Search results for "pattern"

Arrays in rays: terminal addition in echinoderms and its correlation with gene expression

2005

Summary The echinoderms are deuterostomes that superimpose radial symmetry upon bilateral larval morphology. Consequently, they are not the first animals that come to mind when the concepts of segmentation and terminal addition are being discussed. However, it has long been recognized that echinoderms have serial elements along their radii formed in accordance with the ocular plate rule (OPR). The OPR is a special case of terminal growth, forming elements of the ambulacra that define the rays in echinoderms. New elements are added at the terminus of the ray, which may or may not be marked by a calcified element called the terminal plate (the “ocular” of sea urchins). The OPR operates in eve…

An adaptive-PCA algorithm for reflectance estimation from color images

2008

This paper deals with the problem of spectral reflectance estimation from color camera outputs. Because the reconstruction of such functions is an inverse problem, stabilizing the reconstruction process is highly desirable. One way to do this is to decompose reflectance function on a basis functions like PCA. The present work proposes an algorithm making PCA adaptive in reflectance estimation from a color camera output. We propose to adapt the PCA basis derivation by selecting, for each sample, the more relevant elements from the training set elements. The adaptivity criterion is achieved by a likelihood measurement. Finally, the spectral reflectance estimation results are evaluated with th…

Reflectance-based surface saliency

2017

In this paper, we propose an original methodology allowing the computation of the saliency maps for high dimensional RTI data (Reflectance Transformation Imaging). Unlike most of the classical methods, our approach aims at devising an intrinsic visual saliency of the surface, independent of the sensor (image) and the geometry of the scene (light-object-camera). From RTI data, we use the DMD (Discrete Modal Decomposition) technique for the angular reflectance reconstruction, which we extend by a new transformation on the modal basis enabling a rotation-invariant representation of reconstructed reflectances. This orientation-invariance of the resulting reflectance shapes fosters a robust esti…

Aplicación del Estimador de Parámetros de Segmentación por Media-desplazada (EPSM) a las imágenes de satélite de muy alta resolución espacial: Tetuán…

2015

<p>La segmentación de imágenes constituye un paso crucial en el Análisis de Imágenes Basado en Objetos (AIBO). Combinando distintos valores de los parámetros de entrada de los algoritmos de segmentación se obtienen diferentes resultados. En general, los parámetros óptimos seleccionados se determinan mediante interpretación visual; por lo tanto, la definición de las combinaciones óptimas es una tarea considerablemente difícil. En la presente investigación, se propone una herramienta analítica que denominamos Estimador de Parámetros de Segmentación por Media-desplazada (EPSM) aplicada a la selección automatizada de los valores de los parámetros de segmentación en las imágenes de satélit…

On Information Processing in the Cat’s Visual Cortex

1986

We assume that the visual system serves for orientation in space, recognition of objects and the interpretation of scenes and scene sequences. This task breaks up into a series of partially interdependent subproblems which are solved by some 13–15 usually retinotopically organized areas. So far it has not been possible to correlate functions and areas unequivocally. One reason for this could be the inadequacy of the questions posed as a basis for experiments. However, we think it more likely that correlating a function with an area is, as a rule, inadmissible since the degree of the coupling in the whole system does not permit a simple divsion. Rather the type and degree of coupling determi…

Feature creation as a byproduct of attentional processing

1998

Attributing the creation of new features to categorization requirements implies that the exemplars displayed are correctly assigned to their category. This constraint limits the scope of Schyns et al.'s proposal to supervised learning. We present data suggesting that this constraint is unwarranted and we argue that feature creation is better thought of as a byproduct of the attentional, on-line processing of incoming information.

Application of T-pattern analysis in the study of the organization of behavior

2020

Application of multivariate t-pattern analysis in the study of social interactions in rats

2013

A basic tenet in the realm of modern behavioral sciences is that behavior consists of patterns in time. For this reason, investigations of behavior deal with sequences that are not easily perceivable by the unaided observer. This problem calls for improved means of detection, data handling and analysis. This review focuses on the analysis of the temporal structure of behavior carried out by means of a multivariate approach known as T-pattern analysis. Using this technique, recurring sequences of behavioral events, usually hard to detect, can be unveiled and carefully described. T-pattern analysis has been successfully applied in the study of various aspects of human or animal behavior such …

T-Patterns in the study of movement disorders

2019

An intrinsic feature of behaviour orbits around its temporal dimension consisting of patterns in time: investigations on behaviour necessarily deal with sequences often impossible to be perceived by the human eye [Eibl-Eibesfeldt I. Ethology: the biology of behavior. New York: Holt, Rinehart and Winston. 1970]. Thus, the study of behavioural sequencing in terms of higher order arrangements, how the sequences are structured and, importantly, their analysis in normal subjects and in subjects affected by specific movement/behavioural disorders may represent a stimulating but challenging task. By means of T-Pattern analysis (TPA), it is possible to study these hidden features of behaviour and, …

Recurring sequences of multimodal non-verbal and verbal communication during a human psycho-social stress test: A temporal pattern analysis

2020

Abstract Background The Trier Social Stress Test (TSST) is a widely used protocol to study human psycho-social stress responses. Quantitative reports of non-verbal behaviors have been carried out by means of the Ethological Coding System for Interviews (ECSI). However, no data have described whether and how non-verbal and verbal behaviors take part in the composition of multimodal sequences of communication during the test. Method Five non-verbal ECSI categories and four verbal behaviors related with communication were included in the Ethogram. A focal sampling was employed to ensure a high temporal resolution of the behavioral annotation. T-Pattern Analysis was employed to detect statistic…