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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.
541

Modélisation ontologique des recommandations de pratique clinique pour une aide à la décision à niveaux d'abstraction variables / Ontological modeling of clinical practice guidelines to provide flexible decision support

Galopin, Alexandre 16 September 2015 (has links)
Conformément aux principes de la médecine factuelle, les guides de bonne pratique clinique (GBPC) sont élaborés dans un but d'amélioration de la qualité des soins. Pourtant, le suivi des recommandations par les médecins reste faible, même lorsqu'elles sont intégrées dans des systèmes informatisés d'aide à la décision. En effet, elles sont souvent critiquées pour leur manque de flexibilité, et leur incapacité à gérer la singularité des patients rencontrés en pratique clinique. En particulier, leur orientation monopathologique est en inadéquation avec la réalité de patients bien souvent polypathologiques. Nos travaux portent sur la proposition d'une méthode basée sur un raisonnement ontologique pour permettre la conciliation de GBPC pour la prise en charge flexible de patients polypathologiques au sein d'un système d'aide à la décision. Les bases de connaissances reposent sur des règles construites par formalisation des recommandations, dont les critères patients sont organisés par une ontologie du domaine, permettant de produire un graphe des profils cliniques structuré par généralisation. Le raisonnement ontologique permet une juste adaptation des connaissances aux niveaux d'abstraction variables de la description du patient. Cette méthode a été implémentée dans un système d'aide à la décision, appelé GO-DSS, et appliquée à la prise en charge de patients diabétiques et hypertendus, à partir des GBPC produits par la société VIDAL (VIDAL Recos). Le prototype et ses interfaces ont été évalués qualitativement par un échantillon d'utilisateurs comprenant à la fois des informaticiens avec des connaissances médicales et des médecins avec des compétences en informatique. / Clinical practice guidelines (CPGs) are elaborated according to evidence-based medicine principles in order to improve healthcare quality. However, even when they are integrated into clinical decision support systems, recommendations are poorly implemented by physicians. Indeed, CPGs are often criticized for their lack of flexibility, and their inability to handle the singularity of patients encountered in clinical practice. In particular, CPGs are usually elaborated for a single pathology whereas patients usually suffer from multiple pathologies and comorbidities. We have proposed a method based on an ontological reasoning to enable the reconciliation of single-pathology CPGs to support the flexible management of patients with multiple pathologies. Knowledge bases are made of decision rules that formalize the content of single-pathology CPGs. Patient criteria are organized by a domain ontology, which allows the generation of a generalization-ordered graph of clinical patient profiles. The ontological reasoning allows to reason at different levels of abstraction to process clinical cases described with different levels of completeness. This method has been implemented in a decision support system called GO-DSS, and applied to the management of patients suffering from both arterial hypertension and type 2 diabetes, on the basis of CPGs produced by the VIDAL company (VIDAL Recos). The prototype and its user interfaces have been qualitatively evaluated by a sample of users including both computer scientists with medical knowledge and physicians with computer skills.
542

Konstrukce malého CNC soustruhu / Design of small CNC turning machine

Podloucký, Milan January 2012 (has links)
The aim of this master thesis is construction a small CNC lathe ideal for small series of mostly minor workpieces or for learning needs. In the first part of the work is carried out general literature search containing turning technology, tools for turning and the allocation of turning machines. There is also retrieval of small lathes located not only in our market. Based on research are selected technical parameters of the machine and carried out construction calculations. Also included is a 3D model of the entire assembly and assembly drawings of machine nodes.
543

Pohon a vedení laserového ukazovátka / Drive and leading of laser pointer

Dostál, Petr January 2013 (has links)
This master thesis deals with a construction solution for traversing of laser pointer, which is used for position identification for stock removal from the storage unit SSI Logimat, including a construction solution of leading of this traversing. The first part contains a research of storage systems used in logistics, as well as systems upgraded with laser pointer. In main part are described the suggestions of leading of laser pointer traversing, together with the design of mechanical transmission and components associated with mechanical transmission. Subsequently the drive of spin of the laser and drive of mechanical transmission are designed. Selection of drives is verified by calculation. The final part contains the check of leading of traversing by strength calculation for bending, from which is suggested the design of leading reinforcement.
544

Design and characterization of Silicon Photonic structures for third order nonlinear effects / Conception et caractérisation de structures photoniques sur silicium pour les effets non linéaires du troisième ordre

Serna Otálvaro, Samuel Felipe 28 November 2016 (has links)
Le présent travail a été consacré à l'étude des non linéarités de troisième ordre dans des structures intégrées à base de silicium exploitant des configurations de cavités à miroir de Bragg (nanobeam) et guides à cristaux photoniques à modes lents. Tout d'abord, nous avons développé une méthode non destructive à faisceau unique pour caractériser les effets de troisième ordre instantanés, c’est-à-dire la quantification de la susceptibilité complexe effective dans les guides d'ondes. La méthode a été dénommée "Top-hat D-Scan bi-directionnelle" et constitue un analogue temporel de la méthode Top-hat Z-Scan développée précédemment. Nous avons établi un modèle analytique et numérique et nous rendons compte de la première mesure d'un guide d'ondes en silicium utilisant une impulsion mis en forme dans un étireur et complétée par une procédure d’injection bi-directionnelle. L’ensemble instrumental développé constitue une expérience de métrologie des effets non-linéaires dans des guides d’ondes silicium au meilleur niveau de l’état de l’art. La méthode proposée a été validée dans des guides SiGe, chalcogénures et nitrure du silicium. Forts de cet outil métrologique, nos travaux d’exploration des interactions non linéaires lumière-matière ont été consacrés à deux grandes familles de nanostructures photoniques : des microcavités optiques et guides d'ondes en régime de lumière lente. Dans la première des deux situations, les variations d'indice provoquées par les non linéarités sont responsables d’un décalage des fréquences de résonance excluant sa coïncidence avec la fréquence du signal d'excitation et diminuant ainsi l'efficacité de l'injection optique de manière drastique. Afin de maintenir le bénéfice de localisation de la lumière tout au long de l'excitation pulsée, nous avons expérimentalement et numériquement étudié le comportement d'une cavité en silicium conçue, fabriquée, et enfin excitée par une impulsion présentant une puissance crête élevée. En contrôlant temporellement la phase des composantes spectrales injectée, la relation de phase spectrale compensant la dérive de fréquence non linéaire de la résonance de la cavité, nous avons effectué la première démonstration expérimentale de l'excitation cohérente d'une micro-cavité silicium non linéaire. Enfin, nous avons consacré des efforts importants pour concevoir, fabriquer et caractériser des guides d'ondes à cristaux photoniques (SPhCW) en silicium à fente, matrice d’une intégration hybride de matériaux optiques non-linéaires sur silicium. Les résultats rapportés fournissent la première preuve expérimentale d’un contrôle précis des propriétés de dispersion de guides à cristaux photoniques à fente propres à être remplis par des matériaux souples comme des polymères ou des couches minces dopées. La dispersion de groupe des modes lents guidés est contrôlable en signe et en amplitude et correspond à des bandes passantes optiques exploitables (~10nm). Ces résultats démontrent l’intérêt direct pour le traitement des données tout-optique sur puce des guides à modes lents à cœur creux utilisant des effets optiques non linéaires d’ordre trois pour le traitement tout-optique des données sur puce. / All-optical signal processing implemented in silicon photonics is considered as a promising route to solve several bottlenecks for the realization of future dense and mixed integrated electronic and photonic chips including ultrahigh data bit rate issues and power consumption constraints. In the context of the planar silicon photonics technology, a dramatic reduction of the needed power to reach optical nonlinear effects is obtained due to the sub-micrometer size of silicon wires (~450nmX260nm) in the telecommunication wavelength window, although silicon does not exhibit second-order response (χ^((2))) due to the centrosymmetry of its lattice. Moreover, third-order effects (χ^((3))) are partially spoiled in this material due to the strength of the two-photon-absorption (TPA) effect, which in turn generates free-carriers inducing additional absorption and refractive index changes. One way to overcome this limitation is the hybrid integration on silicon of low index soft materials with luminescence or nonlinear optical properties lacking to silicon. In this context, the present work is devoted to the study of third order nonlinearities in silicon-based integrated structures exploiting enhanced electromagnetic field effects (e.g. in Si resonators and slow light waveguides). First, we have developed a dedicated single beam non-destructive method to characterize the instantaneous third order effects though the quantification of complex effective waveguide susceptibility. The method is named “Bi-directional top-hat D-Scan” and consists on a temporal analogous of the top-hat Z-Scan. We have established an analytical and numerical model and we report the first measurement of a silicon waveguide by using a pulse shaping set-up and a bi-directional procedure. The originality of our methods stands in the capability to measure in two steps : the 3rd order nonlinear Figure-Of-Merit (FOM) independently of the injection losses, and the effective nonlinear waveguide parameters (Kerr and TPA) taking into account measured coupling losses at each facet. Furthermore, we apply the method to other integrated novel materials including Ge-rich GeSi alloys, carbon nanotube doped thin films, and chalcogenide waveguides. Additionally, two further enhancements of light-matter nonlinear interactions have been explored within this work: optical microcavities and slow light waveguides. In the first picture, index variations caused by non-linearities shift the resonance frequencies precluding the coincidence with the excitation signal frequency, thereby decreasing the injection efficiency. In order to maintain the benefit of light localization throughout the pulsed excitation, we have experimentally and numerically studied the behavior of a designed and fabricated silicon nanobeam cavity excited by a high power tailored chirped pulse whose spectral phase relation compensates for the nonlinear frequency drift of the cavity resonance. We report a numerical study of this first experimental demonstration of the coherent excitation of a nonlinear micro-cavity, leading to an enhanced intra-cavity nonlinear interaction. Finally, we have dedicated efforts to engineer, fabricate and characterize silicon slot photonic crystal waveguides (SPhCW) in order to compensate their strong dispersion present in the slow light regime while taking benefit from large group index light propagation. We showed that their frequency dispersion properties can be engineered from anomalous to normal dispersion, along with zero group velocity dispersion (ZGVD) crossing points exhibiting a Normalized Delay Bandwidth Product (NDBP) as high as 0.156. The reported results provide the first experimental evidence for an accurate control of the dispersion properties of fillable periodical slotted structures in silicon photonics, which is of direct interest for on-chip all-optical data treatment using nonlinear optical effects in hybrid-on-silicon technologies.
545

Vilket stöd erbjuder lärarhandledningar? : En studie om lärarhandledningar med fokus på matematiska samtal och resonemang / What kind of support do teacher guides offer? : A study about teacher guides with focus on mathematical discussions and reasoning

Andersson, Lovisa January 2020 (has links)
Sedan Lgr11 infördes i skolan har förmågan att kommunicera och resonera i matematik genom samtal och diskussioner fått en ny plats i undervisningen. I kunskapskraven står det att ska elevernas förmåga att muntligt resonera och kommunicera i matematik ska bedömas i årskurs 6 vilket innebär att lärarna behöver ge eleverna möjlighet att träna dessa förmågor. Syftet med denna studie är att analysera vilket stöd lärarna erbjuds genom lärarhandledningar för att kunna utveckla elevernas förmåga att samtala med och om matematik samt att föra matematiska resonemang. En innehållsanalys av lärarhandledningar visar att det finns stöd för lärarna att utveckla elevernas förmåga att samtala med och om matematik samt att föra matematiska resonemang, men att stödet varierar i stor utsträckning mellan de olika lärarhandledningarna. Innehållsanalysen är baserad på Shulmans ramverk om vilka kunskaper en lärare behöver ha för att undervisa, MKT-ramverket från Ball et al. som kopplar Shulmans ramverk till matematik samt Niss och Højgaard-Jensens ramverk om vilka kunskaper en matematiklärare behöver ha. Analysen visar att samtliga lärarhandledningar erbjuder stöd till lärare i sina ämnesdidaktiska kunskaper i form av aktiviteter som kan användas för att utveckla elevernas muntliga förmåga. Däremot varierar antalet förekomster av stöd för lärarna till sina ämnesdidaktiska- samt ämneskunskaper. / When the new curriculum was introduced in Sweden, 2011, the ability to communicate and reason in mathematics through discussions was put forward. The students’ ability to orally reason and communicate in mathematics is to be assessed in grade 6, which means that teachers need to give students opportunities to practice these skills. The purpose of the study is to analyze what kind of support teacher guides offer the teacher to help them develop the students’ ability to discuss with and about mathematics as well as to apply mathematical reasoning. A content analysis of teacher guides showed that there is support for teachers to develop the students’ ability to discuss with and about mathematics and to apply mathematical reasoning, but that the support varies to a great extend amongst teacher guides. The content analysis is based on Shulman’s knowledge base framework describing what a teacher needs to know in order to teach, the MKT-framework from Ball and colleagues that connects Shulman’s framework to mathematics and Niss och Højgaard-Jensen’s framework about which knowledge a mathematics teacher needs for teaching. The analysis shows that all analyzed teacher guides offer support in pedagogical content knowledge consisting of activities that can be used to develop the students’ orally ability. However, the amount of support varies concerning both pedagogical content knowledge and content knowledge.
546

Vers les technologies quantiques basées sur l’intrication photonique / Towards quantum applications based on photonic entanglement

Vergyris, Panagiotis 28 November 2017 (has links)
Le but de cette thèse est de développer des sources d’intrication photonique en vue d'applications en sciences information quantique. Dans ce contexte, nous présentons une source très performante et entièrement guidée permettant, au moyen d'une boucle de Sagnac, la génération d'états hyper-intriqués en polarisation et en énergie-temps. La configuration guidée rend le dispositif versatile, efficace et compatible avec une large bande spectrale, répondant ainsi au besoin des systèmes et réseaux de communication fibrés. À cette fin, nous avons distribué simultanément dans différents canaux télécoms des paires de photons hyper-intriqués au moyen de multiplexeurs en longueur d'onde à 5 canaux (DWDM), augmentant de fait le débit. La qualité de l'intrication est validée par la violation d'une inégalité de Bell étendue à un espace de Hilbert à 16 dimensions. Afin de pouvoir interfacer des photons aux longueurs d'ondes des télécommunications avec les bandes d'absorption des mémoires quantiques situées dans le visible, nous avons également développé une interface cohérente en longueur d'ondes. Un nouveau dispositif de métrologie quantique permettant la mesure avec une précision inégalée des effets de la dispersion chromatique dans les fibres optiques standards est également proposé. Notre approche "quantique" améliore la précision par un facteur 2.6 par rapport aux méthodes de mesures conventionnelles. Dans ce même contexte, nous avons aussi implémenté un nouveau protocole de métrologie de la phase de deux photons en ne détectant uniquement qu'un seul photon. Cette réalisation ouvre la voie à des applications potentielles simples s'appuyant sur peu de ressources au niveau de la détection. Finalement, dans la perspective de la miniaturisation de dispositifs quantiques, nous avons démontré un générateur d'intrication annoncée intégré sur puce qui trouve des applications en calcul et métrologie quantique. / The aim of this thesis was to develop photonic entanglement sources and study their implementation in the general field of quantum information technologies. To this end, a novel fully wave-guided, high performance photonic entanglement source is presented, able to generate hyper-entangled states in the observables of polarization and energy-time by means of a nonlinear Sagnac loop. The waveguide-based design makes it flexible, reliable, and adaptable to a wide spectral range, paving the way towards compact photonic entanglement generators, compatible with fiber-based communication systems and networks. This has been underlined by generating and distributing hyperentanglement in 5x2 dense wavelength division multiplexed channel telecom pairs, simultaneously, towards higher bit rates. The quality of the generated entanglement has been qualified by violating the Bell inequalities in a 16-dimension Hilbert space. Moreover, to adapt the wavelength of the entangled telecom photon pairs to the absorption wavelength of current quantum memory systems, a coherent wavelength converter is demonstrated. Furthermore, within the framework of quantum metrology, a new concept for a high-precision chromatic dispersion (CD) measurement in standard single mode fibers is introduced and demonstrated. In this demonstration, due to conceptual advantages enabled by quantum optics, an unprecedented 2.6 times higher accuracy on CD measurements is shown, compared to state-of-the-art techniques. In the same context, a new protocol for measuring two-photon phase shifts is performed using single photon detection only, promising scalable and potential real device applications with limited resources and simplified detection schemes. Finally, any potential application of quantum optics will be realized using small-scale devices. In this framework, an integrated on-chip heralded path entanglement generator is demonstrated, and shown to be adaptable to logic gate operations.
547

[pt] APLICAÇÃO DE MÉTODOS VARIACIONAIS E FORMULAÇÕES HEURÍSTICAS PARA ANÁLISE E SÍNTESE NUMÉRICA DE TRANSFORMADORES EM GUIA DE ONDA RETANGULARES / [en] APPLICATION OF VARIATIONAL METHODS AND HEURISTIC FORMULATIONS FOR ANALYZES AND NUMERICAL SYNTHESIS OF RECTANGULAR WAVEGUIDE TRANSFORMERS

08 October 2010 (has links)
[pt] Transformadores de guia de onda são amplamente empregados no projeto de componentes em onda guiada e são encontrados em praticamente todas as cadeias alimentadoras de antenas e demais estruturas de onda guiada na faixa de microondas. Embora a teoria de transformadores seja conhecida, os requisitos de ordem sistêmica têm levado os projetos de transformadores de guia de onda ao seu limite. Para tal nível de exigência, e considerando o número de variáveis no projeto de transformadores, técnicas numéricas de análise (tais como FDTD e expansão modal dentre outros), e otimização têm sido obrigatoriamente empregadas. Por outro lado, o número de variáveis de um transformador, acaba sendo um processo de alto consumo de tempo computacional, incoerente com o porte e objetivo de custo desses transformadores. Este trabalho propõe uma possibilidade alternativa para a análise mais rápida para essas estruturas, através do emprego de formulações fechadas derivadas de métodos varacionais. Um modelo heurístico é proposto para o caso de descontinuidades em dois planos, sejam para o caso de descontinuidades homogêneas ou para não-homogêneas. / [en] Waveguide transformers are widely used on antenna’s feeder chains and other microwave devices. Although the theory of quarter wavelength transformers is well known, the current electrical performance of such microwave devices has been pushing the waveguide transformers design to its limit. For attending such level of requirements, and considering the number of existing variables on a waveguide transformer design, very accurate numerical techniques has been applied on its analyses, (such as FDTD, mode matching, etc), and optimization techniques as well. On the other hand, such numerical techniques are very memory and/or CPU/time consuming, which do not match with the cost objective of those simple concept transformers. This work proposes an alternative technique, based on close-form models derived from varational theory. A heuristic model is also proposed for attending the two plane transformer case, which can be easily applied for both homogeneous and inhomogeneous structures. Keywords Waveguide;
548

Interpretation and Execution of Chords on the Double Bass from Select Movements of the Bach Cello Suites

Chen, Der-Shiuan 08 1900 (has links)
The Bach Cello Suites have become widely transcribed and studied on the double bass. They have also become essential teaching material as most US orchestra auditions demand solo Bach for bass auditions. Transcribing the chords in Bach Cello Suites presents many difficulties on the bass because of the different tuning of our instrument (cello in 5ths; double bass in 4ths). There is no unified solution to all the problems presented in chord playing at this time. The purpose of this project, therefore is to give bass players solutions to the problems by looking at historical interpretation of chords, technical execution of the chords on cello and bass, tonal and resonance considerations and fingering solutions. The chords chosen represent the most common and most difficult to transcribe to the double bass from the Cello Suites.
549

Shortcuts With the Help of the Digital World : A Study of Study Guide Websites and Their Presence in the EFL Upper Secondary Classrooms

Daniel, Windy January 2020 (has links)
This study aims to explore students’ use of study guide websites when assigned novels and similar literary works in the EFL classroom in Swedish upper secondary schools. The study is based on the mixed-method approach and the findings reveal that all students that participated in the questionnaire and the interviews used study guide websites in a sense. By further exploring the reasons behind the use of these websites, three categories were discovered based on the conducted interviews: time, comprehension and interest. The findings also reveal that a few students used the study guide websites as an aid, other students used them to substitute reading the assigned literary work, while a few students used the study guide websites both as an aid and as a substitute. Finally, the study concludes that all the participants from the interviews acknowledge that study guide websites cannot substitute literary works entirely and even though they acknowledge the use of them, they do not believe that these websites include enough detailed information about the literary work.
550

Olika stöd kan mediera olika handling : En undersökande studie om och hur design av lärarhandledningar i matematik kan påverka undervisning / Various forms of support can mediate different actions : An exploratory study of and how the design of teacher guides in mathematic can affect teaching

Lilja, Victoria, Åkerlund, Emelie January 2023 (has links)
Lärarhandledningar för matematikundervisning kan designas på olika sätt och ger därigenom olika typer av stöd för läraren att genomföra undervisningen. En lärarhandlednings design kan alltså mediera idéer och direktiv som kan påverka lärarens genomförande av undervisning. Syftet med denna studie är att undersöka om och i så fall hur läromedels design kan bidra till att påverka undervisningens karaktär. Syftet uppfylls genom observationer av fyra matematiklektioner som utgick ifrån två läromedel med olika design, med uppföljande intervjuer. Resultatet, som är en karaktärisering av undervisningen som observerades utifrån de två olika läromedlen, indikerar att designen av en lärarhandledning på flera sätt medierar agerande i planering och genomförande av undervisning. / Teachers’ guides in mathematics can be designed in different ways and thereby provide various supports for the teacher to carry out teaching activities. A teachers´ guide in mathematics can mediate ideas and directives that affects the teaching strategies in the classroom. The aim of this study is to investigate whether, and in that case how, the design of the learning materials can contribute to affect the nature of the teaching. The aim is fulfilled by observing four mathematic lessons which was based on two learning materials with different designs, with follow-up interviews. The results, which is a characterization of the teaching that was observed based on the two different teaching materials indicates that the design of a teacher's guide in several ways mediates action in planning and implementation of teaching.

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