Envelopes and exteriority

Green envelopes classification: the comparative analysis of efficient factors on the thermal and energy performance of green envelopes

This paper classifies green envelopes as green roofs and green walls according to effective factors, which were derived from literature to compare the green envelopes’ thermal and energy performance in a more effective way. For this purpose, an extensive literature review was carried out by searching keywords in databases and studying related journal papers and articles. The research meth...

Envelopes - notion and definiteness

We examine critically some of the existing descriptions of the envelope of a 1-parameter family of surfaces in 3-space. An old, natural, description is that the envelope is the union of the characteristic curves (defined as the “limit intersection curves” of surfaces from the family). This description fell in disrepute during the 20th century. We claim that this relegation of the limit intersec...

Envelopes and Indifference

Envelopes, indicators and conservativeness

A well known theorem proved (independently) by J. Paris and H. Friedman states that BΣn+1 (the fragment of Arithmetic given by the collection scheme restricted to Σn+1–formulas) is a Πn+2–conservative extension of IΣn (the fragment given by the induction scheme restricted to Σn–formulas). In this paper, as a continuation of our previous work on collection schemes for ∆n+1(T)–formulas (see [4]),...

Uncertainty envelopes

We introduce a new class of problems: computing the set of all the convex combinations of sites when their position is uncertain and depends linearly on shared parameters which vary according to a uniform distribution. The boundary of the set, called the uncertainty envelope, is useful in optimizing processes where there is uncertainty on the site positions and the objective functions. We provi...