cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Optically driven spin-alignment precession
Creators: name: Fomin, A. A.
name: Petrov, M. Yu.
name: Pazgalev, A. S.
name: Kozlov, G. G.
name: Zapasskii, V. S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The effect of optically driven spin precession discovered by Bell and Bloom [W. E. Bell and A. L. Bloom, Phys. Rev. Lett. 6, 280 (1961)] is widely used nowadays as a basis for numerous experiments in fundamental physics and for diverse applications. In this paper we consider a much less popular version of the light-induced spin precession that does not imply coherent precession of the spin-system magnetization and is excited by linearly (rather than circularly) polarized light. Pump-probe measurements performed on the D2 line of cesium vapor show that the magnitude of the signal of the optically driven spin-alignment precession, in "vacuum" cells (with no buffer gas) is close to that of classical spin-orientation precession. In the presence of buffer gas, however, the signal of spin-alignment precession appears to be strongly suppressed. The discovered effect is ascribed to spin mixing of excited states of cesium atoms in the cycle of optical pumping.
description: 7 pages, 4 figures
Spatio-temporal dynamics of anisotropic emission from nano second laser produced aluminium plasma
Creators: name: R., Geethika B.
name: Thomas, Jinto
name: Patel, Milaan
name: R., Renjith Kumar
name: Joshi, Hem Chandra
Publisher: name: arXiv
Year: 2023
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Polarized emission carries captivating information and can help understand various elementary processes involving collisions within the plasma as well as in radiative transitions. In this work, we investigate the spatio-temporal dependence of the emission anisotropy of a nanosecond laser produced aluminium plasma at 100 mbar background pressure. We observe that the anisotropy of the emission spectra exhibits interesting spatio-temporal characteristics which in turn depend on the charge state of the emitting species. The degree of polarization (DOP) is found to reverse its sign along the plume propagation direction. Observed behaviour in DOP appears to be due to the contribution from various involved atomic processes. However, closer to the sample the contribution from the self-generated magnetic field predominantly affect the polarization. On the other hand, the effect of the self generated magnetic field on the observed polarized emission is insignificant as the plume propagates away from the sample. This is of particular interest in polarization resolved laser induced breakdown spectroscopy as spatio-temporal profile of the degree of polarization has to be properly taken into account prior to the spectral analysis.
Rothberger gaps in fragmented ideals
Creators: name: Brendle, Jörg
name: Mejía, Diego A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics
subject: (2010) Primary 03E05, Secondary 03E15, 03E17, 03E35

description: The~\emph{Rothberger number} $\mathfrak{b} (\mathcal{I})$ of a definable ideal $\mathcal{I}$ on $ω$ is the least cardinal $κ$ such that there exists a Rothberger gap of type $(ω,κ)$ in the quotient algebra $\mathcal{P} (ω) / \mathcal{I}$. We investigate $\mathfrak{b} (\mathcal{I})$ for a subclass of the $F_σ$ ideals, the fragmented ideals, and prove that for some of these ideals, like the linear growth ideal, the Rothberger number is $\aleph_1$ while for others, like the polynomial growth ideal, it is above the additivity of measure. We also show that it is consistent that there are infinitely many (even continuum many) different Rothberger numbers associated with fragmented ideals.
description: 28 pages
Supplementary document for Undersampling Raster Scans in Spectromicroscopy for reduced dose and faster measurements - 6070626.pdf
Creators: name: Townsend, Oliver
name: Gazzola, Silvia
name: Dolgov, Sergey
name: Quinn, Paul
Publisher: name: Optica Publishing Group
Year: 2022
Subjects: Uncategorized

description: Supplemental document providing further details on mathematical derivations and methods
Technical constraints on interstellar interferometry and spatially resolving the pulsar magnetosphere
Creators: name: Popov, M. V.
name: Bartel, N.
name: Andrianov, A. S.
name: Burgin, M. S.
name: Fadeev, E. N.
name: Rudnitskiy, A. G.
name: Smirnova, T. V.
name: Soglasnov, V. A.
name: Zuga, V. A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Scintillation of pulsar radio signals caused by the interstellar medium can in principle be used for interstellar interferometry. Changes of the dynamic spectra as a function of pulsar longitude were in the past interpreted as having spatially resolved the pulsar magnetosphere. Guided by this prospect we used VLBI observations of PSR B1237+25 with the Arecibo and Green Bank radio telescopes at 324 MHz and analyzed such scintillation at separate longitudes of the pulse profile. We found that the fringe phase characteristics of the visibility function changed quasi-sinusoidally as a function of longitude. Also, the dynamic spectra from each of the telescopes shifted in frequency as a function of longitude. Similar effects were found for PSR B1133+16. However, we show that these effects are not signatures of having resolved the pulsar magnetosphere. Instead the changes can be related to the effect of low-level digitizing of the pulsar signal. After correcting for these effects the frequency shifts largely disappeared. Residual effects may be partly due to feed polarization impurities. Upper limits for the pulse emission altitudes of PSR B1237+25 would likely be well below the pulsar light cylinder radius. In view of our analysis we think that observations with the intent of spatially resolving the pulsar magnetosphere need to be critically evaluated in terms of these constraints on interstellar interferometry.
description: 19 pages, 11 figures, published in The Astrophysical Journal
Improving VTE Identification through Adaptive NLP Model Selection and Clinical Expert Rule-based Classifier from Radiology Reports
Creators: name: Deng, Jamie
name: Wu, Yusen
name: Hayssen, Hilary
name: Englum, Brain
name: Kankaria, Aman
name: Mayorga-Carlin, Minerva
name: Sahoo, Shalini
name: Sorkin, John
name: Lal, Brajesh
name: Yesha, Yelena
name: Nguyen, Phuong
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computation and Language (cs.CL)
subject: Information Retrieval (cs.IR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Rapid and accurate identification of Venous thromboembolism (VTE), a severe cardiovascular condition including deep vein thrombosis (DVT) and pulmonary embolism (PE), is important for effective treatment. Leveraging Natural Language Processing (NLP) on radiology reports, automated methods have shown promising advancements in identifying VTE events from retrospective data cohorts or aiding clinical experts in identifying VTE events from radiology reports. However, effectively training Deep Learning (DL) and the NLP models is challenging due to limited labeled medical text data, the complexity and heterogeneity of radiology reports, and data imbalance. This study proposes novel method combinations of DL methods, along with data augmentation, adaptive pre-trained NLP model selection, and a clinical expert NLP rule-based classifier, to improve the accuracy of VTE identification in unstructured (free-text) radiology reports. Our experimental results demonstrate the model's efficacy, achieving an impressive 97\% accuracy and 97\% F1 score in predicting DVT, and an outstanding 98.3\% accuracy and 98.4\% F1 score in predicting PE. These findings emphasize the model's robustness and its potential to significantly contribute to VTE research.
Signatures of primordial black hole dark matter
Creators: name: Belotsky, K. M.
name: Dmitriev, A. D.
name: Esipova, E. A.
name: Gani, V. A.
name: Grobov, A. V.
name: Khlopov, M. Yu.
name: Kirillov, A. A.
name: Rubin, S. G.
name: Svadkovsky, I. V.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The nonbaryonic dark matter of the Universe is assumed to consist of new stable forms of matter. Their stability reflects symmetry of micro world and mechanisms of its symmetry breaking. In the early Universe heavy metastable particles can dominate, leaving primordial black holes (PBHs) after their decay, as well as the structure of particle symmetry breaking gives rise to cosmological phase transitions, from which massive black holes and/or their clusters can originate. PBHs can be formed in such transitions within a narrow interval of masses about $10^{17}$g and, avoiding severe observational constraints on PBHs, can be a candidate for the dominant form of dark matter. PBHs in this range of mass can give solution of the problem of reionization in the Universe at the redshift $z\sim 5... 10$. Clusters of massive PBHs can serve as a nonlinear seeds for galaxy formation, while PBHs evaporating in such clusters can provide an interesting interpretation for the observations of point-like gamma-ray sources. Analysis of possible PBH signatures represents a universal probe for super-high energy physics in the early Universe in studies of indirect effects of the dark matter.
STERLING: Self-Supervised Terrain Representation Learning from Unconstrained Robot Experience
Creators: name: Karnan, Haresh
name: Yang, Elvin
name: Farkash, Daniel
name: Warnell, Garrett
name: Biswas, Joydeep
name: Stone, Peter
Publisher: name: arXiv
Year: 2023
Subjects: subject: Robotics (cs.RO)
subject: Artificial Intelligence (cs.AI)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Terrain awareness, i.e., the ability to identify and distinguish different types of terrain, is a critical ability that robots must have to succeed at autonomous off-road navigation. Current approaches that provide robots with this awareness either rely on labeled data which is expensive to collect, engineered features and cost functions that may not generalize, or expert human demonstrations which may not be available. Towards endowing robots with terrain awareness without these limitations, we introduce Self-supervised TErrain Representation LearnING (STERLING), a novel approach for learning terrain representations that relies solely on easy-to-collect, unconstrained (e.g., non-expert), and unlabelled robot experience, with no additional constraints on data collection. STERLING employs a novel multi-modal self-supervision objective through non-contrastive representation learning to learn relevant terrain representations for terrain-aware navigation. Through physical robot experiments in off-road environments, we evaluate STERLING features on the task of preference-aligned visual navigation and find that STERLING features perform on par with fully supervised approaches and outperform other state-of-the-art methods with respect to preference alignment. Additionally, we perform a large-scale experiment of autonomously hiking a 3-mile long trail which STERLING completes successfully with only two manual interventions, demonstrating its robustness to real-world off-road conditions.
description: Project website: https://hareshkarnan.github.io/sterling/
Approximately Stationary Bandits with Knapsacks
Creators: name: Fikioris, Giannis
name: Tardos, Éva
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Bandits with Knapsacks (BwK), the generalization of the Bandits problem under global budget constraints, has received a lot of attention in recent years. Previous work has focused on one of the two extremes: Stochastic BwK where the rewards and consumptions of the resources of each round are sampled from an i.i.d. distribution, and Adversarial BwK where these parameters are picked by an adversary. Achievable guarantees in the two cases exhibit a massive gap: No-regret learning is achievable in the stochastic case, but in the adversarial case only competitive ratio style guarantees are achievable, where the competitive ratio depends either on the budget or on both the time and the number of resources. What makes this gap so vast is that in Adversarial BwK the guarantees get worse in the typical case when the budget is more binding. While ``best-of-both-worlds'' type algorithms are known (single algorithms that provide the best achievable guarantee in each extreme case), their bounds degrade to the adversarial case as soon as the environment is not fully stochastic. Our work aims to bridge this gap, offering guarantees for a workload that is not exactly stochastic but is also not worst-case. We define a condition, Approximately Stationary BwK, that parameterizes how close to stochastic or adversarial an instance is. Based on these parameters, we explore what is the best competitive ratio attainable in BwK. We explore two algorithms that are oblivious to the values of the parameters but guarantee competitive ratios that smoothly transition between the best possible guarantees in the two extreme cases, depending on the values of the parameters. Our guarantees offer great improvement over the adversarial guarantee, especially when the available budget is small. We also prove bounds on the achievable guarantee, showing that our results are approximately tight when the budget is small.
Posterior predictive checks to quantify lack-of-fit in admixture models of latent population structure
Creators: name: Mimno, David
name: Blei, David M
name: Engelhardt, Barbara E
Publisher: name: arXiv
Year: 2014
Subjects: subject: Methodology (stat.ME)
subject: Genomics (q-bio.GN)
subject: Populations and Evolution (q-bio.PE)
subject: Applications (stat.AP)
subject: FOS: Computer and information sciences
subject: FOS: Biological sciences

description: Admixture models are a ubiquitous approach to capture latent population structure in genetic samples. Despite the widespread application of admixture models, little thought has been devoted to the quality of the model fit or the accuracy of the estimates of parameters of interest for a particular study. Here we develop methods for validating admixture models based on posterior predictive checks (PPCs), a Bayesian method for assessing the quality of a statistical model. We develop PPCs for five population-level statistics of interest: within-population genetic variation, background linkage disequilibrium, number of ancestral populations, between-population genetic variation, and the downstream use of admixture parameters to correct for population structure in association studies. Using PPCs, we evaluate the quality of the model estimates for four qualitatively different population genetic data sets: the POPRES European individuals, the HapMap phase 3 individuals, continental Indians, and African American individuals. We found that the same model fitted to different genomic studies resulted in highly study-specific results when evaluated using PPCs, illustrating the utility of PPCs for model-based analyses in large genomic studies.
MPEC 2024-R327 : 2024 RJ16
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2024
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2024 RJ16

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
A Polling Model with Smart Customers
Creators: name: Boon, Marko
name: van Wijk, Sandra
name: Adan, Ivo
name: Boxma, Onno
Publisher: name: arXiv
Year: 2014
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: In this paper we consider a single-server, cyclic polling system with switch-over times. A distinguishing feature of the model is that the rates of the Poisson arrival processes at the various queues depend on the server location. For this model we study the joint queue length distribution at polling epochs and at server's departure epochs. We also study the marginal queue length distribution at arrival epochs, as well as at arbitrary epochs (which is not the same in general, since we cannot use the PASTA property). A generalised version of the distributional form of Little's law is applied to the joint queue length distribution at customer's departure epochs in order to find the waiting time distribution for each customer type. We also provide an alternative, more efficient way to determine the mean queue lengths and mean waiting times, using Mean Value Analysis. Furthermore, we show that under certain conditions a Pseudo-Conservation Law for the total amount of work in the system holds. Finally, typical features of the model under consideration are demonstrated in several numerical examples.
TODDLERS: A new UV-mm emission library for star-forming regions. 1. Integration with SKIRT and public release
Creators: name: Kapoor, Anand Utsav
name: Baes, Maarten
name: van der Wel, Arjen
name: Gebek, Andrea
name: Camps, Peter
name: Nersesian, Angelos
name: Meidt, Sharon E.
name: Smith, Aaron
name: Vicens, Sebastien
name: D'Eugenio, Francesco
name: Martorano, Marco
name: Barrientos, Daniela
name: Sartorio, Nina Sanches
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present and publicly release a new star-forming regions emission library TODDLERS (Time evolution of Observables including Dust Diagnostics and Line Emission from Regions containing young Stars) for the publicly available radiative transfer code SKIRT. The library generation involves the spherical evolution of a homogeneous gas cloud around a young stellar cluster that accounts for stellar feedback processes including stellar winds, supernovae, and radiation pressure, as well as the gravitational forces on the gas. The semi-analytical evolution model is coupled with the photoionization code Cloudy to calculate time-dependent UV-mm spectral energy distributions (SEDs) from star-forming regions of varying metallicity, star-formation efficiency, birth-cloud density, and mass. The calculated SEDs include the stellar, nebular, and dust continuum emission along with a wide range of emission lines originating from H ii, photo-dissociation, and molecular gas regimes tabulated at high resolution. The SEDs incorporated in SKIRT are generated by calculating a stellar-mass normalized luminosity, which assumes that each emission source is composed of a power-law population of star-forming clouds. When compared to the previous treatment of star-forming regions in SKIRT, TODDLERS shows a better agreement with low-redshift observational data in the IR wavelength range while offering a more comprehensive line-emission support. This paves the way for a variety of applications using simulated galaxies at low and high redshift.
description: Accepted for publication in MNRAS on 27/09/23
A topological approach to periodic oscillations related to the Liebau phenomenon
Creators: name: Cid, José Ángel
name: Infante, Gennaro
name: Tvrdý, Milan
name: Zima, Mirosława
Publisher: name: arXiv
Year: 2014
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 34B18 (Primary), 34B27 (Secondary), 34B60

description: We give some sufficient conditions for existence, non-existence and localization of positive solutions for a periodic boundary value problem related to the Liebau phenomenon. Our approach is of topological nature and relies on the Krasnosel'ski\uı-Guo theorem on cone expansion and compression. Our results improve and complement earlier ones in the literature.
description: 12 pages, 4 figures
Interaction dust-plasma in Titan's ionosphere: feedbacks on the gas phase composition
Creators: name: Chatain, Audrey
name: Carrasco, Nathalie
name: Vettier, Ludovic
name: Guaitella, Olivier
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Plasma Physics (physics.plasm-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Titan's organic aerosols are formed in the ionosphere, a layer ionized by solar VUV photons and energetic particles from the magnetosphere of Saturn, forming a natural N2-CH4-H2 plasma. Previous works showed some chemical evolution processes: VUV photons slightly alter the aerosols nitrile bands, hydrogen atoms tend to hydrogenate their surface and carbon-containing species participate to the growth of the aerosols. This work investigates the effect of the other plasma species, namely the N2-H2 derived ions, radicals and excited states. Industrial plasmas often use N2-H2 discharges to form ammonia-based fertilizers, for metal nitriding, and to erode organic surfaces. Consequently, these are likely to affect Titan's organic aerosols. We therefore developed the THETIS experiment to study the interactions between analogues of Titan's aerosols (tholins) and the erosive N2-H2 plasma species found in Titan's ionosphere. Following a first paper on the evolution of the solid phase by Scanning Electron Microscopy and IR transmission spectroscopy (Chatain et al., Icarus, 2020), this paper focuses on evolution of the gas phase composition, by neutral and ion mass spectrometry. Newly formed HCN, NH3-CN and C2N2 are extracted from the tholins as well as some other carbon-containing species and their derived ions. On the other hand, the production of ammonia strongly decreases, probably because the H, NH and N radicals are rather used for the production of HCN at the surface of tholins. Heterogeneous processes are suggested: chemical processes induced by radicals at the surface would modify and weaken the tholin structure, while ion sputtering would desorb small molecules and highly unsaturated ions. The effect of plasma erosion on aerosols in Titan's ionosphere could therefore lead to the formation of CN bonds in the aerosol structure and the production of HCN or R-CN species in the gas phase.
description: This paper has been published in Icarus (2023). The current version in arXiv is the accepted version
Supplementary document for Visualization of Localized Facet Joule Heating induced Optical Degradation on Mid-infrared Quantum Cascade Lasers - 6105080.pdf
Creators: name: Wang, Siyi
name: xu, chao
name: Tam, Man chun
name: Vaillancourt, Kailyn
name: Wasilewski, Zbigniew
name: Wei, Lan
name: Ban, Dayan
Publisher: name: Optica Publishing Group
Year: 2022
Subjects: Uncategorized

description: Supplemental Material
Towards a Complete Metamorphic Testing Pipeline
Creators: name: Duque-Torres, Alejandra
name: Pfahl, Dietmar
Publisher: name: arXiv
Year: 2023
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences
subject: D.2.5

description: Metamorphic Testing (MT) addresses the test oracle problem by examining the relationships between input-output pairs in consecutive executions of the System Under Test (SUT). These relations, known as Metamorphic Relations (MRs), specify the expected output changes resulting from specific input changes. However, achieving full automation in generating, selecting, and understanding MR violations poses challenges. Our research aims to develop methods and tools that assist testers in generating MRs, defining constraints, and providing explainability for MR outcomes. In the MR generation phase, we explore automated techniques that utilise a domain-specific language to generate and describe MRs. The MR constraint definition focuses on capturing the nuances of MR applicability by defining constraints. These constraints help identify the specific conditions under which MRs are expected to hold. The evaluation and validation involve conducting empirical studies to assess the effectiveness of the developed methods and validate their applicability in real-world regression testing scenarios. Through this research, we aim to advance the automation of MR generation, enhance the understanding of MR violations, and facilitate their effective application in regression testing.
description: 5 pages
Supplementary document for Visualization of Localized Facet Joule Heating induced Optical Degradation on Mid-infrared Quantum Cascade Lasers - 6127656.pdf
Creators: name: Wang, Siyi
name: xu, chao
name: Tam, Man chun
name: Vaillancourt, Kailyn
name: Wasilewski, Zbigniew
name: Wei, Lan
name: Ban, Dayan
Publisher: name: Optica Publishing Group
Year: 2022
Subjects: Uncategorized

description: Supplemental Information
(Re-)Tracing History Action Framework
Creators: name: Fisher, Vicky
name: Karrouche, Norah
name: Nabibaks, Farida
name: Pieters, Toine
name: Plate, Liedeke
Publisher: name: Zenodo
Year: 2022
Subjects: Heritage, action-based research, oral history, dance performance, virtual dialogue

description: The research project (Re-)Tracing History sought to develop innovative methods to include unknown, overlooked and ignored traces of the past in contemporary heritage practice. In three action-based research projects, collaborative teams of researchers, (grassroots) cultural organisations and general public investigated how oral history, dance performance and virtual dialogue could be applied to make unacknowledged traces of the past tangible, palpable, and negotiable in the public domain. This action framework summarises the project’s lessons learned and offers suggestions to those seeking to integrate unknown, overlooked and ignored traces of the past in their own work.
Hands-on experiments on intelligent behavior for mobile robots
Creators: name: Cuevas, Erik
name: Zaldivar, Daniel
name: Perez-, Marco
name: Ramirez, Marte
Publisher: name: arXiv
Year: 2014
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: In recent years, Artificial Intelligence techniques have emerged as useful tools for solving various engineering problems that were not possible or convenient to handle by traditional methods. AI has directly influenced many areas of computer science and becomes an important part of the engineering curriculum. However, determining the important topics for a single semester AI course is a nontrivial task, given the lack of a general methodology. AI concepts commonly overlap with many other disciplines involving a wide range of subjects, including applied approaches to more formal mathematical issues. This paper presents the use of a simple robotic platform to assist the learning of basic AI concepts. The study is guided through some simple experiments using autonomous mobile robots. The central algorithm is the Learning Automata. Using LA, each robot action is applied to an environment to be evaluated by means of a fitness value. The response of the environment is used by the automata to select its next action. This procedure holds until the goal task is reached. The proposal addresses the AI study by offering in LA a unifying context to draw together several of the topics of AI and motivating the students to learn by building some hands on laboratory exercises. The presented material has been successfully tested as AI teaching aide in the University of Guadalajara robotics group as it motivates students and increases enrolment and retention while educating better computer engineers.
description: 11 Pages
Numerical Tests of Rotational Mixing in Massive Stars with the new Population Synthesis Code BONNFIRES
Creators: name: Lau, Herbert H. B.
name: Izzard, Robert G.
name: Schneider, Fabian R. N.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We use our new population synthesis code BONNFIRES to test how surface abundances predicted by rotating stellar models depend on the numerical treatment of rotational mixing, such as spatial resolution, temporal resolution and computation of mean molecular weight gradients. We find that even with identical numerical prescriptions for calculating the rotational mixing coefficients in the diffusion equation, different timesteps lead to a deviation of the coefficients and hence surface abundances. We find the surface abundances vary by 10-100% between the model sequences with short timestep of 0.001Myr to model sequences with longer timesteps. Model sequences with stronger surface nitrogen enrichment also have longer main-sequence lifetimes because more hydrogen is mixed to the burning cores. The deviations in main-sequence lifetimes can be as large as 20%. Mathematically speaking, no numerical scheme can give a perfect solution unless infinitesimally small timesteps are used. However, we find that the surface abundances eventually converge within 10% between modelling sequences with sufficiently small timesteps below 0.1Myr. The efficiency of rotational mixing depends on the implemented numerical scheme and critically on the computation of the mean molecular weight gradient. A smoothing function for the mean molecular weight gradient results in stronger rotational mixing. If the discretization scheme or the computational recipe for calculating the mean molecular weight gradient is altered, re-calibration of mixing parameters may be required to fit observations. If we are to properly understand the fundamental physics of rotation in stars, it is crucial that we minimize the uncertainty introduced into stellar evolution models when numerically approximating rotational mixing processes.
description: 8 pages, 6 figures, accepted by A&A
Stackings and effective models of bilayer dice lattices
Creators: name: Sukhachov, P. O.
name: Oriekhov, D. O.
name: Gorbar, E. V.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We introduce and classify nonequivalent commensurate stackings for bilayer dice or $\mathcal{T}_3$ lattice. For each of the four stackings with vertical alignment of sites in two layers, a tight-binding model and an effective model describing the properties in the vicinity of the threefold band-crossing points are derived. Focusing on these band-crossing points, we found that although the energy spectrum remains always gapless, depending on the stacking, different types of quasiparticle spectra arise. They include those with flat, tilted, anisotropic semi-Dirac, and $C_3$-corrugated energy bands. We use the derived tight-binding models to calculate the density of states and the spectral function. The corresponding results reveal drastic redistribution of the spectral weight due to the inter-layer coupling that is unique for each of the stackings.
description: 15 pages, 9 multi-panel figures
Supplementary document for Visualization of Localized Facet Joule Heating induced Optical Degradation on Mid-infrared Quantum Cascade Lasers - 6129728.pdf
Creators: name: Wang, Siyi
name: xu, chao
name: Tam, Man chun
name: Vaillancourt, Kailyn
name: Wasilewski, Zbigniew
name: Wei, Lan
name: Ban, Dayan
Publisher: name: Optica Publishing Group
Year: 2022
Subjects: Uncategorized

description: Supplemental Information
Towards a Procedure Optimised Steerable Microcatheter for Deep Seated Neurosurgery
Creators: name: Aktas, Ayhan
name: Demircali, A. Anil
name: Secoli, Riccardo
name: Temelkuran, Burak
name: Baena, F. Rodriguez y
Publisher: name: arXiv
Year: 2023
Subjects: subject: Medical Physics (physics.med-ph)
subject: Robotics (cs.RO)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: In recent years, the steerable needles have attracted significant interest in Minimally Invasive Surgery (MIS). Amongst these, the flexible Programmable-bevel tip needle (PBN) concept has successfully achieved an in-vivo demonstration to evaluate the feasibility of Convection Enhanced Delivery (CED) of chemotherapeutics within the ovine model, with a 2.5 mm PBN prototype. However, further size reduction is necessary for other diagnostic and therapeutic procedures involving deep-seated tissue structures. Since PBNs have a complex cross-section geometry, standard production methods, such as extrusion, fails as the outer diameter is reduced further. This paper presents our first attempt to demonstrate a new manufacturing method for the PBN that employs thermal drawing technology. Experimental characterisation tests were performed for the 2.5 mm PBN and a new 1.3 mm Thermally Drawn (TD) PBN prototype described here. The results show that thermal drawing presents a significant advantage in miniaturising complex needle structures. However, the steering behaviour is affected due to the choice of material in this first attempt, a limitation which will be addressed in future work.
Microscopic Analysis of Lattice Distortion Effects in Rashba Systems
Creators: name: Ogawa, Yuuki
name: Funato, Takumi
name: Kohno, Hiroshi
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We theoretically study the effects of dynamical lattice distortion in a three-dimensional Rashba system based on a tight-binding model. Considering an $sp$-electron system on a tetragonal lattice with broken inversion symmetry, lattice distortions are incorporated through hopping-integral and crystal-axis modulations. The effective Hamiltonian for the $p_z$- or $s$-derived band is found to have Rashba modulation terms, which induce various types of spin currents, such as Rashba, quadrupolar, perpendicular, and helicity currents. The results are compared with those obtained by the method of local coordinate transformation.
description: 5pages, 3figures
A Polling Model with Reneging at Polling Instants
Creators: name: Boon, Marko
Publisher: name: arXiv
Year: 2014
Subjects: subject: Probability (math.PR)
subject: Performance (cs.PF)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: In this paper we consider a single-server, cyclic polling system with switch-over times and Poisson arrivals. The service disciplines that are discussed, are exhaustive and gated service. The novel contribution of the present paper is that we consider the reneging of customers at polling instants. In more detail, whenever the server starts or ends a visit to a queue, some of the customers waiting in each queue leave the system before having received service. The probability that a certain customer leaves the queue, depends on the queue in which the customer is waiting, and on the location of the server. We show that this system can be analysed by introducing customer subtypes, depending on their arrival periods, and keeping track of the moment when they abandon the system. In order to determine waiting time distributions, we regard the system as a polling model with varying arrival rates, and apply a generalised version of the distributional form of Little's law. The marginal queue length distribution can be found by conditioning on the state of the system (position of the server, and whether it is serving or switching).
Improving style transfer in dynamic contrast enhanced MRI using a spatio-temporal approach
Creators: name: Tattersall, Adam G.
name: Goatman, Keith A.
name: Kershaw, Lucy E.
name: Semple, Scott I. K.
name: Dahdouh, Sonia
Publisher: name: arXiv
Year: 2023
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Style transfer in DCE-MRI is a challenging task due to large variations in contrast enhancements across different tissues and time. Current unsupervised methods fail due to the wide variety of contrast enhancement and motion between the images in the series. We propose a new method that combines autoencoders to disentangle content and style with convolutional LSTMs to model predicted latent spaces along time and adaptive convolutions to tackle the localised nature of contrast enhancement. To evaluate our method, we propose a new metric that takes into account the contrast enhancement. Qualitative and quantitative analyses show that the proposed method outperforms the state of the art on two different datasets.
Quantum estimation of the Schwarzschild space-time parameters of the Earth
Creators: name: Bruschi, David Edward
name: Datta, Animesh
name: Ursin, Rupert
name: Ralph, Timothy C.
name: Fuentes, Ivette
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We propose a quantum experiment to measure with high precision the Schwarzschild space-time parameters of the Earth. The scheme can also be applied to measure distances by taking into account the curvature of the Earth's space-time. As a wave-packet of (entangled) light is sent from the Earth to a satellite it is red-shifted and deformed due to the curvature of space-time. Measurements after the propagation enable the estimation of the space-time parameters. We compare our results with the state of the art, which involves classical measurement methods, and discuss what developments are required in space-based quantum experiments to improve on the current measurement of the Schwarzschild radius of the Earth.
description: 11 pages, no figures. Ivette Fuentes previously published as Ivette Fuentes-Guridi and Ivette Fuentes-Schuller
A comparative study on different neural network architectures to model inelasticity
Creators: name: Rosenkranz, Max
name: Kalina, Karl A.
name: Brummund, Jörg
name: Kästner, Markus
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences

description: The mathematical formulation of constitutive models to describe the path-dependent, i.e., inelastic, behavior of materials is a challenging task and has been a focus in mechanics research for several decades. There have been increased efforts to facilitate or automate this task through data-driven techniques, impelled in particular by the recent revival of neural networks (NNs) in computational mechanics. However, it seems questionable to simply not consider fundamental findings of constitutive modeling originating from the last decades research within NN-based approaches. Herein, we propose a comparative study on different feedforward and recurrent neural network architectures to model inelasticity. Within this study, we divide the models into three basic classes: black box NNs, NNs enforcing physics in a weak form, and NNs enforcing physics in a strong form. Thereby, the first class of networks can learn constitutive relations from data while the underlying physics are completely ignored, whereas the latter two are constructed such that they can account for fundamental physics, where special attention is paid to the second law of thermodynamics in this work. Conventional linear and nonlinear viscoelastic as well as elastoplastic models are used for training data generation and, later on, as reference. After training with random walk time sequences containing information on stress, strain, and, for some models, internal variables, the NN-based models are compared to the reference solution, whereby interpolation and extrapolation are considered. Besides the quality of the stress prediction, the related free energy and dissipation rate are analyzed to evaluate the models. Overall, the presented study enables a clear recording of the advantages and disadvantages of different NN architectures to model inelasticity and gives guidance on how to train and apply these models.
Resource-Rational Lossy-Context Surprisal (Model Files)
Creators: name: Hahn, Michael
Publisher: name: Zenodo
Year: 2022

description: Resource-Rational Lossy-Context Surprisal is a computationally implemented model of how humans process language, predicting at what points in complex sentences they experience comprehension difficulty. It unifies the memory-based and expectation-based paradigms in psycholinguistics, and provides a more refined account of when hierarchical structure is difficult for humans. This repository contains both basic parameter files for the inference networks, and a number of replicates of the retention probability parameter files, controlling for variability in different model parameters. The model is developed by Michael Hahn. It was first described in the following publication: Lexical Effects in Structural Forgetting: Evidence for Experience-Based Accounts and a Neural Network Model (Michael Hahn, Richard Futrell, Edward Gibson), 33rd Annual CUNY Human Sentence Processing Conference, 2020 https://people.umass.edu/bwdillon/CUNY_2020_Abstracts/HAHN_Final_Manuscript.pdf
Correlated percolation models of structured habitat in ecology
Creators: name: Huth, G.
name: Lesne, A.
name: Munoz, F.
name: Pitard, E.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: Percolation offers acknowledged models of random media when the relevant medium characteristics can be described as a binary feature. However, when considering habitat modeling in ecology, a natural constraint comes from nearest-neighbor correlations between the suitable/unsuitable states of the spatial units forming the habitat. Such constraints are also relevant in the physics of aggregation where underlying processes may lead to a form of correlated percolation. However, in ecology, the processes leading to habitat correlations are in general not known or very complex. As proposed by Hiebeler [Ecology {\bf 81}, 1629 (2000)], these correlations can be captured in a lattice model by an observable aggregation parameter $q$, supplementing the density $p$ of suitable sites. We investigate this model as an instance of correlated percolation. We analyze the phase diagram of the percolation transition and compute the cluster size distribution, the pair-connectedness function $C(r)$ and the correlation function $g(r)$. We find that while $g(r)$ displays a power-law decrease associated with long-range correlations in a wide domain of parameter values, critical properties are compatible with the universality class of uncorrelated percolation. We contrast the correlation structures obtained respectively for the correlated percolation model and for the Ising model, and show that the diversity of habitat configurations generated by the Hiebeler model is richer than the archetypal Ising model. We also find that emergent structural properties are peculiar to the implemented algorithm, leading to questioning the notion of a well-defined model of aggregated habitat. We conclude that the choice of model and algorithm have strong consequences on what insights ecological studies can get using such models of species habitat.
MPEC 2024-R328 : 2024 RK16
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2024
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2024 RK16

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Molecular states in $D_s^{(*)+}Ξ_c^{(',*)}$ systems
Creators: name: Yalikun, Nijiati
name: Dong, Xiang-Kun
name: Zou, Bing-Song
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The possible hadronic molecules in $D_s^{(*)+}Ξ_c^{(',*)}$ systems with $J^P=1/2^-,3/2^-$ and $5/2^-$ are investigated with interactions described by light meson exchanges. By varying the cutoff in a phenomenologically reasonable range of $1\sim2.5$ GeV, we find ten near-threshold (bound or virtual) states in the single-channel case. After introducing the coupled-channel dynamics of $D_s^{+}Ξ_c$-$D_s^{+}Ξ_c^{'}$-$D_s^{*+}Ξ_c$-$D_s^{+}Ξ_c^{*}$-$D_s^{*+}Ξ_c^{'}$-$D_s^{*+}Ξ_c^{*}$ systems, these states, except those below the lowest channels in each $J^{P}$ sector, move into the complex energy plane and become resonances in the mass range of $4.43\sim4.76$ GeV. Their spin-parities and nearby thresholds are $1/2^-(D_s^{+}Ξ_c)$, $1/2^-(D_s^{+}Ξ_c^{'})$, $1/2^-(D_s^{*+}Ξ_c)$,$1/2^-(D_s^{*+}Ξ_c^{'})$, $1/2^-(D_s^{*+}Ξ_c^{*})$ , $3/2^-(D_s^{*+}Ξ_c)$, $3/2^-(D_s^{+}Ξ_c)$, $3/2^-(D_s^{*+}Ξ_c^{'})$, $3/2^-(D_s^{*+}Ξ_c^{*})$, and $5/2^-(D_s^{*+}Ξ_c^{*})$. The impacts of the $δ(r)$-term in the one-boson-exchange model on these states are presented. Setting $Λ=1.5$ GeV as an illustrative value, it is found that $1/2^-(D_s^{+}Ξ_c)$ is a stable bound state (becoming unstable if turning on the coupling to lower channels), $1/2^-(D_s^{*+}Ξ_c)$ and $3/2^-(D_s^{*+}Ξ_c)$ are physical resonances in both cases of including or excluding the $δ(r)$-term, while the other seven states are physical resonances or ``virtual-state-like" poles near thresholds, depending on including the $δ(r)$-term or not. In addition, the partial decay widths of the physical resonances are provided. These double-charm hidden-strangeness pentaquark states, as the partners of experimentally observed $P_c$ and $P_{cs}$ states, can be searched for in the $D^{(*)}Λ_c$ final states in future.
description: 15 pages, 6 figures, 9 tables
Efficient and affordable catadioptric spectrograph designs for 4MOST and Hector
Creators: name: Saunders, Will
Publisher: name: arXiv
Year: 2014
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Spectrograph costs have become the limiting factor in multiplexed fiber-based spectroscopic instruments, because tens of millions of resolution elements (spectral x spatial) are now required. Catadioptric (Schmidt-like) designs allow faster cameras and hence reduced detector costs, and recent advances in aspheric lens production make the overall optics costs competitive with transmissive designs. Classic Schmidt designs suffer from obstruction losses caused by the detector being within the beam. A new catadioptric design puts the detector close to the spectrograph pupil, and hence largely in the shadow of the telescope top-end obstruction. The throughput is competitive with the best transmissive designs, and much better in the Blue, where it is usually most valuable. The design also has milder aspheres and is more compact than classic Schmidts, and avoids most of their operational difficulties.
description: 13pp, SPIE 9147-223 2014
Supersymmetry, shape invariance and the hypergeometric equation
Creators: name: Das, Ashok K.
name: Kalauni, Pushpa
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: It has been shown earlier that the solubility of the Legendre and the associated Legendre equations can be understood as a consequence of an underlying supersymmetry and shape invariance. We have extended this result to the hypergeometric equation. Since the hypergeometric equation as well as the hypergeometric function reduce to various orthogonal polynomials, this study shows that the solubility of all such systems can also be understood as a consequence of an underlying supersymmetry and shape invariance. Our analysis leads naturally to closed form expressions (Rodrigues' formula) for the orthogonal polynomials.
description: 5 pages