Un enfoque orientado a objetos para software context-aware

Uno de los problemas asociados a las aplicaciones context-aware es que no hay una definición universalmente aceptada que indique qué es el contexto de una aplicación. Hasta el momento se han planteado dos visiones de contexto: • La positivista, que lo ve como un problema de representación. Su principal objetivo es encontrar una representación formal del contexto y codificarlo en una máquina. • La fenomenológica, que lo ve como un problema de interacción. Bajo esta visión el contexto es un emergente de la actividad que no puede ser formalizado. En este momento la tendencia es tomar al contexto como un conjunto de información pasiva (como un problema de representación), sobre la cual el sistema tiene que razonar y tomar decisiones. A pesar que no es el objetivo de este trabajo entrar en la discusión de qué es el contexto ni cómo debe definirse, sí se planteará un modelo de contexto desde un punto de vista distinto al utilizado actualmente. En lugar de pensar al contexto como una entidad completamente definida, la idea es descomponerlo en un conjunto de aspectos de contexto (modelados con objetos) y sus interacciones. Esto significa que el contexto deja de ser modelado como una entidad única y formal y pasa a ser un emergente de la interacción entre los objetos, similar la visión fenomenológica. Este modelo surge del trabajo centrado en ambientes puros de objetos y de una visión de contexto basada en la interacción hombre-máquina. Concretamente, el primer objetivo de esta tesis es comprobar que esta forma de ver al contexto resulta adecuada para lograr diversos tipos de adaptaciones, al tiempo que se mantiene un modelo de objetos correcto. El segundo objetivo del trabajo es proponer una arquitectura que responda a la visión de contexto anteriormente mencionada. Esta arquitectura debe ser independiente de la plataforma, así como de los dispositivos sobre los que se esté ejecutando (PDA, PC de escritorio, tablet PC, etc) y debe poder adaptarse al trabajo sobre redes heterogéneas. Dado que no es posible adelantarse a todos los posibles contextos ni a la forma en que la aplicación debe reaccionar, este trabajo hará especial hincapié en la escalabilidad y la adaptabilidad a los cambios.Facultad de Informátic

Un enfoque orientado a objetos para software context-aware

Uno de los problemas asociados a las aplicaciones context-aware es que no hay una definición universalmente aceptada que indique qué es el contexto de una aplicación. Hasta el momento se han planteado dos visiones de contexto: • La positivista, que lo ve como un problema de representación. Su principal objetivo es encontrar una representación formal del contexto y codificarlo en una máquina. • La fenomenológica, que lo ve como un problema de interacción. Bajo esta visión el contexto es un emergente de la actividad que no puede ser formalizado. En este momento la tendencia es tomar al contexto como un conjunto de información pasiva (como un problema de representación), sobre la cual el sistema tiene que razonar y tomar decisiones. A pesar que no es el objetivo de este trabajo entrar en la discusión de qué es el contexto ni cómo debe definirse, sí se planteará un modelo de contexto desde un punto de vista distinto al utilizado actualmente. En lugar de pensar al contexto como una entidad completamente definida, la idea es descomponerlo en un conjunto de aspectos de contexto (modelados con objetos) y sus interacciones. Esto significa que el contexto deja de ser modelado como una entidad única y formal y pasa a ser un emergente de la interacción entre los objetos, similar la visión fenomenológica. Este modelo surge del trabajo centrado en ambientes puros de objetos y de una visión de contexto basada en la interacción hombre-máquina. Concretamente, el primer objetivo de esta tesis es comprobar que esta forma de ver al contexto resulta adecuada para lograr diversos tipos de adaptaciones, al tiempo que se mantiene un modelo de objetos correcto. El segundo objetivo del trabajo es proponer una arquitectura que responda a la visión de contexto anteriormente mencionada. Esta arquitectura debe ser independiente de la plataforma, así como de los dispositivos sobre los que se esté ejecutando (PDA, PC de escritorio, tablet PC, etc) y debe poder adaptarse al trabajo sobre redes heterogéneas. Dado que no es posible adelantarse a todos los posibles contextos ni a la forma en que la aplicación debe reaccionar, este trabajo hará especial hincapié en la escalabilidad y la adaptabilidad a los cambios.Facultad de Informátic

Prostaglandin pathway gene expression in human placenta, amnion and choriodecidua is differentially affected by preterm and term labour and by uterine inflammation

BACKGROUND: Elucidation of the biochemical pathways involved in activation of preterm and term human labour would facilitate the development of effective management and inform judgements regarding the necessity for preterm tocolysis and post-term induction. Prostaglandins act at all stages of human reproduction, and are potentially activators of labour. METHODS: Expression of 15 genes involved in prostaglandin synthesis, transport and degradation was measured by qPCR using tissue samples from human placenta, amnion and choriodecidua at preterm and full-term vaginal and caesarean delivery. Cellular localisation of eight prostaglandin pathway proteins was determined by immunohistochemistry. RESULTS: Expression of prostaglandin pathway genes was differentially affected by factors including gestational age at delivery, and the incidence and duration of labour. Chorioamnionitis/deciduitis was associated with upregulation of PTGS2 (prostaglandin-endoperoxide synthase 2 (prostaglandin G/H synthase and cyclooxygenase)), along with the inflammatory genes IL8 (interleukin 8), S100A8 (S100 calcium binding protein A8) and TLR2 (toll-like receptor 2), in amnion and choriodecidua, and with downregulation of CBR1 (carbonyl reductase 1) and HPGD (hydroxyprostaglandin dehydrogenase 15-(NAD)) in choriodecidua. Protein localisation differed greatly between the various maternal and fetal cell types. CONCLUSIONS: Preterm and term labour are associated with distinct prostaglandin pathway expression profiles; inflammation provokes specific changes, unrelated to the presence of labour; spontaneous and induced term labour are indistinguishable

Architectural and Implementation Issues for a Context-Aware Hypermedia Platform

In this paper we present the rationale and the main components of a modular and extensible architecture for building and deploying mobile hypermedia software. Using some simple archetypical examples we show how to provide context-aware assistance to the mobile user, as he explores the physical world. We also show that this kind of software systems poses strong requirements on supporting software (such as Web browsers) and we explain how to provide a modular software substrate to support these requirements. This paper shows how to use some simple concepts to develop complex context-aware systems, which are evolvable and easy to extend.Facultad de InformáticaLaboratorio de Investigación y Formación en Informática Avanzada (LIFIA

Context-Aware Services for Physical Hypermedia Applications

In this paper we present an approach for designing and deploying context-aware services in the context of physical hypermedia applications, those applications in which mobile users explore real and digital objects using the hypermedia paradigm. We show how to adapt the objects’ response to the user’s navigation context by changing the role these objects play in the user’s travel. We first motivate our research with a simple example and survey some related work; next we introduce the concept of travel object and show that physical objects might assume the role of different type of travel objects. We then present an architectural approach for context-aware services and describe its evolution into a software substrate for physical hypermedia services. We conclude by indicating some further work we are pursuing.Publicado en: OTM'06 Proceedings of the 2006 international conference on On the Move to Meaningful Internet Systems: AWeSOMe, CAMS, COMINF, IS, KSinBIT, MIOS-CIAO, MONET - Volume Part IIFacultad de InformáticaLaboratorio de Investigación y Formación en Informática Avanzada (LIFIA

Dealing with Variability in Context-Aware Mobile Software

Mobile context-aware software pose a set of challenging requirements to developers as these applications exhibit novel features, such as handling varied sensing devices and dynamically adapting to the user’s context (e.g. his or her location), and evolve quickly according to technological advances. In this paper, we discuss how to handle variability both across different domains and during the evolution of a single application. We present a set of design structures for solving different problems related with mobility (such as location sensing, behaviour adaptation, etc.), together with the design rationale underlying them, and show how these sound micro-architectural constructs impact on variability. Our presentation is illustrated with case studies in different domains.Facultad de Informátic

Context-Aware Services for Physical Hypermedia Applications

In this paper we present an approach for designing and deploying context-aware services in the context of physical hypermedia applications, those applications in which mobile users explore real and digital objects using the hypermedia paradigm. We show how to adapt the objects’ response to the user’s navigation context by changing the role these objects play in the user’s travel. We first motivate our research with a simple example and survey some related work; next we introduce the concept of travel object and show that physical objects might assume the role of different type of travel objects. We then present an architectural approach for context-aware services and describe its evolution into a software substrate for physical hypermedia services. We conclude by indicating some further work we are pursuing.Publicado en: OTM'06 Proceedings of the 2006 international conference on On the Move to Meaningful Internet Systems: AWeSOMe, CAMS, COMINF, IS, KSinBIT, MIOS-CIAO, MONET - Volume Part IIFacultad de InformáticaLaboratorio de Investigación y Formación en Informática Avanzada (LIFIA

Dealing with Variability in Context-Aware Mobile Software

Mobile context-aware software pose a set of challenging requirements to developers as these applications exhibit novel features, such as handling varied sensing devices and dynamically adapting to the user’s context (e.g. his or her location), and evolve quickly according to technological advances. In this paper, we discuss how to handle variability both across different domains and during the evolution of a single application. We present a set of design structures for solving different problems related with mobility (such as location sensing, behaviour adaptation, etc.), together with the design rationale underlying them, and show how these sound micro-architectural constructs impact on variability. Our presentation is illustrated with case studies in different domains.Facultad de Informátic

Model-Based Concerns Mashups for Mobile Hypermedia

Mobile (or Physical) Hypermedia combines the navigational style typical of Web applications with the functionality of location and context-aware software. Users explore digital and physical relationships while accessing to information about their actual location, e.g. the object in front of them. Similar to “conventional” Web applications one might suffer usability problems when dealing with multiple informational concerns, but the situation gets worse because of screen size issues, the need to avoid user distraction, etc. In this paper we outline our model based approach for building mobile hypermedia applications by combining (“mashing up”) information corresponding to multiple concerns in a modular, usable way. Architectural issues are discussed and a simple example is presented together with its implementation.Laboratorio de Investigación y Formación en Informática Avanzad

Physical Hypermedia: a Context-Aware approach

In this paper we describe an original architecture for building and deploying physical hypermedia applications, i.e. those applications in which digital and real world objects are linked together using the well-known navigational metaphor of the World Wide Web. We also explain how our architecture evolved from a substrate for implementing location-based services to a powerful and open basis for supporting different navigation semantics and for building travel assistance services according to the current user’s context. After motivating our research and describing the architecture, we illustrate our ideas with some simple examples and compare our research with other related work in the subject.Facultad de InformáticaLaboratorio de Investigación y Formación en Informática Avanzad