Search results for "video"
showing 10 items of 1348 documents
Buffalaxed Super-diversity: Representations of the Other on YouTube
2013
The effect of social information from live demonstrators compared to video playback on blue tit foraging decisions.
2019
Video playback provides a promising method to study social interactions, and the number of video playback experiments has been growing in recent years. Using videos has advantages over live individuals as it increases the repeatability of demonstrations, and enables researchers to manipulate the features of the presented stimulus. How observers respond to video playback might, however, differ among species, and the efficacy of video playback should be validated by investigating if individuals’ responses to videos are comparable to their responses to live demonstrators. Here, we use a novel foraging task to compare blue tits’ (Cyanistes caeruleus) responses to social information from a live …
Wider implications of video-assisted thoracic surgery versus open approach for lung metastasectomy
2015
ABSTRACT Lung metastasectomy is considered a safe and potentially curative procedure despite there is not a strong evidence that metastasectomy prolongs long-term survival in patients with lung metastases. Moreover, the debate is open regarding the best approach for lung metastasectomy, video-assisted thoracic surgery versus open approach. A systematic review of literature to clarify what is the best approach to prolong survival in patients with lung metastases was performed. Our study confirms that overall survival is equivalent for video-assisted thoracic surgery and thoracotomy, therefore the ‘gold standard’ surgical treatment for lung metastases remains a point of debate. The choice o…
Por qué a Deivid le gusta Madonna. Imágenes de una "star" entre clásica y moderna
2004
Este artículo es una breve meditación sobre el nacimiento y el posterior desarrollo de una de las más importantes formas de comunicación visual de finales del siglo XX, el vídeo musical pop, y su consiguiente explotación por Madonna. La cantante estadounidense ha reciclado las iconografías clásicas del siglo XX para ofrecer en sus vídeos e imágenes promocionales un envoltorio artístico a su carrera musical dirigida a la sociedad de consumo y de los grandes medios de comunicación. (A)
The automated assesment of artery hemodynamic parameters from ultrasound video
2012
The custom designed video processing software for analysis of B-mode and Doppler-mode ultrasound video has been proposed in this work. The software allows adjusting user-defined thresholds and tolerance levels to enhance contour detection in noisy and artifacted ultrasound images. The developed software is able to evaluate 16 hemodynamic parameters (artery diameter, pulse rate and flow velocity related parameters) in each cardiac cycle. The measurements were performed intermittently recording artery diameter (B-mode) and flow velocity (Doppler-mode). Software has validated in femoral artery measurements. The hemodynamic parameters computed by software were consistent with those obtained by …
Pulse rate variability measurement with camera-based photoplethysmography
2021
Electrocardiogram (ECG) has been used by doctors and biomedical researchers to measure cardiac parameters such as Heart Rate (HR) and Heart Rate Variability (HRV). HR is a medical index for health monitoring and the HRV is a sign to reflect the activities of Autonomic Nervous System (ANS) and can be used for emotion recognition applications. Recently, remote photoplethysmography (rPPG) has evolved as a non-contact technique for measuring vital cardiac signs. Compared with ECG, this technique is non-invasive, low-cost, comfortable and possibly utilized in long-term monitoring. It has great potential in remote health assessment and emotion detection. However, the rPPG is a video-based method,…
Design of an efficient digital down-converter for a SDR-based DVB-S receiver
2007
This paper presents the design of an area-power efficient digital down-converter suitable for broadband communication systems. The DVB-S standard has been used as a design example. It has been shown that by selecting a bandpass sampling to generate only one spectral image, the case in which the relationship between the digital carrier frequency and the sampling frequency is 1/4, not only gives the smallest area but the lowest power consumption.
Cartoon filter via adaptive abstraction
2016
We propose a non-parametric methodology to realize abstraction images.The redundant wavelet "a trous" algorithm is applied for details detection.An multi-scale circular median filter is used as a smoothing filter.The proposed algorithm is simple and fast on low-cost entry-level hardware. Abstraction in computer graphics defines a procedure that discriminates the essential information that is worth keeping. Usually details, that correspond to higher frequency components, allow to distinguish otherwise similar images. Vice versa, low frequencies are related to the main information, which are larger structures. Contours themselves may also be identified by high frequencies and separate each pi…
Segmentando el mercado de internautas atendiendo a su nivel de afinidad: (I)fuerte, (II)medio y (III)débil
2017
Esta investigación pretende confrontar el Marketing con Causa con el Marketing de Afinidad. Para ello se descompone la audiencia de una campaña de Marketing con Causa viral en segmentos de internautas con distinto nivel de afinidad: i) fuerte (con experiencia previa de marca y de causa); ii) medio (con experiencia previa o de marca o de causa); iii) débil (sin experiencia previa ni de marca ni de causa). El objetivo es justificar la utilidad de este criterio como vía para optimizar el resultado de la comunicación segmentada. Con dicho fin, se ha estudiado un caso real planteado de forma experimental midiendo las actitudes de una muestra de 276 internautas antes y después de visualizar un sp…
Mutations in spalt cause a severe but reversible neurodegenerative phenotype in the embryonic central nervous system ofDrosophila melanogaster
2002
The gene spalt is expressed in the embryonic central nervous system of Drosophila melanogaster but its function in this tissue is still unknown. To investigate this question, we used a combination of techniques to analyse spalt mutant embryos. Electron microscopy showed that in the absence of Spalt, the central nervous system cells are separated by enlarged extracellular spaces populated by membranous material at 60% of embryonic development. Surprisingly, the central nervous system from slightly older embryos (80% of development) exhibited almost wild-type morphology. An extensive survey by laser confocal microscopy revealed that thespalt mutant central nervous system has abnormal levels o…