cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Unified First-Principles Study of the Anomalous Hall Effect Based on Exact Muffin-Tin Orbitals
Creators: name: Wang, Lei
name: Min, Tai
name: Xia, Ke
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Based on the exact muffin-tin orbitals (EMTOs), we developed a first-principles method to calculate the current operators and investigated the anomalous Hall effect in bcc Fe as an example, with which we successfully separated the skew scattering contribution from the side jump and intrinsic contributions by fitting the scaling law with the introduction of sparse impurities. By investigating the temperature dependence of the anomalous Hall effect in bulk Fe, we predicted a fluctuated anomalous Hall angle as a function of temperature when considering only phonons, which, in the future, can be measured in experiments by suppressing magnon excitation, e.g., by applying a high external magnetic field.
Towards the understanding of human dynamics
Creators: name: Zhou, Tao
name: Han, Xiaopu
name: Wang, Binghong
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: Quantitative understanding of human behaviors provides elementary comprehension of the complexity of many human-initiated systems. A basic assumption embedded in the previous analyses on human dynamics is that its temporal statistics are uniform and stationary, which can be properly described by a Poisson process. Accordingly, the interevent time distribution should have an exponential tail. However, recently, this assumption is challenged by the extensive evidence, ranging from communication to entertainment and work patterns, that the human dynamics obeys non-Poisson statistics with heavy-tailed interevent time distribution. This review article summarizes the recent empirical explorations on human activity pattern, as well as the corresponding theoretical models for both task-driven and interest-driven systems. Finally, we outline some future open questions in the studies of the statistical mechanics of human dynamics.
description: 28 pages, 16 figures
A Young Stellar Cluster Surrounding the Peculiar Eruptive Variable V838 Monocerotis
Creators: name: Afşar, Melike
name: Bond, Howard E.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The unusual variable star V838 Monocerotis underwent an eruption in 2002. It continues to illuminate a spectacular series of light echoes, as the outburst light is scattered from circumstellar dust. V838 Mon has an unresolved B3 V companion star. We serendipitously discovered that a neighboring 16th-mag star is also of type B. We then carried out a survey of other stars in the vicinity, revealing two more B-type stars within 45" of V838 Mon. We have determined the distance to this sparse, young cluster, based on spectral classification and photometric main-sequence fitting of the three B stars. The cluster distance is found to be 6.2+-1.2 kpc, in excellent agreement with the geometric distance to V838 Mon of 5.9 kpc obtained from Hubble Space Telescope polarimetry of the light echoes. Using our distance determination, we show that the B3 V companion of V838 Mon is sufficient to account for the entire luminosity of the star measured on survey photographs before its outburst. The B3 star is currently, however, about 1 mag fainter than before the eruption, suggesting that it is now suffering extinction due to dust ejected from V838 Mon. Considerations of the pre-outburst luminosity and cluster age appear to leave stellar-collision or -merger scenarios as one of the remaining viable explanations for the outburst of V838 Mon.
description: 10 pages, 3 figures, 2 tables; accepted for publication in the Astronomical Journal, January 2007
Two types of distribution of the gas velocity dispersion of MaNGA galaxies
Creators: name: Pilyugin, L. S.
name: Zinchenko, I. A.
name: Lara-Lopez, M. A.
name: Nefedyev, Y. A.
name: Vilchez, J. M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The distribution of the gas velocity dispersion sigma across the images of 1146 MaNGA galaxies is analyzed. We find that there are two types of distribution of the gas velocity dispersion across the images of galaxies: (i) the distributions of 909 galaxies show a radial symmetry with or without the sigma enhancement at the center (R distribution) and (ii) distributions with a band of enhanced sigma along the minor axis in the images of 159 galaxies with or without the sigma enhancement at the center (B distribution) The sigma distribution across the images of 78 galaxies cannot be reliable classified. We select 806 galaxies with the best defined characteristics (this sample includes 687 galaxies with R distribution and 119 galaxies with B distribution) and compare the properties of galaxies with R and B distributions. We find that the median value of the gas velocity dispersion sigma_m in galaxies with B distribution is higher by around 5 km/s, on average, than that of galaxies with R distribution. The optical radius R_25 of galaxies with B distribution is lower by around 0.1 dex, on average, than that of galaxies with similar masses with R distribution. Thus the properties of a galaxy are related to the type of distribution of the gas velocity dispersion across its image. This suggests that the presence of the band of the enhanced gas velocity dispersion can be an indicator of a specific evolution (or a specific stage in the evolution) of a galaxy.
description: 5 pages, 4 figures, accepted to Astron.Astrophys. arXiv admin note: text overlap with arXiv:2005.12744
uGMRT HI 21-cm absorption observations of two extremely inverted spectrum sources
Creators: name: Mhaskey, Mukul
name: Paul, Surajit
name: Gupta, Neeraj
name: Mukherjee, Dipanjan
name: Gopal-Krishna
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We report the detection of HI 21-cm absorption in a member of the rare and recently discovered class of compact radio sources, 'Extremely Inverted Spectrum Extragalactic Radio Sources (EISERS)'. EISERS conceivably form a special sub-class of the inverted spectrum radio galaxies since the spectral index of the optically thick part of the spectrum for these sources crosses the synchrotron self absorption limit of $α=+2.5$ (S($ν$) $\propto$ $ν^α$). We have searched for HI absorption in two EISERS using the recently upgraded Giant Metrewave Radio Telescope (uGMRT) and detected an absorption feature in one of them. The strong associated HI absorption detected against the source J1209$-$2032 ($z$=0.4040) implies an optical depth of 0.178$\pm$0.02 corresponding to an HI column density of 34.8$\pm$2.9 $\times$10$^{20}$ cm$^{-2}$, for an assumed HI spin temperature of 100 K and covering factor of 1. This is among the highest known optical depth and HI column densities found for compact radio sources of GPC/CSS type and supports the free-free absorption model for the steeply inverted radio spectrum of this source. For the other source, J1549$+$5038 ($z$ = 2.171), no HI absorption was detected in our observations.
description: Accepted for publication in A&A
The Covariant Description of Electromagnetically Polarizable Media
Creators: name: Dereli, T.
name: Gratus, J.
name: Tucker, R. W.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The form of the phenomenological stress-energy-momentum tensor for the electromagnetic field in a class of inhomogeneous, anisotropic magneto-electric media is calculated from first principles, leading to a coherent understanding of the phenomenological stresses and energy-momentum exchanges induced by electromagnetic interactions with such matter in terms of a fully relativistic covariant variational framework.
description: To appear in Physics Letters A
Opto-electronic properties and solar cell efficiency modelling of Cu$_2$ZnXS$_4$ (X=Sn,Ge,Si) kesterites
Creators: name: Ratz, Thomas
name: Raty, Jean-Yves
name: Brammertz, Guy
name: Vermang, Bart
name: Nguyen, Ngoc Duy
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In this work, first principle calculations of Cu$_2$ZnSnS$_4$ (CZTS), Cu$_2$ZnGeS$_4$ (CZGS) and Cu$_2$ZnSiS$_4$ (CZSS) are performed to highlight the impact of the cationic substitution on the structural, electronic and optical properties of kesterite compounds. Direct bandgaps are reported with values of 1.32, 1.89 and 3.06 eV respectively for CZTS, CZGS and CZSS. In addition, absorption coefficient values of the order of $10^4$ cm$^{-1}$ are obtained, indicating the applicability of these materials as absorber layer for solar cell applications. In the second part of this study, ab initio results are used as input data to model the electrical power conversion efficiency of kesterite-based solar cell. In that perspective, we used an improved version of the Shockley-Queisser theoretical model including non-radiative recombination via an external parameter defined as the internal quantum efficiency. Based on predicted optimal absorber layer thicknesses, the variation of the solar cell maximal efficiency is studied as a function of the non-radiative recombination rate. Maximal efficiencies of 25.88, 19.94 and 3.11% are reported respectively for CZTS, CZGS and CZSS for vanishing non-radiative recombination rate. Using an internal quantum efficiency providing $V_{OC}$ values comparable to experimental measurements, solar cell efficiencies of 15.88, 14.98 and 2.66% are reported respectively for CZTS, CZGS and CZSS (for an optimal thickness of 1.15 $μ$m). With this methodology, we confirm the suitability of CZTS in single junction solar cells, with a possible efficiency improvement of 10% enabled through the reduction of the non-radiative recombination rate. In addition, CZGS appears to be an interesting candidate as top cell absorber layer for tandem approaches whereas CZSS might be interesting for transparent PV windows.
description: 11 pages, 6 figures and 3 tables
Beyond traditional assumptions in fair machine learning
Creators: name: Kilbertus, Niki
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: This thesis scrutinizes common assumptions underlying traditional machine learning approaches to fairness in consequential decision making. After challenging the validity of these assumptions in real-world applications, we propose ways to move forward when they are violated. First, we show that group fairness criteria purely based on statistical properties of observed data are fundamentally limited. Revisiting this limitation from a causal viewpoint we develop a more versatile conceptual framework, causal fairness criteria, and first algorithms to achieve them. We also provide tools to analyze how sensitive a believed-to-be causally fair algorithm is to misspecifications of the causal graph. Second, we overcome the assumption that sensitive data is readily available in practice. To this end we devise protocols based on secure multi-party computation to train, validate, and contest fair decision algorithms without requiring users to disclose their sensitive data or decision makers to disclose their models. Finally, we also accommodate the fact that outcome labels are often only observed when a certain decision has been made. We suggest a paradigm shift away from training predictive models towards directly learning decisions to relax the traditional assumption that labels can always be recorded. The main contribution of this thesis is the development of theoretically substantiated and practically feasible methods to move research on fair machine learning closer to real-world applications.
description: PhD Thesis submitted at the University of Cambridge, October 2020. The thesis is based on a number of previous works also available on arxiv (see Chapter 1)
Superconformal Invariants or How to Relate Four-point AdS Amplitudes
Creators: name: Drummond, J. M.
name: Gallot, L.
name: Sokatchev, E.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Using the form of N=2 superconformal invariants we derive the explicit relation between the bottom and top components of the correlator of four stress-tensor multiplets in N=4 Super Yang-Mills. The result is given in terms of an eighth order differential operator acting on the function of two variables which characterises these correlators. It allows us to show a non-trivial consistency relation between the known results for the corresponding supergravity amplitudes on AdS5.
description: 11 pages
The development of a holistic approach to modeling driver behavior : accounting for driver heterogeneity in car-following models
Creators: name: James, Rachel Michelle
name: 0000-0001-9138-510X
Publisher: name: The University of Texas at Austin
Year: 2019
Subjects: Naturalistic data
Behavioral heterogeneity
Car-following models
Calibration

description: Car-following behavior has been studied since the 1940s. However, complex calibration requirements and challenges with collecting high-resolution data have stunted advancements in this domain. Thus, methodologies to adequately capture naturalistic behavioral heterogeneity are largely missing from the literature. For this dissertation, a sample from the second Strategic Highway Research Program Naturalistic Driving Study was analyzed. This sample contains 665 trips completed on freeways in clear weather conditions. Driver demographics, vehicle CAN bus, and external sensor data are available for each trip. The trajectories in this sample were processed and used to calibrate the Gipps, Intelligent Driver Model, and Wiedemann 99 car-following models. This dissertation seeks to improve how inter-driver heterogeneity in car-following behavior is accounted for in microsimulation models. This dissertation has three primary objectives. Objective 1 identifies which driver attributes are sources of inter-driver heterogeneity. Objective 2 explores the viability of using census-level data to calibrate microsimulation models. Objective 3 develops and evaluates a new mechanism for properly capturing inter-driver heterogeneity in microsimulation: an ensemble car-following model. To achieve these objectives, first, Kruskal-Wallis one-way analysis of variance tests were applied to show statistically significant differences in both the estimated car-following model calibration coefficients and the overall model performance across groups of drivers categorized by commonalities in their driver attributes. Next, the Expectation Maximization clustering algorithm was applied to show that, despite differences in driver behavior, homogeneous driver groups, or groups of drivers that behave similarly, exist in the dataset. Moreover, this dissertation shows that drivers can be classified into their proper homogeneous driver group only knowing their driver specific attributes. Finally, VISSIM was used to implement the homogeneous driver groups in microsimulation. This case study illustrated that when inter-driver differences in driving behavior are explicitly modeled, there are notable impacts on the performance metrics collected from the microsimulation models. These performance metrics are ultimately used by decision makers to evaluate alternatives for transportation funding. Thus, this dissertation provides evidence of the importance of appropriately modeling inter-driver differences to improve the quality of the microsimulation model results and inform better funding allocation decisions.
Fluctuation analysis of mechanochemical coupling depending on the type of bio-molecular motor
Creators: name: Nishikawa, Masatoshi
name: Takagi, Hiroaki
name: Iwane, Atsuko H.
name: Yanagida, Toshio
Publisher: name: arXiv
Year: 2008
Subjects: subject: Subcellular Processes (q-bio.SC)
subject: FOS: Biological sciences

description: Mechanochemical coupling was studied for two different types of myosin motors in cells: myosin V, which carries cargo over long distances by as a single molecule; and myosin II, which generates a contracting force in cooperation with other myosin II molecules. Both mean and variance of myosin V velocity at various [ATP] obeyed Michaelis-Menten mechanics, consistent with tight mechanochemical coupling. Myosin II, working in an ensemble, however, was explained by a loose coupling mechanism, generating variable step sizes depending on the ATP concentration and realizing a much larger step (200 nm) per ATP hydrolysis than myosin V through its cooperative nature at zero load. These different mechanics are ideal for the respective myosin's physiological functions.
Detection of soft tissue abnormalities in mammographic images for early diagnosis of breast cancer
Creators: name: Sameti, Mohammad
Publisher: name: University of British Columbia
Year: 2009

description: Treatment of breast cancer is currently effective only if it is detected at an early stage. X-ray mammography is the most effective method for early detection, however, mammographic images are complex. Researchers have been utilizing image processing and image analysis techniques to assist radiologists in their difficult task of detecting tumors in mammographic images. To aid radiologists in earlier detection of breast cancer, a retrospective study of mammograms was conducted. In this pioneer study, screening mammograms taken prior to the detection of a malignant mass were analyzed. The aim is to determine if there exists any signs of cancer development in the screening mammograms prior to the detection of a mass by the radiologist. For 58 biopsy proven breast cancer patients who were diagnosed by identifying a malignant mass in their mammograms, 224 previous screening mammograms were collected. These mammograms were reviewed by an expert radiologist and three regions were marked on each of the two mammographic projections of each case: 1) the region which corresponds to the site in which the malignant mass subsequently developed, 2) a similar normal region on the same mammogram, and 3) the normal region on the previous screening mammogram of the opposite breast which corresponds to region 1. Sixty-two texture and photometric image features were calculated for all the marked areas. A stepwise discriminant analysis found that six of these features best distinguish between the normal and abnormal regions. The best linear classification function resulted in 72% average classification. A t its current stage, the system can be used by a radiologist to examine suspicious patterns in a mammogram. The regions which are flagged by the system have a 72% chance of developing a malignant mass by the time of the next screening. Therefore, further evaluation of these patients (e.g., a screening examination sooner than the usual one year interval) can result in earlier detection of breast cancer. A novel segmentation algorithm for mammogram partitioning based on fuzzy sets theory was also devised. This algorithm considers the fact that malignant masses and parenchymal patterns have unclear and fuzzy boundaries in a mammogram. It also takes into account the effects of neighboring pixels for this segmentation. This algorithm was evaluated in combination with a texture feature extraction step for detection of malignant masses in mammograms. The mass detection scheme resulted in 94.3% true-positive detection rate and 0.24 false-positives per image on a set of 35 mammograms.
title: Exploring for the Future overview fact sheet
Creators: name: T., Steeper
name: T., Steeper
Publisher: name: Commonwealth of Australia (Geoscience Australia)
Year: 2021
Subjects: subject: EARTH SCIENCES
subject: communication
subject: EFTF
subject: fieldwork
subject: Exploring For The Future
subject: Published_External

description: This fact sheet sets out the goals, vision and benefits of the Exploring for the Future program, as well as the ways we conduct fieldwork and what the information gathered is used for.
Constraints on f(R) Cosmology in the Palatini Formalism
Creators: name: Li, Baojiu
name: Chan, K. C.
name: Chu, M. -C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this work we derive the covariant and gauge invariant perturbation equations in general theories of $f(R)$ gravity in the Palatini formalism to linear order and calculate the cosmic microwave background (CMB) and matter power spectra for an extensively discussed model, $f(R) = R + α(-R)^β$, which is a possible candidate for the late-time cosmic accelerating expansion found recently. These spectra are discussed and found to be sensitively dependent on the value of $β$. We are thus able to make stringent constraints on $β$ from cosmological data on CMB and matter power spectra: The three-year Wilkinson Microwave Anisotropy Probe (WMAP) data alone gives a constraint $|β| \lesssim \mathcal{O}(10^{-3})$ while the joint WMAP, Supernova Lagacy Survey (SNLS) and Sloan Digital Sky Survey (SDSS) data sets tightens this to $β\sim \mathcal{O}(10^{-6})$, about an order of magnitude more stringent than the constraint from SDSS data alone, which makes this model practically indistinguishable from the standard $Λ\mathrm{CDM}$ paradigm.
description: 9 pages, 7 figures. Modified version to appear in Physical Review D
Short-term Operational Planning Problem of the Multiple-Energy Carrier Hybrid AC/DC Microgrids
Creators: name: Bayani, Reza
name: Bushlaibi, Mohammed
name: Manshadi, Saeed D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In this paper, the short-term operation problem for a multiple energy carrier hybrid AC/DC microgrid is discussed. The hybrid microgrid consists of AC and DC parts, which are connected by means of inverters as well as natural gas network. The microgrid includes photovoltaic (PV) unit, wind turbine (WT), battery storage unit and gas-fired microturbines. A mixed integer linear programming is formed to minimize the overall cost of the microgrid including cost of natural gas supply, the value of lost load and battery degradation cost. The presented case study explored the importance of inverter characteristics and pipeline capacity.
Turbo charging time-dependent density-functional theory with Lanczos chains
Creators: name: Rocca, Dario
name: Gebauer, Ralph
name: Saad, Yousef
name: Baroni, Stefano
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We introduce a new implementation of time-dependent density-functional theory which allows the \emph{entire} spectrum of a molecule or extended system to be computed with a numerical effort comparable to that of a \emph{single} standard ground-state calculation. This method is particularly well suited for large systems and/or large basis sets, such as plane waves or real-space grids. By using a super-operator formulation of linearized time-dependent density-functional theory, we first represent the dynamical polarizability of an interacting-electron system as an off-diagonal matrix element of the resolvent of the Liouvillian super-operator. One-electron operators and density matrices are treated using a representation borrowed from time-independent density-functional perturbation theory, which permits to avoid the calculation of unoccupied Kohn-Sham orbitals. The resolvent of the Liouvillian is evaluated through a newly developed algorithm based on the non-symmetric Lanczos method. Each step of the Lanczos recursion essentially requires twice as many operations as a single step of the iterative diagonalization of the unperturbed Kohn-Sham Hamiltonian. Suitable extrapolation of the Lanczos coefficients allows for a dramatic reduction of the number of Lanczos steps necessary to obtain well converged spectra, bringing such number down to hundreds (or a few thousands, at worst) in typical plane-wave pseudopotential applications. The resulting numerical workload is only a few times larger than that needed by a ground-state Kohn-Sham calculation for a same system. Our method is demonstrated with the calculation of the spectra of benzene, C$_{60}$ fullerene, and of chlorofyll a.
description: 15 pages, 7 figures, to be pdflatex + bibtex
XX model on the circle
Creators: name: De Pasquale, A.
name: Costantini, G.
name: Facchi, P.
name: Florio, G.
name: Pascazio, S.
name: Yuasa, K.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We diagonalize the XX model with a finite number of spins and periodic boundary conditions. We solve for the ground state, focus on the rapidity of the convergence to the thermodynamic limit and study the features of multipartite entanglement.
description: 12 pages, 11 figures
Higgs boson production at $\mu^+\mu^+$ colliders
Creators: name: Hamada, Yu
name: Kitano, Ryuichiro
name: Matsudo, Ryutaro
name: Okawa, Shohei
name: Takai, Ryoto
name: Takaura, Hiromasa
name: Treuer, Lukas
Publisher: name: Deutsches Elektronen-Synchrotron, DESY, Hamburg
Year: 2024

description: We study Higgs boson production at $\mu^+ \mu^+$ colliders at high energy. Since both initial-state particles are positively charged, there is no $W$ boson fusion at the leading order, as it requires a $W^+ W^-$ pair. However, we find that the cross section of the higher-order, $\gamma$- and $Z$-mediated $W$ boson fusion process is large at high center-of-mass energies $\sqrt s$, growing as $(\log s)^3$. This is in contrast to the $\log s$ behavior of the leading-order $W$ boson fusion. Thus, even though it is a higher-order process, the rate of Higgs boson production for 10 TeV energies at $\mu^+ \mu^+$ colliders with polarized beams can be as high as about half of the one at $\mu^+ \mu^-$ colliders, assuming the same integrated luminosity. To calculate the cross section of this process accurately, we carefully treat the collinear emission of the photon in the intermediate state. The thereby obtained large cross section furthermore shows the significance of Higgs production with an extra $W$ boson in the final state also at $\mu^+ \mu^-$ and $e^+ e^-$ colliders.
L???Apparato dell???Esperimento SFERA dei LNF
Creators: name: L. Cacciotti
name: L. Catani
name: R. Sorchetti
name: F. Tazzioli
Publisher: name: INFN Open Access Repository
Year: 2001

description: E' descritto l'apparato dell'esperimento SFERA del Gruppo V presso i LNF, che ha per scopo lo studio di foto emettitori robusti per i catodi degli acceleratori lineari avanzati di elettroni che trovano applicazione nei colliders e nei FEL. Sono illustrati gli apparati di misura del rendimento quantico di emissione e della distribuzione temporale degli impulsi emessi. Vengono inoltre accennati i metodi di misura e di elaborazione dei dati.
Grammatical elicitation: Nasalization and ordering of suffixes, negation
Creators: name: Ovelar, Irma Easty
name: Russell, Katherine
name: Dabkowski, Maksymilian
name: Jarvis, Rebecca
name: Michael, Lev
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2021
Subjects: subject: gug

description: Various combinations of oral and harmonic suffixes after nasal roots; negation in various phonological environments (loanwords, roots with final diphthongs, ideophones); two suffixes which trigger leftward nasalization (-rõ, -rã).
Polarization-controlled single photons
Creators: name: Wilk, T.
name: Webster, S. C.
name: Specht, H. P.
name: Rempe, G.
name: Kuhn, A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Vacuum-stimulated Raman transitions are driven between two magnetic substates of a rubidium-87 atom strongly coupled to an optical cavity. A magnetic field lifts the degeneracy of these states, and the atom is alternately exposed to laser pulses of two different frequencies. This produces a stream of single photons with alternating circular polarization in a predetermined spatio-temporal mode. MHz repetition rates are possible as no recycling of the atom between photon generations is required. Photon indistinguishability is tested by time-resolved two-photon interference.
description: 4 pages, 3 figures
Predominance of non-adiabatic effects in zero-point renormalization of the electronic band gap
Creators: name: Miglio, Anna
name: Brousseau-Couture, Véronique
name: Godbout, Emile
name: Antonius, Gabriel
name: Chan, Yang-Hao
name: Louie, Steven G.
name: Côté, Michel
name: Giantomassi, Matteo
name: Gonze, Xavier
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Electronic and optical properties of materials are affected by atomic motion through the electron-phonon interaction: not only band gaps change with temperature, but even at absolute zero temperature, zero-point motion causes band-gap renormalization. We present a large-scale first-principles evaluation of the zero-point renormalization of band edges beyond the adiabatic approximation. For materials with light elements, the band gap renormalization is often larger than 0.3 eV, and up to 0.7 eV. This effect cannot be ignored if accurate band gaps are sought. For infrared-active materials, global agreement with available experimental data is obtained only when non-adiabatic effects are taken into account. They even dominate zero-point renormalization for many materials, as shown by a generalized Fröhlich model that includes multiple phonon branches, anisotropic and degenerate electronic extrema, whose range of validity is established by comparison with first-principles results.
description: Note that the supplementary material, included in the main file, is structured differently than in the published version, with a different numbering scheme
Magnetic higher-order nodal lines
Creators: name: Zhang, Zeying
name: Yu, Zhi-Ming
name: Yang, Shengyuan A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Nodal lines, as one-dimensional band degeneracies in momentum space, usually feature a linear energy splitting. Here, we propose the concept of magnetic higher-order nodal lines, which are nodal lines with higher-order energy splitting and realized in magnetic systems with broken time reversal symmetry. We provide sufficient symmetry conditions for stabilizing magnetic quadratic and cubic nodal lines, based on which concrete lattice models are constructed to demonstrate their existence. Unlike its counterpart in nonmagnetic systems, the magnetic quadratic nodal line can exist as the only band degeneracy at the Fermi level. We show that these nodal lines can be accompanied by torus surface states, which form a surface band that span over the whole surface Brillouin zone. Under symmetry breaking, these magnetic nodal lines can be transformed into a variety of interesting topological states, such as three-dimensional quantum anomalous Hall insulator, multiple linear nodal lines, and magnetic triple-Weyl semimetal. The three-dimensional quantum anomalous Hall insulator features a Hall conductivity $σ_{xy}$ quantized in unit of $e^2/(hd)$ where $d$ is the lattice constant normal to the $x$-$y$ plane. Our work reveals previously unknown topological states, and offers guidance to search for them in realistic material systems.
description: 10 pages, 8 figures
Ricci flows and expansion in axion-dilaton cosmology
Creators: name: Bakas, Ioannis
name: Orlando, Domenico
name: Petropoulos, P. Marios
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study renormalization-group flows by deforming a class of conformal sigma-models. We consider overall scale factor perturbation of Einstein spaces as well as more general anisotropic deformations of three-spheres. At leading order in alpha, renormalization-group equations turn out to be Ricci flows. In the three-sphere background, the latter is the Halphen system, which is exactly solvable in terms of modular forms. We also analyze time-dependent deformations of these systems supplemented with an extra time coordinate and time-dependent dilaton. In some regimes time evolution is identified with renormalization-group flow and time coordinate can appear as Liouville field. The resulting space-time interpretation is that of a homogeneous isotropic Friedmann-Robertson-Walker universe in axion-dilaton cosmology. We find as general behaviour the superposition of a big-bang (polynomial) expansion with a finite number of oscillations at early times. Any initial anisotropy disappears during the evolution.
description: 22 pages
Nutrition controversies
Creators: name: Maelán Fontes-Villalba
Publisher: name: F1000Research
Year: 2015

description: Dietary guidelines, focusing on macronutrient composition and energy balance, have some limitations for the prevention and treatment of western diseases. Understanding food as a conglomeration of bioactive compounds might provide new insights into the relationship between what we eat and western diseases.

Focusing on food choice from an evolutionary perspective in randomised controlled trials should be the new paradigm shift in nutrition sciences to improve dietary recommendations.
RELATIONSHIP BETWEEN ANEMIA AND HAPTOGLOBIN GENOTYPE IN PATIENTS WITH RHEUMATOID ARTHRITIS
Creators: name: Shodikulova, Gulandon
name: Pulatov, Ulugbek
name: Kobilov, Umid
Publisher: name: Zenodo
Year: 2024

description: Despite the use of modern treatments for patients with RA, the incidence of anemia, unwanted complications, and disability in the working population remains very high. The purpose of the study is to improve the principles of proportional treatment, taking into account the structure of anemia in rheumatoid arthritis, its occurrence, and haptoglobin phenotypes. In 2016-2020, a total of 214 patients treated with a diagnosis of rheumatoid arthritis in the cardiorheumatology department of the Samarkand City Medical Association and 20 relatively healthy people as a control group were selected for the study. Examination of patients was carried out using generally accepted clinical, laboratory, and instrumental methods. Changes in iron metabolism parameters are observed in RA patients and are more pronounced in patients with anemia, and such changes depend on the degree of anemia.
Bose condensation and spin superfluidity of magnons in a perpendicularly magnetized film of yttrium iron garnet
Creators: name: Vetoshko, P. M.
name: Knyazev, G. A.
name: Kuzmichev, A. N.
name: Holin, A. A.
name: Belotelov, V. I.
name: Bunkov, Yu. M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The formation of a Bose condensate of magnons in a perpendicularly magnetized film of yttrium iron garnet under radio-frequency pumping in a strip line is studied experimentally. The characteristics of nonlinear magnetic resonance and the spatial distribution of the Bose condensate of magnons in the magnetic field gradient are investigated. In these experiments, the Bosonic system of magnons behaves similarly to the Bose condensate of magnons in the antiferromagnetic superfluid 3He-B, which was studied in detail earlier. Magnonic BEC forms a coherently precessing state with the properties of magnonic superfluidity. Its stability is determined by the repulsive potential between excited magnons, which compensates for the inhomogeneity of the magnetic field.
description: 5 pages, 4 figures
A school district's decision-making process regarding implementation of school choice : the case of one Texas public school district
Creators: name: Carlin-Gonzalez, Laura D.
Publisher: name: The University of Texas at Austin
Year: 2020
Subjects: School choice
Decision-making
Superintendent
School district

description: As school districts are challenged with facing the many demands of meeting the needs of all students, school choice is presented as one way to meet those needs. School choice is anchored in the economic theory of competition in that if parents and students are offered options for choice, then they will choose the best educational opportunities presented. In addition, if competition is injected into the educational system, all schools will improve as a result. Benefits and challenges have been identified regarding school choice. Despite the challenges, many traditional public-school superintendents and school leaders consider school choice implementation as a method of school reform. While there has been research regarding school choice benefits and challenges, further exploration was warranted regarding the decision-making process used to consider whether or not to implement school choice. The purpose of this study was to determine the decision-making process employed to decide whether or not to implement schools of choice within a single school district. It also focused on what factors contributed to the exploration of school choice implementation, and how the specific process employed, by the school superintendent, was influenced by the emerging factors considered for choice implementation. Thus, the researcher explored the actions taken by the superintendent and district leaders as they considered school choice implementation. The researcher employed a constructionism epistemology with a qualitative single case study approach. Data was collected, coded, and analyzed using a deductive process. The researcher used multiple data sources in order to triangulate the data. Findings suggested that factors that influenced the superintendent and school district leaders to explore school choice implementation were competition with neighboring schools, student achievement and student interests, and building on early successes. The findings further revealed the decision-making process employed by the district that included five phases: setting a vision, gathering data, soliciting community input, researching programs based on data, and creating tightly aligned implementation plans. The findings of the study discovered that the emerging factors influenced the decision-making process to be student-centered, highly data-driven and research based, and collaborative.
Probing CP-Violation in Top-HiggsInteractions
Creators: name: Labe, Finn
Publisher: name: Deutsches Elektronen-Synchrotron, DESY, Hamburg
Year: 2018

description: Bachelorarbeit, Hamburg University, 2018; 48 pp. (2018). = Bachelorarbeit, Hamburg University, 2018
description: The search for physics beyond the standard model of particle physics that canexplain the unsolved mysteries of the universe, such as the matter-antimatter asymmetry,is of high importance in todays research. The interaction of quarks with theHiggs boson is a candidate for such physics, possibly resulting in a new source ofCP-violation. This work analyses multiple observables on their sensitivity to theCP coupling in this interaction by performing an analysis using simulated data fort ¯th production in pp collider events. The data is evaluated on parton level both beforeand after acceptance cuts are applied. In addition, a detector simulation for theCMS detector at the LHC is executed. A hypothesis test that can evaluate the observablesis presented and their usability in a real detector experiment is discussed.In the final state leptons a promising candidate for observables sensitive to the CPcoupling in the process is found.
A spatial simulation model for evaluating the response of rare and endangered species to conservation strategies and forest practices: a case study on the northern spotted owl
Creators: name: Demarchi, Donald Andrew
Publisher: name: University of British Columbia
Year: 2009

description: A spatially explicit forest harvesting and individual-based population simulation model has been developed. This model was used to assess the response of rare or endangered forest wildlife to forest harvesting policies and conservation options. A specific focus was on the examining the efficacy of proposed management options for the northern spotted owl population in British Columbia. The forest harvest simulation component was used to construct spatial and temporal patterns of logging activities in the Fraser and Soo timber supply areas. Forest simulations were based on a forest inventory database of 25-ha resolution, and simulated harvests were subject to constraints imposed by the Forest Practices Code and wildlife conservation options. The delineation of breeding territories over this database was done using a submodel that maps likely territory areas following geographic constraints of the landscape, resulting in a "mosaic" of variously shaped territories. This allowed for aggregation of the finer scale forest-state data into simple indices of habitat quality for owls. These indices were updated on a yearly basis as the forest either aged or was harvested. The individual-based population simulator used "coarser" territory/habitat maps to simulate dispersal, location and fates of individual female owls (i.e., breeding pairs). Simulations suggest that a major limiting factor is the low survival rate of dispersing juvenile owls. The proposed management plans do not adequately address this problem and may, in fact, be detrimental to the owl population. These small conservation areas increase logging pressure on the surrounding areas. As a result, juveniles are forced to disperse from their natal habitats into marginal habitats where the risk of mortality is increased. Reduction in the annual allowable cut is more important than any proposed configuration of Spotted Owl Conservation Areas.
Scaling of disordered recursive networks
Creators: name: Tian, Liang
name: Shi, Da-Ning
Publisher: name: arXiv
Year: 2008
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: In this brief report, we present a disordered version of recursive networks. Depending on the structural parameters $u$ and $v$, the networks are either fractals with a finite fractal dimension $d_{f}$ or transfinite fractals (transfractal) with a infinite fractal dimension. The scaling behavior of degree and dimensionality are studied analytically and by simulations, which are found to be different from those in ordered recursive networks. The transfractal dimension $\tilde{d}_f$, which is recently introduced to distinguish the differences between networks with infinite fractal dimension, scales as $\tilde{d}_f\sim \frac{1}{u+v-1}$ for transfractal networks. Interestingly, the fractal dimension for fractal networks with $u=v$ is found to approach 3 in large limit of $u$, which is thought to be the effect of disorder. We also investigate the diffusion process on this family of networks, and the scaling behavior of diffusion time is observed numercally as $τ\sim N^{(d_{f}+1)/d_{f}}$ for fractal networks and $τ\sim \frac{1}{\tilde{d}_f}N$ for transfractal ons. We think that the later relation will give a further understanding of transfractal dimension.
description: 5 pages, 5 figures
Decay times in turnover statistics of single enzymes
Creators: name: Lindén, Martin
Publisher: name: arXiv
Year: 2008
Subjects: subject: Biological Physics (physics.bio-ph)
subject: FOS: Physical sciences

description: The first passage times for enzymatic turnovers in non-equilibrium steady state display a statistical symmetry property related to non-equilibrium fluctuation theorems, that makes it possible to extract the chemical driving force from single molecule trajectories in non-equilibrium steady state. Below, we show that this system violates the general expectation that the number of decay constants needed to fit a first passage time distribution reflects the number of states in the escape problem. In fact, the structure of the kinetic mechanism makes half of the decay times vanish identically from the turnover time distribution. The terms that cancel out correspond to the eigenvalues of a certain sub-matrix of the master equation matrix for the first exit time problem. We discuss how these results make modeling and data analysis easier for such systems, and how the turnovers can be measured.
description: 4 pages, 1 figure v2: Published version, minor corrections in response to referee comments
Neural networks for semantic segmentation of historical city maps: Cross-cultural performance and the impact of figurative diversity
Creators: name: Petitpierre, Rémi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Human-Computer Interaction (cs.HC)
subject: Image and Video Processing (eess.IV)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: I.4.6; I.5.4; I.2.10

description: In this work, we present a new semantic segmentation model for historical city maps that surpasses the state of the art in terms of flexibility and performance. Research in automatic map processing is largely focused on homogeneous corpora or even individual maps, leading to inflexible algorithms. Recently, convolutional neural networks have opened new perspectives for the development of more generic tools. Based on two new maps corpora, the first one centered on Paris and the second one gathering cities from all over the world, we propose a method for operationalizing the figuration based on traditional computer vision algorithms that allows large-scale quantitative analysis. In a second step, we propose a semantic segmentation model based on neural networks and implement several improvements. Finally, we analyze the impact of map figuration on segmentation performance and evaluate future ways to improve the representational flexibility of neural networks. To conclude, we show that these networks are able to semantically segment map data of a very large figurative diversity with efficiency.
description: MSc thesis
Unexorcized ghost in DGP brane world
Creators: name: Izumi, Keisuke
name: Koyama, Kazuya
name: Tanaka, Takahiro
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The braneworld model of Dvali-Gabadadze-Porrati realizes the self-accelerating universe. However, it is known that this cosmological solution contains a spin-2 ghost. We study the possibility of avoiding the appearance of the ghost by slightly modifying the model, introducing the second brane. First we consider a simple model without stabilization of the separation of the brane. By changing the separation between the branes, we find we can erase the spin-2 ghost. However, this can be done only at the expense of the appearance of a spin-0 ghost instead. We discuss why these two different types of ghosts are correlated. Then, we examine a model with stabilization of the brane separation. Even in this case, we find that the correlation between spin-0 and spin-2 ghosts remains. As a result we find we cannot avoid the appearance of ghost by two-branes model.
description: 19 pages, 1 figure