Papers by Alejandro Alonso
Revista Iberoamericana de Automática e Informática Industrial RIAI, 2014
En los sistemas distribuidos modernos, como la Internet o Web de las Cosas, la seguridad juega un... more En los sistemas distribuidos modernos, como la Internet o Web de las Cosas, la seguridad juega un papel preponderante. Debe prestarse especial atención a la consideración de estos aspectos en las primeras etapas de desarrollo. En este contexto, el desarrollo guiado por modelos de requisitos no funcionales (NF) presenta especial interés, ya que aborda dichas características NF en la etapa de diseño, cuando todavía se pueden realizar análisis, y aún hay margen para modificaciones antes de que éstas sean muy costosas. El uso de estas metodologías guiadas por modelos ofrece beneficios tales como el aumento de la productividad, una mayor reutilización de los elementos de diseño, o una mejor mantenibilidad del sistema. Este artículo presenta una estrategia de desarrollo que permite integrar aspectos NF de seguridad (confidencialidad, integridad, y control de acceso) en los sistemas de software empotrado.
Lecture Notes in Computer Science, 1992
The component library for both the cyclic and tasking executives has been released for distributi... more The component library for both the cyclic and tasking executives has been released for distribution by the Spanish Ministry of Defense. The approximate size for each of the executive subsytems is about 8000 loc. The test code adds up to 50000 loc for each subsystem.
Lecture Notes in Computer Science, 2004
The capability to monitor the amount of processor time that is used by real-time tasks is crucial... more The capability to monitor the amount of processor time that is used by real-time tasks is crucial for building real-time systems that are robust with respect to worst case execution time estimations. Executiontime clocks and timers have been proposed to be added to the language in order to support this functionality. Since a wide class of systems which may benefit from this mechanism are likely to use the Ada tasking subset known as the Ravenscar profile, it is important to check that the proposed execution-time clocks can be implemented on top of the simplified runtime systems that are used to support this profile. This paper describes a pilot implementation of execution-time clocks for the ORK kernel, and gives some examples of their possible usage in Ravenscar programs.
ACM SIGAda Ada Letters, 1993
During the last year, our group has been involved in the design and development of two reusabl e ... more During the last year, our group has been involved in the design and development of two reusabl e executive components to develop hard real-time systems [4][1][17]. This paper deals with one of them, the tasking executive. It is based on the rate monotonic and deadline monotoni c scheduling methods and takes full advantage of Ada features. It is not an executive built fro m scratch but rather a set of building blocks that allow users to develop hard real-time systems. This executive is designed in such a way that hard real-time ...
The European Physical Journal C, 2014
Distributions sensitive to the underlying event in QCD jet events have been measured with the ATL... more Distributions sensitive to the underlying event in QCD jet events have been measured with the ATLAS detector at the LHC, based on 37 pb −1 of proton-proton collision data collected at a centre-of-mass energy of 7 TeV. Chargedparticle mean p T and densities of all-particle E T and chargedparticle multiplicity and p T have been measured in regions azimuthally transverse to the hardest jet in each event. These are presented both as one-dimensional distributions and with their mean values as functions of the leading-jet transverse momentum from 20 to 800 GeV. The correlation of chargedparticle mean p T with charged-particle multiplicity is also studied, and the E T densities include the forward rapidity region; these features provide extra data constraints for Monte Carlo modelling of colour reconnection and beamremnant effects respectively. For the first time, underlying event observables have been computed separately for inclusive jet and exclusive dijet event selections, allowing more detailed study of the interplay of multiple partonic scattering and QCD radiation contributions to the underlying event. Comparisons to the predictions of different Monte Carlo models show a need for further model tuning, but the standard approach is found to generally reproduce the features of the underlying event in both types of event selection.
The European Physical Journal C, 2014
Many of the interesting physics processes to be measured at the LHC have a signature involving on... more Many of the interesting physics processes to be measured at the LHC have a signature involving one or more isolated electrons. The electron reconstruction and identification efficiencies of the ATLAS detector at the LHC have been evaluated using proton-proton collision data collected in 2011 at √ s = 7 TeV and corresponding to an integrated luminosity of 4.7 fb −1. Tag-and-probe methods using events with leptonic decays of W and Z bosons and J/ψ mesons are employed to benchmark these performance parameters. The combination of all measurements results in identification efficiencies determined with an accuracy at the few per mil level for electron transverse energy greater than 30 GeV. ation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the
2008 12th Enterprise Distributed Object Computing Conference Workshops, 2008
... We aim at using our tools with different concrete syntaxes: the UML Profile for MARTE [15] (t... more ... We aim at using our tools with different concrete syntaxes: the UML Profile for MARTE [15] (to be studied), an architecture language such as AADL [16], or as an stand-alone DSMLs (Domain Specific Modeling Language). ... [5] A. Solberg et al., A Framework for QoS-aware Model ...
2009 International Conference on Advanced Information Networking and Applications Workshops, 2009
Applications of high-quality multimedia embedded systems (HQMES) contain concurrent functionality... more Applications of high-quality multimedia embedded systems (HQMES) contain concurrent functionality pieces; they may have a flexible structure consisting of services, components, or tasks. This allows applications to offer different execution possibilities to provide a same (or different) output quality. Since multimedia applications are typically greedy resource consumers, they may interfere one another's execution; this can be a source of unpredictability, especially in the event of reconfigurations. This paper presents a description on how to minimize such execution uncertainty at different levels: (1) the OS has to offer the basic real-time support, (2) appropriate resource management techniques will have to be built, usually inside a QoSRM (QoS resource manager entity), and (3) applications should be designed in a flexible but yet manageable way. This paper recovers an efficient application characterization as the basis for offering the QoSRM a manageable application structure. On top of this application characterization, a contract model is described to provide predictable execution. Also, two reconfiguration algorithms are presented, so that application execution is kept predictable even during reconfiguration.
2009 7th IEEE International Conference on Industrial Informatics, 2009
Consumer electronics platforms are progressively being introduced in most domains, from personal ... more Consumer electronics platforms are progressively being introduced in most domains, from personal appliances to high-quality multimedia control infrastructures. They are high quality platforms that require that computation resources be used in a cost-effective way. Multimedia applications compete for resources in a greedy manner, which may threaten the safe system execution. Arbitration of application execution is needed to keep system stability, especially in the event of unexpected changes in the resource requirements demanded by applications. Changes may be caused by a modification in the nature of the incoming media or by the user action. Such changes should trigger an adaptation process to handle the new situation in a way that overall system quality is preserved. This paper describes the mechanisms that have been developed to handle situation where adaptation is needed in such a way that stability is preserved avoiding over reaction. An adaptation protocol based on the definition of a safety band for filtering peaks in resource demands is set for this purpose. The paper presents experimental results that show the appropriate filtering of these peaks, which validate the presented concepts.
10th IEEE International Symposium on Object and Component-Oriented Real-Time Distributed Computing (ISORC'07), 2007
RTSJ (Real-Time Specification for Java) extends and adapts the Java technology in order to allow ... more RTSJ (Real-Time Specification for Java) extends and adapts the Java technology in order to allow the development of real time systems. In RTSJ the requirements of distributed systems were not considered. The serialization in Java is an example of a basic operation that ...
Real-Time Systems, 1993
This paper summarizes the support for incremental, heterogeneous and distributed prototyping of r... more This paper summarizes the support for incremental, heterogeneous and distributed prototyping of real time systems developed as a part of the IPTES environment. After describing the overall architecture of the environment and related approaches, the paper focuses on the internal levels of the environment.
Physics Letters B, 2011
This letter reports a measurement of the muon charge asymmetry from W bosons produced in proton-p... more This letter reports a measurement of the muon charge asymmetry from W bosons produced in proton-proton collisions at a centre-of-mass energy of 7 TeV with the ATLAS experiment at the LHC. The asymmetry is measured in the W → µν decay mode as a function of the muon pseudorapidity using a data sample corresponding to a total integrated luminosity of 31 pb −1. The results are compared to predictions based on next-to-leading order calculations with various parton distribution functions. This measurement provides information on the u and d quark momentum fractions in the proton.
Physical Review D, 2012
A generic search is presented for a heavy particle decaying to WZ ! '' 0 ' 0 (', ' 0 ¼ e,) final ... more A generic search is presented for a heavy particle decaying to WZ ! '' 0 ' 0 (', ' 0 ¼ e,) final states. The data were recorded by the ATLAS detector in ffiffi ffi s p ¼ 7 TeV pp collisions at the Large Hadron Collider and correspond to an integrated luminosity of 1:02 fb À1. The transverse mass distribution of the selected WZ candidates is found to be consistent with the standard model expectation. Upper limits on the production cross section times branching ratio are derived using two benchmark models predicting a heavy particle decaying to a WZ pair.
Future Generation Computer Systems, 2012
Future high-quality consumer electronics will contain a number of applications running in a highl... more Future high-quality consumer electronics will contain a number of applications running in a highly dynamic environment, and their execution will need to be efficiently arbitrated by the underlying platform software. The multimedia applications that currently execute in such similar contexts face frequent run-time variations in their resource demands, originated by the greedy nature of the multimedia processing itself. Changes in resource demands are triggered by numerous reasons (e.g. a switch in the input media compression format). Such situations require real-time adaptation mechanisms to adjust the system operation to the new requirements, and this must be done seamlessly to satisfy the user experience. One solution for efficiently managing application execution is to apply quality of service resource management techniques, based on assigning and enforcing resource contracts to applications. Most resource management solutions provide temporal isolation by enforcing resource assignments and avoiding any resource overruns. However, this has a clear limitation over the cost-effective resource usage. This paper presents a simple priority assignment scheme based on uniform priority bands to allow that greedy multimedia tasks incur in safe overruns that increase resource usage and do not threaten the timely execution of non-overrunning tasks. Experimental results show that the proposed priority assignment scheme in combination with a resource accounting mechanism preserves timely multimedia execution and delivery, achieves a higher cost-effective processor usage, and guarantees the execution isolation of non-overrunning tasks.
The European Physical Journal C, 2011
A search for pair-produced scalar particles decaying to a four-jet final state is presented. The ... more A search for pair-produced scalar particles decaying to a four-jet final state is presented. The analysis is performed using an integrated luminosity of 34 pb −1 recorded by the ATLAS detector in 2010. No deviation from the Standard Model is observed. For a scalar mass of 100 GeV (190 GeV) the limit on the scalar gluon pair production cross section at 95% confidence level is 1 nb (0.28 nb). When these results are interpreted as mass limits, scalar-gluons (hyperpions) with masses of 100 to 185 GeV (100 to 155 GeV) are excluded at 95% confidence level with the exception of a mass window of width about 5 GeV (15 GeV) around 140 GeV.
The European Physical Journal C, 2011
We present first measurements of charged and neutral particle-flow correlations in pp collisions ... more We present first measurements of charged and neutral particle-flow correlations in pp collisions using the ATLAS calorimeters. Data were collected in 2009 and 2010 at centre-of-mass energies of 900 GeV and 7 TeV. Events were selected using a minimum-bias trigger which required a charged particle in scintillation counters on either side of the interaction point. Particle flows, sensitive to the underlying event, are measured using clusters of energy in the ATLAS calorimeters, taking advantage of their fine granularity. No Monte Carlo generator used in this analysis can accurately describe the measurements. The results are independent of those based on charged particles measured by the ATLAS tracking systems and can be used to constrain the parameters of Monte Carlo generators.
Control Engineering Practice, 2001
The need to avoid redundant efforts in software development has been recognized for a long time. ... more The need to avoid redundant efforts in software development has been recognized for a long time. Currently, work is focused on the generation of products that are designed to be reused. A reference architecture for robot teleoperation systems has been developed using the domain-engineering process and certain architectural patterns. The architecture has been applied successfully to the development of different teleoperation platforms used in the maintenance activities of nuclear power plants. In particular, this paper presents how the reference architecture has been implemented in different systems, such as the Remotely Operated Service Arm (ROSA), the Teleoperated and Robotized System for Maintenance Operation in Nuclear Power Plants Vessels (TRON) and the Inspection Retrieving Vehicle (IRV).
etsit.upm.es
Objetivo El objetivo general del curso es presentar tecnolog��as, modelos y arquitecturas de apli... more Objetivo El objetivo general del curso es presentar tecnolog��as, modelos y arquitecturas de aplicaciones y servicios avanzados en Internet, con ��nfasis en aquellos aspectos que tratan de mejorar prestaciones, calidad de servicio y escalabilidad. Objetivos adicionales del curso son practicar en lectura efectiva, cr��tica y en la presentaci��n de art��culos, realizar un trabajo de investigaci��n y, si es posible, publicarlo. Breve resumen del contenido del curso.
Uploads
Papers by Alejandro Alonso