18 research outputs found
Sensor networks and distributed CSP: communication, computation and complexity
We introduce SensorDCSP, a naturally distributed benchmark based on a real-world application that arises in the context of networked distributed systems. In order to study the performance of Distributed CSP (DisCSP) algorithms in a truly distributed setting, we use a discrete-event network simulator, which allows us to model the impact of different network traffic conditions on the performance of the algorithms. We consider two complete DisCSP algorithms: asynchronous backtracking (ABT) and asynchronous weak commitment search (AWC), and perform performance comparison for these algorithms on both satisfiable and unsatisfiable instances of SensorDCSP. We found that random delays (due to network traffic or in some cases actively introduced by the agents) combined with a dynamic decentralized restart strategy can improve the performance of DisCSP algorithms. In addition, we introduce GSensorDCSP, a plain-embedded version of SensorDCSP that is closely related to various real-life dynamic tracking systems. We perform both analytical and empirical study of this benchmark domain. In particular, this benchmark allows us to study the attractiveness of solution repairing for solving a sequence of DisCSPs that represent the dynamic tracking of a set of moving objects.This work was supported in part by AFOSR (F49620-01-1-0076, Intelligent Information Systems Institute and MURI F49620-01-1-0361), CICYT (TIC2001-1577-C03-03 and TIC2003-00950), DARPA (F30602-00-2- 0530), an NSF CAREER award (IIS-9734128), and an Alfred P. Sloan Research Fellowship. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the US Government
Implementaci贸n de una herramienta did谩ctica para la manipulaci贸n de aut贸matas finitos y expresiones regulares
En este trabajo presentamos una herramienta que pretende facilitar la labor docente de la asignatura Lenguajes, gram谩ticas y aut贸matas, y en particular el uso y manejo de aut贸matas finitos y expresiones regulares. Esta aplicaci贸n permite completar el temario de la asignatura ofreciendo al estudiante la posibilidad de realizar pr谩cticas en el laboratorio, encaminadas tanto a la manipulaci贸n y comprensi贸n de los objetos presentados en el aula, como a la incorporaci贸n de nuevos algoritmos
Algorithms and cryptographic protocols using elliptic curves
En els darrers anys, la criptografia amb corbes el.l铆ptiques ha
adquirit una import脿ncia creixent, fins a arribar a formar part en
la actualitat de diferents est脿ndards industrials. Tot i que s'han
dissenyat variants amb corbes el.l铆ptiques de criptosistemes
cl脿ssics, com el RSA, el seu m脿xim inter猫s rau en la seva
aplicaci贸 en criptosistemes basats en el Problema del Logaritme
Discret, com els de tipus ElGamal. En aquest cas, els
criptosistemes el.l铆ptics garanteixen la mateixa seguretat que els
constru茂ts sobre el grup multiplicatiu d'un cos finit primer, per貌
amb longituds de clau molt menor.
Mostrarem, doncs, les bones propietats d'aquests criptosistemes,
aix铆 com els requeriments b脿sics per a que una corba
sigui criptogr脿ficament 煤til, estretament relacionat amb la seva
cardinalitat. Revisarem alguns m猫todes que permetin descartar
corbes no criptogr脿ficament 煤tils, aix铆 com altres que permetin
obtenir corbes bones a partir d'una de donada. Finalment,
descriurem algunes aplicacions, com s贸n el seu 煤s en Targes
Intel.ligents i sistemes RFID, per concloure amb alguns aven莽os
recents en aquest camp.The relevance of elliptic curve cryptography has grown in recent
years, and today represents a cornerstone in many industrial
standards. Although elliptic curve variants of classical
cryptosystems such as RSA exist, the full potential of elliptic
curve cryptography is displayed in cryptosystems based on the
Discrete Logarithm Problem, such as ElGamal. For these, elliptic
curve cryptosystems guarantee the same security levels as their
finite field analogues, with the additional advantage of using
significantly smaller key sizes.
In this report we show the positive properties of elliptic curve
cryptosystems, and the requirements a curve must meet to be
useful in this context, closely related to the number of points.
We survey methods to discard cryptographically uninteresting
curves as well as methods to obtain other useful curves from
a given one. We then describe some real world applications
such as Smart Cards and RFID systems and conclude with a
snapshot of recent developments in the field
Creaci贸n de una herramienta did谩ctica de apoyo al estudio de series y c谩lculo intregral utilizando el Mathematica
Motivados por la necesidad de facilitar al estudiante la comprensi贸n de los conceptos b谩sicos del C谩lculo, hemos dise帽ado e implementado una herramienta que permita mostrar animadamente tales objetos, empleando para ello el Mathematica como programa base. En esta comunicaci贸n presentamos la primera parte de nuestro trabajo, dedicado al estudio de las sucesiones y series, tanto num茅ricas como de funciones, y al c谩lculo integral
Formaci贸n dual en el m谩ster en ingenier铆a inform谩tica: una nueva orientaci贸n de formaci贸n universitaria
Esta comunicaci贸n presenta una experiencia singular en el sistema universitario espa帽ol de integraci贸n de formaci贸n dual universitaria (FDU) en una titulaci贸n oficial como es el m谩ster en Ingenier铆a Inform谩tica (MEINF) de la Universidad de Lleida. Con este modelo de formaci贸n se pretende mejorar el proceso de adquisici贸n de competencias y habilidades, as铆 como la empleabilidad de los estudiantes. El estudiante es contratado a tiempo completo por parte de las empresas, que pasan a tener un papel activo en su formaci贸n. Los tutores acad茅micos y de empresa son corresponsables de la formaci贸n y del seguimiento de los estudiantes, as铆 como de la evaluaci贸n de las competencias y habilidades conseguidas. La implantaci贸n del nuevo modelo FDU ha requerido la adaptaci贸n del curr铆culum de los estudios de m谩ster oficial, as铆 como el dise帽o de un nuevo modelo organizativo y de evaluaci贸n para garantizar la calidad del proceso de aprendizaje y la adquisici贸n de competencias y habilidades. Para ello se han tenido que afrontar retos relacionados con la adaptaci贸n de los equipos docentes universitarios, as铆 como la cultura empresarial, adem谩s de diferentes aspectos jur铆dicos y laborales. El programa comenz贸 en 2015 y los primeros resultados se muestran muy alentadores en t茅rminos de satisfacci贸n, tanto de los estudiantes, como de los empleadores, con el proceso de aprendizaje y el alto nivel de competencias adquirido. Adem谩s, esta metodolog铆a ha resultado un aspecto relevante para la atracci贸n de estudiantes, tanto nacionales como internacionales, a los estudios de m谩ster.This paper presents a unique experience in the Spanish university system for the integration of dual university education (FDU) in an official degree studies such as the Master's Degree in Informatics Engineering at the University of Lleida. This learning model aims to improve the process of acquiring skills and abilities, as well as the employability of students. The student is hired fulltime by companies, which play an active role in their training. The academic and business tutors are responsible for the training and follow-up of the students, as well as for the evaluation of the competences and skills acquired. The implementation of the new FDU model has required the adaptation of the curriculum, as well as the design of a new organizational and evaluation model to guarantee the quality of the learning process and the acquisition of competences and skills by the students. To this end, It was necessary to face challenges related to the adaptation of university teaching teams, as well as the business culture and different legal and labor aspects. The program started in 2015 and the first results are very encouraging in terms of satisfaction, both for students and employers, with the learning process and the high level of skills acquired. In addition, this methodology has been a relevant aspect for attracting both national and international students to master's degree
Bloc d'internet: administraci贸, aplicacions i seguretat
L'objectiu d'aquesta assignatura 茅s el d'introduir aspectes complementaris dins l'脿rea de les comunicacions entre ordinadors, que puguin ser consolidats seguint una metodologia eminentment pr脿ctica i que acostin a l'alumne a alguns dels aspectes que trobar脿 al m贸n laboral