cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Accelerating Finite-temperature Kohn-Sham Density Functional Theory with Deep Neural Networks
Creators: name: Ellis, J. Austin
name: Fiedler, Lenz
name: Popoola, Gabriel A.
name: Modine, Normand A.
name: Stephens, J. Adam
name: Thompson, Aidan P.
name: Cangi, Attila
name: Rajamanickam, Sivasankaran
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Machine Learning (cs.LG)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We present a numerical modeling workflow based on machine learning (ML) which reproduces the the total energies produced by Kohn-Sham density functional theory (DFT) at finite electronic temperature to within chemical accuracy at negligible computational cost. Based on deep neural networks, our workflow yields the local density of states (LDOS) for a given atomic configuration. From the LDOS, spatially-resolved, energy-resolved, and integrated quantities can be calculated, including the DFT total free energy, which serves as the Born-Oppenheimer potential energy surface for the atoms. We demonstrate the efficacy of this approach for both solid and liquid metals and compare results between independent and unified machine-learning models for solid and liquid aluminum. Our machine-learning density functional theory framework opens up the path towards multiscale materials modeling for matter under ambient and extreme conditions at a computational scale and cost that is unattainable with current algorithms.
[Brev til DKNVS]
Creators: name: Wergeland, Harald Titus Alexis
name: Det Kongelige Norske Videnskabers Selskab (DKNVS)
Publisher: name: Unknown
Year: 1841

description: Skriver at han er forfatter til en prisoppgave
description: Konvolutt med segl. Polydoc nr. 1: 2463. Polydoc nr. 2: 1889.
Determining the Neutrino Mass Hierarchy with Atmospheric Neutrinos
Creators: name: Petcov, S. T.
name: Schwetz, T.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The possibility to determine the type of neutrino mass hierarchy by studying atmospheric neutrino oscillations with a detector capable to distinguish between neutrino and antineutrino events, such as magnetized iron calorimeters, is considered. We discuss how the ability to distinguish between the neutrino mass spectrum with normal and inverted hierarchy depends on detector characteristics like neutrino energy and direction resolutions or charge miss-identification, and on the systematical uncertainties related to the atmospheric neutrino fluxes. We show also how the neutrino mass hierarchy determination depends on the true values of $θ_{13}$ and $θ_{23}$, as well as on the type of the true hierarchy. We find that for $μ$-like events, an accurate reconstruction of the energy and direction of the neutrino greatly improves the sensitivity to the type of neutrino mass spectrum. For $\sin^22θ_{13} \cong 0.1$ and a precision of 5% in the reconstruction of the neutrino energy and $5^\circ$ in the neutrino direction, the type of neutrino mass hierarchy can be identified at the 2$σ$ C.L. with approximately 200 events. For resolutions of 15% for the neutrino energy and $15^\circ$ for the neutrino direction roughly one order of magnitude larger event numbers are required. For a detector capable to distinguish between $ν_e$ and $\barν_e$ induced events the requirements on energy and direction resolutions are, in general, less demanding than for a detector with muon charge identification.
description: 24 pages, 8 figures
Cosmological implication of antisymmetric tensor field on D-brane
Creators: name: Cho, Inyong
name: Chun, Eung Jin
name: Kim, Hang Bae
name: Kim, Yoonbai
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discuss the cosmological implications of an antisymmetric tensor field when it experiences a kind of ``Higgs mechanism,'' including nonlocal interaction terms, on D-branes. Even when a huge magnetic-condensation-inducing anisotropy is assumed in the early universe, the expansion of the universe leads to an isotropic $B$-matter-dominated universe.
description: 16 pages, 4 figures. To appear in the proceedings of the 9th Italian-Korean Symposium on Relativistic Astrophysics, Seoul, South Korea, and Mt. Kumgang, North Korea, 19-24 Jul. 2005. Submitted to J. Korean Phys. Soc. Minor corrections have been made. References have been added
Superconductor to metal transition in overdoped cuprates
Creators: name: Li, Zi-Xiang
name: Kivelson, Steven A.
name: Lee, Dung-Hai
Publisher: name: arXiv
Year: 2020
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We present a theoretical framework for understanding the behavior of the normal and superconducting states of overdoped cuprate high temperature superconductors in the vicinity of the doping-tuned quantum superconductor-to-metal transition. The key ingredients on which we focus are d-wave pairing, a flat antinodal dispersion, and disorder. Even for homogeneous disorder, these lead to effectively granular superconducting correlations and a superconducting transition temperature determined in large part by the superfluid stiffness rather than the pairing scale.
description: 6 pages, 7 figures plus 4 Supplementary pages, 4 Supplementary figures
Linear Theory of Thin, Radially-Stratified Disks
Creators: name: Johnson, Bryan M.
name: Gammie, Charles F.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We consider the nonaxisymmetric linear theory of radially-stratified disks. We work in a shearing-sheet-like approximation, where the vertical structure of the disk is neglected, and develop equations for the evolution of a plane-wave perturbation comoving with the shear flow (a shearing wave, or ``shwave''). We calculate a complete solution set for compressive and incompressive short-wavelength perturbations in both the stratified and unstratified shearing-sheet models. We develop expressions for the late-time asymptotic evolution of an individual shwave as well as for the expectation value of the energy for an ensemble of shwaves that are initially distributed isotropically in k-space. We find that: (i) incompressive, short-wavelength perturbations in the unstratified shearing sheet exhibit transient growth and asymptotic decay, but the energy of an ensemble of such shwaves is constant with time (consistent with Afshordi, Mukhopadhyay & Narayan 2004); (ii) short-wavelength compressive shwaves grow asymptotically in the unstratified shearing sheet, as does the energy of an ensemble of such shwaves; (iii) incompressive shwaves in the stratified shearing sheet have density and azimuthal velocity perturbations δΣ,δv_y ~ t^{-Ri} (for |Ri| << 1), where Ri = N_x^2/(q Ω)^2 is the Richardson number, N_x^2 is the square of the radial Brunt-Vaisala frequency and qΩis the effective shear rate; (iv) the energy of an ensemble of incompressive shwaves in the stratified shearing sheet behaves asymptotically as Ri t^{1-4Ri} for |Ri| << 1. For Keplerian disks with modest radial gradients, |Ri| is expected to be << 1, and there will therefore be weak growth in a single shwave for Ri < 0 and near-linear growth in the energy of an ensemble of shwaves, independent of the sign of Ri.
description: 28 pages, 1 figure, submitted to the Astrophysical Journal
GEORG MAX LUDWIG DERLITZKI (1889-1958)
Creators: name: Derlitzki, Rotraut
name: Schulze, Eberhard
name: Derlitzki, Rotraut
name: Schulze, Eberhard
Publisher: name: Unknown
Year: 2004
Subjects: subject: Labor and Human Capital
subject: Teaching/Communication/Extension/Profession
subject: Labor sciences
subject: agriculture
subject: fascism

description: ZUSAMMENFASSUNG Der Beitrag ist Prof. Dr. Georg Derlitzki, dem Nestor der Arbeitswissenschaften in der deutschen Landwirtschaft und ab 1948 Professor für Arbeitswissenschaften in Halle (Saale), gewidmet. Auf Grund der Ablehnung der von den Nationalsozialisten verfolgten Politik und ihrer Vorstellungen zur Entwicklung der Landwirtschaft wurde er als Direktor der "Versuchs-anstalt für Landarbeitslehre" in Pommritz in Sachsen abgesetzt. ABSTRACT The Discussion Paper is dedicated Prof. Dr. Georg Derlitzki, founder of the agricultural labor sciences in Germany and Professor of labor sciences at the University Halle (Saale) from 1948. Because he disapproved the fascism and its concept of agricultural development he was removed from directory of the "Research station of labor sciences in agriculture" Pommritz in Saxony.
INDUSTRIAL ORGANISATION OF THE FOOD INDUSTRY IN LATVIA: RESULTS OF AN EXPERT SURVEY IN THE DAIRY AND MILLING BRANCHES
Creators: name: Jasjko, Danute
name: Hartmann, Monika
name: Miglavs, Andris
name: Wandel, Jurgen
name: Jasjko, Danute
name: Hartmann, Monika
name: Miglavs, Andris
name: Wandel, Jurgen
Publisher: name: Unknown
Year: 1999
Subjects: Agribusiness
Industrial Organization

description: Based on the analytical framework of the structure-conduct-performance paradigm of the theory of industrial organisation, the paper analyses those economic conditions that determine the degree of competitiveness in the Latvian dairy and milling industry. The analysis is based on information from milk and grain processing enterprises acquired through a survey carried out at the beginning of 1998. It is shown that the development of market conditions and market behaviour in the sectors examined has in general progressed. Privatisation in both sectors has been completed. While in the dairy sector the majority of processing enterprises were privatised as co-operatives, in the milling industry all enterprises have become closed joint-stock companies. Since the legal status of a co-operative has turned out to be quite problematic for enterprise restructuring, more and more dairy enterprises have started to change into joint-stock companies. Competition in the investigated processing sectors can be considered as functioning. However, in the dairy sector tendencies of stronger horizontal concentration can be observed. The majority of enterprises react in quite an active way to the market conditions. Procurement and marketing channels have been diversified, and considerable investments have been undertaken. Further investments, however, are impeded by high interest rates for credits. As for performance, quite a considerable differentiation between the enterprises in the considered branches could be shown. The main problems seen by the processors are the saturation of the domestic Latvian market, the lack of investment funds, the unstable legislation, the absence of any substantial support from the government, and, in the dairy sector, the low quality of the raw milk.
RUSSIA'S AGRICULTURE: EIGHT YEARS IN TRANSITION - CONVERGENCE OR DIVERGENCE OF REGIONAL EFFICIENCY
Creators: name: Uvarovsky, Vladimir
name: Voigt, Peter
name: Uvarovsky, Vladimir
name: Voigt, Peter
Publisher: name: Unknown
Year: 2000
Subjects: subject: International Development
subject: Productivity Analysis
subject: technical efficiency
subject: rural areas
subject: divergence
subject: Russian Federation
subject: agriculture

description: In this paper, we consider how Russian Agriculture has developed since the constitution of the Russian Federation. The analysis is based on Oblast level data of 75 territorial units during the period from 1993 to 1998 and is focusing on technical efficiency (TE), technological change, and (both aggregated as overall index) on Total Factor Productivity (TFP). Given that the initial natural conditions were approximately constant the consistence of political programs, market reforms and restructuring were essential determinants of regional developments of TE and TFP above or below the common trend. If this assumption is widely true an investigation of responsible circumstances for these divergences seems to be an important task in the actual regional-economic research. This paper should provide a step of such an analysis - discover common trends, make divergences visible and detect Oblasts characterised by diverging trends. The results have shown that the agricultural TE and the technological change varied dramatically among regions. Beyond it, we have found a growing gap of TE among regions and a relative homogeneous negative trend of technical change resulting, altogether, in a divergence of regional agricultural TFP. Because agriculture is for many regions the fundamental source of income this fact is alarming, especially when the local agriculture becomes noncompetitiveness in comparison with other regions, actually or in future. .
Tuning the conductance of single-walled carbon nanotubes by ion irradiation in the Anderson localization regime
Creators: name: Gomez-Navarro, C.
name: De Pablo, P. J.
name: Gomez-Herrero, J.
name: Biel, B.
name: Garcia-Vidal, F. J.
name: Rubio, A.
name: Flores, F.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Carbon nanotubes are a good realization of one-dimensional crystals where basic science and potential nanodevice applications merge. Defects are known to modify the electrical resistance of carbon nanotubes. They can be present in as-grown carbon nanotubes, but controlling externally their density opens a path towards the tuning of the nanotube electronic characteristics. In this work consecutive Ar+ irradiation doses are applied to single-walled nanotubes (SWNTs) producing a uniform density of defects. After each dose, the room temperature resistance versus SWNT-length [R(L)] along the nanotube is measured. Our data show an exponential dependence of R(L) indicating that the system is within the strong Anderson localization regime. Theoretical simulations demonstrate that mainly di-vacancies contribute to the resistance increase induced by irradiation and that just a 0.03% of di-vacancies produces an increase of three orders of magnitude in the resistance of a 400 nm SWNT length.
description: 16 pages, 4 figures
Islands and Uhlmann phase: Explicit recovery of classical information from evaporating black holes
Creators: name: Kirklin, Josh
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Recent work has established a route towards the semiclassical validity of the Page curve, and so provided evidence that information escapes an evaporating black hole. However, a protocol to explicitly recover and make practical use of that information in the classical limit has not yet been given. In this paper, we describe such a protocol, showing that an observer may reconstruct the phase space of the black hole interior by measuring the Uhlmann phase of the Hawking radiation. The process of black hole formation and evaporation provides an invertible map between this phase space and the space of initial matter configurations. Thus, all classical information is explicitly recovered. We assume in this paper that replica wormholes contribute to the gravitational path integral.
description: 30 pages, 12 figures. Added references and clarifications, to match published version. Comments highly appreciated
Chiral dynamics of kaon-nucleon interactions, revisited
Creators: name: Borasoy, B.
name: Nissler, R.
name: Weise, W.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The anti-kaon nucleon system close to threshold is analyzed in view of the new accurate DEAR kaonic hydrogen data. The calculations are performed using chiral SU(3) effective field theory in combination with non-perturbative schemes based on coupled channels. Several variants of such approaches are compared with experimental data and the differences in the results are discussed. Coulomb and isospin breaking effects turn out to be important and are both taken into account. The pole structure of the Lambda(1405) resonance close to the anti-kaon nucleon threshold is critically examined.
description: 30 pages, 14 figures, 11 tables
Fractional elliptic systems with critical nonlinearities
Creators: name: Bhakta, Mousomi
name: Chakraborty, Souptik
name: Miyagaki, Olimpio H.
name: Pucci, Patrizia
Publisher: name: arXiv
Year: 2020
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35R11, 35A15, 35B33, 35J60

description: In this paper we study positive solutions to the following nonlocal system of equations: \begin{equation*} \left\{\begin{aligned} &(-Δ)^s u = \fracα{2_s^*}|u|^{α-2}u|v|^β+f(x)\;\;\text{in}\;\mathbb{R}^{N}, &(-Δ)^s v = \fracβ{2_s^*}|v|^{β-2}v|u|^α+g(x)\;\;\text{in}\;\mathbb{R}^{N}, & \qquad u, \, v >0\, \mbox{ in }\,\mathbb{R}^{N}, \end{aligned} \right. \end{equation*} where $N>2s$, $α,\,β>1$, $α+β=2N/(N-2s)$, and $f,\, g$ are nonnegative functionals in the dual space of $\dot{H}^s(\mathbb{R}^{N})$. When $f=0=g$, we show that the ground state solution of the above system is {\it unique}. On the other hand, when $f$ and $g$ are nontrivial nonnegative functionals with ker$(f)$=ker$(g)$, then we establish the existence of at least two different positive solutions of the above system provided that $\|f\|_{(\dot{H}^s)'}$ and $\|g\|_{(\dot{H}^s)'}$ are small enough. Moreover, we also provide a global compactness result, which gives a complete description of the Palais-Smale sequences of the above system.
description: 27 pages
Electronic structure of fullerene-like cages and finite nanotubes of aluminum nitride
Creators: name: Zope, Rajendra R.
name: Dunlap, Brett I.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We report density functional study of alternate fullerene-like cage structures and finite closed capped single-wall nanotubes of aluminum nitride. The cages and nanotubes studied are modeled as Al24N24, Al28N28, Al32N32, Al36N36, Al48N48, and Al96N96. The structure optimization and calculation of the electronic structure, vertical ionization potential, and the electron affinity are performed at the all electron level by the analytic Slater-Roothaan method, using polarized Gaussian basis set of double zeta quality. All structures are energetically stable with binding energy of about 10-11 eV per AlN pair. For the larger Al96N96, the fullerene like cage is energetically less favorable than the two-shell cluster that has Al24N24 as an inner shell. The vertical ionization potential and the electronic affinity are in the range 6.7-6.9 eV and 1.5-2.0 eV, respectively. The binding energy show systematic increase with increase in the length of (4,4) nanotube. The energy band gap, determined using the "Delta SCF" method show that these structures are characterized by a fairly large band gap about 4-5 eV, which is however smaller than the gap for the corresponding boron nitride structures.
description: (6 pages, 5 figure, RevTEx) Submitted to Phys. Rev. B
Numerical Solitons of Generalized Korteweg-de Vries Equations
Creators: name: Han, Houde
name: Xu, Zhenli
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 35Q51;35Q53

description: We propose a numerical method for finding solitary wave solutions of generalized Korteweg-de Vries equations by solving the nonlinear eigenvalue problem on an unbounded domain. The artificial boundary conditions are obtained to make the domain finite. We specially discuss the soliton solutions of the K(m, n) equation and KdV-K(m,n) equation. Furthermore for the mixed models of linear and nonlinear dispersion, the collision behaviors of soliton-soliton and soliton-antisoliton are observed.
description: 9 pages, 4 figures
Ribbon categories and (unoriented) CFT: Frobenius algebras, automorphisms, reversions
Creators: name: Fuchs, Jurgen
name: Runkel, Ingo
name: Schweigert, Christoph
Publisher: name: arXiv
Year: 2005
Subjects: subject: Category Theory (math.CT)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 81T40,18D10,18D35,81T45

description: A Morita class of symmetric special Frobenius algebras A in the modular tensor category of a chiral CFT determines a full CFT on oriented world sheets. For unoriented world sheets, A must in addition possess a reversion, i.e. an isomorphism from A^opp to A squaring to the twist. Any two reversions of an algebra A differ by an element of the group Aut(A) of algebra automorphisms of A. We establish a group homomorphism from Aut(A) to the Picard group of the bimodule category C_AA, with kernel consisting of the inner automorphisms, and we refine Morita equivalence to an equivalence relation between algebras with reversion.
description: 22 pages
Opinion Dynamics of Online Social Network Users: A Micro-Level Analysis
Creators: name: Kozitsin, Ivan V.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Social and Information Networks (cs.SI)
subject: Dynamical Systems (math.DS)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: In this paper, we present an empirical study of the opinion dynamics of a large-scale sample of online social network users. We estimate opinions of users as continuous scalars based on their subscriptions to information sources and analyze how friendship connections affect the dynamics of these estimations. Distinguishing between positive (toward opinions of friends) and negative (away from opinions of friends) opinion shifts, we find that the existence and magnitude of opinion shifts are positively related (largely through a linear form or an inverted U-shaped form) to the degree of divergence in opinions between user and their friends. Additionally, we moderate the balance between positive and negative shifts using opinion divergence: if the opinions of the focal user and their friends are too similar or dissimilar, there is a relatively low chance of a positive shift.
description: 66 pages. The Journal of Mathematical Sociology (2021)
Quantum field theory with an interaction on the boundary
Creators: name: Haba, Z.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We consider quantum theory of fields ϕdefined on a D dimensional manifold (bulk) with an interaction V(ϕ) concentrated on a d
description: 15 pages
Influence of physical habitat on the seasonal movement, growth, and habitat association of individual coastal cutthroat trout
Creators: name: Roberge, Michelle
Publisher: name: University of British Columbia
Year: 2009

description: A multi-stream comparative study conducted in southwestern British Columbia revealed that juvenile coastal cutthroat trout (Oncorhynchus clarki clarki) were found at highest density in narrow (< 3 m), shallow (< 40 cm) streams with non-coarse substrate. To assess how cutthroat trout grow and behave within different physical habitats, I selected three streams for intensive examination from the physical structure gradient that I derived in the multi-stream study: (A) narrow width, shallow, fine substrate; (B) narrow width, shallow, coarse substrate; (C) wide width, deep, coarse substrate. I used radiotelemetry and bi-monthly recapturing of PIT tagged fish from set trap locations to examine individual growth and movement among the stream types over the fall, winter and spring of 1998/99. Individual PIT tagged fish tended to be heavier and grew faster during the spring than the winter or fall in all streams. Growth rate did not seem to be dependent on the physical habitat of the stream. During normal seasonal flood events, movement rate of fish from each of the three stream types was not affected. During a major flood event that occurred in stream types (C) and (B), fluctuations in water depth in stream type (C) displaced several radiotagged fish (> 100 m) and caused a general downstream movement in PIT tagged individuals. Almost no movement was detected during the winter in the three streams for PIT tagged fish (< 0.09 m/day). Density was lowest in stream (C) and highest in stream (A). Past and current provincial forestry practices usually result in removal of riparian vegetation on small streams. This can alter their physical habitat, usually by widening and aggrading the stream bed. Therefore, in streams where riparian logging has occurred, displacement of cutthroat trout during major floods may be a concern.
Circle and torus actions on equal symplectic blow-ups of CP^2
Creators: name: Karshon, Yael
name: Kessler, Liat
Publisher: name: arXiv
Year: 2005
Subjects: subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics

description: A manifold obtained by k simultaneous symplectic blow-ups of CP^2 of equal sizes epsilon (where the size of CP^1 \subset CP^2 is one) admits an effective two dimensional torus action if k <= 3 and admits an effective circle action if (k-1)epsilon < 1. We show that these bounds are sharp if 1/epsilon is an integer.
description: 19 pages
Summary-Oriented Question Generation for Informational Queries
Creators: name: Yin, Xusen
name: Zhou, Li
name: Small, Kevin
name: May, Jonathan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Users frequently ask simple factoid questions for question answering (QA) systems, attenuating the impact of myriad recent works that support more complex questions. Prompting users with automatically generated suggested questions (SQs) can improve user understanding of QA system capabilities and thus facilitate more effective use. We aim to produce self-explanatory questions that focus on main document topics and are answerable with variable length passages as appropriate. We satisfy these requirements by using a BERT-based Pointer-Generator Network trained on the Natural Questions (NQ) dataset. Our model shows SOTA performance of SQ generation on the NQ dataset (20.1 BLEU-4). We further apply our model on out-of-domain news articles, evaluating with a QA system due to the lack of gold questions and demonstrate that our model produces better SQs for news articles -- with further confirmation via a human evaluation.
description: 17 pages
Evolution on distributive lattices
Creators: name: Beerenwinkel, Niko
name: Eriksson, Nicholas
name: Sturmfels, Bernd
Publisher: name: arXiv
Year: 2005
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: Combinatorics (math.CO)
subject: FOS: Biological sciences
subject: FOS: Mathematics

description: We consider the directed evolution of a population after an intervention that has significantly altered the underlying fitness landscape. We model the space of genotypes as a distributive lattice; the fitness landscape is a real-valued function on that lattice. The risk of escape from intervention, i.e., the probability that the population develops an escape mutant before extinction, is encoded in the risk polynomial. Tools from algebraic combinatorics are applied to compute the risk polynomial in terms of the fitness landscape. In an application to the development of drug resistance in HIV, we study the risk of viral escape from treatment with the protease inhibitors ritonavir and indinavir.
description: 22 pages, 4 figures; minor corrections, moved details to appendix. Final version to appear in Journal of Theoretical Biology
PROMOTING CEA AGRICULTURAL EXPORTS THROUGH ASSOCIATION AGREEMENTS WITH THE EU - WHY IT IS NOT WORKING -
Creators: name: Frohberg, Klaus
name: Hartmann, Monika
name: Frohberg, Klaus
name: Hartmann, Monika
Publisher: name: Unknown
Year: 1997
Subjects: International Relations/Trade

description: This paper analyzes why the Association Agreements between the Central and Eastern European countries, referred to as Central European Associates (CEAs), and the European Union (EU) have failed with respect to agriculture. In the first part of the paper the development and importance of agricultural trade in the CEAs is described. It is shown that the EU is the most important trading partner in agricultural and food products for the CEAs. However, in recent years the trade balance for agricultural and food products between these countries and the EU has changed in favor of the latter; this is contrary to the aim of these agreements. Important external and internal factors determining trade relations between the EU and the CEAs are identified and discussed in the second half of the paper. These include the development of the real exchange rates, restrictions in the levels of domestic production, inadequate food quality compared to EU products, and insufficient sanitary standards in and a lack of competitiveness of the processing industry. These factors offset agricultural and food policies which have been aimed at protecting and supporting agriculture and the food processing industry in all CEAs but Bulgaria and Romania. In the last two countries, agricultural and food policies have primarily protected consumers at the expense of these two sectors.
Effect of axion-like particles on the spectrum of the extragalactic gamma-ray background
Creators: name: Liang, Yun-Feng
name: Zhang, Xing-Fu
name: Cheng, Ji-Gui
name: Zeng, Hou-Dun
name: Fan, Yi-Zhong
name: Liang, En-Wei
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Axion-like particles (ALPs) provide a feasible explanation for the observed lower TeV opacity of the Universe. If the anomaly TeV transparency is caused by ALPs, then the fluxes of distant extragalactic sources will be enhanced at photon energies beyond TeV, resulting in an enhancement of the observed extragalactic gamma-ray background (EGB) spectrum. In this work, we have investigated the ALP modulation on the EGB spectrum at TeV energies. Our results show that in the most optimistic case, the existence of ALPs can cause the EGB spectrum to greatly deviate from the prediction of a pure extragalactic-background-light (EBL) absorption scenario. The deviation occurs at approximately $\gtrsim$1 TeV, and the current EGB measurements by Fermi-LAT cannot identify such an effect. We also find that most of the sensitive ALP parameters have been ruled out by existing constraints, leaving only a small region of unrestricted parameters that can be probed using the EGB effect investigated in this work. Observations from forthcoming very-high-energy instruments like LHAASO and CTA may be beneficial for the study of this effect.
description: 14 pages, 5 figures; Accepted for publication in JCAP
Effect of dipolar interactions on the magnetization of a cubic array of nanomagnets
Creators: name: Ortigoza, Marisol Alcantara
name: Klemm, Richard A.
name: Rahman, Talat S.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigated the effect of intermolecular dipolar interactions on a cubic 3D ensemble of 5X5X4=100 nanomagnets, each with spin $S = 5$. We employed the Landau-Lifshitz-Gilbert equation to solve for the magnetization $M(B)$ curves for several values of the damping constant $α$, the induction sweep rate, the lattice constant $a$, the temperature $T$, and the magnetic anisotropy field $H_A$. We find that the smaller the $α$, the stronger the maximum induction required to produce hysteresis. The shape of the hysteresis loops also depends on the damping constant. We find further that the system magnetizes and demagnetizes at decreasing magnetic field strengths with decreasing sweep rates, resulting in smaller hysteresis loops. Variations of $a$ within realistic values (1.5 nm - 2.5 nm) show that the dipolar interaction plays an important role in the magnetic hysteresis by controlling the relaxation process. The $T$ dependencies of $α$ and of $M$ are presented and discussed with regard to recent experimental data on nanomagnets. $H_A$ enhances the size of the hysteresis loops for external fields parallel to the anisotropy axis, but decreases it for perpendicular external fields. Finally, we reproduce and test an $M(B)$ curve for a 2D-system [M. Kayali and W. Saslow, Phys. Rev. B {\bf 70}, 174404 (2004)]. We show that its hysteretic behavior is only weakly dependent on the shape anisotropy field and the sweep rate, but depends sensitively upon the dipolar interactions. Although in 3D systems, dipole-dipole interactions generally diminish the hysteresis, in 2D systems, they strongly enhance it. For both square 2D and rectangular 3D lattices with ${\bm B}||(\hat{\bm x}+\hat{\bm y})$, dipole-dipole interactions can cause large jumps in the magnetization.
description: 15 pages 14 figures, submitted to Phys. Rev. B
[Brev til DKNVS]
Creators: name: Bugge, Frederik Moltke
name: Det Kongelige Norske Videnskabers Selskab (DKNVS)
Publisher: name: Unknown
Year: 1841

description: Ønsker å vite om ikke Oustmyren i Trondheim kunne bebygges fattige som er blitt husløse grunnet brann
Surveying the Multicomponent Scattering Matrix: Unitarity and Symmetries
Creators: name: Diago-Cisneros, L.
name: Flores-Godoy, J. J.
name: Fernández-Anaya, G.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Multicomponent-multiband fluxes of spim-charge carriers, whose components propagate mixed and synchronously, with \emph{a priori} nonzero incoming amplitudes, do not obey the standard unitarity condition on the scattering matrix for an arbitrary basis set. For such cases, we have derived a robust theoretical procedure, which is fundamental in quantum-transport problems for unitarity preservation and we have named after \emph{structured unitarity condition}. Our approach deals with $(N \times N)$ interacting components (for $N \geq 2$), within the envelope function approximation (EFA), and yet the standard unitary properties of the ($N = 1$) scattering matrix are recovered. Rather arbitrary conditions to the basis-set and/or to the output scattering coefficients, are not longer required, if the \emph{eigen}-functions are orthonormalized in both the configuration and the spinorial spaces. We expect the present model to be workable, for different kind of multiband-multicomponent physical systems described by Hermitian Hamiltonians within the EFA, with small transformations if any. We foretell the interplay for the state-vector transfer matrix, together with the large values of its condition number, as a novel complementary tools for a more accurate definition of the threshold for tunnelling channels in a scattering experiment.
description: 32 pages, 7 figures, 1 table
General Relativistic Effects in Weak Lensing Angular Power Spectra
Creators: name: Grimm, Nastassia
name: Yoo, Jaiyul
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Advances in upcoming weak lensing surveys pose new challenges for an accurate modeling of the lensing observables. The wide sky coverage of Euclid makes angular scales down to $l_\mathrm{min}=10$ accessible. At such large angular scales, general relativistic effects manifest themselves, and the lensing magnification cannot be correctly described by the standard lensing convergence only. The impact of line-of-sight velocities on the magnification angular power spectrum, referred to as the Doppler magnification, is already well recognized in literature. In particular, it was suggested that the Doppler magnification could be extracted by measurements of both cosmic shear and magnification. In this work, we point out two previously neglected aspects with respect to this method. Firstly, the impact of the Doppler magnification is reduced through non-vanishing cross terms with the standard lensing convergence. This is particularly relevant when the sources are averaged over a bin of width $Δz\approx 0.1$, such as in Euclid's tomographic weak lensing survey. Secondly, general relativistic potential terms slightly enhance the signal. We present numerical calculations of all relativistic effects in the weak lensing angular power spectra on large scales.
description: 15 pages, 5 figures; published in Phys. Rev. D
Assessing groundwater quality and health risks of fluoride pollution in the Shasler Vagu (SV) watershed of Nalgonda, India
Creators: name: Narsimha Adimalla
name: Sudheer Kumar Marsetty
name: Panpan Xu
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: FOS: Biological sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: Developmental Biology
subject: Science Policy

description: The principal objectives of this study were to evaluate groundwater quality and human health risks of fluoride contamination in Shasler Vagu (SV) watershed of Nalgonda district, India. For this purpose, 107 groundwater samples were collected and analyzed various physcio-chemical parameters including fluoride, and Gibbs diagrams, Hill–Piper trilinear diagram, and groundwater quality index (GWQI) were applied to understand the groundwater chemistry and its suitability for drinking purpose. In addition to this, non-carcinogenic health risks of high fluoride intake were also evaluated using the US Environmental Protection Agency model for adults and children in the study region. Groundwater chemistry is mainly controlled by HCO3−-Ca2+-Mg2+ and Na+-HCO3− type, and rock weathering. Assessment of GWQI indicates that 76% of groundwater sources in the study region have poor quality for drinking uses. Results reveal that fluoride concentration ranged from 1.4 to 5.9 mg/L in the groundwater samples, which was significantly higher than the recommended limit of 1.5 mg/L for drinking uses. Results of hazard quotient (HQ) estimates are in the ranges of 0.90–3.78 and 1.21–5.11 in adults and children populations of the study region, respectively. About 98% of adults and 100% of children population of SV watershed are at very high risks of chronic toxicity by excess fluoride intake.
Theory of coexistence of superconductivity and ferroelectricity
Creators: name: Krivolapov, Y.
name: Mann, A.
name: Birman, Joseph L.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: A new investigation of the coexistence and competition of ferroelectricity and superconductivity is reported. In particular we show that the starting Hamiltonian of a previous study by Birman and Weger (2001) can be exactly diagonalized. The result differs significantly from mean-field theory. A Hamiltonian with a different realization of the coupling between ferroelectricity and superconductivity is proposed. We report the results for mean-field theory applied to this Hamiltonian. We find that the order parameters are strongly affected by this coupling.
description: 3 pages, 1 figure
Contamination and health risk assessment of trace elements in soil at play centers of urban low-income settings
Creators: name: Artwell Kanda
name: Ncube, France
name: Mushati, Elisha
name: Chiboiwa, Elvis
name: Estele Mwanza
name: Makumbe, Peter
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Medicine
subject: Biotechnology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: FOS: Biological sciences
subject: Science Policy

description: Young children are considered critical receptors of potentially toxic trace elements (PTEs) by non-dietary ingestion of contaminated soil. The study assessed the potential enrichment of soil and the health risk of PTEs to 471 children less than seven years via non-dietary soil ingestion at six Early Childhood Development Centers (ECDCs) in urban low-income settings. The total concentrations of PTEs were determined by ICP-AES after wet acid digestion. The extent of soil contamination with PTEs and their source apportionment were assessed by the enrichment factor (EF). The US-EPA risk assessment model was used to determine the risk of PTE exposure by children. Multivariate statistical analyses and the EF suggested anthropogenic origin of PTEs in playgrounds and indoors, especially Cd and Pb from atmospheric deposition. Indoor floor dust at ECDCs was enriched (significant to extreme) with PTEs of anthropogenic origin imported from the outside environment. Children at the six ECDCs were not at significant non-carcinogenic risk of PTEs in soil and dust through non-dietary ingestion. The study setting is typical of urban child play centers in low-income countries which needs regular risk assessment and the enforcement of legislation in order to reduce the exposure of children to PTEs.
Absorption of Sub-MeV Fermionic Dark Matter by Electron Targets
Creators: name: Dror, Jeff A.
name: Elor, Gilly
name: McGehee, Robert
name: Yu, Tien-Tien
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We study a new class of signals where fermionic dark matter is absorbed by bound electron targets. Fermionic absorption signals in direct detection and neutrino experiments are sensitive to dark matter with sub-MeV mass, probing a region of parameter space in which dark matter is otherwise challenging to detect. We calculate the rate and energy deposition spectrum in xenon-based detectors, making projections for current and future experiments. We present two possible models that display fermionic absorption by electrons and study the detection prospects in light of other constraints.
description: 8+4 pages, 5 figures; v3: corrected decay rate expressions and figures; conclusions unchanged
MEGADES: MEGARA galaxy disc evolution survey. Ionised gas diagnosis.
Creators: name: Chamorro-Cazorla, Mario
Publisher: name: Zenodo
Year: 2024
Subjects: subject: Astronomy
subject: Astrophysics
subject: Extragalactic astronomy
subject: Spectroscopy

description: We present the ionised gas properties and metallicity gradients of the central area of a sample of 43 galaxies using observations obtained by the MEGADES survey. Exploiting the technical capabilities of MEGARA (Multi-Espectrógrafo en GTC de Alta Resoluciónpara Astronomía) our observations combine relatively high spectral (R ∼ 6000) and spatial (0.62") resolution to study the properties of the ionised gas, such as using the classic diagnostic BPT diagrams in its [NII] and [SII] variants. We explore how the diagrams vary as a function of both radius and velocity dispersion of the Hα line. We also propose a new diagnostic diagram to assess the relative contributions of AGN, shocks and H II regions in each spatial region as the ratio between the velocity dispersion of the [NII]λ6584 and Hα lines. A considerable number of regions, regardless of their galactocentric distance, have emission line spectra associated with shocks. This inference follows both from their line ratios, typically characterised by high [NII]λ6584/Hα and intermediate [OIII]λ5007/Hβ, and from their position in our diagnostic diagram where they lie between the areas associated with HII regions and with AGN. The better selection of HII-region like emission allows for a robust oxygen abundance determination using the N2 indicator, which we use to measure precise abundance gradients. We discuss the possible implications of these results for the impact of galactic winds on the abundance gradients of galaxies.
Detecting the Standard Model Higgs Boson in the WW decay channel using forward proton tagging at the LHC
Creators: name: Cox, B. E.
name: De Roeck, A.
name: Khoze, V. A.
name: Pierzchala, T.
name: Ryskin, M. G.
name: Nasteva, I.
name: Stirling, W. J.
name: Tasevsky, M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a detailed study of the central exclusive production of the Standard Model Higgs Boson in the WW decay channel at the LHC. We include estimates of the experimental acceptance, including that of the proposed proton tagging detectors at 220m and 420m around either ATLAS and / or CMS, and the level 1 trigger acceptances. We give first estimates of the photon-photon and glue-glue background processes in the semi-leptonic and fully-leptonic decay channels. We find that there will be a detectable signal for Higgs masses between 140 GeV and 200 GeV, and that the backgrounds should be controllable.
description: 12 pages, 6 figures
Evaluating the Security Implications of Serverless Computing Environments: A Focus on Vulnerabilities and Countermeasures
Creators: name: Chowdhury, Naem Azam
Publisher: name: Zenodo
Year: 2024

description: This research investigates the security landscape of serverless computing environments within cloud infrastructures. With a primary focus on identifying and analyzing vulnerabilities specific to serverless applications, the study aims to contribute valuable insights to the evolving field of cybersecurity. The research explores hacking techniques tailored to exploit these vulnerabilities, emphasizing real-world scenarios. Additionally, the paper proposes and evaluates countermeasures, best practices, and security controls to enhance the resilience of serverless applications against cyber threats. By addressing the unique security challenges posed by serverless architectures, this research seeks to advance the understanding of effective measures to secure cloud-based, serverless computing environments.
[Brev til DKNVS]
Creators: name: Heltzen, Iver Ancher
name: Det Kongelige Norske Videnskabers Selskab (DKNVS)
Publisher: name: Unknown
Year: 1841

description: Vedr. lån av bøker samt om hans forsøk på å helbrede spedalske, døvstumme og blinde