A study of the effects of clustering and local search on radio network design: evolutionary computation approaches

Eighth International Conference on Hybrid Intelligent Systems. Barcelona, 10-12 September 2008The goal of this paper is twofold. First, we want to make a study about how evolutionary computation techniques can efficiently solve the radio network design problem. For this goal we test several evolutionary computation techniques within the OPLINK experimental framework and compare them. Second, we propose a clustering approach and a 2-OPT in order to improve the results obtained by the evolutionary algorithms. Experiments carried out provide empirical evidence of how clustering-based techniques help in improving all algorithms tested. Extensive computational tests, including ones without clustering and 2-OPT, are performed with three evolutionary algorithms: genetic algorithms, memetic algorithms and chromosome appearance probability matrix algorithms.Publicad

Diluting the Scalability Boundaries: Exploring the Use of Disaggregated Architectures for High-Level Network Data Analysis

Traditional data centers are designed with a rigid architecture of fit-for-purpose servers that provision resources beyond the average workload in order to deal with occasional peaks of data. Heterogeneous data centers are pushing towards more cost-efficient architectures with better resource provisioning. In this paper we study the feasibility of using disaggregated architectures for intensive data applications, in contrast to the monolithic approach of server-oriented architectures. Particularly, we have tested a proactive network analysis system in which the workload demands are highly variable. In the context of the dReDBox disaggregated architecture, the results show that the overhead caused by using remote memory resources is significant, between 66\% and 80\%, but we have also observed that the memory usage is one order of magnitude higher for the stress case with respect to average workloads. Therefore, dimensioning memory for the worst case in conventional systems will result in a notable waste of resources. Finally, we found that, for the selected use case, parallelism is limited by memory. Therefore, using a disaggregated architecture will allow for increased parallelism, which, at the same time, will mitigate the overhead caused by remote memory.Comment: 8 pages, 6 figures, 2 tables, 32 references. Pre-print. The paper will be presented during the IEEE International Conference on High Performance Computing and Communications in Bangkok, Thailand. 18 - 20 December, 2017. To be published in the conference proceeding

La absorción acústica a ruido de impacto en placas de aislamiento térmico de suelo radiante

Actualmente en el mercado existen una reducida variedad de materiales específicos de ruido de impactos. Los materiales que han de ser utilizados como material resiliente, han de cumplir unos valores muy bajos del módulo de elasticidad E. Mientras el valor del caucho blando está en el orden de los 100 kg/cm2, el valor del acero es de 2.100.000 kg/cm2 (21.000 veces mayor). Estos valores tan bajos hacen que diferencias de apenas 50 kg/cm2 produzcan variaciones muy importantes en las ganancias de aislamiento acústico. La realización de los ensayos de caracterización acústica a ruido de impacto en laboratorio es un proceso largo y caro. En primer lugar se necesita elaborar un forjado de referencia, que ha de ser ensayado de forma independiente. Con posterioridad, se ha de colocar la losa flotante, y volver a realizar la prueba. Con la diferencia de las medidas realizadas, se determinan los valores de módulo de elasticidad. Como alternativa a este método, en la ponencia del congreso “TECNIACÚSTICA GANDÍA 2006” sobre “estudio de cinco métodos para determinar las propiedades dinámicas de capas elásticas para la mejora del aislamiento a ruido de impactos”, presentada por Francisco Simón, David K. Anthony, Mª José Fernández, proponen un total de cinco alternativas al ensayo indicado en la norma. Al margen de las condiciones acústicas, las placas de suelo radiante necesitan garantizar unos valores mínimos de aislamiento térmico. Con las actuales necesidades normativas, la solución habitual consiste en la superposición de dos materiales: en primer lugar, inmediatamente sobre el forjado, se coloca el material encargado de proporcionar el aislamiento acústico, generalmente una lámina flexible de polietileno. Encima de ella se coloca la placa de aislamiento térmico, generalmente una plancha de poliestireno expandido con resaltes en las que se encajan las tuberías que conducen el agua calefactada. El poliestireno expandido convencional, no tiene unos valores de módulo elástico suficientemente bajo para poder actuar como material resiliente. Para conseguir estos valores, es necesario elastificar el material mediante su introducción en una prensa (Poliestireno expandido elastificado EEPS). La utilización de esta técnica es incompatible con el proceso de fabricación de planchas moldeadas con tetones para la integración de los soportes de las tuberías. La lámina flexible de polietileno, si tienes valores aceptables, tanto de aislamiento térmico como acústico, en cambio no es posible la integración de los tetones durante su proceso de fabricación para soportar las canalizaciones de agua. El objetivo de la investigación consiste en integrar en una única placa las características tanto térmicas como acústicas necesarias para satisfacer todas las necesidades. Como se ha indicado más arriba, los materiales resilientes han de cumplir unos valores muy bajos del módulo de elasticidad E. Mientras el valor del caucho blando está en el orden de los 100 kg/cm2, el valor del acero es de 2.100.000 kg/cm2 (21.000 veces mayor). Pero no es menos cierto que con acero, dando la forma adecuada (un helicoide) se consigue un elemento muy elástico, un muelle. Tal es así, que variando la forma se puede conseguir el módulo de elásticidad E deseado, resultando utilidades tan dispares como el resorte de un bolígrafo o la suspensión de un coche. Por otro lado, y como se ha indicado anteriormente, la determinación de los valores mecánicos de los materiales aislantes térmicos es cara y complicada. Como objetivo secundario de la investigación, se establece el proponer un ensayo alternativo, más rápido y económico que el propuesto por la norma para facilitar el estudio de nuevas alternativas, sin tener que hacer grandes desembolsos económicos e

Innovative Risk Assessment Framework for Hydraulic Control of Irrigation Reservoirs´ Breaching

[EN] This research introduces an innovative framework aimed at developing a risk assessment to analyse the breaching hydraulic control of non-impounding reservoirs for irrigation purposes, called irrigation reservoirs (IRs). This approach comprises an analytical method based on several empirical formulas where the one that best fts the diferent geometric characteristics of IR water systems is chosen. Furthermore, a stochastic framework allows for the incorpo ration of the occurrence probability as a tool to characterize the risk analysis of IRs. This occurrence probability has two components: probability based on the bottom elevation of a fnal breach and probability based on the failure mode (piping in this case). In risk assessment terms, the ultimate product comprises the maximum hazard probability maps that allow a signifcant improvement in the representation of the artifcial fooding efect. This research was successfully applied in two dimensions, synthetically and realistically, in the Las Porteras and Macías Picavea IR water systems (Spain). This approach may improve the management of this type of hydraulic infrastructure and its surrounding area by reducing the risk of experiencing negative consequences derived from uncontrolled hydraulic breaching.Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCLE

Caracterización mecánica experimental de un hormigón ligero estructural = Experimental mechanical characterisation of a structural lightweight aggregate concrete

The self load of the structure is usually similar even bigger than any other load load which a structure carries. Due to this fact a number of structure are inefficient. The replacement in concrete of normal aggregate by lightweight aggregate reaches a markedly reduction of the concrete weight. The mechanical behavior of a lightweight aggregate concrete is analyzed in this paper. A number of tests have been done at different ages. These results have been compared with the predicted mechanical values of some regulatio

Consideraciones respecto al comportamiento físico y mecanico de hormigones ligeros estructurales

Resulta paradójico que a pesar de las enormes ventajas que supone en muchas aplicaciones de construcción el empleo del hormigón ligero estructural (HLE) frente a un hormigón convencional (HC), su uso todavía no se haya generalizado. Muy posiblemente, el desconocimiento de su comportamiento físico y mecánico contribuye de forma decisiva a la utilización de un HC en muchas ocasiones en las que su sustitución por HLE sería totalmente competitivo y ventajoso. Este trabajo pretende ampliar el conocimiento del comportamiento del HLE para contribuir a su utilización en todas las situaciones en donde su empleo supone una clara ventaja frente al HC

Autonomy support in the aquatic motivational healthy program through the SDT

This study aimed to test an aquatic motivation healthy program based on the self determination theory (SDT), using a quasi-experimental study. The research data come from different physical, psycho-social and behavioral measures made on 49 women. The sample was divided into two groups, an experimental group consisting of 28 women (M= 43.64; SD= 12.06), with an average experience of 3.05 years, and a control group composed of 21 women (M= 47.14; SD= 10.01), with an average experience of 2.29 years doing physical exercise in an aquatic environment in a large Spanish city. After the intervention with a program based on the SDT and instructor’s autonomy support, both groups perceived physical benefits for health, but the experimental group perceived a better instructor’s autonomy support, a better relationship with others and a greater psychological well-being among the practitioners. The information offered in this study may be of interest to promote for instructor part, these type the aquatic physical exercise programs in favor of the population’s health

Holocene aeolian phases and human settlements along the Atlantic coast of southern Spain

A combined geomorphological, radiocarbon dating, archaeological and historical approach permits a refining of the age of the coastal dune systems related to estuaries in the Gulf of Cadiz. Three dune systems are distinguished in this paper. The oldest one, DI, which accumulated under prevailing WSW winds during the first millennium BC, overlays both the occupational horizons of Late Neolithic-Early Copper Age (fourth millennium BC) and the 'lithic workshop levels' (fourth to second millennia BC). The middle dune system, D2, containing both Roman and medieval remains, accumulated between the thirteenth or fourteenth centuries and the seventeenth century AD. The youngest D3 system is associated with the time of building of watchtowers in the seventeenth century AD but extends to the present; it is related to SW prevailing winds. We explain the absence of aeolian deposits prior to ~2700 cal. BP as the result of trapping of a large part of the sediment supply in the estuaries, which starved the neighbouring beaches and aeolian settings. Aeolian accumulation reached significant values when sedimentation in the coastal zone changed from being mainly aggradational in the estuaries (~6500~2700 cal. BP) to mainly progradational in spit barriers and related dunes (post ~2700 cal. BP). The present analysis of aeolian systems suggests a non-direct correlation, at least in some cases, between coastal progradation of spit barriers and aridity

dReDBox: Materializing a full-stack rack-scale system prototype of a next-generation disaggregated datacenter

Current datacenters are based on server machines, whose mainboard and hardware components form the baseline, monolithic building block that the rest of the system software, middleware and application stack are built upon. This leads to the following limitations: (a) resource proportionality of a multi-tray system is bounded by the basic building block (mainboard), (b) resource allocation to processes or virtual machines (VMs) is bounded by the available resources within the boundary of the mainboard, leading to spare resource fragmentation and inefficiencies, and (c) upgrades must be applied to each and every server even when only a specific component needs to be upgraded. The dRedBox project (Disaggregated Recursive Datacentre-in-a-Box) addresses the above limitations, and proposes the next generation, low-power, across form-factor datacenters, departing from the paradigm of the mainboard-as-a-unit and enabling the creation of function-block-as-a-unit. Hardware-level disaggregation and software-defined wiring of resources is supported by a full-fledged Type-1 hypervisor that can execute commodity virtual machines, which communicate over a low-latency and high-throughput software-defined optical network. To evaluate its novel approach, dRedBox will demonstrate application execution in the domains of network functions virtualization, infrastructure analytics, and real-time video surveillance.This work has been supported in part by EU H2020 ICTproject dRedBox, contract #687632.Peer ReviewedPostprint (author's final draft

Experimental mechanical characterisation of a estructural lightweigth aggregate concrete acording to EC-2

The self load of a structure is usually higher than the loads it has to carry. It means that these kind of structures are quite often inefficient. The replacement in concrete of the normal aggregate by other lighter materials leads to a significant fall in the concrete weight. The normal aggregate has been replaced by lightweight aggregate since Roman Empire Ages. It has let singular buildings as Agripa's Pantheon or the Coliseum in Rome. Teh evolution according to the age of the compression and tensile strength and the Elastic Modulus in a Lightweight Aggregate Concrete (LAC) has been analysed in this paper. The concrete was produced by LAFARGE. Its commercial name is THERMEDIA. The experimental researches has been compared with predicted values by EC-2