1,753 research outputs found
UWE en Sistema de Recomendación de Objetos de Aprendizaje. Aplicando Ingeniería Web: Un Método en Caso de Estudio
La Ingeniería Web propone nuevos métodos para el diseño de aplicaciones que se ejecutan en esta nueva plataforma que es la World Wide Web. Uno de estos métodos es UWE (UML Web Engineering), el cual aprovecha la notación estándar del UML e incorpora elementos que son propios del desarrollo Web. En este artículo se presenta un caso de estudio para el diseño de un Sistema de Recomendación de Objetos de Aprendizaje, donde el modelado básico se realiza mediante el UWE. Se modela una aplicación Web que permite a los usuarios realizar la composición de los Objetos de Aprendizaje que el mismo sistema le recomienda al usuario previo análisis de las características tanto del mismo como de los Objeto de Aprendizaje almacenados en un repositorio especializado llamado AGORA
Risk assessment and mapping of extreme floods in non-dyked communities along the Elbe and Mulde Rivers
International audienceAssessing and mapping damage risk of floods for large river basins is still in its infancy. Damage risk is understood to be the combination of flood hazard and the vulnerability of communities to a flood of a particular return period. Risk is calculated and mapped for two communities in which dykes are not located for flood protection: Meissen on the Elbe River and Döbeln in the Mulde catchment. Different methodologies for the computation of flood depth and inundation extent of varying flood return periods (hazard) are compared. Exposure and relative damage to the flooding (vulnerability) based on land-use coverages of different scale are also compared and discussed. A property asset coverage completes the data requirements for the construction of the risk maps. Recommendations for continued research on risk assessments of large river basins conclude the study
Percutaneous management of thoracolumbar burst fractures: Evolution of techniques and strategy
SummaryIntroductionA number of techniques have been described in the management of thoracolumbar spinal fractures, testimony to the absence of consensus on their treatment. For the past few years, minimally invasive techniques have been developed to limit surgery-related iatrogenic injury. The objective of this study was to report the results of percutaneous management of these lesions and the technical progress made based on our experience.Patients and methodsTwenty-nine patients presenting an A3 fracture, with a mean age of 51 years, were included in this study. All had a balloon kyphoplasty and percutaneous osteosynthesis. Of the first 22 cases, kyphoplasty was the initial procedure performed associated with reduction maneuvers using distraction. Assessment was clinical (neurological status and pain intensity) and radiological (implant positioning, cement leakage, restoration of local kyphosis and any loss of correction).ResultsIn the overall series, the mean local kyphosis correction was 11° with a 2° angle loss at the last follow-up. Pain assessment showed significant improvement, decreasing from 6/10 to 1/10 on discharge. The mean hospital stay lasted 4 days. On the follow-up radiological exams, no cases of extrapedicular screw migration were noted; in two cases, lateral cement leakage was found. The results were equivalent in terms of correction no matter which procedure was performed first, although for the second part of the series the technology was available to bend the spinal fixation rod to the desired curve.DiscussionThe results of this study support the growing interest in minimally invasive techniques in the management of spinal injuries with no neurological deficit. In addition, the evolving material makes it possible to come close to conventional techniques, including reduction maneuvers, while limiting muscle injury by using a purely percutaneous approach. Rigorous patient selection is necessary and the time to learn the procedure must be taken into account. Studies with a longer follow-up are required to confirm the stability of the correction over time.Level of evidenceLevel IV. Retrospective observational study
Desarrollo de un curso en línea para adultos mayores enfocado en el desarrollo de la competencia de creación de contenidos digitales en tiempos de COVID-19
Ante el COVID-19, el empleo de las Tecnologías de la Información y Comunicación (TIC) aumentó considerablemente, y con ello se hicieron evidentes las brechas digitales existentes en diferentes poblaciones. El grupo de los adultos mayores es uno de los que se ve excluido de todos los beneficios y oportunidades que las TIC traen consigo, puesto que son escasos los espacios en los que puedan alfabetizarse digitalmente, y que además se consideren sus características y necesidades particulares. El presente escrito tiene como objetivo dar a conocer el proyecto desarrollado en el Programa de Alfabetización Tecnológica del Instituto Tecnológico de Sonora, México, el cual consiste en un curso en línea de alfabetización digital para adultos mayores en la competencia de creación de contenido digital. El proyecto se considera como de desarrollo y se emplea el modelo de diseño instruccional ADDIE como metodología. Los principales resultados obtenidos son que los participantes desarrollaron la competencia de creación de contenido digital; los productos desarrollados en las actividades son de utilidad en sus diversos ámbitos; y el empleo de los principios andragógicos en el diseño, desarrollo e implementación del curso permitió un mejor aprendizaje de un adulto mayor
Influence of flood frequency on residential building losses
For the purpose of flood risk analysis, reliable loss models are an indispensable need. The most common models use stage-damage functions relating damage to water depth. They are often derived from empirical flood loss data (i.e. loss data collected after a flood event). However, object specific loss data (e.g. losses of single residential buildings) from recent flood events in Germany showed higher average losses in less probable events, regardless of actual water level. Hence, models that were derived from such data tend to overestimate losses caused by more probable events. Therefore, it is the aim of the study to analyse the relation between flood damage and recurrence interval and to propose a method for considering recurrence interval in flood loss modelling. The survey was based on residential building loss data (<i>n</i>=2158) of recent flood events in 2002, 2005 and 2006 in Germany and on-site recurrence interval of the respective events. We discovered a highly significant positive correlation between loss extent and recurrence interval for classified water levels as well as increasing average losses for longer recurrence intervals within each class. The application of principal component analysis revealed the interrelation between factors that influence the damage extent directly or indirectly, and recurrence interval. No single factor or component could be identified that explained the influence of recurrence interval, which led to the conclusion that recurrence interval cannot substitute, but complement other damage influencing factors in flood loss modelling approaches. Finally, a method was developed to include recurrence interval in typical flood loss models and make them applicable to a wider range of flood events. Validation including statistical error analysis showed that the modified models improve loss estimates in comparison to traditional approaches. The proposed multi-parameter model FLEMOps+r performs particularly well
Electromagnetic modeling and optimization of packaged photodetector modules for 100 Gbit/s applications
In this paper, we propose an accurate full 3D EM behavioral model of PD chips for the first time. The model, which is meshed at 130 GHz, runs for about 17 minutes on an Intel Core2 Duo CPU@3 GHz PC with 3.5 GB of RAM. The impact of various parameters in wire- bonding transitions for transmission characteristic is summarized in the Table I. When numbers of bonding wires are placed separately all through strips of CBCPWs as well as keeping an optimized gap of transitions, more than 10 GHz bandwidth improvement can be achieved compared the worst case. We also notice that optimization on bonding wires does not significantly improve the fast decay beyond 60 GHz. Further investigation and optimization of the transition is required including a redesign of the CBCPW
Astroclimatic Characterization of Vallecitos: A candidate site for the Cherenkov Telescope Array at San Pedro Martir
We conducted an 18 month long study of the weather conditions of the
Vallecitos, a proposed site in Mexico to harbor the northern array of the
Cherenkov Telescope Array (CTA). It is located in Sierra de San Pedro Martir
(SPM) a few kilometers away from Observatorio Astron\'omico Nacional. The study
is based on data collected by the ATMOSCOPE, a multi-sensor instrument
measuring the weather and sky conditions, which was commissioned and built by
the CTA Consortium. Additionally, we compare the weather conditions of the
optical observatory at SPM to the Vallecitos regarding temperature, humidity,
and wind distributions. It appears that the excellent conditions at the optical
observatory benefit from the presence of microclimate established in the
Vallecitos.Comment: 16 pages, 16 figures, Publication of the Astronomical Society of the
Pacific, accepte
Critical Behavior of the Three-Dimensional Ising Spin Glass
We have simulated, using parallel tempering, the three dimensional Ising spin
glass model with binary couplings in a helicoidal geometry. The largest lattice
(L=20) has been studied using a dedicated computer (the SUE machine). We have
obtained, measuring the correlation length in the critical region, a strong
evidence for a second-order finite temperature phase transition ruling out
other possible scenarios like a Kosterlitz-Thouless phase transition. Precise
values for the and critical exponents are also presented.Comment: RevTex; 12 pages plus 5 ps figures. Final version to be published in
PR
Low contrast visual acuity testing is associated with cognitive performance in multiple sclerosis: a cross-sectional pilot study
Background: Cognitive impairment and visual deterioration are two key clinical symptoms in MS and affect 50 to 80% of patients. Little is known about the influence of cognitive impairment on visual tests recommended for MS such as low contrast sensitivity testing. Our objective was to investigate whether low contrast sensitivity testing is influenced by cognitive impairment in multiple sclerosis (MS) patients. Methods: Cross-sectional study including 89 patients with relapsing-remitting MS. All patients received cognitive evaluation using Rao’s Brief Repeatable Battery of Neuropsychological Testing (BRB-N). Visual assessments included low contrast sensitivity (CS) by functional acuity contrast testing and high contrast visual acuity (VA) using ETDRS charts. Retinal morphology as visual impairment correlate was measured using retinal nerve fiber layer (RNFL) thickness by optical coherence tomography. Results: In combined analyses using generalized estimating equation models, Paced Auditory Serial Addition Test (PASAT) and RNFL as well as and the Symbol Digit Modalities Test (SDMT) and RNFL predicted CS. To further control for a potential influence of the anterior visual system we performed partial correlation analyses between visual function and cognitive function test results but controlling for RNFL. Even when controlling for RNFL, CS was associated with PASAT performance and SDMT performance. Conclusion: Our data show that: a) cognitive impairment and performance in visual function tests such as low contrast sensitivity testing are associated; b) the main cognitive domains correlating with visual test performance are information processing speed and, to a lesser degree, memory; This preliminary data needs to be substantiated in further studies investigating patients with a higher cognitive burden, healthy controls and in longitudinal settings
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