1,407 research outputs found
Consistencia en la desagregación de la población. El problema del ruido y el age heaping
La población desagregada en edad simple es una herramienta básica para las oficinas estadÃsticas, pues es usada, por ejemplo, como denominador en el cálculo de indicadores. Sin embargo, las cifras de población para algunos ámbitos territoriales solo están disponibles en forma agrupada: normalmente, esta distribución de la población se publica en grupos quinquenales de edad más un intervalo superior abierto donde se acumula la población de mayor edad. Un problema importante al que se suelen enfrentar las diferentes oficinas estadÃsticas, tanto de ámbito estatal como autonómico, es la desagregación de los datos de población en grupos de edad simple, permitiendo, cuando sea requerido, incluir conocimiento demográfico y mantener la consistencia de los resultados obtenidos con las agregaciones de población de los ámbitos territoriales superiores al
desagregado o, incluso, la consistencia en la evolución de ésta a lo largo del tiempo. En este trabajo se consideran técnicas de optimización para dar respuesta a este problema real, aunque muy poco estudiado en la literatura. Los procedimientos propuestos permiten también tratar un problema habitual en este tipo de fuentes estadÃsticas, como es la presencia de ruido de distinta naturaleza en los datos disponibles, y, en particular, el fenómeno conocido como age heaping.Official Statistics call for data by individual age, since a significant number of
statistical operations, such as the calculation of demographic indicators, require the use of degrouped population figures. However, in some countries or regions population data are only available in a grouped form, usually as quinquennial age groups plus a large open-ended interval for elderly people. A challenging problem faced by Official Statistics institutes is how to degroup data by individual age, allowing one, if needed, to include demographic knowledge or to be consistent with the heaped information.
In this paper Mathematical Optimization models are proposed to address this important, yet seldom studied problem. These models also consider a frequent issue in statistical sources: the presence of noise and errors, and, in particular, the phenomenon known as age heaping.Ministerio de EconomÃa y CompetitividadJunta de AndalucÃ
Una propuesta de catalogación de las actividades de cooperación al desarrollo de las universidades madrileñas
Las universidades madrileñas tienen desde hace años un activo papel como actores de la cooperación al desarrollo. Sin embargo, existe una dificultad notable en definir y catalogar sus actividades dado que no existe una definición consensuada del concepto de Cooperación Universitaria al Desarrollo y
los lÃmites son a menudo imprecisos. El presente estudio propone una catalogación de estas actividades, su justificación y una reflexión sobre el valor del concepto de CUD
Representaciones de alumnos universitarios sobre propagación de ondas mecánicas
En este trabajo se presentan resultados de una investigación sobre concepciones de estudiantes universitarios acerca del mecanismo de propagación de una onda y el rol del medio de propagación en la misma. Se analizan razonamientos que emplean estudiantes universitarios al abordar situaciones problemáticas concretas, en función de un marco teórico que articula los esquemas de la teorÃa de campos conceptuales de Vergnaud con los modelos mentales de la teorÃa de Johnson-Laird. Se identifican algunos elementos de los esquemas y las caracterÃsticas principales de los modelos mentales que usarÃan los alumnos para resolver la tarea. Las conclusiones muestran la potencialidad del marco teórico para entender los procesos de construcción de las representaciones de los estudiantes, y para guiar la elaboración de propuestas instruccionales tendentes a un aprendizaje significativo más efectivo.Research results on university students conceptions about the mechanism of wave propagation and the role of propagation medium, are presented. Based on a theoretical framework that articulates the schemes of theory of conceptual fields Vergnaud's theory with the mental models of Johnson-Laird's theory, students reasonings used when approaching a concrete problematic situation are analyzed. The analysis of results allows for the identification of some schemes and the basic characteristics of the mental models that students use to solve the task. The conclusions show the potential of this theoretical framework in understanding the process of representations construction, and for the development of future instructional proposals, that can be used to promote meaningful learning
Effects of acute psychological and physiological stress on rock climbers
Background: The aim of this study was to assess the effects that psychological and physiological stressors have on indoor rock climbers, as well as to identify sex differences. Methods: 14 intermediate rock climbers participated in the study, 10 males and 4 females. Mean age was 31 ± 8 years for males and 21 ± 2 years for females. Day 1 consisted of test familiarization and baseline measurements. Day 2 included two test conditions, startle and fatigue, separated by 20 min. In the startle condition, participants had to lead climb a route, and a loud audio stimulus was presented near the top of the climb. In the fatigue condition, participants were required to climb as fast as they could until muscular failure. The competitive state anxiety inventory second review (CSAI-2R) questionnaire was used to assess somatic anxiety, cognitive anxiety, and self-confidence. The four-square step test (FSST) was used to assess motor control, and cortisol levels were acquired via passive drool (PD). Results: Cortisol concentrations were highest in the pre-startle condition (1.72 μg/dL ± 0.66), and values decreased post-startle (1.67 μg/dL ± 0.74) and post-fatigue (1.42 μg/dL ± 0.72). However, cortisol concentrations increased post-startle in females (1.57 μg/dL ± 0.96). Somatic anxiety in males was significantly higher post-startle (16.36 ± 5.54) than pre-startle (14.23 ± 5.09). Females had significantly higher somatic anxiety post-startle (18.00 ± 8.76), and they had lower self-confidence levels (30.00 ± 5.89) than males. Conclusions: There are differences in the way that males and females prepare and respond to stressful situations. Furthermore, time of day may have had a significant impact on cortisol concentrations
The particle detector in your pocket: The Distributed Electronic Cosmic-ray Observatory
The total area of silicon in cell phone camera sensors worldwide surpasses
that in any experiment to date. Based on semiconductor technology similar to
that found in modern astronomical telescopes and particle detectors, these
sensors can detect ionizing radiation in addition to photons. The Distributed
Electronic Cosmic-ray Observatory (DECO) uses the global network of active cell
phones in order to detect cosmic rays and other energetic particles such as
those produced by radioactive decays. DECO consists of an Android application,
database, and public data browser available to citizen scientists around the
world (https://wipac.wisc.edu/deco). Candidate cosmic-ray events have been
detected on all seven continents and can be categorized by the morphology of
their corresponding images. We present the DECO project, a novel particle
detector with wide applications in public outreach and education.Comment: Presented at ICRC 2017, Busan, Korea. See https://wipac.wisc.edu/deco
for more informatio
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