Large scale scientific computing : 13th International Conference LSSC 2021 Sozopol Bulgaria June 7–11 2021 : revised selected papers This book constitutes revised selected papers from the 13th International Conference on Large Scale Scientific Computing LSSC 23021 which was held in Sozopol Bulgaria during June 7 11 2021. The 60 papers included in this book were carefully reviewed and selected from a total of 73 submissions. The volume also includes two invited talks in full paper length. The papers were organized in topical sections as follows: Fractional diffusion problems: numerical methods algorithms and applications; large scale models: numerical methods parallel computations and applications; application of metaheuristics to large scale problems; advanced discretizations and solvers for coupled systems of partial differential equations; optimal control of ODEs PDEs and applications; tensor and matrix factorization for big data analysis; machine learning and model order reduction for large scale predictive simulations; HPC and big data: algorithms and applications; and contributed papers. Invited Papers Random walk Based Approximate k Nearest Neighbors Algorithm for Diffusion State Distance Model Reduction for Large Scale Systems II Fractional Di_usion Problems: Numerical Methods Algorithms and Applications Constructions of Second Order Approximations of the Caputo Fractional Derivative Parameter Identification Approach for a Fractional Dynamics Model of Honeybee Population A Newton’s Method for Best Uniform Polynomial Approximation Reduced Sum Implementation of the BURA Method for Spectral Fractional Diffusion Problems First order Reaction diffusion System with Space fractional Diffusion in an Unbounded medium Performance Study of Hierarchical Semi Separable Compression Solver for Parabolic Problems with Space fractional Diffusion Numerical Solution of Non Stationary Problems with a Rational Approximation for Fractional Powers of the Operator Large Scale Models: Numerical Methods Parallel Computations and Applications An Exact Schur Complement Method for Time harmonic Optimal Control Problems On the Consistency Order of Runge–Kutta Methods Combined with Active Richardson Extrapolation Study the Recurrence of the Dominant Pollutants in the Formation of AQI Status Over the City of Sofia for the Period 2013 2020 One Solution of Task with Internal Flow in Non uniform Fluid Using CABARET Method Behavior and Scalability of the Regional Climate Model RegCM4 on High Performance Computing Platforms Quantum Effects on 1 2[111] Edge Dislocation Motion in Hydrogen Charged Fe from Ring Polymer Molecular Dynamics Degeneracy of Tetrahedral Partitions Produced by Randomly Generated Red Refinements Effluent Recirculation for Contaminant Removal in Constructed Wetlands under Uncertainty: A Stochastic Numerical Approach Based on Monte Carlo Methodology Sensitivity Study of Large Scale Air Pollution Model Based on Modifications of the Latin Hypercube Sampling Method Sensitivity Operator Based Approach to the Interpretation of Heterogeneous Air Quality Monitoring Data Using the Cauchy Criterion and the Standard Deviation to Evaluate the Sustainability of Climate Simulations Multidimensional Sensitivity Analysis of an Air Pollution Model Based on Modifications of the van der Corput Sequence Running an Atmospheric Chemistry Scheme from a Large Air Pollution Model by Using Advanced Versions of the Richardson Extrapolation Application of Metaheuristics to Large Scale Problems New Clustering Techniques of Node Embeddings Based on Metaheuristic Optimization Algorithms A Comparison of Machine Learning Methods for Forecasting Dow Jones Stock Index Optimal Knockout Tournaments: Definition and Computation Risk Registry Platform for Optimizations in Cases of CBRN and Critical Infrastructure Attacks Influence of the ACO Evaporation Parameter for Unstructured Workforce Planning Problem binMeta: a New Java Package for Meta heuristic Searches Synergy between Convergence and Divergence — Review of Concepts and Methods Advanced Stochastic Approaches Based on Optimization of Lattice Sequences for Large Scale Finance Problems Intuitionistic Fuzzy Approach for Outsourcing Provider Selection in a Refinery Quantitative Relationship Between Particulate Matter and Morbidity Advanced Discretizations and Solvers for Coupled Systems of Partial Differential Equations Decoupling Methods for Systems of Parabolic Equations Optimal Control of ODEs PDEs and Applications Random Lifting of Set valued Maps Höolder Regularity in Bang Bang Type Affine Optimal Control Problems Simultaneous Space time Finite Element Methods for Parabolic Optimal Control Problems A New Algorithm for the LQR Problem with Partially Unknown Dynamics Tensor and Matrix Factorization for Big Data Analysis Solving Systems of Polynomial Equations — a Tensor Approach Nonnegative Tensor train Low rank Approximations of the Smoluchowski Coagulation Equation Boolean Hierarchical Tucker Networks on Quantum Annealers Topic Analysis of Superconductivity Literature by Semantic Non negative Matrix Factorization Machine Learning and Model Order Reduction for Large Scale Predictive Simulations Deep Neural Networks and Adaptive Quadrature for Solving Variational Problems A full order reduced order and machine learning model pipeline for efficient prediction of reactive flows A Multiscale Fatigue Model for the Degradation of Fiber reinforced Materials A Classification Algorithm for Anomaly Detection in Terahertz Tomography Reduced Basis Methods for Efficient Simulation of a Rigid Robot Hand Interacting with Soft Tissue Structured Deep Kernel Networks for Data Driven Closure Terms of Turbulent Flows HPC and Big Data: Algorithms and Applications On the Use of Low discrepancy Sequences in the Training of Neural Networks A PGAS based Implementation for the Parallel Minimum Spanning Tree Algorithm Comparison of Di_erent Methods for Multiple Imputation by Chain Equation Monte Carlo Method for Estimating Eigenvalues Using Error Balancing Multi Lingual Emotion Classification Using Convolutional Neural Networks On Parallel MLMC for Stationary Single Phase Flow Problem Numerical Parameter Estimates of Beta uniform Mixture Models Large Scale Computer Simulation of the Performance of the Generalized Nets Model of the LPF algorithm Contributed Papers A New Error Estimate for a Primal Dual Crank Nicolson Mixed Finite Element Using Lowest Degree Raviart Thomas Spaces for Parabolic Equations A Finite Volume Scheme for a Wave Equation with Several Time Independent Delays Recovering the Time Dependent Volatility in Jump Diffusion Models from Nonlocal Price Observations On the Solution of Contact Problems with Tresca Friction by the Semismooth* Newton Method Fitted Finite Volume Method for Unsaturated Flow Parabolic Problems with Space Degeneration Minimization of p Laplacian via the Finite Element Method in MATLAB Quality Optimization of Seismic derived Surface Meshes of Geological Bodies.