Skip to content

April 2019 arXiv papers — page 4

Showing 301400 of 12,989 papers

  1. Jiacheng Zhang, Melissa C. Brindise, Sean Rothenberger, Susanne Schnell

    This work introduces a 4D-flow magnetic resonance imaging (MRI) pressure reconstruction method which employs weighted least-squares (WLS) for pressure integration. Pressure gradients are calculated from the velocity fields, and velocity errors are estimated from the velocity divergence for incompressible flow. Pressure gradient errors are estimated by propag

  2. Xiaoke Li, Joachim Paier, Joachim Sauer

    Recently, the hydrogen adsorption and diffusion on the CeO2 (111) surface have been a vividly discussed topic because of its outstanding catalytic activity and selectivity in hydrogenation reactions. However, for the strongly reduced CeO2 (111) surface, the structure as well as the stability of hydride anions are still unclear. By virtue of density functiona

  3. Pavel Stovicek

    Let $\{\hat{P}_{n}(x)\}$ be an orthonormal polynomial sequence and denote by $\{w_{n}(x)\}$ the respective sequence of functions of the second kind. Suppose the Hamburger moment problem for $\{\hat{P}_{n}(x)\}$ is determinate and denote by $J$ the corresponding Jacobi matrix operator on $\ell^{2}$. We show that if $J$ is positive definite and $J^{-1}$ belong

  4. Samet Atdag, Haluk O. Bingol

    Identifying noteworthy spreaders in a network is essential for understanding the spreading process and controlling the reach of the spread in the network. The nodes that are holding more intrinsic power to extend the reach of the spread are important due to demand for various applications such as viral marketing, controlling rumor spreading or get a better u

  5. James Bocinsky, Connor McCurley, Daniel Shats, Alina Zare

    Sensors which use electromagnetic induction (EMI) to excite a response in conducting bodies have long been investigated for subsurface explosive hazard detection. In particular, EMI sensors have been used to discriminate between different types of objects, and to detect objects with low metal content. One successful, previously investigated approach is the M

  6. Marjan Alirezaie, Martin Längkvist, Michael Sioutis, Amy Loutfi

    Understanding why machine learning algorithms may fail is usually the task of the human expert that uses domain knowledge and contextual information to discover systematic shortcomings in either the data or the algorithm. In this paper, we propose a semantic referee, which is able to extract qualitative features of the errors emerging from deep machine learn

  7. Wei Ma, Mike Papadakis, Anestis Tsakmalis, Maxime Cordy

    Testing of deep learning models is challenging due to the excessive number and complexity of computations involved. As a result, test data selection is performed manually and in an ad hoc way. This raises the question of how we can automatically select candidate test data to test deep learning models. Recent research has focused on adapting test selection me

  8. Gregor Zens, Maximilian Böck

    This paper investigates the role of high-dimensional information sets in the context of Markov switching models with time varying transition probabilities. Markov switching models are commonly employed in empirical macroeconomic research and policy work. However, the information used to model the switching process is usually limited drastically to ensure sta

  9. Fateme Olia, Shaban Ghalandarzadeh, Amirhossein Amiraslani, Sedighe Jamshidvand

    In this paper, we introduce and analyze a normalization method for solving a system of linear equations over tropical semirings. We use a normalization method to construct an associated normalized matrix, which gives a technique for solving the system. If solutions exist, the method can also determine the degrees of freedom of the system. Moreover, we presen

  10. B. A. Arbuzov, I. V. Zaitsev

    The process $p+p\to W^\pm W^+ W^-$ with lepton decays of $W$-bosons is shown to be promising for improving conditions for studies of parameter $\lambda$, which is the anomalous triple $W$-bosons interaction coupling constant.

  11. Marco Frasca, Alfonso Farina, Moawia Alghalith

    We lay the theoretical and mathematical foundations of the square root of Browniam motion and we prove the existence of such a process. In doing so, we consider Brownian motion on quantized noncommutative Riemannian manifolds and show how a set of stochastic processes on sets of complex numbers can be devised. This class of stochastic processes are shown to

  12. Yu Li

    Cook's theorem is commonly expressed such as any polynomial time-verifiable problem can be reduced to the SAT problem. The proof of Cook's theorem consists in constructing a propositional formula A(w) to simulate a computation of TM, and such A(w) is claimed to be CNF to represent a polynomial time-verifiable problem w. In this paper, we investigate A(w) thr

  13. Alexandru Chirvasitu

    A family of algebra maps $H\to A_i$ whose common domain is a Hopf algebra is said to be jointly inner faithful if it does not factor simultaneously through a proper Hopf quotient of $H$. We show that tensor and free products of jointly inner faithful maps of Hopf algebras are again jointly inner faithful, generalizing a number of results in the literature on

  14. Yuan Wei, Zili Feng, Clarina dela Cruz, Wei Yi

    The antiferromagnetism in $\alpha$-Cu$_3$Mg(OH)$_6$Br$_2$ was studied by magnetic-susceptibility, specific-heat and neutron-diffraction measurements. The crystal structure consists of Cu$^{2+}$ kagome layers with Mg$^{2+}$ ions occupying the centers of the hexagons, separated by Br$^{1-}$ ions. The magnetic system orders antiferromagnetically at 5.4 K with t

  15. Nathan Grieve

    We study the greatest common divisor problem for torus invariant blowing-up morphisms of nonsingular toric Fano varieties. Our main result applies the theory of Okounkov bodies together with an arithmetic form of Cartan's Second Main theorem, which has been established by Ru and Vojta. It also builds on Silverman's geometric concept of greatest common diviso

  16. Amy Tabb, Germán A Holguín, Rachel Naegele

    Images are used frequently in plant phenotyping to capture measurements. This chapter offers a repeatable method for capturing two-dimensional measurements of plant parts in field or laboratory settings using a variety of camera styles (cellular phone, DSLR), with the addition of a printed calibration pattern. The method is based on calibrating the camera us

  17. Reshmi Roy, Purusattam Ray, Parongama Sen

    Dynamical features of tagged particles are studied in a one dimensional $A+A \rightarrow kA$ system for $k=0$ and 1, where the particles $A$ have a bias $\epsilon$ $(0 \leq \epsilon \leq 0.5)$ to hop one step in the direction of their nearest neighboring particle. $\epsilon=0$ represents purely diffusive motion and $\epsilon=0.5$ represents purely determinis

  18. David A. Croydon, Makiko Sasada, Satoshi Tsujimoto

    By encoding configurations of the ultra-discrete Toda lattice by piecewise linear paths whose gradient alternates between $-1$ and $1$, we show that the dynamics of the system can be described in terms of a shifted version of Pitman's transformation (that is, reflection in the past maximum of the path encoding). This characterisation of the dynamics applies

  19. Nathan Grieve

    We revisit work of S. Boucksom, C. Favre, and M. Jonsson (J. Algebraic Geom. \textbf{18} (2009), no. 2, 279--308); Boucksom and H. Chen (Compos. Math. \textbf{147} (2011), no. 4, 1205--1229); and S. Boucksom, A. K\"{u}ronya, C. Maclean, and T. Szemberg (Math. Ann. \textbf{361} (2015), no.~3--4, 811--834). The key point is to associate a Duistermaat-Heckman m

  20. Nataliya Bobrovska, Andrzej Opala, Paweł Miętki, Michał Kulczykowski

    We study nonresonantly pumped exciton-polariton system in the vicinity of the dynamical instability threshold. We find that the system exhibits unique and rich dynamics, which leads to spatiotemporal pattern formation. The patterns have a tree-like structure and are reminiscent of structures that appear in a variety of soft matter systems. Within the approxi

  21. Xianbin Wang, Huazi Zhang, Rong Li, Jiajie Tong

    In this paper, we propose a type of $G_N$-coset codes for a highly parallel stage-permuted turbo-like decoder. The decoder exploits the equivalence between two stage-permuted factor graphs of $G_N$-coset codes. Specifically, the inner codes of a $G_N$-coset code consist of independent component codes, thus are decoded in parallel. The extrinsic information o

  22. Eliana Fiorelli, Pietro Rotondo, Federico Carollo, Matteo Marcuzzi

    Spin-boson Hamiltonians are an effective description for numerous quantum many-body systems such as atoms coupled to cavity modes, quantum electrodynamics in circuits and trapped ion systems. While reaching the limit of strong coupling is possible in current experiments, the understanding of the physics in this parameter regime remains a challenge, especiall

  23. Yurii A. Ermakova, Victor E. Asadchikov, Yurii O. Volkov, Alexander D. Nuzhdin

    The effect of the adsorption of a polypeptide on the lateral interaction of dimyristoylphosphatidylserine molecules in different phase states on the surface of a 10\,mM KCl aqueous solution has been studied. Changes in the surface pressure and Volta potential induced by the adsorption of large poly-D-lysine molecules (about 200 links in a chain) have been de

  24. Shuhan Tan, Jiening Jiao, Wei-Shi Zheng

    In conventional domain adaptation, a critical assumption is that there exists a fully labeled domain (source) that contains the same label space as another unlabeled or scarcely labeled domain (target). However, in the real world, there often exist application scenarios in which both domains are partially labeled and not all classes are shared between these

  25. Abhishek Abhishek, Sanya Bathla Taneja, Garima Malik, Ashish Anand

    Fine-grained Entity Recognition (FgER) is the task of detecting and classifying entity mentions to a large set of types spanning diverse domains such as biomedical, finance and sports. We observe that when the type set spans several domains, detection of entity mention becomes a limitation for supervised learning models. The primary reason being lack of data

  26. Luis Guarracino, Damien Jougnot

    Among the different contributions generating self-potential, the streaming potential is of particular interest in hydrogeology for its sensitivity to water flow. Estimating water flux in porous media using streaming potential data relies on our capacity to understand, model, and upscale the electrokinetic coupling at the mineral-solution interface. Different

  27. R B Paris, Vladimir V Vinogradov

    We evaluate the sum of Gauss hypergeometric functions \[S(\mu,c;x)=\sum_{k\geq 0} \bl(\frac{1-x}{1+\mu}\br)^k\,{}_2F_1(\fs k+\fs, \fs k+1;c;x)\] for $x\in [-1,1]$ and positive parameters $\mu$ and $c$. The domain of absolute convergence of this series is established by determining the growth of the hypergeometric function for $k\to+\infty$. An application to

  28. Manuel Fernandez Lopez, Jaime Merino

    An analysis of the stability of topological states induced by Coulomb repulsion on decorated honeycomb lattices is presented. Based on a mean-field treatment of a spinless extended Hubbard model on the decorated honeycomb lattice we show how the quantum anomalous Hall (QAH) phase is a robust topological phase which emerges at various electron fillings and in

  29. Claudio Corianò, Matteo Maria Maglio, Alessandro Tatullo, Dimosthenis Theofilopoulos

    The general solution of the conformal Ward identities (CWI's) in momentum space, and their matching to perturbation theory, allows to uncover some specific characteristics of the breaking of conformal symmetry, induced by the anomaly. It allows to compare perturbative features of the 1-particle irreducible (1PI, nonlocal) anomaly action with the prediction o

  30. Erisa Karafili, Linna Wang, Emil C. Lupu

    We expect an increase in the frequency and severity of cyber-attacks that comes along with the need for efficient security countermeasures. The process of attributing a cyber-attack helps to construct efficient and targeted mitigating and preventive security measures. In this work, we propose an argumentation-based reasoner (ABR) as a proof-of-concept tool t

  31. Claudio Guarcello, Paolo Solinas, Francesco Giazotto, Alessandro Braggio

    We study thermal transport induced by soliton dynamics in a long Josephson tunnel junction operating in the flux-flow regime. A thermal bias across the junction is established by imposing the superconducting electrodes to reside at different temperatures, when solitons flow along the junction. Here, we consider the effect of both a bias current and an extern

  32. Jun Seok Oh, Qinghai Zhong

    Let $G$ be a finite group and exp$(G)$ = lcm$\{$ord$(g)$$\mid$$g \in G \}$. A finite unordered sequence of terms from $G$, where repetition is allowed, is a product-one sequence if its terms can be ordered such that their product equals the identity element of $G$. We denote by $\mathsf s (G)$ (or $\mathsf E (G)$ respectively) the smallest integer $\ell$ suc

  33. G. Houdek, M. N. Lund, R. Trampedach, J. Christensen-Dalsgaard

    Linear damping rates and modal frequency corrections of radial oscillation modes in selected LEGACY main-sequence stars are estimated by means of a nonadiabatic stability analysis. The selected stellar sample covers stars observed by Kepler with a large range of surface temperatures and surface gravities. A nonlocal, time-dependent convection model is pertur

  34. Sedighe Jamshidvand, Shaban Ghalandarzadeh, Amirhossein Amiraslani, Fateme Olia

    In this paper, we present methods for solving a system of linear equations, $ AX=b $, over tropical semirings. To this end, if possible, we first reduce the order of the system through some row-column analysis, and obtain a new system with fewer equations and variables. We then use the pseudo-inverse of the system matrix to solve the system if solutions exis

  35. Boyan T. Torosov, Nikolay V. Vitanov

    Composite pulses --- sequences of pulses with well defined relative phases --- are an efficient, robust and flexible technique for coherent control of quantum systems. Composite sequences can compensate a variety of experimental errors in the driving field (e.g. in the pulse amplitude, duration, detuning, chirp, etc.) or in the quantum system and its environ

  36. Birgit Stiller, Moritz Merklein, Christian Wolff, Khu Vu

    Acoustic waves can serve as memory for optical information, however, acoustic phonons in the GHz regime decay on the nanosecond timescale. Usually this is dominated by intrinsic acoustic loss due to inelastic scattering of the acoustic waves and thermal phonons. Here we show a way to counteract the intrinsic acoustic decay of the phonons in a waveguide by re

  37. Frank Rathmann, Nikolai N. Nikolaev

    The Standard Model (SM) of Particle Physics is not capable to account for the apparent matter-antimatter asymmetry of our Universe. Physics beyond the SM is required and is either probed by employing highest energies (e.g., at LHC), or by striving for ultimate precision and sensitivity (e.g., in the search for electric dipole moments). Permanent electric dip

  38. Hugo Théveniaut, Fabien Alet

    Determining phase diagrams and phase transitions semi-automatically using machine learning has received a lot of attention recently, with results in good agreement with more conventional approaches in most cases. When it comes to more quantitative predictions, such as the identification of universality class or precise determination of critical points, the t

  39. Chunmei Dong, Yeting Li, Haiming Chen

    The advantages for the presence of an XML schema for XML documents are numerous. However, many XML documents in practice are not accompanied by a schema or by a valid schema. Relax NG is a popular and powerful schema language, which supports the unconstrained interleaving operator. Focusing on the inference of Relax NG, we propose a new subclass of regular e

  40. Cheng Chen, Dushyantha Basnayaka, Ardimas Andi Purwita, Xiping Wu

    LiFi (light-fidelity) is recognised as a promising technology for the next generation wireless access network. However, little research effort has been spent on the uplink transmission system in LiFi networks. In this paper, an analytical framework for the performance analysis of an wireless infrared-based LiFi uplink at system level is presented. This work

  41. Shijie Shang, Tusheng Zhang

    In this paper, we established a quadratic transportation cost inequality for solutions of stochastic reaction diffusion equations driven by multiplicative space-time white noise based on a new inequality we proved for the moments (under the uniform norm) of the stochastic convolution with respect to space-time white noise, which is of independent interest. T

  42. E. Artur de la Villarmois, J. K. Jørgensen, L. E. Kristensen, E. A. Bergin

    (Abridged) The purpose of this paper is to explore and compare the physical and chemical structure of Class I low-mass protostellar sources on protoplanetary disc scales. We present a study of the dust and gas emission towards a representative sample of 12 Class I protostars from the Ophiuchus molecular cloud with the Atacama Large Millimeter/submillimeter A

  43. Munehisa Matsumoto

    The quantum critical point (QCP) in the archetypical heavy-fermion compound CeCu$_6$ doped by Au is described, accounting for the localized $4f$-electron of Ce, using realistic electronic structure calculations combined with dynamical mean-field theory (DMFT). Magnetism trends in Ce(Cu$_{1-\epsilon}$Au$_\epsilon$)$_6$ are compared with those in Co-doped CeCu

  44. Krishnakanta Mondal, Prasenjit Ghosh

    MXenes, a new class of two dimensional materials with several novel properties, are usually prepared from their MAX phases by etching out the A element using strong chemical reagents. This results in passivation of the surfaces of MXene with different functional groups like O, -OH, -F, etc., which in many cases tend to degrade their properties. In this work,

  45. Seolhwa Kim, Ewan D. Stewart

    Affleck-Dine leptogenesis after thermal inflation along the $LH_u$ direction requires $m_L^2+m_{H_u}^2 < 0$ up to the AD scale ($|L|\simeq |H_u|\sim 10^9$ GeV). We renormalised this condition from the AD scale to the soft supersymmetry breaking scale by solving the renormalisation group equations perturbatively in the Yukawa couplings to obtain a semi-analyt

  46. Marius Schöndorf, Adrian Lupascu, Frank K. Wilhelm

    Common flux qubit readout schemes are qubit dominated, meaning they measure in the energy eigenbasis of the qubit. For various applications meausrements in a basis different from the energy eigenbasis are required. Here we present an indirect measurement protocol, which is detector dominated instead of qubit dominated, yielding a projective measurements in t

  47. Yanning Xu

    We show some inductive statements for the index conjecture for log canonical Calabi-Yau pairs. Using it, we show that boundedness of log canonical index for log canonical Calabi Yau pairs with rational DCC coefficients in dimension 3. We also show boundedness of log canonical index for klt log Calabi-Yau pairs in dimension 4 with $B\neq 0$.

  48. Lucas Fresse, Kyo Nishiyama

    For a reductive group $G$, Steinberg established a map from the Weyl group to the set of nilpotent $G$-orbits by using moment maps on double flag varieties. In particular, in the case of the general linear group, it provides a geometric interpretation of the Robinson-Schensted correspondence between permutations and pairs of standard tableaux of the same sha

  49. I. D. Karachentsev, V. E. Karachentseva

    We use a sample of 220 face-on bulge-less galaxies situated in the low density environment to estimate their total mass via orbital motions of supposed rare satellites. Our inspection reveals 43 dwarf companions having the mean projected separation of 130 kpc and the mean-square velocity difference of 96 km/s. For them, we obtain the mean orbital-mass-to-K-b

  50. Delphine Poux, Benjamin Allaert, Jose Mennesson, Nacim Ihaddadene

    Although much progress has been made in the facial expression analysis field, facial occlusions are still challenging. The main innovation brought by this contribution consists in exploiting the specificities of facial movement propagation for recognizing expressions in presence of important occlusions. The movement induced by an expression extends beyond th

  51. Artem Bohdan, Jacek Niemiec, Martin Pohl, Yosuke Matsumoto

    Electron injection at high Mach-number nonrelativistic perpendicular shocks is studied here for parameters that are applicable to young SNR shocks. Using high-resolution large-scale two-dimensional fully kinetic particle-in-cell (PIC) simulations and tracing individual particles we in detail analyze the shock surfing acceleration (SSA) of electrons at the le

  52. D. Geelen, J. Jobst, E. E. Krasovskii, S. J. van der Molen

    In contrast to the in-plane transport electron mean-free path in graphene, the transverse mean-free path has received little attention and is often assumed to follow the 'universal' mean-free path (MFP) curve broadly adopted in surface and interface science. Here we directly measure transverse electron scattering through graphene from 0 to 25 eV above the va

  53. S. Khrapak, P. Huber, H. Thomas, V. Naumkin. V. Molotkov

    In the last experiment with the PK-3 Plus laboratory onboard the International Space Station, interactions of millimeter-size metallic spheres with a complex plasma were studied~[M. Schwabe {\it et al.}, New J. Phys. {\bf 19}, 103019 (2017)]. Among the phenomena observed was the formation of cavities (regions free of microparticles forming a complex plasma)

  54. Zhe Zhao, Hao Song, Runzhou Zhang, Kai Pang

    Novel forms of beam generation and propagation based on structured light and orbital angular momentum (OAM) have gained significant interest over the past several years. Indeed, dynamic OAM can manifest at a given propagation distance in different forms , including: (1) a simple Gaussian-like beam "dot" "revolves" around an offset central axis in time, and (

  55. Mehmet Emre Tasgin, Mehmet Gunay, M. Suhail Zubairy

    Mode-entanglement based criteria and measures become insufficient for broadband emission, e.g. from spasers (plasmonic nano-lasers). We introduce criteria and measures for the (i) total entanglement of two wavepackets, (ii) entanglement of a wavepacket with an ensemble and (iii) total nonclassicality of a wavepacket~(WP). We discuss these criteria in the con

  56. Zhennan Wang, Wenbin Zou, Chen Xu

    In this paper, we analyze the inner product of weight vector w and data vector x in neural networks from the perspective of vector orthogonal decomposition and prove that the direction gradient of w decreases with the angle between them close to 0 or {\pi}. We propose the Projection and Rejection Product (PR Product) to make the direction gradient of w indep

  57. Simon Clinet, William T. M. Dunsmuir, Gareth W. Peters, Kylie-Anne Richards

    The asymptotic distribution of the score test of the null hypothesis that marks do not impact the intensity of a Hawkes marked self-exciting point process is shown to be chi-squared. For local asymptotic power, the distribution against local alternatives is also established as non-central chi-squared. These asymptotic results are derived using existing asymp

  58. S. Sofer, O. Sefi, E. Strizhevsky, S. P. Collins

    Nonlinear interactions between x-rays and long wavelengths can be used as a powerful atomic scale probe for light-matter interactions and for properties of valence electrons. This probe can provide novel microscopic information in solids that existing methods cannot reveal, hence to advance the understanding of many phenomena in condensed matter physics. How

  59. Bogdan R. Bułka, Jakub Łuczak

    We present studies of the electron transport and circular currents induced by the bias voltage and the magnetic flux threading a ring of three quantum dots coupled with two electrodes. Quantum interference of electron waves passing through the states with opposite chirality plays a relevant role in transport, where one can observe Fano resonance with destruc

  60. Luigi Consolino, Annamaria Campa, Davide Mazzotti, Miriam Serena Vitiello

    We report on the development, testing, and performance analysis of a bow-tie resonant cavity for terahertz (THz) radiation, injected with a continuous-wave 2.55 THz quantum cascade laser. The bow-tie cavity employs a wire-grid polarizer as input/output coupler and a pair of copper spherical mirrors coated with an unprotected 500 nm thick gold layer. The impr

  61. Chien-Feng Liao, Yu Tsao, Xugang Lu, Hisashi Kawai

    In a noisy environment, a lossy speech signal can be automatically restored by a listener if he/she knows the language well. That is, with the built-in knowledge of a "language model", a listener may effectively suppress noise interference and retrieve the target speech signals. Accordingly, we argue that familiarity with the underlying linguistic content of

  62. Michele De Regis, Luigi Consolino, Saverio Bartalini, Paolo De Natale

    The 1-10 terahertz (THz) spectral window is emerging as a key region for plenty of applications, requiring not yet available continuous-wave room-temperature THz spectrometers with high spectral purity and ultra-broad tunability. In this regard, the spectral features of stabilized telecom sources can actually be transferred to the THz range by difference fre

  63. Leonid Liokumovich, Konstantin Muravyov, Philipp Skliarov, Nikolai Ushakov

    In the current paper, we have developed an analytical apparatus, allowing to calculate the phase error, produced by miscalibration of modulation parameters. The case of harmonic modulation is considered, the analysis is performed for cases of two parameters miscalibration: amplitude and start phase. Two demodulation algorithms are considered: conventional 4-

  64. Leonid Liokumovich, Andrei Medvedev, Konstantin Muravyov, Philipp Skliarov

    In current paper, distortions in digital demodulation schemes with harmonic phase modulation for interferometric optical sensors are considered. In particular, the influence of target signal variations on phase demodulation errors is theoretically evaluated. An analytical expression, describing the phase error magnitude dependence on first derivative and mea

  65. Omar Cheikhrouhou, Anis Koubaa

    Several IoT applications are tightly dependent on the locations of the devices. However, localization algorithms can be easily compromised by injecting false locations. In this paper, we propose a Blockchain-based secure localization algorithm for the Internet of Things (IoT). The algorithm uses a public ledger (Blockchain) that contains nodes position and t

  66. Tuuelbay Kurbanbaev, Rustam Turdibaev

    All finite-dimensional Leibniz algebra bimodules of a Lie algebra $\mathfrak{sl}_2$ over a field of characteristic zero are described.

  67. Alexander A. Antonov, Maxim V. Gorkunov

    We optimize optical performance of metasurfaces based on periodically corrugated silicon layers by adjusting the Fourier coefficients of their surface profile. For smooth corrugations, we demonstrate an excellent quantitative accuracy of semi-analytical approach based on the Rayleigh hypothesis. We employ the approach to design metasurfaces with anomalous re

  68. N. D. Gilbert, E. A. McDougall

    We describe a formalism, using groupoids, for the study of rewriting for presentations of inverse monoids, that is based on the Squier complex construction for monoid presentations. We introduce the class of pseudoregular groupoids, an example of which now arises as the fundamental groupoid of our version of the Squier complex. A further key ingredient is th

  69. Nikolai Ushakov, Leonid Liokumovich

    A novel approach for measuring fast oscillations of an absolute value of interferometer optical path difference (OPD) has been developed. The principles of frequency-scanning interferometry are utilized for registration of the interferometer spectral function, from which the OPD is calculated. The proposed approach enables one to capture the absolute baselin

  70. Pere Ara, Fernando Lledó, Diego Martínez

    We analyze the dichotomy amenable/paradoxical in the context of (discrete, countable, unital) semigroups and corresponding semigroup rings. We consider also F{\o}lner's type characterizations of amenability and give an example of a semigroup whose semigroup ring is algebraically amenable but has no F{\o}lner sequence. In the context of inverse semigroups $S$

  71. Yuki M. Asano, Christian Rupprecht, Andrea Vedaldi

    We look critically at popular self-supervision techniques for learning deep convolutional neural networks without manual labels. We show that three different and representative methods, BiGAN, RotNet and DeepCluster, can learn the first few layers of a convolutional network from a single image as well as using millions of images and manual labels, provided t

  72. Günter Scharf

    We study inhomogeneous perturbations away from the strongly homogeneous background cosmology previously studied. The problem is greatly simplified by using the mapping on the inner Schwarzschild solution. The resulting linear perturbation equations can be solved by power series. The solution leads to a finite energy density, but the pressure must be zero.

  73. Petr Ivankov

    There are theories of coverings of $C^*$-algebras which can be included into a following list: coverings of commutative $C^*$-algebras, coverings of $C^*$-algebras of groupoids and foliations, coverings of noncommutative tori, the double covering of the quantum group $SO_q(3)$. This work is devoted to a single general theory which includes all theories of th

  74. Nicole Vorderobermeier

    We prove the analyticity of smooth critical points for O'Hara's knot energies $\mathcal{E}^{\alpha,p}$, with $p=1$ and $2<\alpha< 3$, subject to a fixed length constraint. This implies, together with the main result in \cite{BR13}, that bounded energy critical points of $\mathcal{E}^{\alpha,1}$ subject to a fixed length constraint are not only $C^\infty$ but

  75. Oscar Delgado-Mohatar, Julian Fierrez, Ruben Tolosana, Ruben Vera-Rodriguez

    We explore practical tradeoffs in blockchain-based biometric template storage. We first discuss opportunities and challenges in the integration of blockchain and biometrics, with emphasis in biometric template storage and protection, a key problem in biometrics still largely unsolved. Blockchain technologies provide excellent architectures and practical tool

  76. Brais Cancela, Verónica Bolón-Canedo, Amparo Alonso-Betanzos, João Gama

    Classic feature selection techniques remove those features that are either irrelevant or redundant, achieving a subset of relevant features that help to provide a better knowledge extraction. This allows the creation of compact models that are easier to interpret. Most of these techniques work over the whole dataset, but they are unable to provide the user w

  77. A. A. Vladimirov, D. Ihle, N. M. Plakida

    A microscopic theory of the electronic spectrum and of superconductivity within the t-J model on the honeycomb lattice is developed. We derive the equations for the normal and anomalous Green functions in terms of the Hubbard operators by applying the projection technique. Superconducting pairing of d + id'-type mediated by the antiferromagnetic exchange is

  78. Rob Johnson, James Woodcock, Audrey de Nazelle, Thiago de Sa

    Health impact simulation models are used to predict how a proposed intervention or scenario will affect public health outcomes, based on available data and knowledge of the process. The outputs of these models are uncertain due to uncertainty in the structure and inputs to the model. In order to assess the extent of uncertainty in the outcome we must quantif

  79. Luigi Consolino, Francesco Cappelli, Mario Siciliani de Cumis, Paolo De Natale

    Quantum cascade lasers (QCLs) are becoming a key tool for plenty of applications, from the mid-infrared (mid-IR) to the THz range. Progress in related areas, such as the development of ultra-low-loss crystalline microresonators, optical frequency standards, and optical fiber networks for time and frequency dissemination, is paving the way for unprecedented a

  80. Katharina Boguslawski

    The accurate description of doubly-excited states using conventional electronic structure methods is remarkably challenging, primarily because such excited states require the inclusion of doubly or higher excited configurations or the application of multi-reference methods. We present a new approach to target electronically excited states that feature a doub

  81. Katharina Boguslawski

    Wavefunctions restricted to electron pair states are promising models for strongly-correlated systems. Specifically, the pair Coupled Cluster Doubles (pCCD) ansatz allows us to accurately describe bond dissociation processes and heavy-element containing compounds with multiple quasi-degenerate single-particle states. Here, we extend the pCCD method to model

  82. Robin Silber, Ondřej Stejskal, Lukáš Beran, Petr Cejpek

    The magnetooptic Kerr effect (MOKE) is a well known and handy tool to characterize ferro-, ferri- and antiferromagnetic materials. Many of the MOKE techniques employ effects solely linear in magnetization $\bm{M}$. Nevertheless, a higher-order term being proportional to $\bm{M}^2$ and called quadratic MOKE (QMOKE) can additionally contribute to the experimen

  83. R. Dvorak, B. Loibnegger, L. Y. Zhou, L. Zhou

    The presented work investigates the possible formation of terrestrial planets in the habitable zone (HZ) of the exoplanetary system HD 141399. In this system the HZ is located approximately between the planets c (a = 0.7 au) and d (a = 2.1 au). Extensive numerical integrations of the equations of motion in the pure Newtonian framework of small bodies with di

  84. D. Giataganas, N. Tetradis

    We calculate the entanglement entropy in spaces with horizons, such as Rindler or de Sitter space, using holography. We employ appropriate parametrizations of AdS space in order to obtain a Rindler or static de Sitter boundary metric. The holographic entanglement entropy for the regions enclosed by the horizons can be identified with the standard thermal ent

  85. ALICE Collaboration

    The jet radial structure and particle transverse momentum ($p_{\rm{T}}$) composition within jets are presented in centrality-selected Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV. Track-based jets, which are also called charged jets, were reconstructed with a resolution parameter of $R=0.3$ at midrapidity $|\eta_\mathrm{ch\,jet}|<0.6$ for transverse mo

  86. Monica Benito, Xanthe Croot, Christoph Adelsberger, Stefan Putz

    We propose and analyze a novel "flopping-mode" mechanism for electric dipole spin resonance based on the delocalization of a single electron across a double quantum dot confinement potential. Delocalization of the charge maximizes the electronic dipole moment compared to the conventional single dot spin resonance configuration. We present a theoretical inves

  87. Steve Hofmann, José María Martell, Svitlana Mayboroda

    In relatively nice geometric settings, in particular, on Lipschitz domains, absolute continuity of elliptic measure with respect to the surface measure is equivalent to Carleson measure estimates, to square function estimates, and to $\varepsilon$-approximability, for solutions to the second order divergence form elliptic partial differential equations $ Lu=

  88. Alberto Dennunzio, Enrico Formenti, Luciano Margara, Valentin Montmirail

    Boolean automata networks, genetic regulation networks, and metabolic networks are just a few examples of biological modelling by discrete dynamical systems (DDS). A major issue in modelling is the verification of the model against the experimental data or inducing the model under uncertainties in the data. Equipping finite discrete dynamical systems with an

  89. Alexandr Malijevský

    We study complete wetting of solid walls that are patterned by parallel nanogrooves of depth $D$ and width $L$ with a periodicity of $2L$. The wall is formed of a material which interacts with the fluid via a long-range potential and exhibits first-order wetting transition at temperature $T_w$, should the wall is planar. Using a non-local density functional

  90. Xu Yang, Cheng Deng, Feng Zheng, Junchi Yan

    The clustering methods have recently absorbed even-increasing attention in learning and vision. Deep clustering combines embedding and clustering together to obtain optimal embedding subspace for clustering, which can be more effective compared with conventional clustering methods. In this paper, we propose a joint learning framework for discriminative embed

  91. Vladimir Dzhunushaliev, Vladimir Folomeev, Burkhard Kleihaus, Jutta Kunz

    Within general relativity, we determine the energy conditions needed for the existence of a toroidal $T^2$ wormhole. For this purpose, we employ the conditions of the positiveness of the second derivatives of the relevant components of the metric, which describe an increase in the linear sizes (or the area) of the cross section of the throat. The correspondi

  92. Ludwig Staiger

    Using an iterative tree construction we show that for simple computable subsets of the Cantor space Hausdorff, constructive and computable dimensions might be incomputable.

  93. Francesco Curia

    In this work an iterative algorithm based on unsupervised learning is presented, specifically on a Restricted Boltzmann Machine (RBM) to solve a perfect matching problem on a bipartite weighted graph. Iteratively is calculated the weights $w_{ij}$ and the bias parameters $\theta = ( a_i, b_j) $ that maximize the energy function and assignment element $i$ to

  94. Marie Kubínová, Ivana Pultarová

    The paper focuses on numerical solution of parametrized diffusion equations with scalar parameter-dependent coefficient function by the stochastic (spectral) Galerkin method. We study preconditioning of the related discretized problems using preconditioners obtained by modifying the stochastic part of the partial differential equation. We present a simple bu

  95. Wouter Castryck, Raf Cluckers, Philip Dittmann, Kien Huu Nguyen

    We address Heath-Brown's and Serre's dimension growth conjecture (proved by Salberger), when the degree $d$ grows. Recall that Salberger's dimension growth results give bounds of the form $O_{X, \varepsilon} (B^{\dim X+\varepsilon})$ for the number of rational points of height at most $B$ on any integral subvariety $X$ of ${\mathbb P}^n_{\mathbb Q}$ of degre

  96. Ghizlane Mountaser, Maliheh Mahlouji, Toktam Mahmoodi

    The emerging Cloud-RAN architecture within the fifth generation (5G) of wireless networks plays a vital role in enabling higher flexibility and granularity. On the other hand, Cloud-RAN architecture introduces an additional link between the central, cloudified unit and the distributed radio unit, namely fronthaul (FH). Therefore, the foreseen reliability and

  97. Yao Ma, Suhang Wang, Charu C. Aggarwal, Jiliang Tang

    Graph neural networks, which generalize deep neural network models to graph structured data, have attracted increasing attention in recent years. They usually learn node representations by transforming, propagating and aggregating node features and have been proven to improve the performance of many graph related tasks such as node classification and link pr

  98. Michael Magee, Doron Puder

    Let $w$ be a word in the free group on $r$ generators. The expected value of the trace of the word in $r$ independent Haar elements of $\mathrm{O}(n)$ gives a function ${\cal T}r_{w}^{\mathrm{O}}(n)$ of $n$. We show that ${\cal T}r_{w}^{\mathrm{O}}(n)$ has a convergent Laurent expansion at $n=\infty$ involving maps on surfaces and $L^{2}$-Euler characteristi

  99. Blandine Feneuil, Patrick Aimedieu, Mario Scheel, Jonathan Perrin

    We prepare and study cement foam samples with well-controlled structure, i.e. containing monodisperse bubbles. We observe that the foam structure often changes before cement setting and identify ripening as the major destabilization mechanism at stake. Drainage plays only a minor role in cement foam destabilization except when bubble size is large. Then we s

  100. Mohamed A. Alrshah, Mohamed A. Al-Maqri, Mohamed Othman

    In the last decade, the demand for Internet applications has been increased, which increases the number of data centers across the world. These data centers are usually connected to each other using long-distance and high-speed networks. As known, the Transmission Control Protocol (TCP) is the predominant protocol used to provide such connectivity among thes