cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
BICEP2 in Corpuscular Description of Inflation
Creators: name: Dvali, Gia
name: Gomez, Cesar
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A corpuscular quantum description of inflation shows that there is no fundamental problem with trans-Planckian excursions of the inflaton field up to about 100 Planck masses, with the upper bound coming from the corpuscular quantum effects. In this description the r-parameter measures the ratio of occupation numbers of gravitons versus inflatons, which, according to BICEP2, was roughly a half at the time of 60 e-foldings prior to the end of inflation. We stress that in non-Wilsonian UV self-completion of gravity any trans-Planckian mode coupled to inflaton is a black hole. Unlike the Wilsonian case, their integration-out gives an exponentially-suppressed effect and is unable to prevent trans-Planckian excursions of the inflaton field.
description: 7 pages
Epitaxial Ba2IrO4 thin-films grown on SrTiO3 substrates by pulsed laser deposition
Creators: name: Nichols, J.
name: Korneta, O. B.
name: Terzic, J.
name: Cao, G.
name: Brill, J. W.
name: Seo, S. S. A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We have synthesized epitaxial Ba2IrO4 (BIO) thin-films on SrTiO3 (001) substrates by pulsed laser deposition and studied their electronic structure by dc-transport and optical spectroscopic experiments. We have observed that BIO thin-films are insulating but close to the metalinsulator transition boundary with significantly smaller transport and optical gap energies than its sister compound, Sr2IrO4. Moreover, BIO thin-films have both an enhanced electronic bandwidth and electronic-correlation energy. Our results suggest that BIO thin-films have great potential for realizing the interesting physical properties predicted in layered iridates.
description: 3 figures
Total Energy Control for the Automatic Landing of UAS with Large Aspect Ratio and Low Wing Loading
Creators: name:  BRYAN LAABS
name:   NIKOLAI BLOCK
name:   RALPH PAUL
name:   ROBERT LUCKNER
name:   FLAVIO JOSE SILVESTRE
Publisher: name: Proceedings of the Aerospace Europe Conference - EUCASS - CEAS - 2023
Year: 2023
Subjects: HAPS
AUTOLAND
UAS
TECS

description: Automatic landing of unmanned, high-altitude long-endurance aircraft, characterized by large wingspans, very low wing loading and -here -by a tail-dragger configuration, requires control strategies that differ from classical Autoland systems. The paper describes an implementation based on Lam bregts\'s Total Energy Control System concept to ensure accurate tracking of airspeed, pitch attitude, and sink rate throughout the specific flight phases during landing. This novel strategy requires an adaption of the control allocation prior to touchdown using continuous flap settings for vertical speed control. The performance of the design is demonstrated by an extensive Monte Carlo simulation.
AI pipeline for accurate retinal layer segmentation using OCT 3D images
Creators: name: Goswami, Mayank
Publisher: name: arXiv
Year: 2023
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Image data set from a multi-spectral animal imaging system is used to address two issues: (a) registering the oscillation in optical coherence tomography (OCT) images due to mouse eye movement and (b) suppressing the shadow region under the thick vessels/structures. Several classical and AI-based algorithms in combination are tested for each task to see their compatibility with data from the combined animal imaging system. Hybridization of AI with optical flow followed by Homography transformation is shown to be working (correlation value>0.7) for registration. Resnet50 backbone is shown to be working better than the famous U-net model for shadow region detection with a loss value of 0.9. A simple-to-implement analytical equation is shown to be working for brightness manipulation with a 1% increment in mean pixel values and a 77% decrease in the number of zeros. The proposed equation allows formulating a constraint optimization problem using a controlling factor α for minimization of number of zeros, standard deviation of pixel value and maximizing the mean pixel value. For Layer segmentation, the standard U-net model is used. The AI-Pipeline consists of CNN, Optical flow, RCNN, pixel manipulation model, and U-net models in sequence. The thickness estimation process has a 6% error as compared to manual annotated standard data.
description: 16 Page and 11 Figures
Nature of itineracy in CoV$_2$O$_4$: A first principles study
Creators: name: Kaur, Ramandeep
name: Maitra, Tulika
name: Nautiyal, Tashi
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Inspired by recent experiments, we have theoretically explored the nature of itineracy in CoV$_2$O$_4$ under pressure and investigated, using first principles density functional theory calculations, if it has any magnetic and orbital ordering. Our calculations indicate that there could be two possible routes to obtain the experimentally observed pressure induced metallicity in this system. One is the spin-orbit interaction coupled with Coulomb correlation which can take the system from a semiconducting state at ambient pressure to a metallic state under high pressure. The other mechanism, as indicated by our GGA+U calculations, is based on the presence of two types of electrons in the system: localized and itinerant. An effective Falicov-Kimball model could then possibly explain the observed insulator to metal transition. Comparison of the two scenarios with existing experimental observations leads us to believe that the second scenario offers a better explanation for the mechanism of insulator to metal transition in CoV$_2$O$_4$ under pressure.
description: 14 pages, 6 figures
History of Public Education in Baltimore from 1860-1890
Creators: name: Krausse, Harry W.
Publisher: name: Digital Repository at the University of Maryland
Year: 1943

description: Several studies of public education have been made in Maryland and Baltimore; among them being "History of Education in Maryland," "Secondary Education in Maryland before 1800," "Public Educational Work in Baltimore," "Baltimore, 1870 to 1900: Studies in Social History." However, there is no detailed account of the development of the Baltimore City school system covering the period of the Civil War and the years following this war. During this time significant educational hlstory was made as events of great educational importance took place, which events were to affect the future of the Baltimore public schools as well as the future of children attending these schools.
Quantum vacuum interaction between two cosmic strings revisited
Creators: name: Munoz-Castaneda, J. M.
name: Bordag, M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We reconsider the quantum vacuum interaction energy between two straight parallel cosmic strings. This problem was discussed several times in an approach treating both strings perturbatively and treating only one perturbatively. Here we point out that a simplifying assumption made in [1] can be justified and show that, despite the global character of the background, the perturbative approach delivers a correct result. We consider the applicability of the scattering methods, developed in the past decade for the Casimir effect, for the cosmic string and find it not applicable. We calculate the scattering T-operator on one string. Finally, we consider the vacuum interaction of two strings when each carries a two dimensional delta function potential.
description: Submitted to Phys Rev D
Are there universal signatures of topological phases in high harmonic generation? Probably not
Creators: name: Neufeld, Ofer
name: Tancogne-Dejean, Nicolas
name: Hübener, Hannes
name: De Giovannini, Umberto
name: Rubio, Angel
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: High harmonic generation (HHG) has developed in recent years as a promising tool for ultrafast materials spectroscopy. At the forefront of these advancements, several works proposed to use HHG as an all-optical probe for topology of quantum matter by identifying its signatures in the emission spectra. However, it remains unclear if such spectral signatures are indeed a robust and general approach for probing topology. To address this point, we perform here a fully ab-initio study of HHG from prototypical two-dimensional topological insulators in the Kane-Mele quantum spin-Hall and anomalous-Hall phases. We analyze the spectra and previously proposed topological signatures by comparing HHG from the topological and trivial phases. We demonstrate and provide detailed microscopic explanations of why in these systems none of the thus far proposed observables uniquely and universally probe material topology. Specifically, we find that the: (i) HHG helicity, (ii) anomalous HHG ellipticity, (iii) HHG elliptical dichroism and (iv) temporal delays in HHG emission, are all unreliable signatures of topological phases. Our results suggest that extreme care must be taken when interpreting HHG spectra for topological signatures, and that contributions from the crystal symmetries and chemical nature might be dominant over those from topology. They hint that a truly universal topological signature in nonlinear optics is unlikely, and raise important questions regarding possible utilization and detection of topology in systems out-of-equilibrium.
description: 24 figures including appendices
The Effect of a Structured Group Experience on the Transition from the Role of College Student to the Role of Working Professional
Creators: name: Lyons, John C.
Publisher: name: Digital Repository at the University of Maryland
Year: 1980

description: This study was conducted to investigate the effects of a structured group experience on the transition of new college graduates from the role of student to worker. Fifty-seven subjects,who were employed in their first professional job upon graduating from college,were formed into an experimental group of twenty-nine and control group of twenty-eight subjects . A needs assessment identified ten behaviors which supervisors considered to be indications that a new employee was functioning as a worker rather than a learner. A twenty-two item questionnaire was developed which allowed supervisors to evaluate the degree to which their subordinates were performing the ten target behaviors . A second instrument containing seven items was developed which allowed subjects to report the degree to which they felt they were performing these behaviors . Data were collected from supervisors and subjects using these instruments both before and after treatment. Treatment consisted of a workshop having two components: 1) the presentation of the ten behaviors which supervisors had identified as being desirable, and 2) a structured approach to skill mastery which utilized fantasy, planning and problem solving. Post-treatment evaluations of subjects by supervisors were significantly higher than the corresponding pre-treatment evaluations, t (28) = 3.11, p < .01, providing support for the hypothesis that a structured group experience has a beneficial effect on the transition from the role of college student to the role of working professional.
A Search for Stars of Very Low Metal Abundance. VI. Detailed Abundances of 313 Metal-Poor Stars
Creators: name: Roederer, Ian U.
name: Preston, George W.
name: Thompson, Ian B.
name: Shectman, Stephen A.
name: Sneden, Christopher
name: Burley, Gregory S.
name: Kelson, Daniel D.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present radial velocities, equivalent widths, model atmosphere parameters, and abundances or upper limits for 53 species of 48 elements derived from high resolution optical spectroscopy of 313 metal-poor stars. A majority of these stars were selected from the metal-poor candidates of the HK Survey of Beers, Preston, and Shectman. We derive detailed abundances for 61% of these stars for the first time. Spectra were obtained during a 10-year observing campaign using the Magellan Inamori Kyocera Echelle spectrograph on the Magellan Telescopes at Las Campanas Observatory, the Robert G. Tull Coude Spectrograph on the Harlan J. Smith Telescope at McDonald Observatory, and the High Resolution Spectrograph on the Hobby-Eberly Telescope at McDonald Observatory. We perform a standard LTE abundance analysis using MARCS model atmospheres, and we apply line-by-line statistical corrections to minimize systematic abundance differences arising when different sets of lines are available for analysis. We identify several abundance correlations with effective temperature. A comparison with previous abundance analyses reveals significant differences in stellar parameters, which we investigate in detail. Our metallicities are, on average, lower by approx. 0.25 dex for red giants and approx. 0.04 dex for subgiants. Our sample contains 19 stars with [Fe/H] < -3.5, 84 stars with [Fe/H] < -3.0, and 210 stars with [Fe/H] < -2.5. Detailed abundances are presented here or elsewhere for 91% of the 209 stars with [Fe/H] < -2.5 as estimated from medium resolution spectroscopy by Beers, Preston, and Shectman. We will discuss the interpretation of these abundances in subsequent papers.
description: Accepted for publication in the Astronomical Journal. 60 pages, 59 figures, 18 tables. Machine-readable versions of the long tables can be found in the ancillary data files
Phase noise analysis of mutually synchronized spin Hall nano-oscillators
Creators: name: Litvinenko, Artem
name: Kumar, Akash
name: Rajabali, Mona
name: Awad, Ahmad A.
name: Khymyn, Roman
name: Akerman, Johan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The reduction of phase noise in electronic systems is of utmost importance in modern communication and signal processing applications and requires an understanding of the underlying physical processes. Here, we systematically study the phase noise in mutually synchronized chains of nano-constriction spin Hall nano-oscillators (SHNOs). We find that longer chains have improved phase noise figures at low offset frequencies (1/f noise), where chains of two and ten mutually synchronized SHNOs have 2.8 and 6.2 dB lower phase noise than single SHNOs. This is close to the theoretical values of 3 and 10 dB, and the deviation is ascribed to process variations between nano-constrictions. However, at higher offset frequencies (thermal noise), the phase noise unexpectedly increases with chain length, which we ascribe to process variations, a higher operating temperature in the long chains at the same drive current and phase delays in the coupling between nano-constrictions.
Agrypnus delesserti Hayek 1973
Creators: name: Kotru, Akash
name: Chandran, Nithya
name: Dubey, Anil Kumar
name: Prosvirov, Alexander S.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Elateridae
Agrypnus
Agrypnus delesserti

description: Agrypnus delesserti (Candèze, 1882)
Lacon delesserti Candèze, 1882: 9.
Adelocera delesserti (Candèze) Fleutiaux, 1926: 96.
Agrypnus delesserti (Candèze) Hayek, 1973: 148.
Type depository. Lectotype (RBINS)
Type locality. Tamil Nadu (Nilgiri Hills).
Distribution. India: Tamil Nadu (Chakraborty, Chakrabarti, 2000).
Literature. Candèze (1882: 9): original description; Fleutiaux (1926: 96): combination; Hayek (1973: 148): combination; Chakraborty and Chakrabarti (2000: 77): catalogue.
description: Published as part of Kotru, Akash, Chandran, Nithya, Dubey, Anil Kumar & Prosvirov, Alexander S., 2025, A catalogue of Indian Agrypninae Candèze, 1857 (Coleoptera: Elateridae), pp. 1-66 in Zootaxa 5614 (1) on page 16, DOI: 10.11646/zootaxa.5614.1.1, http://zenodo.org/record/15217075
Optimising Management of Behavioural Emergencies in the Emergency Department
Creators: name: YAP, YEN LING
Publisher: name: Monash University
Year: 2022
Subjects: Emergency medicine
Mental health services

description: This thesis provides critical information to optimise the management of behavioural emergencies. Specifically, it addressed information gaps related to the efficacy, safety and cost-efficiency of injectable sedative medications. It has shown intravenous administration of midazolam-droperidol combination therapy appears to be safe, and produces rapid sedation at less cost than monotherapy with either intravenous droperidol or olanzapine. The research also revealed factors that foster a trusting patient-staff relationships, and explored patients’ needs during and after the behavioural emergency. The information generated will facilitate informed decision-makings and improve the quality of emergency care to this group of patients.
Reduced Order Modeling for the prediction of combustion instabilities in liquid rocket engines: coaxial injection response and acoustic damping modeling
Creators: name:  ALEXANDRE FOUGNIE
name:   THOMAS SCHMITT
name:   SEBASTIEN DUCRUIX
Publisher: name: Proceedings of the Aerospace Europe Conference - EUCASS - CEAS - 2023
Year: 2023
Subjects: COMBUSTION INSTABILITIES
LIQUID ROCKET ENGINES
REDUCED ORDER MODELING
ACOUSTIC DAMPING
COAXIAL INJECTION

description: A reduced-order code based on a Garlerkin modal expansion of the pressure oscillations is presented to predict high frequency combustion instabilities in liquid rocket engines. Models to account for acoustic damping are proposed, such as nozzle, thermal or viscous losses. A combustion source term modeling the fuel inflow modulation of a coaxial injection unit through a flame transfer function is derived. A first application is made on the NPCC test bench, retrieving LES data with a nonlinear representation of the damping. Then the BKD combustor of DLR is simulated, and first comparisons with LES results are proposed.
Probing the baryon mass fraction in IGM and its redshift evolution with fast radio bursts using Bayesian inference method
Creators: name: Lin, Hai-Nan
name: Zou, Rui
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We investigate the fraction of baryon mass in intergalactic medium ($f_\mathrm{IGM}$), using 18 well-localized FRBs in the redshift range $z\in (0.0039,0.66)$. We construct a five-parameter Bayesian inference model, with the probability distributions of dispersion measures (DM) of IGM and host galaxy properly taken into account. To check the possible redshift evolution, we parameterize $f_\mathrm{IGM}$ as a mildly evolving function of redshift, $f_\mathrm{IGM}=f_\mathrm{IGM,0}[1+αz/(1+z)]$. By simultaneously constraining five parameters, we get $f_\mathrm{IGM,0} = 0.92^{+0.06}_{-0.12}$ and $α= 0.49^{+0.59}_{-0.47}$, and the median value of DM of host galaxy is $\exp(μ)=72.49^{+33.31}_{-25.62}~{\rm pc ~ cm ^ {-3}}$. By fixing two parameters which can be constrained independently with other observations, we obtain $α=0.11^{+0.24}_{-0.27}$ in the three-parameter fit, which is consistent with zero within $1σ$ uncertainty. Monte Carlo simulations show that even 300 FRBs are not enough to tightly constrain five parameters simultaneously. This is mainly caused by the correlation between parameters. Only if two parameters are fixed, 100 FRBs are necessary to achieve unbiased constraints on the remaining parameters.
Using 4D STEM to probe mesoscale order in molecular glass films prepared by physical vapor deposition
Creators: name: Chatterjee, Debaditya
name: Huang, Shuoyuan
name: Gu, Kaichen
name: Ju, Jianzhu
name: Yu, Junguang
name: Bock, Harald
name: Yu, Lian
name: Ediger, M. D.
name: Voyles, Paul M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Physical vapor deposition can be used to prepare highly stable organic glass systems where the molecules show orientational and translational ordering at the nanoscale. We have used low-dose four-dimensional scanning transmission electron microscopy (4D STEM), enabled by a fast direct electron detector, to map columnar order in glassy samples of a discotic mesogen using a 2 nm probe. Both vapor deposited and liquid cooled glassy films show domains of similar orientation, but their size varies from tens to hundreds of nanometers, depending on processing. Domain sizes are consistent with surface diffusion mediated ordering during film deposition. These results demonstrate the ability of low-dose 4D STEM to characterize mesoscale structure in a molecular glass system which may be relevant to organic electronics.
Experimental Evaluation of Circulation Control Aerodynamics on a Cylindrical Body
Creators: name: Ngo, Hieu Thien
Publisher: name: Digital Repository at the University of Maryland
Year: 1987

description: In this study, an experimental investigation is conducted on a two-dimensional circulation control cylinder with blowing taking place from a single spanwise slot to determine its aerodynamic characteristics. The results include detailed pressure distributions (both chordwise and spanwise) for a range of momentum coefficients and slot locations. The measured results showed that the lift coefficients up to 4.8 were produced at momentum coefficients of 0.14 in a turbulent flow condition. The experimental results of lift coeffficients Were correlated satisfactorily with analytical results. The surface flow patterns were observed using the oil and smoke techniques. Also flow field surveys of the model Were obtained using total pressure, yaw and pitch probes. A color video display technique was used to present the results of the flow field surveys. Based on this evidence, a flow field model of the circulation control cylinder is presented.
Proximal Iteratively Reweighted Algorithm with Multiple Splitting for Nonconvex Sparsity Optimization
Creators: name: Lu, Canyi
name: Wei, Yunchao
name: Lin, Zhouchen
name: Yan, Shuicheng
Publisher: name: arXiv
Year: 2014
Subjects: subject: Numerical Analysis (math.NA)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: This paper proposes the Proximal Iteratively REweighted (PIRE) algorithm for solving a general problem, which involves a large body of nonconvex sparse and structured sparse related problems. Comparing with previous iterative solvers for nonconvex sparse problem, PIRE is much more general and efficient. The computational cost of PIRE in each iteration is usually as low as the state-of-the-art convex solvers. We further propose the PIRE algorithm with Parallel Splitting (PIRE-PS) and PIRE algorithm with Alternative Updating (PIRE-AU) to handle the multi-variable problems. In theory, we prove that our proposed methods converge and any limit solution is a stationary point. Extensive experiments on both synthesis and real data sets demonstrate that our methods achieve comparative learning performance, but are much more efficient, by comparing with previous nonconvex solvers.
The Life Cycles, Ecology, and Evolution of the Witch-hazel Leaf Gall Aphid, Hormaphis hamamelidis (Fitch) (Homoptera: Aphidida)
Creators: name: Von Dohlen, Carol Dean
Publisher: name: Digital Repository at the University of Maryland
Year: 1987

description: Two divergent life cycles based on geographic location have been documented for the witch-hazel leaf gall aphid, Hormaphis hamamelidis (Fitch, 1851). At low elevations in northern Virginia, the aphid was found to have seven distinct generations alternating between the primary host, Witch-hazel (Hamamelis virginiana L.), and a secondary host, river birch (Betula nigra L.). These findings confirm the original published life cycle description from the same locality. A second, abbreviated life cycle consisting of only three generations restricted to witch-hazel was discovered at high (1000 m) elevations in north central and northwestern Virginia. Aphids with each life cycle were sympatric at an intermediate elevation site. Based on available life cycle and geographic data, a preliminary Phylogeny of the tribe Hormaphidini is proposed that suggests an unusual polarity in the evolution of aphid life cycles. Several features of intraspecific interactions and host-plant relations were examined in both lowland and highland populations of Hormaphis. In contrast to previous publications documenting severe competition, density effects, and habitat heterogeneity for another galling, host-alternating aphid, Pemphigus betae on Populus angustifolia, the effects of density and host-plant qualities on Hormaphis hamamelidis were fewer and more benign. Aphids did not compete for gall sites, and gall Position and final leaf area did not influence reproduction. High gall densities negatively affected gall growth and aphid fecundity. Factors accounting for the differences in Population dynamics between Hormaphis and Pemphigus are hypothesized and discussed.
Anti-windup coordination strategy around a fair equilibrium in resource sharing networks
Creators: name: Agner, Felix
name: Kergus, Pauline
name: Rantzer, Anders
name: Tarbouriech, Sophie
name: Zaccarian, Luca
Publisher: name: arXiv
Year: 2023
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper aims at coordinating interconnected agents where the control input of each agent is limited by the control input of others. In that sense, the systems have to share a limited resource over a network. Such problems can arise in different areas and it is here motivated by a simplified district heating example. When the shared resource is insufficient for the combined need of all systems, the resource will have to be shared in an optimal fashion. In this scenario, we want the systems to automatically converge to an optimal equilibrium. The contribution of this paper is the proposal of a control architecture where each separate system is controlled by a local PI controller. The controllers are then coordinated through a global rank-one anti-windup signal. It is shown that the equilibrium of the proposed closed-loop system minimizes the infinity-norm of stationary state deviations. Convergence is investigated via a randomized numerical study, and a district heating-inspired example illustrates the utility of the proposed method.
Opening the random forest black box by the analysis of the mutual impact of features
Creators: name: Voges, Lucas F.
name: Jarren, Lukas C.
name: Seifert, Stephan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Random forest is a popular machine learning approach for the analysis of high-dimensional data because it is flexible and provides variable importance measures for the selection of relevant features. However, the complex relationships between the features are usually not considered for the selection and thus also neglected for the characterization of the analysed samples. Here we propose two novel approaches that focus on the mutual impact of features in random forests. Mutual forest impact (MFI) is a relation parameter that evaluates the mutual association of the featurs to the outcome and, hence, goes beyond the analysis of correlation coefficients. Mutual impurity reduction (MIR) is an importance measure that combines this relation parameter with the importance of the individual features. MIR and MFI are implemented together with testing procedures that generate p-values for the selection of related and important features. Applications to various simulated data sets and the comparison to other methods for feature selection and relation analysis show that MFI and MIR are very promising to shed light on the complex relationships between features and outcome. In addition, they are not affected by common biases, e.g. that features with many possible splits or high minor allele frequencies are prefered.
Imaging exoplanets with coronagraphic instruments
Creators: name: Galicher, Raphaël
name: Mazoyer, Johan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Exoplanetary science is a very active field of astronomy nowadays, with questions still opened such as how planetary systems form and evolve (occurrence, process), why such a diversity of exoplanets is observed (mass, radius, orbital parameters, temperature, composition), and what are the interactions between planets, circumstellar disk and their host star. Several complementary methods are used for the detection of exoplanets. Among these, imaging aims at the direct detection of the light reflected, scattered or emitted by exoplanets and circumstellar disks. This allows their spectral and polarimetric characterization. Such imaging remains challenging because of the large luminosity ratio (1e4-1e10$) and the small angular separation (fraction of an arcsecond) between the star and its environment. Over the past two decades, numerous techniques, including coronagraphy, have been developed to make exoplanet imaging a reality. This review gives a broad overview of the subsystems that make up a coronagraphic instrument for imaging exoplanetary systems. It is especially intended for non-specialists or newcomers in the field. We explain the principle of coronagraphy and propose a formalism to understand their behavior. We discuss the impact of wavefront aberrations on the performance of coronagraphs and how they induce stellar speckles in the scientific image. Finally, we present instrumental and signal processing techniques used for on-sky minimization or a posteriori calibration of these speckles in order to improve the performance of coronagraphs.
description: Accepted for publication in Comptes Rendus Physique. 48 pages (including 12 pages of references). 16 figures
MUQOBIL ENERGIYA MANBALARIDAN QO‘SHIMCHA ELEKTR ENERGIYA OLISH
Creators: name: Toychiyeva Mahliyo Obidjon Qizi
Publisher: name: Tafakkur manzili
Year: 2023

description: Annotatsiya: Maqolada muqobil energiya manbalaridan elektr energisini olish hamda ularni transport yo‘llari sohasida qo‘llash
Open-loop tomography with artificial neural networks on CANARY: on-sky results
Creators: name: Osborn, J.
name: Juez, F. J. De Cos
name: Guzman, D.
name: Basden, A.
name: Morris, T. J.
name: Gendron, E.
name: Butterley, T.
name: Myers, R. M.
name: Gueslaga, A.
name: Lasheras, F. S.
name: Victoria, M. G.
name: Rodriguez, M. L. S.
name: Gratadour, D.
name: Rousset, G.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: We present recent results from the initial testing of an Artificial Neural Network (ANN) based tomographic reconstructor Complex Atmospheric Reconstructor based on Machine lEarNing (CARMEN) on Canary, an Adaptive Optics demonstrator operated on the 4.2m William Herschel Telescope, La Palma. The reconstructor was compared with contemporaneous data using the Learn and Apply (L&A) tomographic reconstructor. We find that the fully optimised L&A tomographic reconstructor outperforms CARMEN by approximately 5% in Strehl ratio or 15nm rms in wavefront error. We also present results for Canary in Ground Layer Adaptive Optics mode to show that the reconstructors are tomographic. The results are comparable and this small deficit is attributed to limitations in the training data used to build the ANN. Laboratory bench tests show that the ANN can out perform L&A under certain conditions, e.g. if the higher layer of a model two layer atmosphere was to change in altitude by ~300~m (equivalent to a shift of approximately one tenth of a subaperture).
description: 8 pages, 6 figures
The STAR Vertex Position Detector
Creators: name: Llope, W. J.
name: Zhou, J.
name: Nussbaum, T.
name: Hoffmann, G. W.
name: Asselta, K.
name: Brandenburg, J. D.
name: Butterworth, J.
name: Camarda, T.
name: Christie, W.
name: Crawford, H. J.
name: Dong, X.
name: Engelage, J.
name: Eppley, G.
name: Geurts, F.
name: Hammond, J.
name: Judd, E.
name: McDonald, D. L.
name: Perkins, C.
name: Ruan, L.
name: Scheblein, J.
name: Schambach, J. J.
name: Soja, R.
name: Xin, K.
name: Yang, C.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The 2x3 channel pseudo Vertex Position Detector (pVPD) in the STAR experiment at RHIC has been upgraded to a 2x19 channel detector in the same acceptance, called the Vertex Position Detector (VPD). This detector is fully integrated into the STAR trigger system and provides the primary input to the minimum-bias trigger in Au+Au collisions. The information from the detector is used both in the STAR Level-0 trigger and offline to measure the location of the primary collision vertex along the beam pipe and the event "start time" needed by other fast-timing detectors in STAR. The offline timing resolution of single detector channels in full-energy Au+Au collisions is ~100 ps, resulting in a start time resolution of a few tens of picoseconds and a resolution on the primary vertex location of ~1 cm.
description: 15 pages, 6 figures
Rayleigh-Taylor instabilities with sheared magnetic fields
Creators: name: Ruderman, M. S.
name: Terradas, J.
name: Ballester, J. L.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Magnetic Rayleigh-Taylor (MRT) instabilities may play a relevant role in many astrophysical problems. In this work the effect of magnetic shear on the growth rate of the MRT instability is investigated. The eigenmodes of an interface and a slab model under the presence of gravity are analytically calculated assuming that the orientation of the magnetic field changes in the equilibrium, i.e., there is magnetic shear. We solve the linearised magnetohydrodynamic (MHD) equations in the incompressible regime.We find that the growth rate is bounded under the presence of magnetic shear. We have derived simple analytical expressions for the maximum growth rate, corresponding to the most unstable mode of the system. These expressions provide the explicit dependence of the growth rate on the various equilibrium parameters. For small angles the growth time is linearly proportional to the shear angle, and in this regime the single interface problem and the slab problem tend to the same result. On the contrary, in the limit of large angles and for the interface problem the growth time is essentially independent of the shear angle. In this regime we have also been able to calculate an approximate expression for the growth time for the slab configuration. Magnetic shear can have a strong effect on the growth rates of the instability. As an application of the results found in this paper we have indirectly determined the shear angle in solar prominence threads using their lifetimes and the estimation of the Alfvén speed of the structure.
Probing the incompressibility of dense hadronic matter near QCD phase transition in relativistic heavy-ion collisions
Creators: name: Wu, Zhi-Min
name: Yong, Gao-Chan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Based on the extended hadronic transport model of relativistic heavy-ion collisions, the incompressibility of dense hadronic matter created in relativistic Au+Au heavy-ion collisions at $\sqrt{s_{NN}} = 3$ GeV is studied. By comparing experimental proton directed flow, productions of strange hadrons $ϕ$, $K^{-}$ as well as their ratio $ϕ/K^{-}$, proton high-order cumulants to the model calculations, a large incompressibility of dense hadronic matter is obtained from nucleon observabels while a rather small incompressibility is needed to fit the data of strange hadrons. This may indicate hadronic matter possesses different incompressibilities in different density regions, i.e., the incompressibility may become stiffer from saturation density to a certain baryon density and then turn to soft before reaching hadron-quark phase transition. The study also shows that the incompressibility significantly affects the critical baryon density of hadron-quark phase transition.
description: 5 pages, 4 figures, accepted by PRC, in production
Self-consistent linear response for the spin-orbit interaction related properties
Creators: name: Solovyev, I. V.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: In many cases, the relativistic spin-orbit (SO) interaction is regarded to be small and can be treated using perturbation theory. The major obstacle on this route comes from the fact that the SO interaction can also polarize the electron system and produce additional contributions to the perturbation theory, arising from the electron-electron interactions. In electronic structure calculations, it may even lead to necessity to abandon the perturbation theory and return to the self-consistently solution of Kohn-Sham-like equations with the effective potential $\hat{v}$, incorporating the effects of the electron-electron interactions and the SO coupling, even though the latter is small. In this work, we present the theory of self-consistent linear response (SCLR), which allows us to get rid of numerical self-consistency and formulate it analytically in the first order of the SO coupling. This strategy is applied to the Hartree-Fock solution of the effective Hubbard model, derived from electronic structure calculations in the Wannier basis. By using $\hat{v}$, obtained from SCLR, one can successfully reproduce results of ordinary calculations for the orbital magnetization and other properties in the first order of the SO coupling. Particularly, SCLR appears to be extremely useful for calculations of antisymmetric Dzyaloshinskii-Moriya (DM) interactions based on the magnetic force theorem. Furthermore, due to the powerful 2n+1 theorem, the SCLR theory allows us to calculate the magnetic anisotropy energy up to the third order of the SO coupling. The fruitfulness of this approach is illustrated on a number of example, including the spin canting in YTiO$_3$ and LaMnO$_3$, formation of spiral magnetic order in BiFeO$_3$, and the magnetic inversion symmetry breaking in BiMnO$_3$, which gives rise to both ferroelectric activity and DM interactions, responsible for the ferromagnetism.
description: 42 pagse, 5 figure, 6 tables
Measuring the cross section of the $^{15}$N($α$,$γ$)$^{19}$F reaction using a single-fluid bubble chamber
Creators: name: Neto, D.
name: Bailey, K.
name: Benesch, J. F.
name: Cade, B.
name: DiGiovine, B.
name: Freyberger, A.
name: Grames, J. M.
name: Hofler, A.
name: Holt, R. J.
name: Kazimi, R.
name: Meekins, D.
name: McCaughan, M.
name: Moser, D.
name: O'Connor, T.
name: Poelker, M.
name: Rehm, K. E.
name: Riordan, S.
name: Suleiman, R.
name: Talwar, R.
name: Ugalde, C.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: $^{15}$N($α$,$γ$)$^{19}$F is believed to be the primary means of stellar nucleosynthesis of fluorine. Here we present the use of a single-fluid bubble chamber to measure the cross section of the time-inverse photo-dissociation reaction. The method benefits from a luminosity increase of several orders of magnitude due to the use of a thicker liquid target -- when compared to thin films or gas targets -- and from the reciprocity theorem. We discuss the results of an experiment at the Thomas Jefferson National Accelerator Facility, where the cross section of the photodisintegration process $^{19}$F($γ$, $α$)$^{15}$N was measured by bombarding a superheated fluid of C$_3$F$_8$ with bremsstrahlung $γ$-rays produced by impinging a 4 - 5.5 MeV electron beam on a Cu radiator. From the photodissociation yield the cross section was extracted by performing a convolution with a Monte Carlo-generated $γ$-ray beam spectrum. The measurement produced a cross section that was then time inverted using the reciprocity theorem. The cross section for the $^{15}$N($α$,$γ$)$^{19}$F reaction was determined down to a value in the range of hundreds of picobarns. With further improvements of the experimental setup the technique could potentially push cross section measurements down to the single picobarn range.
description: Corrected Typos. Accepted for Publication in Physical Review C
Usage Statistics of e-Resources during Pandemic Period: A Case Study of Chandigarh University Library
Creators: name: Veer, Ram
name: Panda, Subhajit
Publisher: name: figshare
Year: 2023
Subjects: Library studies
Library and information studies not elsewhere classified

description: Electronic resources are the electronic representation of information. Because of the easy accessibility, low cost and effective presentation with multimedia tools, e-resources have become the most popular source of information. The present research focuses on the usage statistics of e-resources during the pandemic period lockdown and restricts its scope to Chandigarh University Library. This study survey was conducted by distributing 200 questionnaires structured on a Google Form among the students, staff and faculty members of Chandigarh University. Out of all distributed questionnaires, 158 questionnaires were selected as a valid response for the study. Various statistical methods have been used for the analysis of the survey data. According to the findings, the majority of the library users are aware of the e-Resources available in the CU Library & use them efficiently according to their particular needs. Furthermore, the paper describes the difficulties students and faculty members faced in obtaining e-resources, as well as their perspectives on the utility of the e-resources.
Epicatechin Supplementation on Muscular Atrophy: Systematic Review
Creators: name: German, Iris
name: Tadashi Cosin Shindo, João Vitor
name: Shinohara, André Luis
name: Pomini, Karina Torres
Publisher: name: figshare
Year: 2022
Subjects: subject: Medicine
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: Anatomy

description: Polyphenol epicatechin has been investigated by the biological effects on the reduction of the catabolic process in skeletal musculature-related diseases. Due to the potential benefits described in the literature and clinical relevance, the purpose of this systematic review was to conduct an analysis of epicatechin effects on muscular atrophy in humans and animals.
D3.7- Data products final report
Creators: name: Tsardanidis, Iason
Publisher: name: Zenodo
Year: 2023

description: The objective of this deliverable is to provide a comprehensive description of the data products that
were developed and used in the ENVISION business cases. Specifically, it is related to the following
tasks of the "WP3 Earth Observation data products":

Task 3.3: Analytics on Vegetation and Soil Index Time-series
Task 3.4: Cultivated Crop Type Maps
Task 3.5: Grassland Mowing Events Detection
Task 3.6: Soil Condition Monitoring
Task 3.7: Monitoring organic farming requirements
Do We Train on Test Data? The Impact of Near-Duplicates on License Plate Recognition
Creators: name: Laroca, Rayson
name: Estevam, Valter
name: Britto, Alceu S.
name: Minetto, Rodrigo
name: Menotti, David
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: This work draws attention to the large fraction of near-duplicates in the training and test sets of datasets widely adopted in License Plate Recognition (LPR) research. These duplicates refer to images that, although different, show the same license plate. Our experiments, conducted on the two most popular datasets in the field, show a substantial decrease in recognition rate when six well-known models are trained and tested under fair splits, that is, in the absence of duplicates in the training and test sets. Moreover, in one of the datasets, the ranking of models changed considerably when they were trained and tested under duplicate-free splits. These findings suggest that such duplicates have significantly biased the evaluation and development of deep learning-based models for LPR. The list of near-duplicates we have found and proposals for fair splits are publicly available for further research at https://raysonlaroca.github.io/supp/lpr-train-on-test/
description: Accepted for presentation at the International Joint Conference on Neural Networks (IJCNN) 2023
Iron and neutron-capture element abundance variations in the globular cluster M2 (NGC 7089)
Creators: name: Yong, David
name: Roederer, Ian U.
name: Grundahl, Frank
name: Da Costa, Gary S.
name: Karakas, Amanda I.
name: Norris, John E.
name: Aoki, Wako
name: Fishlock, Cherie K.
name: Marino, A. F.
name: Milone, A. P.
name: Shingles, Luke J.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present CN and CH indices and CaII triplet metallicities for 34 giant stars and chemical abundances for 33 elements in 14 giants in the globular cluster M2. Assuming the program stars are cluster members, our analysis reveals (i) an extreme variation in CN and CH line strengths, (ii) a metallicity dispersion with a dominant peak at [Fe/H] = -1.7 and smaller peaks at -1.5 and -1.0, (iii) star-to-star abundance variations and correlations for the light elements O, Na, Al and Si and (iv) a large (and possibly bimodal) distribution in the abundances of all elements produced mainly via the s-process in solar system material. Following Roederer et al. (2011), we define two groups of stars, "r+s" and "r-only", and subtract the average abundances of the latter from the former group to obtain a "s-process residual". This s-process residual is remarkably similar to that found in M22 and in M4 despite the range in metallicity covered by these three systems. With recent studies identifying a double subgiant branch in M2 and a dispersion in Sr and Ba abundances, our spectroscopic analysis confirms that this globular cluster has experienced a complex formation history with similarities to M22, NGC 1851 and omega Centauri.
description: Accepted for publication in MNRAS