cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Interfaces between buckling phases in Silicene: Ab initio density functional theory calculations
Creators: name: Lima, Matheus P.
name: Fazzio, A.
name: da Silva, Antonio J. R.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The buckled structure of silicene leads to the possibility of new kinds of line defects that separate regions with reversed buckled phases. In the present work we show that these new grain boundaries have very low formation energies, one order of magnitude smaller than grain boundaries in graphene. These defects are stable along different orientations, and they can all be differentiated by STM images. All these defects present local dimerization between the Si atoms, with the formation of $π$-bonds. As a result, these defects are preferential adsorption sites when compared to the pristine region. Thus, the combination of low formation energy and higher reactivity of these defects may be cleverly used to design new nano-structures embedded in silicene.
description: 8 pages, 8 figures
A New Class of Solvable Two-dimensional Scalar Potentials for Graphene
Creators: name: Ioffe, M. V.
name: Nishnianidze, D. N.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In the present paper, a systematic approach is presented for solution of two-dimensional massless Dirac equation with external electrostatic potential applied. This approach is based on the new - asymmetric - form of SUSY-like intertwining relations. It allows to build a wide variety of pairs of SUSY-partner external scalar potentials. If one of them is simple enough to be solvable, its partner is also solvable although it may have a non-trivial dependency on both coordinates. Physically, this kind of problems is related to the description of graphene and some other materials with external potential. Solvability obtained by means of asymmetric form of SUSY intertwining relations allows to extend the class of analytically solvable two-dimensional models.
description: 30 p.p
Anamnesic Neural Differential Equations with Orthogonal Polynomial Projections
Creators: name: De Brouwer, Edward
name: Krishnan, Rahul G.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Neural ordinary differential equations (Neural ODEs) are an effective framework for learning dynamical systems from irregularly sampled time series data. These models provide a continuous-time latent representation of the underlying dynamical system where new observations at arbitrary time points can be used to update the latent representation of the dynamical system. Existing parameterizations for the dynamics functions of Neural ODEs limit the ability of the model to retain global information about the time series; specifically, a piece-wise integration of the latent process between observations can result in a loss of memory on the dynamic patterns of previously observed data points. We propose PolyODE, a Neural ODE that models the latent continuous-time process as a projection onto a basis of orthogonal polynomials. This formulation enforces long-range memory and preserves a global representation of the underlying dynamical system. Our construction is backed by favourable theoretical guarantees and in a series of experiments, we demonstrate that it outperforms previous works in the reconstruction of past and future data, and in downstream prediction tasks.
description: Accepted at ICLR 2023
Joint Task Offloading and Resource Optimization in NOMA-based Vehicular Edge Computing: A Game-Theoretic DRL Approach
Creators: name: Xu, Xincao
name: Liu, Kai
name: Dai, Penglin
name: Jin, Feiyu
name: Ren, Hualing
name: Zhan, Choujun
name: Guo, Songtao
Publisher: name: arXiv
Year: 2022
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Vehicular edge computing (VEC) becomes a promising paradigm for the development of emerging intelligent transportation systems. Nevertheless, the limited resources and massive transmission demands bring great challenges on implementing vehicular applications with stringent deadline requirements. This work presents a non-orthogonal multiple access (NOMA) based architecture in VEC, where heterogeneous edge nodes are cooperated for real-time task processing. We derive a vehicle-to-infrastructure (V2I) transmission model by considering both intra-edge and inter-edge interferences and formulate a cooperative resource optimization (CRO) problem by jointly optimizing the task offloading and resource allocation, aiming at maximizing the service ratio. Further, we decompose the CRO into two subproblems, namely, task offloading and resource allocation. In particular, the task offloading subproblem is modeled as an exact potential game (EPG), and a multi-agent distributed distributional deep deterministic policy gradient (MAD4PG) is proposed to achieve the Nash equilibrium. The resource allocation subproblem is divided into two independent convex optimization problems, and an optimal solution is proposed by using a gradient-based iterative method and KKT condition. Finally, we build the simulation model based on real-world vehicle trajectories and give a comprehensive performance evaluation, which conclusively demonstrates the superiority of the proposed solutions.
A featureless transmission spectrum for the Neptune-mass exoplanet GJ 436b
Creators: name: Knutson, Heather A.
name: Benneke, Björn
name: Deming, Drake
name: Homeier, Derek
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: GJ 436b is a warm-- approximately 800 K--extrasolar planet that periodically eclipses its low-mass (half the mass of the Sun) host star, and is one of the few Neptune-mass planets that is amenable to detailed characterization. Previous observations have indicated that its atmosphere has a methane-to-CO ratio that is 100,000 times smaller than predicted by models for hydrogen-dominated atmospheres at these temperatures. A recent study proposed that this unusual chemistry could be explained if the planet's atmosphere is significantly enhanced in elements heavier than H and He. In this study we present complementary observations of GJ 436b's atmosphere obtained during transit. Our observations indicate that the planet's transmission spectrum is effectively featureless, ruling out cloud-free, hydrogen-dominated atmosphere models with an extremely high significance of 48 sigma. The measured spectrum is consistent with either a high cloud or haze layer located at a pressure of approximately 1 mbar or with a relatively hydrogen-poor (three percent hydrogen and helium mass fraction) atmospheric composition.
description: 23 pages, 12 figures, published in Nature 505, 66 (2014)
Speed of convergence of time Euler schemes for a stochastic 2D Boussinesq model
Creators: name: Bessaih, Hakima
name: Millet, Annie
Publisher: name: arXiv
Year: 2022
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60H15, 60H35, 65M12, 76D03, 76M35

description: We prove that an implicit time Euler scheme for the 2D-Boussinesq model on the torus $D$ converges. Various moment of the $W^{1,2}$-norms of the velocity and temperature, as well as their discretizations, are computed. We obtain the optimal speed of convergence in probability, and a logarithmic speed of convergence in $L^2(Ω)$. These results are deduced from a time regularity of the solution both in $L^2(D)$ and $W^{1,2}(D)$, and from an $L^2(Ω)$ convergence restricted to a subset where the $W^{1,2}$-noms of the solutions are bounded.
NILMTK: An Open Source Toolkit for Non-intrusive Load Monitoring
Creators: name: Batra, Nipun
name: Kelly, Jack
name: Parson, Oliver
name: Dutta, Haimonti
name: Knottenbelt, William
name: Rogers, Alex
name: Singh, Amarjeet
name: Srivastava, Mani
Publisher: name: arXiv
Year: 2014
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Non-intrusive load monitoring, or energy disaggregation, aims to separate household energy consumption data collected from a single point of measurement into appliance-level consumption data. In recent years, the field has rapidly expanded due to increased interest as national deployments of smart meters have begun in many countries. However, empirically comparing disaggregation algorithms is currently virtually impossible. This is due to the different data sets used, the lack of reference implementations of these algorithms and the variety of accuracy metrics employed. To address this challenge, we present the Non-intrusive Load Monitoring Toolkit (NILMTK); an open source toolkit designed specifically to enable the comparison of energy disaggregation algorithms in a reproducible manner. This work is the first research to compare multiple disaggregation approaches across multiple publicly available data sets. Our toolkit includes parsers for a range of existing data sets, a collection of preprocessing algorithms, a set of statistics for describing data sets, two reference benchmark disaggregation algorithms and a suite of accuracy metrics. We demonstrate the range of reproducible analyses which are made possible by our toolkit, including the analysis of six publicly available data sets and the evaluation of both benchmark disaggregation algorithms across such data sets.
description: To appear in the fifth International Conference on Future Energy Systems (ACM e-Energy), Cambridge, UK. 2014
Type Ia Supernova Hubble Residuals and Host-Galaxy Properties
Creators: name: Kim, A. G.
name: Aldering, G.
name: Antilogus, P.
name: Aragon, C.
name: Bailey, S.
name: Baltay, C.
name: Bongard, S.
name: Buton, C.
name: Canto, A.
name: Cellier-Holzem, F.
name: Childress, M.
name: Chotard, N.
name: Copin, Y.
name: Fakhouri, H. K.
name: Feindt, U.
name: Fleury, M.
name: Gangler, E.
name: Greskovic, P.
name: Guy, J.
name: Kowalski, M.
name: Lombardo, S.
name: Nordin, J.
name: Nugent, P.
name: Pain, R.
name: Pecontal, E.
name: Pereira, R.
name: Perlmutter, S.
name: Rabinowitz, D.
name: Rigault, M.
name: Runge, K.
name: Saunders, C.
name: Scalzo, R.
name: Smadja, G.
name: Tao, C.
name: Thomas, R. C.
name: Weaver, B. A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Kim et al. (2013) [K13] introduced a new methodology for determining peak-brightness absolute magnitudes of type Ia supernovae from multi-band light curves. We examine the relation between their parameterization of light curves and Hubble residuals, based on photometry synthesized from the Nearby Supernova Factory spectrophotometric time series, with global host-galaxy properties. The K13 Hubble residual step with host mass is $0.013\pm 0.031$ mag for a supernova subsample with data coverage corresponding to the K13 training; at $\ll 1σ$, the step is not significant and lower than previous measurements. Relaxing the data coverage requirement the Hubble residual step with host mass is $0.045\pm 0.026$ mag for the larger sample; a calculation using the modes of the distributions, less sensitive to outliers, yields a step of 0.019 mag. The analysis of this article uses K13 inferred luminosities, as distinguished from previous works that use magnitude corrections as a function of SALT2 color and stretch parameters: Steps at $>2σ$ significance are found in SALT2 Hubble residuals in samples split by the values of their K13 $x(1)$ and $x(2)$ light-curve parameters. $x(1)$ affects the light-curve width and color around peak (similar to the $Δm_{15}$ and stretch parameters), and $x(2)$ affects colors, the near-UV light-curve width, and the light-curve decline 20 to 30 days after peak brightness. The novel light-curve analysis, increased parameter set, and magnitude corrections of K13 may be capturing features of SN~Ia diversity arising from progenitor stellar evolution.
description: 17 pages, 6 figures. Accepted by Astrophysical Journal
Extreme-scale many-against-many protein similarity search
Creators: name: Selvitopi, Oguz
name: Ekanayake, Saliya
name: Guidi, Giulia
name: Awan, Muaaz G.
name: Pavlopoulos, Georgios A.
name: Azad, Ariful
name: Kyrpides, Nikos
name: Oliker, Leonid
name: Yelick, Katherine
name: Buluç, Aydın
Publisher: name: arXiv
Year: 2023
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: Performance (cs.PF)
subject: Genomics (q-bio.GN)
subject: FOS: Computer and information sciences
subject: FOS: Biological sciences

description: Similarity search is one of the most fundamental computations that are regularly performed on ever-increasing protein datasets. Scalability is of paramount importance for uncovering novel phenomena that occur at very large scales. We unleash the power of over 20,000 GPUs on the Summit system to perform all-vs-all protein similarity search on one of the largest publicly available datasets with 405 million proteins, in less than 3.5 hours, cutting the time-to-solution for many use cases from weeks. The variability of protein sequence lengths, as well as the sparsity of the space of pairwise comparisons, make this a challenging problem in distributed memory. Due to the need to construct and maintain a data structure holding indices to all other sequences, this application has a huge memory footprint that makes it hard to scale the problem sizes. We overcome this memory limitation by innovative matrix-based blocking techniques, without introducing additional load imbalance.
description: 2022 ACM Gordon Bell Prize Finalist
Stellar structure model in the post-Newtonian approximation
Creators: name: Kremer, Gilberto Medeiros
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In this work the influence of the post-Newtonian corrections to the equations of stellar structure is analysed. The post-Newtonian Lane-Emden equation follows from the corresponding momentum density balance equation. From a polytropic equation of state the solutions of the Lane-Endem equations in the Newtonian and post-Newtonian theories are determined and the physical quantities for the \textit{Sun}, for the white dwarf \textit{Sirius B} and for neutron stars with masses $M\simeq1.4M_\odot, 1.8M_\odot$ and $2.0M_\odot$ are calculated. It is shown that the post-Newtonian corrections to the fields of mass density, pressure and temperature are negligible for the \textit{Sun} and \textit{Sirius B}, but for stars with strong fields the differences become important. For the neutron stars analysed here the central pressure and the central temperature which follow from the post-Newtonian Lane-Emden equation are about fifty to sixty percent greater than those of the Newtonian theory and the central mass density is about three to four percent smaller.
description: 8 pages, 3 figures
Out-of-plane and in-plane actuation effects on atomic-scale friction
Creators: name: Fajardo, O. Y.
name: Gnecco, E.
name: Mazo, J. J.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The influence of out-of-plane and in-plane contact vibrations and temperature on the friction force acting on a sharp tip elastically pulled on a crystal surface is studied using a generalized Prandtl- Tomlinson model. The average friction force is significantly lowered in a frequency range determined by the "washboard" frequency of the stick-slip motion and the viscous damping accompanying the tip motion. An approximately linear relation between the actuation amplitude and the effective corrugation of the surface potential is derived in the case of in-plane actuation, extending a similar conclusion for out-of-plane actuation. Temperature causes an additional friction reduction with a scaling relation in formal agreement with the predictions of reaction rate theory in absence of contact vibrations. In this case the actuation effects can be described by the effective energy or, more accurately, by introducing an effective temperature.
description: To appear in Physical Review B
Better Heisenberg limits, coherence bounds, and energy-time tradeoffs via quantum Rényi information
Creators: name: Hall, Michael J. W.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: An uncertainty relation for the Rényi entropies of conjugate quantum observables is used to obtain a strong Heisenberg limit of the form ${\rm RMSE} \geq f(α)/(\langle N\rangle+\frac12)$, bounding the root mean square error of any estimate of a random optical phase shift in terms of average photon number, where $f(α)$ is maximised for non-Shannon entropies. Related simple yet strong uncertainty relations linking phase uncertainty to the photon number distribution, such as $ΔΦ\geq \max_n p_n$, are also obtained. These results are significantly strengthened via upper and lower bounds on the Rényi mutual information of quantum communication channels, related to asymmetry and convolution, and applied to the estimation (with prior information) of unitary shift parameters such as rotation angle and time, and to obtain strong bounds on measures of coherence. Sharper Rényi entropic uncertainty relations are also obtained, including time-energy uncertainty relations for Hamiltonians with discrete spectra. In the latter case almost-periodic Rényi entropies are introduced for nonperiodic systems.
description: 17+8 pages, 1 figure; v2: minor clarifications, close to accepted version
Chemical models of adenine precursors cyanamide and carbodiimide in the interstellar medium
Creators: name: Zhang, Xia
name: Quan, Donghui
name: Li, Runxia
name: Esimbek, Jarken
name: Chen, Long-Fei
name: Zhao, Guoming
name: Zhou, Yan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Cyanamide (NH2CN) and its isomer, carbodiimide (HNCNH), may form adenine in the interstellar medium (ISM) via a series of reactions. Therefore, they are considered key prebiotic molecules in the study of the origin of life. We used the three-phase NAUTILUS chemical code, which includes the gas, the dust surface, and the icy mantle, to investigate the formation and destruction of cyanamide and carbodiimide. We added over 200 new chemical reactions of the two isomers and related species, and established a relatively complete network. We applied cold core, hot corino/core and shock models to simulate the different physical environments, and found that the two isomers are mainly produced by the free radical reactions on grain surfaces. Our simulated results suggest that cyanamide and carbodiimide molecules come from surface chemistry at early evolutionary stages. Then they are released back to the gas phase, either by thermal process (in hot cores, hot corinos) or shock-induced desorption (in shock regions).We speculate that it is an inefficient route to form a tautomer of adenine by starting from molecules cyanoacetylene (C3NH), cyanamide and carbodiimide in ISM.
description: 13 pages, 6 figures, 7 tables, accepted for publication in MNRAS
Importance of Various E-Cigarette Device and E-Liquid Characteristics by Smoking Status among Young Adults Who Vape
Creators: name: Whaley, Reid C.
name: Harlow, Alyssa F.
name: Krueger, Evan A.
name: Stone, Matthew D.
name: Dimofte, Claudiu V.
name: Strong, David R.
name: Barrington-Trimis, Jessica L.
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Science Policy
subject: Plant Biology
subject: FOS: Biological sciences

description: E-cigarette product characteristics are known to influence appeal among young adults. Understanding which characteristics appeal to individuals with (vs. without) a history of combusted tobacco use is essential for developing effective tobacco control policies. Anonymous, self-report data were collected from young adults (18-30 years) who had used e-cigarettes in the past 30 days (n = 295) online via Prolific from September-October 2019. Using a visual analogue scale (range: 0-100), participants rated the importance of ten e-cigarette device and nine e-liquid characteristics. Adjusted linear regression models were used to evaluate the association of combusted tobacco use status (never, former, current) with mean rating scores for each of the nineteen characteristics. The most important e-cigarette device characteristics were price (Mean = 81.1; [SD = 17.9]), size (Mean = 75.5 [SD = 20.9]), and hit strength (Mean = 73.8 [SD = 20.4]) while the most important e-liquid characteristics were flavor (M = 85.1 [SD = 16.3]), price (M = 80.9 [SD = 18.4]), and nicotine level (M = 77.8 [18.9]). Differences by combusted tobacco use status were observed for device brand, temperature/voltage, customizability, color, and popularity, with the highest ratings generally observed among those concurrently using combustible tobacco products. For e-liquids, differences by use status were observed for flavor, price, and bottle type. Notably, those concurrently using combusted products rated flavor as less important than those with no history of combustible tobacco use (B=-5.01[95%CI=-9.97, −0.05]). The self-rated importance of e-cigarette device and e-liquid attributes varies by combustible tobacco use status among young adults which may be used to inform regulatory decisions regarding e-cigarette product characteristics.
Диалог релятивиста с реалистом о релятивистском эффекте «замедления времени»
Creators: name: Плясовских, Александр
Publisher: name: Zenodo
Year: 2024

description: В работе приведен диалог релятивиста с реалистом о релятивистском эффекте «замедления времени». В основу этого диалога положены фрагменты реального обсуждения противоречий, к которым приводит релятивистский эффект «замедления времени». В ходе диалога релятивист попадает в тупик, выбраться из которого он не в состоянии. Суть возникшего противоречия состоит в том, что одно и то же событие происходит одновременно в два совершенно разных момента времени по одним и тем же часам. Этого быть не может. Реалист рассказывает о теории аберрации – первой альтернативной СТО теории, которая подтверждена экспериментально. Именно эту теорию следует использовать для решения практических задач, связанных с движущимися часами, например, задач в области спутниковых навигационных систем.
Quality of service based radar resource management for synchronisation problems
Creators: name: Müller, Tobias
name: Durst, Sebastian
name: Marquardt, Pascal
name: Brüggenwirth, Stefan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: An intelligent radar resource management is an essential building block of any modern radar system. The quality of service based resource allocation model (Q-RAM) provides a framework for profound and quantifiable decision-making but lacks a representation of inter-task dependencies that can e.g. arise for tracking and synchronisation tasks. As a consequence, synchronisation is usually performed in fixed non-optimal patterns. We present an extension of Q-RAM which enables the resource allocation to consider complex inter-task dependencies and can produce adaptive and intelligent synchronisation schemes. The provided experimental results demonstrate a significant improvement over traditional strategies.
description: 4 pages, 6 figures
Scaling behaviour under the influence of a homogeneous size-dependent perturbation
Creators: name: Turban, L.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the finite-size scaling behaviour at the critical point, resulting from the addition of a homogeneous size-dependent perturbation, decaying as an inverse power of the system size. The scaling theory is first formulated in a general framework and then illustrated using three concrete problems for which exact results are obtained.
description: 16 pages, 3 figures
A note on Boolean stochastic processes
Creators: name: Fidaleo, francesco
Publisher: name: arXiv
Year: 2014
Subjects: subject: Operator Algebras (math.OA)
subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60G09, 46L53, 46L05, 46L30, 46N50

description: For the quantum stochastic processes generated by the Boolean Commutation Relations, we prove the following version of De Finetti Theorem: each of such Boolean process is exchangeable if and only if it is independent and identically distributed with respect to the tail algebra.
description: 9 pages
A Comparison of Remote Versus in-Person Assessments of Substance Use and Related Constructs Among Adolescents
Creators: name: Wade, Natasha E.
name: Patel, Herry
name: Pelham, William E.
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Medicine
subject: Pharmacology
subject: Biotechnology
subject: Sociology
subject: FOS: Sociology
subject: Developmental Biology
subject: Mental Health

description: Objective: Underreporting of adolescent substance use is a known issue, with format of assessment (in-person vs. remote) a potentially important factor. We investigate whether being assessed remotely (via phone or videoconference) versus in-person affects youth report of substance use patterns, attitudes, and access, hypothesizing remote visits would garner higher levels of substance use reporting and more positive substance use attitudes. Methods: We used the Adolescent Brain and Cognitive DevelopmentSM [ABCD] Study data between 2021-2022 during the COVID-19 pandemic. Participants chose whether to complete assessments in-person (n=615; 49% female; meanage=13.9; 57% White) or remotely (n=1,467; 49% female, meanage=13.7; 49% White). Regressions predicted substance use patterns, attitudes, and access, by visit format, controlling for relevant sociodemographic factors. Effect sizes and standardized mean differences are presented. Results: 17% of adolescent participants reported any level of substance use. Youth interviewed remotely reported more negative expectancies of alcohol and cannabis. In addition, those queried remotely were less likely to endorse use), sipping alcohol, eating cannabis), and reported less curiosity or intent to try alcohol, though these differences did not survive an adjustment for multiple testing. Effect sizes ranged from small to medium. Conclusions: Preliminary evidence suggests youth completing remote visits were more likely to disclose negative expectancies toward alcohol and cannabis. Effect sizes were modest, though 37 of 39 variables examined trended toward restricted reporting during remote sessions. Thus, format of substance use assessment should be controlled for, but balanced by other study needs (e.g., increasing accessibility of research to all sociodemographic groups).
The UV window on counter rotating ETGs: insight from SPH simulations with chemo-photometric implementation
Creators: name: Bettoni, Daniela
name: Mazzei, Paola
name: Rampazzo, Roberto
name: Marino, Antonina
name: Galletta, Giuseppe
name: Buson, Lucio M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Galaxy Evolution Explorer (GALEX) detected ultraviolet emission in about 50% of multi-spin early-type galaxies (ETGs), suggesting the occurrence of a recent rejuvenation episode connected to the formation of these kinematical features. With the aim at investigating the complex evolutionary scenario leading to the formation of counter rotating ETGs (CR-ETGs) we use our Smooth Particle Hydrodynamic (SPH) code with chemo-photometric implementation. We discuss here the UV evolutionary path of two CR-ETGs, NGC 3593 and NGC 5173, concurrently best fitting their global observed properties, i.e., morphology, dynamics, as well as their total B-band absolute magnitude and spectral energy distribution (SED) extended over three orders of magnitude in wavelength. These simulations correspond to our predictions about the target evolution which we follow in the color-magnitude diagram (CMD), near-UV (NUV) versus r-band absolute magnitude, as a powerful diagnostic tool to emphasize rejuvenation episodes.
description: 7 pages, 3 figures, accepted for publication in ApSS
Multi-GPU thermal lattice Boltzmann simulations using OpenACC and MPI
Creators: name: Xu, Ao
name: Li, Bo-Tao
Publisher: name: arXiv
Year: 2022
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We assess the performance of the hybrid Open Accelerator (OpenACC) and Message Passing Interface (MPI) approach for multi-graphics processing units (GPUs) accelerated thermal lattice Boltzmann (LB) simulation. The OpenACC accelerates computation on a single GPU, and the MPI synchronizes the information between multiple GPUs. With a single GPU, the two-dimension (2D) simulation achieved 1.93 billion lattice updates per second (GLUPS) with a grid number of $8193^{2}$, and the three-dimension (3D) simulation achieved 1.04 GLUPS with a grid number of $385^{3}$, which is more than 76% of the theoretical maximum performance. On multi-GPUs, we adopt block partitioning, overlapping communications with computations, and concurrent computation to optimize parallel efficiency. We show that in the strong scaling test, using 16 GPUs, the 2D simulation achieved 30.42 GLUPS and the 3D simulation achieved 14.52 GLUPS. In the weak scaling test, the parallel efficiency remains above 99% up to 16 GPUs. Our results demonstrated that, with improved data and task management, the hybrid OpenACC and MPI technique is promising for thermal LB simulation on multi-GPUs.
description: 31 pages, 12 figures
Some speculations about local thermalization of nonequilibrium extended quantum systems
Creators: name: Coppola, M.
name: Karevski, D.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We discuss the possibility of defining an emergent local temperature in extended quantum many-body systems evolving out of equilibrium. For the most simple case of free-fermionic systems, we give an explicit formula for the effective temperature in the case of, not necessarily unitary, Gaussian preserving dynamics. In this framework, we consider the hopping fermions on a one-dimensional lattice submitted to randomly distributed projective measurements of the local occupation numbers. We show from the average over many quantum trajectories that the effective temperature relaxes exponentially towards infinity.
description: 13 pages, 1 figure
A Distributed Deadlock Free Quorum Based Algorithm for Mutual Exclusion
Creators: name: Naimi, M.
name: Thiare, O.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: Quorum based mutual exclusion algorithms enjoy many advantages such as low message complexity and high failure resiliency. The use of quorums is a well known approach to achieving mutual exclusion in distributed environments. Several distributed based quorum mutual exclusion was presented.
description: 7 pages, 9 figures
Benestar digital amb perspectiva de gènere
Creators: name: Sáinz Ibáñez, Milagros
Publisher: name: Zenodo
Year: 2024
Subjects: Education
Digital skills
Empowerment
Well-Being
Gender perspective

description: Recurs educatiu sobre benestar i empoderament digital amb perspectiva de gènere, adreçat a professorat i estudiants d’educació secundària.

La publicació s’ha elaborat en el marc del projecte Reto. El projecte d’investigació ha estat impulsat per EduAlter amb el suport financer de l’Agència Catalana de Cooperació al Desenvolupament (ACCD) i ha estat coordinat per Milagros Sáinz, directora del grup Gènere i TIC de l’IN3 a la Universitat Oberta de Catalunya, com a investigadora principal.
Merging of Dirac points through uniaxial modulation on an optical lattice
Creators: name: López, A.
name: Montañes, B.
name: Medina, E.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We analyze the scenario of modulating the potential strength of bound atoms in an optical honeycomb lattice patterned by an electric field to emulate uniaxial strain. This modulation can be achieved by a combination of the strength of the patterned electric field and gauge vector effects using the Floquet approach. We show that such a modulation allows one to follow through a topological transition between a semi-metal and a band insulator, when two non-equivalent $K$ points merge as a function of the electric field strength. We explicitly compute the wavefunctions for the moving $K$ points and the Chern numbers up to the transition. Anisotropic effective masses and the insulating gap are described close to the semimetal-insulator transition.
description: 12 pages, 5 figures
Survey On The Estimation Of Mutual Information Methods as a Measure of Dependency Versus Correlation Analysis
Creators: name: Gencaga, D.
name: Malakar, N. K.
name: Lary, D. J.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences
subject: 94A17

description: In this survey, we present and compare different approaches to estimate Mutual Information (MI) from data to analyse general dependencies between variables of interest in a system. We demonstrate the performance difference of MI versus correlation analysis, which is only optimal in case of linear dependencies. First, we use a piece-wise constant Bayesian methodology using a general Dirichlet prior. In this estimation method, we use a two-stage approach where we approximate the probability distribution first and then calculate the marginal and joint entropies. Here, we demonstrate the performance of this Bayesian approach versus the others for computing the dependency between different variables. We also compare these with linear correlation analysis. Finally, we apply MI and correlation analysis to the identification of the bias in the determination of the aerosol optical depth (AOD) by the satellite based Moderate Resolution Imaging Spectroradiometer (MODIS) and the ground based AErosol RObotic NETwork (AERONET). Here, we observe that the AOD measurements by these two instruments might be different for the same location. The reason of this bias is explored by quantifying the dependencies between the bias and 15 other variables including cloud cover, surface reflectivity and others.
Perceptions of the Addictiveness of Low-Nicotine Cigarettes Versus Typical Cigarettes and Exposure to Tobacco Industry-Sponsored Corrective Campaign
Creators: name: Chido-Amajuoyi, Onyema Greg
name: Mantey, Dale S.
name: Igbinomwanhia, Efehi
name: Omega-Njemnobi, Onyinye
name: Onyeaka, Henry
name: Yu, Robert K.
name: Agaku, Israel
name: Shete, Sanjay
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Science Policy
subject: Mental Health

description: In 2017, the U.S. Food and Drug Administration (FDA) announced a regulatory plan to reduce the nicotine content of cigarettes. This study examines the association of exposure to industry-sponsored corrective statements on perceptions of the addictiveness of low-nicotine cigarettes relative to typical cigarettes within the general US population. The study comprised 4975 US adult respondents of the 2019 Health Information National Trends Survey (HINTS 5, Cycle 3). Multinomial logistic regression models were used to examine associations between exposure to tobacco industry corrective messages and perceptions of the addictiveness of low-nicotine cigarettes relative to typical cigarettes. In the overall population, 4.1% reported that low-nicotine cigarettes were much more addictive than typical cigarettes, 67.5% said they were equally addictive, while 28.4% reported they were slightly/much less addictive. Adults exposed to industry-sponsored corrective messages had higher odds of perceiving low-nicotine cigarettes as equally addictive as typical cigarettes (aOR 1.57; 95% CI, 1.13–2.19) than those who saw no corrective messages. Those exposed to the corrective messages specifically about the addictiveness of smoking and nicotine had higher odds of perceiving low-nicotine cigarettes as equally addictive as typical cigarettes (aOR, 1.73; 95% CI, 1.07–2.81) compared to those who saw no corrective message. Our findings suggest that exposure to court-ordered tobacco industry corrective statements may have reinforced perceptions on the addictive potential of nicotine. However, study findings indicate a need for campaigns specifically tailored to address misperceptions observed in this study. 67.5% of US adults perceived low-nicotine cigarettes and typical cigarettes as being equally addictive Exposure to court-ordered corrective statements increased the odds of equal addictiveness perception Exposure to corrective statements specifically tailored to addiction increased the odds of equal addictiveness perception
Quantifying the LiDAR Sim-to-Real Domain Shift: A Detailed Investigation Using Object Detectors and Analyzing Point Clouds at Target-Level
Creators: name: Huch, Sebastian
name: Scalerandi, Luca
name: Rivera, Esteban
name: Lienkamp, Markus
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: LiDAR object detection algorithms based on neural networks for autonomous driving require large amounts of data for training, validation, and testing. As real-world data collection and labeling are time-consuming and expensive, simulation-based synthetic data generation is a viable alternative. However, using simulated data for the training of neural networks leads to a domain shift of training and testing data due to differences in scenes, scenarios, and distributions. In this work, we quantify the sim-to-real domain shift by means of LiDAR object detectors trained with a new scenario-identical real-world and simulated dataset. In addition, we answer the questions of how well the simulated data resembles the real-world data and how well object detectors trained on simulated data perform on real-world data. Further, we analyze point clouds at the target-level by comparing real-world and simulated point clouds within the 3D bounding boxes of the targets. Our experiments show that a significant sim-to-real domain shift exists even for our scenario-identical datasets. This domain shift amounts to an average precision reduction of around 14 % for object detectors trained with simulated data. Additional experiments reveal that this domain shift can be lowered by introducing a simple noise model in simulation. We further show that a simple downsampling method to model real-world physics does not influence the performance of the object detectors.
Solving optimal control problems with non-smooth solutions using an integrated residual method and flexible mesh
Creators: name: Nita, Lucian
name: Kerrigan, Eric C.
name: Vila, Eduardo M. G.
name: Nie, Yuanbo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: Solutions to optimal control problems can be discontinuous, even if all the functionals defining the problem are smooth. This can cause difficulties when numerically computing solutions to these problems. While conventional numerical methods assume state and input trajectories are continuous and differentiable or smooth, our method is able to capture discontinuities in the solution by introducing time-mesh nodes as decision variables. This allows one to obtain a higher accuracy solution for the same number of mesh nodes compared to a fixed time-mesh approach. Furthermore, we propose to first solve a sequence of suitably-defined least-squares problems to ensure that the error in the dynamic equation is below a given tolerance. The cost functional is then minimized subject to an inequality constraint on the dynamic equation residual. We demonstrate our implementation on an optimal control problem that has a chattering solution. Solving such a problem is difficult, since the solution involves infinitely many switches of decreasing duration. This simulation shows how the flexible mesh is able to capture discontinuities present in the solution and achieve superlinear convergence as the number of mesh intervals is increased.
description: 6 pages
La perspectiva de género en el ámbito escolar
Creators: name: Sáinz Ibáñez, Milagros
Publisher: name: Zenodo
Year: 2024
Subjects: Education
Gender perspective
Digital skills
Empowerment

description: Recurso educativo sobre empoderamiento digital con perspectiva de género, dirigido a profesorado y a estudiantes de educación secundaria.

La publicación se ha elaborado en el marco del proyecto Reto. El proyecto de investigación ha sido impulsado por EduAlter con el apoyo financiero de la Agencia Catalana de Cooperación al Desarrollo (ACCD) y ha estado coordinado por Milagros Sáinz, directora del grupo Género y TIC del IN3 en la Universitat Oberta de Catalunya, como investigadora principal.
Nonlinear optomechanical pressure
Creators: name: Conti, Claudio
name: Boyd, Robert
Publisher: name: arXiv
Year: 2014
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A transparent material exhibits ultra-fast optical nonlinearity and is subject to optical pressure if irradiated by a laser beam. However, the effect of nonlinearity on optical pressure is often overlooked, even if a nonlinear optical pressure may be potentially employed in many applications, as optical manipulation, biophysics, cavity optomechanics, quantum optics, optical tractors, and is relevant in fundamental problems as the Abraham-Minkoswky dilemma, or the Casimir effect. Here we show that an ultra-fast nonlinear polarization gives indeed a contribution to the optical pressure that also is negative in certain spectral ranges; the theoretical analysis is confirmed by first-principles simulations. An order of magnitude estimate shows that the effect can be observable by measuring the deflection of a membrane made by graphene.
description: 10 pages, 6 figures, minor corrections to text and references, Physical Review A, to be published
Panoramic Spectroscopy of Galaxies with Star-formation Regions. A Study of SBS 1202+583
Creators: name: Hakopian, S. A.
name: Balayan, S. K.
name: Dodonov, S. N.
name: Moiseev, A. V.
name: Smirnova, A. A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The methods of panoramic (3D) spectroscopy are used in a detailed study of galaxies with ongoing star formation chosen from among objects in seven selected fields of the Second Byurakan Survey (SBS). This article deals with the irregular galaxy SBS 1202+583, which our classification scheme identifies as being in a continuous phase of starformation. Observations were made with the panoramic spectrographs MPFS at the 6-m telescope of the Special Astrophysical Observatory (SAO) of the Russian Academy of Sciences and VAGR at the 2.6-m telescope of the Byurakan Astrophysical Observatory (BAO) in Armenia. The data are used to construct charts of the radiative fluxes in the continuum and various emission lines. Special attention is devoted to analyzing the emission in the Hα hydrogen recombination line and in the forbidden low-ionization doublets of nitrogen [NII]λλ6548, 6583 and sulfur [SII]λλ 6716,6731, and the ratios of the intensities of the forbidden lines to Hα. The observable characteristics (sizes, Hα fluxes, etc.) of nine HII regions are studied. The estimated current rates of starformation in the individual HII regions based on the Hα fluxes lie within the range of 0.3-1.2 Msun/year. The dependence of the ratio of the intensities of the emission in these two forbidden doublets on the rate of star formation in the HII regions is found.
description: 13 pages,8 figures and 3 tables
Spin-wave Resonance in Arrays of Nanoscale Synthetic-antiferromagnets
Creators: name: Borynskyi, Vladyslav
name: Polishchuk, Dmytro
name: Sharai, Iryna
name: Melnyk, Andrii
name: Kravets, Anatolii
name: Tovstolytkin, Alexandr
name: Korenivski, Vladislav
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The study concerns dynamics of standing spin waves in arrays of sub-100 nm elliptic synthetic-antiferromagnet (SAF) nanodisks. We performed a detailed ferromagnetic resonance analysis in conjunction with micromagnetic modeling to find out several prominent traits of such systems. One broad line is shown to be the sole resonant response for a SAF of the considered sizes. We demonstrate that this mode is degenerated, and its excitation map resembles a superposition of in-center and edge-type oscillations. We also show how this hybrid excitation leads to almost twofold enhancement in the shape-induced anisotropy of the mode.
description: 3 pages, 1 figure, submitted to 2022 IEEE 12th International Conference Nanomaterials: Applications & Properties (NAP)
La perspectiva de gènere en l'àmbit escolar
Creators: name: Sáinz Ibáñez, Milagros
Publisher: name: Zenodo
Year: 2024
Subjects: Education
Gender perspective
Digital skills
Empowerment

description: Recurs educatiu sobre empoderament digital amb perspectiva de gènere, adreçat a professorat i estudiants d’educació secundària.

La publicació s’ha elaborat en el marc del projecte Reto. El projecte d’investigació ha estat impulsat per EduAlter amb el suport financer de l’Agència Catalana de Cooperació al Desenvolupament (ACCD) i ha estat coordinat per Milagros Sáinz, directora del grup Gènere i TIC de l’IN3 a la Universitat Oberta de Catalunya, com a investigadora principal.
Expanding the Grammar of Biology
Creators: name: Yamagishi, Michel Eduardo Beleza
name: Herai, Roberto Hirochi
Publisher: name: arXiv
Year: 2013
Subjects: subject: Genomics (q-bio.GN)
subject: FOS: Biological sciences

description: We metaphorically call "Grammar of Biology" a small field of genomic research, whose main objective is to search for intrinsic DNA sequence properties. Erwin Chargaff inaugurated it back in 50s, but since then little progress has been made. It remained almost neglected until early 90s, when Vinayakumar V. Prabhu made a major contribution determining the Symmetry Principle. Remarkably, different sciences have contributed for its development, for instance, Chargaff used his Chemistry background to discover the so-called Chargaff's rules; taking advantage of several publicly available genomic sequences, and through Computational and Statistical analyses, Prabhu identified the Symmetry Principle and, recently, using a Mathematical approach, we have discovered four new Generalized Chargaff's rules. Our work has expanded the "Grammar of Biology", and created the conceptual and theoretical framework necessary to further developments.
description: 9 pages, 1 figure