Finally, intervention variables d j,t are dummy (indicator) variables that are used to capture structural breaks or outlying (irregular) observations.
The phenomenon was found in the 1930s as irregular ionosonde observations and was termed equatorial spread F (ESF).
The proposed approach is based on the simultaneous analysis of the irregular absolute observations and the continuous time-series deltaF, widely used for estimating the data quality.
b, c For small targets (R (_{rm T}) (<,sim 100 km), low gravity or irregular shape prevents observation at a close steady orbit (i.e. R (_{rm T}) R (_{rm O})), and the size of the imaging footprint on the surface can change dramatically over time or even in a single orbit (Hong and Romaine 2014).
An empirical (geo)statistical modelling scheme is developed to address the challenges of modelling the severity and distribution of groundwater droughts given their spatially and temporally heterogeneous nature and given typically highly irregular groundwater level observations in space and time.
Reflection on surfaces of an ice block is irregular preventing clear visual observation.
In the cases where IPCL were observable, the observations of irregular shapes, calibers, and courses of the IPCL were assessed for potential carcinomas.
Observation was irregular at best, though in mercantile Boston, for example, shops had been advertising the ritual exchange of Christmas gifts since at least 1808.
In this study, a reduced Latin Square design was used, resulting in irregular concentration intervals with observation over only 5 concentrations.
Histologically hypercontraction can be established through the observation of irregular Z bands or as hyaline fibers, which form as a result of excess calcium [ 116, 117] and leads to the coagulation of the contractile proteins within the cells [ 117].
