Página 12 dos resultados de 3715 itens digitais encontrados em 0.067 segundos

Análise de arquiteturas e desenvolvimento de uma plataforma para residências inteligentes.; Architecture analysis and development of framework for intelligent houses.

Bolzani, Caio Augustus Morais
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 18/12/2009 Português
Relevância na Pesquisa
47.47798%
No início do século XX, poucas décadas depois do início da eletrificação das casas, o conceito de uma residência automatizada já era utilizado como símbolo de um futuro livre das tarefas domésticas. No entanto, mesmo com o desenvolvimento de tecnologias de suporte, a automação de residências nunca contemplou uma ampla disseminação e uso. Este trabalho realiza uma análise social, econômica, tecnológica, cultural e de saúde da sociedade, desde o início do século XX até os dias atuais, para entender o comportamento humano relativo ao ambiente residencial e identificar as possíveis causas que não favoreceram a implantação de sistemas de controle e automação nestes ambientes. Ele ainda propõe uma arquitetura de sistemas eletrônicos e computacionais para o ambiente residencial, baseada em um conjunto de requerimentos e de abstrações coerentes com o contexto socioeconômico vigente e factível diante das atuais disponibilidades tecnológicas, a fim de direcionar os esforços na área e fomentar o desenvolvimento de aplicações. Adicionalmente, é apresentada uma plataforma de desenvolvimento hardware, firmware e software , denominada Home Sapiens, cuja concepção, projeto e desenvolvimento foram feitos no contexto desta tese. Baseada em nós de controle distribuídos...

A shared-memory multiprocessor system using the raw tiled architecture

Jakab, Levente, 1981-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 208 p.; 9811968 bytes; 9841236 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
47.47324%
Recent trends in microprocessor design have moved away from dedicated hardware mechanisms to exposed architectures in which basic functionality is implemented in software. To demonstrate the flexibility of this scheme, I implement a shared memory system on Raw, a tiled multiprocessor. A traditional directory-based cache coherence system is used. The directories are fully resident on several tiles, and the remaining tiles act as users, with cache maintenance routines accessed via interrupt. Previous implementations of shared-memory systems have mostly relied on a combination of dedicated hardware and user-enabled software hooks, with one notable exception, Alewife, combining basic hardware with software support for corner cases. Here, the focus is moved to placing as much support for basic cases into software as possible. The system is designed to minimise custom hardware and user responsibilities. I prove the feasibility of such a design on an exposed architecture such as Raw.; by Levente Jakab.; Thesis (M. Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.; Includes bibliographical references (p. 203-208).

Lightweigth Adaptive fault-tolerant data storage system (AFTSYS)

Carretero Pérez, Jesús
Fonte: Universidade Carlos III de Madrid Publicador: Universidade Carlos III de Madrid
Tipo: Relatório Formato: application/pdf
Publicado em 24/11/2008 Português
Relevância na Pesquisa
47.46247%
Research group ARCOS of Universidad Carlos III de Madrid (Spain) have been working on flexible and adaptive data storage systems for several years. The storage systems developed are featured by software governance, making them portable across different hardware storage resources, and their dynamic adaptativy to the different circumstances of computer systems following the autonomic system paradigm. They also allow getting high performance storage by using data distribution or striping across multiple devices. One of the group’s technologies y the AFTSYS system. A fault-tolerant storage system for persistent distributed objects, user configurable and adaptive to system behaviour.

Reconstructing Palladio's villas : an analysis of Palladio's villa design and construction process

Sass, Lawrence
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 385 p.; 12905990 bytes; 12934527 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
47.461504%
The thesis is a presentation of a method of reconstruction using a computational device to represent and evaluate two of Palladio's un-built villas in three-dimensions. The first of The Four Books of Architecture contains text and images explaining Palladio's design and construction systems in the form of text and graphic rules. These design guidelines or rules were written for the masons and craftsmen of the 16th century, offering one and two-dimensional data on each of Palladio's villas, palaces and churches. The text only offers general treatment of the villas; it missing construction data and rules needed to execute a full reconstruction of an un-built building. Many have attempted to reconstruct Palladio's work in drawings, wooden models and computation. This thesis presents a new method of reconstruction through the definition of construction rules in addition to shape and proportional rules defined by previous scholars. This reconstruction of the Villa Trissino in Meledo and the Villa Mocenigo on the Brenta River in the form of physical models, cad drawings and computer renderings from fragmented information offered in the Four Books. The end product will serve as a method for reconstruction in the form of a three-dimensional analysis of Palladio's design and construction rules and a demonstration of the new rules...

User authentication and remote execution across administrative domains

Kaminsky, Michael, 1976-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 77 p.; 4200828 bytes; 4208861 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
47.484434%
(cont.) selectively delegates authority to processes running on remote machines that need to access other resources. The delegation mechanism lets users incrementally construct trust policies for remote machines. Measurements of the system demonstrate that the modularity of REX's architecture does not come at the cost of performance.; A challenge in today's Internet is providing easy collaboration across administrative boundaries. Using and sharing resources between individuals in different administrative domains should be just as easy and secure as sharing them within a single domain. This thesis presents a new authentication service and a new remote login and execution utility that address this challenge. The authentication service contributes a new design point in the space of user authentication systems. The system provides the flexibility to create cross-domain groups in the context of a global, network file system using a familiar, intuitive interface for sharing files that is similar to local access control mechanisms. The system trades off freshness for availability by pre-fetching and caching remote users and groups defined in other administrative domains, so the file server can make authorization decisions at file-access time using only local information. The system offers limited privacy for group lists and has all-or-nothing delegation to other administrative domains via nested groups. Experiments demonstrate that the authentication server scales to groups with tens of thousands of members. REX contributes a new architecture for remote execution that offers extensibility and security. To achieve extensibility...

Advanced data bus architecture using CDMA for highly reliable systems

Haque, Naoshin
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 70 p.
Português
Relevância na Pesquisa
47.47324%
Conventional fault-tolerant architectures require extensive cross-strapping of redundant modules. The purpose of this thesis is to prove the feasibility of the use of code division multiple access (CDMA) to permit shared data bus architecture for fault-tolerant applications. Four families of pseudorandom codes, the Barker, gold, maximal length, and GPS C/A codes, were evaluated for their performances with respect to minimum signal gain under different uncertainties, such as varying voltage and noise levels. For data buses with three devices, the GPS C/A code performed the best. A voting process consisting of two rounds of voting, based on an extension of a solution to the Byzantine general's problem, was used to demonstrate that CDMA could be used successfully to contain a single fault in a data bus with three devices. Finally, extensions of this thesis were considered, such as having a variable number of devices on the advanced data bus system.; by Naoshin Haque.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.; This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.; Includes bibliographical references (p. 69-70).

Distilling scenarios from patterns for software architecture evaluation

Zhu, Liming; Ali Babar, Muhammad
Fonte: IEEE Computer Society Publicador: IEEE Computer Society
Tipo: info:eu-repo/semantics/conferenceObject; all_ul_research; ul_published_reviewed
Português
Relevância na Pesquisa
47.46496%
peer-reviewed; Software architecture (SA) evaluation is a quality assurance technique that is increasingly attracting significant research and commercial interests. A number of SA evaluation methods have been developed. Most of these methods are scenario-based, which relies on the quality of the scenarios used for the evaluation. Most of the existing techniques for developing scenarios use stakeholders and requirements documents as main sources of collecting scenarios. Recently, architectures of large software systems are usually composed of patterns and styles. One of the purposes of using patterns is to develop systems with predictable quality attributes. Since patterns are documented in a format that requires the inclusion of problem, solution and quality consequences, we observed that scenarios are, though as informal text, pervasive in patterns description, which can be extracted and documented for the SA evaluation. Thus, we claim that the patterns can be another source of collecting quality attributes sensitive scenarios. This position paper presents arguments and examples to support our claim.

Supporting migration to services using software architecture reconstruction

O'Brien, Liam; Smith, Dennis; Lewis, Grace
Fonte: IEEE Computer Society Publicador: IEEE Computer Society
Tipo: info:eu-repo/semantics/conferenceObject; all_ul_research; ul_published_reviewed
Português
Relevância na Pesquisa
47.503516%
peer-reviewed; There are many good reasons why organizations should perform software architecture reconstructions. However, few organizations are willing to pay for the effort. Software architecture reconstruction must be viewed not as an effort on its own but as a contribution in a broader technical context, such as the streamlining of products into a product line or the modernization of systems that hit their architectural borders, that is require major restructuring. In this paper we propose the use of architecture reconstruction to support System Modernization through the identification and reuse of legacy components as services in a Service- Oriented Architecture (SOA). A case study showing how architecture reconstruction was used on a system to support an organization’s decision-making process is presented.

A File System Abstraction for Sense and Respond Systems

Tilak, Sameer; Pisupati, Bhanu; Chiu, Kenneth; Brown, Geoffrey; Abu-Ghazaleh, Nael
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 28/03/2005 Português
Relevância na Pesquisa
47.475713%
The heterogeneity and resource constraints of sense-and-respond systems pose significant challenges to system and application development. In this paper, we present a flexible, intuitive file system abstraction for organizing and managing sense-and-respond systems based on the Plan 9 design principles. A key feature of this abstraction is the ability to support multiple views of the system via filesystem namespaces. Constructed logical views present an application-specific representation of the network, thus enabling high-level programming of the network. Concurrently, structural views of the network enable resource-efficient planning and execution of tasks. We present and motivate the design using several examples, outline research challenges and our research plan to address them, and describe the current state of implementation.; Comment: 6 pages, 3 figures Workshop on End-to-End, Sense-and-Respond Systems, Applications, and Services In conjunction with MobiSys '05

A Survey of Home Energy Management Systems in Future Smart Grid Communications

Khan, I.; Javaid, N.; Ullah, M. N.; Mahmood, A.; Farooq, M. U.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 26/07/2013 Português
Relevância na Pesquisa
47.46834%
In this paper we present a systematic review of various home energy management (HEM) schemes. Employment of home energy management programs will make the electricity consumption smarter and more efficient. Advantages of HEM include, increased savings for consumers as well as utilities, reduced peak to average ratio (PAR) and peak demand. Where there are numerous applications of smart grid technologies, home energy management is probably the most important one to be addressed. Utilities across the globe have taken various steps for efficient consumption of electricity. New pricing schemes like, Real Time Pricing (RTP), Time of Use (ToU), Inclining Block Rates (IBR), Critical Peak Pricing (CPP) etc, have been proposed for smart grid. Distributed Energy Resources (DER) (local generation) and/or home appliances coordination along with different tariff schemes lead towards efficient consumption of electricity. This work also discusses a HEM systems general architecture and various challenges in implementation of this architecture in smart grid.; Comment: IEEE 8th International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA'13), Compiegne, France

'Virtual World', Defined from a Technological Perspective, and Applied to Video Games, Mixed Reality and the Metaverse

Nevelsteen, Kim J. L.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 26/11/2015 Português
Relevância na Pesquisa
47.48351%
There is no generally accepted definition for a virtual world, with many complimentary terms and acronyms having emerged implying a virtual world. Advances in systems architecture techniques such as, host migration between instances, mobile ad-hoc networking, and distributed computing, bring in to question whether those architectures can actually support a virtual world. Without a concrete definition, controversy ensues and it is problematic to design an architecture for a virtual world. Several researchers provided a definition but aspects of each definition are still problematic and simply can not be applied to contemporary technologies. The approach of this article is to sample technologies using grounded theory, and obtain a definition for a `virtual world' that is directly applicable to technology. The obtained definition is compared with related work and used to classify advanced technologies, such as: a pseudo-persistent video game, a MANet, Virtual and Mixed Reality, and the Metaverse. The results of this article include: a break down of which properties set apart the various technologies; a definition that is validated by comparing it with other definitions; an ontology showing the relation of the different complimentary terms and acronyms; and...

Performance Provisioning and Energy Efficiency in Cloud and Distributed Computing Systems

Rizvandi, Nikzad Babaii
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 11/05/2014 Português
Relevância na Pesquisa
47.46682%
In recent years, the issue of energy consumption in high performance computing (HPC) systems has attracted a great deal of attention. In response to this, many energy-aware algorithms have been developed in different layers of HPC systems, including the hardware layer, service layer and system layer. These algorithms are of two types: first, algorithms which directly try to improve the energy by tweaking frequency operation or scheduling algorithms; and second, algorithms which focus on improving the performance of the system, with the assumption that efficient running of a system may indirectly save more energy. In this thesis, we develop algorithms in both layers. First, we introduce three algorithms to directly improve the energy of scheduled tasks at the hardware level by using Dynamic Voltage Frequency Scaling (DVFS). Second, we propose two algorithms for modelling and resource provisioning of MapReduce applications (a well-known parametric distributed framework currently used by Google, Yahoo, Facebook and LinkedIn) based on its configuration parameters. Certainly, estimating the performance (e.g., execution time or CPU clock ticks) of a MapReduce application can be later used for smart scheduling of such applications in clouds or clusters. To evaluate the algorithms...

Cyber-Physical Control over Wireless Sensor and Actuator Networks with Packet Loss

Xia, Feng; Kong, Xiangjie; Xu, Zhenzhen
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 13/11/2010 Português
Relevância na Pesquisa
47.470205%
There is a growing interest in design and implementation of cyber-physical control systems over wireless sensor and actuator networks (WSANs). Thanks to the use of wireless communications and distributed architectures, these systems encompass many advantages as compared to traditional networked control systems using hard wirelines. While WSANs are enabling a new generation of control systems, they also introduce considerable challenges for quality-of-service (QoS) provisioning. In this chapter we examine some of the major QoS challenges raised by WSANs, including resource constraints, platform heterogeneity, dynamic network topology, and mixed traffic. These challenges make it difficult to fulfill the requirements of cyber-physical control in terms of reliability and real-time. The focus of this chapter is on addressing the problem of network reliability. Specifically, we analyze the behavior of wireless channels via simulations based on a realistic link-layer model. Packet loss rate (PLR) is taken as a major metric for the analysis. The results confirm the unreliability of wireless communications and the uncertainty of packet loss over WSANs. To tackle packet loss, we present a simple solution that can take advantage of existing prediction algorithms. Simulations are conducted to evaluate the performance of several classical prediction algorithms used for packet loss compensation. The results give some insights into how to deal with packet loss in cyber-physical control systems over unreliable WSANs.; Comment: in Book: Wireless Networking Based Control...

From Software Architecture Structure and Behavior Modeling to Implementations of Cyber-Physical Systems

Ringert, Jan Oliver; Rumpe, Bernhard; Wortmann, Andreas
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 25/08/2014 Português
Relevância na Pesquisa
47.472476%
Software development for Cyber-Physical Systems (CPS) is a sophisticated activity as these systems are inherently complex. The engineering of CPS requires composition and interaction of diverse distributed software modules. Describing both, a systems architecture and behavior in integrated models, yields many advantages to cope with this complexity: the models are platform independent, can be decomposed to be developed independently by experts of the respective fields, are highly reusable and may be subjected to formal analysis. In this paper, we introduce a code generation framework for the MontiArcAutomaton modeling language. CPS are modeled as Component & Connector architectures with embedded I/O! automata. During development, these models can be analyzed using formal methods, graphically edited, and deployed to various platforms. For this, we present four code generators based on the MontiCore code generation framework, that implement the transformation from MontiArcAutomaton models to Mona (formal analysis), EMF Ecore (graphical editing), and Java and Python (deployment. Based on these prototypes, we discuss their commonalities and differences as well as language and application specific challenges focusing on code generator development.; Comment: 16 pages...

A Comprehensive Perspective on the Pilot-Job Systems

Turilli, Matteo; Santcroos, Mark; Jha, Shantenu
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
47.476636%
Pilot-Job systems play an important role in supporting distributed scientific computing. They are used to consume more than 700 million CPU hours a year by the Open Science Grid communities, and by processing up to 1 million jobs a day for the ATLAS experiment on the Worldwide LHC Computing Grid. With the increasing importance of task-level parallelism in high-performance computing, Pilot-Job systems are also witnessing an adoption beyond traditional domains. Notwithstanding the growing impact on scientific research, there is no agreement upon a definition of Pilot-Job system and no clear understanding of the underlying abstraction and paradigm. Pilot-Job implementations have proliferated with no shared best practices or open interfaces and little interoperability. Ultimately, this is hindering the realization of the full impact of Pilot-Jobs by limiting their robustness, portability, and maintainability. This paper offers a comprehensive analysis Pilot-Job systems critically assessing their motivations, evolution, properties, and implementation. The three main contributions of this paper are: (i) an analysis of the motivations and evolution of Pilot-Job systems; (ii) an outline of the Pilot abstraction, its distinguishing logical components and functionalities...

Proceedings 10th International Workshop on the Foundations of Coordination Languages and Software Architectures

Mousavi, Mohammad Reza; Ravara, Antonio
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 28/07/2011 Português
Relevância na Pesquisa
47.46306%
Computation nowadays is becoming inherently concurrent, either because of characteristics of the hardware (with multicore processors becoming omnipresent) or due to the ubiquitous presence of distributed systems (incarnated in the Internet). Computational systems are therefore typically distributed, concurrent, mobile, and often involve composition of heterogeneous components. To specify and reason about such systems and go beyond the functional correctness proofs, e.g., by supporting reusability and improving maintainability, approaches such as coordination languages and software architecture are recognised as fundamental. The goal of the this workshop is to put together researchers and practitioners of the aforementioned fields, to share and identify common problems, and to devise general solutions in the context of coordination languages and software architectures.; Comment: EPTCS 58, 2011

A hybrid neuro--wavelet predictor for QoS control and stability

Napoli, Christian; Pappalardo, Giuseppe; Tramontana, Emiliano
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 12/06/2014 Português
Relevância na Pesquisa
47.48723%
For distributed systems to properly react to peaks of requests, their adaptation activities would benefit from the estimation of the amount of requests. This paper proposes a solution to produce a short-term forecast based on data characterising user behaviour of online services. We use \emph{wavelet analysis}, providing compression and denoising on the observed time series of the amount of past user requests; and a \emph{recurrent neural network} trained with observed data and designed so as to provide well-timed estimations of future requests. The said ensemble has the ability to predict the amount of future user requests with a root mean squared error below 0.06\%. Thanks to prediction, advance resource provision can be performed for the duration of a request peak and for just the right amount of resources, hence avoiding over-provisioning and associated costs. Moreover, reliable provision lets users enjoy a level of availability of services unaffected by load variations.

Computer networks new generation in the use of RES

Jaroslav, Kultan; Matej, Kultan
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 25/11/2014 Português
Relevância na Pesquisa
47.477344%
The paper is aimed at analyzing the potential of new information networks to solve the problems of energy management network with the use of renewable energy sources. One of the basic problems of renewable energy sources is their temporal and spatial variability. It is mainly about resources based on direct solar radiation and wind speed. New computer systems that use only classical connection-based solid structure of computer network connections but also on the basis of short-range connections allow accurate prediction of the active intensity changes observed energy. Using the system thus created can control precisely the basic energy equipment / generator and operable appliances / gradient to reduce the power needed resources or from work. This approach is one of the directions of further development of smart appliances and smart elements in the energy sector.; Comment: 6 pages, 7 figures

An Efficient Method for Optimizing RFID Reader Deployment and Energy Saving

Hsu, Ching-Hsien; Zhang, Daqiang; Yang, Chao-Tung; Chu, Hai-Cheng
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 14/05/2013 Português
Relevância na Pesquisa
47.456553%
The rapid proliferation of Radio Frequency IDentification (RFID) systems realizes integration of physical world with the cyber ones. One of the most promising is the Internet of Things (IoT), a vision in which the Internet extends into our daily activities through wireless networks of uniquely identifiable objects. Given that modern RFID systems are being deployed in large-scale for different applications, without optimizing reader's distribution, many of the readers will be redundant, resulting waste of energy. Additionally, eliminating redundant eaders can also decrease probability of reader collisions, as a result, enhancing system performance and efficiency. In this paper, an overlap aware (OA) technique is proposed for eliminating redundant readers. The OA is a distributed approach, which does not need to collect global information for centralizing control, aims to detect maximum amount of redundant readers could be safely removed or turned off with preserving original RFID network coverage. A significant improvement of the OA scheme is that the amount of "write-to-tag" operations could be largely reduced during the redundant reader identification phase. In order to accurately evaluate the performance of the proposed method, it was performed in a variety of scenarios. The experiment results show that the proposed method can provide reliable performance with detecting higher redundancy and has lower algorithm overheads as compared with several well known methods...

FutureGRID: A Program for long-term research into GRID systems architecture

Crowcroft, Jon; Hand, S M; Harris, T L; Herbert, A J; Parker, Michael A; Pratt, I A
Fonte: Universidade de Cambridge Publicador: Universidade de Cambridge
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
47.49681%
Proceedings of the 2003 UK e-Science All Hands Meeting, 31st August - 3rd September, Nottingham UK; This is a project to carry out research into long-term GRID architecture, in the University of Cambridge Computer Laboratory and the Cambridge eScience Center, with support from the Microsoft Research Laboratory, Cambridge. It is part of a larger vision for future systems architectures for public computing platforms, including both scientitic GRID and commodity level computing such as games, peer2peer computing and storage services and so forth, based on work in the laboratories in recent years into massively scaleable distributed systems for storage, computation, content distribution and collaboration[26].