cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A rigorous derivation of the defocusing cubic nonlinear Schrödinger equation on $\mathbb{T}^3$ from the dynamics of many-body quantum systems
Creators: name: Sohinger, Vedran
Publisher: name: arXiv
Year: 2014
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: In this paper, we will obtain a rigorous derivation of the defocusing cubic nonlinear Schrödinger equation on the three-dimensional torus $\mathbb{T}^3$ from the many-body limit of interacting bosonic systems. This type of result was previously obtained on $\mathbb{R}^3$ in the work of Erdős, Schlein, and Yau \cite{ESY2,ESY3,ESY4,ESY5}, and on $\mathbb{T}^2$ and $\mathbb{R}^2$ in the work of Kirkpatrick, Schlein, and Staffilani \cite{KSS}. Our proof relies on an unconditional uniqueness result for the Gross-Pitaevskii hierarchy at the level of regularity $α=1$, which is proved by using a modification of the techniques from the work of T. Chen, Hainzl, Pavlović and Seiringer \cite{ChHaPavSei} to the periodic setting. These techniques are based on the Quantum de Finetti theorem in the formulation of Ammari and Nier \cite{AmmariNier1,AmmariNier2} and Lewin, Nam, and Rougerie \cite{LewinNamRougerie}. In order to apply this approach in the periodic setting, we need to recall multilinear estimates obtained by Herr, Tataru, and Tzvetkov \cite{HTT}. Having proved the unconditional uniqueness result at the level of regularity $α=1$, we will apply it in order to finish the derivation of the defocusing cubic nonlinear Schrödinger equation on $\mathbb{T}^3$, which was started in the work of Elgart, Erdős, Schlein, and Yau \cite{EESY}. In the latter work, the authors obtain all the steps of Spohn's strategy for the derivation of the NLS \cite{Spohn}, except for the final step of uniqueness. Additional arguments are necessary to show that the objects constructed in \cite{EESY} satisfy the assumptions of the unconditional uniqueness theorem. Once we achieve this, we are able to prove the derivation result. In particular, we show \emph{Propagation of Chaos} for the defocusing Gross-Pitaevskii hierarchy on $\mathbb{T}^3$ for suitably chosen initial data.
description: 38 pages. 2 figures
Aggregate Characterization of User Behavior in Twitter and Analysis of the Retweet Graph
Creators: name: Bild, David R.
name: Liu, Yue
name: Dick, Robert P.
name: Mao, Z. Morley
name: Wallach, Dan S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Social and Information Networks (cs.SI)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Most previous analysis of Twitter user behavior is focused on individual information cascades and the social followers graph. We instead study aggregate user behavior and the retweet graph with a focus on quantitative descriptions. We find that the lifetime tweet distribution is a type-II discrete Weibull stemming from a power law hazard function, the tweet rate distribution, although asymptotically power law, exhibits a lognormal cutoff over finite sample intervals, and the inter-tweet interval distribution is power law with exponential cutoff. The retweet graph is small-world and scale-free, like the social graph, but is less disassortative and has much stronger clustering. These differences are consistent with it better capturing the real-world social relationships of and trust between users. Beyond just understanding and modeling human communication patterns and social networks, applications for alternative, decentralized microblogging systems-both predicting real-word performance and detecting spam-are discussed.
description: 17 pages, 21 figures
Iterative structure of finite loop integrals
Creators: name: Caron-Huot, Simon
name: Henn, Johannes M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this paper we develop further and refine the method of differential equations for computing Feynman integrals. In particular, we show that an additional iterative structure emerges for finite loop integrals. As a concrete non-trivial example we study planar master integrals of light-by-light scattering to three loops, and derive analytic results for all values of the Mandelstam variables $s$ and $t$ and the mass $m$. We start with a recent proposal for defining a basis of loop integrals having uniform transcendental weight properties and use this approach to compute all planar two-loop master integrals in dimensional regularization. We then show how this approach can be further simplified when computing finite loop integrals. This allows us to discuss precisely the subset of integrals that are relevant to the problem. We find that this leads to a block triangular structure of the differential equations, where the blocks correspond to integrals of different weight. We explain how this block triangular form is found in an algorithmic way. Another advantage of working in four dimensions is that integrals of different loop orders are interconnected and can be seamlessly discussed within the same formalism. We use this method to compute all finite master integrals needed up to three loops. Finally, we remark that all integrals have simple Mandelstam representations.
description: 26 pages plus appendices, 5 figures
Experimental determination of radiated internal wave power without pressure field data
Creators: name: Lee, Frank M.
name: Paoletti, M. S.
name: Swinney, Harry L.
name: Morrison, P. J.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We present a method to determine, using only velocity field data, the time-averaged energy flux $\left$ and total radiated power $P$ for two-dimensional internal gravity waves. Both $\left$ and $P$ are determined from expressions involving only a scalar function, the stream function $ψ$. We test the method using data from a direct numerical simulation for tidal flow of a stratified fluid past a knife edge. The results for the radiated internal wave power given by the stream function method agree to within 0.5% with results obtained using pressure and velocity data from the numerical simulation. The results for the radiated power computed from the stream function agree well with power computed from the velocity and pressure if the starting point for the stream function computation is on a solid boundary, but if a boundary point is not available, care must be taken to choose an appropriate starting point. We also test the stream function method by applying it to laboratory data for tidal flow past a knife edge, and the results are found to agree with the direct numerical simulation. Supplementary Material includes a Matlab code with a graphical user interface (GUI) that can be used to compute the energy flux and power from any two-dimensional velocity field data.
description: 27 pages, 11 figures
Real-Time Hand Shape Classification
Creators: name: Nalepa, Jakub
name: Kawulok, Michal
Publisher: name: arXiv
Year: 2014
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: The problem of hand shape classification is challenging since a hand is characterized by a large number of degrees of freedom. Numerous shape descriptors have been proposed and applied over the years to estimate and classify hand poses in reasonable time. In this paper we discuss our parallel framework for real-time hand shape classification applicable in real-time applications. We show how the number of gallery images influences the classification accuracy and execution time of the parallel algorithm. We present the speedup and efficiency analyses that prove the efficacy of the parallel implementation. Noteworthy, different methods can be used at each step of our parallel framework. Here, we combine the shape contexts with the appearance-based techniques to enhance the robustness of the algorithm and to increase the classification score. An extensive experimental study proves the superiority of the proposed approach over existing state-of-the-art methods.
description: 11 pages
Self-organization towards optimally interdependent networks by means of coevolution
Creators: name: Wang, Zhen
name: Szolnoki, Attila
name: Perc, Matjaz
Publisher: name: arXiv
Year: 2014
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Social and Information Networks (cs.SI)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Biological sciences

description: Coevolution between strategy and network structure is established as a means to arrive at optimal conditions for resolving social dilemmas. Yet recent research highlights that the interdependence between networks may be just as important as the structure of an individual network. We therefore introduce coevolution of strategy and network interdependence to study whether it can give rise to elevated levels of cooperation in the prisoner's dilemma game. We show that the interdependence between networks self-organizes so as to yield optimal conditions for the evolution of cooperation. Even under extremely adverse conditions cooperators can prevail where on isolated networks they would perish. This is due to the spontaneous emergence of a two-class society, with only the upper class being allowed to control and take advantage of the interdependence. Spatial patterns reveal that cooperators, once arriving to the upper class, are much more competent than defectors in sustaining compact clusters of followers. Indeed, the asymmetric exploitation of interdependence confers to them a strong evolutionary advantage that may resolve even the toughest of social dilemmas.
description: 14 pages, 4 figures; accepted for publication in New Journal of Physics
$μ$SR and inelastic neutron scattering investigations of the noncentrosymmetric antiferromagnet CeNiC$_2$
Creators: name: Bhattacharyya, A.
name: Adroja, D. T.
name: Strydom, A. M.
name: Hillier, A. D .
name: Taylor, J. W.
name: Thamizhavel, A.
name: Dhar, S. K.
name: Kockelmann, W. A.
name: Rainford, B. D.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The magnetic state of the noncentrosymmetric antiferromagnet CeNiC$_2$ has been studied by magnetic susceptibility, heat capacity, muon spin relaxation ($μ$SR) and inelastic neutron scattering (INS) measurements. CeNiC$_2$ exhibits three magnetic phase transitions at $T_{N_1}$ = 20 K, $T_{N_2}$ = 10 K and $T_{N_3}$ = 2.5 K. The presence of long range magnetic order below 20 K is confirmed by the observation of oscillations in the $μ$SR spectra between 10 and 20 K and a sharp increase in the muon depolarization rate. INS studies reveal two well-defined crystal electric field (CEF) excitations around 8 and 30 meV. INS data have been analyzed using a CEF model and the wave functions were evaluated. We also calculated the direction and magnitude of the ground state moment using CEF wave functions and compare the results with that proposed from the neutron diffraction. Our CEF model correctly predicts that the moments order along the $b-$axis (or $y$-axis) and the observed magnetic moment is 0.687(5) $μ_B$, which is higher than the moment observed from the neutron diffraction (0.25 $μ_B$/Ce). We attribute the observed reduced moment due to the Kondo screening effect.
description: 10 pages, 13 figures
title: Research Proposal: The Effects of Therapeutic Interventions on Illicit Drug Abuse Among Homeless Adolescents
Creators: name: Baillio, Alice
name: Stanley, Meghan
name: Kroupa, Sarah
name: Ajaj, Rania
name: Rabidoux, Paige
Publisher: name: Old Dominion University Libraries
Year: 2017

description: Aim: To compare case management versus community-based therapy on illicit drug abuse among homeless adolescents

Background: Homeless adolescents are at high risk for illicit drug abuse.

Methods:

• A quasi-experimental, multiple baseline time series design

• 52 sessions over a 12-month period

• Baseline assessment and survey on demographics

• Follow-up: closed-ended questionnaire (every four months)

Analysis: Repeated ANOVA test and dependent t-test

Limitations: Lack of recent evidence-based research, a small sample size, self-report data, and length of the study.
Solitary state at the edge of synchrony in ensembles with attractive and repulsive interaction
Creators: name: Maistrenko, Yuri
name: Penkovsky, Bogdan
name: Rosenblum, Michael
Publisher: name: arXiv
Year: 2014
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Dynamical Systems (math.DS)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We discuss the desynchronization transition in networks of globally coupled identical oscillators with attractive and repulsive interactions. We show that, if attractive and repulsive groups act in antiphase or close to that, a solitary state emerges with a single repulsive oscillator split up from the others fully synchronized. With further increase of the repulsing strength, the synchronized cluster becomes fuzzy and the dynamics is given by a variety of stationary states with zero common forcing. Intriguingly, solitary states represent the natural link between coherence and incoherence. The phenomenon is described analytically for phase oscillators with sine coupling and demonstrated numerically for more general amplitude models.
description: 5 pages, 4 figures
Anatomizing Exotic Production of the Higgs Boson
Creators: name: Yu, Felix
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We discuss exotic production modes of the Higgs boson and how their phenomenology can be probed in current Higgs analyses. We highlight the importance of differential distributions in disentangling standard production mechanisms from exotic modes. We present two model benchmarks for exotic Higgs production arising from chargino-neutralino production and study their impact on the current Higgs dataset. As a corollary, we emphasize that current Higgs coupling fits do not fully explore the space of new physics deviations possible in Higgs data.
description: 27 pages
Stability of generic cylindrical thin shell wormholes
Creators: name: Mazharimousavi, S. Habib
name: Halilsoy, M.
name: Amirabi, Z.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We revisit the stability analysis of cylindrical thin shell wormholes which have been studied in literature so far. Our approach is more systematic and in parallel to the method which is used in spherically symmetric thin shell wormholes. The stability condition is summarized as the positivity of the second derivative of an effective potential at the equilibrium radius, i.e. $V^{\prime \prime}\left(a_{0}\right) >0$. This may serve as the master equation in all stability problems for the cylindrical thin-shell wormholes.
description: 7 pages, 2 figures. Final version, accepted for publication in Phys. Rev. D
Ultrafast reflectivity modulation in AlGaAs/InAlGaAs multiple quantum well photonic crystal waveguides
Creators: name: Garcia-Deniz, A. Z.
name: Murzyn, P.
name: Fox, A. M.
name: Kundys, D. O.
name: Wells, J-P. R.
name: Whittaker, D. M.
name: Skolnick, M. S.
name: Krauss, T. F.
name: Roberts, J. S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We report an ultrafast optical tuning of the reflectivity of AlGaAs/InAlGaAs multiple quantum well photonic crystal waveguides using a reflection geometry, pump-probe technique.
Spin Dependent Lifetimes and Spin-orbit Hybridization Points in Heusler Compounds
Creators: name: Kaltenborn, Steffen
name: Schneider, Hans Christian
Publisher: name: arXiv
Year: 2014
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present an ab initio calculation of the k and spin-resolved electronic lifetimes in the half-metallic Heusler compounds Co(2)MnSi and Co(2)FeSi. We determine the spin-flip and spin-conserving contributions to the lifetimes and study in detail the behavior of the lifetimes around states that are strongly spin-mixed by spin-orbit coupling. We find that, for non-degenerate bands, the spin mixing alone does not determine the energy dependence of the (spin-flip) lifetimes. Qualitatively, the lifetimes reflect the lineup of electron and hole bands. We predict that different excitation conditions lead to drastically different spin-flip dynamics of excited electrons and may even give rise to an enhancement of the non-equilibrium spin polarization.
description: 6 pages, 5 figures
A Computer Program for the Newman-Janis Algorithm
Creators: name: Gutierrez-Chavez, Carlos
name: Frutos-Alfaro, Francisco
name: Cordero-Garcia, Ivan
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: A REDUCE code for the Newman-Janis algorithm is described. This algorithm is intended to include rotation into nonrotating solutions of the Einstein field equations with spherically symmetry or perturbed spherically symmetry and has been successfully applied to many spacetimes. The applicability of the code is restricted to metrics containing potentials of the form 1/r.
Mindfulness training for smoking cessation in adults participating in Alcoholics Anonymous
Creators: name: Jacob, Micky
Publisher: name: No Publisher Supplied
Year: 2023

description: Purpose: Smoking is the leading cause of preventable disease. Smokers die an average of ten years earlier than individuals who do not smoke. Over 34 million adults in the United States smoke. The goal of this study is to use mindfulness training to increase smoking cessation rates.Methods: This quality improvement study examined the effectiveness of mindfulness training exercises and smoking cessation rates in adults who attended an alcoholics anonymous meeting in Central New Jersey. Participants completed a pre-test and were then taught how to use mindfulness training exercises when the urge to smoke a cigarette arises. After four weeks of using mindfulness training, the same participants completed a post-test to examine whether mindfulness training exercises aided in smoking cessation.Results: This study showed that the mean number of cigarettes smoked in a day decreased from 17.5 to 14.77 (n=44, p=<0.001, 95% CI) after mindfulness training exercises were used. There was a 15.58% change in the number of cigarettes smoked after using the mindfulness training exercises. 70.4% of participants in this study found mindfulness training helpful in smoking cessation.Implications: This study showed a statistically significant reduction in the number of cigarettes smoked after mindfulness training exercises. Mindfulness training was more effective with individuals who have smoked for five years or less. Habit and stress were shown to be the main reasons why individuals in this study smoked. There was no correlation between living with a smoker and cessation rates.
CONTROLS ON VOLCANIC ARC WEATHERING RATES INFERRED USING COSMOGENIC NUCLIDES
Creators: name: Moore, Angus K
Publisher: name: Purdue University Graduate School
Year: 2023
Subjects: Geology not elsewhere classified

description: Chemical weathering of highly reactive mafic and ultramafic igneous rocks may be a key sink in the global carbon cycle. Understanding how uplift of these rocks during arc-arc and arc-continent collisions through earth history has affected the evolution of global climate, including the onset of icehouse periods, requires improved constraints on the relative sensitivity of their weathering rates to physical erosion vs. climate. If weathering rates depend chiefly on erosion, then tectonic uplift of mafic and ultramafic rocks may have a strongly destabilizing effect on global climate. Conversely, if weathering rates are limited primarily by temperature or runoff, then a negative feedback mechanism between weathering and climate may attenuate the effects of rock uplift. This work characterizes the relationship between chemical weathering rates, physical erosion rates, and climate in tropical, montane watersheds in Puerto Rico that are underlain by volcanic arc rocks and associated ophiolitic serpentinite. Key to this analysis are new constraints on long-term erosion rates on these rocks from cosmogenic Cl-36 produced in situ in magnetite. These cosmogenic erosion rates are paired with classical measurements of stream solute fluxes and sediment geochemistry across runoff gradients to quantify the limits to volcanic arc rock and serpentinite weathering rates.
 This work is divided into three chapters. Chapter 2 constrains the altitude scaling behavior of Cl-36 production in magnetite. This allows erosion rates to be determined more accurately in watersheds near sea level in Puerto Rico. Chapter 3 demonstrates that volcanic arc rock weathering rates in the humid tropics are more strongly limited by physical erosion than by climatic factors. However, a positive correlation between erosion and runoff observed in this landscape may enhance the coupling between climate and weathering rates. Chapter 4 finds that, in contrast to volcanic arc rocks, serpentinite weathering is strongly limited by runoff and weakly limited by erosion. These results are presented as empirical power-law relationships that can be readily applied in global carbon cycle modeling.
Time-dependent Hartree-Fock calculations for multi-nucleon transfer processes: Effects of particle evaporation on production cross sections
Creators: name: Sekizawa, Kazuyuki
name: Yabana, Kazuhiro
Publisher: name: arXiv
Year: 2014
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We present a microscopic calculation of multi-nucleon transfer reactions employing the time-dependent Hartree-Fock (TDHF) theory. In our previous publication [Phys. Rev. C 88, 014614 (2013)], we reported our analysis for the multi-nucleon transfer processes for several systems. Here we discuss effects of particle evaporation processes on the production cross sections. Since particle evaporation processes may not be described adequately by the TDHF calculations, we evaluate them using a statistical model. As an input of the statistical model, excitation energies of the final fragments are necessary. We evaluate them from the TDHF wave function after collisions, extending the particle number projection technique. From the calculation, the particle evaporation effects are found to improve descriptions of the production cross sections. However, the production cross sections are still underestimated for processes where a number of protons are transferred. Possible origins of the discrepancy are discussed.
description: 4 pages, 1 figure, Talk given at VI International Conference FUSION14, Feb. 24-28, 2014, New Delhi, India
The Photon Underproduction Crisis
Creators: name: Kollmeier, Juna A.
name: Weinberg, David H.
name: Oppenheimer, Benjamin D.
name: Haardt, Francesco
name: Katz, Neal
name: Davé, Romeel A.
name: Fardal, Mark
name: Madau, Piero
name: Danforth, Charles
name: Ford, Amanda B.
name: Peeples, Molly S.
name: McEwen, Joseph
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We examine the statistics of the low-redshift Lyman-alpha forest from smoothed particle hydrodynamic simulations in light of recent improvements in the estimated evolution of the cosmic ultraviolet background (UVB) and recent observations from the Cosmic Origins Spectrograph (COS). We find that the value of the metagalactic photoionization rate required by our simulations to match the observed properties of the low-redshift Lyman-alpha forest is a factor of 5 larger than the value predicted by state-of-the art models for the evolution of this quantity. This mismatch results in the mean flux decrement of the Lyman-alpha forest being underpredicted by at least a factor of 2 (a 10-sigma discrepancy with observations) and a column density distribution of Lyman-alpha forest absorbers systematically and significantly elevated compared to observations over nearly two decades in column density. We examine potential resolutions to this mismatch and find that either conventional sources of ionizing photons (galaxies and quasars) must be significantly elevated relative to current observational estimates or our theoretical understanding of the low-redshift universe is in need of substantial revision.
description: Submitted to ApJ Letters; 6 pages including 3 figures
Estimation of Medium Access Control Layer Packet Delay Distribution for IEEE 802.11
Creators: name: Alkadeki, Hatm
name: Wang, Xingang
name: Odetayo, Michael
Publisher: name: arXiv
Year: 2014
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: The most important standard in wireless local area networks is IEEE 802.11. This is why much of the research work for the enhancement of wireless network is usually based on the behavior of IEEE 802.11 protocol. However, some of the ways in which IEEE 802.11 medium access control layer behaves is still unreliable to guarantee quality of service. For instance, medium access control layer packet delay, jitter and packet loss rate still remain a challenge. The main objective of this research is to propose an accurate estimation of the medium access control layer packet delay distribution for IEEE 802.11. This estimation considers the differences between busy probability and collision probability. These differences are employed to achieve a more accurate estimation. Finally, the proposed model and simulation are implemented and validated - using MATLAB program for the purpose of simulation, and Maple program to undertake the calculation of the equations.
description: 10pages, 4figures, journal publication
Untitled Item
Creators: name: Ramos Vera, Celia
name: Fernández-Castrillo, Carolina
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 470101
subject: Communication studies
classificationCode: 470105
subject: Journalism studies
classificationCode: 470107
subject: Media studies

description: Supplementary material to the research "Post-photojournalism: Challenges and threats of post-truth for visual reportage in the coverage of the Russian-Ukrainian war".
Dynamic Behavior of Interacting between Epidemics and Cascades on Heterogeneous Networks
Creators: name: Jiang, Lurong
name: Jin, Xinyu
name: Xia, Yongxiang
name: Ouyang, Bo
name: Wu, Duanpo
Publisher: name: arXiv
Year: 2014
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Epidemic spreading and cascading failure are two important dynamical processes over complex networks. They have been investigated separately for a long history. But in the real world, these two dynamics sometimes may interact with each other. In this paper, we explore a model combined with SIR epidemic spreading model and local loads sharing cascading failure model. There exists a critical value of tolerance parameter that whether the epidemic with high infection probability can spread out and infect a fraction of the network in this model. When the tolerance parameter is smaller than the critical value, cascading failure cuts off abundant of paths and blocks the spreading of epidemic locally. While the tolerance parameter is larger than the critical value, epidemic spreads out and infects a fraction of the network. A method for estimating the critical value is proposed. In simulation, we verify the effectiveness of this method in Barabási-Albert (BA) networks.
title: Is it all in the eye of the beholder?
title: The importance of situation construal for situational judgment test performance
titleType: Subtitle
Creators: name: Freudenstein, Jan‐Philipp
name: Schäpers, Philipp
name: Roemer, Lena
name: Mussel, Patrick
name: Krumm, Stefan
Publisher: name: Freie Universität Berlin
Year: 2020
Subjects: subject: person × situation interaction
subject: situation construal
subject: situational judgment test
subject: validity
subject: 100 Philosophie und Psychologie::150 Psychologie::150 Psychologie

description: Recent research challenges the importance of situation descriptions for situational judgment test (SJT) performance. This study contributes to resolving the ongoing debate on whether SJTs are situational measures, by incorporating findings on person × situation interactions into SJT research. Specifically, across three studies (NTotal = 1,239), we first tested whether situation construal (i.e., the individual perception of situations in SJTs) predicts responses to SJT items. Second, we assessed whether the relevance of situation construal for SJT performance depends on test elements (i.e., situation descriptions and response options) and item features (i.e., description‐dependent vs. description‐independent SJT items). Lastly, we determined whether situation construal has incremental validity for job‐related criteria over and above SJT performance. The results showed that, for most SJT items, situation construal significantly contributed to SJT performance, even if only response options were available. This was also true for SJT items that are significantly more difficult to solve when situation descriptions are omitted (i.e., description‐dependent SJT items). Finally, situation construal explained variance in relevant criteria over and above SJT performance. Despite recent efforts to reconceptualize SJTs, our results suggest that they can still be viewed as situational measures. However, situation descriptions may be less crucial for these underlying situational processes. Theoretical and practical implications are discussed.
Dynamical and radiative simulations of $γ$-ray jets in microquasars
Creators: name: Smponias, T.
name: Kosmas, T. S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The emission of $γ$-rays in jets emanating from the vicinity of collapsed stellar remnants, in binary systems known as microquasars, is investigated using a three dimensional relativistic hydrocode (PLUTO), in combination with two in-house radiative transfer codes. Even though a great number of stellar systems may be addressed by such models, we restrict ourselves to the concrete example of the SS433 X-ray binary, the only microquasar with a definite hadronic content in its jets, as verified from spectral line observations. A variety of system configurations have been examined, by employing a hadron-based emission mechanism. The dependence of the $γ$-ray emissions on certain dynamical source properties, such as the hydrodynamic parameters of the mass-flow density, the gas-pressure and the temperature of the ejected matter, is simulated. Radiative properties, especially the assumed high energy proton population inside the jet plasma, and its effect on the calculated emission, are also examined. Two sets of initial conditions of the chosen microquasar are employed, in order to cover different scenarios pertaining to the system under consideration.
description: 15 pages, 10 figures, 1 table, MNRAS accepted
SMA millimeter observations of Hot Molecular Cores
Creators: name: Hernández-Hernández, Vicente
name: Zapata, Luis
name: Kurtz, Stan
name: Garay, Guido
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present Submillimeter Array observations, in the 1.3 mm continuum and the CH_3CN(12-11) line of 17 hot molecular cores associated with young high-mass stars. The angular resolution of the observations ranges from 1".0 to 4".0. The continuum observations reveal large (>3500 AU) dusty structures with gas masses from 7 to 375 Msun, that probably surround multiple young stars. The CH_3CN line emission is detected toward all the molecular cores at least up to the K=6-component and is mostly associated with the emission peaks of the dusty objects. We used the multiple K-components of the CH_3CN and both the rotational diagram method and a simultaneous synthetic LTE model with the XCLASS program to estimate the temperatures and column densities of the cores. For all sources, we obtained reasonable fits from XCLASS by using a model that combines two components: an extended and warm envelope, and a compact hot core of molecular gas, suggesting internal heating by recently formed massive stars. The rotational temperatures lie in the range of 40-132 K and 122-485 K for the extended and compact components, respectively. From the continuum and CH_3CN results, we infer fractional abundances from 10^{-9} to 10^{-7} toward the compact inner components, that increase with the rotational temperature. Our results agree with a chemical scenario in which the CH_3CN molecule is efficiently formed in the gas phase above 100-300 K, and its abundance increases with temperature.
description: 22 pages, 8 figures, Accepted to ApJ
Do Bats Have the Necessary Prerequisites for Symbolic Communication?
Creators: name: Knörnschild, Mirjam
name: Fernandez, Ahana Aurora
Publisher: name: Freie Universität Berlin
Year: 2020
Subjects: subject: symbols
subject: indexical communication
subject: social learning
subject: cognitive skills
subject: touchscreen
subject: training paradigm
subject: bats
subject: associative learning
subject: 100 Philosophie und Psychologie::150 Psychologie::150 Psychologie

description: Training animals such as apes, gray parrots, or dolphins that communicate via arbitrary symbols with humans has revealed astonishing mental capacities that may have otherwise gone unnoticed. Albeit bats have not yet been trained to communicate via symbols with humans, we are convinced that some species, especially captive Pteropodid bats (“flying foxes”), show the potential to master this cognitive task. Here, we briefly review what is known about bats’ cognitive skills that constitute relevant prerequisites for symbolic communication with humans. We focus on social learning in general, trainability by humans, associative learning from humans, imitation, vocal production learning and usage learning, and social knowledge. Moreover, we highlight potential training paradigms that could be used to elicit simple “symbolic” bat-human communication, i.e., training bats to select arbitrary symbols on a touchscreen to elicit a desired behavior of the human caregiver. Touchscreen-proficient bats could participate in cognition research, e.g., to study their numerical competence or categorical perception, to further elucidate how nonhuman animals learn and perceive the world.
An Online Expectation-Maximisation Algorithm for Nonnegative Matrix Factorisation Models
Creators: name: Yildirim, Sinan
name: Cemgil, A. Taylan
name: Singh, Sumeetpal S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Machine Learning (cs.LG)
subject: Computation (stat.CO)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: In this paper we formulate the nonnegative matrix factorisation (NMF) problem as a maximum likelihood estimation problem for hidden Markov models and propose online expectation-maximisation (EM) algorithms to estimate the NMF and the other unknown static parameters. We also propose a sequential Monte Carlo approximation of our online EM algorithm. We show the performance of the proposed method with two numerical examples.
description: 6 pages, 3 figures
Fast Radio Burst Discovered in the Arecibo Pulsar ALFA Survey
Creators: name: Spitler, L. G.
name: Cordes, J. M.
name: Hessels, J. W. T.
name: Lorimer, D. R.
name: McLaughlin, M. A.
name: Chatterjee, S.
name: Crawford, F.
name: Deneva, J. S.
name: Kaspi, V. M.
name: Wharton, R. S.
name: Allen, B.
name: Bogdanov, S.
name: Brazier, A.
name: Camilo, F.
name: Freire, P. C. C.
name: Jenet, F. A.
name: Karako-Argaman, C.
name: Knispel, B.
name: Lazarus, P.
name: Lee, K. J.
name: van Leeuwen, J.
name: Lynch, R.
name: Lyne, A. G.
name: Ransom, S. M.
name: Scholz, P.
name: Siemens, X.
name: Stairs, I. H.
name: Stovall, K.
name: Swiggum, J. K.
name: Venkataraman, A.
name: Zhu, W. W.
name: Aulbert, C.
name: Fehrmann, H.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Recent work has exploited pulsar survey data to identify temporally isolated, millisecond-duration radio bursts with large dispersion measures (DMs). These bursts have been interpreted as arising from a population of extragalactic sources, in which case they would provide unprecedented opportunities for probing the intergalactic medium; they may also be linked to new source classes. Until now, however, all so-called fast radio bursts (FRBs) have been detected with the Parkes radio telescope and its 13-beam receiver, casting some concern about the astrophysical nature of these signals. Here we present FRB 121102, the first FRB discovery from a geographic location other than Parkes. FRB 121102 was found in the Galactic anti-center region in the 1.4-GHz Pulsar ALFA survey with the Arecibo Observatory with a DM = 557.4 $\pm$ 3 pc cm$^{-3}$, pulse width of $3\; \pm 0.5$ ms, and no evidence of interstellar scattering. The observed delay of the signal arrival time with frequency agrees precisely with the expectation of dispersion through an ionized medium. Despite its low Galactic latitude ($b = -0.2^{\circ}$), the burst has three times the maximum Galactic DM expected along this particular line-of-sight, suggesting an extragalactic origin. A peculiar aspect of the signal is an inverted spectrum; we interpret this as a consequence of being detected in a sidelobe of the ALFA receiver. FRB 121102's brightness, duration, and the inferred event rate are all consistent with the properties of the previously detected Parkes bursts.
description: 9 pages, 3 figures, submitted to ApJ
Metacommunity Structures of Macroinvertebrates and Diatoms in High Mountain Streams, Yunnan, China
Creators: name: Kurthen, Angelika L.
name: He, Fengzhi
name: Dong, Xiaoyu
name: Maasri, Alain
name: Wu, Naicheng
name: Cai, Qinghua
name: Jähnig, Sonja C.
Publisher: name: Freie Universität Berlin
Year: 2020
Subjects: subject: dispersal
subject: network
subject: connectivity
subject: Hengduan Mountains (Hengduanshan)
subject: elevation
subject: distance-decay
subject: biotic interactions
subject: 500 Naturwissenschaften und Mathematik::570 Biowissenschaften; Biologie::577 Ökologie

description: The metacommunity concept has received increasing interest in the past two decades. However, there has been limited research examining metacommunity structure of communities in high mountain streams. These ecosystems are often physically constrained and can display large environmental gradients within a relatively small spatial extent. Here, we examined metacommunity structures of stream organisms in a high mountain region, which is part of the Hengduan Mountains region in Southwest China. Macroinvertebrates and diatoms were collected from six streams in two opposite aspects of the same mountain with different connectivity between streams. On the west aspect, streams are tributaries of a river (i.e., river-connected) while streams flow into a lake (i.e., lake-connected) on the east aspect. We used Elements of Metacommunity Structure analysis to explore the metacommunity structuring of these two biological models. We also compared the contribution of dispersal and environmental filtering in structuring metacommunities by looking at Euclidean, network, topographic, and environmental distances. Communities of diatoms and macroinvertebrates were structured with clear turnover on both aspects. Further, diatom communities exhibited Clementsian structure on both aspects. Macroinvertebrates exhibited different metacommunity structures on the river-connected aspect (Quasi-Clementsian) and lake-connected aspect (Clementsian). Our results indicated that on the lake-connected aspect, environmental filtering had a stronger association with community dissimilarity than on the river-connected aspect for both macroinvertebrate and diatom communities. Diatom communities were more influenced by environmental filtering on the east aspect with weakened network connectivity compared with those on the west aspect. Our results also emphasized the potential effects of biotic interactions between macroinvertebrates and diatoms on shaping community structures of one other. Our study provides substantial elements to further understand metacommunity structure and highlights the necessity of future research to reveal the underlying mechanisms of community structuring in these remote ecosystems.
Partitions of 4d Transition Metal Nuclei and Related Correlations Using the Core Cluster Model
Creators: name: Mageed, K. E. Abd El
name: Shalaby, A. G.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In the present work we attempt to study the cluster model in the transition metal region. The spectrum fitting method is studied for the selected nuclei (88,90,92^Sr, 92,94^Zr, 98,100^Mo, 100,102,104, 106^Ru, 108,110^Pd and 112,114,116,118^Cd) with proton number (38 < ZT< 48) and mass number (88 < AT < 118). The core cluster charge products are correlated with the transition probability B(E2 2+ -> 0+), the excitation energies and the product of valence nucleon numbers of the parent nuclei.
description: 14 Pages, 10 Figures
PROTOCOL OF A SYSTEMATIC REVIEW - NEPHROLOGY AND COVID-19
Creators: name: Chambergo-Michilot, Diego
name: Torres-Gomez, Lucero
Publisher: name: figshare
Year: 2020
Subjects: subject: 110312 Nephrology and Urology
subject: FOS: Clinical medicine

description: We are uploading the protocol of our systematic review that has already been registered at PROSPERO.
Rediscovering Black Phosphorus: A Unique Anisotropic 2D Material for Optoelectronics and Electronics
Creators: name: Xia, Fengnian
name: Wang, Han
name: Jia, Yichen
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Anisotropy refers to the property of a material exhibiting directionally dependent features. In this paper, we introduce black phosphorous (BP), the most stable allotrope of phosphorus in layered orthorhombic structure with a bandgap of 0.3 eV in bulk, as a unique 2D material in which electrons, phonons and their interactions with photons behave in a highly anisotropic manner within the plane of the layers. The unique anisotropic nature of BP thin films is revealed using angle-resolved Raman and infrared spectroscopies, together with angle-resolved transport study. For 15 nm thick BP, we measure Hall mobility of 1000 and 600 cm^2/Vs for holes along the light (x) and heavy (y) effective mass directions, respectively, at 120 K. These BP thin films also exhibit large and anisotropic in-plane optical conductivity from 2 to 5 micrometer wavelength. Field effect transistors using 4 to 30 layers of BP (2 to 15 nm) as channel material exhibit an on-off current ratio exceeding 10^5, a field-effect mobility of 205 cm^2/Vs, and good saturation properties all at room temperature, suggesting its promising future in high performance thin film electronics. By introducing narrow bandgap BP into the 2D material family, we fill the space between semi-metallic graphene and large bandgap TMDCs, where great potentials for infrared optoelectronics lie. Most importantly, the unique anisotropic nature of this intriguing material creates unprecedented possibilities for the realization of conceptually new optoelectronic and electronic devices in which angle-dependent physical properties are highly desirable.
Weighted sparsity and sparse tensor networks for least squares approximation
Creators: name: Trunschke, Philipp
name: Eigel, Martin
name: Nouy, Anthony
Publisher: name: Weierstrass Institute
Year: 2023
Subjects: subject: Least squares
subject: sample efficiency
subject: sparse tensor networks
subject: alternating least squares
subject: 15A69
subject: 41A30
subject: 62J02
subject: 65Y20
subject: 68Q25

description: The approximation of high-dimensional functions is a ubiquitous problem in many scientific fields that is only feasible practically if advantageous structural properties can be exploited. One prominent structure is sparsity relatively to some basis. For the analysis of these best ??-term approximations a relevant tool is the Stechkin's lemma. In its standard form, however, this lemma does not allow to explain convergence rates for a wide range of relevant function classes. This work presents a new weighted version of Stechkin's lemma that improves the best n-term rates for weighted ℓp-spaces and associated function classes such as Sobolev or Besov spaces. For the class of holomorphic functions, which for example occur as solutions of common high-dimensional parameter dependent PDEs, we recover exponential rates that are not directly obtainable with Stechkin's lemma. This sparsity can be used to devise weighted sparse least squares approximation algorithms as known from compressed sensing. However, in high-dimensional settings, classical algorithms for sparse approximation suffer the curse of dimensionality. We demonstrate that sparse approximations can be encoded efficiently using tensor networks with sparse component tensors. This representation gives rise to a new alternating algorithm for best n-term approximation with a complexity scaling polynomially in n and the dimension. We also demonstrate that weighted ℓpsummability not only induces sparsity of the tensor but also low ranks. This is not exploited by the previous format. We thus propose a new low-rank tensor train format with a single weighted sparse core tensor and an ad-hoc algorithm for approximation in this format. To analyse the sample complexity for this new model class we derive a novel result of independent interest that allows to transfer the restricted isometry property from one set to another sufficiently close set. We then prove that the new model class is close enough to the set of weighted sparse vectors such that the restricted isometry property transfers. Numerical examples illustrate the theoretical results for a benchmark problem from uncertainty quantification. Although they lead up to the analysis of our final model class, our contributions on weighted Stechkin and the restricted isometry property are of independent interest and can be read independently.
Black dreams: a cultural history of the American dream in Black popular culture in the 20th and 21st centuries
Creators: name: Allen-Lamphere, Reniqua
Publisher: name: No Publisher Supplied
Year: 2020

description: This dissertation explores how the American dream has been understood in Black popular culture in the 20th and 21st centuries, providing a cultural history of the idea in three distinct periods in Black America: the great migration, the civil rights movement, and the hip-hop era. Although the dream has been an accessible and prevalent way to explore notions of success and mobility in America, it also has been a problematic myth that has not adequately described lack of opportunity in Black America. African American popular culture has therefore responded to the ideology of the dream through both a material lens of upward class mobility but also a moral frame of a struggle for justice and freedom. By complicating our interpretation of the Black American dream, we can better understand the history of this marginalized community and how hope and aspiration were deployed in the Black community from the great migration to the age of President Donald Trump.