Multi-Device Design in Contexts of Interchange and Task Migration

Com a miniaturização dos componentes digitais e o vasto desenvolvimento tecnológico dos últimos anos, a sociedade tem presenciado a redefinição dos "computadores pessoais" pelo advento dos dispositivos móveis. Além da inovação, eles introduziram o desafio do design multi-dispositivo para as aplicações desktop. Enquanto algumas abordagens criaram interfaces móveis sem aproveitar qualquer modelo, outras buscaram adaptações automáticas visando reduzir a sobrecarga de designo Em ambas, o foco do design deixou de ser o usuário, tornando as interfaces tão diferentes ao ponto de comprometerem a usabilidade na realização de uma mesma tarefa em vários dispositivos. Esta tese afirma que não existe uma abordagem de design multi-dispositivo capaz de garantir boa usabilidade em todos os contextos porque o usuário pode escolher apenas uma forma de acesso à aplicação ou alternar seu uso por meio de vários dispositivos. No primeiro caso, o usuário aprende a usar a interface para realizar suas tarefas, sendo relevante uma abordagem que aproveite os recursos do dispositivo e trate suas limitações. No segundo, o usuário já conhece uma das interfaces, o que gera uma expectativa no uso das demais. Logo, é necessário combinar abordagens com objetivos diferentes para atender ao usuário de acordo com o seu contexto de uso. Neste sentido, propõe-se o design multi-dispositivo por meio da preservação de uma hierarquia de prioridades de consistência definida em três níveis. Enquanto os dois primeiros dão suporte à expectativa do usuário em contextos de uso alternado (propensos à execução de tarefas em dispositivos diferentes) e migração de tarefas (iniciando tarefas com um dispositivo e concluindo com outro), o terceiro nível garante a personalização das tarefas de maior interesse visando eficiência e satisfação de uso em um dispositivo específico. A avaliação desta metodologia foi feita por meio de um experimento com três interfaces de pocket PC construídas a partir de uma aplicação desktop do domínio de Educação a Distância: a primeira delas era uma réplica da original (Migração Direta), a segunda não mantinha consistência de layout e era baseada em um processo de design personalizado adequado ao dispositivo (Linear) e a terceira aplicava apenas os dois primeiros níveis da hierarquia de prioridades (Overview). Os resultados da avaliação subjetiva mostraram que a abordagem Overview foi capaz de manter o modelo mental do usuário com maior precisão por preservar os atributos de facilidade, eficiência e segurança de uso na interação inter-dispositivo. Além disso, os resultados medidos para a eficácia (exatidão das respostas) e eficiênciá (tempo médio de execução das tarefas) foram iguais ou melhores com essa abordagem. Por outro lado, os usuários revelaram uma preferência pela personalização de tarefas presente na abordagem Linear. Este resultado dá suporte à proposta desta tese, mostrando que a eficácia gerada pelos dois primeiros níveis da hierarquia de prioridades (percepção e execução das tarefas) deve ser combinada com o terceiro nível de personalização. Para isso, sugere-se a disponibilização de padrões de interface criados pelo designer para escolha do usuário durante a interação. Essa combinação deve garantir usabilidade no acesso a uma aplicação feito sempre por um mesmo dispositivo ou em contextos de uso alternado e migração de tarefasWith the miniaturization of digital components and the vast technological development of the past years, society has remarked the redefinition of "personal computers" by the advent of modern mobile devices. Besides the innovation, these handhelds also introduced the challenge to develop multi-device interfaces for today's desktop applications. While some created mobile interfaces from scratch to get the best from the devices, others looked for automatic adaptations to reduce the load imposed to the designeI. In both cases, the user wasn't the focus anymore, which resulted interfaces so different from each other to the point of compromising usability when peHorming one task on many devices. This thesis claims that there is no multi-device approach capable to provi de full usability in every context because the user may choose only one interface to access the application or interchange its use via many devices. In the first case, the user learns to perform tasks with the given device, which makes relevant an approach that takes advantage of its resources and solves its limitations. In the second, the user already knows one of the available interfaces, which generates an expectation for the others. Therefore, it is necessary to combine approaches with different goals and suit the user according to the appropriate context. In this sense, we propose multi-device design via maintenance of a consistency priorities hierarchy defined in three levels. The first two levels give support to the user's expectation in contexts of interchange (prone to task execution with different devices) and task migration (starting tasks with one device and finishing with other). On the other side, the third level provides task personalization according to the user's interest towards higher efficiency and satisfaction of use with a specific device. The evaluation of this methodology was conducted by an experiment with three pocket PC interfaces designed from an e-learning desktop application: the first interface was an exact replica of the original desktop version (Direct Migration), the second didn't maintain layout consistency and was based in a personalized design process adequate to the device (Linear) while the third applied only the first two levels of the consistency priorities hierarchy (Overview). The subjective evaluation results pointed the Overview approach as the best to maintain the user's mental model by preserving easiness, efficiency and safety of use on inter-device interaction. Additionally, both measured efficacy (task result accuracy) and efficiency (task execution mean time) were the same or even better with this approach. On the other hand, users revealed their preference for the task personalization present in the Linear approach. This result gives support to our proposal, corroborating that the efficacy generated by the first two levels of the consistency priorities hierarchy (task perception and execution) should be combined with the third level of personalization. This could be done by letting designers create interface patterns and make them available to users during interaction. Such combination should guarantee usability while constantly accessing one application through the same device or in contexts of alternated use and task migratio

Study of Tools Interoperability

Interoperability of tools usually refers to a combination of methods and techniques that address the problem of making a collection of tools to work together. In this study we survey different notions that are used in this context: interoperability, interaction and integration. We point out relation between these notions, and how it maps to the interoperability problem. We narrow the problem area to the tools development in academia. Tools developed in such environment have a small basis for development, documentation and maintenance. We scrutinise some of the problems and potential solutions related with tools interoperability in such environment. Moreover, we look at two tools developed in the Formal Methods and Tools group1, and analyse the use of different integration techniques

Meeting the information challenge: exploring partnerships with Africa

Africa suffers from the disadvantages of marginality within the global technical system and a legacy of externally driven infrastructure. Developments in information and communication technologies now offer the chance to redress these but the technologies require skills and capacities which are scarce. The technologies themselves can be used to leverage existing resources so that the necessary skills can be developed. However this process needs to take account of African priorities and requirements if the current inequitable situation is not to be reproduced in a new global infrastructure. The key to this is a balance between external partnership and internal collaboration. The African diaspora offers a means of moderating such relationships

Changing Trains at Wigan: Digital Preservation and the Future of Scholarship

This paper examines the impact of the emerging digital landscape on long term access to material created in digital form and its use for research; it examines challenges, risks and expectations.

MULTI-SCALE SCHEDULING TECHNIQUES FOR SIGNAL PROCESSING SYSTEMS

A variety of hardware platforms for signal processing has emerged, from distributed systems such as Wireless Sensor Networks (WSNs) to parallel systems such as Multicore Programmable Digital Signal Processors (PDSPs), Multicore General Purpose Processors (GPPs), and Graphics Processing Units (GPUs) to heterogeneous combinations of parallel and distributed devices. When a signal processing application is implemented on one of those platforms, the performance critically depends on the scheduling techniques, which in general allocate computation and communication resources for competing processing tasks in the application to optimize performance metrics such as power consumption, throughput, latency, and accuracy. Signal processing systems implemented on such platforms typically involve multiple levels of processing and communication hierarchy, such as network-level, chip-level, and processor-level in a structural context, and application-level, subsystem-level, component-level, and operation- or instruction-level in a behavioral context. In this thesis, we target scheduling issues that carefully address and integrate scheduling considerations at different levels of these structural and behavioral hierarchies. The core contributions of the thesis include the following. Considering both the network-level and chip-level, we have proposed an adaptive scheduling algorithm for wireless sensor networks (WSNs) designed for event detection. Our algorithm exploits discrepancies among the detection accuracy of individual sensors, which are derived from a collaborative training process, to allow each sensor to operate in a more energy efficient manner while the network satisfies given constraints on overall detection accuracy. Considering the chip-level and processor-level, we incorporated both temperature and process variations to develop new scheduling methods for throughput maximization on multicore processors. In particular, we studied how to process a large number of threads with high speed and without violating a given maximum temperature constraint. We targeted our methods to multicore processors in which the cores may operate at different frequencies and different levels of leakage. We develop speed selection and thread assignment schedulers based on the notion of a core's steady state temperature. Considering the application-level, component-level and operation-level, we developed a new dataflow based design flow within the targeted dataflow interchange format (TDIF) design tool. Our new multiprocessor system-on-chip (MPSoC)-oriented design flow, called TDIF-PPG, is geared towards analysis and mapping of embedded DSP applications on MPSoCs. An important feature of TDIF-PPG is its capability to integrate graph level parallelism and actor level parallelism into the application mapping process. Here, graph level parallelism is exposed by the dataflow graph application representation in TDIF, and actor level parallelism is modeled by a novel model for multiprocessor dataflow graph implementation that we call the Parallel Processing Group (PPG) model. Building on the contribution above, we formulated a new type of parallel task scheduling problem called Parallel Actor Scheduling (PAS) for chip-level MPSoC mapping of DSP systems that are represented as synchronous dataflow (SDF) graphs. In contrast to traditional SDF-based scheduling techniques, which focus on exploiting graph level (inter-actor) parallelism, the PAS problem targets the integrated exploitation of both intra- and inter-actor parallelism for platforms in which individual actors can be parallelized across multiple processing units. We address a special case of the PAS problem in which all of the actors in the DSP application or subsystem being optimized can be parallelized. For this special case, we develop and experimentally evaluate a two-phase scheduling framework with three work flows --- particle swarm optimization with a mixed integer programming formulation, particle swarm optimization with a simulated annealing engine, and particle swarm optimization with a fast heuristic based on list scheduling. Then, we extend our scheduling framework to support general PAS problem which considers the actors cannot be parallelized

Proceedings of the 2012 Workshop on Ambient Intelligence Infrastructures (WAmIi)

This is a technical report including the papers presented at the Workshop on Ambient Intelligence Infrastructures (WAmIi) that took place in conjunction with the International Joint Conference on Ambient Intelligence (AmI) in Pisa, Italy on November 13, 2012. The motivation for organizing the workshop was the wish to learn from past experience on Ambient Intelligence systems, and in particular, on the lessons learned on the system architecture of such systems. A significant number of European projects and other research have been performed, often with the goal of developing AmI technology to showcase AmI scenarios. We believe that for AmI to become further successfully accepted the system architecture is essential