14 research outputs found

    A systematic review and trend analysis of personal learning environments research

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    The concept of personal learning environments (PLEs) is relatively new and is continuously developing. Over the past decade, there has been a significant upsurge in the number of PLEs-related research. Nevertheless, there is a lack of recent systematic reviews and trend analysis covering many PLEs studies; to the best of our knowledge. Therefore, the current systematic review is significant and indispensable in reviewing journal articles that discussed PLEs between 2000 and 2020. We searched Web of Science, Scopus, Sciences Direct, JSTOR, Springer, Google Scholar, and IEEE Xplore for studies published in English without limit in location or time to retrieve accurate results. Trend graphics for the extracted themes were also analyzed using descriptive statistics in Excel. According to the defined inclusion criteria, one hundred forty-eight articles were selected for the analysis. This study reveals that literature on PLEs has progressed from 2000 to 2020; the majority of PLEs-related articles were published between 2011 and 2020, with the year 2013 having the highest number of published articles (17 articles), followed by 16 papers published in both years 2014 and 2017. We found that the published PLEs research originated from 46 countries; 26 (17.6%) were from Spain. The majority of the authors had education, computer science, information technology and engineering backgrounds. This review also showed that numerous platforms had been used in PLEs research, with Web 2.0 the most commonly used platform. We noted that the most common objectives of the included articles were PLEs custom system development, analysis of the PLEs, description of experiments, investigations, development of factor models, framework development, and examination. The most common theoretical perspectives in the published articles were self-regulated learning, self-directed learning, and constructivism. The current systematic review and trend analysis can become a guidance platform for researchers, educators, policymakers or even journal publishers for future research in PLEs research

    A Reinforcement Learning Quality of Service Negotiation Framework For IoT Middleware

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    The Internet of Things (IoT) ecosystem is characterised by heterogeneous devices dynamically interacting with each other to perform a specific task, often without human intervention. This interaction typically occurs in a service-oriented manner and is facilitated by an IoT middleware. The service provision paradigm enables the functionalities of IoT devices to be provided as IoT services to perform actuation tasks in critical-safety systems such as autonomous, connected vehicle system and industrial control systems. As IoT systems are increasingly deployed into an environment characterised by continuous changes and uncertainties, there have been growing concerns on how to resolve the Quality of Service (QoS) contentions between heterogeneous devices with conflicting preferences to guarantee the execution of mission-critical actuation tasks. With IoT devices with different QoS constraints as IoT service providers spontaneously interacts with IoT service consumers with varied QoS requirements, it becomes essential to find the best way to establish and manage the QoS agreement in the middleware as a compromise in the QoS could lead to negative consequences. This thesis presents a QoS negotiation framework, IoTQoSystem, for IoT service-oriented middleware. The QoS framework is underpinned by a negotiation process that is modelled as a Markov Decision Process (MDP). A model-based Reinforcement Learning negotiation strategy is proposed for generating an acceptable QoS solution in a dynamic, multilateral and multi-parameter scenarios. A microservice-oriented negotiation architecture is developed that combines negotiation, monitoring and forecasting to provide a self-managing mechanism for ensuring the successful execution of actuation tasks in an IoT environment. Using a case study, the developed QoS negotiation framework was evaluated using real-world data sets with different negotiation scenarios to illustrate its scalability, reliability and performance

    Ubiquitous Computing

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    The aim of this book is to give a treatment of the actively developed domain of Ubiquitous computing. Originally proposed by Mark D. Weiser, the concept of Ubiquitous computing enables a real-time global sensing, context-aware informational retrieval, multi-modal interaction with the user and enhanced visualization capabilities. In effect, Ubiquitous computing environments give extremely new and futuristic abilities to look at and interact with our habitat at any time and from anywhere. In that domain, researchers are confronted with many foundational, technological and engineering issues which were not known before. Detailed cross-disciplinary coverage of these issues is really needed today for further progress and widening of application range. This book collects twelve original works of researchers from eleven countries, which are clustered into four sections: Foundations, Security and Privacy, Integration and Middleware, Practical Applications

    ATTACKS AND COUNTERMEASURES FOR WEBVIEW ON MOBILE SYSTEMS

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    ABSTRACT All the mainstream mobile operating systems provide a web container, called ``WebView\u27\u27. This Web-based interface can be included as part of the mobile application to retrieve and display web contents from remote servers. WebView not only provides the same functionalities as web browser, more importantly, it enables rich interactions between mobile apps and webpages loaded inside WebView. Through its APIs, WebView enables the two-way interaction. However, the design of WebView changes the landscape of the Web, especially from the security perspective. This dissertation conducts a comprehensive and systematic study of WebView\u27s impact on web security, with a particular focus on identifying its fundamental causes. This dissertation discovers multiple attacks on WebView, and proposes new protection models to enhance the security of WebView. The design principles of these models are also described as well as the prototype implementation in Android platform. Evaluations are used to demonstrate the effectiveness and performance of these protection models

    GLUE!: an architecture for the integration of external tools in virtual learning environments

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    La integración de herramientas externas en VLE (Virtual Learning Environments - Entornos deAprendizaje Virtual) tiene como objetivo enriquecer las actividades de aprendizaje que los profesionales de la educación pueden diseñar y poner en marcha. Tradicionalmente, las herramientas externas han sido integradas mediante desarrollos ad hoc, siendo esta solución muy poco eficiente a medida que aumentaba el número de VLE y herramientas utilizados por estos profesionales. Además, aquellas aproximaciones genéricas que abordan la integración de múltiples herramientas en múltiples VLE no han conseguido obtener una amplia adopción, principalmente debido al alto esfuerzo de desarrollo necesario para integrar nuevas herramientas y VLE, y a las restricciones impuestas sobre los proveedores. Algunos trabajos recientes han intentado superar estas dos limitaciones proponiendo una integración ligera de herramientas. Sin embargo, estos trabajos no facilitan la instanciación y puesta en marcha de situaciones de aprendizaje colaborativo, lo que impide de forma significativa que se puedan emplear las propiedades colaborativas específicas que proporcionan los VLE para la gestión de usuarios y grupos. Esta tesis propone una arquitectura middleware de integración denominada GLUE! (Group Learning Uniform Environment - Entorno Uniforme de Aprendizaje en Grupo) que permite la integración ligera de múltiples herramientas externas existentes en múltiples VLE existentes, superando estas limitaciones. GLUE! fomenta esta integración imponiendo pocas restricciones sobre los proveedores de VLE y herramientas, así como demandando un esfuerzo asumible por parte de los desarrolladores. Además, GLUE! facilita la instanciación y puesta en marcha de situaciones de aprendizaje colaborativo desde los VLE, aprovechando las propiedades específicas de éstos para la gestión de usuarios y grupos. Por medio de GLUE!, los profesionales de la educación pueden utilizar herramientas externas como si fueran herramientas nativas de los VLE, y además sin tener que renunciar a los VLE a los que están acostumbrados. GLUE! ha sido evaluado con la ayuda de tres situaciones de aprendizaje colaborativo auténticas, las cuales fueron diseñadas para cubrir las necesidades pedagógicas de tres cursos de educación superior. Estas tres situaciones se utilizaron en cuatro experimentos diferentes con educadores y estudiantes reales. Los resultados de esta evaluación mostraron que GLUE! permite la instanciación y puesta en marcha de situaciones de aprendizaje colaborativo que requieran la integración de herramientas externas, reduce la carga asociada a la instanciación de actividades colaborativas complejas, y facilita a los estudiantes la realización de estas actividades en colaboración. Curiosamente, el esfuerzo de desarrollo necesario por el software de integración fue similar al de otras aproximaciones de integración genéricas que ofrecen un menor grado de funcionalidad.Departamento de Teoría de la Señal y Comunicaciones e Ingeniería Telemática2012-11-2

    Investigation into a best practice model for providing an integrated user experience with mobile cloud applications

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    Mobile Cloud Computing promises to overcome the physical limitations of mobile devices by executing demanding mobile applications on cloud infrastructure. In practice, implementing this paradigm is difficult; network disconnection often occurs, bandwidth may be limited, and a large power draw is required from the battery, resulting in a poor user experience. This thesis presents a mobile cloud middleware solution, Context Aware Mobile Cloud Services (CAMCS), which provides cloudbased services to mobile devices, in a disconnected fashion. An integrated user experience is delivered by designing for anticipated network disconnection, and low data transfer requirements. CAMCS achieves this by means of the Cloud Personal Assistant (CPA); each user of CAMCS is assigned their own CPA, which can complete user-assigned tasks, received as descriptions from the mobile device, by using existing cloud services. Service execution is personalised to the user's situation with contextual data, and task execution results are stored with the CPA until the user can connect with his/her mobile device to obtain the results. Requirements for an integrated user experience are outlined, along with the design and implementation of CAMCS. The operation of CAMCS and CPAs with cloud-based services is presented, specifically in terms of service description, discovery, and task execution. The use of contextual awareness to personalise service discovery and service consumption to the user's situation is also presented. Resource management by CAMCS is also studied, and compared with existing solutions. Additional application models that can be provided by CAMCS are also presented. Evaluation is performed with CAMCS deployed on the Amazon EC2 cloud. The resource usage of the CAMCS Client, running on Android-based mobile devices, is also evaluated. A user study with volunteers using CAMCS on their own mobile devices is also presented. Results show that CAMCS meets the requirements outlined for an integrated user experience

    Application of service composition mechanisms to Future Networks architectures and Smart Grids

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    Aquesta tesi gira entorn de la hipòtesi de la metodologia i mecanismes de composició de serveis i com es poden aplicar a diferents camps d'aplicació per a orquestrar de manera eficient comunicacions i processos flexibles i sensibles al context. Més concretament, se centra en dos camps d'aplicació: la distribució eficient i sensible al context de contingut multimèdia i els serveis d'una xarxa elèctrica intel·ligent. En aquest últim camp es centra en la gestió de la infraestructura, cap a la definició d'una Software Defined Utility (SDU), que proposa una nova manera de gestionar la Smart Grid amb un enfocament basat en programari, que permeti un funcionament molt més flexible de la infraestructura de xarxa elèctrica. Per tant, revisa el context, els requisits i els reptes, així com els enfocaments de la composició de serveis per a aquests camps. Fa especial èmfasi en la combinació de la composició de serveis amb arquitectures Future Network (FN), presentant una proposta de FN orientada a serveis per crear comunicacions adaptades i sota demanda. També es presenten metodologies i mecanismes de composició de serveis per operar sobre aquesta arquitectura, i posteriorment, es proposa el seu ús (en conjunció o no amb l'arquitectura FN) en els dos camps d'estudi. Finalment, es presenta la investigació i desenvolupament realitzat en l'àmbit de les xarxes intel·ligents, proposant diverses parts de la infraestructura SDU amb exemples d'aplicació de composició de serveis per dissenyar seguretat dinàmica i flexible o l'orquestració i gestió de serveis i recursos dins la infraestructura de l'empresa elèctrica.Esta tesis gira en torno a la hipótesis de la metodología y mecanismos de composición de servicios y cómo se pueden aplicar a diferentes campos de aplicación para orquestar de manera eficiente comunicaciones y procesos flexibles y sensibles al contexto. Más concretamente, se centra en dos campos de aplicación: la distribución eficiente y sensible al contexto de contenido multimedia y los servicios de una red eléctrica inteligente. En este último campo se centra en la gestión de la infraestructura, hacia la definición de una Software Defined Utility (SDU), que propone una nueva forma de gestionar la Smart Grid con un enfoque basado en software, que permita un funcionamiento mucho más flexible de la infraestructura de red eléctrica. Por lo tanto, revisa el contexto, los requisitos y los retos, así como los enfoques de la composición de servicios para estos campos. Hace especial hincapié en la combinación de la composición de servicios con arquitecturas Future Network (FN), presentando una propuesta de FN orientada a servicios para crear comunicaciones adaptadas y bajo demanda. También se presentan metodologías y mecanismos de composición de servicios para operar sobre esta arquitectura, y posteriormente, se propone su uso (en conjunción o no con la arquitectura FN) en los dos campos de estudio. Por último, se presenta la investigación y desarrollo realizado en el ámbito de las redes inteligentes, proponiendo varias partes de la infraestructura SDU con ejemplos de aplicación de composición de servicios para diseñar seguridad dinámica y flexible o la orquestación y gestión de servicios y recursos dentro de la infraestructura de la empresa eléctrica.This thesis revolves around the hypothesis the service composition methodology and mechanisms and how they can be applied to different fields of application in order to efficiently orchestrate flexible and context-aware communications and processes. More concretely, it focuses on two fields of application that are the context-aware media distribution and smart grid services and infrastructure management, towards a definition of a Software-Defined Utility (SDU), which proposes a new way of managing the Smart Grid following a software-based approach that enable a much more flexible operation of the power infrastructure. Hence, it reviews the context, requirements and challenges of these fields, as well as the service composition approaches. It makes special emphasis on the combination of service composition with Future Network (FN) architectures, presenting a service-oriented FN proposal for creating context-aware on-demand communication services. Service composition methodology and mechanisms are also presented in order to operate over this architecture, and afterwards, proposed for their usage (in conjunction or not with the FN architecture) in the deployment of context-aware media distribution and Smart Grids. Finally, the research and development done in the field of Smart Grids is depicted, proposing several parts of the SDU infrastructure, with examples of service composition application for designing dynamic and flexible security for smart metering or the orchestration and management of services and data resources within the utility infrastructure

    Teenustele orienteeritud ja tõendite-teadlik mobiilne pilvearvutus

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    Arvutiteaduses on kaks kõige suuremat jõudu: mobiili- ja pilvearvutus. Kui pilvetehnoloogia pakub kasutajale keerukate ülesannete lahendamiseks salvestus- ning arvutusplatvormi, siis nutitelefon võimaldab lihtsamate ülesannete lahendamist mistahes asukohas ja mistahes ajal. Täpsemalt on mobiilseadmetel võimalik pilve võimalusi ära kasutades energiat säästa ning jagu saada kasvavast jõudluse ja ruumi vajadusest. Sellest tulenevalt on käesoleva töö peamiseks küsimuseks kuidas tuua pilveinfrastruktuur mobiilikasutajale lähemale? Antud töös uurisime kuidas mobiiltelefoni pilveteenust saab mobiilirakendustesse integreerida. Saime teada, et töö delegeerimine pilve eeldab mitmete pilve aspektide kaalumist ja integreerimist, nagu näiteks ressursimahukas töötlemine, asünkroonne suhtlus kliendiga, programmaatiline ressursside varustamine (Web APIs) ja pilvedevaheline kommunikatsioon. Nende puuduste ületamiseks lõime Mobiilse pilve vahevara Mobile Cloud Middleware (Mobile Cloud Middleware - MCM) raamistiku, mis kasutab deklaratiivset teenuste komponeerimist, et delegeerida töid mobiililt mitmetele pilvedele kasutades minimaalset andmeedastust. Teisest küljest on näidatud, et koodi teisaldamine on peamisi strateegiaid seadme energiatarbimise vähendamiseks ning jõudluse suurendamiseks. Sellegipoolest on koodi teisaldamisel miinuseid, mis takistavad selle laialdast kasutuselevõttu. Selles töös uurime lisaks, mis takistab koodi mahalaadimise kasutuselevõttu ja pakume lahendusena välja raamistiku EMCO, mis kogub seadmetelt infot koodi jooksutamise kohta erinevates kontekstides. Neid andmeid analüüsides teeb EMCO kindlaks, mis on sobivad tingimused koodi maha laadimiseks. Võrreldes kogutud andmeid, suudab EMCO järeldada, millal tuleks mahalaadimine teostada. EMCO modelleerib kogutud andmeid jaotuse määra järgi lokaalsete- ning pilvejuhtude korral. Neid jaotusi võrreldes tuletab EMCO täpsed atribuudid, mille korral mobiilirakendus peaks koodi maha laadima. Võrreldes EMCO-t teiste nüüdisaegsete mahalaadimisraamistikega, tõuseb EMCO efektiivsuse poolest esile. Lõpuks uurisime kuidas arvutuste maha laadimist ära kasutada, et täiustada kasutaja kogemust pideval mobiilirakenduse kasutamisel. Meie peamiseks motivatsiooniks, et sellist adaptiivset tööde täitmise kiirendamist pakkuda, on tagada kasutuskvaliteet (QoE), mis muutub vastavalt kasutajale, aidates seeläbi suurendada mobiilirakenduse eluiga.Mobile and cloud computing are two of the biggest forces in computer science. While the cloud provides to the user the ubiquitous computational and storage platform to process any complex tasks, the smartphone grants to the user the mobility features to process simple tasks, anytime and anywhere. Smartphones, driven by their need for processing power, storage space and energy saving are looking towards remote cloud infrastructure in order to solve these problems. As a result, the main research question of this work is how to bring the cloud infrastructure closer to the mobile user? In this thesis, we investigated how mobile cloud services can be integrated within the mobile apps. We found out that outsourcing a task to cloud requires to integrate and consider multiple aspects of the clouds, such as resource-intensive processing, asynchronous communication with the client, programmatically provisioning of resources (Web APIs) and cloud intercommunication. Hence, we proposed a Mobile Cloud Middleware (MCM) framework that uses declarative service composition to outsource tasks from the mobile to multiple clouds with minimal data transfer. On the other hand, it has been demonstrated that computational offloading is a key strategy to extend the battery life of the device and improves the performance of the mobile apps. We also investigated the issues that prevent the adoption of computational offloading, and proposed a framework, namely Evidence-aware Mobile Computational Offloading (EMCO), which uses a community of devices to capture all the possible context of code execution as evidence. By analyzing the evidence, EMCO aims to determine the suitable conditions to offload. EMCO models the evidence in terms of distributions rates for both local and remote cases. By comparing those distributions, EMCO infers the right properties to offload. EMCO shows to be more effective in comparison with other computational offloading frameworks explored in the state of the art. Finally, we investigated how computational offloading can be utilized to enhance the perception that the user has towards an app. Our main motivation behind accelerating the perception at multiple response time levels is to provide adaptive quality-of-experience (QoE), which can be used as mean of engagement strategy that increases the lifetime of a mobile app

    Automated Bidding in Computing Service Markets. Strategies, Architectures, Protocols

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    This dissertation contributes to the research on Computational Mechanism Design by providing novel theoretical and software models - a novel bidding strategy called Q-Strategy, which automates bidding processes in imperfect information markets, a software framework for realizing agents and bidding strategies called BidGenerator and a communication protocol called MX/CS, for expressing and exchanging economic and technical information in a market-based scheduling system
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