85 research outputs found
FACTORES DE RIESGO DE OBESIDAD EN MUJERES ADOLESCENTES DE COLEGIOS SECUNDARIOS DEL CERCADO DE TACNA
Introducción: El objetivo fue determinar los factores de riesgo de obesidad en adolescentes mujeres de 12 a 17 años de edad de los colegios de la ciudad de Tacna; en base al índice de Masa Corporal (IMC), actividad física e ingestión calórica de cada adolescente. Material y Métodos: Durante el año 2007 se llevó a cabo un estudio de corte transversal en una muestra de 320 adolescentes de colegios secundarios de la ciudad de Tacna. Las alumnas fueron seleccionadas por muestreo aleatorio ya todas se les tomó sus medidas antropométricas como peso, talla, circunferencia de cintura y cadera; asimismo su ingesta calórica total y actividad física, a través de una encuesta recordatoria de 24 botas y de una semana. Resultados: El promedio de peso corporal fue mayor en adolescentes de los colegios particulares sin diferencia significativa. Las adolescentes de colegios particulares presentaron una mayor talla y un IMC inferior a las de estatales (p<0.05); el promedio de la circunferencia de la cintura/cadera fue mayor en las estudiantes de colegios estatales (p<0.05). No hubo diferencias en la ingestión calórica total a excepción de las grasas, que fue mayor en estudiantes de colegios particulares (p<0.05). Se encontró una prevalencia general de sobrepeso de 10.6% y obesidad de 1.9%. De las alumnas con sobrepeso 38.4% presentaron obesidad glúteo-femoral, 56.0% intermedio y 5.6% abdominal. Se encontró una correlación invertida entre el IMC de las adolescentes, su actividad física y su ingestión calórica (p<0.05). Conclusiones: La prevalencia de peso y obesidad es similar a las encontradas en países latinoamericanos, pero menor a la de los países industrializados. Los factores que más afectaron el IMC fueron la actividad fisica, independientemente de la ingestión calórica y de la composición de la dieta
Terrestrial laser scanner data processing
The introduction of new terrestrial laser scanner devices in the survey field has increased the possibility of more accurate and complete 3D models of the acquired objects to be obtained. This happens, above all, in the architectural and archaeological survey field in which the shape of an object is usually remarkably complex. Acquisition with laser scanner devices is, in addition, very fast and cheap and the 3D models that are obtained are very useful for users. However, particular attention must be paid during the analysis, the processing and the modelling phases of the laser scanner data. The acquired data are often characterized by the presence of elevated noise (usually gross errors and outliers) which must be removed with ad hoc techniques before starting with the manipulation of the data. Usually architectural and archaeological objects have a very complex shape and one scan is not enough to obtain the complete description of the object. In these cases, in order to eliminate the shaded areas, two or more scans must be taken from different points of view of the same object. To obtain the final 3D model of the object it is therefore necessary to align and to georefer the single scans using suitable registration techniques. In addition, when it is necessary to align a large series of scans, the use of triangulation algorithms represents the only way to avoid distortions of the 3D model, in complete analogy with the case of long single strips in photogrammetry. All these aspects have been considered and a specific software that is able to correctly process terrestrial laser scanner data has been developed by the authors. The paper presents the algorithms and the solutions adopted in order to prepare the laser scanner data to th
Terrestrial laser scanner data processing
The introduction of new terrestrial laser scanner devices in the survey field has increased the possibility of more accurate and complete 3D models of the acquired objects to be obtained. This happens, above all, in the architectural and archaeological survey field in which the shape of an object is usually remarkably complex. Acquisition with laser scanner devices is, in addition, very fast and cheap and the 3D models that are obtained are very useful for users. However, particular attention must be paid during the analysis, the processing and the modelling phases of the laser scanner data. The acquired data are often characterized by the presence of elevated noise (usually gross errors and outliers) which must be removed with ad hoc techniques before starting with the manipulation of the data. Usually architectural and archaeological objects have a very complex shape and one scan is not enough to obtain the complete description of the object. In these cases, in order to eliminate the shaded areas, two or more scans must be taken from different points of view of the same object. To obtain the final 3D model of the object it is therefore necessary to align and to georefer the single scans using suitable registration techniques. In addition, when it is necessary to align a large series of scans, the use of triangulation algorithms represents the only way to avoid distortions of the 3D model, in complete analogy with the case of long single strips in photogrammetry. All these aspects have been considered and a specific software that is able to correctly process terrestrial laser scanner data has been developed by the authors. The paper presents the algorithms and the solutions adopted in order to prepare the laser scanner data to th
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