4,706 research outputs found
The complex of formal operations on the Hochschild chains of commutative algebras
We compute the homology of the complex of formal operations on the Hochschild
complex of differential graded commutative algebras as defined by Wahl and
prove that these can be built as infinite sums of operations obtained from
Loday's shuffle operations, Connes' boundary operator and the shuffle product.Comment: 19 page
Planning Hybrid Driving-Stepping Locomotion on Multiple Levels of Abstraction
Navigating in search and rescue environments is challenging, since a variety
of terrains has to be considered. Hybrid driving-stepping locomotion, as
provided by our robot Momaro, is a promising approach. Similar to other
locomotion methods, it incorporates many degrees of freedom---offering high
flexibility but making planning computationally expensive for larger
environments.
We propose a navigation planning method, which unifies different levels of
representation in a single planner. In the vicinity of the robot, it provides
plans with a fine resolution and a high robot state dimensionality. With
increasing distance from the robot, plans become coarser and the robot state
dimensionality decreases. We compensate this loss of information by enriching
coarser representations with additional semantics. Experiments show that the
proposed planner provides plans for large, challenging scenarios in feasible
time.Comment: In Proceedings of IEEE International Conference on Robotics and
Automation (ICRA), Brisbane, Australia, May 201
Value Iteration Networks on Multiple Levels of Abstraction
Learning-based methods are promising to plan robot motion without performing
extensive search, which is needed by many non-learning approaches. Recently,
Value Iteration Networks (VINs) received much interest since---in contrast to
standard CNN-based architectures---they learn goal-directed behaviors which
generalize well to unseen domains. However, VINs are restricted to small and
low-dimensional domains, limiting their applicability to real-world planning
problems.
To address this issue, we propose to extend VINs to representations with
multiple levels of abstraction. While the vicinity of the robot is represented
in sufficient detail, the representation gets spatially coarser with increasing
distance from the robot. The information loss caused by the decreasing
resolution is compensated by increasing the number of features representing a
cell. We show that our approach is capable of solving significantly larger 2D
grid world planning tasks than the original VIN implementation. In contrast to
a multiresolution coarse-to-fine VIN implementation which does not employ
additional descriptive features, our approach is capable of solving challenging
environments, which demonstrates that the proposed method learns to encode
useful information in the additional features. As an application for solving
real-world planning tasks, we successfully employ our method to plan
omnidirectional driving for a search-and-rescue robot in cluttered terrain
COSMO-RS: The currently most predictive model for free energies of molecules in solution and its extension to inhomogeneous and self-organizing systems
Dr. Klamt founded Cosmologic in 1999 as a new company to commercialize computational methods that he developed while working in the research labs of Bayer AG. He, his company, and other researchers (such as Prof Stan Sandler of Delaware and Prof Steve Lustig of Northeastern, who spoke at URI in fall 2017) have continued to advance these methods further for predicting the thermodynamic properties of liquids and liquid mixtures
Assoziation zwischen Allergien vom Soforttyp und Diabetes mellitus Typ 1 bei Kindern und Jugendlichen
Diabetes mellitus Typ 1 und Allergien vom Soforttyp gehören zu den häufigsten chronischen Erkrankungen des Kindes- und Jugendalters. Diabetes mellitus Typ 1 wird verursacht durch eine autoimmune Zerstörung der Beta-Zellen des Pankreas. Aus immunologischer Sicht wird dieser Prozess durch TH1-Zellen dominiert. Im Gegensatz dazu wird vermutet, dass Allergien vom Soforttyp, wie die allergische Rhinitis, das allergische Asthma und die allergische Urtikaria mit TH2-Zellen assoziiert seien. Die Hypothese, dass TH1- und TH2-Zellen sich gegenseitig in ihrer Aktivität hemmen, ist immer noch gültig. Ziel unserer Fall-Kontroll-Studie war es, die Assoziation zwischen Typ 1 Diabetes und IgE-vermittelten Allergien zu untersuchen. Zur Prüfung unserer Forschungshypothese wurden ein standardisierter, evaluierter Fragebogen sowie verschiedene Laboranalysen herangezogen. Es konnte gezeigt werden, dass Diabetes mellitus Typ 1 mit einem erhöhten Risiko für das gleichzeitige anamnestische Vorliegen IgE-vermittelter allergischer Symptome assoziiert sein könnte. Somit konnten wir bestätigen, dass die noch heute weit verbreitete TH1/TH2-Hypothese eine Vereinfachung tatsächlich viel komplizierterer immunologischer Vorgänge darstellt. Um diese Assoziation im Detail zu prüfen, bedarf es jedoch weiteren populationsbasierten epidemiologischen Studien.:I. Bibliographische Beschreibung 7
II. Abkürzungsverzeichnis 9
1. Einführung 11
1.1 Epidemiologie und Pathogenese des Diabetes mellitus Typ 1 11
1.2 Epidemiologie und Pathogenese von Allergien vom Soforttyp 13
1.3 Aktueller Forschungsstand zum Thema 14
2. Das Promotionsprojekt 17
2.1 Forschungshypothese und Fragestellung 17
2.2 Patienten und Methoden 17
2.3 Statistische Datenauswertung 19
2.4 Ergebnisse 20
2.5 Einordnung in den aktuellen wissenschaftlichen Diskurs 23
3. Publikationsmanuskript 29
4. Zusammenfassung der Arbeit 43
5. Literaturverzeichnis 47
III. Erklärung über die eigenständige Abfassung der Arbeit 55
IV. Curriculum Vitae 57
V. Liste der Veröffentlichungen 59
VI. Danksagung 6
Computing knock out strategies in metabolic networks
Given a metabolic network in terms of its metabolites and reactions, our goal
is to efficiently compute the minimal knock out sets of reactions required to
block a given behaviour. We describe an algorithm which improves the
computation of these knock out sets when the elementary modes (minimal
functional subsystems) of the network are given. We also describe an algorithm
which computes both the knock out sets and the elementary modes containing the
blocked reactions directly from the description of the network and whose
worst-case computational complexity is better than the algorithms currently in
use for these problems. Computational results are included.Comment: 12 page
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