This paper develops a model of endogenous product selection by firms. The theory is motivated by new evidence we present on the importance of product switching by U.S. manufacturers. Two-thirds of continuing firms change their product mix every five years, and product switches involve more than 40% of firm output and almost half of existing products. The theoretical model incorporates heterogen...

A Software Product Line (SPL) is a set of related programs. A SPL of a SPL (SPL), or a product line of a product line, is a fundamental scaling of product line concepts. A member of a SPL is not a program, but a SPL. The idea recurses: a SPL is a SPL of a SPL, and so on. The depth of recursion is the rank of the product line. We present an algebra to understand and build feature-based product l...

The properties and applications of kronecker product in quantum theory is studied thoroughly. The use of kronecker product in quantum information theory to get the exact spin Hamiltonian is given. The proof of non-commutativity of matrices, when kronecker product is used between them is given. It is shown that the non-commutative matrices after kronecker product are similar or they are similar ...

The objective of this study was to evaluate low and high Brix diets, treated or not with 5 g of calcium oxide per kg of natural matter, and corn silage on intake, digestibility and performance of beef cattle. Forty cattle with initial body weight (BW) of 350 kg were used: five composed the control group, 30 were distributed into random blocks (control) and the other five were distributed in a 5...

Silage normally contains between 12 and 22 % crude protein (CP). While such levels 5 should be adequate for most productive livestock, in silages they are not. This is because of poor 6 utilization of N in silage. Most silage-based production rations require supplemental protein to meet 7 requirements for growth or lactation in ruminants. Silage protein is highly degradable in the rumen and as ...

Abstract Requirements engineering and requirements management are essential sub-processes of product development an integrated part virtually all models industrial process descriptions. Proprietary context specific processes for working with used in design practice. However, these not appropriately reflected existing development. Existing standards describe the content generation documents but ...

In this article, by using a partial on locally compact semi-direct product groups, we present a compatible extension of the Fourier transform. As a consequence, we extend the fundamental theorems of Abelian Fourier transform to non-Abelian case.