Jeff Moss (hacker) also works with Mr. Robot's technical consulting team. DEF CON was portrayed in "The X-Files" episode "Three of a Kind" featuring an appearance by The lone gunmen. DEF CON was portrayed as a United States government-sponsored convention instead of a civilian convention. Actor Will Smith visited DEF CON 21 to watch a talk by Apollo Robbins, the gentleman thief and to study the DEF CON culture for an upcoming movie role. Jeff Moss (hacker) Jeff Moss, also known as Dark Tangent, (born January 1, 1975) is an American hacker, computer and internet security expert who founded the Black Hat and
Item-item collaborative filtering Earlier collaborative filtering systems based on rating similarity between users (known as user-user collaborative filtering) had several problems: Item-item models resolve these problems in systems that have more users than items. Item-item models use rating distributions "per item", not "per user". With more users than items, each item tends to have more ratings than each user, so an item's average rating usually doesn't change quickly. This leads to more stable rating distributions in the model, so the model doesn't have to be rebuilt as often. When users consume and then rate an item, that item's similar items are picked from