Uso de recursos online y rendimiento académico del alumnado

En los últimos años se ha generalizado el uso de plataformas de aprendizaje online como complemento a las clases presenciales. Estos entornos son utilizados para facilitar la comunicación con los estudiantes y poner a su disposición material para seguir las asignaturas, o profundizar en ellas, entregar trabajos, abrir foros de dudas, debates, etc. Hemos estudiado durante dos cursos la actividad de los estudiantes en el aula Moodle de la asignatura "Autómatas y Lenguajes Formales". Hemos analizado los accesos que hace cada estudiante, atendiendo especialmente al tipo de elementos que utilizan, distinguiendo usos básicos, complementarios y avanzados. La investigación realizada refuerza la hipótesis que desliga el logro de las competencias de la asignatura del uso de la plataforma online.Peer Reviewe

SENTENCE ANALYSIS WITH ARTIFICIAL INTELLIGENCE MACHINE LEARNING USING FINITE STATE AUTOMATA

Sentence pattern in Indonesian is very important. Incorrect pattern can cause misinterpretation and different meaning. The basic sentence pattern consists of subject, predicate, and object (SPO). To analyze the sentence, this project implements Finite State Automata (FSA) algorithm, which is useful to identify the class of words in a sentence. The given sentence processed through parsing process to break down the sentence into array of tokens. The program will then examine the tokens to determine the class of each word. The discovered pattern will be checked against existing vocabularies on the database. If the word exists, the program will return a response in accordance to the existing one. Otherwise, the program will store the word onto a temporary file until it find the class of the word. The Intelligence of the program depends on the number of vocabularies on the database. This program supports learning process, so the more sentences given, the more intelligent it gets

Uso de recursos online y rendimiento académico del alumnado

En los últimos años se ha generalizado el uso de plataformas de aprendizaje online como complemento a las clases presenciales. Estos entornos son utilizados para facilitar la comunicación con los estudiantes y poner a su disposición material para seguir las asignaturas, o profundizar en ellas, entregar trabajos, abrir foros de dudas, debates, etc. Hemos estudiado durante dos cursos la actividad de los estudiantes en el aula Moodle de la asignatura "Autómatas y Lenguajes Formales". Hemos analizado los accesos que hace cada estudiante, atendiendo especialmente al tipo de elementos que utilizan, distinguiendo usos básicos, complementarios y avanzados. La investigación realizada refuerza la hipótesis que desliga el logro de las competencias de la asignatura del uso de la plataforma online.Este trabajo ha sido parcialmente financiado con el apoyo de la Comisión Europea en el marco del Lifelong Learning Program de la EACEA (Education, Audiovisual and Culture Executive Agency)

Monitoring using Heterogeneous Autonomous Agents.

This dissertation studies problems involving different types of autonomous agents observing objects of interests in an area. Three types of agents are considered: mobile agents, stationary agents, and marsupial agents, i.e., agents capable of deploying other agents or being deployed themselves. Objects can be mobile or stationary. The problem of a mobile agent without fuel constraints revisiting stationary objects is formulated. Visits to objects are dictated by revisit deadlines, i.e., the maximum time that can elapse between two visits to the same object. The problem is shown to be NP-complete and heuristics are provided to generate paths for the agent. Almost periodic paths are proven to exist. The efficacy of the heuristics is shown through simulation. A variant of the problem where the agent has a finite fuel capacity and purchases fuel is treated. Almost periodic solutions to this problem are also shown to exist and an algorithm to compute the minimal cost path is provided. A problem where mobile and stationary agents cooperate to track a mobile object is formulated, shown to be NP-hard, and a heuristic is given to compute paths for the mobile agents. Optimal configurations for the stationary agents are then studied. Several methods are provided to optimally place the stationary agents; these methods are the maximization of Fisher information, the minimization of the probability of misclassification, and the minimization of the penalty incurred by the placement. A method to compute optimal revisit deadlines for the stationary agents is given. The placement methods are compared and their effectiveness shown using numerical results. The problem of two marsupial agents, one carrier and one passenger, performing a general monitoring task using a constrained optimization formulation is stated. Necessary conditions for optimal paths are provided for cases accounting for constrained release of the passenger, termination conditions for the task, as well as retrieval and constrained retrieval of the passenger. A problem involving two marsupial agents collecting information about a stationary object while avoiding detection is then formulated. Necessary conditions for optimal paths are provided and rectilinear motion is demonstrated to be optimal for both agents.PhDAerospace EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/111439/1/jfargeas_1.pd

Adaptive object-modeling : patterns, tools and applications

Tese de Programa Doutoral. Informática. Universidade do Porto. Faculdade de Engenharia. 201

Formal Verification of Instruction Dependencies in Microprocessors

In microprocessors, achieving an efficient utilization of the execution units is a key factor in improving performance. However, maintaining an uninterrupted flow of instructions is a challenge due to the data and control dependencies between instructions of a program. Modern microprocessors employ aggressive optimizations trying to keep their execution units busy without violating inter-instruction dependencies. Such complex optimizations may cause subtle implementation flaws that can be hard to detect using conventional simulation-based verification techniques. Formal verification is known for its ability to discover design flaws that may go undetected using conventional verification techniques. However, with formal verification come two major challenges. First, the correctness of the implementation needs to be defined formally. Second, formal verification is often hard to apply at the scale of realistic implementations. In this thesis, we present a formal verification strategy to guarantee that a microprocessor implementation preserves both data and control dependencies among instructions. Throughout our strategy, we address the two major challenges associated with formal verification: correctness and scalability. We address the correctness challenge by specifying our correctness in the context of generic pipelines. Unlike conventional pipeline hazard rules, we make no distinction between the data and control aspects. Instead, we describe the relationship between a producer instruction and a consumer instruction in a way such that both instructions can speculatively read their source operands, speculatively write their results, and go out of their program order during execution. In addition to supporting branch and value prediction, our correctness criteria allow the implementation to discard (squash) or replay instructions while being executed. We address the scalability challenge in three ways: abstraction, decomposition, and induction. First, we state our inter-instruction dependency correctness criteria in terms of read and write operations without making reference to data values. Consequently, our correctness criteria can be verified for implementations with abstract datapaths. Second, we decompose our correctness criteria into a set of smaller obligations that are easier to verify. All these obligations can be expressed as properties within the Syntactically-Safe fragment of Linear Temporal Logic (SSLTL). Third, we introduce a technique to verify SSLTL properties by induction, and prove its soundness and completeness. To demonstrate our overall strategy, we verified a term-level model of an out-of-order speculative processor. The processor model implements register renaming using a P6-style reorder buffer and branch prediction with a hybrid (discard-replay) recovery mechanism. The verification obligations (expressed in SSLTL) are checked using a tool implementing our inductive technique. Our tool, named Tahrir, is built on top of a generic interface to SMT solvers and can be generally used for verifying SSLTL properties about infinite-state systems

Computational Methods for Combinatorial and Number Theoretic Problems

Computational methods have become a valuable tool for studying mathematical problems and for constructing large combinatorial objects. In fact, it is often not possible to find large combinatorial objects using human reasoning alone and the only known way of accessing such objects is to use computational methods. These methods require deriving mathematical properties which the object in question must necessarily satisfy, translating those properties into a format that a computer can process, and then running a search through a space which contains the objects which satisfy those properties. In this thesis, we solve some combinatorial and number theoretic problems which fit into the above framework and present computational strategies which can be used to perform the search and preprocessing. In particular, one strategy we examine uses state-of-the-art tools from the symbolic computation and SAT/SMT solving communities to execute a search more efficiently than would be the case using the techniques from either community in isolation. To this end, we developed the tool MathCheck2, which combines the sophisticated domain-specific knowledge of a computer algebra system (CAS) with the powerful general-purpose search routines of a SAT solver. This fits into the recently proposed SAT+CAS paradigm which is based on the insight that modern SAT solvers (some of the best general-purpose search tools ever developed) do not perform well in all applications but can be made more efficient if supplied with appropriate domain-specific knowledge. To our knowledge, this is the first PhD thesis which studies the SAT+CAS paradigm which we believe has potential to be used in many problems for a long time to come. As case studies for the methods we examine, we study the problem of computing Williamson matrices, the problem of computing complex Golay sequences, and the problem of computing minimal primes. In each case, we provide results which are competitive with or improve on the best known results prior to our work. In the first case study, we provide for the first time an enumeration of all Williamson matrices up to order 45 and show that 35 is the smallest order for which Williamson matrices do not exist. These results were previously known under the restriction that the order was odd but our work also considers even orders, as Williamson did when he defined such matrices in 1944. In the second case study, we provide an independent verification of the 2002 conjecture that complex Golay sequences do not exist in order 23 and enumerate all complex Golay sequences up to order 25. In the third case study, we compute the set of minimal primes for all bases up to 16 as well for all bases up to 30 with possibly a small number of missing elements