Descripción: “...It shows than inmigrants in different cities do not find employment in modern economy; in this case, inmigrants look for subemployment.The next theory relates the underground economy and its incomes, shows that uneven incomes and high costs are translated  in obstacles to generate formal enterprises in the same way, regarding good and services demand and consumer low budgets prompt  background economy marketing.Another theory, claims the background economy as a result of the official system relates to the regulations and absence at regulations. ...”

Descripción: “...Palabras Claves: Bases de Datos (BD), Conjuntos Difusos, Cluster,   C-Means, Minería de DatosABSTRACT: The data  mining has become an investigation and development area, in which are intending technicals that point to find the hidden information in a huge data. These data contain valuable information that can be used to improve the  competitiveness  of institutions owners of these data.The information  to discover can have many forms,  among  them associative  rules or groups of denominated  sets (Cluster), if to this we add the capacity that  has the Fuzzy Logic of breaking up with the third  excluded principle and to allow the relevancy from an element to several Cluster, we have a quite useful methodology when classifying in sets the content of the database.associative  rules or groups of denominated sets (Cluster), if to this we add the capacity that  has the Fuzzy Logic of breaking up with the third  excluded principle and to allow the relevancy from an element to several Cluster, we have a quite useful methodology when classifying in sets the content of the databases.In this paper is shown the implementation  of an  algorithm denominated C -Means for the grouping of data in fuzzy sets, this it has been implemented with the development of a  denominated program  (Software  Mining Data Fuzzy) SM2D 1.21.0  Beta.Key words: Data Bases (BD), Fuzzy Sets, Cluster, C-Means, Data Mining. ...”

Descripción: “...Abstract— In this research association discovering and clustering techniques for the resolution of the low efficiency problem in the sterilization service in a hospital under study were used. The aim was to find and to discriminate the main causes of the problem under study and then to apply corrective solutions. ...”

Descripción: “...The separated one-dimensional differential equations for the electron and the hole motions in the radial direction we solve by using the trigonometric sweep method, while the solutions of the equations for rotational motions we find by means of the Fourier series expansion technique. ...”

Descripción: “...Stastiscally the results were evaluated by the homogeneity of proportions test (exact probe of Fisher) to find the correlation degree between blood smear and serological test, where p>0.05 was not considered significant. ...”