AM-FM methods for image and video processing

This dissertation is focused on the development of robust and efficient Amplitude-Modulation Frequency-Modulation (AM-FM) demodulation methods for image and video processing (there is currently a patent pending that covers the AM-FM methods and applications described in this dissertation). The motivation for this research lies in the wide number of image and video processing applications that can significantly benefit from this research. A number of potential applications are developed in the dissertation. First, a new, robust and efficient formulation for the instantaneous frequency (IF) estimation: a variable spacing, local quadratic phase method (VS-LQP) is presented. VS-LQP produces much more accurate results than current AM-FM methods. At significant noise levels (SNR \u3c 30dB), for single component images, the VS-LQP method produces better IF estimation results than methods using a multi-scale filterbank. At low noise levels (SNR \u3e 50dB), VS-LQP performs better when used in combination with a multi-scale filterbank. In all cases, VS-LQP outperforms the Quasi-Eigen Approximation algorithm by significant amounts (up to 20dB). New least squares reconstructions using AM-FM components from the input signal (image or video) are also presented. Three different reconstruction approaches are developed: (i) using AM-FM harmonics, (ii) using AM-FM components extracted from different scales and (iii) using AM-FM harmonics with the output of a low-pass filter. The image reconstruction methods provide perceptually lossless results with image quality index values bigger than 0.7 on average. The video reconstructions produced image quality index values, frame by frame, up to more than 0.7 using AM-FM components extracted from different scales. An application of the AM-FM method to retinal image analysis is also shown. This approach uses the instantaneous frequency magnitude and the instantaneous amplitude (IA) information to provide image features. The new AM-FM approach produced ROC area of 0.984 in classifying Risk 0 versus Risk 1, 0.95 in classifying Risk 0 versus Risk 2, 0.973 in classifying Risk 0 versus Risk 3 and 0.95 in classifying Risk 0 versus all images with any sign of Diabetic Retinopathy. An extension of the 2D AM-FM demodulation methods to three dimensions is also presented. New AM-FM methods for motion estimation are developed. The new motion estimation method provides three motion estimation equations per channel filter (AM, IF motion equations and a continuity equation). Applications of the method in motion tracking, trajectory estimation and for continuous-scale video searching are demonstrated. For each application, we discuss the advantages of the AM-FM methods over current approaches

Acompañamiento a la estrategia organizativa comunitaria de la Unión de Campesinos Organizados de la cuenca de San Dionisio(UCOSD), en las comunidades de Piedra Colorada, Los Limones y El Carrizal, durante el II semestre del 2015

El presente seminario tiene como tema Acompañamiento de la estrategia organizativa comunitaria desde la UCOSD, en las comunidades de Piedra Colorada, Los Limones y El Carrizal, del municipio de San Dionisio, en el segundo semestre del 2015. Su objetivo principal el poder dar respuesta a la problemática de la UCOSD, como es la falta de organización y confianza entre los socios, a través de la elaboración de una estrategia organizativa comunitaria. Esta investigación hizo uso del enfoque cualitativo con la aplicación de la metodología llamada Investigación Acción Participativa (IAP), aunque además de este enfoque, para dicho acompañamiento se recurrieron a analizar variables cuantitativas. La investigación fue elaborada en tres fases esenciales, la primera, la formación de los equipos de trabajo comunitario, en donde se concibió el primer encuentro con los socios de parte de los investigadores, sirviendo estos de facilitadores. La segunda fase, el análisis de la situación financiera en las comunidades, donde se trató de analizar en plenario qué se podía realizar como comunidad ante tal aspecto. La tercera fase, la gestión de herramientas de planificación comunitaria, su objetivo primordial era el poder darle a entender a cada socio de la importancia de planificar. En conclusión se logró facilitar la formación de los equipos de trabajo comunitario, se determinó mediante el análisis que las comunidades investigadas poseen una situación deudora deficiente del 61% de deuda en general, al obtener por comunidad un porcentaje deudor mayor del 50%, además de poder obtener las ideas comunitarias para tratar de dar solución a dicha situación financiera y al final se logró dar a conocer a los socios la importancia que tiene la planificación anual de sus actividades económicas mediante la presentación de propuestas de matrices de gastos familiares y planificación de la producción. Palabras Claves: Acompañamiento, Equipos de trabajo, Situación Financiera y Planificación Comunitari

Trust and Distrust Aggregation Enhanced with Path Length Incorporation

Trust networks are social networks in which users can assign trust scores to each other. In order to estimate these scores for agents that are indirectly connected through the network, a range of trust score aggregators has been proposed. Currently, none of them takes into account the length of the paths that connect users; however, this appears to be a critical factor since longer paths generally contain less reliable information. In this paper, we introduce and evaluate several path length incorporating aggregation strategies in order to strike the right balance between generating more predictions on the one hand and maintaining a high prediction accuracy on the other hand.European Union (EU) TIN2010-17876; TIC-5299; TIC-05991FW

Early prediction of critical events in infants with single ventricle physiology in critical care using routinely collected data

Intensive care units (ICUs) provide care for critically-ill patients who require constant monitoring and the availability of specialized equipment and personnel. In this environment, a high volume of information and a high degree of uncertainty present a burden to clinicians. In specialized cohorts, such as pediatric patients with congenital heart defects (CHDs), this burden is exacerbated by increased complexity, the inadequacy of existing decision support aids, and the limited and decreasing availability of highly-specialized clinicians. Among CHD patients, infants with single ventricle (SV) physiology are one of the most complex and severely-ill sub-populations. While SV mortality rates have dropped, patient deterioration may happen unexpectedly in the period before patients undergo stage-2 palliative surgery. Even in expert hands, critical and potentially catastrophic events (CEs), such as cardiopulmonary resuscitation (CPR), emergent endotracheal intubation (EEI), or extracorporeal membrane oxygenation (ECMO) are common in SV patients, and may negatively impact morbidity, mortality, and hospital length of stay. There is a clinical need of predictive tools that help intensivists assess and forecast the advent of CEs in SV infants. Although ubiquitous, widely adopted ICU severity-of-illness scores or early warning systems (EWS), e.g., PRISM and PIM, have not met this need. They are often developed for general ICU use and do not generalize well to specialized populations. Furthermore, most EWS are developed for prediction of patient mortality. Among SV patients, however, death is semi-elective. On the other hand, prediction of CEs may help clinicians improve patient care by anticipating the advent of patient deterioration. In this dissertation, we aimed to develop and validate predictive models that achieve early and accurate prediction of CEs in infants with SV physiology. Such models may provide early and actionable information to clinicians and may be used to perform clinical interventions aimed at preventing CEs, and to reducing morbidity, mortality, and healthcare costs. We assert that our work is significant in that it addresses an unmet clinical need by achieving state-of-the-art, early prediction of patient deterioration in a challenging and vulnerable population

Academic goals orientation questionnaire for Colombian nursing students:Validity and reliability study

Background Academic motivation guides students toward the achievement of academic objectives and influences their learning. However, there is little research on this subject in nursing education, and validated instruments are not available in Latin America. Objective To determine the validity and reliability of the Academic Goals Orientation Questionnaire in Colombian nursing students. Design Cross-sectional psychometric study developed in the second semester of 2016. Settings and participants. Undergraduate students in nursing at the National University of Colombia (n = 323). Methods The Academic Goals Orientation Questionnaire was administered electronically. In addition, the variables of age, sex and academic year were collected. An analysis of construct validity was carried out by exploratory and confirmatory factor analysis. The reliability of the questionnaire was studied with Cronbach's alpha. Results The exploratory factor analysis revealed the presence of four factors that explain 53.4% of the total variance and that correspond to the dimensions of the original instrument. The overall reliability was α = 0.714. The confirmatory factor analysis verified a good fit of the model (χ2 = 128, p = .024); its standardized mean square residue (SRMR) was 0.0471; the root mean square error of approximation (RMSEA) was 0.03 (IC95% = 0.011–0.044), and the comparative fit index (CFI) was 0.972. The learning or task goal obtained the highest average score (m = 4.67, 95% CI = 4.629–4.712), and the Work avoidance goal was the worst rated (m = 2.126, 95% CI = 2.055–2.198) by the students. Conclusion The Academic Goal Orientation Questionnaire has an adequate validity and reliability in the Colombian context that allows it to be applied in nursing students. However, it is recommended to expand the study with larger samples and other countries in the same context