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#

History-based User Delay Model

The psychological model is content-based. It
predicts user delay length knowing what users will see. In some
cases, it may be difficult to know beforehand the user interface
content. Therefore, we devise a user delay model based on history,
, multiple observations from the past. It works in a fashion
similar to the median filter in order to filter out randomness in
user behavior. Let denote the th last observed delay for
an STD state and the total number of user delays recorded for
that state.
The delay record is sorted to generate a new series so that

Then we define the *habitual set* as

where
with a typical value of
. contains the central
items of the sorted series. It is a set extension of the concept
of a median. Let denote the mean of . Then the
next user delay for the state is predicted as

where . is called the factor.
When , the above approach reduces to using the median of
the delays in the recorded history. When , it reduces to
using the mean instead.

** Next:** Utilizing User Delays for
** Up:** Dynamic Power Optimization of
** Previous:** Motor delay
Lin Zhong
2003-12-20