Now showing items 98-117 of 134

    • Optimal policy for multi-class scheduling in a single server queue 

      Osipova N.; Ayesta U.; Avrachenkov K. (21st International Teletraffic Congress, ITC 21: Traffic and Performance Issues in Networks of the Future - Final Programme, 2009-12-31)
      In this paper we apply the Gittins optimality result to characterize the optimal scheduling discipline in a multi-class M/G/1 queue. We apply the general result to several cases of practical interest where the service time ...
    • Optimal routing in parallel, non-observable queues and the price of anarchy revisited 

      Anselmi J.; Gaujal B. (2010 22nd International Teletraffic Congress - Proceedings, ITC 22, 2010-12-31)
      We consider a network of parallel, non-observable queues and analyze the "price of anarchy", an index measuring the worst-case performance loss of a decentralized system with respect to its centralized counterpart in ...
    • An optimization tool to design the field of a Solar Power Tower plant allowing heliostats of different sizes 

      Carrizosa E.; Domínguez-Bravo C.; Fernández-Cara E.; Quero M. (International Journal of Energy Research, 2016-10-30)
      The design of a Solar Power Tower plant involves the optimization of the heliostat field layout. Fields are usually designed to have all heliostats of identical size. Although the use of a single heliostat size has been ...
    • A parallel Branch-and-Fix Coordination based matheuristic algorithm for solving large sized multistage stochastic mixed 0-1 problems 

      Aldasoro U.; Escudero L.F.; Merino M.; Pérez G. (European Journal of Operational Research, 2016-08-26)
      A parallel matheuristic algorithm is presented as a spin-off from the exact Branch-and-Fix Coordination (BFC) algorithm for solving multistage stochastic mixed 0-1 problems. Some steps to guarantee the solution’s optimality ...
    • Path Planning for Single Unmanned Aerial Vehicle by Separately Evolving Waypoints 

      Yang P.; Tang K.; Lozano J.A.; Cao X. (IEEE Transactions on Robotics, 2015-12-31)
      Evolutionary algorithm-based unmanned aerial vehicle (UAV) path planners have been extensively studied for their effectiveness and flexibility. However, they still suffer from a drawback that the high-quality waypoints in ...
    • Penalized composite link mixed models for two-dimensional count data 

      Ayma D.; Durbán M.; Lee D.-J.; Eilers P.H.C. (2015-05)
      Mortality data provide valuable information for the study of the spatial distribution of mortality risk, in disciplines such as spatial epidemiology, medical demography, and public health. However, they are often available ...
    • Penalized composite link models for aggregated spatial count data: a mixed model approach 

      Ayma D.; Durbán M.; Lee D.-J.; Eilers P.H.C. (Spatial Statistics, 2016-01-01)
      Mortality data provide valuable information for the study of the spatial distri- bution of mortality risk, in disciplines such as spatial epidemiology and public health. However, they are frequently available in an aggregated ...
    • perm mateda: A matlab toolbox of estimation of distribution algorithms for permutation-based combinatorial optimization problems 

      Irurozki E.; Ceberio J.; Santamaria J.; Santana R.; Mendiburu A. (ACM Transactions on Mathematical Software, 2018)
      Permutation problems are combinatorial optimization problems whose solutions are naturally codified as permutations. Due to their complexity, motivated principally by the factorial cardinality of the search space of ...
    • Predicting Pregnancy Outcomes Using Longitudinal Information: A Penalized Splines Mixed–Effects Model Approach 

      De la Cruz R.; Fuentes C.; Meza C.; Lee D.-J.; Arribas-Gil A. (Statistics in Medicine, 2017-02-09)
      We propose a semiparametric mixed–effects model (SNMM) using penalized splines to clas- sify longitudinal data and improve the prediction of a binary outcome. The work is motivated by a study in which different hormone ...
    • PrEveCOPD: A computer application to predict adverse events in the short-term evolution of patients with exacerbation of COPD 

      Arostegui I.; Legarreta Maria J.; Barrio I.; Esteban C.; Garcia-Gutierrez S.; Quintana J.M.; IRYSS-COPD Group (Journal of Medical Internet Research, 2018)
      Background: Chronic obstructive Pulmonary Disease (COPD) is a common chronic disease. Exacerbations of COPD (eCOPD) contribute to worsening of the disease and patient´s evolution. There are some clinical prediction rules ...
    • Price of anarchy in non-cooperative load balancing games 

      Ayesta U.; Brun O.; Prabhu B.J. (Performance Evaluation, 2011-12-31)
      We investigate the price of anarchy of a load balancing game with K dispatchers. The service rates and holding costs are assumed to depend on the server, and the service discipline is assumed to be processor-sharing at ...
    • Properties of the gittins index with application to optimal scheduling 

      Aalto S.; Ayesta U.; Righter R. (Probability in the Engineering and Informational Sciences, 2011-12-31)
      We consider the optimal scheduling problem for a single-server queue without arrivals. We allow preemptions, and our purpose is to minimize the expected flow time. The optimal nonanticipating discipline is known to be the ...
    • Regularized optimization methods for convex MINLP problems 

      de Oliveira W. (TOP, 2016-01-01)
      We propose regularized cutting-plane methods for solving mixed-integer nonlinear programming problems with nonsmooth convex objective and constraint functions. The given methods iteratively search for trial points in certain ...
    • Resource-sharing in a single server with time-varying capacity 

      Ayesta U.; Erausquin M.; Jacko P. (2011 49th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2011, 2011-12-31)
      We investigate the problem of sharing the resources of a single server with time-varying capacity with the objective of minimizing the mean delay. We formulate the resource allocation problem as a Markov Decision Process. ...
    • A review on distance based time series classification 

      Abanda A.; Mori U.; Lozano JA. (Data Mining and Knowledge Discovery,, 2018-11-01)
      Time series classification is an increasing research topic due to the vast amount of time series data that is being created over a wide variety of fields. The particularity of the data makes it a challenging task and ...
    • Sample size impact on the categorisation of continuous variables in clinical prediction 

      Barrio I.; Arostegui I.; Rodríguez-Álvarez M.X. (Trends in Mathematics. Research Perspectives CRM Barcelona. Extended Abstracts Fall 2015. Biomedical Big Data; Statistics for Low Dose Radiation Research, 2017-12)
      Recent advances in information technologies are generating a growth in the amount of available biomedical data. In this paper, we studied the impact sample size may have on the categorisation of a continuous predictor ...
    • Scheduling of users with Markovian time-varying transmission rates 

      Cecchi F.; Jacko P. (Performance Evaluation Review, 2013-12-31)
      We address the problem of developing a well-performing and implementable scheduler of users with wireless connection to the base station. The main feature of such real-life systems is that the quality conditions of the ...
    • A simple Bayesian linear excess relative risk model 

      Higueras M.; Harbron R.W.; Pearce M.S. (2017-07-11)
      A new Bayesian Poisson relative risk model is proposed for displaying the excess relative risk associated to a unique exposure as a probability distribution in a closed form. The background risk can be modelled by a unique ...
    • Smooth additive mixed models for predicting aboveground biomass 

      Sánchez-González M.; Durbán M.; Lee D.-J.; Cañellas I.; Sixto H. (Journal of Agricultural, Biological and Environmental Statistics, 2016-12-01)
      Aboveground biomass estimation in short-rotation forestry plantations is an essential step in the development of crop management strategies as well as allowing the economic viability of the crop to be determined prior to ...
    • Soft range information for network localization 

      Mazuelas S.; Conti A.; Allen J.C.; Win M.Z. (IEEE Transactions on Signal Processing, 2018-06-15)
      The demand for accurate localization in complex environments continues to increase despite the difficulty in extracting positional information from measurements. Conventional range-based localization approaches rely on ...