Lenguajes de ontologías web aplicados al sector turístico

El presente artículo describe los resultados del proyecto de investigación titulado “Plataforma TIC para propiciar la organización y colaboración de los diferentes actores del sector turístico en el Caribe Colombiano” y desarrolla algunos conceptos sobre aplicaciones de Ontologías Web al sector turismo. Una ontología defne los términos a utilizar para describir y representar un área de conocimiento. Las ontologías son utilizadas por personas, bases de datos y aplicaciones que necesitan compartir un dominio de información común e incluyen defniciones de conceptos básicos del dominio, y las relaciones entre ellos. El articulo inicia con el análisis del concepto de ontologías, los componentes que lo conforman y algunos lenguajes de ontologías web frecuentemente utilizados y explica cómo se pueden aplicar las ontologías al sector turístico. El artículo fnaliza explicando cómo se construyó un buscador de atractivos turísticos basado en ontologías.Abstract: This article describes the results of the research project entitled “ICT platform to promote the organization and collaboration of diferent actors in the tourism sector in the Colombian Caribbean” and develops some concepts about Web Ontology applications for tourism. An ontology defnes the terms to use to describe and represent an area of knowledge. Ontologies are used by people, databases and applications that need to share a common information domain and include defnitions of domain concepts and relations between them. The article begins with an analysis of the concept of ontologies, its components and some web ontology languages commonly used and explains how ontologies can be applied to the tourism sector. The article concludes by explaining how was built a seeker engine for sites based on ontologies

Numerical modelling of orthogonal cutting: Influence of cutting conditions and separation criterion

6 pages, 5 figures.-- Issue title: "EURODYMAT 2006 - 8th International Conference on Mehanical and Physical Behaviour of Materials under Dynamic Loading" (Dijon, France, Sep 11-15, 2006).Chip formation is a high strain rate process studied with analytical and numerical models. Analytical models have the advantage of a small calculation time, however, they are often based on some assumptions which are difficult to verify. Finite element modelling (FEM) of chip formation process provides more details on the chip process formation, such as plastic strain, strain rate or stress fields. FEM can be used to improve the analytical models' assumptions. There is still a wide dispersion of formulations and numerical parameters adopted in order to obtain accurate results in numerical models. In the Lagrangian approach, it is of crucial importance to establish realistic criteria for element deletion, allowing chip separation from original workpiece. In the arbitrary Lagrangian Eulerian (ALE) formulation no element deletion is needed. This work is focused in modelization of orthogonal cutting. A comparison between both numerical approaches, Lagrangian and ALE is shown. The effects of geometrical parameters, erosion criterion and cutting speed are evaluated. Comparisons between numerical and theoretical results are performed, and the results obtained from the numerical approach are used as an input of analytical model, improving its accuracy."Program of Creation and Consolidation of Research Teams" University Carlos III of Madrid (2005).Publicad

Residual stresses in orthogonal cutting of metals: the effect of thermo-mechanical coupling parameters and of friction

21 pages, 13 figures.The generation of residual stresses in orthogonal machining is analysed by using an Arbitrary Lagrangian Eulerian (ALE) finite element approach. It is shown that a substantial level of tensile residual stresses can be obtained in the vicinity of the machined surface without any contribution of thermal effects. This motivates the development of a parametric study to analyse the effects of the thermomechanical coupling parameters on residual stresses. The roles of thermal expansion, of thermal softening and of the Taylor-Quinney coefficient (controlling the heat generated by plastic flow) are considered separately. The influence of friction is also analysed by assuming dry cutting conditions and a Coulomb friction law. The friction coefficient has a complex effect by controlling heat generation (frictional heating) along the tool rake and clearance faces and the propensity for the chip to stick to the tool. Geometrical effects such as the tool rake angle and the tool edge radius are also discussed.The authors are indebted, for the financial support of this work, to the Ministry of Science and Education of Spain (under project DPI2005-08018) and to the Comunidad Autónoma de Madrid and University Carlos III of Madrid (under project CCG07-UC3M/DPI-3396).Publicad

Experimental and numerical study of the thermo-viscoplastic behavior of nicro 12.1 for perforation tests

Dynamic impact tests using thin metal plates for ballistic characterization have received significant attention in recent years. The Johnson–Cook (J–C) model is extensively used in numerical modeling of impact and penetration in metals. The AISI (American Iron and Steel Institute) 301 steel family presents good impact behavior, excellent formability, and high corrosion resistance. Thus, NICRO (Nickel and Hard Chrome Plated Steel) 12.1 (part of the AISI 301 steel family) was chosen in this work, although parameters of the J–C model or impact results were not found in the literature. In this work, NICRO 12.1 steel plates, were characterized in ballistics with an initial impact velocity up to 200 m/s and three shape nose projectiles. The Johnson–Cook parameters for the NICRO 12.1 steel were calculated for a large range of temperatures and strain rates. Impact tests were carried out using three projectiles: conical, hemispherical, and blunt. The ballistic curves, failure mode, and maximum deformation obtained with each projectile, experimentally and numerically, were compared, and a good correlation was obtaine

Dynamic behavior of aluminum alloy AW 5005 undergoing interfacial friction and specimen configuration in split hopkinson pressure bar system at high strain rates and temperatures

This article belongs to the Special Issue Behavior, Damage and Fracture of Aluminum Alloy: Experiments and Modeling.In this paper, experimental and numerical results of an aluminum alloy’s mechanical behavior are discussed. Over a wide range of strain rates (10−4 s−1 ≤ έ ≤ 103 s−1) the influence of the loading impact, velocity and temperature on the dynamic response of the material was analyzed. The interface friction effect on the material’s dynamic response is examined using a split Hopkinson pressure bar (SHPB) in a high temperature experiment using finite element analysis (FEA). The effect of different friction conditions between the specimen and the transmitted/incident bars in the SHPB system was examined using cylinder bulk specimens and cylinder plates defined with four-layer configurations. The results of these tests alongside the presented numerical simulations allow a better understanding of the phenomenon and reduces (minimizes) errors during compression tests at high and low strain rates with temperatures ranging from 21 to 300 °C

E-commerce y exportación de ropa a Bolivia de la empresa Manufacturas San Isidro S.A.C, Lima Perú 2023

En la tesis se plantea el problema cómo afecta la falta de estrategias sobre la evolución del E-commerce y esto influye de forma directa a las Exportaciones que se pueden realizar y tener más rentabilidad. Tuvo como objetivo determinar la relación entre las variables E-commerce y Exportación de ropa de la empresa Manufacturas San Isidro S.A.C, Lima Perú 2023. El tipo de investigacion fue básica; con método de enfoque cuantitativo, diseño correlacional, no experimental y transversal. Siendo la técnica la encuesta; y el instrumento cuestionario, aplicando un cuestionario de 36 preguntas a una muestra de 66 trabajadores seleccionados mediante un muestreo probabilístico aleatorio simple. El proyecto se evaluó mediante la estadística descriptiva inferencial, en el Software Estadístico SPSS versión 25. Se aplicó el coeficiente de correlación de Rho de Spearman para realizar el análisis de hipótesis. Teniendo los resultados de correlación entre la V1 E-commerce y V2 Exportación, con un coeficiente de correlación de (rho = 0,513), un valor de sig. bilateral p(<0,001) es menor que <0,05 lo cual quiere decir que es muy significativa moderada, se concluye que se acepta la hipótesis alterna (Ha) y se rechaza la hipótesis nula (Ho). Conclusión, existe correlación entre las variables

Computer Visual Syndrome in Medical Students From a Private University in Paraguay: A Survey Study

"Purpose: To determine the prevalence and factors associated with computer vision syndrome in medical students at a private university in Paraguay. Methods: A survey study was conducted in 2021 in a sample of 228 medical students from the Universidad del Pacífico, Paraguay. The dependent variable was CVS, measured with the Computer Visual Syndrome Questionnaire (CVS-Q). Its association with covariates (hours of daily use of notebook, smartphone, tablet and PC, taking breaks when using equipment, use of preventive visual measures, use of glasses, etc.) was examined. Results: The mean age was 22.3 years and 71.5% were women. CVS was present in 82.5% of participants. Higher prevalence of CVS was associated with wearing a framed lens (PR = 1.11, 95% CI: 1.03–1.20). In contrast, taking a break when using electronic equipment at least every 20 min and every 1 h reduced 7% (PR = 0.93, 95% CI: 0.87–0.99) and 6% (PR = 0.94, 95% CI: 0.89–0.99) the prevalence of CVS, respectively. Conclusion: Eight out of 10 students experienced CVS during the COVID-19 pandemic. The use of framed lenses increased the presence of CVS, while taking breaks when using electronic equipment at least every 20 min and every 1 h reduced CVS.

Thermo-Viscoplastic Behavior of Ni-Based Superalloy Haynes 282 and Its Application to Machining Simulation

Ni-based superalloys are extensively used in high-responsibility applications in components of aerospace engines and gas turbines with high temperature service lives. The wrought, gamma'-strengthened superalloy Haynes 282 has been recently developed for applications similar to other common superalloys, such as Waspaloy or Inconel 718, with improved creep behavior, thermal stability, and fabrication ability. Despite the potential of Haynes 282, there are still important gaps in the knowledge of the mechanical behavior of this alloy. In fact, it was not possible to find information concerning the mechanical behavior of the alloy under impulsive loading. This paper focuses on the mechanical characterization of the Haynes 282 at strain rates ranging from 0.1 to 2800 s(-1) and high temperatures ranging from 293 to 523 K using Hopkinson bar compression tests. The experimental results from the thermo-mechanical characterization allowed for calibration of the Johnson-Cook model widely used in modeling metallic alloy's responses under dynamic loading. Moreover, the behavior of Haynes 282 was compared to that reported for Inconel 718, and the results were used to successfully model the orthogonal cutting of Haynes 282, being a typical case of dynamic loading requiring previous characterization of the alloy.This work was supported by the Spanish Ministry of Economy and Competitiveness, and the FEDER program under grant DPI2014-56137-C2-2-R

Menor peso corporal, de índice de masa corporal y de perímetro de cintura se asocian a una disminución en factores de riesgo cardiovascular en población chilena = Effects of a lower body weight or waist circumference on cardiovascular risk. Findings from the Chilean health survey

Background: Overall and central obesity are important risk factors for cardiovascular disease. Aim: To investigate the association of body weight, body mass index (BMI) and waist circumference (WC) with cardiovascular risk factors in Chile. Material and methods: We included 5,157 participants from the National Health Survey 2009-2010. Prevalence of type 2 diabetes, hypertension, metabolic syndrome and dyslipidemia (high total cholesterol and triglyceride levels and low HDL-cholesterol) were defined using international recommendations. BMI and WC were measured using standardized protocols. Results: A five percent lower body weight, BMI and WC were associated with a significant reduction in cardiovascular risk factors. For each 5% reduction in body weight, the risk for hypertension decreased by 8 and 9% in women and men respectively. Similar risk reductions were observed for diabetes (9 and 11% respectively), metabolic syndrome (23 and 30% respectively), low HDL cholesterol (13 and 13% respectively), high triglyceride levels (16 and 18% respectively) and total cholesterol (8 and 10% respectively). Similar findings were observed for BMI and WC. Conclusions: Lower body weight, BMI or WC are associated with important reductions in cardiovascular risk factors. A 5% reduction in these adiposity markers could be a perfectly feasible goal for lifestyle interventions

High strain rate effect on tensile ductility and fracture of AM fabricated Inconel 718 with voided microstructures

The paper describes Electromagnetic Ring Expansion Tests (ERET) performed on Laser Melting Powder Bed Fusion (LPBF) Inconel 718 stress relieved test pieces, to establish the effect of a randomly dispersed spherically voided microstructure on tensile ductility, fracture, and fragmentation at high strain rate (10-3 < e < 104 s-1). An empirical model to predict porosity type and growth rates as a function of laser energy density was established, to select the LPBF process parameters to fabricate test pieces under stable conduction and keyhole melting. The size, shape, distribution of macro and keyhole pores in the test pieces obtained for ERET testing were characterised. At high strain rate the number of ring fragments for the highest porosity doubled, accompanied by a reduction in true strain at maximum uniform elongation and fracture strain. The trend for reducing fracture strain with increasing porosity at high strain rate was described by a decaying power law. Overall, there was a significant positive strain rate effect on tensile ductility at lower porosities attributed strain rate hardening (Hart, 1967) [1]. Fracture surfaces containing the highest porosity identified four different void coalescence mechanisms that helped explain the influence of larger pores on the stress state in the alloy.The AM of IN718 and tensile testing was funded by the UoD, College of Science and Engineering Research Excellence Framework (REF) funding for the Director of IISE (P. Wood) and AM Researcher (U. Gunputh). The support of G. Williams for IN718 sample preparation and M. Pawlik for tensile testing is acknowledged. A. Rusinek acknowledges the program UC3M-Santander Chair of Excellence in additive manufacturing. The expanding ring tests investigations were funded by the Polish Ministry of Science and Higher Education, Centre for Research and Development under research grant No. TECHMATSTRATEG2/410049/12/NCBR/2019