cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Hamiltonian of a spinning test-particle in curved spacetime
Creators: name: Barausse, Enrico
name: Racine, Etienne
name: Buonanno, Alessandra
Publisher: name: arXiv
Year: 2009
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: Using a Legendre transformation, we compute the unconstrained Hamiltonian of a spinning test-particle in a curved spacetime at linear order in the particle spin. The equations of motion of this unconstrained Hamiltonian coincide with the Mathisson-Papapetrou-Pirani equations. We then use the formalism of Dirac brackets to derive the constrained Hamiltonian and the corresponding phase-space algebra in the Newton-Wigner spin supplementary condition (SSC), suitably generalized to curved spacetime, and find that the phase-space algebra (q,p,S) is canonical at linear order in the particle spin. We provide explicit expressions for this Hamiltonian in a spherically symmetric spacetime, both in isotropic and spherical coordinates, and in the Kerr spacetime in Boyer-Lindquist coordinates. Furthermore, we find that our Hamiltonian, when expanded in Post-Newtonian (PN) orders, agrees with the Arnowitt-Deser-Misner (ADM) canonical Hamiltonian computed in PN theory in the test-particle limit. Notably, we recover the known spin-orbit couplings through 2.5PN order and the spin-spin couplings of type S_Kerr S (and S_Kerr^2) through 3PN order, S_Kerr being the spin of the Kerr spacetime. Our method allows one to compute the PN Hamiltonian at any order, in the test-particle limit and at linear order in the particle spin. As an application we compute it at 3.5PN order.
description: Corrected typo in the ADM Hamiltonian at 3.5 PN order (eq. 6.20)
Observational Signatures of Gravitational Couplings in DBI Inflation
Creators: name: Easson, Damien A.
name: Mukohyama, Shinji
name: Powell, Brian A.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In scalar-tensor theories the scalar fields generically couple nontrivially to gravity. We study the observable properties of inflationary models with non-minimally coupled inflaton and Dirac-Born-Infeld (DBI) kinetic term. Within the assumptions of the priors of our Monte-Carlo simulations we find these models can generate new interesting observable signatures. Our discussion focuses on string theory inspired phenomenological models of relativistic D-brane inflation. While successful string theory constructions of ultra-violet DBI brane inflation remain elusive, we show that in suitable regions of the parameter space it is possible to use cosmological observables to probe the non-minimial coupling. Fortunately, the most observationally promising range of parameters include models yielding intermediate levels of non-gaussianity in the range consistent with WMAP 5-year data, and to be constrained further by the Planck satellite.
description: Minor revisions and references added. Version to appear in PRD
Fluctuations of entropy and log-normal superstatistics
Creators: name: Abe, Sumiyoshi
Publisher: name: arXiv
Year: 2010
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Nonequilibrium complex systems are often effectively described by the mixture of different dynamics on different time scales. Superstatistics, which is "statistics of statistics" with two largely separated time scales, offers a consistent theoretical framework for such a description. Here, a theory is developed for log-normal superstatistics based on the fluctuation theorem for entropy changes as well as the maximum entropy method. This gives novel physical insight into log-normal statistics, other than the traditional multiplicative random processes. A comment is made on a possible application of the theory to the fluctuating energy dissipation rate in turbulence.
description: 14 pages, no figures. A discussion about an application of the fluctuation theorem added. Typos corrected. The version published in Phys. Rev. E
Bayesian methods to overcome the winner's curse in genetic studies
Creators: name: Xu, Lizhen
name: Craiu, Radu V.
name: Sun, Lei
Publisher: name: arXiv
Year: 2009
Subjects: subject: Applications (stat.AP)
subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Parameter estimates for associated genetic variants, report ed in the initial discovery samples, are often grossly inflated compared to the values observed in the follow-up replication samples. This type of bias is a consequence of the sequential procedure in which the estimated effect of an associated genetic marker must first pass a stringent significance threshold. We propose a hierarchical Bayes method in which a spike-and-slab prior is used to account for the possibility that the significant test result may be due to chance. We examine the robustness of the method using different priors corresponding to different degrees of confidence in the testing results and propose a Bayesian model averaging procedure to combine estimates produced by different models. The Bayesian estimators yield smaller variance compared to the conditional likelihood estimator and outperform the latter in studies with low power. We investigate the performance of the method with simulations and applications to four real data examples.
description: Published in at http://dx.doi.org/10.1214/10-AOAS373 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Periodic Sturm-Liouville problems related to two Riccati equations of constant coefficients
Creators: name: Khmelnytskaya, K. V.
name: Rosu, H. C.
name: Gonzalez, A.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We consider two closely related Riccati equations of constant parameters whose particular solutions are used to construct the corresponding class of supersymmetrically-coupled second-order differential equations. We solve analytically these parametric periodic problems along the positive real axis. Next, the analytically solved model is used as a case study for a powerful numerical approach that is employed here for the first time in the investigation of the energy band structure of periodic not necessarily regular potentials. The approach is based on the well-known self-matching procedure of James (1949) and implements the spectral parameter power series solutions introduced by Kravchenko (2008). We obtain additionally an efficient series representation of the Hill discriminant based on Kravchenko's series
description: 15 pages, 4 eps figures, a few minor changes, version accepted to Ann. Phys
Rigid Symmetries and Conservation Laws in Non-Lagrangian Field Theory
Creators: name: Kaparulin, D. S.
name: Lyakhovich, S. L.
name: Sharapov, A. A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Analysis of PDEs (math.AP)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Making use of the Lagrange anchor construction introduced earlier to quantize non-Lagrangian field theories, we extend the Noether theorem beyond the class of variational dynamics.
description: Minor corrections, references added
Structure and organization of the real estate brokerage industry
Creators: name: Seto, Suzanna
Publisher: name: University of British Columbia
Year: 2010

description: The major objective of the present study is to analyze the real estate brokerage industry in British Columbia with respect to its organization, structure, and conduct. The industry has been criticized for overly high real estate commission rates, an excessively large sales force which contributes to high turnover, heavy competition leading to unethical practices and low wages for some salesmen. These allegations led to a provincial inquiry that was to examine many of the problems faced by the industry. The federal government created further controversy with the enactment of the new Combines Investigation Act. The Act prohibited the setting of minimum or fixed commission rates that had been a traditional practice of the real estate industry. In view of the public concern over issues relating to real estate, the present study proposes to examine the basic structure and performance of the industry so that one may have a clearer understanding of the problems that it faces. The study utilizes two approaches to investigate the current situation of the industry. On the one hand it encompasses a statistical survey of real estate agents and salesmen in British Columbia, and on the other it uses primary and secondary sources to analyze the conduct of the industry. The statistics concerning the real estate industry is derived mainly from three surveys conducted during the summer of 1975. The real estate brokerage industry in British Columbia has reached a period when many changes are needed to revitalize its operations. Since the industry has always been a self-regulatory system, these changes would be most effective if they are initiated from within. Until now, the industry has not made any serious attempts to instigate new policies which will improve the relation of agents and salesmen, to curb the size of the sales force by using responsible hiring practices, or to encourage more comprehensive brokerage services by endorsing a. flexible commission rate system. Many of the criticisms mentioned above can be corrected by concerted effort of industry leaders. The recommendations made by the present study are directed toward the brokerage industry and deals with many of the aforementioned issues. The writer believes that reforms must be instigated soon, before lack of public confidence in the industry necessitates government intervention.
External leg amputation in conformal invariant three-point function
Creators: name: Mitra, Indrajit
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Amputation of external legs is carried out explicitly for the conformal invariant three-point function involving two spinors and one vector field. Our results are consistent with the general result that amputing an external leg in a conformal invariant Green function replaces a field by its conformal partner in the Green function. A new star-triangle relation, involving two spinors and one vector field, is derived and used for the calculation.
description: 16 pages; last paragraph added in Sec. 10, presentation improved, to appear in Eur. Phys. J. C
Global Citizenship Education in der Praxis: Erfahrungen, Erfolge, Beispiele in österreichischen Schulen.
Creators: name: Österreichische UNESCO-Kommission
Publisher: name: Österreichische UNESCO-Kommission
Year: 2018

description: Die Broschüre beinhaltet Projekte und Schulentwicklungsprozesse im Bereich Global Citizenship Education (GCED) vorwiegend an Schulen des österreichischen UNESCO-Schulnetzwerks und soll damit zur Nachahmung anregen. Darüber hinaus gibt sie einen Einblick in Aktivitäten zu GCED in der Pädagog*innenbildung. Zusätzlich enhält die Broschüre einen Leitfaden zu den Kriterien, die bei der Schul- und Unterrichtsentwicklung zu GCED Berücksichtigung finden sollten.
UZAQBAY PIRJANOV PROZASÍNDA PEYZAJLÍQ SÚWRETLEWLERDIŃ QOLLANÍLÍW SHEBERLIGI
Creators: name: Kulimbetova, Aysholpan
Publisher: name: Zenodo
Year: 2024

description: Biz bul maqalamızdan qaraqalpaq ádebiyatı sonıń ishinde prozamızda óziniń ayrıqsha ornına iye jazıwshı Uzaqbay Pirjanovtıń shıǵarmalarında peyzajlıq suwretlewlerdiń qollanılıwı hám sol arqalı jazıwshı sheberligin úyreniwge háreket ettik.
Non-Hermitian topological phase transitions in superlattices and the optical Dirac equation
Creators: name: Longhi, Stefano
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Optical superlattices with sublattice symmetry subjected to a synthetic imaginary gauge field undergo a topological phase transition in the Bloch energy spectrum, characterized by the change of a spectral winding number. For a narrow gap, the phase transition is of universal form and described by a non-Hermitian Dirac equation with Lorentz-symmetry violation. A simple photonic system displaying such a phase transition is discussed, which is based on light coupling in co-propagating gratings.
description: 5 pages, 4 figures
Valutazione della psoriasi ungueale come fattore di rischio per lo sviluppo di artropatia psoriasica - studio pilota
Evaluation of nail psoriasis as a risk factor for the development of psoriatic arthritis - Pilot Study
Creators: name: Rech, Giulia <1979>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2013
Subjects: MED/35 Malattie cutanee e veneree

description: Scopo della tesi è verificare se i pazienti affetti da psoriasi puramente ungueale sviluppano psoriasi artropatica e se esistono parametri clinici che possano permettere di predire lo sviluppo del danno articolare.
Viene inoltre valutato l'impatto che la psoriasi ungueale, associata alla psoriasi artropatica, determina sulla qualità di vita dei nostri pazienti.
L'artrite psoriasica è spesso associata a psoriasi ungueale, che è più frequente nei pazienti con artrite psoriasica rispetto ai pazienti con psoriasi cutanea. Vi è una stretta relazione funzionale tra l'unghia e l'articolazione interfalangea distale, i tendini e i legamenti: lo sviluppo di entesite della falange distale è infatti associato ad una infiammazione dell'apparato ungueale.
Riportiamo i dati preliminari emersi dal nostro studio pilota, che conferma come siano necessari e doverosi ulteriori studi su popolazioni più ampie per determinare la relazione che sussiste fra psoriasi ungueale e psoriasi artropatica
description: The purpose of our study is to verify if patients with psoriasis limited to the nails develop psoriatic arthritis (PsA), and if there are clinical parameters that permit to predict it. We will also assess the impact of nail psoriasis associated or not with PsA on the quality of life.
Psoriatic arthritis is often associated with nail psoriasis, which is more frequent in patients with PsA than in patients with cutaneous psoriasis. There is a close functional relation between the nail and the distal interphalangeal joint, its tendons and ligaments: enthesitis of the distal phalanx is in fact associated with inflammation of the nail apparatus. 
We report preliminary data concerning our experience on a restricted group of patient affected by nail psoriasis.
Our pilot study suggests that further studies should be performed and are mandatory, to better understand the relationship between nail psoriasis and PsA.
Energy Dependence of Directed Flow in Au+Au Collisions from a Multi-phase Transport Model
Creators: name: Chen, J. Y.
name: Zuo, J. X.
name: Cai, X. Z.
name: Liu, F.
name: Ma, Y. G.
name: Tang, A. H.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The directed flow of charged hadron and identified particles has been studied in the framework of a multi-phase transport (AMPT) model, for $^{197}$Au+$^{197}$Au collisions at $\sqrt{s_{NN}}=$200, 130, 62.4, 39, 17.2 and 9.2 GeV. The rapidity, centrality and energy dependence of directed flow for charged particles over a wide rapidity range are presented. AMPT model gives the correct $v_1(y)$ slope, as well as its trend as a function of energy, while it underestimates the magnitude. Within the AMPT model, the proton $v_1$ slope is found to change its sign when the energy increases to 130 GeV - a feature that is consistent with ``anti-flow''. Hadronic re-scattering is found having little effect on $v_1$ at top RHIC energies. These studies can help us to understand the collective dynamics at early times in relativistic heavy-ion collisions, and they can also be served as references for the RHIC Beam Energy Scan program.
description: 5 pages,4 figures
title: Carbon Prices and Inflation in a World of Shocks: Systematically significant prices and industrial policy targeting in Germany
Creators: name: Weber, Isabella Maria
name: Thie, Jan-Erik
name: Jauregui, Jesus Lara
name: Teixeira, Lucas
Publisher: name: University of Massachusetts Amherst
publisherIdentifier: https://ror.org/0072zz521
publisherIdentifierScheme: ROR
Year: 2025

description: Climate change and geopolitical tensions render supply shocks more likely, which can trigger inflation (shockflation). Additionally, the EU’s reliance upon an emissions trading system as its chief climate mitigation policy can give rise to inflation (carbonflation). Through simulations using an input-output price model for Germany, we show that the same systemically significant sectors – those essential for human livelihoods, production and commerce – present points of vulnerability for shockflation and also carbonflation, if carbon markets are the only policy tool deployed to cut emissions. A total of up to 91.3 percent of potential carbonflation can be attributed to just six systemically significant sectors. Our findings remain robust under varying assumptions regarding substitution and passthrough effects. The challenge for policymakers is to design policies that combine transformation with stabilization. Enhancing resilience, dampening price volatility and designing green industrial policies for these key sectors can reduce the macroeconomic risks of both carbonflation and shockflation.
Combinatorics of 1-particle irreducible n-point functions via coalgebra in quantum field theory
Creators: name: Mestre, Angela
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mathematical Physics (math-ph)
subject: Combinatorics (math.CO)
subject: Rings and Algebras (math.RA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We give a coalgebra structure on 1-vertex irreducible graphs which is that of a cocommutative coassociative graded connected coalgebra. We generalize the coproduct to the algebraic representation of graphs so as to express a bare 1-particle irreducible n-point function in terms of its loop order contributions. The algebraic representation is so that graphs can be evaluated as Feynman graphs.
Multivariate Log-Concave Distributions as a Nearly Parametric Model
Creators: name: Schuhmacher, Dominic
name: Huesler, Andre
name: Duembgen, Lutz
Publisher: name: arXiv
Year: 2009
Subjects: subject: Probability (math.PR)
subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62A01, 62G05, 62G07, 62G15, 62G35

description: In this paper we show that the family P_d of probability distributions on R^d with log-concave densities satisfies a strong continuity condition. In particular, it turns out that weak convergence within this family entails (i) convergence in total variation distance, (ii) convergence of arbitrary moments, and (iii) pointwise convergence of Laplace transforms. Hence the nonparametric model P_d has similar properties as parametric models such as, for instance, the family of all d-variate Gaussian distributions.
description: updated two references, changed the local technical report number
Inducing elliptically polarized high-order harmonics from aligned molecules with linearly polarized femtosecond pulses
Creators: name: Etches, Adam
name: Madsen, Christian Bruun
name: Madsen, Lars Bojer
Publisher: name: arXiv
Year: 2009
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: A recent paper reported elliptically polarized high-order harmonics from aligned N$_2$ using a linearly polarized driving field [X. Zhou \emph{et al.}, Phys. Rev. Lett. \textbf{102}, 073902 (2009)]. This observation cannot be explained in the standard treatment of the Lewenstein model and has been ascribed to many-electron effects or the influence of the Coulomb force on the continuum electron. We show that non-vanishing ellipticity naturally appears within the Lewenstein model when using a multi-center stationary phase method for treating the dynamics of the continuum electron. The reason for this is the appearance of additional contributions, that can be interpreted as quantum orbits in which the active electron is ionized at one atomic center within the molecule and recombines at another. The associated exchange harmonics are responsible for the non-vanishing ellipticity and result from a correlation between the ionization site and the recombination site in high-order harmonic generation.
description: 6 pages, 7 figures, submitted to PRA
Dense crystalline dimer packings of regular tetrahedra
Creators: name: Chen, Elizabeth R.
name: Engel, Michael
name: Glotzer, Sharon C.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Metric Geometry (math.MG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We present the densest known packing of regular tetrahedra with density phi = 4000/4671 = 0.856347... Like the recently discovered packings of Kallus et al. [arXiv:0910.5226] and Torquato-Jiao [arXiv:0912.4210], our packing is crystalline with a unit cell of four tetrahedra forming two triangular dipyramids (dimer clusters). We show that our packing has maximal density within a three-parameter family of dimer packings. Numerical compressions starting from random configurations suggest that the packing may be optimal at least for small cells with up to 16 tetrahedra and periodic boundaries.
description: 43 pages, revision of the proofs and the appendices, data for small unit cell packings in appendix D
Low eigenvalues and one-dimensional collapse
Creators: name: Lu, Zhiqin
name: Rowlett, Julie
Publisher: name: arXiv
Year: 2008
Subjects: subject: Spectral Theory (math.SP)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 58J50

description: Our main result is that if a generic convex domain in $\R^n$ collapses to a domain in $\R^{n-1}$, then the difference between the first two Dirichlet eigenvalues of the Euclidean Laplacian, known as the fundamental gap, diverges. The boundary of the domain need not be smooth, merely Lipschitz continuous. To motivate the general case, we first prove the analogous result for triangular and polygonal domains. In so doing, we prove that the first two eigenvalues of triangular domains cannot be polyhomogeneous on the moduli space of triangles without blowing up a certain point. Our results show that the gap generically diverges under one dimensional collapse and is bounded only if the domain is sufficiently close to a rectangle in two dimensions or a cylinder in higher dimensions.
Dynamic filter application in graph convolutional networks for enhanced spectral feature analysis and class discrimination in medical imaging
Creators: name: Singh, Aryan
name: van de Ven, Pepijn
name: Eising, Ciarán
name: Denny, Patrick
Publisher: name: University of Limerick
Year: 2024
Subjects: classificationCode: 40
subject: Engineering

description: Graph Neural Networks (GNNs) offer a promising direction for medical image analysis, particularly due to their ability to capture complex relationships and handle non-Euclidean data structures often encountered in this domain. This study aims to demonstrate the potential of GNNs in medical image classification, showcasing their comparable performance to leading CNNs while using significantly fewer parameters. We introduce a novel GNN model, Graph Convolution Neural Network Enhanced Connectivity (GCNN-EC), incorporating an enhanced connectivity technique that leverages interrelationships between RGB channel features. Evaluated on the MedMNIST dataset, a standardized benchmark for medical image analysis, GCNN-EC performs competitively against pre-trained DNNs, highlighting its potential as an efficient and effective approach for medical image analysis. Importantly, we do not claim that GCNN-EC outperforms all CNNs in every scenario, but rather aim to showcase the potential of GNNs as a valuable tool in the medical imaging toolkit that can be used on its own or in conjuction with CNNs to further advance the state of the art. Additionally, our model outperforms traditional GNNs on standard image datasets like MNIST and CIFAR-10, mitigating the common issue of over-smoothing. These findings underscore the effectiveness of GCNs with dynamic filtering and encourage further research into GNN-based approaches for medical imaging and broader computer vision tasks.
Two-stage high frequency pulse tube cooler for refrigeration at 25 K
Creators: name: Dietrich, M.
name: Thummes, G.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: A two-stage Stirling-type U-shape pulse tube cryocooler driven by a 10 kW-class linear compressor was designed, built and tested. A special feature of the cold head is the absence of a heat exchanger at the cold end of the first stage, since the intended application requires no cooling power at this intermediate temperature. Simulations where done using Sage-software to find optimum operating conditions and cold head geometry. Flow-impedance matching was required to connect the compressor designed for 60 Hz operation to the 40 Hz cold head. A cooling power of 12.9 W at 25 K with an electrical input power of 4.6 kW has been achieved up to now. The lowest temperature reached is 13.7 K.
Similarities of magnetoconvection in the umbra and in the penumbra of sunspots
Creators: name: Löptien, B.
name: Lagg, A.
name: van Noort, M.
name: Solanki, S. K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. It is unclear why there is a rather sharp boundary in sunspots between the umbra and the penumbra. Both regions exhibit magnetoconvection, manifesting in penumbral filaments in the penumbra and in umbral dots in the umbra. Aims. Here we compare the physical properties of umbral dots and penumbral filaments. Our goal is to understand how the properties of these convective features change across the boundary between the umbra and the penumbra and how this is related to the rapid increase in brightness at the umbra-penumbra boundary. Methods. We derived ensemble averages of the physical properties of different types of convective features based on observations of two sunspots with Hinode. Results. There are strong similarities between the convective features in the outer parts of the umbra and the ones in the penumbra, with most physical parameters being smooth and continuous functions of the length of the features. Conclusions. Our results indicate that the transition in brightness from the umbra to the penumbra is solely caused by an increased effectiveness of magnetoconvection within individual convective cells. There is no significant difference in the number density of convective elements between the outer umbra and the inner penumbra. Penumbral filaments exhibit a larger area and a higher brightness compared to umbral dots. It is still unclear, how exactly the underlying magnetic field causes the increase in size and brightness of convective features in the penumbra.
description: 8 pages, 5 figures. Accepted for publication in Astronomy & Astrophysics
Principal manifolds and graphs in practice: from molecular biology to dynamical systems
Creators: name: Gorban, A. N.
name: Zinovyev, A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: We present several applications of non-linear data modeling, using principal manifolds and principal graphs constructed using the metaphor of elasticity (elastic principal graph approach). These approaches are generalizations of the Kohonen's self-organizing maps, a class of artificial neural networks. On several examples we show advantages of using non-linear objects for data approximation in comparison to the linear ones. We propose four numerical criteria for comparing linear and non-linear mappings of datasets into the spaces of lower dimension. The examples are taken from comparative political science, from analysis of high-throughput data in molecular biology, from analysis of dynamical systems.
description: 12 pages, 9 figures
Electron transport properties of industrial grade multi-walled carbon nanotubes
Creators: name: Chen, Junjie
Publisher: name: figshare
Year: 2022
Subjects: subject: 91299 Materials Engineering not elsewhere classified
subject: FOS: Materials engineering

description: Carbon nanotubes have remarkable electronic, mechanical, and chemical properties. Depending on their specific diameter and the bonding arrangement of their carbon atoms, carbon nanotubes exhibit either metallic or semiconducting behaviour. Electrical conduction within a perfect carbon nanotube is ballistic (negligible scattering), with low thermal dissipation. As a result, a wire made from a carbon nanotube, or a nanowire, can carry much more current than an ordinary metal wire of comparable size. At 1.4 nanometres in diameter, carbon nanotubes are about a hundred times smaller than the gate width of silicon semiconductor devices. Individual carbon nanotubes may be metallic or semiconducting, depending on the helical orientation of the rows of hexagonal rings in the walls of the carbon nanotubes. Rather than conducting electricity via electron transport, a diffusive process that results in electron scattering and conductive heating, single-walled carbon nanotubes exhibit ballistic transport, a highly efficient and fast conduction process in which electrons, prevented from diffusing through the wall of the carbon nanotube or around its circumference by the regular hexagonal array of carbon atoms, propagate rapidly along the axis of the carbon nanotube. Open-ended single-walled carbon nanotubes emit electrons at currents that attain approximately 100 nanoamperes (billionths of an ampere). Owing to such remarkable properties, electrical conductors made of bundles of carbon nanotubes should exhibit zero energy loss. Aligned multi-walled carbon nanotubes show promise as field-emission devices with potential applications in electronic flat-panel displays. Carbon nanotubes may also be used as highly resilient probe tips for scanning tunneling microscopes and atomic force microscopes. Contributor: Junjie Chen, ORCID: 0000-0001-5055-4309, E-mail address: komcjj@gmail.com, Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China
Optimal Switching of One-Dimensional Reflected BSDEs, and Associated Multi-Dimensional BSDEs with Oblique Reflection
Creators: name: Tang, Shanjian
name: Zhong, Wei
name: Koo, Hyeng Keun
Publisher: name: arXiv
Year: 2008
Subjects: subject: Probability (math.PR)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 93E20, 60H10, 90A15

description: In this paper, an optimal switching problem is proposed for one-dimensional reflected backward stochastic differential equations (RBSDEs, for short) where the generators, the terminal values and the barriers are all switched with positive costs. The value process is characterized by a system of multi-dimensional RBSDEs with oblique reflection, whose existence and uniqueness are by no means trivial and are therefore carefully examined. Existence is shown using both methods of the Picard iteration and penalization, but under some different conditions. Uniqueness is proved by representation either as the value process to our optimal switching problem for one-dimensional RBSDEs, or as the equilibrium value process to a stochastic differential game of switching and stopping. Finally, the switched RBSDE is interpreted as a real option.
description: 39 pages
Evolution of Field Line Helicity in Magnetic Relaxation
Creators: name: Yeates, A. R.
name: Russell, A. J. B.
name: Hornig, G.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Plasma relaxation in the presence of an initially braided magnetic field can lead to self-organization into relaxed states that retain non-trivial magnetic structure. These relaxed states may be in conflict with the linear force-free fields predicted by the classical Taylor theory, and remain to be fully understood. Here, we study how the individual field line helicities evolve during such a relaxation, and show that they provide new insights into the relaxation process. The line helicities are computed for numerical resistive-magnetohydrodynamic simulations of a relaxing braided magnetic field with line-tied boundary conditions, where the relaxed state is known to be non-Taylor. Firstly, our computations confirm recent analytical predictions that line helicity will be predominantly redistributed within the domain, rather than annihilated. Secondly, we show that self-organization into a relaxed state with two discrete flux tubes may be predicted from the initial line helicity distribution. Thirdly, for this set of line-tied simulations we observe that the sub-structure within each of the final tubes is a state of uniform line helicity. This uniformization of line helicity is consistent with Taylor theory applied to each tube individually. However, it is striking that the line helicity becomes significantly more uniform than the force-free parameter.
description: 30 pages, 12 figures. This article has been accepted for publication by AIP Physics of Plasmas
Prograde rotation of protoplanets by accretion of pebbles in a gaseous environment
Creators: name: Johansen, Anders
name: Lacerda, Pedro
Publisher: name: arXiv
Year: 2009
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We perform hydrodynamical simulations of the accretion of pebbles and rocks onto protoplanets of a few hundred kilometres in radius, including two-way drag force coupling between particles and the protoplanetary disc gas. Particle streams interacting with the gas far out within the Hill sphere of the protoplanet spiral into a prograde circumplanetary disc. Material is accreted onto the protoplanet due to stirring by the turbulent surroundings. We speculate that the trend for prograde rotation among the largest asteroids is primordial and that protoplanets accreted 10%-50% of their mass from pebbles and rocks during the gaseous solar nebula phase. Our model also offers a possible explanation for the narrow range of spin periods observed among the largest bodies in the asteroid and trans-Neptunian belts, and predicts that 1000 km-scale Kuiper belt objects that have not experienced giant impacts should preferentially spin in the prograde direction.
description: Accepted for publication in MNRAS. Minor changes in response to referee report, general language changes throughout the paper
Optimal topological simplification of discrete functions on surfaces
Creators: name: Bauer, Ulrich
name: Lange, Carsten
name: Wardetzky, Max
Publisher: name: arXiv
Year: 2010
Subjects: subject: Computational Geometry (cs.CG)
subject: Combinatorics (math.CO)
subject: Geometric Topology (math.GT)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: F.2.2; G.2.1

description: We solve the problem of minimizing the number of critical points among all functions on a surface within a prescribed distance δ from a given input function. The result is achieved by establishing a connection between discrete Morse theory and persistent homology. Our method completely removes homological noise with persistence less than 2δ, constructively proving the tightness of a lower bound on the number of critical points given by the stability theorem of persistent homology in dimension two for any input function. We also show that an optimal solution can be computed in linear time after persistence pairs have been computed.
description: 27 pages, 8 figures
On weight distributions of perfect colorings and completely regular codes
Creators: name: Krotov, Denis
Publisher: name: arXiv
Year: 2009
Subjects: subject: Combinatorics (math.CO)
subject: Information Theory (cs.IT)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 05B99

description: A vertex coloring of a graph is called "perfect" if for any two colors $a$ and $b$, the number of the color-$b$ neighbors of a color-$a$ vertex $x$ does not depend on the choice of $x$, that is, depends only on $a$ and $b$ (the corresponding partition of the vertex set is known as "equitable"). A set of vertices is called "completely regular" if the coloring according to the distance from this set is perfect. By the "weight distribution" of some coloring with respect to some set we mean the information about the number of vertices of every color at every distance from the set. We study the weight distribution of a perfect coloring (equitable partition) of a graph with respect to a completely regular set (in particular, with respect to a vertex if the graph is distance-regular). We show how to compute this distribution by the knowledge of the color composition over the set. For some partial cases of completely regular sets, we derive explicit formulas of weight distributions. Since any (other) completely regular set itself generates a perfect coloring, this gives universal formulas for calculating the weight distribution of any completely regular set from its parameters. In the case of Hamming graphs, we prove a very simple formula for the weight enumerator of an arbitrary perfect coloring. Codewords: completely regular code; equitable partition; partition design; perfect coloring; perfect structure; regular partition; weight distribution; weight enumerator.
description: 17pp; partially presented at "Optimal Codes and Related Topics" OC2009, Varna (Bulgaria). V.2: the title was changed (old: "On weight distributions of perfect structures"), Sect.5 "Weight enumerators ..." was added
MPEC 2023-Y69 : 2023 TD167
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2023 TD167

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Selection of nurse’s role behaviors and identification of determinant factors in development of such roles
Creators: name: Farhang Mehr, Mahnaz
Publisher: name: University of British Columbia
Year: 2010

description: The purpose of this exploratory study was to determine the role behavior and the determinant factors influencing the achievement of such role behaviors by the B.S.N, graduates, May 1976, in the basic program of the University of British Columbia School of Nursing. Questions asked were: 1. What kind of role behaviors do University of British Columbia graduates have at the time of graduation, May 1976, and after three months employment in the hospital? 2. What are the determinant factors that influenced achievement of role behaviors of these B.S.N, graduates of the University of British Columbia School of Nursing? Marlene Kramer's Integrative Role Behavior scale and open-ended questionnaire were used to derive the information pertinent to the research problem. Kramer's Integrative Role Behavior scale was administered twice, once at graduation time, and the other three months after employment in the hospital. The open-ended questionnaire was administered after employment only. The study sample were 17 B.S.N.'s who were working in the hospitals throughout British Columbia and answered both sets of questionnaires at the two designated times. Analysis of the data included descriptive analysis, frequency tables, and the use of the T. test. The findings of the study showed that the University of British Columbia B.S.N.'s selected professional role behavior significantly higher at graduation time than upon employment. Besides, role behaviors appeared to be immediately responsive to exposure to the work system. The changes of role behavior upon employment were a higher selection of bureaucratic and integrative role behavior and lower selection of professional role behavior. The changes in selection of bureaucratic and integrative role behaviors were not statistically significant, but the trend of change was as literature suggested. The determinant factors in development of role behavior were mostly the result of ideal nursing education and actual work as a nurse following employment. In the educational setting instructors were instrumental in shaping the ideas of the nurse's role among B.S.N.'s. The study showed that these B.S.N.'s valued their education positively and their work settings (hospitals) negatively. The study suggests more extensive research on the problem. In the meantime, the three groups involved - i.e. nurse educators, nursing service administrators and B.S.N.'s involved - should share their frustrations and suggestions for better client care.
La caratterizzazione endofenotipica del rimuginio
Creators: name: Ottaviani, Cristina <1974>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: M-PSI/01 Psicologia generale

description: Rumination, defined as the tendency to think about the negative affect evoked by stressful events, has been identified as potentially playing a role in the development of cardiovascular diseases. Specifically, recent studies suggest that ruminative thoughts might be mediators of the prolonged physiological effects of stress. The main goal of this research was to study the effect of rumination, evoked in the laboratory, during the subsequent 24 hours. As rumination has been associated with the activity of several physiological systems, including the cardiovascular, endocrine, and immune system, we also aimed at studying the process from a psychoneuroendocrine point of view. Levels 
of anxiety, depression, anger, hostility, and trait rumination were assessed by the use of validated  questionnaires. Impedance cardiography-derived measures, skin conductance, respiration, and beat-to-beat blood pressure (BP) were monitored continuously in 60 subjects during baseline, the Anger Recall Inteview, a reading task and two recovery periods. Half of the sample was randomly 
assigned to a distracter condition after the Anger Recall Inteview. Cortisol, plasma concentrations of epinephrine, norepinephrine, and  inflammatory biomarkers (CRP, sICAM-1) were also obtained at baseline and at the end of the session. Then, all subjects were asked to wear an ambulatory BP monitor for 24 hours. Results show that the distracter was effective in stopping rumination in the 
laboratory but did not have a long-lasting effect in the subsequent 24 hours. Rumination was associated with prolonged sympathetic activity, vagal withdrawal, cortisol secrection, pro-inflammatory reaction and mood impairment compared to the reading task. After controlling for age 
and body mass index, rumination also proved to be a strong predictor of daily moods, and ambulatory HR and BP. Personality traits did not have an effect in determining the frequency or duration of daily rumination. Findings suggest that perseverative cognition can prolong stress-
related affective and physiological activation and might act directly on somatic disease via the cardiovascular, immune, endocrine, and neurovisceral systems.
Sink Hollow Volume 7
Creators: name: Utah State University
Publisher: name: Utah State University
Year: 2019

description: This issue marks my last as both an undergraduate student and as Sink Hollow's Editor-in-Chief. I have been with this precious publication since I was a freshman, new and green in the creative writing world.
My time with Sink Hollow has been invaluable. It has given me a deep appreciation for the vulnerability of creators and writers alike who share their work with us. It is terrifying to not only bring your creativity into actuality, but to share it publicly for the world to see. I have sat back in awe through every submission period at the bravery of all our artists and writers who find a home in our publication.
I thank every submitter for making our publication possible. Without your bravery, we wouldn't exist.
I'd also like to thank the people that made my tenure as Editor-in-Chief possible. Thank you to Robb Kunz, who has been a teacher, a cheerleader, and a friend, to my staff who works tirelessly to ensure the quality of this publication, and to Dax Lehman, who taught me to trust my eye and have faith in the creative process.
I am so grateful for my time with this magazine. It is, of all the things I've done in my undergraduate career, my greatest accomplishment.
So, enjoy Issue 7. It is a triumph of transformative writing and art in all its forms. I am honored to have been even a small part of it.
Jess Nani
Editor-in-Chief
A new formation scenario of a counter-rotating circumstellar disk: spiral-arm accretion from a circumbinary disk in a triple protostar system
Creators: name: Takaishi, Daisuke
name: Tsukamoto, Yusuke
name: Suto, Yasushi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present the evolution of rotational directions of circumstellar disks in a triple protostar system simulated from a turbulent molecular cloud core with no magnetic field. We find a new formation pathway of a counter-rotating circumstellar disk in such triple systems. The tertiary protostar forms via the circumbinary disk fragmentation and the initial rotational directions of all the three circumstellar disks are almost parallel to that of the orbital motion of the binary system. Their mutual gravito-hydrodynamical interaction for the subsequent $\sim10^4\thinspace\rm{yr}$ greatly disturbs the orbit of the tertiary, and the rotational directions of the tertiary disk and star are reversed due to the spiral-arm accretion of the circumbinary disk. The counter-rotation of the tertiary circumstellar disk continues to the end of the simulation ($\sim6.4\times10^4\thinspace\rm{yr}$ after its formation), implying that the counter-rotating disk is long-lived. This new formation pathway during the disk evolution in Class 0/I Young Stellar Objects possibly explains the counter-rotating disks recently discovered by ALMA.
description: Accepted for publication in PASJ
Sink Hollow Volume 10
Creators: name: Utah State University
Publisher: name: Utah State University
Year: 2020

description: This year felt like a thunderstorm. Rain pelting down on us so hard it burns. Lightning strikes so stark we have to close our eyes. Thunder rumbling so ominously we feel it deep in our bones. So many things we hold dear have been lost in this storm.
But something we have found is the human ability to feel a raw and powerful pain. We are intrinsically bound to each other, to nature, and to this world by the pain we feel. A pain so powerful and deep you feel it is sucking you under and drowning you.
The pieces in this issue explore this pain.
As I write this editor's note, my last one as Editor in Chief of Sink Hollow, I find myself much more emotional than I thought I would be. It's painful to leave something that has been so influential in my life for so many years. Something that has seen both the best and the worst of me. As you read this issue, I hope you feel the pain that has rained down on me. But, as you close the last pages, I hope you are able to look up and feel renewed.
Sometimes some water on the head is a new start.
Brianne Sorensen
Editor in Chief