ACT 08-TPIA
Transcripción
ACT 08-TPIA
ACT-08 1st Year Progress Report Pro grama Bicentenario CDBIEMEXCHILE COMCYT de Ciencia y Tecno(ogIa in The World Bank PROYECTOS DE ANILLOS DE INVESTIGACION EN CIENCIA Y TECNOLOGIA INFORME TECNICO I. PRESENTACION TITULO DEL PROYECTO: Redes en Matemáticas y Ciencias de la Ingenierla Investigadores Titulares: NOMBRE 1. Marcos Kiwi 2. Martin Matamala 3. Ivan Rapaport CODIGO: ACT 8 FIRMA -:: Investigadores Asociados 1. José R. Correa 2. Eduardo Moreno Institución Principal Universidad de Chile Representante legal NOMBRE FIRMA INDICAR EL PERIODO DE EJECUCION QUE SE ESTA INFORMANDO Mes/Aflo - Mes/Afio Diciembre / 2005 - Noviembre 2006 1 II. RESUMEN EJECUTIVO En las siguientes 2 páginas (como máximo) presente un resumen de los logros obtenidos hasta la fecha en el proyecto, incluyendo tanto aquellos relacionados con los objetivos de investigación de su proyecto, como con las actividades de colaboración internacional y de difusión a través de vias tradicionales (publicaciones y congresos) y aquellas abiertas a püblico no especialista. La información contenida en esta sección es püblica y se dará a conocer en el sitio web de CONICYT. Este resurnen debe informar a los evaluadores sobre el cumplimiento de los propósitos para el perlodo y sobre la forma en cómo este cumplimiento se realizó. Dado que es posible que personas no expertas en su area de especialidad también deban acceder a esta información, le solicitamos haga este resumen apto para ser leldo por profesionales que no sean de la especialidad. Durante el primer año de ejecución del proyecto se desarrollaron actividades de acuerdo a las cuatro lIneas de acción de la propuesta: investigación, vinculación internacional, formación y difusión. Lo anterior, en el marco de la intención central de convertir al grupo de investigadores del proyecto en un referente cientifico para la region en el ámbito de las matemáticas discretas y la informática teórica. La investigación realizada en las areas del proyecto ha involucrado a todos sus participantes y, a pesar del poco tiempo transcurrido desde su inicio, ya ha dado origen a publicaciones internacionales, inclusive conjuntas. Gruesamente, los problemas estudiados y los resultados obtenidos pueden ordenarse entre los relativos a propiedades dinámicas de las redes y aquellos que dicen relación con sus propiedades estáticas o estructurales. Entre los aspéctos dinámicos, se ban estudiado procesos de interacción local para generar en las redes subestructuras especificas y dos tipos de juegos en redes; uno de ellos con varios jugadores que envIan flujo buscando minimizar sus funciones objetivos, siendo una fracciOn importante del flujo total manejado por unos pocos; el otro, con muchos jugadores uno de los cuales envIa flujo con el fin de congestionar la red y los otros, uno por cada nodo de la red, que deben buscar la mejor manera de encarninar el flujo a su destino, respetando las capacidades de la red y sin contar con un mecanismo de coordinación central. Respecto de los aspectos estáticos, se ban propuesto algoritmos para modificar las redes agregando arcos para que la red transformada tenga buenas propiedades algorItmicas. También, se ha propuesto un algoritmo para detectar ciertas estructuras extremas en redes donde los arcos que dejan un nodo son distinguibles. Por otro lado, se ban propuesto algoritmos aproximados con garantlas de desempeflo para el caso de funciones de costo racionales. La actividad anterior ha dado ongen a la publicaciOn de 7 articulos, la edición de 2 libros, 5 trabajos sometidos, y 2 artIculos más en que colaboradores agradecen el apoyo del proyecto. En la segunda lInea de acción uno de nuestros objetivos especIficos era la organización del congreso internacional LATIN '06. Para dimensionar el impacto de esta actividad, destacamos que se recibieron 224 trabajos originales provenientes de más de 20 paises, una cifra sin precedentes en la region, pudiendo aceptarse solamente el 29%. Dentro de esta misma linea, se asistió a 12ongresosinternacionales y se reahzaron 14 visitas a centros internacionales de investigaclon Ademas, sicibieron 13 visitas que, junto a invitados nacionales, dictaron 16 charlas. Cabe destacar que un invefijador del CNRS (centro de excelencia frances) nos está visitando por el periodo Junio 2006-Mayo 2007 con financiamiento de su gobierno y que está tramitando la extensiOn de su permanencia un año más. Especial mención merece el fuerte intercambio que gatillo el proyecto con uno de los grupos sud-amencanos de mayor relevancia en el area de la informática teOrica, a saber, el de la Universidad de Sao Paulo, rea!izándose en el periodo 9 visitas en uno u otro sentido. 2 El tercer eje de nuestra propuesta, la formación, tenla como objetivo la guIa de estudiantes, tanto de pregrado corno de postgrado, asi como la vinculaciOn de jóvenes cientIficos a nuestro quehacer en la modalidad de postdoctorado. Durante este año se han finalizado 2 memorias de tItulo de ingenieria, se encuentran en curso otra más, y 4 estudiantes de postgrado, 3 de los cuales son de doctorado, han comenzado a desarrollar sus tesis. Por otra pane el ilamado a concurso de postdoctorado tuvo un enorrne éxito recibiéndose más de doce candidaturas, al menos la mitad de muy buen nivel. En los hechos, un joven investigador polaco formado en Francia está realizando una estadia por un aflo y ha solicitado extender este periodo por un año más. Otro aspecto de la formación es la vinculación de nuestros estudiantes en el concierto intemacional a través de la asistencia a escuelas de verano tanto en el extranjero (3 estudiantes) como en el pals (17 estudiantes) además de Ia asistencia a congresos internacionales en la region (17 estudiantes). Las actividades de difusión se concretaron en el auspicio de la obra de teatro "Quebrando cOdigos" acerca de la vida de Alan Turing, en el auspicio y concepción de la muestra "Ruedas Cuadradas" en el Museo Interactivo Mirador, en el auspicio de la Escuela de Verano para estudiantes de enseflanza media y en el auspicio de La iniciativa "Mapas de redes de computadores". Finalmente, cabe destacar la inserción laboral del más joven de los investigadores del proyecto, Eduardo Moreno, quien obtuvo un cargo de Profesor a Jornada Completa en la Facultad de Ingenierla de la Universidad Adolfo Ibáñez. Tenemos la convicción que el referido logro personal, inserto en el contexto de una colaboración grupal, ayuda a consolidar la proyeccion del grupo de cara al futuro. 3 III. RESULTADOS EN INVESTIGACION Utilice un máximo de 8 páginas para dar cuenta de los resultados de las actividades de investigación realizadas en el perIodo de ejecución correspondiente. La información contenida en esta sección es estrictamente confidencial y los evaluadores de ella estarán sujetos a un acuerdo firmado con el objeto de cumplir con esta cláusula. Para completar esta sección siga las instrucciones indicadas a continuación. a. Se sugiere organizar esta sección de acuerdo a los objetivos especificos del proyecto planificados para el perIodo de ejecución correspondiente indicando posibles dificultades técnicas que hayan generado cambios en ci enfoque técnico u obj etivos planteados. b. Si ci equipo de investigación considera necesario indicar resultados negativos que haya obtenido en este periodo y que crea necesario discutir puede ocupar este espacio para hacerlo. c. Inciuya los anexos (bajo el encabezamiento indicado) que le parezcan necesarios considerando que los expertos que evaluarán su informe dispondrán de un plazo limitado para hacerlo. Limite las figuras a aquellas que enfoquen de manera más sucinta y global lo que quiere dar a conocer. d. Si existen publicaciones en proceso que expliquen sus resultados y/o avances es preferibie incluirlos en esta sección ya sea como apartados o manuscritos y hacer referencia a ellos cuando sea necesario en ci texto en vez de repetir la información en la forma de informe. DISCUSSION OF RESULTS Roberto Cominetti, José R. Correa (Anillo's associate researcher) and Nicolas Stier (Anillo's visiting scholar), have worked on games in networks when players that have market power (i.e. they control significant amount of flow) and other players that do not (i.e. they are infinitesimally small) compete for resources. Although these type of games, known as "games with atomic players", are not well understood, bounds were obtained on the price of anarchy under some assumptions on the congestion functions. These results have been published in the proceedings of the 331(1 International Colloquium in Automata Languages and Programming (ICALP 2006), Lecture Notes in Computer Science, Volume 4051, July 9-16, Viena, Italy. Furthermore, Correa in collaboration with Nicolas Stier, has looked at the closely related stackelberg game in which only one player has market power and also plays first (and can anticipate the responses of the rest of the players). This work is still in progress. José R. Correa (Anillo's associate researcher), Cristina Fernandes (Anillo's visiting scholar) and Yoshiko Wakabayashi (Anillos's visiting scholar), have looked at the problem of finding approximation algorithms for combinatorial problems with a rational objective 4 function. The main result obtained thus far is that for a large class of combinatorial problems (which for instance contain all covering integer programming problems) if there is an r-approximation algorithm for minimizing a linear objective, then there is an rapproximation algorithm for minimizing a rational objective. Their results were recently I published in the Proceedings of the 01Scandinavian Workshop on Algorithm Theory (SWAT 2006). Lecture Notes in Computer Science, Volume 4059, July 6-8, 2006. Riga, Latvia. Ivan Rapaport (Anillo's PT) in collaboration with Florent Becker and Eric Remila, designed fixed finite tile systems that assemble into particular classes of shapes. Moreover, given an arbitrary n, they show how to calculate the tile concentrations in order to ensure that the expected size of the produced shape is n. For the case of rectangles and squares, their constructions are optimal (in terms of size and time). Finally, they introduce the class of diamonds and construct, for this class, a non trivial tile system having linear parallel time 26th Conference on complexity. These results have recently appeared in Proceedings of the Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2006), Lecture Notes in Computer Science, Volume 4337, December 13-15, 2006, Kolkata, India. Ivan Rapaport (Anillo's PT), in collaboration with K. Suchan (Anillo's Posdoc) and Joan Todinca study the minimal proper interval completion problem. Their main result is a linear time algorithm computing a minimal proper interval completion of an arbitrary graph. One of the main tools they used is a special ordering of the proper interval graph, called biocompatible ordering. They define a family of orderings such that the associated proper interval graph is a minimal proper interval completion. They also give a linear-time algorithm computing such an ordering. The ordering can be efficiently transformed into a proper interval model. These results where published in the Proceedings of the International Workshop on Graph-Theoretic Concepts in Computer Science (WG 2006), Lecture Notes in Computer Science, Volume 4271, 217-228, June 22-24, 2006, Bergen, Norway. The problem of finding the Eulerian circuit of lexicographically minimal label was studied by Martin Matamala (Anillo's P1) and Eduardo Moreno (Anillo's associate researcher). They prove that this problem is NP-complete in general, but if the labeling is locally injective (arcs going out from each vertex have different labels) it is solvable in linear time, and they give an algorithm that constructs such circuit. Their work appeared in the 7th Latin American Theoretical Computer Science Symposium (LATIN Proceedings of the 2006), Lecture Notes in Computer Science, Volume 3887, March 20-24, 2006, Valdivia, Chile. Marcos Kiwi (Anillo's PT), Mauricio Soto and Christopher Thraves studied routing and scheduling problems on Kelly type networks where the injection process is under the control of an adversary. The novelty of the model they consider is that the adversary injects requests of distinct types. Resources are subject to switch-over delays or setups when they begin servicing a new request class. Their model is an extension of the Adversarial Queuing Theory (AQT) model introduced by Andrews et al. In particular, they show that the model is robust in the sense that universal stability of work conserving packet routing protocols is preserved for natural variants of the underlying model. Also, the model's equivalence to so called token networks is established. Their work was submitted to Theoretical Computer Science A and is currently undergoing peer review. 5 Continuing with the line of research discussed in the previous paragraph Christopher Thraves (PhD student advisee of Anillo's PT) in collaboration with Maria José Blesa et al proposed an extension to the AQT model and named it Continous Adversarial Queuing Theory model (CAQT). In this model, packets have arbitrary length and the network links can have different speeds (or bandwidths) and propagation delays. Issues such as end-toend delays, network stability and characterization of stable networks are addressed. Moreover, Christopher Thraves, in collaboration with J. Céspedes et al further generalized the CAQT model to the scenario where network clocks are not synchronized. These results will appear in Theory of Computing Systems (in press) and in the Proceedings of the IEEE Symposium on Computers and Communications (ISCC'07), July 1-4, 2007, Aveiro, Portugal. Marcos Kiwi (Anillo's PT) and Martin Loebl (Anillo's international associate researcher), initiated the study of pattern avoidance in bipartite multigraphs. They derive a generalized Gessel identity for the number of bipartite 2-regular multigraphs avoiding a specific (monotone) pattern (Gessel's identity is a generating function formula for the distribution of the longest increasing sequence in a randomly chosen permutation). This result is part of an ongoing effort of these researchers in which they try to determine, through the application of graph theoretic concepts and tools, the limiting behavior of the length of the longest common subsequence of two randomly chosen words. Martin Loebl (Anillo's international associate researcher) dedicated a significant part of his effort during the visit to the Department of Mathematical Engineering that took place during the whole of 2006, to the write up of his book "Discrete Mathematics and Statistical Physics". The purpose of the book is to briefly describe some of the basic concepts interlasing discrete mathematics, statistical physics and knot theory. The book is currently in its final draft version. It will be published by Vieweg. Karol Suchan (Anillo's Posdoc) and loan Todinca studied path-width of circular-arc graphs and gave the first polynomial time algorithm computing the path-width of an arbitrary circular-arc graph. This is the first result on path-width of graphs of unbounded tree-width, rd where path-width and tree-width do not coincide. The preprint was submitted to the 33 International Workshop on Graph-Theoretic Concepts in Computer Science whose proceedings are part of the Lecture Notes in Computer Science series of Springer-Verlag. Finally we would like to make special mention of a publication by José Soto, an undergraduate advisee of Marcos Kiwi (Anillo's PT), with a researcher with which none of the Anillo's P1 has ever collaborated. The work, co-authored with Jiri Fiala explores whether given a matrix M there is a graph G whose degree sequence corresponds to M and in addition has an extra (technical) condition. This work gave rise to a Technical Report, ITT Series No. 2006-315, 2006, which was submitted to the European Journal of Combinatoncs. LIST OF PUBLICATIONS Published and accepted articles 1. R. Cominetti, J.R. Correa and N.E. Stier Moses. Network Games with Atomic 331c1 International Colloquium on Players. Extended abstract in Proceedings of the Automata, Languages and Programming (ICALP 2006). Lecture Notes in Computer Science, Volume 4337, 525-536, 2006. Springer-Verlag. 11 2. J.R. Correa, C.G. Fernandes and Y. Wakabayashi. Approximating Rational Objectives is as easy as Approximating Linear Ones. Extended abstract in 10th Scandinavian Workshop on Algorithm Theory (SWAT Proceedings of the 2006). Lecture Notes in Computer Science, Volume 4059, 351-362, 2006. Springer-Verlag. ^51 'c 3. M.J. Blesa, D. Caizada, A. Fernández, L. LOpez, A.L. Martinez, A. Santos, M.J. Serna, C. Thraves. Adversarial Queueing Model for Continuous Network Dynamics, Theory of Computing Systems, in press. 4. M. Matamala and E. Moreno, Minimal Eulerian circuits and Minimal de Bruijn sequences. Extended abstract in Proceedings of the 7 th Latin American Theoretical Informatics Symposium (LATIN 2006). Lecture Notes in Computer. Science, Volume 3887, 737-744, 2006. Springer-Verlag. 5. J. Céspedes, A. Fernández, J.L López-Preza, M.A. Lorenzo, P. Manzano, J. Martinez-Romo, A. Mozo, A. Puig-Centelles, A. Santos, C. Thraves. Performance of Scheduling Policies in Adversarial Networks with Non-synchronized Clocks. Extended abstract in Proceedings of the IEEE Symposium on Computers and Communications, (ISCC'07), Aveiro, Portugal, July 1-4, 2007. 6. F. Becker, I. Rapaport and E. Rémila. Self-assemblying classes of shapes, fast and 1h Conference on with minimal number of tiles. In Proceedings of the 26 Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2006), Lecture Notes in Computer Science, Volume 4337, December 13-15, 2006, Kolkata, India.. 7. I. Rapaport, K. Suchan and I. Todinca. Minimal proper interval completions. In Proceedings of the International Workshop on Graph-Theoretic Concepts in Computer Science (WG 2006), Lecture Notes in Computer Science, Volume 4271, 217-228, June 22-24, 2006, Bergen, Norway Books 1h 1. Proceedings of the 7 Latin-american Theoretical Computer Science Symposium, J.R. Correa, A. Hevia, and M. Kiwi (eds.). Lecture Notes in Computer Science, Volume 3887, Springer-Verlag, 2006. ISBN 3-540-32755-X 2. M. Loebi. Discrete Mathematics and Statistical Physics. Vieweg Publisher (to 7 appear). Articles submitted 1. M. Kiwi, C. Thraves, and M. Soto. Adversarial Queuing Theory with Setups. Submitted to Theoretical Computer Science A, 2006. 2. J. Fiala and J. Soto, Block Transitivity and Degree Matrices. Technical Report ITI Series No. 2006-3 15, 2006. Submitted to European Journal of Combinatorics. 3. K. Suchan, I. Todinca. Pathwidth of Circular-arc Graphs. Submitted to the 33" International Workshop on Graph-Theoretic Concepts in Computer Science (WG 2007). To be held June 21-23, 2007. Dorngbur near Jena, Germany. Proceedings which are part of Lecture Notes in Computer Science, Springer-Verlag. 4. J.R. Correa and M. Matamala. Some Results about Factors of Graphs. Submitted to the Journal of Graph Theory, 2006. 5. M. Matamala and E. Moreno, Minimal de Bruijn circuits and Minimal de Bruijn sequence. Submitted to Discrete Mathematics, 2006. Other publications acknowled ging support of the Anillo 3. M. Loebl and lain Moffatt. The chromatic polynomial of fat graphs and its categorification. Submitted to Advances in Mathematics, 2006. 4. M. Kang and M. Loebl. The enumeration of planar graphs via Wick's theorem. Submitted to Advances in Mathematics, 2006. 8 IV. COLABORACION INTERNACIONAL Si durante el perlodo de ejecución correspondiente organizó actividades de intercambio como conferencias, workshops, symposia u otros, en los cuales se dieron a conocer resultados del proyecto, adjunte los resümenes presentados y una breve reseña de la actividad que incluya el programa y los participantes (bajo el encabezamiento indicado). Se incluyen aqul también las presentaciones a congresos nacionales e internacionales, de las cuales también se requiere el resumen y el programa del congreso u otro evento. Si durante el periodo de ejecución correspondiente visitó laboratorios privados o pertenecientes a una o más universidades, empresas, centros o institutos de investigación que permitieron desarrollar sus objetivos de investigación u otros, señálelo en esta sección indicando los objetivos de la estadIa o visita y su relevancia dentro del quehacer del proyecto. Identifique el lugar y persona o personas de contacto. Se incluyen aqul también las visitas breves y/o estadlas de mayor aliento de investigadores extranjeros que se hayan realizado con el mismo fin. Para ello también indique objetivos, resultados especIficos e identifique la o las personas invitadas, su especialidad y la institución u organización de origen. CONFERENCE ORGANIZATION LATIN was launched in 1992 to foster the interaction between the Latin-American community and computer scientists around the world. LATIN'Oó was the seventh of a series, after Sao Paulo, Brazil (1992); Valparaiso, Chile (1995); Campinas, Brazil (1998) and Punta del Este, Uruguay (2000), Cancun, Mexico (2002), Buenos Aires, Argentina (2004). LATIN is the most prestigious and important conference held in Latin-America in the area of Theoretical Informatics. The Conference's main focus is on mathematical aspects of computer science: Complexity theory and efficient algorithms. Randomized, distributed, online and approximation algorithms. Formal languages, computational learning and mathematical machines. Cryptography. Semantics and verification of programs. Symbolic computation. Quantum computing. Computational Geometry, Bioinformatics, Computer vision. LAT1N'06 proceedings were published by Springer-Verlag, in the Lecture Notes in Computer Science Series, Volume 3887, 2006. A special issue of Algorithmica, also edited by Springer-Verlag, will be dedicated to a selection of papers accepted to the conference. The Program Committee Chair for LAT1N'06 was Marcos Kiwi (Anillo's P1). The local organizers were José R. Correa (Anillo's associate researcher) and Alejandro Hevia, all of which were also editors of the conference proceedings. The two first will also be guest editors of the conference's Algorithmica special issue. Martin Matamala (Anillo's PT) and José R. Correa were Program Committee members for the conference. A record high of 224 submissions where received (up from 178 in LATIN'04). The acceptance rate fell to 29% (from 33% in LATIN'04). Approximately 120 people attended the conference from 22 different nationalities and authors of accepted papers came from 24 different countries. There were 7 keynote speakers participating in the conference: • Ricardo Baeza-Yates, U. Chile • Anne Condon, U. British Columbia • Ferran Hurtado, U. Politècnica de Catalunya • R. Ravi, Carnegie Mellon U. • Madhu Sudan, MIT • Sergio Verdñ, Princeton U. • Avi Wigderson, Institute for Advanced Study Additional information about the conference can be obtained at its website: www.1atin06.org NEW NETWORKS OF COLLABORATION Especially noteworthy is the collaboration the Anillo has triggered with one of the strongest regional research groups in the area of theoretical informatics: the one of the U. Sao Paolo. Over 9 research visits took place during the first year of execution of the project. Moreover, there are 2 ongoing research projects under development. The scientific exchange has been especially strong with Cristina Gomez Fernandes (Anillos's visiting scholar), Yoshiharu Kohayakawa (Anillos's visiting scholar) and Yoshiko Wakabayashi (Anillos's visiting scholar). We are convinced that this new network of collaboration will have long lasting fruitful scientific consequences for the Anillos's researchers as well as a non-negligible regional impact. LIST OF VISITS ABROAD CARRIED OUT BY THE ANILLO'S RESEARCHERS Participation in Conferences and Workshops Ivan Rapaport (Anillo's P1) • 10ih Combinatorial and Computational Aspects of Optimization, Topology and Algebra (ACOTA 2006). • December 3-9, 2006, Puerto Vallarta, Mexico. • Talk: "Communities in graphs". Mar-tin Matamala (Anillo's P1) 10 • 6th Czech-Slovak International Symposium on Combinatorics, Graph Theory, Algorithms and Applications. • July 10-15, 2006, Prague, Czech Republic. • Talk: "Vertex partitions and maximum degenerated subgraphs". • 19rh International Symposium on Mathematical Programming. • July 30 - August 4, 2006, Rio de Janeiro, Brazil. • Talk: "Some remarks about factors". Eduardo Moreno (Artillo's associate researcher) • 6ih Czech-Slovak International Symposium on Corn binatorics, Graph Theory, Algorithms and Applications. a July 10-15, 2006, Prague, Czech Republic. • Summer School and Workshop on Probabilistic Methods in Cam binatorics. a July 16-22, 2006, Graz, Austria. • 7th Latin American Symposium on Theoretical Informatics (LATIN 2006) • March 20-24, 2006, Valdivia, Chile. • Talk: "Minimal Eulerian Circuit in a Labeled Digraph". José R. Correa (Anillo's associate researcher) • 10" Aussois Workshop in Combinatorial Optimization o January 2006 • 33rd International Colloquium on Automata, Languages and Programming (ICALP 2006) • July 9-16, 2006, Venice, Italy. • Talk: "Network Games With Atomic Players". • 19th International Symposium on Mathematical Programming (ISMP 2006). • July 30 - August 4, 2006, Rio de Janeiro, Brazil. • Talk: "Approximation Algorithms for Packing and Scheduling Problems" (Tucker prize finalist talk). • INFORMS Annual Meeting 2006 • November 5-8, 2006, Pittsburgh, PA • Talk: "Network Games With Atomic Players". Marcos Kiwi (Anillo's P1) • 4th IFIP International Conferences on Theoretical Computer Science (TCS 2006) • August 20-25, Santiago, Chile • Talk: "Adversarial Queueing Theory Revisited" (Keynote Talk) 11 Martin Loebi (Anillo's international associate researcher) • Reunion Anual de la Union Matemática Argentina • September 18-22, 2006, Buenos Aires, Argentina • Talk: "Discrete tools in statistical physics" Visits to Research Centers Abroad Eduardo Moreno • Université de Marne-la- Vallée, Paris, France. • July 1-9, 2006, Paris, France. • Collaborator: Dominique Perrin. José R. Correa • Columbia University, New York, USA. • February 1-28, 2006. • Collaborator: Nicolas Stier-Moses. • Talk: "Network Games With Atomic Players". • Also spent two days at the IBM T.J. Watson research center collaborating with Nikhil Bansal and Maxim Sviridenko. • Université de Clermont II, Clermont-Ferrand, France. • July 17-20, 2006. • Collaborator: Mourad Baiou. • Talk: "Approximating Rational Objectives" • Carnegie Mellon University, Pittsburgh, USA. • November 9-10, 2006. • Collaborator: R. Ravi • Talk: "The Impact of Oligopolistic Competition in Networks". • University of Sao Paulo, Brazil. • November 26-December 1, 2006. • Collaborator: Cristina G. Fernandes, Yoshiko Wakabayashi • Talk: "The Impact of Oligopolistic Competition in Networks". Martin Matamala • École Normale Superiéure de Lyon, France. • January 16- February 5,2006. • Collaborator: Eric Rémila. • Talk: "Quelques remarques sur les facteurs de graphes". 12 • University of Sao Paolo, Brazil. • November 26-December 1, 2006. • Collaborator: Cristina G. Fernandes, Yoshiko Wakabayashi. Ivan Rapaport • Université d 'Orleans, France. • February 3-28, 2006. • Collaborator: loan Todinca. • Talk: "Cellular automata and communication complexity" • École Norm ale Superiéure de Lyon, France. • June 18- July 17, 2006. • Collaborator: Eric Rémila. • Universidad Nacional Autónoma de Mexico. • November 20 -December 14, 2006. • Collaborator: Sergio Rajsbaum. • Talk: "Long-lived consensus" Marcos Kiwi • Boston U., Yale U, U Connecticut, USA. • February 4— 18, 2006. • Collaborators: Shang-Hua Teng, Daniel Spielman and Alex Russell. • Talk: "Length of Longest Common Subsequences of Random Words over Large Alphabets" • University of Sao Paolo, Brazil. o November 26-December 1, 2006. o Collaborator: Yoshiharu Kohayakawa. LIST OF VISITORS SUPPORTED BY THE ANILLO1 Name Period Affiliation Status Antonio Fernandez U. Rey Juan Carlos Martin Loebi Charles U. Jan 5-Dec 31, 2006 Visiting scholar Pierre Fraigmaud . U. Pans-Sud Jan 6-13, 2006 Lecturer in the Escuela de Verano 06 Visiting scholar Follow link to researchers webpage for further information. 13 Jaroslav N esetril Charles U. Jan 9-15, 2006 Lecturer in the Escuela de Verano'06 Sergio Raj sbaum UNAM Jan 7-13,2006 Lecturer in the Escuela de Verano'06 Columbia U. May 9-19, 2006 Visiting Scholar U. São Paulo Sep 2-9, 2006 Visiting Scholar Cristina U. São Paulo Gomez Fernandes Sep 2-9, 2006 Visiting Scholar Yosh iko Wakabashashi U. Sao Paulo Sep 2-9, 2006 Visiting Scholar Miguel Pizafla U. Autónoma Metropolitana Sep 2-16, 2006 Visiting Scholar Eric Remila Ecole Nor-male Superieure de Lyon Nov 6-24, 2006 Visiting Scholar Florent Becker Ecole Normale Superieure de Lyon Oct 20-Nov 20, 2006 Visiting Scholar Nov 26-Dec 1, 2006 Visiting Scholar Nicolás Stier Moses Vchhcirii Kohayakawa Eduardo San y PUC-Rio Laber 14 V. RESULTADOS DE ENTRENAMIENTO Y FORMACION DE ESTUDIANTES E INVESTIGADORES JOVENES Si considera relevante incluir los resultados obtenidos por algün estudiante de pregrado o postgrado, investigador joven u otra persona que sea parte de este Anillo, haga referencia a ello en la sección anterior (Sección III- INVESTIGACION). LIST OF STUDENTS ADVISED BY ANILLO'S RESEARCHERS Undergraduate 1. Rodolfo Carvajal. Engineering thesis student (completed). Advisor: Ivan Rapaport (Anillo's P1). Currently holds Instructor position at the Department of Mathematical Engineering of the University of Chile. 2. Gonzalo Sanchez. Engineering thesis students (current). Advisor: Martin Matamala (Anillo's P1). 3. José Soto. Engineering thesis student (completed). Advisor: Marcos Kiwi (Anillo's PT). Currently pursuing graduate studies at MIT, Applied Math PhD program. Graduate 1. Flavio Guiflez. PhD in Mathematical Modelling (current). Advisor: Martin Matamala (Anillo's PT). 2. Claudio Telha. Master in Computer Science (current). Advisor: Marcos Kiwi (Anillo's PT) 3. Christopher Thraves. PhD in Mathematical Modelling (current). Co-advisors: Marcos Kiwi (Anillo's P1) and Antonio Fernandez (Anillo's visiting scholar). 4. José Zamora. PhD in Mathematical Modelling (current). Co-advisors: Martin Matamala (Anillo's PT) and Martin Loebl (Anillo's international associate researcher). ORGANIZATION OF SEMINARS There is no such thing as an Anillo Project seminar. Instead we have put more effort in increasing the activity of the Discrete Math Seminar (U. Chile). Each seminar is hosted by a specific researcher. Below we list the seminars hosted by Anillo's participants: 15 Date: Title: Speaker: Affiliation: Nov 24, 2006 Competitive Algorithms for Evaluating Functions Eduardo Laber PUC Rio Date: Title: Speaker: Affiliation: Nov 10, 2006 Self-assembly Florent Becker Ecole Normale Supérieure de Lyon Date: Title: Oct 27, 2006 MIR Inequalities, Mixed Integer Knapsack Problems and the Closure of Single-row Systems Marcos Goycoolea Universidad Adolfo Ibáñez Speaker: Affiliation: Date: Title: Speaker: Affiliation: Oct 20, 2006 A study of stochastic 2D Minority CA: Would wearing stripes be a fatality for snob people? Nicolas Schabanel CNRS CMM, Chile Date: Title: Speaker: Affiliation: Oct 13, 2006 Interval completions Karol Suchan DIM, Universidad de Chile and AGH University of Science and Technology, Cracow, Poland Date: Title: Oct 6, 2006 Pull-Based Data Broadcast with Dependencies: Be Fair to Users, not to Items Julien Robert Ecole Normale Supérieur de Lyon Speaker: Affiliation: Speaker: Affiliation: Sep 29, 2006 Some observations on combinatorial zeta function in discrete mathematics and theoretical physics Martin Loebl Charles U., Prague and DIM, U. Chile Date: Title: Speaker: Affiliation: Sep 8, 2006 Consideraciones Topologicas sobre la Grafica de Clanes Miguel Pizaña Universidad Autónoma Metropolitana-Iztapalapa Date: Title: Date: I Sep 8, 2006 16 Title: Speaker: Affiliation: Extremal and Ramsey type random and pseudorandom graphs Yoshiharu Kohayakawa U. of Sao Paulo results for subgraphs of Speaker: Affiliation: Sep 1, 2006 Asynchronous Behavior of Double-quiescent Elementary Cellular Automata Damien Regnault ENS - Lyon, France Date: Title: Speaker: Affiliation: Sep 1, 2006 Universally Composable Simultaneous Broadcast Alejandro Hevia DCC - Universidad de Chile Date: Title: Speaker: Affiliation: Aug 25, 2006 Matroids, Secretary Problems, and Online Mechanisms Nicole Immorlica Microsoft Research Date: Title: Speaker: Affiliation: May 12, 2006 Network Games With Atomic Players Nicolas Stier Columbia University Date: Title: Speaker: Affiliation: May 5, 2006 El Problema del Vendedor Viajero (TSP) y Programación Entera Daniel Espinoza Depto. Ingenierla Industrial, Universidad de Chile Date: Title: Speaker: Affiliation Dec 30, 2005 Acerca de LLL y el algoritmo de Gauss Antonio Vera GREYC, Université de Caen Basse-Normandie Date: Title: Speaker: Affiliation: Dec 16, 2005 Planificación y encaminamiento de paquetes bajo modelos de adversario Antonio Fernández Universidad Rey Juan Carlos Date: Title: Speaker: Affiliation: Dec 7, 2005 Complexity Aspects of Convexity on Graphs Fábio Protti U. Federal de Rio de Janeiro, Brasil Date: Title: 17 ORGANIZATION OF SCHOOLS AND CONFERENCES 1St Summer School in Discrete Mathematics The school took place between January 9 and 13 at the Instituto de Sisternas Complejos de Valparaiso. The format of the conference was morning lectures and homework discussion among the students during the afternoon. The School courses where: • Graph exploration and graph searching Lecturer: Pierre Fraigniaud, CNRS, Universite Paris-Sud, France. • Many facets of graph colorings: structure and complexity Lecturer: Jaroslav Nesetril, Charles University, Prague, Czech Republic. • Fun damentos de cómputo distribuido Lecturer: Sergio Rajsbaum, Universidad Nacional Autónoma de Mexico. A total of 17 graduate and advanced undergraduate attended the conference. They came from 4 distinct universities and 6 distinct graduate and undergraduate programs. POSTDOC POSITIONS The Anillo made a first call for applications for a postdoctoral fellowship in March 2006. The process was quite successful, over a dozen applications were received -most of very high standards- for a single position. The selection process was rigorous and decisions were made based not only on the potential of the candidates but also on the fit with research interests of our group. Applications came from all over the world including six from France, two from Germany, and one from each of Austria, Ireland, Israel, Switzerland and the USA (the variety of nationalities is even wider). A shorter list of five candidates was preselected. It is important to point out that all these later candidates had enough merits to deserve the position. For instance, they had published in first rate journals such as SIAM Journal on Computing, SIAM Journal on Discrete Mathematics, Discrete Applied Mathematics, Discrete Mathematics, and Networks, as well as top conferences including ESA, WG, ACM EC, STACS, SODA, INFOCOM, and ICALP. Two offers were made, and one of the candidates, namely Karol Suchan, accepted it. It is worth mentioning that Karol has adapted very well to the group and actually has decided to stay an extra year in Chile. SUPPORT OF STUDENT PARTICIPATION IN SCHOOLS, CONFERENCES, ETC. • The European Graduate Program "Combinatorics, geometry and computation" in Berlin and the DIMATIA Centre at the Charles University, Prague, offered a onesemester study programme for PhD students and students preparing to enter a PhD 18 programme in areas: Combinatorics and Graph Theory; Discrete and Computational Geometry; Combinatorial Optimization; Discrete Structure. This school is a highly respected advanced undergraduate and graduate student activity. José Soto (an advisee of the Anillo's PT, Marcos Kiwi) and José Zamora (a graduate student of the Anillo's P1, Martin Matamala) were supported by the Anillo in order to participate in DocCourse. Taking part in DocCourse turned out to be an stimulating experience for both of them. 7th • A total of 16 full fellowships were given to Chilean students for attending the Latin American Theoretical Informatics Symposium (LATLN'06), March 20-24, Validivia, Chile. VI. ACTIVIDADES DE OUTREACH Se incluyen entre éstas todas aquellas actividades de difusión que no incluyan los medios habituales de entrega de resultados en la especialidad. Las actividades de transferencia de conocimientos generados por el proyecto a otros profesionales que no sean de la especialidad del proyecto, a empresas, estudiantes o instituciones de enseñanza media y básica o pñblico en general. Debe resumirse brevemente la actividad y sus objetivos adjuntando todo el material que se considere necesario para informar de ella (Adjunte esta información bajo el encabezamiento de Anexo correspondiente). Sponsorship of the play "Breakin g the code" The play is a biography of the English mathematician Alan Turing, who was one of the inventors of the digital computer and one of the key figures in the breaking of the Enigma code, used by the Germans to send secret orders to their U-boats in World War II. Turing was also a homosexual in Britain at a time when this was illegal, besides being a security risk. Marcos Kiwi (Anillo's PT) met with the play actors and explained some of the scientific background of Turing's work, his contributions and gave advice on how to put the play on stage. The Anillo sponsored the play and distributed over 80 free tickets among the School of Engineering graduate and undergraduate students as well as Faculty. The main objective of this activity was to make known to a wider audience the work of Turing, sometimes referred to as "the founding father" of computer science, many of whose contributions are predecessors of the general paradigms addressed throughout this Anillo. Design and sponsorship of the exhibit "Squared Wheel" of the Museo Interactivo Mirador This exhibition represents the starting point of the Anillo's collaboration with the 19 Museo Interactivo Mirador (Chile's most successful children science museum). The long term goal is to collaborate in the creation of a hail, at the museum, exclusively devoted to mathematics (with emphasis in discrete mathematics). In order to build a working relationship with the Museum, a first very ludic exhibition was set up, based on a model from the Exploratorium of San Francisco and adapted by Stan Wagon, a mathematician at Macalester College in St. Paul, Minn. Ivan Rapaport (Anillo's PT) supervised the construction of a square-wheel bicycle that smoothly rolls over a surface of evenly spaced bumps of just the right shape (catenary). Since last October 2006, "Squared Wheel" is a permanent exhibit of the Museum. Sponsorship of the "School of Engineering Summer School for High School Students, 2007" The project changed focus from its intended objective of sponsoring the Chilean Mathematical Olympiad, to supporting an ongoing effort of the School of Engineering of the University Chile consisting in the annual organization of a summer school for high school students. The main goal of the school is to stimulate the appreciation and interest among teenagers of science and technology. Initially, the Anillo's sponsorship has been financial. Plans are being developed in order to incorporate to the next summer school activities and sessions that dwelve on topics relating to algorithms, graphs, and discrete optimization which are the focus of study of the Anillo. Sponsorship of a "Network Mapping Initiative" Marcos Kiwi (Anillo's P1) has developed some basic scripts in order to map public segments of computer networks and has experimented in ways of visualizing them. The visualizations obtained will be publicized among the general public in order elicit awareness on the pervasiveness, complexity and beauty of network structures. A first step has consisted in mapping the public networks of the School of Engineering of the University of Chile. The derived map will be included in several pamfiets for prospective students. A second map, currently being generated, corresponds to the public network of the University of Chile. Larger network mapping initiatives are planned for the future in collaboration with the Computer Emergency Response Team for the .cl domain (CLCERT). Anillo's Website A website for the proyect was set up by Eduardo Moreno (Anillo 's associate researcher) and Marcos Kiwi (Anillo's PT). Its URL is http://www.dim.uchile.cl/redes . All news and project's activities are informed through the website. Among the sections it currently includes are; • A section of news, project objectives, participants, contact information, etc • A list of relevant links • A list of invited researchers • A photo gallery section • Separate sections for each conference and school organized by the Anillo. 20 VII. INDICADORES Y ESTADISTICAS La siguiente sección es solo para fines de seguimiento y no forma parte del proceso de evaluación del Proyecto Anillo. La informaciOn requerida atafle al grupo completo de participantes del Proyecto Anillo, y tiene como propósito cumplir con la puesta al dia de las estadIsticas de CONICYT. NUMERO DE INVESTIGADORES' EN EL PROYECTO INDICADOR POR ANILLO Ntmero Total de publicaciones IS! acumuladas al año de ejecución 7 del proyecto gue se informa (I) Nümero de publicaciones ISI con co-autores internacionales 6 acumuladas al año de ejecución gue se informa (ii) Nimero de citas en revistas internacionales acumuladas al año de ejecución gue se informa (iii) Nümero de estudiantes de doctorado que están siendo formados 3 dentro del programa. NUmero de investigadores con post-doctorado presentes en el 1 grupo de investigación Todos los participantes en el proyecto excluyendo, colaboradores e mvestigadores intemacionales, personal técnico y estudiantes sin grado académico (i) (ii) (iii) Este Item hace referencia al nñmero total de publicaciones 1ST acumuladas existentes dentro del anillo, considerando en conjunto las publicaciones ISI de todos los investigadores pertenecientes al grupo de investigación para el año de ejecuciOn respectivo. En este punto, al igual que en el anterior, se debe tomar en cuenta agregadamente, las publicaciones con co-autorlas internacionales acumuladas de todos los investigadores pertenecientes al anillo. El Item considera el total de citas en revistas intemacionales acumuladas hasta el año de ejecución que se informa tomando agregadamente las citas para todos los investigadores en conjunto en el aflo en referencia. ** En la categorla de "investigadores" no están incluidos los gestores y administradores que desarrollan actividades de planificación y gestiOn de los aspectos cientificos como tampoco el personal técnico (de laboratono u otro). Los estudiantes de postgrado a nivel de doctorado que participan en tareas de I+D deben considerarse como investigadores. 21 Tahla 2. Indicador por Anillo Cantidad de fondos recibidos para la puesta en marcha del proyecto, provenientes de fuentes externas al programa (expresados en pesos chilenos) (iv) Cantidad de patentes solicitadas por grupo de investigación al año del perlodo informado (v) Cantidad de patentes otorgadas por grupo de investigación al año de informe (vi) Nümero de acuerdos de transferencia de matenales por grupo de investigacion. (vii) I Fuente Nacional Fuente Internacional None None None (iv) "Fuentes de financiamiento externas al programa", indica cualquier forma de financiamiento que no provenga del PBCT, por lo cual éste puede provenir de recursos internacionales o también de recursos nacionales independientes del Programa Bicentenario en Ciencia y TecnologIa. ESTE DATO SERA COMPLETADO POR EL PBCT, NO ES NECESARIO QUE LO COLOQUE. (v) Se debe considerar el nümero de patentes que han solicitado (en cualquier momento del tiempo) los integrantes del grupo de investigación para cualquier investigaciOn que hayan realizado, independiente de La relación que pueda existir o no, con el proyecto de investigación emprendido dentro del aniLLo. Hay que tomar en cuenta ci nümero total de patentes solicitadas para todos los investigadores en conjunto. (vi) La iogica a seguir con el nürnero de patentes otorgadas por grupo de investigación es la misma que con el nümero de patentes solicitadas. (vii) Un acuerdo de transferencia de materiales, es un documento que está hecho para transferir materiales de investigación tangibles entre dos organizaciones, sin que exista una colaboración de investigación entre ambas. El beneficiario del acuerdo intenta satisfacer sus propósitos de investigación mediante este sistema. Algunos ejempios de transferencia son el traspaso de reactivos, compuestos quimicos, lineas celulares, a veces softwares, etc. Las clases de transferencia más comunes son, entre Instituciones académicas o de investigación, entre instituciones académicas y la industria. 22 VIII. ANEXOS 1) Anexo de actividades de investigación 2) Anexo actividades de formación 3) Anexo organización de conferencias internacionales 4) Anexos de actividades de difusión. 23