As redes sociais virtuais são um meio de comunicação que se diferencia da mídia tradicional por uma razão fundamental: a distribuição entre os usuários da capacidade de comunicar. O usuário dessas redes não se limita à posição de espectador, pois ele pode ser também autor, produtor e promotor de textos ou outros materiais. Cai, portanto, o modelo top-down unidirecional, e ganha espaço uma comunicação bidirecional (entre usuários) e difusa, o que representa a transição de uma topologia de árvore para outra, oposta, de rizoma. O objetivo deste trabalho é compreender a comunicação nas redes sociais virtuais, o que será feito analisando-as externa e internamente. Visa-se a formar, dessa maneira, um construto sobre essas redes quanto à sua técnica e seus usuários, sua forma e suas identidades, o que delas irradia e nelas se desenvolve, e, assim, precisar as características fundamentais da comunicação nesses espaços. / Virtual social networks are a means of communication that differs from traditional media due to one fundamental reason: the power to communicate is distributed among their users. In these networks, the user is not merely the spectator, but also the author, the producer, and the promoter of texts or other materials. Therefore, these networks put aside the unidirectional top-down model, giving ground to the emergence of a bidirectional and diffuse communication, which represents a topological transition from tree to rhizome. This research looks for understanding the communication in virtual social networks by analyzing them internally and externally. It seeks building a construct on these networks\' technique and users, their shape and identities, what irradiates from them and what grows in them, thus allowing the understanding of the fundamental communication characteristics in these spaces.

O projeto consiste em uma pesquisa sobre a comunicação digital, especialmente sobre os blogs , como ferramenta de relacionamento direta entre a organização e seus públicos. Neste contexto, as relações públicas (dentro do contexto da comunicação organizacional) são fundamentais para identificar que públicos têm condições de se relacionar por meio da Web e qual é o melhor conteúdo, layout, ferramenta e funcionalidades que o meio digital deve apresentar para atingir com efetividade o target visado. Além disso, acredita-se que a comunicação simétrica de mão dupla ganha força com a comunicação digital, o que contribui para o fortalecimento dos relacionamentos criados pela comunicação organizacional e pelas relações públicas digitais. / This project consists of research about digital communication, especially weblogs, as a relationship tool between the companies and their publics. In this context, the public relations are fundamental to identify which publics have conditions to interact via web and what are the best content, layout, tool and functionality that digital vehicles should present to target the audiences effectively. Besides that, the simetric and bidirectional communication gets stronger with digital communications, which contributes to a better relationship created by digital public relations.

O presente trabalho é uma pesquisa tecnológica (P&D) de inovação tecnológica de produto para o mercado brasileiro, que visa desenvolver um transmissor de pressão inteligente de alta exatidão com protocolo HART e sensor piezoresistivo em parceria LSI-USP / MEMS Ltda. Fornecendo assim um protótipo de um produto competitivo no mercado brasileiro. Neste trabalho se apresenta uma arquitetura baseada nos transmissores 4-20 mA de alta exatidão da MEMS Ltda. Essa arquitetura mantém as características de desemprenho da medição analógica e adiciona os componentes necessários para suportar as funções do padrão HART com camada física Bell 202. Além da arquitetura, neste documento é apresentado: o desenvolvimento das interfaces entre o algoritmo de compensação e os algoritmos responsáveis da comunicação digital, as modificações no circuito de controle da corrente de laço para permitir a modulação do sinal de 1200 Hz e 2200 Hz usado pela comunicação digital, e o projeto de alimentação do transmissor, que foi projetado visando a eficiência para respeitar os limites de consumo de corrente. Os resultados obtidos com essa nova arquitetura, apresentam que são mantidas as características dos transmissores 4-20 mA usados como base, e que a medição digital tem um nível de erro 0,05 %FS (porcentagem de fundo de escala) menor do que a saída analógica do mesmo transmissor, valor considerável comparado com o 0,2 %FS que é o nível de erro total do sistema. Os protótipos usados para as medições foram caracterizados num processo que levou 35 dias de operação continua, validando assim o projeto elétrico e software desenvolvido. / This thesis consists of a technical research (P&D) on technological innovations of a highly accurate intelligent pressure transmitter using a HART protocol and piezoresistive sensors in collaboration with LSI-USP / MEMS Ltda. The outcome consists of a prototype of a competitive product in the Brazilian market. This project presents a product architecture based on highly accurate 4-20mA MEMS Ltda. transmitters. It maintains the features necessary for analogical measurements and adds components, which are compatible with the functions of HART with a Bell 202 physical layer. In addition to the architecture, this document presents the development of: interfaces between the compensation algorithm and digital communication algorithms, modifications of the current loop control circuit to allow signal modulation used by digital communications of 1200Hz and 2000Hz, a voltage source project, which envisioned efficiency and considered the limits of current consumption. Results of this architecture show that the 4-20mA transmitter´s characteristics, used as a starting point for the product, are maintained and that digital measurements present 0.05%FS (Full Scale) less error than analogical measurements taken by the same transmitter. This presents a significant error reduction when compared to the total error of the system, which is 0, 2 %FS. The prototypes used for measurements were tested during 35 continuous days, validating their electrical installation and software.

Esta Tese apresenta uma contribuição para avaliação da comunicação digital na operação de veículos aéreos não tripulados (VANT) no ambiente aeronáutico. A comunicação digital aeronáutica relaciona-se diretamente ao nível de segurança crítica desejado para o controle do fluxo de tráfego aéreo, por parte de autoridades e de órgãos normativos, os quais possuem como objetivo tornar a comunicação uniforme para todos os continentes. Diversas são as discussões acerca do nível de segurança crítica que a comunicação digital entre VANT e controle em terra possa exibir, sempre buscando redução da exposição a riscos inerentes à operação desse tipo de veículo. Nesse contexto, a proposta desta Tese é avaliar a segurança na comunicação digital, por meio do uso de injeção de falhas, para operações de veículos aéreos não tripulados. Este trabalho descreve a importância de analisar as interferências causadas por falhas na comunicação digital, relacionadas ao envio de mensagens entre o órgão de controle e a aeronave não tripulada. Também são definidos quais os tipos de falhas que causam um maior impacto na comunicação, bem como quais os parâmetros que devem ser utilizados para manipulação das variáveis de falhas na comunicação. Para atender a avaliação proposta, foi utilizado o ambiente simulado que reúne as características do ambiente aeronáutico, denominado PipE-SEC (Plataforma Integrada para Ensaios de Sistemas Embarcados Críticos), bem como o protocolo CPDLC (Controller-Pilot Data Link Communications) para troca de mensagens digitais. / This thesis presents a contribution to the evaluation of digital communication in the operation of unmanned aerial vehicles (UAV) in the aeronautical environment. Aeronautical digital communication relates directly to the critical safety level required for controlling the air traffic flow by authorities and regulatory agencies, which are aimed at making communication uniform for all continents. There are several discussions about the safety critical level that digital communication between UAVs and ground control can display, always seeking to reduce exposure to risks inherent in the operation of such vehicles. In this context, the proposal of this thesis is to evaluate the safety in digital communication, through the use of fault injection for operations of UAV. This work describes the importance of analyzing the interference caused by faults in digital communication related to sending messages between the control agency and the UAV. There are also defined what types of faults cause a greater impact on communication as well as which parameters should be used to simulate communication faults. To answer the proposed evaluation, we used the simulated environment that combines the features of the aeronautical environment, called PIpE-SEC (Integrated Platform for Test Critical Embedded Systems), as well as the protocol CPDLC (Controller-Pilot Data Link Communications) to exchange digital messages.

This qualitative study aims to examine how Tillväxt Motala AB are working strategically to market Motala, a middle-sized city in Sweden. The study is implemented through qualitative semi-structured interviews with employees at Tillväxt Motala AB. The theories on which this study is built are strategic communication, place branding and marketing communication, and a few concepts regarding propaganda. The results show an integration of marketing and communication work roles at the organisation of interest. A deficiency concerning internal communication at Tillväxt Motala AB, due to lack of time, was found. Furthermore, Tillväxt Motala AB has a unique contact with both local and external networks from which employees benefit in their work regarding the place branding. Consensus in the interpretation of place branding as a definition was found among the employees - to highlight a place's positive qualities through communication to meet the needs of the business sector, visitors and residents and to differentiate themselves.

Purpose and problem discussion: Nowadays, it is crucial to implement social responsibility to business operations to succeed as a business. Companies face increased demands from customers and stakeholders to show their actions regarding social responsibility. At the same time, digital development is shaping the communication industry, creating new communication platforms in the world. The purpose of this study is to explore digital communication agencies role in the production and implementation of digital products within digital channels to best understand digital social responsibility. The study aims to answer the research questions: What social responsibilities does a digital communication agency have in regard to the products and messages they produce for digital channels? and How do digital communication agencies become socially responsible when using digital channels? Method: An abductive analysis method was applied to semi-structured interviews with digital communication agencies in Jönköping, Sweden. The analysis of the empirical findings has resulted in deeper understanding of social responsibility in digital environments; a study area that has not been explored before. Four digital communication agencies represent the average digital social responsibility mindset and business culture in Jönköping, Sweden. This gave us the possibility to research social responsibility on digital channels. Results, discussion and conclusions: The results show that the digital communication agencies clients are entirely responsible for the digital material published on their own digital channels. Although, the agencies do need to make sure they produce the best possible material for their clients to avoid bad relationships with stakeholders and a bad reputation. The results also show that social responsibility is not first priority for any company; profitability always comes first. The key to digital social responsibility is to work with the right clients and thoroughly analyse the client’s business operations to bring out the best in each case and to be prepared for backlashes. The digital communication agencies could also benefit from a crisis plan, to minimise stress and optimize the problem solving if a crisis would occur. If doing this correctly,the agencies enable genuine and honest digital communication, which minimises the risk of being perceived unfairly on digital platforms. This is especially of importance on digital platforms, where the speed, great reach and two-way communication makes it even easier to receive negativity and face backlashes. A digital communication agency can become socially responsible by working with the right clients, as well as producing and publishing genuine and honest digital communication.

The boom in data communications that started in the 1960s is a long way from abating. The early and mid 1980s will see a new generation of digital data transmission services come into operation that could change the ways business is conducted. "Information management and exploitation will change the fabric of society", according to Nicolas Mokhoff, Associate Editor of IEEE Spectrum Magazine. Manipulated by microelectronic, computer, radio and other electronic disciplines, information has become a vital commodity at the trade exchange. But unlike the prices of most commodities today, the price for exchange of information is decreasing because of electronics. One of the principal contributors to this decrease has been the geosynchronous telecommunications satellite, due to rapid advances in space and communications technology and the resulting cost-effectiveness achieved in applying that technology. Advances in IC technology have made digital telephony an equal partner with analogue. The inherent advantages of digital reliability, low cost and smaller packaging are prompting Telecom to phase out present equipment and expand new services with a digital hierarchy, such as the Digital Data Service being introduced in late 1982. Services employing advanced satellite and microwave technology, and also the existing and upgraded telephone systems, will have at least two things in common: they will transmit and switch data digitally, including coded speech, and the data will be transmitted in bursts. The technology that may expand fastest is the second generation of commercial communications satellites. Pier Bargellini, a senior scientist at Comsat Laboratories, says that "without the use of satellites as reflectors for source and data channels, television signals could not be shared by remote areas, long-distance telephone services would be constricted and the data exchange for the business world would be hampered." Changes in the communications industry have been so dramatic (particularly with regard to satellites) that government bodies (including the Australian Federal Government) have been forced to reexamine long-standing communications practices. In October 1979 the Minister for Post and Telecommunications announced the Governments decision that it would be in the national interest to establish a communications satellite system for Australia. At that time, the Minister also announced that, a Satellite Project Office would be established within the Postal and Telecommunications Department to set in train the planning activities necessary for the introduction of the system. The SPO has been operational within the Department since late 1979, and 2. consultation of system service requirements in particular has involved liaison with a broad spectrum of interests including Commonwealth departments. Figure 1 of Appendix A testifies to the Australian Government's policy of supplying outback communities with improved communications services (including television) by using satellite facilities. Very little is known about the benefits and needs (in Australia) that a data communications satellite system might be able to fulfil, including those needs of the Department of Social Security. This is mainly due to the lack of specific details about the final configurations and costs of the separate satellite services, which wont be known until late 1981. This paper is , therefore, an initial but detailed examination of the hardware and software subsystems which constitute a domestic telecommunications satellite system. More specifically, the paper considers the on-board equipment of a communications satellite (the space segment - including satellite launch and orbit characteristics, and signal propagation delay and attenuation), and the earth stations (the ground segment - including signal modulation, multiple access and computer application considerations); all as dictated by Australian geographical, economic and communications traffic density characteristics. The paper then considers some of the possible methods Australian corporations and government departments may adopt to utilise satellite communications links, particularly for data communications. A second paper will re-examine the situation by applying the specific facilities and costs, when they are known (these will be announced by the Satellite Project Office after contracts for the space and ground segments have been let), to a large, low-traffic, interactive multipoint network such as that of the Department of Social Security.

The recent advance in Field Programmable Gate Array (FPGA) technology has been largely embraced by the communication industry, which views this technology as an effective and economical alternative to the design of Application Specific Integrated Circuits (ASICs). The primary reasons for switching to FPGAs are lower development and non-recurring engineering costs, the flexibility to design to a preliminary standard and adapt the design as the standard evolves, as well as the option of performing software updates in the field.<p> A sector with strong interest in FPGAs is the coaxial cable TV/Internet distribution industry. The creation of soft preliminary standards by the standards organization governing the industry has been the main catalyst for the massive adoption of FPGAs by small to medium size companies, which see this technology as an opportunity to compete in this open market.<p> Both the circuit speed and the economy of FPGA technology depend upon using algorithms that map efficiently into its fabric. Often it is prudent to sacrifice performance to improve either clock speed or economy when developing with FPGAs. The purpose of this research is to both revise and devise synchronization algorithms / structures for cable digital receivers that are to be implemented in FPGA. <p> The main communication scheme used by the coaxial cable distribution industry is digital Quadrature Amplitude Modulation (QAM). The problem of synchronizing to the QAM signal in the receiver is not a new topic and several synchronization-related circuits, which were devised with ASICs implementation in mind, can be found in the open literature. Of interest in this thesis is the non-data-aided digital timing synchronizer that was proposed by D'Andrea to recover timing with no knowledge of the transmitted data. Accurate timing estimation was achieved by reshaping the received signal with a prefilter prior to estimating the timing. <p> A problem with D'Andrea's synchronizer is that the prefilter for reshaping the signal is a relatively long Finite Impulse Response (FIR) filter, whose implementation requires a large number of multipliers. This may not have been an issue with ASICs in as much as the number of hardwired multipliers on a chip is not limited as it is in an FPGA chip. One contribution in this research is to propose an alternative to D'Andrea's synchronizer by replacing the long FIR filter with two single-pole Infinite Impulse Response (IIR) filters that are directly placed inside the timing recovery loop. This novel architecture, which drastically reduces the number of multipliers, is well suited for FPGA implementation.<p> Non-data-aided feedforward synchronizers, which use the same prefilter as D'Andrea's synchronizer, have been receiving significant attention in recent years. Detailed performance analysis for these synchronizers can be found in the open literature. These synchronizers have the advantage of using a feedfordward structure rather than a feedback structure, as it is the case in D'Andrea's synchronizer, to estimate the timing. While D'Andrea's synchronizer has an advantage in performance over a non-data-aided feedforward synchronizer, this has not been reported in the literature. In this thesis a second contribution consists of thoroughly analyzing the steady state timing jitter in D'Andrea synchronizer by deriving a closed-form expression for the noise power spectrum and a simple equation to estimate the timing jitter variance. <p> A third contribution is a novel low-complexity and fast acquisition coherent detector for the detection of Quadrature Phase Shift Keying (QPSK) (i.e., 4-QAM) symbols. This detector performs carrier phase synchronization much faster than a conventional coherent detector. The acquisition time is comparable to that of a differential detector. The fast acquisition comes at the expense of phase jitter, and the end result is a 1 dB performance loss over theoretical coherent detection. This detector can be used in place of the differential detector with no economic penalty. Doing so yields a performance advantage of about 2 dB over differential detection.

The purpose of this thesis is to demonstrate the effects of mismatch errors that occur in time-interleaved analog-to-digital converters (TI-ADC) and how these are compensated for by proprietary methods from Signal Processing Devices Sweden AB. This will be demonstrated by two different implementations, both based on the combined digitizer/generator SDR14. These demonstrations shall be done in a way that is easy to grasp for people with limited knowledge in signal processing. The first implementation is an analog video demo where an analog video signal is sampled by such an TI-ADC in the SDR14, and then converted back to analog and displayed with the help of a TV tuner. The mismatch compensation can be turned on and off and the difference on the resulting video image is clearly visible. The second implementation is a digital communication demo based on W-CDMA, implemented on the FPGA of the SDR14. Four parallel W-CDMA signals of 5 MHz are sent and received by the SDR14. QPSK, 16-QAM, and 64-QAM modulated signals were successfully sent and the mismatch effects were clearly visible in the constellation diagrams. Techniques used are, for example: root-raised cosine pulse shaping, RF modulation, carrier recovery, and timing recovery.

The recent advance in Field Programmable Gate Array (FPGA) technology has been largely embraced by the communication industry, which views this technology as an effective and economical alternative to the design of Application Specific Integrated Circuits (ASICs). The primary reasons for switching to FPGAs are lower development and non-recurring engineering costs, the flexibility to design to a preliminary standard and adapt the design as the standard evolves, as well as the option of performing software updates in the field.<p> A sector with strong interest in FPGAs is the coaxial cable TV/Internet distribution industry. The creation of soft preliminary standards by the standards organization governing the industry has been the main catalyst for the massive adoption of FPGAs by small to medium size companies, which see this technology as an opportunity to compete in this open market.<p> Both the circuit speed and the economy of FPGA technology depend upon using algorithms that map efficiently into its fabric. Often it is prudent to sacrifice performance to improve either clock speed or economy when developing with FPGAs. The purpose of this research is to both revise and devise synchronization algorithms / structures for cable digital receivers that are to be implemented in FPGA. <p> The main communication scheme used by the coaxial cable distribution industry is digital Quadrature Amplitude Modulation (QAM). The problem of synchronizing to the QAM signal in the receiver is not a new topic and several synchronization-related circuits, which were devised with ASICs implementation in mind, can be found in the open literature. Of interest in this thesis is the non-data-aided digital timing synchronizer that was proposed by D'Andrea to recover timing with no knowledge of the transmitted data. Accurate timing estimation was achieved by reshaping the received signal with a prefilter prior to estimating the timing. <p> A problem with D'Andrea's synchronizer is that the prefilter for reshaping the signal is a relatively long Finite Impulse Response (FIR) filter, whose implementation requires a large number of multipliers. This may not have been an issue with ASICs in as much as the number of hardwired multipliers on a chip is not limited as it is in an FPGA chip. One contribution in this research is to propose an alternative to D'Andrea's synchronizer by replacing the long FIR filter with two single-pole Infinite Impulse Response (IIR) filters that are directly placed inside the timing recovery loop. This novel architecture, which drastically reduces the number of multipliers, is well suited for FPGA implementation.<p> Non-data-aided feedforward synchronizers, which use the same prefilter as D'Andrea's synchronizer, have been receiving significant attention in recent years. Detailed performance analysis for these synchronizers can be found in the open literature. These synchronizers have the advantage of using a feedfordward structure rather than a feedback structure, as it is the case in D'Andrea's synchronizer, to estimate the timing. While D'Andrea's synchronizer has an advantage in performance over a non-data-aided feedforward synchronizer, this has not been reported in the literature. In this thesis a second contribution consists of thoroughly analyzing the steady state timing jitter in D'Andrea synchronizer by deriving a closed-form expression for the noise power spectrum and a simple equation to estimate the timing jitter variance. <p> A third contribution is a novel low-complexity and fast acquisition coherent detector for the detection of Quadrature Phase Shift Keying (QPSK) (i.e., 4-QAM) symbols. This detector performs carrier phase synchronization much faster than a conventional coherent detector. The acquisition time is comparable to that of a differential detector. The fast acquisition comes at the expense of phase jitter, and the end result is a 1 dB performance loss over theoretical coherent detection. This detector can be used in place of the differential detector with no economic penalty. Doing so yields a performance advantage of about 2 dB over differential detection.