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Reference Fields Analysis of a Markov Random Field Model to Improve Image Segmentation

ERIKA DANAE LOPEZ ESPINOZA LEOPOLDO ALTAMIRANO ROBLES (2010)

Markov random field (MRF) models, parameters such as internal and external reference fields are used. In this paper, the influence of these parameters in the segmentation quality is analyzed, and it is shown that, for image segmentation, a MRF model with a priori energy function defined by means of non-homogeneous internal and external field has better segmentation quality than a MRF model defined only by a homogeneous internal reference field. An analysis of the MRF models in terms of segmentation quality, computational time and tests of statistical significance is done. Significance tests showed that the segmentations obtained with MRF model defined by means of non-homogeneous reference fields are significant at levels of 85% and 75%.

Article

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA Image segmentation unsupervised segmentation Markov random field non-homogeneous random field

Reference fields analysis of a Markov random field model to improve image segmentation

ERIKA DANAE LOPEZ ESPINOZA LEOPOLDO ALTAMIRANO ROBLES (2010)

In Markov random field (MRF) models, parameters such as internal and external reference fields are used. In this paper, the influence of these parameters in the segmentation quality is analyzed, and it is shown that, for image segmentation, a MRF model with a priori energy function defined by means of non-homogeneous internal and external field has better segmentation quality than a MRF model defined only by a homogeneous internal reference field. An analysis of the MRF models in terms of segmentation quality, computational time and tests of statistical significance is done. Significance tests showed that the segmentations obtained with MRF model defined by means of non-homogeneous reference fields are significant at levels of 85% and 75%.

Article

Image segmentation Unsupervised segmentation Markov random field Non-homogeneous random field CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA MATEMÁTICAS CIENCIA DE LOS ORDENADORES CIENCIA DE LOS ORDENADORES

Reference Fields Analysis of a Markov Random Field Model to Improve Image Segmentation

ERIKA DANAE LOPEZ ESPINOZA LEOPOLDO ALTAMIRANO ROBLES (2010)

Markov random field (MRF) models, parameters such as internal and external reference fields are used. In this paper, the influence of these parameters in the segmentation quality is analyzed, and it is shown that, for image segmentation, a MRF model with a priori energy function defined by means of non-homogeneous internal and external field has better segmentation quality than a MRF model defined only by a homogeneous internal reference field. An analysis of the MRF models in terms of segmentation quality, computational time and tests of statistical significance is done. Significance tests showed that the segmentations obtained with MRF model defined by means of non-homogeneous reference fields are significant at levels of 85% and 75%.

Article

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA Image segmentation unsupervised segmentation Markov random field non-homogeneous random field

Using a Markov random field for image Re-ranking based on visual and textual features

Utilizando un campo aleatorio de Markov para el reordenamiento de imágenes basado en atributos Visuales y textuales

Ricardo Omar Chavez García Manuel Montes y Gómez Luis Enrique Sucar Succar (2011)

We propose a novel method to re-order the list of images returned by an image retrieval system (IRS). The method combines the original order obtained by the IRS, the similarity between images obtained with visual and textual features, and a relevance feedback approach, all of them with the purpose of separating relevant from irrelevant images, and thus, obtaining a more appropriate order. The method is based on a Markov random field (MRF) model, in which each image in the list is represented as a random variable that could be relevant or irrelevant. The energy function proposed for the MRF combines two factors: the similarity between the images in the list (internal similarity); and information obtained from the original order and the similarity of each image with the query (external similarity). Experiments were conducted with resources from the Image CLEF 2008 forum for the photo retrieval track, taking into account textual and visual features. The results show that the proposed method improves, according to the MAP measure, the order of the original list up to 63% (in the textual case) and up to 55% (in the visual case); and suggest future work using a combination of both kind of features.

En este trabajo proponemos un método novedoso para re-ordenar una lista de imágenes recuperadas por un sistema de recuperación de imágenes (SRI). El método combina el orden original obtenido por el SRI, la similitud entre imágenes, obtenida con las características visuales y textuales, y un enfoque de retroalimentación de relevancia, todos ellos con el propósito de separar las imágenes relevantes de las irrelevantes, y así, obtener un orden más apropiado. El método está basado en el modelo de un campo aleatorio de Markov (CAM), en el que cada imagen en la lista fue representada como una variable aleatoria con dos posibles valores: relevante o irrelevante. La función de energía propuesta para el campo aleatorio de Markov combina dos factores: la similitud entre imágenes en la lista (similitud interna); y la información obtenida del orden original y la similitud de cada imagen con la consulta (similitud externa). Los experimentos fueron realizados con los recursos del foro Image CLEF 2008 para la tarea de recuperación de fotografías, tomando en cuenta los atributos textuales y visuales. Los resultados mostraron que el método propuesto mejora, de acuerdo con la medida MAP, el orden de la lista original hasta en un 63% (en el caso textual) y hasta un 55% (en el caso visual); y sugieren como trabajo a futuro el utilizar una combinación de ambos tipos de atributos.

Article

Image Re-ranking Image Retrieval Markov Random Field Relevance Feedback Re-ordenamiento de Imágenes Recuperación de Imágenes Campos Aleatorios de Markov Retroalimentación de Relevancia CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA MATEMÁTICAS CIENCIA DE LOS ORDENADORES CIENCIA DE LOS ORDENADORES

Bayesian entropy estimation applied to non-gaussian robust image segmentation

JOSE ISMAEL DE LA ROSA VARGAS (2012)

We introduce a new approach for robust image segmentation combining two strategies within a Bayesian framework. The first one is to use a Markov random field (MRF) which allows to introduce prior information with the purpose of image edges preservation. The second strategy comes from the fact that the probability density function (pdf) of the likelihood function is non-Gaussian or unknown, so it should be approximated by an estimated version, which is obtained by using the classical non-parametric or kernel density estimation. This lead us to the definition of a new maximum a posteriori (MAP) estimator based on the minimization of the entropy of the estimated pdf of the likelihood function and the MRF at the same time, named MAP entropy estimator (MAPEE). Some experiments were made for different kind of images degraded with impulsive noise (salt & pepper) and the segmentation results are very satisfactory and promising.

Producción Científica de la Universidad Autónoma de Zacatecas UAZ

Conference paper

INGENIERÍA Y TECNOLOGÍA Robust filtering Markov random field (MRF), Bayes estimation Bayes estimation

Ideales basados en gráficas y sus invariantes cardinales

José de Jesús Pelayo Gómez (2014)

Instituto de Física y Matemáticas. Facultad de Ciencias Físico Matemáticas. Unidad Morelia del Instituto de Matemáticas de la UNAM. Programa Conjunto de Maestría en Matemáticas

The aim of this work is studding some ideals based on graphs, specially the ideals Gaff, Gc and the random graph ideal. Also we want to say something about its cardinal invariants. It’s spected that the reader has knowledge of descriptive set theory, graph theory (although this is not necessary) and cardinal invariants like b, r y s. You can find about it in [7] and [8].

La idea de este trabajo es estudiar algunos ideales basados en gráficas, en particular lo ideales Gfc, Gc y el ideal de la gráfica aleatoria, además decir algo acerca de sus invariantes cardinales. Se espera que el lector tenga conocimientos básicos de teoría descriptiva de conjuntos, una referencia sobre el tema la puede encontrar en [7]; tenga algunos conocimientos acerca de teoría de graficas (aunque esto no es tan necesario, como referencia puede consultar [8]) y conozca algunos invariantes cardinales del continuo, tales como b, r y s.

Master thesis

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA IFM-M-2014-0096 Tesina Random Invariante

Enhanced tunneling through nonstationary barriers

JUAN PEDRO PALOMARES BAEZ BORIS IVLEV JOSE LUIS RODRIGUEZ LOPEZ (2007)

"Quantum tunneling through a nonstationary barrier is studied analytically and by a direct numerical solution of Schrödinger equation. Both methods are in agreement and say that the main features of the phenomenon can be described in terms of classical trajectories which are solutions of Newton’s equation in complex time. The probability of tunneling is governed by analytical properties of a time-dependent perturbation and the classical trajectory in the plane of complex time. Some preliminary numerical calculations of Euclidean resonance (an easy penetration through a classical nonstationary barrier due to an underbarrier interference) are presented."

Article

Time Approximation Field Decay Wave CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA

Análisis de compuestos fenólicos totales, L-Dopa y actividad antioxidante en dos métodos de secado de Vicia faba L.

MARLY ORTIZ LÓPEZ (2019)

Tesis (Maestría en Ciencias, especialista en Estrategias para el Desarrollo Agrícola Regional).- Colegio de Postgraduados, Campus Puebla, 2019.

El haba (Vicia faba L.) es una fuente rica de compuestos fenólicos y L-DOPA, se sabe que el contenido de estos componentes bioactivos puede verse afectado por condiciones como: siembra, etapa de desarrollo de la planta, tejido, variedad y el método de proceso de secado. El estudio consistió de dos experimentos, el primero tuvo como objetivo establecer una metodología cualitativa para mostrar la presencia de L-DOPA y detectar la mejor condición de crecimiento de las plántulas para promover una cantidad mayor de metabolitos secundarios, mediante el análisis del contenido de compuestos fenólicos totales (CFT) en plántulas de 10, 15 y 20 días después de la emergencia (DDE) de un cultivar de haba, secadas por estufa (SE) en aire forzado a 38 °C y por liofilización (LIOF) a –80 °C y sembradas en invernadero y campo. El segundo experimento tuvo como objetivo analizar la influencia de los dos métodos de secado (SE y LIOF), previamente probados sobre los CFT, L-DOPA y actividad antioxidante frente al radical DPPH (CI50) en plántulas de 10, 15 y 20 DDE y en las flores de dos variedades de haba: Diamante y Zac-22 sembradas en campo. Los CFT se analizaron por un método colorimétrico, la detección de L-DOPA se realizó por cromatografía en capa fina, y la cuantificación por cromatografía líquida de alta resolución (HPLC). La capacidad antioxidante de analizó frente al radical DPPH/CI50. Del primer experimento se observó un contenido mayor de CFT en las plantas de 10 DDE (80.24 mg•g-1 MS) y 15 DDE (72.08 mg•g-1 MS) sembradas en campo y secadas por el método de LIOF. En el segundo experimento las concentraciones más altas de CFT (145.67 mg•g-1 MS) y de L-DOPA (93.39 mg•g-1 MS) se obtuvieron en las muestras procesadas por SE. Las flores con SE en la variedad Diamante (90.43 mg•g-1 MS) y Zac-22 (96.36 mg•g-1 MS) mostraron los valores mayores de L-DOPA. La actividad antioxidante se conservó mejor por el método de SE en las plántulas, en las flores no se detectó variación. La condición de crecimiento en campo promovió una cantidad mayor de CFT, el SE tuvo una mejor influencia en preservar los CFT, L-Dopa y la actividad antioxidante en las plántulas y flores de Vicia faba L. _______________ ANALYSIS OF TOTAL PHENOLIC COMPOUNDS, L-DOPA AND ANTIOXIDANT ACTIVITY IN TWO DRYING METHODS OF Vicia faba L. ABSTRACT: The faba bean (Vicia faba L.) is a rich source of phenolic compounds and L-DOPA, it is known that the content of these bioactive components may be affected by growing conditions, developmental stage of the plant, tissue, variety and drying method. The study consisted of two experiments: the first aimed to establish a qualitative methodology to show the presence of L-DOPA and detect the best growth condition of the seedlings, in order to promote a greater quantity of secondary metabolites. By means of the analysis of the content of total phenolic compounds (TPC) in seedlings of 10, 15 and 20 days after the emergence (DAE) of a broad bean cultivar, dried by forced air oven (DO) at 38 °C and by lyophilization (LIOF) at -80 °C and seeded in greenhouse and field. The objective of the second experiment was to analyze the influence of the two drying methods (DO and LIOF), previously tested on TPC, L-DOPA and antioxidant activity against the DPPH radical (IC50) in seedlings of 10, 15 and 20 DAE and in the flowers of two varieties of faba bean: Diamante and Zac-22 sown in the field. The TPC were analyzed by a colorimetric method, detection of L-DOPA was performed by thin layer chromatography and quantification by high performance liquid chromatography (HPLC). The antioxidant capacity was analyzed against the DPPH/IC50 radical. From the first experiment, a higher TPC content was observed in the plants of 10 DAE (80.24 mgˑg-1 MS) and 15 DAE (72.08 mgˑg-1 MS) sown in the field and dried by LIOF. In the second experiment, the highest concentrations of TPC (145.67 mgˑg-1 MS) and L-DOPA (93.39 mgˑg-1 MS) were obtained in the samples processed by DO. The flowers processed by DO in the variety Diamante (90.43 mgˑg-1 MS) and Zac-22 (96.36 mgˑg-1 MS) showed the highest values of L-DOPA. The antioxidant activity was better preserved by the DO method in the seedlings, but in the flowers, no variation was detected. The growth conditions in the field promoted a greater amount of TPC, the DO had a better influence in preserving the TPC, L-Dopa and the antioxidant activity in the seedlings and flowers of Vicia faba L.

Master thesis

Vicia faba L. Campo Invernadero Secado Fitoquímicos CI50 Field Greenhouse Drying Phytochemicals IC50 EDAR Estrategias para el Desarrollo Agrícola Regional Maestría CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGRARIAS AGRONOMÍA NUTRICIÓN VEGETAL