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
17 results
Search Results
Now showing 1 - 10 of 17
Item Restricted Predicates for Hypothetical Datalog(2015) Sáenz Pérez, FernandoHypotheticalDatalog 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.- Project number: 137
Item Técnicas de evaluación e intervención en Logopedia: base de datos audiovisual de la Unidad Clínica de Logopedia.(2015) 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 TeresaEl 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. Item Enhancing set constraint solvers with bound consistency(Expert Systems with Applications, 2018) Correas Fernández, Jesús; Estévez Martín, Sonia; Sáenz Pérez, Fernando; Lin, BinshanConstraint solvers have proved to be a powerful tool for both expressing and solving complex problems in many contexts, in particular in Automated Planning and Scheduling. In this work, we propose new constraints to enhancing an implementation of a constraint solver for sets of integers (ic_sets) embedded in the ECLiPSe system. This way, we confer a new vision of modelling that in particular allows a task to be planned on alternate days. In addition, these new constraints make finite domain and finite sets domains to cooperate, reducing the search space and improving the efficiency of the existing set solvers for some specific cases. We report on a prototype implementation and apply these constraints to modelling scheduling problems as benchmarks for a performance analysis. Experiments reveal a relevant improvement with respect to the standard ic_sets solver which only features cardinality as cooperation mechanism between domains. Both enhanced expressiveness and performance are key points for practical applications of such solvers.Item R-SQL: An SQL Database System with Extended Recursion(2013) Aranda López, Gabriel; Nieva Soto, Susana; Sáenz Pérez, Fernando; Sánchez Hernández, JaimeThe 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.- Project number: 259
Item Evaluación y mejora de la herramienta on-line DESweb para la enseñanza de bases de datos (2)(2021) Sáenz Pérez, Fernando; Arroyo Gallardo, Javier; Francisco Gilmartín, Virginia; Garmendia Salvador, Luis; Gómez Gauchía, Héctor; Sánchez Padial, AntonioEl objetivo es la herramienta DESweb de apoyo a la docencia virtual y presencial para la enseñanza de bases de datos relacionales (SQL) y deductivas (Datalog). Esta solicitud es continuación de un proyecto de la convocatoria anterior. - Project number: 387
Item Evaluación del impacto sobre el aprendizaje de bases de datos del juez automático LearnSQL(2022) Martín Martín, Enrique; Correas Fernández, Jesús; Garmendia Salvador, Luis; Montenegro Montes, Manuel; Riesco Rodríguez, Adrián; Rubio Cuéllar, Rubén Rafael; Sáenz Pérez, FernandoUtilizamos el juez automático "LearnSQL" en la docencia de varios grupos de la asignatura "Bases de Datos" y medimos de manera rigurosa y extensiva el impacto que este tiene sobre el aprendizaje de los estudiantes. Item Sistema de identificación y explotación de paralelismo en programas lógico-funcionales(2002) Sáenz Pérez, Fernando; Ruz Ortíz, José JaimeLos 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.Item Deductive databases(2011) Sáenz Pérez, FernandoWe 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.Item Implementing a Fixpoint Semantics for a Constraint Deductive Database based on Hereditary Harrop Formulas(PPDP '09 Proceedings of the 11th ACM SIGPLAN conference on Principles and practice of declarative programming, 2009) Aranda López, Gabriel; Nieva Soto, Susana; Sáenz Pérez, Fernando; Sánchez Hernández, JaimeThis 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.Item Extending the TOY System with the ECLiPSe Solver over Sets of Integers(2012) Estévez Martín, Sonia; Correas Fernández, Jesús; Sáenz Pérez, Fernando; Springer. T. Schrijvers and P. Thiemann, editors.Starting from a computational model for the cooperation of constraint domains in the CFLP context (with lazy evaluation and higher-order functions), we present the theoretical basis for the coordination domain C tailored to the cooperation of three pure domains: the domain of finite sets of integers (FS), the finite domain of integers (FD) and the Herbrand domain (H). We also present the adaptation of the goal-solving calculus CCLNC(C) (Cooperative Constraint Lazy Narrowing Calculus over C) to this particular case, as well as soundness and limited completeness results. An implementation of this cooperation in the CFLP system TOY is presented. Our implementation is based on interprocess communication between TOY and the external solvers for sets of integers and finite domain of ECLiPSe.