cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Three-point correlators: Examples from Lunin-Maldacena background
Creators: name: Arnaudov, D.
name: Rashkov, R. C.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Recently there has been progress on the calculation of three-point functions with two "heavy" operators via semiclassical methods. We extend this analysis to the case of the Lunin-Maldacena background, and examine the suggested procedure for several simple string solutions. By making use of AdS/CFT duality, we derive the relevant correlation functions of operators belonging to the dual N=1 superconformal gauge theory, and recover an important relation connecting the dimensions of "heavy" states and the structure constants.
description: 11 pages, no figures, incorrect subsection removed, typos fixed, references added and updated
Architectural Design Decision Documentation through Reuse of Design Patterns
Creators: name: Durdik, Zoya
Publisher: name: Karlsruhe
Year: 2014
Subjects: software architecture
design patterns
design decisions
design decision documentation
design rationale
architectural knowledge reuse

description: While design decisions on the application of architectural design patterns involve complex trade-offs between functionality and quality properties, such decisions are often spontaneous, and documentation of decisions and trace links to related artefacts is usually insufficient. The approach proposed in this thesis provides a support to overcome these problems. It combines support for evaluation of design pattern application, and semi-automated documentation of decisions and trace links.
Localization of correlated fermions in optical lattices with speckle disorder
Creators: name: Semmler, D.
name: Wernsdorfer, J.
name: Bissbort, U.
name: Byczuk, K.
name: Hofstetter, W.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Strongly correlated fermions in three- and two-dimensional optical lattices with experimentally realistic speckle disorder are investigated. We extend and apply the statistical dynamical mean-field theory, which treats local correlations non-perturbatively, to incorporate on-site and hopping-type randomness on equal footing. Localization due to disorder is detected via the probability distribution function of the local density of states. We obtain a complete paramagnetic ground state phase diagram for experimentally realistic parameters and find a strong suppression of the correlation-induced metal insulator transition due to disorder. Our results indicate that the Anderson-Mott and the Mott insulator are not continuously connected due to the specific character of speckle disorder. Furthermore, we discuss the effect of finite temperature on the single-particle spectral function.
description: 12 pages, 16 figures, published version
Magnetically Enhanced Centrifugation for Industrial Use
Creators: name: Lindner, Johannes
name: Keller, Karsten
name: Grim, Gunnar
name: Feller, Johannes
name: Nielsen, Christian Fiil
name: Dalgaard, Niels
name: Menzel, Katharina
name: Nirschl, Hermann
Publisher: name: Karlsruhe
Year: 2014

description: Magnetically enhanced centrifugation is a new approach in high-gradient magnetic separation possible in continuous mode, which promises a large potential for industrial use. Magnetic particles are separated to a wire filter, from which they are cleaned by centrifugal forces to the chamber wall. The simulation of magnetic particles collected by a wire were possible by the discrete element method. The simulation shows the detachment of particles from the wires by the centrifugal force. Two prototype machines were set up to investigate the process. The discharge of particles from the wire filter depends on the magnetic field strength and the centrifugal velocity. It was possible to set up a machine reaching a separation efficiency of 99 % at a volume flow of 1 m3/h (excluding dead times) in a batch-wise mode. A second machine built as magnetically enhanced decanter separates particles and transports them out of the bowl by a screw conveyor in a completely continuous mode. Instead of the common electromagnets a permanent magnet assembly can be combined with a magnetically enhanced centrifuge to save costs.
Design and Performance of a Pilot Scale High-Gradient Magnetic Filter Using a Mandhala Magnet and Its Application for Soy-Whey Protein Purification
Creators: name: Menzel, Katharina
name: Amasifuen, Victor Alvan
name: Nirschl, Hermann
Publisher: name: Karlsruhe
Year: 2014

description: The scalability of economic high-gradient magnetic separation (HGMS) technology is essential in order to demonstrate the feasibility of the concept. One of the means is the application of a permanent magnet with a hollow cylindrical volume made from identical magnetic blocks (e.g., Mandhala), another is the development of a High-Gradient Magnetic Filter (HGMF) with a new backwashing concept. The Mandhala (Magnetic Arrangement for Novel Discrete Halbach Layout) magnet produces a dipolar transversal magnetic field in the center of the bore and its usable volume is easily adaptable to the separation device's extensions. The chapter presents the pilot scale design of the Mandhala magnet and the HGMF as well as experimental performance tests using a water-magnetic beads model system. Subsequently, experiments using soy-whey as a real feedstock demonstrate the purification of the protein Bowman-Birk inhibitor (BBI), an agent against cancer and multiples sclerosis.
An Industrial Approach to High Gradient Magnetic Fishing in the Food Industry
Creators: name: Nielsen, Christian Fiil
name: Keller, Karsten
name: Rasmussen, Susanne
name: Dalgaard, Niels
name: Hobley, Timothy John
name: Sondergaard, Wickie
name: Nirschl, Hermann
name: Lindner, Johannes
Publisher: name: Karlsruhe
Year: 2014

description: High-gradient magnetic filtration bases on the separation of target media by synthetic particles with magnetic core and an adsorbent immobilized on the surface. The process was used in a pilot line at liter-scale for the separation of a protein Bowman-Birk protease Inhibitor (BBI) out of an industrial coproduct stream in the soy industry. The target protein has potential applications as pharmaceutical or food additive. The starting medium is challenging as the product cost is low, its concentration is low and its purity needs to be high. The main method tested was magnetically enhanced centrifugation in a batch-wise mode with anion exchange ligands. The separation of the target protein at large scale was successful and economical. The efficiency was low due to the low ligand selectivity and the batch-wise processing. For commercialization, high ligand selectivity and continuous processing would make this new magnetic separation process very attractive. An economic study was performed to determine the influence of different parameters on prices. Competing technologies were evaluated. A risk analysis of nanoparticles used in the pilot line was performed.
Dynamical gap generation in graphene nanoribbons: An effective relativistic field theoretical model
Creators: name: Chaves, A. J.
name: Lima, G. D.
name: de Paula, W.
name: Cordeiro, C. E.
name: Delfino, A.
name: Frederico, T.
name: Oliveira, O.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We show that the assumption of a nontrivial zero band gap for a graphene sheet within an effective relativistic field theoretical model description of interacting Dirac electrons on the surface of graphene describes the experimental band gap of graphene nanoribbons for a wide range of widths. The graphene band gap is dynamically generated, corresponding to a nontrivial gapless solution, found in the limit of an infinitely wide graphene ribbon. The nanoribbon band gap is determined by the experimental graphene work function.
Dynamical bifurcation as a semiclassical counterpart of a quantum phase transition
Creators: name: Buonsante, Pierfrancesco
name: Penna, Vittorio
name: Vezzani, Alessandro
Publisher: name: arXiv
Year: 2011
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We illustrate how dynamical transitions in nonlinear semiclassical models can be recognized as phase transitions in the corresponding -- inherently linear -- quantum model, where, in a Statistical Mechanics framework, the thermodynamic limit is realized by letting the particle population go to infinity at fixed size. We focus on lattice bosons described by the Bose-Hubbard (BH) model and Discrete Self-Trapping (DST) equations at the quantum and semiclassical level, respectively. After showing that the gaussianity of the quantum ground states is broken at the phase transition, we evaluate finite populations effects introducing a suitable scaling hypothesis; we work out the exact value of the critical exponents and we provide numerical evidences confirming our hypothesis. Our analytical results rely on a general scheme obtained from a large-population expansion of the eigenvalue equation of the BH model. In this approach the DST equations resurface as solutions of the zeroth-order problem.
description: 4 pages, 3 figures; a few changes made in the layout of equations; improved visibility of some figures; added some references and endnotes
Eine Studie zur Validierung in der Produktentstehung am Beispiel der Entwicklung einer neuartigen Untersuchungsmethode für 
Quetschöldämpfer = A Study to Validation Activities in Product Development based on the Development of a new Research Method for Squeeze Film Damper
Creators: name: Jäger, Steffen
Publisher: name: Karlsruhe
Year: 2014
Subjects: Validierung
Quetschöldämpfer
Produktentstehung

description: Zur Entwicklung neuer Produkte ist es erforderlich stets angepasste Methoden und Prozessmodelle einzusetzen. In der vorliegenden Arbeit wird eine Untersuchungsmethode entwickelt und zur Verfügung gestellt. Hierbei wird insbesondere der Prozess der Methodengenerierung und deren Validierung betrachtet. Der gewählte Validierungsansatz wird diskutiert. Als Beispielsystem kommt ein Quetschöldämpfer zum Einsatz, wie er in Flugzeugtriebwerken zur äußeren Lagerdämpfung eingesetzt wird.
Time-Dependent Route Planning with Contraction Hierarchies
Creators: name: Batz, Gernot Veit Eberhard
Publisher: name: Karlsruhe
Year: 2014
Subjects: algorithm engineering
earliest arrival problem
road networks
server-based route planning
time-dependent shortest path
travel time profile

description: Design and experimental evaluation of route planning algorithms for time-dependent road networks, which model regular effects like congestions. By generalizing contraction hierarchies, we achieve fast and space efficient computation of minimum travel time routes and profiles. We also consider additional constant costs (e.g., to penalize detours and motorway tolls), which makes route planning NP-hard. Then, routes become heuristic, but we get quite near to the optimum as experiments show.
Phase Transitions of Charged Scalars at Finite Temperature and Chemical Potential
Creators: name: Rosen, Rachel A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We calculate the grand canonical partition function at the one-loop level for scalar quantum electrodynamics at finite temperature and chemical potential. A classical background charge density with a charge opposite that of the scalars ensures the neutrality of the system. For low density systems we find evidence of a first order phase transition. We find upper and lower bounds on the transition temperature below which the charged scalars form a condensate. A first order phase transition may have consequences for helium-core white dwarf stars in which it has been argued that such a condensate of charged helium-4 nuclei could exist.
description: 20 pages, 3 figures. Version accepted for publication in JHEP
A Transformerless Single-Phase PV Inverter Circuit for Thin-Film or Back-Side Contacted Solar Modules
Creators: name: Gommeringer, Mario
name: Kammerer, Felix
name: Schmitt, Alexander
name: Braun, Michael
Publisher: name: Karlsruhe
Year: 2014
Subjects: Power
Electronic
Converters

description: This paper deals with a new transformerless single-phase photovoltaic inverter circuit. The circuit is well suited for thin-film or back-side contacted solar modules because one pole of the solar module can be directly connected to the neutral conductor. The circuit uses a flying capacitor for one of both half-waves, requires only five transistors and is capable of providing inductive as well as capacitive reactive power.
Vortex and gap generation in gauge models of graphene
Creators: name: Oliveira, O.
name: Cordeiro, C. E.
name: Delfino, A.
name: de Paula, W.
name: Frederico, T.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Effective quantum field theoretical continuum models for graphene are investigated. The models include a complex scalar field and a vector gauge field. Different gauge theories are considered and their gap patterns for the scalar, vector, and fermion excitations are investigated. Different gauge groups lead to different relations between the gaps, which can be used to experimentally distinguish the gauge theories. In this class of models the fermionic gap is a dynamic quantity. The finite-energy vortex solutions of the gauge models have the flux of the "magnetic field" quantized, making the Bohm-Aharonov effect active even when external electromagnetic fields are absent. The flux comes proportional to the scalar field angular momentum quantum number. The zero modes of the Dirac equation show that the gauge models considered here are compatible with fractionalization.
The Tensor Hierarchies of Pure N=2,d=4,5,6 Supergravities
Creators: name: Huebscher, Mechthild
name: Ortin, Tomas
name: Shahbazi, C. S.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the supersymmetric tensor hierarchy of pure (gauged) N=2,d=4,5,6 supergravity and compare them with those of the pure, ungauged, theories (worked out by Gomis and Roest for d=5) and the predictions of the Kac-Moody approach made by Kleinschmidt and Roest. We find complete agreement in the ungauged case but we also find that, after gauging, new Stueckelberg symmetries reduce the number of independent "physical" top-forms. The analysis has to be performed to all orders in fermion fields. We discuss the construction of the worldvolume effective actions for the p-branes which are charged with respect to the (p+1)-form potentials and the relations between the tensor hierarchies and p-branes upon dimensional reduction.
description: LaTeX2e file, 20 pages, 1 figure Results refined by extension of the analysis to all orders in fermions
title: The Effects of Self-Regulated Learning on Community College Students Metacognition, Motivation and Achievement in Geoscience Courses
Creators: name: Loney, Melani A.
Publisher: name: Old Dominion University
publisherIdentifier: https://ror.org/04zjtrb98
publisherIdentifierScheme: ROR
Year: 2023

description: This study investigated the impact of training in self-regulated learning on community college, geoscience students’ achievement, metacognition, time management, and science motivation scales. The study also investigated the impact of SRL training on these outcomes as a function of gender and ethnicity. During the Fall of 2022, 70 community college geoscience students from 9 different classes participated in the study. The classes were bifurcated with one half of the students in each class randomly assigned to the SRL treatment and the other half to the control condition. Each week, for 10 weeks during the semester, students in the treatment group utilized a component from each of the three phases of Zimmerman’s (2002) cyclical self-regulated learning model as one of their geoscience class assignments. At the beginning of the week students in the treatment group would set instructional goals and create a calendar that included class time, study time, work, and relaxation time. During the week the same students would monitor their class attendance and study practices. At the end of the week, students would reflect on whether they attained their goals set at the beginning of the week and reflect on the reasons for their success or failure. As an alternate activity students in the control group were assigned to write a brief summary of a famous geoscientist’s biography. All students’ final exam and final course grades were examined to determine the impact of SRL training on science achievement. Study participants completed a questionnaire containing metacognition, time management, and science motivation items. No significant differences were found between students in the SRL treatment and those in the control group.
Controlling the transmission line shape of molecular t-stubs and potential thermoelectric applications
Creators: name: Stadler, Robert
name: Markussen, Troels
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Asymmetric line shapes can occur in the transmission function describing electron transport in the vicinity of a minimum caused by quantum interference effects. Such asymmetry can be used to increase the thermoelectric efficiency of molecular junctions. So far, however, asymmetric line shapes have been only empirically found for just a few rather complex organic molecules where the origins of the line shapes relation to molecular structure were not resolved. In the present work we introduce a method to analyze the structure dependence of the asymmetry of interference dips from simple two site tight-binding models, where one site corresponds to a molecular $π$ orbital of the wire and the other to an atomic $p_z$ orbital of a side group, which allows us to analytically characterize the peak shape in terms of just two parameters. We assess our scheme with first-principles electron transport calculations for a variety of {\it t-stub} molecules and also address their suitability for thermoelectric applications.
description: 11 pages, 5 figures; J. Chem. Phys., in print (2011)
Instabilities in neutron stars with toroidal magnetic fields
Creators: name: Lander, S. K.
name: Jones, D. I.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We study $m=1$ oscillations and instabilities of magnetised neutron stars, by numerical time-evolution of linear perturbations of the system. The background stars are stationary equilibrium configurations with purely toroidal magnetic fields. We find that an $m=1$ instability of toroidal magnetic fields, already known from local analyses, may also be found in our relatively low-resolution global study. We present quantitative results for the instability growth rate and its suppression by rotation. The instability is discussed as a possible trigger mechanism for Soft Gamma Repeater (SGR) flares. Although our primary focus is evolutions of magnetised stars, we also consider perturbations about unmagnetised background stars in order to study $m=1$ inertial modes. We track these modes up to break-up frequency, extending known slow-rotation results.
description: 9 pages, 8 figures. Very minor changes from v1 and one reference added, to match MNRAS-accepted version
Rescaling citations of publications in physics
Creators: name: Radicchi, Filippo
name: Castellano, Claudio
Publisher: name: arXiv
Year: 2010
Subjects: subject: Digital Libraries (cs.DL)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: We analyze the citation distributions of all papers published in Physical Review journals between 1985 and 2009. The average number of citations received by papers published in a given year and in a given field is computed. Large variations are found, showing that it is not fair to compare citation numbers across fields and years. However, when a rescaling procedure by the average is used, it is possible to compare impartially articles across years and fields. We make the rescaling factors available for use by the readers. We also show that rescaling citation numbers by the number of publication authors has strong effects and should therefore be taken into account when assessing the bibliometric performance of researchers.
description: 8 pages, 10 figures, 1 table
Isothermes Kurzzeitermüdungsverhalten der hoch-warmfesten Aluminium-Knetlegierung 2618A (AlCu2Mg1,5Ni)
Creators: name: Khalil, Osama
Publisher: name: Karlsruhe
Year: 2014
Subjects: LCF
Mitteldehnungseinfluss
Temperatureinfluss
Kerbwirkung
Größeneinfluss

description: Das Radialverdichterrad wird standardmäßig aus der warmfesten Al-Legierung 2618A gefertigt. Die Arbeit soll dazu beitragen, eine verbesserte Vorgehensweise zur Lebensdauerberechnung von Al-Verdichterrädern zu entwickeln. Eine Lebensdauervorhersage kann nur auf der Basis solider Daten erfolgreich sein. Zur Schaffung einer derartigen Datenbasis wurden zahlreiche LCF-Versuche durchgeführt. Ferner wurde der Einfluss der Bauteilgröße auf das LCF- und das Schädigungsverhalten untersucht.
Electroweak Symmetry Breaking from Gauge/Gravity Duality
Creators: name: Anguelova, Lilia
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We use the gauge/gravity duality to study a model of walking technicolor. The latter is a phenomenologically promising framework for dynamical electroweak symmetry breaking. A traditional problem for technicolor models has been the need to address gauge theories at strong coupling. Recent developments in gauge/gravity duality provide a powerful tool for handling this problem. First, we revisit previously considered holographic models of QCD-like technicolor from D-branes. In particular, we develop analytical understanding of earlier numerical computations of the Peskin-Takeuchi S-parameter. Then we apply this method to the investigation of a model of walking technicolor, obtained by embedding D7 - anti-D7 probe branes in a recently discovered type IIB background dual to walking behaviour. As a necessary step, we also show that there is an embedding of the techniflavor branes, that realizes chiral symmetry breaking. Finally, we show that the divergences that appear in the S-parameter can be removed by using holographic renormalization.
description: 33 pages; minor clarification, references added, journal version
Gasspeicherbewertung: Strukturelle Analyse und Algorithmen
Creators: name: Riess, Viola Sonja Clara
Publisher: name: Karlsruhe
Year: 2014

description: Das Gasspeicheroptimierungsproblem wird als Markovsches Entscheidungsproblem in diskreter Zeit mit endlichem Horizont
modelliert. Es wird angenommen, dass die maximalen Änderungsraten vom aktuellen Speicherstand abhängen. Neben Aussagen in einigen Spezialfällen, wird die Struktur der optimalen Entscheidungsregeln vorgestellt. Diese findet Verwendung in der Entwicklung und Verbesserung von Algorithmen zur Gasspeicherbewertung, die vorgestellt und auf ein Beispiel angewendet werden.
Matters of Coercion-Resistance in Cryptographic Voting Schemes
Creators: name: Kempka, Carmen
Publisher: name: Karlsruhe
Year: 2014
Subjects: Cryptography
E-voting

description: This work addresses coercion-resistance in cryptographic voting schemes. It focuses on three particularly challenging cases: write-in candidates, internet elections and delegated voting. Furthermore, this work presents a taxonomy for analyzing and comparing a huge variety of voting schemes, and presents practical experiences with the voting scheme Bingo Voting.
πN transition distribution amplitudes: Their symmetries and constraints from chiral dynamics
Creators: name: Pire, Bernard
name: Semenov-Tian-Shansky, Kirill
name: Szymanowski, Lech
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Baryon to meson transition distribution amplitudes (TDAs) extend the concept of generalized parton distributions. Baryon to meson TDAs appear as building blocks in the collinear factorized description of amplitudes for a class of hard exclusive reactions, prominent examples of which being hard exclusive meson electroproduction off a nucleon in the backward region and baryon-antibaryon annihilation into a meson and a lepton pair. We study the general properties of these objects following from the underlying symmetries of QCD. In particular, the Lorentz symmetry results in the polynomiality property of the Mellin moments in longitudinal momentum fractions. We present a detailed account of the isotopic and permutation symmetry properties of nucleon to pion (πN) TDAs. This restricts the number of independent leading twist πN TDAs to eight functions, providing description of all isotopic channels. Using chiral symmetry and the crossing relation between πN TDAs and πN generalized distribution amplitudes we establish soft pion theorems for πN TDAs, which determine the magnitude of πN TDAs. Finally, we build a simple resonance exchange model for πN TDAs considering N and Δ(1232) exchange contributions into the isospin-1/2 and isospin-3/2 πN TDAs.
description: 42 pages, 2 figures; Corrections included to match the journal version
Thermal field methods of the shallow subsurface
Creators: name: Wagner, Valentin Kurt
Publisher: name: Karlsruhe
Year: 2014
Subjects: Heat transport
Thermal response tes
Thermal tracer test
Geothermal energy

description: Temperature is one major physical quantity of the subsurface and therefore, heat can be used as a tracer. This thesis further promotes heat as a tracer by evaluating a thermal tracer test and comparing the obtained results to previous studies. Additionally, a new thermal field test for the hydraulic characterization of the subsurface is developed. This new development transfers the thermal response test, to a powerful hydrogeological field test, by introducing a new evaluation approach.
Gradient corrections to the local density approximation for trapped superfluid Fermi gases
Creators: name: Almásy, András Csordás. Orsolya
name: Szépfalusy, Péter
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Two species superfluid Fermi gas is investigated on the BCS side up to the Feshbach resonance. Using the Greens's function technique gradient corrections are calculated to the generalized Thomas-Fermi theory including Cooper pairing. Their relative magnitude is found to be measured by the small parameter $(d/R_{TF})^4$, where $d$ is the oscillator length of the trap potential and $R_{TF}$ is the radial extension of the density $n$ in the Thomas-Fermi approximation. In particular at the Feshbach resonance the universal %constant $A_{TF}$ has the %correction in the center $A=A_{TF}+A_2(d/R_{TF})^4+\...$ corrections to the local density approximation are calculated and a universal prefactor $κ_W=7/27$ is derived for the von Weizsäcker type correction $κ_W(\hbar^2/2m)(\nabla^2 n^{1/2}/n^{1/2})$.
description: 13 pages, 8 figures
Group Activity Recognition Using Wearable Sensing Devices
Creators: name: Gordon, Dawud
Publisher: name: Karlsruhe
Year: 2014
Subjects: subject: Group Activity Recognition
subject: Emergent Behavior
subject: Distributed Computing
subject: FOS: Computer and information sciences
subject: Mobile Computing
subject: Wearable Computing

description: Understanding behavior of groups in real time can help prevent tragedy in crowd emergencies. Wearable devices allow sensing of human behavior, but the infrastructure required to communicate data is often the first casualty in emergency situations. Peer-to-peer (P2P) methods for recognizing group behavior are necessary, but the behavior of the group cannot be observed at any single location. The contribution is the methods required for recognition of group behavior using only wearable devices.
Dynamical decoupling sequence construction as a filter-design problem
Creators: name: Biercuk, M. J.
name: Doherty, A. C.
name: Uys, H.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Over the past decade we have seen an explosion of demonstrations of quantum coherence in atomic, optical, and condensed matter systems. These developments have placed a new emphasis on the production of robust and optimal quantum control techniques in the presence of environmental noise. We discuss the use of dynamical decoupling as a form of open-loop quantum control capable of suppressing the effects of dephasing in quantum coherent systems. We introduce the concept of dynamical decoupling pulse-sequence construction as a filter-design problem, making connections with filter design from control theory and electrical engineering in the analysis of pulse-sequence performance for the preservation of the phase degree of freedom in a quantum superposition. A detailed mathematical description of how dephasing and the suppression of dephasing can be reduced to a linear control problem is provided, and used as motivation and context for studies of the filtration properties of various dynamical decoupling sequences. Our work then takes this practical perspective in addressing both "standard" sequences derived from nuclear magnetic resonance and novel optimized sequences developed in the context of quantum information. Additionally, we review new techniques for the numerical construction of optimized pulse sequences using the filter-design perspective. We show how the filter-design perspective permits concise comparisons of the relative capabilities of these sequences and reveals the physics underlying their functionality. The use of this new analytical framework allows us to derive new insights into the performance of these sequences and reveals important limiting issues, such as the effect of digital clocking on optimized sequence performance.
description: Added new control-theoretic description of DD-based filtering. Updated references
STM Characterization of Phenylene-Ethynylene Oligomers on Au(111) and their Integration into Carbon Nanotube Nanogaps
Creators: name: Thiele, Cornelius
Publisher: name: Karlsruhe
Year: 2014

description: Molecular electronics requires both profound knowledge of a molecule's structure and functionality on a surface and controlled positioning between electrodes with nanometer-sized gaps. In the first part of this work, a detailed scanning tunneling microscope study of two variants of oligo(phenylene ethynylene) molecules is presented. In the second part, methods of fabricating carbon nanotube nanogap electrodes as direct contacts to these molecules are explored.
A Continuous Grasp Representation for the Imitation Learning of Grasps on Humanoid Robots
Creators: name: Do, Martin Minh Thong
Publisher: name: Karlsruhe
Year: 2014

description: Models and methods are presented which enable a humanoid robot to learn reusable, adaptive grasping skills. Mechanisms and principles in human grasp behavior are studied. The findings are used to develop a grasp representation capable of retaining specific motion characteristics and of adapting to different objects and tasks. Based on the representation a framework is proposed which enables the robot to observe human grasping, learn grasp representations, and infer executable grasping actions.
Analysis and Simulation of Hybrid Models for Reaction Networks
Creators: name: Kreim, Michael
Publisher: name: Karlsruhe
Year: 2014
Subjects: Chemical Master equation
Liouville equation
Fokker-Planck equation
hybrid model
scaled reaction network

description: The dynamics of biochemical reaction networks can be described by a variety of models, like the Reaction Rate equation (RRE), the Chemical Master equation (CME) or the Fokker-Planck equation (FPE). In this thesis, the behaviour of these different models is analysed. It is shown that the FPE can be motivated as an approximation of the CME and convergence is proven. Furthermore, two hybrid models are constructed by combining different approaches and convergence properties are proven and discussed.
Structural studies on iron-based exhaust gas catalysts by means of X-ray absorption spectroscopy
Creators: name: Boubnov, Alexey
Publisher: name: Karlsruhe
Year: 2014
Subjects: Iron catalysts
X-ray absorption spectroscopy
XANES
EXAFS
pre-edge

description: X-ray absorption near-edge structure (XANES) and pre-edge spectroscopy of supported iron oxide catalysts showed that the state of the catalytic sites varies between Fe2+ and Fe3+ without altering the number of nearest oxygen neighbours. The preferential location of Fe at the octahedral lattice sites of gamma-Al2O3 was verified by extended X-ray absorption fine structure (EXAFS). Valence-to-core X-ray emission spectroscopy (V2C-XES) gave new insight into intermediate species during catalytic deNOx.
Memorandum from Charles Dollard to Frederick P. Keppel, February 10, 1939
Creators: name: Dollard, Charles, 1907-1977
Publisher: name: Columbia University
Year: 2019
Subjects: Race relations
African Americans--Social conditions
Endowments

description: Record of meeting between Gunnar Myrdal, Richard Sterner, Charles Dollard, and John M. Russell.
Speeding up parallel tempering simulations
Creators: name: Hasenbusch, Martin
name: Schaefer, Stefan
Publisher: name: arXiv
Year: 2010
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We discuss methods that allow to increase the step-size in a parallel tempering simulation of statistical models and test them at the example of the three-dimensional Heisenberg spin glass. We find an overall speed-up of about two for contemporary lattices.
description: 12 pages, 1 figure, final version, minor changes and references added
Deriving bases for Abelian functions
Creators: name: England, Matthew
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mathematical Physics (math-ph)
subject: Algebraic Geometry (math.AG)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 14H40, 14H42, 15A15, 33E05, 14H70, 14H55, 14K25, 37K20, 14H70

description: We present a new method to explicitly define Abelian functions associated with algebraic curves, for the purpose of finding bases for the relevant vector spaces of such functions. We demonstrate the procedure with the functions associated with a trigonal curve of genus four. The main motivation for the construction of such bases is that it allows systematic methods for the derivation of the addition formulae and differential equations satisfied by the functions. We present a new 3-term 2-variable addition formulae and a complete set of differential equations to generalise the classic Weierstrass identities for the case of the trigonal curve of genus four.
description: 35pages
Hoch aufgelöste Strömungssimulation naturnaher Fließgewässerstrukturen - Detaillierte Modellierung auf Basis des terrestrischen Laserscannings zur Untersuchung ökohydraulischer Fragestellungen
Creators: name: Czerny, Rebekka Christina
Publisher: name: Karlsruhe
Year: 2014
Subjects: HN-Modellierung
terrestrisches Laserscanning
topografische Modellierung
naturnahe Fließgewässer
Ökohydraulik

description: Die numerische Modellierung naturnaher, strukturreicher Fließgewässer erfordert eine topografische Datenbasis mit einem hohen Detaillierungsgrad. In dieser Dissertation wird ein Konzept für die Erhebung und Verarbeitung von terrestrischen Laserscanning-Daten als Grundlage für ein hoch aufgelöstes Strömungsmodell speziell für naturnahe Gewässer vorgestellt. Anhand von vier Beispielen wird diese Methodik angewendet. Zudem wird ein neues Schema zur Klassifizierung komplexer 3D-Strömungszustände als Grundlage für eine ökohydraulische Bewertung präsentiert.
Pions in Large-$N$ Quantum Chromodynamics
Creators: name: Weinberg, Steven
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: An effective field theory of quarks, gluons, and pions, with the number $N$ of colors treated as large, is proposed as a basis for calculations of hadronic phenomena at moderate energies. The qualitative consequences of the large $N$ limit are similar though not identical to those in pure quantum chromodynamics, but because constituent quark masses appear in the effective Lagrangian, the `t Hooft coupling in the effective theory need not be strong at moderate energies. To leading order in $1/N$ the effective theory is renormalizable, with only a finite number of terms in the Lagrangian.
description: Version to be published in Phys. Rev. Letters. Two figures added, text and abstract revised and shortened. Clearer statement of aims of work. 9 pages
High Dynamic Rotor Oriented Current Control for Permanent Magnet Synchronous Machines with Saturation Characteristics
Creators: name: Gemassmer, Tobias
name: Richter, Jan
name: Schnarrenberger, Mathias
name: Braun, Michael
Publisher: name: Karlsruhe
Year: 2014

description: This paper presents a new approach to adapt classic linear current control design to permanent magnet synchronous machines with saturation characteristics. All needed parameters for the current controller are online calculated from stationary machine measurements. The additional effort compared to control of linear machines is kept as low as possible in order to meet user-oriented requirements. The developed current control scheme is veriﬁed by simulation as well as by experimental results.
CMB Bispectrum from Primordial Scalar, Vector and Tensor non-Gaussianities
Creators: name: Shiraishi, Maresuke
name: Nitta, Daisuke
name: Yokoyama, Shuichiro
name: Ichiki, Kiyotomo
name: Takahashi, Keitaro
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We present an all-sky formalism for the Cosmic Microwave Background (CMB) bispectrum induced by the primordial non-Gaussianities not only in scalar but also in vector and tensor fluctuations. We find that the bispectrum can be formed in an explicitly rationally invariant way by taking into account the angular and polarization dependences of the vector and tensor modes. To demonstrate this and present how to use our formalism, we consider a specific example of the correlation between two scalars and a graviton as the source of non-Gaussianity. As a result, we show that the CMB reduced bispectrum of the intensity anisotropies is evaluated as a function of the multipole and the coupling constant between two scalars and a graviton denoted by $g_{tss}$; $|b_{\ell \ell \ell}| \sim \ell^{-4} \times 8 \times 10^{-18} |g_{tss}|$. By estimating the signal-to-noise ratio, we find that the constraint as $|g_{tss}| < 6$ will be expected from the PLANCK experiment.
description: 19 pages, 4 figures. Accepted for publication in PTP
Cosmic string loop distribution on all length scales and at any redshift
Creators: name: Lorenz, Larissa
name: Ringeval, Christophe
name: Sakellariadou, Mairi
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We analytically derive the expected number density distribution of Nambu-Goto cosmic string loops at any redshift soon after the time of string formation to today. Our approach is based on the Polchinski-Rocha model of loop formation from long strings which we adjust to fit numerical simulations and complement by a phenomenological modelling of gravitational backreaction. Cosmological evolution drives the loop distribution towards scaling on all length scales in both the radiation and matter era. Memory of any reasonable initial loop distribution in the radiation era is shown to be erased well before Big Bang Nucleosynthesis. In the matter era, the loop distribution reaches full scaling, up to some residual loops from the radiation era which may be present for extremely low string tension. Finally, the number density of loops below the gravitational cutoff is shown to be scale independent, proportional to a negative power of the string tension and insensitive to the details of the backreaction modelling. As an application, we show that the energy density parameter of loops today cannot exceed 10^(-5) for currently allowed string tension values, while the loop number density cannot be less than 10^(-6) per Mpc^3. Our result should provide a more robust basis for studying the cosmological consequences of cosmic string loops.
description: 24 pages, 4 figures, uses iopart. References added, matches published version
An Extensible Parallel Computing Framework for Ultra-Fast X-Ray Imaging
Creators: name: Vogelgesang, Matthias
Publisher: name: Karlsruhe
Year: 2014

description: Die Entwicklung paralleler Hardwaresysteme ermöglicht die fortschreitende Ausnutzung Leistungssteigerung trotz stagnierender Taktfrequenz. In dieser Arbeit wurden Konzepte erarbeitet, um auf parallelen, heterogenen Rechensystemen schnelle Datenverarbeitung für bildgebende Röntgenverfahren durchzuführen. Das entwickelte System ist über Architekturgrenzen hinweg skalierbar und ermöglicht damit regelbare Experimente, die in der Form bisher nicht möglich waren.
Thermal Management for Dependable On-Chip Systems
Creators: name: Ebi, Thomas
Publisher: name: Karlsruhe
Year: 2014
Subjects: Thermal Management
Dependability
Multi-core
Microarchitecture
Agents

description: This thesis addresses the dependability issues in on-chip systems from a thermal perspective. This includes an explanation and analysis of models to show the relationship between dependability and tempature. Additionally, multiple novel methods for on-chip thermal management are introduced aiming to optimize thermal properties. Analysis of the methods is done through simulation and through infrared thermal camera measurements.
High-resolution optical spectroscopy of V838 Monocerotis in 2009
Creators: name: Tylenda, R.
name: Kamiński, T.
name: Schmidt, M.
name: Kurtev, R.
name: Tomov, T.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: V838 Mon erupted at the beginning of 2002. In the course of the outburst the object evolved to low effective temperatures and declined as a very late M-type supergiant. Among various scenarios proposed to explain the nature of the outburst, the most promising is a stellar merger event. We aim at studying the structure and evolution of the object in the decline from the 2002 eruption. We obtained spectroscopic observations of V838 Mon in January--March 2009 with UVES/VLT. The results are analysed and compared with similar observations obtained in October 2005 with HIRES/Keck. The most striking difference between 2009 and 2005 is a complete absence of the B3V component and of the [FeII] emission lines in 2009. The present spectrum displays only the spectrum of the 2002 eruption remnant. It resembles that of an M6 giant, although the molecular bands in V838 Mon are deeper than those in standard stellar spectra of a similar spectral class. Several atomic lines, which displayed P-Cyg profiles in 2005, are now dominated by pure absorptions. Some of these lines, however, show a narrow emission component, which, as we argue, measures the radial velocity of V838 Mon. The resulting heliocentric velocity is 71 km/s, which very well agrees with the velocity obtained from SiO maser observations. The atomic lines and the molecular bands show very complex kinematics. In some atomic lines and high-excitation molecular bands we observe matter infalling in the object atmosphere. The infall components were already observed in 2005, but were less pronounced and present in fewer lines than in 2009. We argue that the most negative radial velocity components seen in the resonance atomic lines and in the low-excitation molecular bands were formed in the ejecta of the 2002 eruption. The B3V companion most probably became engulfed in an opaque dusty matter of the 2002 V838 Mon ejecta.
description: A&A, in press
Representation stability for the cohomology of the moduli space M_g^n
Creators: name: Rolland, Rita Jimenez
Publisher: name: arXiv
Year: 2011
Subjects: subject: Geometric Topology (math.GT)
subject: Algebraic Geometry (math.AG)
subject: Algebraic Topology (math.AT)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics

description: Let M_g^n be the moduli space of Riemann surfaces of genus g with n labeled marked points. We prove that, for g \geq 2, the cohomology groups {H^i(M_g^n;Q)}_{n=1}^{\infty} form a sequence of Sn representations which is representation stable in the sense of Church-Farb [CF]. In particular this result applied to the trivial Sn representation implies rational "puncture homological stability" for the mapping class group Mod_g^n. We obtain representation stability for sequences {H^i(PMod^n(M);Q)}_{n=1}^{\infty}, where PMod^n(M) is the mapping class group of many connected manifolds M of dimension d \geq 3 with centerless fundamental group; and for sequences {H^i(BPDiff^n(M);Q)}_{n=1}^{\infty}, where BPDiff^n(M) is the classifying space of the subgroup PDiff^n(M) of diffeomorphisms of M that fix pointwise n distinguished points in M.
description: 30 pages
Theory of Bernstein Modes in Graphene
Creators: name: Roldan, R.
name: Goerbig, M. O.
name: Fuchs, J. -N.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present a theoretical description of Bernstein modes that arise as a result of the coupling between plasmon-like collective excitations (upper-hybrid mode) and inter-Landau-level excitations, in graphene in a perpendicular magnetic field. These modes, which are apparent as avoided level crossings in the spectral function obtained in the random-phase approximation, are described to great accuracy in a phenomenological model. Bernstein modes, which may be measured in inelastic light-scattering experiments or in photo-conductivity spectroscopy, are a manifestation of the Coulomb interaction between the electrons and may be used for a high-precision measurement of the upper-hybrid mode at small non-zero wave vectors.
description: 5 pages. 2 figures; slightly extended version, title changed; accepted for publication in Phys. Rev. B