• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 78
  • 52
  • 29
  • 21
  • 12
  • 7
  • 5
  • 3
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 251
  • 65
  • 46
  • 44
  • 29
  • 28
  • 24
  • 24
  • 23
  • 23
  • 22
  • 20
  • 20
  • 19
  • 19
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
241

Critérios para identificação de veículos leves do ciclo Otto com elevadas emissões, utilizando dispositivo de sensoriamento remoto / Criteria for identification of Otto cycle light duty vehicles with high emissions, using remote sensing device

Bruni, Antonio de Castro 12 March 2018 (has links)
Ocorrem anualmente aproximadamente 600.000 mortes de crianças com até cinco anos, no mundo. Pneumonia é a principal causa e mais de 50 por cento destas mortes são atribuídas à poluição do ar. Ela ainda é responsável pelo aumento do risco de infecções respiratórias, asma, condições neonatais adversas e anomalias congênitas. A poluição do ar também afeta o desenvolvimento cognitivo de crianças e induz o desenvolvimento de doenças crônicas na idade adulta. Entre 70 e 80 por cento da poluição do ar em nações em desenvolvimento são de origem veicular. Objetivando definir critérios baseados em medições com sensoriamento remoto para identificação de veículos automotores leves do ciclo Otto com elevadas emissões de monóxido de carbono, hidrocarbonetos ou óxido nítrico, foram utilizados os dados secundários gerados pela Remote Sensing do Brasil Ltda dos quais foram selecionados 179.142 veículos em uso da frota circulante da cidade de São Paulo com medições completas dos índices de emissão dos poluentes monóxido de carbono (CO), hidrocarbonetos (HC) e óxido nítrico (NO) e ainda velocidade e aceleração do veículo quando da medição e inclinação da pista no local escolhido para as medições. Foram ajustados modelos estatísticos da classe Generalised Additive Models for Location, Scale and Shape (GAMLSS) visando testar a influência do Tipo de Combustível, da Potência Específica do Veículo (VSP) e das Fases do Programa de Controle da Poluição do Ar por Veículos Automotores (Proconve) sobre as emissões de CO, HC e NO, medidos usando o Remote Sensing Device (RSD). As emissões foram então conceitualmente subdivididas em dois grupos: veículos com emissões normais e com emissões anormais, isso para os diversos poluentes em veículos das Fases L3, L4 e L5 que são as fases de interesse para o gerenciamento da qualidade do ar. Variáveis latentes foram definidas para indicarem as distribuições dos veículos em relação a esses grupos e Fases. O algoritmo Expectation-Maximization (EM) foi empregado para identificação dos parâmetros das distribuições. Para determinação dos valores associados aos veículos com elevadas emissões de determinado poluente e fase do Proconve, foi empregado o percentil 98 por cento da distribuição ajustada para os veículos dos grupos com emissões normais. Assim sendo, o Erro de Tipo I foi fixado em 2 por cento sendo que esse percentual foi estabelecido considerando o Erro de Tipo II, de apontar o veículo como tendo emissão normal quando na realidade trata-se de um high emitter. Através desta abordagem foram determinados os valores indicativos de veículos com elevadas emissões segundo o poluente e a Fase do Proconve. Os resultados apontaram decréscimo nas emissões de CO e de HC segundo as Fases do Proconve. Para o NO, o comportamento das emissões não acompanhou as reduções impostas pelas Fases do Proconve. Foi constatado que os veículos de 2005 a 2009, movidos exclusivamente a gasool, foram os que apresentaram as maiores emissões de NO. Diversos possíveis fatores causadores deste comportamento diferenciado do NO foram discutidos neste trabalho. Os dados de qualidade do ar detectaram aumento significativo nas concentrações ambientais de Óxidos de Nitrogênio (NOx) em 2007, quando foi monitorado este parâmetro no período de inverno, o que pode indicar a influência dos high emitters, mas necessita de estudos mais aprofundados para confirmação da causa deste comportamento. / Approximately 600,000 deaths occur worldwide annually for children up to five years of age. Pneumonia is the leading cause and more than 50 per cent of these deaths are attributed to air pollution. It is still responsible for increased risk of respiratory infections, asthma, adverse neonatal conditions and congenital anomalies. Air pollution also affects the cognitive development of children and induces future development of chronic diseases in adulthood. In order to define criteria based on remote sensing measurements to identify Otto cycle light duty vehicles (LDV) with high emissions of carbon monoxide, hydrocarbons or nitric oxide it was used secondary data produced by Remote Sensing do Brasil Ltda, from which 179,142 inuse vehicles were selected, that belongs to the city of São Paulos current fleet. All those vehicles had complete measurements of emission of carbon monoxide (CO), hydrocarbons (HC) and nitric oxide (NO), and also speed and acceleration of the vehicle during measurements, and slope of the track at the place chosen for the measurements. Statistical models of the Generalized Additive Models for Location, Scale and Shape (GAMLSS) class were adjusted to test the influence of fuel type, Vehicle Specific Power (VSP) and of the Brazilian Vehicle Emission Control Program [Proconve] phases on CO, HC and NO emissions, measured using Remote Sensing Device (RSD). The emissions were then conceptually subdivided into two groups: vehicles with normal and abnormal emission, for the various pollutants in vehicles of L3, L4 and L5 phases of Proconve, which were of interest for the air quality management. Latent variables were defined to indicate the distribution of vehicles in relation to those groups and phases. The algorithm Expectation Maximization (EM) was employed to identify all parameters of the distributions. We use the 98 per cent percentiles of the statistical distribution set, for vehicles of groups with normal emissions to determine the limit values for vehicles with high emissions of pollutants and Proconve Phase. Therefore, the Type I Error was set at 2 per cent and this percentage was established considering the Type II Error to point the vehicle as having normal emission when in fact it is a high emitter. Through this approach, the indicative values of vehicles with high emissions according to the pollutant and the Proconve Phase were determined. Results of emissions measured with the RSD technique indicated a decrease in CO and HC emissions according to the Proconve Phase. For the NO, the emissions behavior did not follow the reductions imposed by the Proconve Phases. It was found that newer vehicles year model from 2005 to 2009 exclusively gasohol-powered vehicles, were the ones that presented the highest NO emissions. Several possible causative factors of this differential behavior of NO were discussed in this study. A significant increase in the environmental concentrations of Nitrogen Oxides (NOx) was detected in 2007, when this parameter was monitored in the winter period. This may indicate the influence of the high emitter vehicles, but it requires a more in-depth cause-effect study for confirmation of this behavior.
242

La Russie en Arctique occidental : strategies d'Etat et interactions des acteurs / Russia in the Occidental Arctic, State Strategies and Interactions among actors

Alvarado, Adrian 17 October 2016 (has links)
Au cours de la première décennie du XXIe siècle l'Arctique a fait l’objet d’une attention croissante de la part des chercheurs, des politiciens et des multinationales. En effet, les problématiques liées au changement climatique, et le regain d’interêt politique et économique des Etats côtiers et non côtiers, a peu à peu fait apparaître cette région comme un endroit stratégique sur l'échiquier des grandes puissances. Depuis 2001, la Fédération de Russie a entrepris plusieurs actions afin de garantir ses intérêts nationaux dans ce qu'elle considère comme l’Arctique russe, un espace qui comprend environ 22600 kilomètres de littoral avec l'océan Arctique. Or, le changement climatique, les développements socio-économiques et les impératifs stratégiques ont conditionné cette politique pour l’Arctique. Les oblasts de Mourmansk et d’Arkhangelsk jouent, de nos jours, un rôle majeur dans la mise en œuvre de la stratégie russe pour la région arctique. Ce travail évaluera donc les défis majeurs de stratégie et de sécurité nationale russes en Arctique occidental au regard des récents changements du modèle politique et économique russe, du rôle émergent d'acteurs privés et étrangers ainsi que des spécificités des régions arctiques et sous-arctiques. Dans une première partie de notre travail nous essayerons de souligner l’importance stratégique et économique de l’Arctique Occidental pour la Fédération de Russie. Une approche historique nous permettra de mieux comprendre le rôle actuel des oblasts de Mourmansk et d’Arkhangelsk tandis que l’analyse de l’évolution démographique, industrielle et commerciale de ces régions nous fera apprécier son potentiel socio-économique. Enfin, une analyse de l’adaptation des industries énergétiques et du complexe militaro-industriel aux marchés internationaux sera entreprise ainsi qu’une évaluation des risques liés au changement climatique et à la pollution industrielle. Dans une deuxième partie, nous analyserons les principales problématiques rencontrés par les acteurs étatiques et privés en Arctique occidental. Afin d’identifier les principaux enjeux, nous avons transposé des théories des relations internationales à la géopolitique (Waltz, Keohane, Putnam). Tout particulièrement, nous utiliserons pour cette analyse les modèles conceptuels de Graham Allison et son approche sur les intérêts nationaux. / During the first decade of the XXIth century, the Arctic has received growing attention from scholars, policymakers and multinational corporations. Climate change as well as renewed political and economical interests from coastal and non-coastal States had repositioned this region as a prospective theater in the Great powers chessboard. Since 2001, the Russian Federation has taken several international and domestic actions to guarantee its national interest in what it considers as the Russian Arctic, a space that comprises about 22 600 kilometers of national coastline with the Arctic Ocean. But climate change, historical socio-economic developments and strategic imperatives have conditioned this engagement.The Murmansk and Arkhangelsk oblasts plays nowadays a leading role in the implementation of a cross-domain Russian strategy for the Arctic region. This dissertation will then assess the central challenges of Russian National Security and Strategy in the Occidental Arctic taking in consideration recent changes in the Russian Federation political and economical model, the emerging role of private and foreign actors and the specificity of Arctic and sub-Arctic regions.The first part of this dissertation will try to underline the past/current strategic and economical relevance of the Occidental Arctic for the Russian Federation. A historical approach will allow us to better understand the current role of Murmansk and Arkhangelsk oblasts while we will appreciate its socio-economic potential thanks to the analysis of demographic, industrial and commercial developments of these regions. Finally, a study on defense and energy industries adaptation to international markets will be conducted as well as a regional risk-assessment concerning climate change and industrial pollution.In a second part, our main objective is to demonstrate the strategic and economical importance of the Murmansk and Arkhangelsk oblasts for the Russian Arctic policy. This will lead us to analyse core issues in the Occidental Arctic for state and industry actors. The methodology applied to identify the main trends in these issues is a combination of the French school of geopolitics with relevant theories of international relations (Waltz, Keohane, Putnam). Graham Allison’s conceptual models and his approach on national interests will be applied in the analysis.
243

Critérios para identificação de veículos leves do ciclo Otto com elevadas emissões, utilizando dispositivo de sensoriamento remoto / Criteria for identification of Otto cycle light duty vehicles with high emissions, using remote sensing device

Antonio de Castro Bruni 12 March 2018 (has links)
Ocorrem anualmente aproximadamente 600.000 mortes de crianças com até cinco anos, no mundo. Pneumonia é a principal causa e mais de 50 por cento destas mortes são atribuídas à poluição do ar. Ela ainda é responsável pelo aumento do risco de infecções respiratórias, asma, condições neonatais adversas e anomalias congênitas. A poluição do ar também afeta o desenvolvimento cognitivo de crianças e induz o desenvolvimento de doenças crônicas na idade adulta. Entre 70 e 80 por cento da poluição do ar em nações em desenvolvimento são de origem veicular. Objetivando definir critérios baseados em medições com sensoriamento remoto para identificação de veículos automotores leves do ciclo Otto com elevadas emissões de monóxido de carbono, hidrocarbonetos ou óxido nítrico, foram utilizados os dados secundários gerados pela Remote Sensing do Brasil Ltda dos quais foram selecionados 179.142 veículos em uso da frota circulante da cidade de São Paulo com medições completas dos índices de emissão dos poluentes monóxido de carbono (CO), hidrocarbonetos (HC) e óxido nítrico (NO) e ainda velocidade e aceleração do veículo quando da medição e inclinação da pista no local escolhido para as medições. Foram ajustados modelos estatísticos da classe Generalised Additive Models for Location, Scale and Shape (GAMLSS) visando testar a influência do Tipo de Combustível, da Potência Específica do Veículo (VSP) e das Fases do Programa de Controle da Poluição do Ar por Veículos Automotores (Proconve) sobre as emissões de CO, HC e NO, medidos usando o Remote Sensing Device (RSD). As emissões foram então conceitualmente subdivididas em dois grupos: veículos com emissões normais e com emissões anormais, isso para os diversos poluentes em veículos das Fases L3, L4 e L5 que são as fases de interesse para o gerenciamento da qualidade do ar. Variáveis latentes foram definidas para indicarem as distribuições dos veículos em relação a esses grupos e Fases. O algoritmo Expectation-Maximization (EM) foi empregado para identificação dos parâmetros das distribuições. Para determinação dos valores associados aos veículos com elevadas emissões de determinado poluente e fase do Proconve, foi empregado o percentil 98 por cento da distribuição ajustada para os veículos dos grupos com emissões normais. Assim sendo, o Erro de Tipo I foi fixado em 2 por cento sendo que esse percentual foi estabelecido considerando o Erro de Tipo II, de apontar o veículo como tendo emissão normal quando na realidade trata-se de um high emitter. Através desta abordagem foram determinados os valores indicativos de veículos com elevadas emissões segundo o poluente e a Fase do Proconve. Os resultados apontaram decréscimo nas emissões de CO e de HC segundo as Fases do Proconve. Para o NO, o comportamento das emissões não acompanhou as reduções impostas pelas Fases do Proconve. Foi constatado que os veículos de 2005 a 2009, movidos exclusivamente a gasool, foram os que apresentaram as maiores emissões de NO. Diversos possíveis fatores causadores deste comportamento diferenciado do NO foram discutidos neste trabalho. Os dados de qualidade do ar detectaram aumento significativo nas concentrações ambientais de Óxidos de Nitrogênio (NOx) em 2007, quando foi monitorado este parâmetro no período de inverno, o que pode indicar a influência dos high emitters, mas necessita de estudos mais aprofundados para confirmação da causa deste comportamento. / Approximately 600,000 deaths occur worldwide annually for children up to five years of age. Pneumonia is the leading cause and more than 50 per cent of these deaths are attributed to air pollution. It is still responsible for increased risk of respiratory infections, asthma, adverse neonatal conditions and congenital anomalies. Air pollution also affects the cognitive development of children and induces future development of chronic diseases in adulthood. In order to define criteria based on remote sensing measurements to identify Otto cycle light duty vehicles (LDV) with high emissions of carbon monoxide, hydrocarbons or nitric oxide it was used secondary data produced by Remote Sensing do Brasil Ltda, from which 179,142 inuse vehicles were selected, that belongs to the city of São Paulos current fleet. All those vehicles had complete measurements of emission of carbon monoxide (CO), hydrocarbons (HC) and nitric oxide (NO), and also speed and acceleration of the vehicle during measurements, and slope of the track at the place chosen for the measurements. Statistical models of the Generalized Additive Models for Location, Scale and Shape (GAMLSS) class were adjusted to test the influence of fuel type, Vehicle Specific Power (VSP) and of the Brazilian Vehicle Emission Control Program [Proconve] phases on CO, HC and NO emissions, measured using Remote Sensing Device (RSD). The emissions were then conceptually subdivided into two groups: vehicles with normal and abnormal emission, for the various pollutants in vehicles of L3, L4 and L5 phases of Proconve, which were of interest for the air quality management. Latent variables were defined to indicate the distribution of vehicles in relation to those groups and phases. The algorithm Expectation Maximization (EM) was employed to identify all parameters of the distributions. We use the 98 per cent percentiles of the statistical distribution set, for vehicles of groups with normal emissions to determine the limit values for vehicles with high emissions of pollutants and Proconve Phase. Therefore, the Type I Error was set at 2 per cent and this percentage was established considering the Type II Error to point the vehicle as having normal emission when in fact it is a high emitter. Through this approach, the indicative values of vehicles with high emissions according to the pollutant and the Proconve Phase were determined. Results of emissions measured with the RSD technique indicated a decrease in CO and HC emissions according to the Proconve Phase. For the NO, the emissions behavior did not follow the reductions imposed by the Proconve Phases. It was found that newer vehicles year model from 2005 to 2009 exclusively gasohol-powered vehicles, were the ones that presented the highest NO emissions. Several possible causative factors of this differential behavior of NO were discussed in this study. A significant increase in the environmental concentrations of Nitrogen Oxides (NOx) was detected in 2007, when this parameter was monitored in the winter period. This may indicate the influence of the high emitter vehicles, but it requires a more in-depth cause-effect study for confirmation of this behavior.
244

Robert Searle and the Rise of the English in the Caribbean

Alford, Brandon Wade 01 January 2019 (has links)
This research examines the career of Robert Searle, an English privateer, that conducted state-sponsored attacks against the Spanish and Dutch in the Caribbean from 1655 to 1671. Set within the Buccaneering Period of the Golden Age of Piracy (1650-1680), Robert Searle’s personal actions contributed to the rise of the English in the Caribbean to a position of dominance over Spain, which dominated the region from 1492 until the 1670s. Searle serves as a window into the contributions of thousands of nameless men who journeyed to the Caribbean as a member of Oliver Cromwell’s Western Design Fleet. These men failed in their endeavor to take Hispaniola from the Spanish, successfully invaded Jamaica, and spent the next fifteen years securing England’s largest possession in the region, transitioning Jamaica from a military outpost to a successful plantation colony. These men, including Searle himself, have been overshadowed in the history of English Jamaica by more well-known figures such as Sir Henry Morgan, the famed “Admiral of the Buccaneers.” Searle and his compatriots pursued the objectives of the core in London throughout the contested periphery of the Caribbean region. These goals were first framed as the complete destruction of the Spanish Empire in the Americas and later as achieving trade between Jamaica and Spain’s American colonies. The examination of Robert Searle through the core-periphery relationship between the metropole and the Caribbean illustrates how the totality of his actions contributed to the rising English position in the Caribbean. Ultimately, Searle and his fellow privateers proved vital to Spain conceding to England the rights of trade and formal recognition of their colonies in the region with a series of succeeding Treaties of Madrid.
245

Impact of a landing obligation on coupled dynamics ecosystem-fishers : individual-based modelling approach applied to Eastern English Channel / Impact d'une obligation de débarquement sur les dynamiques couplées écosystème-pêcheurs : approche par modélisation individu-centrée appliquée à la Manche Orientale

Bourdaud, Pierre 23 January 2018 (has links)
L'objectif de cette thèse était d'anticiper les effets de l'Obligation de Débarquement (OD) mise en place en UE depuis début 2015 en Manche Orientale (MO). Pour accomplir ces objectifs, il a été prévu de : i) mieux comprendre la distribution spatiale saisonnière d'espèces commerciales à l'aide d'observations embarquées sur des navires commerciaux, ii) les comparer avec la distribution de l'effort de pêche à fine échelle des chalutiers de fonds (OTB), et iii) développer un modèle individu-centré de dynamique des flotilles, DSVM, à intégrer avec le modèle écosystémique OSMOSE pour simuler l'OD. L'utilité des données d'observations embarquées a été prouvée pour une majeure partie des espèces échantillonnées, en utilisant une validation par la bibliographie et un indicateur géostatique. Ensuite la comparaison de l'effort de pêche à fine échelle a fourni une amélioration de la quantification de l'effort de pêche effectif et mis en valeur l'importance de la seiche et du rouget barbet pour la distribution des OTB en MO. De plus, l'intensité de ciblage des OTB a été quantifiée en octobre à l'aide d'un nouvel indicateur, et démontré l'intérêt pour les mêmes espèces, mais aussi la contrainte d'un faible quota de cabillaud pour les pêcheurs. Les résultats du couplage OSMOSE-DSVM montrent que k'OD aurait des effets négatifs à court terme pour le revenu des pêcheurs, induits par le déplacement de l'effort de pêche afin d'éviter les dépassements de quota, mais serait profitable à moyen terme. Cependant, l'OD provoquerait une hausse de la pression de prédation produite par le cabillaud et le merlan sur les autres espèces, ce qui n'améliorerait pas l'état global de l'écosystème. / The objective of this thesis was to anticipate the effects if the EU Landing Obligation (LO) implemented since the beginning of 2015 in the Eastern English Channel (EEC). To achieve these objectives, it was planned to : i) better understand seasonal spatial distribution of commercial species using on-board commercial vessels observation data, ii) compare them with the final scale fishing effort distribution of EEC bottom otter trawlers (OTB), and iii) develop an individual-based model of fleet-dynamics, DSVM, to be integrated within the ecosystem model OSMOSE to simulate a LO. The usefulness of on-board observation data was proved for a main part of a species sample, using validation from the literature and a geostatistical indicator. Then the comparison of fine scale fishing effort provided an improvement of the quantification of effective fishing effort and emphasized the importance of cuttlefish and red mullet for the global distribution of EEC OTB. In addition, the targeting intensity of OTB was quantified in October using a newly-developed indicator, and demonstrated the attractiveness of the same species, but also the constraint of low cod quota for fishers. Results of the OSMOSE-DSVM coupling show that the LO would have short-term negative effects on fishers' revenue, induced by a large reallocation of their fishing effort to avoid quota over-shooting, but would be profitable in the medium-term. However, the LO would induce an increase of the predatory pressure operated by cod and withing on the other species, which would not improve the overall ecosystem health.
246

Energieffektivisering inom transportsektorn : En fallstudie på ett företagsfordonspark

Isak, Eklöv January 2021 (has links)
Energy efficiency within the transport sector - A case study on the vehicle fleet of a companyIsak EklövThe environmental objective of zero net emissions of greenhouse gases by 2045 asdecided by the Swedish parliament establishes a framework for a standard thatimplies a demand for considerable changes within many sectors at both technical and political level. The need for long term efficiency solutions with respect tosustainability to be able to reach this goal is great and one step towards this couldpotentially be an adaption to an increased amount of vehicles with alternative fuelsin the vehicle fleet of Sweden. This thesis examined the potential for companiesto reduce their life-cycle emissions of greenhouse gases as well as the total cost ofownership (TCO) for their vehicles by changing the composition of their vehiclefleet.The project started with a literature review of a general character where data forlife-cycle emissions of greenhouse gases as well as TCO for different vehicle typeswas examined and collected. Then the life-cycle emissions of greenhouse gases andTCO were calculated for the different vehicle types through a case study on thevehicle fleet of a company. Finally a programming script was developed to increasethe efficiency of the process which was then used to create scenarios with differentcompositions of the vehicle fleet. A sensitivity analysis was also carried out to evaluate the robustness of the life cycle calculations where the parameters individuallywere altered and the effect on the final result was examined.The result of the case study showed that alternative fueled vehicles are expected tolead to lower life-cycle emissions of greenhouse gases compared to the conventionalalternatives for all vehicle types where alternative fuels are commercially available.The only exception for this was the electric fringe benefit vehicle with a 100 kWhbattery which was expected to lead to higher life-cycle emissions than its fossilalternatives. The result of the cost analysis showed a similar pattern but in thiscase the service vehicle fueled with gas was expected to lead to a higher value ofTCO than its fossil alternatives. The sensitivity analysis for life-cycle emissionsof greenhouse gases showed that production of lithium-ion batteries, vehicle base production and tailpipe emissions were the most contributing parameters forfringe benefit vehicles. The purchase cost was found to be the most contributingparameter for TCO.The result of the scenario analysis showed that there is a potential to decreaseiiilife-cycle emissions of greenhouse gases by 22 % of the total life-cycle emissionsfor the vehicle fleet according to the Base-case scenario. The potential to decreaseTCO was found to be 1,1 %. The other scenarios showed a potential decrease forlife-cycle emissions of 37 % and a cost decrease of 7 % individually.Key words: greenhouse gas emissions, alternative fuels, electric vehicles, totalcost of ownership, life cycle assessment, sustainable vehicle fleet
247

Transportörer och transportköpares väg mot fullständig elektrifiering av tunga transporter : En fallstudie kring implementering och uppskalning / Carriers’ and transport buyers’ path towards complete electrification of heavy transports’ : A case study about implementation and scaling up

Jaktfalk, Linnéa, Arvidsson, Julia January 2024 (has links)
Transporter står idag för en stor andel av Sveriges koldioxidutsläpp. Det gör att logistikfrågor blir extra viktiga då vidareutveckling och omformning av logistiksystem kan göra stor skillnad. Elektrifiering av fordon är en framtida lösning på problemet. Däremot anses det fortfarande vara ett förhållandevis nytt och osäkert område och det finns idag få exempel på implementering av elektrifierade fordon. Transportören Renall och transportköparen Returpack är två framstående företag med starkt hållbarhetsfokus som agerar fallföretag för studien. De har högt uppsatta mål, däribland elektrifiering av en stor andel av sina fordonsflottor till 2030. Studiens syfte är därför formulerat som följande: Syftet är att utreda hur transportörer och transportköpare kan arbeta mot fullständig elektrifiering av tunga transporter. Studien är uppdelad i tre primära delar. Den första delen utvecklar en metodik för hur elektrifierade fordon ska implementeras i verksamheter för att sedan kunna skalas upp. Denna metodik har resulterat i tre primära delar. Den första delen är utformning av ett elektrifierat logistiksystem där större strukturförändringar i logistiksystemet måste göras med syfte att öka effektivitet, nyttjandegrad och förutsägbarhet. Den andra delen är utformning av fordonsflotta där beslut om lämpliga batterikapaciteter för varje enskilt fordon tas. Den tredje delen utformning av laddstrategi beslutar om lämplig laddstrategi utifrån fordons- och uppdragskarakteristik. Den utformade metodiken appliceras sedan på fallföretagens presenterade empiri för att resultera i rekommendationer för hur de bör utforma sina elektrifierade logistiksystem, fordonsflottor samt laddstrategier. Efter analys av lösningar som ämnar anpassa logistiksystemet till elektrifiering presenteras rekommendationer för fallföretagen utifrån deras specifika situationer. Det kan dock konstateras att en stark maktposition, ett välutvecklat systemstöd samt kompetens inom elektrifiering underlättar arbetet mot ett elektrifierat logistiksystem. Vid utformning av fordonsflottan presenteras det samlade resultatet av ekonomiska analyser samt bedömningar av genomförbarheten för respektive fordon. Resultatet påvisar att det för cirka hälften av fordonen är ekonomiskt fördelaktigt med ett mindre batteri men att detta oftast begränsas av brist på laddinfrastruktur och behov av flexibilitet vilket innebär behov av överdimensionering. Det samlade resultatet innebär att cirka 20% av fordonsflottan rekommenderas mindre batterier. Vid utveckling av laddstrategier är rekommendationerna liknande för fallföretagen vilket beror på att en laddstrategi är beroende av enskilda fordons karakteristik snarare än en aktörs roll. Fallföretagen rekommenderas att utveckla två primära laddstrategier: en return to base strategi för laddning mellan skift samt en on route strategi för laddning under pågående rutt. Därtill utvecklas även en kostnadsmodell för att kunna genomföra en kostnadsanalys av hur kostnader förändras vid byte från nuvarande bränsle till elektrifierad drivlina. Den visar att sänkning eller höjning av kostnader vid byte av drivlina varierar mellan olika fordonstyper och områden, men att lönsamhet kan uppnås i många fall. Däremot krävs ibland justeringar och förändringar av logistiksystemet. Främst ses att långa avtalsperioder och hög nyttjandegrad av fordonen är att föredra. Likaså ger minskade inköpspriser stort utslag på resultatet. / Transport related activities currently account for a significant portion of Sweden’s carbon dioxide emissions. This makes logistics issues particularly important, as further development and transformation of logistics systems can make a big difference. Electrification of heavy trucks is a future solution to the problem. However, it is still considered a relatively new and uncertain area, and there are currently few examples of the implementation of electrified heavy trucks. The carrier Renall and the transport buyer Returpack are two prominent companies with a strong sustainability focus, acting as case companies for the study. They have currently set ambitious goals, including electrifying a large portion of their heavy truck fleets by the year 2030. Therefore, the purpose of the study is formulated as follows: The purpose is to investigate how carriers’ and transport buyers’ can work towards complete electrification of heavy transports. The study is divided into three primary parts. The first part develops a methodology for implementing electrified heavy trucks in operations, with the goal of scalability. This methodology has resulted in three sub-parts. The first sub-part is the design of an electrified logistics system, where significant structural changes in the logistics system are necessary to increase efficiency, utilization, and predictability. The second sub-part involves designing the heavy truck fleet, including decisions on appropriate battery capacities for each individual heavy truck. The third sub-part focuses on designing a charging strategy based on truck and mission characteristics. The formulated methodology is then applied to the empirical data presented by the case companies, resulting in recommendations on how they should design their electrified logistics systems, heavy truck fleets, and charging strategies. Solutions aimed at adapting the logistics system to electrification are analyzed, which result in recommendations for the case companies based on their specific situations. However, it can be noted that a strong market position, well-developed system support, and knowledge in electrification can ease the transition to an electrified logistics system.In the design of the heavy truck fleet, the combined results of economic analyses and feasibility assessments for each vehicle are presented. The results indicate that for approximately half of the vehicles, it is economically advantageous to have a smaller battery. However, this is often limited by a lack of charging infrastructure and the need for flexibility, which necessitate overdimensioning. The combined result is that approximately 20% of the vehicle fleet is recommended to have smaller batteries.In the development of charging strategies, the recommendations are similar for the case companies, as a charging strategy depends on the characteristics of individual vehicles rather than the role of the operator. The case companies are recommended to develop two primary charging strategies: a return to base strategy for charging between shifts and an on route strategy for charging during the ongoing route. Lastly, a cost model is developed to conduct a cost analysis of how expenses change when transitioning from heavy trucks fueled by HVO or biogas to electrified heavy trucks. It shows that cost reduction or cost increase upon fuel conversion varies among different truck types and regions, but profitability can be achieved in many cases. However, adjustments and changes to the logistics system are sometimes necessary. Long contract periods and high vehicle utilization are particularly favorable. Similarly, reduced purchase prices have a significant impact on the outcome.
248

Leveraging technology for business fleet applications : a case study of fleet management system implemented in Kenya Power & Lighting Company Limited

Waiyaki, Edward Chege 18 October 2013 (has links)
This study aimed to evaluate the effectiveness of a modern fleet management system in improving the logistics of transporting staff, goods and materials in Kenya Power & Lighting Company, a utility firm in power distribution. In today’s competitive marketplace which is characterised by rapidly changing business requirements, leveraging leading edge technologies and adopting best practices are essential in order to ensure sound logistical support that guarantees both effectiveness and efficiency in the transportation processes. The sampling procedure of one-stage, cluster sampling and the use of the simple random sampling technique were used in this study to select a sample size which was sufficiently representative of the whole population. Both the descriptive study approach and the survey research strategy were adopted to enable the collection of data in a manner that allowed in-depth examination while gathering information that explained the relationships between constructs, in particular, cause and effect relationships. The main purpose of this dissertation was therefore to establish that the use of information technology is feasible in transport industries, explain possible obstacles and also any major advantages of its implementation. Secondly, as regards the theoretical aspect, a broadened view on the use of online tracking for vehicles using a global positioning system is presented, together with practical examples, to illustrate its successful implementation in a fleet management system. The study concludes by offering suggestions and recommendations from the research results and the researcher’s experiences for future studies. / Transport Economics, Logistics & Tourism / M. Com. (Transport Economics)
249

EmbarcaÃÃes a vela do litoral do Estado do Cearà construÃÃo, construtores, navegaÃÃo e aspectos pesqueiros / Vessels sailing the coast of Cearà State building, builders, navigation and fisheries issues

Miguel Savio de Carvalho Braga 27 February 2013 (has links)
CAPITULO 1 â Perfil dos carpinteiros artesanais de embarcaÃÃes a vela do litoral do estado do Cearà No contexto mundial, durante o sÃculo XV, a construÃÃo naval das embarcaÃÃes veleiras passaram por evoluÃÃes que propiciaram o empreendimento de grandes viagens. Chegando ao Brasil iniciou-se um longo processo de interaÃÃo construtiva das embarcaÃÃes locais com o conhecimento europeu. As jangadas inicialmente construÃdas sem velas evoluÃram e se propagaram por todo o nordeste e, principalmente no Cearà como embarcaÃÃo de pesca artesanal, evoluindo das jangadas de troncos Ãs atuais de tÃbuas, assim como ocorreu evoluÃÃo construtiva artesanal das canoas e botes. O litoral cearense foi percorrido no perÃodo de setembro de 2010 a maio de 2012, identificando-se in loco os tipos de embarcaÃÃes construÃdas, e localizando e entrevistando construtores artesanais de embarcaÃÃes a vela, foco principal deste trabalho. Foram entrevistados 36 carpinteiros de comprovado reconhecimento local, que responderam questionÃrio estruturado com perguntas direcionadas diretamente à identificaÃÃo do construtor artesanal, seu perfil profissional e da sua arte construtiva, permitindo registros fotogrÃficos, filmagens e gravaÃÃes. Os dados de cada questionÃrio foram transcritos para planilhas eletrÃnicas e analisadas, combinando com as gravaÃÃes de entrevistas transcritas e das filmagens. A pesquisa constatou a baixa escolaridade dos carpinteiros artesanais entrevistados, com 44% de alfabetizados e 42% de analfabetos; a inexistÃncia de qualquer registro construtivo empregado; mÃdia de idade; media de tempo de trabalho e frequÃncia da distribuiÃÃo do tempo de trabalho entre os carpinteiros entrevistados; influÃncia e origem do aprendizado e ausÃncia de enquadramento funcional destes jà que nÃo se aposentam como construtores artesanais. Resultados importantes foram obtidos sobre o perfil do carpinteiro artesanal cearense, considerados importantes para a manutenÃÃo da tradiÃÃo cultural de suas tÃcnicas aplicadas à construÃÃo de embarcaÃÃes a vela, e que compÃem o patrimÃnio histÃrico e socioeconÃmico do estado. CAPITULO 2 â A construÃÃo dos diferentes tipos de embarcaÃÃes a vela do litoral do estado do Cearà As embarcaÃÃes a vela sÃo usadas na pesca desde a Idade MÃdia e foram introduzidas no Brasil no inÃcio do descobrimento. No CearÃ, a frota veleira à constituÃda por jangadas, paquetes, canoas e botes, e este estudo objetivou descrever os aspectos e processo construtivos destas embarcaÃÃes, e verificar a existÃncia de diferenciaÃÃo entre localidades quanto aos custos, tempo de construÃÃo, materiais, ferramentas manuais, posicionamento dos mastros com os tipos e tamanhos de vela e elaboraÃÃo de planos de linhas. A metodologia constou de levantamentos de dados in loco, no perÃodo de maio 2010 a dezembro de 2012, com entrevistas com 36 carpinteiros artesanais em 25 localidades de praia de dezoito municÃpios, e aplicaÃÃo de questionÃrios e registros por gravaÃÃo, fotografia e filmagem. O mÃtodo construtivo adotado pelos construtores à o do âesqueleto primeiroâ, ao qual os diversos componentes sÃo acrescentados. O principio para a construÃÃo dos botes triÃngulo e bastardo à o mesmo adotado por toda a forÃa de trabalho, que sÃo idÃnticos no aspecto construtivo e de estrutura de casco, diferem no tipo de mastro e vela, tendo o bastardo um mastro fixo com vela latina bastarda e o bote triÃngulo vela latina triangular. Os custos de construÃÃo variam em ordem decrescente para botes, jangadas, canoas e paquetes, determinados pelo comprimento da embarcaÃÃo e tipo de madeira. Pontualmente, registrou-se em Bitupità a existÃncia da vela quadrangular latina, denominada de âvela quatro punhosâ, envergada em mastro bastardo nas canoas de curral. CAPITULO 3 â A navegaÃÃo praticada por mestres marcadores nas embarcaÃÃes a vela no estado do Cearà A orientaÃÃo praticada a bordo de embarcaÃÃes veleiras para navegaÃÃo e pesca utiliza referÃncias de terra para compor as linhas de posiÃÃo denominadas caminho e assento que, ao se cruzarem, determinam o local desejado. Esta atividade vem acontecendo desde a existÃncia da jangada de piÃba e se perpetua por transmissÃo entre geraÃÃes. O estudo foi desenvolvido com mestres marcadores de trÃs localidades, Baleia, Fortaleza e Redonda, onde predominam canoas, jangadas e botes, respectivamente. A prÃtica desta modalidade de navegaÃÃo à idÃntica para os diferentes tipos de embarcaÃÃo e diferem pouco entre as localidades estudadas. O exercÃcio da orientaÃÃo exige que o mestre marcador tenha boa visÃo e memÃria para encontrar caminho e assento, alÃm de sofrer restriÃÃes na ausÃncia da luz solar. Essa atividade à iniciada pelos marcadores ainda na juventude, e esses conhecimentos sÃo adquiridos independentes do grau de instruÃÃo e se consolidam tanto pelo exercÃcio da pesca quando pela experiÃncia adquirida. A observaÃÃo de estrelas e planetas revela a direÃÃo do caminho de volta ao porto de origem tendo a estrela do porto vÃrias denominaÃÃes no litoral cearense. A falta de visibilidade do litoral, ocasionada por chuva, cerraÃÃo ou outros fatores, interfere negativamente na identificaÃÃo de pontos de referÃncia existentes no litoral. A marcaÃÃo terrestre vem sendo gradativamente substituÃda pelo uso do GPS na localizaÃÃo dos pesqueiros mais produtivos, com grande aceitaÃÃo pelos mais jovens. O baixo preÃo e eficiÃncia comprovada desse equipamento tÃm justificado sua difusÃo ao longo de todo o litoral do CearÃ. CAPITULO 4 â EmbarcaÃÃes a vela do litoral do estado do CearÃ, distribuiÃÃo espacial da frota e da produÃÃo pesqueira O Cearà possui 573 km de litoral, distribuÃdo por 20 municÃpios costeiros e conta com 113 localidades de pesca estuarina e marinha. Este estudo se baseia nos seguintes dados estatÃsticos do Programa ESTATPESCA a- composiÃÃo da frota por tipo de barco e municÃpio; b- produÃÃo de pescado por tipo de barco e municÃpio; c- produÃÃo das principais espÃcies de peixe por tipo de embarcaÃÃo. Foi feita a descriÃÃo das caracterÃsticas das embarcaÃÃes a vela do Cearà de uma forma mais detalhada que as dividiu em jangadas ocada e de isopor; paquetes ocado e de isopor; canoa de Paracuru; canoa de Moitas-Baleia; canoa de Camocim (bianas); Canoa de Acarau-PreÃ-BitupitÃ; canoas de currais de BitupitÃ; canoa-paquete de Fleixeiras-Guagiru e botes triangulo e bastardo. Os resultados mostram que os paquetes sÃo maioria numÃrica e com maior distribuiÃÃo geogrÃfica, destacam-se pela versatilidade, por serem leves para encalhe e movimentaÃÃo na faixa de praia, pela necessidade de pequena tripulaÃÃo e baixo custo de construÃÃo e manutenÃÃo. Os botes tÃm a menor abrangÃncia territorial, com o bastardo bem concentrados em Camocim e o triÃngulo com maior concentraÃÃo em IcapuÃ. A canoa tem predominÃncia exclusiva no litoral oeste e a jangada, no litoral leste. Em termos relativos, as embarcaÃÃes participaram da captura nas seguintes proporÃÃes: canoas = 45,3 %; paquete = 22,3 %; botes = 22,4%, destacando-se os municÃpios de Camocim, Itarema, Icapuà e AcaraÃ. Estes tÃm produÃÃo mais seleta, capturando espÃcies de maior valor comercial, a saber guaiÃba, cavala, pargo, sirigado, carapitanga e dourado. As jangadas vÃm perdendo importÃncia relativa na captura do pescado, mas ainda com destaque para os municÃpios de Fortaleza, Aquiraz, Beberibe Cascavel e Aracati. / CHAPTER 1 â Profile of the artisanal carpenters of sail crafts in Cearà State In a worldwide scenario, during the XV Century, the naval building of sail craft underwent an evolutionary development that enabled the undertaking of long-length voyages across the oceans. By arriving at Brazil, an intensive interaction process between local sail boat construction and that of European-derived knowledge. The sail rafts, at first built without sail, were deployed over the whole Brazilian northeast, mainly in Cearà State, as artisanal crafts, evolving from simple dugouts to the actual wooden ones as well as canoes and rowboats. For this research work, the Cearà Stateâs coast was surveyed from September, 2010 to May, 2012, taking in situ stock of all types of constructed crafts, and pinpointing and interviewing artisanal builders of sailboats, who are than main target population of this survey. To this aim, 36 accomplished carpenters, locally recognized as such, were required to answer a number of questionnaires directed toward a full appraisal of the artisanal naval builders, its professional profile and handicraft, for which photographic records, pictures and sound recordings were obtained. The derived data were transferred to electronic spreadsheets and then analyzed by crosschecking the recorded interviews and the movie pictures. This survey led to the following results: occurrence of low reading ability by the artisanal carpenters so that 44 per cent were found to be illiterate; non-existence of any kind of professional registration by the competent public offices; mean age of 22.1 years; high mean working time and frequency of distribution among the sampled population; factors of influence and origin of learning techniques and absence of functional framing, since they to do not retire as naval builders. Significant results were got as to the artisanal carpentersâs profile in Cearà State, which were deemed quite relevant for the maintenance of the folklore of their techniques applied to the construction of sail crafts, and round up the historic and socioeconomic heritage of the Cearà Stateâs coastline . CHAPTER 2 â Construction of different types of sail craft along Cearà Stateâs coastline The sailboats are used in fisheries since the middle ages and were introduced in Brazil at the beginning of its discovery. The Cearà Stateâs fleet is made up of rafts, canoes and boats whose study was meant for describing aspects of the building process and for ascertaining the existence of differentiation among fishing communities as to costs, construction time, basic materials, hand tools and positioning of masts according to boat size, sail types and setting of lining patterns. The methodology consisted of data surveys carried out locally, in the period from May, 2010 through December, 2012, by means of interviews with 36 artisanal carpenters in 25 fishing sites of 18 costal counties, by applying questionnaires and data gathering by recording, photography and movie pictures. The constructive technique consists of mounting a âprimary skeletonâ to which all other component parts are attached. The building principle of the triangle and bastard boats is the same as adopted by the whole of the labor force, which are identical as to their constructive pattern and hull framework, but differ as to the types of masts ands sails, namely the bastard one having a fixed mast and a storm jib, and the triangle one having a triangular storm jib. The construction costs vary in a decreasing order for boats, rafts and canoes, as determined by the craft length and kind of timber. Somewhat exceptionally there was identified in BitupitÃ, Barroquinha county, the existence of a square storm jib named âfour-fist sailâ, bent up as a bastard mast in the fish-weir canoes. CHAPTER 3 â The navigation practiced by master position markers on board sail boats in Cearà State The orientation carried out on board sailboats for navigation and fishing makes use of landmarks in order to compose the position lines named pathway and outpost that, while intercrossing, determine the sought after site. This activity has been taking place since the very early existence of the sail raft and it endures itself from generation to generation. This study was undertaken by master markers in some fishing localities, namely Baleia, Fortaleza and Redonda where canoes, sail rafts and boats are respectively predominant. The practice of this kind of navigation is similar for the various types of boats and diverges from one another very little among the studied landing points. The exercise of orientation requires that the master marker has got good eyesight and memory in order to find out the pathway and the outpost, besides undergoing setbacks from the absence of sunlight. That activity is started when the fisherman is still young, and his long-lived expertise is acquired independently of the educational degree as it is derived from both the fishing chores and the accumulated experience. The observation of stars and planets reveals the way back to the home port whose identifying star receives many nominations along Cearà Stateâs coastline. The lack of visibility brought about by rain, clouding, and other factors meddle with the identification of conspicuous landmarks. This age- old technique has been gradually replaced by the use of GPS devices for pinpointing the most productive fishing grounds, with a high degree of acceptance by the young generation. The low purchase price and the proved efficiency of that equipment has accounted for the diffusion of their advantages among the fishing communities of Cearà State. CHAPTER 4 â Sail crafts in Cearà Stateâs coastline: fleet and fishing production spatial distribution The Cearà Stateâs coastline spreads over 573 km distributed by 20 coastal counties, and 113 estuarine and marine fishing communities. This study is based on the following statistical data gathered through the ESTATPESCA Program: fleet composition by types of boat and county; fish production by type of boat and county; catch composition of the main fish species by type of boat. A detailed description of the sailboats in Cearà was presented in order to provide information on a number of variants of their main types, namely hollow raft, styrofoam-fulled rafts, canoe from Paracuru, canoe from Moitas-Baleia; canoe from Camocim; canoe from AcaraÃ-PreÃ-BitupitÃ; canoe from Bitupità fish-weirs, canoe-raft from Fleixeiras-Guagiru, triangle boat and bastard boat. The results show the small raft holds a numeric majority and a wider geographic distribution, standing out by being lighter to anchor on the beach sand, requiring fewer crew, and entailing lower construction and maintenance costs. The boats show a narrower territorial range, with the bastard ones being concentrated in Camocim county and the triangle ones more frequent in Icapuà county. The canoe and the large-sized raft hold an outstanding predominance on the western and the eastern sides of Cearà Stateâs coastline, respectively. In relative terms, the main types of fishing craft took part in the caches according to the following proportions: canoes = 45.3 per cent; small raft = 22.3 per cent; boats = 22.4 per cent. Among their home counties stand out Camocim, Itarema, Icapuà and AcaraÃ, the ones that boast a more exclusive fish production made out of such species as yellowtail snapper, king mackerel, Caribbean red snapper, black grouper, dog snapper and dolphin. The large-sized rafts have shown of late a tendency for playing a lesser part in fish catching, but they are still relevant in such Cearà Stateâs counties as Fortaleza, Aquiraz, Beberibe Cascavel and Aracati.
250

Leveraging technology for business fleet applications : a case study of fleet management system implemented in Kenya Power & Lighting Company Limited

Waiyaki, Edward Chege 06 1900 (has links)
This study aimed to evaluate the effectiveness of a modern fleet management system in improving the logistics of transporting staff, goods and materials in Kenya Power & Lighting Company, a utility firm in power distribution. In today’s competitive marketplace which is characterised by rapidly changing business requirements, leveraging leading edge technologies and adopting best practices are essential in order to ensure sound logistical support that guarantees both effectiveness and efficiency in the transportation processes. The sampling procedure of one-stage, cluster sampling and the use of the simple random sampling technique were used in this study to select a sample size which was sufficiently representative of the whole population. Both the descriptive study approach and the survey research strategy were adopted to enable the collection of data in a manner that allowed in-depth examination while gathering information that explained the relationships between constructs, in particular, cause and effect relationships. The main purpose of this dissertation was therefore to establish that the use of information technology is feasible in transport industries, explain possible obstacles and also any major advantages of its implementation. Secondly, as regards the theoretical aspect, a broadened view on the use of online tracking for vehicles using a global positioning system is presented, together with practical examples, to illustrate its successful implementation in a fleet management system. The study concludes by offering suggestions and recommendations from the research results and the researcher’s experiences for future studies. / Transport Economics, Logistics and Tourism / M. Com. (Transport Economics)

Page generated in 0.0578 seconds