Analysis of a metallic pedestrian bridge under dynamic human loads in pre and post reinforcement phases

The purpose of this work is to study the dynamic behavior of a pedestrian bridge in Alicante, Spain. It is a very slender footbridge with vertical and horizontal vibration problems during the passage of pedestrians. Accelerations have been recorded by accelerometers installed at various locations of the bridge. Two scenarios, in free vibration (after the passage of a certain number of pedestrians on the bridge) and forced vibration produced by a fixed number of pedestrians walking on the bridge at a certain speed and frequency. In each test, the effect on the comfort of the pedestrians, the natural frequencies of vibration, the mode shapes and damping factors have been estimated. It has been found that the acceleration levels are much higher than the allowable by the Spanish standards and this should be considered in the restoration of the footbridge.

Valores morales, empatía e identificación con los personajes de ficción: el universo representativo de “Cuéntame cómo pasó” (TVE)

En la presente investigación se muestran los resultados de un estudio de base experimental sobre el análisis de los valores morales presentes en la serie emitida por Televisión Española “Cuéntame cómo pasó”. La discusión se centra en los valores morales como el aspecto nuclear de este constructo audiovisual, en especial en su posible correlación con la identificación de los personajes y la empatía ficcional del formato. En el estudio participaron 47 estudiantes universitarios y 36 personas de más edad, quienes fueron sometidos a unos cuestionarios analíticos anteriores y posteriores al visionado de dos capítulos de la serie televisiva. Tras la aplicación pre-test y post-test de la Escala de Comportamientos Morales Controvertidos, y las escalas EDI (Identificación con los personajes de relatos audiovisuales de ficción) e IRI (Interpersonal Reactivity Index), se revela que aunque el sexo y la edad no son factores explicativos, el visionado del capítulo de ficción es capaz de provocar un cambio en la escala moral en los sujetos.

Detection and mapping of burnt areas from time series of MODIS-derived NDVI data in a Mediterranean region

Moderate resolution remote sensing data, as provided by MODIS, can be used to detect and map active or past wildfires from daily records of suitable combinations of reflectance bands. The objective of the present work was to develop and test simple algorithms and variations for automatic or semiautomatic detection of burnt areas from time series data of MODIS biweekly vegetation indices for a Mediterranean region. MODIS-derived NDVI 250m time series data for the Valencia region, East Spain, were subjected to a two-step process for the detection of candidate burnt areas, and the results compared with available fire event records from the Valencia Regional Government. For each pixel and date in the data series, a model was fitted to both the previous and posterior time series data. Combining drops between two consecutive points and 1-year average drops, we used discrepancies or jumps between the pre and post models to identify seed pixels, and then delimitated fire scars for each potential wildfire using an extension algorithm from the seed pixels. The resulting maps of the detected burnt areas showed a very good agreement with the perimeters registered in the database of fire records used as reference. Overall accuracies and indices of agreement were very high, and omission and commission errors were similar or lower than in previous studies that used automatic or semiautomatic fire scar detection based on remote sensing. This supports the effectiveness of the method for detecting and mapping burnt areas in the Mediterranean region.