High capacity optical links for datacentre connectivity

There is a timely and growing demand for high capacity optical data transport solutions to provide connectivity inside data centres and between data centres located at different geographical locations. The requirements for reach are in the order of 2 km for intra-datacentre and up to 100 km for inter-datacentre connectivity. Moreover, the requirements for such connectivity solutions include also low cost, high data rate and desirable features such as energy efficiency and reduced interfacing cost. In this paper we review several approaches for intra and inter datacentre that use advanced modulation formats and multiplexing techniques to cope with the requirement of high capacity as well as techniques for reach extension

Frequency of dermatological lesions in adult intensive care patients

Objetivo: describir la frecuencia de las lesiones dermatológicas en pacientes de la Unidad de Cuidados Intensivos (UCI) de adultos del Hospital de San José y del Hospital Infantil Universitario de San José entre enero y abril de 2012. Pacientes y métodos: se realizó un estudio descriptivo de corte transversal. Se incluyeron pacientes mayores de 18 años con estancia mínima de 72 horas en UCI, ingresados por patología dermatológica o valorados por dermatología por aparición de lesiones en piel durante su estancia. Resultados: se evaluaron 595 pacientes, encontrando lesiones dermatológicas en 30% (182 pacientes). La edad promedio fue de 63.5 años ± 19.1 sin diferencias de género. La admisión a la UCI se debió principalmente a motivos no quirúrgicos con un porcentaje de 57.3% (105 pacientes). Las lesiones cutáneas más frecuentes fueron las lesiones terciarias observada en 91.8% (168 pacientes), seguida por lesiones secundarias, con predominio infeccioso 6% (11 pacientes) y las últimas fueron las primarias con sólo 1.6% (3 pacientes). Conclusiones: las lesiones dermatológicas en los pacientes de UCI son más frecuentes de lo esperado y en algunos casos pueden ser la causa directa del ingreso a la UCI poniendo en riesgo la vida de los pacientes, por lo tanto, consideramos importante un examen exhaustivo de piel en estos pacientes y el trabajo interdisciplinario con dermatología que permita disminuir el riesgo de mortalidad a causa de complicaciones de origen dermatológico.Objective: to describe the frequency of dermatological lesions in patients of the Intensive Care Unit (ICU) of adults of the Hospital de San José and the Hospital Infantil Universitario de San José between January and April 2012. Patients and Methods: a descriptive cross-sectional study was carried out. Patients older than 18 years with a minimum stay of 72 hours in the ICU admitted for dermatological pathology or assessed by dermatology due to the appearance of skin lesions during their stay, were included. Results: 595 patients were evaluated, finding dermatological lesions in 30% (182 patients). The average age was 63.5 years ± 19.1 without gender differences. Admission to the ICU was mainly due to non-surgical reasons with a percentage of 57.3% (105 patients). The most frequent skin lesions were the tertiary lesions observed in 91.8% (168 patients), followed by secondary lesions, with an infectious predominance of 6% (11 patients) and the last ones were the primary ones with only 1.6% (3 patients). Conclusions: dermatological lesions in ICU patients are more frequent than expected and in some cases may be the direct cause of admission to the ICU putting patients’ lives at risk; therefore, we consider important a thorough skin examination in these patients and interdisciplinary work with dermatology to reduce the risk of mortality due to dermatological complication

Link abstraction models based on mutual information for LTE downlink

Postprint (author’s final draft

Machine learning adaptive computational capacity prediction for dynamic resource management in C-RAN

Efficient computational resource management in 5G Cloud Radio Access Network (C-RAN)environments is a challenging problem because it has to account simultaneously for throughput, latency,power efficiency, and optimization tradeoffs. The assumption of a fixed computational capacity at thebaseband unit (BBU) pools may result in underutilized or oversubscribed resources, thus affecting the overallQuality of Service (QoS). As resources are virtualized at the BBU pools, they could be dynamically instan-tiated according to the required computational capacity (RCC). In this paper, a new strategy for DynamicResource Management with Adaptive Computational capacity (DRM-AC) using machine learning (ML)techniques is proposed. Three ML algorithms have been tested to select the best predicting approach: supportvector machine (SVM), time-delay neural network (TDNN), and long short-term memory (LSTM). DRM-AC reduces the average of unused resources by 96 %, but there is still QoS degradation when RCC is higherthan the predicted computational capacity (PCC). To further improve, two new strategies are proposed andtested in a realistic scenario: DRM-AC with pre-filtering (DRM-AC-PF) and DRM-AC with error shifting(DRM-AC-ES), reducing the average of unsatisfied resources by 98 % and 99.9 % compared to the DRM-AC, respectivelyThis work was supported in part by the Spanish ministry of science through the project CRIN-5G (RTI2018-099880-B-C32) withERDF (European Regional Development Fund) and in part by the UPC through COST CA15104 IRACON EU Project and theFPI-UPC-2018 Grant.Peer ReviewedPostprint (published version

IMPACTO AMBIENTAL GENERADO POR EL USO DE OSMOSIS INVERSA EN LA REMOCIÓN DE ARSÉNICO PARA LA OBTENCIÓN DE AGUA POTABLE

Para mitigar la exposición de la población al consumo de agua con altas concentraciones de arsénico, se han instalado en el Estado de Chihuahua, más de 300 sistemas de osmosis inversa (POI) en 273 comunidades. Las plantas de osmosis inversa, concentran el contaminante en el  agua de rechazo. La disposición inadecuada de dichos residuos, está generando una problemática ambiental en suelo y agua superficial. El presente estudio tuvo como objetivo analizar el impacto ambiental de la disposición del agua de rechazo en suelo agrícola. Se determinó la concentración de As en el agua de rechazo, y su disposición, en las POI de diferentes poblados. Los resultados indican que el 58% de las descargas son en los drenajes, y el 18% son utilizadas para riego agrícola. Para las POI de la zona, la disposición en suelo agrícola, concentra el metaloide en la superficie con  velocidades de saturación al límite (NOM) de hasta 23 días/m2. Una alternativa de recuperación del  agua de rechazo, control del As y con ello limitación de los impactos lo constituye el uso de humedales construidos

Link level simulator for LTE downlink

3GPP LTE is the evolution of UMTS which will make possible to deliver next generation high quality multimedia services according to the users’ expectations. The flexibility of the downlink OFDM radio interface with Adaptive Modulation and Coding (AMC), MIMO and HARQ plays a crucial role in achieving the low latency and high spectral efficiency promised by the new radio access standard. This paper presents a link level simulator for LTE downlink whose main purpose is to generate suitable look-up tables to interface with a system level simulator. The obtained results include curves of mean link level throughput for different AMC formats and MIMO configurations. The methodology for training the Exponential Effective SINR model is also described with an example.Postprint (published version

Comparison of different distributed scheduling strategies for static/dynamic LTE scenarios

Postprint (published version

Exponential effective SIR link performance model for LTE downlink

Postprint (published version

Comparison of 3G-LTE DL scheduling strategies

Postprint (published version

Link and system level simulation of downlink LTE

3GPP LTE is the evolution of the UMTS which will make possible to deliver next generation high quality multimedia services according to the users’ expectations. Since Radio Resource Management (RRM) has been recognized as a key point to successfully accomplish this target, the performance evaluation of a multi-cell resource allocation scheme applied to LTE downlink (DL) is presented in this paper. A semi-distributed and a fully-distributed RRM framework are compared on the basis of the obtained system throughput. Detailed link level simulations have also been carried out to properly back up the system level results.Postprint (published version