Recursos de colección

Archivo Digital UPM (123.000 recursos)

This is an institutional repository providing access to the research output of the institution. Primarily contains thesis.

Materia = Informática

Mostrando recursos 1 - 20 de 62

  1. Agent-based modeling and simulation for the design of the future european Air Traffic Management system: the experience of CASSIOPEIA

    Molina, Martin; Carrasco, Sergio; Martín Cristobal, Jorge
    The SESAR (Single European Sky ATM Research) program is an ambitious re-search and development initiative to design the future European air traffic man-agement (ATM) system. The study of the behavior of ATM systems using agent-based modeling and simulation tools can help the development of new methods to improve their performance. This paper presents an overview of existing agent-based approaches in air transportation (paying special attention to the challenges that exist for the design of future ATM systems) and, subsequently, describes a new agent-based approach that we proposed in the CASSIOPEIA project, which was developed according to the goals of the...

  2. Sized Type Analysis for Logic Programs (Technical Communication)

    Serrano Mena, Alejandro; López García, Pedro; Bueno Carrillo, Francisco; Hermenegildo, Manuel V.
    We present a novel analysis for relating the sizes of terms and subterms occurring at diferent argument positions in logic predicates. We extend and enrich the concept of sized type as a representation that incorporates structural (shape) information and allows expressing both lower and upper bounds on the size of a set of terms and their subterms at any position and depth. For example, expressing bounds on the length of lists of numbers, together with bounds on the values of all of their elements. The analysis is developed using abstract interpretation and the novel abstract operations are based on setting...

  3. Supporting pruning in tabled LP

    Chico de Guzmán, Pablo; Hermenegildo, Manuel V.; Carro Liñares, Manuel
    This paper analyzes issues which appear when supporting pruning operators in tabled LP. A version of the once/1 control predicate tailored for tabled predicates is presented, and an implementation analyzed and evaluated. Using once/1 with answer-on-demand strategies makes it possible to avoid computing unneeded solutions for problems which can benefit from tabled LP but in which only a single solution is needed, such as model checking and planning. The proposed version of once/1 is also directly applicable to the efficient implementation of other optimizations, such as early completion, cut-fail loops (to, e.g., prune at the top level), if-then-else, and constraint-based...

  4. Mandate M 376: new software accessibility requirements

    Martínez Normand, Loïc; Pluke, Michael
    Software needs to be accessible for persons with disabilities and there are several guidelines to assist developers in building more accessible software. Regulation activities are beginning to make the accessibility of software a mandatory requirement in some countries. One such activity is the European Mandate M 376, which will result in a European standard (EN 301 549) defining functional accessibility requirements for information and communication technology products and services. This paper provides an overview of Mandate M 376 and EN 301 549, and describes the requirements for software accessibility defined in EN 301 549, according to a feature-based approach

  5. A first approach to the optimization of Bogotá's TransMilenio BRT system

    Jiménez Martín, Antonio; Mateos Caballero, Alfonso; Peña Escobar, Francisco J.
    Bus rapid transit (BRT) systems are massive transport systems with medium/high capacity, high quality service and low infrastructure and operating costs. TransMilenio is Bogotá's most important mass transportation system and one of the biggest BRT systems in the world, although it only has completed its third construction phase out of a total of eight. In this paper we review the proposals in the literature to optimize BRT system operation, with a special emphasis on TransMilenio, and propose a mathematical model that adapts elements of the above proposals and incorporates novel elements accounting for the features of TransMilenio system.

  6. An interactive method of fuzzy probability elicitation in risk analysis

    Vicente Cestero, Eloy; Jiménez Martín, Antonio; Mateos Caballero, Alfonso
    Expert knowledge is used to assign probabilities to events in many risk analysis models. However, experts sometimes find it hard to provide specific values for these probabilities, preferring to express vague or imprecise terms that are mapped using a previously defined fuzzy number scale. The rigidity of these scales generates bias in the probability elicitation process and does not allow experts to adequately express their probabilistic judgments. We present an interactive method for extracting a fuzzy number from experts that represents their probabilistic judgments for a given event, along with a quality measure of the probabilistic judgments, useful in a...

  7. Software industry experiments: a systematic literature review

    Dieste Tubio, Oscar; Juristo Juzgado, Natalia; Martínez, Mauro Danilo
    There is no specialized survey of experiments conducted in the software industry. Goal: Identify the major features of software industry experiments, such as time distribution, independent and dependent variables, subject types, design types and challenges. Method: Systematic literature review, taking the form of a scoping study. Results: We have identified 10 experiments and five quasi-experiments up to July 2012. Most were run as of 2003. The main features of these studies are that they test technologies related to quality and management and analyse outcomes related to effectiveness and effort. Most experiments have a factorial design. The major challenges faced by...

  8. Generating reference models for structurally complex data: application to the stabilometry medical domain

    Alonso Amo, Fernando; Lara Torralbo, Juan Alfonso; Martínez Normand, Loïc; Pérez Pérez, Aurora; Caraça-Valente Hernández, Juan Pedro
    We present a framework specially designed to deal with structurally complex data, where all individuals have the same structure, as is the case in many medical domains. A structurally complex individual may be composed of any type of singlevalued or multivalued attributes, including time series, for example. These attributes are structured according to domain-dependent hierarchies. Our aim is to generate reference models of population groups. These models represent the population archetype and are very useful for supporting such important tasks as diagnosis, detecting fraud, analyzing patient evolution, identifying control groups, etc.

  9. STONE: a stream-based DDoS defense framework

    Callau-Zori, Mar; Jiménez-Peris, Ricardo; Gulisano, Vincenzo Massimiliano; Papatriantafilou, Marina; Fu, Zhang; Patiño-Martínez, Marta
    An effective Distributed Denial of Service (DDoS) defense mechanism must guarantee legitimate users access to an Internet service masking the effects of possible attacks. That is, it must be able to detect threats and discard malicious packets in a online fashion. Given that emerging data streaming technology can enable such mitigation in an effective manner, in this paper we present STONE, a stream-based DDoS defense framework, which integrates anomaly-based DDoS detection and mitigation with scalable data streaming technology. With STONE, the traffic of potential targets is analyzed via continuous data streaming queries maintaining information used for both attack detection and...

  10. A syntactic and functional correspondence between reduction semantics and reduction-free full normalisers

    García-Pérez, Álvaro; Nogueira, Pablo
    Olivier Danvy and others have shown the syntactic correspondence between reduction semantics (a small-step semantics) and abstract machines, as well as the functional correspondence between reduction-free normalisers (a big-step semantics) and abstract machines. The correspondences are established by program transformation (so-called interderivation) techniques. A reduction semantics and a reduction-free normaliser are interderivable when the abstract machine obtained from them is the same. However, the correspondences fail when the underlying reduction strategy is hybrid, i.e., relies on another sub-strategy. Hybridisation is an essential structural property of full-reducing and complete strategies. Hybridisation is unproblematic in the functional correspondence. But in the syntactic...

  11. Towards a systematic benchmarking of ontology-based query rewriting systems

    Mora, José; Corcho, Oscar
    Query rewriting is one of the fundamental steps in ontologybased data access (OBDA) approaches. It takes as inputs an ontology and a query written according to that ontology, and produces as an output a set of queries that should be evaluated to account for the inferences that should be considered for that query and ontology. Different query rewriting systems give support to different ontology languages with varying expressiveness, and the rewritten queries obtained as an output do also vary in expressiveness. This heterogeneity has traditionally made it difficult to compare different approaches, and the area lacks in general commonly agreed...

  12. A model-driven approach to teaching concurrency

    Carro Liñares, Manuel; Mariño Carballo, Julio; Herranz Nieva, Ángel
    We present an undergraduate course on concurrent programming where formal models are used in different stages of the learning process. The main practical difference with other approaches lies in the fact that the ability to develop correct concurrent software relies on a systematic transformation of formal models of inter-process interaction (so called shared resources), rather than on the specific constructs of some programming language. Using a resource-centric rather than a language-centric approach has some benefits for both teachers and students. Besides the obvious advantage of being independent of the programming language, the models help in the early validation of concurrent...

  13. Note on Friedman's "what informatics is and isn't"

    Maojo García, Víctor Manuel
    Friedman’s article ‘What informatics is and isn’t’, presents a necessary and timely analysis of the field of informatics.

  14. Reachability-based acyclicity analysis by Abstract Interpretation

    Genaim, Samir; Zanardini, Damiano
    In programming languages with dynamic use of memory, such as Java, knowing that a reference variable x points to an acyclic data structure is valuable for the analysis of termination and resource usage (e.g., execution time or memory consumption). For instance, this information guarantees that the depth of the data structure to which x points is greater than the depth of the data structure pointed to by x.f for any field f of x. This, in turn, allows bounding the number of iterations of a loop which traverses the structure by its depth, which is essential in order to prove the...

  15. Secure optical networks based on quantum key distribution and weakly trusted repeaters

    Elkouss Coronas, David; Martinez Mateo, Jesus; Ciurana Aguilar, Alex; Martín Ayuso, Vicente
    Abstract—In this paper we explore how recent technologies can improve the security of optical networks. In particular, we study how to use quantum key distribution(QKD) in common optical network infrastructures and propose a method to overcome its distance limitations. QKD is the first technology offering information theoretic secretkey distribution that relies only on the fundamental principles of quantum physics. Point-to-point QKDdevices have reached a mature industrial state; however, these devices are severely limited in distance, since signals at the quantum level (e.g., single photons) are highly affected by the losses in the communication channel and intermediate devices. To overcome this limitation, intermediate nodes (i.e., repeaters) are used. Both...

  16. Probabilistic reasoning with an enzyme-driven DNA device

    Sainz de Murieta Fuentes, Iñaki; Rodríguez-Patón Aradas, Alfonso
    We present a biomolecular probabilistic model driven by the action of a DNA toolbox made of a set of DNA templates and enzymes that is able to perform Bayesian inference. The model will take single-stranded DNA as input data, representing the presence or absence of a specific molecular signal (the evidence). The program logic uses different DNA templates and their relative concentration ratios to encode the prior probability of a disease and the conditional probability of a signal given the disease. When the input and program molecules interact, an enzyme-driven cascade of reactions (DNA polymerase extension, nicking and degradation) is...

  17. INDICIa: a new distributed clustering protocol

    Callau-Zori, Mar
    Many data streaming applications produces massive amounts of data that must be processed in a distributed fashion due to the resource limitation of a single machine. We propose a distributed data stream clustering protocol. Theoretical analysis shows preliminary results about the quality of discovered clustering. In addition, we present results about the ability to reduce the time complexity respect to the centralized approach.

  18. Federating queries in SPARQL 1.1: syntax, semantics and evaluation

    Buil-Aranda, C.; Arenas, M.; Corcho, Oscar; Polleres, Axel
    Given the sustained growth that we are experiencing in the number of SPARQL endpoints available, the need to be able to send federated SPARQL queries across these has also grown. To address this use case, the W3C SPARQL working group is defining a federation extension for SPARQL 1.1 which allows for combining graph patterns that can be evaluated over several endpoints within a single query. In this paper, we describe the syntax of that extension and formalize its semantics. Additionally, we describe how a query evaluation system can be implemented for that federation extension, describing some static optimization techniques and reusing a query engine...

  19. Prion crystalization model and its application to recognition pattern

    Cordero Moreno, Paula; Lahoz-Beltra, Rafael; Castellanos Peñuela, Juan Bautista
    This paper introduces APA (?Artificial Prion Assembly?): a pattern recognition system based on artificial prion crystalization. Specifically, the system exhibits the capability to classify patterns according to the resulting prion self- assembly simulated with cellular automata. Our approach is inspired in the biological process of proteins aggregation, known as prions, which are assembled as amyloid fibers related with neurodegenerative disorders.

  20. A workflow PROV-corpus based on taverna and wings

    Belhajjame, K.; Zhao, Jun; Garijo Verdejo, Daniel; Garrido, Aleix; Soiland-Reyes, Stian; Alper, P.; Corcho, Oscar
    We describe a corpus of provenance traces that we have collected by executing 120 real world scientific workflows. The workflows are from two different workflow systems: Taverna [5] and Wings [3], and 12 different application domains (see Figure 1). Table 1 provides a summary of this PROV-corpus.

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