1. Methodological framework for hierarchical modeling of energy systems 2. Hierarchical modeling in energy sector 3. Hierarchical modeling in expansion planning of electric power systems 4. Hierarchical modeling principles for operation and control of electric power systems 5. Hierarchical modeling for development of pipeline energy systems, coal supply systems, and integrated energy systems 6. Hierarchical modeling of analysis and control of operating conditions of pipeline energy systems 7. Hierarchy of mathematical modeling and optimization problems of advanced co-generation systems and fuel coproduction power generation systems