cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Gravitational Faraday effect from on-shell amplitudes
Creators: name: Chen, Wei-Ming
name: Chung, Ming-Zhi
name: Huang, Yu-tin
name: Kim, Jung-Wook
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Effects of massive object's spin on massive-massless $2 \to 2$ classical scattering is studied. Focus is set on the less-considered dimensionless expansion parameter $λ/b$, where $λ$ is the massless particle's wavelength and $b$ is the impact parameter. Corrections in $λ/b$ start to appear from $\mathcal{O}(G^2)$, with leading correction terms tied to the gravitational Faraday effect, which is a special case of the Lense-Thirring effect. We compute the eikonal phase up to $\mathcal{O}(G^2)$ and extract spin effect on the scattering angle and time delay up to 14th order in spin. The gravitational Faraday effect at linear order in spin is reproduced by $λ/b$ correction terms, which we compute to higher orders in spin. We find that the equivalence principle, or universality, holds up to NLO for general spinning bodies, i.e. away from geometric optics limit. Furthermore, in the black hole limit, we confirm the absence of particular spin structure observed, along with the associated shift symmetry, and argue that it holds to arbitrary spin order at $\mathcal{O}(G^2)$ in the massless probe limit.
description: published version; changed title; expanded discussions on the special role of Kerr coupling in exponentiation; additional references; 45 pages, 4 figures, 1 ancillary file
Graphene and Cousin Systems
Creators: name: Drissi, Lalla Btissam
name: Saidi, El Hassan
name: Bousmina, Mosto
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Graphene is a new material that exhibits remarkable properties from both fundamental and applied issues. This is a 2D matter system whose physical and mechanical features have been approached by using tight binding model, first principle calculations based on DFT and membrane theory. Graphene as a carbon molecule has also hidden symmetries that motivated extensions in various dimensions such as chain-type configurations, that are frequently observed as the graphene bridge narrowed down to a few- or single-atom width, graphene multi-layers thought of as electric capacitors, doped graphene to gain more physical properties as well as cousin systems such as diamond and hyperdiamond. In this work, we use tight binding model ideas and field theory method as well as the hidden symmetries of the underlying crystals to study physical aspects of 2D graphene and its homologues. We also study the relation between 2D graphene with the Boriçi-Creutz fermions considered recently in literature as an adequate model to perform numerical simulations in 4D lattice QCD where the two Dirac zeros are interpreted in terms of the light quarks up and down.
description: 34 pages, 14 figures
El rifle gotcha
Creators: name: Pérez Caballero, Jesús
Publisher: name: Zenodo
Year: 2023
Subjects: México
sátira
J. Barcos Leal
estereotipos
mexicanismos
ensayo
El Mañana de Nuevo Laredo
prensa de México
Jorge Ibargüengoitia

description: «Al personaje, mi amigo lo llama el come evidencias, un sujeto que devora las evidencias insertando a una afirmación su contraria (la segunda parte de la frase anula la primera), pero con tal efecto que todo parece que siga igual (pero no, no sigue igual: cuanto menos, se han agrandado más la mentira y la confusión). El ejemplo paradigmático es el tianguero que ofrece “kg completos”, cuando todo kg, para serlo, debe ser completo... Así que kg completo es una tautología, aunque pudiera ser un guiño a la historia de la moneda, un filtro al cliente no habitual, o una inercia compensada por la calidad y baratez del producto».
description: Columna «Desde la frontera», publicada en El Mañana de Nuevo Laredo, p. 4 (local).
Supplementary materials for the article: Extraction of Transformer Parameters from Femm Simulations and Automated Creation of a Transformer Spice Model Using a Scripting Language
Creators: name: ZAIKIN, DENYS
Publisher: name: figshare
Year: 2023
Subjects: Engineering electromagnetics
Electrical machines and drives
Electrical circuits and systems

description: Supplementary materials for the article: Extraction of Transformer Parameters from Femm Simulations and Automated Creation of a Transformer Spice Model Using a Scripting Language. Includes FEMM and LTspice source files.
title: Azimuthal asymmetry in collective electron dynamics in relativistically transparent laser–foil interactions
Creators: name: Gray, Ross
name: McKenna, Paul
Publisher: name: University of Strathclyde
Year: 2014
Subjects: Laser-plasma
Laser-solid
Gemini
Astra-Gemini
Relativistic induced transparency
Self induced transparency
Break out afterburner

description: Asymmetry in the collective dynamics of ponderomotively-driven electrons in the interaction of an ultraintense laser pulse with a relativistically transparent target is demonstrated experimentally. The 2D profile of the beam of accelerated electrons is shown to change from an ellipse aligned along the laser polarization direction in the case of limited transparency, to a double-lobe structure aligned perpendicular to it when a significant fraction of the laser pulse co-propagates with the electrons. The temporally-resolved dynamics of the interaction are investigated via particle-in-cell simulations. The results provide new insight into the collective response of charged particles to intense laser fields over an extended interaction volume, which is important for a wide range of applications, and in particular for the development of promising new ultraintense laser-driven ion acceleration mechanisms involving ultrathin target foils.

Dataset contains experimental data taken using the Astra-Gemini laser facility at the Rutherford Appleton Laboratory. Simulations were conducted using EPOCH code and the ARCHER supercomputer.
Angular momentum and chaos bound of charged particles around Einstein-Euler-Heisenberg AdS black holes
Creators: name: Chen, Deyou
name: Gao, Chuanhong
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper, we investigate influences of the charge and angular momentum of a particle around a charged Einstein-Euler-Heisenberg AdS black hole on a Lyapunov exponent, and find spatial regions where the chaos bound is violated. Positions of circular orbits are gotten by fixing the charge and angular momentum of the particle, respectively. The positions gradually move away from the event horizon with the increase of the angular momentum when the charge is fixed and with the decrease of the charge when the angular momentum is fixed. For certain values of the charge, angular momentum and Euler-Heisenberg parameter, the spatial regions where the bound is violated are found. When the charge is fixed and the Euler-Heisenberg parameter is large, a small angular momentum causes the violation. Although the angular momentum is small, the corresponding spatial region is not small. An interesting discovery is that the bound is violated by the black hole when the particle's charge is less than 1 and $Λ=0$, but this requires the black hole's charge to be large enough. This violation may be related to the dynamical stability of the black hole. The backreaction of the particle on the background spacetime isn't considered in the investigation.
description: 22 pages
A Radiation Transfer Solver for Athena using Short Characteristics
Creators: name: Davis, Shane W.
name: Stone, James M.
name: Jiang, Yan-Fei
Publisher: name: arXiv
Year: 2012
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: We describe the implementation of a module for the Athena magnetohydrodynamics (MHD) code which solves the time-independent, multi-frequency radiative transfer (RT) equation on multidimensional Cartesian simulation domains, including scattering and non-LTE effects. The module is based on well-known and well-tested algorithms developed for modeling stellar atmospheres, including the method of short characteristics to solve the RT equation, accelerated Lambda iteration to handle scattering and non-LTE effects, and parallelization via domain decomposition. The module serves several purposes: it can be used to generate spectra and images, to compute a variable Eddington tensor (VET) for full radiation MHD simulations, and to calculate the heating and cooling source terms in the MHD equations in flows where radiation pressure is small compared with gas pressure. For the latter case, the module is combined with the standard MHD integrators using operator-splitting and we describe this approach in detail. Implementation of the VET method for radiation pressure dominated flows is described in a companion paper. We present results from a suite of test problems for both the RT solver itself, and for dynamical problems that include radiative heating and cooling. These tests demonstrate that the radiative transfer solution is accurate, and confirm that the operator split method is stable, convergent, and efficient for problems of interest. We demonstrate there is no need to adopt ad-hoc assumptions of questionable accuracy to solve RT problems in concert with MHD: the computational cost for our general-purpose module for simple (e.g. LTE grey) problems can be comparable to or less than a single timestep of Athena's MHD integrators, and only few times more expensive than that for more general problems. (Abridged)
description: 20 pages, 13 figures, accepted for publication in ApJ Supplement Series
Learning Content Selection Rules for Generating Object Descriptions in Dialogue
Creators: name: Jordan, P. W.
name: Walker, M. A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: A fundamental requirement of any task-oriented dialogue system is the ability to generate object descriptions that refer to objects in the task domain. The subproblem of content selection for object descriptions in task-oriented dialogue has been the focus of much previous work and a large number of models have been proposed. In this paper, we use the annotated COCONUT corpus of task-oriented design dialogues to develop feature sets based on Dale and Reiters (1995) incremental model, Brennan and Clarks (1996) conceptual pact model, and Jordans (2000b) intentional influences model, and use these feature sets in a machine learning experiment to automatically learn a model of content selection for object descriptions. Since Dale and Reiters model requires a representation of discourse structure, the corpus annotations are used to derive a representation based on Grosz and Sidners (1986) theory of the intentional structure of discourse, as well as two very simple representations of discourse structure based purely on recency. We then apply the rule-induction program RIPPER to train and test the content selection component of an object description generator on a set of 393 object descriptions from the corpus. To our knowledge, this is the first reported experiment of a trainable content selection component for object description generation in dialogue. Three separate content selection models that are based on the three theoretical models, all independently achieve accuracies significantly above the majority class baseline (17%) on unseen test data, with the intentional influences model (42.4%) performing significantly better than either the incremental model (30.4%) or the conceptual pact model (28.9%). But the best performing models combine all the feature sets, achieving accuracies near 60%. Surprisingly, a simple recency-based representation of discourse structure does as well as one based on intentional structure. To our knowledge, this is also the first empirical comparison of a representation of Grosz and Sidners model of discourse structure with a simpler model for any generation task.
Beyond the darkness
Creators: name: Barukčić, Ilija
Publisher: name: Zenodo
Year: 2023
Subjects: Dark energy
Dark matter
General theory of realtivity
Unified field theory
Cause
Effect
Causation
Causality
Barukčić, Ilija
Ilija Barukčić
Barukcic
Barukčić
Uploaded on Zenodo November 23, 2023

description: Background:
The intricate exploration of dark matter and dark energy stands as a formidable and enduring challenge within the realms of physics. While the cosmos reveals its dazzling array of phenomena, the elusive nature of these mysterious entities continues to captivate the scientific community.
Material and methods:
This study addresses the profound mystery surrounding dark matter and dark energy by leveraging the foundational principles of Einstein's General Relativity. Employing advanced Tensor calculus methods, particularly delving into the intricacies of tensors and anti-tensors, our approach is meticulously designed to unravel the complexities that shroud these cosmic enigmas.
Results:
The culmination of our investigation marks a pivotal moment – the successful resolution of the longstanding conundrum of dark matter. Drawing upon the power of Tensor calculus and insights derived from General Relativity, our findings illuminate the previously obscured nature of dark matter. This epistemological transformation signifies not just a departure from darkness to clarity, but a groundbreaking leap forward in our understanding of the basics of objective reality.
Conclusion:
No longer hidden behind epistemological obscurity, dark matter emerges from the shadows. Through the lens of Einstein's General Relativity and the precision of Tensor calculus, we unveil a more nuanced comprehension of dark matter and dark energy. This newfound clarity opens pathways for profound insights, even beyond the darkness, into the most far-reaching foundational aspects of nature itself.
Glacial isostatic adjustment of laterally homogeneous vs. heterogeneous earth models
Creators: name: Ni, Zhihong
Publisher: name: University of Calgary
Year: 1998
Subjects: subject: QE511 .N5 1998A
subject: Additional Copy: QE511 .N5 1998 in the Gallagher Library of Geology and Geophysics
subject: Isostatic pressing
subject: Glacial landforms
subject: Earth--Mathematical models

description: Bibliography: p. 127-136
Temporally-ultralong biphotons with a linewidth of 50 kHz
Creators: name: Wang, Yu-Sheng
name: Li, Kai-Bo
name: Chang, Chao-Feng
name: Lin, Tan-Wen
name: Li, Jian-Qing
name: Hsiao, Shih-Si
name: Chen, Jia-Mou
name: Lai, Yi-Hua
name: Chen, Ying-Cheng
name: Chen, Yong-Fan
name: Chuu, Chih-Sung
name: Yu, Ite A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We report the generation of biphotons, with a temporal full width at the half maximum (FWHM) of 13.4$\pm$0.3 $μ$s and a spectral FWHM of 50$\pm$1 kHz, via the process of spontaneous four-wave mixing. The temporal width is the longest, and the spectral linewidth is the narrowest up to date. This is also the first biphoton result that obtains a linewidth below 100 kHz, reaching a new milestone. The very long biphoton wave packet has a signal-to-background ratio of 3.4, which violates the Cauchy-Schwarz inequality for classical light by 4.8 folds. Furthermore, we demonstrated a highly-tunable-linewidth biphoton source and showed that while the biphoton source's temporal and spectral width were controllably varied by about 24 folds, its generation rate only changed by less than 15\%. A spectral brightness or generation rate per pump power per linewidth of 1.2$\times$10$^6$ pairs/(s$\cdot$mW$\cdot$MHz) was achieved at the temporal width of 13.4 $μ$s. The above results were made possible by the low decoherence rate and high optical depth of the experimental system, as well as the nearly phase-mismatch-free scheme employed in the experiment. This work has demonstrated a high-efficiency ultranarrow-linewidth biphoton source, and has made a substantial advancement in the quantum technology utilizing heralded single photons.
description: 9 pages, 4 figures, 1 table
Jet-veto in bottom-quark induced Higgs production at next-to-next-to-leading order
Creators: name: Harlander, Robert
name: Wiesemann, Marius
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present results for associated Higgs+n-jet production in bottom quark annihilation, for n=0 and n>=1 at NNLO and NLO accuracy, respectively. We consider both the cases with and without b-tagging. Numerical results are presented for parameters relevant for experiments at the LHC.
description: 27 pages, 13 figures, 8 tables
Molecular cloning, characterization and functional analysis of cysteine protease cDNAs from leishmania donovani chagasi and trypanosoma cruzi
Creators: name: Omara-Opyene, A.L.
Publisher: name: University of Calgary
Year: 1997
Subjects: subject: RC153 .O63 1997
subject: Leishmaniasis - Epidemiology
subject: Chagas' disease.

description: Bibliography: p. 203-210
A Dark Energy Model in Lyra Manifold
Creators: name: Hova, Hoavo
Publisher: name: arXiv
Year: 2012
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We consider, in normal-gauge Lyra's geometry, evolution of a homogeneous isotropic universe in a gravitational model involving only the standard matter in interaction with a displacement vector field $ϕ_μ$. Considering both constant and time-dependent displacement vector field we show that the observed cosmic acceleration could be explained without considering an alien energy component with a negative pressure.
description: 15 pages, 2 figures, LaTeX file
title: Laser pulse propagation and enhanced energy coupling to fast electrons in dense plasma gradients
Creators: name: Gray, Ross
name: McKenna, Paul
Publisher: name: University of Strathclyde
Year: 2014
Subjects: Laser-plasma
Plasma density gradient
Vulcan TAP
Fast Ignition
Relativistic self focusing
Laser-solid

description: Dataset for a study of laser energy absorption to fast electrons during the interaction of an ultra-intense (1020 W cm−2), picosecond laser pulse with a solid as a function of the plasma density scale length. It is shown that there is an optimum density gradient for efficient energy coupling to electrons and that this arises due to strong self-focusing and channeling driving energy absorption over an extended length in the preformed plasma. At longer density gradients the laser filaments, resulting in significantly lower overall energy coupling. As the scale length is further increased, a transition to a second laser energy absorption process is observed experimentally via multiple diagnostics. The results demonstrate that it is possible to significantly enhance laser energy absorption and coupling to fast electrons by dynamically controlling the plasma density gradient. These results are of general importance for understanding absorption in laser-solid interactions but are specifically relevant for conditions where long plasma density scale lengths are expected such as in the corona of imploded targets in the fast ignition approach to inertial confinement fusion.

Experimental and simulation data published in New Journal of Physics 16 (11), 113075. Experimental data was taken in April 2010 using the VULCAN-TAP laser facility at the Rutherford Appleton Laboratory. Simulations were conducted using the PRISM hydrodynamic code and EPOCH PIC code on the ARCHIE-west cluster.
Characterization of the testis-specific transcription facters TTF-D and CREMtau, which regulate the RT7 gene
Creators: name: Oosterhuis, Jessica Helen
Publisher: name: University of Calgary
Year: 1998
Subjects: subject: QL966 .O67 1998
subject: Spermatogenesis - Genetic aspects
subject: Spermatozoa - Physiology

description: Bibliography: p. 208-221
A Godunov Method for Multidimensional Radiation Magnetohydrodynamics based on a variable Eddington tensor
Creators: name: Jiang, Yan-Fei
name: Stone, James M.
name: Davis, Shane W.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We describe a numerical algorithm to integrate the equations of radiation magnetohydrodynamics in multidimensions using Godunov methods. This algorithm solves the radiation moment equations in the mixed frame, without invoking any diffusion-like approximations. The moment equations are closed using a variable Eddington tensor whose components are calculated from a formal solution of the transfer equation at a large number of angles using the method of short characteristics. We use a comprehensive test suite to verify the algorithm, including convergence tests of radiation-modified linear acoustic and magnetosonic waves, the structure of radiation modified shocks, and two-dimensional tests of photon bubble instability and the ablation of dense clouds by an intense radiation field. These tests cover a very wide range of regimes, including both optically thick and thin flows, and ratios of the radiation to gas pressure of at least 10^{-4} to 10^{4}. Across most of the parameter space, we find the method is accurate. However, the tests also reveal there are regimes where the method needs improvement, for example when both the radiation pressure and absorption opacity are very large. We suggest modifications to the algorithm that will improve accuracy in this case. We discuss the advantages of this method over those based on flux-limited diffusion. In particular, we find the method is not only substantially more accurate, but often no more expensive than the diffusion approximation for our intended applications.
description: 42 pages, 22 figures, 2 tables, accepted by ApJS
Wiederaufbaupläne für Burg Fürstenberg am Rhein
Creators: name: Gondorf, Bernhard
Publisher: name: Burgen und Schlösser - Zeitschrift für Burgenforschung und Denkmalpflege
Year: 2020

description: -
description: Burgen und Schlösser - Zeitschrift für Burgenforschung und Denkmalpflege, Bd. 32 Nr. 1 (1991): Burgen und Schlösser - Zeitschrift für Burgenforschung und Denkmalpflege
Ideal two-dimensional electron systems with a giant Rashba-type spin splitting in real materials: surfaces of bismuth tellurohalides
Creators: name: Eremeev, Sergey V.
name: Nechaev, Ilya A.
name: Koroteev, Yury M.
name: Echenique, Pedro M.
name: Chulkov, Evgueni V.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Spintronics is aimed at active controlling and manipulating the spin degrees of freedom in semiconductor devices. A promising way to achieve this goal is to make use of the tunable Rashba effect that relies on the spin-orbit interaction (SOI) in a two-dimensional (2D) electron system immersed in an inversion-asymmetric environment. The SOI induced spin-splitting of the 2D-electron state provides a basis for many theoretically proposed spintronic devices. However, the lack of semiconductors with large Rashba effect hinders realization of these devices in actual practice. Here we report on a giant Rashba-type spin splitting in 2D electron systems which reside at tellurium-terminated surfaces of bismuth tellurohalides. Among these semiconductors, BiTeCl stands out for its isotropic metallic surface-state band with the Gamma-point energy lying deep inside the bulk band gap. The giant spin-splitting of this band ensures a substantial spin asymmetry of the inelastic mean free path of quasiparticles with different spin orientations.
description: 12 pages, 5 figures
On bi-skew braces and brace blocks
Creators: name: Stefanello, L.
name: Trappeniers, S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Group Theory (math.GR)
subject: Quantum Algebra (math.QA)
subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics

description: L. N. Childs defined a bi-skew brace to be a skew brace such that if we swap the role of the two operations, then we find again a skew brace. In this paper, we give a systematic analysis of bi-skew braces. We study nilpotency and solubility, and connections between bi-skew braces and set-theoretic solutions of the Yang--Baxter equation. Further, we deal with Byott's conjecture in the case of bi-skew braces, and we use bi-skew braces as a tool to solve a classification problem proposed by L. Vendramin. In the final part, we investigate brace blocks, defined by A. Koch to be families of group operations on a given set such that any two of them yield a bi-skew brace. We provide a characterisation of brace blocks, illustrate how all known constructions in literature follow in a natural way from our characterisation, and give several new examples.
description: Final version, published in Journal of Pure and Applied Algebra
Dr.-Johannes-Romberg-Stiftung für Denkmalpflege
Creators: name: Kerber, Dieter
Publisher: name: Burgen und Schlösser - Zeitschrift für Burgenforschung und Denkmalpflege
Year: 2020

description: -
description: Burgen und Schlösser - Zeitschrift für Burgenforschung und Denkmalpflege, Bd. 32 Nr. 1 (1991): Burgen und Schlösser - Zeitschrift für Burgenforschung und Denkmalpflege
Dynamic negative capacitance regime in GeTe Rashba ferroelectric
Creators: name: Orlova, N. N.
name: Timonina, A. V.
name: Kolesnikov, N. N.
name: Deviatov, E. V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We experimentally investigate capacitance response of a thick ferroelectric GeTe single-crystal flake on the Si/SiO2 substrate, where p-doped Si layer serves as a gate electrode. We confirm by resistance measurements, that for three-dimensional flakes, electron concentration is not sensitive to the gate electric field due to the screening by bulk carriers. Unexpectedly, we observe that sample capacitance C is strongly diminishing for both gate field polarities, so C(Vg) is a maximum near the zero gate voltage. Also, we observe well-developed hysteresis with the gate voltage sweep direction for the experimental C(Vg) curves. From our analysis, the capacitance behavior is explained by the known dependence of the Rashba parameter on the electric field for giant Rashba splitting in GeTe. In this case, the hysteresis in capacitance should be ascribed to polarization evolution in GeTe surface layers, which also allows to realize the regime of dynamic negative capacitance. The latter can be directly observed in time-dependent resistive measurements, as non-monotonic evolution of voltage response to the step-like current pulse. Thus, the negative capacitance regime can indeed improve performance and, therefore, the energy efficiency of electronic devices.
An experimental investigation of the flow structure and stability limits of jet diffusion flames in a co-flowing oxidizing stream
Creators: name: Papanikolaou, Nancy
Publisher: name: University of Calgary
Year: 1998
Subjects: subject: QD516 .P37 1998
subject: Flame - Research
subject: Combustion research
subject: Gases - Thermal properties
subject: Combustion engineering

description: Bibliography: p. 184-196
Production of the blood anticoagulant, hirudin, in plants
Creators: name: Parmenter, Dana L.
Publisher: name: University of Calgary
Year: 1998
Subjects: subject: TP248.6 .P37 1998
subject: Anticoagulants (Medicine)
subject: Plant genetic engineering.
subject: Genetic engineering
subject: Biotechnology

description: Bibliography: p. 201-222
Machine Learning-based models in particle-in-cell codes for advanced physics extensions
Creators: name: Badiali, Chiara
name: Bilbao, Pablo J.
name: Cruz, Fábio
name: Silva, Luis O.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: In this paper we propose a methodology for the efficient implementation of Machine Learning (ML)-based methods in particle-in-cell (PIC) codes, with a focus on Monte-Carlo or statistical extensions to the PIC algorithm. The presented approach allows for neural networks to be developed in a Python environment, where advanced ML tools are readily available to proficiently train and test them. Those models are then efficiently deployed within highly-scalable and fully parallelized PIC simulations during runtime. We demonstrate this methodology with a proof-of-concept implementation within the PIC code OSIRIS, where a fully-connected neural network is used to replace a section of a Compton scattering module. We demonstrate that the ML-based method reproduces the results obtained with the conventional method and achieves better computational performance. These results offer a promising avenue for future applications of ML-based methods in PIC, particularly for physics extensions where an ML-based approach can provide a higher performance increase.
description: 12 pages, 5 figures
Event-Triggered Impulsive Control for Nonlinear Systems with Actuation Delays
Creators: name: Zhang, Kexue
name: Braverman, Elena
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optimization and Control (math.OC)
subject: Systems and Control (eess.SY)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper studies impulsive stabilization of nonlinear systems. We propose two types of event-triggering algorithms to update the impulsive control signals with actuation delays. The first algorithm is based on continuous event detection, while the second type makes decision about updating the impulsive control inputs according to periodic event detection. Sufficient conditions are derived to ensure asymptotic stability of the impulsive control systems with the designed event-triggering algorithms. Lower bounds of the time period between two consecutive events are also obtained, so that the closed-loop impulsive systems are free of Zeno behavior. That is to say that the pulse phenomena are excluded from the event-triggered impulsive control systems, in the community of impulsive differential equations. An illustrative example demonstrates effectiveness of the proposed algorithms and our theoretical results.
Das Bestandsaufmaß als Grundlage der Bauanalyse
Creators: name: Bingenheimer, Klaus
Publisher: name: Burgen und Schlösser - Zeitschrift für Burgenforschung und Denkmalpflege
Year: 2020

description: -
description: Burgen und Schlösser - Zeitschrift für Burgenforschung und Denkmalpflege, Bd. 32 Nr. 2 (1991): Burgen und Schlösser - Zeitschrift für Burgenforschung und Denkmalpflege
Data-driven evolutionary algorithm for oil reservoir well-placement and control optimization
Creators: name: Chen, Guodong
name: Luo, Xin
name: Jiao, Jimmy Jiu
name: Xue, Xiaoming
Publisher: name: arXiv
Year: 2022
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: Optimal well placement and well injection-production are crucial for the reservoir development to maximize the financial profits during the project lifetime. Meta-heuristic algorithms have showed good performance in solving complex, nonlinear and non-continuous optimization problems. However, a large number of numerical simulation runs are involved during the optimization process. In this work, a novel and efficient data-driven evolutionary algorithm, called generalized data-driven differential evolutionary algorithm (GDDE), is proposed to reduce the number of simulation runs on well-placement and control optimization problems. Probabilistic neural network (PNN) is adopted as the classifier to select informative and promising candidates, and the most uncertain candidate based on Euclidean distance is prescreened and evaluated with a numerical simulator. Subsequently, local surrogate model is built by radial basis function (RBF) and the optimum of the surrogate, found by optimizer, is evaluated by the numerical simulator to accelerate the convergence. It is worth noting that the shape factors of RBF model and PNN are optimized via solving hyper-parameter sub-expensive optimization problem. The results show the optimization algorithm proposed in this study is very promising for a well-placement optimization problem of two-dimensional reservoir and joint optimization of Egg model.
A practical guide to verifiable, evidence-based conservation: monitoring.
Creators: name: Funk, Stephan M
Publisher: name: Zenodo
Year: 2023
Subjects: conservation plan
conservation management
conservation standards
evidence-based conservation
monitoring plan

description: Effective conservation monitoring is essential for assessing the impact of efforts to protect populations, species, biodiversity and ecosystems. Establishing a monitoring plan guided by SMART criteria ensures that both short-term actions and long-term goals are evaluated accurately. Baseline data, especially when combined with a counterfactual set-up or other tests, are crucial for discerning the true effects of conservation activities. The selection of robust indicators and methods, including emerging technologies like environmental DNA (eDNA), camera traps, and remote sensing, enables precise monitoring of diverse ecological parameters. The commitment of sufficient resources and expertise underpins the success of these methods. Analysing, sharing, and synthesizing data close the feedback loop, allowing for the refinement of conservation strategies and promoting sustainable practices that can adapt to changing environmental conditions.
title: Restoration Strategies for Wetlands in the Arid West: Seeding and Planting Approaches for Lakeshore Ecosystems
Creators: name: Braun, Jes
Publisher: name: Utah State University
Year: 2023

description: Wetlands are widely recognized for their valuable benefits such as providing habitat, improving water quality, and reducing the impacts of flooding. However, wetlands face threats from development, drought, and invasive species. This is particularly apparent in the arid west, where upstream water use and drought make water scarcer and contribute to dramatically changing water levels. Here, I investigated revegetation techniques for lakeshore wetlands, using Utah Lake as a case study. Although recent management efforts have minimized invasive Phragmites cover, the desired plant communities are not returning as quickly as needed, highlighting the need to research restoration techniques. Through my research, I discuss the optimal seeding density and elevation, as well as the ideal arrangement of plugs to promote establishment success without excessive competition. The findings suggest that seeding at lower elevations and planting plugs at a less dense arrangement can lead to better outcomes. Additionally, I provide a guidebook for restoration and management of lakeshores in the eastern Great Basin, offering practical applications and background information for nine recommended best practices. Overall, I emphasize the importance of effective revegetation techniques for wetland restoration and the need for further research and decision-making to facilitate successful outcomes for wetlands in the eastern Great Basin.
Relational Dynamic Bayesian Networks
Creators: name: Domingos, P.
name: Sanghai, S.
name: Weld, D.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Stochastic processes that involve the creation of objects and relations over time are widespread, but relatively poorly studied. For example, accurate fault diagnosis in factory assembly processes requires inferring the probabilities of erroneous assembly operations, but doing this efficiently and accurately is difficult. Modeled as dynamic Bayesian networks, these processes have discrete variables with very large domains and extremely high dimensionality. In this paper, we introduce relational dynamic Bayesian networks (RDBNs), which are an extension of dynamic Bayesian networks (DBNs) to first-order logic. RDBNs are a generalization of dynamic probabilistic relational models (DPRMs), which we had proposed in our previous work to model dynamic uncertain domains. We first extend the Rao-Blackwellised particle filtering described in our earlier work to RDBNs. Next, we lift the assumptions associated with Rao-Blackwellization in RDBNs and propose two new forms of particle filtering. The first one uses abstraction hierarchies over the predicates to smooth the particle filters estimates. The second employs kernel density estimation with a kernel function specifically designed for relational domains. Experiments show these two methods greatly outperform standard particle filtering on the task of assembly plan execution monitoring.
Seven Etudes on dynamical Keldysh Model
Creators: name: Efremov, D. V.
name: Kiselev, M. N.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We present a comprehensive pedagogical discussion of a family of models describing the propagation of a single particle in a multicomponent non-Markovian Gaussian random field. We report some exact results for single-particle Green's functions, self-energy, vertex part and T-matrix. These results are based on a closed form solution of the Dyson equation combined with the Ward identity. Analytical properties of the solution are discussed. Further we describe the combinatorics of the Feynman diagrams for the Green's function and the skeleton diagrams for the self-energy and vertex, using recurrence relations between the Taylor expansion coefficients of the self-energy. Asymptotically exact equations for the number of skeleton diagrams in the limit of large N are derived. Finally, we consider possible realizations of a multicomponent Gaussian random potential in quantum transport via complex quantum dot experiments.
description: 42 pages, 14 figures; extended version
The degeneracy between star-formation parameters in dwarf galaxy simulations and the Mstar-Mhalo relation
Creators: name: Cloet-Osselaer, Annelies
name: De Rijcke, Sven
name: Schroyen, Joeri
name: Dury, Vanessa
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present results based on a set of N-Body/SPH simulations of isolated dwarf galaxies. The simulations take into account star formation, stellar feedback, radiative cooling and metal enrichment. The dark matter halo initially has a cusped profile, but, at least in these simulations, starting from idealised, spherically symmetric initial conditions, a natural conversion to a core is observed due to gas dynamics and stellar feedback. A degeneracy between the efficiency with which the interstellar medium absorbs energy feedback from supernovae and stellar winds on the one hand, and the density threshold for star formation on the other, is found. We performed a parameter survey to determine, with the aid of the observed kinematic and photometric scaling relations, which combinations of these two parameters produce simulated galaxies that are in agreement with the observations. With the implemented physics we are unable to reproduce the relation between the stellar mass and the halo mass as determined by Guo et al. (2010), however we do reproduce the slope of this relation.
description: Accepted for publication in MNRAS | 12 pages, 8 figures
Thermalization by a synthetic horizon
Creators: name: Mertens, Lotte
name: Moghaddam, Ali G.
name: Chernyavsky, Dmitry
name: Morice, Corentin
name: Brink, Jeroen van den
name: van Wezel, Jasper
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Other Condensed Matter (cond-mat.other)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Synthetic horizons in models for quantum matter provide an alternative route to explore fundamental questions of modern gravitational theory. Here, we apply these concepts to the problem of emergence of thermal quantum states in the presence of a horizon, by studying ground-state thermalization due to instantaneous horizon creation in a gravitational setting and its condensed matter analogue. By a sudden quench to position-dependent hopping amplitudes in a one-dimensional lattice model, we establish the emergence of a thermal state accompanying the formation of a synthetic horizon. The resulting temperature for long chains is shown to be identical to the corresponding Unruh temperature, provided that the post-quench Hamiltonian matches the entanglement Hamiltonian of the pre-quench system. Based on detailed analysis of the outgoing radiation we formulate the conditions required for the synthetic horizon to behave as a purely thermal source, paving a way to explore this interplay of quantum-mechanical and gravitational aspects experimentally.
New Method for Exploring Super-Eddington AGNs by Near-infrared Observations
Creators: name: Kawakatu, Nozomu
name: Ohsuga, Ken
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We propose a new method to explore the candidate super-Eddington active galactic nuclei (AGNs). We examine the properties of infrared (IR) emission from the inner edge of the dusty torus in AGNs, which are powered by super- or sub-Eddington accretion flows around black holes, by considering the dependence of the polar angle on the radiation flux of accretion flows (Watarai et al. 2005). We find that for super-Eddington AGNs, of which the mass accretion rate is more than 10^2 times larger than the Eddington rate, the ratio of the AGN IR luminosity and the disc bolometric luminosity is less than 10^-2, unless the half opening angle of the torus (theta_torus) is small (theta_torus <65 degree). This is due to the self-occultation effect, whereby the self-absorption at the outer region of the super-Eddington flow dilutes the illumination of the torus. Such a small luminosity ratio is not observed in sub-Eddington AGNs, whose mass accretion rate is comparable to or no more than 10 times larger than the Eddington mass accretion rate, except for extremely thin tori (theta_torus >85 degree). We also consider the properties of the near-IR (NIR) emission radiated from hot dust >1000 K. We find that super-Eddington AGNs have a ratio of the NIR luminosity to the bolometric luminosity, L_NIR,AGN/L_bol,disc, at least one order of magnitude smaller than for sub-Eddington AGNs for a wide range of half opening angle (theta_torus > 65 degree), for various types of dusty torus model. Thus, a relatively low L_NIR,AGN/L_bol,disc is a property that allows identification of candidate super-Eddington AGNs. Lastly, we discuss the possibility that NIR-faint quasars at redshift z=6 discovered by a recent deep SDSS survey may be young quasars whose black holes grow via super-Eddington accretion.
description: 10pages, 6figures, 1table, Accepted for publication in MNRAS
Brown representability for triangulated categories with a linear action by a graded ring
Creators: name: Letz, Janina C.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Category Theory (math.CT)
subject: FOS: Mathematics
subject: 18G80

description: In this paper we give necessary and sufficient conditions for a functor to be representable in a strongly generated triangulated category which has a linear action by a graded ring, and we discuss some applications and examples.
description: 10 pages, small changes for version 2, appeared in Archiv der Mathematik
title: Optimal Stopping of Multi-Robot Exploration for Unknown, Bounded Environments
Creators: name: Crowther, Trey D.
Publisher: name: Utah State University
Year: 2023

description: Limited resources and uncertainty pose a substantial problem for multi-robot exploration of unknown environments. This research paper looks to determine the optimal time to terminate robot exploration while maximizing information gathered. Whilst making this determination, the system's resources and capabilities must be taken into account. To see if our strategy works, we ran many simulations in varying environments. The results of this research are important for real-world uses like robot exploration, search and rescue missions, and automated surveillance. Determining when to stop exploring can help the system save resources, explore faster, and make better decisions.
Project Poseidon: Position Paper
Creators: name: Goh, Kheng Lim
name: De Silva, Rangika Thilan
name: Pasbakhsh, Pooria
name: Zivkovic, Vladimir
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 410503
subject: Groundwater quality processes and contaminated land assessment
classificationCode: 410504
subject: Surface water quality processes and contaminated sediment assessment
classificationCode: 401102
subject: Environmentally sustainable engineering
classificationCode: 401106
subject: Waste management, reduction, reuse and recycling

description: The Poseidon project, a collaboration between SLINTEC, Monash University Malaysia, and Newcastle University, has developed the Poseidon filter unit, a groundbreaking portable water filtration device. This position paper highlights its technological breakthrough, heavy metal removal focus, global compliance, and environmental considerations. Emphasizing the need for continued support, it discusses future directions, including smart technology integration, global collaborations, and educational initiatives. The paper underscores Poseidon's positive impact on clean water accessibility, especially in disaster-prone regions, and advocates for ongoing innovation and collaboration for sustainable water solutions.
Magnetic Forces in Paramagnetic Fluids
Creators: name: Butcher, T. A.
name: Coey, J. M. D.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: An overview of the effect of a magnetic field gradient on fluids with linear magnetic susceptibilities is given. It is shown that two commonly encountered expressions, the magnetic field gradient force and the concentration gradient force for paramagnetic species in solution are equivalent for incompressible fluids. The magnetic field gradient and concentration gradient forces are approximations of the Kelvin force and Korteweg-Helmholtz force densities, respectively. The criterion for the appearance of magnetically induced convection is derived. Experimental work in which magnetically induced convection plays a role is reviewed.
Macro- and micro-strain in GaN nanowires on Si(111)
Creators: name: Jenichen, Bernd
name: Brandt, Oliver
name: Pfueller, Carsten
name: Dogan, Pinar
name: Knelangen, Mathias
name: Trampert, Achim
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We analyze the strain state of GaN nanowire ensembles by x-ray diffraction. The nanowires are grown by molecular beam epitaxy on a Si(111) substrate in a self-organized manner. On a macroscopic scale, the nanowires are found to be free of strain. However, coalescence of the nanowires results in micro-strain with a magnitude from +-0.015% to +-0.03%.This micro-strain contributes to the linewidth observed in low-temperature photoluminescence spectra.