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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.
31

Análise cromatografica de biocidas anti-incrustantes em amostras de água de mar e tecido de moluscos / Chromatographic analysis of booster antifouling biocides in seawater samples and molluscs tissue

Lia Gracy Rocha Diniz 02 September 2016 (has links)
A indústria naval é uma das mais importantes para economia e desenvolvimento de um país, no entanto, as diversas atividades desenvolvidas em zonas portuárias contribuem para o impacto ambiental a ambientes costeiros, dentre os vários grupos de micropoluentes orgânicos potencialmente danosos a esses ecossistemas, emergiram nos últimos anos os biocidas anti-incrustantes. Pinturas anti-incrustantes são tratamentos utilizados para minimizar processos corrosivos, diminuindo custos com manutenção, economizando combustíveis e reduzindo a veiculação de espécies não nativas entre ecossistemas costeiros. Neste estudo foi desenvolvido, validado e aplicado um método analítico para determinação dos biocidas anti-incrustantes, clorotalonil, diuron, irgarol e tiram em amostras de água, e tecido biológico em diferentes regiões portuárias da costa brasileira e da Ilha de Gran Canaria -Espanha. / The maritime industry is an important aspect of a countries economy, however, the cumulative activities of port areas has an impact on coastal environments, this can include the addition of harmful micro-organic material. Among the potentially harmful micro-organic material being added to ecosystems, are recently emerged anti-fouling biocidal paints. Anti-fouling paints are used as a treatment to minimize corrosive processes, reduce maintenance costs, save fuel and reduce the transmission of non-native species to coastal ecosystems. This study developed, validated and applied an analytical method for the determination of the anti-fouling biocidal paints, chlorothalonil, diuron, irgarol and tiram in water samples and biological tissue in different port areas of the Brazilian coast and the Gran Canaria Island in Spain.
32

Multimedia Analysis Over 3G Wireless Interface

Tay, Jeremy Yee Chiat January 2003 (has links)
Recent rapid advancements in mobile communication and emerging demands for complicated multimedia content and services over mobile systems have caused a dramatic increase in research interest in this area. Among the topics covering multimedia service performance over the wireless interface, the quality of received multimedia content is an important issue. With the increase of visual media in mobile services, user opinion acquired through perception of received image quality will play an increasingly important role in determining the effectiveness of such services. The work documented in this thesis is motivated by the general lack of published work on software test beds for Third Generation Mobile Network (3G) and in particular for investigating mobile environment multimedia quality degradation. A 3G multimedia quality analysis system is presented, subjecting the input multimedia stream to the simulated 3G radio activities and measuring its degradation in terms of human perception. This approach takes a new and different model of multimedia quality measurement in a wireless communication domain, showing the possibility of a more effective approach that can be applied in many cases for assisting service quality assurance research across this area. The development of this software system is covered in detail together with in-depth analysis of multimedia image quality over a simulated 3G radio interface. Universal Mobile Telecommunications System (UMTS) is the 3G standard chosen for study in this work. The suggested test bed simulates a single Frequency Division Duplex (FDD) downlink UMTS Territorial Radio Access (UTRA) channel, where the received media's image analysis is performed using a Human Vision System (HVS) based image quality metric. The system aims to provide a multipurpose and versatile multimedia 3G test bed for use in testing of various solutions for protecting multimedia data across a 3G radio interface. Furthermore, it produces effective human vision oriented feedback on visual media degradation, providing a new and efficient method to address effectiveness of solutions in multimedia delivery over a mobile environment. This thesis shows the ability of HVS-based image quality metric in analyzing degradation of visual media over a noisy mobile environment. This presents a novel direction in the area of telecommunication service multimedia quality analysis, with potential user quality perception being considered on top of data or signal-based error measurements. With such a new approach, development of multimedia protection solutions can be made more effective. Effective feedback provided by considering quality measurement with strong correlation to human perception allows close analysis of user visual discrimination across an image. An example of the usefulness of this information is especially visible if considering development of a content-based multimedia data protective system that provides different levels of protection, depending on the importance of visual media. An apparent potential application of this thesis is in the testing of a multimedia/image protection protocol in a downlink channel. Future work might aim to extend the current system by adding network level traffic simulations and further addition of dynamic network control components, further considering network traffic conditions.
33

Υλοποίηση αλγορίθμου και προσομοίωση για τη βέλτιστη διαχείρηση φορητών συσκευών σε ετερογενή ασύρματα δίκτυα

Αυλωνίτης, Αθανάσιος, Λαμπρόπουλος, Αναστάσιος 11 January 2010 (has links)
Η διπλωματική εργασία υλοποιεί και προσομοιώνει αλγόριθμο για τη βέλτιστη διαχείριση φορητών συσκευών σε ετερογενή ασύρματα δίκτυα. Στο πρώτο κεφάλαιο γίνεται μια εισαγωγή στις γενικές αρχές των Κυτταρικών Συστημάτων Κινητών Επικοινωνιών παρουσιάζοντας την βασική ιδέα των διαφόρων γενιών κινητών επικοινωνιών. Στο δεύτερο κεφάλαιο αναλύονται τα συστήματα τρίτης γενιάς – 3G. Στο τρίτο κεφάλαιο αναφέρονται τα τεχνικά χαρακτηριστικά, τα πλεονεκτήματα και οι σχέσεις της πλατφόρμας TETRA. Στο τέταρτο κεφάλαιο περιγράφεται το σύστημα και οι λειτουργίες του TETRAPOL καθώς και τα πλεονεκτήματα και οι υπηρεσίες που προσφέρει αυτό. Στο 5ο κεφάλαιο αναλύονται τα συστατικά οι υπηρεσίες και οι λειτουργίες του iDen. Στο κεφάλαιο 6 γίνεται μια αναφορά στο πρωτόκολλο WiMax. Στα κεφάλαια 7 & 8 παρουσιάζονται ο αλγόριθμος της διαχείρισης συσκευών και η εξομοίωσή του σε MATLAB. / -
34

Optimizing The DSSC Fabrication Process Using Lean Six Sigma

January 2012 (has links)
abstract: Alternative energy technologies must become more cost effective to achieve grid parity with fossil fuels. Dye sensitized solar cells (DSSCs) are an innovative third generation photovoltaic technology, which is demonstrating tremendous potential to become a revolutionary technology due to recent breakthroughs in cost of fabrication. The study here focused on quality improvement measures undertaken to improve fabrication of DSSCs and enhance process efficiency and effectiveness. Several quality improvement methods were implemented to optimize the seven step individual DSSC fabrication processes. Lean Manufacturing's 5S method successfully increased efficiency in all of the processes. Six Sigma's DMAIC methodology was used to identify and eliminate each of the root causes of defects in the critical titanium dioxide deposition process. These optimizations resulted with the following significant improvements in the production process: 1. fabrication time of the DSSCs was reduced by 54 %; 2. fabrication procedures were improved to the extent that all critical defects in the process were eliminated; 3. the quantity of functioning DSSCs fabricated was increased from 17 % to 90 %. / Dissertation/Thesis / M.S.Tech Technology 2012
35

[en] PLANNING OF THIRD GENERATION MOBILE COMMUNICATION SYSTEMS (WCDMA-FDD) / [pt] PLANEJAMENTO DE SISTEMAS CELULARES DE TERCEIRA GERAÇÃO (WCDMA-FDD)

WALDIR GALLUZZI NUNES 22 July 2002 (has links)
[pt] Os sistemas de comunicações móveis celulares de terceira geração trazem a promessa de oferta de serviços diversos e avançados de comunicação. Estes serviços implicam em requisitos heterogêneos de desempenho da comunicação, e na conseqüente influência de diferentes parcelas de carga sobre a infra-estrutura empregada. Este trabalho contempla a questão do planejamento, dado que pode haver cargas heterogêneas simultâneas, e avalia fatores relacionados à carga, propondo uma ferramenta para modelá-la estatisticamente, de forma que se possa escolher raios de célula apropriados como subsídio à atividade de planejamento. / [en] Third generation mobile communication systems bring the promise of several and advanced communication services, which implies in heterogeneous performance requirements and consequent influence of diferent weighted loads over the communication infra-structure aplyed. This work treats the planning issue, given that there can be heterogeneous simultaneous loads, evaluating factors relateds to this loads and proposing a tool for its tatistical modeling, which allows to choose apropriated cell rays in aid of planning procedures.
36

The changing nature of academic development: exploring student perceptions and experiences of a learning skills programme in higher education

Petrenko, Karen January 2011 (has links)
Magister Educationis - MEd / In this paper, I focus on the issue of student perceptions and experiences of a 3rd generation academic development programme in higher education. I set out to explore the issue from two perspectives: firstly from the perspective of the higher education institution’s approach to academic development, namely, a learning skills programme and a first year sociology course, and secondly from the perspective of students’ intentions, expectations and experiences of such a programme. The research questions focused on the learning priorities embedded in the curriculum of a learning skills programme at Monash University, South Africa and the learning experiences of students in this programme.The methodology used in this study includes a case study which focused on the responses of six participants from a number of African countries completing their BA degrees. Semistructured interviews held and the content analysis method was used to analyse the data. The study concludes: that the main priority of the learning skills programme is to prepare students for their university learning rather than to prepare students for the world of work i.e. it falls within Street’s (2004) academic socialization model and that the Learning Skills programme can be seen as an example of Boughey’s (2007) 3rd generation academic development programmes.The study also suggests that there is a need to explore Volbrecht’s (2003) argument on the limitations of discipline-based models of academic development, the need to examine how academic literacy is constructed and how identity and power relations intersect in this construction. It further highlights the importance of the idea of multi-literacies as put forward by Street (2004) and suggests that as practitioners we should include a consideration of these literacies in academic development programmes to improve the quality of students’ learning and meaning making.
37

Evolution of multi-drug resistant HCV clones from pre-existing resistant-associated variants during direct-acting antiviral therapy determined by third-generation sequencing / 第三世代シーケンシングにより明らかになった、抗ウイルス薬投与下におけるC型肝炎ウイルスの多剤耐性クローンの進化

Takeda, Haruhiko 26 March 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20989号 / 医博第4335号 / 新制||医||1027(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 朝長 啓造, 教授 松田 文彦, 教授 小柳 義夫 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
38

Mesure des performances de reconstruction des électrons et recherche de Supersymétrie dans les canaux avec deux leptons de même charge dans les donnéesdu détecteur ATLAS / Measurement of electron reconstruction performance and search for Supersymmetry in final states with two same sign leptons in ATLAS detector data.

Maurer, Julien 20 September 2013 (has links)
Les trois premières années de fonctionnement de l'expérience ATLAS au LHC, aux résultats fructueux, ont ouvert l'accès à la physique à l'échelle du TeV. Les travaux effectués dans ce contexte ont porté à la fois sur des aspects de performance (reconstruction des électrons) et d'analyse (recherche de nouvelle physique). La première partie est consacrée aux mesures in-situ des efficacités de reconstruction et d'identification des électrons. La méthodologie employée pour réaliser ces mesures dans les données est présentée en détails ainsi que les méthodes développées pour l'estimation du bruit de fond résiduel. La deuxième partie traite de la recherche de Supersymétrie dans les événements avec deux leptons (électrons ou muons) de charges identiques, accompagnés de jets et éventuellement d'énergie transverse manquante, basée sur l'ensemble des données collectées par ATLAS en 2012 (soit 21 fb-1 à sqrt{s}= 8 TeV). Ces états finaux sont particulièrement appropriés à la recherche de gluinos ou de squarks de troisième génération. Les principaux aspects de l'analyse sont décrits, notamment les méthodes d'estimation des différents bruits de fond. L'absence d'excès dans les régions de signal par rapport aux prédictions du Modèle Standard est interprétée en termes de limites sur les masses des superpartenaires, dans le cadre de modèles aux spectres de masse simplifiés. Ainsi, dans les modes de désintégrations étudiés, l'existence de gluinos de masse inférieure à 1 TeV, ou de sbottoms de masse inférieure à 500 GeV, est exclue. / The first three years of operation of the ATLAS experiment at LHC, with fruitful results, have opened the way to physics at the TeV scale. The work realized in this context included some performance aspects (electron reconstruction) as well as analysis (search for new physics). The first part is devoted to in-situ measurements of electron reconstruction and identification efficiencies. The methodology employed to perform these measurements in data is presented in details, as well as the methods developped for estimating the residual background. The second part deals with a search for Supersymmetry in events with two leptons (electrons or muons) of identical charges, together with jets and in some cases missing transverse energy, based on the whole dataset colledcted by ATLAS in 2012 (namely 21 fb-1 at 8 TeV). These final states are particularly adapted to searches for gluinos or third generation squarks. The main aspects of the analysis are described, in particular the methods used to estimate the various backgrounds. The absence of excess in the signal regions with respect to the Standard Model predictions is interpreted in terms of limits on the masses of superpartners, in the frame of models with simplified mass spectra. Thus, in the studied decay modes, the existence of gluinos with masses below 1 TeV or sbottoms with masses below 500 GeV is excluded.
39

Machine learning for epigenetics : algorithms for next generation sequencing data

Mayo, Thomas Richard January 2018 (has links)
The advent of Next Generation Sequencing (NGS), a little over a decade ago, has led to a vast and rapid increase in the generation of genomic data. The drastically reduced cost has in turn enabled powerful modifications that can be used to investigate not just genetic, but epigenetic, phenomena. Epigenetics refers to the study of mechanisms effecting gene expression other than the genetic code itself and thus, at the transcription level, incorporates DNA methylation, transcription factor binding and histone modifications amongst others. This thesis outlines and tackles two major challenges in the computational analysis of such data using techniques from machine learning. Firstly, I address the problem of testing for differential methylation between groups of bisulfite sequencing data sets. DNA methylation plays an important role in genomic imprinting, X-chromosome inactivation and the repression of repetitive elements, as well as being implicated in numerous diseases, such as cancer. Bisulfite sequencing provides single nucleotide resolution methylation data at the whole genome scale, but a sensitive analysis of such data is difficult. I propose a solution that uses a powerful kernel-based machine learning technique, the Maximum Mean Discrepancy, to leverage well-characterised spatial correlations in DNA methylation, and adapt the method for this particular use. I use this tailored method to analyse a novel data set from a study of ageing in three different tissues in the mouse. This study motivates further modifications to the method and highlights the utility of the underlying measure as an exploratory tool for methylation analysis. Secondly, I address the problem of predictive and explanatory modelling of chromatin immunoprecipitation sequencing data (ChIP-Seq). ChIP-Seq is typically used to assay the binding of a protein of interest, such as a transcription factor or histone, to the DNA, and as such is one of the most widely used sequencing assays. While peak callers are a powerful tool in identifying binding sites of sparse and clean ChIPSeq profiles, more broad signals defy analysis in this framework. Instead, generative models that explain the data in terms of the underlying sequence can help uncover mechanisms that predicting binding or the lack thereof. I explore current problems with ChIP-Seq analysis, such as zero-inflation and the use of the control experiment, known as the input. I then devise a method for representing k-mers that enables the use of longer DNA sub-sequences within a flexible model development framework, such as generalised linear models, without heavy programming requirements. Finally, I use these insights to develop an appropriate Bayesian generative model that predicts ChIP-Seq count data in terms of the underlying DNA sequence, incorporating DNA methylation information where available, fitting the model with the Expectation-Maximization algorithm. The model is tested on simulated data and real data pertaining to the histone mark H3k27me3. This thesis therefore straddles the fields of bioinformatics and machine learning. Bioinformatics is both plagued and blessed by the plethora of different techniques available for gathering data and their continual innovations. Each technique presents a unique challenge, and hence out-of-the-box machine learning techniques have had little success in solving biological problems. While I have focused on NGS data, the methods developed in this thesis are likely to be applicable to future technologies, such as Third Generation Sequencing methods, and the lessons learned in their adaptation will be informative for the next wave of computational challenges.
40

Energy systems studied of biogas : Generation aspects of renewable vehicle fuels in the transport system

Magnusson, Mimmi January 2012 (has links)
The transport sector is seen as particularly problematic when concerns about climate change and dependency on fossil energy are discussed. Because of this, bioenergy is strongly promoted for use in the transport sector, both on a European level and nationally in Sweden. Even though bioenergy is considered one of the key solutions, it is generally agreed that both supply- and demand-side measures will be needed to achieve a change to a more sustainable transport system. One of the reasons for this is the limited availability of biomass, especially agricultural feedstocks competing with food or feed production. Woody biomass, however more abundant, is also exposed to tough competition from other sectors. In this thesis, the role of biogas as a vehicle fuel in a future sustainable transport system is discussed together with the prerequisites needed to realise such a transport system. Biogas is a biofuel that could be produced in several different ways: by anaerobic digestion, which is a first-generation production route, by gasification, which is a second-generation process, and by catalytic reduction of carbon dioxide, a third-generation technology. The main focus in this thesis is on biogas produced by anaerobic digestion and the results show that there is a significant potential for an increase compared to today’s production. Biogas from anaerobic digestion, however, will only be able to cover a minor part of the demand in the Swedish transport sector. Considering biogas of the second and third generations, the potential for production is more uncertain in a mid-term future, mainly due to competition for feedstock, the possibility to produce other fuels by these processes, and the present immaturity of the technology. The limited potential for replacing fossil vehicle fuels, either by biogas or other renewable fuels, clearly shows the need for demand-side measures in the transport system as well. This thesis shows the importance of technical and non-technical means to decrease the demand for transport and to make the transport as efficient as possible. The results show that both energy-efficient vehicles and behavioural and infrastructural changes will be required. Policies and economic incentives set by governments and decision-making bodies have a prominent role to play, in order to bring about a shift to a more sustainable transport system, however, measures taken on individual level will also have a great impact to contribute to a more sustainable transport system. / <p>QC 20121116</p>

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