Toward a multidisciplinary model of context to support context-aware computing

Capturing, defining, and modeling the essence of context are challenging, compelling, and prominent issues for interdisciplinary research and discussion. The roots of its emergence lie in the inconsistencies and ambivalent definitions across and within different research specializations (e.g., philosophy, psychology, pragmatics, linguistics, computer science, and artificial intelligence). Within the area of computer science, the advent of mobile context-aware computing has stimulated broad and contrasting interpretations due to the shift from traditional static desktop computing to heterogeneous mobile environments. This transition poses many challenging, complex, and largely unanswered research issues relating to contextual interactions and usability. To address those issues, many researchers strongly encourage a multidisciplinary approach. The primary aim of this article is to review and unify theories of context within linguistics, computer science, and psychology. Summary models within each discipline are used to propose an outline and detailed multidisciplinary model of context involving (a) the differentiation of focal and contextual aspects of the user and application's world, (b) the separation of meaningful and incidental dimensions, and (c) important user and application processes. The models provide an important foundation in which complex mobile scenarios can be conceptualized and key human and social issues can be identified. The models were then applied to different applications of context-aware computing involving user communities and mobile tourist guides. The authors' future work involves developing a user-centered multidisciplinary design framework (based on their proposed models). This will be used to design a large-scale user study investigating the usability issues of a context-aware mobile computing navigation aid for visually impaired people

Engineering context-aware systems and applications:A survey

Context-awareness is an essential component of systems developed in areas like Intelligent Environments, Pervasive & Ubiquitous Computing and Ambient Intelligence. In these emerging fields, there is a need for computerized systems to have a higher understanding of the situations in which to provide services or functionalities, to adapt accordingly. The literature shows that researchers modify existing engineering methods in order to better fit the needs of context-aware computing. These efforts are typically disconnected from each other and generally focus on solving specific development issues. We encourage the creation of a more holistic and unified engineering process that is tailored for the demands of these systems. For this purpose, we study the state-of-the-art in the development of context-aware systems, focusing on: (A) Methodologies for developing context-aware systems, analyzing the reasons behind their lack of adoption and features that the community wish they can use; (B) Context-aware system engineering challenges and techniques applied during the most common development stages; (C) Context-aware systems conceptualization

Engineering context-aware systems and applications: a survey

Context-awareness is an essential component of systems developed in areas like Intelligent Environments, Pervasive & Ubiquitous Computing and Ambient Intelligence. In these emerging fields, there is a need for computerized systems to have a higher understanding of the situations in which to provide services or functionalities, to adapt accordingly. The literature shows that researchers modify existing engineering methods in order to better fit the needs of context-aware computing. These efforts are typically disconnected from each other and generally focus on solving specific development issues. We encourage the creation of a more holistic and unified engineering process that is tailored for the demands of these systems. For this purpose, we study the state-of-the-art in the development of context-aware systems, focusing on: A) Methodologies for developing context-aware systems, analyzing the reasons behind their lack of adoption and features that the community wish they can use; B) Context aware system engineering challenges and techniques applied during the most common development stages; C) Context aware systems conceptualization

Context-Sensitive Data Structures Supporting Software Development in Ad Hoc Mobile Settings

Context-aware computing, an emerging paradigm in which applications sense and adapt their behavior to changes in their operational environment, is key to developing dependable software for use in the often unpredictable settings of ad hoc networks. However, designing an application which gathers, maintains, and adapts to context can be a difficult undertaking, even for a seasoned programmer. Our goal is to simplify the programming task by hiding such issues from the programmer, allowing one to quickly and reliably produce a context-aware application for use in ad hoc networks. With this goal in mind, we introduce a novel abstraction called context-sensitive data structures (CSDS). The programmer interacts with the CSDS through a familiar programming interface, without direct knowledge of the context gathering and maintenance tasks that occur behind the scenes. In this paper, we define a model of context-sensitive data structures and present protocols which enable the programmer to construct and main-tain a CSDS as a distributed structure over a mobile ad hoc network in a state of flux

Supporting policy-based contextual reconfiguration and adaptation in ubiquitous computing

In order for pervasive computing systems to be able to perform tasks which support us in everyday life without requiring attention from the users of the environment, they need to adapt themselves in response to context. This makes context-awareness in general, and context-aware adaptation in particular, an essential requirement for pervasive computing systems. Two of the features of context-awareness are: contextual reconfiguration and contextual adaptation in which applications adapt their behaviour in response to context. We combine both these features of context-awareness to provide a broad scope of adaptation and put forward a system, called Policy-Based Contextual Reconfiguration and Adaptation (PCRA) that provides runtime support for both. The combination of both context-aware reconfiguration and context-aware adaptation provides a broad scope of adaptation and hence allows the development of diverse adaptive context-aware applications. However, another important issue is the choice of an effective means for developing, modifying and extending such applications. The main argument forming the basis of this thesis is that we advocate the use of a policy-based programming model and argue that it provides more effective means for developing, modifying and extending such applications. This thesis addresses other important surrounding issues which are associated with adaptive context-aware applications. These include the management of invalid bindings and the provision of seamless caching support for remote services involved in bindings for improved performance. The bindings may become invalid due to failure conditions that can arise due to network problems or migration of software components, causing bindings between the application component and remote service to become invalid. We have integrated reconfiguration support to manage bindings, and seamless caching support for remote services in PCRA. This thesis also describes the design and implementation of PCRA, which enables development of adaptive context-aware applications using policy specifications. Within PCRA, adaptive context-aware applications are modelled by specifying binding policies and adaptation policies. The use of policies within PCRA simplifies the development task because policies are expressed at a high-level of abstraction, and are expressed independently of each other. PCRA also allows the dynamic modification of applications since policies are independent units of execution and can be dynamically loaded and removed from the system. This is a powerful and useful capability as applications may evolve over time, i.e. the user needs and preferences may change, but re-starting is undesirable. We evaluate PCRA by comparing its features to other systems in the literature, and by performance measures

Simplifying Context-Aware Agent Coordination Using Context-Sensitive Data Structures

Context-aware computing, an emerging paradigm in which applications sense and adapt their behavior to changes in their operational environment, is key to developing dependable agent-based soft-ware systems for use in the often unpredictable settings of ad hoc net-works. However, designing an application agent which interacts with other agents to gather, maintain, and adapt to context can be a difficult undertaking in an open and continuously changing environment, even for a seasoned programmer. Our goal is to simplify the programming task by hiding the details of agent coordination from the programmer, allowing one to quickly and reliably produce a context-aware application agent for use in large-scale ad hoc networks. With this goal in mind, we introduce a novel abstraction called context-sensitive data structures (CSDS). The programmer interacts with the CSDS through a familiar programming interface, without direct knowledge of the context gathering and maintenance tasks that occur behind the scenes. In this paper, we define a model of context-sensitive data structures, and we identify key requirements and issues associated with building an infrastructure to support the development of context-sensitive data structures

A Query-Centric Approach to Supporting the Development of Context-Aware Applications for Mobile Ad Hoc Networks, Doctoral Dissertation, August 2006

The wide-spread use of mobile computing devices has led to an increased demand for applications that operate dependably in opportunistically formed networks. A promising approach to supporting software development for such dynamic settings is to rely on the context-aware computing paradigm, in which an application views the state of the surrounding ad hoc network as a valuable source of contextual information that can be used to adapt its behavior. Collecting context information distributed across a constantly changing network remains a significant technical challenge. This dissertation presents a query-centered approach to simplifying context interactions in mobile ad hoc networks. Using such an approach, an application programmer views the surrounding world asa single data repository over which descriptive queries can be issued. Distributed context information appears to be locally available, effectively hiding the complex networking tasks required to acquire context in an open and dynamic setting. This dissertation identifies the research issues associated with developing a query-centric approach and discusses solutions to providing query-centric support to application developers. To promote rapid and dependable software development, a query-centric middleware is provided to the application programmer. These solutions provide the means to reason about the correctness of an application\u27s design and potentially to reduce programmer effort and error

Context-Aware Computation Offloading for Mobile Cloud Computing: Requirements Analysis, Survey and Design Guideline

AbstractAlong with the rise of mobile handheld devices the resource demands of respective applications grow as well. However, mobile devices are still and will always be limited related to performance (e.g., computation, storage and battery life), context adaptation (e.g., intermittent connectivity, scalability and heterogeneity) and security aspects. A prominent solution to overcome these limita- tions is the so-called computation offloading, which is the focus of mobile cloud computing (MCC). However, current approaches fail to address the complexity that results from quickly and constantly changing context conditions in mobile user scenarios and hence developing effective and efficient MCC applications is still challenging. Therefore, this paper first presents a list of re- quirements for MCC applications together with a survey and classification of current solutions. Furthermore, it provides a design guideline for the selection of suitable concepts for different classes of common cloud-augmented mobile applications. Finally, it presents open issues that developers and researchers should be aware of when designing their MCC-approach

A formal approach to modelling and verification of context-aware systems

The evolution of smart devices and software technologies has expanded the domain of computing from workplaces to other areas of our everyday life. This trend has been rapidly advancing towards ubiquitous computing environments, where smart devices play an important role in acting intelligently on behalf of the users. One of the sub fields of the ubiquitous computing is context-aware systems. In context-aware systems research, ontology and agent-based technology have emerged as a new paradigm for conceptualizing, designing, and implementing sophisticated software systems. These systems exhibit complex adaptive behaviors, run in highly decentralized environment and can naturally be implemented as agent-based systems. Usually context-aware systems run on tiny resource-bounded devices including smart phones and sensor nodes and hence face various challenges. The lack of formal frameworks in existing research presents a clear challenge to model and verify such systems. This thesis addresses some of these issues by developing formal logical frameworks for modelling and verifying rule-based context-aware multi-agent systems. Two logical frameworks LOCRS and LDROCS have been developed by extending CTL* with belief and communication modalities, which allow us to describe a set of rule-based context-aware reasoning agents with bound on time, memory and communication. The key idea underlying the logical approach of context-aware systems is to define a formal logic that axiomatizes the set of transition systems, and it is then used to state various qualitative and quantitative properties of the systems. The set of rules which are used to model a desired system is derived from OWL 2 RL ontologies. While LOCRS is based on monotonic reasoning where beliefs of an agent cannot be revised based on some contradictory evidence, the LDROCS logic handles inconsistent context information using non-monotonic reasoning. The modelling and verification of a healthcare case study is illustrated using Protégé IDE and Maude LTL model checker

Performance Feedback A Common Thread in the Process to Provide Optimal Heart Failure Care⁎⁎Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology.

Current software community players like academy and industry have been changing the traditional paradigms of software engineering towards context-awareness and distributed computing. Nowadays, service-oriented computing and context-aware computing are two emerging paradigms that are changing the way of designing, developing, providing and consuming software services. Whilst service-oriented computing is based on service-oriented architectures and it is focused on modelling functionality and providing flexible software services, context-aware computing is based on the context life cycle and it allows processing and changing the behaviour of such services given certain context information. The synergy between both paradigms is a core research topic in ubiquitous and pervasive computing widely applied to the Internet of Things and Smart Cities.In the present PhD thesis, we exploit this synergy by focusing on context-aware computing from the perspective of service-oriented computing, which is also known as context-aware service-oriented computing. Such research topic involves the management of context within different essential phases of the context life cycle that show how the context data moves from phase to phase in software services within the paradigm of the service-oriented computing. Hence, the work done in this thesis involves different components and processes that have the aim to accomplish the context life cycle, namely the acquisition, modelling, reasoning and dissemination of the context in service-oriented computing. Particularly, we make an effort to provide both a context ontology for context modelling, context reasoning and high-level context dissemination, and a context-aware monitoring architecture for context acquisition and low-level context dissemination.Such work of the thesis has been motivated for contributing in the solution of different issues mainly identified in the phases of context modelling and context acquisition that are a strong basis of the context life cycle. Firstly, in the context modelling we mainly identified the proliferation of several context models presenting some problems about: reusability, extensibility and adaptation. Secondly, in the context acquisition we mainly identified that existing monitoring infrastructures are not prepared to support the constant changes in their context and the context of other entities, including the services that they are supervising which provoke the provisioning of context data that is not reliable. In summary, this thesis explores three big research questions: 1) What context data to acquire and to model? This involves the study of the current state of the art of context models, specifically: which are these proposals and how are they related, what are their structural characteristics, what context information is the most addressed, and what are their most consolidated definitions. 2) How to model context data? This involves the development of a three-level context ontology with the aim of improving the reusability, extensibility and adaptation capabilities of existing context models. 3) How to acquire context data? This involves the development of a context-aware monitoring architecture that can be easily configured, adapted or evolved according to the constant changes of the context.The context model and the architecture proposed in this PhD thesis are validated through different scenarios and use cases, highlighting their integration in SUPERSEDE (www.supersede.eu), a European project in the H2020 program for fulfilling some requirements of data acquisition and management demonstrating that the context life cycle is supported.Els actors actuals de la comunitat de software, com l'acadèmia o la indústria, han anat canviant els paradigmes tradicionals de l'enginyeria de software cap a la sensibilitat al context i la computació distribuïda. Avui dia, la computació orientada a serveis i la computació conscient del context són dos paradigmes emergents que estan canviant la forma de dissenyar, desenvolupar, proporcionar i consumir serveis de software. Mentre que la computació orientada a serveis es basa en arquitectures orientades a serveis i se centra en el modelatge de la funcionalitat i la prestació de serveis de software flexibles, la computació sensible al context es basa en el cicle de vida del context i permet el processament i canviar el comportament d'aquest tipus de serveis donada una determinada informació del context. La sinergia entre els dos paradigmes és un tema central de recerca a la computació ubiqua i omnipresent, àmpliament aplicada a la Internet de les coses i les ciutats intel·ligents. En la present tesi doctoral explotem aquesta sinèrgia, centrant-se en la computació sensible al context des de la perspectiva de la computació orientada a serveis, que també es coneix com computació orientada a serveis sensibles al context. Tal tema de recerca implica la gestió de contexts en diferents fases essencials del cicle de vida del context que mostren com les dades de context es mouen d'una fase a l’altra en serveis de software dins del paradigma de la computació orientada a serveis. Per tant, el treball realitzat en aquesta tesi consisteix en diferents components i processos que tenen l'objectiu d'aconseguir el cicle de vida del context, és a dir, l'adquisició, el modelatge, el raonament i la difusió del context en computació orientada a serveis. En particular, fem un esforç per proporcionar tant una ontologia de context per a la modelització, raonament i difusió del context d'alt nivell, i una arquitectura de monitorització sensible al context per a l'adquisició i difusió del context de baix nivell. Aquest treball de tesi ha estat motivat per contribuir a la solució dels diferents problemes identificats principalment en les fases de modelatge de context i adquisició de context que són una base sòlida del cicle de vida del context. En primer lloc, en el modelatge de context es van identificar principalment la proliferació de diversos models de context que presenten alguns problemes sobre: reutilització, l'extensibilitat i l'adaptació. En segon lloc, en l'adquisició del context identifiquem principalment que les infraestructures de monitorització existents no estan preparats per suportar els canvis constants en el seu context i el context d'altres entitats, incloent-hi els serveis que s'estan supervisant, que provoquen un aprovisionament de dades de context que no és fiable. En resum, aquesta tesi explora tres grans preguntes de recerca: 1) Quines dades de context cal adquirir i modelar? Això implica l'estudi de l'estat actual de la tècnica dels models de context, en concret: ¿quines són aquestes propostes i com es relacionen, quines són les seves característiques estructurals, quina informació de context és la més adreçada, i quines són les seves definicions més consolidades. 2) Com modelar les dades de context? Això implica el desenvolupament d'una ontologia de context de tres nivells amb l'objectiu de millorar les capacitats de reutilització, extensibilitat i adaptació dels models de context existents. 3) Com adquirir dades de context? Això implica el desenvolupament d'una arquitectura de monitorització sensible al context que pot ser fàcilment configurat o adaptat d'acord amb els canvis del context. El model de context i l'arquitectura proposada en aquesta tesi doctoral es validen a través de diferents escenaris i casos d'ús, destacant la seva integració en SUPERSEDE, un projecte europeu en el programa H2020 per al compliment d'alguns requisits d'adquisició i gestió de dades que demostra que es dóna suport al cicle de vida del context