933 research outputs found
A Comparative Evaluation of a New Unsupervised Sentence Boundary Detection Approach on Documents in English and Portuguese
Get PDFIn this paper, we describe a new unsupervised sentence boundary detection system and present a comparative study evaluating its performance against dierent systems found in the literature that have been used to perform the task of automatic text segmentation into sentences for English and Portuguese documents. The results achieved by this new approach were as good as those of the previous systems, especially considering that the method does not require any additional training resources
Kreative Problemlösungsprozesse in Kleingruppen
No full textSchiepek G, Küppers G, Mittelmann K, Strunk G. Kreative Problemlösungsprozesse in Kleingruppen. In: Langthaler W, Schiepek G, eds. Selbstorganisation und Dynamik in Gruppen. Münster: LIT-Verlag; 1995: 236-255
Der naturwissenschaftliche Sachunterricht in Lehrplänen, Unterrichtsmaterialien und Schulpraxis - Eine quantitative Analyse der Entwicklung in den letzten 25 Jahren
Get PDFStrunk U, Lück G, Demuth R. Der naturwissenschaftliche Sachunterricht in Lehrplänen, Unterrichtsmaterialien und Schulpraxis - Eine quantitative Analyse der Entwicklung in den letzten 25 Jahren. Zeitschrift für Didaktik der Naturwissenschaften : ZfDN ; Biologie, Chemie, Physik. 1998;4(1):69-80
The energy-critical nonlinear Schrodinger equation on a product of spheres
No full textHerr S, Strunk N. The energy-critical nonlinear Schrodinger equation on a product of spheres. Mathematical Research Letters. 2015;22(3):741-761.Let (M, g) be a compact smooth 3-dimensional Riemannian manifold without boundary. It is proved that the energy-critical nonlinear Schrodinger equation is globally well-posed for small initial data in H-1(M), provided that a certain tri-linear estimate for free solutions holds true. This estimate is known to hold true on the sphere and tori in 3d and verified here in the case S x S-2. The necessity of a weak form of this tri-linear estimate is also discussed
Recommended from our members
Trial of Prof. Ira G. Strunk, in the Floyd Circuit Court, for killing Charles V. Hoover at New Albany, Indiana, July 27, 1886.
No full textRecommended from our members
Trial of Prof. Ira G. Strunk, in the Floyd Circuit Court, for killing Charles V. Hoover at New Albany, Indiana, July 27, 1886.
No full text
Investigation of carbon nanotube quantum dots connected to ferromagnetic leads
Get PDFThe implementation of ferromagnetic contacts in complex nanoelectronic devices,
e.g. in spin-valves bears great potential for applications and fundamental
investigations. Spin-valves are structures with two magnetic contacts and
a non-magnetic medium (M) in-between, where a step-like change in magnetoresistance
(MR) is observed when the relative orientation of the strip magnetization
is changed by an external magnetic field. There is already a very
successful use of the electron spin in electronic devices for magnetic field sensing
for example in read-and-write heads of computer hard discs. Another upcoming
application of spin valves are for example non-volatile random-access
memories (MRAMs) for data storage.
However, electronic devices which use the electron spin directly, like in a spintransistor
or as quantum bits requires materials for the non-magnetic
medium exhibiting long coherence times and electrical tunability. Carbon
based materials like graphene or carbon nanotubes are due to their intrinsic
large coherence times in principle ideal candidates for spintronic devices, as
demonstrated in nonlocal spin-accumulation experiments on graphene or in
electrically tunable spin valves on carbon nanotubes.
Especially the observation of a gate dependent magneto-resistance in carbon
nanotube quantum dots contacted with ferromagnetic leads in 2005 by S. Sahoo
promises an electrical control over spin transport. These devices analog
to field-effect transistors might pave the way for multi-functional spintronic
devices. However, the implementation of ferromagnetic contacts in nanoelectronic
devices has been a proven challenging task due to the complex nature
of ferromagnets and interfaces, where oxidation, surface roughness and mesoscopic
details may induce uncontrolled instabilities in transport measurements.
Spintransport experiments on carbon nanotube quantum dots suffer mainly
from irreproducibilities in the magneto resistance and from the low yield of
electrical contacts to the nanotube. Therefore in this thesis carbon nanotube
quantum dots connected to ferromagnetic leads are investigated, focusing on
the fabrication of stable devices with higher contact yields and first experiments
on stable devices. This allows for further investigations of the not well
understood gate dependence of the magneto resistance in such devices. Moreover
with such stable devices, even more complex experiments or applications like detectors
for spin entanglement can become possible
Obstetric litigation is asphyxiating our maternity services
No full textCopyright © 2006 The American College of Obstetricians and GynecologistsObstetric care in the United States, as judged by maternal mortality, neonatal mortality, stillbirth rates, or any other metric, has never been better. Despite this, litigation over "bad outcomes" is threatening the specialty, not only now, but into the future. Despite damage to our specialty, the injured party often benefits little, if at all, from the process. Potential solutions include an emphasis on evidence-based medicine, a qualification and review process for medical experts, and a more rational and fair health court system.Hankins, Gary D. V.; MacLennan, Alastair H.; Speer, Michael E.; Strunk, Albert JD; Nelson, Kari
Der Scherbenhügel in der Siegburger Aulgasse /
No full textBd. 1. Die Formen der Keramik von ihren Anfängen bis zum Beginn der sogenannten Blütezeit (Perioden 1 bis 4) / mit Beiträgen von H. Heide und G. Strunk-Lichtenberg
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