1,894 research outputs found

    Multilevel governance patterns and the protection of groundwater and drinking water in Florida and the Netherlands

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    This paper develops a model of ‘governance’ as an aid for comparing such\ud governance structures and applies these to a particular policy arena: policies\ud on the protection of groundwater and on drinking water quality in the\ud Netherlands and Florida.\ud The research questions examined by this paper are:\ud 1. Which elements make up a governance structure?\ud 2. In what ways do these elements influence each other?\ud 3. What are the differences between the multilevel structure of protection for\ud aquifers in Florida and the Netherlands, and how do these differences\ud relate to other differences in the governance structure?\ud The analysis in this paper has shown that ‘governance’ involves more\ud elements than policy objectives and the means to implement policy. These\ud elements are not simply the sum of individual aspects but are closely\ud interlinked. We have tried to illustrate how these interrelations work. The case\ud study we used for this was the comparison between the Netherlands and\ud Florida regarding the protection of the quality of groundwater and drinking\ud water. The high degree of similarity between both states highlights the\ud differences, which exist as well. The interrelations between these differences\ud can be understood by using our hypotheses of the mechanisms by which they\ud work

    An Efficient Data-aided Synchronization in L-DACS1 for Aeronautical Communications

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    L-band Digital Aeronautical Communication System type-1 (L-DACS1) is an emerging standard that aims at enhancing air traffic management (ATM) by transitioning the traditional analog aeronautical communication systems to the superior and highly efficient digital domain. L-DACS1 employs modern and efficient orthogonal frequency division multiplexing (OFDM) modulation technique to achieve more efficient and higher data rate in comparison to the existing aeronautical communication systems. However, the performance of OFDM systems is very sensitive to synchronization errors. L-DACS1 transmission is in the L-band aeronautical channels that suffer from large interference and large Doppler shifts, which makes the synchronization for L-DACS more challenging. This paper proposes a novel computationally efficient synchronization method for L-DACS1 systems that offers robust performance. Through simulation, the proposed method is shown to provide accurate symbol timing offset (STO) estimation as well as fractional carrier frequency offset (CFO) estimation in a range of aeronautical channels. In particular, it can yield excellent synchronization performance in the face of a large carrier frequency offset.Comment: In the proceeding of International Conference on Data Mining, Communications and Information Technology (DMCIT

    Energy-efficiency improvements for optical access

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    This article discusses novel approaches to improve energy efficiency of different optical access technologies, including time division multiplexing passive optical network (TDM-PON), time and wavelength division multiplexing PON (TWDM-PON), point-to-point (PTP) access network, wavelength division multiplexing PON (WDM-PON), and orthogonal frequency division multiple access PON (OFDMA-PON). These approaches include cyclic sleep mode, energy-efficient bit interleaving protocol, power reduction at component level, or frequency band selection. Depending on the target optical access technology, one or a combination of different approaches can be applied
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