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  • 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.
21

CARACTERIZAÇÃO DE POSTES DE MADEIRA PARA USO NA REDE ELÉTRICA / WOOD POLES CHARACTERISATION FOR USE IN ELECTRICAL LINES

Schneid, Eduardo 06 February 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Wood poles used in electrical lines were from Eucalyptus species. These poles should present adequate mechanical characteristics in order to ensure the security and structure of electrical lines. Wood poles should be treated with products able to protect the wood against insects and fungus to increase service life. Taking these into account, this study aims to evaluate mechanical properties of wood poles and qualify preservative treatment used in the wood poles. Mechanical evaluation of wood poles was performed through nondestructive tests of ultrasonic wave propagation and destructive tests according to NBR 6231 (ABNT, 1980) in order to establish a method to estimate mechanical properties through nondestructive tests. Preservative treatments through full-cell method were carried out for 60, 90 and 120 minutes with pressure of 10 and 12 kgf/cm2 using a CCA-C preservative solution. Tests of penetration and retention of the solution were performed to evaluating the preservative treatments. Chemical analysis of wood was done through extractives content, Klason lignin content and infrared spectroscopy (ATR-IR). The evaluation of mechanical properties showed not significant correlation coefficients between MOEeng. and dynamic modulus of elasticity, proving the inefficiency of nondestructive method in this study. The results of preservative treatments showed that CCA-C penetration on wood was deep and irregular in 50-70% of poles for both species. On the other hand, retention did not present the minimum value required by NBR 8456 (ABNT, 1984). This analysis showed that higher pressure and time of treatment, higher is CCA-C retention. Wood from both species presented similar results for extractives content and Klason lignin content. Infrared spectroscopy (ATR-IR) technique did not show a efficiency to predict the chemical modification in treated wood. / Os postes de madeira que são utilizados nas redes elétricas no Brasil são oriundos, na sua grande maioria, de madeira da espécie Eucalyptus. Esses postes devem apresentar características mecânicas adequadas garantindo segurança a estrutura das redes. Para garantir uma maior vida útil, a madeira dos postes deve receber tratamento preservativo com soluções capazes de resistir ataques de insetos e fungos degradadores da madeira. Sendo assim, o presente estudo tem por objetivo avaliar as propriedades mecânicas e qualificar o tratamento preservativo utilizado nos postes de madeira. A avaliação das propriedades mecânicas dos postes de madeira foi realizada por meio de testes não destrutivos de propagação de ondas de ultrassom e testes mecânicos destrutivos conforme a norma NBR 6231 (ABNT, 1980), a fim de estabelecer uma metodologia, com intuito de estimar as propriedades mecânicas da madeira por meio de ensaio não destrutivos. Também foram realizados tratamentos preservativos por meio do processo de célula cheia em períodos de 60, 90 e 120 minutos com pressão de 10 e 12 kgf/cm², utilizando a solução preservante Arseniato de Cobre Cromatado tipo C (CCA-C). Na avaliação do tratamento preservativo da madeira, foram realizados testes de penetração e retenção da solução preservativa. Ainda, realizaram-se análises químicas da madeira, por meio da quantificação de teor de extrativos, teor de lignina Klason e análises qualitativas com ensaios de espectroscopia no infravermelho (ATR-IR). Na avaliação das propriedades mecânicas dos postes de madeira, observaram-se coeficientes de correlação não significativos ente MOEeng. e módulo de elasticidade dinâmico, evidenciando a ineficiência do método não destrutivo no presente estudo. Os resultados para os tratamentos preservativos mostraram que a penetração do CCA-C na madeira foi profunda e irregular em 50 a 70% dos postes de ambas as espécies. Já as análises de retenção, mostraram que a maioria dos postes de madeira não apresentaram as retenções mínimas exigidas pela norma NBR 8456 (ABNT, 1984). Ainda, essas análises mostraram que quanto maior a pressão aplicada e maior o tempo de tratamento, melhores são os resultados para a retenção do CCA-C. As madeiras de ambas as espécies apresentaram resultados semelhantes tanto para o teor de extrativos quanto para o teor de lignina Klason. Já a técnica de espectroscopia no infravermelho (ATR-IR) não apresentou eficiência quanto à predição de modificações químicas na madeira tratada.
22

Transfer pricing : råder harmonisering mellan Sverige och USA enligt OECDs riktlinjer? / Transfer pricing – does harmonization exist between Sweden and the USA in accordance with the OECD Guidelines?

Stellan, Cecilia, Lorentsen, Sebastian January 2016 (has links)
Världsekonomin är i ständig tillväxt. Till följd av globaliseringen av ekonomin har allt fler multinationella koncerner etablerats. För att kunna effektivisera och vinstmaximera inom sina organisationer har multinationella bolag utnyttjat olika länders skattesystem. Det genom att förflytta sina vinster till skatteparadis eller andra länder med längre skatt för att på så vis uppnå ett högre resultat för koncernen i helhet. Det leder till att skattebaserna i länder med höga skattesatser eroderas. Av den anledningen har ett behov av en global accepterad standard rörande internprissättning uppkommit. Organisation for Economic Co-oporation and Development har gett ut riktlinjer som de anslutande medlemsländerna ska följa vilka går under namnet Transfer Pricing Gudelines For Multinational Enterprises And Tax Authorities. Riktlinjerna behandlar de viktigaste områdena inom internprissättning och består av totalt nio kapitel.Studien syftar till att undersöka om svensk respektive amerikansk lagstiftning och hänvisningar inom området internprissättning är harmoniserade. Detta med hänsyn till OECDs riktlinjer. För att ta reda på om länderna är harmoniserade inom området har en komparativ studie genomförts. I uppsatsen har en undersökning av kapitel 1, 2, 5, 8 ur OECDs riktlinjer utförts, vilka berör armlängdsprincipen, CCA, prissättningsmetoder och dokumentation. För att kunna avgöra om harmonisering råder inom samtliga områden har en kvalitativ metod använts för att kunna studera ekonomisk och juridisk litteratur. Det för att kunna lägga grund till den slutgiltiga analysen av empiri i form av lagtext och hänvisningar.Studien har bidragit med ökad kunskap för hur OECDs riktlinjer är utformade inom området. Genom djupare förståelse för dess utformning har det bidragit med en inblick i hur OECDs riktlinjer påverkar medlemsländernas utformning av sina hänvisningar och lagstiftningar inom internprissättning. Vid granskning av OECDs utformning inom samtliga områden som tas med i studien har en analys kunnat genomföras för att se hur dessa implementerats inom de två medlemsländerna som är utvalda i studien. Studien har dessutom bidragit med en ökad förståelse för hur de svenska respektive amerikanska hänvisningarna och lagstiftningarna ser ut inom området.Uppsatsen resulterar i att harmonisering råder mellan Sverige och USA inom området internprissättning. Genom analysering av lagar och hänvisningar har stora likheter kunnat urskiljas i enighet med OECDs riktlinjer. Vid genomförandet av studien har viss olikhet och differentiering i utformandet kunnat identifieras men inte i tillräckligt stor utsträckning för att kunna påverka vår slutsats om att det råder harmonisering mellan Sverige och USA i enighet med OECD. / The world economy is in constant growth. As a result of the globalization of the economy, more multinational enterprises have established. In order to streamline and maximize profits within their organizations, multinational companies have exploited various countries tax bases. By moving their profits to tax havens or other countries with lower tax rates they achieve higher earnings for the business as a group. Which leads to that the tax bases in countries with high tax rates will be eroded. Because of this a need for a globally accepted standard on Transfer pricing arise. Organisation for Economic Co-oporation and Development has issued guidelines that acceding member states should follow which is known as Transfer Pricing Guidelines for Multinational Enterprises and Tax Authorities. The OECD guidelines consist of nine chapters and address the key areas of Transfer pricing.This study aims to examine the Swedish and US laws and references to see if they are harmonized in the field of transfer pricing in regard with the OECD guidelines. To find out if the countries are harmonized within the region a comparative study has been select. In the study, a survey of Chapters 1, 2, 5, 8 of the OECD Guidelines were performed, which contains the arm's length principle, CCA, transfer pricing methods and documentation. In order to determine whether harmonization exists, a qualitative method has been used to study economic and legal literatures to lay the foundation for the final analysis of empirical data in the form of legal texts and references.This study has contributed to increased knowledge of how the OECD Guidelines are designed in the area. Through a deeper understanding of its design, it has given a glimpse of how the OECD guidelines affect the member countries design on their references and laws in the area of transfer pricing. Upon review of the OECDs guidelines of all the areas included in the study, an analysis has been carried out to see how these are implemented in the two member states that are selected in this thesis. The study has also contributed to a better understanding of how the Swedish and American references and legislation are implemented in the field.The thesis results in that harmonization exists between Sweden and the United States within the area of transfer pricing. By analyzing the laws and references great similarities have discernible in unity with the OECD guidelines. In the implementation of the study some diversity and differentiation in the design have been identified, but not sufficiently to affect our conclusion that there is harmonization between the United States and Sweden in unity with the OECD guidelines.This paper is hereinafter written in Swedish.
23

Genotyping bacterial and fungal pathogens using sequence variation in the gene for the CCA-adding enzyme

Franz, Paul, Betat, Heike, Mörl, Mario 15 June 2016 (has links) (PDF)
Background: To allow an immediate treatment of an infection with suitable antibiotics and bactericides or fungicides, there is an urgent need for fast and precise identification of the causative human pathogens. Methods based on DNA sequence comparison like 16S rRNA analysis have become standard tools for pathogen verification. However, the distinction of closely related organisms remains a challenging task. To overcome such limitations, we identified a new genomic target sequence located in the single copy gene for tRNA nucleotidyltransferase fulfilling the requirements for a ubiquitous, yet highly specific DNA marker. In the present study, we demonstrate that this sequence marker has a higher discriminating potential than commonly used genotyping markers in pro- as well as eukaryotes, underscoring its applicability as an excellent diagnostic tool in infectology. Results: Based on phylogenetic analyses, a region within the gene for tRNA nucleotidyltransferase (CCA-adding enzyme) was identified as highly heterogeneous. As prominent examples for pro- and eukaryotic pathogens, several Vibrio and Aspergillus species were used for genotyping and identification in a multiplex PCR approach followed by gel electrophoresis and fluorescence-based product detection. Compared to rRNA analysis, the selected gene region of the tRNA nucleotidyltransferase revealed a seven to 30-fold higher distinction potential between closely related Vibrio or Aspergillus species, respectively. The obtained data exhibit a superb genome specificity in the diagnostic analysis. Even in the presence of a 1,000-fold excess of human genomic DNA, no unspecific amplicons were produced. Conclusions: These results indicate that a relatively short segment of the coding region for tRNA nucleotidyltransferase has a higher discriminatory potential than most established diagnostic DNA markers. Besides identifying microbial pathogens in infections, further possible applications of this new marker are food hygiene controls or metagenome analyses.
24

Genotyping bacterial and fungal pathogens using sequence variation in the gene for the CCA-adding enzyme

Franz, Paul, Betat, Heike, Mörl, Mario January 2016 (has links)
Background: To allow an immediate treatment of an infection with suitable antibiotics and bactericides or fungicides, there is an urgent need for fast and precise identification of the causative human pathogens. Methods based on DNA sequence comparison like 16S rRNA analysis have become standard tools for pathogen verification. However, the distinction of closely related organisms remains a challenging task. To overcome such limitations, we identified a new genomic target sequence located in the single copy gene for tRNA nucleotidyltransferase fulfilling the requirements for a ubiquitous, yet highly specific DNA marker. In the present study, we demonstrate that this sequence marker has a higher discriminating potential than commonly used genotyping markers in pro- as well as eukaryotes, underscoring its applicability as an excellent diagnostic tool in infectology. Results: Based on phylogenetic analyses, a region within the gene for tRNA nucleotidyltransferase (CCA-adding enzyme) was identified as highly heterogeneous. As prominent examples for pro- and eukaryotic pathogens, several Vibrio and Aspergillus species were used for genotyping and identification in a multiplex PCR approach followed by gel electrophoresis and fluorescence-based product detection. Compared to rRNA analysis, the selected gene region of the tRNA nucleotidyltransferase revealed a seven to 30-fold higher distinction potential between closely related Vibrio or Aspergillus species, respectively. The obtained data exhibit a superb genome specificity in the diagnostic analysis. Even in the presence of a 1,000-fold excess of human genomic DNA, no unspecific amplicons were produced. Conclusions: These results indicate that a relatively short segment of the coding region for tRNA nucleotidyltransferase has a higher discriminatory potential than most established diagnostic DNA markers. Besides identifying microbial pathogens in infections, further possible applications of this new marker are food hygiene controls or metagenome analyses.
25

Coexistence Between BLE and IEEE 802.15.4 Networks

Lustig, Jasper January 2018 (has links)
As increasingly more IoT devices are being deployed simultaneously in the dense 2.4 GHz ISM band, interference could start occurring. BLE, and IEEE 802.15.4 are two protocols used in IoT devices, that both are now also capable of using IPv6 communication. Since the protocols coexist in this same frequency band, interference could become a problem. However, uncooperative coexistence between these two protocols under higher IPv6 data rates is understudied, and could be unfair. This thesis aims to study possible coexistence, and mitigate it using CCA.An experimental test setup consisting of two nodes for each protocol in close proximity was used to measure possible reliability issues and data rate decrease by logging sent connection based packets over serial, while limiting the amount of available overlapping data channels for each protocol.The results show that even though PDR is maintained, throughput can decrease. While still using all channels, BLE suffers a throughput decrease of 2.25% and IEEE 802.15.4 a decrease of only 0.34%. In the most extreme case BLE can suffer a decrease of 73.3% in throughput, while IEEE sees a mean throughput decrease of 10.9%. When enabling CCA in this extreme case, an improvement of 54.6% in throughput was observed for BLE, while IEEE 802.15.4 saw a relative loss of 3.5%. Therefore, the conclusion could be made that enabling CCA in IEEE 802.15.4 can enable more fair coexistence between the protocols. / Eftersom allt fler IoT-enheter distribueras samtidigt i det täta 2,4 GHz ISM-bandet kan störningar inträffa. BLE och IEEE 802.15.4 är två protokoll som används i IoT-enheter, som båda nu också kan använda IPv6-kommunikation. Eftersom protokoll existerar i samma frekvensband kan störningar bli ett problem. Men osammanhängande samexistens mellan dessa två protokoll under högre IPv6-datahastigheter är underskattad och kan vara orättvist. Avhandlingen syftar till att studera eventuell samexistens och mildra den med hjälp av CCA.En experimentell testinställning bestående av två noder för varje protokoll i närheten, användes för att mäta eventuella pålitlighetsproblem och minskning av datahastighet genom att logga skickade anslutningsbaserade paket över seriell, samtidigt som man begränsar mängden tillgängliga överlappande datakanaler för varje protokoll.Resultaten visar att även om PDR upprätthålls kan genomströmningen minska. Medan BLE fortfarande använder alla kanaler, har BLE en genomströmningsminskning på 2.25% och IEEE 802.15.4 en minskning med endast 0.34%. I det mest extrema fallet kan BLE drabbas av en minskning med 73.3% i genomströmning, medan IEEE ser en genomsnittlig genomströmningsminskning på 10.9%. Vid aktivering av CCA i detta extrema fall observerades en förbättring av 54.6% i genomströmning för BLE medan IEEE 802.15.4 såg en relativ förlust på 3.5%. Därför kan slutsatsen dras att en attityd till CCA i IEEE 802.15.4 kan möjliggöra en mer rättvis samexistens mellan protokollen.
26

Activités spécifiques du cortex cingulaire antérieur et du cortex préfrontal dorsolatéral et interactions lors de l’adaptation des comportements / Anterior cingulate and dorsolateral prefrontal cortical areas specific activity and interactions during behavioral adaptation

Rothé, Marie 30 November 2010 (has links)
Agir de façon optimale dans un environnement incertain nécessite d'évaluer et de comparer les coûts et bénéfices des différentes alternatives. Cela implique aussi de réguler et de contrôler le comportement de façon flexible pour optimiser les périodes de recherche de gains ou de ressources et les périodes d'exploitation des acquis. Une des hypothèses actuelles sur les mécanismes neurobiologiques impliqués, propose que cortex cingulaire antérieur (CCA), associé à l’évaluation de l’action, et cortex préfrontal dorsolatéral (CPFdl), associé au contrôle cognitif, interagiraient pour réguler le comportement. Les travaux réalisés au cours de cette thèse ont permis de préciser le rôle joué par le CCA dans la détection et l’évaluation des performances ainsi que ses interactions avec le CPFdl au sein d'une boucle du contrôle cognitif. Menés grâce à des enregistrements électrophysiologiques chez le singe en comportement, ils apportent des précisions sur la séquence d’activation du CCA et du CPFdl dans la bande de fréquences gamma lors de l'adaptation du comportement. L’étude des potentiels de champs locaux de ces deux régions amènent à poser des hypothèses sur les mécanismes oscillatoires sous-jacents et notamment sur le rôle des communications basses fréquences entre le CCA et le CPFdl et leur implication différentielle entre recherche et exploitation. / Acting optimally in uncertain environments requires evaluating costs and benefits of choosing each alternative. It also requires to flexibly regulate between exploration for and exploitation of resources. One current hypothesis is that the anterior cingulate cortex (ACC), involved in action valuation, and dorsolateral prefrontal cortex (dlPFC), involved in cognitive control, interact to elaborate an optimal regulation of behaviour. Studies achieved during this thesis allowed to precise the role of ACC in the detection and valuation of action outcomes as well as to describe the interactions with dlPFC in a cognitive control loop. Thanks to neurophysiological recordings in behaving monkey our work give new clues on the sequential activation of ACC and dlPFC during adaptation. The analyses of local field potentials allowed us to suggest hypotheses on the underlying oscillatory mechanisms, in particular on low frequency communications between ACC and dlPFC, and their modulation during exploration and exploitation.
27

New Technique for Soil Reclamation and Conservation: In Situ Stabilization of Trace Elements in Contaminated Soils

Negim, Osama 17 July 2009 (has links) (PDF)
L'accumulation de métaux toxiques dans le sol est principalement héritée de matériaux parents ou d'éléments résultant de l'activité humaine. Par conséquent, de nouvelles techniques sont en cours d'élaboration pour remédier à ces contaminations dans les sols pollués, telles que la phytoremédiation et la stabilisation in situ. La stabilisation in situ est une technique commune de réduction des effets négatifs des métaux et métalloïdes, tels que As, Cr, Cu, Cd et Zn dans les sols contaminés par l'ajout d'amendements. L'application de matières alcalines telles que les laitiers d'aciéries et un laitier modifié enrichie en phosphates dans le sol constitue un outil prometteur pour la réduction de la mobilité et la biodisponibilité des éléments traces dans les sols contaminés ainsi que pour l'assainissement du sol et l'amélioration de ses propriétés physique, chimique et minéralogique, ainsi que la production végétale.
28

Activités spécifiques du cortex cingulaire antérieur et du cortex préfrontal dorsolatéral et interactions lors de l'adaptation des comportements

Rothé, Marie 30 November 2010 (has links) (PDF)
Agir de façon optimale dans un environnement incertain nécessite d'évaluer et de comparer les coûts et bénéfices des différentes alternatives. Cela implique aussi de réguler et de contrôler le comportement de façon flexible pour optimiser les périodes de recherche de gains ou de ressources et les périodes d'exploitation des acquis. Une des hypothèses actuelles sur les mécanismes neurobiologiques impliqués, propose que cortex cingulaire antérieur (CCA), associé à l'évaluation de l'action, et cortex préfrontal dorsolatéral (CPFdl), associé au contrôle cognitif, interagiraient pour réguler le comportement. Les travaux réalisés au cours de cette thèse ont permis de préciser le rôle joué par le CCA dans la détection et l'évaluation des performances ainsi que ses interactions avec le CPFdl au sein d'une boucle du contrôle cognitif. Menés grâce à des enregistrements électrophysiologiques chez le singe en comportement, ils apportent des précisions sur la séquence d'activation du CCA et du CPFdl dans la bande de fréquences gamma lors de l'adaptation du comportement. L'étude des potentiels de champs locaux de ces deux régions amènent à poser des hypothèses sur les mécanismes oscillatoires sous-jacents et notamment sur le rôle des communications basses fréquences entre le CCA et le CPFdl et leur implication différentielle entre recherche et exploitation.
29

Evaluation and implementation of neural brain activity detection methods for fMRI

Breitenmoser, Sabina January 2005 (has links)
<p>Functional Magnetic Resonance Imaging (fMRI) is a neuroimaging technique used to study brain functionality to enhance our understanding of the brain. This technique is based on MRI, a painless, noninvasive image acquisition method without harmful radiation. Small local blood oxygenation changes which are reflected as small intensity changes in the MR images are utilized to locate the active brain areas. Radio frequency pulses and a strong static magnetic field are used to measure the correlation between the physical changes in the brain and the mental functioning during the performance of cognitive tasks.</p><p>This master thesis presents approaches for the analysis of fMRI data. The constrained Canonical Correlation Analysis (CCA) which is able to exploit the spatio-temporal nature of an active area is presented and tested on real human fMRI data. The actual distribution of active brain voxels is not known in the case of real human data. To evaluate the performance of the diagnostic algorithms applied to real human data, a modified Receiver Operating Characteristics (modified ROC) which deals with this lack of knowledge is presented. The tests on real human data reveal the better detection efficiency with the constrained CCA algorithm.</p><p>A second aim of this thesis was to implement the promising technique of constrained CCA into the software environment SPM. To implement the constrained CCA algorithms into the fMRI part of SPM2, a toolbox containing Matlab functions has been programmed for the further use by neurological scientists. The new SPM functionalities to exploit the spatial extent of the active regions with CCA are presented and tested.</p>
30

Plant Condition Measurement from Spectral Reflectance Data / Växttillståndsmätningar från spektral reflektansdata

Johansson, Peter January 2010 (has links)
<p>The thesis presents an investigation of the potential of measuring plant condition from hyperspectral reflectance data. To do this, some linear methods for embedding the high dimensional hyperspectral data and to perform regression to a plant condition space have been compared. A preprocessing step that aims at normalized illumination intensity in the hyperspectral images has been conducted and some different methods for this purpose have also been compared.A large scale experiment has been conducted where tobacco plants have been grown and treated differently with respect to watering and nutrition. The treatment of the plants has served as ground truth for the plant condition. Four sets of plants have been grown one week apart and the plants have been measured at different ages up to the age of about five weeks. The thesis concludes that there is a relationship between plant treatment and their leaves' spectral reflectance, but the treatment has to be somewhat extreme for enabling a useful treatment approximation from the spectrum. CCA has been the proposed method for calculation of the hyperspectral basis that is used to embed the hyperspectral data to the plant condition (treatment) space. A preprocessing method that uses a weighted normalization of the spectrums for illumination intensity normalization is concluded to be the most powerful of the compared methods.</p>

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