According to Moore's law, Integrated Chips (IC) doubles its capacity every 18 months. This causes an exponential increase of the available area, and hence,the complexity of modern digital designs. This consistent enormous gross challenges different research areas in Electronic Design Automation (EDA). Thus, various EDA applications such as equivalence checking, model checking, Automatic Test Pattern Generation (ATPG), functional Bi-decomposition, and technology mapping need to keep pace with these challenges. In this thesis, we are concerned with improving the quality and performance of different EDA algorithms particularly in area of hardware verification and synthesis. First, we introduce algorithms to manipulate Reduced Ordered Binary Decision Diagrams (ROBDD) on multi-core machines. In order to perform multiple BDD operations concurrently, our algorithm uses a breadth-first search (BFS). As ROBDD algorithms are memory-intensive, maintaining locality of data is an important issue. Therefore, we propose the usage of Hopscotch hashing technique for both Unique Table and BFS Queues to improve the construction time of ROBDD on the parallel platform. Hopscotch hashing technique not only improves the locality of the manipulating data, but also provides a way to cache recently performed BDD operation. Consequently, The time and space usage can be traded off. Secondly, we used static implications to enhance the performance of SAT-based Bounded Model Checking (BMC) problem. we propose a parallel deduction engine to efficiently utilize low-cost off-shelf multi-core processors to compute the implications. With this engine, we can significantly reduce the computational processing time in analyzing the deduced implications. Secondly, we formulate the clause filter problem as an elegant set-covering problem. Thirdly, we propose a novel greedy algorithm based on the Johnson's algorithm to find the optimal set of clauses that would accelerate BMC solution. Thirdly, we proposed a novel synthesis paradigm to achieve timing-closure called Timing-Aware CUt Enumeration (TACUE). In TACUE, optimization is conducted through three aspects: First, we propose a new divide-and-conquer strategy that generates multiple sub-cuts on the critical parts of the circuit. Secondly, cut enumeration have been applied in two cutting strategies. In the topology-aware cutting strategy, we preserve the general topology of the circuit by applying TACUE in only self-contained cuts. Meanwhile, the topology-masking cutting strategy investigates circuit cuts beyond their current topology. Thirdly, we proposed an efficient parallel synthesis framework to reduce computation time for synthesizing TACUE sub-cuts. We conducted experiments on large and difficult industrial benchmarks. Finally, we proposed the first scalable SAT-based approaches for Observability Dont Care (ODC) clock gating. Moreover we intelligently choose those inductive invariants candidates such that their validation will benefit the purpose in clock-gating-based low-power design. / Ph. D.

Off-road autonomous navigation faces a significant challenge due to the lack of maps or road markings for planning paths. Classical path planning methods assume a perfectly known envi- ronment, neglecting the inherent perception and sensing uncertainty from detecting terrain and obstacles in off-road environments. This research proposes an uncertainty-aware path planning method, URA*, using aerial images for autonomous navigation in off-road environments. An ensemble convolutional neural network model is used to perform pixel-level traversability estima- tion from aerial images of the region of interest. Traversability predictions are represented as a grid of traversal probability values. An uncertainty-aware planner is applied to compute the best path from a start point to a goal point, considering these noisy traversal probability estimates. The proposed planner also incorporates replanning techniques for rapid replacement during online robot operation. The method is evaluated on the Massachusetts Road Dataset, DeepGlobe dataset, and aerial images from CAVS proving grounds at MSU.

Em NGN (Next Generation Networks), os usuários podem se conectar em diferentes tecnologias de rede e desejam, além de uma comunicação transparente, novos serviços personalizados. Neste sentido, este trabalho explora informações de contexto em NGN. O principal objetivo é capturar as informações de contexto envolvidas no momento da utilização da rede sem fio, na escolha do novo ponto de acesso e no procedimento do handover. Este contexto capturado é aplicado para serviços cientes de contexto. A proposta é validada por meio de dois cenários, o primeiro é um mashup que exibe as redes sem fio disponíveis de um determinado local e o segundo um protótipo gerenciador de conexões para atender as preferências do usuário. Adicionalmente, são realizadas duas avaliações do impacto do uso de contexto em handovers. Para tanto, foi implantado um testbed NGN com o protocolo Mobile IP / In the NGN (Next Generation Networks) users can connect their Internet devices to different network technologies. In addition to a seamless communication, users desire new and personalized services. In this sense, this thesis exploits the context-aware information in NGN environments. The main propose is to capture the context information about the time involved by the use of wireless link for selecting the target access point and on the handover procedure. This context information is applied to the context-aware services. The propose is validated through two scenarios: the first is a mashup that shows the availability of wireless networks in a particular location, and the second is a prototype of a connection manager to attend user´s preferences. In addition, two evaluations are accomplished on the impact by the use of context information over handovers. Thus, an NGN testbed is deployed with Mobile IP protocol

Em NGN (Next Generation Networks), os usuários podem se conectar em diferentes tecnologias de rede e desejam, além de uma comunicação transparente, novos serviços personalizados. Neste sentido, este trabalho explora informações de contexto em NGN. O principal objetivo é capturar as informações de contexto envolvidas no momento da utilização da rede sem fio, na escolha do novo ponto de acesso e no procedimento do handover. Este contexto capturado é aplicado para serviços cientes de contexto. A proposta é validada por meio de dois cenários, o primeiro é um mashup que exibe as redes sem fio disponíveis de um determinado local e o segundo um protótipo gerenciador de conexões para atender as preferências do usuário. Adicionalmente, são realizadas duas avaliações do impacto do uso de contexto em handovers. Para tanto, foi implantado um testbed NGN com o protocolo Mobile IP / In the NGN (Next Generation Networks) users can connect their Internet devices to different network technologies. In addition to a seamless communication, users desire new and personalized services. In this sense, this thesis exploits the context-aware information in NGN environments. The main propose is to capture the context information about the time involved by the use of wireless link for selecting the target access point and on the handover procedure. This context information is applied to the context-aware services. The propose is validated through two scenarios: the first is a mashup that shows the availability of wireless networks in a particular location, and the second is a prototype of a connection manager to attend user´s preferences. In addition, two evaluations are accomplished on the impact by the use of context information over handovers. Thus, an NGN testbed is deployed with Mobile IP protocol

Submitted by Kamila Costa (kamilavasconceloscosta@gmail.com) on 2015-06-23T17:26:53Z No. of bitstreams: 1 Dissertação-Wesley de S Viana.pdf: 3248107 bytes, checksum: 052d64e91b1af49c56df079ee11e65af (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-07T18:08:42Z (GMT) No. of bitstreams: 1 Dissertação-Wesley de S Viana.pdf: 3248107 bytes, checksum: 052d64e91b1af49c56df079ee11e65af (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-07T18:23:03Z (GMT) No. of bitstreams: 1 Dissertação-Wesley de S Viana.pdf: 3248107 bytes, checksum: 052d64e91b1af49c56df079ee11e65af (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-07T18:39:44Z (GMT) No. of bitstreams: 1 Dissertação-Wesley de S Viana.pdf: 3248107 bytes, checksum: 052d64e91b1af49c56df079ee11e65af (MD5) / Made available in DSpace on 2015-07-07T18:39:44Z (GMT). No. of bitstreams: 1 Dissertação-Wesley de S Viana.pdf: 3248107 bytes, checksum: 052d64e91b1af49c56df079ee11e65af (MD5) Previous issue date: 2015-03-30 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / The distance education is a technology-mediated education mode in which the teacher becomes an intermediary of knowledge and the student is primarily responsible for the pursuit of knowledge and learning. In recent years, there has been a rapid growth in the use of this form of education in public and private institutions, boosting the development of new technologies and technological tools in order to support this growth. In this context, the Learning Management System (LMS) have become very used to support for distance education. However, these environments present some limitations, requiring the construction of technological tools to circumvent such restrictions. In the midst of this information it has been found that some teachers have difficulties in tracking students in designated locations for supervised internship, both physically and by E-learning support environment. Therefore, this paper proposes an approach involving mobile technologies and location context to enable the preparation and realization of tasks in specific locations. This allows the teacher to create a task and assign it to a specific location and make sure that the student was at the scene, because the task will be available only in the location set. In addition, we developed a Multi-agent System (SMA) to notify about deadlines and tasks available in the environment through SMS and email. The approach was validated in two disciplines of distance courses and internship in a pilot course conducted at the Federal University of Amazonas (UFAM) that allowed the initial validation with real users in various scenarios of applicability of the approach. / A Educação a Distância (EaD) é uma modalidade de educação mediada por tecnologia no qual o professor torna-se um intermediário do saber e o aluno é o principal responsável pela busca do conhecimento e aprendizado. Nos últimos anos, houve um crescimento acelerado na utilização dessa forma de educação em instituições públicas e privadas, impulsionando o desenvolvimento de novas tecnologias e ferramentas tecnológicas a fim de apoiar esse crescimento. Nesse contexto, os Ambientes Virtuais de Aprendizagem (AVAs) tornaram-se muito utilizados para suporte à EaD. No entanto, esses ambientes apresentam algumas limitações, sendo necessária a construção de ferramentas tecnológicas para contornar tais limitações. Em meio a essas informações foi constatado que alguns professores possuem dificuldades em acompanhar os alunos em locais designados para a realização de estágio supervisionado, tanto fisicamente quanto pelo ambiente de suporte à EaD. Portanto, o presente trabalho propõe uma abordagem envolvendo tecnologias móveis e contexto por localização para possibilitar a elaboração e a realização de tarefas em locais específicos. Isso permite ao professor criar uma tarefa e designá-la a um local especifico e se certificar-se que o aluno foi ao local, pois a tarefa será disponibilizada apenas no local definido. Além disso, foi desenvolvido um Sistema Multiagente (SMA) para notificar sobre prazos e tarefas disponíveis no ambiente por meio de SMS e e-mail. A abordagem foi validada em duas disciplinas de estágio em cursos a distância e em um curso piloto conduzido na Universidade Federal do Amazonas (UFAM) que permitiu a validação inicial com usuários reais em vários cenários de aplicabilidade da abordagem.

Aggressive scaling of nanoscale CMOS integrated circuits has created significant design challenges arising from increasing power densities, thermal concerns, and rising wire delays. The main contribution of this dissertation is the development of unified physical and high-level synthesis techniques for the design of ASICs with optimal chip temperatures and interconnect delays. Thermal issues are becoming a serious problem in high-performance VLSI circuits, adversely impacting performance, reliability, power consumption, and cooling costs. To address this, we present a temperature-aware behavioral synthesis (TABS) framework that combines power minimization with temperature-aware task scheduling, resource binding, and floorplanning. Compared to conventional low-power synthesis methods, our approach is effective in synthesizing circuits with lower chip temperatures and more uniform thermal distributions, with temperature reductions up to 23% when compared to low-power synthesis. We propose three techniques to address interconnect delays during high-level synthesis: (1) a simulated annealing (SA) based layout-aware high-level synthesis technique for 3-D integrated circuits, that tightly couples the synthesis tasks of resource binding and 3-D floorplanning. The proposed algorithm significantly outperforms a conventional synthesis flow that separates the binding and floorplanning steps, with improvements in the total wirelength by 29% and of the longest wirelength by 21%; (2) a floorplan-aware high-level synthesis technique that uses the topology of multi-terminal nets to improve interconnect delay estimates during resource binding. Experiments show that the use of accurate wire delay estimates during binding can reduce wire delays by as much as 49% in 70nm technology; (3) an iterative high-level design-space exploration engine that uses a priori stochastic wirelength estimates to guide binding decisions during high-level synthesis. The proposed approach offers a significant speed-up during design space exploration when compared to approaches that use traditional place-and-route to evaluate candidate solutions. Finally, we present a genetic algorithm (GA) based approach for high-level synthesis. We propose novel GA encoding, crossover, and mutation operators for the problem. The quality of the results generated by the GA are superior to those of several other techniques reported in the literature.

Mobile ad hoc networks (MANETs) can be formed dynamically without the support of any existing infrastructure or any centralized administration. They consist of heterogeneous mobile nodes which are powered by batteries, move arbitrarily and are connected by wireless links. Battery energy limitation is one of the main challenges in the MANETs. Several hardware and software based techniques have been proposed in this field. Most of the previous studies have considered only the energy minimization of individual nodes and disregarded the overall network lifetime. Topology management is another important problem in MANETs, in this sense / several new computing paradigms have been developed by the researchers, and the topology management has not been studied clearly in most of these models. In this study, we propose two new techniques that deal with the topology management in order to facilitate the nodes&rsquo / cooperation towards energy saving. The developed computing model considers heterogeneous mobile nodes. A node that faces shortage in its resources (energy and processing capability) sends its work to one of the nearby devices which is able to execute the work. In addition, we propose two algorithm for dynamic and two for static task scheduling, to prolong the network life time. Comprehensive experiments showed that the proposed schemes achieve a significant improvement in the network lifetime while simultaneously reducing the energy consumption and time delay for each task.

In the future, computers will be virtually everywhere: carried by everyone and integrated into the environment. The increased computation and communication capabilities will enable intelligent environments that react to occupants through automated decision-making. Devices (sensors and actuators) are the key to making intelligent environments a reality. We believe that devices must be made more approachable for average users. Existing approaches to application development for intelligent environments require detailed knowledge about devices and their low-leveling programming interfaces, which greatly limits the number of potential users. Instead of limiting users, we must enable everyone to program the devices around them. Intelligent environments will not be commonplace until average people can set up and manage the hardware and software necessary for their personalized applications. In simplifying the programming of intelligent environments, we first made sensors and actuators accessible to average programmers then extended our work to end-users. We term the former contribution Sensor Enablement for Average Programmers (SEAP); the latter work is Sensor Enablement for End-Users (SEEU). In our experience, devices’ disparate, niche programming languages and communication protocols presented great difficulty in developing intelligent environments. To ease the development effort for average programmers, we abstracted and standardized complex sensor and actuator interactions, allowing users to instead think in terms of well-understood web applications. Users have said that SEAP is easy-to-use and exciting. But what about average people, end-users? We found that end-users are incredibly interested in intelligent environments. By engaging end-users we can create intelligent environments even faster and allow domain experts to tailor their environment. This dissertation’s second contribution, Sensor Enablement for End-Users (SEEU) provides a visual programming interface that allows users to create personalized automated behaviors given available devices and data. We performed several user studies to uncover people’s desires for intelligent environments and determine the best interface for managing an intelligent environment. SEEU combines an intuitive interface with the power and flexibility of SEAP. SEEU is a usable end-user programming framework that allows average people to create useful applications for their intelligent environments. With SEEU and SEAP, we simplified the development of intelligent environments, reducing barriers to adoption of emerging sensing and actuation technologies. We demonstrated the feasability with a series of user studies. / text

Catering to society’s demand for high performance computing, billions of transistors are now integrated on IC chips to deliver unprecedented performances. With increasing transistor density, the power consumption/density is growing exponentially. The increasing power consumption directly translates to the high chip temperature, which not only raises the packaging/cooling costs, but also degrades the performance/reliability and life span of the computing systems. Moreover, high chip temperature also greatly increases the leakage power consumption, which is becoming more and more significant with the continuous scaling of the transistor size. As the semiconductor industry continues to evolve, power and thermal challenges have become the most critical challenges in the design of new generations of computing systems. In this dissertation, we addressed the power/thermal issues from the system-level perspective. Specifically, we sought to employ real-time scheduling methods to optimize the power/thermal efficiency of the real-time computing systems, with leakage/ temperature dependency taken into consideration. In our research, we first explored the fundamental principles on how to employ dynamic voltage scaling (DVS) techniques to reduce the peak operating temperature when running a real-time application on a single core platform. We further proposed a novel real-time scheduling method, “M-Oscillations” to reduce the peak temperature when scheduling a hard real-time periodic task set. We also developed three checking methods to guarantee the feasibility of a periodic real-time schedule under peak temperature constraint. We further extended our research from single core platform to multi-core platform. We investigated the energy estimation problem on the multi-core platforms and developed a light weight and accurate method to calculate the energy consumption for a given voltage schedule on a multi-core platform. Finally, we concluded the dissertation with elaborated discussions of future extensions of our research.

The prevalent visions of ambient intelligence leverage natural interactions between users and available services in a smart space. In recent years, we have seen a huge interest from industry and academia in using handheld devices to interact with things, places and people in the real world. To facilitate such interactions, things are usually annotated with RFID tags or visual markers. These tags or markers are read by a handheld device equipped with an integrated RFID reader or a camera, in order to fetch related information and initiate further actions. Interacting with the Internet of Things (IoT) in a real environment has become increasingly desirable and feasible. This thesis contributes to the domain of physical interactions with IoT; however, we use a spatial-geometric approach instead of RFID or marker based solutions. Using this approach, for example, a user can point his/her handheld device to an annotated thing, from a distance, for the purpose of interaction. The pointing direction and location is determined based on the fusion of the mobile position and of the accelerometer data of the handheld device. To annotate things, their geometric coordinates are specified and related information or services are associated to them. In this thesis, we present a comprehensive and extensible framework to integrate various physical interactions with IoT into multimedia applications. The framework supports the implementations of pointMe, touchMe, and context-aware based interactions with geometrically annotated IoT. We define specific methods and practices that can be incorporated in order to build the interactions. We realize smart home, atlas learning, presentation interaction, smart haptic interaction, and learning based video interaction game prototypes in order to perform experiments and demonstrate the applicability and potential of the proposed geometric based annotation approach. In the analysis of the interaction techniques of the prototypes, we present the advantages and disadvantages of the geometric based annotation of IoT as seen by potential users, in comparison to RFID tags or visual markers based approaches.