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Riscos corporativos em uma rede de cooperação: o caso das empresas associadas à Rede Arrozeiras do Sul; Corporate risks in a network for co-operation: the case of companies associated to the Brazilian southern rice processing network

Reske Filho, Antônio
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 26/05/2014 PT
Relevância na Pesquisa
36.21%
Esta tese trata das Redes de Cooperação e seus riscos corporativos. As Redes de Cooperação ficam definidas como associações de empresas atuantes em um mesmo setor da economia, explorando mercados de fatores e mercados de produção. A Rede Arrozeiras do Sul, com sede em Santa Maria/RS, organizada em 2005, é a primeira rede de indústrias orizícolas do Brasil. Surgiu com onze empresas associadas, para fortalecer suas cooperadas, abrangendo inicialmente toda a região central do Estado do Rio Grande do Sul. Atualmente, conta com dezesseis indústrias de beneficiamento de arroz e tem como missão criar diferenciais competitivos às cooperadas no que diz respeito à compra, industrialização e comercialização de arroz. As associadas à Rede Arrozeiras do Sul recorrem praticamente aos mesmos fornecedores de matérias-prima e insumos, e/ou concorrem pela preferência dos mesmos clientes em potencial. Quando bem gerenciado, esse tipo de empreendimento, que alguns veem como uma associação que se destina a unir esforços e interesses comuns a todos os cooperados, reduz os riscos decorrentes de se operar em mercados competitivos no curto e médio prazo. Paradoxalmente, no longo prazo, podem surgir riscos de um ou mais participantes colocarem seus interesses particulares acima e em oposição aos objetivos da Rede. Em outras palavras...

Ação política em política pública: uma experiência em rede no Programa Telecentros.BR; Politic action in a public policy: a network experience in the Telecentros.BR Program

Valentim, Gustavo Giolo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 08/04/2015 PT
Relevância na Pesquisa
36.21%
O objetivo desta pesquisa foi desvelar o modo de articulação de rede constituído na Rede de Formaçãopara Inclusão Digital do programa Telecentros.BR e compreender sua relevância paraos processos de articulação de rede entre pessoas e instituições. Atuei neste programa como um dos profissionais responsáveis pela articulação desta rede e opercurso metodológico norteou-se pela resgate e construção de nexos entre osregistros e as memórias das experiênciasque tive neste trabalho.Por meio da costura de um relato, entremeiam-seaspectos da história, dos elementos e dos movimentos da Rede de Formaçãocommeus princípios e valores, evidenciandoaspectos do fenômeno ao mesmo tempo em queoprisma segundo o qual erainterrogado. Diversos diálogos em espaços públicos de pesquisa contribuíram para o consequente processo reflexivo descortinador dos fios de sentido desta experiência e que revelaram aqui três modos de ser rede da Rede de Formação:política pública, pro-ducção para corresponsabilização,e rede para formar-ação.No primeiro deles, política pública, a rede é influenciada prioritariamente pelo modo de governo burocrático da qual ela emerge e para o qual se destina. Já no segundo, o aumento da convivência tanto presencialquanto em encontros mediados pelas tecnologias da informação e comunicação trouxe as necessidades dos atores para a cena e redefiniuosobjetivos e processosda rede. Já no terceiro e último modo aqui desvelado...

Network programming as a service : an innovation friendly business model; Programabilidade de redes como serviço : um modelo de negócios propício à inovação

Jesus, Wanderson Paim de
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
ENG
Relevância na Pesquisa
36.22%
Computer networks have evolved to accommodate a wide variety of services, such as streaming of high quality videos and delay-sensitive content delivery. These services have increased the demand for features not originally considered in the Internet. Aiming to address novel network demands quickly, some researchers proposed Programmable Networks, in which network devices behavior can be changed using applications. Notwithstanding, such behavior might not be a consensus between computer network stakeholders. The emergence of Virtualized Networks overcame this issue by allowing the coexistence of multiple virtual networks on the same physical infrastructure. Finally, the convergence of programmability and virtualization techniques are explored within a third concept, the Programmable Virtual Networks (PVN). Faced with this new reality, network administrators are no longer just looking at network devices. They are looking at a system made of virtual devices and applications that define each virtual network behavior. This requires not just new tools and management approaches, over and above that, requires new thinking. PVN deployments are found mostly in shared experimental facilities (also known as testbeds) and Cloud Computing environments. Testbeds are very innovation friendly...

Network virtualisation from an operator perspective

Melo, Márcio Daniel Tavares de
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
36.23%
Network virtualisation is seen as a promising approach to overcome the so-called “Internet impasse” and bring innovation back into the Internet, by allowing easier migration towards novel networking approaches as well as the coexistence of complementary network architectures on a shared infrastructure in a commercial context. Recently, the interest from the operators and mainstream industry in network virtualisation has grown quite significantly, as the potential benefits of virtualisation became clearer, both from an economical and an operational point of view. In the beginning, the concept has been mainly a research topic and has been materialized in small-scale testbeds and research network environments. This PhD Thesis aims to provide the network operator with a set of mechanisms and algorithms capable of managing and controlling virtual networks. To this end, we propose a framework that aims to allocate, monitor and control virtual resources in a centralized and efficient manner. In order to analyse the performance of the framework, we performed the implementation and evaluation on a small-scale testbed. To enable the operator to make an efficient allocation, in real-time, and on-demand, of virtual networks onto the substrate network...

Network Sampling and Classification: An Investigation of Network Model Representations

Airoldi, Edoardo Maria; Bai, Xue; Carley, Kathleen
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.21%
Methods for generating a random sample of networks with desired properties are important tools for the analysis of social, biological, and information networks. Algorithm-based approaches to sampling networks have received a great deal of attention in recent literature. Most of these algorithms are based on simple intuitions that associate the full features of connectivity patterns with specific values of only one or two network metrics. Substantive conclusions are crucially dependent on this association holding true. However, the extent to which this simple intuition holds true is not yet known. In this paper, we examine the association between the connectivity patterns that a network sampling algorithm aims to generate and the connectivity patterns of the generated networks, measured by an existing set of popular network metrics. We find that different network sampling algorithms can yield networks with similar connectivity patterns. We also find that the alternative algorithms for the same connectivity pattern can yield networks with different connectivity patterns. We argue that conclusions based on simulated network studies must focus on the full features of the connectivity patterns of a network instead of on the limited set of network metrics for a specific network type. This fact has important implications for network data analysis: for instance...

Agent Organization in the Knowledge Plane

Li, Ji
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Formato: 191 p.
Relevância na Pesquisa
36.2%
In designing and building a network like the Internet, we continue to face the problems of scale and distribution. With the dramatic expansion in scale and heterogeneity of the Internet, network management has become an increasingly difficult task. Furthermore, network applications often need to maintain efficient organization among the participants by collecting information from the underlying networks. Such individual information collection activities lead to duplicate efforts and contention for network resources.The Knowledge Plane (KP) is a new common construct that provides knowledge and expertise to meet the functional, policy and scaling requirements of network management, as well as to create synergy and exploit commonality among many network applications. To achieve these goals, we face many challenging problems, including widely distributed data collection, efficient processing of that data, wide availability of the expertise, etc.In this thesis, to provide better support for network management and large-scale network applications, I propose a knowledge plane architecture that consists of a network knowledge plane (NetKP) at the network layer, and on top of it, multiple specialized KPs (spec-KPs). The NetKP organizes agents to provide valuable knowledge and facilities about the Internet to the spec-KPs. Each spec-KP is specialized in its own area of interest. In both the NetKP and the spec-KPs...

Identificação não linear usando uma rede fuzzy wavelet neural network modificada

Araújo Júnior, José Medeiros de
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia Elétrica; Automação e Sistemas; Engenharia de Computação; Telecomunicações Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia Elétrica; Automação e Sistemas; Engenharia de Computação; Telecomunicações
Tipo: Tese de Doutorado Formato: application/pdf
POR
Relevância na Pesquisa
36.23%
In last decades, neural networks have been established as a major tool for the identification of nonlinear systems. Among the various types of networks used in identification, one that can be highlighted is the wavelet neural network (WNN). This network combines the characteristics of wavelet multiresolution theory with learning ability and generalization of neural networks usually, providing more accurate models than those ones obtained by traditional networks. An extension of WNN networks is to combine the neuro-fuzzy ANFIS (Adaptive Network Based Fuzzy Inference System) structure with wavelets, leading to generate the Fuzzy Wavelet Neural Network - FWNN structure. This network is very similar to ANFIS networks, with the difference that traditional polynomials present in consequent of this network are replaced by WNN networks. This paper proposes the identification of nonlinear dynamical systems from a network FWNN modified. In the proposed structure, functions only wavelets are used in the consequent. Thus, it is possible to obtain a simplification of the structure, reducing the number of adjustable parameters of the network. To evaluate the performance of network FWNN with this modification, an analysis of network performance is made...

Solution Methods for Service Network Design with Resource Management Consideration

Vu, Duc Minh
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
EN
Relevância na Pesquisa
36.22%
La gestion des ressources, équipements, équipes de travail, et autres, devrait être prise en compte lors de la conception de tout plan réalisable pour le problème de conception de réseaux de services. Cependant, les travaux de recherche portant sur la gestion des ressources et la conception de réseaux de services restent limités. La présente thèse a pour objectif de combler cette lacune en faisant l’examen de problèmes de conception de réseaux de services prenant en compte la gestion des ressources. Pour ce faire, cette thèse se décline en trois études portant sur la conception de réseaux. La première étude considère le problème de capacitated multi-commodity fixed cost network design with design-balance constraints(DBCMND). La structure multi-produits avec capacité sur les arcs du DBCMND, de même que ses contraintes design-balance, font qu’il apparaît comme sous-problème dans de nombreux problèmes reliés à la conception de réseaux de services, d’où l’intérêt d’étudier le DBCMND dans le contexte de cette thèse. Nous proposons une nouvelle approche pour résoudre ce problème combinant la recherche tabou, la recomposition de chemin, et une procédure d’intensification de la recherche dans une région particulière de l’espace de solutions. Dans un premier temps la recherche tabou identifie de bonnes solutions réalisables. Ensuite la recomposition de chemin est utilisée pour augmenter le nombre de solutions réalisables. Les solutions trouvées par ces deux méta-heuristiques permettent d’identifier un sous-ensemble d’arcs qui ont de bonnes chances d’avoir un statut ouvert ou fermé dans une solution optimale. Le statut de ces arcs est alors fixé selon la valeur qui prédomine dans les solutions trouvées préalablement. Enfin...

Network Similarity Measures and Automatic Construction of Graph Models using Genetic Programming

Harrison, Kyle Robert
Fonte: Brock University Publicador: Brock University
Tipo: Electronic Thesis or Dissertation
ENG
Relevância na Pesquisa
36.2%
A complex network is an abstract representation of an intricate system of interrelated elements where the patterns of connection hold significant meaning. One particular complex network is a social network whereby the vertices represent people and edges denote their daily interactions. Understanding social network dynamics can be vital to the mitigation of disease spread as these networks model the interactions, and thus avenues of spread, between individuals. To better understand complex networks, algorithms which generate graphs exhibiting observed properties of real-world networks, known as graph models, are often constructed. While various efforts to aid with the construction of graph models have been proposed using statistical and probabilistic methods, genetic programming (GP) has only recently been considered. However, determining that a graph model of a complex network accurately describes the target network(s) is not a trivial task as the graph models are often stochastic in nature and the notion of similarity is dependent upon the expected behavior of the network. This thesis examines a number of well-known network properties to determine which measures best allowed networks generated by different graph models, and thus the models themselves...

Network Construction and Graph Theoretical Analysis of Functional Language Networks in Pediatric Epilepsy

Salah Eddin, Anas
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
Relevância na Pesquisa
36.21%
This dissertation introduces a new approach for assessing the effects of pediatric epilepsy on the language connectome. Two novel data-driven network construction approaches are presented. These methods rely on connecting different brain regions using either extent or intensity of language related activations as identified by independent component analysis of fMRI data. An auditory description decision task (ADDT) paradigm was used to activate the language network for 29 patients and 30 controls recruited from three major pediatric hospitals. Empirical evaluations illustrated that pediatric epilepsy can cause, or is associated with, a network efficiency reduction. Patients showed a propensity to inefficiently employ the whole brain network to perform the ADDT language task; on the contrary, controls seemed to efficiently use smaller segregated network components to achieve the same task. To explain the causes of the decreased efficiency, graph theoretical analysis was carried out. The analysis revealed no substantial global network feature differences between the patient and control groups. It also showed that for both subject groups the language network exhibited small-world characteristics; however, the patient’s extent of activation network showed a tendency towards more random networks. It was also shown that the intensity of activation network displayed ipsilateral hub reorganization on the local level. The left hemispheric hubs displayed greater centrality values for patients...

The European Competition Network: Structure, Management and Initial Experiences of Policy Enforcement

CENGIZ, Firat
Fonte: European University Institute Publicador: European University Institute
Tipo: Trabalho em Andamento Formato: application/pdf; digital
EN
Relevância na Pesquisa
36.21%
The European Competition Network came into life in 2004 as an atypical network with a relatively hierarchical and highly regulated structure. As a result, predictions regarding the future functioning of this network were largely sceptical at the time of its inception. Now the network is about to complete its fifth year in operation and the European Commission is due to present a report to the European Parliament and the Council regarding experiences of policy enforcement by this network. Therefore, it is particularly timely to have a retrospective look at the European Competition Network and assess its achievements and failures. This paper reviews the structure and management methods of the European Competition Network in the light of the policy network literature and comments on initial experiences with its operation. The paper argues that in general the sceptical predictions regarding the operation of the network have not been realised. The network has been successful particularly in terms of accelerating communication between the competition authorities of Europe and increasing their contribution to the design of European competition policy. However, the paper also reveals certain weaknesses of the operation of this network. Particularly the inefficiencies of investigations by the national competition authorities...

Improving Networking Server Performance with Programmable Network Interfaces

Kim, Hyong-youb; Kim, Hyong-youb
Fonte: Universidade Rice Publicador: Universidade Rice
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
36.21%
Masters Thesis; Networking servers, such as web servers, have been widely deployed in recent years. While developments in the operating system and applications continue to improve server performance, programmable network interfaces with local memory provide new opportunities to improve server performance through extended network services on the network interface. However, due to their embedded nature, programmable processors on the network interface may suffer from inadequate processing power when compared to non-programmable application-specific network interfaces. This thesis first shows that exploiting a multiprocessor architecture and task-level concurrency in network interface processing enables programmable network interfaces to overcome the performance disadvantages over application-specific network interfaces that result from programmability. Then, the thesis presents a network service on a programmable network interface that exploits the storage capacity of the interfaces to alleviate the local I/O interconnect bottleneck, thereby improving server performance. Thus, these two results show that programmable network interfaces can offset the performance disadvantages due to programmability and improve networking server performance through extended network services that exploit their computation power and storage capacity.

Algoritmo para determinar la posibilidad de aplicar técnicas de codificación de red interflujo sobre redes malladas inalámbricas; Algorithm to assess the feasibility of inter-flow network coding techniques over wireless mesh networks

Garrido Ortiz, Pablo
Fonte: Universidade de Cantabria Publicador: Universidade de Cantabria
Tipo: Dissertação de Mestrado
SPA
Relevância na Pesquisa
36.22%
RESUMEN: Este trabajo pretende estudiar la aplicabilidad de las técnicas de Network Coding sobre escenarios con un carácter aleatorio. Esta técnica, propuestas por Ahlswede, pretende mejorar el rendimiento mediante la combinación de paquetes pertenecientes a diferentes flujos de información. En concreto, se plantea su uso sobre redes malladas inalámbricas. La demanda de capacidad de los dispositivos inalámbricos ha sufrido un vertiginoso crecimiento en los últimos años y se espera que esta dinámica se mantenga, debido principalmente debe al aumento de dispositivos de comunicaciones inalámbricas y las capacidades que se ofrecen a los usuarios (videos, juegos, redes sociales...). Se marcan dos grandes retos para satisfacer las exigencias del mercado: ampliar la cobertura y mejorar el rendimiento, entendiendo que este último factor es una de las grandes debilidades de las comunicaciones inalámbricas. En el intento de mejorar ambos aspectos surgen las técnicas de Network Coding sobre redes malladas. Por un lado, las redes malladas pretenden aumentar el área de cobertura de despliegues más tradicionales y, por otro, las técnicas de Network Coding buscan mejorar el rendimiento que se alcanza en la comunicación bajo los estándares actuales de IEEE 802.11 (a nivel de enlace) y TCP/IP (a nivel de transporte y red). Para evaluar la aplicabilidad de estas técnicas se despliegan escenarios aleatorios y se desarrolla un algoritmo que permite evaluar si existe la opción de utilizar Network Coding. A pesar de que los escenarios aleatorios generados tienen ciertas características que favorecen el uso de Network Coding...

Pandemic Influenza Virus Surveillance in Portugal: The Laboratory Network for the Diagnosis of Influenza A(H1N1)2009 Infection

Guiomar, Raquel; Pechirra, Pedro; Gonçalves, Paulo; Cordeiro, Rita; Conde, Patrícia; Arraiolos, Ana; Batista, Inês; Paixão, Eleonora; Nunes, Baltazar; Furtado (on behalf of the Laboratory Network for the Diagnosis of Influenza A(H1N1)2009 Infection),
Fonte: Instituto Nacional de Saúde Doutor Ricardo Jorge, IP Publicador: Instituto Nacional de Saúde Doutor Ricardo Jorge, IP
Tipo: Conferência ou Objeto de Conferência
Publicado em /11/2010 ENG
Relevância na Pesquisa
46.09%
In April 2009 a new influenza A(H1N1) virus of swine origin disseminated throughout the world, resulting in the first pandemic of the XXI century. To face the increasing number of diagnosis being requested, a National Laboratory Network for Influenza Surveillance of the new influenza A(H1N1)pandemic virus was activated in Portugal. This is a descriptive study of the Influenza-like Ilness (ILI) cases reported by this network. Association between the variables was evaluated by chi-squared test. Over 62089 ILI cases were notified, 25594 (41.2%) cases were laboratory confirmed A(H1N1)pdm virus, from week 17/2009 to week 15/2010. In the week 33 (summer) were detected 1039 (4.1%) positive cases for A(H1N1)pdm virus although the winter peak occurred in week 46 with 3131 (12.5%) A(H1N1)pdm positive cases. In the age group of 5-14 years old were detected the majority of positive cases 9983 / 15785 (63.0%) opposite in the elderly group (>65 years old) was detected the lower number of A(H1N1)pdm positive cases, 280/2361 (11.0%). The distribution by gender accounts 40.4% of female and 42.3% of male positive cases. The signs and/or symptoms present were analysed revealing that headache (49.7%), cough and myalgies (46.5%) and odinophagia (46.1%) were statistically associated with A(H1N1)pdm positive cases. The chronic pulmonary disease seemed to be more associated with laboratory confirmed A(H1N1)pdm cases. Ninety five strains were isolated and antigenically characterised...

Contribution of the Portuguese Laboratory Network for the Diagnosis of Influenza A(H1N1)pdm09 Infection during the 2009/2010 and 2010/2011 influenza seasons

Portuguese Laboratory Network for the Diagnosis of Influenza Infection
Fonte: European Centre For Disease Prevention and Control Publicador: European Centre For Disease Prevention and Control
Tipo: Artigo de Revista Científica
Publicado em /07/2012 ENG
Relevância na Pesquisa
46.09%
Members of the Portuguese Laboratory Network for the Diagnosis of Influenza Infection: Raquel Guiomar; Pedro Pechirra; Paulo Gonçalves; Ana Arraiolos; Patrícia Conde; Baltazar Nunes; Eleonora Paixão; Inês Batista; Cristina Furtado; Jorge Machado; Maria José Silvestre; Madalena Almeida Santos, Joana Sobrinho Simões; Maria do Rosário Costa; João Tiago Guimarães; Graça Ribeiro; João Vaz; Álvaro Beleza; Roger Oliveira; Aida Fernandes; Luís Milho; João Rego; Paula Luísa Fernandes; Graça Andrade; Luísa Mota Vieira; Rita Cabral Veloso; Jácome Bruges Armas; Ana Rita Pimentel Couto; Rute Marcelino; Teresa Porta Nova; José Melo Cristino; Dinah Carvalho; Carlos Ribeiro; Rosário Barreto; Virgínia Penim; Rita Corte Real; Paula Branquinho; Lurdes Gonçalves; Maria Helena Ramos; Ana Paula Castro; Filomena Caldeira; Manuel Maurílio.; This article describes the data obtained by the Portuguese Laboratory Network, reactivated following the World Health Organization declaration of the 2009 influenza pandemic, on the diagnoses of influenza A(H1N1)pdm09 infection during the pandemic (2009/10) and post-pandemic (2010/11) influenza seasons. The laboratories analysed and reported cases of influenza-like illness (ILI) and severe acute respiratory infection (SARI) to the National Influenza Reference Laboratory...

Mapping, awareness, and virtualization network administrator training tool (MAVNATT) architecture and framework

McBride, Daniel C.
Fonte: Monterey, California: Naval Postgraduate School Publicador: Monterey, California: Naval Postgraduate School
Tipo: Tese de Doutorado
Relevância na Pesquisa
36.2%
Approved for public release; distribution is unlimited; Tactical networks are becoming more critical in maintaining centers of gravity for military operations as cyberspace becomes contested at all levels of war. As a result, the growth of network centric operations and increased operational tempo in the cyber domain has created a significant training gap for tactical network administrators. This research suggests that a computer-based environment can integrate the operational network and a training network into the same system to allow tactical network administrators to concurrently administer the network and conduct realistic training on an identical virtual network. A review of commercial and open-source tools identifies the baseline for an architecture and framework for this system. The architecture consists of a modular design comprised of mapping, awareness, and virtualization modules. The framework integrates these modules by defining a network topology format, programming language, graphical user interface solution, and virtualization solution. This research concludes by providing an implementation that demonstrates desired capabilities. While we demonstrate that the project goals are attainable, there is a need for further research and development to deploy this capability to fleet units.; ; Major...

Maestro: Achieving scalability and coordination in centralizaed network control plane

Cai, Zheng
Fonte: Universidade Rice Publicador: Universidade Rice
Tipo: Thesis; Text Formato: 125 p.; application/pdf
ENG
Relevância na Pesquisa
36.21%
Modem network control plane that supports versatile communication services (e.g. performance differentiation, access control, virtualization, etc.) is highly complex. Different control components such as routing protocols, security policy enforcers, resource allocation planners, quality of service modules, and more, are interacting with each other in the control plane to realize complicated control objectives. These different control components need to coordinate their actions, and sometimes they could even have conflicting goals which require careful handling. Furthermore, a lot of these existing components are distributed protocols running on large number of network devices. Because protocol state is distributed in the network, it is very difficult to tightly coordinate the actions of these distributed control components, thus inconsistent control actions could create serious problems in the network. As a result, such complexity makes it really difficult to ensure the optimality and consistency among all different components. Trying to address the complexity problem in the network control plane, researchers have proposed different approaches, and among these the centralized control plane architecture has become widely accepted as a key to solve the problem. By centralizing the control functionality into a single management station...

Confiabilidade de rede GPS de referência cadastral municipal - estudo de caso : rede do município de Vitória (ES); Reliability of network GPS of municipal cadastral reference - study of case : network of the municipal district of Vitória (ES)

Amorim, Geraldo Passos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 25/03/2004 PT
Relevância na Pesquisa
36.22%
A proposta deste trabalho é estudar as teorias de análise de qualidade de rede GPS, baseando-se nas teorias de confiabilidade de rede propostas por Baarda, em 1968. As hipóteses estatísticas para detecção de "outliers" constituem a base desse estudo, pois são fundamentais para elaboração dos testes de detecção de "outliers", localização e eliminação de erros grosseiros e, também, para a análise da confiabilidade da rede. A confiabilidade, que traduz a controlabilidade da rede e depende do número de redundância, é estudada em dois aspectos: confiabilidade interna e confiabilidade externa. A rede de referência cadastral do município de Vitória – ES, escolhida para o estudo de caso foi estabelecida por GPS, em 2001, tendo como concepção básica a implantação de 37 pares de vértices intervisíveis, privilegiando locais públicos e de livre acesso. Essa rede foi ajustada em 2001 pela Prefeitura Municipal de Vitória, e as coordenadas ajustadas dos vértices são usadas, deste então, para apoiar todos os levantamentos topográficos e cadastrais realizados no município. O ajustamento dessa rede, em 2001, constituiu-se de um ajustamento simples em que os testes estatísticos de detecção de "outliers", a localização e eliminação dos erros grosseiros não foram levados em conta. A parte prática desta pesquisa compreendeu a medição de 21 novos vetores (linhas bases) para formar uma rede de controle...

Systematic network coding for lossy line networks

Saxena, Paresh
Fonte: [Barcelona] : Universitat Autònoma de Barcelona, Publicador: [Barcelona] : Universitat Autònoma de Barcelona,
Tipo: Tesis i dissertacions electròniques; info:eu-repo/semantics/doctoralThesis; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2015 ENG
Relevância na Pesquisa
36.26%
Esta tesis doctoral se centra en esquemas de codificación de red sistemáticos (SNC por sus siglas en inglés para systematic network coding) a nivel de paquete para proporcionar resistencia a la pérdida de paquetes en redes lineales con pérdidas. En la teoría, la codificación de red ( network coding ) es conocida por la mejora en rendimiento y fiabilidad en redes con pérdidas. Sin embargo, la traducción de la teoría del network coding en soluciones prácticas comprende algunos desafíos críticos. Esta tesis aborda estos desafíos e investiga soluciones de network coding que puedan ser usadas en la práctica para diferentes instancias de redes lineales con pérdidas. Los objetivos principales de esta tesis doctoral son: 1) desarrollar un modelo matricial que permita el tratamiento analítico de network coding para redes con pérdidas, 2) investigar de manera semi-analítica el rendimiento alcanzable y la fiabilidad para redes lineales, un simple pero útil modelo de red conceptual, 3) desarrollar esquemas prácticos de network coding para redes lineales que superen significativamente el rendimiento del estado del arte en esquemas basados puramente en la correción de borrado hacia adelante (FEC por sus siglas en ingles para forward erasure correction)...

Enterprise network convergence: path to cost optimization

Sridharan, Vidhumana
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
36.21%
During the past two decades, telecommunications has evolved a great deal. In the eighties, people were using television, radio and telephone as their communication systems. Eventually, the introduction of the Internet and the WWW immensely transformed the telecommunications industry. This internet revolution brought about a huge change in the way businesses communicated and operated. Enterprise networks now had an increasing demand for more bandwidth as they started to embrace newer technologies. The requirements of the enterprise networks grew as the applications and services that were used in the network expanded. This stipulation for fast and high performance communication systems has now led to the emergence of converged network solutions. Enterprises across the globe are investigating new ways to implement voice, video, and data over a single network for various reasons – to optimize network costs, to restructure their communication system, to extend next generation networking abilities, or to bridge the gap between their corporate network and the existing technological progress. To date, organizations had multiple network services to support a range of communication needs. Investing in this type of multiple communication infrastructures limits the networks ability to provide resourceful bandwidth optimization services throughout the system. Thus...