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695 results, page 1 of 10

Algoritmo robusto de marcas de agua usando similitudes basado en la codificación fractal

PEDRO AARON HERNANDEZ AVALOS (2008)

The explosive growth of the internet in the last years along with the great increase

in computers performance has facilitated the multimedia information exchange, images

particularly. The necessity to protect such images against piracy has become an extremely

important issue. Digital watermarking in images has been used as a way of copyright

protection, although this can be used for different applications.

In this research an algorithm of digital watermarking for 8-bit gray scale images is

developed. This algorithm utilizes a selection of interest points, local searching regions

and similarities embedding, and it is created by a scheme based on fractal codification of

images. Five different approaches have been compared with this new algorithm.

The principal contribution of this work is a decrease in the distortion generated by the

mark embedding in the carrier image, besides a better robustness is achieved compared

with the reference scheme based on fractal code. This new algorithm achieves resistance

to JPEG compression and low pass filter.

El crecimiento desmedido de Internet en los últimos años, junto con el gran incremento

del rendimiento de las computadoras ha facilitado el intercambio de información

multimedia, específicamente imágenes. La necesidad de proteger dichas imágenes en contra

de la piratería se ha vuelto un tema de vital importancia. Las marcas de agua digitales

en imágenes se han utilizado como un medio de protección de derechos de autor, sin embargo

éstas pueden servir para diferentes aplicaciones.

En esta investigación se desarrolla un algoritmo de marcas de agua digitales en

imágenes de ocho bits en escala de grises utilizando selección de puntos característicos,

regiones de búsqueda local e inserciones de similitudes. El algoritmo se crea utilizando el

esquema basado en la codificación fractal de imágenes. Cinco diferentes enfoques fueron

comparados con el nuevo algoritmo.

La contribución principal de esta investigación es que se logró disminuir la distorsión

generada por la incrustación de la marca en la imagen portadora, al mismo tiempo se

alcanzó una mayor robustez que el esquema basado en la codificación fractal, logrando

así un nuevo algoritmo resistente a compresión JPEG y filtrado pasa bajas.

Master thesis

Digital water marking Security of data Image processing Fractals CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA MATEMÁTICAS CIENCIA DE LOS ORDENADORES LENGUAJES DE PROGRAMACIÓN

Formal approaches to textual entailment, polarity, and pronominal anaphora

Jesús Lavalle (2017)

This dissertation is about the interaction of computational semantics and formal methods,

in the aim of finding answers to the question: How does natural language work? On the

last three decades, statistical and machine learning methods have taken command giving

good results in solving very specific tasks. Unfortunately, good results does not mean

good understanding. To know that a ninety per cent of the times I will get certain result

does not mean that I am comprehending the phenomenon under study.

This work shows how three aspects of computational semantics have been solved from

the point of view of formal methods. The main goal was to solve the problem of Recognizing

Textual Entailment, but very soon aspects of polarity computing and anaphora

resolution had to be considered as well. Fortunately, a characterization of the entailments

that can be done with Natural Logic have been found. Also, the computable concept

of polarity has coincided with respect to the algorithms analyzed. About pronominal

anaphora resolution it should be said that a method to solve anaphora in parsing time

has been found, without the need of a logical form. The method can solve Donkey, intra

and intersentencial anaphora.

Esta tesis trata de la interacción entre semántica computacional y métodos formales, con

el objetivo de encontrar respuestas a la pregunta: ¿Cómo funciona el lenguaje natural?

En las ´ ultimas tres décadas, los método estadísticos y de aprendizaje computacional han

dominado y dado buenos resultados al resolver tareas muy especıficas. Desafortunadamente,

buenos resultados no significan buen entendimiento. Saber que el noventa por

ciento de las veces se obtiene cierto resultado no significa que se está comprendiendo el

fenómeno estudiado.

Este trabajo muestra como tres aspectos de la semántica computacional han sido

resueltos desde el punto de vista de los método formales. El principal objetivo era

resolver el problema del Reconocimiento de Implicación Textual, pero muy pronto

también se tuvieron que considerar aspectos como el cálculo de polaridad y la resolución

de anáfora. Afortunadamente, se ha encontrado una caracterización de las implicaciones

que se pueden hacer con Lógica Natural. También, que el concepto computable de

polaridad coincide con respecto a los algoritmos analizados. Sobre la resolución de

anáfora pronominal se debe decir que se ha encontrado un método para resolverla al

momento de hacer el análisis sintáctico, sin necesitar alguna forma lógica. El método

puede resolver anáforas tipo Donkey, intra e intersentenciales.

Doctoral thesis

Natural logic Textual entailment Polarity marking Pronominal anaphora resolution Model checking INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ORDENADORES LENGUAJES DE PROGRAMACIÓN

Surrogate-assisted evolutionary multi-objective full model selection

ALEJANDRO ROSALES PEREZ (2016)

Classification problems have become a popular task in pattern recognition. This is,

perhaps, because they can be used in a number of problems, such as text categorization,

handwriting recognition, etc. This has resulted in a large number of methods. Some

of theses methods, called pre-processing, aim at preparing the data to be used and

others, called learning algorithms, aim at learning a model that maps from the input

data into a category. Additionally, most of them have a set of adjustable parameters,

called hyper-parameters, that directly impact the performance of the learned models.

Hence, when a classification model is constructed, one has to choose among the set of

methods and to configure the corresponding hyper-parameters, which can result in a

decision with a high number of degrees of freedom. The latter could be a shortcoming

when non-expert machine learning users have to face such a problem.

Doctoral thesis

Decision marking Evolution strategy Genetic algorithms Mechasnisms for validation CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA MATEMÁTICAS CIENCIA DE LOS ORDENADORES MODELOS CAUSALES

Artificial Treatment Wetlands: An Alternative to Remove Arsenic Form Water

MARIA TERESA ALARCON HERRERA MARIO ALBERTO OLMOS MARQUEZ MARIA CECILIA VALLES ARAGON IGNACIO MARTIN (2012)

Arsenic can be removed from water through rhizofirtration using phytostabirizing plants. The

performanc e ol Eteocharis macrostachya in artificial or constructed wetlands for arsenic

removal was determined at the prototype level. The concentrations of arsenic in the inlet

water were maintained constant at five levels (0.05, 0.1, 0.2, 0.3 and 0.4 mg/L), and a flow

rate of 130 L/d). Water samples were taken at the inlet and outlet of the wetlands during the

entire testing period. Plant growth was also monitored to determine tolerance at the tested

arsenic concentrations. The prototypes with plants were able to retain an average of 85 to

90% of the arsenic present in feed water containing concentrations in the range of 0.01 to

0.4mg/L. Plant reproduction values were above 116%, and no difference in growth size with

respect to the control was observed. Results show that Eteacharis macrostachya tolerates

high arsenic concentrations in flooded environments and behaves as a rhizofilterer retaining

arsenic from water in artificial wetlands.

Article

Arsenic Eleocharis Macrostachya Water BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA OTRAS ESPECIALIDADES DE LA BIOLOGÍA OTRAS

Application of spheroidal agglomerates of γ-Al2O3 in the fluoride removal from aqueous medium

Aplicación de aglomerados esferoidales de γ-Al2O3 en la remoción de fluoruro de medio acuoso

RAFAEL ROMERO TOLEDO VICTOR RUIZ SANTOYO ULISES ZURITA LUNA GUSTAVO RANGEL PORRAS MERCED MARTINEZ ROSALES (2019)

En el presente estudio se investigó un adsorbente aglomerado esferoidal de γ-Al2O3 obtenido a partir de pseudoboehmita para la eliminación eficaz de fluoruro de un medio acuoso. Las propiedades superficiales se caracterizaron por diversas técnicas: XRD, fisisorción de N2, FE-SEM/EDS, RMN 27Al, adsorción de piridina por FT-IR, PZy tamaño de partícula. Se llevaron a cabo experimentos en lotes y se compararon con una alúmina activada comercial (AA). El proceso se llevó a cabo a pH 5, 7 y 9, a 25 y 35 ºC. Los resultados experimentales indicaron que los aglomerados esferoidales de γ-Al2O3 eliminan hasta 15 mg/g, con una capacidad de adsorción mayor que AA de 13 mg/g, a pH 5, estudiados a 25 y 35 ºC. El proceso de adsorción de F-en γ-Al2O3 y AA siguió la cinética de pseudo-primer orden y la isoterma de Langmuir. Los resultados muestran un adsorbente eficaz para la eliminación de F-.

A spheroidal agglomerate γ-Al2O3 adsorbent obtained from pseudoboehmite for effective removal of fluoride from aqueous medium was investigated in the present study. The surface properties were characterized by several techniques: XRD, physisorption of N2, FE-SEM/EDS, 27Al NMR, FT-IR Pyridine adsorption, PZ and particle size. Batch experiments were conducted and they were compared with a commercial activated alumina (AA). The process was carried out at pH 5, 7, and 9, then at 25 and 35 ºC. Batch experimental results indicated that the spheroidal agglomerates of γ-Al2O3 remove up to 15 mg/g with a higher adsorption capacity than AA of 13 mg/g, at pH 5, studied at 25 and 35 °C. The F−adsorption processes in γ-Al2O3 and AA followed the pseudo-first-order kinetics and the Langmuir isotherm. The results showed an adsorbent effective for removal of F−.

Article

BIOLOGÍA Y QUÍMICA Fluoride γ-Al2O3 Spheroidal agglomerates Adsorbent Water Fluoruro γ-Al2O3 Aglomerados esferoidales Adsorbente Agua

Gestión del agua público-urbana en la cabecera municipal de Tepexi de Rodríguez, Puebla

MARIO MIRANDA TREJO (2013)

Tesis (Maestría en Ciencias, especialista en Estrategias para el Desarrollo Agrícola Regional).- Colegio de Postgraduados, 2013.

El objetivo de la presente investigación fue analizar los procesos de administración y de distribución del agua público-urbana para los usos doméstico, público e industrial, que controla el Ayuntamiento de Tepexi de Rodríguez, Pue. El enfoque teórico utilizado fue el de la Gestión Integral de Recursos Hídricos (GIRH), bajo el cual se evaluaron los procesos de planeación, seguimiento, participación ciudadana; principios de transparencia y equidad en el acceso al agua; así como el papel de actores sociales clave como los empresarios del mármol. Fueron entrevistados 89 habitantes de la localidad con la técnica de encuesta. La muestra (n) se calculó a través de muestreo aleatorio simple, considerando como población (N) el total de viviendas particulares habitadas de la localidad. Además se hicieron entrevistas semiestructuradas a informantes clave. Los resultados muestran que la cobertura del servicio es de 87%, aunque el tiempo de disposición promedio (1-3 horas/semana) obliga a 64.5% de los hogares a comprar agua. Por otra parte, el Ayuntamiento carece de procesos para aplicar los principios de transparencia y equidad en la planificación de obra. 92.2% de la población no ha asistido a talleres de planeación participativa y 89.3% desconoce proyectos próximos sobre agua potable. Uno de los factores principales de la inequidad en el acceso al agua es el papel de los empresarios del mármol, quienes aprovechando su influencia en el Ayuntamiento, ha utilizado las fuentes de abasto público para fines industriales. Se sugiere realizar investigación sobre el impacto de la industria del mármol en la dinámica hidrológica de la región; además, comenzar a incluir en los planes de gestión hídrica del municipio algunos principios de la GIRH, como la participación social y la equidad. _______________ ARRENGEMENTS ON PUBLIC – URBAN WATERS IN THE CABECERA MUNICIPAL DE TEPEXI DE RODRIGUEZ, PUEBLA. ABSTRACT: The main objective of this investigation was to analyze the process of administration and distribution of public – urban water for domestic, public and industrial use, which is controlled by the Ayuntamiento de Tepexi de Rodriguez, Pue. The theoric approach used for this Project was the Integral arrengements of Hydric Resources (GIRH), the evaluation of planning processes, follow up, pupolation participation; transparency principles and equal to water access; as well as the role of social actors such as marble industry entepreneurs were analized under this approach. Eighty-nine local residents were interviewed under the inquiry technic. The data sample (n) was calculated over simple random data colletcion, considering as population (N) the total amount of homes occupied in the comunity. Moreover semi structured interviews were applied to key informants. The results show that the service coverage is 87%, nonetheless, the average time of availability (1-3 hours/week) forces 64.5% of those homes to buy water. On the other hand, there is a lack of mechanisms for applying the transparency and equability principles by the Ayuntamiento in the planification of the Projects. 92.2% of the population have not attended to the participative planification workshops and 89.3% do not know the forhtcoming projects related to potable water. One of the main factors in the inequability in the acces to water is the role of entrepeneurs of marble industry, who, take advantage of their influence over the Ayuntamiento, have used the sources of public coverage for industrial purposes. It is suggested to perform investigation over the impact of marble industry in the hydrolyc dinamycs in the region; furthermore, to start including some GIRH principles in the planification of hydryc arrengements by the comunity such as the social participation and equity.

Master thesis

Agua Equidad Gestión Integral de Recursos Hídricos Transparencia Equity Hydric Resources Integral Arrangements Water Transparency Estrategias para el Desarrollo Agrícola Regional EDAR Maestría CIENCIAS SOCIALES

Exchanged Cations and Water during Reactions in Polypyrrole Macroions from Artificial Muscles

LAURA VALERO CONZUELO TORIBIO FERNÁNDEZ OTERO Jose G Martinez (2014)

The movement of the bilayer (polypyrrole–dodecylbenzenesulfonate/tape) during artificial muscle bending under flow of current square waves was studied in aqueous solutions of chloride salts. During current flow, polypyrrole redox reactions result in variations in the volumes of the films and macroscopic bending: swelling by reduction with expulsion of cations and shrinking by oxidation with the insertion of cations. The described angles follow a linear function, different in each of the studied salts, of the consumed charge: they are faradaic polymeric muscles. The linearity indicates that cations are the only exchanged ions in the studied potential range. By flow of the same specific charge in every electrolyte, different angles were described by the muscle. The charge and the angle allow the number and volume of both the exchanged cations and the water molecules (related to a reference) between the film to be determined, in addition to the electrolyte per unit of charge during the driving reaction. The attained apparent solvation numbers for the exchanged cations were: 0.8, 0.7, 0.6, 0.5, 0.5, 0.4, 0.25, and 0.0 for Na+, Mg2+, La3+, Li+, Ca2+, K+, Rb+, and Cs+, respectively.

Article

Water Reactions Polypyrrole Artificial Muscles BIOLOGÍA Y QUÍMICA

Sistema hidrológico del acuífero Atlixco-Izúcar de Matamoros: tendencias hidrológicas.

HUGO BAUTISTA ATLIXQUEÑO (2020)

Tesis (Maestría en Ciencias, especialista en Estrategias para el Desarrollo Agrícola Regional).- Colegio de Postgraduados, Campus Puebla, 2020.

El acuífero Atlixco – Izúcar de Matamoros abastece de agua a ciudades importantes en el estado de Puebla, como Atlixco e Izúcar de Matamoros, y para la producción agrícola de regadío. Estos dos usos presionan cada día más el recurso hídrico del acuífero. Los registros oficiales no consideran actualmente al acuífero como sobreexplotado, porque no se tiene un estudio que evalúe objetivamente esto. Este estudio tuvo como objetivo conocer la disponibilidad de agua y su intensidad de uso, la variación en los niveles estáticos y la tasa de abatimiento del Acuífero Atlixco - Izúcar de Matamoros. Se obtuvo la información de cuatro estudios no procesados disponibles en la Comisión Nacional del Agua (CONAGUA) de los años 1980, 1996, 1997 y 2003 y se realizó una medición en campo en el año 2019 para 32 pozos de la red de monitoreo de la CONAGUA. Se estimó la intensidad de uso del agua del acuífero, se analizó estadísticamente la información de los pozos con los estadísticos de Brown-Forsythe y de Welch, y con la prueba de comparación de medias de Games-Howell. Para la obtención de planos de igual elevación se utilizó el programa Surfer versión 8. Los resultados mostraron que el crecimiento poblacional es ya un factor que aumenta la demanda de agua del acuífero, se tiene una alta variabilidad espacial importante en los niveles estáticos de los pozos y se tiene un abatimiento del nivel estático medio del acuífero de 0.099 m/año. Se concluyó que el acuífero está en una fase inicial de sobreexplotación del recurso hídrico. _______________ HYDROLOGICAL SYSTEM OF THE ATLIXCO - IZUCAR DE MATAMOROS AQUIFER: HYDROLOGICAL TRENDS. ABSTRACT: The Atlixco - Izúcar de Matamoros aquifer supplies water to important cities in the state of Puebla, such as Atlixco and Izúcar de Matamoros, and for irrigated agricultural production. These two uses cause water stress in the aquifer. Official records do not currently consider that the aquifer is experiencing groundwater depletion, but this has not been objectively evaluated. The aim of this study was to know the availability of water and its intensity of use, the variation in the static levels and the abatement rate of the Atlixco - Izúcar de Matamoros Aquifer. Information from four unprocessed studies available from the National Water Commission (CONAGUA), from the years 1980, 1996, 1997 and 2003, was obtained, and a field measurement was carried out in 2019 for 32 wells of the monitoring network of the CONAGUA. The intensity of aquifer water use was estimated, and the information from the wells was statistically analyzed with the Brown-Forsythe and Welch statistics, and with the Games-Howell mean comparison test. The Surfer version 8 program was used to obtain maps of the same elevation. It was found that human population growth is already a factor that increases the water demand of the aquifer, there is a high significant spatial variability in the static levels of the wells, and that the average static level of the aquifer is declining at a rate of 0.099 m/year. It was concluded that the aquifer is in an initial phase of groundwater depletion.

Master thesis

Agua Estático Nivel Sobreexplotación Water Static Level Depletion Aquifer Estrategias para el Desarrollo Agrícola Regional Maestría EDAR CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO HIDROLOGÍA AGUAS SUBTERRÁNEAS

H2Ti3O7 nanotubes decorated with silver nanoparticles for photocatalytic degradation of atenolol

MARIANA HINOJOSA REYES ROBERTO CAMPOSECO SOLIS FACUNDO RUIZ NEREYDA NIÑO MARTINEZ VICENTE RODRIGUEZ GONZALEZ MARTHA EUGENIA COMPEAN JASSO (2017)

"The photocatalytic degradation/adsorption process of the β-blocker atenolol (ATL) under UV irradiation is described using two types of silver decorated catalysts: silver/titania and silver/titanates. The silver ions were reduced on the surface of TiO2-P25-Degussa using gallic acid. Silver/titanates were prepared by a microwave-assisted hydrothermal method using the silver/titania as the starting material to obtain the hydrogen titanate (H2Ti3O7) structure with tubular morphology. These materials were characterized by X-ray diffraction, UV-Vis spectroscopy, N2 physisorption, temperature programmed reduction, TEM, and FTIR spectroscopy. During the photocatalytic process, the ATL molecules were completely converted to amino-diol byproducts. It is the first time that these materials have been applied during the photocatalytic process in the degradation of pharmaceuticals products. The success of the silver nanoparticles (2 nm) consists of the homogeneous distribution over the surface of titanate nanotubes inhibiting the hole/electron recombination promoting the oxidation process. The Ag@H2Ti3O7 with a concentration of silver as 1.0% shows the highest adsorption/degradation of ATL than the Ag@TiO2 and the P25-Degussa. The great performance in the reuse test consists in the strong attachment of the silver nanoparticles on the titanium surface that inhibits the silver lixiviation during the photocatalytic tests."

Article

TiO2 Pharmaceuticals Arrays Water INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS

Screening of commercial sorbents for the removal of phosphates from water and modeling by molecular simulation

LORENA DELGADILLO VELASCO VIRGINIA HERNANDEZ MONTOYA NORMA AUREA RANGEL VAZQUEZ FRANCISCO JAVIER CERVANTES CARRILLO Miguel A Montes Morán MA. DEL ROSARIO MORENO VIRGEN (2018)

"Eight commercial sorbents of different origin and nature were studied in the present work for the removal of phosphate from water using synthetic solutions and a wastewater from an anodizing company. The materials included activated carbons, bone char, catalytic carbon, natural silica, natural zeolite, a manganese(II) oxide composite and iron(III) hydroxide. These materials were characterized with different analytical techniques such as nitrogen adsorption isotherms at ?196?°C, FT-IR spectroscopy, SEM/EDX analysis and X-ray diffraction. The adsorption studies were performed in batch systems. Iron(III) hydroxide was found the best sorbent, showing a maximum adsorption capacity of 193.75?mg/g at pH?7 in contrast with natural zeolite and silica, which registered very low adsorption values (2.92 and 4.17?mg/g, respectively). According to molecular simulation studies, the adsorption of phosphates from water on iron(III) hydroxide allowed the formation of the complex ?FePO4H2, with a Gibbs free energy of ?21.38?kcal/mol, showing that it is possible to recover the phosphates and reuse them later. The adsorbed amount of phosphates on iron(III) hydroxide using synthetic solutions and the industrial wastewater was similar thus suggesting that iron(III) hydroxide is a selective sorbent for the removal of phosphates."

Article

Phosphates Sorbents Water Molecular simulation BIOLOGÍA Y QUÍMICA QUÍMICA QUÍMICA