Rigid covariance, equivalence principle and Fermi rigid coordinates: gravitational waves

For a given space-time and for an arbitrary time-like geodes ic, we analyze the conditions for the construction of Fermi coordinates so that they are also rigi d covariant. We then apply these conditions to linear plane gravitational wavesPostprint (author's final draft

The Intelligent Web

Many people are working on the Semantic Web with the main objective being to enhance web searches. Our proposal is a new research strategy based on the existence of a discrete set of semantic relations for the creation and exploitation of semantic networks on the web. To do so, we have defined in a previous paper (Álamo, Martínez, Jaén) the Rhetoric-Semantic Relation (RSR) based on the results of the Rhetoric Structure Theory. We formulate a general set of RSR capable of building discourse and making it possible to express any concept, procedure or principle in terms of knowledge nodes and RSRs. These knowledge nodes can then be elaborated in the same way. This network structure in terms of RSR makes the objective of developing automatic answering systems possible as well as any other type of utilities oriented towards the exploitation of semantic structure, such as the automatic production of web pages or automatic e-learning generation

Didactic Networks and exemplification

After a general overview in a previous paper [AMJ10b], in which we proposed Didactic Networks (DN) as a new way for developing and exploiting web-learning content, we offer here a deeper study showing how to use them for web-learning design and content generation based on Instructional Theory with the coherence guaranty of the RST [MT99]. By using a set of expressivity patterns, it is possible to obtain different final ¿products¿ from the DNs such as different level or different aspect web-learning lessons, depending on the target, documents or evaluation tests. In parallel we are defining the Fundamental Cognitive Networks (FCN), in which we deal with the most common patterns human being uses to think and communicate ideas. This FCN set reuses the representation of Concepts, Procedures and Principles defined here, and it is the main topic of a paper we are working on for the very near future

Rigid covariance as a natural extension of Painleve-Gullstrand space-times: gravitational waves

The group of rigid motions is considered to guide the search for a natural system of space-time coordinates in General Relativity. This search leads us to a natural extension of the space-times that support Painlevé–Gullstrand synchronization. As an interesting example, here we describe a system of rigid coordinates for the cross mode of gravitational linear plane waves.Postprint (author's final draft

Didactic Networks: A proposal for e-learning content generation

The Didactic Networks proposed in this paper are based on previous publications in the field of the RSR (Rhetorical-Semantic Relations). The RSR is a set of primitive relations used for building a specific kind of semantic networks for artificial intelligence applications on the web: the RSN (Rhetorical-Semantic Networks). We bring into focus the RSR application in the field of elearning, by defining Didactic Networks as a new set of semantic patterns oriented to the development of eleaming applications. The different lines we offer in our research Jail mainly into three levels: • The most basic one is in the field of computational linguistics and related to Logical Operations on RSR (RSR Inverses and plurals. RSR combinations, etc), once they have been created. The application of Walter Bosma 's results regarding rhetorical distance application and treatment as semantic weighted networks is one of the important issues here. • In parallel, we have been working on the creation of a knowledge representation and storage model and data architecture capable of supporting the definition of knowledge networks based on RSR. • The third strategic line is in the meso-level, the formulation of a molecular structure of knowledge based on the most frequently used patterns. The main contribution at this level is the set of Fundamental Cognitive Networks (FCN) as an application of Novak's mental maps proposal. This paper is part of this third intermediate level, and the Fundamental Didactic Networks (FDN) are the result of the application of rhetorical theoiy procedures to the instructional theory. We have formulated a general set of RSR capable of building discourse, making it possible to express any concept, procedure or principle in terms of knowledge nodes and RSRs. The instructional knowledge can then be elaborated in the same way. This network structure expressing the instructional knowledge in terms of RSR makes the objective of developing web-learning lessons semi-automutkally possible, as well as any other type of utilities oriented towards the exploitation of semantic structure, such as the automatic question answering systems

Continguts semivirtuals

Peer Reviewe

An evaluation tool for physics applets

Physics applets are well known appealing resources to teach and learn physics, and a large number of them are available on the Internet. Nevertheless, not all of them are of the same quality, because such applets do not fit every specific teaching/learning purpose. The start question was which features should have a physics applet in order that it can be considered a good applet according to our experience as teachers or lecturers. The answer should be based on practical evaluations of applets from the Internet, taking quality evaluation criteria already published into account. In this way, an evaluation tool was developed as a rubric which draws attention to the different aspects of an applet that are relevant for teaching or learning a physics topic, grouping these aspects into five categories. Each category is given a separate scoring based on a preparatory qualitative evaluation of the aforementioned aspects. This evaluation tool has been tested on five physics applets by four secondary-school teachers as experts in first-year students’ background. The results show the suitability degree of each of these applets as resources for different teaching/learning environments, as well as the suitability of the evaluation tool itself. In addition, the evaluation tool simplifies the interchange of information on physics applets among teachers and lecturers.Postprint (author's final draft

Itineraris de navegació per aprendre electromagnetisme

El títol fa referència a un projecte subvencionat pel DURSI en la primera convocatòria de projectes per la Millora de la Qualitat Docent a la tardor de 2000. L'objectiu principal era elaborar mòduls en català, basats en l'ús de recursos via web per facilitar l'aprenentatge de l'electromagnetisme. En aquesta comunicació es presenten la justificació i el context en el que es va realitzar la proposta del projecte, a continuació es descriu el contingut i el pla de treball proposat així com el grau d'execució en funció de les diferents decisions que es van anar prenent. Des del moment de l'elaboració de la proposta fins a la seva finalització van transcorre tres anys, del 2000 al 2003, que han estat claus en el desenvolupament de recursos educatius via web. Actualment s'està vivint una situació més estacionària, si la comparem a la d'anys precedents, respecte de l'ús d'innovacions en entorns educatius, situació que permet reflexionar sobre la millor manera de fer servir els entorns web perquè siguin útils com a eines d'aprenentatge. En aquesta línia, la realització d'aquest projecte ens ha permès identificar alguns aspectes rellevants a l'hora de dissenyar entorns web i que exposem en les darreres seccions en relació als resultats obtinguts i a la valoració de l'experiència

On the meaning of Painlevé–Gullstrand synchronization

Following on from two recent papers, here we examine the relationship between Newtonian gravitation and general relativity in more depth. This allows us to define a scalar potential which is just the proper time of the vector potential when the latter is interpreted as the geodesic velocity field. The results are closely related to spacetimes that admit Painlevé–Gullstrand synchronization.Postprint (published version

Urbanismo del paisaje en ecosistemas degradados reasentamiento en el litoral de Sarita Colonia a partir de sus humedales costeros

La desarticulación existente entre Sarita Colonia y el ecosistema deteriorado de humedales en el litoral central del Callao, trae como consecuencia el asentamiento de más de 13 mil personas sobre este paisaje frágil por la falta de espacio en la ciudad, magnificando los riesgos naturales y estructurales presentes en las viviendas asentadas próximas al borde costero. En consecuencia, el proyecto indaga en las capacidades que tiene el urbanismo para incluir la regeneración progresiva de humedales costeros en un nuevo modelo sostenible de asentamiento de borde como transición entre el litoral y la zona urbana consolidada. De esta manera, partiendo del entendimiento de las dinámicas de crecimiento territorial de esta zona del litoral, se proponen estrategias progresivas de diseño y transformación del paisaje. Esto con el fin de controlar la expansión de asentamientos y rehabilitar el potencial paisajístico de las zonas marinas, costeras y urbanas de Sarita Colonia, invirtiendo el ideal de riesgo y desigualdad urbana en asentamientos construidos sobre ecosistemas enfermos. Finalmente, el proyecto a partir del urbanismo del paisaje del litoral, brinda nuevas herramientas para crear ciudades y comunidades sostenibles, aprovechando los recursos eco-sistémicos de los humedales para mitigar riesgos naturales, sanitarios y estructurales. En este sentido, el PFC plantea una mirada al futuro de no solo la relación de Sarita Colonia con su ecosistema preexistente, sino también, repensar al Callao como una ciudad sostenible, reivindicándola con su litoral y sus humedales, teniendo a los asentamientos humanos de borde como la transición entre estos