On the economics of design

The emerging field of building economics is gradually penetrating both professional practice and academic curricula in architectural design. This essay focuses on the contribution of building economics to architectural design. This contribution hinges on the notion of time. Building economics offers a systematic framework for the representation of time. An economic evaluation of a building is in fact impossible without the time-profile of the economic process it contains. This can be perceived as a problem of finding some numbers to “plug in” the prescribed formulae, but it can also be perceived as a valuable framework for design and building in time. The latter perspective is undeniably more challenging and exciting. The scope of architectural design is thereby considerably widened and enriched.     

Ordering Properties of Convolutions of Exponential Random Variables

Convolutions of independent random variables are usually compared. In this paper, after a synthetic comparison with respect to hazard rate ordering between sums of independent exponential random variables, we focus on the special case where one sum is identically distributed. So, for a given sum of n independent exponential random variables, we deduce the "best" Erlang-n bounds, with respect to each of the usual orderings: mean ordering, stochastic ordering, hazard rate ordering and likelihood ratio ordering.