Abstract: A vertical takeoff and landing aircraft using a hybrid electric propulsion system and a control method therefor according to an embodiment of the present invention: performs control such that, during vertical takeoff and landing of an aircraft (1), a generator (20), a power management device (4), and a battery management system (60) simultaneously provide power to a motor (80); and performs control such that, during a cruise flight or transition flight of the aircraft (1), the thrust of a second propeller (82) is increased and a battery (62) of the battery management system (60) is charged with redundant power generated by the generator (20).

Abstract: Disclosed is a book recommendation method utilizing similarity between books. Provided according to one aspect of the present invention is the book recommendation method on the basis of similarity between books, including the steps of: (1) generating, by a book recommendation server, a story flow emotion graph for each of a plurality of books; (2) calculating, by the book recommendation server, similarity between a story flow emotion graph of a first book and a story flow emotion graph of a second book; and (3) outputting, by the book recommendation server, according to the similarity, at least one similar book similar to the first book.