Motion Estimation from Disparity Images

A new method for 3D rigid motion estimation from stereo is proposed in this paper. The appealing feature of this method is that it directly uses the disparity images obtained from stereo matching. We assume that the stereo rig has parallel cameras and show, in that case, the geometric and topological properties of the disparity images. Then we introduce a rigid transformation (called d-motion) that maps two disparity images of a rigidly moving object. We show how it is related to the Euclidean rigid motion and a motion estimation algorithm is derived. We show with experiments that our approach is simple and more accurate than standard approaches

Plan-view Trajectory Estimation with Dense Stereo Background Models

In a known environment, objects may be tracked in multiple views using a set of back-ground models. Stereo-based models can be illumination-invariant, but often have undefined values which inevitably lead to foreground classification errors. We derive dense stereo models for object tracking using long-term, extended dynamic-range imagery, and by detecting and interpolating uniform but unoccluded planar regions. Foreground points are detected quickly in new images using pruned disparity search. We adopt a 'late-segmentation' strategy, using an integrated plan-view density representation. Foreground points are segmented into object regions only when a trajectory is finally estimated, using a dynamic programming-based method. Object entry and exit are optimally determined and are not restricted to special spatial zones

Gesture + Play Exploring Full-Body Navigation for Virtual Environments

Navigating virtual environments usually requires a wired interface, game console, or keyboard. The advent of perceptual interface techniques allows a new option: the passive and untethered sensing of users’ pose and gesture to allow them maneuver through and manipulate virtual worlds. We describe new algorithms for interacting with 3-D environments using real-time articulated body tracking with standard cameras and personal computers. Our method is based on rigid stereo-motion estimation algorithms and uses a linear technique for enforcing articulation constraints. With our tracking system users can navigate virtual environments using 3-D gesture and body poses. We analyze the space of possible perceptual interface abstractions for full-body navigation, and present a prototype system based on these results. We finally describe an initial evaluation of our prototype system with users guiding avatars through a series of 3-D virtual game worlds.</p

Association between adiposity and iron status in women of reproductive age: data from the UK National Diet and Nutrition Survey 2008-2019 (NDNS):Data from the UK National Diet and Nutrition Survey (NDNS) 2008–2019

BACKGROUND: Overweight/obesity and iron deficiency are highly prevalent in women of reproductive age (WRA), impacting on women's health. Obesity is a risk factor for nutritional deficiencies but its association with iron deficiency is unclear.OBJECTIVE: To determine the association between adiposity and markers of iron status and iron deficiency prevalence in WRA.METHODS: This cross-sectional study analyzed the National Diet and Nutrition Survey (NDNS, 2008-2019) data, focusing on women aged 18-49y with BMI ≥18.5 kg/m 2. Prevalence of anemia, Iron Deficiency Anemia (IDA), and Iron Deficiency (ID) were analyzed. Ferritin was adjusted for C-reactive protein. Iron status was assessed across high and low BMI, waist circumference (WC), waist-to-height (WHtR), and waist-to-hip ratio (WHR). Chi 2, linear and logistic regression were performed adjusting for covariates. RESULTS: Among 1,098 WRA, 496 normal weight and 602 overweight/obesity, prevalence rates were: anemia 9.2% and IDA 6.8%. Anemia was more prevalent in those with higher WHtR and WHR (11.9% vs 5.9% and 16.7% vs 6.5%, both p&lt;0.001). WRA with increased WC, WHtR, and WHR had higher IDA prevalence than those with lower adiposity. (8.5% vs 4.3%, p=0.005; 9.4% vs 3.3%, p&lt;0.001; 12.1% vs 4.9%, p&lt;0.001). ID prevalence was 49.7% (ferritin cut-off 30 μg/L) and 19.6% (ferritin cut-off 15 μg/L), showing similar rates across adiposity groups. ID prevalence defined by soluble transferrin receptor (sTfR) was higher in women with increased WHR (p=0.001). Higher WHR predicted ID categorized by sTfR (aOR 2.104, p=0.004), and WHtR and WHR predicted anemia and IDA (anemia: WHtR aOR 2.006 p=0.036; WHR aOR 4.489 p&lt;0.001; IDA: WHtR: aOR 2.942, p=0.012; WHR aOR 4.142, p&lt;0.001).CONCLUSIONS: At least one in five WRA in the UK are iron deficient, highlighting the need to revise current policies. Greater central adiposity was strongly associated with impaired iron status and the development of anemia, IDA, and ID.</p

Maternal Adiposity and Inflammation: Risk Factors for Iron Deficiency in Pregnancy

Background: Obesity and iron deficiency (ID) are global health concerns in pregnancy, with serious consequences for mother and offspring. The inflammatory state associated with obesity and its potential contribution to ID/anemia is unclear. Objectives: This study aims to investigate the associations among maternal adiposity, the mediating role of inflammation, and iron status. We also aim to examine how adiposity affects the predictive accuracy of early pregnancy iron markers for late pregnancy ID risk. Methods: This secondary analysis of a double-blind randomized controlled trial included singleton pregnancies supplemented with a multivitamin containing 17 mg/d of iron. Body mass index (BMI), body composition [12 gestational weeks (GW)], iron markers (12, 28, 36 GW), and hemoglobin/hematological indices (12, 28 GW, postpartum) were assessed. Proinflammatory cytokines were used to calculate an inflammation score and categorized as high/low inflammation. Results: A total of 125 pregnant women were included: 43 normal weight, 44 overweight, and 38 with obesity. At 36 GW, ID was present in 50% of women with obesity, 40.9% of those overweight, and 30.2% with normal BMI. High BMI and fat mass index (FMI) at 12 GW predicted lower ferritin at 36 GW (BMI β = –0.253, P = 0.020; FMI β = –0.265, P = 0.010), and all adiposity measures predicted higher soluble transferrin receptor (sTfR). Transferrin saturation was lower in women with obesity at 12 and 28 GW (12 GW 23.9%, 24.5%, 30.3%, P = 0.016; 28 GW 13.2%, 17.7%, 17.2% P &lt; 0.001, obesity, overweight, and normal weight, respectively). At 36 GW, pregnant women with obesity and higher inflammation score had lower ferritin than normal weight women (15.0 compared with 20.3 μg/L, P = 0.041). sTfR at 12 GW was the best predictor of ID at 36 GW [area under curve (AUC) = 0.738, P &lt; 0.001], especially in overweight/obesity (AUC = 0.744, P &lt; 0.001). Conclusions: High adiposity, mediated by inflammation, increases the risk of ID in the late third trimester. sTfR in early pregnancy emerges as an effective marker for predicting ID in late pregnancy.</p

Using multiple-hypothesis disparity maps and image velocity for 3-D motion estimation

In this paper we explore a multiple hypothesis approach to estimating rigid motion from a moving stereo rig. More precisely, we introduce the use of Gaussian mixtures to model correspondence uncertainties for disparity and image velocity estimation. We show some properties of the disparity space and show how rigid transformations can be represented. An algorithm derived from standard random sampling-based robust estimators, that efficiently estimates rigid transformations from multi-hypothesis disparity maps and velocity fields is given

La filosofía política clásica : de la Antigüedad al Renacimiento

La decisión de publicar esta compilación de textos referidos a la filosofía política clásica reconoce al menos dos fuentes. En primer lugar es una respuesta a las necesidades prácticas surgidas de una experiencia docente de quince años al frente de la cátedra de Teoría Política y Social I de la Carrera de Ciencia Política de la Universidad de Buenos Aires. A lo largo de estos años hemos llegado a la convicción de que la imprescindible e irremplazable lectura de los clásicos que ningún comentarista puede compensar podría verse favorecida y estimulada por un texto en el cual quienes tienen la responsabilidad de impartir la materia pudieran sistematizar sus reflexiones sobre los diversos autores que se examinan a lo largo del curso. Por otro lado, nos ha parecido que las limitaciones que, de manera cada vez más ostensible, afectan al saber convencional de la ciencia política exigían concentrar nuestros esfuerzos en la recuperación del riquísimo legado de la tradición de la filosofía política. Con esta publicación pretendemos promover una discusión cada vez más sofisticada sobre los grandes temas de la filosofía política y, muy especialmente, aquellos ligados a la producción teórica de los autores más significativos del período que comienza con la antigüedad clásica en la Atenas del Siglo V antes de Cristo y que culmina con el Renacimiento y el advenimiento de la sociedad burguesa. El retorno a las fuentes clásicas es no sólo necesario sino también imprescindible. Sin embargo, éste no podrá encararse exitosamente si no se repara en el íntimo nexo existente entre teoría, historia y sociedad. Esto implica que nuestro regreso actual a Platón, Aristóteles o Maquiavelo más que una excursión al pasado sea una permanente "ida y vuelta" que resignifique los conceptos y teorías de la tradición clásica a la luz de nuestra coyuntura histórica y los rasgos que caracterizan a las estructuras y procesos del capitalismo "realmente existente" en este turbulento fin de siglo. Se trata, en realidad, de interpelar a una "tradición viva" y no de adentrarse en un cementerio de ideas, o de internarse en el oscuro laberinto donde yacen los restos arqueológicos de la historia del pensamiento político. Interpelarla para, siguiendo una bella metáfora borgeana, hacer que esos textos venerables recuperen su voz y vuelvan a hablar. Necesitamos esas voces porque en los tiempos que corren, dominados por la deletérea combinación de neoliberalismo y posmodernismo, estamos hambrientos de buenas ideas y nobles utopías. Este libro pretende facilitar la recuperación de tales voces y garantizar su resonancia en el espacio público.Índice Prólogo Atilio Boron (CLACSO/UBA) Introducción Atilio Boron (CLACSO/UBA) La filosofía política clásica y la biblioteca de Borges Capítulo I Armando R. Poratti Teoría política y práctica política en Platón Capítulo II Rubén Dri Filosofía política aristotélica Capítulo III Miguel Ángel Rossi Agustín: El pensador político Capítulo IV Rubén Dri Teología política de Santo Tomás Capítulo V Claudia D Amico El Conciliarismo y la teoría ascendente del poder en las postrimerías de la Edad Media Capítulo VI Tomás Várnagy El pensamiento político de Martín Lutero Capítulo VII A. L. Morton La isla de los Santos Capítulo VIII Eduardo Grüner La astucia del león y la fuerza del zorro Apéndice Javier Amadeo y Gonzalo Rojas La categoría de Guerra en el pensamiento platónico-aristotélico Liliana Demirdjian y Sabrina González La triada Paideia, gobernante y legislación en el pensamiento platónic