A True panel vs a Pooled cross section Often loosely use the term panel data to refer to any data set that has both a cross sectional dimension and a time-series dimension More precisely it's only data following the same cross-section units over time Otherwise it's a pooled cross-section Economics 20- Prof anderson
Functional form e We' ve seen that a linear regression can really fit nonlinear relationships 2 Can use logs on RHS, LHS or both Can use quadratic forms ofx's Can use interactions ofx's e How do we know if we've gotten the right functional form for our model? Economics 20- Prof anderson
Being aimed to developing intermetallic base structural materials to be worked at above 1000℃, a systematic investigation has been performed of the fundamental crystallographic structure, phase constitution map, density-composition dependence, oxidation resistance and general mechanical behaviour for the ternary intermetallic alloys in the Nb-Ti-Al system. Promissing results have been obtained at the initial stage in the current program. The 1100℃ high temperature strength at the strain rate of 10-2/s and 10-5/s for the ternary compound NbTiAl3 （γ1） base alloys are generally much higher than that of the binary compound TiAl （γ）, especially in the γ1 + α2 phase region, it is as high as twice as that of TiAl. The densities are 4.1-4.79g/cm3, depending on relative amount of the intermetallics involved and the density difference between the intermetallics. The oxidation resistance at th
