A sufficient condition to polynomially compute a minimum separating DFA

This is the author’s version of a work that was accepted for publication in Information Sciences. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Information Sciences 370–371 (2016) 204–220. DOI 10.1016/j.ins.2016.07.053.The computation of a minimal separating automaton (MSA) for regular languages has been studied from many different points of view, from synthesis of automata or Grammatical Inference to the minimization of incompletely specified machines or Compositional Verification. In the general case, the problem is NP-complete, but this drawback does not prevent the problem from having a real application in the above-mentioned fields. In this paper, we propose a sufficient condition that guarantees that the computation of the MSA can be carried out with polynomial time complexity. © 2016 Elsevier Inc. All rights reserved.Vázquez-De-Parga Andrade, M.; García Gómez, P.; López Rodríguez, D. (2016). A sufficient condition to polynomially compute a minimum separating DFA. Information Sciences. 370-371:204-220. doi:10.1016/j.ins.2016.07.053S204220370-37

DFA minimization: Double reversal versus split minimization algorithms

“NOTICE: this is the author’s version of a work that was accepted for publication in Theoretical Computer Science. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published inTheoretical Computer Science, [Volume 583, 7 June 2015, Pages 78–85] DOI 10.1016/j.tcs.2015.04.002In this paper, we show the relationship between the two most widely used approaches for the minimization of deterministic finite automata: minimization by split of partitions and minimization by double reversal. Even though the double reversal approach has usually been considered to be unconventional with respect to the more common split approach, we show that any double reversal minimization algorithm can be related to a split minimization algorithm and vice versa.García Gómez, P.; López Rodríguez, D.; Vázquez-De-Parga Andrade, M. (2015). DFA minimization: Double reversal versus split minimization algorithms. Theoretical Computer Science. 583:78-85. doi:10.1016/j.tcs.2015.04.002788558

Experiencia de clase inversa en el grado de ingeniería informática

La amplia disponibilidad de herramientas de generación de contenido multimedia hace posible la incorporación de nuevos recursos que complementen la actividad habitual en el aula. En la experiencia que se expone, se analizaron los recursos que existían relacionados con la materia de Teoría de Autómatas del Grado de Informática de la Universidad Politécnica de Valencia. Este análisis permitió detectar algunos aspectos clave que no eran convenientemente asimilados por el alumnado. Para cada uno de estos se elaboró material audiovisual que presentaba el contenido así como ejercicios de autoevaluación a realizar antes de la clase presencial. Se comprobó que el efecto de facilitar de forma anticipada al estudiante de este material permite al alumno, si bien en principio no completamente, trabajar ciertos conceptos, permitiendo plantear las dudas de forma más orientada. Pese a que el grupo piloto de esta experiencia estaba formado exclusivamente por voluntarios, lo que puede suponer un sesgo en la valoración, la experiencia se considera muy positiva

A Decision-Making Tool for a Regional Network of Clinical Laboratories

For healthcare systems that operate in large, geographically dispersed areas, the quality of the services provided requires the effective management of a complex transportation problem. We present a decision support system to help healthcare managers improve the delivery of biological samples collected from patients in hospitals and outpatient clinics to laboratories that perform tests on them. We develop an optimization model for supporting strategic decisions on the transport of samples and the assignment of work in a large healthcare network with geographically dispersed hospitals, clinics, and testing laboratories. We embed our model in a Web-based tool to provide planners with interactive functions, enabling them to explore solutions and interactively access data to facilitate the analysis of what-if scenarios. The tool proved invaluable in helping the Andalusian Healthcare System obtain significant improvements in efficiency, quality of service, and outsourcing costsJunta de Andalucía TEP-606

A split-based incremental deterministic automata minimization algorithm

The final publication is available at Springer via http://dx.doi.org/10.1007/s00224-014-9588-y. La fecha de publicación corresponde a la versión First OnlineWe here study previous results due to Hopcroft and Almeida et al. to propose an incremental split-based deterministic automata minimization algorithm whose average running-time does not depend on the size of the alphabet. The experimentation carried out shows that our proposal outperforms the algorithms studied whenever the automata have more than a (quite small) number of states and symbols.García Gómez, P.; Vázquez-De-Parga Andrade, M.; Velasco, JA.; López Rodríguez, D. (2014). A split-based incremental deterministic automata minimization algorithm. Theory of Computing Systems. 1-18. doi:10.1007/s00224-014-9588-y118Hopcroft, J.E., Ullman, J.D.: Introduction to Automata Theory, Languages and Computation. Addison-Wesley Publishing Company (1979)Watson, B.W., Daciuk, J.: An efficient incremental DFA minimization algorithm. Nat. Lang. Eng. 9(1), 49–64 (2003)Almeida, M., Moreira, N., Reis, R.: Incremental DFA minimisation. In: Domaratzki, M., Salomaa, K. (eds.) CIAA, of Lecture Notes in Computer Science, vol. 6482, pp 39–48. Springer (2010)Hopcroft, J.E.: An n ⋅ log n $n\cdot \log n$ algorithm for minimizing states in a finite automaton. Technical report, Stanford, University, Stanford (1971)Moore, E.F.: Gedanken experiments on sequential machines. In: Shannon, C.E., Mc-Carthy, J. (eds.) Automata Studies. Princeton Universty Press, Princeton (1956)Berstel, J., Boasson, L., Carton, O., Fagnot, I.: Automata: from Mathematics to Applications, chapter Minimization of automata. European Mathematical Society. (arXiv: 1010.5318v3. ) To appear.David, J.: Average complexity of Moore’s and Hopcroft’s algorithms. Theor. Comput. Sci. 417, 50–65 (2012)Almeida, M., Moreira, N., Reis, R.: Aspects of enumeration and generation with a string automata representation. In: Leung, H., Pighizzini, G. (eds.) DCFS, pp 58–69. New Mexico State University, Las Cruces (2006)Gries, D.: Describing an algorithm by Hopcroft. Acta Informatica 2, 97–109 (1973)Aho, A., Hopcroft, J.E., Ullman, J.D.: The Design and Analysis of Computer Algorithms. Addison-Wesley Publishing Company (1974)Blum, N.: A O ( n log n ) $\mathcal {O}(n\log n)$ implementation of the standard method for minimizing n-state finite automata. Inf. Process. Lett. 57, 65–69 (1996)Knuutila, T.: Re-describing an algorithm by Hopcroft. Theor. Comput. Sci. 250, 333–363 (2001)Veanes, M.: Minimization of symbolic automata. Technical report, Microsoft Research, MSR-TR-2013-48 (2013)Lothaire, M.: Applied Combinatorics on Words chap. 1. Cambridge University Press, Cambridge (2005

Project Management at University: Towards an Evaluation Process around Cooperative Learning

The enrollment in current Master's degree programs usually pursues gaining the expertise required in real-life workplaces. The experience we present here concerns the learning process of "Project Management Methodology (PMM)", around a cooperative/collaborative mechanism aimed at affording students measurable learning goals and providing the teacher with the ability of focusing on the weaknesses detected. We have designed a mixed summative/formative evaluation, which assures curriculum engage while enriches the comprehension of PMM key concepts. In this experience we converted the students into active actors in the evaluation process itself and we endowed ourselves as teachers with a flexible process in which along with qualifications (score), other attitudinal feedback arises. Despite the high level of self-affirmation on their discussion within the interactive assessment sessions, they ultimately have exhibited a great ability to review and correct the wrong reasoning when that was the case

Determinación de un plan operativo semanal para la Red Andaluza de Laboratorios Clínicos

Presentamos un modelo para coordinar el funcionamiento en una Red Regional de Laboratorios Clínicos, cuya resolución permite la reasignación de recursos, la redistribución de cargas y la reorganización de los flujos de muestras clínicas en dicha. Para ello, se determina un plan de producción y transporte: primero en un nivel táctico (anual) y luego a un nivel operativo (semanal). Se plantea como un problema de flujo multicommodity que conduce a una formulación entera mixta. Se presenta experimentación aplicada a la reordenación de las derivaciones de muestras entre los 32 nodos principales de la Red Andaluza de Laboratorios Clínicos.Andalucía. Junt

A Tandem Drone-ground Vehicle for Accessing Isolated Locations for First Aid Emergency Response in Case of Disaster

The collapse of infrastructures is very often a complicating factor for the early emergency actuations after a disaster. A proper plan to better cover the needs of the affected people within the disaster area while maintaining life-saving relief operations is mandatory hence. In this paper, we use a drone for flying over a set of difficult-to-access locations for imaging issues to get information to build a risk assessment as the earliest stage of the emergency operations. While the drone provides the flexibility required to visit subsequently a sort of isolated locations, it needs a commando vehicle in ground for (i) monitoring the deployment of operations and (ii) being a recharging station where the drone gets fresh batteries. This work proposes a decision-making process to plan the mission, which is composed by the ground vehicle stopping points and the sequence of locations visited for each drone route. We propose a Genetic Algorithm (GA) which has proven to be helpful in finding good solutions in short computing times. We provide experimental analysis on the factors effecting the performance of the output solutions, around an illustrative test instance. Results show the applicability of these techniques for providing proper solutions to the studied problem

DFA minimization: from Brzozowski to Hopcroft

Minimization of automata is a classic problem in Computer Sci- ence which is still studied nowadays. In this paper, we first propose a polynomial minimization method directly derived from Brzozowski¿s algorithm, and second, we show how the consideration of some effi- ciency improvements on this algorithm lead to obtain an algorithm equivalent to Hopcroft¿s.García Gómez, P.; López Rodríguez, D.; Vázquez-De-Parga Andrade, M. (2013). DFA minimization: from Brzozowski to Hopcroft. http://hdl.handle.net/10251/2762

Un Algoritmo Evolutivo para Resolver el Problema de Coloración Robusta

Let G and \bar{G} be two complementary graphs. Given a penalty function defined over the edges of \bar{G}, it is said that the rigidity of a k-coloring of G is the summation ofthe penalties of the edges of G that join vertices whose endpoint are equally colored. Based on this previous definition, the Robust Coloring Problem is set when searching the valid k-coloring of minimum rigidity. Yáñez and Ramírez proved that this is an NP-hard problem. In this work we present an evolutive algorithm based in the scatter search technique, which obtains optimal solutions for those instances for which an optimal solution is known, and obtains the best known solutions compared to other heuristics, such as: simulated annealing, tabu search and partial enumeration.Sean G y bar{G} un par de gráficas complementarias. Dada una función de peso definida sobre las aristas de \bar{G}, se dice que la rigidez de una k-coloración válida de G es la suma de los pesos de las aristas de \bar{G} que unen vértices del mismo color. Con base en la anterior definición, se plantea el Problema de Coloración Robusta al buscar la k-coloración válida de rigidez mínima. Yáñez y Ramírez probaron que este problema es NP-duro. En este trabajo se presenta un algoritmo evolutivo basado en la técnica de búsqueda dispersa, la cual obtiene soluciones óptimas, en las instancias para las que se conoce la solución óptima, y obtiene las mejores soluciones conocidas comparadas con otras heurísticas, tales como: recocido simulado, búsqueda tabú y enumeración parcial