6,596 research outputs found
Application of digital holographic interferometry to pressure measurements of symmetric, supercritical and circulation-control airfoils in transonic flow fields
Six airfoil interferograms were evaluated using a semiautomatic image-processor system which digitizes, segments, and extracts the fringe coordinates along a polygonal line. The resulting fringe order function was converted into density and pressure distributions and a comparison was made with pressure transducer data at the same wind tunnel test conditions. Three airfoil shapes were used in the evaluation to test the capabilities of the image processor with a variety of flows. Symmetric, supercritical, and circulation-control airfoil interferograms provided fringe patterns with shocks, separated flows, and high-pressure regions for evaluation. Regions along the polygon line with very clear fringe patterns yielded results within 1% of transducer measurements, while poorer quality regions, particularly near the leading and trailing edges, yielded results that were not as good
Redundant space calibration of hexagonal and Y-shaped beamforming radars and interferometric radiometers
Sobre la convergencia del modelo GARCH(1,1)-M al movimiento geométrico browniano con reversión a la media
This paper shows, under certain conditions, the convergence of the GARCH (1.1)-M model to the geometric Brownian motion with mean reversion (diffusion GARCH process). The importance from this result is that the problem of inference on the parameters of the valuation models of options with stochastic volatility can be reduced by estimating the model GARCH (1.1)-M. It is also carried out a discussion on the assumptions that ensure the existence and uniqueness of the limit process. Finally, it is provided a quick demonstration of the convergence, which is less formal, but more intuitive and easy to remember.Convergencia de procesos estocásticos, valuación de derivados, volatilidad estocástica
El trastorno por estrés postraumático en los supervivientes al cáncer: una revisión de los tratamientos psicológicos disponibles
Objective: Posttraumatic stress disorder (PTSD) appears frequently in cancer survivors, but not all survivors meet the criteria proposed by the DSM-V to be diagnosed with PTSD. This situation may lead an underestimation of the problem and furthermore, in this patient group, PTSD is related with different aspects of psychological well-being, such as depression, anxiety or quality of life, However, there are only a few psychological interventions designed to reduce these symptoms in cancer survivors. Method: A review of the psychological treatments available for PTSD in cancer survivors in the last 10 years was performed. The data bases used were PubMed, Web of Science (WOS) and PsycInfo with the following descriptors: PTSD (posttraumatic stress disorder) treatment cancer survivors y PTSS (posttraumatic stress symptoms) treatment cancer survivors. Results: The psychological interventions with more evidence are: cognitive-behavioral therapy and mindfulness, ahead other strategies such as stress management training, neuro-emotional therapy, coping skills training and counseling. Conclusions: Despite the relevance of PTSD in this patients group, psychological interventions needs more evidence to establish their efficacy to reduce these symptoms in survivors.Objetivo: El trastorno por estrés postraumático (TEP) aparece con frecuencia en los supervivientes al cáncer, pero no todos los supervivientes cumplen con los criterios propuestos por el DSM-V para ser diagnosticados. Esta situación puede provocar la subestimación del problema y además, en este grupo de pacientes el TEP se relaciona con diferentes aspectos del bienestar psicológico, como la depresión, la ansiedad o la calidad de vida. Sin embargo, solo hay unas pocas intervenciones psicológicas diseñadas para reducir estos síntomas en los supervivientes al cáncer. Método: Se realizó una revisión de los tratamientos psicológicos disponibles para el TEP en los supervivientes al cáncer en los últimos 10 años. Las bases de datos utilizadas fueron PubMed, Web of Science (WOS) y PsycInfo con los siguientes descriptores: PTSD (posttraumatic stress disorder), treatment cancer survivors y PTSS (posttraumatic stress symptoms) treatment cancer survivors. Resultados: Las intervenciones psicológicas con una mayor evidencia son: la terapia de tipo cognitivo-conductual y el mindfulness, por delante del entrenamiento en el manejo del estrés, la terapia neuro-emocional, el entrenamiento en habilidades de afrontamiento y el counseling. Conclusiones: A pesar de la relevancia del TEP en este grupo de pacientes, las intervenciones psicológicas necesitan de una mayor evidencia para establecer su eficacia para reducir estos síntomas en los supervivientes
Analytical Modeling of Interference Aware Power Control for the Uplink of Heterogeneous Cellular Networks
Inter-cell interference is one of the main limiting factors in current
Heterogeneous Cellular Networks (HCNs). Uplink Fractional Power Control (FPC)
is a well known method that aims to cope with such limiting factor as well as
to save battery live. In order to do that, the path losses associated with
Mobile Terminal (MT) transmissions are partially compensated so that a lower
interference is leaked towards neighboring cells. Classical FPC techniques only
consider a set of parameters that depends on the own MT transmission, like
desired received power at the Base Station (BS) or the path loss between the MT
and its serving BS, among others. Contrary to classical FPC, in this paper we
use stochastic geometry to analyze a power control mechanism that keeps the
interference generated by each MT under a given threshold. We also consider a
maximum transmitted power and a partial compensation of the path loss.
Interestingly, our analysis reveals that such Interference Aware (IA) method
can reduce the average power consumption and increase the average spectral
efficiency. Additionally, the variance of the interference is reduced, thus
improving the performance of Adaptive Modulation and Coding (AMC) since the
interference can be better estimated at the MT.Comment: 13 pages, 1 table and 7 figures. This work has been submitted to the
IEEE for possible publication. Copyright may be transferred without notice,
after which this version may no longer be accessibl
Condrosarcoma en pie
El condrosarcoma óseo en el pie es una lesión muy rara. Se presenta 1 caso de bajo
grado de malignidad histológico y primario en su origen, que afecta al primer radio, tratado
mediante resección amplia y sin signos de recidiva a los 3 años y medio de evolución.Bone chondrosarcoma very rarely affccts the foot. We report a case of primary
bone chondrosarcoma vvith low grade malignancy involving the first metatarsal bone. Tumor was
treated by wide resection. Three and half years later, there was not signs of recurrence
New Trends in Using Augmented Reality Apps for Smart City Contexts
The idea of virtuality is not new, as research on visualization and simulation dates back
to the early use of ink and paper sketches for alternative design comparisons. As technology has
advanced so the way of visualizing simulations as well, but the progress is slow due to difficulties
in creating workable simulations models and effectively providing them to the users. Augmented
Reality and Virtual Reality, the evolving technologies that have been haunting the tech industry,
receiving excessive attention from the media and colossal growing are redefining the way we interact,
communicate and work together. From consumer application to manufacturers these technologies
are used in different sectors providing huge benefits through several applications. In this work,
we demonstrate the potentials of Augmented Reality techniques in a Smart City (Smart Campus)
context. A multiplatform mobile app featuring Augmented Reality capabilities connected to GIS
services are developed to evaluate different features such as performance, usability, effectiveness and
satisfaction of the Augmented Reality technology in the context of a Smart Campus
Organizational learning and innovation as sources of strategic fit
Purpose
The purpose of this paper is to analyze the roles played by organizational learning (OL) and innovation in organizations immersed in the processes of adaptation and strategic fit in dynamic and turbulent environments. The authors analyze whether OL and innovation act as sources of strategic fit, and whether strategic fit positively affects performance.
Design/methodology/approach
The authors use data from a survey of a representative sample of 204 respondents from European firms active in high-technology sectors (response rate: 10.42 percent) and structural equation modeling (using the EQS 6.1 program) to undertake a transversal study.
Findings
The model confirms that OL and the capacity to innovate positively influence managers’ decisions to adapt their organizations to changes in dynamic environments. The achievement of strategic fit, in turn, improves organizational performance. The authors propose considering the innovation climate as a facilitator of new product and process development, although the innovation climate is not a direct antecedent of fit.
Research limitations/implications
This study is limited by the fact that the analysis is cross-sectional and by the fact that all measures used are based on managers’ perceptions.
Practical implications
Managers should create and support an entrepreneurial culture that stresses continuous learning. They should also foster programs aimed at developing abilities, and promote the development of capabilities that facilitate acceptance of organizational change. Investments in building certain capabilities, such as OL and the capacity to innovate, are strategically justified, especially in turbulent environments.
Originality/value
This study is one of the first to investigate the complex interactions among OL, innovation, strategic fit, and performance. The results improve our understanding of the links between strategic fit and performance
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