167,942 research outputs found
Computation of Consistent Price Indices
The price index, a pervasive long established institution for economics, is a number issued by the Statistical Office that should tell anyone the ratio of costs of maintaining a given standard of living in two periods where prices differ. For a chain of three periods, the product of the ratios for successive pairs must coincide with the ratio for the endpoints. This is the chain consistency required of price indices. A usual supposition is that the index is determined by a formula involving price and quantity data for the two reference periods, as with the one or two hundred in the collection of Irving Fisher, joined with the question of which one to choose and the perplexity that chain consistency is not obtained with any. Hence finally they should all be abandoned. This situation reflects ‘The Index Number Problem’. Now with any number of periods consistent prices indices are all computed together to make a resolution of the ‘Problem’, proved unique and hence never to be joined by others to make a Fisher-like proliferationprice index, price level, index numbers (economics), index number problem
BSML: A Binding Schema Markup Language for Data Interchange in Problem Solving Environments (PSEs)
We describe a binding schema markup language (BSML) for describing data
interchange between scientific codes. Such a facility is an important
constituent of scientific problem solving environments (PSEs). BSML is designed
to integrate with a PSE or application composition system that views model
specification and execution as a problem of managing semistructured data. The
data interchange problem is addressed by three techniques for processing
semistructured data: validation, binding, and conversion. We present BSML and
describe its application to a PSE for wireless communications system design
L-Convex Polyominoes are Recognizable in Real Time by 2D Cellular Automata
A polyomino is said to be L-convex if any two of its cells are connected by a
4-connected inner path that changes direction at most once. The 2-dimensional
language representing such polyominoes has been recently proved to be
recognizable by tiling systems by S. Brocchi, A. Frosini, R. Pinzani and S.
Rinaldi. In an attempt to compare recognition power of tiling systems and
cellular automata, we have proved that this language can be recognized by
2-dimensional cellular automata working on the von Neumann neighborhood in real
time.
Although the construction uses a characterization of L-convex polyominoes
that is similar to the one used for tiling systems, the real time constraint
which has no equivalent in terms of tilings requires the use of techniques that
are specific to cellular automata
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