Inclusión digital de los estudiantes adultos que acceden a la universidad: análisis de sus actitudes y competencias digitales

Esta investigación se propone identificar las actitudes y competencias de los estudiantes adultos en relación con el uso de las TIC, con especial atención al uso de plataformas digitales de aprendizaje y redes sociales (Web 2.0). Asimismo, evalúa la incidencia de algunas variables sociodemográficas (género y edad) en el uso estas herramientas y en la autopercepción de los estudiantes sobre sus competencias digitales. Se ha realizado un estudio tipo encuesta con una muestra de 382 estudiantes que acceden a la Universidad de Sevilla a través de las vías establecidas para mayores de 25, de 40 y 45 años. Los resultados ponen de manifiesto una actitud generalmente positiva ante las TIC que puede calificarse como de pragmática, ya que estas herramientas se valoran positivamente en función de sus potenciales beneficios en los procesos de aprendizaje. Se constata a la vez que no han recibido formación específica en el uso de las TIC. El nivel de competencia que este alumnado percibe tener en el uso de estos recursos es medio-bajo. Además, el grupo de estudiantes mayores de 45 años se considera menos competente que los mayores de 25 y de 40 años. En consecuencia, se realizan algunas propuestas para mejorar la participación de los estudiantes maduros en la enseñanza universitaria.

Orthogonal chirp division multiplexing for coherent optical fiber communications

In this paper, we propose an orthogonal chirp division multiplexing (OCDM) technique for coherent optical communication. OCDM is the principle of orthogonally multiplexing a group of linear chirped waveforms for high-speed data communication, achieving the maximum spectral efficiency (SE) for chirp spread spectrum, in a similar way as the orthogonal frequency division multiplexing (OFDM) does for frequency division multiplexing. In the coherent optical (CO)-OCDM, Fresnel transform formulates the synthesis of the orthogonal chirps; discrete Fresnel transform (DFnT) realizes the CO-OCDM in the digital domain. As both the Fresnel and Fourier transforms are trigonometric transforms, the CO-OCDM can be easily integrated into the existing CO-OFDM systems. Analyses and numerical results are provided to investigate the transmission of CO-OCDM signals over optical fibers. Moreover, experiments of 36-Gbit/s CO-OCDM signal are carried out to validate the feasibility and confirm the analyses. It is shown that the CO-OCDM can effectively compensate the dispersion and is more resilient to fading and noise impairment than OFDM.

Proposta de estratégia metodológica para a promoção da Cultura Digital de professores do 1º e 2º Ciclo do Ensino Secundário

A Cultura Digital é uma realidade do século XXI, onde as relações humanas são fortemente mediadas pelas tecnologias e pelo digital. O Digital tem mudado o comportamento das pessoas e influenciado o seu meio cultural. O conceito de Cultura digital inclui saber onde encontrar informação, ferramentas e sistemas, necessários para cumprir uma determinada tarefa de forma não só eficaz, mas também mais eficiente. As competências para explorar as tecnologias que o permitam, são cada vez mais exigidas na interação em sociedade. Tendo em consideração estudos existentes associados com as competências TIC, nomeadamente os propostos pela UNESCO e pelo Executivo Angolano no seu Plano Nacional de Desenvolvimento para 2013-2017, em que está enquadrada a iniciativa da Rede de Mediatecas de Angola, foi tomada a Cultural Digital e a sua promoção no ambito das Mediatecas. Numa primeira avaliação desde da abertura da Mediateca em Fevereiro de 2014, verificamos uma fraca adesão dos professores na utilização dos serviços da Mediateca do Huambo – Angola. Coloca-se neste contexto a questão do porquê que é que os professores não exploram as TIC para as atividades docentes ou da sua aprendizagem? Desta forma, é considerada a questão de investigação: Quais as estratégias a desenvolver para incrementar a exploração das TIC pelos professores e como a Mediateca do Huambo pode servir de espaço para a promoção da Cultura Digital. Foi realizado um estudo de caso, no contexto da Mediateca do Huambo, em que foi efetuada uma recolha de dados pela (a) aplicação de questionários aos professores do 1º e 2º Ciclo do Ensino Secundário do Município do Huambo para mapear as competências TIC dos professores segundo os padrões da UNESCO e o apuramento da formação e uso das TIC em contexto educativo, (b) pela aplicação de um conjunto de tarefas com o objetivo de verificar quais as competências digitais dos professores e por último (c), a implementação do projeto-piloto denominado “ Mediateca +Escola” com o objetivo de levar à Mediateca professores e alunos para desenvolver um projeto TIC onde os professores teriam uma oportunidade de demostrar as competências que afirmavam possuir. Como resultado final obtido neste estudo de caso podemos concluir que 71,27% indicanos que os professores têm a perceção que necessitam de mais formação e desenvolvimento de competências TIC, 27,50% confirma que os professores creem que têm confiança nas TIC. Em face das respostas com valores negativos que apontam para a necessidade de delinear estratégia para capacitar este grupo em competências TIC de forma a incluí-los na sociedade em rede providos de uma Cultura Digital foi proposto o modelo que permite validar os dados obtidos pelo questionário permitindo também delinear estratégias com vista à promoção da Cultura Digital.

Context-awareness privacy in data communications

Internet users consume online targeted advertising based on information collected about them and voluntarily share personal information in social networks. Sensor information and data from smart-phones is collected and used by applications, sometimes in unclear ways. As it happens today with smartphones, in the near future sensors will be shipped in all types of connected devices, enabling ubiquitous information gathering from the physical environment, enabling the vision of Ambient Intelligence. The value of gathered data, if not obvious, can be harnessed through data mining techniques and put to use by enabling personalized and tailored services as well as business intelligence practices, fueling the digital economy. However, the ever-expanding information gathering and use undermines the privacy conceptions of the past. Natural social practices of managing privacy in daily relations are overridden by socially-awkward communication tools, service providers struggle with security issues resulting in harmful data leaks, governments use mass surveillance techniques, the incentives of the digital economy threaten consumer privacy, and the advancement of consumergrade data-gathering technology enables new inter-personal abuses. A wide range of fields attempts to address technology-related privacy problems, however they vary immensely in terms of assumptions, scope and approach. Privacy of future use cases is typically handled vertically, instead of building upon previous work that can be re-contextualized, while current privacy problems are typically addressed per type in a more focused way. Because significant effort was required to make sense of the relations and structure of privacy-related work, this thesis attempts to transmit a structured view of it. It is multi-disciplinary - from cryptography to economics, including distributed systems and information theory - and addresses privacy issues of different natures. As existing work is framed and discussed, the contributions to the state-of-theart done in the scope of this thesis are presented. The contributions add to five distinct areas: 1) identity in distributed systems; 2) future context-aware services; 3) event-based context management; 4) low-latency information flow control; 5) high-dimensional dataset anonymity. Finally, having laid out such landscape of the privacy-preserving work, the current and future privacy challenges are discussed, considering not only technical but also socio-economic perspectives.

Unidad Cifradora/Descifradora de Mensajes con información digital, Sistema y Método de Cifrado/Descifrado para Comunicaciones Digitales en Tiempo Real

La invención consiste en un sistema implementado en un microcontrolador o FPGA que cifra y descifra la información mediante un algoritmo de cifrado simétrico basado en una tabla de claves que es recorrida usando un generador de filtro no lineal, produciendo de esta forma una secuencia cifrante que es operada mediante una operación XOR bit a bit dando lugar de este modo palabras de mensaje cifrado o mensaje en claro, dependiendo de si la entrada es el mensaje en claro o el mensaje cifrado respectivamente y mediante la cual, un mismo mensaje puede ser cifrado de muy diferentes formas, dependiendo del momento en el que se cifra.

Security through Obscurity: Layout Obfuscation of Digital Integrated Circuits using Don't Care Conditions

Contemporary integrated circuits are designed and manufactured in a globalized environment leading to concerns of piracy, overproduction and counterfeiting. One class of techniques to combat these threats is circuit obfuscation which seeks to modify the gate-level (or structural) description of a circuit without affecting its functionality in order to increase the complexity and cost of reverse engineering. Most of the existing circuit obfuscation methods are based on the insertion of additional logic (called “key gates”) or camouflaging existing gates in order to make it difficult for a malicious user to get the complete layout information without extensive computations to determine key-gate values. However, when the netlist or the circuit layout, although camouflaged, is available to the attacker, he/she can use advanced logic analysis and circuit simulation tools and Boolean SAT solvers to reveal the unknown gate-level information without exhaustively trying all the input vectors, thus bringing down the complexity of reverse engineering. To counter this problem, some ‘provably secure’ logic encryption algorithms that emphasize methodical selection of camouflaged gates have been proposed previously in literature [1,2,3]. The contribution of this paper is the creation and simulation of a new layout obfuscation method that uses don't care conditions. We also present proof-of-concept of a new functional or logic obfuscation technique that not only conceals, but modifies the circuit functionality in addition to the gate-level description, and can be implemented automatically during the design process. Our layout obfuscation technique utilizes don’t care conditions (namely, Observability and Satisfiability Don’t Cares) inherent in the circuit to camouflage selected gates and modify sub-circuit functionality while meeting the overall circuit specification. Here, camouflaging or obfuscating a gate means replacing the candidate gate by a 4X1 Multiplexer which can be configured to perform all possible 2-input/ 1-output functions as proposed by Bao et al. [4]. It is important to emphasize that our approach not only obfuscates but alters sub-circuit level functionality in an attempt to make IP piracy difficult. The choice of gates to obfuscate determines the effort required to reverse engineer or brute force the design. As such, we propose a method of camouflaged gate selection based on the intersection of output logic cones. By choosing these candidate gates methodically, the complexity of reverse engineering can be made exponential, thus making it computationally very expensive to determine the true circuit functionality. We propose several heuristic algorithms to maximize the RE complexity based on don’t care based obfuscation and methodical gate selection. Thus, the goal of protecting the design IP from malicious end-users is achieved. It also makes it significantly harder for rogue elements in the supply chain to use, copy or replicate the same design with a different logic. We analyze the reverse engineering complexity by applying our obfuscation algorithm on ISCAS-85 benchmarks. Our experimental results indicate that significant reverse engineering complexity can be achieved at minimal design overhead (average area overhead for the proposed layout obfuscation methods is 5.51% and average delay overhead is about 7.732%). We discuss the strengths and limitations of our approach and suggest directions that may lead to improved logic encryption algorithms in the future. References: [1] R. Chakraborty and S. Bhunia, “HARPOON: An Obfuscation-Based SoC Design Methodology for Hardware Protection,” IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, vol. 28, no. 10, pp. 1493–1502, 2009. [2] J. A. Roy, F. Koushanfar, and I. L. Markov, “EPIC: Ending Piracy of Integrated Circuits,” in 2008 Design, Automation and Test in Europe, 2008, pp. 1069–1074. [3] J. Rajendran, M. Sam, O. Sinanoglu, and R. Karri, “Security Analysis of Integrated Circuit Camouflaging,” ACM Conference on Computer Communications and Security, 2013. [4] Bao Liu, Wang, B., "Embedded reconfigurable logic for ASIC design obfuscation against supply chain attacks,"Design, Automation and Test in Europe Conference and Exhibition (DATE), 2014 , vol., no., pp.1,6, 24-28 March 2014.

Phase noise and spur reduction in an array of direct digital synthesizers

Many applications, including communications, test and measurement, and radar, require the generation of signals with a high degree of spectral purity. One method for producing tunable, low-noise source signals is to combine the outputs of multiple direct digital synthesizers (DDSs) arranged in a parallel configuration. In such an approach, if all noise is uncorrelated across channels, the noise will decrease relative to the combined signal power, resulting in a reduction of sideband noise and an increase in SNR. However, in any real array, the broadband noise and spurious components will be correlated to some degree, limiting the gains achieved by parallelization. This thesis examines the potential performance benefits that may arise from using an array of DDSs, with a focus on several types of common DDS errors, including phase noise, phase truncation spurs, quantization noise spurs, and quantizer nonlinearity spurs. Measurements to determine the level of correlation among DDS channels were made on a custom 14-channel DDS testbed. The investigation of the phase noise of a DDS array indicates that the contribution to the phase noise from the DACs can be decreased to a desired level by using a large enough number of channels. In such a system, the phase noise qualities of the source clock and the system cost and complexity will be the main limitations on the phase noise of the DDS array. The study of phase truncation spurs suggests that, at least in our system, the phase truncation spurs are uncorrelated, contrary to the theoretical prediction. We believe this decorrelation is due to the existence of an unidentified mechanism in our DDS array that is unaccounted for in our current operational DDS model. This mechanism, likely due to some timing element in the FPGA, causes some randomness in the relative phases of the truncation spurs from channel to channel each time the DDS array is powered up. This randomness decorrelates the phase truncation spurs, opening the potential for SFDR gain from using a DDS array. The analysis of the correlation of quantization noise spurs in an array of DDSs shows that the total quantization noise power of each DDS channel is uncorrelated for nearly all values of DAC output bits. This suggests that a near N gain in SQNR is possible for an N-channel array of DDSs. This gain will be most apparent for low-bit DACs in which quantization noise is notably higher than the thermal noise contribution. Lastly, the measurements of the correlation of quantizer nonlinearity spurs demonstrate that the second and third harmonics are highly correlated across channels for all frequencies tested. This means that there is no benefit to using an array of DDSs for the problems of in-band quantizer nonlinearities. As a result, alternate methods of harmonic spur management must be employed.

Plataforma digital de promoción y difusión musical

La industria musical a nivel mundial atraviesa una etapa de transición en varios procesos análogos a digitales y también de formatos físicos, como CD´s por mp3, esto representa para los artistas, nuevos caminos para generar ingresos y facilidades de introducción en la industria. En Ecuador, no se puede hablar de industria musical pues, lo que se ha desarrollado hasta este momento es solo una “escena musical” en donde los artistas intentan salir hacia mercados extranjeros utilizando diferentes herramientas de difusión tanto tradicionales como digitales, siendo pocos quienes consiguen este objetivo y además, rentabilidad en sus carreras musicales. El proyecto de intervención denominado “Construcción de una plataforma digital para la promoción y difusión de artistas musicales del género pop y rock de la ciudad de Cuenca, fundamentado en estrategias digitales creadas bajo el concepto ‘Mezcla de comunicaciones de marketing’, período 2015 -2016”, genera un modelo de negocio experimental basado en soportes digitales y estrategias de marketing y comunicación que benefician la difusión, venta y promoción de los artistas y su material musical. Todo esto con miras a aportar al desarrollo de la escena musical en Ecuador. El modelo de negocio experimental se basa en tres actividades que el Staff 4.32 (nombre de la plataforma digital) brindará como servicios a sus consumidores: 1) generador de contenidos con temáticas referentes a la industria musical, 2) distribución digital de música en tiendas online y 3) sello representante de artistas que forman parte del catálogo de músicos del Staff.

Digital literacy matters. Increasing workforce productivity through blended English language programmes

Current workplace demands newer forms of literacies that go beyond the ability to decode print. These involve not only competence to operate digital tools, but also the ability to create, represent, and share meaning in different modes and formats; ability to interact, collaborate and communicate effectively using digital tools, and engage critically with technology for developing one’s knowledge, skills, and full participation in civic, economic, and personal matters. This essay examines the application of the ecology of resources (EoR) model for delivering language learning outcomes (in this case, English) through blended classroom environments that use contextually available resources. The author proposes the implementation of the EoR model in blended learning environments to create authentic and sustainable learning environments for skilling courses. Applying the EoR model to Indian skilling instruction contexts, the article discusses how English language and technology literacy can be delivered using contextually available resources through a blended classroom environment. This would facilitate not only acquisition of language and digital literacy outcomes, but also consequent content literacy gain to a certain extent. This would ensure satisfactory achievement of not only communication/language literacy and technological literacy, but also active social participation, lifelong learning, and learner autonomy.

How do customers of a financial services institution judge its communications

Communications are important for relationships within a marketing channel from both a theoretical and managerial perspective. Yet it is a problematic area for scholars. Thus, this research addresses the problem of how do customers of a financial services institution perceive communications with an ideal institution? This study's case research methodology used in-depth interviews with 34 carefully selected customers of a building society. The factors that make up customers' attitudes about corporate communications for an ideal financial services institution were identified and actual perceptions were compared against that ideal. The findings confirmed the importance of communications for customers in a relationship with a financial services provider and suggested communication priorities for customers in this context. In addition, the findings suggested sources of communication dissatisfaction for customers. These findings build upon the literature that speculates about customer perceptions of communications with organizations but provides little evidence to support hypotheses. The contributions arose from the emphasis on the customers' own attitudes and the patterns found within them.

The Coming of Post-reflexive Society: Commodification and Language in Digital Capitalism

Language is a unique aspect of human communication because it can be used to discuss itself in its own terms. For this reason, human societies potentially have superior capacities of co-ordination, reflexive self-correction, and innovation than other animal, physical or cybernetic systems. However, this analysis also reveals that language is interconnected with the economically and technologically mediated social sphere and hence is vulnerable to abstraction, objectification, reification, and therefore ideology – all of which are antithetical to its reflexive function, whilst paradoxically being a fundamental part of it. In particular, in capitalism, language is increasingly commodified within the social domains created and affected by ubiquitous communication technologies. The advent of the so-called ‘knowledge economy’ implicates exchangeable forms of thought (language) as the fundamental commodities of this emerging system. The historical point at which a ‘knowledge economy’ emerges, then, is the critical point at which thought itself becomes a commodified ‘thing’, and language becomes its “objective” means of exchange. However, the processes by which such commodification and objectification occurs obscures the unique social relations within which these language commodities are produced. The latest economic phase of capitalism – the knowledge economy – and the obfuscating trajectory which accompanies it, we argue, is destroying the reflexive capacity of language particularly through the process of commodification. This can be seen in that the language practices that have emerged in conjunction with digital technologies are increasingly non-reflexive and therefore less capable of self-critical, conscious change.