Inscriere cercetatori

Premii Ad Astra

premii Ad Astra

Asociația Ad Astra a anunțat câștigătorii Premiilor Ad Astra 2022: Proiectul și-a propus identificarea și popularizarea modelelor de succes, a rezultatelor excepționale ale cercetătorilor români din țară și din afara ei.

Asociatia Ad Astra a cercetatorilor romani lanseaza BAZA DE DATE A CERCETATORILOR ROMANI DIN DIASPORA. Scopul acestei baze de date este aceea de a stimula colaborarea dintre cercetatorii romani de peste hotare dar si cu cercetatorii din Romania. Cercetatorii care doresc sa fie nominalizati in aceasta baza de date sunt rugati sa trimita un email la

Using a Quick-Basic Application Based on the DAC Statistic to Detect Spatial Clusters

Domenii publicaţii > Matematica + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: Alexandru I. Petrisor, Liviu Dragomirescu, J. Wanzer Drane, Kirby L. Jackson, David J. Cowen

Editorial: Journal of Control Engineering and Applied Informatics, 4(1), p.55-64, 2002.


Spatial distributions find applications in various fields, such as public health, biology, ecology, geography, economics or sociology. The DAC statistic is the difference between the empirical cumulative distribution of cases and that of non-cases at a particular point. This study uses the longitude and latitude as the coordinates of the homes of mothers in Spartanburg County, SC who gave birth to their babies in 1989 or 1990. A priori, clusters are expected in areas of high population densities, especially considering risk factors for low birthweight. The chosen axes are east-west (x) and north-south (y). From a mathematical perspective the choice is arbitrary. For any size of a random sample of locations taken from the 6434 live births there is a noticeable variation of the location of the DAC statistic with random rotations within a given sample, when transformed back to original longitude and latitude. Simulations indicated that the location of the maximum DAC statistic is not unique, moreover there is a geometrical locus of it, and this varies as the orientation of the axes changes. Therefore, the DAC statistic should be used with caution, but its usefulness as a set of spatial descriptive statistic is not diminished in the least.

Cuvinte cheie: statistica spatiala (bidimensionala), test DAC, cluster, certificat de nastere, geocodificare, subponderalitate // spatial statistics, DAC statistic, cluster, birth certificates, geocoding, low birth weight