Thesis (M.E.)--University of Florida, 2001. / Title from first page of PDF file. Document formatted into pages; contains xi, 68 p.; also contains graphics. Vita. Includes bibliographical references (p. 66-67).

Orientador: Yuzo Iano / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-20T16:13:03Z (GMT). No. of bitstreams: 1 Noboa_FranciscoJoseViudes_M.pdf: 2562716 bytes, checksum: 8090bd81ec54aaeab629033ee45a1ef0 (MD5) Previous issue date: 2012 / Resumo: Considerando-se que para controlar e possibilitar a entrega de diversos conteúdos e serviços a qualquer tipo de acesso fazia-se necessário um núcleo bem definido e estruturado, surgiu o IMS (IP Multimedia Subsystem) com o propósito de prover a integração completa das redes e serviços. O IMS define uma arquitetura completa e framework que habilita a convergência de voz, vídeo, dados e tecnologia de rede móvel através de uma infraestrutura baseada em IP, preenchendo a distância entre os dois paradigmas de comunicação mais bem sucedidos, celular e tecnologia IP. Este trabalho apresenta a arquitetura IMS como controle central de todas as redes, e uma arquitetura para o desenvolvimento de aplicações móveis que incorporem voz, vídeo e dados. A arquitetura IMS apesar de promissora apresenta inúmeras oportunidades de melhoria no seu mecanismo de segurança, muitas dessas oportunidades de melhoria estão relacionadas a falhas e até mesmo a falta de especificações de segurança quando a arquitetura foi originalmente implementada. Assim o maior desafio na implantação e globalização da arquitetura IMS são as falhas de segurança e a vulnerabilidade que a arquitetura possui a diversos tipos de ataques que podem atingir e prejudicar, tanto operadoras quanto usuários da rede. O objetivo deste projeto de pesquisa é apresentar uma análise detalhada sobre a estrutura da arquitetura IMS focando principalmente na arquitetura de segurança desenvolvida pela 3GPP, e assim prover análises e soluções para os ataques, vulnerabilidades e falhas de segurança que atingem a arquitetura tanto do ponto de vista de operadoras e provedores de serviço quanto na perspectiva do usuário / Abstract: Considering that to control and enable the delivery of diverse content and services to any type of access it should make necessary a core well-defined and structuralized, appeared the IMS (IP Multimedia Subsystem) in order to provide the complete integration of networks and services. IMS defines a complete architecture and framework that enables the convergence of voice, video, data and mobile network technology over an infrastructure based on IP, in addition to filling the gap between the two communications paradigms most successful, cellular and IP technology. This paper presents the IMS architecture as central control of all networks, and architecture for developing mobile applications that incorporate voice, video and data. The IMS architecture despite being promising presents numerous opportunities for improvement in its security mechanism, many of these opportunities for improvement are related to failures and even the lack of security specifications when creating the architecture. So the biggest challenge in the implementation of the IMS architecture and globalization are the security issues and vulnerabilities that the architecture faces being vulnerable to several types of attacks that can reach and affect carriers and network users. The objective of this research project is to present a detailed analysis on the structure of the IMS architecture focusing primarily on security architecture developed by 3GPP, and thus provide analysis and solutions about the attacks, vulnerabilities and security issues that affect the architecture from the point of view of carriers, service providers and from the network users / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Rapid advances in machine learning have made information analysis more efficient than ever before. However, to extract valuable information from trillion bytes of data for learning and decision-making, general-purpose computing systems or cloud infrastructures are often deployed to train a large-scale neural network, resulting in a colossal amount of resources in use while themselves exposing other significant security issues. Among potential approaches, the neuromorphic architecture, which is not only amenable to low-cost implementation, but can also deployed with in-memory computing strategy, has been recognized as important methods to accelerate machine intelligence applications. In this dissertation, theoretical and practical properties of a hybrid neural computing architecture are introduced, which utilizes a dynamic reservoir having the short-term memory to enable the historical learning capability with the potential to classify non-separable functions. The hybrid neural computing architecture integrates both spatial and temporal processing structures, sidestepping the limitations introduced by the vanishing gradient. To be specific, this is made possible through four critical features: (i) a feature extractor built based upon the in-memory computing strategy, (ii) a high-dimensional mapping with the Mackey-Glass neural activation, (iii) a delay-dynamic system with historical learning capability, and (iv) a unique learning mechanism by only updating readout weights. To support the integration of neuromorphic architecture and deep learning strategies, the first generation of delay-feedback reservoir network has been successfully fabricated in 2017, better yet, the spatial-temporal hybrid neural network with an improved delay-feedback reservoir network has been successfully fabricated in 2020. To demonstrate the effectiveness and performance across diverse machine intelligence applications, the introduced network structures are evaluated through (i) time series prediction, (ii) image classification, (iii) speech recognition, (iv) modulation symbol detection, (v) radio fingerprint identification, and (vi) clinical disease identification. / Doctor of Philosophy / Deep learning strategies are the cutting-edge of artificial intelligence, in which the artificial neural networks are trained to extract key features or finding similarities from raw sensory information. This is made possible through multiple processing layers with a colossal amount of neurons, in a similar way to humans. Deep learning strategies run on von Neumann computers are deployed worldwide. However, in today's data-driven society, the use of general-purpose computing systems and cloud infrastructures can no longer offer a timely response while themselves exposing other significant security issues. Arose with the introduction of neuromorphic architecture, application-specific integrated circuit chips have paved the way for machine intelligence applications in recently years. The major contributions in this dissertation include designing and fabricating a new class of hybrid neural computing architecture and implementing various deep learning strategies to diverse machine intelligence applications. The resulting hybrid neural computing architecture offers an alternative solution to accelerate the neural computations required for sophisticated machine intelligence applications with a simple system-level design, and therefore, opening the door to low-power system-on-chip design for future intelligence computing, what is more, providing prominent design solutions and performance improvements for internet of things applications.

Submitted by Maria Aparecida (cidazen@gmail.com) on 2017-08-31T13:25:42Z No. of bitstreams: 1 Claudio Manoel.pdf: 2235875 bytes, checksum: 09f2ae854210974f87252bad3c5b1df9 (MD5) / Made available in DSpace on 2017-08-31T13:27:28Z (GMT). No. of bitstreams: 1 Claudio Manoel.pdf: 2235875 bytes, checksum: 09f2ae854210974f87252bad3c5b1df9 (MD5) Previous issue date: 2015-05-27 / The use and popularity of mobile devices has been growing vertiginously, as well an the cloud computing as instrument to store data and services, making feasible the combination of these two technologies. One of the biggest obstacles is the mobile device’s security and ergonomics to provide security for transporting its data without performance degradation. This work proposes a context-aware security mechanism for mobile devices in cloud computing. In addition, it is used the TLS technology to create a secure channel of data sent between mobile device’s client and the cloud server, authenticating them via public key cryptography. At the same time, it provides an appropriate level of security, and analyses the context of the mobile device from the Fuzzy logic. The impact of the mechanism on the mobile device’s performance were measured through experiments. / O uso e a popularidade dos dispositivos móveis vem crescendo vertiginosamente, bem como a computação em nuvem como instrumento para armazenar dados e serviços, tornando-se viável a união dessas duas tecnologias. Um dos maiores obstáculos é a questão da segurança e ergonomia do dispositivo móvel que necessita provê-lo ao trafegar dados sem haver degradação de seu desempenho. Este trabalho propõe então um mecanismo de segurança ciente do contexto para Computação em Nuvem Móvel. Em adição, utiliza-se a tecnologia Transport Layer Security (TLS) para criar um canal seguro de envio de dados entre o cliente do dispositivo móvel e o servidor da Nuvem, autenticando-o por meio de criptografia de chave pública. Paralelamente, para prover um nível de segurança apropriado, analisase o contexto do dispositivo móvel a partir da lógica Fuzzy. O impacto do mecanismo no desempenho do dispositivo móvel foi medido por meio de experimentos.

Orientadores: Varese Salvador Timóteo, Francisco José Arnold / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-24T09:10:01Z (GMT). No. of bitstreams: 1 CesarioJunior_JoseMaria_M.pdf: 2596300 bytes, checksum: 6b11eb547957a0632bbc647946da04ce (MD5) Previous issue date: 2014 / Resumo: A crescente evolução mundial dos sistemas de medição inteligentes, a liberação de regulamentações Brasileiras, incentivando a adoção de sistemas de medição de energia elétrica inteligentes, direcionaram a presente dissertação a propor um sistema composto de um equipamento eletrônico para medição, em tempo real, das grandezas de corrente, tensão e calcular a energia consumida e terá canais de comunicação com as tecnologias Wi-Fi, GSM/GPRS e GPS. As informações sobre consumo serão disponibilizadas para os usuários finais com o objetivo de mudar o padrão de consumo de energia elétrica, ou até reduzi-lo, através da conscientização e disponibilização das informações de consumo em tempo real / Abstract: The growing worldwide trend of smart metering systems, the release of Brazilian regulations, encouraging the adoption of smart electricity metering systems, guided this dissertation to propose a system composed of an electronic device for measuring, in real time, the magnitudes of current, voltage and calculate the consumed power and will have communication channels based on Wi-Fi, GSM /GPRS and GPS technologies. The consumption information will be made available to end users with the goal of changing the electricity consumption pattern, or even reduce it, through awareness and provision of consumer information in real time / Mestrado / Tecnologia e Inovação / Mestre em Tecnologia

In the pursuit for ever-increasing compute power, and with Moore's law slowly coming to an end, high-performance computing started to scale-out to larger systems. Alongside the increasing system size, the interconnection network is growing to accommodate and connect tens of thousands of compute nodes. These networks have a large influence on total cost, application performance, energy consumption, and overall system efficiency of the supercomputer. Unfortunately, state-of-the-art routing algorithms, which define the packet paths through the network, do not utilize this important resource efficiently. Topology-aware routing algorithms become increasingly inapplicable, due to irregular topologies, which either are irregular by design, or most often a result of hardware failures. Exchanging faulty network components potentially requires whole system downtime further increasing the cost of the failure. This management approach becomes more and more impractical due to the scale of today's networks and the accompanying steady decrease of the mean time between failures. Alternative methods of operating and maintaining these high-performance interconnects, both in terms of hardware- and software-management, are necessary to mitigate negative effects experienced by scientific applications executed on the supercomputer. However, existing topology-agnostic routing algorithms either suffer from poor load balancing or are not bounded in the number of virtual channels needed to resolve deadlocks in the routing tables. Using the fail-in-place strategy, a well-established method for storage systems to repair only critical component failures, is a feasible solution for current and future HPC interconnects as well as other large-scale installations such as data center networks. Although, an appropriate combination of topology and routing algorithm is required to minimize the throughput degradation for the entire system. This thesis contributes a network simulation toolchain to facilitate the process of finding a suitable combination, either during system design or while it is in operation. On top of this foundation, a key contribution is a novel scheduling-aware routing, which reduces fault-induced throughput degradation while improving overall network utilization. The scheduling-aware routing performs frequent property preserving routing updates to optimize the path balancing for simultaneously running batch jobs. The increased deployment of lossless interconnection networks, in conjunction with fail-in-place modes of operation and topology-agnostic, scheduling-aware routing algorithms, necessitates new solutions to solve the routing-deadlock problem. Therefore, this thesis further advances the state-of-the-art by introducing a novel concept of routing on the channel dependency graph, which allows the design of an universally applicable destination-based routing capable of optimizing the path balancing without exceeding a given number of virtual channels, which are a common hardware limitation. This disruptive innovation enables implicit deadlock-avoidance during path calculation, instead of solving both problems separately as all previous solutions.

本論文研究在於一行動計算網路上建構一個具有服務品質保障之以代理人為基礎的服務系統以提供用戶及行動代理人的行動能力管理。此研究主要的貢獻可分為以下三方面： (1) 提出行動能力管理機制，使行動用戶能以單一用戶ID漫遊於不同的網路上 (2) 提出行動代理人行動能力管理機制，幫助系統搜尋一已派遣出之代理人以加強對代理人的管理 (3) 提出一個「以代理人 (Agent) 為基礎之有服務品質 (QoS) 保障的管理架構」以支援行動代理人及行動用戶之行動能力的管理，並確保服務品質 在本論文中，我們將探討如下的研究課題： (1) 對行動用戶之行動能力的管理 (A) 多個廣域網路管理中心架構 (B) 用戶行動能力與網路通訊時間之分析 (C) 訂定欲註冊之GNMC、LNMC選擇策略 (D) 行動用戶移動時的註冊及註銷策略 (E) 對行動用戶之位置的定位及追蹤 (F) 使用暫存器記錄以提昇用戶位置追蹤的效率 (2) 對行動代理人之管理 (A) 對行動代理人之多種搜尋策略 (B) 於每次搜尋時，移除最多之代理人不可能停留之主機的個數 (C) 預測代理人位於某一特定主機的機率 (D) 動態轉換搜尋策略的機制 (E) 計算搜尋某一代理人所需拜訪之主機的期望個數 (F) 搜尋時配合代理人監聽的機制 (3) 設計及建構一「有服務品質保障之以代理人為基礎的服務系統」 (A) 系統架構 (B) 定義代理人服務系統中每一元件之功用及實作細節 (C) 代理人管理機制 (D) 服務品質表示方法 (E) 有服務品質保障之服務 / In this research, we study the issues of building a QoS agent-based service system in managing client mobility and agent mobility for mobile computing network. Our major contribution is classified into the following three categories: (1) Propose sets of client mobility management strategies to support clients roaming on different networks (2) Propose mobile agent search strategies to manage mobile agent mobility (3) Propose a QoS agent-based management architecture to manage clients and agents mobilities; and provide service to clients with QoS guarantee. The details are elaborated as follows: (1) Mobile client mobility management (A) Multiple GNMCs Architecture (B) Modeling client mobility behavior and network communication time (C) Criteria of choosing GNMC and LNMC for registration (D) Registration and de-registration strategies of mobile clients (E) Location tracking of mobile clients (F) Location tracking with cache policy (2) Mobile agent mobility management (A) Search strategies for mobile agents (B) Maximizing number of excluded servers in each probe (C) Estimating the residing probability that an agent resides in a server (D) Dynamic switching agent search policy (E) Evaluating the expected probing number when searches an agent (F) Agent search with listening agent (3) Design and implement a QoS agent-based service system (A) An proposed agent system architecture (B) Functionalities and implementation details of the system components (C) Agent manager design details (D) User QoS assignment and mapping to system QoS (E) Service with QoS guarantee