Protocolo de roteamento para redes oportunistas utilizando otimização por enxame de partículas

In this research work, a new routing protocol for Opportunistic Networks is presented. The proposed protocol is called PSONET (PSO for Opportunistic Networks) since the proposal uses a hybrid system composed of a Particle Swarm Optimization algorithm (PSO). The main motivation for using the PSO is to take advantage of its search based on individuals and their learning adaptation. The PSONET uses the Particle Swarm Optimization technique to drive the network traffic through of a good subset of forwarders messages. The PSONET analyzes network communication conditions, detecting whether each node has sparse or dense connections and thus make better decisions about routing messages. The PSONET protocol is compared with the Epidemic and PROPHET protocols in three different scenarios of mobility: a mobility model based in activities, which simulates the everyday life of people in their work activities, leisure and rest; a mobility model based on a community of people, which simulates a group of people in their communities, which eventually will contact other people who may or may not be part of your community, to exchange information; and a random mobility pattern, which simulates a scenario divided into communities where people choose a destination at random, and based on the restriction map, move to this destination using the shortest path. The simulation results, obtained through The ONE simulator, show that in scenarios where the mobility model based on a community of people and also where the mobility model is random, the PSONET protocol achieves a higher messages delivery rate and a lower replication messages compared with the Epidemic and PROPHET protocols.

Parallel Cyclostationarity-Exploiting Algorithm for Energy-Efficient Spectrum Sensing

The evolution of wireless communication systems leads to Dynamic Spectrum Allocation for Cognitive Radio, which requires reliable spectrum sensing techniques. Among the spectrum sensing methods proposed in the literature, those that exploit cyclostationary characteristics of radio signals are particularly suitable for communication environments with low signal-to-noise ratios, or with non-stationary noise. However, such methods have high computational complexity that directly raises the power consumption of devices which often have very stringent low-power requirements. We propose a strategy for cyclostationary spectrum sensing with reduced energy consumption. This strategy is based on the principle that p processors working at slower frequencies consume less power than a single processor for the same execution time. We devise a strict relation between the energy savings and common parallel system metrics. The results of simulations show that our strategy promises very significant savings in actual devices.

LA REINVENCIÓN DE LA PRODUCCIÓN EDITORIAL EN LA ERA DIGITAL; DENTRO DEL PROCESO DE GENERACIÓN Y TRANSFERENCIA DEL CONOCIMIENTO

Analiza la producción editorial a la luz de los cambios propuestos por los avances de la tecnología de los sistemas de información y comunicación. Señala impactos de internet en la producción y difusión de contenidos en ambientes y organizaciones de enseñanza e investigación. Enfatiza la responsabilidad compartida de la bibliotecología y ciencias de la información con la industria editorial, en el proceso de transferencia de información y la creación de conocimiento.

Editorial

This volume of the Bulletin LIBRARIES and the next intended as a means of inspiration. Inspiration to propose ideas to offer to the community library paths to adapt to global culture and technology which revolves around the progress of information and communication systems. Ideas that move us to innovate, to make mistakes and correct them.Because the information age it is also of creativity. Creativity is the competitive advantage of professional and modern organizations. Ideas to change attitudes toward open to new projects that facilitate the transformation and to the challenge of "going global". Inspiration to measure and produce constructive thinking to help us define new goals by the desire to create and share knowledge.

A test method for analysing disturbed ethernet data streams

Ethernet connections, which are widely used in many computer networks, can suffer from electromagnetic interference. Typically, a degradation of the data transmission rate can be perceived as electromagnetic disturbances lead to corruption of data frames on the network media. In this paper a software-based measuring method is presented, which allows a direct assessment of the effects on the link layer. The results can directly be linked to the physical interaction without the influence of software related effects on higher protocol layers. This gives a simple tool for a quantitative analysis of the disturbance of an Ethernet connection based on time domain data. An example is shown, how the data can be used for further investigation of mechanisms and detection of intentional electromagnetic attacks. © 2015 Author(s).

Motion compensation with minimal residue dispersion matching criteria

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnoloigia, 2016.

A influência das aplicações móveis na percepção da imagem de marcas comerciais

A história da humanidade é marcada por invenções a nível tecnológico que provocam grandes alterações na sociedade e, consequentemente, no mundo. Depois do aparecimento da Internet há algumas décadas, assistimos atualmente ao surgimento de um novo grande marco histórico ao nível tecnológico: a era do marketing digital e da comunicação móvel. Nos últimos anos, o crescimento exponencial e o desenvolvimento do mercado de smartphones e das aplicações móveis fizeram com que estas se tornassem num dos principais meios de comunicação e impusessem novas dinâmicas quanto à forma de interagir, pesquisar informação, efetuar compras/pagamentos, organizar as mais diversas tarefas diárias, jogar e até de trabalhar. Os novos ritmos de vida garantem aos consumidores uma menor disponibilidade de exposição aos conteúdos e às atividades das marcas. Deste modo, e devido ao reconhecimento das potencialidades dos canais móveis, o conceito da mobilidade tem vindo a ganhar uma crescente valorização. A necessidade de criação de novas plataformas interativas que facilitem a vida dos consumidores é cada vez maior e permite às marcas uma relação de proximidade constante e sem barreiras com os seus consumidores em qualquer lugar e a qualquer hora através de dispositivos móveis que são, hoje em dia, uma ferramenta imprescindível tanto a nível pessoal e social como a nível profissional.

Time-Reversal Massive Multipath Effect and Bandwidth Heterogeneity

The proliferation of new mobile communication devices, such as smartphones and tablets, has led to an exponential growth in network traffic. The demand for supporting the fast-growing consumer data rates urges the wireless service providers and researchers to seek a new efficient radio access technology, which is the so-called 5G technology, beyond what current 4G LTE can provide. On the other hand, ubiquitous RFID tags, sensors, actuators, mobile phones and etc. cut across many areas of modern-day living, which offers the ability to measure, infer and understand the environmental indicators. The proliferation of these devices creates the term of the Internet of Things (IoT). For the researchers and engineers in the field of wireless communication, the exploration of new effective techniques to support 5G communication and the IoT becomes an urgent task, which not only leads to fruitful research but also enhance the quality of our everyday life. Massive MIMO, which has shown the great potential in improving the achievable rate with a very large number of antennas, has become a popular candidate. However, the requirement of deploying a large number of antennas at the base station may not be feasible in indoor scenarios. Does there exist a good alternative that can achieve similar system performance to massive MIMO for indoor environment? In this dissertation, we address this question by proposing the time-reversal technique as a counterpart of massive MIMO in indoor scenario with the massive multipath effect. It is well known that radio signals will experience many multipaths due to the reflection from various scatters, especially in indoor environments. The traditional TR waveform is able to create a focusing effect at the intended receiver with very low transmitter complexity in a severe multipath channel. TR's focusing effect is in essence a spatial-temporal resonance effect that brings all the multipaths to arrive at a particular location at a specific moment. We show that by using time-reversal signal processing, with a sufficiently large bandwidth, one can harvest the massive multipaths naturally existing in a rich-scattering environment to form a large number of virtual antennas and achieve the desired massive multipath effect with a single antenna. Further, we explore the optimal bandwidth for TR system to achieve maximal spectral efficiency. Through evaluating the spectral efficiency, the optimal bandwidth for TR system is found determined by the system parameters, e.g., the number of users and backoff factor, instead of the waveform types. Moreover, we investigate the tradeoff between complexity and performance through establishing a generalized relationship between the system performance and waveform quantization in a practical communication system. It is shown that a 4-bit quantized waveforms can be used to achieve the similar bit-error-rate compared to the TR system with perfect precision waveforms. Besides 5G technology, Internet of Things (IoT) is another terminology that recently attracts more and more attention from both academia and industry. In the second part of this dissertation, the heterogeneity issue within the IoT is explored. One of the significant heterogeneity considering the massive amount of devices in the IoT is the device heterogeneity, i.e., the heterogeneous bandwidths and associated radio-frequency (RF) components. The traditional middleware techniques result in the fragmentation of the whole network, hampering the objects interoperability and slowing down the development of a unified reference model for the IoT. We propose a novel TR-based heterogeneous system, which can address the bandwidth heterogeneity and maintain the benefit of TR at the same time. The increase of complexity in the proposed system lies in the digital processing at the access point (AP), instead of at the devices' ends, which can be easily handled with more powerful digital signal processor (DSP). Meanwhile, the complexity of the terminal devices stays low and therefore satisfies the low-complexity and scalability requirement of the IoT. Since there is no middleware in the proposed scheme and the additional physical layer complexity concentrates on the AP side, the proposed heterogeneous TR system better satisfies the low-complexity and energy-efficiency requirement for the terminal devices (TDs) compared with the middleware approach.

Propuesta de un marco de referencia simplificado para la implementación de un Gobierno de TI en Pymes de Servicios en Colombia

El siguiente trabajo de grado propone un modelo simplificado de gobierno y gestión de las tecnologías de información en las pequeñas y medianas empresas de servicios en Colombia, a partir de la selección e integración de procesos enunciados por algunos de los marcos de trabajo y buenas prácticas de TI que gozan de un reconocimiento generalizado -- En concreto, se han tomado elementos de COBIT 5, ISO/IEC 20000, ITIL V3, CMMI 1.3, PMBOK 5 e ISO/IEC 27000 -- Para el diseño del modelo propuesto se han identificado cada uno de los procesos dispuestos por los diferentes marcos de referencia -- Acto seguido se ha procedido a identificar todos los procesos comunes entre los diferentes modelos de gestión, seleccionando aquellos que se consideran imprescindibles en la generación de valor y evitando aquellos que complejizaran la gestión para el foco de nuestro alcance -- Los procesos identificados y seleccionados fueron agrupados bajo áreas de proceso, las cuales, a su vez, describen subprocesos que tienen un propósito declarado y unas estrategias de gestión y actividades propuestas, que seguidas, satisfacen el objetivo establecido para cada uno de los subprocesos, y en conjunto, suponen un modelo de gobierno de TI adecuado para las pequeñas y medianas empresas prestadoras de servicios en Colombia

Testing the level of interactivity of institutional websites: From museums 1.0 to museums 2.0

The Internet has changed the way in which organizations communicate with their publics, and museums are not an exception. The consolidation of Web 2.0 has not only given museums access to a powerful new tool for disseminating information, but has involved significant changes in the relationship between institutions and their publics, facilitating and enhancing the interaction between them. The overall objective of this paper is to analyze the degree of interactivity implemented in the websites of major international art museums, in order to assess if museums are evolving towards more dialogic systems with relation to their publics. The results indicate that museums still have a low level of interactivity on their websites, both in the tools used to present information and the resources available for interaction with virtual visitors. But it has also observed that museums are progressively implementing interactive and dialogic sources, suggesting a clear trend towards new ways of managing these platforms in order to establish more participatory and collaborative communication systems with virtual users.

Un modelo de indicadores de gestión de comunicación organizacional para la Universidad de Antioquia: un aporte a la gestión estratégica de la comunicación en instituciones universitarias

El presente trabajo tiene como propósito formular un sistema de indicadores de comunicación que se constituya en un instrumento valioso para el ejercicio de planeación, seguimiento y evaluación de la gestión comunicativa al interior de la Universidad de Antioquia -- Además de la mejora continua del proceso de comunicación institucional y una toma de decisiones más efectiva, se espera que la implementación del sistema de indicadores permita un posicionamiento estratégico del área de comunicaciones en articulación con sus diferentes dependencias, al valorar con mayor claridad su contribución al logro de los objetivos estratégicos planteados por la Alma Máter -- Para el logro de dicho objetivo trazaron tres etapas -- La primera comprende un estado del arte en el que se incluyen los aportes teóricos sobre la medición y la evaluación de la comunicación en las organizaciones, la información de contexto requerida sobre la institución objeto de estudio y un diagnóstico sobre el estado de la comunicación en la misma, basado en estudios elaborados previamente por la institución -- La segunda etapa corresponde al trabajo de campo, que parte de una combinación de técnicas investigativas cuantitativas (encuesta) y cualitativas (grupo focal) -- Con el análisis de la información obtenida en tales fases, al final se formula una propuesta de indicadores de cumplimiento, satisfacción e impacto para cada uno de los asuntos de trabajo del proceso de comunicación institucional proyectado en la actualidad por la Universidad de Antioquia

A probabilistic approach to user mobility prediction for wireless services.

Mobile and wireless networks have long exploited mobility predictions, focused on predicting the future location of given users, to perform more efficient network resource management. In this paper, we present a new approach in which we provide predictions as a probability distribution of the likelihood of moving to a set of future locations. This approach provides wireless services a greater amount of knowledge and enables them to perform more effectively. We present a framework for the evaluation of this new type of predictor, and develop 2 new predictors, HEM and G-Stat. We evaluate our predictors accuracy in predicting future cells for mobile users, using two large geolocation data sets, from MDC [11], [12] and Crawdad [13]. We show that our predictors can successfully predict with as low as an average 2.2% inaccuracy in certain scenarios.

A method of fraud & intrusion detection for e-payment systems in mobile

The need for paying with mobile devices has urged the development of payment systems for mobile electronic commerce. In this paper we have considered two important abuses in electronic payments systems for detection. The fraud, which is an intentional deception accomplished to secure an unfair gain, and an intrusion which are any set of actions that attempt to compromise the integrity, confidentiality or availability of a resource. Most of the available fraud and intrusion detection systems for e-payments are specific to the systems where they have been incorporated. This paper proposes a generic model called as Activity-Event-Symptoms(AES) model for detecting fraud and intrusion attacks which appears during payment process in the mobile commerce environment. The AES model is designed to identify the symptoms of fraud and intrusions by observing various events/transactions occurs during mobile commerce activity. The symptoms identification is followed by computing the suspicion factors for event attributes, and the certainty factor for a fraud and intrusion is generated using these suspicion factors. We have tested the proposed system by conducting various case studies, on the in-house established mobile commerce environment over wired and wire-less networks test bed.

Designing tools that enhance communication and understanding between multiple stakeholders: the case of mobile payment value networks

The pervasive use of mobile technologies has provided new opportunities for organisations to achieve competitive advantage by using a value network of partners to create value for multiple users. The delivery of a mobile payment (m-payment) system is an example of a value network as it requires the collaboration of multiple partners from diverse industries, each bringing their own expertise, motivations and expectations. Consequently, managing partnerships has been identified as a core competence required by organisations to form viable partnerships in an m-payment value network and an important factor in determining the sustainability of an m-payment business model. However, there is evidence that organisations lack this competence which has been witnessed in the m-payment domain where it has been attributed as an influencing factor in a number of failed m-payment initiatives since 2000. In response to this organisational deficiency, this research project leverages the use of design thinking and visualisation tools to enhance communication and understanding between managers who are responsible for managing partnerships within the m-payment domain. By adopting a design science research approach, which is a problem solving paradigm, the research builds and evaluates a visualisation tool in the form of a Partnership Management Canvas. In doing so, this study demonstrates that when organisations encourage their managers to adopt design thinking, as a way to balance their analytical thinking and intuitive thinking, communication and understanding between the partners increases. This can lead to a shared understanding and a shared commitment between the partners. In addition, the research identifies a number of key business model design issues that need to be considered by researchers and practitioners when designing an m-payment business model. As an applied research project, the study makes valuable contributions to the knowledge base and to the practice of management.