cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Geometric Feature Based Face-Sketch Recognition
Creators: name: Pramanik, Sourav
name: Bhattacharjee, Debotosh
Publisher: name: arXiv
Year: 2013
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: This paper presents a novel facial sketch image or face-sketch recognition approach based on facial feature extraction. To recognize a face-sketch, we have concentrated on a set of geometric face features like eyes, nose, eyebrows, lips, etc and their length and width ratio because it is difficult to match photos and sketches because they belong to two different modalities. In this system, first the facial features/components from training images are extracted, then ratios of length, width, and area etc. are calculated and those are stored as feature vectors for individual images. After that the mean feature vectors are computed and subtracted from each feature vector for centering of the feature vectors. In the next phase, feature vector for the incoming probe face-sketch is also computed in similar fashion. Here, K-NN classifier is used to recognize probe face-sketch. It is experimentally verified that the proposed method is robust against faces are in a frontal pose, with normal lighting and neutral expression and have no occlusions. The experiment has been conducted with 80 male and female face images from different face databases. It has useful applications for both law enforcement and digital entertainment.
description: 7 pages, International Conference
Efficient and accurate simulation of dynamic dielectric objects
Creators: name: Barros, Kipton
name: Sinkovits, Daniel
name: Luijten, Erik
Publisher: name: arXiv
Year: 2014
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Electrostatic interactions between dielectric objects are complex and of a many-body nature, owing to induced surface bound charge. We present a collection of techniques to simulate dynamical dielectric objects. We calculate the surface bound charge from a matrix equation using the Generalized Minimal Residue method (GMRES). Empirically, we find that GMRES converges very quickly. Indeed, our detailed analysis suggests that the relevant matrix has a very compact spectrum for all non-degenerate dielectric geometries. Each GMRES iteration can be evaluated using a fast Ewald solver with cost that scales linearly or near-linearly in the number of surface charge elements. We analyze several previously proposed methods for calculating the bound charge, and show that our approach compares favorably.
description: 16 pages, 2 figures
Application of the Variational Autoencoder to Detect the Critical Points of the Anisotropic Ising Model
Creators: name: Baul, Anshumitra
name: Walker, Nicholas
name: Moreno, Juana
name: Tam, Ka-Ming
Publisher: name: arXiv
Year: 2021
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We generalize the previous study on the application of variational autoencoders to the two-dimensional Ising model to a system with anisotropy. Due to the self-duality property of the system, the critical points can be located exactly for the entire range of anisotropic coupling. This presents an excellent testbed for the validity of using a variational autoencoder to characterize an anisotropic classical model. We reproduce the phase diagram for a wide range of anisotropic couplings and temperatures via a variational autoencoder without the explicit construction of an order parameter. Considering that the partition function of $(d+1)$-dimensional anisotropic models can be mapped to that of the $d$-dimensional quantum spin models, the present study provides numerical evidence that a variational autoencoder can be applied to analyze quantum systems via Quantum Monte Carlo.
description: 11 pages, 5 figures
Research on su shi's zen thoughts
Creators: HuGuoping
Publisher: name: University of Alberta Library
Year: 1994

Su shi's writings are as vast as the sea, and his zen writings are more unique and profound.. Su shi's zen thoughts are inseparable from his own ups and downs of life experience and his own free and unrestrained character, more importantly, su shi has a profound background of Buddhism. Under the social background of harmony of zen and religion, Su shi is engaged in many buddhist activities, but the root of his thoughts is that Su shi was most influenced by zen. This test will expound su shi's zen thoughts through three chapters. The first chapter analyzes su shi's thought of zen, mainly introducing su shi's thought of prajna emptiness and his thought of no thoughts and no living. The first section introduces the development of zen in song dynasty. Firstly, the test analyzes the historical background of the development of zen in the song dynasty and the key factor of promoting the development of zen in the song dynasty, that is, the emperor's policy of worshipping Buddhism; After that, it introduces the general situation of the development of Zen in the Song Dynasty., Text Zen is an important and unique form of Zen development in the Song Dynasty, it is closely related to Su Shi's Zenessays ,therefore, it introduces the general situation of the Northern Song Dynasty. Thesecond section mainly introduces Su Shi's prajna thoughts, first introduces the emptiness of Zen, and then explores the emptiness in Su Shi's article. The third section introduce sushi's prajnaparamita emptiness and his zen thought of no thoughts and noliving as well as his pursuit of a quiet and free life The second chapter summarizes Su Shi's Zen cultivation and Zen characteristics. The first section introduces Su Shi’s criticism of the problem of Zen scholarship at the time and summarizes Su Shi’s concept of Zen cultivation, which reflects Su Shi’s strong social responsibility and lofty admiration for the spirit of Zen. The second section summarizes the characteristics of meditation, practicality and dialectical rationality in Su Shi's Zen ideology, which has important reference and enlightenment significance for later life and meditation. The third chapter introduces the book "Dongpo Zen Xiji", which is a special collection and arrangement of Su Shi's Zen prose. Su Shi's Zen thought is mainly embodied in his prose articles, therefore, this book is of great significance for the study of Su Shi's Zen thoughts, however, the academic circles have not paid enough attention to this book. Therefore, the book is detailed in this book. Introduction to arouse the attention of the academic community. The final content of the article is the conclusion. It is pointed out that Su Shi is fundamentally a practitioner who takes the essence of Zen thought to guide life practice and improve the realm of life and analyzes the tension between Confucianism, Buddhism and Taoism in Su Shi's thought and the contradiction in his life.
Proton structure functions at low $x$: the Fractal distributions
Creators: name: Mohsenabadi, Samira Shoeibi
name: Tehrani, Shahin Atashbar
name: Taghavi-Shahri, Fatemeh
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this paper, we present the extraction of the Parton Distribution Functions (PDFs) at small momentum fractions x and at the next-to-leading order (NLO) accuracy in perturbative QCD. We show that the "sea quark distribution functions" have "Fractal" or self-similar behaviour with fixed exponent at $x<0.01$. To this end, a simple parametrization for the Parton Distribution Functions and especially for the sea quarks PDFs based on the "Fractal" approach is considered. The small $x$ experimental datasets on electron-proton ($e^-p$) and positron-proton ($e^+p$) in DIS processes at HERA for the range of $1.5< Q^2 < 650$ ($GeV^2$) and $x<0.01$ are included in this analysis. The estimations of the uncertainty in the present analysis are carried out using the standard "Hessian" method. In total, considering the overall value of $χ^2/{\rm dof}$ and theory/data comparisons, the results indicate nice agreements between the experimental datasets and the theory predictions at small momentum fractions $x$. Finally, we present detailed comparisons between predictions for the relevant small-$x$ observables obtained with various recent models of proton PDFs available in literature.
11Be(beta-p), a quasi-free neutron decay?
Creators: name: Riisager, K.
name: Forstner, O.
name: Borge, M. J. G.
name: Briz, J. A.
name: Carmona-Gallardo, M.
name: Fraile, L. M.
name: Fynbo, H. O. U.
name: Giles, T.
name: Gottberg, A.
name: Heinz, A.
name: Johansen, J. G.
name: Jonson, B.
name: Kurcewicz, J.
name: Lund, M. V.
name: Nilsson, T.
name: Nyman, G.
name: Rapisarda, E.
name: Steier, P.
name: Tengblad, O.
name: Thies, R.
name: Winkler, S. R.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We have observed beta-delayed proton emission from the neutron-rich nucleus 11Be by analysing a sample collected at the ISOLDE facility at CERN with accelerator mass spectrometry (AMS). With a branching ratio of (8.4 +- 0.6) 10^{-6} the strength of this decay mode, as measured by the B(GT)-value, is unexpectedly high. The result is discussed within a simple single-particle model and could be interpreted as a quasi-free decay of the 11Be halo neutron into a single-proton state.
description: 6 pages, 2 figures
Degree of Polarization and Source Counts of Faint Radio Sources from Stacking Polarized Intensity
Creators: name: Stil, J. M.
name: Keller, B. W.
name: George, S. J.
name: Taylor, A. R.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present stacking polarized intensity as a means to study the polarization of sources that are too faint to be detected individually in surveys of polarized radio sources. Stacking offers not only high sensitivity to the median signal of a class of radio sources, but also avoids a detection threshold in polarized intensity, and therefore an arbitrary exclusion of source with a low percentage of polarization. Correction for polarization bias is done through a Monte Carlo analysis and tested on a simulated survey. We show that the non-linear relation between the real polarized signal and the detected signal requires knowledge of the shape of the distribution of fractional polarization, which we constrain using the ratio of the upper quartile to the lower quartile of the distribution of stacked polarized intensities. Stacking polarized intensity for NVSS sources down to the detection limit in Stokes I, we find a gradual increase in median fractional polarization that is consistent with a trend that was noticed before for bright NVSS sources, but is much more gradual than found by previous deep surveys of radio polarization. Consequently, the polarized radio source counts derived from our stacking experiment predict fewer polarized radio sources for future surveys with the Square Kilometre Array and its pathfinders.
description: 14 pages, 10 Black-and-white figures. Accepted for publication in the Astrophysical Journal
Collisions of young disc galaxies in the early universe
Creators: name: Guo, Beibei
name: Wu, Xufen
name: Chen, Guangwen
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In the local universe, disc galaxies are generally well evolved and Toomre stable. Their collisions with satellite galaxies naturally produce ring structures, which has been observed and extensively studied. In contrast, at high redshifts, disc galaxies are still developing and clumpy. These young galaxies interact with each other more frequently. However, the products of their collisions remain elusive. Here we systematically study the minor collisions between a clumpy galaxy and a satellite on orbits with different initial conditions, and find a new structure that is different from the local collisional ring galaxies. The clumpness of the target galaxy is fine-tuned by the values of Toomre parameter, $Q$. Interestingly, a thick and knotty ring structure is formed without any sign of a central nucleus in the target galaxy. Our results provide a promising explanation of the empty ring galaxy recently observed in R5519 at redshift $z=2.19$. Moreover, we show that the clumpy state of the collided galaxy exists for a much longer timescale, compared to isolated self-evolved clumpy galaxies that have been widely investigated.
description: 12 pages, 11 figures, accepted for publication in ApJ
title: Introduction: Nursing Research Project Posters
Creators: name: Martin, Jamela
name: Hawkins,  Janice Evans
Publisher: name: Old Dominion University Libraries
Year: 2017

description: Nursing 363, Principles of Practice: Research as Foundation for Practice, is a required course in the undergraduate nursing curriculum at Old Dominion University. This course, offered every spring, focuses on the theories and concepts utilized in the scientific investigation of nursing practice. Students are introduced to scientific inquiry in nursing which forms the basis for nursing practice and theory. To meet course requirements, student groups create professional scientific research posters of their research proposal projects. What follows is a compilation of their research posters which were presented at the College of Health Sciences Interprofessional Poster Presentation day in the spring of 2017 and 2018. The research proposals address multiple community health issues such as illicit drug abuse in homeless adolescents, nutritional habits of school-aged children, and the perceived threat of nitrate-contaminated water in a rural community. From lessons learned from the research proposal projects, students are better equipped to design health promotion projects to improve health knowledge, attitudes, behaviors and the environments of the community.
Field redefinitions, Weyl invariance, and nature of mavericks
Creators: name: Prester, Predrag Dominis
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In the theories of gravity with non-minimally coupled scalar fields there are "mavericks" -- unexpected solutions with odd properties, e.g., black holes with scalar hair in theories with scalar potential bounded from below. Probably the most famous example is Bocharova-Bronnikov-Melnikov-Bekenstein (BBMB) black hole solution in a theory with a scalar field conformally coupled to the gravity and with vanishing potential. Its existence naively violates no-hair conjecture without violating no-hair theorems because of the singular behavior of the scalar field at the horizon. Despite being discovered more than 40 years ago, nature of BBMB solution is still the subject of research and debate. We argue here that the key in understanding nature of maverick solutions is the proper choice of field redefinition schemes in which the solutions are regular. It appears that in such "regular" schemes mavericks have different physical interpretations, in particular they are not elementary but composite objects. For example, BBMB solution is not an extremal black hole but a collection of a wormhole and a naked singularity. In the process we show that Weyl-invariant formulation of gravity is a perfect tool for such analyzes.
description: 12 pages, 1 figure
Firewalls and flat mirrors: An alternative to the AMPS experiment which evades the Harlow-Hayden obstacle
Creators: name: Oppenheim, Jonathan
name: Unruh, William G.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: If quantum gravity does not lead to a breakdown of predictability, then Almheiri, Marolf, Polchinski and Sully (AMPS) have argued that an observer falling into a black hole can perform an experiment which verifies a violation of entanglement monogamy - that late time Hawking radiation is maximally entangled with early time Hawking radiation and also with infalling radiation - something impossible in quantum field theory. However, as pointed out by Hayden and Harlow, this experiment is infeasible, as the time required to perform the experiment is almost certainly longer than the lifetime of the black hole. Here we propose an alternative firewall experiment which could actually be performed within the black hole's lifetime. The alternative experiment involves forming an entangled black hole in which the unscrambling of information is precomputed on a quantum memory prior to the creation of the black hole and without acting on the matter which forms the black hole or emerges from it. This would allow an observer near a black hole to signal faster than light. As another application of our precomputing strategy, we show how one can produce entangled black holes which acts like ``flat mirrors'', in the sense that information comes out almost instantly (as in the Hayden-Preskill scenario), but also emerge unscrambled, so that it can actually be observed instantly as well. Finally, we prove that a black hole in thermal equilibrium with its own radiation, is uncorrelated with this radiation.
Detecting scattered light from low-mass molecular cores at 3.6 $μ$m - Impact of global effects on the observation of coreshine
Creators: name: Steinacker, J.
name: Andersen, M.
name: Thi, W. -F.
name: Bacmann, A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Recently discovered scattered light at 3-5 $μ$m from low-mass cores (so-called "coreshine") reveals the presence of grains around 1 $μ$m, which is larger than the grains found in the low-density interstellar medium. But only about half of the 100+ cores investigated so far show the effect. This prompts further studies on the origin of this detection rate. From the 3D continuum radiative transfer equation, we derive the expected scattered light intensity from a core placed in an arbitrary direction seen from Earth. We use the approximation of single scattering, consider extinction up to 2nd-order Taylor approximation, and neglect spatial gradients in the dust size distribution. The impact of the directional characteristics of the scattering on the detection of scattered light from cores is calculated for a given grain size distribution, and local effects like additional radiation field components are discussed. The surface brightness profiles of a core with a 1D density profile are calculated for various Galactic locations, and the results are compared to the approximate detection limits. We find that for optically thin radiation and a constant size distribution, a simple limit for detecting scattered light from a low-mass core can be derived that holds for grains with sizes smaller than 0.5 $μ$m. The extinction by the core prohibits detection in bright parts of the Galactic plane, especially near the Galactic center. For scattered light received from low-mass cores with grain sizes beyond 0.5 $μ$m, the directional characteristics of the scattering favors the detection of scattered light above and below the Galactic center, and to some extent near the Galactic anti-center. We identify the local incident radiation field as the major unknown causing deviations from this simple scheme.
description: 10 pages, 10 figures, accepted by Astronomy & Astrophysics
Integrated semi-quantum layered communication
Creators: name: Bala, Rajni
name: Asthana, Sooryansh
name: Ravishankar, V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In recent times, secure quantum communication in layered networks has emerged as an important area of study. In this paper, we harness the potential offered by multidimensional states in secure quantum communication with only one quantum participant and all the other classical participants. We propose three protocols for (i) entanglement-based layered semi--quantum key distribution, (ii) layered semi-quantum secret sharing, and, (iii) integrated layered semi-quantum key distribution and secret sharing to share secret information in an arbitrarily layered network. These protocols integrate the features of semi quantum communication in layered networks. All three protocols allow for the simultaneous distribution of secure information in all the layers of a network, thanks to the employment of multidimensional states. We present these protocols for a small network of at most five participants and three layers and show the robustness of the same against various eavesdropping strategies. Finally, we provide a detailed procedure for the generalization of the proposed protocols to distribute keys/secrets in any arbitrarily structured quantum network.
Supplementary document for Increasing the Field-of-View in Oblique Plane Microscopy via optical tiling - 6042470.pdf
Creators: name: Chen, Bingying
name: Chang, Bo-Jui
name: Zhou, Felix
name: Daetwyler, Stephan
name: Sapoznik, Etai
name: Nanes, Benjamin
name: Terrazas, Isabella
name: Gihana, Gabriel
name: Castro, Lizbeth Perez
name: Chan, Isaac
Publisher: name: Optica Publishing Group
Year: 2022
Subjects: Cell Biology
Biological Techniques

description: Supplement 1
Probabilistic Learning of Treatment Trees in Cancer
Creators: name: Yao, Tsung-Hung
name: Wu, Zhenke
name: Bharath, Karthik
name: Li, Jinju
name: Baladandayuthapan, Veerabhadran
Publisher: name: arXiv
Year: 2022
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Accurate identification of synergistic treatment combinations and their underlying biological mechanisms is critical across many disease domains, especially cancer. In translational oncology research, preclinical systems such as patient-derived xenografts (PDX) have emerged as a unique study design evaluating multiple treatments administered to samples from the same human tumor implanted into genetically identical mice. In this paper, we propose a novel Bayesian probabilistic tree-based framework for PDX data to investigate the hierarchical relationships between treatments by inferring treatment cluster trees, referred to as treatment trees (Rx-tree). The framework motivates a new metric of mechanistic similarity between two or more treatments accounting for inherent uncertainty in tree estimation; treatments with a high estimated similarity have potentially high mechanistic synergy. Building upon Dirichlet Diffusion Trees, we derive a closed-form marginal likelihood encoding the tree structure, which facilitates computationally efficient posterior inference via a new two-stage algorithm. Simulation studies demonstrate superior performance of the proposed method in recovering the tree structure and treatment similarities. Our analyses of a recently collated PDX dataset produce treatment similarity estimates that show a high degree of concordance with known biological mechanisms across treatments in five different cancers. More importantly, we uncover new and potentially effective combination therapies that confer synergistic regulation of specific downstream biological pathways for future clinical investigations. Our accompanying code, data, and shiny application for visualization of results are available at: https://github.com/bayesrx/RxTree.
Quantum transport, master equations, and exchange fluctuations
Creators: name: Hussein, Robert
name: Kohler, Sigmund
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We investigate to which extent a many-body Bloch-Redfield master equation description of quantum transport is consistent with the exact generalized equilibrium conditions known as exchange fluctuation theorems. Thereby we identify a class of master equations for which this is the case. Beyond this class, we find deviations which exhibit characteristic scaling laws as functions of the dot-lead tunneling, the inter-dot tunneling, and the temperature. These deviations are accompanied by an increase of lead energy fluctuations inherent in the Bloch-Redfield equation beyond rotating-wave approximation. We illustrate our results with numerical data for a double quantum dot attached to four leads.
description: 8 pages
How chromium doping affects the correlated electronic structure of V2O3
Creators: name: Grieger, Daniel
name: Lechermann, Frank
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The archetypical strongly correlated Mott-phenomena compound V2O3 is known to show a paramagnetic metal-insulator transition driven by doping with chromium atoms and/or (negative) pressure. Via charge self-consistent density-functional theory+dynamical mean-field theory calculations we demonstrate that these two routes cannot be understood as equivalent. To this end, the explicit description of Cr-doped V2O3 by means of supercell calculations and the virtual crystal approximation is performed. Already the sole introduction of chromium's additional electron to the system is shown to modify the overall correlated electronic structure substantially. Correlation-induced charge transfers between Cr and the remaining V ions occur and the transition-metal orbital polarization is increased by the electron doping, in close agreement with experimental findings.
description: 6 pages, 8 figures
Vectorization of a thread-parallel Jacobi singular value decomposition method
Creators: name: Novaković, Vedran
Publisher: name: arXiv
Year: 2022
Subjects: subject: Numerical Analysis (math.NA)
subject: Mathematical Software (cs.MS)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: G.1.3; G.4
subject: 65F15 (Primary) 65F25, 65Y05, 65Y10 (Secondary)

description: The eigenvalue decomposition (EVD) of (a batch of) Hermitian matrices of order two has a role in many numerical algorithms, of which the one-sided Jacobi method for the singular value decomposition (SVD) is the prime example. In this paper the batched EVD is vectorized, with a vector-friendly data layout and the AVX-512 SIMD instructions of Intel CPUs, alongside other key components of a real and a complex OpenMP-parallel Jacobi-type SVD method, inspired by the sequential xGESVJ routines from LAPACK. These vectorized building blocks should be portable to other platforms that support similar vector operations. Unconditional numerical reproducibility is guaranteed for the batched EVD, sequential or threaded, and for the column transformations, that are, like the scaled dot-products, presently sequential but can be threaded if nested parallelism is desired. No avoidable overflow of the results can occur with the proposed EVD or the whole SVD. The measured accuracy of the proposed EVD often surpasses that of the xLAEV2 routines from LAPACK. While the batched EVD outperforms the matching sequence of xLAEV2 calls, speedup of the parallel SVD is modest but can be improved and is already beneficial with enough threads. Regardless of their number, the proposed SVD method gives identical results, but of somewhat lower accuracy than xGESVJ.
description: A corrected version of the paper from SIAM Journal on Scientific Computing. A separate "supplementary materials" document has been appended to the main paper as Appendix for technical reasons
General Rotational Surfaces in the Four-dimensional Minkowski Space
Creators: name: Ganchev, Georgi
name: Milousheva, Velichka
Publisher: name: arXiv
Year: 2013
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53A35, 53B25

description: General rotational surfaces as a source of examples of surfaces in the four-dimensional Euclidean space have been introduced by C. Moore. In this paper we consider the analogue of these surfaces in the Minkowski 4-space. On the base of our invariant theory of spacelike surfaces we study general rotational surfaces with special invariants. We describe analytically the flat general rotational surfaces and the general rotational surfaces with flat normal connection. We classify completely the minimal general rotational surfaces and the general rotational surfaces consisting of parabolic points.
description: 12 pages. arXiv admin note: text overlap with arXiv:1011.4379, arXiv:1105.3370, arXiv:1012.0751, arXiv:1205.6350
What is the minimal model of magnetic interactions in Fe-based superconductors?
Creators: name: Glasbrenner, J. K.
name: Velev, J. P.
name: Mazin, I. I.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Using noncollinear first-principles calculations we perform a systematic study of the magnetic order in several families of ferropnictides. We find a fairly universal energy dependence on the magnetization order in all cases. Our results confirm that a simple Heisenberg model fails to account for the energy dependence of the magnetization in couple of ways: first a biquadratic term is present in all cases and second the magnetic moment softens depending on the orientation. We also find that hole doping substantially reduces the biquadratic contribution, although the antiferromagnetic stripe state remains stable within the whole range of doping concentrations, and thus the reported lack of the orthorhombicity in Na-doped BaFe$_2$As$_2$ is probably due to factors other than a sign reversal of the biquadratic term. Finally, we discovered that even with the biquadratic term, there is a limit to the accuracy of mapping the density functional theory energetics onto Heisenberg-type models, independent of the range of the model.
description: 8 pages, 3 figures, submitted to Phys. Rev. B
Enumeration of corner polyhedra and 3-connected Schnyder labelings
Creators: name: Fusy, Éric
name: Narmanli, Erkan
name: Schaeffer, Gilles
Publisher: name: arXiv
Year: 2022
Subjects: subject: Combinatorics (math.CO)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 05A15, 05A16

description: We show that corner polyhedra and 3-connected Schnyder labelings join the growing list of planar structures that can be set in exact correspondence with (weighted) models of quadrant walks via a bijection due to Kenyon, Miller, Sheffield and Wilson. Our approach leads to a first polynomial time algorithm to count these structures, and to the determination of their exact asymptotic growth constants: the number $p_n$ of corner polyhedra and $s_n$ of 3-connected Schnyder labelings of size $n$ respectively satisfy $(p_n)^{1/n}\to 9/2$ and $(s_n)^{1/n}\to 16/3$ as $n$ goes to infinity. While the growth rates are rational, like in the case of previously known instances of such correspondences, the exponent of the asymptotic polynomial correction to the exponential growth does not appear to follow from the now standard Denisov-Wachtel approach, due to a bimodal behavior of the step set of the underlying tandem walk. However a heuristic argument suggests that these exponents are $-1-π/\arccos(9/16)\approx -4.23$ for $p_n$ and $-1-π/\arccos(22/27)\approx -6.08$ for $s_n$, which would imply that the associated series are not D-finite.
description: 28 pages
Presentation: New Insight Of Surface And Subsurface Sedimentology Of Salodik Group, Banggai Basin
Creators: name: Firman Herdiansyah
name: M Burhannudinnur
name: M Ali Jambak
name: Irano, Teddy
Publisher: name: Zenodo
Year: 2020

description: This material presented in 2nd ICESE 2020
Experimental study on Modified Linear Quadratic Gaussian Control for Adaptive Optics
Creators: name: Fu, Qiang
name: Pott, Jörg-Uwe
name: Dethard, Peter
name: Shen, Feng
name: Rao, Changhui
name: Li, Xinyang
Publisher: name: arXiv
Year: 2014
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: To achieve high resolution imaging the standard control algorithm used for classical adaptive optics (AO) is the simple but efficient proportional-integral (PI) controller. The goal is to minimize the root mean square (RMS) error of the residual wave front. However, with the PI controller one does not reach this minimum. A possibility to achieve is to use Linear Quadratic Gaussian Control (LQG). In practice, however this control algorithm still encounters one unexpected problem, leading to the divergence of control in AO. In this paper we propose a Modified LQG (MLQG) to solve this issue. The controller is analyzed explicitly. Test in the lab shows strong stability and high precision compared to the classical control.
Ricci Dark Energy of Amended FRW Universe in Chern-Simon Modified Gravity
Creators: name: Amir, M. Jamil
name: Ali, Sarfraz
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The energy density of the universe is proportional to the Ricci scalar curvature in the dynamical Chern-Simon (CS) modified gravity. In this paper, we consider the Amended Friedman-Robertson-Walker (AFRW) universe and explore its scale factor and the Ricci Dark Energy. THese turned out to be well-defined and definite. We compare the scale factors of FRW \cite{[17]}, Generalized Chaplygin gas (GCG) \cite{[18]} and AFRW models graphically. The combined graph of these models show that the behavior of both FRW and AFRW models is similar as these overlap each other for choosing particular values of the integration constants. Also, we draw a combined graph of the Ricci dark energy densities of FRW and AFRW models, in CS gravity, and the energy density of GCG. It shows that the densities of former two models are increasing with time while the energy density of GCG is decreasing.
description: 11 pages,2 graphs. arXiv admin note: text overlap with arXiv:0909.1267 by other authors without attribution
Core-assisted gas capture instability: a new mode of giant planet formation by gravitationally unstable discs
Creators: name: Nayakshin, Sergei
name: Helled, Ravit
name: Boley, Aaron C.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Giant planet formation in the core accretion (CA) paradigm is predicated by the formation of a core, assembled by the coagulation of grains and later by planetesimals within a protoplanetary disc. In contrast, in the disc instability paradigm, giant planet formation is believed to be independent of core formation: massive self-gravitating gas fragments cool radiatively and collapse as a whole. We show that giant planet formation in the disc instability model may be also enhanced by core formation for reasons physically very similar to the CA paradigm. In the model explored here, efficient grain sedimentation within an initial fragment (rather than the disc) leads to the formation of a core composed of heavy elements. We find that massive atmospheres form around cores and undergo collapse as a critical core mass is exceeded, analogous to CA theory. The critical mass of the core to initiate such a collapse depends on the fragment mass and metallicity, as well as core luminosity, but ranges from less than 1 to as much as $\sim80$ Earth masses. We therefore suggest that there are two channels for the collapse of a gaseous fragment to planetary scales within the disc instability model: (i) H$_2$ dissociative collapse of the entire gaseous clump, and (ii) core-assisted gas capture, as presented here. We suggest that the first of these two is favoured in metal-poor environments and for fragments more massive than $\sim 5-10$ Jupiter masses, whereas the second is favored in metal-rich environments and fragments of lower mass. [Abridged]
description: Accepted to MNRAS. 13 pages
Offline Text-Independent Writer Identification based on word level data
Creators: name: Kumar, Vineet
name: Sundaram, Suresh
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: This paper proposes a novel scheme to identify the authorship of a document based on handwritten input word images of an individual. Our approach is text-independent and does not place any restrictions on the size of the input word images under consideration. To begin with, we employ the SIFT algorithm to extract multiple key points at various levels of abstraction (comprising allograph, character, or combination of characters). These key points are then passed through a trained CNN network to generate feature maps corresponding to a convolution layer. However, owing to the scale corresponding to the SIFT key points, the size of a generated feature map may differ. As an alleviation to this issue, the histogram of gradients is applied on the feature map to produce a fixed representation. Typically, in a CNN, the number of filters of each convolution block increase depending on the depth of the network. Thus, extracting histogram features for each of the convolution feature map increase the dimension as well as the computational load. To address this aspect, we use an entropy-based method to learn the weights of the feature maps of a particular CNN layer during the training phase of our algorithm. The efficacy of our proposed system has been demonstrated on two publicly available databases namely CVL and IAM. We empirically show that the results obtained are promising when compared with previous works.
Menulis Artikel Jurnal: Pengecekan Ulang
Creators: name: Wekke, Ismail Suardi
name: Herianto, H
Publisher: name: Zenodo
Year: 2020

description: Short Course Penulisan Artikel Jurnal, HMI Cabang Gowa Raya dan DPP Rumah Produktif Indonesia, 16 November 2020
Non-linear eigenvalue problems arising from growth maximization of positive linear dynamical systems
Creators: name: Calvez, Vincent
name: Gabriel, Pierre
name: Gaubert, Stéphane
Publisher: name: arXiv
Year: 2014
Subjects: subject: Analysis of PDEs (math.AP)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: We study a growth maximization problem for a continuous time positive linear system with switches. This is motivated by a problem of mathematical biology (modeling growth-fragmentation processes and the PMCA protocol). We show that the growth rate is determined by the non-linear eigenvalue of a max-plus analogue of the Ruelle-Perron-Frobenius operator, or equivalently, by the ergodic constant of a Hamilton-Jacobi (HJ) partial differential equation, the solutions or subsolutions of which yield Barabanov and extremal norms, respectively. We exploit contraction properties of order preserving flows, with respect to Hilbert's projective metric, to show that the non-linear eigenvector of the operator, or the "weak KAM" solution of the HJ equation, does exist. Low dimensional examples are presented, showing that the optimal control can lead to a limit cycle.
description: 8 pages
Performance Analysis of Optimally Coordinated Connected and Automated Vehicles in a Mixed Traffic Environment
Creators: name: Valencia, Alejandra
name: Mahbub, A M Ishtiaque
name: Malikopoulos, Andreas A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Trajectory planning of connected and automated vehicles (CAVs) poses significant challenges in a mixed traffic environment due to the presence of human-driven vehicles (HDVs). In this paper, we apply a framework that allows coordination of CAVs and HDVs traveling through a traffic corridor consisting of an on-ramp merging, a speed reduction zone, and a roundabout. We study the impact of different penetration rates of CAVs and traffic volumes on the efficiency of the corridor. We provide extensive simulation results and report on the benefits in terms of total travel time and fuel economy.
description: 6 pages conference
Correlation functions of conserved currents in four dimensional conformal field theory with higher spin symmetry
Creators: name: Stanev, Yassen S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We report some recent progress in the computation of the n-point correlation functions of conserved currents in a class of four dimensional conformal field theories with higher spin symmetry. Global conformal invariance leads to very strong constraints on both the general form and the singularity structure of the correlation functions of conserved currents. Namely, all these functions have to be rational functions with at most double pole singularities. We show that this implies that the 4-, 5- and 6-point correlation functions of the (symmetric, conserved and traceless) stress-energy tensor are linear combinations of the three free field expressions. Hence, in four dimensions, any globally conformal invariant theory is free.
description: 6 pages, Invited talk at the Second Bulgarian National Congress in Physics, Sofia, September 2013
Warm formaldehyde in the Oph IRS 48 transitional disk
Creators: name: van der Marel, Nienke
name: van Dishoeck, Ewine F.
name: Bruderer, Simon
name: van Kempen, Tim A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Simple molecules like H2CO and CH3OH in protoplanetary disks are the starting point for the production of more complex organic molecules. So far, the observed chemical complexity in disks has been limited due to freeze out of molecules onto grains in the bulk of the cold outer disk. Complex molecules can be studied more directly in transitional disks with large inner holes, as these have a higher potential of detection, through UV heating of the outer disk and the directly exposed midplane at the wall. We use Atacama Large Millimeter/submillimeter Array (ALMA) Band 9 (~680 GHz) line data of the transitional disk Oph IRS 48, previously shown to have a large dust trap, to search for complex molecules in regions where planetesimals are forming. We report the detection of the H2CO 9(1,8)-8(1,7) line at 674 GHz, which is spatially resolved as a semi-ring at ~60 AU radius centered south from the star. The inferred H2CO abundance is ~10^{-8} derived by combining a physical disk model of the source with a non-LTE excitation calculation. Upper limits for CH3OH lines in the same disk give an abundance ratio H2CO/CH3OH>0.3, which points to both ice formation and gas-phase routes playing a role in the H2CO production. Upper limits on the abundances of H13CO+, CN and several other molecules in the disk are also derived and found to be consistent with full chemical models. The detection of the H2CO line demonstrates the start of complex organic molecules in a planet-forming disk. Future ALMA observations should be able to push down the abundance detection limits of other molecules by 1-2 orders of magnitude and test chemical models of organic molecules in (transitional) disks.
description: Updated references and minor changes to text, approved by language editor
Survey of Landing Methods on Small Bodies : Benefits of Robotics Manipulators to the Field
Creators: name: Peñarroya, Pelayo
name: Vyas, Shubham
name: Paoli, Roberto
name: Kajak, Karl M
Publisher: name: Zenodo
Year: 2020

description: In this poster, a summary of the landing techniques used in missions to small bodies is given and their performance, flexibility, and robustness are assessed. Based on these criteria, the overall gaps that these techniques present are identified and classified. Furthermore, a study on space-based robotic manipulators is presented, and their benefits are highlighted. A novel landing technique to land on small bodies that tries to fill the gaps in current landing systems with the possibilities that the robotic manipulators offer is introduced. A compilation of the possible applications that such a landing technique provides is given, and its potential performance is assessed and compared to the state of the art. Finally, the feasibility of using a robotic arm for posterior mission phases, such as hopping to traverse around the surface of the small body, is discussed.
Graph clustering with Boltzmann machines
Creators: name: Miasnikof, Pierre
name: Bagherbeik, Mohammad
name: Sheikholeslami, Ali
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Discrete Mathematics (cs.DM)
subject: Optimization and Control (math.OC)
subject: Computation (stat.CO)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Graph clustering is the process of grouping vertices into densely connected sets called clusters. We tailor two mathematical programming formulations from the literature, to this problem. In doing so, we obtain a heuristic approximation to the intra-cluster density maximization problem. We use two variations of a Boltzmann machine heuristic to obtain numerical solutions. For benchmarking purposes, we compare solution quality and computational performances to those obtained using a commercial solver, Gurobi. We also compare clustering quality to the clusters obtained using the popular Louvain modularity maximization method. Our initial results clearly demonstrate the superiority of our problem formulations. They also establish the superiority of the Boltzmann machine over the traditional exact solver. In the case of smaller less complex graphs, Boltzmann machines provide the same solutions as Gurobi, but with solution times that are orders of magnitude lower. In the case of larger and more complex graphs, Gurobi fails to return meaningful results within a reasonable time frame. Finally, we also note that both our clustering formulations, the distance minimization and $K$-medoids, yield clusters of superior quality to those obtained with the Louvain algorithm.
Exact Solutions in Modified Massive Gravity and Off-Diagonal Wormhole Deformations
Creators: name: Vacaru, Sergiu I.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: There are explored off-diagonal deformations of "prime" metrics in Einstein gravity (for instance, for wormhole configurations) into "target" exact solutions in f(R,T)-modified and massive/ bi-metric gravity theories. The new classes of solutions may posses, or not, Killing symmetries and can be characterized by effective induced masses, anisotropic polarized interactions and cosmological constants. For nonholonomic deformations with (conformal) ellipsoid/ toroid and/or solitonic symmetries and, in particular, for small eccentricity rotoid configurations, we can generate wormholes like objects matching external black ellipsoid - de Sitter geometries. We conclude that there are nonholonomic transforms and/or non-trivial limits to exact solutions in general relativity when modified/ massive gravity effects are modeled by off-diagonal and/or nonholonomic parametric interactions.
description: 30 pages, accepted to EJPC; moderators permitted on March 3, 2014, to resubmit this work from April 1, 2013
A Simple Combinatorial Proof of Szemerédi's Theorem via Three Levels of Infinities
Creators: name: Jin, Renling
Publisher: name: arXiv
Year: 2022
Subjects: subject: Logic (math.LO)
subject: Combinatorics (math.CO)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 03C98, 11B25

description: We present a nonstandard simple elementary proof of Szemerédi's theorem by a straightforward induction with the help of three levels of infinities and four different elementary embeddings in a nonstandard universe.