The

quadratic time trend method is more flexible as compared with linear time trend method and it performs better at the end points of data set.

I also include a

quadratic time trend in order to capture more flexibly common unobservable factors.

To estimate provincial trends, for each logit model the binary overweight/obesity response was regressed on four factors--a linear and

quadratic time trend, and sex and grade covariates.

It follows that our extended genus-distribution algorithm can be applied to any of them in

quadratic time, and that we do not need to further explore the distinctions between the varying definitions of "series-parallel graphs".

section]) A

quadratic time effect indicates a significant but nonlinear trend in prevalence over time.

In the figure shows the closing series, see that trend is not simply linear therefore the analysis is continued under consideration of

quadratic time trend.

Finally, I tested not only the impact of the main effects of disability on the risk of graduation, but also its interaction with linear and

quadratic time, as follows:

where Quality is composite process quality, P4P is equal to 1 for hospitals in Massachusetts after the program was implemented and 0 otherwise, u is a vector of hospital fixed effects, and Time is a

quadratic time trend (including a squared term).

Temporal changes were analyzed by using logistic regression analyses that assessed linear and

quadratic time effects simultaneously and controlled for sex, race/ethnicity, and grade.

For CD62, there were no significant initial differences in CD62 values among the tubes, there was a significant linear time effect and a significant

quadratic time effect, there were no significant differences among the tubes for the increase over time, and all tubes showed an increase at first, followed by a negative quadratic curvature.

t] is a vector of year dummies or a

quadratic time trend, [U.

A

quadratic time (QT) trend calculated using the logarithm of real GDP.