773 resultados para issues in GIS
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Includes bibliography
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Includes bibliography
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Includes bibliography
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The United Nations Economic Commission for Latin America and the Caribbean (ECLAC) is seeking to provide support to the Governments of Guyana, Jamaica and Barbados in researching the potential for employing renewable energy technologies to mitigate climate change. This exercise involves the study of different types of renewable technologies and mitigative strategies, with the aim of making recommendations to the governments on the development of their renewable energy sector. The recommendations may also assist in achieving their long-term objectives of reducing poverty and promoting healthy economies and sustainable livelihoods in keeping with the Millennium Development Goals. Guyana, Jamaica and Barbados each face common and specific challenges in their efforts to adequately define and implement their energy and climate policies, in a way that allows them to contribute to the mitigation effort against climate change, while promoting sustainable development within their countries. Each country has demonstrated an understanding of the global and national challenges pertaining to climate change. They have attempted to address these challenges through policies and various programmes implemented by local and international agencies. Documented and undocumented policies have sought to outline the directions to be taken by each territory as they seek to deploy new technologies to address issues related to energy and the environment. While all territories have sought to deploy multiple alternate and renewable technologies simultaneously, it is clear that, given their sizes and resource limitations, no one territory can achieve excellence in all these areas. Guyana has demonstrated the greatest potential for hydro energy and should pursue it as their main area of expertise. The country also has an additional major strategy that includes forest credits and the Reduced Emissions from Deforestation and Degradation (REDD) programme. This approach will be brought to the negotiation table in the upcoming climate change meeting in Copenhagen in December 2009. Of the three countries, Jamaica has the only active significant wind farm deployment, while Barbados has a long tradition in solar energy. Each country might then supplement their energy and fuel mix with other energy and fuel sources and draw from the experience of other countries. Given the synergies that might accrue from adopting a regional approach, the Caribbean Community Climate Change Centre (CCCCC) might be well positioned to play a coordinating role. This focus on renewable energy and biofuels should yield good, long-term results as it relates to mitigation against climate change, and good, short- and medium-term results as it relates to the development of sustainable economies. Each country might also achieve energy security, reduced oil dependence, significant reduction in harmful emissions and better foreign exchange management if they pursue good policies and implementation practices. Human and financial resources are critical to the success of planned interventions, and it will be necessary to successfully mobilize these resources in order to be effective in executing key plans.
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Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)
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In this paper, we perform a thorough analysis of a spectral phase-encoded time spreading optical code division multiple access (SPECTS-OCDMA) system based on Walsh-Hadamard (W-H) codes aiming not only at finding optimal code-set selections but also at assessing its loss of security due to crosstalk. We prove that an inadequate choice of codes can make the crosstalk between active users to become large enough so as to cause the data from the user of interest to be detected by other user. The proposed algorithm for code optimization targets code sets that produce minimum bit error rate (BER) among all codes for a specific number of simultaneous users. This methodology allows us to find optimal code sets for any OCDMA system, regardless the code family used and the number of active users. This procedure is crucial for circumventing the unexpected lack of security due to crosstalk. We also show that a SPECTS-OCDMA system based on W-H 32(64) fundamentally limits the number of simultaneous users to 4(8) with no security violation due to crosstalk. More importantly, we prove that only a small fraction of the available code sets is actually immune to crosstalk with acceptable BER (<10(-9)) i.e., approximately 0.5% for W-H 32 with four simultaneous users, and about 1 x 10(-4)% for W-H 64 with eight simultaneous users.
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Mapping of soil has been highlighted in the scientific community, because as alertness about the environment increases, it is necessary to understand more and more about the distribution of the soil in the landscape, as well as its potential and its limitations for the use. In that way the main aim of this study was to apply indices representing landscape with the use of geoprocessing to give support in the delimitation of different compartments of landscape. Primary indices used were altitude above channel network (AACN) and secondary channel network base level (CNBL), multiresolution index of valley bottom flatness (MRVBF) and Wetness index (ITW), having as object of study the Canguiri Experimental Farm, located in Pinhais, Curitiba's Metropolitan region. To correlate the chemical attributes and granulometric ones in sampling groups, totalizing 17 points (Sugamosto, 2002), a matrix of a simple linear correlation (Pearson) with the indices of the landscape were generated in the Software Statistica. The conclusion is that the indices representing the landscape used in the analysis of groupings were efficient as support to map soil at the level of suborder of Brazilian Soil Classification System.