23 research outputs found

    Incremento de la capacidad del canal óptico submarino mediante técnicas MISO en presencia de dispersión y turbulencia oceánica

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    En este trabajo se presenta un sistema con múltiples transmisores y un único receptor (MISO) con el objetivo de analizar las prestaciones en términos de capacidad ergódica de un canal óptico submarino bajo efecto de desvanecimiento de la potencia óptica recibida inducido por la dispersión del medio y turbulencias oceánicas bajo diferentes tipos de agua, distancias y severidad de turbulencias. Con este fin, se obtienen nuevas expresiones matemáticas en forma cerrada que permiten obtener la capacidad ergódica del sistema. Además, se aportan expresiones asintóticas que facilitan el análisis de las prestaciones en función de los diferentes parámetros físicos del sistema. Los resultados obtenidos confirman la mejora de prestaciones del sistema mediante el uso de un mayor número de transmisores en los diferentes escenarios estudiados. Todos los resultados presentados son validados a través de simulaciones Monte Carlo.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Caracterización estadística del desvanecimiento inducido por dispersión en sistemas de comunicación óptica inalámbrica submarina

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    An accurate underwater channel characterization is necessary for underwater optical wireless communication (UOWC) in order to improve its current limitations. This paper presents a new statistical model to characterize the scattering effect in terms of a fading never considered before by means of a Gamma distribution by using only one degree of freedom in clear ocean and coastal waters. The developed fading model is employed to compute the performance of UOWC systems in terms of bit error rate (BER) along with salinity-induced oceanic turbulence modeled by a Weibull distribution. The results demonstrate that the scattering-induced fading effect produces a strong performance degradation particularly in long link distances and, hence, it cannot be neglected when designing advanced communication systems. The analytical results are verified by Monte Carlo simulations.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Modelado estadístico del efecto de burbujas de aire en sistemas de comunicaciones ópticos inalámbricos submarinos.

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    The studies regarding underwater optical communications require an in-deep characterization of the water itself since its properties of absorption and scattering of light affect the transmission in an optical link. That said, this paper presents the modeling and characterization of the statistical behavior regarding the scattering caused by air bubbles of different sizes in an underwater optical wireless channel. It also provides the best statistical fitting according to each case in which a bimodal statistical form was discovered for a large-size air bubbles matter. Furthermore, it explains how all the assembly and installation are made at the laboratory in order to achieve the results obtained. It also features an audio interface as an easy way to get data variations.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Effectiveness of an intervention for improving drug prescription in primary care patients with multimorbidity and polypharmacy:Study protocol of a cluster randomized clinical trial (Multi-PAP project)

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    This study was funded by the Fondo de Investigaciones Sanitarias ISCIII (Grant Numbers PI15/00276, PI15/00572, PI15/00996), REDISSEC (Project Numbers RD12/0001/0012, RD16/0001/0005), and the European Regional Development Fund ("A way to build Europe").Background: Multimorbidity is associated with negative effects both on people's health and on healthcare systems. A key problem linked to multimorbidity is polypharmacy, which in turn is associated with increased risk of partly preventable adverse effects, including mortality. The Ariadne principles describe a model of care based on a thorough assessment of diseases, treatments (and potential interactions), clinical status, context and preferences of patients with multimorbidity, with the aim of prioritizing and sharing realistic treatment goals that guide an individualized management. The aim of this study is to evaluate the effectiveness of a complex intervention that implements the Ariadne principles in a population of young-old patients with multimorbidity and polypharmacy. The intervention seeks to improve the appropriateness of prescribing in primary care (PC), as measured by the medication appropriateness index (MAI) score at 6 and 12months, as compared with usual care. Methods/Design: Design:pragmatic cluster randomized clinical trial. Unit of randomization: family physician (FP). Unit of analysis: patient. Scope: PC health centres in three autonomous communities: Aragon, Madrid, and Andalusia (Spain). Population: patients aged 65-74years with multimorbidity (≥3 chronic diseases) and polypharmacy (≥5 drugs prescribed in ≥3months). Sample size: n=400 (200 per study arm). Intervention: complex intervention based on the implementation of the Ariadne principles with two components: (1) FP training and (2) FP-patient interview. Outcomes: MAI score, health services use, quality of life (Euroqol 5D-5L), pharmacotherapy and adherence to treatment (Morisky-Green, Haynes-Sackett), and clinical and socio-demographic variables. Statistical analysis: primary outcome is the difference in MAI score between T0 and T1 and corresponding 95% confidence interval. Adjustment for confounding factors will be performed by multilevel analysis. All analyses will be carried out in accordance with the intention-to-treat principle. Discussion: It is essential to provide evidence concerning interventions on PC patients with polypharmacy and multimorbidity, conducted in the context of routine clinical practice, and involving young-old patients with significant potential for preventing negative health outcomes. Trial registration: Clinicaltrials.gov, NCT02866799Publisher PDFPeer reviewe

    Gestión del conocimiento: perspectiva multidisciplinaria. Volumen 11

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    El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 11, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro cuenta con el apoyo de los grupos de investigación: Universidad Sur del Lago “Jesús María Semprúm” (UNESUR), Zulia – Venezuela; Universidad Politécnica Territorial de Falcón Alonso Gamero (UPTAG), Falcón – Venezuela; Universidad Politécnica Territorial de Mérida Kleber Ramírez (UPTM), Mérida – Venezuela; Universidad Guanajuato (UG) - Campus Celaya - Salvatierra - Cuerpo Académico de Biodesarrollo y Bioeconomía en las Organizaciones y Políticas Públicas (C.A.B.B.O.P.P), Guanajuato – México; Centro de Altos Estudios de Venezuela (CEALEVE), Zulia – Venezuela, Centro Integral de Formación Educativa Especializada del Sur (CIFE - SUR) - Zulia - Venezuela, Centro de Investigaciones Internacionales SAS (CIN), Antioquia - Colombia.y diferentes grupos de investigación del ámbito nacional e internacional que hoy se unen para estrechar vínculos investigativos, para que sus aportes científicos formen parte de los libros que se publiquen en formatos digital e impreso

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Análisis de técnicas de diversidad espacial adaptadas al canal óptico submarino en presencia de dispersión y turbulencia oceánica.

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    High absorption and scattering of the seawater impose new challenges in the design of novel underwater optical wireless transceivers. This paper presents a comprehensive comparison in terms of BER of Multiple-Input/Single-Output (MISO) UOWC systems using an alternative spatial repetition coding (SRC) and transmit laser selection (TLS) scheme over salinity-induced oceanic turbulence in clear ocean and coastal waters. We consider an SRC system to efficiently increase the total transmitted power while satisfying eye-safety requirements, and a novel feasible TLS scheme, which contemplates an imperfect channel state information (CSI) at the transmitter. Novel closed-form expressions and asymptotic results are derived to compute such a BER performance. The presented results demonstrate that the MISO improvement is more significant when the SRC scheme is adopted for all the UOWC scenarios, as well as a realistic TLS system presents a dramatic tendency to be affected by errors in the CSI at the transmitter block. Monte Carlo simulations verify analytical and asymptotic results.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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