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Hierarchical Cores Applied to an Analysis of Use of Technologies Level among Higher Education Students in Mexico

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Open Journal of Statistics 2014年第10期4卷 837-850页

作者： francisco casanova-del-angel SEPI-ESIA Unit ALM of the Polytechnic Institute National Mexico City Mexico

Using the theory shown, Cores Optimal Criterion, three factors from which hierarchical aggregation of variables under study was built, as well as hierarchical cores showing the level of use of pocket computing technologies by students. The principal factors influencing the level of use of pocket computing technologies among higher education students are analyzed from a theoretical aggregation development based on hierarchical cores. The theoretical part includes the development of an algorithm used to obtain an interesting class or partition from a hierarchy. The experimental work carried out included design, preparation and application of a questionnaire to higher education students in Mexico. A pilot test was carried out to check timing and repetition of questions. Data was recorded, validated, and mathematically and statistically analyzed.

关键词： Use of Technologies Higher Education Questionnaire Pocket Calculators Hierarchical Cores

Fractal Geometry of a Dendrogram

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Journal of Mathematics and System Science 2014年第1期4卷 14-18页

作者： francisco casanova-del-angel Superior School of Engineering and Architecture. National Polytechnic Institue.Mexico City. 07320 M~xico.

The fractal structure shown by the poligonal created by unions of middle points of vertices, nodes or peaks of dendograms terminal classes is presented. Its generating fractal, the details of its construction, and the way to measure its segments are defined; its property of inverted scale, the type of meshing, its property of axial symmetry and a theorem on transformation of linear affinity are considered. This is exemplified by means of one application with real data.

关键词： Dendrogram fractal axial symmetry engenderer.

Fractal Cracks Propagation in Aluminum

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Modeling and Numerical Simulation of Material Science 2013年第3期3卷 23-32页

作者： francisco casanova del angel Jaime Retama Velasco IINGEN Universidad Nacional Autónoma de México Mexico City Mexico SEPI ESIA Instituto Politécnico Nacional Mexico City Mexico

The theory of the fractal structure characterizing propagation of a crack through identification of its generator is presented. It’s generating fractal, the peculiarities of its construction and the way to measure its segments are defined, and a theorem on the inverse scale property of such and other of the axial symmetry property of the fractal generator are presented and demonstrated. The theory is applied on 6061-T6 aluminum samples, using SENB probes. Direction of crack propagation and its fractal dimension are calculated numerically. Results obtained from modeling the direction of crack propagation through mechanics of elastic linear fracture and the one proposed here, called geometrical fractal fracture, are compared, thus developing the mirror case.

关键词： Geometrical Fractal Fracture Crack Propagation Aluminum Stress Intensity Factor Fractal Dimension

Fracture Mechanics on Aluminum Specimens

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World Journal of Mechanics 2021年第12期11卷 237-257页

作者： Juan Jose Mejia Briseno francisco casanova-del-angel Tecnologico Nacional de Mexico Instituto Tecnol&#243 gico de Pachuca Pachuca Estado de Hidalgo Mexico Seccion de Estudios de Posgrado e Investigació n Escuela Superior de Ingenier&#237 a y Arquitectura Unit. Adolfo Lopez Mateos Instituto Polit&#233 cnico Nacional Ciudad de M&#233 xico Mexico

ASTM standards for A413 aluminum alloy specimen assays were used based on standard E399-05, with a minimum requirement of three specimens. Linear elastic fracture mechanic testing was carried out in plane strain conditions and fracture toughness of the tested aluminum, critical stress intensity factor was determined. Four specimens with the selected geometry were made, since in the pre-cracking process a non-acceptable propagation of crack may be present, i.e., the crack does not propagate in a parabolic manner. In like manner, the Type SE (B) specimen, that is, a beam subject to bending under a monotonic load, was used. Stress efforts were induced in the experiment, the load mode for such experiments is mode I, determining a temporary value of the KQ apparent stress intensity factor. When such value complies with the validity criteria of E-399 Standard, it becomes the stress intensity factor KIC of material.

关键词： Metallography A413 Aluminum Fracture Mechanics Stress Efforts Fractography

Metallography of an Underground Oil Pipeline

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Open Journal of Metal 2018年第3期8卷 35-54页

作者： francisco casanova-del-angel Alejandra Córdova-Castillo Sección de Estudios de Posgrado e Investigación Escuela Superior de Ingeniería y Arquitectura Unidad Profesional Adolfo López Mateos Instituto Politécnico Nacional Mexico City Mexico

The purpose of this article is to show a metallographic analysis of an underground pipeline taken out of operation upon failure. The pipeline had an 8.89 cm (3.5”) diameter and a 7 mm thickness. The study was based on a 45 cm long pipe sample, visibly and entirely corroded, with a fish-mouth crack along its length. The work contributes to finding new ways to prevent structural failure, which has high-impact consequences from the point of view of production, damage to property, pollution, and risks to human live. Through this analysis the knowledge on behavior of failures in terrestrial ducts has been extended. Development of the research included metallographic, chemical, and mechanical tests on the sample in order to know the composition of the material, its strength and its physical conditions upon taking it out of operation. After the analysis of the laboratory tests, the physical and chemical features were compared to existing national and international regulations, which allowed a specific characterization of the conditions of the sample. In accordance with the regulations, the grade of the pipe was between ×65 and ×70. Tensile testing was carried out to obtain mechanical properties in order to corroborate the grade of pipeline steel and complement the metallographic analysis.

关键词： Metallography Microscopy Oil Pipeline Failure Tensile Testing

Analytical Model on Steel Tanks Damaged by Corrosion

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World Journal of Mechanics 2015年第12期5卷 274-285页

作者： francisco casanova-del-angel Moisés Gaytán-López National Polytechnic Institute Mexico City Mexico SACM SMA Government of Mexico City Mexico City Mexico

The mechanical behavior of steel employed in the hull of a steel tank damaged by corrosion has been analyzed. The tank was used to filter a deep-water well for an 8-year period. Influence of porosity and dissolution of material may be introduced in the main constitutive relation adding a new damage variable C, which describes electrochemical damage. An elastoplastic theoretical model coupled to damage of a member, and other for damage related to thermodynamic energy are developed. This theoretical development has been used to analyze mechanical behavior of steel used in the body of a steel tank damaged by corrosion in water purifier plants, Eastern System, Mexico City, where three of every ten filters show excessive corrosion inside the steel plate filtration tanks. With samples taken from steel of the tank’s hull and reinforcement of false bottom supporting filtering material inside the tank, metallography tests were carried out;localized and generalized types of corrosion were determined, as well as the type of corrosion composites generated due to anticorrosive coating used inside the tank from its manufacturing.

关键词： Structural Corrosion Damage Mechanics Steel Spectrometry Tensile Stress Loss

Probabilistic Model of Cumulative Damage in Pipelines Using Markov Chains

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Journal of Applied Mathematics and Physics 2020年第4期8卷 620-642页

作者： francisco casanova-del-angel Esteban Flores-Méndez Karina Guadalupe Cortes-Yah Sección de Estudios de Posgrado e Investigación. Escuela Superior de Ingeniería y Arquitectura Unidad Profesional ALM Instituto Politécnico Nacional Ciudad de México Mexico

This paper presents a probabilistic model of cumulative damage based on Markov chains theory to model propagation of internal corrosion depth localized in a hydrocarbons transport pipeline. The damage accumulation mechanism is unit jump type, depending on the state. It uses a shock model based on Bernoulli trials and probabilities to remain in the same state or the next one. Data are adjusted to Lognormal distribution and proven with a Kolmogórov-Smirnov test. The vector obtained from multiplying the initial state vector with the transition matrix was developed and the system of equations to find each transition probability with a single inspection report was solved. In order to calculate propagation of internal corrosion after inspection, an exponential equation was proposed and a parameter was adjusted to the data. Time to expected failure was obtained by adding the time expected in each damage state. Each time step was adjusted to real time.

关键词： Localized Corrosion Cumulative Damage Failure Pipelines Markov Chains

An approximate Kerr-Newman-like metric endowed with a magnetic dipole and mass quadrupole

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Communications in Theoretical Physics 2024年第8期76卷 124-138页

作者： francisco Frutos-Alfaro Space Research Center and School of Physics University of Costa RicaSan PedroSan JoseCosta Rica

Approximate all-terrain spacetimes for astrophysical applications are presented. The metrics possess five relativistic multipole moments, namely, mass, rotation, mass quadrupole, charge,and magnetic dipole moment. All these spacetimes approximately satisfy the Einstein-Maxwell field equations. The first metric is generated using the Hoenselaers-Perjés method from given relativistic multipoles. The second metric is a perturbation of the Kerr-Newman metric, which makes it a relevant approximation for astrophysical calculations. The last metric is an extension of the Hartle-Thorne metric that is important for obtaining internal models of compact objects perturbatively. The electromagnetic field is calculated using Cartan forms for locally non-rotating observers. These spacetimes are relevant for inferring properties of compact objects from astrophysical observations. Furthermore, the numerical implementations of these metrics are straightforward, making them versatile for simulating potential astrophysical applications.

关键词： Gravitation Einstein-Maxwell equations Compact objects

A Tutorial on Federated Learning from Theory to Practice:Foundations,Software Frameworks,Exemplary Use Cases,and Selected Trends

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 824-850页

作者： M.Victoria Luzón Nuria Rodríguez-Barroso Alberto Argente-Garrido Daniel Jiménez-López Jose M.Moyano Javier del Ser Weiping Ding francisco Herrera Department of Software Engineering Andalusian Research Institute in Data Science and Computational Intelligence(DaSCI)University of GranadaGranada 18071Spain Department of Computer Science and Artificial Intelligence Andalusian Research Institute in Data Science and Computational Intelligence(DaSCI)University of GranadaGranada 18071Spain Department of Communications Engineering University of the Basque Country(UPV/EHU)and also with TECNALIABasque Research&Technology Alliance(BRTA)Spain School of Information Science and Technology Nantong UniversityNantong 226019China

When data privacy is imposed as a necessity,Federated learning(FL)emerges as a relevant artificial intelligence field for developing machine learning(ML)models in a distributed and decentralized *** allows ML models to be trained on local devices without any need for centralized data transfer,thereby reducing both the exposure of sensitive data and the possibility of data interception by malicious third *** paradigm has gained momentum in the last few years,spurred by the plethora of real-world applications that have leveraged its ability to improve the efficiency of distributed learning and to accommodate numerous participants with their data *** virtue of FL,models can be learned from all such distributed data sources while preserving data *** aim of this paper is to provide a practical tutorial on FL,including a short methodology and a systematic analysis of existing software ***,our tutorial provides exemplary cases of study from three complementary perspectives:i)Foundations of FL,describing the main components of FL,from key elements to FL categories;ii)Implementation guidelines and exemplary cases of study,by systematically examining the functionalities provided by existing software frameworks for FL deployment,devising a methodology to design a FL scenario,and providing exemplary cases of study with source code for different ML approaches;and iii)Trends,shortly reviewing a non-exhaustive list of research directions that are under active investigation in the current FL *** ultimate purpose of this work is to establish itself as a referential work for researchers,developers,and data scientists willing to explore the capabilities of FL in practical applications.

关键词： Data privacy distributed machine learning federated learning software frameworks