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Publisher: Springer-Verlag (Total: 2574 journals)

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Showing 1 - 200 of 2574 Journals sorted by number of followers
Intl. J. on Digital Libraries     Hybrid Journal   (Followers: 757, SJR: 0.441, CiteScore: 2)
Information Retrieval     Hybrid Journal   (Followers: 658, SJR: 0.352, CiteScore: 2)
Trends in Organized Crime     Hybrid Journal   (Followers: 525, SJR: 0.26, CiteScore: 1)
Crime, Law and Social Change     Hybrid Journal   (Followers: 485, SJR: 0.357, CiteScore: 1)
J. of Police and Criminal Psychology     Hybrid Journal   (Followers: 431, SJR: 0.35, CiteScore: 1)
Diabetologia     Hybrid Journal   (Followers: 321, SJR: 3.228, CiteScore: 5)
Innovative Higher Education     Hybrid Journal   (Followers: 307, SJR: 0.586, CiteScore: 1)
Natural Hazards     Hybrid Journal   (Followers: 289, SJR: 0.767, CiteScore: 2)
Gyroscopy and Navigation     Hybrid Journal   (Followers: 237, SJR: 0.292, CiteScore: 1)
Biodiversity and Conservation     Open Access   (Followers: 218, SJR: 1.243, CiteScore: 3)
Dysphagia     Hybrid Journal   (Followers: 184, SJR: 0.99, CiteScore: 2)
Pharmaceutical Research     Hybrid Journal   (Followers: 177, SJR: 1.077, CiteScore: 3)
Higher Education     Hybrid Journal   (Followers: 177, SJR: 1.782, CiteScore: 2)
Archives and Museum Informatics     Hybrid Journal   (Followers: 169, SJR: 0.101, CiteScore: 0)
European J. of Information Systems     Hybrid Journal   (Followers: 161, SJR: 1.628, CiteScore: 4)
Crime Prevention and Community Safety     Hybrid Journal   (Followers: 153, SJR: 0.268, CiteScore: 1)
Space Science Reviews     Hybrid Journal   (Followers: 95, SJR: 3.262, CiteScore: 7)
J. of Autism and Developmental Disorders     Hybrid Journal   (Followers: 86, SJR: 1.81, CiteScore: 4)
Intensive Care Medicine     Hybrid Journal   (Followers: 74, SJR: 3.293, CiteScore: 4)
Education and Information Technologies     Hybrid Journal   (Followers: 72, SJR: 0.403, CiteScore: 1)
Ethics and Information Technology     Hybrid Journal   (Followers: 70, SJR: 0.512, CiteScore: 2)
Archival Science     Hybrid Journal   (Followers: 68, SJR: 0.745, CiteScore: 2)
Applied Microbiology and Biotechnology     Hybrid Journal   (Followers: 67, SJR: 1.182, CiteScore: 4)
European J. of Law and Economics     Hybrid Journal   (Followers: 63, SJR: 0.375, CiteScore: 1)
Marine Biology     Hybrid Journal   (Followers: 62, SJR: 1.085, CiteScore: 2)
Landscape Ecology     Hybrid Journal   (Followers: 62, SJR: 1.858, CiteScore: 4)
J. of Archaeological Method and Theory     Hybrid Journal   (Followers: 62, SJR: 2.014, CiteScore: 3)
Educational Technology Research and Development     Partially Free   (Followers: 61)
Climatic Change     Open Access   (Followers: 61, SJR: 2.035, CiteScore: 4)
J. of Information Technology     Hybrid Journal   (Followers: 60, SJR: 1.752, CiteScore: 4)
Research in Higher Education     Hybrid Journal   (Followers: 58, SJR: 1.702, CiteScore: 2)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 58, SJR: 1.09, CiteScore: 1)
Oecologia     Hybrid Journal   (Followers: 57, SJR: 1.695, CiteScore: 3)
J. of the Indian Society of Remote Sensing     Hybrid Journal   (Followers: 57, SJR: 0.337, CiteScore: 1)
J. of Experimental Criminology     Hybrid Journal   (Followers: 57, SJR: 2.639, CiteScore: 4)
Machine Learning     Hybrid Journal   (Followers: 57, SJR: 0.695, CiteScore: 3)
Earth, Moon, and Planets     Hybrid Journal   (Followers: 57, SJR: 0.63, CiteScore: 1)
J. of Business Ethics     Hybrid Journal   (Followers: 56, SJR: 1.276, CiteScore: 3)
Experimental Techniques     Hybrid Journal   (Followers: 56, SJR: 0.296, CiteScore: 1)
Intl. J. for Philosophy of Religion     Hybrid Journal   (Followers: 56, SJR: 0.354, CiteScore: 0)
Cambridge journal of evidence-based policing     Hybrid Journal   (Followers: 54)
Applied Composite Materials     Hybrid Journal   (Followers: 53, SJR: 0.58, CiteScore: 2)
Advances in Polymer Science     Hybrid Journal   (Followers: 49, SJR: 1.04, CiteScore: 3)
J. of Earth System Science     Open Access   (Followers: 49, SJR: 0.366, CiteScore: 1)
Intl. J. of Historical Archaeology     Hybrid Journal   (Followers: 49, SJR: 0.427, CiteScore: 1)
J. of Archaeological Research     Hybrid Journal   (Followers: 48, SJR: 2.159, CiteScore: 4)
European J. of Applied Physiology     Hybrid Journal   (Followers: 47, SJR: 1.186, CiteScore: 2)
Memory & Cognition     Hybrid Journal   (Followers: 47, SJR: 1.379, CiteScore: 2)
J. of Astrophysics and Astronomy     Open Access   (Followers: 47, SJR: 0.266, CiteScore: 0)
Environmental Management     Open Access   (Followers: 47, SJR: 0.921, CiteScore: 2)
Canadian J. of Anesthesia/J. canadien d'anesthésie     Hybrid Journal   (Followers: 46, SJR: 0.908, CiteScore: 2)
Contemporary Political Theory     Hybrid Journal   (Followers: 46, SJR: 0.331, CiteScore: 0)
Applied Biochemistry and Biotechnology     Hybrid Journal   (Followers: 44, SJR: 0.571, CiteScore: 2)
Bulletin of Materials Science     Open Access   (Followers: 43, SJR: 0.31, CiteScore: 1)
J. of Family Violence     Hybrid Journal   (Followers: 43, SJR: 0.679, CiteScore: 1)
Astrophysics and Space Science     Hybrid Journal   (Followers: 43, SJR: 0.616, CiteScore: 1)
Metallurgical and Materials Transactions A     Hybrid Journal   (Followers: 42, SJR: 1.093, CiteScore: 2)
Comparative European Politics     Hybrid Journal   (Followers: 42, SJR: 1.24, CiteScore: 2)
Demography     Hybrid Journal   (Followers: 41, SJR: 2.345, CiteScore: 3)
Foundations of Physics     Hybrid Journal   (Followers: 41, SJR: 0.454, CiteScore: 1)
J. of Intl. Business Studies     Hybrid Journal   (Followers: 41, SJR: 5.198, CiteScore: 7)
Water Resources Management     Open Access   (Followers: 40, SJR: 1.185, CiteScore: 3)
Qualitative Sociology     Hybrid Journal   (Followers: 40, SJR: 0.984, CiteScore: 1)
Advances in Atmospheric Sciences     Hybrid Journal   (Followers: 40, SJR: 0.956, CiteScore: 2)
Intl. J. of Earth Sciences     Hybrid Journal   (Followers: 40, SJR: 1.125, CiteScore: 2)
Data Mining and Knowledge Discovery     Hybrid Journal   (Followers: 40, SJR: 0.864, CiteScore: 4)
Mindfulness     Hybrid Journal   (Followers: 39, SJR: 1.132, CiteScore: 3)
Environment, Development and Sustainability     Hybrid Journal   (Followers: 39, SJR: 0.392, CiteScore: 1)
European Political Science     Hybrid Journal   (Followers: 39, SJR: 0.25, CiteScore: 0)
Economia Politica     Hybrid Journal   (Followers: 38, SJR: 0.277, CiteScore: 1)
Experimental Astronomy     Hybrid Journal   (Followers: 38, SJR: 0.908, CiteScore: 2)
Metal Science and Heat Treatment     Hybrid Journal   (Followers: 38, SJR: 0.279, CiteScore: 0)
Solar Physics     Hybrid Journal   (Followers: 37, SJR: 1.517, CiteScore: 3)
European J. of Health Economics     Hybrid Journal   (Followers: 37, SJR: 1.153, CiteScore: 2)
Scientometrics     Hybrid Journal   (Followers: 37, SJR: 1.125, CiteScore: 3)
IMF Economic Review     Hybrid Journal   (Followers: 37, SJR: 3.287, CiteScore: 2)
Climate Dynamics     Hybrid Journal   (Followers: 37, SJR: 2.445, CiteScore: 4)
Environmental Monitoring and Assessment     Hybrid Journal   (Followers: 37, SJR: 0.589, CiteScore: 2)
Aquatic Ecology     Hybrid Journal   (Followers: 37, SJR: 0.656, CiteScore: 2)
Educational Psychology Review     Hybrid Journal   (Followers: 37, SJR: 2.204, CiteScore: 4)
J. of World Prehistory     Hybrid Journal   (Followers: 36, SJR: 2.022, CiteScore: 3)
J. of Quantitative Criminology     Hybrid Journal   (Followers: 36, SJR: 3.562, CiteScore: 4)
Behavioral Ecology and Sociobiology     Hybrid Journal   (Followers: 36, SJR: 1.323, CiteScore: 2)
JOM J. of the Minerals, Metals and Materials Society     Hybrid Journal   (Followers: 36, SJR: 1.054, CiteScore: 2)
European J. of Nutrition     Hybrid Journal   (Followers: 35, SJR: 1.408, CiteScore: 3)
Annals of Finance     Hybrid Journal   (Followers: 35, SJR: 0.579, CiteScore: 1)
Advances in Health Sciences Education     Hybrid Journal   (Followers: 35, SJR: 1.64, CiteScore: 2)
Biotechnology Letters     Hybrid Journal   (Followers: 34, SJR: 0.621, CiteScore: 2)
Forensic Science, Medicine, and Pathology     Hybrid Journal   (Followers: 33, SJR: 0.695, CiteScore: 1)
Child and Adolescent Social Work J.     Hybrid Journal   (Followers: 33, SJR: 0.444, CiteScore: 1)
Plant Ecology     Hybrid Journal   (Followers: 32, SJR: 0.914, CiteScore: 2)
Political Behavior     Hybrid Journal   (Followers: 32, SJR: 2.708, CiteScore: 2)
Reviews in Fish Biology and Fisheries     Open Access   (Followers: 32, SJR: 1.8, CiteScore: 4)
Analytical and Bioanalytical Chemistry     Hybrid Journal   (Followers: 32, SJR: 0.978, CiteScore: 3)
Metallurgical and Materials Transactions B     Hybrid Journal   (Followers: 32)
European J. of Epidemiology     Hybrid Journal   (Followers: 32, SJR: 3.228, CiteScore: 6)
Der Onkologe     Hybrid Journal   (Followers: 32, SJR: 0.119, CiteScore: 0)
Ecosystems     Hybrid Journal   (Followers: 32, SJR: 2.081, CiteScore: 4)
Australian Educational Researcher     Hybrid Journal   (Followers: 31, SJR: 0.675, CiteScore: 1)
Italian Economic J.     Hybrid Journal   (Followers: 31, SJR: 0.181, CiteScore: 0)
J. of the American Society for Mass Spectrometry     Hybrid Journal   (Followers: 31, SJR: 1.058, CiteScore: 3)
Accreditation and Quality Assurance: J. for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 31, SJR: 0.316, CiteScore: 1)
Intl. Politics     Hybrid Journal   (Followers: 31, SJR: 0.728, CiteScore: 1)
Academic Psychiatry     Full-text available via subscription   (Followers: 30, SJR: 0.53, CiteScore: 1)
Boundary-Layer Meteorology     Hybrid Journal   (Followers: 30, SJR: 1.262, CiteScore: 2)
Resonance     Hybrid Journal   (Followers: 29, SJR: 0.15, CiteScore: 0)
Motivation and Emotion     Hybrid Journal   (Followers: 29, SJR: 1.136, CiteScore: 2)
Transportation     Hybrid Journal   (Followers: 29, SJR: 1.911, CiteScore: 3)
J. of Population Economics     Hybrid Journal   (Followers: 29, SJR: 1.574, CiteScore: 2)
AAPS J.     Hybrid Journal   (Followers: 29, SJR: 1.118, CiteScore: 4)
Information Systems Frontiers     Hybrid Journal   (Followers: 29, SJR: 0.821, CiteScore: 4)
Clinical Social Work J.     Hybrid Journal   (Followers: 29, SJR: 0.498, CiteScore: 1)
American J. of Community Psychology     Hybrid Journal   (Followers: 29, SJR: 1.329, CiteScore: 2)
J. of Economic Growth     Hybrid Journal   (Followers: 29, SJR: 5.529, CiteScore: 5)
Current Diabetes Reports     Hybrid Journal   (Followers: 29, SJR: 1.618, CiteScore: 4)
GPS Solutions     Hybrid Journal   (Followers: 29, SJR: 1.674, CiteScore: 5)
ADHD Attention Deficit and Hyperactivity Disorders     Hybrid Journal   (Followers: 28, SJR: 0.72, CiteScore: 2)
Knee Surgery, Sports Traumatology, Arthroscopy     Hybrid Journal   (Followers: 28, SJR: 1.845, CiteScore: 3)
CEAS Aeronautical J.     Hybrid Journal   (Followers: 28, SJR: 0.248, CiteScore: 1)
Environmental Earth Sciences     Hybrid Journal   (Followers: 28, SJR: 0.552, CiteScore: 2)
J. of Risk and Uncertainty     Hybrid Journal   (Followers: 28, SJR: 1.471, CiteScore: 2)
J. of Happiness Studies     Hybrid Journal   (Followers: 28, SJR: 0.827, CiteScore: 2)
Flow, Turbulence and Combustion     Hybrid Journal   (Followers: 28, SJR: 0.934, CiteScore: 2)
Microsystem Technologies     Hybrid Journal   (Followers: 27, SJR: 0.346, CiteScore: 1)
IIC - Intl. Review of Intellectual Property and Competition Law     Hybrid Journal   (Followers: 27, SJR: 0.28, CiteScore: 0)
Law and Philosophy     Hybrid Journal   (Followers: 27, SJR: 0.471, CiteScore: 1)
Landslides     Hybrid Journal   (Followers: 27, SJR: 1.802, CiteScore: 4)
Astrophysics     Hybrid Journal   (Followers: 27, SJR: 0.225, CiteScore: 0)
Intl. J. of Information Security     Hybrid Journal   (Followers: 27, SJR: 0.555, CiteScore: 3)
Educational Assessment, Evaluation and Accountability     Hybrid Journal   (Followers: 26, SJR: 0.599, CiteScore: 1)
Higher Education Policy     Hybrid Journal   (Followers: 26, SJR: 0.652, CiteScore: 1)
J. of Ornithology     Hybrid Journal   (Followers: 26)
J. of Analytical Chemistry     Hybrid Journal   (Followers: 26, SJR: 0.265, CiteScore: 1)
J. of Financial Services Research     Hybrid Journal   (Followers: 26, SJR: 1.31, CiteScore: 1)
Applied Physics B: Lasers and Optics     Hybrid Journal   (Followers: 26, SJR: 0.74, CiteScore: 2)
Aquaculture Intl.     Hybrid Journal   (Followers: 26, SJR: 0.591, CiteScore: 2)
J. of Computational Neuroscience     Hybrid Journal   (Followers: 25, SJR: 0.888, CiteScore: 2)
J. of Banking Regulation     Hybrid Journal   (Followers: 25, SJR: 0.22, CiteScore: 0)
J. of Thermal Analysis and Calorimetry     Hybrid Journal   (Followers: 25, SJR: 0.587, CiteScore: 2)
Water, Air, & Soil Pollution     Open Access   (Followers: 25, SJR: 0.589, CiteScore: 2)
Intl. J. of Sexuality and Gender Studies     Hybrid Journal   (Followers: 25)
Review of Accounting Studies     Hybrid Journal   (Followers: 25, SJR: 2.757, CiteScore: 2)
Public Choice     Hybrid Journal   (Followers: 25, SJR: 0.991, CiteScore: 1)
J. of Nutrition, Health and Aging     Hybrid Journal   (Followers: 25, SJR: 1.249, CiteScore: 3)
Continental Philosophy Review     Partially Free   (Followers: 25, SJR: 0.145, CiteScore: 0)
Human Rights Review     Hybrid Journal   (Followers: 25, SJR: 0.175, CiteScore: 1)
European Business Organization Law Review (EBOR)     Full-text available via subscription   (Followers: 25, SJR: 0.409, CiteScore: 1)
Acta Mechanica     Hybrid Journal   (Followers: 25, SJR: 1.04, CiteScore: 2)
Human Ecology     Open Access   (Followers: 25, SJR: 0.752, CiteScore: 2)
Evolutionary Biology     Hybrid Journal   (Followers: 25, SJR: 0.81, CiteScore: 2)
European J. of Clinical Microbiology & Infectious Diseases     Hybrid Journal   (Followers: 25, SJR: 1.312, CiteScore: 3)
Russian Aeronautics (Iz VUZ)     Hybrid Journal   (Followers: 24, SJR: 0.136, CiteScore: 0)
Meteorology and Atmospheric Physics     Hybrid Journal   (Followers: 24, SJR: 0.543, CiteScore: 1)
The European Physical J. D - Atomic, Molecular, Optical and Plasma Physics     Hybrid Journal   (Followers: 24, SJR: 0.387, CiteScore: 1)
Wetlands     Hybrid Journal   (Followers: 24, SJR: 0.755, CiteScore: 2)
Mechanics of Composite Materials     Hybrid Journal   (Followers: 24, SJR: 0.313, CiteScore: 1)
J. of Public Health Policy     Partially Free   (Followers: 24, SJR: 0.715, CiteScore: 1)
World J. of Surgery     Hybrid Journal   (Followers: 24, SJR: 1.359, CiteScore: 2)
J. of Chemical Sciences     Partially Free   (Followers: 24, SJR: 0.352, CiteScore: 1)
Experimental Economics     Hybrid Journal   (Followers: 24, SJR: 2.276, CiteScore: 2)
J. of Pharmacokinetics and Pharmacodynamics     Hybrid Journal   (Followers: 24, SJR: 0.784, CiteScore: 2)
Biological Invasions     Hybrid Journal   (Followers: 24, SJR: 1.514, CiteScore: 3)
Experimental Mechanics     Hybrid Journal   (Followers: 24, SJR: 0.947, CiteScore: 2)
Breast Cancer Research and Treatment     Hybrid Journal   (Followers: 24, SJR: 2.066, CiteScore: 4)
Intl. J. of Mental Health and Addiction     Hybrid Journal   (Followers: 24, SJR: 0.49, CiteScore: 1)
Intl. J. of Science and Mathematics Education     Hybrid Journal   (Followers: 24, SJR: 0.737, CiteScore: 1)
Russian J. of Non-Ferrous Metals     Hybrid Journal   (Followers: 23, SJR: 0.281, CiteScore: 1)
J. of Materials Science     Hybrid Journal   (Followers: 23, SJR: 0.807, CiteScore: 3)
Breast Cancer     Hybrid Journal   (Followers: 23, SJR: 0.653, CiteScore: 2)
Diabetes Therapy     Open Access   (Followers: 23, SJR: 1.094, CiteScore: 3)
Canadian J. of Public Health     Hybrid Journal   (Followers: 23, SJR: 0.609, CiteScore: 1)
Critical Criminology     Hybrid Journal   (Followers: 23, SJR: 0.34, CiteScore: 1)
J. of Materials Engineering and Performance     Hybrid Journal   (Followers: 23, SJR: 0.611, CiteScore: 2)
Fluid Dynamics     Hybrid Journal   (Followers: 23, SJR: 0.345, CiteScore: 1)
Animal Cognition     Hybrid Journal   (Followers: 23, SJR: 1.389, CiteScore: 3)
Erkenntnis     Hybrid Journal   (Followers: 23, SJR: 1.502, CiteScore: 1)
Ethical Theory and Moral Practice     Hybrid Journal   (Followers: 23, SJR: 0.402, CiteScore: 1)
European Spine J.     Hybrid Journal   (Followers: 23, SJR: 1.535, CiteScore: 2)
Behavior Research Methods     Hybrid Journal   (Followers: 22, SJR: 2.099, CiteScore: 4)
J. of Public Health     Hybrid Journal   (Followers: 22, SJR: 0.265, CiteScore: 1)
Archaeological and Anthropological Sciences     Hybrid Journal   (Followers: 22, SJR: 1.052, CiteScore: 2)
Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity     Hybrid Journal   (Followers: 22, SJR: 0.572, CiteScore: 2)
Electrical Engineering     Hybrid Journal   (Followers: 22, SJR: 0.323, CiteScore: 1)
Cancer Immunology, Immunotherapy     Hybrid Journal   (Followers: 22, SJR: 1.899, CiteScore: 5)
Astronomy and Astrophysics Review     Hybrid Journal   (Followers: 22, SJR: 3.385, CiteScore: 5)
American J. of Psychoanalysis     Hybrid Journal   (Followers: 22, SJR: 0.314, CiteScore: 0)
Current Microbiology     Hybrid Journal   (Followers: 22, SJR: 0.562, CiteScore: 1)
Science & Education     Hybrid Journal   (Followers: 22)
Applied Solar Energy     Hybrid Journal   (Followers: 22, SJR: 0.225, CiteScore: 0)
Environmental and Resource Economics     Hybrid Journal   (Followers: 22, SJR: 1.186, CiteScore: 2)
Chromatographia     Hybrid Journal   (Followers: 22, SJR: 0.514, CiteScore: 1)
Heat and Mass Transfer     Hybrid Journal   (Followers: 22, SJR: 0.448, CiteScore: 1)
Netherlands Intl. Law Review     Full-text available via subscription   (Followers: 22, SJR: 0.274, CiteScore: 0)
Human Nature     Hybrid Journal   (Followers: 22, SJR: 1.092, CiteScore: 2)
Coral Reefs     Hybrid Journal   (Followers: 21, SJR: 1.307, CiteScore: 3)
Hydrogeology J.     Hybrid Journal   (Followers: 21, SJR: 0.886, CiteScore: 2)
Astronomy Letters     Hybrid Journal   (Followers: 21, SJR: 0.452, CiteScore: 1)
African Archaeological Review     Hybrid Journal   (Followers: 21, SJR: 0.862, CiteScore: 1)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 21, SJR: 0.812, CiteScore: 1)
Artificial Intelligence Review     Hybrid Journal   (Followers: 21, SJR: 0.833, CiteScore: 4)

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Similar Journals
Journal Cover
Advances in Computational Mathematics
Journal Prestige (SJR): 0.812
Citation Impact (citeScore): 1
Number of Followers: 21  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1572-9044 - ISSN (Online) 1019-7168
Published by Springer-Verlag Homepage  [2574 journals]
  • A hierarchical a posteriori error estimator for the Reduced Basis Method
    • Abstract: In this contribution, we are concerned with tight a posteriori error estimation for projection-based model order reduction of \(\inf \)-\(\sup \) stable parameterized variational problems. In particular, we consider the Reduced Basis Method in a Petrov-Galerkin framework, where the reduced approximation spaces are constructed by the (weak) greedy algorithm. We propose and analyze a hierarchical a posteriori error estimator which evaluates the difference of two reduced approximations of different accuracy. Based on the a priori error analysis of the (weak) greedy algorithm, it is expected that the hierarchical error estimator is sharp with efficiency index close to one, if the Kolmogorov N-with decays fast for the underlying problem and if a suitable saturation assumption for the reduced approximation is satisfied. We investigate the tightness of the hierarchical a posteriori estimator both from a theoretical and numerical perspective. For the respective approximation with higher accuracy, we study and compare basis enrichment of Lagrange- and Taylor-type reduced bases. Numerical experiments indicate the efficiency for both, the construction of a reduced basis using the hierarchical error estimator in a greedy algorithm, and for tight online certification of reduced approximations. This is particularly relevant in cases where the \(\inf \)-\(\sup \) constant may become small depending on the parameter. In such cases, a standard residual-based error estimator—complemented by the successive constrained method to compute a lower bound of the parameter dependent \(\inf \)-\(\sup \) constant—may become infeasible.
      PubDate: 2019-11-14
       
  • Mass conservative reduced order modeling of a free boundary osmotic cell
           swelling problem
    • Abstract: We consider model order reduction for a free boundary problem of an osmotic cell that is parameterized by material parameters as well as the initial shape of the cell. Our approach is based on an Arbitrary-Lagrangian-Eulerian description of the model that is discretized by a mass-conservative finite element scheme. Using reduced basis techniques and empirical interpolation, we construct a parameterized reduced order model in which the mass conservation property of the full-order model is exactly preserved. Numerical experiments are provided that highlight the performance of the resulting reduced order model.
      PubDate: 2019-11-13
       
  • H${\mathscr{H}}$ -matrix approximability of inverses of discretizations of
           the fractional Laplacian
    • Abstract: The integral version of the fractional Laplacian on a bounded domain is discretized by a Galerkin approximation based on piecewise linear functions on a quasiuniform mesh. We show that the inverse of the associated stiffness matrix can be approximated by blockwise low-rank matrices at an exponential rate in the block rank.
      PubDate: 2019-11-13
       
  • A transport-based multifidelity preconditioner for Markov chain Monte
           Carlo
    • Abstract: Markov chain Monte Carlo (MCMC) sampling of posterior distributions arising in Bayesian inverse problems is challenging when evaluations of the forward model are computationally expensive. Replacing the forward model with a low-cost, low-fidelity model often significantly reduces computational cost; however, employing a low-fidelity model alone means that the stationary distribution of the MCMC chain is the posterior distribution corresponding to the low-fidelity model, rather than the original posterior distribution corresponding to the high-fidelity model. We propose a multifidelity approach that combines, rather than replaces, the high-fidelity model with a low-fidelity model. First, the low-fidelity model is used to construct a transport map that deterministically couples a reference Gaussian distribution with an approximation of the low-fidelity posterior. Then, the high-fidelity posterior distribution is explored using a non-Gaussian proposal distribution derived from the transport map. This multifidelity “preconditioned” MCMC approach seeks efficient sampling via a proposal that is explicitly tailored to the posterior at hand and that is constructed efficiently with the low-fidelity model. By relying on the low-fidelity model only to construct the proposal distribution, our approach guarantees that the stationary distribution of the MCMC chain is the high-fidelity posterior. In our numerical examples, our multifidelity approach achieves significant speedups compared with single-fidelity MCMC sampling methods.
      PubDate: 2019-11-13
       
  • A bilinear ℋ2$\mathcal {H}_{2}$ model order reduction approach to linear
           parameter-varying systems
    • Abstract: This paper focuses on the model reduction problem for a special class of linear parameter-varying systems. This kind of systems can be reformulated as bilinear dynamical systems. Based on the bilinear system theory, we give a definition of the \(\mathcal {H}_{2}\) norm in the generalized frequency domain. Then, a model reduction method is proposed based on the gradient descent on the Grassmann manifold. The merit of the method is that by utilizing the gradient flow analysis, the algorithm is guaranteed to converge, and further speedup of the convergence rate can be achieved as well. Two numerical examples are tested to demonstrate the proposed method.
      PubDate: 2019-11-13
       
  • Preconditioning RBF collocation method by adapted finite difference matrix
    • Abstract: In this paper, we shall consider an adapted finite difference preconditioning technique for radial basis function (RBF) method. This technique, for the system of equations that arises from solving Helmholtz equation with Dirichlet boundary conditions by RBF collocation method, is considered. We prove that the eigenvalues of preconditioned matrices are bounded for one and two-dimensional cases. We also show that RBF interpolating matrix can be well-conditioned by using appropriate number of polynomial bases in augmented term of RBF approximation. Numerical experiments show the efficiency and robustness of the preconditioning procedure, particularly when there are non-zero boundary conditions.
      PubDate: 2019-11-13
       
  • Stability and convergence analysis of rotational velocity correction
           methods for the Navier–Stokes equations
    • Abstract: The velocity correction method has shown to be an effective approach for solving incompressible Navier–Stokes equations. It does not require the initial pressure and the inf-sup condition may not be needed. However, stability and convergence analyses have not been established for the nonlinear case. The challenge arises from the splitting associated with the nonlinear term and rotational term. In this paper, we carry out stability and convergence analysis of the first-order method in the nonlinear case. Our technique is a new Gauge–Uzawa formulation, which brings forth a telescoping symmetry into the rotational form. We also provide a stability proof for the second-order method in the linear case. Numerical results are provided for both first- and second-order methods.
      PubDate: 2019-11-12
       
  • Variational Monte Carlo—bridging concepts of machine learning and
           high-dimensional partial differential equations
    • Abstract: A statistical learning approach for high-dimensional parametric PDEs related to uncertainty quantification is derived. The method is based on the minimization of an empirical risk on a selected model class, and it is shown to be applicable to a broad range of problems. A general unified convergence analysis is derived, which takes into account the approximation and the statistical errors. By this, a combination of theoretical results from numerical analysis and statistics is obtained. Numerical experiments illustrate the performance of the method with the model class of hierarchical tensors.
      PubDate: 2019-10-05
       
  • POD model order reduction with space-adapted snapshots for incompressible
           flows
    • Abstract: We consider model order reduction based on proper orthogonal decomposition (POD) for unsteady incompressible Navier-Stokes problems, assuming that the snapshots are given by spatially adapted finite element solutions. We propose two approaches of deriving stable POD-Galerkin reduced-order models for this context. In the first approach, the pressure term and the continuity equation are eliminated by imposing a weak incompressibility constraint with respect to a pressure reference space. In the second approach, we derive an inf-sup stable velocity-pressure reduced-order model by enriching the velocity-reduced space with supremizers computed on a velocity reference space. For problems with inhomogeneous Dirichlet conditions, we show how suitable lifting functions can be obtained from standard adaptive finite element computations. We provide a numerical comparison of the considered methods for a regularized lid-driven cavity problem.
      PubDate: 2019-09-11
       
  • An offline/online procedure for dual norm calculations of parameterized
           functionals: empirical quadrature and empirical test spaces
    • Abstract: We present an offline/online computational procedure for computing the dual norm of parameterized linear functionals. The approach is motivated by the need to efficiently compute residual dual norms, which are used in model reduction to estimate the error of a given reduced solution. The key elements of the approach are (i) an empirical test space for the manifold of Riesz elements associated with the parameterized functional and (ii) an empirical quadrature procedure to efficiently deal with parametrically non-affine terms. We present a number of theoretical and numerical results to identify the different sources of error and to motivate the proposed technique, and we compare the approach with other state-of-the-art techniques. Finally, we investigate the effectiveness of our approach to reduce both offline and online costs associated with the computation of the time-averaged residual indicator proposed in Fick et al. (J. Comput. Phys. 371, 214–243 2018).
      PubDate: 2019-09-11
       
  • Nyström method for BEM of the heat equation with moving boundaries
    • Abstract: A direct boundary integral equation method for the heat equation based on Nyström discretization is proposed and analyzed. For problems with moving geometries, a weakly and strongly singular Green’s integral equation is formulated. Here the hypersingular integral operator, i.e., the normal trace of the double-layer potential, must be understood as a Hadamard finite part integral. The thermal layer potentials are regarded as generalized Abel integral operators in time and discretized with a singularity-corrected trapezoidal rule. The spatial discretization is a standard quadrature rule for smooth surface integrals. The discretized systems lead to an explicit time stepping scheme and is effective for solving the Dirichlet and Neumann boundary value problems based on both the weakly and/or strongly singular integral equations.
      PubDate: 2019-08-27
       
  • Computing the closest real normal matrix and normal completion
    • Abstract: In this article, we consider the problems (unsolved in the literature) of computing the nearest normal matrix X to a given non-normal matrix A, under certain constraints, that are (i) if A is real, we impose that also X is real; (ii) if A has known entries on a given sparsity pattern Ω and unknown/uncertain entries otherwise, we impose to X the constraint xij = aij for all entries (i,j) in the pattern Ω. As far as we know, there do not exist in the literature specific algorithms aiming to solve these problems. For the case in which all entries of A can be modified, there exists an algorithm by Ruhe, which is able to compute the closest normal matrix. However, if A is real, the closest computed matrix by Ruhe’s algorithm might be complex, which motivates the development of a different algorithm preserving reality. Normality is characterized in a very large number of ways; in this article, we consider the property that the square of the Frobenius norm of a normal matrix is equal to the sum of the squares of the moduli of its eigenvalues. This characterization allows us to formulate as equivalent problem the minimization of a functional of an unknown matrix, which should be normal, fulfill the required constraints, and have minimal distance from the given matrix A.
      PubDate: 2019-08-27
       
  • Long-time momentum and actions behaviour of energy-preserving methods for
           semi-linear wave equations via spatial spectral semi-discretisations
    • Abstract: It is known that wave equations have physically very important properties which should be respected by numerical schemes in order to predict correctly the solution over a long time period. In this paper, the long-time behaviour of momentum and actions for energy-preserving methods is analysed for semi-linear wave equations. A full discretisation of wave equations is derived and analysed by firstly using a spectral semi-discretisation in space and then by applying the adopted average vector field (AAVF) method in time. This numerical scheme can exactly preserve the energy of the semi-discrete system. The main theme of this paper is to analyse another important physical property of the scheme. It is shown that this scheme yields near conservation of a modified momentum and modified actions over long times. The results are rigorously proved based on the technique of modulated Fourier expansions in two stages. First, a multi-frequency modulated Fourier expansion of the AAVF method is constructed, and then two almost-invariants of the modulation system are derived.
      PubDate: 2019-08-16
       
  • Computing images of polynomial maps
    • Abstract: The image of a polynomial map is a constructible set. While computing its closure is standard in computer algebra systems, a procedure for computing the constructible set itself is not. We provide a new algorithm, based on algebro-geometric techniques, addressing this problem. We also apply these methods to answer a question of W. Hackbusch on the non-closedness of site-independent cyclic matrix product states for infinitely many parameters.
      PubDate: 2019-08-08
       
  • Numerical modelling of generalized Newtonian fluids in bypass tube
    • Abstract: The following paper describes a numerical simulation of a complete bypass of a stenosed human artery. The considered geometry consists of the narrowed host tube and the bypass graft with a 45-degree angle of connection. Different diameters of the narrowing are tested. Blood is the fluid with shear rate–dependent viscosity; therefore, various rheology mathematical models for generalized Newtonian fluids are considered, namely Cross model, modified Cross model, Carreau model, and Carreau-Yasuda model. The fundamental system of equations is based on the system of generalized Navier-Stokes equations. Generalized Newtonian fluids flow in a bypass tube is numerically simulated by using a SIMPLE algorithm included in the open-source CFD tool, OpenFOAM. The aim of this work is to compare the numerical results for the different mathematical models of the viscosity with the changing diameter of the narrowed channel.
      PubDate: 2019-08-01
       
  • An arriving decision problem in a discrete-time queueing system
    • Abstract: This paper discusses a discrete-time queueing system in which an arriving customer may adopt four different strategies; two of them correspond to a LCFS discipline where displacements or expulsions occur, and in the other two, the arriving customer decides to follow a FCFS discipline or to become a negative customer eliminating the customer in the server, if any. The different choices of the involved parameters make this model to enjoy a great versatility, having several special cases of interest. We carry out a thorough analysis of the system, and using a generating function approach, we derive analytical results for the stationary distributions obtaining performance measures for the number of customers in the queue and in the system. Also, recursive formulae for calculating the steady-state distributions of the queue and system size has been developed. Making use of the busy period of an auxiliary system, the sojourn times of a customer in the queue and in the system have also been obtained. Finally, some numerical examples are given.
      PubDate: 2019-08-01
       
  • On continuous inkjet systems: a printer driver for expiry date labels on
           cylindrical surfaces
    • Abstract: Continuous inkjet systems are commonly used to print expiry date labels for food products. These systems are designed to print on flat surfaces; however, a lot of food products package have a cylindrical shape (e.g., bottled and canned products) which causes an enlargement in characters at the ends of the label. In this work, we present an algorithm to correct this defect by calculating the extra-distance that an ink drop travels when the printing surface approaches an elliptic cylinder. Each charged ink drop is modeling as a solid particle which is affected by the air drag, Earth’s gravitation, and voltage due to the electrical field that causes the perturbation in the ink drop path. Numerical results show the correction of the enlargement mentioned above by varying the electric field along the width of the label. In addition, the equation and the values of a second electric field to correct the printing’s inclination caused by the method of the system’s operation are presented.
      PubDate: 2019-08-01
       
  • A probabilistic extension to Conway’s Game of Life
    • Abstract: The “Game of life” model was created in 1970 by the mathematician John Horton Conway using cellular automata. Since then, different extensions of these cellular automata have been used in many applications. In this work, we introduce probabilistic cellular automata which include non-deterministic rules for transitions between successive generations of the automaton together with probabilistic decisions about life and death of the cells in the next generation of the automaton. Different directions of the neighbours of each cell are treated with the possibility of applying distinct probabilities. This way, more realistic situations can be modelled and the obtained results are also non-deterministic. In this paper, we include a brief state of the art, the description of the model and some examples obtained with an implementation of the model made in Java.
      PubDate: 2019-08-01
       
  • Regularization theory in the study of generalization ability of a
           biological neural network model
    • Abstract: This paper focuses on the generalization ability of a dendritic neuron model (a model of a simple neural network). The considered model is an extension of the Hodgkin-Huxley model. The Markov kinetic schemes have been used in the mathematical description of the model, while the Lagrange multipliers method has been applied to train the model. The generalization ability of the model is studied using a method known from the regularization theory, in which a regularizer is added to the neural network error function. The regularizers in the form of the sum of squared weights of the model (the penalty function), a linear differential operator related to the input-output mapping (the Tikhonov functional), and the square norm of the network curvature are applied in the study. The influence of the regularizers on the training process and its results are illustrated with the problem of noise reduction in images of electronic components. Several metrics are used to compare results obtained for different regularizers.
      PubDate: 2019-08-01
       
  • Numerical simulation of unsteady flows through a radial turbine
    • Abstract: The article deals with the numerical simulation of unsteady flows through the turbine part of the turbocharger. The main focus of the article is the extension of the in-house CFD finite volume solver for the case of unsteady flows in radial turbines and the coupling to an external zero-dimensional model of the inlet and outlet parts. In the second part, brief description of a simplified one-dimensional model of the turbine is given. The final part presents a comparison of the results of numerical simulations using both the 3D CFD method and the 1D simplified model with the experimental data. The comparison shows that the properly calibrated 1D model gives accurate predictions of mass flow rate and turbine performance at much less computational time than the full 3D CFD method. On the other hand, the more expensive 3D CFD method does not need any specific calibration and allows detailed inspections of the flow fields.
      PubDate: 2019-08-01
       
 
 
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