Sentence examples for by the gravity model from inspiring English sources
The selenoid is determined by the gravity model of degree 660 in the spherical harmonics obtained by the Gravity Recovery and Interior Laboratory (GRAIL) (Lemonie et al. 2013).
Transaction values among sub-regions of each sector are estimated by the gravity-RAS method, in which the initial values are obtained by the gravity model.
Recent empirics based on sound theoretical foundations have led to a richer and more accurate estimation and interpretation of the spatial relations described by the gravity model (Anderson [2011]).
In Eq. 3.1, ( N ) denotes the number of cities, ( Q_{ji} left( t right) ) denotes the traffic volume to city ( i ) from city ( j ) at time ( t ), determined by the gravity model expressed in Eq. 3.2.
where the variables with hats denote the predicted ones by the gravity model with some modification to fulfill the condition that the sum of the "total" column is equal to that of the "total" row.7 This condition means that the sum of the exports within prefectures concerned is equal to the sum of the imports within the same prefectures.
The assimilation of Flickr traces addressed some of the limitations of the gravity model: on the one hand, the flows over large distances, which are consistently underestimated by the gravity model due to the fast decay of the gravity law as a function of distance, can be successfully predicted by a hybrid gravity model.
Parameters a and b were optimized by employing Eq. (3) for generating a synthetic population of commuters such that the resulting probability density function of travel distances matches that obtained by using the gravity model of Eq. (1).
We also compared the pipe model to a "gravity" model where the probability of travel is scaled by physical distance; the gravity model did not differ significantly from the pipe model.
The improved prediction by CDM model over the gravity model, especially in the very high-hazard zone, is due to its ability to account for anthropogenic hazards along the roads.
The parameters of the kernel were optimized on the basis of the distance to work/school distribution as resulting by the application of the gravity model employed for assigning travel destinations (see Text S1).
We are grateful to Koji Matsumoto for providing us the gravity model by using data obtained by GRAIL.
