... 4}$. The parameters of the clumps and of the inter-clump medium, derived from the SFXT flaring behavior, are in good agreement with macro-clumping scenario and line-driven instability simulations. SFXT are likely to have larger orbital radius than classical sgHMXB.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18024
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TY - CHAP
A1 - Cassinelli, Joseph P.
A1 - Ignace, R.
A1 - Waldron, W.
A1 - Cho, J.
A1 - Murphy, N.
A1 - Lazarian, A.
T1 - X-ray line emission produced in clump bow shocks
N2 - We summarize Chandra observations of the emission line profiles from 17 OB stars. The lines tend to be broad and unshifted. The forbidden/intercombination line ratios arising from Helium-like ions provide radial distance information for the X-ray emission sources, while the H-like to He-like line ratios provide X-ray temperatures, and thus also source temperature versus radius distributions. OB stars usually show power law differential emission measure distributions versus temperature. In models of bow shocks, we find a power law differential emission measure, a wide range of ion stages, and the bow shock flow around the clumps provides transverse velocities comparable to HWHM values. We find that the bow shock results for the line profile properties, consistent with the observations of X-ray line emission for a broad range of OB star properties.
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18057
ER -