Arcady A Putilov 
Geometry of Individual Variation in Personality and Sleep-Wake Adaptability [PDF ebook] 

Scientific investigation is often aimed on generation and description of a low dimensional simple form that is, however, an accurate representation of the structure of numerous empirically obtained variables. In despite of this aim, some scientific descriptions of real world structures are difficult to visualize due to their dimensional complexity. This new book considers two such structures, the structure of personality lexicon and the structure of adaptive ability of the sleep-wake cycle.