Investigating shape representation in area V4 with HMAX: Orientation and Grating selectivities

The question of how shape is represented is of central interest to understanding visual processing in cortex. While tuning properties of the cells in early part of the ventral visual stream, thought to be responsible for object recognition in the primate, are comparatively well understood, several different theories have been proposed regarding tuning in higher visual areas, such as V4. We used the model of object recognition in cortex presented by Riesenhuber and Poggio (1999), where more complex shape tuning in higher layers is the result of combining afferent inputs tuned to simpler features, and compared the tuning properties of model units in intermediate layers to those of V4 neurons from the literature. In particular, we investigated the issue of shape representation in visual area V1 and V4 using oriented bars and various types of gratings (polar, hyperbolic, and Cartesian), as used in several physiology experiments. Our computational model was able to reproduce several physiological findings, such as the broadening distribution of the orientation bandwidths and the emergence of a bias toward non-Cartesian stimuli. Interestingly, the simulation results suggest that some V4 neurons receive input from afferents with spatially separated receptive fields, leading to experimentally testable predictions. However, the simulations also show that the stimulus set of Cartesian and non-Cartesian gratings is not sufficiently complex to probe shape tuning in higher areas, necessitating the use of more complex stimulus sets.

Fictional characters' emotional state representation : What is its degree of specificity?

Resumen tomado de la publicaci??n

Modeling and Classifying Breast Tissue Density in Mammograms

We present a new approach to model and classify breast parenchymal tissue. Given a mammogram, first, we will discover the distribution of the different tissue densities in an unsupervised manner, and second, we will use this tissue distribution to perform the classification. We achieve this using a classifier based on local descriptors and probabilistic Latent Semantic Analysis (pLSA), a generative model from the statistical text literature. We studied the influence of different descriptors like texture and SIFT features at the classification stage showing that textons outperform SIFT in all cases. Moreover we demonstrate that pLSA automatically extracts meaningful latent aspects generating a compact tissue representation based on their densities, useful for discriminating on mammogram classification. We show the results of tissue classification over the MIAS and DDSM datasets. We compare our method with approaches that classified these same datasets showing a better performance of our proposal

Scene Classification Using a Hybrid Generative/Discriminative Approach

We investigate whether dimensionality reduction using a latent generative model is beneficial for the task of weakly supervised scene classification. In detail, we are given a set of labeled images of scenes (for example, coast, forest, city, river, etc.), and our objective is to classify a new image into one of these categories. Our approach consists of first discovering latent ";topics"; using probabilistic Latent Semantic Analysis (pLSA), a generative model from the statistical text literature here applied to a bag of visual words representation for each image, and subsequently, training a multiway classifier on the topic distribution vector for each image. We compare this approach to that of representing each image by a bag of visual words vector directly and training a multiway classifier on these vectors. To this end, we introduce a novel vocabulary using dense color SIFT descriptors and then investigate the classification performance under changes in the size of the visual vocabulary, the number of latent topics learned, and the type of discriminative classifier used (k-nearest neighbor or SVM). We achieve superior classification performance to recent publications that have used a bag of visual word representation, in all cases, using the authors' own data sets and testing protocols. We also investigate the gain in adding spatial information. We show applications to image retrieval with relevance feedback and to scene classification in videos

Large-Area Photo-Mosaics Using Global Alignment and Navigation Data

Seafloor imagery is a rich source of data for the study of biological and geological processes. Among several applications, still images of the ocean floor can be used to build image composites referred to as photo-mosaics. Photo-mosaics provide a wide-area visual representation of the benthos, and enable applications as diverse as geological surveys, mapping and detection of temporal changes in the morphology of biodiversity. We present an approach for creating globally aligned photo-mosaics using 3D position estimates provided by navigation sensors available in deep water surveys. Without image registration, such navigation data does not provide enough accuracy to produce useful composite images. Results from a challenging data set of the Lucky Strike vent field at the Mid Atlantic Ridge are reported

Unsupervised active regions for multiresolution image segmentation

An unsupervised approach to image segmentation which fuses region and boundary information is presented. The proposed approach takes advantage of the combined use of 3 different strategies: the guidance of seed placement, the control of decision criterion, and the boundary refinement. The new algorithm uses the boundary information to initialize a set of active regions which compete for the pixels in order to segment the whole image. The method is implemented on a multiresolution representation which ensures noise robustness as well as computation efficiency. The accuracy of the segmentation results has been proven through an objective comparative evaluation of the method

Response to instruction, English language learners and disproportionate representation : The role of assessment

Resumen tomado de la publicaci??n

Expert supervision based on cases

The paper focuses on taking advantage of large amounts of data that are systematically stored in plants (by means of SCADA systems), but not exploited enough in order to achieve supervisory goals (fault detection, diagnosis and reconfiguration). The methodology of case base reasoning (CBR) is proposed to perform supervisory tasks in industrial processes by re-using the stored data. The goal is to take advantage of experiences, registered in a suitable structure as cam, avoiding the tedious task of knowledge acquisition and representation needed by other reasoning techniques as expert systems. An outlook of CBR terminology and basic concepts are presented. The adaptation of CBR in performing expert supervisory tasks, taking into account the particularities and difficulties derived from dynamic systems, is discussed. A special interest is focused in proposing a general case definition suitable for supervisory tasks. Finally, this structure and the whole methodology is tested in a application example for monitoring a real drier chamber

Representation of Structure

Organic Molecules: Depiction of Structure - The Basics. Powerpoint presentation of A Level revision material for 1st year undergraduates written by Jeremy Hinks, School of Chemistry in 2002.

How to convert a Word 2003 document into HTML

How to convert Word 2003 into HTML with associated resources folder. Includes examples showing how to create simple navigation within the document.

Anàlisi del document recopilatori de dades referides a la cobertura de la necessitat d'alimentació a Mallorca 2009. 'Análisis del documento recopilatorio de datos referidos a la cobertura de la necesidad de alimentación en Mallorca 2009'.

Resumen tomado del autor

Análisis empresarial comparado de las mejores prácticas en la internacionalización del sector cosméticos

En el presente trabajo se hace un análisis empresarial comparado de las mejores prácticas en la internacionalización del sector cosméticos a través del método de casos de estudio, en el que se analizan tres compañías de diferentes países latinoamericanos, Natura de Brasil, Belcorp de Perú, y Laboratorio de cosméticos VOGUE como la cuota colombiana, se define y enmarca el sector cosméticos para darle un contexto al trabajo y seguido a esto se estudian las empresas escogidas teniendo en cuenta cual ha sido su proceso de internacionalización y cuál es su posición actual en el mundo, así como algunas cifras que reflejan su salud financiera actual. Lo anterior como cuerpo y base para el levantamiento del panorama competitivo en el cual se realiza la conocida T, adaptándola para lograr el objetivo principal del presente documento: la identificación de las mejores prácticas por medio de la comparación de casos empresariales. Así pues, del Panorama competitivo, se obtienen las principales variables a considerar por parte de las empresas a la hora de emprender el camino hacia la internacionalización, así como se extraerá la aplicación de las teorías en este sentido. Lo que a su vez arrojara cuales son las practicas más comunes para abarcar exitosamente los mercados internacionales. A lo largo del trabajo se ilustrará tanto la posición internacional de las compañías como la ruta emprendida por cada una de estas para llegar a posicionarse en dichos países. Así mismo se dispondrá de una tabla comparativa de la aplicación de las teorías, esto con el fin de darle más claridad al lector sobre los resultados obtenidos tras la aplicación de la herramienta –Panorama competitivo. Con lo anterior, y a manera de conclusión tras la comparación de métodos y estrategias de las 3 compañías estudiadas, se definirán las mejores prácticas del sector, que se enmarcan en gran medida por las tendencias del sector – hacia lo natural, por medio de canales de venta directa, como Modelo principal Uppsala y con cada día una mayor participación de la teoría de redes a la hora de iniciar el arduo pero necesario camino de la internacionalización.

L'ús del document arqueològic en l'ensenyament de la prehistòria. 'El uso del documento arqueológico en la enseñanza de la prehistoria'.

Resumen tomado de la publicación

L'escola narrada : el diari d'una mestra com a document de reflexió sobre la pràctica. 'La escuela narrada : el diario de una maestra como documento de reflexión sobre la práctica'.

Resumen tomado de la propia revista