Abstract: A user state determination device that can simply determine a location at which a user has fallen into a user state in which the user has lost an article or the like is provided. The user state determination device 100 includes: a user information acquiring unit 101 configured to acquire moving history information of a user; and a state determining unit 102 configured to determine that one spot (one location) serving as a start point of a predetermined moving pattern is likely to be a specific spot (a specific location) at which the user has fallen into a predetermined state (a state in which the user has lost an article) when the moving history information indicates the moving pattern. The predetermined state of a user refers to a state in which an article has been lost and is a state in which the user needs to perform a non-purposeful visit to the one spot (a visit to retrieve the lost article).

Abstract: The invention relate to a magnetic recording medium which comprises a magnetic layer on a support. The magnetic layer contains an iron-aluminum alloy magnetic powder and a carbon black having a BET specific surface area of from 15 to 80 m.sup.2 /g and a DBP oil absorption of the carbon black from 110 to 200 ml/100 g.

Abstract: A magnetic recording medium comprising a nonmagnetic support having thereon a magnetic recording layer comprising a magnetic layer containing ferromagnetic metal powder wherein the magnetic metal powder has a BET specific surface area of not less than 40 m.sup.2 /g and the magnetic recording layer contains a fatty acid having a neutralization value of not more than 250, an ester of fatty acid and a carbon black having a DBP oil absorption of not less than 110 ml/100 g and an average particle size of not more than 60 m.mu.. The magnetic recording medium is improved on the electromagnetic conversion property as well as on the running endurance.