cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Anisotropic ac dissipation at the surface of mesoscopic superconductors
Creators: name: Hernandez, Alexander D.
name: Lopez, Arturo
name: Dominguez, Daniel
Publisher: name: arXiv
Year: 2007
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In this work we study the ac dissipation of mesoscopic superconductors at microwave frequencies using the time dependent Ginzburg-Landau equations. Our numerical simulations show that the ac dissipation is strongly dependent on the orientation of the ac magnetic field ($h_{ac}$) relative to the dc magnetic field ($H_{dc}$). When $h_{ac}$ is parallel to $H_{dc}$ we observe that each vortex penetration event produces a significant supression of the ac losses because the imaginary part of the ac susceptibility as a function of $H_{dc}$ increases before the penetration of vortices, and then it decreases abruptly after vortices have entered into the sample. In the second case, when $h_{ac}$ is perpendicular to $H_{dc}$, we observe that the jumps in dissipation occur at the same values of $H_{dc}$ but are much smaller than in the parallel configuration. The behavior of the dissipation in the perpendicular configuration is similar to previous results obtained in recent microwave experiments using mesoscopic litographed squares of Pb [J. Low Temp. Phys. 135, 119 (2004)].
description: 4 pages, 2 figures
Contact line stability of ridges and drops
Creators: name: Mechkov, S.
name: Oshanin, G.
name: Rauscher, M.
name: Brinkmann, M.
name: Cazabat, A. M.
name: Dietrich, S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Within the framework of a semi-microscopic interface displacement model we analyze the linear stability of sessile ridges and drops of a non-volatile liquid on a homogeneous, partially wet substrate, for both signs and arbitrary amplitudes of the three-phase contact line tension. Focusing on perturbations which correspond to deformations of the three-phase contact line, we find that drops are generally stable while ridges are subject only to the long-wavelength Rayleigh-Plateau instability leading to a breakup into droplets, in contrast to the predictions of capillary models which take line tension into account. We argue that the short-wavelength instabilities predicted within the framework of the latter macroscopic capillary theory occur outside its range of validity and thus are spurious.
description: 6 pages, 1 figure
On Asymptotic Rigidity and Continuity Problems in Nonlinear Elasticity on Manifolds and Hypersurfaces
Creators: name: Chen, Gui-Qiang G.
name: Li, Siran
name: Slemrod, Marshall
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 74B20, 74Q15, 53Z05, 35R01, 53C24

description: Intrinsic nonlinear elasticity deals with the deformations of elastic bodies as isometric immersions of Riemannian manifolds into the Euclidean spaces (see Ciarlet [9,10]). In this paper, we study the rigidity and continuity properties of elastic bodies for the intrinsic approach to nonlinear elasticity. We first establish a geometric rigidity estimate for mappings from Riemannian manifolds to spheres (in the spirit of Friesecke-James-Müller [23]), which is the first result of this type for the non-Euclidean case as far as we know. Then we prove the asymptotic rigidity of elastic membranes under suitable geometric conditions. Finally, we provide a simplified geometric proof of the continuous dependence of deformations of elastic bodies on the Cauchy-Green tensors and second fundamental forms, which extends the Ciarlet-Mardare theorem in [18] to arbitrary dimensions and co-dimensions.
description: 25 pages, Journal de Math\'ematiques Pures et Appliqu\'ees (to appear)
Initial fields and instability in the classical model of the heavy-ion collision
Creators: name: Fukushima, Kenji
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Color Glass Condensate (CGC) provides a classical description of dense gluon matter at high energies. Using the McLerran-Venugopalan (MV) model we calculate the initial energy density ε(τ) in the early stage of the relativistic nucleus-nucleus collision. Our analytical formula reproduces the quantitative results from lattice discretized simulations and leads to an estimate ε(τ=0.1fm)=40-50GeV/fm^3 in the Au-Au collision at RHIC energy. We then formulate instability with respect to soft fluctuations that violate boost invariance inherent to hard CGC backgrounds. We find unstable modes arising as a result of ensemble average over the initial CGC fields.
description: 5 pages, 2 figures
AirCode: A Robust Object Encoding Method
Creators: name: Xu, Kuan
name: Wang, Chen
name: Chen, Chao
name: Wu, Wei
name: Scherer, Sebastian
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Object encoding and identification are crucial for many robotic tasks such as autonomous exploration and semantic relocalization. Existing works heavily rely on the tracking of detected objects but have difficulty recalling revisited objects precisely. In this paper, we propose a novel object encoding method, which is named as AirCode, based on a graph of key-points. To be robust to the number of key-points detected, we propose a feature sparse encoding and object dense encoding method to ensure that each key-point can only affect a small part of the object descriptors, leading it to be robust to viewpoint changes, scaling, occlusion, and even object deformation. In the experiments, we show that it achieves superior performance for object identification than the state-of-the-art algorithms and is able to provide reliable semantic relocalization. It is a plug-and-play module and we expect that it will play an important role in various applications.
description: IEEE Robotics and Automation Letters (RA-L), 2022
Strong decay $Δ^{++} \to pπ$ with light-cone QCD sum rules
Creators: name: Wang, Zhi-Gang
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this article, we calculate the strong coupling constant $g_{ΔNπ}$ and study the strong decay $Δ^{++} \to pπ$ with the light-cone QCD sum rules. The numerical value of the strong coupling constant $g_{ΔNπ}$ is consistent with the experimental data. The small discrepancy maybe due to failure to take into account the perturbative $\mathcal {O}(α_s)$ corrections.
description: 15 pages, 2 figures, 7-version
On The Inclusion of One Double Within CIS and TD-DFT
Creators: name: Athavale, Vishikh
name: Teh, Hung-Hsuan
name: Subotnik, Joseph
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We present an improved approach for generating a set of optimized frontier orbitals (HOMO and LUMO) that minimizes the energy of one double configuration. We further benchmark the effect of including such a double within a CIS or TD-DFT configuration interaction Hamiltonian for a set of test cases. We find that, although we cannot achieve quantitative accuracy, the algorithm is quite robust and routinely delivers an enormous qualitative improvement to standard single-reference electronic structure calculations.
The Casimir Force in Randall Sundrum Models
Creators: name: Frank, Mariana
name: Turan, Ismail
name: Ziegler, Lorric
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discuss and compare the effects of one extra dimension in the Randall Sundrum models on the evaluation of the Casimir force between two parallel plates. We impose the condition that the result reproduce the experimental measurements within the known uncertainties in the force and the plate separation, and get an upper bound kR < 20 if the curvature parameter k of AdS_5 is equal to the Planck scale. Although the upper bound decreases as k decreases, kR ~ 12, which is the required value for solving the hierarchy problem, is consistent with the Casimir force measurements. For the case where the 5th dimension is infinite, the correction to the Casimir force is very small and negligible.
description: 16 pages, 2 figures, references added, text improved, accepted for publication in PRD
A high-velocity transient outflow in Eta Carinae
Creators: name: Behar, Ehud
name: Nordon, Raanan
name: Soker, Noam
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We analyze velocity profiles of the X-ray spectral lines emitted by the Eta Carinae stellar binary at four epochs, just before the X-ray minimum (associated with periastron) and more than two years before the minimum (~apastron). The profiles are nicely resolved by the HETGS spectrometer on board Chandra. Far from periastron, we find symmetrical lines that are more or less centered at zero velocity. Closer to periastron, the lines broaden, shift towards the blue, and become visibly asymmetric. While the quiescent X-ray emission and slight (<200 km/sec) centroid shifts can be ascribed to the ordinary continuous binary wind interaction and to the orbital velocity of the secondary star, the observed high-velocity emission up to ~2,000 km/sec and the abrupt flares during which it occurs can not. This leads us to interpret the high-velocity flaring emission as due to a fast collimated outflow of ionized gas.
description: Accepted by ApJ Letters
Non-Hermitian von Roos Hamiltonian's $η$-weak-pseudo-Hermiticity, isospectrality and exact solvability
Creators: name: Mustafa, Omar
name: Mazharimousavi, S. Habib
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A complexified von Roos Hamiltonian is considered and a Hermitian first-order intertwining differential operator is used to obtain the related position dependent mass $η$-weak-pseudo-Hermitian Hamiltonians. Using a Liouvillean-type change of variables, the $η$-weak-pseudo-Hermitian von Roos Hamiltonians H(x) are mapped into the traditional Schrodinger Hamiltonian form H(q), where exact isospectral correspondence between H(x) and H(q) is obtained. Under a user-friendly position dependent mass settings, it is observed that for each exactly-solvable $η$-weak-pseudo-Hermitian reference-Hamiltonian H(q)there is a set of exactly-solvable $η$-weak-pseudo-Hermitian isospectral target-Hamiltonians H(x). A non-Hermitian PT-symmetric Scarf II and a non-Hermitian periodic-type PT-symmetric Samsonov-Roy potentials are used as reference models and the corresponding $η$-weak-pseudo-Hermitian isospectral target-Hamiltonians are obtained.
description: 11 pages, no figures,
SleepTransformer: Automatic Sleep Staging with Interpretability and Uncertainty Quantification
Creators: name: Phan, Huy
name: Mikkelsen, Kaare
name: Chén, Oliver Y.
name: Koch, Philipp
name: Mertins, Alfred
name: De Vos, Maarten
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Background: Black-box skepticism is one of the main hindrances impeding deep-learning-based automatic sleep scoring from being used in clinical environments. Methods: Towards interpretability, this work proposes a sequence-to-sequence sleep-staging model, namely SleepTransformer. It is based on the transformer backbone and offers interpretability of the model's decisions at both the epoch and sequence level. We further propose a simple yet efficient method to quantify uncertainty in the model's decisions. The method, which is based on entropy, can serve as a metric for deferring low-confidence epochs to a human expert for further inspection. Results: Making sense of the transformer's self-attention scores for interpretability, at the epoch level, the attention scores are encoded as a heat map to highlight sleep-relevant features captured from the input EEG signal. At the sequence level, the attention scores are visualized as the influence of different neighboring epochs in an input sequence (i.e. the context) to recognition of a target epoch, mimicking the way manual scoring is done by human experts. Conclusion: Additionally, we demonstrate that SleepTransformer performs on par with existing methods on two databases of different sizes. Significance: Equipped with interpretability and the ability of uncertainty quantification, SleepTransformer holds promise for being integrated into clinical settings.
description: This article has been published in IEEE Transactions on Biomedical Engineering
Super finite elements for nonlinear static and dynamic analysis of stiffened plate structures
Creators: name: Koko, Tamunoiyala Stanley
Publisher: name: University of British Columbia
Year: 2011

description: The analysis of stiffened plate structures subject to complex loads such as air-blast pressure waves from external or internal explosions, water waves, collisions or simply large static loads is still considered a difficult task. The associated response is highly nonlinear and although it can be solved with currently available commercial finite element programs, the modelling requires many elements with a huge amount of input data and very expensive computer runs. Hence this type of analysis is impractical at the preliminary design stage. The present work is aimed at improving this situation by introducing a new philosophy. That is, a new formulation is developed which is capable of representing the overall response of the complete structure with reasonable accuracy but with a sacrifice in local detailed accuracy. The resulting modelling is relatively simple thereby requiring much reduced data input and run times. It now becomes feasible to carry out design oriented response analyses. Based on the above philosophy, new plate and stiffener beam finite elements are developed for the nonlinear static and dynamic analysis of stiffened plate structures. The elements are specially designed to contain all the basic modes of deformation response which occur in stiffened plates and are called super finite elements since only one plate element per bay or one beam element per span is needed to achieve engineering design level accuracy at minimum cost. Rectangular plate elements are used so that orthogonally stiffened plates can be modelled. The von Karman large deflection theory is used to model the nonlinear geometric behaviour. Material nonlinearities are modelled by von Mises yield criterion and associated flow rule using a bi-linear stress-strain law. The finite element equations are derived using the virtual work principle and the matrix quantities are evaluated by Gauss quadrature. Temporal integration is carried out using the Newmark-β method with Newton-Raphson iteration for the nonlinear equations at each time step. A computer code has been written to implement the theory and this has been applied to the static, vibration and transient analysis of unstiffened plates, beams and plates stiffened in one or two orthogonal directions. Good approximations have been obtained for both linear and nonlinear problems with only one element representations for each plate bay or beam span with significant savings in computing time and costs. The displacement and stress responses obtained from the present analysis compare well with experimental, analytical or other numerical results.
Природа сил гравитации, инерции, движения планет
Creators: name: Ильченко Леонид Иванович
Publisher: name: Проблемы современной науки и образования
Year: 2017
Subjects: ПАРАДОКСЫ ЗАКОНА ВСЕМИРНОГО ТЯГОТЕНИЯ
PARADOXES OF THE LAW OF UNIVERSAL GRAVITATION
ТРЕТИЙ ЗАКОН КЕПЛЕРА
THE THIRD LAW OF KEPLER
ГРАВИТАЦИЯ
GRAVITATION
ЭКВИВАЛЕНТНОСТЬ МАСС
EQUIVALENCE OF MASSES
ИНЕРЦИЯ
INERTIA
ЭЛЛИПСНОСТЬ ОРБИТ
ELLIPSE OF ORBITS
УСКОРЕНИЕ СВОБОДНОГО ПАДЕНИЯ
ACCELERATION OF FREE FALL
ЭФИРНЫЙ ВИХРЬ
ETHER'S VORTEX NULL

description: Анализируя движение планет и их спутников, сделан вывод о том, что все физические тела взаимодействуют с окружающей всепроникающей средой, название которой может быть различным (в том числе эфиром), вихрь скорости которой наряду с магнитным полем определяется вращением ядер центральных космических тел. Показано, что сила гравитации определяется не массой тел, а ускорением вихря среды и суммарной массой элементарных частиц взаимодействующего физического тела; сила же инерции проявляется благодаря взаимодействию при ускоренном или замедленном движении непосредственно самих тел относительно среды. Предлагается объяснение эллипсности орбит и наблюдаемому постоянному увеличению радиуса орбиты Луны. Обосновано предположение о необычном свойстве окружающей среды, близком к физическим свойствам твердого тела, объясняющее обратно квадратичную зависимость уменьшения гравитации и третий закон Кеплера. Показана возможность управления гравитацией в локальных масштабах, искусственно побуждая электромагнитным полем движение среды.
Non-local Andreev reflection in superconducting quantum dots
Creators: name: Golubev, D. S.
name: Zaikin, A. D.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: With the aid of the Keldysh technique we develop a microscopic theory of non-local electron transport in three-terminal NSN structures consisting of a chaotic superconducting quantum dot attached to one superconducting and two normal electrodes. Our theory fully accounts for non-equilibrium effects and disorder in a superconducting terminal. We go beyond perturbation theory in tunneling and derive a general expression for the system conductance matrix which remains valid in both weak and strong tunneling limits. We demonstrate that the proximity effect yields a decrease of crossed Andreev reflection (CAR). Beyond weak tunneling limit the contribution of CAR to the non-local conductance does not cancel that of direct electron transfer between two normal terminals. We argue that temperature dependence of the non-local resistance of NSN devices is determined by the two competing processes -- Andreev reflection and charge imbalance -- and it has a pronounced peak occurring at the crossover between these two processes. This behavior is in a good agreement with recent experimental observations.
description: 10 pages, 5 figures
Resolving the Formation of Protogalaxies. I. Virialization
Creators: name: Wise, John H.
name: Abel, Tom
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: (Abridged) Galaxies form in hierarchically assembling dark matter halos. With cosmological three dimensional adaptive mesh refinement simulations, we explore in detail the virialization of baryons in the concordance cosmology, including optically thin primordial gas cooling. We focus on early protogalaxies with virial temperatures of 10^4 K and their progenitors. Without cooling, virial heating occurs in shocks close to the virial radius for material falling in from voids. Material in dense filaments penetrates deeper to about half that radius. With cooling the virial shock position shrinks and also the filaments reach scales as small as a third the virial radius. The temperatures in protogalaxies found in adiabatic simulations decrease by a factor of two from the center and show flat entropy cores. In cooling halos the gas reaches virial equilibrium with the dark matter potential through its turbulent velocities. We observe turbulent Mach numbers ranging from one to three in the cooling cases. This turbulence is driven by the large scale merging and interestingly remains supersonic in the centers of these early galaxies even in the absence of any feedback processes. The virial theorem is shown to approximately hold over 3 orders of magnitude in length scale with the turbulent pressure prevailing over the thermal energy. The turbulent velocity distributions are Maxwellian and by far dominate the small rotation velocities associated with the total angular momentum of the galaxies. Decomposing the velocity field using the Cauchy-Stokes theorem, we show that ample amounts of vorticity are present around shocks even at the very centers of these objects.
description: 13 pages, 6 figures. Submitted to ApJ on 8 March 2007. Revised manuscript. Comments welcome
Mode coupling on a geometrodynamical quantization of an inflationary universe
Creators: name: Brizuela, David
name: de Leon, Irene
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: A geometrodynamical quantization of an inflationary universe is considered in order to estimate quantum-gravity effects for the primordial perturbations. Contrary to previous studies in the literature, the back-reaction produced by all the modes of the system is included in our computations. Even if at a classical level the assumption that every mode evolves independently provides a good estimate for the dynamics, our results explicitly show that this is not the case when considering quantum-gravity effects. More precisely, both the self-interaction, as well as the back-reaction from other modes, provide a correction of the same order of magnitude to the usual power spectrum as computed in the approximation of quantum field theory on classical backgrounds. In particular, these quantum-gravity effects introduce certain characteristic scale-dependence on the expression of the power spectrum.
description: Published version. Some clarifications and comments added
Adiabatic Rotation, Quantum Search and Preparation of Superposition States
Creators: name: Siu, M. Stewart
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We introduce the idea of using adiabatic rotation to generate superpositions of a large class of quantum states. For quantum computing this is an interesting alternative to the well-studied "straight line" adiabatic evolution. In ways that complement recent results, we show how to efficiently prepare three types of states: Kitaev's toric code state, the cluster state of the measurement-based computation model and the history state used in the adiabatic simulation of quantum circuit. We also show that the method, when adapted for quantum search, provides quadratic speedup as other optimal methods do with the advantages that the problem Hamiltonian is time-independent and that the energy gap above the ground state is strictly nondecreasing with time. Likewise the method can be used for optimization as an alternative to the usual adiabatic algorithm.
description: Expanded to 6 pages; Accepted by Phys. Rev. A
Partially quenched chiral perturbation theory in the epsilon-regime
Creators: name: Damgaard, Poul H.
name: Fukaya, Hidenori
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We calculate meson correlators in the epsilon-regime within partially quenched chiral perturbation theory. The valence quark masses and sea quark masses can be chosen arbitrary and all non-degenerate. Taking some of the sea quark masses to infinity, one obtains a smooth connection among the theories with different number of flavors, as well as the quenched theory. These results can be directly compared with lattice QCD simulations.
description: 40pages, 7figures, Minor changes, references added
Evaluation of the perception of Iranian nurses towards spirituality in NICUs
Creators: name: Karimollahi, Mansoureh
Publisher: name: figshare
Year: 2021
Subjects: Health Care

description: Background: Holistic care is the evaluation of the physical and mental states of individuals. Considering the importance of spirituality in healthcare and its pivotal role as the first step toward providing spiritual care, this study was conducted to determine the perception of Iranian nurses towards spirituality in neonatal intensive care units (NICUs).
Methods: This study was conducted on nine participants using qualitative content analysis. In addition, purposive sampling was used to select the participants. Study setting was the NICUs at hospitals affiliated to Ardabil University of Medical Sciences, Ardabil, Iran. Data collection was performed through semi-structured interviews with the samples.
Results: Three main categories were discussed in this study, as follows: 1) “Meaning of spirituality” with three subcategories of “connectedness to God”, “sincerity”, and “prayers or recourse to Ahl-al-Bayt”; 2) “nature of spirituality” with three subcategories of “peace of mind”, “nursing performance beyond physical health care”, and “problem-solving”; 3) “respect for spiritual beliefs” with two subcategories of “respect for beliefs and values” and “persistent faith”.
Conclusion: The results of this study indicated that the perception of Iranian nurses toward spirituality is directly influenced by their religious tendencies, which denotes the importance of educational courses on spirituality for nurses. Therefore, it is recommended that nursing managers and directors implement training programs for the personnel in order to enhance spirituality.
Analysis procedures for caisson-retained island type structures
Creators: name: Salgado, Francisco Manuel Goncalves Alves
Publisher: name: University of British Columbia
Year: 2011

description: This thesis is concerned with the analysis of large offshore gravity structures used for oil exploration and recovery in the Beaufort Sea. Because of the high ice loads and the water depths involved, these structures comprise a large steel box infilled with a sand core for stability. One such structure was subjected to severe ice loading in April 1986 causing portions of the sand core to liquefy and bring the structure to a near failure condition. This structure was heavily monitored and thus serves as a case study against which the proposed analysis procedure can be checked. The behaviour of these soil-structure systems is highly complex depending upon the characteristics of the soil, the structural elements and the soil-structure interface. In this thesis a three-dimensional Finite Element computer program with soil, interface and structural elements is developed. Emphasis is placed on the three-dimensional stress-strain constitutive law both in terms of its ability to model observed laboratory response as well as the determination of the constitutive law parameters from in situ testing. The results obtained in terms of displacement, acceleration and zones of liquefaction by the analysis were then compared with the field measurements obtained during the April 1986 ice load event. The good agreement obtained between predicted and observed response is a validation of the proposed procedure.
Cohomology of Fiber Products of Local Rings
Creators: name: Moore, W. Frank
Publisher: name: arXiv
Year: 2007
Subjects: subject: Commutative Algebra (math.AC)
subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 13D02, 13D07, 13D40, 16S10, 16E30

description: Let $S$ and $T$ be local rings with common residue field $k$, let $R$ be the fiber product $S \times_k T$, and let $M$ be an $S$-module. The Poincaré series $P^R_M$ of $M$ has been expressed in terms of $P^S_M$, $P^S_k$ and $P^T_k$ by Kostrikin and Shafarevich, and by Dress and Krämer. Here, an explicit minimal resolution, as well as theorems on the structure of $\Ext_R(k,k)$ and $\Ext_R(M,k)$ are given that illuminate these equalities. Structure theorems for the cohomology modules of fiber products of modules are also given. As an application of these results, we compute the depth of cohomology modules over a fiber product.
description: 13 pages
Local elastic properties of polystyrene nanocomposites increase significantly due to non-affine deformations
Creators: name: Beltukov, Yaroslav M.
name: Conyuh, Dmitry A.
name: Solov'yov, Ilia A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We investigate the local elastic properties of polystyrene doped with SiO2 nanoparticles by analyzing the local density fluctuations. The density fluctuations were established from coarse-grained molecular dynamics simulations performed with the MARTINI force field. A significant increase in polystyrene stiffness was revealed within a characteristic range of 1.4 nm from the nanoparticle, while polystyrene density saturates to the bulk value at significantly shorter distances. The enhancement of the local elastic properties of the polymer was attributed to the effect of non-affine deformations at the length scale below 1 nm, which was further confirmed through the random matrix model with variable strength of disorder.
Difference Discrete Connection and Curvature on Cubic Lattice
Creators: name: Wu, Ke
name: Zhao, Wei-Zhong
name: Guo, Han-Ying
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mathematical Physics (math-ph)
subject: Differential Geometry (math.DG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: In a way similar to the continuous case formally, we define in different but equivalent manners the difference discrete connection and curvature on discrete vector bundle over the regular lattice as base space. We deal with the difference operators as the discrete counterparts of the derivatives based upon the differential calculus on the lattice. One of the definitions can be extended to the case over the random lattice. We also discuss the relation between our approach and the lattice gauge theory and apply to the discrete integrable systems.
description: 29 pages
Colossal magnon-phonon coupling in multiferroic Eu$_{0.75}$Y$_{0.25}$MnO$_3$
Creators: name: Aguilar, R. Valdés
name: Sushkov, A. B.
name: Zhang, C. L.
name: Choi, Y. J.
name: Cheong, S. -W.
name: Drew, H. D.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report the spectra of magnetically induced electric dipole absorption in Eu$_{0.75}$Y$_{0.25}$MnO$_3$ from temperature dependent far infrared spectroscopy (10-250 cm$^{-1}$). These spectra, which occur only in the $e||a$ polarization, consist of two relatively narrow electromagnon features that onset at $T_{FE}=30$ K and a broad absorption band that persists to temperatures well above $T_N=47$ K. The observed excitations account for the step up of the static dielectric constant in the ferroelectric phase. The electromagnon at 80 cm$^{-1}$ is observed to be strongly coupled to the nearby lowest optical phonon which transfers more than 1/2 of its spectral weight to the magnon. We attribute the origin of the broad background absorption to the two magnon emission decay process of the phonon.
description: 4 pages, 3 figures
Planting trees and shrubs - Sadzenie drzew i krzewów
Creators: name: Nowak Wojciech (Ed.)
Publisher: name: Zenodo
Year: 2016
Subjects: trees
bushes
planting

description: Broszura prezentuje podstawowe zasady sadzenia drzew i krzewów.  - The brochure presents in an easy way following steps to plant trees and bushes.
Learning Graph Structures with Transformer for Multivariate Time Series Anomaly Detection in IoT
Creators: name: Chen, Zekai
name: Chen, Dingshuo
name: Zhang, Xiao
name: Yuan, Zixuan
name: Cheng, Xiuzhen
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Cryptography and Security (cs.CR)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Many real-world IoT systems, which include a variety of internet-connected sensory devices, produce substantial amounts of multivariate time series data. Meanwhile, vital IoT infrastructures like smart power grids and water distribution networks are frequently targeted by cyber-attacks, making anomaly detection an important study topic. Modeling such relatedness is, nevertheless, unavoidable for any efficient and effective anomaly detection system, given the intricate topological and nonlinear connections that are originally unknown among sensors. Furthermore, detecting anomalies in multivariate time series is difficult due to their temporal dependency and stochasticity. This paper presented GTA, a new framework for multivariate time series anomaly detection that involves automatically learning a graph structure, graph convolution, and modeling temporal dependency using a Transformer-based architecture. The connection learning policy, which is based on the Gumbel-softmax sampling approach to learn bi-directed links among sensors directly, is at the heart of learning graph structure. To describe the anomaly information flow between network nodes, we introduced a new graph convolution called Influence Propagation convolution. In addition, to tackle the quadratic complexity barrier, we suggested a multi-branch attention mechanism to replace the original multi-head self-attention method. Extensive experiments on four publicly available anomaly detection benchmarks further demonstrate the superiority of our approach over alternative state-of-the-arts. Codes are available at https://github.com/ZEKAICHEN/GTA.
description: 12 pages, 5 figures, Accepted by IEEE Internet of Things Journal 2021
MOESM5 of A comprehensive genome-wide profiling comparison between HBV and HCV infected hepatocellular carcinoma
Creators: name: Sun, Suofeng
name: Li, Yuan
name: Han, Shuangyin
name: Jia, Hongtao
name: Li, Xiuling
name: Li, Xiaofang
Publisher: name: figshare
Year: 2019
Subjects: subject: Space Science
subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Genetics
subject: Molecular Biology
subject: Physiology
subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Mental Health
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: Additional file 5: Figure S1. The Circos plot of differential methylation in HCV-infected compared with HBV-infected HCCs. The outer layer represents CpG islands heatmap. Red color represents CpG islands are hypermethylated. Blue color represents CpG islands are hypomethylated. The middle layer represents the scatter plot of a single CpG site. Each dot represents a significant different DNA methylation changes, with p-value associated at Y-axis. The inner layer of circular plot is top 25 genes with the largest betafc value in DNA methylation changes of CpG islands.
A cosmic ray current driven instability in partially ionised media
Creators: name: Reville, B.
name: Kirk, J. G.
name: Duffy, P.
name: Sullivan, S. O.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate the growth of hydromagnetic waves driven by streaming cosmic rays in the precursor environment of a supernova remnant shock. It is known that transverse waves propagating parallel to the mean magnetic field are unstable to anisotropies in the cosmic ray distribution, and may provide a mechanism to substantially amplify the ambient magnetic field. We quantify the extent to which temperature and ionisation fractions modify this picture. Using a kinetic description of the plasma we derive the dispersion relation for a collisionless thermal plasma with a streaming cosmic ray current. Fluid equations are then used to discuss the effects of neutral-ion collisions. We calculate the extent to which the environment into which the cosmic rays propagate influences the growth of the magnetic field, and determines the range of possible growth rates. If the cosmic ray acceleration is efficient, we find that very large neutral fractions are required to stabilise the growth of the non-resonant mode. For typical supernova parameters in our galaxy, thermal effects do not significantly alter the growth rates. For weakly driven modes, ion-neutral damping can dominate over the instability at more modest ionisation fractions. In the case of a supernova shock interacting with a molecular clouds, such as in RX J1713.7-3946, with high density and low ionisation, the modes can be rapidly damped.
description: 5 pages, 2 figures, accepted to A&A. Corrections made. Applications added
Deep Indexed Active Learning for Matching Heterogeneous Entity Representations
Creators: name: Jain, Arjit
name: Sarawagi, Sunita
name: Sen, Prithviraj
Publisher: name: arXiv
Year: 2021
Subjects: subject: Databases (cs.DB)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Given two large lists of records, the task in entity resolution (ER) is to find the pairs from the Cartesian product of the lists that correspond to the same real world entity. Typically, passive learning methods on such tasks require large amounts of labeled data to yield useful models. Active Learning is a promising approach for ER in low resource settings. However, the search space, to find informative samples for the user to label, grows quadratically for instance-pair tasks making active learning hard to scale. Previous works, in this setting, rely on hand-crafted predicates, pre-trained language model embeddings, or rule learning to prune away unlikely pairs from the Cartesian product. This blocking step can miss out on important regions in the product space leading to low recall. We propose DIAL, a scalable active learning approach that jointly learns embeddings to maximize recall for blocking and accuracy for matching blocked pairs. DIAL uses an Index-By-Committee framework, where each committee member learns representations based on powerful pre-trained transformer language models. We highlight surprising differences between the matcher and the blocker in the creation of the training data and the objective used to train their parameters. Experiments on five benchmark datasets and a multilingual record matching dataset show the effectiveness of our approach in terms of precision, recall and running time. Code is available at https://github.com/ArjitJ/DIAL
description: VLDB 2022
Gravitational collapse of spherically symmetric plasmas in Einstein-Maxwell spacetimes
Creators: name: Lasky, Paul
name: Lun, Anthony
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We utilize a recent formulation of a spherically symmetric spacetime endowed with a general decomposition of the energy momentum tensor [Phys. Rev. D, 75, 024031 (2007)] to derive equations governing spherically symmetric distributions of electromagnetic matter. We show the system reduces to the Reissner-Nordstrom spacetime in general, spherically symmetric coordinates in the vacuum limit. Furthermore, we show reduction to the charged Vaidya spacetime in non-null coordinates when certain equations of states are chosen. A model of gravitational collapse is discussed whereby a charged fluid resides within a boundary of finite radial extent on the initial hypersurface, and is allowed to radiate charged particles. Our formalism allows for the discussion of all regions in this model without the need for complicated matching schemes at the interfaces between successive regions. As further examples we consider the collapse of a thin shell of charged matter onto a Reissner-Nordstrom black hole. Finally, we reduce the entire system of equations to the static case such that we have the equations for hydrostatic equilibrium of a charged fluid.
description: Accepted for publication in Phys. Rev. D
16-20 Jupiter mass RV companion orbiting the brown dwarf candidate ChaHa8
Creators: name: Joergens, V.
name: Mueller, A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the discovery of a 16-20 Jupiter mass radial velocity companion around the very young (~3 Myr) brown dwarf candidate ChaHa8 (M5.75-M6.5). Based on high-resolution echelle spectra of ChaHa8 taken between 2000 and 2007 with UVES at the VLT, a companion was detected through RV variability with a semi-amplitude of 1.6 km/s. A Kepler fit to the data yields an orbital period of the companion of 1590 days and an eccentricity of e=0.49. A companion minimum mass M2sini between 16 and 20 Jupiter masses is derived when using model-dependent mass estimates for the primary. The mass ratio q= M2/M1 might be as small as 0.2 and, with a probability of 87%, it is less than 0.4. ChaHa8 harbors most certainly the lowest mass companion detected so far in a close (~ 1 AU) orbit around a brown dwarf or very low-mass star. From the uncertainty in the orbit solution, it cannot completely be ruled out that the companion has a mass in the planetary regime. Its discovery is in any case an important step towards RV planet detections around BDs. Further, ChaHa8 is the fourth known spectroscopic brown dwarf or very low-mass binary system with an RV orbit solution and the second known very young one.
description: 8 pages, 1 figure, ApJ Letter in press
Evaluating shear wave velocity and pore pressure data from the seismic cone penetration test
Creators: name: Gillespie, Donald G. (Donald Gardner)
Publisher: name: University of British Columbia
Year: 2011

description: Recent developments in cone penetration testing have resulted in the addition of both pore pressure measurements and seismometers. The seismometers allow shear wave velocity testing to be performed at designated intervals. Both of these additions were researched to improve their application and interpretation. The significant factors effecting the pore pressure generated during cone penetration tests are discussed. The importance of various factors is especially dependent upon permeability, strength, and stiffness. For all sands tested, pore pressures lower than static were recorded behind the tip and higher than static were recorded on the face of the cone. It is believed that the large compressive stresses on the cone face result in positive pore pressures. As the cone tip passes a soil element unloading and continued shearing generate pore pressures lower than static in all sands. The sign of this pore pressure (higher or lower than static) was therefore considered primarily a function of the test equipment. Pore pressure response and the rate of dissipation of excess pore pressures were found useful in distinguishing fine granular soils and explaining soil stratigraphy. In cohesive soils the details of pore pressure measurement were found to be important only in stiff soils. Pore pressures at all measurement locations were found to increase with soil strength in soft to firm clays but may be negative of static in very stiff clays. Pore pressures behind the cone tip were often negative of static in stiff clays. Measurement techniques were refined to improve the accuracy of downhole shear wave velocity measurements. Comparisons of downhole and crosshole measurements were made at three well documented sites validating the technique. At several sites it was found useful to consider the Gmax values determined from shear wave velocity and density to distinguish soil type. Gmax to cone resistance ratios were shown to vary systematically with cone resistance values in sands. A wide range in Gmax to cone resistance was observed in clays. The dependence of both cone penetration resistance and Gmax to increased stress level or overburden stress is discussed.
Ergodic properties of Poissonian ID processes
Creators: name: Roy, Emmanuel
Publisher: name: arXiv
Year: 2007
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60G10, 60E07, 37A05 (Primary) 37A40, 60G55 (Secondary)

description: We show that a stationary IDp process (i.e., an infinitely divisible stationary process without Gaussian part) can be written as the independent sum of four stationary IDp processes, each of them belonging to a different class characterized by its Lévy measure. The ergodic properties of each class are, respectively, nonergodicity, weak mixing, mixing of all order and Bernoullicity. To obtain these results, we use the representation of an IDp process as an integral with respect to a Poisson measure, which, more generally, has led us to study basic ergodic properties of these objects.
description: Published at http://dx.doi.org/10.1214/009117906000000692 in the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Constraining density and metallicity of the Milky Way's hot gas halo from O VII spectra and ram-pressure stripping
Creators: name: Martynenko, Nickolay
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Milky Way's hot gaseous halo extends up to the Galactic virial radius ($\sim 200$ kpc) and contains a significant component of baryon mass of the Galaxy. The halo properties can be constrained from X-ray spectroscopic observations and from satellite galaxies' ram-pressure stripping studies. Results of the former method crucially depend on the gas metallicity assumptions while the latter one's are insensitive to them. Here, a joint analysis of both kinds of data is presented to constrain electron density and metallicity of the gas. The power law is assumed for the electron density radial profile, while for the metallicity, a common-used constant-metallicity assumption is relaxed by introducing of a physically motivated spherical profile. The model is fitted to a sample of 431 (18) sight lines for O VII emission (absorption) measurements and 7 electron density constraints from ram-pressure stripping studies. The best-fitting halo-associated electron density profile of $n_e\propto r^{-(0.9...1.1)}$ (where $r\gg1$ kpc is the galactocentric radius) is found. The metallicity is constrained as $Z \approx (0.1...0.7) Z_{\odot}$ (subscript $\odot$ represents the solar values) at $r>50$ kpc. These imply a total hot gas mass of $M \approx (2.4...8.7) \times 10^{10} M_{\odot}$, which accounts for $\sim(17...100)$ per cent of the Milky Way's missing baryon mass. The model uncertainties are discussed, and the results are examined in the context of previous studies.
description: 16 pages, 10 figures. v2: Minor changes in filtering procedure, discussion extended (Fig. 8 and 9). Main results unchanged. Accepted by MNRAS
Asymptotics of Tracy-Widom distributions and the total integral of a Painlevé II function
Creators: name: Baik, Jinho
name: Buckingham, Robert
name: DiFranco, Jeffery
Publisher: name: arXiv
Year: 2007
Subjects: subject: Functional Analysis (math.FA)
subject: Mathematical Physics (math-ph)
subject: Probability (math.PR)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 15A52; 33E17; 35Q15

description: The Tracy-Widom distribution functions involve integrals of a Painlevé II function starting from positive infinity. In this paper, we express the Tracy-Widom distribution functions in terms of integrals starting from minus infinity. There are two consequences of these new representations. The first is the evaluation of the total integral of the Hastings-McLeod solution of the Painlevé II equation. The second is the evaluation of the constant term of the asymptotic expansions of the Tracy-Widom distribution functions as the distribution parameter approaches minus infinity. For the GUE Tracy-Widom distribution function, this gives an alternative proof of the recent work of Deift, Its, and Krasovsky. The constant terms for the GOE and GSE Tracy-Widom distribution functions are new.
description: 29 pages, 1 figure