954 resultados para alternative economic networks
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The paper describes a novel neural model to estimate electrical losses in transformer during the manufacturing phase. The network acts as an identifier of structural features on electrical loss process, so that output parameters can be estimated and generalized from an input parameter set. The model was trained and assessed through experimental data taking into account core losses, copper losses, resistance, current and temperature. The results obtained in the simulations have shown that the developed technique can be used as an alternative tool to make the analysis of electrical losses on distribution transformer more appropriate regarding to manufacturing process. Thus, this research has led to an improvement on the rational use of energy.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Open access philosophy applied by regulatory agencies may lead to a scenario where captive consumers will solely face the responsibility on distribution network's losses even with Independent Energy Producers (also known as Distributed Generation) and Independent Energy Consumers connected to the system. This work proposes the utilization of a loss allocation method in distribution systems where open access is allowed, in which cross-subsidies, that appear due to the influence the generators have over the system losses, are minimized. Thus, guaranteeing to some extent the efficiency and transparency of the economic signals of the market. Results obtained through the Zbus loss allocation method adapted for distribution networks are processed in such a way that the corresponding allocation to the generation buses is divided among the consumer buses, while still considering consumers spatial characteristics. © 2007 IEEE.
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In this work, a heuristic model for integrated planning of primary distribution network and secondary distribution circuits is proposed. A Tabu Search (TS) algorithm is employed to solve the planning of primary distribution networks. Evolutionary Algorithms (EA) are used to solve the planning model of secondary networks. The planning integration of both networks is carried out by means a constructive heuristic taking into account a set of integration alternatives between these networks. These integration alternatives are treated in a hierarchical way. The planning of primary networks and secondary distribution circuits is carried out based on assessment of the effects of the alternative solutions in the expansion costs of both networks simultaneously. In order to evaluate this methodology, tests were performed for a real-life distribution system taking into account the primary and secondary networks.
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This work presents an alternative approach based on neural network method in order to estimate speed of induction motors, using the measurement of primary variables such as voltage and current. Induction motors are very common in many sectors of the industry and assume an important role in the national energy policy. The nowadays methodologies, which are used in diagnosis, condition monitoring and dimensioning of these motors, are based on measure of the speed variable. However, the direct measure of this variable compromises the system control and starting circuit of an electric machinery, reducing its robustness and increasing the implementation costs. Simulation results and experimental data are presented to validate the proposed approach. © 2003-2012 IEEE.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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There are significant, fundamental changes taking place in global air and sea surface temperatures and sea levels. The Fourth Assessment Report of the Intergovernmental Panel on Climate Change noted that many of the warmest years on the instrumental record of global surface temperatures have occurred within the last twelve years, i.e. 1995-2006 (IPCC, 2007). The Caribbean tourism product is particularly vulnerable to climate change. On the demand side, mitigation measures in other countries – for example, measures to reduce the consumption of fossil fuels – could have implications for airfares and cruise prices and, therefore, for the demand for travel, particularly to long-haul destinations such as the Caribbean (Clayton, 2009). On the supply side, sea level rise will cause beaches to disappear and damage coastal resorts. Changes in the frequency and severity of hurricanes are likely to magnify that damage. Other indirect impacts on the tourism product include rising insurance premiums and competition for water resources (Cashman, Cumberbatch, & Moore, 2012). The present report has used information on historic and future Caribbean climate data to calculate that the Caribbean tourism climatic index (TCI) ranges from −20 (impossible) to +100 (ideal). In addition to projections for the Caribbean, the report has produced TCI projections for the New York City area (specifically, Central Park), which have been used as comparators for Caribbean country projections. The conditions in the source market provide a benchmark against which visitors may judge their experience in the tourism destination. The historical and forecasted TCIs for the Caribbean under both the A2 and B2 climate scenarios of the IPCC suggest that climatic conditions in the Caribbean are expected to deteriorate, and are likely to become less conducive to tourism. More specifically, the greatest decline in the TCI is likely to occur during the northern hemisphere summer months from May to September. At the same time, the scenario analysis indicates that home conditions during the traditional tourist season (December – April) are likely to improve, which could make it more attractive for visitors from these markets to consider ‘staycations’ as an alternative to overseas trips.
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Expertise, skills, experiences, understandings and capabilities (knowledge) aid development, not just by informing decision-making, but also by providing ideas for actions and activities that can be taken. Due to their size, and economic and environmental vulnerabilities, Caribbean Small Island developing States (SIDS) faces special challenges when working towards their economic, social and environmental development goals. These challenges have contributed to the creation of knowledge gaps, and that which is already available is located in isolated pockets, throughout the Caribbean. Migration of skilled persons compounds the issue, thereby removing much needed knowledge to beyond the traditional borders of the Caribbean. It is necessary to find ways to connect these dispersed knowledge resources. Knowledge networks are tools that can connect the existing skills, expertise, experiences and understandings accessible and create new ones to move towards greater development in the Caribbean. The purpose of this paper is to explore and highlight the role that knowledge networks can play as an aid in the development of Caribbean SIDS. It offers, with Caribbean examples, definitions and discussions of the components, types, and the advantages and disadvantages they hold for the subregion. The paper goes further to provide some ideas on assembling and analysing the different types of knowledge networks. It concludes with a few recommendations geared toward improving the availability of knowledge in the Caribbean.
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This report analyses the agriculture, energy, and health sectors in Trinidad and Tobago to assess the potential economic impacts of climate change on the sectors. The fundamental aim of this report is to assist with the development of strategies to deal with the potential impact of climate change on Trinidad and Tobago. It also has the potential to provide essential input for identifying and preparing policies and strategies to help advance the Caribbean subregion closer to solving problems associated with climate change and attaining individual and regional sustainable development goals. Some of the key anticipated impacts of climate change for the Caribbean include elevated air and sea-surface temperatures, sea-level rise, possible changes in extreme events and a reduction in freshwater resources. The economic impact of climate change on the three sectors was estimated for the A2 and B2 IPCC scenarios until 2050. An exploration of various adaptation strategies was also undertaken for each sector using standard evaluation techniques. The study of the impact of climate change on the agriculture sector focused on root crops, green vegetables and fisheries. For these sectors combined, the cumulative loss under the A2 scenario is calculated as approximately B$2.24 and approximately B$1.72 under the B2 scenario by 2050. This is equivalent to 1.37% and 1.05% of the 2008 GDP under the A2 and B2 scenarios, respectively. Given the potential for significant damage to the agriculture sector a large number of potential adaptation measures were considered. Out of these a short-list of 10 potential options were selected by applying 10 evaluation criteria. All of the adaptation strategies showed positive benefits. The analysis indicate that the options with the highest net benefits are: (1) Building on-farm water storage, (2) Mainstreaming climate change issues into agricultural management and (3) Using drip irrigation. Other attractive options include water harvesting. The policy decisions by governments should include these assessments, the omitted intangible benefits, as well as the provision of other social goals such as employment. The analysis of the energy sector has shown that the economic impact of climate change during 2011-2050 is similar under the A2 (US$142.88 million) and B2 (US$134.83 million) scenarios with A2 scenario having a slightly higher cost (0.737% of 2009 GDP) than the B2 scenario (0.695% of 2009 GDP) for the period. On the supply side, analyses indicate that Trinidad and Tobago’s energy sector will be susceptible to the climate change policies of major energy-importing countries (the United States of America and China), and especially to their renewable energy strategies. Implementation of foreign oil substitution policy by the United States of America will result in a decline in Trinidad and Tobago’s Liquefied Natural Gas (LNG) export (equivalent to 2.2% reduction in 2009 GDP) unless an alternative market is secured for the lost United States of America market. China, with its rapid economic growth and the highest population in the world, offers a potential replacement market for Trinidad and Tobago’s LNG export. In this context the A2 scenario will offer the best option for Trinidad and Tobago’s energy sector. The cost-benefit analysis undertaken on selected adaptation strategies reveal that the benefit-cost ratio of replacing electric water heaters with solar water heaters is the most cost-effective. It was also found that the introduction of Compact Fluorescent Light (CFL) and Variable Refrigerant Volume (VRV) air conditioners surpasses the projected cost of increased electricity consumption due to climate change, and provides an economic rationale for the adoption of these adaptation options even in a situation of increased electricity consumption occasioned by climate change. Finally, the conversion of motor fleets to Compressed Natural Gas (CNG) is a cost-effective adaptation option for the transport sector, although it has a high initial cost of implementation and the highest per capita among the four adaptation options evaluated. To investigate the effect of climate change on the health sector dengue fever, leptospirosis, food borne illnesses, and gastroenteritis were examined. The total number of new dengue cases for the period 2008 to 2050 was 204,786 for BAU, 153,725 for A2 and 131,890 for the B2 scenario. With regard to the results for leptospirosis, A2 and B2 seem to be following a similar path with total number of new cases in the A2 scenario being 9,727 and 9,218 cases under the B2 scenario. Although incidence levels in the BAU scenario coincided with those of A2 and B2 prior to 2020, they are somewhat lower post 2020. A similar picture emerges for the scenarios as they relate to food-borne illnesses and to gastroenteritis. Specifically for food-borne illnesses, the BAU scenario recorded 27,537 cases, the A2 recorded 28,568 cases and the B2 recorded 28,679 cases. The focus on the selected sources of morbidity in the health sector has highlighted the fact that the vulnerability of the country’s health sector to climate change does not depend solely on exogenously derived impacts, but also on the behaviour and practices among the population. It is clear that the vulnerability which became evident in the analysis of the impacts on dengue fever, leptospirosis and food-borne illnesses is not restricted solely to climate or other external factors. The most important adaptation strategy being recommended targets lifestyle, behaviour and attitude changes. The population needs to be encouraged to alter their behaviours and practices so as to minimise their exposure to harmful outcomes as it relates to the incidence of these diseases.