Cognitive Research -- Heterogeneous Formal Neurons and Modeling of Multi-Transmitter Neural Ensembles -- Methods for Recognition of Frustration-Derived Reactions in Social Media -- Identification of the Network State Based on the ART-2 Neural Network with a Hierarchical Memory Structure in Parallel Mode -- Data Mining, Machine Learning, Classification -- Ranking Weibull Survival Model: Boosting Concordance Index of Weibull Time-to-event Prediction Model with Ranking Losses -- Predicting Different Health and Lifestyle Behaviors of Social Media Users -- Methods for Finding Consequences with Specified Properties -- Data Mining Methods for Analysis and Forecast of Emerging Technology Trend: A Systematic Mapping Study from SCOPUS Papers -- Machine Learning for Assessment of Cardiometabolic Risk Factors Predictive Potential and Prediction of Obstructive Coronary Arteries Lesions -- Knowledge Engineering -- Application of FCA for Domain Model Theory Investigation -- The Metagraph Model for Complex Networks: Definition, Calculus and Granulation Issues -- Subjective Expert Evaluations in the Model-Theoretic Representation of Object Domain Knowledge -- Multiagent Systems and Robotics -- Q-Mixing Network for Multi-Agent Path Finding in Partially Observable Grid Environments -- Subdefinite Computations for Reducing the Search Space in Mobile Robot Localization Task -- Enhancing Exploration Algorithms for Navigation with Visual SLAM -- Natural Language Processing -- Relying on Discourse Trees to Extract Medical Ontologies from Text -- TITANIS: A Tool for Intelligent Text Analysis in Social Media -- Approach to the Automated Development of Scientific Subject Domain Ontologies Based on Heterogeneous Ontology Design Patterns -- Fuzzy Models and Soft Computing -- PC-algorithm of Algebraic Bayesian Network Secondary Structure Training -- Logistic-based Design of Fuzzy Interpretable Classifiers -- Intelligent Systems -- Knowledge-Based Diagnostic Systemwith a Precedent Library -- Semiotic Models in Monitoring and Decision Support Systems -- Cognitive Patterns for Semantic Presentation of Natural-language Descriptions of Well-formalizable Problems -- Detecting Anomalous Behavior of Users of Data Centers based on the Application of Artificial Neural Networks -- Tools for Designing Intelligent Systems -- Study of the Feasibility of Creating of a Real-time Neuronetwork Infrared Ground Objects Recognition System -- The Implementation of the Ontological Approach to Control of the Processes of Designing Integrated Expert Systems Based on the Problem-oriented Methodology -- A Module for Industrial Safety Inspection Planning Based on Self-organization.-.

This book constitutes the proceedings of the 19th Russian Conference on Artificial Intelligence, RCAI 2021, held in Moscow, Russia, in October 2021. The 19 full papers and 7 short papers presented in this volume were carefully reviewed and selected from 80 submissions. The conference deals with a wide range of topics, categorized into the following topical headings: cognitive research; data mining, machine learning, classification; knowledge engineering; multi-agent systems and robotics; natural language processing; fuzzy models and soft computer; intelligent systems; and tools for designing intelligent systems.