Thesis (M.A. Sc.)--Dept. of Electrical and Computer Engineering, Concordia University, 1995. / "March 1995." Includes bibliographical references (leaves 150-151). Available also on the Internet.

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A influência das práticas e recursos provenientes do ensino presencial, bem como as especulações filosóficas sobre as transformações sociais e cognitivas promovidas pela expansão das redes digitais e tecnologias de telecomunicação, constituem os principais entraves a criação de uma perspectiva teórica mais adequada para o uso educativo dos ambientes disponíveis nas redes digitais. Investigar os usos espontâneos destas tecnologias no cotidiano é a forma mais eficiente de descobrir características e elementos capazes de contribuir para a construção de uma perspectiva teórica compatível com os propósitos educacionais. Este estudo analisa as interações comunicativas entre os participantes dos grupos de discussão da Internet para tentar estabelecer os mecanismos sobre os quais se dá a construção do conhecimento nas redes digitais e, a partir destas indicações, busca oferecer suporte teórico para a criação de uma perspectiva pragmática em Informática Educativa. O aporte conceitual utilizado como ponto de partida origina-se das formulações teóricas de Winograd e Flores, Habermas, Himanen e Vigotsky. / The influence of the practices and resources coming from the face-to-face teaching, and the philosophical speculations about the social and cognitive transformations promoted by the expansion of the digital networks and telecommunication technologies, are both impediments to create a more appropriate theoretical perspective about the educational use of the available environments in the nets. The investigation of the spontaneous uses of those in the daily life, is the most efficient form of discovering characteristics and elements capable of contributing for the construction of a compatible theoretical perspective with educational purposes. This study analyzes the communicative interactions among the participants of newsgroups, groups of discussion on the Internet, and try to elaborate a perspective about the construction of the knowledge in the digital nets and, starting from that, offer theoretical support for a pragmatic foundation for use of the information technology in Education. The conceptual contribution used as a starting point arises the theoretical formulations of Winograd & Flores, Habermas, Himanen and Vigotsky.

This dissertation describes the development of a new system whereby the Public Switch Telephone Network (PSTN), which is not secure, can perform like a private network. Integrated Services Digital Network (ISDN) forms a technical platform for other communication technologies, such as frame relay and Switched Megabit Data Service (SMDS). This is an original and innovative hardware and software design which can be embedded into the ISDN Customer Premises Equipment (CPE) to privatize the public ISDN without the need to upgrade the existing switching equipment. This research incorporates original design and development of the following hardware and software modules to provide real-time encryption and decryption of images and data in the ISDN medium: 1. ISDN Communications Module with customized Caller-ID access. 2. Token Access Control module for secure log-in. 3. A Hybrid Cryptographic Module, public key for key management and authentication, and private key for privacy. This Cryptographic module, the Security Extension Module to the Terminal Adapter (SEMTA), was implemented in software, and then optimized in hardware. This work proves that medical images and legal documents can be transmitted through the PSTN without any security breach, guaranteeing the privacy, confidentiality, and authenticity of the data.

A influência das práticas e recursos provenientes do ensino presencial, bem como as especulações filosóficas sobre as transformações sociais e cognitivas promovidas pela expansão das redes digitais e tecnologias de telecomunicação, constituem os principais entraves a criação de uma perspectiva teórica mais adequada para o uso educativo dos ambientes disponíveis nas redes digitais. Investigar os usos espontâneos destas tecnologias no cotidiano é a forma mais eficiente de descobrir características e elementos capazes de contribuir para a construção de uma perspectiva teórica compatível com os propósitos educacionais. Este estudo analisa as interações comunicativas entre os participantes dos grupos de discussão da Internet para tentar estabelecer os mecanismos sobre os quais se dá a construção do conhecimento nas redes digitais e, a partir destas indicações, busca oferecer suporte teórico para a criação de uma perspectiva pragmática em Informática Educativa. O aporte conceitual utilizado como ponto de partida origina-se das formulações teóricas de Winograd e Flores, Habermas, Himanen e Vigotsky. / The influence of the practices and resources coming from the face-to-face teaching, and the philosophical speculations about the social and cognitive transformations promoted by the expansion of the digital networks and telecommunication technologies, are both impediments to create a more appropriate theoretical perspective about the educational use of the available environments in the nets. The investigation of the spontaneous uses of those in the daily life, is the most efficient form of discovering characteristics and elements capable of contributing for the construction of a compatible theoretical perspective with educational purposes. This study analyzes the communicative interactions among the participants of newsgroups, groups of discussion on the Internet, and try to elaborate a perspective about the construction of the knowledge in the digital nets and, starting from that, offer theoretical support for a pragmatic foundation for use of the information technology in Education. The conceptual contribution used as a starting point arises the theoretical formulations of Winograd & Flores, Habermas, Himanen and Vigotsky.

In the design of the third generation of multi-media wireless networks, we are primarily concerned with the greatly varying information source rates, the quality requirements of various traffic types, the characteristics of the wireless environment, as well as the complexity and cost. Code Division Multiple Access (CDMA) cellular system is one of the most important candidates for supporting the future universal communications services. The objective of this research is to improve the capacity and the quality of service (QOS), as well as to reduce the complexity of cellular CDMA with integrated services, through improving or optimizing the design of system level operations. To facilitate the system performance and capacity evaluation, the multi-cell multi-user interference is analyzed through a new approach. The area averaged probability density function (PDF) of interference power from one active user is evaluated. The Gamma distribution is proposed for modelling the area averaged PDF of the interference power. An efficient method for evaluating system performance is developed. Differing from the Gaussian approximation, this method is very effective and accurate for both a large number and a small number of users. In this research, differing from the distance membership determination, the statistical effect of handoff is considered. The effects of soft handoff operation on multi-cell multi-user interference are analyzed. Membership statistics which are determined by soft handoff are investigated. A simple binomial model is proposed for modelling the distribution of the number of users belonging to a base station. Considering the call arrival statistics, user membership statistics and a finite number of channels available at a base station, we evaluate the call blocking/dropping rate. The minimum number of channels required at a base-station, which ensures a specified quality of service at a given capacity requirement, is determined. System capacity is further evaluated considering both outage probability limited by interference and call blocking/dropping rate limited by finite number of channels. A pilot assisted channel allocation method is proposed to minimize the number of channels required at a base station. Based on the analysis of a CDMA cellular system with a single traffic type, the design issues in developing a multi-media wireless networks are further discussed. The capacity of a CDMA cellular system with high quality requirements and mixed stream and packet types of traffic is assessed. The impact of the choice of a line rate (bit transmission rate through channel) on the system capacity is investigated. It is also shown that the power allocated to different types of traffic can be optimized to achieve maximum capacity. The optimum power allocation suggests that the power assignments to different traffic types are mainly determined by their quality requirements. / Graduate

O trabalho pretende apresentar a tese de que o netativismo pode ser lido a partir de três conceitos complementares: a Dádiva e a Reciprocidade, O Contra-Estado e o Comum. Sustentamos que é a articulação entre esses três elementos que permite uma chave de entendimento ampla à política nas redes digitais. Para desenvolver essa tese propomos um percurso histórico constitutivo da sociedade digital. Nesse processo, apresentamos uma metodologia que se ancora no princípio das afinidades ecológicas para debater o quadro histórico que nos trouxe até aqui. Feito isso o trabalho divide o netativismo em dois períodos distintos e, ao final, de posso desse conjunto apresentamos algumas expressões da política e do netativismo e suas repercussões no nosso cotidiano. / This work intends to support the thesis that netactivism can be read from three complementary concepts: \'Gift and Reciprocity\', \'Against-State\' and \'Commons\'. We allege that it is the articulation between these three elements that allows for a broad understanding of politics in digital networks.In order to develop this idea, we propose a historical background of digital society. The methodology used in doing so is anchored in the principle of ecological affinities, which is used to discuss the historical context that brought us to this moment. We then divide netactivism into two distinct eras and, in conclusion, we present some expressions of politics and netactivism and what their repercussions on our daily lives are.

Este trabalho busca compreender as amarras e as potencialidades em torno do uso das mídias digitais por ativistas autônomos anticapitalistas. O objetivo é partir da discussão sobre a potência democratizante que a Internet ativa e chegar à análise de coletivos autônomos que produzem e divulgam no espaço digital um discurso anticapitalista. Embora as novas mídias façam parte da indústria na qual a informação é mercadoria e meio de reprodução da lógica de produção vigente, a existência de grupos que usufruem das mídias digitais para criticar o atual modelo político, econômico e social contribui para o crescimento descentralizado da construção e difusão do pensamento antissistêmico. Portanto, interessa a esta pesquisa refletir sobre as origens desse ativismo e seu potencial de transformação social. A narração de episódios recentes da trajetória do movimento autônomo - o levante zapatista, a Ação Global dos Povos e as ocupações de 2011- vai ajudar na compreensão de elementos encontrados nos protestos de junho de 2013 e na formação de uma rede de coletivos em espaços físicos e virtuais. A coleta de dados de redes sociais e entrevistas com militantes basearão a descrição das ações comunicativas empreendidas por esses ativistas. / This paper seeks to understand the limits and potentialities surrounding the use of digital media by autonome anticapitalist activists. The purpose is to depart from the discussion about the democratizing potency that Internet activates and reach the analysis of autonome movements that produce and publish in the digital environment an anticapitalist speech. Although new media takes part of industry where information is merchandise and way of reproducing the logic of the current production, the existence of groups that take advantage of digital media to criticize the current political, economic and social model contributes to the decentralized growth of construction and dissemination of antisystemic thought. Therefore, this research is interested in reflect on the origins of this activism and its potential for social transformation. The narration of recent episodes of the trajectory of the autonomous movement - the Zapatista insurrection, the People\'s Global Action and occupations in 2011 - will help in the understanding of elements found in the protests of June 2013 and the formation of a network of collectives in physical and virtual spaces. The collection of data from social networks and interviews with militants will base the description of communicative actions undertaken by these activists.

M.Ing. / The Internet is evolving into a global communication infrastructure that is expected to support an overabundance of new applications such as IP telephony, interactive TV, and e-commerce. The existing best effort service is no longer sufficient. It is not enough to provide differentiated services and to meet QoS requirements of these different traffic types. As a result, there is an urgent need to provide more services that are powerful such as guaranteed services, flow protection etc, merged in one IP network, referred to as Integrated Services Packet-Switching Network (ISPN) in this thesis. To provide these services, QoS aware network architectures are required to implement the services. This dissertation presents a survey on two network architectures: Fair Queuing (FQ) and Scalable Core (SCORE), which attempt to provide QoS solutions in ISPN. We theoretically analyse scheduling as an important element in providing QoS in these architectures. The important thread in scheduling is performance and implementation complexity. SCORE based scheduling have less implementation complexity but cannot exactly match the high performance of FQ solutions, which suffer implementation complexity. The contribution of this work is a feedback protocol that minimises congestion in SCORE scheduling scheme called Core stateless fair queuing (CSFQ). The flow rates are adjusted by sending rate signal to a transmitting node from a receiving node, to adjust ill-behaved flow rate during congestion to a fair share rate of receiving node. We use CSFQ based theoretical analysis and simulations to demonstrate the performance of the feedback protocol.

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