207 research outputs found

    Data Center Top of Rack Switch to Multiple Spine Switches Optical Wireless Uplinks

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    Infrared (IR) uplinks can achieve high data rates, which are essential in a range of applications. This paper introduces a novel approach to enable data centre uplink communication. We introduce a novel method to enable communication between racks and spine switches. In our proposed data centre, we consider three racks, each of which has its own angle diversity transmitter (ADT) that is located on top of the rack. Four wide field of view receivers are fixed to the ceiling of the data centre. Each such receiver is connected to a spine switch. We evaluate the performance of our proposed system when each link operates at a data rate above 2.8 Gb/s. Multiple links can be used to achieve higher data rates using the space or wavelength dimensions. The results show that our proposed system has the ability to work at a high data rate with good performance while using simple on-off-keying

    Q-learning algorithm for resource allocation in WDMA-based optical wireless communication networks

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    Visible Light Communication (VLC) has been widely investigated during the last decade due to its ability to provide high data rates with low power consumption. In general, resource management is an important issue in cellular networks that can highly effect their performance. In this paper, an optimisation problem is formulated to assign each user to an optimal access point and a wavelength at a given time. This problem can be solved using mixed integer linear programming (MILP). However, using MILP is not considered a practical solution due to its complexity and memory requirements. In addition, accurate information must be provided to perform the resource allocation. Therefore, the optimisation problem is reformulated using reinforcement learning (RL), which has recently received tremendous interest due to its ability to interact with any environment without prior knowledge. In this paper, the resource allocation optimisation problem in VLC systems is investigated using the basic Q-learning algorithm. Two scenarios are simulated to compare the results with the previously proposed MILP model. The results demonstrate the ability of the Q-learning algorithm to provide optimal solutions close to the MILP model without prior knowledge of the system

    Diagn?stico del uso del fideicomiso como herramienta eficiente para promover proyectos de vivienda social masiva

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    La presente investigaci?n se propone los siguientes objetivos: - Proponer alternativas para mitigar el d?ficit habitacional a trav?s de lineamientos y pol?ticas de vivienda social masiva mejorando y ampliando los esquemas de financiamiento para los proyectos de vivienda social masiva. - Analizar la normativa peruana, identificar posibles deficiencias y proponer el uso de la figura del fideicomiso como mecanismo de acceso a la vivienda social para las mayor?as. - Proponer a trav?s del fideicomiso la construcci?n de viviendas para disminuir la autoconstrucci?n, las invasiones que permitan construcciones a menos costos, en zonas seguras y asegurar la calidad de vida de los pobladores de menos recursos

    Proceso de construcci?n de una cultura de paz en los ni?os de transici?n de la instituci?n educativa Armando Romero Lozano de Sevilla Valle, a trav?s de estrategias did?cticas sensibilizadoras

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    121 p. Recurso Electr?nicoEl presente proyecto de investigaci?n ?proceso de construcci?n de una cultura de paz en los ni?os de preescolar, a trav?s de estrategias did?cticas sensibilizadoras? consiste en visibilizar los alcances en la mejora de las habilidades de resoluci?n de conflictos a trav?s de actividades l?dicas y art?sticas en los ni?os de preescolar de Instituci?n Educativa Armando Romero Lozano del municipio de Sevilla valle. Todo esto se realiz? partiendo del planteamiento de los objetivos, los cuales permitir?n lograr su cometido; en primer lugar, identificar a partir de los resultados qu? problem?ticas de comportamiento tienen los ni?os, en segundo lugar, implementar un plan de intervenci?n orientado a mejorar las relaciones interpersonales de los ni?os y en tercer lugar, evaluar el impacto generado con el plan de intervenci?n propuesto para tal fin. En cuanto al marco te?rico, se busc? el soporte en los postulados de diferentes autores, los cuales resultaron pertinentes para el abordaje conceptual de este, ya que hablan del desarrollo de la capacidad creadora, principios, normas y valores que hacen un clima escolar acorde para una educaci?n para la paz y una participaci?n democr?tica, como aspectos importantes a tener en cuenta en esta investigaci?n. Respecto a la metodolog?a, se desarroll? en base a la investigaci?n la investigaci?n acci?n-participativa y cooperativa, con un enfoque etnogr?fico, dentro del paradigma cualitativo. Tras esto, el resultado que se obtendr? del proceso estudiado, que junto a referentes te?ricos ayuda a explicar los procesos de la pr?ctica escolar estudiada.This research project process of building a culture of peace in preschool children through teaching strategies visible sensitizer is the scope in improving the skills of conflict resolution through recreational and artistic activities preschoolers educational institution Armando Romero Lozano the municipality of Seville valley. All this was done based on the approach of objectives, which will allow achieve its mission; first identified from the results which problematic behavior have children, secondly, implement an intervention plan aimed at improving interpersonal relationships of children and thirdly, to assess the impact generated with the intervention plan proposed for this purpose. As for the theoretical framework, support the propositions of different authors, which were relevant to the conceptual approach to this is sought, as they speak of the development of creativity, principles, norms and values that make a chord school climate for education for peace and democratic participation, as important aspects to consider in this research. Reading methodology was developed based on the research-participatory and cooperative action with an ethnographic approach, within the qualitative research paradigm. After this, the result you get the process under study, which together with theoretical framework helps explain the processes studied school practice Keywords: skills, peace, transition, norms, values and family

    Joint Source and Relay Optimization for Parallel MIMO Relay Networks

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    In this article, we study the optimal structure of the source precoding matrix and the relay amplifying matrices for multiple-input multiple-output (MIMO) relay communication systems with parallel relay nodes. Two types of receivers are considered at the destination node: (1) The linear minimal mean-squared error (MMSE) receiver; (2) The nonlinear decision feedback equalizer based on the minimal MSE criterion. We show that for both receiver schemes, the optimal source precoding matrix and the optimal relay amplifying matrices have a beamforming structure. Using such optimal structure, joint source and relay power loading algorithms are developed to minimize the MSE of the signal waveform estimation at the destination. Compared with existing algorithms for parallel MIMO relay networks, the proposed joint source and relay beamforming algorithms have significant improvement in the system bit-error-rate performance

    Autenticidad a partir de RV como método de documentación de patrimonio cultural. Aproximación teórica basada en prácticas de conservación y documetnación

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    [EN] The visualization of 3D reconstructed artifacts often requires significant computing resources. The implementation of an object in a virtual reality (VR) application even necessitates the reduction of the polygonal mesh. Consequently, the communication and dissemination of “authentic” 3D reconstructions via immersive VR technologies has been a nearly impossible feat for many researchers. However, is the issue really computing resources, or is it rather the notion of authenticity in an “auratic” sense, i.e., an excessive focus on physical evidence and survey data? In the present paper, we will discuss the authenticity requirements for virtual archaeology as set by the Seville Principles(2011), and we will analyse some limitations related to the current approaches. Furthermore, we will propose a pluralistic notion based on the contextualization of 3D objects in VR environments with synesthetic (i.e. multisensory) information. This new notion of authenticity relies on conservation meanings rather than physical features. In line with this approach, two case studies will be commented: the multimodal 3D-documentation of the Jupiter Column(2AD) in Ladenburg, and the VR-based re-enactment of a modern work of art, the audio-kinetic sculpture Kaleidophonic Dog(1967) by Stephan von Huene. These two projects provide valuable data for a revision of the notion of authenticity in both virtual archaeology and art conservation.[ES] La visualización deartefactos reconstruidos en 3D requiere a menudo demasiados recursos computacionales. La implementación en una aplicación de realidad virtual (RV) requiere incluso la reducción de la red poligonal delobjeto.Consecuentemente,la comunicación y la divulgaciónde reconstrucciones 3D “auténticas”representa todavía una tarea casi imposiblepara muchos investigadores. ¿Pero se trata realmente solo de una cuestión de computación, o tiene algo que ver con una noción de autenticidad en un sentido“aurático”, es decir, con un enfoqueexcesivo sobre pruebas materiales y datosmensurables?En esteartículo discutimos los requisitos de autenticidad para la arqueología virtual tal y como se formulan en los “Principios de Sevilla” (2011) y analizamos algunaslimitaciones de los enfoques actuales. Proponemos,además,una noción pluralista basada en la contextualización de objetos 3D en entornos de RV con información sinestésica (es decir, multisensorial). Esta nueva noción de autenticidad se basa más enla conservación de significados que en la conservación de características físicas. En línea con esta propuesta teórica, se comentarán dos casos de estudio: la documentación multimodal 3D de la Columna de Júpiterde Ladenburg (II d.C.) y la recreación en RV de una obra de arte moderno, la escultura audio-cinética Kaleidophonic Dog(1967) de Stephan von Huene. Estos dos proyectos ofrecen experiencias valiosas para una revisión de la noción de autenticidad tanto en la arqueología virtual como en la conservación de arte.This work was supported by the Stadt Karlsruhe (“Interdisziplinärer Fördertopf”) and the HEiKAResearch fonds (HEiKA, Heidelberg Karlsruhe Research Partnership)Muñoz Morcillo, J.; Schaaf, F.; Schneider, RH.; Robertson-Von Trotha, CY. (2017). Authenticity through VR-based documentation of cultural heritage. A theoretical approach based on conservation and documentation practices. Virtual Archaeology Review. 8(16):35-43. doi:10.4995/var.2017.5932.SWORD354381

    Influence of Polymorphisms Involved in Platelet Activation and Inflammatory Response on Aspirin-Related Upper Gastrointestinal Bleeding: A Case-Control Study

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    Background: Despite the wide benefits of aspirin and its cost-effectiveness, aspirin prescriptions have been reduced due to idiosyncratic responses in susceptible individuals. Low-dose aspirin and single-nucleotide polymorphisms (SNPs) are independently associated with increased risk of gastrointestinal hemorrhage; however, to-date, no studies investigated the SNP-aspirin interaction effect on upper gastrointestinal hemorrhage (UGIH). Therefore, we aimed to evaluate the role of 25 SNPs in multiple genes involved in platelet activation, angiogenesis and inflammatory response in aspirin-related UGIH. Methods: A multicenter, full case-control study was conducted in patients exposed and unexposed to aspirin. Three hundred twenty-six cases diagnosed with UGIH were matched with 748 controls (1:3) by age, gender, health center, and recruitment date. Only adults of European origin were included. Participants were stratified by aspirin exposure and genotype [(Aspirin(-), wild-type), (Aspirin(+), wild-type), (Aspirin(+), genetic variation), (Aspirin(-), genetic variation)]. For each SNP, the Odds Ratio of UGIH and their 95% confidence intervals were estimated in each subgroup by using the generalized linear mixed models for dependent binomial variables. SNP-aspirin interaction effect was estimated through Relative Excess Risk due to Interaction (RERI) measures. Results: We observed two categories of SNPs that might modify the risk magnitude of UGIH in aspirin consumers. Seven SNPs (rs1387180 A > G, rs2238631 T > C, rs1799964 T > C, rs5050 T > C/T > G, rs689466 T > C, rs1799983 T > A/T > G, and rs7756935 C > A) were "positive modifiers" associated with an excess of risk from aspirin exposure and carrying that genetic variation (1.75 T, rs1131882 G > A, rs4311994 C > T, rs10120688 G > A, rs4251961 T > C, rs3778355 G > C, rs1330344 C > T, rs5275 A > G/A > T, and rs3779647 C > T) were "negative modifiers" and associated with a reduced risk in aspirin users (-2.74 </= RERI </= -0.95). Conclusion: This preliminary study suggests that polymorphisms in genes involved in platelets activity, angiogenesis and inflammatory response might modify the risk of aspirin-related UGIH. Further studies with larger sample size and in different populations are needed to confirm our findings. If confirmed, this might have great impact on public health, thanks to aspirin's prophylactic properties in diseases of high incidence and severity

    Rationale and design of the RESOLVE trial: lanreotide as a volume reducing treatment for polycystic livers in patients with autosomal dominant polycystic kidney disease

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    Contains fulltext : 109282.pdf (publisher's version ) (Open Access)BACKGROUND: A large proportion of patients with autosomal dominant polycystic kidney disease (ADPKD) suffers from polycystic liver disease. Symptoms arise when liver volume increases. The somatostatin analogue lanreotide has proven to reduce liver volume in patients with polycystic liver disease. However, this study also included patients with isolated polycystic liver disease (PCLD). The RESOLVE trial aims to assess the efficacy of lanreotide treatment in ADPKD patients with symptomatic polycystic livers. In this study we present the design of the RESOLVE trial. METHODS/DESIGN: This open-label clinical trial evaluates the effect of 6 months of lanreotide in ADPKD patients with symptomatic polycystic livers. Primary outcome is change in liver volume determined by computerised tomography-volumetry. Secondary outcomes are changes in total kidney volume, kidney intermediate volume and renal function. Furthermore, urinary (NGAL, alpha1-microglobulin, KIM-1, H-FABP, MCP-1) and serum (fibroblast growth factor 23) biomarkers associated with ADPKD disease severity are assessed to investigate whether these biomarkers predict treatment responses to lanreotide. Moreover, safety and tolerability of the drug in ADPKD patients will be assessed. DISCUSSION: We anticipate that lanreotide is an effective therapeutic option for ADPKD patients with symptomatic polycystic livers and that this trial aids in the identification of patient related factors that predict treatment response. TRIAL REGISTRATION NUMBER: Clinical trials.gov NCT01354405
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