Examples of retracts in a free group that are not the fixed subgroup of any group of automorphisms

Let F be a free group of rank at least three. We show that some retracts of F previously studied by Martino-Ventura are not equal to the fixed subgroup of any group of automorphisms of F. This shows that, in F, there exist subgroups that are equal to the fixed subgroup of some set of endomorphisms but are not equal to the fixed subgroup of any set of automorphisms. Moreover, we determine the Galois monoids of these retracts, where, by the Galois monoid of a subgroup H of F, we mean the monoid consisting of all endomorphisms of F that fix H.

Negotiation advantages of professional associations in health care

In several instances, third-party payers negotiate prices of health care services with providers. We show that a third-party payer may prefer to deal with a professional association than with the sub-set constituted by the more efficient providers, and then apply the same price to all providers. The reason for it is the increase in the bargaining position of providers. The more efficient providers are also the ones with higher profits in the event of negotiation failure. This allows them to ext act a higher surplus from the third-party payer.

Aproximació al disseny de procediments i instruments per a la personalització de l'ensenyament a l'etapa primària des d'una perspectiva inclusiva

The main objective of this research is to found a new process about the personalization's curriculum for pupils with especial educational needs. In this research there are two objectives: the first objective is to describe a procedure for to do the individual planning for this pupils. This procedure is called "Procediment per cartes de personalització" (Pedragosa 2002). The other objective is centered to validate this procedure for teachers who are in active service in primary's etapa and to check if it's a good process for to do the individual planning in an inclusive approach. The procedure's cobcretion is about three basic referents: In the first, we consult with the current regulations, in the second we incorporate the inclusion's approach and the fundamentals of universal learning design, and finally we consult Ruiz's (1999) provides. We obtain the information for the research until, during and after of the formation's course (in 2003/2004). We introduced two questionnaire (until and after of formation sessions) and we register all of the sessions with a parlimentary report. About the main research results we can to affirm that the procedure is a good option for the professional's practice. It's an organized, ordered and coherent design with our curriculum. But, in spite of, we can to probate that there some interesting variables which are to influence to the procedure's efficiency.

Not all university degrees yield the same return: private and social returns to higher education for males in Spain

In this paper we use micro data from the Spanish Family Expenditure Survey for 1990 to estimate, for the first time, the private and social rates of return of different university degrees in Spain. We compute internal rates of return and include investment on higher education financed by the public purse to estimate social rates of return. Our main finding is that, as presumed, there is large heterogeneity in rates of return amongst different university

Urban spatial structure and suburbanisation. The case of the Barcelona Metropolitan

The metropolitan spatial structure displays various patterns, sometimes monocentricity and sometimes multicentricity, which seems much more complicated than the exponential density function used in classic works such as Clark (1961), Muth (1969) or Mills (1973) among others, can effectively represent. It seems that a more flexible density function,such as cubic spline function (Anderson (1982), Zheng (1991), etc.) to describe the density-accessibility relationship is needed. Also, accessibility, the fundamental determinant of density variations, is only partly captured by the inclusion of distance to the city centre as an explanatory variable. Steen (1986) has proposed to correct that miss-especification by including an additional gradient for distance to the nearest transportation axis. In identifying the determinants of urban spatial structure in the context of inter-urban systems, some of the variables proposed by Muth (1969), Mills (1973) and Alperovich (1983) such as city age or population, make no sense in the case of a single urban system. All three criticism to the exponential density function and its determinants apply for the Barcelona Metropolitan Region, a polycentric conurbation structured on well defined transportation axes.

The Cuntz semigroup, the Elliott conjecture, and dimension functions on C*-Algebras

We prove that the Cuntz semigroup is recovered functorially from the Elliott invariant for a large class of C¤-algebras. In particular, our results apply to the largest class of simple C¤-algebras for which K-theoretic classification can be hoped for. This work has three significant consequences. First, it provides new conceptual insight into Elliott's classification program, proving that the usual form of the Elliott conjecture is equivalent, among Z-stable algebras, to a conjecture which is in general substantially weaker and for which there are no known counterexamples. Second and third, it resolves, for the class of algebras above, two conjectures of Blackadar and Handelman concerning the basic structure of dimension functions on C¤-algebras. We also prove in passing that the Kuntz-Pedersen semigroup is recovered functorially from the Elliott invariant for all simple unital C¤-algebras of interest.

1st National Accessiblity Plan 2004-2012: achieving equal opportunities and full participation through design for all

According to official statistics, disabled people in Spain number 3.5 million and make up 8.8% of the Spanish population. This group of people are increasingly being recognised as members of society with equal rights, and many of their demands are gradually being transformed into solutions that benefit society as a whole. One example is improved accessibility. Accessible built environments are more human and inclusive places, as well as being easier to get around. Improved accessibility is now recognised as a requirement shared by all members of society, although it is achieved thanks to the demands of disabled people and their representatives. The 1st National Accessibility Plan is a strategic framework for action aimed at ensuring that new products, services and built environments are designed to be accessible for as many people as possible (Design for All) and that existing ones are gradually duly adapted.

Construcció modular d'agents basats en components: estudi i desenvolupament

La complexitat de disseny d’agents mòbils creix a mesura que s’incrementen les seves funcionalitats. Aquest projecte proposa enfocar el problema des d’un punt de vista modular. S’ha realitzat un estudi tant dels propis agents com de les parts que ho integren. De la mateixa forma, s’han establert i s'han implementat els mecanismes necessaris per habilitar les comunicacions segures entre agents. Finalment, s’han desenvolupat dos components que ofereixen les funcionalitats de seguiment de l’agent mòbil i la recuperació dels resultats generats. El desenvolupament d’agents basats en components tracta d’aplicar la vella estratègia "divideix i venceràs" a la fase de disseny, reduint, així,la seva gran complexitat.

Codificación a nivel de paquete para comunicaciones móviles por satélite

Una de les opcions que es contemplen per transmetre continguts multimèdia i proporcionar accés a Internet a grups de usuaris mòbils és fer servir satèl·lits. Les condiciones de propagació del canal mòbil impliquen que d'una manera o altra haurem de garantir la qualitat de servei. Això té fins i tot més importància si tenim en compte que, en el cas d'accés a Internet, no es té la capacitat d'assumir cert percentatge de pèrdua de dades que tenim, per exemple, en la transmissió de so o vídeo (rebaixant la qualitat). Entre les principals alternatives per a aquesta classe d’entorns es troba la inclusió de codificacions a nivell de paquet. El funcionament d'aquesta tècnica es basa en incloure a la transmissió paquets redundants, obtinguts mitjançant un determinat algoritme. El receptor podrà recuperar la informació original que es volia enviar, sempre que hagi rebut una certa quantitat de paquets, similar a la quantitat de paquets originals. A aquest mecanisme se'l coneix com Forward Error Correction (FEC) a nivell de paquet. En aquesta memòria es valoren breument les alternatives existents i s'expliquen algunes de les codificacions per a FEC més importants. A continuació es realitza un estudi compartiu d’algunes d'elles: les variants de LDPC (Low Density Parity Check) conegudes com LDGM (Low Density Generator Matrix), i la codificació Raptor

Integració de tècniques per a la comprovació eficient de restriccions d'integritat en la generació de programari per entorns web

Estudi elaborat a partir d’una estada al Politecnico de Milano, Itàlia, entre gener i juny del 2006. Un dels principals objectius de l’Enginyeria del Programari és automatitzar el màxim possible el procés de desenvolupament del programari, reduint costos mitjançant la generació automàtica del programari a partir de la seva especificació. Per assolir-ho, entre altres, cal resoldre el problema de la comprovació eficient de restriccions, que són una part fonamental de l’especificació del programari. Aquest és precisament l’àmbit en què s’està desenvolupant una tesi que presentarà un mètode que poden integrar totes les eines generadores de codi per tal d’assolir una implementació eficient de les restriccions d’integritat. En l’actual fase del projecte s’ha treballat per validar el mètode de la tesi, optimitzant-lo pel cas específic de les aplicacions web i estendre’l per poder tractar també aplicacions basades en workflows. Pel que fa a l’optimització del mètode per aplicacions web, s’han definit una sèrie de paràmetres que permeten configurar la implementació del mètode tenint en compte les necessitats específiques de rendiment de cada aplicació web en particular. Respecte als workflows (cada cop més populars i que s’usen com a definició d’alt nivell per a les aplicacions a desenvolupar) s’ha estudiat quins són els tipus de restriccions que impliquen i com després es pot aplicar el mètode de la tesi sobre aquestes restriccions per tal de generar de forma eficient també les aplicacions basades en workflows.

Label Space Reduction in All-Optical Label Switchiing Networks

Report for the scientific sojourn at the Department of Information Technology (INTEC) at the Ghent University, Belgium, from january to june 2007. All-Optical Label Swapping (AOLS) forms a key technology towards the implementation of All-Optical Packet Switching nodes (AOPS) for the future optical Internet. The capital expenditures of the deployment of AOLS increases with the size of the label spaces (i.e. the number of used labels), since a special optical device is needed for each recognized label on every node. Label space sizes are affected by the wayin which demands are routed. For instance, while shortest-path routing leads to the usage of fewer labels but high link utilization, minimum interference routing leads to the opposite. This project studies and proposes All-Optical Label Stacking (AOLStack), which is an extension of the AOLS architecture. AOLStack aims at reducing label spaces while easing the compromise with link utilization. In this project, an Integer Lineal Program is proposed with the objective of analyzing the softening of the aforementioned trade-off due to AOLStack. Furthermore, a heuristic aiming at finding good solutions in polynomial-time is proposed as well. Simulation results show that AOLStack either a) reduces the label spaces with a low increase in the link utilization or, similarly, b) uses better the residual bandwidth to decrease the number of labels even more.

Pulmonary involvement in Schistosomiasis mansoni

The post-treatment pulmonary alterations were evaluated in patients (Study 1) and in mice (Study 2) infected with Schistosoma mansoni. Study 1: the patients were examined pre and post-treatment (with ora oxamniquine) and the following exams were performed: sputum for eosinophils and chest x-ray. Study 2: four groups of mice (total = 64) were studied; Group I (infected and treated with oxamniquine); II (infected and not treated); III (not infected and treated) and IV (not infected and not treated). All were x-rayed to check for pulmonary abnormalities pre and post-treatment and lung specimens were studied by optical microscopy and immunofluorescence. We have found abnormalities in the parameters checked in both studies and the results suggest an immunological reaction, probably due to deposition of immune complexes in the lungs, with subsequent activation of the complement system. The experimental study showed that the alterations are not dependent of the presence of eggs and/or worms of S. mansoni in the lungs, thus corroborating the hypothesis of deposition of circulating material.