Keiko Verônica Ono Fonseca

Distributed Diagnosis of Dynamic Events in Partitionable Arbitrary Topology Networks

This work introduces the Distributed Network Reachability (DNR) algorithm, a distributed system-level diagnosis algorithm that allows every node of a partitionable arbitrary topology network to determine which portions of the network are reachable and unreachable. DNR is the first distributed diagnosis algorithm that works in the presence of network partitions and healings caused by dynamic fault and repair events. Both crash and timing faults are assumed, and a faulty node is indistinguishable of a network partition. Every link is alternately tested by one of its adjacent nodes at subsequent testing intervals. Upon the detection of a new event, the new diagnostic information is disseminated to reachable nodes. New events can occur before the dissemination completes. Any time a new event is detected or informed, a working node may compute the network reachability using local diagnostic information. The bounded correctness of DNR is proved, including the bounded diagnostic latency, bounded startup and accuracy. Simulation results are presented for several random and regular topologies, showing the performance of the algorithm under highly dynamic fault situations.

HyperBone: A Scalable Overlay Network Based on a Virtual Hypercube

This paper presents HyperBone, an overlay network based on a virtual hypercube that offers services such as monitoring and routing, allowing the execution of distributed applications across the Internet hypercubes are scalable by definition, presenting several properties such as symmetry and logarithmic diameter, that are advantageous for distributed and parallel applications. HyperBone nodes run the distributed virtual hypercube algorithm (DiVHA) in order to maintain the topology. DiVHA keeps the hypercube properties even when the number of nodes is not a power of two, or under a dynamic fault situation, in which nodes fail and recover continuously, leaving and joining the system. HyperBone was implemented and experimental results are presented, obtained from the execution of a set of MPI parallel applications on a virtual hypercube spread across the world built with PlanetLab nodes.

Ensaios de Transmissão e Recepção de TV Digital Terrestre na Região Metropolitana de Curitiba

Este artigo apresenta uma ferramenta desimulacao do modulador ISDB-TB, que permite realizaranalises complexas em cada estagio de processamento. Apartir de um arquivo Broadcast Transport Stream (BTS) epossivel acompanhar o processamento realizado em cadabloco do modulador ate o estagio final de transmissao.Utilizando um gerador de sinal vetorial e possivel realizartransmissoes reais com os arquivos de RF gerados nosimulador. Uma abordagem matematica e pratica sobre ofuncionamento de cada bloco que constitui o modulador erealizada iniciando pela descricao do sinal BTS ate oestagio final de transmissao.This article will explain some of the general ideas and specific techniques for usingambience in live broadcast audio that the author has developed over the past 30 years in thetelevision industry. The paper is concerned with stereo sound fields. The use of ambiencein a surround matrix is similar in approach, though it of course involves the perspective offront/back in addition to left/right.Este artigo apresenta medidas praticas da area de cobertura de uma emissora de televisao digital experimental da empresa Linear Equipamentos Eletronicos, operando em rede de frequencia unica (Single Frequency Network - SFN) na cidade de Santa Rita do Sapucai, Minas Gerais. O trabalho aborda aspectos teoricos de multiplos sinais resguardados por um prefixo ciclico, a utilizacao de distribuicao de conteudo por satelite, o emprego de enlaces terrestres na faixa de microondas para distribuicao de BTS e as particularidades em se empregar moduladores de diferentes fabricantes.Os receptores de TV Digital terrestre possuem umsoftware de sistema operacional que eventualmente necessita seratualizado pelo fabricante. Alem dos metodos tradicionais viaporta USB, internet, ou atraves das redes de servicos autorizados,surge a possibilidade desta atualizacao ser realizada pelo aratraves do proprio sinal digital que esta sendo recebido, sem anecessidade de intervencao do usuario. O sistema japones de TVDigital, onde o sistema brasileiro esta baseado tambem para aatualizacao de receptores via ar, possui uma entidadecentralizadora que e responsavel por controlar o conteudo detodos os fabricantes e envia-los aos receptores. No Brasil, por naoexistir tal entidade, criou-se um modelo de transmissao onde epossivel que cada emissora seja capaz de gerenciar seu proprioconteudo de download e envia-lo de acordo com o especificadopor cada fabricante. Este trabalho apresenta o estudo realizado,juntamente com o grupo de pesquisas da norma ABNT NBR15603 e os fabricantes de receptores, com a finalidade de definir aestrutura necessaria para cada radiodifusor, de forma a permitirque o envio de dados seja feito de maneira descentralizada e semque haja perdas para o usuario final.Este trabalho pretende continuar a discussao, em nivel teorico, desenvolvida no Congresso Set 2007, sobre o planejamento da grade de programacao em Televisao Digital Interativa. No atual cenario, os emissores tem o desafio de adequar as multiplas possibilidades de producao e distribuicao de conteudo da mais alta tecnologia, para um publico de cultura heterogenea e de contrastes sociais marcantes. Com a digitalizacao, a midia se transforma para alem da experiencia de assistir a uma programacao sequencial e se torna pervasiva, favorecendo, inclusive, o uso de recursos interativos em ambientes moveis e portateis. A televisao, enfim, adquire o status tecnologico que possibilita sua definitiva integracao ao ciberespaco, levando consigo, pela usabilidade, pelo entretenimento e pelo sentido de comunhao, a parcela da populacao que o computador, sozinho, nao alcanca. Contudo, a questao mais relevante, no processo de convergencia, esta na constituicao de uma grade que mantenha seu foco nas experiencias genuinamente televisivas. Aquelas que estimulam a interacao social, do publico entre si e com o assunto em pauta. O HDTV aumenta o prazer compartilhado de assistir televisao em casa. Os dispositivos moveis sao digitais e seus usuarios, interativos. Nesse cenario, tem muito a ganhar a programacao que souber conciliar a liberdade individual de escolhas com a satisfacao da experiencia comum, que primeiro estabelecer seus paradigmas “televisivos” de interacao com o publico.Com o advento do Sistema Brasileiro de TV Digital (SBTVD), e tendo em conta osseus recursos de universalizacao previstos no cronograma de implantacao, umagrande variedade de tecnologias de displays (incluindo receptores de altaresolucao, displays de celulares, etc.) ira requerer ensaios de resposta e defidedignidade colorimetrica para a adequada insercao no mercado brasileiro.Neste contexto, e importante destacar que a qualidade da resposta cromatica, naotica do telespectador, depende nao somente da adequacao dos parâmetros doSistema transmissor, mas tambem do desempenho dos displays (modernosdisplays planos ou Flat Panel Displays -FPD), dos efeitos de distorcoes em corproduzidas por nao linearidades nos set-top box e outros dispositivos detratamento de sinal de video.De uma maneira geral, a questao da fidelidade da resposta cromatica de displaysextrapola questoes ou elementos de apreciacao puramente subjetiva (qualidadeda resposta de um receptor de TV), assumindo cada vez mais relevância nomundo moderno a associacao das coordenadas de cor do elemento cromatico dodisplay a um dado mensurando: na area da saude, as cores apresentadas nosdisplays estao relacionadas a diagnosticos; no campo da ciencia, o espectrocromatico esta associado, cada vez de forma mais ampla, a novos mensurandos(altitude, temperatura, pressao, vazao, tipo de vegetacao, caracteristicasgeologicas, etc.).O objetivo deste trabalho e apresentar os testes a serem adotadas pelo CPqD eDIOPT/Inmetro no sentido de efetuar a caracterizacao de FPDs, em conformidadecom normas e recomendacoes internacionais e cadeias de rastreabilidadeenvolvidas.Este artigo apresenta um estudo de obras audiovisuais que utilizam a interatividade em sua narrativa, os chamados videos interativos, presentes na web e em DVD. Desenvolve uma discussao sobre as diferencas entre interacao e interatividade em videos interativos. Estabelece uma classificacao em modalidades das formas interativas em audiovisualEste trabalho pretende apresentar uma metodologia para mensuracao das degradacoes sofridas pelo sinal de video quando e transportado por redes IP....

Remote RF and Baseband Video Measurement Laboratory Based Upon Open-Code Software

An application based on open-code source resources is developed to allow remote operation of test instruments over the web. The application was deployed using LINUX, JAVA, and CamServ and shows potential use as a didactic tool, as well as in laboratories dealing with different types of test instruments. The tool is an alternative to commercial applications used with the same purposes. Specification and development issues are described, as well as testing and validation schemes.

Analyzing the acoustic urban environment: A geofencing-centered approach in the Curitiba Metropolitan Region, Brazil

The industrial development and Brazilian economic context led to important structural changes, among others, the increase of population migration (rural to urban spaces), number of private vehicles (due to tax reduction and state subsidies for new cars and fuel), among others. Such changes impact not only the urban mobility at big cities but also the urban life quality, which is directly affected by pollutant emissions and noise. In order to limit emission impacts on sensitive population (children, elderly people, for example), city managers can enforce bounds on emissions and noise pollution generated by the city traffic in specific regions defined by geographical boundaries. This paper aims to contribute to the challenge of managing urban noise by exploring and analyzing the data with a geofencing approach. In particular, we present a exploratory data analysis toward a case study in Curitiba (1,800,000 inhabitants, a southern Brazilian city) aiming at analyzing possible sources of noise based on a particular data set of noise measurements, geographical information data, traffic, transportation and city licensing data.

Combining K-means method and complex network analysis to evaluate city mobility

Complex networks have been used to model public transportation systems (PTS) considering the relationship between bus lines and bus stops. Previous works focused on statistically characterize either the whole network or their individual bus stops and lines. The present work focused on statistically characterize different regions of a city (Curitiba, Brazil) assuming that a passenger could easily access different unconnected bus stops in a geographic area. K-means algorithm was used to partition the bus stops in (K =) 2 to 40 clusters with similar geographic area. Results showed strong inverse relationship (p < 2 × 10−16 and R2 = 0.74 for K = 40 in a log model) between the degree and the average path length of clustered bus stops. Regarding Curitiba, it revealed well and badly served regions (downtown area, and few suburbs in Southern and Western Curitiba, respectively). Some of these well served regions showed quantitative indication of potential bus congestion. By varying K, city planners could obtained zoomed view of the behavior of their PTS in terms of complex networks metrics.

VHDL implementation of a No-Reference video quality metric using the Levenberg-Marquardt method

Video quality evaluation is an important subject in video broadcasting. No-Reference (NR) metrics are especially interesting, given that it does not demand the original video for the quality assessment, thus it is adequate for industrial applications. This work describes the implementation of a NR technique in an FPGA platform that can be potentially employed in real time video quality assessment in broadcast systems.

A scalable monitoring strategy for highly dynamic systems

This paper presents an autonomic monitoring strategy for highly-dynamic systems based on DiVHA - the distributed virtual hypercube algorithm. Hypercubes are scalable by definition, presenting several advantageous properties such as symmetry and logarithmic diameter. A system based on DiVHA keeps the hypercube properties even when the number of nodes is not a power of two, or under a dynamic fault situation, in which nodes fail and recover continuously, leaving and joining the system. In particular, the paper describes a strategy for dealing with unstable nodes, which also allows the discovery of nodes that present a more predictable behaviour. The system was implemented in PlanetLab, a highly-dynamic large scale environment that spans the globe, and and experimental results are presented.

Open Code Application for Web-Based Remote Measurements

An application based on open source resources was developed to allow remote operation of test instruments over the web. The application was deployed using Linux, Java and CamServ and shows a potential use as a didactic tool and also in laboratories dealing with different types of test instruments. The tool is an alternative to commercial applications used with the same purposes. Specification and development issues are described, as well testing and validation schemes.

Securing Smart Metering applications in Untrusted Clouds with the SecureCloud Platform

Data security in smart metering applications is important not only to secure the customer privacy but also to protect the power utility against fraud attempts. Usual deployment of metering applications rely on the power utility infrastructure, assuming its Advanced Metering Infrastructure (AMI) as trustworthy. This paper describes the design and deployment of a smart metering system focusing on the security of the AMI (smart meters, data aggregator on the field, Metering Data Collection system and metering database) considering the data processing on untrusted clouds. We discuss one use case of the SecureCloud project, an ongoing project that investigates how security and privacy requirements of smart grid applications can be met with a secure cloud platform based on Intel SGX enclaves. The paper describes the components of the advanced metering system as well as the security approach adopted to meet its requirements. A smart metering application has been prototyped in the SecureCloud platform and the integration challenges are discussed from the perspectives of security, privacy and scalability.