cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Searching for photon-ALPs mixing effects in AGN gamma-ray energy spectra
Creators: name: Yu, Qixin
name: Horns, Dieter
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: High energy gamma-rays propagating in external magnetic fields may convert into axion-like particles (ALPs). In this case, the observed gamma-ray spectra are modified by the resulting energy-dependent conversion probability. In this study, we use the energy spectra of 20 extra-galactic gamma-ray sources recorded during 10 years of \textit{Fermi}-LAT observations. We define a test statistics based upon the likelihood ratio to test the hypothesis for a spectral model without vs. a model with photon-ALPs coupling. The conversion probability is calculated for fixed values of the mass and two-photon coupling of the pseudo-scalar particle while the external magnetic field is characterized by the additional free parameters length scale $s$ and average field strength $B$. As a consistency check and in order to extend the analysis to include very high energy gamma-ray data, another test statistics is defined with the $χ^2$ method. We find for 18 of the 20 sources a favorable fit, particularly for Markarian~421 and NGC~1275 a significant improvement, with the hypothesis of photon-ALPs coupling in likelihood analysis. The test statistics of the sources are combined and the significance has been estimated $5.3~σ$ (test statistics summed in local maxima of all sources) and $6.0~σ$ (global maxima). The significance is estimated from dedicated simulations under the null hypotheses. The locally best-fitting values of $B$ and $s$ fall into the range that is expected for large scale magnetic fields present in relevant astrophysical environments.
description: 40pages, 45figures
title: Gewölbe eingestürzt: Was nun? Von der Theorie zur Stabilisierung des historischen Chorgewölbes der ehemaligen Jesuitenkirche St.Konrad in Konstanz
Creators: name: Falz, Thomas
name: Bergmann, Norbert
Publisher: name: University Library Heidelberg
Year: 2014

description: Denkmalpflege in Baden-Württemberg – Nachrichtenblatt der Landesdenkmalpflege, Bd. 43, Nr. 4 (2014), Beginn und Erscheinungsfrequenz: Ausgaben pro Band: 4
Field induced large magnetocaloric effect and magnetoresistance in ErNiSi
Creators: name: Gupta, Sachin
name: Rawat, R.
name: Suresh, K. G.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Large magnetocaloric effect (MCE) and magnetoresistance (MR) together with negligible hysteresis loss has been observed in ErNiSi compound, which undergoes metamagnetic transition at low temperatures. Magnetization, heat capacity and resistivity measurements confirm the metamagnetic transition. The maximum value of isothermal entropy change and MR for a field change of 50 kOe are found to be 19.1 J/kg K and -34 %. Large MCE with negligible magnetic hysteresis loss could make this material promising for low temperature magnetic refrigeration.
description: 12 pages, 5 figures
Dark Matter Phase Transition Constrained at O(0.1) eV with LSB Rotation Curves
Creators: name: Mastache, Jorge
name: de la Macorra, Axel
name: Cervantes-Cota, Jorge L.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences
subject: J.2
subject: 85-06

description: In order to unravel the nature of the dark matter (DM) we have proposed a particle-physics motivated model called Bound Dark Matter (BDM) that consist in DM massless particles above a threshold energy Ec that acquire mass below it due to nonperturbative methods. Therefore, the BDM model describes DM particles which are relativistic, hot dark matter (HDM) in the denser (inner) regions of galaxies and describes nonrelativistic, cold dark matter (CDM) where halo density is below rho_c = Ec^4. We test this model by fitting rotation curves from Low Surface Brightness (LSB) galaxies from The HI Nearby Galaxy Survey (THINGS). We use a particular DM cored profile that contains three parameters: a typical scale length (rs) and density (rho_0) of the halo, and a core radius (rc) stemming from the relativistic nature of the BDM model. Since the energy Ec parameterizes the phase transition due to the underlying particle physics model, it is independent on the details of galaxy and/or structure formation and therefore the DM profile parameters rs, rc, Ec are constrained, leaving only two free parameters. Through the results we agree with previous ones implying that cored profiles are preferred over the N-body motivated cuspy profiles. We also compute 2D likelihoods of the BDM parameters rc and Ec for the different galaxies and matter contents, and find an average galaxy core radius rc = 1.48kpc and a transition energy between hot and cold dark matter at Ec = 0.06 eV. The phase transition scale Ec is a new fundamental scale for our DM model well motivated theoretical origin from gauge group dynamics.
description: 6 pages, 2 figures, Conference 8th International Workshop on the Dark Side of the Universe : DSU 2012. CNUM: C12-06-10
Ferroelectric control of charge-to-spin conversion in WTe$_{2}$
Creators: name: Jafari, Homayoun
name: Roy, Arunesh
name: Sławińska, Jagoda
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Ferroelectric materials hold great potential for alternative memories and computing, but several challenges need to be overcome before bringing the ideas to applications. In this context, the recently discovered link between electric polarization and spin textures in some classes of ferroelectrics expands the perspectives of the design of devices that could simultaneously benefit from ferroelectric and spintronic properties. Here, we explore the concept of non-volatile ferroelectric control of charge-to-spin conversion in semimetallic WTe$_2$, which may provide a way for non-destructive read-out of the polar state. Based on the first-principles simulations, we show that the Rashba-Edelstein effect (REE) that converts electric currents into spin accumulation switches its sign upon the reversal of the electric polarization. The numerical values of REE, calculated for the first time for both bulk and bilayer WTe$_2$, demonstrate that the conversion is sizable, and may remain large even at room temperature. The ferroelectric control of spin transport in non-magnetic materials provides functionalities similar to multiferroics and allows the design of memories or logic-in-memory devices that combine ferroelectric writing of information at low power with the spin-orbit read-out of state.
Temperature Effects on Brain Tissue in Compression
Creators: name: Rashid, Badar
name: Destrade, Michel
name: Gilchrist, Michael
Publisher: name: arXiv
Year: 2013
Subjects: subject: Medical Physics (physics.med-ph)
subject: Biological Physics (physics.bio-ph)
subject: Tissues and Organs (q-bio.TO)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Extensive research has been carried out for at least 50 years to understand the mechanical properties of brain tissue in order to understand the mechanisms of traumatic brain injury (TBI). The observed large variability in experimental results may be due to the inhomogeneous nature of brain tissue and to the broad range of test conditions. However, test temperature is also considered as one of the factors influencing the properties of brain tissue. In this research, the mechanical properties of porcine brain have been investigated at 22C (room temperature) and at 37C (body temperature) while maintaining a constant preservation temperature of approximately 4-5C. Unconfined compression tests were performed at dynamic strain rates of 30 and 50/s using a custom made test apparatus. There was no significant difference (p = 0.8559 - 0.9290) between the average engineering stresses of the brain tissue at the two different temperature conditions. The results of this study should help to understand the behavior of brain tissue at different temperature conditions, particularly in unconfined compression tests.
description: arXiv admin note: text overlap with arXiv:1302.4535
The electrodynamic origin of the wave-particle duality
Creators: name: López, Álvaro García
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A derivation of pilot waves from electrodynamic self-interactions is presented. For this purpose, we abandon the current paradigm that describes electrodynamic bodies as point masses. Beginning with the Liénard-Wiechert potentials, and assuming that inertia has an electromagnetic origin, the equation of motion of a nonlinear time-delayed oscillator is obtained. We analyze the response of the uniform motion of the electromagnetic charged extended particle to small perturbations, showing that very violent oscillations are unleashed as a result. The frequency of these oscillations is intimately related to the zitterbewegung frequency appearing in Dirac's relativistic wave equation. Finally, we compute the self-energy of the particle. Apart from the rest and the kinetic energy, we uncover a new contribution presenting the same fundamental physical constants that appear in the quantum potential.
DATA.doc
Creators: name: Azad, Yashpal
name: Rani, Komal
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 520102
subject: Educational psychology
classificationCode: 520505
subject: Social psychology
classificationCode: 520303
subject: Counselling psychology
classificationCode: 520304
subject: Health psychology

description: This study aims to explore the impact of gender and depression on the academic performance and psychological well-being of college students in the Sirmaur district of Himachal Pradesh, India. Utilizing a 2×2 factorial design, the research investigated a randomly selected sample of N=120 college students (60 boys; 60 girls) enrolled in their second and third years of graduation courses.
title: Ein „buntes“ Programm. Denkmalreise und Tag des offenen Denkmals 2014
Creators: name: Koltermann, Grit
name: Plein, Irene
name: Prier, Linda
Publisher: name: University Library Heidelberg
Year: 2014

description: Denkmalpflege in Baden-Württemberg – Nachrichtenblatt der Landesdenkmalpflege, Bd. 43, Nr. 4 (2014), Beginn und Erscheinungsfrequenz: Ausgaben pro Band: 4
Importance sampling for the simulation of reinsurance losses
Creators: name: Hofmann, Georg
Publisher: name: arXiv
Year: 2013
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Importance sampling is a well developed method in statistics. Given a random variable $X$, the problem of estimating its expected value $μ$ is addressed. The standard approach is to use the sample mean as an estimator $\bar x$. In importance sampling, a suitable variable $L$ is introduced such that the random variable $X/L$ has an estimator with a smaller variance than that of $\bar x$. As a result, a smaller sample size can lead to the same estimation accuracy. In the simulation of reinsurance financial terms for catastrophe loss, choosing a general variable $L$ is difficult: Even before the application of financial terms, the loss distribution is often not modelled by a closed-form distribution. After that, a wide range of financial terms can be applied that makes the final distribution unpredictable. However, it is evident that the heavy tail of the resulting net loss distribution makes the use of importance sampling desirable. We propose an importance sampling technique using a power function transformation on the cumulative distribution function. The benefit of this technique is that no prior knowledge of the loss distribution is required. It is a new technique that has not been documented in the literature. The transformation depends on the choice of the exponent $k$. For a specific example we investigate desirable values of $k$.
title: Das Martyrium des hl. Sebastian in Original und Kopie. Die Sebastianuskapelle in Tauberbischofsheim schmücken fortan zwei gleiche Reliefs
Creators: name: Breuer, Judith
Publisher: name: University Library Heidelberg
Year: 2014

description: Denkmalpflege in Baden-Württemberg – Nachrichtenblatt der Landesdenkmalpflege, Bd. 43, Nr. 4 (2014), Beginn und Erscheinungsfrequenz: Ausgaben pro Band: 4
SPICA-FT: The new fringe tracker of the CHARA array
Creators: name: Pannetier, Cyril
name: Berio, Philippe
name: Mourard, Denis
name: Rousseau, Sylvain
name: Allouche, Fatme
name: Dejonghe, Julien
name: Bailet, Christophe
name: Lecron, Daniel
name: Cassaing, Frédéric
name: Bouquin, Jean-Baptiste Le
name: Perraut, Karine
name: Monnier, John D.
name: Anugu, Narsireddy
name: Brummelaar, Theo ten
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: SPICA-FT is part of the CHARA/SPICA instrument which combines a visible 6T fibered instrument (SPICAVIS) with a H-band 6T fringe sensor. SPICA-FT is a pairwise ABCD integrated optics combiner. The chip is installed in the MIRC-X instrument. The MIRC-X spectrograph could be fed either by the classical 6T fibered combiner or by the SPICA-FT integrated optics combiner. SPICA-FT also integrates a dedicated fringe tracking software, called the opd-controller communicating with the main delay line through a dedicated channel. We present the design of the integrated optics chip, its implementation in MIRC-X and the software architecture of the group-delay and phase-delay control loops. The final integrated optics chip and the software have been fully characterized in the laboratory. First on-sky tests of the integrated optics combiner began in 2020. We continue the on-sky tests of the whole system (combiner + software) in Spring and Summer 2022. We present the main results, and we deduce the preliminary performance of SPICA-FT.
On multiplicative functions with small partial sums
Creators: name: Sachpazis, Stelios
Publisher: name: arXiv
Year: 2022
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11N37, 11N56, 11N64

description: In analytic number theory, several results make use of information regarding the prime values of a multiplicative function in order to extract information about its averages. Examples of such results include Wirsing's theorem and the Landau-Selberg-Delange method. In this paper, we are interested in the opposite direction. In particular, we prove that when $f$ is a suitable divisor-bounded multiplicative function with small partial sums, then $f(p)\approx-p^{iγ_1}-\ldots-p^{iγ_m}$ on average, where the $γ_j$'s are the imaginary parts of the zeros of the Dirichet series of $f$ on the line $\Re(s)=1$. This extends a result of Koukoulopoulos and Soundararajan and it builds upon ideas coming from previous work of Koukoulopoulos for the case where $|f|\leqslant 1$.
description: 22 pages; A few typos were corrected and part of Section 2 has been rewritten
Feasibility, Efficiency, and Robustness of Secure Computation
Creators: name: Nguyen, Hai H
Publisher: name: Purdue University Graduate School
Year: 2022
Subjects: Cryptography

description: Secure computation allows mutually distrusting parties to compute over private data. Such collaborations have widespread applications in social, scientific, commercial, and security domains. However, the overhead of achieving security is a major bottleneck to the adoption of such technologies. In this context, this thesis aims to design the most secure protocol within budgeted computational or network resources by mathematically formulating it as an optimization problem. With the rise in CPU power and cheap RAM, the offline-online model for secure computation has become the prominent model for real-world security systems. This thesis investigates the above-mentioned optimization problem in the information-theoretic offline-online model. In particular, this thesis presents the following selected sample of our research in greater detail. Round and Communication Complexity: Chor-Kushilevitz-Beaver characterized the round and communication complexity of secure two-party computation. Since then, the case of functions with randomized output remained unexplored. We proved the decidability of determining these complexities. Next, if such a protocol exists, we construct the optimal protocol; otherwise, we present an obstruction to achieving security. Rate and Capacity of secure computation: The efficiency of converting the offline samples into secure computation during the online phase is essential. However, investigating this ``production rate'' for general secure computations seems analytically intractable. Towards this objective, we introduce a new model of secure computation -- one without any communication -- that has several practical applications. We lay the mathematical foundations of formulating rate and capacity questions in this framework. Our research identifies the first tight rate and capacity results (a la Shannon) in secure computation. Reverse multiplication embedding: We identify a new problem in algebraic complexity theory that unifies several efficiency objectives in cryptography. Reverse multiplication embedding seeks to implement as many (base field) multiplications as possible using one extension field multiplication. We present optimal construction using algebraic function fields. This embedding has subsequently led to efficient improvement of secure computation, homomorphic encryption, proof systems, and leakage-resilient cryptography. Characterizing the robustness to side-channel attacks: Side-channel attacks present a significant threat to the offline phase. We introduce the cryptographic analog of common information to characterize the offline phase's robustness quantitatively. We build a framework for security and attack analysis. In the context of robust threshold cryptography, we present a state-of-the-art attack, threat assessment, and security fix for Shamir's secret-sharing.
k-Nearest Neighbor with Map Reduce MPI
Creators: name: Saule, Erik
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 460607
subject: High performance computing

description: Contribution for Peachy Assignment presented at EduHPC 2023; see https://tcpp.cs.gsu.edu/curriculum/?q=peachy for the assignment repository.Assignment to implement k-nearest neighbor in map reduce paradigm on top of MPI.
Understanding the stochastic dynamics of sequential decision-making processes: A path-integral analysis of multi-armed bandits
Creators: name: Li, Bo
name: Yeung, Chi Ho
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Physics and Society (physics.soc-ph)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: The multi-armed bandit (MAB) model is one of the most classical models to study decision-making in an uncertain environment. In this model, a player chooses one of $K$ possible arms of a bandit machine to play at each time step, where the corresponding arm returns a random reward to the player, potentially from a specific unknown distribution. The target of the player is to collect as many rewards as possible during the process. Despite its simplicity, the MAB model offers an excellent playground for studying the trade-off between exploration versus exploitation and designing effective algorithms for sequential decision-making under uncertainty. Although many asymptotically optimal algorithms have been established, the finite-time behaviors of the stochastic dynamics of the MAB model appear much more challenging to analyze, due to the intertwine between the decision-making and the rewards being collected. In this paper, we employ techniques in statistical physics to analyze the MAB model, which facilitates the characterization of the distribution of cumulative regrets at a finite short time, the central quantity of interest in an MAB algorithm, as well as the intricate dynamical behaviors of the model. Our analytical results, in good agreement with simulations, point to the emergence of an interesting multimodal regret distribution, with large regrets resulting from excess exploitation of sub-optimal arms due to an initial unlucky output from the optimal one.
Dynamical synchronization, the horizon problem, and initial conditions for inflation
Creators: name: Cotsakis, Spiros
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider the evolution of homogeneous cosmologies towards the future in a dynamical systems formulation. Using a variational equation approach, we show that there is a short period in which transient solutions between the end of a Mixmaster era and a subsequent Friedmannian state exist. Implications about the generic inhomogeneous evolution towards the future, the recollapse problem, the horizon problem, and the initial conditions required for inflation are briefly discussed.
description: v2: final version to appear in LHEP, new results and explanations added, slightly different title
K-means clustering: An assignment for OpenMP, MPI, and CUDA/OpenCL
Creators: name: García-Álvarez, Diego
name: Gonzalez-Escribano, Arturo
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 460607
subject: High performance computing

description: Contribution for Peachy Assignment presented at EduHPC 2023; see https://tcpp.cs.gsu.edu/curriculum/?q=peachy for the assignment repository.Assignment implementing k-means clustering in any/all of OpenMP, MPI, and CUDA.
Kondo effect in monolayer and bilayer graphene: physical realizations of the multi-channel Kondo models
Creators: name: Kharitonov, Maxim
name: Kotliar, Gabriel
Publisher: name: arXiv
Year: 2013
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We perform a general group-theoretical study of the Kondo problem in monolayer and bilayer graphene around the charge neutrality point. Utilizing the group representation theory, we derive from symmetry considerations a family of the Kondo models for all symmetric placements with either 3- or 6-fold rotational axis of an impurity atom in an arbitrary orbital state. We find six possible classes of the partially anisotropic four-channel Kondo model. As the key result, we argue several possibilities to realize the regime of the dominant channel-symmetric two-channel Kondo effect, protected by the local symmetry and specifics of the graphene band structure. Our findings open prospects for the observation of the rich multi-channel Kondo physics in graphene and the associated non-Fermi-liquid behavior.
description: 5 pages main text, 3 pages supplementary material, 1 fig
Resetting mediated navigation of active Brownian searcher in a homogeneous topography
Creators: name: Sar, Gourab Kumar
name: Ray, Arnob
name: Ghosh, Dibakar
name: Hens, Chittaranjan
name: Pal, Arnab
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Physical sciences

description: Designing navigation strategies for search time optimization remains of interest in various interdisciplinary branches in science. In here, we focus on microscopic self-propelled searchers namely active Brownian walkers in noisy and confined environment which are mediated by one such autonomous strategy namely resetting. As such, resetting stops the motion and compels the walkers to restart from the initial configuration intermittently according to an external timer that does not require control by the walkers. In particular, the resetting coordinates are either quenched (fixed) or annealed (fluctuating) over the entire topography. Although the strategy relies upon simple rules, it shows a significant ramification on the search time statistics in contrast to the original search. We show that the resetting driven protocols mitigate the performance of these active searchers based, robustly, on the inherent search time fluctuations. Notably, for the annealed condition, resetting is always found to expedite the search process. These features, as well as their applicability to more general optimization problems starting from queuing systems, computer science to living systems, make resetting based strategies universally promising.
Dispersive Friedmann universes and synchronization
Creators: name: Cotsakis, Spiros
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We introduce consideration of dispersive aspects of standard perfect fluid Friedmann cosmology and study the new qualitative behaviours of cosmological solutions that emerge as the fluid parameter changes and zero eigenvalues appear in the linear part of the Friedmann equations. We find that due to their insufficient degeneracy, the Milne, flat, Einstein-static, and de Sitter solutions cannot properly bifurcate. However, the dispersive versions of Milne and flat universes contained in the versal unfolding of the standard Friedmann equations possess novel long-term properties not met in their standard counterparts. We apply these results to the horizon problem and show that unlike their hyperbolic versions, the dispersive Milne and flat solutions completely synchronize in the future, hence offering a solution to the homogeneity, isotropy, and causal connectedness puzzles.
description: v3: 64 pages, fully expanded version to appear in Gen. Rel. Grav., added explanations and new results, slightly changed title
Near infrared and gamma-ray monitoring of TANAMI gamma-ray bright sources
Creators: name: Nesci, R.
name: Tosti, G.
name: Pursimo, T.
name: Ojha, R.
name: Kadler, M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Spectral energy distribution and its variability are basic tools for understanding the physical processes operating in active galactic nuclei (AGN). In this paper we report the results of a one-year near infra red (NIR) and optical monitoring of a sample of 22 AGN known to be gamma-ray emitters, aimed at discovering correlations between optical and gamma-ray emission. We observed our objects with the Rapid Eye Mount (REM) telescope in J, H, K, and R bands nearly twice every month during their visibility window and derived light curves and spectral indexes. We also analyzed the gamma-ray data from the Fermi gamma-ray Space Telescope, making weekly averages. Six sources were never detected during our monitoring, proving to be fainter than their historical Two micron all sky survey (2MASS) level. All of the sixteen detected sources showed marked flux density variability, while the spectral indexes remained unchanged within our sensitivity limits. Steeper sources showed, on average, a larger variability. From the NIR light curves we also computed a variability speed index for each detected source. Only one source (PKS 0208-512) underwent an NIR flare during our monitoring. Half of the sources showed a regular flux density trend on a one-year time scale, but do not show any other peculiar characteristic. The broadband spectral index alpha_ro appears to be a good proxy of the NIR spectral index only for BL Lac objects. No clear correlation between NIR and gamma-ray data is evident in our data, save for PKS 0537-441, PKS 0521-360, PKS 2155-304, and PKS 1424-418. The gamma-ray/NIR flux ratio showed a large spread, QSO being generally gamma-louder than BL Lac, with a marked correlation with the estimated peak frequency nu_peak of the synchrotron emission.
description: accepted for Astronomy and Astrophysics, 6 pages, 5 figures
Reducing molecular electronic Hamiltonian simulation cost for Linear Combination of Unitaries approaches
Creators: name: Loaiza, Ignacio
name: Khah, Alireza Marefat
name: Wiebe, Nathan
name: Izmaylov, Artur F.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We consider different Linear Combination of Unitaries (LCU) decompositions for molecular electronic structure Hamiltonians. Using these LCU decompositions for Hamiltonian simulation on a quantum computer, the main figure of merit is the 1-norm of their coefficients, which is associated with the quantum circuit complexity. It is derived that the lowest possible LCU 1-norm for a given Hamiltonian is half of its spectral range. This lowest norm decomposition is practically unattainable for general Hamiltonians; therefore, multiple practical techniques to generate LCU decompositions are proposed and assessed. A technique using symmetries to reduce the 1-norm further is also introduced. In addition to considering LCU in the Schrödinger picture, we extend it to the interaction picture, which substantially further reduces the 1-norm.
Soil microbial biomass C, N in biocrust: A meta-analysis
Creators: name: Tian, Chang
Publisher: name: Zenodo
Year: 2022

description: The biological soil crust (biocrust) has many crucial ecological functions in dryland ecosystems. Differentiation of soil microbial biomass in different ecosystems' biocrust under various climatic and soil conditions remains unknown, restricting our knowledge of biocrust microbiomes regulating terrestrial carbon and nitrogen cycling globally. We selected 255 paired observations from 45 global study sites for meta-analysis to quantify the effect of biocrust type, soil texture, and ecosystem type on soil microbial biomass in biocrust and identify the underlying impact factors. The results showed that biocrust had significantly higher soil microbial carbon and nitrogen contents (SMBC and SMBN, respectively) than bare (non-crust) soil (P < 0.05). Biocrust also significantly increased total nitrogen (TN) (143.68%), soil organic carbon (SOC) and TN ratio (C: N) (9.93%), and soil water content (SWC) (60.18%), and decreased pH (0.72%) (P < 0.05). Overall, the SMBC significantly differed between biocrust type, ecosystem type, and soil texture (P < 0.05). Compared with other biocrust types, lichen crust had the strongest positive effect on SMBC (822.48%). Grassland ecosystems had stronger positive effects on SMBC in biocrust than forest ecosystems, and sand and sandy loam soils had higher SMBC in biocrust than loam soils. Notably, altitude drives the positive effects of biocrust on SMBN and the negative effects of biocrust on SMBC and SMBC and SMBN ratio (SMBC: SMBN). Mean annual temperature (MAT) positively affected SMBC based on regression analysis. Further analysis revealed that SMBC and SMBN positively correlated with SOC, C: N, SWC, and urease activity and negatively correlated with pH. The random forest analysis confirmed that SOC, C: N, and altitude could be considered determinants of SMBC, SMBN, and SMBC: SMBN, respectively. Climatic factors and soil nutrients differently affected soil microbial biomass C, N and their ratio in biocrust. The high contribution of lichen crust to SMBC should be incorporated into regional and global models to predict the effects of climate change on soil carbon budgets in ecosystems worldwide.
description: Funding provided by: National Natural Scientific Foundation of China*
Crossref Funder Registry ID:
Award Number: Funding provided by: National Key Research and Development Program of China
Crossref Funder Registry ID: http://dx.doi.org/10.13039/501100012166
Award Number:
Extracting Medication Changes in Clinical Narratives using Pre-trained Language Models
Creators: name: Ramachandran, Giridhar Kaushik
name: Lybarger, Kevin
name: Liu, Yaya
name: Mahajan, Diwakar
name: Liang, Jennifer J.
name: Tsou, Ching-Huei
name: Yetisgen, Meliha
name: Uzuner, Özlem
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: An accurate and detailed account of patient medications, including medication changes within the patient timeline, is essential for healthcare providers to provide appropriate patient care. Healthcare providers or the patients themselves may initiate changes to patient medication. Medication changes take many forms, including prescribed medication and associated dosage modification. These changes provide information about the overall health of the patient and the rationale that led to the current care. Future care can then build on the resulting state of the patient. This work explores the automatic extraction of medication change information from free-text clinical notes. The Contextual Medication Event Dataset (CMED) is a corpus of clinical notes with annotations that characterize medication changes through multiple change-related attributes, including the type of change (start, stop, increase, etc.), initiator of the change, temporality, change likelihood, and negation. Using CMED, we identify medication mentions in clinical text and propose three novel high-performing BERT-based systems that resolve the annotated medication change characteristics. We demonstrate that our proposed systems improve medication change classification performance over the initial work exploring CMED.
Countable strongly annihilated ideals in commutative rings
Creators: name: Mohamadian, Rostam
Publisher: name: arXiv
Year: 2022
Subjects: subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics

description: In this paper we introduce and study the concept of countable strongly annihilated ideal in commutative rings, in particular in rings of continuous functions. We show that a maximal ideal in $C(X)$ is countable strongly annihilated if and only if it is a real maximal $z^\circ$-ideal. It turns out that $X$ is an almost $P$-space if and only if countable strongly annihilated ideals and strongly divisible $z$-ideals coincide if and only if every $M_x$ is a countable strongly annihilated ideal, for any $x\in X$. We observe that an almost $P$-space $X$ is Lindelof if and only if every countable strongly annihilated ideal is fixed. We give a negative answer to a question raised by Gilmer and McAdam.
description: Example 3.1 in this article is given by Dr. A. Azarang. This example gives a negative answer to Question 4 of Gilmer R., McAdam S.: Ideals contracted from each extension ring. Comm. Alg. 7, 287{311 (1979)
title: A Scenario-Based Model Comparison for Short-Term Day-Ahead Electricity Prices in Times of Economic and Political Tension
Creators: name: Baskan, Denis E.
name: Meyer, Daniel
name: Mieck, Sebastian
name: Faubel, Leonhard
name: Klöpper, Benjamin
name: Strem, Nika
name: Wagner, Johannes A.
name: Koltermann, Jan J.
Publisher: name: MDPI
Year: 2023

description: In recent years, energy prices have become increasingly volatile, making it more challenging to predict them accurately. This uncertain market trend behavior makes it harder for market participants, e.g., power plant dispatchers, to make reliable decisions. Machine learning (ML) has recently emerged as a powerful artificial intelligence (AI) technique to get reliable predictions in particularly volatile and unforeseeable situations. This development makes ML models an attractive complement to other approaches that require more extensive human modeling effort and assumptions about market mechanisms. This study investigates the application of machine and deep learning approaches to predict day-ahead electricity prices for a 7-day horizon on the German spot market to give power plants enough time to ramp up or down. A qualitative and quantitative analysis is conducted, assessing model performance concerning the forecast horizon and their robustness depending on the selected hyperparameters. For evaluation purposes, three test scenarios with different characteristics are manually chosen. Various models are trained, optimized, and compared with each other using common performance metrics. This study shows that deep learning models outperform tree-based and statistical models despite or because of the volatile energy prices.
Frequency dependence of specific heat in supercooled liquid water and emergence of correlated dynamics
Creators: name: Saito, Shinji
name: Ohmine, Iwao
name: Bagchi, Biman
Publisher: name: arXiv
Year: 2013
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Molecular origin of the well-known specific heat anomaly in supercooled liquid water is investigated here by using extensive computer simulations and theoretical analyses. A rather sharp increase in the values of isobaric specific heat with lowering temperature and the weak temperature dependence of isochoric specific heat in the same range are reproduced in simulations. We calculated the spatiotemporal correlation among temperature fluctuations and examined the frequency dependent specific heat. The latter shows a rapid growth in the low frequency regime as temperature is cooled below 270 K. In order to understand the microscopic basis of this increase, we have performed a shell wise decomposition of contributions of distant molecules to the temperature fluctuations in a central molecule. This decomposition reveals the emergence, at low temperatures, of temporally slow, spatially long ranged large temperature fluctuations. The temperature fluctuation time correlation function (TFCF) can be fitted to a William-Watts stretched exponential form with the stretching parameter close to 0.6 at low temperatures, indicating highly non-exponential relaxation. Temperature dependence of the relaxation time of the correlation function can be fitted to Vogel-Fulcher-Tamermann expression which provides a quantitative measure of the fragility of the liquid. Interestingly, we find that the rapid growth in the relaxation time of TFCF with lowering temperature undergoes a sharp crossover from a markedly fragile state to a weakly fragile state around 220 K.
description: 19 pages, 6 figures (including 1 supplemental figure)
Submillimeter H2O Maser in Circinus Galaxy - A New Probe for the Circumnuclear Region of Active Galactic Nuclei
Creators: name: Hagiwara, Yoshiaki
name: Miyoshi, Makoto
name: Doi, Akihiro
name: Horiuchi, Shinji
Publisher: name: arXiv
Year: 2013
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present the first detection of extragalactic submillimeter H2O maser in the 321 GHz transition toward the center of Circinus galaxy, the nearby Type 2 Seyfert using the Atacama Large Millimeter/Submillimeter Array. We find that Doppler features of the detected 321 GHz H2O maser straddle the systemic velocity of the galaxy as seen in the spectrum of the known 22 GHz H2O maser in the galaxy. By comparing the velocities of the maser features in both transitions, it can be deduced that the 321 GHz maser occurs in a region similar to that of the 22 GHz maser, where the sub-parsec-scale distribution of the 22 GHz maser was revealed by earlier very long baseline interferometry observations. The detected maser features remain unresolved at the synthesized beam of ~0".66 (~15 pc) and coincide with the 321 GHz continuum peak within small uncertainties. We also present a tentative detection of the highest velocity feature (redshifts up to ~635 km/s) in the galaxy. If this high-velocity feature arises from a Keplerian rotating disk well established in this galaxy, it is located at a radius of ~0.018 pc (~1.2 x 10^5 Schwarzschild radii), which might probe molecular material closest to the central engine.
description: 6 pages, 4 figures
The Challenge of Regional Inequalities in Argentina and South Africa
Creators: name: Chonco-Spambo, Thabile
name: Del Tredici, Romina
name: González, Lucas
Publisher: name: Eurac Research
Year: 2023

description: In all developing countries access to local services is a trenchant social issue. The place where you are born determines a large part of your wellbeing, including the probability of not dying at birth or being killed in a homicide, living a longer and decent life, having access to basic and good quality health, education, and security.
A Novel Reconfigurable Architecture of a DSP Processor for Efficient Mapping of DSP Functions using Field Programmable DSP Arrays
Creators: name: Sinha, Amitabha
name: Sarkar, Mitrava
name: Acharyya, Soumojit
name: Chakraborty, Suranjan
Publisher: name: arXiv
Year: 2013
Subjects: subject: Hardware Architecture (cs.AR)
subject: FOS: Computer and information sciences
subject: 68R01

description: Development of modern integrated circuit technologies makes it feasible to develop cheaper, faster and smaller special purpose signal processing function circuits. Digital Signal processing functions are generally implemented either on ASICs with inflexibility, or on FPGAs with bottlenecks of relatively smaller utilization factor or lower speed compared to ASIC. Field Programmable DSP Array (FPDA) is the proposed DSP dedicated device, redolent to FPGA, but with basic fixed common modules (CMs) (like adders, subtractors, multipliers, scaling units, shifters) instead of CLBs. This paper introduces the development of reconfigurable system architecture with a focus on FPDA that integrates different DSP functions like DFT, FFT, DCT, FIR, IIR, and DWT etc. The switching between DSP functions is occurred by reconfiguring the interconnection between CMs. Validation of the proposed architecture has been achieved on Virtex5 FPGA. The architecture provides sufficient amount of flexibility, parallelism and scalability.
description: 8 Pages, 12 Figures, ACM SIGARCH Computer Architecture News. arXiv admin note: substantial text overlap with arXiv:1305.3251
Cross-domain Variational Capsules for Information Extraction
Creators: name: Nagaraj, Akash
name: K, Akhil
name: Venkatesh, Akshay
name: HR, Srikanth
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: In this paper, we present a characteristic extraction algorithm and the Multi-domain Image Characteristics Dataset of characteristic-tagged images to simulate the way a human brain classifies cross-domain information and generates insight. The intent was to identify prominent characteristics in data and use this identification mechanism to auto-generate insight from data in other unseen domains. An information extraction algorithm is proposed which is a combination of Variational Autoencoders (VAEs) and Capsule Networks. Capsule Networks are used to decompose images into their individual features and VAEs are used to explore variations on these decomposed features. Thus, making the model robust in recognizing characteristics from variations of the data. A noteworthy point is that the algorithm uses efficient hierarchical decoding of data which helps in richer output interpretation. Noticing a dearth in the number of datasets that contain visible characteristics in images belonging to various domains, the Multi-domain Image Characteristics Dataset was created and made publicly available. It consists of thousands of images across three domains. This dataset was created with the intent of introducing a new benchmark for fine-grained characteristic recognition tasks in the future.
description: This paper was originally written in 2020
Supplementary material to "Publish or perish? A content analysis of scholarship criteria in R1 academic libraries' promotion and tenure documentation"
Creators: name: Schultz, Teresa
name: Boss, Emily
name: Azadbakht, Elena
Publisher: name: Zenodo
Year: 2025
Subjects: LIS
academic libraries
promotion
tenure
scholarship

description: These are the supplementary files related to the manuscript "Publish or perish? A content analysis of scholarship criteria in R1 academic libraries’ promotion and tenure documentation" that has been accepted for publication in College & Research Libraries. The files include a list of the study population (R1 universities that offer tenure or continuing appointment to librarians) and the codebook used to analzye promotion and tenure documentation identified at these universities and the language around scholarship.
Supplementary text, Spatio-temporal surveillance and early detection of SARS-CoV-2 variants of concern: a retrospective analysis
Creators: name: Cavallaro, Massimo
name: Dyson, Louise
name: Tildesley, Michael J.
name: Todkill, Dan
name: Keeling, Matt J.
Publisher: name: The Royal Society
Year: 2023
Subjects: classificationCode: 310299
subject: Bioinformatics and computational biology not elsewhere classified
classificationCode: 310402
subject: Biogeography and phylogeography
classificationCode: 490102
subject: Biological mathematics

description: Supplementary text, sections S1, S2, S3, S4, and S5
Learning to Solve Optimization Problems with Hard Linear Constraints
Creators: name: Li, Meiyi
name: Kolouri, Soheil
name: Mohammadi, Javad
Publisher: name: arXiv
Year: 2022
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Constrained optimization problems appear in a wide variety of challenging real-world problems, where constraints often capture the physics of the underlying system. Classic methods for solving these problems rely on iterative algorithms that explore the feasible domain in the search for the best solution. These iterative methods are often the computational bottleneck in decision-making and adversely impact time-sensitive applications. Recently, neural approximators have shown promise as a replacement for the iterative solvers that can output the optimal solution in a single feed-forward providing rapid solutions to optimization problems. However, enforcing constraints through neural networks remains an open challenge. This paper develops a neural approximator that maps the inputs to an optimization problem with hard linear constraints to a feasible solution that is nearly optimal. Our proposed approach consists of four main steps: 1) reducing the original problem to optimization on a set of independent variables, 2) finding a gauge function that maps the infty-norm unit ball to the feasible set of the reduced problem, 3)learning a neural approximator that maps the optimization's inputs to an optimal point in the infty-norm unit ball, and 4) find the values of the dependent variables from the independent variable and recover the solution to the original problem. We can guarantee hard feasibility through this sequence of steps. Unlike the current learning-assisted solutions, our method is free of parameter-tuning and removes iterations altogether. We demonstrate the performance of our proposed method in quadratic programming in the context of the optimal power dispatch (critical to the resiliency of our electric grid) and a constrained non-convex optimization in the context of image registration problems.
Higher dualisations of linearised gravity and the $A_1^{+++}$ algebra
Creators: name: Boulanger, Nicolas
name: Cook, Paul P.
name: O'Connor, Josh A.
name: West, Peter
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The non-linear realisation based on $A_1^{+++}$ is known to describe gravity in terms of both the graviton and the dual graviton. We extend this analysis at the linearised level to find the equations of motion for the first higher dual description of gravity that it contains. We also give a systematic method for finding the additional fields beyond those in the non-linear realisation that are required to construct actions for all of the possible dual descriptions of gravity in the non-linear realisation. We show that these additional fields are closely correlated with the second fundamental representation of $A_1^{+++}\,$.
description: 46 pages, no figures. Published version. One reference added, some content moved to an appendix