Investigations into the effect of LOS signal blocking on capacity of an indoor MIMO system

In indoor environments the properties of communication channel are affected by the presence of various objects which block the Line Of Sight signal propagation. For example, this occurs because of presence of movement of humans and furniture. In this paper, the effect of reflection and scattering due to the presence of such objects is studied with respect to the capacity of a multiple input multiple output (MIMO) wireless system. The carried out investigations are performed by applying a simple electromagnetic model, in which transmitting and receiving antennas of MIMO system, as well as signal blocking objects, are represented by wire dipoles. In order to provide a fair assessment, calculations of MIMO capacity are performed under both fixed transmitted power and fixed received power conditions.

RSA-Grid: A grid computing based framework for power system reliability and security analysis

Grid computing is an emerging technology for providing the high performance computing capability and collaboration mechanism for solving the collaborated and complex problems while using the existing resources. In this paper, a grid computing based framework is proposed for the probabilistic based power system reliability and security analysis. The suggested name of this computing grid is Reliability and Security Grid (RSA-Grid). Then the architecture of this grid is presented. A prototype system has been built for further development of grid-based services for power systems reliability and security assessment based on probabilistic techniques, which require high performance computing and large amount of memory. Preliminary results based on prototype of this grid show that RSA-Grid can provide the comprehensive assessment results for real power systems efficiently and economically.

Low-cost real-time gesture recognition

A major impediment to developing real-time computer vision systems has been the computational power and level of skill required to process video streams in real-time. This has meant that many researchers have either analysed video streams off-line or used expensive dedicated hardware acceleration techniques. Recent software and hardware developments have greatly eased the development burden of realtime image analysis leading to the development of portable systems using cheap PC hardware and software exploiting the Multimedia Extension (MMX) instruction set of the Intel Pentium chip. This paper describes the implementation of a computationally efficient computer vision system for recognizing hand gestures using efficient coding and MMX-acceleration to achieve real-time performance on low cost hardware.

Advanced receivers for next generation wireless communication systems

Despite extensive progress on the theoretical aspects of spectral efficient communication systems, hardware impairments, such as phase noise, are the key bottlenecks in next generation wireless communication systems. The presence of non-ideal oscillators at the transceiver introduces time varying phase noise and degrades the performance of the communication system. Significant research literature focuses on joint synchronization and decoding based on joint posterior distribution, which incorporate both the channel and code graph. These joint synchronization and decoding approaches operate on well designed sum-product algorithms, which involves calculating probabilistic messages iteratively passed between the channel statistical information and decoding information. Channel statistical information, generally entails a high computational complexity because its probabilistic model may involve continuous random variables. The detailed knowledge about the channel statistics for these algorithms make them an inadequate choice for real world applications due to power and computational limitations. In this thesis, novel phase estimation strategies are proposed, in which soft decision-directed iterative receivers for a separate A Posteriori Probability (APP)-based synchronization and decoding are proposed. These algorithms do not require any a priori statistical characterization of the phase noise process. The proposed approach relies on a Maximum A Posteriori (MAP)-based algorithm to perform phase noise estimation and does not depend on the considered modulation/coding scheme as it only exploits the APPs of the transmitted symbols. Different variants of APP-based phase estimation are considered. The proposed algorithm has significantly lower computational complexity with respect to joint synchronization/decoding approaches at the cost of slight performance degradation. With the aim to improve the robustness of the iterative receiver, we derive a new system model for an oversampled (more than one sample per symbol interval) phase noise channel. We extend the separate APP-based synchronization and decoding algorithm to a multi-sample receiver, which exploits the received information from the channel by exchanging the information in an iterative fashion to achieve robust convergence. Two algorithms based on sliding block-wise processing with soft ISI cancellation and detection are proposed, based on the use of reliable information from the channel decoder. Dually polarized systems provide a cost-and spatial-effective solution to increase spectral efficiency and are competitive candidates for next generation wireless communication systems. A novel soft decision-directed iterative receiver, for separate APP-based synchronization and decoding, is proposed. This algorithm relies on an Minimum Mean Square Error (MMSE)-based cancellation of the cross polarization interference (XPI) followed by phase estimation on the polarization of interest. This iterative receiver structure is motivated from Master/Slave Phase Estimation (M/S-PE), where M-PE corresponds to the polarization of interest. The operational principle of a M/S-PE block is to improve the phase tracking performance of both polarization branches: more precisely, the M-PE block tracks the co-polar phase and the S-PE block reduces the residual phase error on the cross-polar branch. Two variants of MMSE-based phase estimation are considered; BW and PLP.

MÍDIAS SOCIAIS ON-LINE: o consumidor fala, mas quem escuta?

Sob o prisma da comunicação mercadológica, esse trabalho se propõe investigar o novo perfil de consumidor que, conectado a uma ampla rede de pessoas, influencia e até comanda diversas mudanças na forma de produzir e vender bens e serviços. A comunicação passa a ser mais horizontal do que vertical, pois os consumidores manifestam-se nas mídias sociais on-line e interagem com seus pares, e muitas empresas demonstram dificuldades em perceber o início desse crescente poder de manifestação do consumidor. O propósito desta pesquisa é investigar até que ponto os consumidores estão conseguindo ser ouvidos pelas empresas por meio das mídias sociais on-line. A metodologia aplicada foi o Estudo de Casos Múltiplos de empresas do setor de telefonia celular. Construiu-se um instrumento de pesquisa e, por meio de análise de conteúdo dos comentários coletados durante três meses nas páginas da TIM e da CLARO no Facebook, os resultados apontam uma dificuldade muita grande das empresas do setor de telefonia em ouvir os consumidores.

O ENSINO DA COMUNICAÇÃO EMPRESARIAL EM MATO GROSSO DO SUL: dificuldades e desafios para incorporar as novas mídias on-line

A comunicação empresarial se desenvolve a passos largos, acompanhando as mudanças ocorridas no mercado, no universo da comunicação e na própria sociedade. A gestão do relacionamento com os públicos de interesse das organizações se tornou mais complexa e faz com que os profissionais da área atentem para as novas realidades do mercado. Em função desse novo cenário, é fundamental a capacitação do profissional para lidar com as mídias sociais, e ela deve se iniciar já no momento de sua formação universitária. Para a pesquisa bibliográfica, utilizamos como principais autores Bueno (2009), Scott (2008; 2011) e Terra (2011).Por serem assuntos relativamente novos, foram realizadas, ainda, entrevistas semiestruturadas com autores/pesquisadores da área para verificar as situações ideais do ensino da comunicação organizacional atuais. Com objetivo de apresentarmos as condições, percepções e desafios da formação do profissional da comunicação de Mato Grosso do Sul para trabalhar com a comunicação empresarial, foram feitas entrevistas semiestruturadas com os professores das faculdades e fechadas com os acadêmicos, de forma que demos atenção especial para seus conhecimentos e suas práticas nesses novos ambientes de interação. Dentre os resultados encontrados estão a necessidade da formação ampla do profissional com conhecimento da área da comunicação e organizações e a conclusão que essa formação integral garante à atuação dele em qualquer mídia/ferramenta.