A Educação Ubíqua, tema de pesquisa desta tese, tem como objetivo relacionar os aprendizes com o ambiente em seu entorno, formando uma rede virtual e real de pessoas, objetos e situações, auxiliando para uma aprendizagem contínua, contextualizada e significativa. A consciência do contexto do aprendiz constitui-se do elemento fundamental neste tipo de educação. A partir das pesquisas realizadas, concluiu-se que, atualmente, os ambientes virtuais de suporte à Educação Ubíqua possuem um contexto de atuação específico ou localizado, além de um ambiente computacional próprio. Desta forma, o problema de pesquisa desta tese consiste em identificar os elementos básicos necessários para auxiliar uma aprendizagem independente de lugar, de tempo, do contexto em que ela ocorre e do ambiente computacional de suporte. A partir desses aspectos, esta tese aborda a hipótese de que o desenvolvimento de um ambiente educacional ubíquo deve ser apoiado por mecanismos computacionais pró-ativos, providos por um ambiente de suporte à ubiqüidade, que possibilite perceber o contexto do aprendiz e o uso de diversas tecnologias de acesso. Cabe ao ambiente educacional adaptar os recursos disponíveis, levando em consideração a dinamicidade com que eles se alteram, de forma contínua e transparente, criando um ambiente propício para a aprendizagem. Desta forma, este trabalho propõe um modelo de Educação Ubíqua orientado à consciência do contexto do aprendiz denominado GlobalEdu. Neste, o aprendiz tem a possibilidade de aprender de forma contínua e integrada com o seu contexto. O GlobalEdu provê uma organização em camadas. A camada de Aplicação é representada por um Agente Pedagógico, cujo objetivo é auxiliar a interação do aprendiz no ambiente. A camada de Sistema consitui-se de um conjunto de módulos Educacionais e de Suporte, necessários para auxiliar no processo educacional do aprendiz no ambiente, manipulando o contexto do aprendiz, seu perfil e seus conteúdos, além de elementos que auxiliem a execução do agente e dos recursos que ele manipula. As principais contribuições dessa tese consistem em aprofundar os aspectos referentes à consciência do contexto do aprendiz, bem como a proposta e desenvolvimento do modelo e sua integração com ambientes de suporte à Computação Ubíqua. Além disso, a partir de uma ontologia para representação de contexto, o modelo permite o mapeamento de contextos diversos. A partir da avaliação do sistema, identificou-se a importância do ambiente educacional preocupar-se com os processos educacionais, enquanto o ambiente computacional suporta os elementos necessários para prover à consciência do contexto e os demais aspectos relacionados à ubiqüidade. / This research is about Ubiquitous Learning. The idea of ubiquitous learning is to create a network of devices, people and situation that allows learning experiences to play out. The learner’s context-aware is a fundamental element of this type of education. Thus, the ubiquitous learning environment supports omnipresense processes, learner autonomy and integration with learner’s surrounding environment. The current related works are oriented for specific contexts. We are investigating what subset of functionality is required for to provide learning can occur anywhere, anytime, with continued computing support and no-specific computational environment. Our hypothesis is that it is possible to develop ubiquitous learning environment using ubiquitous computing support, because this type of computing can provide the context aware characteristics and support several access technologies. With this, the learning environment provides continuous learning resources, creating a propitious environment for the learning. This work proposes a ubiquitous learning model addressed to learner’s context-aware called GlobalEdu. This model supports learning on ubiquitous computing environments. It is composed by Pedagogical Agent, Educational Services and Support Services. The Pedagogical Agent is an agent that runs in the device that the learner is using, assisting the educational process in the ubiquitous environment. It contains an interface to the Educational Services and provides a ubiquitous vision through ubiquitous environment. The Educational Services and Support Services provide the support to agent execution in the ubiquitous environment, through identification and adaptation of resources in agreement with the learner’s profile and learner’s context. The main contributions of this work are concentrated in the surrounding context of the learner. An ontology for context representation was proposed. Moreover, it was proposed a ubiquitous learning model and its integration with a ubiquitous environment. We concluded that the integration of learning environment and ubiquitous environment is important. The ubiquitous environment supports context information and others ubiquitous aspects while the learning environment is dedicated to the educational process.

Cloud computing enables the delivery of remote computing, software and storage services through web browsers following pay-as-you-go model. In addition to successful commercial applications, many research efforts including DOE Magellan Cloud project focus on discovering the opportunities and challenges arising from the computing and data-intensive scientific applications that are not well addressed by the current supercomputers, Linux clusters and Grid technologies. The elastic resource provision, noninterfering resource sharing and flexible customized configuration provided by the Cloud infrastructure has shed light on efficient execution of many scientific applications modeled as Directed Acyclic Graph (DAG) structured workflows to enforce the intricate dependency among a large number of different processing tasks. Meanwhile, the Cloud environment poses various challenges. Cloud providers and Cloud users pursue different goals. Providers aim to maximize profit by achieving higher resource utilization and users want to minimize expenses while meeting their performance requirements. Moreover, due to the expanding Cloud services and emerging newer technologies, the ever-increasing heterogeneity of the Cloud environment complicates the challenges for both parties. In this thesis, we address the workflow scheduling problem from different applications and various objectives. For batch applications, due to the increasing deployment of many data centers and computer servers around the globe escalated by the higher electricity price, the energy cost on running the computing, communication and cooling together with the amount of CO2 emissions have skyrocketed. In order to maintain sustainable Cloud computing facing with ever-increasing problem complexity and big data size in the next decades, we design and develop energy-aware scientific workflow scheduling algorithm to minimize energy consumption and CO2 emission while still satisfying certain Quality of Service (QoS) such as response time specified in Service Level Agreement (SLA). Furthermore, the underlying Cloud hardware/Virtual Machine (VM) resource availability is time-dependent because of the dual operation modes namely on-demand and reservation instances at various Cloud data centers. We also apply techniques such as Dynamic Voltage and Frequency Scaling (DVFS) and DNS scheme to further reduce energy consumption within acceptable performance bounds. Our multiple-step resource provision and allocation algorithm achieves the response time requirement in the step of forward task scheduling and minimizes the VM overhead for reduced energy consumption and higher resource utilization rate in the backward task scheduling step. We also evaluate the candidacy of multiple data centers from the energy and performance efficiency perspectives as different data centers have various energy and cost related parameters. For streaming applications, we formulate scheduling problems with two different objectives, namely one is to maximize the throughput under a budget constraint while another is to minimize execution cost under a minimum throughput constraint. Two different algorithms named as Budget constrained RATE (B-RATE) and Budget constrained SWAP (B-SWAP) are designed under the first objective; Another two algorithms, namely Throughput constrained RATE (TP-RATE) and Throughput constrained SWAP (TP-SWAP) are developed under the second objective.

Wireless sensor networks (WSNs) have been used in many applications by deploying tiny and stationary sensors. In recent years, a lot of studies proposed to introduce mobility capability to sensor nodes in order to exploit the advantages of mobility, particularly to restore connectivity in disjoint WSNs. While the studies demonstrated various capabilities of the proposed connectivity algorithms via simulation, real node and testbed implementations were mostly lacking due to unavailability of proper mobile nodes. Since this may hinder the direct applicability of the algorithms in realistic settings, testbeds which can be constructed with low-cost and commercial-off-the-shelf (COTS) hardware are required for realistic evaluations of the connectivity restoration algorithms. In this thesis, we design a low-cost mobile sensor node called iRobotSense, by integrating iRobot Create platform with IRIS sensor. Then, a mobile sensor network (MSN) testbed of iRobotSense nodes is used to implement and evaluate a widely used connectivity restoration algorithms, namely PADRA. Furthermore, all of the previous works exploiting mobility of the nodes to achieve recovery in a partitioned network have assumed reachability of the nodes to the selected destinations via a direct path movement. However, in real-world applications, such assumption makes the schemes impractical in case of encountering obstacles or intolerable terrains. Besides, even if direct path movement is successful, optimal energy efficiency cannot be attained by neglecting the elevation or friction of the terrain. Thus, in the recovery efforts, terrain type, elevation as well as the obstacles should be taken into account. In this thesis, we re-design an existing connectivity restoration approach in disjoint MSNs to fit these requirements and evaluate the performance issues when realistic terrains are assumed. Rather than following a direct path, movement trajectory is determined based on a path planning algorithm which considers the risk and elevation of terrain sections to be visited while avoiding obstacles and highly elevated terrain sections.

Traditional theories of gender performativity, grounded in the tradition of Judith Butler, fail to capture the experience of encountering a gendered subject. By reducing gender to a series of discursive acts and ignoring the aesthetic dimension of gender, these theories neglect the possibility for alternative gender performances divorced from the materiality of the body, except through acknowledging the ficticious nature of gender as a consequence of citational acts. In contrast, this dissertation presents a theory of gender as aware, or the “aboutness” that emerges through the repeated citational acts that make present gender in our lived experience. Gender, therefore, does not possess any ontological essence except insofar as it is articulated by citational practices, without which it cannot exist. To this end, this dissertation argues for an expansion of our discourse on gender through appealing to Japanese aesthetic and poetic concepts of aware and mono no aware to demonstrate the aesthetic nature of gender. In so doing this dissertation will present gender as fundamentally aesthetic through appeal to no, kabuki, and the Takarazuka Revue, all sites which divorced gender form biological sex for the purpose of an aesthetic praxis.

Heterogeneous processors intended for mobile devices are composed of a number of different CPU cores that enable the processor to optimize performance under strict power limits that vary over time. Design space exploration techniques can be used to discover a candidate set of potential cores that could be implemented on a heterogeneous processor. However, candidate sets contain far more cores than can feasibly be implemented. Heterogeneous processor composition therefore requires solutions to the selection problem and the evaluation problem. Cores must be selected from the candidate set, and these cores must be shown to be quantitatively superior to alternative selections. The qualitative criterion for a selection of cores is diversity. A diverse set of heterogeneous cores allows a processor to execute tasks with varying dynamic behaviors at a range of power and performance levels that are appropriate for conditions during runtime. This thesis presents a detailed description of the selection and evaluation problems, and establishes a theoretical framework for reasoning about the runtime behavior of power-limited, heterogeneous processors. The evaluation problem is specifically concerned with evaluating the collective attributes of selections of cores rather than evaluating the features of individual cores. A suite of metrics is defined to address the evaluation problem. The metrics quantify considerations that could otherwise only be evaluated subjectively. The selection problem is addressed with an iterative, diversity-preserving algorithm that emphasizes the flexibility available to programs at runtime. The algorithm includes facilities for guiding the selection process with information from an expert, when available. Three variations on the selection algorithm are defined. A thorough analysis of the proposed selection algorithm is presented using data from a large-scale simulation involving 33 benchmarks and 3000 core types. The three variations of the algorithm are compared to each other and to current, state-of-the-art selection techniques. The analysis serves as both an evaluation of the proposed algorithm as well as a case study of the metrics.

Aplicações cientes de contexto precisam de mecanismos para recuperar informações sobre o seu contexto de execução. Com base no contexto atual, tais aplicações são capazes de se autoadaptar para fornecer informações e serviços adequados aos seus usuários. A abordagem comum para infraestruturas de apoio às aplicações sensíveis ao contexto fornece serviços para a descoberta de recursos através da utilização de pares <chave-valor> e motores que executam apenas correspondência sintática. Esta abordagem não considera as possíveis relações semânticas entre as palavras-chave usadas. Portanto, a sua expressividade semântica limitada, leva a um serviço de descoberta que provê baixa taxa de recuperação e baixa acurácia. Este trabalho apresenta a utilização de uma outra abordagem para o serviço de contexto e descoberta, que utiliza ontologias para representar os recursos do contexto de execução e capturar a semântica da consulta do usuário, melhorando assim o processo de descoberta para a autoadaptação de sistemas sensíveis ao contexto. A abordagem proposta oferece também pontos de extensão para as aplicações clientes através da utilização de outras ontologias. Esta abordagem foi integrada à infraestrutura CDRF, de forma a adicionar semântica aos serviços desenvolvidos neste projeto. Exemplos de aplicações são também propostos para demonstrar a utilização dos novos serviços. / Context-aware applications demand ways of retrieving context information from the environment. Based on the current context, such applications are able to self-adapt to provide the correct information and services to its users. The usual approach for supporting infrastructures for context-aware applications provides facilities for resource discovery using <key-value> pairs and discovery engines that perform syntactic matching. This approach does not consider the possible semantic relations between the keywords used. So its limited semantic expressiveness often leads to poor discovery results. This paper presents the use of a different approach for service discovery that uses ontologies to represent resources and capture the semantics of the users query, improving the discovery process for self-adaptation of context-aware systems. The proposed approach also offers extension hooks to the client applications through the use of other ontologies. This approach is integrated into the CDRF framework and adds semantics to the services developed in that project. Example applications are also proposed to demonstrate the use of the new services.

Smart Cyber-Physical Systems (sCPS) are complex systems performing smart coordination that often require decentralized and network resilient operation. New development in the fields of the robotic systems, Industry 4.0 and autonomous vehicular system brings challenges that can be tackled with deployment of ensemble based sCPS, but require further refinement in terms of network resilience and data propagation. This thesis maps the use cases of the sCPS in the aforementioned domains, discusses requirements on the ensemble based architecture in terms of network properties, and proposes recommendations and technical means that help to design network aware ensemble based sCPS. The proposed solutions are evaluated by the means of target systems simulation using state of the art realistic network and vehicular simulators.

abstract: Android has been the dominant platform in which most of the mobile development is being done. By the end of the second quarter of 2014, 84.7 percent of the entire world mobile phones market share had been captured by Android. The Android library internally uses the modified Linux kernel as the part of its stack. The I/O scheduler, is a part of the Linux kernel, responsible for scheduling data requests to the internal and the external memory devices that are attached to the mobile systems. The usage of solid state drives in the Android tablet has also seen a rise owing to its speed of operation and mechanical stability. The I/O schedulers that exist in the present Linux kernel are not better suited for handling solid state drives in particular to exploit the inherent parallelism offered by the solid state drives. The Android provides information to the Linux kernel about the processes running in the foreground and background. Based on this information the kernel decides the process scheduling and the memory management, but no such information exists for the I/O scheduling. Research shows that the resource management could be done better if the operating system is aware of the characteristics of the requester. Thus, there is a need for a better I/O scheduler that could schedule I/O operations based on the application and also exploit the parallelism in the solid state drives. The scheduler proposed through this research does that. It contains two algorithms working in unison one focusing on the solid state drives and the other on the application awareness. The Android application context aware scheduler has the features of increasing the responsiveness of the time sensitive applications and also increases the throughput by parallel scheduling of request in the solid state drive. The suggested scheduler is tested using standard benchmarks and real-time scenarios, the results convey that our scheduler outperforms the existing default completely fair queuing scheduler of the Android. / Dissertation/Thesis / Masters Thesis Computer Science 2014

abstract: As people age, the desire to grow old independently and in place becomes larger and takes greater importance in their lives. Successful aging involves the physical, mental and social well-being of an individual. To enable successful aging of older adults, it is necessary for them to perform both activities of daily living (ADL) and instrumental activities of daily living (IADL). Embedded assessment has made it possible to assess an individual's functional ability in-place, however the success of any technology depends largely on the user than the technology itself. Previous researches in in-situ functional assessment systems have heavily focused on the technology rather than on the user. This dissertation takes a user-centric approach to this problem by trying to identify the design and technical challenges of deploying and using a functional assessment system in the real world. To investigate this line of research, a case study was conducted with 4 older adults in their homes, interviews were conducted with 8 caregivers and a controlled lab experiment was conducted with 8 young healthy adults at ASU, to test the sensors. This methodology provides a significant opportunity to advance the scientific field by expanding the present focus on IADL task performance to an integrated assessment of ADL and IADL task performance. Doing so would not only be more effective in identifying functional decline but could also provide a more comprehensive assessment of individuals' functional abilities with independence and also providing the caregivers with much needed respite. The controlled lab study tested the sensors embedded into daily objects and found them to be reliable, and efficient. Short term exploratory case studies with healthy older adults revealed the challenges associated with design and technical aspects of the current system, while inductive analysis performed on interviews with caregivers helped to generate central themes on which future functional assessment systems need to be designed and built. The key central themes were a) focus on design / user experience, b) consider user's characteristics, personality, behavior and functional ability, c) provide support for independence, and d) adapt to individual user's needs. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2015

La miniaturisation des transistors vers ses ultimes limites physiques a exacerbé les effets négatifs qui sont liées à la granularité de la matière. Plusieurs nouvelles sources de variabilités affectent les transistors qui, bien qu'identiquement dessinés, montrent des caractéristiques électriques qui sont variables entre eux et entre différents moments de leur utilisation. Les circuits de mémoire SRAM, qui sont conçues avec des règles de dessin parmi le plus agressives et contiennent un nombre de transistors très élevé, sont menacés en particulier par ce phéomène de variabilité qui représente le plus grand obstacle non seulement pour la réduction de la surface d'un point mémoire SRAM, mais aussi pour la réduction de son tension d'alimentation. L'optimisation des circuits SRAM est devenue une tache cruciale afin de répondre à la fois aux demandes d'augmentation de densité et de la réduction de la consommation, donc une méthodologie statistique permettant de modéliser an amont l'impact de la variabilité à travers des simulations SPICE est devenue un besoin obligatoire. Les travaux de recherches présentés se concentrent sur le développement des nouvelles méthodologies pour la simulation des points mémoires sous l'impact de la variabilité, dans le but d'accomplir une modélisation précise de la tension d'alimentation minimale d'un SRAM quelques soit les conditions d'opérations. La variabilité dynamique liée au bruit RTS qui cause le changement des caractéristiques électrique des transistors au cours de leurs opérations est également étudiée avec un effort particulier de modélisation. Ce travail a donné lieu à de nombreuses publications internationales et à un brevet. Aujourd'hui cette méthodologie est retenue par STMicroelectronics et est utilisé dans la phase d'optimisation des plans mémoires SRAM. / The downscaling of device geometry towards its physical limits exacerbates the impact of the inevitable atomistic phenomena tied to matter granularity. In this context, many different variability sources raise and affect the electrical characteristics of the manufactured devices. The variability-aware design methodology has therefore become a popular research topic in the field of digital circuit design, since the increased number of transistors in the modern integrated circuits had led to a large statistical variability affecting dramatically circuit functionality. Static Random Access Memory (SRAM) circuits which are manufactured with the most aggressive design rules in a given technology node and contain billions of transistor, are severely impacted by the process variability which stands as the main obstacle for the further reduction of the bitcell area and of its minimum operating voltage. The reduction of the latter is a very important parameter for Low-Power design, which is one of the most popular research fields of our era. The optimization of SRAM bitcell design therefore has become a crucial task to guarantee the good functionality of the design at an industrial manufacturing level, in the same time answering to the high density and low power demands. However, the long time required by each new technology node process development means a long waiting time before obtaining silicon results, which is in cruel contrast with the fact that the design optimization has to be started as early as possible. An efficient SPICE characterization methodology for the minimum operating voltage of SRAM circuits is therefore a mandatory requirement for design optimization. This research work concentrates on the development of the new simulation methodologies for the modeling of the process variability in ultra-deep-submicron SRAMs, with the ultimate goal of a significantly accurate modeling of the minimum operating voltage Vmin. A particular interest is also carried on the time-dependent sub-class of the process variability, which appears as a change in the electrical characteristics of a given transistor during its operation and during its life-time. This research work has led to many publications and one patent application. The majority of findings are retained by STMicroelectronics SRAM development team for a further use in their design optimization flow.