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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.
91

Účinnost turbíny jako funkce otáček / Turbine efficiency as a function of speed

Woffová, Helena January 2021 (has links)
The subject of the thesis is condensing steam turbine with the required power of 50MWe and set input and output parameters. The turbine is designed as a two-body turbine. There is also designed balance scheme with reheating, regeneration and air condenser. Subsequently, the thermodynamic calculation for three variations of high pressure part with different speeds is demonstrated. The result is evaluated in terms of calculated efficiency and also in an economic point of view. The output is a selection of the variation with the best parameters. Then the basic dimensioning calculations, the design of the leveling piston and the sealing system follows for this variation. A simplified section of this part is drawn. Finally, the balance scheme is adjusted based on the data and calculated for limited performance as well.
92

Měření a analýza jednofázového transformátoru s pomocí LabVIEW / Measurement and analysis of single-phase transformer

Princ, Pavel January 2010 (has links)
The aim of that diploma thesis is low power transformer simulation via its substitutitional circuitry.As Instrument for matematical description of model and simulation of various operating situations with different amplitude and types of load was used Labview software. The software was simultaneously used for real transformer measurement and to compare these results with calculated values. The created program is also applied for measuring excercise for students. In The thesis is described measured transformer in terms of final elements method in FEMM software and there is showed the procedure of its design.
93

Parní turbina / Steam turbine

Sedlák, Pavel January 2011 (has links)
The diploma thesis concentrates on a project of condensing steam turbine with uncontrolled extraction. These topics are analyzed in more detail: design of thermal diagram, thermodynamic calculation and turbine design concepts. First two topics are solved in the calculation section of the thesis. In the construction part are processed a third topic.
94

Parní turbina pro teplárnu / Steam Turbine CHP

Zemánek, Josef January 2013 (has links)
The diploma thesis concentrates on a project of backpreassure steam turbine. These topics are analyzed in more detail: design of balance schema, thermodynamic calculation, loss coefficient and its effect on the loss. Technical solutions are designed according to given details of a steam and chosen conditions of use.
95

Kondenzační parní turbina / Condensing Steam Turbine

Peterka, Zdeněk January 2014 (has links)
The aim of this Diploma thesis is calculating the parameters of the heat balance diagram as well as creating balance sheet for winter and summer operation. In one of the first parts, the reader is acquainted with two P&I diagrams containing main accessories, which are also used in the heat scheme, KKS marking system is used to name the acces-sories. The main part of the thesis consists of a detailed calculation of the heat transfer surface of the condenser with design of the tube bundle including the main dimensions of the condenser. Last but not least, the calculations of the hydraulic losses of condenser are included in the thesis.
96

Evoluce a integrace XML formátů / XML Formats Evolution and Integration

Klímek, Jakub January 2013 (has links)
In the past decade XML became a wide-spread information exchange data model. Many XML users have many XML formats described by XML schemas. To ease the management of multiple XML schemas modeling similar reality, the conceptual model for XML was defined. With its definition came various challenges that needed to be further researched. This thesis focuses on two of those challenges. The first challenge is to manage the evolution of the multi-level conceptual model as the modeled reality, XML schemas and applications evolve in time. The second challenge is to allow the majority of users who already use XML schemas in their system without the conceptual model to use their schemas to semi-automatically create one. In addition a step towards integration of the conceptual modeling of XML and semantic web techniques was taken.
97

Filmový a malířský obraz oneirického žánru - Problém interpretace / Film and Painting image of Oneiric Genre - The Problem of Interpretation

Malina, Lukáš January 2017 (has links)
The subject of the thesis is a comparative analysis of sign production and the interpretation of the film and painting of oneiric or horror genre focused on Vall Lewton's films and their similarity to the painting in creating an atmosphere of uneasiness and fear. Although these works are based on a sign structure, which is an important key to their interpretation, they are not independent of the different interpretations they allow. On the contrary, it seems that the work's intention is to encourage the viewer to complete the art by projecting his own fear into it. This approach is based on Umberto Eco's and Jan Mukařovský's theory of the interpretation, both of which emphasizing the reader's role in understanding the principle of functioning of the work of art. The concepts of the model author and model reader in Eco's theory and the term semantic gesture within Mukařovský's work are sharing numerous similarities.
98

Hodnocení ošetření zubu Er:YAG laserem ve srovnání s ostatními preparačními metodami / Evaluation of tooth preparation using Er: YAG laser in comparison with other preparation methods

Bučková, Michaela January 2016 (has links)
Er: YAG laser is a new method of preparation that promises gentler and more accurate dental treatment. Its specific characteristics is large absorption of the beam in the water and a small absorption in the tissue without the thermal effect. Therefore the treatment is safer and effectiver. The research has the aim in its theoretical - cognitive part to assess its advantages in comparison with treaditional treatment method - drill. As an essential element will be evaluation of caries lesion in vitro and in vivo. The size of the cavity will be judged on, the shape of developing a smear layer and retention surface in relation to the filling and the . The extracted teeth will be scanned in electronic microscope to assess the formation of contact and non-contact preparation, focusing on the shape and size of the prepared lesion in relation to modern filling materials - low viscosity composites. Extensive research supported by the Ministry of Health (IGA : 9991-4 and 13351-4) that focuses on the the use of various therapeutic methods in the treatment of special needs patients. Dental treatment of a special needs patients is expensive and time-consuming than conventional dental treatment. Therefore, clinical application of theoretical cognitive part will create a electronical support system for the...
99

Cross-layer optimization of cooperative and coordinative schemes for next generation cellular networks / Optimisation inter-couches de schémas de coordination et de coopération pour les futurs réseaux cellulaires

Khreis, Alaa 06 November 2018 (has links)
Les demandes de haut débit, faible latence et grande fiabilité augmentent dans les nouvelles générations de systèmes de radiocommunications. Par conséquent, on propose de combiner la transmission non orthogonale avec les retransmissions HARQ afin de combattre les fluctuations de canal de transmission à haut débit. Dans la première partie de la thèse, on propose des protocoles de retransmissions HARQ avec l'aide d'un relai afin d'améliorer le débit et la fiabilité du système. Une version renforcée du protocole HARQ qui prend en compte le délai de retour est proposée dans la seconde partie de la thèse. / HARQ has become an important research field in the wireless digital communications area during the last years. In this thesis, we improve the HARQ mechanisms in terms of throughput and/or latency which are the bottleneck of next generation wireless communication systems. More precisely, we improve the time-slotted HARQ systems by mimicking NOMA, which means using superposed packets in a single-user context. In the first part of the thesis, we propose HARQ protocols using the help of a relay to improve the transmission rate and reliability. An enhanced HARQ protocol adapted to delayed feedback is proposed in the second part. In this new multi-layer HARQ protocol, additional redundant packets are sent preemptively before receiving the acknowledgement, and in superposition to other HARQ processes.
100

Intégration de Schémas Large Echelle

Saleem, Khalid 27 November 2008 (has links) (PDF)
La mise en correspondance sémantique appliquée à des schémas hétérogènes dans les systèmes de partage de données est une tache fastidieuse et source d'erreurs. La thèse présente une nouvelle méthode automatique et robuste qui intègre un grand nombre de schémas sous forme arborescente et de domaine spécifique. Elle permet de découvrir des correspondances sémantiques entre eux. La méthode crée également les mappings entre des schémas sources et le schéma intégré. Puis, le manuscrit présente une technique pour découvrir d'une manière automatique des correspondances complexes entre deux schémas. <br /><br />Les outils de mise en correspondance existants utilisent des techniques semi-automatiques uniquement entre deux schémas. Dans un scénario à grande échelle, où le partage des données implique un grand nombre de sources de données, ces techniques ne sont pas adaptées. De plus, la mise en correspondance semi-automatique nécessite l'intervention de l'utilisateur pour finaliser les mappings. Bien qu'elle offre la possibilité de découvrir les mappings les plus appropriés, les performances s'en trouvent fortement dégradées. Dans un premier temps, le manuscrit présente en détails l'état de l'art sur la mise en correspondance. Nous expliquons les inconvénients des outils actuellement disponibles pour répondre aux contraintes d'un scénario à grande échelle. Notre approche, PORSCHE (Performance ORiented SCHEma mediation) évite ces inconvénients et ses avantages sont mis en évidence de manière empirique.<br /><br />Le principe de l'algorithme de PORSCHE consiste à regrouper d'abord les nœuds de l'arbre selon la similarité linguistique de leurs labels. Ensuite, des techniques de fouilles d'arbres utilisant les rangs des nœuds calculés au moyen du parcours en profondeur de l'arbre sont appliquées. Cela réduit l'espace de recherche d'un nœud cible et améliore par conséquent les performances, ce qui en fait une technique adaptée au contexte large échelle. PORSCHE implémente une approche hybride, qui crée également en parallèle et de manière incrémentale un schéma intégré qui englobe tous les schémas, tout en définissant les correspondances entre ces derniers et le schéma intégré. L'approche découvre des correspondances 1:1 dans un but d'intégration et de médiation. Finalement, des expérimentations sur des jeux de données réels et synthétiques montrent que PORSCHE passe à l'échelle avec de scénarios de grande échelle. La qualité des correspondances découvertes et l'intégrité du schéma intégré sont également vérifiées par une évaluation empirique.<br /><br />Par ailleurs, nous présentons une technique CMPV ({\bf C}omplex {\bf M}atch {\bf P}roposition et {\bf V}alidation), pour la découverte de correspondances complexes (1:n, n:1 et n:m), entre deux schémas, validée par l'utilisation de mini-taxonomies. Cette partie est une version étendue de l'aspect de mise en correspondance de PORSCHE. Les mini-taxonomies sont extraites d'un vaste ensemble de métadonnées de domaine spécifique représenté comme des structures arborescentes. Nous proposons un cadre, appelé ExSTax ({\bf Ex}tracting {\bf S}tructurally Coherent Mini-{\bf Tax}onomies) basé sur la fouille d'arbres pour appuyer notre idée. C'est l'extension de la méthode fouille d'arbres de PORSCHE. Enfin, on utilise la technique ExSTax pour extraire une taxonomie fiable spécifique à un domaine.

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