cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Modeling plant biomass partitioning: responses to environmental conditions and disturbance
Creators: name: Pezzatti, Gianni
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2011

description: The aim of the present thesis is to contribute to the understanding of the plant phenotypic responses to environmental conditions and disturbances. In particular, the value of the pipe model theory as a measure of morphological plasticity of chestnut tree (Castanea sativa Mill.) in relation to the site conditions was assessed, and the main physiological mechanisms underlying biomass allocation were theoretically explored using modeling technics.

The constancy of the leaf to sapwood area slope coefficient (LASA) in C. sativa was confirmed at the intra-branch level, but showed a considerable variability among branches within a tree. In particular the LASA changed according to branch type (crown branches vs. epicormic shoots) and declined with height. With a generalized linear mixed modeling approach, a new reference parameter (Ground-level LASA), corresponding to a theoretical value of LASA for a branch at ground level, was proposed and validated on an independent dataset. The variation of this measure was investigated in different environmental conditions, confirming that the sweet chestnut is able to greatly vary the allocation patterns. In particular, the Ground-level LASA was high for trees growing in sites with good water supply (concave sites) and low in water poor convex sites. The analysis of the stool uprooting phenomena in over-aged coppice stands provided an indirect evidence of the role of microtopography and water availability in the allocation patterns between above and below ground biomass.

In order to further theoretically explore the key issue of biomass partitioning in plants, a fairly simple model of allocation was developed, based on the interactions between water and carbon transport processes with assimilation and growth. The model is able to reproduce consistent deviations from the allometric trajectory, showing qualitatively correct responses in a range of different environmental conditions (light and water) and during recovery from unbalanced biomass removal (e.g. recover after pruning or fire damages). In this respect this model has the potential to be a good instrument for theoretical investigation of relations between anatomical (e.g. sclerophylly) and functional (e.g. transport resistances) characters and allocation patterns.
CRITERI E VALUTAZIONE DI RESPONSABILITA’ IATROGENA NELLE PROTESI ARTICOLARI DEGLI ARTI INFERIORI
Creators: name: Severino, Pasquale
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2011

description: L’autore dopo aver illustrato le principali complicanze dell’intervento di artroprotesi di anca e ginocchio, prospetta riflessioni di carattere medico-legale circa la metodologia valutativa da adottare per apprezzare l’eventuale ricorrenza di profili di responsabilità professionale medica del chirurgo operatore.
È, poi, prospettata un’indagine conoscitiva relativa a casi clinici giunti all’osservazione di dirigenti medici del Dipartimento di Medicina Pubblica e della Sicurezza Sociale dell’Università degli Studi di Napoli per la valutazione di postumi da applicazione di artroportesi di anca o ginocchio per traumi stradali o presunta errata condotta intraoperatoria.
Valutazione delle prestazioni di algoritmi paralleli fino ad ambienti GPU
Creators: name: Mele, Valeria
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2011

description: In questa tesi, si ripercorrono le caratteristiche delle architetture parallele fino a prendere in considerazione i calcolatori muniti di Graphic Processing Unit (GPU) e si propone un modello per la valutazione delle prestazioni a partire dai risultati classici, calandoli nella realt\`a della macchina in questione ed individuando, attraverso lo studio dei dettagli tecnici e gli esperimenti, parametri che permettono di capire i limiti e interpretare la variazioni nei guadagni ottenuti.
Effective diffusion in thin structures via generalized gradient systems and EDP-convergence
Creators: name: Frenzel, Thomas
name: Liero, Matthias
Publisher: name: Weierstrass Institute
Year: 2019
Subjects: subject: Fokker--Planck equation
subject: dimension reduction
subject: sandwich structure
subject: Γ-convergence
subject: gradient system
subject: EDP-convergence
subject: Wasserstein gradient flow
subject: 35K20
subject: 35K10
subject: 35K57
subject: 49S99

description: The notion of Energy-Dissipation-Principle  convergence (EDP-convergence) is used to derive effective evolution equations for gradient systems describing diffusion in a structure consisting of several thin layers in the  limit of vanishing layer thickness. The thicknesses of the sublayers tend to zero with different rates and the diffusion coefficients scale suitably. The Fokker--Planck equation can be formulated as gradient-flow equation with respect to the logarithmic relative entropy of the system and a  quadratic Wasserstein-type gradient structure. The EDP-convergence of the gradient system is shown by proving suitable asymptotic lower limits of the entropy  and the total dissipation functional. The crucial point is that the limiting evolution is again described by a gradient system, however, now the dissipation  potential is not longer quadratic but is given in terms of the hyperbolic cosine. The latter describes jump processes across the thin layers and is related to  the Marcelin--de Donder kinetics.
A STUDY OF THE BIOTECHNOLOGICAL APPLICATIONS OF NOVOSPHINGOBIUM PUTEOLANUM PP1Y.
Creators: name: Troncone, Luca
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2011

description: Environmental pollution caused by the release of a wide range of xenobiotic compounds has assumed serious proportions. Bioremediation techniques, utilizing microorganisms to reduce the concentration and toxicity of various chemical pollutants such as petroleum hydrocarbons, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, industrial solvents and pesticides, are the most promising strategies for the restoration of polluted environments.
Several bacterial strains with promising degradative abilities have already been isolated and characterized. However, the full exploitation of the potential of bioremediation strategies requires not only the isolation of a large number of strains with wide degradative abilities but also an accurate characterization of these strains both at the microbiological and biochemical/genetic level. This knowledge is necessary to perform a rational planning of bioremediation interventions.
The present work describes isolation of new strains able to degrade aromatic hydrocarbons directly from polluted environments by means of appropriate selection procedures.
Novosphingobium sp. PP1Y, isolated from a surface seawater sample collected from a closed bay in the harbor of Pozzuoli (Naples, Italy), uses fuels as its sole carbon and energy source. Like some other Sphingomonads, this strain can grow as either planktonic free cells or sessile-aggregated flocks. In addition, this strain was found to grow as biofilm on several types of solid and liquid hydrophobic surfaces including polystyrene, polypropylene and diesel oil. Strain PP1Y is not able to grow on pure alkanes or alkane mixtures but is able to grow on a surprisingly wide range of aromatic compounds including mono, bi, tri and tetracyclic aromatic hydrocarbons and heterocyclic compounds.
During growth on diesel oil, the organic layer is emulsified resulting in the formation of small biofilm-coated drops, whereas during growth on aromatic hydrocarbons dissolved in paraffin the oil layer is emulsified but the drops are coated only if the mixtures contain selected aromatic compounds, like pyrene, propylbenzene, tetrahydronaphthalene and heterocyclic compounds.
These peculiar characteristics suggest strain PP1Y has adapted to efficiently grow at the water/fuel interface using the aromatic fraction of fuels as the sole carbon and energy source.
The whole PP1Y genome sequence could provide clues about the metabolism of this species and about the possibility of manipulating it for bioremediation purposes.
The PP1Y genome is comprised of a single 3.9 Mbp circular chromosome and of 3 plasmids, one megaplasmid (Mpl; 1.16 Mbp), one large plasmid (Lpl; 0.19 Mbp), and one small plasmid (Spl; 0.05 Mbp). Notably, this is the first time that a megaplasmid of such size has been identified in a sphingomonad. Our results will help to clarify the molecular basis of the unusual features of this strain and to engineer strains with enhanced cultural and bioremediation abilities.
Photodetachment of H$^{-}$ near a partial reflecting surface
Creators: name: Afaq, A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Theoretical and interpretative study on the subject of photodetachment of H$^{-}$ near a partial reflecting surface is presented, and the absorption effect of the surface is investigated on the total and differential cross sections using a theoretical imaging method. To understand the absorption effect, a reflection parameter $K$ is introduced as a multiplicative factor to the outgoing detached-electron wave of H$^-$ propagating toward the wall. The reflection parameter measures, how much electron wave would reflect from the surface; K=0 corresponds to no reflection and K=1 corresponds to the total reflection.
description: 8 pages, 4 figures
Efficient optomechanical mode-shape mapping of micromechanical devices
Creators: name: Hoch, David
name: Haas, Kevin-Jeremy
name: Moller, Leopold
name: Sommer, Timo
name: Soubelet, Pedro
name: Finley, Jonathan
name: Poot, Menno
Publisher: name: arXiv
Year: 2021
Subjects: subject: Applied Physics (physics.app-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We demonstrate a method to optically map multiple modes of mechanical structures simultaneously. The fast and robust method, based on a modified phase-lock-loop, is demonstrated on a silicon nitride membrane and compared with three different approaches. Line traces and two-dimensional maps of different modes are acquired. The high quality enables us to determine the weights of individual contributions in superpositions of degenerate modes.
Scaling and allometry in the building geometries of Greater London
Creators: name: Batty, Michael
name: Carvalho, Rui
name: Hudson-Smith, Andy
name: Milton, Richard
name: Smith, Duncan
name: Steadman, Philip
Publisher: name: arXiv
Year: 2008
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: Many aggregate distributions of urban activities such as city sizes reveal scaling but hardly any work exists on the properties of spatial distributions within individual cities, notwithstanding considerable knowledge about their fractal structure. We redress this here by examining scaling relationships in a world city using data on the geometric properties of individual buildings. We first summarise how power laws can be used to approximate the size distributions of buildings, in analogy to city-size distributions which have been widely studied as rank-size and lognormal distributions following Zipf and Gibrat. We then extend this analysis to allometric relationships between buildings in terms of their different geometric size properties. We present some preliminary analysis of building heights from the Emporis database which suggests very strong scaling in world cities. The data base for Greater London is then introduced from which we extract 3.6 million buildings whose scaling properties we explore. We examine key allometric relationships between these different properties illustrating how building shape changes according to size, and we extend this analysis to the classification of buildings according to land use types. We conclude with an analysis of two-point correlation functions of building geometries which supports our non-spatial analysis of scaling.
description: 28 pages, 8 figures
Sviluppo del Processo Friction Stir Welding
per Leghe Innovative Alluminio-Litio
Creators: name: Villano, Maria Grazia
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2011

description: Nel presente lavoro sono stati perseguiti i seguenti obiettivi principali:
•	Sviluppo delle conoscenze sui componenti, sulle configurazioni e sulle relative attrezzature per la saldatura FSW che consentano di ottenere un’elevata qualità del giunto ed un’alta ripetibilità del processo;
•	Studio della lega futuribile Al-Li 2198 e della relativa saldabilità FSW per applicazioni strutturali;
•	Analisi delle principali caratteristiche meccaniche, metallurgiche e di resistenza alla corrosione dei giunti di testa, “butt joints”, ottenuti da provini saldati in leae A-Li 2198 con una attrezzatura FSW  innovativa.
Theory of the pairbreaking superconductor-metal transition in nanowires
Creators: name: Del Maestro, Adrian
name: Rosenow, Bernd
name: Sachdev, Subir
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We present a detailed description of a zero temperature phase transition between superconducting and diffusive metallic states in very thin wires due to a Cooper pair breaking mechanism. The dissipative critical theory contains current reducing fluctuations in the guise of both quantum and thermally activated phase slips. A full cross-over phase diagram is computed via an expansion in the inverse number of complex components of the superconducting order parameter (one in the physical case). The fluctuation corrections to the direct current electrical and thermal conductivities are determined, and we find that the electrical conductivity has a non-monotonic temperature dependence in the metallic phase which may be consistent with recent experimental results on ultra-narrow wires. In the quantum critical regime, the ratio of the thermal to electrical conductivity displays a linear temperature dependence and thus the Wiedemann-Franz law is obeyed, with a new universal experimentally verifiable Lorenz number.
description: 91 pages, 18 figures, single column format
An Extensive Analytical Approach on Human Resources using Random Forest Algorithm
Creators: name: papineni, Swarajya lakshmi v
name: Reddy, A. Mallikarjuna
name: yarlagadda, Sudeepti
name: Yarlagadda, Snigdha
name: Akkinen, Haritha
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computers and Society (cs.CY)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: The current job survey shows that most software employees are planning to change their job role due to high pay for recent jobs such as data scientists, business analysts and artificial intelligence fields. The survey also indicated that work life imbalances, low pay, uneven shifts and many other factors also make employees think about changing their work life. In this paper, for an efficient organisation of the company in terms of human resources, the proposed system designed a model with the help of a random forest algorithm by considering different employee parameters. This helps the HR department retain the employee by identifying gaps and helping the organisation to run smoothly with a good employee retention ratio. This combination of HR and data science can help the productivity, collaboration and well-being of employees of the organisation. It also helps to develop strategies that have an impact on the performance of employees in terms of external and social factors.
Filtered asymmetric dark matter during the Peccei-Quinn phase transition
Creators: name: Ahmadvand, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: In this paper, we propose a bubble filtering-out mechanism for an asymmetric dark matter scenario during the Peccei-Quinn (PQ) phase transition. Based on a QCD axion model, extended by extra chiral neutrinos, we show that the PQ phase transition can be first order in the parameter space of the model and regarding the PQ symmetry breaking scale, the mechanism can generate PeV-scale heavy neutrinos as a dark matter candidate. Considering a CP-violating source, during the phase transition, discriminating between the neutrino and antineutrino number density, we find the observed dark matter relic abundance, such that the setup can be applied to the first order phase transition with different strengths. We then calculate effective couplings of the QCD axion addressing the strong CP problem within the model. We also study the energy density spectrum of gravitational waves generated from the first order phase transition and show that the signals can be detected by future ground-based detectors such as Einstein Telescope. In particular, for a visible heavy axion case of the model, it is shown that gravitational waves can be probed by DECIGO and BBO interferometers. Furthermore, we discuss the dark matter-standard model neutrino annihilation process as a source for the creation of PeV-scale neutrinos.
description: 20 pages, 6 figures; matches published version
title: The Vortex in the (2 + 1)-dimensional O(2) Model and Effective Low-Energy Theory for Spin Chains in a Strong Magnetic Field
Creators: name: Hornung, Manes
Publisher: name: Universität Bern
Year: 2021
Subjects: subject: 530 Physics

description: Part I: The (2+1)-dimensional O(2) model in the continuum limit at the Wilson-Fisher fixed point approached from the broken phase contains massless Goldstone bosons and vortices. The latter are infraparticles and therefore have a mass that is expected to diverge logarithmically with the volume due to the infinite cloud of massless Goldstone bosons that surrounds them. Making use of the exact duality that relates the O(2) model on the lattice to a gauge theory with integer-valued link variables, we perform Monte Carlo simulations to calculate the mass of the vortex as a function of the finite and C-periodic volume non-perturbatively. We confirm the logarithmic divergence of the vortex mass numerically, and calculate the strength of the divergence that is related to the vortex charge, to be b = 3:55(9). This constitutes a universal amplitude ratio associated with the Wilson-Fisher fixed point.

Part II: In a large external magnetic field, spin chains saturate. We study defects in the saturated state for the XXZ Heisenberg spin chain as well as for a SU(3) spin chain that is related to a regularization of the CP(2) model suitable for quantum simulation. The Hamiltonian is diagonalized in the one- and two-defects sectors and the results are matched to an effective theory of non-relativistic point particles with a contact interaction. We find that the defects in the saturated state of the SU(3) spin chain are equivalent to the ones in an antiferromagnetic, anisotropic XXZ Heisenberg spin chain, and that they interact repulsively.
Preliminary study of the anti-K N interaction in a chiral constituent quark model
Creators: name: Huang, F.
name: Wang, W. L.
name: Zhang, Z. Y.
name: Yu, Y. W.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: A preliminary investigation of the anti-K N interaction is performed within a chiral constituent quark model by solving the resonating group method (RGM) equation. The model parameters are taken from our previous work, which gave a satisfactory description of the S-, P-, D-, F-wave KN scattering phase shifts. The channel-coupling between anti-K N, pi Lambda and pi Sigma is considered, and the scattering phase shifts as well as the bound-state problem of anti-K N are dynamically studied. The results show that the S-wave anti-K N interaction in the isospin I=0 channel is attractive, and in the extended chiral SU(3) quark model such an attraction can make for an anti-K N bound state, which appears as a pi Sigma resonance in the coupled-channel calculation, while the chiral SU(3) quark model cannot accommodate the existence of an anti-K N bound state. It seems that the vector meson exchanges are necessary to be introduced in the quark-quark interactions if one tries to explain the Lambda(1405) as an anti-K N bound state or a pi Sigma - anti-K N resonance state.
description: 4 pages, 6 figures
Transport coefficients of multi-particle collision algorithms with velocity-dependent collision rules
Creators: name: Ihle, Thomas
Publisher: name: arXiv
Year: 2008
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Detailed calculations of the transport coefficients of a recently introduced particle-based model for fluid dynamics with a non-ideal equation of state are presented. Excluded volume interactions are modeled by means of biased stochastic multiparticle collisions which depend on the local velocities and densities. Momentum and energy are exactly conserved locally. A general scheme to derive transport coefficients for such biased, velocity dependent collision rules is developed. Analytic expressions for the self-diffusion coefficient and the shear viscosity are obtained, and very good agreement is found with numerical results at small and large mean free paths. The viscosity turns out to be proportional to the square root of temperature, as in a real gas. In addition, the theoretical framework is applied to a two-component version of the model, and expressions for the viscosity and the difference in diffusion of the two species are given.
description: 31 pages, 8 figures, accepted by J. Phys. Cond. Matter
Correlations Between Learning Environments and Dropout Intention
Creators: name: Simmons, Edward
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computers and Society (cs.CY)
subject: Statistics Theory (math.ST)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: This research is comparing learning environments to students dropout intentions. While using statistics I looked at data and the correlations between two articles to see how the two studies looked side to side. Learning environments and dropout intentions can both have vary effects on students. They can both determine if a student does well, or bad in school especially math.
The Orthoglide: Kinematics and Workspace Analysis
Creators: name: Pashkevich, Anatoly
name: Chablat, Damien
name: Wenger, Philippe
Publisher: name: arXiv
Year: 2007
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: The paper addresses kinematic and geometrical aspects of the Orthoglide, a three-DOF parallel mechanism. This machine consists of three fixed linear joints, which are mounted orthogonally, three identical legs and a mobile platform, which moves in the Cartesian x-y-z space with fixed orientation. New solutions to solve inverse/direct kinematics are proposed and a detailed workspace analysis is performed taking into account specific joint limit constraints.
Evolution of CIV Absorbers. II. Where does CIV live?
Creators: name: Hasan, Farhanul
name: Churchill, Christopher W
name: Stemock, Bryson
name: Nielsen, Nikole M
name: Kacprzak, Glenn G.
name: Croom, Mark
name: Murphy, Michael T
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We use the observed cumulative statistics of CIV absorbers and dark matter halos to infer the distribution of CIV-absorbing gas relative to galaxies at redshifts $0\!\leq\!z\!\leq\!5$. We compare the cosmic incidence $dN/dX$ of CIV absorber populations and galaxy halos, finding that massive $L \geq L_{\star}$ halos alone cannot account for all the observed $W_r \geq 0.05$~Å absorbers. However, the $dN/dX$ of lower mass halos exceeds that of $W_r \geq 0.05$~Å absorbers. We also estimate the characteristic gas radius of absorbing structures required for the observed CIV $dN/dX$, assuming each absorber is associated with a single galaxy halo. The $W_r \geq 0.3$~Å and $W_r \geq 0.6$~Å CIV gas radii are $\sim30-70\%$ ($\sim20-40\%$) of the virial radius of $L_{\star}$ ($0.1L_{\star}$) galaxies, and the $W_r \geq 0.05$~Å gas radius is $\sim100-150\%$($\sim60-100\%$) of the virial radius of $L_{\star}$ ($0.1L_{\star}$) galaxies. For stronger absorbers, the gas radius relative to virial radius rises across Cosmic Noon and falls afterwards, while for weaker absorbers, the relative gas radius declines across Cosmic Noon and then dramatically rises at $z\!0.5R_v$) was produced primarily in ancient satellite dwarf galaxy outflows, while the inner halo gas ($<0.5R_v$) originated from the central galaxy and persists as recycled accreting gas.
description: Accepted to ApJ; 22 pages (17 pages main text); 7 figures
Characterization of Subgraphs Relationships and Distribution in Complex Networks
Creators: name: Antiqueira, Lucas
name: Costa, Luciano da Fontoura
Publisher: name: arXiv
Year: 2008
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: A network can be analyzed at different topological scales, ranging from single nodes to motifs, communities, up to the complete structure. We propose a novel intermediate-level topological analysis that considers non-overlapping subgraphs (connected components) and their interrelationships and distribution through the network. Though such subgraphs can be completely general, our methodology focuses the cases in which the nodes of these subgraphs share some special feature, such as being critical for the proper operation of the network. Our methodology of subgraph characterization involves two main aspects: (i) a distance histogram containing the distances calculated between all subgraphs, and (ii) a merging algorithm, developed to progressively merge the subgraphs until the whole network is covered. The latter procedure complements the distance histogram by taking into account the nodes lying between subgraphs, as well as the relevance of these nodes to the overall interconnectivity. Experiments were carried out using four types of network models and four instances of real-world networks, in order to illustrate how subgraph characterization can help complementing complex network-based studies.
description: 14 pages, 13 figures, a working manuscript
Non-adiabatic ionization with tailored laser pulses
Creators: name: Azizi, Sajad
name: Saalmann, Ulf
name: Rost, Jan M
Publisher: name: arXiv
Year: 2021
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Non-adiabatic photo-ionization is difficult to control as it relies on the derivatives of the envelope and not on phase-details of the short ionizing pulse. Here, we introduce a catalyzing state, whose presence render non-adiabatic ionization sensitive to phase-details of tailored pulses. Since a catalyzing state is in general easy to create, this opens a perspective for coherent control of ultra-fast ionization.
description: 9 pages, 5 figures, 2 appendices
Particle creation, classicality and related issues in quantum field theory: I. Formalism and toy models
Creators: name: Mahajan, Gaurang
name: Padmanabhan, T.
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The quantum theory of a harmonic oscillator with a time dependent frequency arises in several important physical problems, especially in the study of quantum field theory in an external background. While the mathematics of this system is straightforward, several conceptual issues arise in such a study. We present a general formalism to address some of the conceptual issues like the emergence of classicality, definition of particle content, back reaction etc. In particular, we parametrize the wave function in terms of a complex number (which we call excitation parameter) and express all physically relevant quantities in terms it. Many of the notions -- like those of particle number density, effective Lagrangian etc., which are usually defined using asymptotic in-out states -- are generalized as time-dependent concepts and we show that these generalized definitions lead to useful and reasonable results. Having developed the general formalism we apply it to several examples. Exact analytic expressions are found for a particular toy model and approximate analytic solutions are obtained in the extreme cases of adiabatic and highly non-adiabatic evolution. We then work out the exact results numerically for a variety of models and compare them with the analytic results and approximations. The formalism is useful in addressing the question of emergence of classicality of the quantum state, its relation to particle production and to clarify several conceptual issues related to this. In Paper II (arXiv:0708.1237), which is a sequel to this, the formalism will be applied to analyze the corresponding issues in the context of quantum field theory in background cosmological models and electric fields.
description: RevTeX 4; 32 pages; 28 figures; first of a series of two papers, the second being arXiv:0708.1237 [gr-qc]; high resolution figures available from the authors on request
Combating Informational Denial-of-Service (IDoS) Attacks: Modeling and Mitigation of Attentional Human Vulnerability
Creators: name: Huang, Linan
name: Zhu, Quanyan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cryptography and Security (cs.CR)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: This work proposes a new class of proactive attacks called the Informational Denial-of-Service (IDoS) attacks that exploit the attentional human vulnerability. By generating a large volume of feints, IDoS attacks deplete the cognitive resources of human operators to prevent humans from identifying the real attacks hidden among feints. This work aims to formally define IDoS attacks, quantify their consequences, and develop human-assistive security technologies to mitigate the severity level and risks of IDoS attacks. To this end, we use the semi-Markov process to model the sequential arrivals of feints and real attacks with category labels attached in the associated alerts. The assistive technology strategically manages human attention by highlighting selective alerts periodically to prevent the distraction of other alerts. A data-driven approach is applied to evaluate human performance under different Attention Management (AM) strategies. Under a representative special case, we establish the computational equivalency between two dynamic programming representations to reduce the computation complexity and enable online learning with samples of reduced size and zero delays. A case study corroborates the effectiveness of the learning framework. The numerical results illustrate how AM strategies can alleviate the severity level and the risk of IDoS attacks. Furthermore, the results show that the minimum risk is achieved with a proper level of intentional inattention to alerts, which we refer to as the law of rational risk-reduction inattention.
Subjective Evaluation of Forms in an Immersive Environment
Creators: name: Petiot, Jean-François
name: Chablat, Damien
Publisher: name: arXiv
Year: 2007
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: User's perception of product, by essence subjective, is a major topic in marketing and industrial design. Many methods, based on users' tests, are used so as to characterise this perception. We are interested in three main methods: multidimensional scaling, semantic differential method, and preference mapping. These methods are used to built a perceptual space, in order to position the new product, to specify requirements by the study of user's preferences, to evaluate some product attributes, related in particular to style (aesthetic). These early stages of the design are primordial for a good orientation of the project. In parallel, virtual reality tools and interfaces are more and more efficient for suggesting to the user complex feelings, and creating in this way various levels of perceptions. In this article, we present on an example the use of multidimensional scaling, semantic differential method and preference mapping for the subjective assessment of virtual products. These products, which geometrical form is variable, are defined with a CAD model and are proposed to the user with a spacemouse and stereoscopic glasses. Advantages and limitations of such evaluation is next discussed..
Electro-optically modulated lasers: pulse energy and contrast enhancement derived from theoretical spectrum
Creators: name: Marion, Denis
name: Lhermite, Jérôme
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: In this article, we derive analytically the complex optical spectrum of a pulsed laser source obtained when a frequency comb generated by phase modulation is input into a synchronized intensity modulator. We then show how this knowledge of the spectrum may help to achieve unprecedented accuracy during the experimental spectrum correction step usually carried out with an optical spectrum processor. In numerical examples, for a given average power we present up to a 75 % increase in peak power and an enhancement of the extinction ratio by at least three orders of magnitude. This method also enables large-factor rate-multiplications of these versatile coherent sources using the Talbot effect with negligible degradation of the signal.
Report from Sessions 1 and 3, including the Local Bubble Debate
Creators: name: Shelton, Robin L.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: This report summarizes the discussions in the Session 1 and Session 3 groups which met to discuss the questions: ``What Physical Processes Drive the Multiphase Interstellar Medium in the Local Bubble?'', and ``What are the Energy and Pressure Balances in the Local Bubble?'' Most of our understanding of the Local Bubble has come from soft X-ray observations, but recent appreciation of the importance of solar wind charge exchange (SWCX) reactions has shown that the heliosphere produces some fraction of the soft X-rays that were previously ascribed to the Local Bubble. Some astronomers suggest that the SWCX X-rays rather than Local Bubble emission could explain most of the locally produced X-rays. Our discussions, therefore, also included a debate concerning the Local Bubble's existence.
description: 8 pages, refereed, written version of the oral reports for two of the sessions at the 2007 ISSI conference entitled "From the Outer Heliosphere to the Local Bubble: Comparisons of New Observations with Theory", accepted for publication in the conference proceedings and in Space Science Reviews
Localized Backreacted Flavor Branes in Holographic QCD
Creators: name: Burrington, Benjamin A.
name: Kaplunovsky, Vadim S.
name: Sonnenschein, Jacob
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We investigate the perturbative (in $g_s N_{D8}$) backreaction of localized D8 branes in D4-D8 systems including in particular the Sakai Sugimoto model. We write down the explicit expressions of the backreacted metric, dilaton and RR form. We find that the backreaction remains small up to a radial value of $u \ll \ell_s/(g_s N_{D8})$, and that the background functions are smooth except at the D8 sources. In this perturbative window, the original embedding remains a solution to the equations of motion. Furthermore, the fluctuations around the original embedding, describing scalar mesons, do not become tachyonic due to the backreaction in the perturbative regime. This is is due to a cancelation between the DBI and CS parts of the D8 brane action in the perturbed background.
description: 1+48 pages (7 figures) + 15 pages, citations added & minor corrections
Evolving and Merging Hebbian Learning Rules: Increasing Generalization by Decreasing the Number of Rules
Creators: name: Pedersen, Joachim Winther
name: Risi, Sebastian
Publisher: name: arXiv
Year: 2021
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: Generalization to out-of-distribution (OOD) circumstances after training remains a challenge for artificial agents. To improve the robustness displayed by plastic Hebbian neural networks, we evolve a set of Hebbian learning rules, where multiple connections are assigned to a single rule. Inspired by the biological phenomenon of the genomic bottleneck, we show that by allowing multiple connections in the network to share the same local learning rule, it is possible to drastically reduce the number of trainable parameters, while obtaining a more robust agent. During evolution, by iteratively using simple K-Means clustering to combine rules, our Evolve and Merge approach is able to reduce the number of trainable parameters from 61,440 to 1,920, while at the same time improving robustness, all without increasing the number of generations used. While optimization of the agents is done on a standard quadruped robot morphology, we evaluate the agents' performances on slight morphology modifications in a total of 30 unseen morphologies. Our results add to the discussion on generalization, overfitting and OOD adaptation. To create agents that can adapt to a wider array of unexpected situations, Hebbian learning combined with a regularising "genomic bottleneck" could be a promising research direction.
Dispersive representation and shape of K_{l3} form factors
Creators: name: Passemar, Emilie
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The Callan-Treiman low-energy theorem offers an opportunity to test electroweak couplings of light quarks to the gauge boson W. To that aim, we introduce a model-independent and accurate dispersive parametrization of the two K_{l3} form factors. We then discuss three applications to the analysis of K_{e3} and K_{mu3} measurements: the prediction of the ratios Gamma(K_{mu3})/Gamma(K_{e3}), the extraction of |f_+(0)V_{us}| and finally the possible measurement of m_u - m_d induced isospin breaking asymmetry.
description: 7 pages, 4 figures. Discussion slightly extended in section 2. Talk given at the KAON07 International Conference, May 21-25 2007, Frascati, Italy
Dynamics of Density Imbalanced Bilayer Holes in the Quantum Hall Regime
Creators: name: Misra, S.
name: Bishop, N. C.
name: Tutuc, E.
name: Shayegan, M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report magnetotransport measurements on bilayer GaAs hole systems with unequal hole concentrations in the two layers. At magnetic fields where one layer is in the integer quantum Hall state and the other has bulk extended states at the Fermi energy, the longitudinal and Hall resistances of the latter are hysteretic, in agreement with previous measurements. For a fixed magnetic field inside this region and at low temperatures ($T\le$ 350 mK), the time evolutions of the longitudinal and Hall resistances show pronounced jumps followed by slow relaxations, with no end to the sequence of jumps. Our measurements demonstrate that the jumps occur simultaneously in pairs of contacts 170 $μ$m apart, and appear to involve changes in the charge configuration of the bilayer. In addition, the jumps can occur with either random or regular periods, excluding thermal fluctuations as a possible origin for the jumps. Finally, while remaining at a fixed field, we warm the sample to above 350 mK, where the jumps disappear. Upon recooling the sample below this temperature, the jumps reappear, indicating that the jumps do not result from nearly dissipationless eddy currents either.
The energetics of quantum vacuum friction: Field fluctuations
Creators: name: Guo, Xin
name: Milton, Kimball A.
name: Kennedy, Gerard
name: McNulty, William P.
name: Pourtolami, Nima
name: Li, Yang
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Atomic Physics (physics.atom-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum fluctuations can induce a friction on a neutral but polarizable particle and cause it to radiate energy even if the particle is moving in free space filled with blackbody radiation, and is not in contact with or close to any surface or other object. We explore the energetics of such a particle moving uniformly in vacuum, continuing our previous investigations of quantum friction. The intrinsic polarizability of the particle is considered to be purely real before it is dressed by radiation. The particle is then guaranteed to be in the nonequilibrium steady state (NESS), where it absorbs and emits energy at the same rate. We first calculate the quantum frictional power and force on the particle in the rest frame of the blackbody radiation from first principles, namely the Maxwell-Heaviside equations and the Lorentz force law. Then we provide a simpler method of obtaining the same quantities in the rest frame of the particle by using the principle of virtual work. The equivalence of the two approaches is illustrated. The formulas we derive for quantum vacuum frictional power and force are fully relativistic and applicable to finite temperature. In NESS, the quantum vacuum frictional force on the particle is shown to be a true drag, independent of the model for polarizability and the polarization state of the particle. Finally, we give an estimate of the quantum vacuum friction on a gold atom and comment on the feasibility of detecting such quantum vacuum frictional effects.
Realistic Rendering of Kinetostatic Indices of Mechanisms
Creators: name: Chablat, Damien
name: Bennis, Fouad
Publisher: name: arXiv
Year: 2007
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: The work presented in this paper is related to the use of a haptic device in an environment of robotic simulation. Such device introduces a new approach to feel and to understand the boundaries of the workspace of mechanisms as well as its kinetostatic properties. Indeed, these concepts are abstract and thus often difficult to understand for the end-users. To catch his attention, we propose to amplify the problems of the mechanisms in order to help him to take the good decisions.
Flipped spinfoam vertex and loop gravity
Creators: name: Engle, Jonathan
name: Pereira, Roberto
name: Rovelli, Carlo
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We introduce a vertex amplitude for 4d loop quantum gravity. We derive it from a conventional quantization of a Regge discretization of euclidean general relativity. This yields a spinfoam sum that corrects some difficulties of the Barrett-Crane theory. The second class simplicity constraints are imposed weakly, and not strongly as in Barrett-Crane theory. Thanks to a flip in the quantum algebra, the boundary states turn out to match those of SO(3) loop quantum gravity -- the two can be identified as eigenstates of the same physical quantities -- providing a solution to the problem of connecting the covariant SO(4) spinfoam formalism with the canonical SO(3) spin-network one. The vertex amplitude is SO(3) and SO(4)-covariant. It rectifies the triviality of the intertwiner dependence of the Barrett-Crane vertex, which is responsible for its failure to yield the correct propagator tensorial structure. The construction provides also an independent derivation of the kinematics of loop quantum gravity and of the result that geometry is quantized.
description: 37 pages, 4 figures
code book.docx
Creators: name: HUSSAIN, MUDASSAR
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 470101
subject: Communication studies
classificationCode: 470103
subject: Environmental communication
classificationCode: 470105
subject: Journalism studies
classificationCode: 470107
subject: Media studies

description: The study in hand quantitatively content analyzes the news frames in the leading Pakistani newspapers. The frames include episodic frames, thematic frames, scientific consensus, political conflict, , effects of climate change like disaster appeal, effects on environment, national security, economy and public health, and the climate efficacy variables of general moral responsibility, self-efficacy, external efficacy and response efficacy. The universe for the study is the coverage of climate change on front pages, lead editorials and the sub-editorials of Dawn, The Express Tribune and popular Urdu language dailies of Jang and Express between 2018 and 2021. There were three hundred and seventy two news articles (n = 372).
Benford's laws tests on S&P500 daily closing values and the corresponding daily log-returns both point to huge non-conformity
Creators: name: Ausloos, Marcel
name: Ficcadenti, Valerio
name: Dhesi, Gurjeet
name: Shakeel, Muhammad
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Finance (q-fin.ST)
subject: General Finance (q-fin.GN)
subject: Trading and Market Microstructure (q-fin.TR)
subject: FOS: Economics and business

description: The so-called Benford's laws are of frequent use in order to observe anomalies and regularities in data sets, in particular, in election results and financial statements. Yet, basic financial market indices have not been much studied, if studied at all, within such a perspective. This paper presents features in the distributions of S\&P500 daily closing values and the corresponding daily log returns over a long time interval, [03/01/1950 - 22/08/2014], amounting to 16265 data points. We address the frequencies of the first, second, and first two significant digits counts and explore the conformance to Benford's laws of these distributions at five different (equal size) levels of disaggregation. The log returns are studied for either positive or negative cases. The results for the S&P500 daily closing values are showing a huge lack of non-conformity, whatever the different levels of disaggregation. Some "first digits" and "first two digits" values are even missing. The causes of this non-conformity are discussed, pointing to the danger in taking Benford's laws for granted in huge databases, whence drawing "definite conclusions". The agreements with Benford's laws are much better for the log returns. Such a disparity in agreements finds an explanation in the data set itself: the inherent trend in the index. To further validate this, daily returns have been simulated calibrating the simulations with the observed data averages and tested against Benford's laws. One finds that not only the trend but also the standard deviation of the distributions are relevant parameters in concluding about conformity with Benford's laws.
ประสิทธิผลการดำเนินงานซุปเปอร์ไรเดอร์จิตอาสาในระบบดูแลผู้ป่วยโควิด 19 ที่บ้านผ่านบริการสุขภาพทางไกล ณ สถานพยาบาลแห่งหนึ่งในกรุงเทพมหานคร
Creators: name: สุทธิสา จันทร์เพ็ง
Publisher: name: สถาบันป้องกันควบคุมโรคเขตเมือง
Year: 2023
Subjects: จิตอาสา
โควิด 19
บริการสุขภาพทางไกล

description: วารสารสถาบันป้องกันควบคุมโรคเขตเมือง, 8, 2, 49-66