cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Trends in Nuclear Astrophysics
Creators: name: Schatz, Hendrik
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Nuclear Astrophysics is a vibrant field at the intersection of nuclear physics and astrophysics that encompasses research in nuclear physics, astrophysics, astronomy, and computational science. This paper is not a review. It is intended to provide an incomplete personal perspective on current trends in nuclear astrophysics and the specific role of nuclear physics in this field.
description: 26 pages, 1 figure, part of "Focus on 40 years of research in Journal of Physics G"
Energy exchanges in reconnection outflows
Creators: name: Lapenta, Giovanni
name: Goldman, Martin V.
name: Newman, Davd L.
name: Markidis, Stefano
Publisher: name: arXiv
Year: 2016
Subjects: subject: Space Physics (physics.space-ph)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Reconnection outflows are highly energetic directed flows that interact with the ambient plasma or with flows from other reconnection regions. Under these conditions the flow becomes highly unstable and chaotic, as any flow jets interacting with a medium. We report here massively parallel simulations of the two cases of interaction between outflow jets and between a single outflow with an ambient plasma. We find in both case the development of a chaotic magnetic field, subject to secondary reconnection events that further complicate the topology of the field lines. The focus of the present analysis is on the energy balance. We compute each energy channel (electromagnetic, bulk, thermal, for each species) and find where the most energy is exchanged and in what form. The main finding is that the largest energy exchange is not at the reconnection site proper but in the regions where the outflowing jets are destabilized.
description: 14 pages, 5 figures
Orientation-Preservation Conditions on an Iso-parametric FEM in Cavitation Computation
Creators: name: Su, Chunmei
name: Li, Zhiping
Publisher: name: arXiv
Year: 2016
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: The orientation-preservation condition, i.e., the Jacobian determinant of the deformation gradient $\det \nabla u$ is required to be positive, is a natural physical constraint in elasticity as well as in many other fields. It is well known that the constraint can often cause serious difficulties in both theoretical analysis and numerical computation, especially when the material is subject to large deformations. In this paper, we derive a set of sufficient and necessary conditions for the quadratic iso-parametric finite element interpolation functions of cavity solutions to be orientation preserving on a class of radially symmetric large expansion accommodating triangulations. The result provides a practical quantitative guide for meshing in the neighborhood of a cavity and shows that the orientation-preservation can be achieved with a reasonable number of total degrees of freedom by the quadratic iso-parametric finite element method.
description: 26 pages, 8 figures, to appear in Science China Mathematics
A walk in the city: using large data sets to analyze urban sidewalks
Creators: name: Hosseini, Maryam Sadat
Publisher: name: No Publisher Supplied
Year: 2022

description: While cities worldwide are increasingly promoting streets and public spaces that prioritize pedestrians over vehicles, significant data gaps have made mapping, analysis, and assessment of pedestrian infrastructure, challenging to carry out. Even in industrialized economies, most cities still lack information about the location, connectivity, and quality of their sidewalks, making it difficult to implement research on pedestrian infrastructure and holding the technology industry back from developing accurate, location-based Apps for different users. Moreover, despite the growing attention to urban data analysis, there is a gap between the real needs of researchers and practitioners directly studying urban problems and the urban analysis tools being developed. Standing at the intersection of economics, urban planning, and computer science, my dissertation aims at addressing both issues by providing theory-rich tools for large-scale assessment of urban sidewalks at two scales: at the human scale, using street-level images by proposing CitySurfaces for classifying eight classes of surface materials, and at the city, scale using aerial imagery, by proposing Tile2Net to create pedestrian networks from aerial imagery. Both studies use computer vision techniques to design frameworks and models for analyzing pedestrian facilities.This dissertation addresses some of the challenges of semantic segmentation models regarding the high cost of image annotation by employing different techniques, such as active learning to offer solutions tailored to the specific qualities of urban problems.
MuonGalaxy - tools, workflows and more for muons and materials science
Creators: name: Austin, Patrick
name: Davies, Joel
name: Gonzalez-Beltran, Alejandra
name: Liborio, Leandro
Publisher: name: Zenodo
Year: 2023
Subjects: Galaxy Platform
Workflows
Muons
Muon Spectroscopy

description: In this three-page poster and accompanying video, we - the Muon Spectroscopy Computational Project (MSCP) - present the results of ongoing work to use the Galaxy platform in the field of Muon Spectroscopy. The MSCP is a collaboration between the Scientific Computing Department and ISIS neutron and muon source at STFC in the UK. We develop Python tools for computational tasks in the field of muon spectroscopy, and started to use Galaxy in 2021. We are members of the Euro Science Gateway project, and have been supported in our efforts by members of the Galaxy Europe community. The poster covers the tools, workflows and visualisations created for muon spectroscopy tasks, as well as discussing challenges we faced in bringing muon spectroscopy to Galaxy. This material was produced for and presented at the Galaxy Community Conference (GCC2023).
Polyvinylpyrrolidone (PvP) Interaction with Biomembrane-Like Layers
Creators: name: Nelson, Andrew
name: Crow, Bethany
name: Kapur, Nik
name: Owen, Joshua
name: Busquets, Marti
name: Stokes, William
Publisher: name: Zenodo
Year: 2023
Subjects: Polvinylpyrrolidone
PVP
nanomaterials

description: Polvinylpyrrolidone (PvP) is a water soluble polymer made from the monomer N-vinylpyrrolidone (N-vP) and has extensive use in the synthesis and stabilisation of nanomaterials. Recently, this laboratory found that PvP interacted very strongly with the HISENTS biomembrane sensor, a response which is directly related to cell membrane damage by compounds. Comprehensive studies were therefore instigated to look at the effect of PvP on the HISENTS biomembrane sensor element. 5 lengths of PvP were investigated of monomer number (PvPm) from 31 to 11697 and dissolved in MilliQ water as stock solutions. Working solutions were prepared therefrom in phosphate buffered saline (PBS) at pH 7.4 and screened on the dioleoyl phosphatidylcholine (DOPC) sensor element. Interactions of PvP with the sensor element are shown as depressions of the two capacitance current peaks on the rapid cyclic voltammogram (1a). The limit of detection (LoD) metric of the PvP affinity for the sensor element is the lowest solution concentration of PvP, which can structurally modify the DOPC layer. Calibration curves are linear for low PvPm (31, 90) but Langmuirean for higher PvPm (495, 3239, 11697) indicating that PvP is adsorbing on and damaging the DOPC layer surface and structure. Plots of -log LoD versus PvPm show an increase corresponding to a greater interaction of the PvP with the DOPC layer with increasing length (1b). However a plot of (-log LoD)/PvPm versus PvPm gives a reciprocal relationship (1c) from which a realistic value of LoD for N-vP can be extracted. A plot of log (1/(PvPm x LoD)) versus PvPm shows a sharp decrease at low PvPm values and an increase at higher PvPm values (1d). If the physical nature of the PvP plays no role in the PvP interaction with DOPC, the value of log (1/(PvPm x LoD)) should remain constant (blue line in 1d). The reason for the decrease at low PvPm values is due to the decrease in entropy as the PvP chain moves from a 3D to a 2D environment. The increase in values at higher PvPm is caused by the increased self-assembly forces between the longer chains on the DOPC surface. This work was funded by EU Horizon 2020: HISENTS GA: 685817 and SABYDOMA GA: 862296.
D2.10 Harmonization and Standardization Reports M12
Creators: name: , Ignacio
Publisher: name: Zenodo
Year: 2023

description: This specification applies to the project VALKYRIES: Harmonization and Pre-Standardization of Equipment, Training and Tactical Coordinated procedures for First Aid Vehicles deployment on European multi-victim Disasters funded under the SU-DRS03-2018-2019-2020 (IA), subtopic 3 Grant Agreement of the Horizon 2020 (H2020) tendering conditions. The document presents the status of the project in terms of standardisation and harmonisation in month 12.
D2.6 Harmonization and Standardization Reports M6
Creators: name: Hernandez, Ignacio
Publisher: name: Zenodo
Year: 2022

description: This specification applies to the project VALKYRIES: Harmonization and PreStandardization of Equipment, Training and Tactical Coordinated procedures for First Aid Vehicles deployment on European multi-victim Disasters funded under the SU-DRS03-2018- 2019-2020 (IA), subtopic 3 Grant Agreement of the Horizon 2020 (H2020) tendering conditions. The document presents the status of the project in terms of standardisation and harmonisation in month 6.
The feedback effect caused by bed load on a turbulent liquid flow
Creators: name: Franklin, Erick de Moraes
name: de Figueiredo, Fabíola Tocchini
name: Rosa, Eugênio Spanó
Publisher: name: arXiv
Year: 2016
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Experiments on the effects due solely to a mobile granular layer on a liquid flow are presented (feedback effect). Nonintrusive measurements were performed in a closed conduit channel of rectangular cross section where grains were transported as bed load by a turbulent water flow. The water velocity profiles were measured over fixed and mobile granular beds of same granulometry by Particle Image Velocimetry. The spatial resolution of the measurements allowed the experimental quantification of the feedback effect. The present findings are of importance for predicting the bed-load transport rate and the pressure drop in activities related to the conveyance of grains.
description: Accepted Manuscript for the Journal of the Brazilian Society of Mechanical Sciences and Engineering, v. 36, p. 725-736, 2014. The final publication is available at Springer via http://dx.doi.org/10.1007/s40430-013-0122-y
Indications of stellar prominence oscillations on fast rotating stars: the cases of HK Aqr and PZ Tel
Creators: name: Leitzinger, M.
name: Odert, P.
name: Zaqarashvili, T. V.
name: Greimel, R.
name: Hanslmeier, A.
name: Lammer, H.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present the analysis of six nights of spectroscopic monitoring of two young and fast rotating late-type stars, namely the dMe star HK Aqr and the dG/dK star PZ Tel. On both stars we detect absorption features reminiscent of signatures of co-rotating cool clouds or prominences visible in H$α$. Several prominences on HK Aqr show periodic variability in the prominence tracks which follow a sinusoidal motion (indication of prominence oscillations). On PZ Tel we could not find any periodic variability in the prominence tracks. By fitting sinusoidal functions to the prominence tracks we derive amplitudes and periods which are similar to those of large amplitude oscillations seen in solar prominences. In one specific event we also derive a periodic variation of the prominence track in the H$β$ spectral line which shows an anti-phase variation with the one derived for the H$α$ spectral line. Using these parameters and estimated mass density of a prominence on HK Aqr we derive a minimum magnetic field strength of $\sim$2G. The relatively low strength of the magnetic field is explained by the large height of this stellar prominence ($\ge$ 0.67 stellar radii above the surface).
Phonons and Thermal Transport in Graphene and Graphene-Based Materials
Creators: name: Nika, Denis L.
name: Balandin, Alexander A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: A discovery of the unusual thermal properties of graphene stimulated experimental, theoretical and computational research directed at understanding phonon transport and thermal conduction in two-dimensional material systems. We provide a critical review of recent results in the graphene thermal field focusing on phonon dispersion, specific heat, thermal conductivity, and comparison of different models and computational approaches. The correlation between the phonon spectrum in graphene-based materials and the heat conduction properties is analyzed in details. The effects of the atomic plane rotations in bilayer graphene, isotope engineering, and relative contributions of different phonon dispersion branches are discussed. For readers' convenience, the summaries of main experimental and theoretical results on thermal conductivity as well as phonon mode contributions to thermal transport are provided in the form of comprehensive annotated tables.
description: 56 pages, 14 figures; invited review of recent developments in graphene phonon field
Charge neutrality breakdown in confined aqueous electrolytes: theory and simulation
Creators: name: Colla, Thiago
name: Girotto, Matheus
name: Santos, Alexandre P. dos
name: Levin, Yan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We study, using Density Functional theory and Monte Carlo simulations, aqueous electrolyte solutions between charged infinite planar surfaces, in a contact with a bulk salt reservoir. In agreement with recent experimental observations [Z. Luo et al., Nat. Comm. 6, 6358 (2015)], we find that the confined electrolyte lacks local charge neutrality. We show that a Density Functional Theory (DFT) based on a bulk- HNC expansion properly accounts for strong electrostatic correlations and allows us to accurately calculate the ionic density profiles between the charged surfaces, even for electrolytes containing trivalent counterions. The DFT allows us to explore the degree of local charge neutrality violation, as a function of plate separation and bulk electrolyte concentration, and to accurately calculate the interaction force between the charged surfaces.
GGOS Iberatlantic: Towards a new GGOS affiliate
Creators: name: Azcue Infanzón, Esther
name: López Fernández, José Antonio
name: Ferrándiz Leal, José Manuel
name: VMS. Moniz, Luisa
Publisher: name: Zenodo
Year: 2022
Subjects: GGOS
space geodesy
geodetic infrastructure
GGOS affiliate

description: The Global Geodetic Observing System (GGOS) works together with the IAG components for monitoring the Earth System and global change research. In order to achive these goals and promote geodetic activities in specific regions, GGOS affiliates were created. A GGOS affiliates is a national or regional organization that coordinate geodetic activities and encourage organizations to participate in space-geodetic discussions, and to own and operate space-geodetic infrastructure. An initiative of establishing a new GGOS affiliate in the Iberatlantic region has emerged as a result of the collaboration of different Spanish and Portuguese organizations in space-geodetic projects. The origin of this initiative, status and future steps are presented in this contribution.
Robust conversion of singlet spin order in coupled spin-1/2 pairs by adiabatically switched RF-fields
Creators: name: Pravdivtsev, Andrey N.
name: Kiryutin, Alexey S.
name: Yurkovskaya, Alexandra V.
name: Vieth, Hans-Martin
name: Ivanov, Konstantin L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose a robust and highly efficient NMR technique to create singlet spin order from longitudinal spin magnetization in coupled spin-1/2 pairs and to perform backward conversion (singlet order)$\to$magnetization. In this method we exploit adiabatic switching of an RF-field in order to drive transitions between the singlet state and the $T_\pm$ triplet states of a spin pair under study. We demonstrate that the method works perfectly for both strongly and weakly coupled spin pairs, providing a conversion efficiency between the singlet spin order and magnetization, which is equal to the theoretical maximum. We anticipate that the proposed technique is useful for generating long-lived singlet order, for preserving spin hyperpolarization and for assessing singlet spin order in nearly equivalent spin pairs in specially designed molecules and in low-field NMR studies.
description: 21 pages, 11 figures
GGOS DAYS 2023
Creators: name: López Fernández, José Antonio
name: Azcue Infanzón, Esther
name: Ferrándiz Leal, José Manuel
name: Miyahara, Basara
Publisher: name: Zenodo
Year: 2022
Subjects: GGOS days 2023

description: The venue of the GGOS Days 2023, a video introduction to Yebes Observatory and useful information for the next meeting are presented in this contribution.
Superrotations and Black Hole Pair Creation
Creators: name: Strominger, Andrew
name: Zhiboedov, Alexander
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Recent work has shown that the symmetries of classical gravitational scattering in asymptotically flat spacetimes include, at the linearized level, infinitesimal superrotations. These act like Virasoro generators on the celestial sphere at null infinity. However, due to the singularities in these generators, the physical status of finite superrotations has remained unclear. Here we address this issue in the context of the breaking of a cosmic string via quantum black hole pair nucleation. This process is described by a gravitational instanton known as the $C$-metric. After pair production, the black holes are pulled by the string to null infinity with a constant acceleration. At late times the string decays and the spacetime settles into a vacuum state. We show that the early and late spacetimes before and after string decay differ by a finite superrotation. This provides a physical interpretation of superrotations. They act on spacetimes which are asymptotically flat everywhere except at isolated singularities with cosmic string defects.
description: 18 pages
Auxetic Black Phosphorus: A 2D Material with Negative Poisson's Ratio
Creators: name: Du, Yuchen
name: Maassen, Jesse
name: Wu, Wangran
name: Luo, Zhe
name: Xu, Xianfan
name: Ye, Peide D.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The Poisson's ratio of a material characterizes its response to uniaxial strain. Materials normally possess a positive Poisson's ratio - they contract laterally when stretched, and expand laterally when compressed. A negative Poisson's ratio is theoretically permissible but has not, with few exceptions of man-made bulk structures, been experimentally observed in any natural materials. Here, we show that the negative Poisson's ratio exists in the low-dimensional natural material black phosphorus, and that our experimental observations are consistent with first principles simulations. Through application of uniaxial strain along zigzag and armchair directions, we find that both interlayer and intralayer negative Poisson's ratios can be obtained in black phosphorus. The phenomenon originates from the puckered structure of its in-plane lattice, together with coupled hinge-like bonding configurations.
Regge approach to the reaction of $γN \to K^* Λ$
Creators: name: Yu, Byung-Geel
name: Oh, Yongseok
name: Kong, Kook-Jin
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Photoproduction of $K^*$ vector mesons off nucleon is investigated within the Regge framework where the electromagnetic vertex of $γK^*K^*$ fully takes into account the magnetic dipole and electric quadrupole moments of spin-1 $K^*$ vector meson. The $t$-channel $K^*(892)$, $K(494)$ and $κ(800)$ meson exchanges are considered for the analysis of the production mechanism. The experimentally observed rapid decrease of the cross sections for the $γp \to K^{*+} Λ$ reaction beyond the resonance region is well reproduced by the dominance of the exchange of $K$-meson trajectory. The role of the scalar $κ$-meson trajectory is found to be minor in both $γp$ and $γn$ reactions. The cross sections for the $γn \to K^{*0} Λ$ reaction are predicted to be about twice those of the $γp \to K^{*+}Λ$ reaction. The role of the $K^*$ electromagnetic multipoles and the proton anomalous magnetic moment is studied through the total and differential cross sections and spin/parity asymmetries. We suggest the measurement of the photon polarization asymmetry as a tool for identifying the role of the magnetic dipole and electric quadrupole moments of the $K^*$ vector meson.
description: 5 pages, 4 figures
Dissipative entanglement of solid-state spins in diamond
Creators: name: Rao, D. D. Bhaktavatsala
name: Yang, Sen
name: Wrachtrup, Jörg
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Generating robust entanglement among solid-state spins is key for applications in quantum information processing and precision sensing. We show here a dissipative approach to generate such entanglement among the hyperfine coupled electron nuclear spins using the rapid optical decay of electronic excited states. The combined dark state interference effects of the optical and microwave driving fields in the presence of spontaneous emission from the short-lived excited state leads to a dissipative formation of an entangled steady state. We show that the dissipative entanglement is generated for any initial state conditions of the spins and is resilient to external field fluctuations. We analyze the scheme both for continuous and pulsed driving fields in the presence of realistic noise sources.
description: 4 pages, 3 figures
An application of incomplete pairwise comparison matrices for ranking top tennis players
Creators: name: Bozóki, Sándor
name: Csató, László
name: Temesi, József
Publisher: name: arXiv
Year: 2016
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Computer Science and Game Theory (cs.GT)
subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Pairwise comparison is an important tool in multi-attribute decision making. Pairwise comparison matrices (PCM) have been applied for ranking criteria and for scoring alternatives according to a given criterion. Our paper presents a special application of incomplete PCMs: ranking of professional tennis players based on their results against each other. The selected 25 players have been on the top of the ATP rankings for a shorter or longer period in the last 40 years. Some of them have never met on the court. One of the aims of the paper is to provide ranking of the selected players, however, the analysis of incomplete pairwise comparison matrices is also in the focus. The eigenvector method and the logarithmic least squares method were used to calculate weights from incomplete PCMs. In our results the top three players of four decades were Nadal, Federer and Sampras. Some questions have been raised on the properties of incomplete PCMs and remains open for further investigation.
description: 14 pages, 2 figures
Study of Eclipsing Binary and Multiple Systems in OB Associations IV: Cas OB6 Member DN Cas
Creators: name: Bakis, V.
name: Bakis, H.
name: Bilir, S.
name: Eker, Z.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: An early-type, massive, short-period ($P_{\rm orb}=2^{\rm d}.310951$) eclipsing spectroscopic binary DN Cas has been re-visited with new spectral and photometric data. The masses and radii of the components have been obtained as $M_1=19.04\pm0.07 M_\odot$, $M_2=13.73\pm 0.05M_\odot$ and $R_1=7.22\pm0.06 R_\odot$, $R_2=5.79\pm0.06R_\odot$, respectively. Both components present synchronous rotation ($V_{\rm rot1}=160\,$km s$^{-1}$, $V_{\rm rot2}=130\,$km s$^{-1}$) with their orbit. Orbital period analysis yielded a physically bound additional component in the system with a minimum mass of $M_3=0.88 M_\odot$ orbiting in an eccentric orbit ($e=0.37\pm0.2$) with an orbital period of $P_{12}=42\pm9$ yrs. High precision absolute parameters of the system allowed us to derive a distance to DN Cas as 1.7$\pm$0.2 kpc which locates the system within the borders of the Cas OB6 association (d=1.8 kpc; Mel'nik & Dambis, 2009). The space velocities and the age of DN Cas are in agreement with those of Cas OB6. The age of DN Cas ($τ=$3-5 Myr) is found to be 1-2 Myr older than the embedded clusters (IC 1795, IC 1805 and IC 1848) in the Cas OB6 association, which implies a sequential star formation in the association.
description: 10 pages, including 5 figures and 5 tables, accepted for publication in PASA
Performance of a nonempirical exchange functional from the density matrix expansion: comparative study with different correlation
Creators: name: Mo, Yuxiang
name: Tian, Guocai
name: Tao, Jianmin
Publisher: name: arXiv
Year: 2016
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Recently, Tao and Mo proposed an accurate meta-generalized gradient approximation for the exchange-correlation energy. The exchange part is derived from the density matrix expansion, while the correlation part is obtained by improving the TPSS correlation in the low-density limit. To better understand this exchange functional, in this work, we combine the TM exchange with the original TPSS correlation, which we call TMTPSS, and make a systematic assessment on molecular properties. The test sets include the 223 G3/99 enthalpies of formation, 58 electron affinities, 8 proton affinities, 96 bond lengths, 82 harmonic frequencies, and 10 hydrogen-bonded molecular complexes. Our calculations show that the TMTPSS functional is competitive with or even more accurate than TM functional for some properties. In particular, it is the most accurate nonempirical semilocal DFT for the enthalpies of formation and harmonic vibrational frequencies, suggesting the robustness of TM exchange.
Do USDA Reports Contribute to Extreme Price Volatility? The Case of the Soybean Complex
Creators: name: Yang, Yao
name: Karali, Berna
name: Yang, Yao
name: Karali, Berna
Publisher: name: Unknown
Year: 2022
Subjects: subject: Crop Production/Industries
subject: Demand and Price Analysis
subject: coexceedance
subject: extreme volatility
subject: ordinal logistic regression
subject: soybean complex

description: USDA reports are publicly available and provide important fundamental information on agricultural commodities. An extensive literature finds evidence of price or volatility spikes following USDA report releases, especially for major crops. These crops are not only used for direct consumption, but also serve as intermediate goods in the production of other products. This study focuses on the joint occurrence of extreme price volatility in commodity markets linked in a supply chain on report release days. We investigate the commodities in the soybean complex and use an ordinal logistic model to investigate whether the releases of USDA reports increase the probability of joint occurrence of extreme events. After controlling for other sources, such as releases of macroeconomic reports, we find that the USDA reports released in March have the largest impact on the joint occurrence of extreme volatility in all three markets.
Variation of transition temperatures and residual resistivity ratio in vapor-grown FeSe
Creators: name: Böhmer, A. E.
name: Taufour, V.
name: Straszheim, W. E.
name: Wolf, T.
name: Canfield, P. C.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The study of the iron-based superconductor FeSe has blossomed with the availability of high quality single crystals, obtained through flux/vapor-transport growth techniques below the structural transformation temperature of its tetragonal phase, T~450 C. Here, we report on the variation of sample morphology and properties due to small modifications in the growth conditions. A considerable variation of the superconducting transition temperature Tc, from 8.8 K to 3 K, which cannot be correlated with the sample composition, is observed. Instead, we point out a clear correlation between Tc and disorder, as measured by the residual resistivity ratio. Notably, the tetragonal-to-orthorhombic structural transition is also found to be quite strongly disorder dependent (Ts =72 - 90 K), and linearly correlated with Tc.
Radio-Selected NIR-Dark galaxies: the ALMA view behind the dust
Creators: name: Gentile, Fabrizio
Publisher: name: Zenodo
Year: 2023

description: Since the first (sub)mm observations, it has been clear that the cosmic census of high-z galaxies based on deep optical/NIR surveys is far from complete. The ”darkest galaxies”, in which significant amounts of dust absorb the stellar emission, are in fact missed by these surveys, even though their contribution to the cosmic Star Formation Rate Density and to the evolution of massive galaxies is thought to be significantly high. Due to their elusive nature - however - most of the studies regarding these extremely obscured sources still rely on low statistics and are potentially biased by cosmic variance. In this talk, I will illustrate the potentialities of a radio selection, paired to the lack of a NIR counterpart, to assemble the largest homogeneous sample of ”dark” star-forming galaxies currently known. I will present the Radio-Selected NIR-Dark galaxies collected in the COSMOS field, their properties estimated through SED-fitting and their likely evolutionary path (Gentile 2023a, subm.). Finally, I will discuss our first results on these sources obtained through a new series of ALMA observations and the future perspectives of this project (Gentile 2023b, in prep.).
Quasi-phase-matched high harmonic generation in corrugated micrometer-scale waveguides
Creators: name: Husakou, Anton
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The high harmonic generation in periodically corrugated submicrometer waveguides is studied numerically. Plasmonic field enhancement in the vicinity of the corrugations allows to use low pump intensities. Simultaneously, periodic placement of the corrugations leads to quasi-phase-matching and corresponding increase of the high harmonic efficiency. The optimization of waveguide geometry is performed, and the resulting spectra are analyzed by the means of (1+1)D numerical model.
description: 5 figures, 13 pages
Strongly Interacting Fermi Gases
Creators: name: Zwerger, W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: The experimental realization of stable, ultracold Fermi gases near a Feshbach resonance allows to study gases with attractive interactions of essentially arbitrary strength. They extend the classic paradigm of BCS into a regime which has never been accessible before. We review the theoretical concepts which have been developed in this context, including the Tan relations and the notion of fixed points at zero density, which are at the origin of universality. We discuss in detail the universal thermodynamics of the unitary Fermi gas which allows a fit free comparison between theory and experiment for this strongly interacting system. In addition, we adress the consequences of scale invariance at infinite scattering length and the subtle violation of scale invariance in two dimensions. Finally we discuss the Fermionic excitation spectrum accessible in momentum resolved RF-spectroscopy and the origin of universal lower bounds for the shear viscosity and the spin diffusion constant.
description: Varenna Lectures, July 2014
Effect of nonmagnetic impurities on $s_\pm$ superconductivity in the presence of incipient bands
Creators: name: Chen, X.
name: Mishra, V.
name: Maiti, S.
name: Hirschfeld, P. J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Several Fe chalcogenide superconductors without hole pockets at the Fermi level display high temperature superconductivity, in apparent contradiction to naive spin fluctuation pairing arguments. Recently, scanning tunneling microscopy measurements have measured the influence of impurities on some of these materials, and claimed that non-magnetic impurities do not create in-gap states, leading to the conclusion that the gap must be $s_{++}$, i.e. conventional $s$ wave with no gap sign change. Here we critique this argument, and give various ways sign-changing gaps can be consistent with the absence of such bound states. In particular, we calculate the bound states for an $s_\pm$ system with a hole pocket below the Fermi level, and show that the nonmagnetic impurity bound state energy generically tracks the gap edge $E_{min}$ in the system, thereby rendering it unobservable. A failure to observe a bound state in the case of a nonmagnetic impurity can therefore not be used as an argument to exclude sign-changing pairing states.
description: 6 pages, 13 figures
Generation of arbitrary radially polarized array beams by modulating the correlation structure
Creators: name: Zhu, Shijun
name: Wang, Jing
name: Li, Zhenhua
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We demonstrate a convenient approach for simultaneously manipulating the amplitude and polarization of light beams by means of the modulation of the correlation structure. As an illustration, we constructed a periodic correlation structure that can generate an arbitrary radially polarized array (RPA) beam of a radial or rectangular symmetry array in the focal plane from a radially polarized (RP) beam. The physical realizability conditions for such source and the far-field beam condition are derived. It is illustrated that the beamlet shape and the state of polarization (SOP) can be effectively controlled by the initial correlation structure and the coherence width. Furthermore, by designing the source correlation structure, a tunable OK-shaped RPA beam and an optical cage are demonstrated, which can find widespread applications in non-destructive manipulation of particles and living biological cells. The arbitrariness in the design of correlation structure prompted us to find more convenient approaches for controlling the statistics of light beams in terms of amplitude and polarization.
Do Hospital Mergers Reduce Waiting Times? Theory and Evidence from the English NHS
Creators: name: Cirulli, Vanessa
name: Marini, Giorgia
name: Marini, Marco A.
name: Straume, Odd Rune
Publisher: name: Unknown
Year: 2023
Subjects: subject: Health Economics and Policy
subject: Productivity Analysis
subject: Public Economics
subject: hospital merger
subject: waiting times
subject: profit-orientation

description: We analyse – theoretically and empirically – the effect of hospital mergers on waiting times in healthcare markets where prices are fixed. Using a spatial modelling framework where patients choose provider based on travelling distance and waiting times, we show that the effect is theoretically ambiguous. In the presence of cost synergies, the scope for lower waiting times as a result of the merger is larger if the hospitals are more profit-oriented. This result is arguably confirmed by our empirical analysis, which is based on a conditional flexible difference-indifferences methodology applied to a long panel of data on hospital mergers in the English NHS, where we find that the effects of a merger on waiting times crucially rely on a legal status that can reasonably be linked to the degree of profit-orientation. Whereas hospital mergers involving Foundation Trusts tend to reduce waiting times, the corresponding effect of mergers involving hospitals without this legal status tends to go in the opposite direction
The first moment of azimuthal anisotropy in nuclear collisions from AGS to LHC energies
Creators: name: Singha, Subhash
name: Shanmuganathan, Prashanth
name: Keane, Declan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We review topics related to the first moment of azimuthal anisotropy ($v_1$), commonly known as directed flow, focusing on both charged particles and identified particles from heavy-ion collisions. Beam energies from the highest available, at the CERN LHC, down to projectile kinetic energies per nucleon of a few GeV per nucleon, as studied in experiments at the Brookhaven AGS, fall within our scope. We focus on experimental measurements and on theoretical work where direct comparisons with experiment have been emphasized. The physics addressed or potentially addressed by this review topic includes the study of Quark Gluon Plasma, and more generally, investigation of the Quantum Chromodynamics phase diagram and the equation of state describing the accessible phases.
description: Accepted for publication in Advances in High Energy Physics
Rapidly rotating red giants
Creators: name: Gehan, Charlotte
name: Mosser, Benoît
name: Michel, Eric
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Stellar oscillations give seismic information on the internal properties of stars. Red giants are targets of interest since they present mixed modes, which behave as pressure modes in the convective envelope and as gravity modes in the radiative core. Mixed modes thus directly probe red giant cores, and allow in particular the study of their mean core rotation. The high-quality data obtained by CoRoT and Kepler satellites represent an unprecedented perspective to obtain thousands of measurements of red giant core rotation, in order to improve our understanding of stellar physics in deep stellar interiors. We developed an automated method to obtain such core rotation measurements and validated it for stars on the red giant branch. In this work, we particularly focus on the specific application of this method to red giants having a rapid core rotation. They show complex spectra where it is tricky to disentangle rotational splittings from mixed-mode period spacings. We demonstrate that the method based on the identification of mode crossings is precise and efficient. The determination of the mean core rotation directly derives from the precise measurement of the asymptotic period spacing ΔΠ1 and of the frequency at which the crossing of the rotational components is observed.
description: 4 pages, 2 figures, 2 tables, to be published in the Astro Fluid 2016 Conference Proceedings, editor EAS Publications Series
Program Repair by Stepwise Correctness Enhancement
Creators: name: Diallo, Nafi
name: Ghardallou, Wided
name: Mili, Ali
Publisher: name: arXiv
Year: 2016
Subjects: subject: Software Engineering (cs.SE)
subject: Discrete Mathematics (cs.DM)
subject: Logic in Computer Science (cs.LO)
subject: Programming Languages (cs.PL)
subject: FOS: Computer and information sciences

description: Relative correctness is the property of a program to be more-correct than another with respect to a given specification. Whereas the traditional definition of (absolute) correctness divides candidate program into two classes (correct, and incorrect), relative correctness arranges candidate programs on the richer structure of a partial ordering. In other venues we discuss the impact of relative correctness on program derivation, and on program verification. In this paper, we discuss the impact of relative correctness on program testing; specifically, we argue that when we remove a fault from a program, we ought to test the new program for relative correctness over the old program, rather than for absolute correctness. We present analytical arguments to support our position, as well as an empirical argument in the form of a small program whose faults are removed in a stepwise manner as its relative correctness rises with each fault removal until we obtain a correct program.
description: In Proceedings PrePost 2016, arXiv:1605.08096
Gauss-Bonnet Gravitational Baryogenesis
Creators: name: Odintsov, S. D.
name: Oikonomou, V. K.
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this letter we study some variant forms of gravitational baryogenesis by using higher order terms containing the partial derivative of the Gauss-Bonnet scalar coupled to the baryonic current. This scenario extends the well known theory that uses a similar coupling between the Ricci scalar and the baryonic current. One appealing feature of the scenario we study is that the predicted baryon asymmetry during a radiation domination era is non-zero. We calculate the baryon to entropy ratio for the Gauss-Bonnet term and by using the observational constraints we investigate which are the allowed forms of the $R+F(\mathcal{G})$ gravity controlling the evolution. Also we briefly discuss some alternative higher order terms that can generate a non-zero baryon asymmetry, even in the conformal invariance limit.
description: PLB accepted
A PSF-based approach to Kepler/K2 data. II. Exoplanet candidates in Praesepe (M 44)
Creators: name: Libralato, M.
name: Nardiello, D.
name: Bedin, L. R.
name: Borsato, L.
name: Granata, V.
name: Malavolta, L.
name: Piotto, G.
name: Ochner, P.
name: Cunial, A.
name: Nascimbeni, V.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In this work we keep pushing K2 data to a high photometric precision, close to that of the Kepler main mission, using a PSF-based, neighbour-subtraction technique, which also overcome the dilution effects in crowded environments. We analyse the open cluster M 44 (NGC 2632), observed during the K2 Campaign 5, and extract light curves of stars imaged on module 14, where most of the cluster lies. We present two candidate exoplanets hosted by cluster members and five by field stars. As a by-product of our investigation, we find 1680 eclipsing binaries and variable stars, 1071 of which are new discoveries. Among them, we report the presence of a heartbeat binary star. Together with this work, we release to the community a catalogue with the variable stars and the candidate exoplanets found, as well as all our raw and detrended light curves.
description: 21 pages, 5 tables, 12 figures. Accepted for publication in MNRAS. Online materials will be available on the Journal website and at http://groups.dfa.unipd.it/ESPG/Kepler-K2.html soon
Nanosecond-level time synchronization of AERA using a beacon reference transmitter and commercial airplanes
Creators: name: Huege, Tim
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Radio detection of cosmic-ray air showers requires time synchronization of detectors on a nanosecond level, especially for advanced reconstruction algorithms based on the wavefront curvature and for interferometric analysis approaches. At the Auger Engineering Radio Array, the distributed, autonomous detector stations are time-synchronized via the Global Positioning System which, however, does not provide sufficient timing accuracy. We thus employ a dedicated beacon reference transmitter to correct for event-by-event clock drifts in our offline data analysis. In an independent cross-check of this "beacon correction" using radio pulses emitted by commercial airplanes, we have shown that the combined timing accuracy of the two methods is better than 2 nanoseconds.
description: To be published in the Proceedings of the ARENA2016 conference, Groningen, The Netherlands
Secure Massive MIMO Systems with Limited RF Chains
Creators: name: Zhu, Jun
name: Xu, Wei
name: Wang, Ning
Publisher: name: arXiv
Year: 2016
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: In future practical deployments of massive multi-input multi-output (MIMO) systems, the number of radio frequency (RF) chains at the base stations (BSs) may be much smaller than the number of BS antennas to reduce the overall expenditure. In this paper, we propose a novel design framework for joint data and artificial noise (AN) precoding in a multiuser massive MIMO system with limited number of RF chains, which improves the wireless security performance. With imperfect channel state information (CSI), we analytically derive an achievable lower bound on the ergodic secrecy rate of any mobile terminal (MT), for both analog and hybrid precoding schemes. The closed-form lower bound is used to determine optimal power splitting between data and AN that maximizes the secrecy rate through simple one-dimensional search. Analytical and numerical results together reveal that the proposed hybrid precoder, although suffers from reduced secrecy rate compared with theoretical full-dimensional precoder, is free of the high computational complexity of large-scale matrix inversion and null-space calculations, and largely reduces the hardware cost.
description: Accepted by IEEE Transactions on Vehicular Technology
Model-based Testing of Mobile Systems -- An Empirical Study on QuizUp Android App
Creators: name: Gudmundsson, Vignir
name: Lindvall, Mikael
name: Aceto, Luca
name: Bergthorsson, Johann
name: Ganesan, Dharmalingam
Publisher: name: arXiv
Year: 2016
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: We present an empirical study in which model-based testing (MBT) was applied to a mobile system: the Android client of QuizUp, the largest mobile trivia game in the world. The study shows that traditional MBT approaches based on extended finite-state machines can be used to test a mobile app in an effective and efficient way. Non-trivial defects were detected on a deployed system that has millions of users and was already well tested. The duration of the overall testing effort was of three months, including the construction of the models. Maintaining a single behavioral model for the app was key in order to test it in an efficient way.
description: In Proceedings PrePost 2016, arXiv:1605.08096