检索结果-内蒙古大学图书馆

Signaling games for log-concave distributions: Number of bins and properties of equilibria

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Kazıklı, Ertan Sarıtaş, Serkan Gezici, Sinan Linder, Tamás Yüksel, Serdar The Department of Mathematics and Statistics Queen's University KingstonONK7L 3N6 Canada Ankara06800 Turkey The Department of Electrical and Electronics Engineering Bilkent University Ankara06800 Turkey

We investigate the equilibrium behavior for the decentralized cheap talk problem for real random variables and quadratic cost criteria in which an encoder and a decoder have misaligned objective functions. In prior work, it has been shown that the number of bins in any equilibrium has to be countable, generalizing a classical result due to Crawford and Sobel who considered sources with density supported on [0, 1]. In this paper, we first refine this result in the context of log-concave sources. For sources with two-sided unbounded support, we prove that, for any finite number of bins, there exists a unique equilibrium. In contrast, for sources with semi-unbounded support, there may be a finite upper bound on the number of bins in equilibrium depending on certain conditions stated explicitly. Moreover, we prove that for log-concave sources, the expected costs of the encoder and the decoder in equilibrium decrease as the number of bins increases. Furthermore, for strictly log-concave sources with two-sided unbounded support, we prove convergence to the unique equilibrium under best response dynamics which starts with a given number of bins, making a connection with the classical theory of optimal quantization and convergence results of Lloyd's method. In addition, we consider more general sources which satisfy certain assumptions on the tail(s) of the distribution and we show that there exist equilibria with infinitely many bins for sources with two-sided unbounded support. Further explicit characterizations are provided for sources with exponential, Gaussian, and compactly-supported probability distributions. Copyright © 2020, The Authors. All rights reserved.

关键词： Game theory

Wrinkles in the opening angle method

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Destrade, Michel Lusetti, Irene Mangan, Robert Sigaeva, Taisiya School of Mathematics Statistics and Applied Mathematics NUI Galway University Road Galway Ireland School of Mechanical and Materials Engineering University College Dublin Belfield Dublin 4 Ireland Politecnico di Milano piazza Leonardo da Vinci 32 Milano20133 Italy Department of Mechanical and Manufacturing Engineering University of Calgary CalgaryAB Canada Department of Mechanical Engineering Lassonde School of Engineering York University TorontoON Canada

We investigate the stability of the deformation modeled by the opening angle method, often used to give a measure of residual stresses in arteries and other biological soft tubular structures. Specifically, we study the influence of stiffness contrast, dimensions and inner pressure on the onset of wrinkles when an open sector of a soft tube, coated with a stiffer film, is bent into a full cylinder. The tube and its coating are made of isotropic, incompressible, hyperelastic materials. We provide a full analytical exposition of the governing equations and the associated boundary value problem for the large deformation and for the superimposed small-amplitude wrinkles. For illustration, we solve them numerically with a robust algorithm in the case of Mooney-Rivlin materials. We confront the results to experimental data that we collected for soft silicone sectors. We study the influence of axial stretch and inner pressure on the stability of closed-up coated tubes with material parameters comparable with those of soft biological tubes such as arteries and veins, although we do not account for anisotropy. We find that the large deformation described in the opening angle method does not always exist, as it can become unstable for certain combinations of dimensions and material parameters. Copyright © 2020, The Authors. All rights reserved.

关键词： Boundary value problems

Deep Variational Network Toward Blind Image Restoration

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Yue, Zongsheng Yong, Hongwei Zhao, Qian Zhang, Lei Meng, Deyu Wong, Kwan-Yee K. The School of Mathematics and Statistics Xi’an Jiaotong University Xi’an China The Department of Computer Science The University of Hong Kong Hong Kong The Department of Computing The Hong Kong Polytechnic University Hong Kong The School of Mathematics and Statistics Ministry of Education Key Lab of Intelligent Networks and Network Security Xi’an Jiaotong University Xi’an China The Macau Institute of Systems Engineering Macau University of Science and Technology Taipa China

Blind image restoration (IR) is a common yet challenging problem in computer vision. Classical model-based methods and recent deep learning (DL)-based methods represent two different methodologies for this problem, each with its own merits and drawbacks. In this paper, we propose a novel blind image restoration method, aiming to integrate both the advantages of them. Specifically, we construct a general Bayesian generative model for the blind IR, which explicitly depicts the degradation process. In this proposed model, a pixel-wise non-i.i.d. Gaussian distribution is employed to fit the image noise. It is with more flexibility than the simple i.i.d. Gaussian or Laplacian distributions as adopted in most of conventional methods, so as to handle more complicated noise types contained in the image degradation. To solve the model, we design a variational inference algorithm where all the expected posteriori distributions are parameterized as deep neural networks to increase their model capability. Notably, such an inference algorithm induces a unified framework to jointly deal with the tasks of degradation estimation and image restoration. Further, the degradation information estimated in the former task is utilized to guide the latter IR process. Experiments on two typical blind IR tasks, namely image denoising and super-resolution, demonstrate that the proposed method achieves superior performance over current state-of-the-arts. The source code is available at https://***/zsyOAOA/VIRNet. © 2020, CC BY-NC-SA.

关键词： Image reconstruction

Data assimilation in large-prandtl rayleigh-Bénard convection from thermal measurements

学校读者我要写书评

暂无评论

arXiv 2019年

作者： Farhat, A. Glatt-Holtz, N.E. Martinez, V.R. McQuarrie, S.A. Whitehead, J.P. Department of Mathematics Florida State University Department of Mathematics Tulane University Department of Mathematics and Statistics Hunter College CUNY Institute for Computational Engineering Sciences University of Texas Austin United States Mathematics Department Brigham Young University

This work applies a continuous data assimilation scheme-a particular framework for reconciling sparse and potentially noisy observations to a mathematical model-to Rayleigh-Bénard convection at infinite or large Prandtl numbers using only the temperature field as observables. These Prandtl numbers are applicable to the earth's mantle and to gases under high pressure. We rigorously identify conditions that guarantee synchronization between the observed system and the model, then confirm the applicability of these results via numerical simulations. Our numerical experiments show that the analytically derived conditions for synchronization are far from sharp;that is, synchronization often occurs even when the conditions of our theorems are not met. We also develop estimates on the convergence of an infinite Prandtl model to a large (but finite) Prandtl number generated set of observations. Numerical simulations in this hybrid setting indicate that the mathematically rigorous results are accurate, but of practical interest only for extremely large Prandtl *** Codes 76E06, 62M20, 35Q35 Copyright © 2019, The Authors. All rights reserved.

关键词： Prandtl number

Wafer-scale transfer route for top–down III-nitride nanowire LED arrays based on the femtosecond laser lift-off technique

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2021年第2期7卷 205-219页

作者： Nursidik Yulianto Andam Deatama Refino Alina Syring Nurhalis Majid Shinta Mariana Patrick Schnell Ruri Agung Wahyuono Kuwat Triyana Florian Meierhofer Winfried Daum Fatwa F.Abdi Tobias Voss Hutomo Suryo Wasisto Andreas Waag Institute of Semiconductor Technology(IHT) Technische Universität BraunschweigHans-Sommer-Straße 66Braunschweig38106Germany Laboratory for Emerging Nanometrology(LENA) Technische Universität BraunschweigLanger Kamp 6Braunschweig38106Germany Research Center for Physics Indonesian Institute of Sciences(LIPI)Jl.Kawasan Puspiptek No.441-442TangerangSelatan15314Indonesia Engineering Physics Program Institut Teknologi Sumatera(ITERA)Jl.Terusan RyacuduWay HuwiLampung SelatanLampung35365Indonesia Institute of Energy Research and Physical Technologies Technische Universität ClausthalLeibnizstraße 4Clausthal-Zellerfeld38678Germany Institute for Solar Fuels Helmholtz-Zentrum Berlin für Materialien und Energie GmbHHahn-Meitner-Platz 1Berlin14109Germany Department of Engineering Physics Institut Teknologi Sepuluh Nopember(ITS)Jl.Arif Rahman HakimITS Campus SukoliloSurabaya60111Indonesia Department of Physics Faculty of Mathematics and Natural SciencesUniversitas Gadjah MadaSekip Utara PO Box BLS 21Yogyakarta55281Indonesia

The integration of gallium nitride(GaN)nanowire light-emitting diodes(nanoLEDs)on flexible substrates offers opportunities for applications beyond rigid solid-state lighting(e.g.,for wearable optoelectronics and bendable inorganic displays).Here,we report on a fast physical transfer route based on femtosecond laser lift-off(fs-LLO)to realize wafer-scale top–down GaN nanoLED arrays on unconventional *** with photolithography and hybrid etching processes,we successfully transferred GaN blue nanoLEDs from a full two-inch sapphire substrate onto a flexible copper(Cu)foil with a high nanowire density(~107 wires/cm2),transfer yield(~99.5%),and *** nanoanalytical measurements were conducted to evaluate the performance and limitations of the fs-LLO technique as well as to gain insights into physical material properties such as strain relaxation and assess the maturity of the transfer *** work could enable the easy recycling of native growth substrates and inspire the development of large-scale hybrid GaN nanowire optoelectronic devices by solely employing standard epitaxial LED wafers(i.e.,customized LED wafers with additional embedded sacrificial materials and a complicated growth process are not required).

关键词： sapphire transfer lighting

Correction to: Mitigation strategies against cascading failures within a project activity network

学校读者我要写书评

暂无评论

Journal of Computational Social Science 2021年第1期5卷 1097-1098页

作者： Ellinas, Christos Nicolaides, Christos Masuda, Naoki Nodes and Links Ltd Cambridge UK Department of Business and Public Administration University of Cyprus Nicosia Cyprus Initiative on the Digital Economy Massachusetts Institute of Technology Cambridge USA Department of Mathematics State University of New York at Buffalo Buffalo USA Computational and Data-Enabled Science and Engineering Program State University of New York at Buffalo Buffalo USA Faculty of Management and Economics Dalian University of Technology Dalian China

Transformations between deep neural networks

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Bertalan, Tom Dietrich, Felix Kevrekidis, Ioannis G. Department of Chemical and Biomolecular Engineering Johns Hopkins University BaltimoreMD United States Department of Informatics Technical University of Munich Munich Germany Departments of Chemical and Biomolecular Engineering & Applied Mathematics and Statistics Johns Hopkins University BaltimoreMD United States

We propose to test, and when possible establish, an equivalence between two different artificial neural networks by attempting to construct a data-driven transformation between them, using manifold-learning techniques. In particular, we employ diffusion maps with a Mahalanobis-like metric. If the construction succeeds, the two networks can be thought of as belonging to the same equivalence class. We first discuss transformation functions between only the outputs of the two networks;we then also consider transformations that take into account outputs (activations) of a number of internal neurons from each network. In general, Whitney’s theorem dictates the number of measurements from one of the networks required to reconstruct each and every feature of the second network. The construction of the transformation function relies on a consistent, intrinsic representation of the network input space. We illustrate our algorithm by matching neural network pairs trained to learn (a) observations of scalar functions;(b) observations of two-dimensional vector fields;and (c) representations of images of a moving three-dimensional object (a rotating horse). The construction of such equivalence classes across different network instantiations clearly relates to transfer learning. We also expect that it will be valuable in establishing equivalence between different Machine Learning-based models of the same phenomenon observed through different instruments and by different research groups. Copyright © 2020, The Authors. All rights reserved.

关键词： Equivalence classes

Identification of Magnetite Material (Fe3O4) Based on Natural Materials as Catalyst for Industrial Raw Material Application 1

学校读者我要写书评

暂无评论

Identification of Magnetite Material (Fe3O4) Based on Natura...

1st International Conference on Education, Science and Technology, ICON-EST 2018

作者： Maulinda Zein, Ikramullah Jalil, Zulkarnain Industrial Engineering Study Program Engineering Faculty of Serambi Mekkah University Banda Aceh Indonesia Material Physics Laboratory Department of Physics Faculty of Mathematics and Natural Science SyiahKuala University Banda Aceh Indonesia

Identification of magnetite nanoparticles synthesized from natural iron sand with a chemical treatment that is by using thecoprecipitation method on temperature and heated spaces, using a pair of acids and bases, i.e. HCL as a solvent NH4OH and as its precipation. The Crystal structure, the percentage of elements, the particle size and properties of the magnetism material characterization by XRD, XRF identification testing, and permagraph. From the results obtained in the Analysis that the value of the percentage purity of Fe3O4 are derived from Natural Sands before Extraction is of 81.42%, and once on extract 86.73% increase to its purity. From the results of the analysis of properties of ferrite magnet to Fe3O4from sand iron retrieved the value of Saturation Magnetization (Ms) produced amounted to 0.29 T, or residual magnetization Remanence (Br) of 0081 T, and Coercivityy(Hc) amounted to 1.82 kA/m expected data analysis results may explain the comparison characteristics in structure and magnetic properties of material with a natural sand Fe3O4 Aldrich so it can be an additional related information value added (added value) the local SDA. © Published under licence by IOP Publishing Ltd.

关键词： Magnetite

Multilevel Constructions: Coding, Packing and Geometric Uniformity

学校读者我要写书评

暂无评论

Multilevel Constructions: Coding, Packing and Geometric Unif...

作者： Bollauf, Maiara F. Zamir, Ram Costa, Sueli I. R. Institute of Mathematics Statistics and Computer Science University of Campinas Campinas13083-859 Brazil Department of Electrical and Computer Engineering Texas A and M University at Qatar Doha Qatar Department of Electrical Engineering-Systems Tel Aviv University Tel Aviv6997801 Israel

Lattice and special nonlattice multilevel constellations constructed from binary codes, such as Constructions A, C, and D, have relevant applications in mathematics (sphere packing) and in Communication (multi-stage decoding and efficient vector quantization). In this work, we explore some properties of Construction C, in particular its geometric uniformity. We then propose a new multilevel construction, inspired by bit interleaved coded modulation (BICM), that we call Construction C∗. We investigate the geometric uniformity, latticeness, and minimum distance properties of Construction C∗ , and discuss its superior packing efficiency when compared to Construction C. © 1963-2012 IEEE.

关键词： Geometry