Educação matemática pela arte
Gusmão, Lucimar Donizete
2013-08-28
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General-purpose programming languages provide limited facilities for
expressing domain-specific concepts in a natural manner. All domain concepts
need to be captured using the same generic syntactic and semantic constructs.
Generative programming methods and program transformation techniques can
be used to overcome this lack of abstraction in general-purpose languages.
In this tutorial we describe the METABORG method for embedding domainspeci
c languages, tailored syntactically and semantically to the application domain
at hand, in a general-purpose language. METABORG is based on Stratego/
XT, a language and toolset for the implementation of program transformation
systems, which is used for the definition of syntactic embeddings and assimilation
of the embedded constructs into the surrounding code.
We illustrate METABORG with three exa...
Assume that a set of imprecise points is given, where each point is specified by a region
in which the point may lie. We study the problem of computing the smallest and largest
possible convex hulls, measured by length and by area. Generally we assume the imprecision
region to be a square, but we discuss the case where it is a segment or circle as well. We give
polynomial time algorithms for several variants of this problem, ranging in running time from
O(n log n) to O(n13), and prove NP-hardness for some other variants.
Between December 25th 1983 and January 7th 1984 59 cases of dysentery bacteriologically proven to be caused by Shigella flexneri 2 occurred in the Netherlands. For a further 34 cases of gastroenteritis, strong epidemiological evidence was present to allow the diagnosis of shigellosis. In approximately 80 additional cases of gastroenteritis the disease was probably also caused by Shigella (Bijkerk, H., personal communication, 18th January 1984). The epidemic caused death in 14 patients, all aged over 70. The earliest sign of the epidemic came from a home for elderly people. 28 of the 208 residents and 2 of the 22 staff fell ill with fever and gastroenteritis.
The shrimp cocktail served at the Christmas dinner was suspected to be the source of infection. The history of other patients substantiated the aetiological role of the shrimps. T...
The interpretation of 220- and 300-MHz P.M.R. spectra and the accurate chemical shifts and coupling constants of a number of per-O-trimethylsilyl-(TMS-)D -fructose derivatives and TMS-oligosaccharides containing beta-D-fructofuranose residues are presented. On the basis of calculations with an adapted Karplus equation it is concluded that TMS-alpha- and -beta-D-fructopyranose occur in the 2C5(D) chair conformation whereas the D-glucopyranose rings in the oligosaccharides adopt the usual 4C1(D) chair conformation. The structure of the latter units is very similar to that of TMS-alpha-D-glucopyranose. The 4E(D) envelope and 4T5(D) twist are the principal conformations of the D-fructofuranose rings. The conformation of the furanose ring depends on the number and kind of monosaccharide units attached thereto. The calculated, preferred conf...
Abraham Fraenkel was one of the first non-partizan mathematicians to
take a serious interest in intuitionism. In the second edition of his "Einleitung in die Mengenlehre" he extensively discussed the foundational situation in the early twenties. Brouwer implicitly gave his fiat to the presentation by reading the proofs and suggesting corrections.
Central serotonin (5-hydroxytryptamine; 5-HT) metabolism can be disturbed in a subgroup of patients with vital (endogenous, primary) depression. Presumably these disturbances do not result from the depression and have a predisposing rather than a causative relationship to it. This latter statement is based on two observations. First, in a majority of patients, the 5-HT disturbances persist after depression has abated. Secondly, 5-hydroxytryptophan seems to have prophylactic value, in particular in patients with persistent abnormalities in central 5-HT metabolism. In this study we approached the hypothesis that 5-HT disturbances are a predisposing factor to the occurence of depression from still another perspective. If this hypothesis is correct, then depressive patients with persistent 5-HT disturbances should have higher frequencies o...
Granules of potato starch and amylopectin potato starch were methylated in aqueous alkaline suspension. Here, an overview is given of all structural aspects that have been studied with respect to the determination of the location of the substituents. Methods, which are generally applicable, were developed for the separation of different areas of derivatised starch granules, followed by determination of the substitution level. For methylated starch granules it was found that methyl groups are predominantly present in branched regions and amorphous domains, and that amylose is higher substituted than amylopectin. No differences were found between substitution levels of granules of various sizes, nor radially across the granules
