265 research outputs found
The contact process in heterogeneous and weakly-disordered systems
The critical behavior of the contact process (CP) in heterogeneous periodic
and weakly-disordered environments is investigated using the supercritical
series expansion and Monte Carlo (MC) simulations. Phase-separation lines and
critical exponents (from series expansion) and (from MC
simulations) are calculated. A general analytical expression for the locus of
critical points is suggested for the weak-disorder limit and confirmed by the
series expansion analysis and the MC simulations. Our results for the critical
exponents show that the CP in heterogeneous environments remains in the
directed percolation (DP) universality class, while for environments with
quenched disorder, the data are compatible with the scenario of continuously
changing critical exponents.Comment: 5 pages, 3 figure
Joint Freshman Recital: Caitlin Fallert, Alto Saxophone; Chloe West, Alto Saxophone; Lu Witzig, Piano; March 8, 2024
Kemp Recital HallMarch 8, 2024Friday Evening6:00 p.m
IMPACT OF DAIRY PRODUCT IMPORTS ON U.S. MILK PRICE
Demand and Price Analysis, International Relations/Trade, Livestock Production/Industries,
Multilinguale Herausforderungen in der SacherschlieĂung
In einer Zeit, in der vermehrt automatische Verfahren der InhaltserschlieĂung eingesetzt und (weiter)entwickelt werden, leistet die vorliegende Studie einen Beitrag zur Diskussion um die Bedeutung der intellektuellen SacherschlieĂung beim Information Retrieval in einem multilingualen Kontext. Am Fallbeispiel des Online-Katalogs des Ibero-Amerikanischen Instituts wird in einem Retrievaltest die Beteiligung der uÌberwiegend deutschsprachigen Schlagworte aus einem lokalen Thesaurus beim Auffinden von Dokumenten evaluiert. In der Studie werden 80 aus einem Logfile gewonnene Suchanfragen getestet, die in zwei gleich groĂe Purpose Samples unterteilt wurden: ein deutsch- und ein fremdsprachiges. Ein zentrales Ergebnis der Analyse ist, dass die Indexierung mit lokalen Schlagworten fuÌr einen erheblichen Anteil der zu den Suchanfragen aufgefundenen Dokumenten verantwortlich ist. Es lassen sich jedoch unter BeruÌcksichtigung der MultilingualitĂ€t der Suchanfragen deutliche Unterschiede mit Blick auf die Bedeutung der lokalen Schlagworte ausmachen. Auch das VerhĂ€ltnis der intellektuellen SacherschlieĂung zur automatischen Indexierung von Elementen der Kataloganreicherung (Inhaltsverzeichnisse, Volltexte o.Ă.) wird nĂ€her beleuchtet und StĂ€rken und SchwĂ€chen der verschiedenen ErschlieĂungsformen werden diskutiert. AbschlieĂend werden Möglichkeiten aufgezeigt, das Potential der lokalen Schlagworte insbesondere fuÌr fremdsprachige Suchanfragen stĂ€rker einzusetzen, um die zeit- und damit kostenintensive intellektuelle SacherschlieĂung sinnvoll nachzunutzen
The contact process in disordered and periodic binary two-dimensional lattices
The critical behavior of the contact process in disordered and periodic
binary 2d-lattices is investigated numerically by means of Monte Carlo
simulations as well as via an analytical approximation and standard mean field
theory. Phase-separation lines calculated numerically are found to agree well
with analytical predictions around the homogeneous point. For the disordered
case, values of static scaling exponents obtained via quasi-stationary
simulations are found to change with disorder strength. In particular, the
finite-size scaling exponent of the density of infected sites approaches a
value consistent with the existence of an infinite-randomness fixed point as
conjectured before for the 2d disordered CP. At the same time, both dynamical
and static scaling exponents are found to coincide with the values established
for the homogeneous case thus confirming that the contact process in a
heterogeneous environment belongs to the directed percolation universality
class.Comment: submitted to Physical Review
User-Centered Engineering of an Interactive Land Use Exploration Tool
In this paper we showcase a system for visualizing and predicting land-use data. The time series-based visualization application strives to improve science communication by facilitating the understanding of land-use change and is backed up by a machine learning-based land-use prediction application that imputes historic data and generates predictions of land use in the future. To present the project, we discuss the system's requirements which were developed by means of a User-Centered Engineering approach, elaborate on its current, early state of development and the corresponding results and finally discuss areas of potential improvement
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