Computational Methods, Algorithms and Scientific Applications -- A convergence analysis of a multistep method applied to an advection-diffusion equation in 1-D The influence of reordering algorithms on the convergence of a preconditioned restarted GMRES method -- Generalized Invariants of Multiple Scattered Polarized Radiation at Arbitrary Non-Symmetrical Optical Levels of a Uniform Slab. User-friendly expressions of the coefficients of some exponentially fitted methods -- CFD prediction of retractable landing gear aerodynamics -- CFD Prediction of Aircraft Control Surfaces Aerodynamics -- Optimal Online Electric Vehicle Charging Scheduling in Unbalanced Three-phase Power System -- Bounds for Complete Arcs in PG(3,q) and Covering Codes of Radius 3, Codimension 4, under a Certain Probabilistic Conjecture -- Numerical simulation of the reactive transport at the pore scale -- Multivalue almost collocation methods with diagonal coefficient matrix -- Characterizing and Analyzing the Relation betweenBin-Packing Problem and Tabu Search Algorithm -- Efficient Speed-up of Radial Basis Functions Approximation and Interpolation Formula Evaluation -- Numerical Risk Analyses of the Impact of Meteorological Conditions on Probability of Airport Runway Excursion Accidents -- Simplified models for electromechanics of cardiac myocyte -- Electrotonic effect on action potential dispersion with cellular automata -- Hybrid Model for the Analysis of Human Gait: a Non-Linear Approach -- Improving Fresh Fruit Bunches Unloading Process At Palm Oil Mills With Discrete-Event Simulation -- OpenFOAM Numerical Simulations with Different Lid Driven Cavity Shapes -- Mathematical Modelling and Identification of a Quadrotor -- The effect of a phase change during the deposition stage in Fused Filament Fabrication -- Diameter and Convex Hull of Points Using Space Subdivision in E2 and E3 -- Automated selection of the computational parameters for the higher-order parabolic equation numerical methods -- A biased random-key genetic algorithm for bandwidth reduction -- DTN-SMTP: A Novel Mail Transfer Protocol with Minimized Interactions for Space Internet -- Spatial Modelling of Black Scabbardfish Fishery off the Portuguese Coast -- Folding-BSD algorithm for binary sequence decomposition -- Construction of the regular dodecahedron with the MATHEMATIC -- GPU Memory Access Optimization for 2D Electrical Wave Propagation -- through Cardiac Tissue and Karma Model using Time and Space blocking -- Optimization of the use of critical resources in the development of offshore oil Fields -- Extending Maxima Capabilities for Performing Elementary Matrix Operations -- A Graph-based Clustering Analysis of the QM9 Dataset via SMILES Descriptors -- Q-Learning Based Forwarding Strategy in Named Data Networks -- Comparative Performance Analysis of Job Scheduling Algorithms in a Real-World Scientific Application -- A colaitional approach for resource distribution in self-organizing open systems.-A New Library of Bio-Inspired Algorithms -- Numerical Enhancements and Parallel GPU Implementation of a 3D Gaussian Beam Model -- A Digital Twin Platform for Diagnostics and Rehabilitation of Multiple Sclerosis -- Classification of carcass fatness degree in finishing cattle using machine Learning -- Skin Cancer Classification using Inception Network and Transfer Learning -- A Criterion for IDS Deployment on IoT edge nodes -- How to improve the recommendation's accuracy in POI domains? -- An Evaluation of Low-quality Content Detection Strategies: Which Attributes Are Still Relevant, Which Are Not? -- eighted Ensemble Methods for Predicting Train Delays -- A Smart Ecosystem for Learning and Inclusion: An Architectural Overview -- -- Unsupervised Learning and Feature Extraction in Hyperspectral Imagery -- Factors Affecting the Cost to Accuracy Balance for Real-Time Video-Based Action Recognition -- Innovation, technology and user experience in museums: Insights from scientific Literature -- Kalman Filter Employment in Image Processing -- Migrationof Artificial Neural Networks to Smartphones -- A Hybrid Deep Learning Approach for Systemic Financial Risk Prediction -- Ambient intelligence systems for the elderly: A privacy perspective -- Synchronization Analysis in Models of Coupled Oscillators -- Classification of Actors in Social Networks using RLVECO -- Detecting Apples in Orchards using YOLO-v3 -- Complex Network Construction for Interactive Image Segmentation using Particle Competition and Cooperation: A New Approach -- Convolutional Neural Networks for Automatic Classification of Diseased Leaves: The Impact of Dataset Size and Fine-tuning -- A Kinect-based Gesture Acquisition and Reproduction System for Humanoid Robots -- A Novel Big Data Analytics Approach for Supporting Cyber Attack Detection via Non-Linear Analytic Prediction of IP Addresses -- A Big-Data Variational Bayesian Framework for Supporting the Prediction of Functional Outcomes in Wake-Up Stroke Patients -- Latent Weights Generating for Few Shot Learning Using Information Theory -- Improving the clustering algorithms automatic generation process with cluster quality indexes -- Dynamic community detection into analyzing of wildfires events.

The seven volumes LNCS 12249-12255 constitute the refereed proceedings of the 20th International Conference on Computational Science and Its Applications, ICCSA 2020, held in Cagliari, Italy, in July 2020. Due to COVID-19 pandemic the conference was organized in an online event. Computational Science is the main pillar of most of the present research, industrial and commercial applications, and plays a unique role in exploiting ICT innovative technologies. The 466 full papers and 32 short papers presented were carefully reviewed and selected from 1450 submissions. Apart from the general track, ICCSA 2020 also include 52 workshops, in various areas of computational sciences, ranging from computational science technologies, to specific areas of computational sciences, such as software engineering, security, machine learning and artificial intelligence, blockchain technologies, and of applications in many fields. .