in this paper, the definition of meet-continuity on $l$-directedcomplete posets (for short, $l$-dcpos) is introduced. as ageneralization of meet-continuity on crisp dcpos, meet-continuity on$l$-dcpos, based on the generalized scott topology, ischaracterized. in particular, it is shown that every continuous$l$-dcpo is meet-continuous and $l$-continuous retracts ofmeet-continuous $l$-dcpos are al...

Data from the United Nations and the International Civil Aviation Organization Information Systems were used as a base for characterizing, classifying and comparing air transport demand and supply features of 156 countries. Relevant data from 1980 were chosen to reflect five sets of characteristics namely, air transport, 50cm-economic status, population demography, geographical and environmenta...