Studie utav ett larmsystem ur ett signalteoretiskt perspektiv
Study of a detector by a signal detection theory
In present-day situation many libraries use detectors so that they can be able to prevent attempts too take out books without registering them. The university library in Jonkoping is one of the libraries that have such a detector. But unfortunately it doesn?t always work correct and can also react on other things a part from books. This is a big problem since the library staff don?t have time to check all signals that comes from detector. This paper will focus to help the university library in Jonkoping to identify the causes of the false alarms.This paper have the purpose to help library staff to decrease the false alarms so they can be able to get more time over to examine the essential signals from the detector. To be able to identify the causes of the false alarms two experiments was implemented. 180 persons participated, they were divided into three subgroups. In the other experiment 400 persons participated, of whom 200 was female and 200 male. Astonishing to see was that the outcome of the experiments showed that the cause of the false alarms wasn?t the detector, instead the results showed that it was two other factors that affected the detector. One factor was the books that were send from other libraries in Sweden, they hadn?t been unimagnetised and the other reason was the self-service machine.In the conclusion and discussion two simple recommendations have been given to help the personnel:? To inform all other libraries that send books about the problems that the university library in Jonkoping has with books that aren?t unimagnetised. In this way they will be more careful before they send away the books.? To write a note with information about the self-service machine so that the students learn how to use this service.These simple recommendations will help the library to decrease the false alarm.