Person:
Sáenz Pérez, Fernando

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First Name
Fernando
Last Name
Sáenz Pérez
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Informática
Department
Ingeniería del Software e Inteligencia Artificial
Area
Lenguajes y Sistemas Informáticos
Identifiers
UCM identifierORCIDScopus Author IDDialnet IDGoogle Scholar ID

Search Results

Now showing 1 - 10 of 15
  • Publication
    Mejora del aprendizaje de SQL con realimentación semántica
    (2018-06-13) Sáenz Pérez, Fernando; Caballero Roldán, Rafael; García Ruiz, Yolanda; Garméndia Salvador, Luis
  • Publication
    Evaluación y mejora de la herramienta on-line DESweb para la enseñanza de bases de datos
    (2020-07-01) Sáenz Pérez, Fernando; Francisco Gilmartín, Virginia; García Merayo, María de las Mercedes; Garmendia Salvador, Luis; Gómez Gauchía, Héctor
    El objetivo de este proyecto es evaluar en clase y mejorar la herramienta on-line DESweb para la enseñanza de bases de datos relacionales (con SQL) y deductivas (con Datalog y Prolog). Esta solicitud es continuación de un proyecto de la convocatoria anterior.
  • Publication
    Restricted Predicates for Hypothetical Datalog
    (2015-12-22) Sáenz Pérez, Fernando
    HypotheticalDatalog is based on an intuitionistic semantics rather than on a classical logic semantics, and embedded implications are allowed in rule bodies. While the usual implication (i.e., the neck of a Horn clause) stands for inferring facts, an embedded implication plays the role of assuming its premise for deriving its consequence. A former work introduced both a formal framework and a goal-oriented tabled implementation, allowing negation in rule bodies. While in that work positive assumptions for both facts and rules can occur in the premise, negative assumptions are not allowed. In this work, we cover this subject by introducing a new concept: a restricted predicate, which allows negative assumptions by pruning the usual semantics of a predicate. This new setting has been implemented in the deductive system DES.
  • Publication
    R-SQL: An SQL Database System with Extended Recursion
    (2013) Aranda López, Gabriel; Nieva Soto, Susana; Sáenz Pérez, Fernando; Sánchez Hernández, Jaime
    The relational database language SQL:1999 standard supports recursion, but thisapproach is limited to the linear case. Moreover, mutual recursion is not supported,and negation cannot be combined with recursion. We designed the language R-SQLto overcome these limitations in [ANSS13], improving termination properties in re-cursive definitions. In addition we developed a proof of concept implementation ofan R-SQL system. In this paper we describe in detail an improved system enhanc-ing performance. It can be integrated into existing RDBMS’s, extending them withthe aforementioned benefits of R-SQL. The system processes an R-SQL databasedefinition obtaining its extension in tables of an RDBMS (such as PostgreSQL andDB2). It is implemented in SWI-Prolog and it produces a Python script that, uponexecution, computes the result of the R-SQL relations. We provide some perfor-mance results showing the efficiency gains w.r.t. the previous version. We alsoinclude a comparative analysis including some representative relational a deductive systems.
  • Publication
    Técnicas de evaluación e intervención en Logopedia: base de datos audiovisual de la Unidad Clínica de Logopedia.
    (2015-02-20) Nieva Ramos, Silvia; Bartuilli Pérez, Mónica; González Calero, Pedro Antonio; Melle Hernández, Natalia; Murillo Sanz, Eva; Pareja Lora, Antonio; Sáenz Pérez, Fernando; Schüller Moreno, Maria Teresa
    El proyecto consiste en creación y virtualización de una base de datos audiovisual estructurada de sesiones de evaluación e intervención llevadas a cabo con pacientes que acuden a tratamiento a la Clínica de Logopedia de la UCM con objetivos docentes y de investigación, dando acceso a los alumnos al visionado de vídeos para realizar sesiones de análisis y estudio de casos clínicos a partir de los procesos de evaluación e intervención para las distintas patologías que son su ámbito de estudio.
  • Publication
    Improving the Deductive System DES with Persistence by Using SQL DBMS’s
    (2015-01-08) Sáenz Pérez, Fernando
    This work presents how persistent predicates have been included in the in-memory deductive system DES by relying on external SQL database management systems. We introduce how persistence is supported from a user-point of view and the possible applications the system opens up, as the deductive expressive power is projected to relational databases. Also, we describe how it is possible to intermix computations of the deductive engine and the external database, explaining its implementation and some optimizations. Finally, a performance analysis is undertaken, comparing the system with current relational database systems.
  • Publication
    Implementing a Fixpoint Semantics for a Constraint Deductive Database based on Hereditary Harrop Formulas
    (Assoc Computing Machinery, 2009) Aranda López, Gabriel; Nieva Soto, Susana; Sáenz Pérez, Fernando; Sánchez Hernández, Jaime
    This work is aimed to show a concrete implementation of a deductive database system based on the scheme HH-(C) (Hereditary Harrop Formulas with Negation and Constraints) following a fixpoint semantics proposed in a previous work. We have developed a Prolog implementation for this scheme that is constraint system independent. therefore allowing to use it as a base for any instance of the formal scheme. We have developed several specific constraint systems: Real numbers, integers, Boolean and user-defined enumerated types. We have added types to the database so that relations become typed (as tables in relational databases) and each constraint is mapped to its corresponding constraint system. The predicates that compute the fixpoint giving the meaning to a database are described. In particular, we show the implementation of a forcing relation (for derivation steps) and highlight how the inherent difficulties have been overcome in a system allowing hypothetical queries, which make the database dynamically grow.
  • Publication
    Deductive databases
    (2011-09-21) Sáenz Pérez, Fernando
    We have witnessed a new interest on deductive databases, languages and technologies. Also, emerging companies promoting deductive technologies transfer these technological outcomes to practical applications. Datalog, as a preeminent deductive query language has been extensively studied and is gaining a renowned interest thanks to their application to ontologies, semantic web, social networks, policy languages, and even for optimization. Thus, the aim of this talk is to try to look at deductive databases from a renowned viewpoint as more features are being added making them more appealing. In addition to review some relevant deductive systems and technologies, we'll base our presentation on the grounds of DES (Datalog Educational System), which includes several extensions to the pure Datalog language, and its interactiveness makes it an adequate tool to rapidly acquire fundamentals. Fernando Sáenz Pérez is currently an Associate Professor attached to the Department of Artifcial Intelligence and Sofware Engineering. Since 1987, he has been involved in researching at the University Complutense of Madrid (Spain), and at the Institut für Informatik at Aachen (Germany). His current research interests include: declarative and constraint programming, and deductive databases. He has taken part in many basic research projects and development projects in tight touch with several corporations such as Repsol YPF, Enagás, Cofares, and Ente Público RTVE, performing actual research transfers. Sáenz-Pérez has been a member of several program committees and referee for both international and national conferences. He is also actively involved in several free, open-source projects such as DES.
  • Publication
    Sistema de identificación y explotación de paralelismo en programas lógico-funcionales
    (Universidad Complutense de Madrid, Servicio de Publicaciones, 2002) Sáenz Pérez, Fernando; Ruz Ortíz, José Jaime
    Los lenguajes declarativos en general y los lógico-funcionales en particular poseen una capacidad expresiva para resolver problemas de índole simbólico mayor que los lenguajes imperativos. Sin embargo, esta mayor capacidad expresiva requiere mayor tiempo de cómputo y uso de memoria. El objetivo de esta tesis es el aumento de la eficiencia de un lenguaje lógico- funcional mediante el desarrollo de un sistema de identificación y explotación del paralelismo implícito en los programas. En primer lugar se desarrolla un procedimiento para la identificación local de paralelismo en programas secuenciales con el que se generan programas paralelos. Se desarrollan varias estrategias de icación y de incorporación de granularidad que se estudian y comparan. En egundo lugar se rolla un análisis de independencia de los programas p ara obtener información global de las reglas en el programa para la simplificación de las reglas paralelas. Para ello se liza la interpretación abstracta y se presentan y comparan tres niveles de análisis. En rcer lugar se diseña una máquina abstracta paralela de memoria compartida basada en pilas para la explotación del paralelismo identificado. Esta máquina retiene las limizaciones de las máquinas secuenciales, fundamentalmente durante el cómputo hacia atrás en la desasignación de memoria. Finalmente, se realiza una implementación de la máquina abstracta paralela sobre un multiprocesador de memoria compartida simulado en vhdl, realizándose su validación funcional y tomando medidas de rendimiento. Se plantean diferentes alternativas de diseño para el bus y la memoria cache, que se comparan a partir de las medidas obtenidas.
  • Publication
    Evaluación de la realimentación semántica de SQL en DES
    (2019-06-24) Sáenz Pérez, Fernando; Correas Fernández, Jesús; García Merayo, Mercedes; Gómez Gauchía, Héctor
    El objetivo de este proyecto ha sido evaluar en clase la herramienta de realimentación semántica de consultas SQL, desarrollada sobre el sistema DES, ampliarla y mejorarla. Esta solicitud es continuación de un proyecto de la convocatoria anterior (curso 2017-2018). Se ha mejorado tanto el componente nuclear DES como la interfaz de usuario web. Los alumnos han usado y evaluado la herramienta en clases de bases de datos de varias facultades, completando las encuentas que se les han proporcionado.