54 resultados para 291700 Communications Technologies


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Avui en dia les Tecnologies de la Informació i la Comunicació (TIC) s’han convertit en eines d’ús quotidià i alhora invisibles en diversos àmbits de la societat i les escoles no n’estan al marge. No cal ensenyar a fer servir eines tecnològiques, sinó que cal entendre-les com un suport. Recerques recents han demostrat que un bon ús d’aquestes potencien un bon ensenyament i aprenentatge. Al mateix temps, es potencien mètodes globalitzats a les aules que permeten construir coneixements significatius a partir de situacions i problemes. Per això, l’objectiu principal d’aquest estudi consisteix en investigar quins canvis s’observen en la motivació de l’alumnat i quins canvis succeeixen a l’aula en general quan s’usen les TIC com a suport en un mètode globalitzat anomenat la recerca del medi. Per tal de resoldre aquest problema d’investigació es recullen diverses dades d’una intervenció didàctica basada en aquest mètode que es porta a terme en dos cursos de cinquè de Primària. Tal com s’observarà, l’ús de les noves tecnologies en un mètode que permet apropar els infants a la realitat n’augmenta la motivació i promou canvis a l’aula que ajuden i faciliten la tasca del docent i alhora afavoreix un aprenentatge significatiu.

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This paper analyses the adoption of new information and communication technologies (ICTs) by Spanish journalists specialising in science. Applying an ethnographic research model, this study was based on a wide sample of professionals, aiming to evaluate the extent by which science journalists have adopted the new media and changed the way they use information sources. In addition, interviewees were asked whether in their opinion the Web 2.0 has had an impact on the quality of the news. The integration of formats certainly implies a few issues for today’s newsrooms. Finally, with the purpose of improving the practice of science information dissemination, the authors put forward a few proposals, namely: Increasing the training of Spanish science journalists in the field of new technologies; Emphasising the accuracy of the information and the validation of sources; Rethinking the mandates and the tasks of information professionals.

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This paper deals with the goodness of the Gaussian assumption when designing second-order blind estimationmethods in the context of digital communications. The low- andhigh-signal-to-noise ratio (SNR) asymptotic performance of the maximum likelihood estimator—derived assuming Gaussiantransmitted symbols—is compared with the performance of the optimal second-order estimator, which exploits the actualdistribution of the discrete constellation. The asymptotic study concludes that the Gaussian assumption leads to the optimalsecond-order solution if the SNR is very low or if the symbols belong to a multilevel constellation such as quadrature-amplitudemodulation (QAM) or amplitude-phase-shift keying (APSK). On the other hand, the Gaussian assumption can yield importantlosses at high SNR if the transmitted symbols are drawn from a constant modulus constellation such as phase-shift keying (PSK)or continuous-phase modulations (CPM). These conclusions are illustrated for the problem of direction-of-arrival (DOA) estimation of multiple digitally-modulated signals.

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The problem of robust beamformer design for mobile communicationsapplications in the presence of moving co-channel sources isaddressed. A generalization of the optimum beamformer based on a statisticalmodel accounting for source movement is proposed. The new methodis easily implemented and is shown to offer dramatic improvements overconventional optimum beamforming for moving sources under a varietyof operating conditions.

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A general criterion for the design of adaptive systemsin digital communications called the statistical reference criterionis proposed. The criterion is based on imposition of the probabilitydensity function of the signal of interest at the outputof the adaptive system, with its application to the scenario ofhighly powerful interferers being the main focus of this paper.The knowledge of the pdf of the wanted signal is used as adiscriminator between signals so that interferers with differingdistributions are rejected by the algorithm. Its performance isstudied over a range of scenarios. Equations for gradient-basedcoefficient updates are derived, and the relationship with otherexisting algorithms like the minimum variance and the Wienercriterion are examined.

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Printed electronics is an emerging concept in electronics manufacturing and it is in very early development stage. The technology is not stable, design kits are not developed, and flows and Computer Aided Design (CAD) tools are not fixed yet. The European project TDK4PE addresses all this issues and this PFC has been realized on this context. The goal is to develop an XML-based information system for the collection and management of information from the technology and cell libraries developed in TDK4PE. This system will ease the treatment of that information for a later generation of specific Design Kits (DK) and the corresponding documentation. This work proposes a web application to generate technology files and design kits in a formatted way; it also proposes a structure for them and a database implementation for storing the needed information. The application will allow its users to redefine the structure of those files, as well as export and import XML files, between other formats.

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Wireless Sensor Networks (WSN) are formed by nodes with limited computational and power resources. WSNs are finding an increasing number of applications, both civilian and military, most of which require security for the sensed data being collected by the base station from remote sensor nodes. In addition, when many sensor nodes transmit to the base station, the implosion problem arises. Providing security measures and implosion-resistance in a resource-limited environment is a real challenge. This article reviews the aggregation strategies proposed in the literature to handle the bandwidth and security problems related to many-to-one transmission in WSNs. Recent contributions to secure lossless many-to-one communication developed by the authors in the context of several Spanish-funded projects are surveyed. Ongoing work on the secure lossy many-to-one communication is also sketched.

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Three different pixels based on single-photon avalanche diodes for triggered applications, such as fluorescence lifetime measurements and high energy physics experiments, are presented. Each pixel consists of a 20µm x 100µm (width x length) single photon avalanche diode and a monolithically integrated readout circuit. The sensors are operated in the gated mode of acquisition to reduce the probability to detect noise counts interferring with real radiation events. Each pixel includes a different readout circuit that allows to use low reverse bias overvoltages. Experimental results demonstrate that the three pixels present a similar behaviour. The pixels get rid of afterpulses and present a reduced dark count probability by applying the gated operation. Noise figures are further improved by using low reverse bias overvoltages. The detectors exhibit an input dynamic range of 13.35 bits with short gated"on" periods of 10ns and a reverse bias overvoltage of 0.5V. The three pixels have been fabricated in a standard HV-CMOS process.

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The possible use of polyethylene naphthalate as substrate for low-temperature deposited solar cells has been studied in this paper. The transparency of this polymer makes it a candidate to be used in both substrate and superstrate configurations. ZnO:Al has been deposited at room temperature on top of PEN. The resulting structure PEN/ZnO:Al presented good optical and electrical properties. PEN has been successfully textured (nanometer and micrometer random roughness) using hot-embossing lithography. Reflector structures have been built depositing Ag and ZnO:Al on top of the stamped polymer. The deposition of these layers did not affect the final roughness of the whole. The reflector structure has been morphologically and optically analysed to verify its suitability to be used in solar cells.

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Conferència Organitzada per l'Escola Politècnica Superior, Universitat de Vic en col·laboració amb Servei d'Estadística de la Universitat Autònoma de Barcelona i CosmoCaixa Barcelona. Celebrada del 18 al 22 de juny de 2012 a Barcelona

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In this article authors present main objectives and progress of the EU ERASMUS CD project: European Study Programme for Advanced Networking Technologies (ESPANT)

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This paper analyses the determinants of broadband Internet access prices in a group of 15 EU countries between 2008 and 2011. Using a rich panel dataset of broadband plans, we show the positive effect of downstream speed on prices, and report that cable and fibre-to-the-home technologies are available at lower prices per Mbps than x DSL technology. Operators’marketing strategies are also analysed as we show how much prices rise when the broadband service is offered in a bundle with voice telephony and/or television, and how much they fall when download volume caps are included. The most insightful results of this study are provided by a group of metrics that represent the situation of competition and entry patterns in the broadband market. We show that consumer segmentation positively affects prices. On the other hand, broadband prices are higher in countries where entrants make greater use of bitstream access and lower when they use more intensively direct access -local loop unbundling-. However, we do not find a significant effect of inter-platform competition on prices.

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The paper reviews the historical transformation of the European regulatory framework for electronic communications from the era dominated by state-owned enterprises to the presence of regulated competition. In the course of these developments, the vision of the roles of the public and private sectors in electronic communications changed in expected and unexpected ways. While the period is characterized by a shift toward less direct state intervention, the intensity of regulation has increased in many areas. Most recently, in the wake of the financial crisis, new forms of state intervention can be observed, including public investment in communications infrastructure and public-private partnerships. As a result of the reforms, Europe has been able to achieve major successes but it also suffered unanticipated setbacks compared to other regions. The European Union emerged as the global leader in mobile communications during the 1990s and was able to roll-out first-generation broadband access networks more rapidly than many of its peers. Recently, however, Europe as a whole has not performed as well in deploying next-generation networks and advanced mobile communications services. The paper offers a political-economic explanation for these developments and assesses their effects on the performance of the European electronic communications sector and the economy. From this analysis, the European model emerges as a unique institutional arrangement with peculiar advantages and disadvantages. Once these are recognized, sensible next steps to build the strengths while avoiding the weaknesses of the model can be seen more clearly.

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This study was aimed to analyze and assess the use and perception of electronic health records (EHRs) by nurses. The study sample included 113 nurses from different shifts of primary health facilities in Catalonia, Spain, devoted to adult as well as pediatric outpatients using EHRs throughout the year 2010. A majority of the sample (87.5%) were women and 12.5% were men. The average age was 44.27 years and the average time working in primary healthcare was 47.15 months. A majority (80.4%) received specific training on the use of the EHR and 19.6% did not. The use of the application required side technical support (mean: 3.42) and it is considered necessary to learn more about the performance of the application (mean: 3.50). The relationship between the average ratings that nurses have about the EHR and age shows that there is no statistically significant linear relationship (r = - 0.002, p-value = 0.984). As to how long they have used the EHRs, there are significant differences (r= -0.304, p-value = 0.00), so the more time the nurse takes using the EHR, the greater degree of satisfaction is shown. In addition, there are significant differences between nurses" perceptions regarding the EHR and gender (t = - 0.421, p-value = 0.675). Nurses assessed as positive the contribution of the EHRs in their nursing care day work (average score: 2.55/5). Considering that the usability of the EHR device is assessed as satisfactory, the results of the perception of nurses show that we must also take into account the training and emphasize the need for a side technical support in the implementation process of the EHR. Doing so, the positive perception that nurses have in regard to information and communication technology in general and with respect to the EHR in particular may be increased.

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This study was aimed to analyze and assess the use and perception of electronic health records (EHRs) by nurses. The study sample included 113 nurses from different shifts of primary health facilities in Catalonia, Spain, devoted to adult as well as pediatric outpatients using EHRs throughout the year 2010. A majority of the sample (87.5%) were women and 12.5% were men. The average age was 44.27 years and the average time working in primary healthcare was 47.15 months. A majority (80.4%) received specific training on the use of the EHR and 19.6% did not. The use of the application required side technical support (mean: 3.42) and it is considered necessary to learn more about the performance of the application (mean: 3.50). The relationship between the average ratings that nurses have about the EHR and age shows that there is no statistically significant linear relationship (r = - 0.002, p-value = 0.984). As to how long they have used the EHRs, there are significant differences (r= -0.304, p-value = 0.00), so the more time the nurse takes using the EHR, the greater degree of satisfaction is shown. In addition, there are significant differences between nurses" perceptions regarding the EHR and gender (t = - 0.421, p-value = 0.675). Nurses assessed as positive the contribution of the EHRs in their nursing care day work (average score: 2.55/5). Considering that the usability of the EHR device is assessed as satisfactory, the results of the perception of nurses show that we must also take into account the training and emphasize the need for a side technical support in the implementation process of the EHR. Doing so, the positive perception that nurses have in regard to information and communication technology in general and with respect to the EHR in particular may be increased.