Search results
Results from the WOW.Com Content Network
In full generality, the accelerated failure time model can be specified as [2] (|) = ()where denotes the joint effect of covariates, typically = ([+ +]). (Specifying the regression coefficients with a negative sign implies that high values of the covariates increase the survival time, but this is merely a sign convention; without a negative sign, they increase the hazard.)
Failure rate is the frequency with which any system or component fails, expressed in failures per unit of time. It thus depends on the system conditions, time interval, and total number of systems under study. [1]
Models for recurrent events can be specified by considering the probability distribution for the number of recurrences in short intervals [, +), given the history of event occurrence before time . The intensity function describes the instantaneous probability of an event occurring at time t {\displaystyle t} , conditional on the process history ...
Hence, has been chosen accordingly in order to maintain the boundedness of the solution and the time interval of validity of the approximation is < <. The average theorem assumes existence of a connected and bounded region D ⊂ R n {\displaystyle D\subset \mathbb {R} ^{n}} which affects the time interval L {\displaystyle L} of the result validity.
A unit of time is any particular time interval, used as a standard way of measuring or expressing duration. The base unit of time in the International System of Units (SI), and by extension most of the Western world , is the second , defined as about 9 billion oscillations of the caesium atom.
Renewal theory texts usually also define the spent time or the backward recurrence time (or the current lifetime) as () = (). Its distribution can be calculated in a similar way to that of the residual time. Likewise, the total life time is the sum of backward recurrence time and forward recurrence time.
A sequence of events is isochronous if the events occur regularly, or at equal time intervals. The term isochronous is used in several technical contexts, but usually refers to the primary subject maintaining a constant period or interval (the reciprocal of frequency), despite variations in other measurable factors in the same system.
Coherence time is actually a statistical measure of the time duration over which the channel impulse response is essentially invariant, and quantifies the similarity of the channel response at different times. In other words, coherence time is the time duration over which two received signals have a strong potential for amplitude correlation.