This article presents the development of an analytic model of variation of power or energy in function of the band width of the IEEE 802.15.4a UWB channel. This analytic model characterizes the fade depth of the channel UWB IEEE 802.15.4a, also shows that the power in the frequency domain of the UWB channel follows a Gamma statistical distribution. The overall results are obtained by simulation in Matlab, validated by Kolmogorov-Smirnov test and calculating the mean square error. Finally the theoretical results are compared with measurement campaigns done by other authors.

RESUMENObjetivo: Comparar las medidas cefalométricas posteroanteriores (PA) presentes en una población adulta de padres con hijos con labio y/o paladar hendido (LPH) y de padres con hijos sin hendidura orofacial (HOF). Materiales y métodos: Se realizó un estudio observacional descriptivo de corte transversal, se incluyeron 82 padres: 43 padres de niños con LPH no sindrómico y 39 padres de niños sin HOF. Las variables incluidas en este estudio fueron las sociodemográficas y las cefalométricas PA. Se realizó el cálculo de medidas de resumen y para el bivariado se aplicaron la prueba t de Student o el test de rangos de Wilcoxon según la distribución de los datos. Se obtuvieron radiografías PA de los dos grupos con una técnica standard. Luego se les tomaron fotografías con una cámara digital, se exportaron a un computador, con previa calibración y fueron analizadas utilizando el Software Nemoceph. Resultados: Se hallaron diferencias estadísticamente significativas entre padres con y sin labio y/o paladar fisurado en las siguientes variables: Cg-ENA, ENA-Me, Cg-Me, Ag-gA. Igualmente se halló significancia estadística por género frente a la presencia de hijos con o sin HOF en las variables Cg-ENA, ENA-Me, Cg-Me, Ag-gA, Bc-Me. Conclusiones: Algunas medidas cefalométricas posteroanteriores podrían ser diferentes entre la población con y sin LPH, su importancia en el desarrollo de las HOF permitirá evaluar el riesgo de la presencia de esta anomalía en generaciones futuras. COMPARATIVE STUDY OF POSTEROANTERIOR CEPHALOMETRIC MEASURES OF PARENTS OF CHILDREN WITH LIP AND/OR CLEFT PALATE AND PARENTS OF CHILDREN WITHOUT OROFACIAL CLEFTING ABSTRACTObjective: To compare the posteroanterior cephalometric measures (PA) present in parents of children with cleft lip and/ or palate and of parents of children without orofacial clefting (HOF). Materials and methods:A descriptive cross-sectional and observational study was done. Eighty two parents were selected: fourteen-three parents of children with non-syndromic LPH and 39 parents of children without HOF. Sociodemographic variables and PA cephalometric measures were included. The statistical analysis plan implied the calculation of summary measures and T student and rank Wilcoxon test were applied. PA x-rays of the two groups were obtained using a standard technique. Photos were taken using a digital camera, which were then exported to a computer previously calibrated and they were analyzed using the Software Nemoceph.Results: There were statistically significant differences between parents with and without orofacial fissures in the following variables: Cg-ENA, ENA-Me, Cg-Me, Ag-GA. Equally, there was statistical significance for gender in the presence of children with or without HOF in the variable Cg-ENA, ENA-Me, Cg-Me, Ag-GA, Bc-Me. Conclusions: Some PA cephalometric cranio-facial measures can be different between population with and without LPH, its importance in the development of the HOF will allow the evaluation of the risk of the presence of this anomaly in future generations.