Made available in DSpace on 2015-03-05T13:58:26Z (GMT). No. of bitstreams: 0 Previous issue date: 15 / Nenhuma / A rápida popularização de dispositivos computacionais cada vez mais poderosos está trazendo a computação móvel para um grande número de pessoas. Na medida em que os dispositivos ganham mais poder computacional, diferentes aplicações podem ser desenvolvidas de modo a atender as necessidades de um número cada vez maior de usuários. Esta evolução, entretanto, não é livre de desafios. Com o aumento do número de usuários, a demanda por customização torna-se uma questão chave. Entre as soluções que oferecem a customização encontra-se a mobilidade de código. Neste sentido esta dissertação apresenta um modelo de mobilidade forte de código orientado ao Holoparadigma. Até então somente a mobilidade lógica era suportada, estando à mobilidade de código apenas na especificação. Este modelo é chamado HoloGo e foi desenvolvido tendo como base a HoloVM, uma máquina virtual com suporte a blackboards e programação concorrente. A validação deste modelo ocorreu através da implementação de um protótipo que foi utilizado no desen / The rapid popularization of increasingly powerful computational devices is setting the mobile computing into daily life of a great number of people. As devices evolve along with its computational power, many applications can be developed in order to accomplish the different needs of a growing number of users. This evolution, however, it is not free of challenges. As the number of users increase, the need of customization becomes a major concern. Among the solutions that offer customization to software applications is code mobility. In this way, this dissertation presents a strong code mobility model focused in the Holoparadigm. Until now only logical mobility was provided, being the code mobility only in the specification. This model is called HoloGo and was developed on top of HoloVM, a virtual machine with blackboards and concurrent programming support. HoloGo was validated through the implementation of a prototype used in the development of applications that use code mobility. In this context, the main con

Made available in DSpace on 2015-03-05T14:01:20Z (GMT). No. of bitstreams: 0 Previous issue date: 19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Arquiteturas orientadas a serviços (SOA) voltaram a ganhar destaque, após o surgimento dos web services, como uma tecnologia capaz de melhorar consideravelmente a interoperabilidade entre aplicações de software. Para apoiar a crescente necessidade de colaboração entre pessoas fisicamente separadas, como em sistemas de trabalho ou ensino à distância, ambientes colaborativos estão sendo construídos utilizando a Internet como plataforma. Com a popularização dos dispositivos móveis, softwares que permitem interações entre quaisquer dispositivos, móveis ou não, utilizando tecnologias variadas de comunicação rumo a um mundo ubíquo, vêm ganhando destaque. SOA, por sua vez, está sendo considerada uma das plataformas mais indicadas para sistemas colaborativos ubíquos. Este trabalho apresenta SmallSOA, um motor para execução de composições de serviços em ambientes móveis, um dos componentes centrais da arquitetura orientada a serviços chamada U-SOA que o grupo de pesquisa de Engenharia de Software e Linguagens de Pr / Services-oriented architectures (SOA) restarted to gain prominence after the emergence of web services as a technology able to improve the interoperability between software applications. To support the growing need for collaboration between people physically separated as in distance work or learning systems, collaborative environments are being constructed using the Internet as platform. With the popularization of mobile devices, software that allows interactions between any devices, mobile or not, using different communication technologies towards a ubiquitous world are gaining prominence. SOA, in its turn, is considered one of the most suitable platforms for ubiquitous collaborative systems. This work presents SmallSOA, an engine for services compositions execution on mobile environments, one of the central components of the service oriented architecture called U-SOA that the research team on Software Engineering and Programming Languages at Unisinos is developing. An engine for services compositions exec

[pt] Os sistemas de gerência de workflow são freqüentemente utilizados para modelagem, monitoramento e execução coordenada de atividades realizadas por grupos de usuários em diferentes contextos. Com a atual proliferação de computadores portáteis e seu crescente poder de computação, os sistemas tradicionalmente desenvolvidos têm se mostrado, muitas vezes, excessivamente rígidos, limitando o grau de autonomia dos usuários. O objetivo deste trabalho é identificar e analisar diferentes técnicas de flexibilização e mecanismos que possam ser empregados em um sistema de gerência de work-flow destinado a dar suporte à operação desconectada. O principal desafio é garantir um nível de independência satisfatório entre grupos de pessoas trabalhando de forma conjunta que possibilite a realização coordenada de tarefas, com um objetivo global comum, em ambientes com desconexão. Para testar a viabilidade das idéias discutidas nesta dissertação, foi construído um sistema cujo projeto levou em conta os vários requisitos apresentados e que permite explorar características específicas de diferentes tipos de work-flow, buscando flexibilizar sua execução, sem comprometer a estruturação preestabelecida. / [en] Workflow management systems are frequently used for modeling, monitoring and controlling the coordinated execution of activities performed by workgroups in a variety of contexts. With the widespread use of portable computers and their growing computational power, conventional systems have often proved to be overly restrictive, effectively limiting the level of autonomy of the users involved. The primary goal of this work is to identify and analyze different flexibilization techniques and mechanisms that can be employed in a workflow management system aimed at supporting disconnected operation. The main challenge is to provide a satisfactory degree of independence among individuals in cooperating teams who share a common goal and work in disconnected environments. In order to test the viability of the ideas discussed in this dissertation, a system was built whose design met the requirements presented in the text and which allows the exploration of specific features of different kinds of workflow so as to enhance execution flexibility, without compromising the predefined structure.

Master of Philosophy (Architecture) / Context-aware computing is a mobile computing paradigm in which applications can discover, use, and take advantage of contextual information, such as the location, tasks and preferences of the user, in order to adapt their behaviour in response to changing operating environments and user requirements. A problem that arises is the inability to respond to contextual information that cannot be classified into any known context. Many context-aware applications require all discovered contextual information to exactly match a type of context, otherwise the application will not react responsively. The ability to learn and recall contexts based on the contextual information discovered has not been very well addressed by previous context-aware applications and research. The aim of this thesis is to develop a component middleware technology for mobile computing devices for the discovery and capture of contextual information, using the situated reasoning concept of constructive memory. The research contribution of this thesis lies in developing a modified architecture for context-aware systems, using a constructive memory model as a way to learn and recall contexts from previous experiences and application interactions. Using a constructive memory model, previous experiences can be induced to construct potential contexts, given a small amount of learning and interaction. The learning process is able to map the many variations of contextual information currently discovered by the user with a predicted type of context based on what the application has stored and seen previously. It only requires a small amount of contextual information to predict a context, something common context-aware systems lack, as they require all information before a type of context is assigned. Additionally, some mechanism to reason about the contextual information being discovered from past application interactions will be beneficial to induce contexts for future experiences.

<p>When computational systems become increasingly mobile and ubiquitous, digital information and the use of computational systems may increasingly be immersed into the physical and social world of objects, people and practices. However, the digital, physical and social materials that make up these hybrid spaces have different characteristics and are hard to understand for users. In addition, users are themselves part in constructing and re-constructing the hybrid spaces.</p><p>The main question addressed in this thesis is whether making aspects of the digitally mediated hybrid spaces observable and accessible provides support to users. The observability may provide support for the specific task at hand or help in building an understanding for what the system does and how, an understanding that is needed to explain system output and to cope with service breakdowns. The fundament of the approach is to empower users of computational systems to actively make sense of the system themselves.</p><p>Two prototype services are described, Socifer and MobiTip. Their common denominator was to make digitally mediated parts of the hybrid spaces observable to users. Without disqualifying other kinds of information, the work focussed on digitally mediated social trails of other users.</p><p>Building on experience from the prototype work and an investigation into in seamful design, observability and awareness, I have investigated the effects of making a computational system’s social context observable to users in a way that</p><p>- is separated from the service’s main functionality in the interface, allowing it to become peripheral and non-obtrusive;</p><p>- uses simple models and little interpretation;</p><p>- to some extent opens up the service to allow for user appropriation of both service content and functionality; and</p><p>- is informative rather than proactive in order to empower the user rather than acting on the user’s behalf.</p><p>By designing systems that fulfil these criteria I claim that the user will be supported in performing the task at hand, with or without the service, and that with service use, the user will become more and more aware of the possibilities and limitations of the underlying technology. In addition, the digitally mediated hybrid spaces where physical, social and digital contexts meet constitute application domains in themselves, domains that users may enjoy exploring.</p>

When computational systems become increasingly mobile and ubiquitous, digital information and the use of computational systems may increasingly be immersed into the physical and social world of objects, people and practices. However, the digital, physical and social materials that make up these hybrid spaces have different characteristics and are hard to understand for users. In addition, users are themselves part in constructing and re-constructing the hybrid spaces. The main question addressed in this thesis is whether making aspects of the digitally mediated hybrid spaces observable and accessible provides support to users. The observability may provide support for the specific task at hand or help in building an understanding for what the system does and how, an understanding that is needed to explain system output and to cope with service breakdowns. The fundament of the approach is to empower users of computational systems to actively make sense of the system themselves. Two prototype services are described, Socifer and MobiTip. Their common denominator was to make digitally mediated parts of the hybrid spaces observable to users. Without disqualifying other kinds of information, the work focussed on digitally mediated social trails of other users. Building on experience from the prototype work and an investigation into in seamful design, observability and awareness, I have investigated the effects of making a computational system’s social context observable to users in a way that - is separated from the service’s main functionality in the interface, allowing it to become peripheral and non-obtrusive; - uses simple models and little interpretation; - to some extent opens up the service to allow for user appropriation of both service content and functionality; and - is informative rather than proactive in order to empower the user rather than acting on the user’s behalf. By designing systems that fulfil these criteria I claim that the user will be supported in performing the task at hand, with or without the service, and that with service use, the user will become more and more aware of the possibilities and limitations of the underlying technology. In addition, the digitally mediated hybrid spaces where physical, social and digital contexts meet constitute application domains in themselves, domains that users may enjoy exploring.

This research devises a unified method for the distribution of pseudonyms in hybrid ephemeral vehicular networks (VNs), which are often referred to as vehicular ad hoc networks (VANETs), for the purposes of refill, intra-regional, and inter-regional movement. This work addresses a significant impediment to the use of pseudonyms, which has been almost universally accepted (and is on the verge of being standardized by the Institute for Electrical and Electronic Engineers (IEEE) and the Society for Automotive Engineers (SAE) as the best means to balance attribution and privacy to maximize the value of infrastructure deployment and citizen acceptability (i.e. use). The results include a pseudonym distribution protocol that maximizes ease of use while not compromising the security or privacy pseudonyms afford. These results contribute to the solution, in a scalable, adaptive, and bandwidth efficient manner, one of the remaining impediments to the adoption of VANETs. The new method shows improved performance compared to a baseline pseudonym distribution method that does not take these factors into consideration.

Highly distributed environments (HDEs) are deployment environments that include powerful and robust machines in addition to resource-constrained and mobile devices such as laptops, personal digital assistants (or PDAs), smart-phones, GPS devices, sensors, etc. Developing software for HDEs is fundamentally different from the software development for central systems and stable distributed systems. This argument is discussed deeply and in-details throughout this dissertation. HDE applications are challenged by two problems: unreliable networks, and heterogeneity of hardware and software. Both challenges need careful handling, where the system must continue functioning and delivering the expected QoS. This dissertation is a direct response to the mentioned challenges of HDEs. The contribution of this dissertation is the cloud component model and its related formal language and tools. This is the general title. However, and to make this contribution clear, we prefer to present it in the following detailed form: (1) We propose a paradigm shift from distribution transparency to localization acknowledgment being the first class concern. (2) To achieve the above mentioned objective, we propose a novel component model called cloud component (CC). (3) In this dissertation we propose a new approach to assemble CCs using systematic methodology that maintains the properties of CC model. (4) Cloud component development process and cloud component based systems development process. (5) Location modeling and advanced localization for HDEs are the pivotal key in our contribution. (6) Formal language to model single CC, CC assembly, CC development process, and CC based systems. (7) We finally present our fully-developed supporting tools: the cloud component management system CCMS, and the Registry utility. To respond to the challenges posed by HDEs, and to maintain expected software quality at the user endpoint, we think we need to pass a ¿paradigm shift¿ from the way software is designed and implemented currently to our new vision that this dissertation is devoted to. This is a paradigm shift from distribution transparency to localization acknowledgment being the first class concern. The contribution in this thesis has several faces as explained above, but still, these faces are cohesive. Each of these faces form a partial contribution, however, this partial contribution does not mean anything if isolated from the overall proposal. Moreover, the merit of the overall proposal can not be grasped by reading one partial contribution. The merit of the proposal is evident only if all parts of this work are cohesively organized. Finally, we claim that our proposal spans the entire software development process for HDEs, from requirements to deployment and runtime management.

In this thesis, an emergency management system taking advantage of mobile computing and its awareness on context is provided. The framework primarily aims to create an infrastructure for acquiring implicit and explicit data about an emergency situation by using capabilities of smart mobile devices and converting them into value-added information to be used in phases of emergency management. In addition to conceptual description of the framework, a real prototype implementation is developed and successful application of the framework is demonstrated. Sample cases are analyzed in conjunction with the prototype and an experiment for reporting an emergency situation is carried out by a group of participants in order to demonstrate the applicability and feasibility of the framework. Data collected during the experiment are examined in order to determine the advantages of the proposed system in comparison with traditional emergency reporting efforts.

No description available.