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February 2019 arXiv papers — page 68

Showing 6,7016,800 of 11,389 papers

  1. Sebastian Arnold, Rudolf Schneider, Philippe Cudré-Mauroux, Felix A. Gers

    When searching for information, a human reader first glances over a document, spots relevant sections and then focuses on a few sentences for resolving her intention. However, the high variance of document structure complicates to identify the salient topic of a given section at a glance. To tackle this challenge, we present SECTOR, a model to support machin

  2. Thomas Minier, Hala Skaf-Molli, Pascal Molli

    To provide stable and responsive public SPARQL query services, data providers enforce quotas on server usage. Queries which exceed these quotas are interrupted and deliver partial results. Such interruption is not an issue if it is possible to resume queries execution afterward. Unfortunately, there is no preemption model for the Web that allows for suspendi

  3. Klaus-Dieter Schewe, Andreas Prinz, Egon Börger

    The behavioural theory of concurrent systems states that any concurrent system can be captured by a behaviourally equivalent concurrent Abstract State Machine (cASM). While the theory in general assumes shared locations, it remains valid, if different agents can only interact via messages, i.e. sharing is restricted to mailboxes. There may even be a strict s

  4. Ester Korkus Hamal, Maytal Caspary Toroker

    A catalyst surface may be exposed to strain due to application of load or interfacing with a substrate with large lattice mismatch. In order to test the effect of strain on catalytic efficiency, we use Density Functional Theory +U (DFT+U) to model water oxidation on expanded and contracted surfaces of the Ni1-xFexOOH alloy, one of the best known catalysts fo

  5. Shinnosuke Hisano, Naoyuki Yonemaru, Hiroki Kumamoto, Keitaro Takahashi

    A new detection method for gravitational waves (GWs) with ultra-low frequencies ($f_{\rm GW} \lesssim 10^{-10}~{\rm Hz}$), which is much lower than the range of pulsar timing arrays (PTAs), was proposed in Yonemaru et al. (2016). This method utilizes the statistical properties of spin-down rates of milli-second pulsars (MSPs) and the sensitivity was evaluate

  6. Ismail Aydin, Cihan Unal

    We study totally bounded subsets in weighted variable exponent amalgam and Sobolev spaces. Moreover, this paper includes several detailed generalized results of some compactness criterions in these spaces.

  7. Lorraine A. K. Ayad, Golnaz Badkobeh, Gabriele Fici, Alice Héliou

    A word $x$ that is absent from a word $y$ is called minimal if all its proper factors occur in $y$. Given a collection of $k$ words $y_1,y_2,\ldots,y_k$ over an alphabet $Σ$, we are asked to compute the set $\mathrm{M}^{\ell}_{y_{1}\#\ldots\#y_{k}}$ of minimal absent words of length at most $\ell$ of word $y=y_1\#y_2\#\ldots\#y_k$, $\#\notinΣ$. In data compr

  8. Pravesh K. Kothari, Roi Livni

    We study the expressive power of kernel methods and the algorithmic feasibility of multiple kernel learning for a special rich class of kernels. Specifically, we define \emph{Euclidean kernels}, a diverse class that includes most, if not all, families of kernels studied in literature such as polynomial kernels and radial basis functions. We then describe the

  9. Golam Mortuza Hossain, Chiranjeeb Singha

    In order to achieve a Hamiltonian-based canonical derivation of the Hawking effect, one usually faces multiple hurdles. Firstly, the spacetime foliation using Schwarzschild time does not lead to hyper-surfaces which are always spacelike. Secondly, the null coordinates which are frequently used in covariant approach, do not lead to a true matter Hamiltonian.

  10. Andrea Scarpelli

    The four 10 kt Liquid Argon Time Projection Chambers (LArTPCs) of the future DUNE experiment will enable precise measurements of the oscillation parameters and the discovery of CP violation for leptons, thanks to their excellent 3D imaging capabilities and calorimetric capabilities. One or more modules of the DUNE detector may exploit a Dual Phase (DP) LArTP

  11. Nilkanth D. Vagshette, Sachindra Naik, Madhav. K. Patil

    We present results obtained from the analysis of a total of 110 ks Chandra observations of 3C 320 FR II radio galaxy, located at the centre of a cluster of galaxies at a redshift $z=0.342$. A pair of X-ray cavities have been detected at an average distance of $\sim$38 kpc along the East and West directions with the cavity energy, age and total power equal to

  12. Mehdi Rezaei

    In this study we combine the background and the growth rate data in order to study the ability of the two oscillating dark energy parameterizations, to fit the observational data. Using the likelihood and MCMC method we try to explore the posterior space and put constraints on the free parameters of the models. Based on the values of the well known Akaike an

  13. Deming Yuan, Alexandre Proutiere, Guodong Shi

    We study online linear regression problems in a distributed setting, where the data is spread over a network. In each round, each network node proposes a linear predictor, with the objective of fitting the \emph{network-wide} data. It then updates its predictor for the next round according to the received local feedback and information received from neighbor

  14. P. S. Bhupal Dev, Rabindra N. Mohapatra, Yongchao Zhang

    New physics scenarios beyond the Standard Model (SM) for neutrino mass mechanism often necessitate the existence of a neutral scalar $H$ and/or doubly-charged scalar $H^{\pm\pm}$, which couple to the SM charged leptons in a flavor violating way, while evading all existing constraints. Such scalars could be effectively produced at future lepton colliders like

  15. Jin Yun Guo

    In this paper, we show that for a Koszul $n$-homogeneous algebra $Λ$, the quadratic dual of certain twisted trivial extension is the $(n+1)$-preprojective algebra of its quadratic dual, that is, $ (Δ_νΛ)^{!,op} \simeqΠ( Λ^{ !, op })$. This is applied to the $τ$-slice algebras of stable $n$-translation algebras and gives a noncommutative version of Bernstein-

  16. Daniel Iglesias, Evgeny Senokos, Belén Alemán, Laura Cabana

    The assembly of aligned carbon nanotubes (CNT) into fibers (CNTF) is a convenient approach to exploit and apply the unique physico-chemical properties of CNTs in many fields. CNT functionalization has been extensively used for their implementation into composites and devices. However, CNTF functionalization is still in its infancy, due to the challenges asso

  17. Yong Liu, Jian Li, Guangjun Wu, Lizhong Ding

    Manifold regularization, such as laplacian regularized least squares (LapRLS) and laplacian support vector machine (LapSVM), has been widely used in semi-supervised learning, and its performance greatly depends on the choice of some hyper-parameters. Cross-validation (CV) is the most popular approach for selecting the optimal hyper-parameters, but it has hig

  18. Yoichi Takeda, Inwoo Han, Dong-Il Kang, Byeong-Cheol Lee

    A spectroscopic study was carried out on the surface chemical abundances of CNO and several heavier elements in the primary and secondary components of 5 eclipsing close binaries around A-type (AR Aur, beta Aur, YZ Cas, WW Aur, and RR Lyn), in order to investigate the nature of chemical differences between both components (being comparatively slow rotators a

  19. Rhythm Grover, Debasis Kundu, Amit Mitra

    In various capacities of statistical signal processing two-dimensional (2-D) chirp models have been considered significantly, particularly in image processing$-$ to model gray-scale and texture images, magnetic resonance imaging, optical imaging etc. In this paper we address the problem of estimation of the unknown parameters of a 2-D chirp model under the a

  20. Yue Xu, Feng Yin, Wenjun Xu, Jiaru Lin

    The cloud radio access network (C-RAN) is a promising paradigm to meet the stringent requirements of the fifth generation (5G) wireless systems. Meanwhile, wireless traffic prediction is a key enabler for C-RANs to improve both the spectrum efficiency and energy efficiency through load-aware network managements. This paper proposes a scalable Gaussian proces

  21. Md Moin Uddin Chowdhury, Eyuphan Bulut, Ismail Guvenc

    In this paper, we address the problem of finding the optimal trajectory for an unmanned aerial vehicle (UAV) for improving the wireless coverage of a terrestrial cellular network. In particular, we consider a UAV that is tasked to travel from one point to another within a given time constraint, and it can also simultaneously assist the cellular network by pr

  22. Shalabh K. Anand, Sunil P. Singh

    We investigate structural and dynamical properties of a self-propelled filament using coarse-grained Brownian dynamics simulations. A self-propulsion force is applied along the bond vectors, i.e., tangent to the filament and their locations are considered in two different manners. In case one, force is applied to all beads of the filament, which is termed as

  23. Giridar Vishwanathan, Gabriel Juarez

    We report a novel technique capable of measuring the kinematic shear viscosity of Newtonian liquids with steady streaming in microfluidic devices. This probe-free microrheological method utilizes sub-kilohertz liquid oscillation frequencies around a cylindrical obstacle, ensuring that the inner streaming layer is comparable in size to the cylinder radius. To

  24. Zhao Pan, Jun Chen, Runze Yu, Lokanath Patra

    The discovery of unusual negative thermal expansion (NTE) provides the opportunity to control the common but much desired property of thermal expansion, which is valuable not only in scientific interests but also in practical applications. However, most of the available NTE materials are limited to a narrow temperature range, and the NTE effect is generally

  25. Yanpei Huang, Etienne Burdet, Lin Cao, Phuoc Thien Phan

    In robotic surgery, the surgeon controls robotic instruments using dedicated interfaces. One critical limitation of current interfaces is that they are designed to be operated by only the hands. This means that the surgeon can only control at most two robotic instruments at one time while many interventions require three instruments. This paper introduces a

  26. Xiaoling Dou, Satoshi Kuriki, Gwo Dong Lin, Donald Richards

    We construct by using B-spline functions a class of copulas that includes the Bernstein copulas arising in Baker's distributions. The range of correlation of the B-spline copulas is examined, and the Frechet--Hoeffding upper bound is proved to be attained when the number of B-spline functions goes to infinity. As the B-spline functions are well-known to

  27. S Kiruthika, H. Fjellvag, P Ravindran

    In order to identify potential hydrogen storage materials, worldwide attention has been focused on hydrides with high gravimetric and volumetric capacity. Hydrogen is a unique element that possess positive, negative or neutral oxidation state in solids depending upon the chemical environment. If one can find hydrogen storage materials where hydrogen is prese

  28. M. Naruse, S. Ishii, J. -F. Motte, A. Drezet

    We experimentally demonstrate unidirectional light transmission through two-layer nanostructured materials considering that the horizontal-to-vertical-polarization conversion efficiency in the forward direction and the vertical-to-horizontal efficiency in the backward direction, which are usually equivalent due to optical reciprocity, are different. The diff

  29. Lin Zhu, Yihong Chen

    The focus of WSDM cup 2019 is session-based sequential skip prediction, i.e. predicting whether users will skip tracks, given their immediately preceding interactions in their listening session. This paper provides the solution of our team \textbf{ekffar} to this challenge. We focus on recurrent-neural-network-based deep learning approaches which have previo

  30. Joshua Brakensiek, Sivakanth Gopi, Venkatesan Guruswami

    We study the complexity of Boolean constraint satisfaction problems (CSPs) when the assignment must have Hamming weight in some congruence class modulo M, for various choices of the modulus M. Due to the known classification of tractable Boolean CSPs, this mainly reduces to the study of three cases: 2-SAT, HORN-SAT, and LIN-2 (linear equations mod 2). We cla

  31. Xinfu Li

    In this paper, the Choquard equation with an inverse-square potential and both focusing and defocusing nonlinearities in the energy-subcritical regime is investigated. For all the cases, the local well-posedness result in $H^1(\mathbb{R}^N)$ is established. Moreover, the global existence result for arbitrary initial values is proved in the defocusing case wh

  32. Himangshu Hazarika, Dhiren Kumar Basnet

    Let $\mathbb{F}_{q^n}$ be the extension of the field $\mathbb{F}_q$ of degree n, where $q$ is power of prime $p$, i.e $q=p^k$, where k is a positive integer. In this paper, we provide sufficient condition for the existence of a primitive normal element $α\in\mathbb{F}_{q^n} $ such that $α^2+α+1$ is also primitive normal element over $\mathbb{F}_{q^n}$.

  33. Joachim Gudmundsson, Sampson Wong

    The yolk is an important concept in spatial voting games as it generalises the equilibrium and provides bounds on the uncovered set. We present near-linear time algorithms for computing the yolk in the spatial voting model in the plane. To the best of our knowledge our algorithm is the first algorithm that does not require precomputing the median lines and h

  34. Parsa Rastin, Michael LuValle

    If we assume that earthquakes are chaotic, and influenced locally then chaos theory suggests that there should be a temporal association between earthquakes in a local region that should be revealed with statistical examination. To date no strong relationship has been shown (refs not prediction). However, earthquakes are basically failures of structured mate

  35. Joe Kramer-Miller

    Let $k$ be a perfect field of positive characteristic and let $X$ be a smooth irreducible quasi-compact scheme over $k$. The Drinfeld-Kedlaya theorem states that for an irreducible $F$-isocrystal on $X$, the gap between consecutive generic slopes is bounded by one. In this note we provide a new proof of this theorem. Our proof utilizes the theory of $F$-isoc

  36. Jiaxiang Jiang, Po-Yu Kao, Samuel A. Belteton, Daniel B. Szymanski

    We consider the problem of accurately identifying cell boundaries and labeling individual cells in confocal microscopy images, specifically, 3D image stacks of cells with tagged cell membranes. Precise identification of cell boundaries, their shapes, and quantifying inter-cellular space leads to a better understanding of cell morphogenesis. Towards this, we

  37. Surbhi Goel, Daniel M. Kane, Adam R. Klivans

    We give the first efficient algorithm for learning the structure of an Ising model that tolerates independent failures; that is, each entry of the observed sample is missing with some unknown probability p. Our algorithm matches the essentially optimal runtime and sample complexity bounds of recent work for learning Ising models due to Klivans and Meka (2017

  38. M. LuValle

    Two recent papers on prediction of chaotic systems, one on multi-view embedding1 , and the second on prediction in projection2 provide empirical evidence to support particular prediction methods for chaotic systems. Multi-view embedding1 is a method of using several multivariate time series to come up with an improved embedding based predictor of a chaotic t

  39. Hsin-hui Huang, Saulius Juodkazis, Koji Hatanaka

    Simultaneous measurements of hard X-ray by a Geiger counter and audible sound (10 Hz-20kHz) by a microphone from a thin water film in air were carried out under intense single and double pulse irradiations of femtosecond laser (35 fs, 800 nm, 1 kHz). Emission profiles of X-ray and sound under the single pulse irradiation by changing the water film position a

  40. Domagoj Jakobovic, Stjepan Picek, Marcella S. R. Martins, Markus Wagner

    Substitution Boxes (S-boxes) are nonlinear objects often used in the design of cryptographic algorithms. The design of high quality S-boxes is an interesting problem that attracts a lot of attention. Many attempts have been made in recent years to use heuristics to design S-boxes, but the results were often far from the previously known best obtained ones. U

  41. Ryutaro Sato, Shinzo Bannai

    In this paper, we introduce the terminology of matroids into the study of Zariski-pairs related to rational elliptic surfaces, aiming to simplify the presentation and arguments involved. As an application, we provide new examples of Zariski $N$-ples of relatively low degree. Namely we show that a Zariski 102-ple of degree 18 exists.

  42. Mark D. Baker, Matthias Goerner, Alan W. Reid

    This is a technical report accompanying the paper "All Principal Congruence Link Groups" (arXiv:1802.01275) classifying all principal congruence link complements in S^3 by the same authors. It provides a complete overview of all cases (d,I) that had to be considered, as well as describes the necessary computations and computer programs written for th

  43. Ali Rahmati, Yavuz Yapıcı, Nadisanka Rupasinghe, Ismail Guvenc

    Cellular-connected unmanned aerial vehicles (UAVs) are recently getting significant attention due to various practical use cases, e.g., surveillance, data gathering, purchase delivery, among other applications. Since UAVs are low power nodes, energy and spectral efficient communication is of paramount importance. To that end, multiple access (MA) schemes can

  44. Wenyu Xing, Luyi Qiu, Xirui Wang, Yunyan Yao

    The recent emergence of 2D van der Waals magnets down to atomic layer thickness provides an exciting platform for exploring quantum magnetism and spintronics applications. The van der Waals nature stabilizes the long-range ferromagnetic order as a result of magnetic anisotropy. Furthermore, giant tunneling magnetoresistance and electrical control of magnetis

  45. Tsuyoshi Inoue

    Supernova remnants (SNRs) are believed to be the site of galactic cosmic-ray acceleration. However, the details of the cosmic-ray acceleration are still not well understood. Gamma ray observation is a promising method to study cosmic-ray acceleration in the SNRs, because a hadronic gamma ray can trace high energy cosmic-rays above ~GeV energy. Conventional t

  46. M. Yokoyama, K. Suzuki, K. Tenya, S. Nakamura

    This paper demonstrates the anisotropic response of quantum critical fluctuations with respect to the direction of the magnetic field $B$ in Ni-doped CeCoIn$_5$ by measuring the magnetization $M$ and specific heat $C$. The results show that $M/B$ at $B=0.1\ {\rm T}$ for both the tetragonal $c$ and $a$ directions exhibits $T^{-η}$ dependencies, and that $C/T$

  47. W. J. Ding, F. Y. Li, S. M. Weng, P. Bai

    Coherent transition radiation (CTR) from relativistic electron beam interaction with an overdense plasma foil is investigated by making use of two-dimensional particle-in-cell simulations. Well-defined single electron beam either of uniform profile or having substructures is considered for various beam-plasma parameters. The main purpose is to mimic the comp

  48. E Celledoni, C Evripidou, D I McLaren, B Owren

    In this Letter we propose a systematic approach for detecting and calculating preserved measures and integrals of a rational map. The approach is based on the use of cofactors and Discrete Darboux Polynomials and relies on the use of symbolic algebra tools. Given sufficient computing power, all rational preserved integrals can be found. We show, in two examp

  49. Lei Bi, Yuyu Guo, Qian Wang, Dagan Feng

    Automated segmentation of the optic cup and disk on retinal fundus images is fundamental for the automated detection / analysis of glaucoma. Traditional segmentation approaches depend heavily upon hand-crafted features and a priori knowledge of the user. As such, these methods are difficult to be adapt to the clinical environment. Recently, deep learning met

  50. S. Kumano, Qin-Tao Song

    We report recent theoretical progress on a polarization asymmetry in the proton-deuteron Drell-Yan process with a polarized-deuteron target and the tensor-polarized structure function $b_1$. Experimental measurements are possible at JLab for $b_1$ and at Fermilab for the Drell-Yan process. First, we show a theoretical estimate for the proton-deuteron Drell-Y

  51. Fan Yao, Hongyu Fang, Milos Doroslovacki, Guru Venkataramani

    Recent studies highlighting the vulnerability of computer architecture to information leakage attacks have been a cause of significant concern. Among the various classes of microarchitectural attacks, cache timing channels are especially worrisome since they have the potential to compromise users' private data at high bit rates. Prior works have demonstr

  52. Dong-Chen Zheng, Yan-Qiang Yu, Renyuan Liao

    We develop a method to extract the dissipation for a heavy moving impurity immersed in superfluid Fermi gases. The drag force is derived analytically. As a reward, we are able to extract the dynamical structure factor, from which density excitations of the system is carefully examined. We show that dissipations through drag force is associated with two types

  53. Tadashi Kadowaki, Masayuki Ohzeki

    Quantum devices are affected by intrinsic and environmental noises. An in-depth characterization of noise effects is essential for exploiting noisy quantum computing. To this end, we studied the energy dissipative behavior of a quantum annealer via experiments and numerical simulations. Our investigation adopts a recently proposed technique that interpolates

  54. Yongjie Liu, Sijie Shen

    Illuminant estimation plays a key role in digital camera pipeline system, it aims at reducing color casting effect due to the influence of non-white illuminant. Recent researches handle this task by using Convolution Neural Network (CNN) as a mapping function from input image to a single illumination vector. However, global mapping approaches are difficult t

  55. Thomas Gabor, Sebastian Zielinski, Sebastian Feld, Christoph Roch

    When solving propositional logic satisfiability (specifically 3SAT) using quantum annealing, we analyze the effect the difficulty of different instances of the problem has on the quality of the answer returned by the quantum annealer. A high-quality response from the annealer in this case is defined by a high percentage of correct solutions among the returne

  56. Hefan Li, Cuihua Du, Shuai Liu, Thomas Donlon

    Based on the second Gaia data release (Gaia DR2) and spectroscopy from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Data, we identified 20,089 halo stars kinematically and chemically. The halo streams in the solar neighborhood could be detected in the space of energy and angular momentum. We reshuffle the velocities of these stars t

  57. Pallavi Ray, Debdeep Pati, Anirban Bhattacharya

    This article revisits the problem of Bayesian shape-restricted inference in the light of a recently developed approximate Gaussian process that admits an equivalent formulation of the shape constraints in terms of the basis coefficients. We propose a strategy to efficiently sample from the resulting constrained posterior by absorbing a smooth relaxation of t

  58. Hongliang Shi, Dan Han, Shiyou Chen, Mao-Hua Du

    Based on first-principles calculations, we show that chemically active metal ns2 lone pairs play an important role in exciton relaxation and dissociation in low-dimensional halide perovskites. We studied excited-state properties of several recently discovered luminescent all-inorganic and hybrid organic-inorganic zero-dimensional (0D) Sn and Pb halides. The

  59. Ali Lenjani

    Trajectory following is one of the complicated control problems when its dynamics are nonlinear, stochastic and include a large number of parameters. The problem has significant difficulties including a large number of trials required for data collection and a massive volume of computations required to find a closed-loop controller for high dimensional and s

  60. Davide Donadio

    Thermoelectric devices convert temperature gradients into electrical power and vice versa, thus enabling energy scavenging from waste heat, sensing and cooling. Yet, many of these attractive applications are hindered by the limited efficiency of thermoelectric materials, especially in the low temperature regime. This review provides a summary of the recent a

  61. Thomas Gabor, Marie Kiermeier, Andreas Sedlmeier, Bernhard Kempter

    From formal and practical analysis, we identify new challenges that self-adaptive systems pose to the process of quality assurance. When tackling these, the effort spent on various tasks in the process of software engineering is naturally re-distributed. We claim that all steps related to testing need to become self-adaptive to match the capabilities of the

  62. Yanni Gao, Guangwei Yuan, Shuai Wang, Xudeng Hang

    In this paper, we propose a nonlinear positivity-preserving finite volume element(FVE) scheme for anisotropic diffusion problems on quadrilateral meshes. Based on an overlapping dual partition, the one-sided flux is approximated by the iso-parametric bilinear element. A positivity-preserving nonlinear scheme with vertex-centered unknowns is obtained by a new

  63. Mehrdad Showkatbakhsh, Can Karakus, Suhas Diggavi

    Data privacy is an important concern in machine learning, and is fundamentally at odds with the task of training useful learning models, which typically require the acquisition of large amounts of private user data. One possible way of fulfilling the machine learning task while preserving user privacy is to train the model on a transformed, noisy version of

  64. CDF Collaboration, T. Aaltonen, S. Amerio, D. Amidei

    We report on a search for a spin-zero non-standard-model particle in proton-antiproton collisions collected by the Collider Detector at Fermilab at a center-of-mass-energy of 1.96 TeV. This particle, the $ϕ$ boson, is expected to decay into a bottom-antibottom quark pair and to be produced in association with at least one bottom quark. The data sample consis

  65. Ian F. Akyildiz, Chong Han, Shuai Nie

    In the millimeter wave (30-300 GHz) and Terahertz (0.1-10 THz) frequency bands, high spreading loss and molecular absorption often limit the signal transmission distance and coverage range. In this paper, four directions to tackle the crucial problem of distance limitation are investigated, namely, a physical layer distance-aware design, ultra-massive MIMO c

  66. Patricio Arrangoiz-Arriola, E. Alex Wollack, Zhaoyou Wang, Marek Pechal

    The coherent states that describe the classical motion of a mechanical oscillator do not have well-defined energy, but are rather quantum superpositions of equally-spaced energy eigenstates. Revealing this quantized structure is only possible with an apparatus that measures the mechanical energy with a precision greater than the energy of a single phonon, $\

  67. Jeremy Figgins, Laila S. Mattos, Warren Mar, Yi-Ting Chen

    Recent advances in atomic manipulation techniques have provided a novel bottom-up approach to investigating the unconventional properties and complex phases of strongly correlated electron materials. By engineering artificial condensed matter systems containing tens to thousands of atoms with tailored electronic or magnetic properties, it has become possible

  68. Yiqiu Dong, Per Christian Hansen, Michiel E. Hochstenbach, Nicolai Andre Brogaard Riis

    We consider algebraic iterative reconstruction methods with applications in image reconstruction. In particular, we are concerned with methods based on an unmatched projector/backprojector pair; i.e., the backprojector is not the exact adjoint or transpose of the forward projector. Such situations are common in large-scale computed tomography, and we conside

  69. Tuhin Sarkar, Alexander Rakhlin

    We derive finite time error bounds for estimating general linear time-invariant (LTI) systems from a single observed trajectory using the method of least squares. We provide the first analysis of the general case when eigenvalues of the LTI system are arbitrarily distributed in three regimes: stable, marginally stable, and explosive. Our analysis yields shar

  70. Antonio Cicone, Pietro Dell'Acqua

    Nonstationary and nonlinear signals are ubiquitous in real life. Their decomposition and analysis is an important topic of research in signal processing. Recently a new technique, called Iterative Filtering, has been developed with the goal of decomposing such signals into simple oscillatory components. Several papers have been published regarding the analys

  71. Andrea Tosin, Mattia Zanella

    We develop a hierarchical description of traffic flow control by means of driver-assist vehicles aimed at the mitigation of speed-dependent road risk factors. Microscopic feedback control strategies are designed at the level of vehicle-to-vehicle interactions and then upscaled to the global flow via a kinetic approach based on a Boltzmann-type equation. Then

  72. Hugo Lhachemi, David Saussié, Guchuan Zhu

    This note deals with the boundary control problem of a nonhomogeneous flexible wing evolving under unsteady aerodynamic loads. The wing is actuated at its tip by flaps and is modeled by a distributed parameter system consisting of two coupled partial differential equations. Based on the proposed boundary control law, the well-posedness of the underlying Cauc

  73. Denys Dutykh

    The topic of these notes could be easily expanded into a full one-semester course. Nevertheless, we shall try to give some flavour along with theoretical bases of spectral and pseudo-spectral methods. The main focus is made on Fourier-type discretizations, even if some indications on how to handle non-periodic problems via Tchebyshev and Legendre approaches

  74. P. C. Verpoort, V. Narayan

    We study the relaxation dynamics of non-equilibrium chirality distributions of charge carriers in Rashba systems. We find that at low temperature inter-Rashba band transitions become suppressed due to the combined effect of the Rashba momentum split and the chiral spin texture of a Rashba system. Specifically, we show that momentum exchange between carriers

  75. Vladislav Voronenkov, Andrey Leonidov, Natalia Bochkareva, Ruslan Gorbunov

    A free-standing bulk gallium nitride layer with a thickness of 365 $μ$m and a diameter of 50 mm was obtained by hydride vapor phase epitaxy on a sapphire substrate with a carbon buffer layer. The carbon buffer layer was deposited by thermal decomposition of methane $\textit{in situ}$ in the same process with the growth of a bulk GaN layer. The bulk GaN layer

  76. Max Lieblich, Martin Olsson

    We show that varieties of dimension at least 2 over infinite fields are determined as abstract schemes by their Zariski topological spaces together with the rational equivalence relation on the set of effective divisors. This gives a universal Torelli theorem in the sense of Bogomolov and Tschinkel. The proof relies heavily on a rational version of the class

  77. Tomek Schulz, Kyujoon Lee, Benjamin Krüger, Roberto Lo Conte

    Spin-orbit torques promise ultra-efficient magnetization switching used for advanced devices based on emergent quasi-particles such as domain walls and skyrmions. Recently, the spin structure dynamics, materials and systems with tailored spin-orbit torques are being developed. A method, which allows one to detect the acting torques in a given system as a fun

  78. Jerome Droniou, Robert Eymard

    We present and analyse a numerical framework for the approximation of nonlinear degenerate elliptic equations of the Stefan or porous medium types. This framework is based on piecewise constant approximations for the functions, which we show are essentially necessary to obtain convergence and error estimates. Convergence is established without regularity ass

  79. Erica Fogerty, Baowei Liu, Adam Frank, Jonathan Carroll-Nellenback

    We report on simulations of laboratory experiments in which magnetized supersonic flows are driven through a wire mesh. The goal of the study was to investigate the ability of such a configuration to generate supersonic, MHD turbulence. We first report on the morphological structures that develop in both magnetized and non-magnetized cases. We then analyze t

  80. Seonghoon Choi, Jiří Vaníček

    Geometric integrators of the Schr\"{o}dinger equation conserve exactly many invariants of the exact solution. Among these integrators, the split-operator algorithm is explicit and easy to implement, but, unfortunately, is restricted to systems whose Hamiltonian is separable into a kinetic and potential terms. Here, we describe several implicit geometric inte

  81. Peixin Wang, Hongfei Fu, Amir Kafshdar Goharshady, Krishnendu Chatterjee

    We consider the problem of expected cost analysis over nondeterministic probabilistic programs, which aims at automated methods for analyzing the resource-usage of such programs. Previous approaches for this problem could only handle nonnegative bounded costs. However, in many scenarios, such as queuing networks or analysis of cryptocurrency protocols, both

  82. Yuhao Hu

    Using Cartan's Method of Equivalence, we prove an upper bound for the generality of generic rank-1 Bäcklund transformations relating two hyperbolic Monge-Ampère systems. In cases when the Bäcklund transformation admits a symmetry group whose orbits have codimension 1, 2, or 3, we obtain classification results and new examples of auto-Bäcklund transformat

  83. Ievgen I. Arkhipov, Tai Hyun Yoon, Adam Miranowicz

    We investigate the performance of a certain nonclassicality identifier, expressed via integrated second-order intensity moments of optical fields, in revealing bipartite entanglement of quantum-optical frequency combs (QOFCs), which are generated in both spontaneous and stimulated parametric down-conversion processes. We show that, by utilizing that nonclass

  84. K. M. George, J. T. Morrison, S. Feister, G. Ngirmang

    High intensity laser-plasma interactions produce a wide array of energetic particles and beams with promising applications. Unfortunately, high repetition rate and high average power requirements for many applications are not satisfied by the lasers, optics, targets, and diagnostics currently employed. Here, we address the need for high repetition rate targe

  85. Jonah Kudler-Flam, Ian MacCormack, Shinsei Ryu

    We study the entanglement contour, a quasi-local measure of entanglement, and propose a generic formula for the contour in 1+1d quantum systems. We use this formalism to investigate the real space entanglement structure of various static CFTs as well as local and global quantum quenches. The global quench elucidates the spatial distribution of entanglement e

  86. Arjen van Elteren, Simon Portegies Zwart, Inti Pelupessy, Maxwell Cai

    We perform a simulation using the Astrophysical Multipurpose Software Environment of the Orion Trapezium star cluster in which the evolution of the stars and the dynamics of planetary systems are taken into account. The initial conditions from earlier simulations were selected in which the size and mass distributions of the observed circumstellar disks in th

  87. Amir-Hossein Bateni, Arnak S. Dalalyan

    We consider the problem of estimating the mean of a distribution supported by the $k$-dimensional probability simplex in the setting where an $\varepsilon$ fraction of observations are subject to adversarial corruption. A simple particular example is the problem of estimating the distribution of a discrete random variable. Assuming that the discrete variable

  88. Bob D. de Vos, Jelmer M. Wolterink, Tim Leiner, Pim A. de Jong

    Cardiovascular disease (CVD) is the global leading cause of death. A strong risk factor for CVD events is the amount of coronary artery calcium (CAC). To meet demands of the increasing interest in quantification of CAC, i.e. coronary calcium scoring, especially as an unrequested finding for screening and research, automatic methods have been proposed. Curren

  89. Eirik Holm Fyhn, Karl Yngve Lervåg, Åsmund Ervik, Øivind Wilhelmsen

    The gravity-driven spreading of one fluid in contact with another fluid is of key importance to a range of topics. To describe these phenomena, the two-layer shallow-water equations is commonly employed. When one layer is significantly deeper than the other, it is common to approximate the system with the much simpler one-layer shallow water equations. So fa

  90. Debmalya Mandal, David Parkes

    Marginal Structural Models (MSM) are the most popular models for causal inference from time-series observational data. However, they have two main drawbacks: (a) they do not capture subject heterogeneity, and (b) they only consider fixed time intervals and do not scale gracefully with longer intervals. In this work, we propose a new family of MSMs to address

  91. Antoine Garcon, John W. Blanchard, Gary P. Centers, Nataniel L. Figueroa

    The nature of dark matter, the invisible substance making up over $80\%$ of the matter in the Universe, is one of the most fundamental mysteries of modern physics. Ultralight bosons such as axions, axion-like particles or dark photons could make up most of the dark matter. Couplings between such bosons and nuclear spins may enable their direct detection via

  92. Valmir Bucaj, David Damanik, Jake Fillman, Vitaly Gerbuz

    In this short note, we prove positivity of the Lyapunov exponent for 1D continuum Anderson models by leveraging some classical tools from inverse spectral theory. The argument is much simpler than the existing proof due to Damanik--Sims--Stolz, and it covers a wider variety of random models. Along the way we note that a Large Deviation Theorem holds uniforml

  93. Swamit S. Tannu, Poulami Das, Michael L. Lewis, Robert Krick

    As the scaling of conventional CMOS-based technologies slows down, there is growing interest in alternative technologies that can improve performance or energy-efficiency. Superconducting circuits based on Josephson Junction (JJ) is an emerging technology that can provide devices which can be switched with pico-second latencies and consuming two orders of ma

  94. Mostafa Fazly

    We examine regularity of the extremal solution of nonlinear nonlocal eigenvalue problem \begin{eqnarray} \left\{ \begin{array}{lcl} \hfill \mathcal L u &=& λF(u,v) \qquad \text{in} \ \ Ω, \\ \hfill \mathcal L v &=& γG(u,v) \qquad \text{in} \ \ Ω, \\ \hfill u,v &=&0 \qquad \qquad \text{on} \ \ \mathbb R^n\setminusΩ, \end{array}\right. \end{eqnarray} with an i

  95. Tyler Sypherd, Mario Diaz, Lalitha Sankar, Peter Kairouz

    We present $α$-loss, $α\in [1,\infty]$, a tunable loss function for binary classification that bridges log-loss ($α=1$) and $0$-$1$ loss ($α= \infty$). We prove that $α$-loss has an equivalent margin-based form and is classification-calibrated, two desirable properties for a good surrogate loss function for the ideal yet intractable $0$-$1$ loss. For logisti

  96. Per Bäck, Johan Richter

    The first (associative) Weyl algebra is formally rigid in the classical sense. In this paper, we show that it can however be formally deformed in a nontrivial way when considered as a so-called hom-associative algebra, and that this deformation preserves properties such as the commuter, while deforming others, such as the center, power associativity, the set

  97. Nick Gravin, Yaonan Jin, Pinyan Lu, Chenhao Zhang

    In this paper, we show a tight approximation guarantee for budget-feasible mechanisms with an additive buyer. We propose a new simple randomized mechanism with approximation ratio of $2$, improving the previous best known result of $3$. Our bound is tight with respect to either the optimal offline benchmark, or its fractional relaxation. We also present a si

  98. Wengang Zhang, Francis W. Starr, Jack F. Douglas

    To understand the role of collective motion in the often large changes in interfacial molecular mobility observed in polymer films, we investigate the extent of collective motion in the interfacial regions of a thin supported polymer film and within the film interior by molecular dynamics simulation. Contrary to commonly stated expectations, we find that the

  99. Helen L. Cleaves, Alen Alexanderian, Hayley Guy, Ralph C. Smith

    We present a framework for derivative-based global sensitivity analysis (GSA) for models with high-dimensional input parameters and functional outputs. We combine ideas from derivative-based GSA, random field representation via Karhunen--Loève expansions, and adjoint-based gradient computation to provide a scalable computational framework for computing the p

  100. Alexander J. A. Ty, Zheng Fang, Rivver A. Gonzalez, Paul J. Rozdeba

    Tasking machine learning to predict segments of a time series requires estimating the parameters of a ML model with input/output pairs from the time series. Using the equivalence between statistical data assimilation and supervised machine learning, we revisit this task. The training method for the machine utilizes a precision annealing approach to identifyi