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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.
1

Etude et optimisation de la culture de microalgues en photobioréacteurs solaires / Study and optimization of the microalgae cultivation in solar photobioreactors

Artu, Arnaud 21 October 2016 (has links)
La production industrielle de microalgues a lieu principalement en conditions solaires et dans des bassins de culture ouverts. Dans l’optique d’étendre la gamme de souches cultivables et de réduire les coûts de production de la biomasse, de nombreux systèmes de culture clos (aussi appelés photobioréacteurs ou PBRs) se développent pour la production solaire de microalgues. Néanmoins, en raison de la dynamique du rayonnement solaire et de sa composition spectrale (présence de rayonnements infrarouges et ultraviolets), maximiser les performances d’un photobioréacteur solaire demeure complexe et tient en majeure partie à la gestion de deux paramètres : l’énergie lumineuse et la température de culture. Cette thèse présente l’ensemble des résultats obtenus en photobioréacteurs lors de l’étude de ces paramètres avec comme microalgue de référence, Chlorella vulgaris. La première partie a porté sur l’utilisation de l’énergie lumineuse par les algues au travers de la vitesse spécifique d’absorption de photons (RPA). Les résultats ont montré que l’efficacité de conversion des photons en biomasse était bien liée à la valeur moyenne de RPA dans le volume de PBR (aussi appelé MRPA), et que cette dernière était décroissante avec l’augmentation du MRPA. De plus, outre le MRPA, le profil de RPA peut aussi avoir un impact majeur sur la culture. En effet, il est possible d’inhiber toute croissance en imposant un profil de vitesse d’absorption de photons important dans l’intégralité du volume de culture. La deuxième partie de cette thèse a porté sur la gestion et l’optimisation des postes de consommation énergétique associés à la production solaire en PBR. Lors de cette partie, les coûts énergétiques liés à la production ont été associés aux performances théoriques de différents PBRs plans, afin de comparer ces systèmes entre eux (avec l’exemple d’une production de microalgue sur l’année à Nantes), et mesurer les efforts à réaliser pour envisager la production industrielle de microalgues dans le domaine de l’énergie. / Industrial production of microalgae takes place outdoor in open ponds exposed to solar radiation. To increase biomass production and reduce production costs many closed systems have been developed such as photobioreactors (PBRs). Nevertheless, maximizing the performance of solar PBRs remains a challenge due to difficulties in managing radiant and thermal energy transfer in the PBR. This is mainly due to the dynamic behavior of solar irradiance as it evolves throughout the day and seasons. It is also because of the spectral composition of the solar radiation which consists of ultra-violet and infrared radiation. The latter cannot be utilized by the microalgae for photosynthesis and as a result is converted to heat. This thesis presents results obtained during the study of the effects of temperature and light on the microalgae production of the microalgae Chlorella vulgaris, chosen as a reference species. The first part of the thesis focused on the utilization of light energy by the microalgae with a specific attention paid to the parameter called the rate of photon absorption (RPA). Results show that the photon to biomass conversion efficiency is linked to the volume averaged value of RPA (also called MRPA for mean rate of photon absorption). Photon to biomass conversion efficiency decreased when the MRPA increased. Moreover, in addition to MRPA, the local value of RPA and its profile in the PBR volume can have a major impact on the culture behavior. Indeed, it is possible to inhibit cell growth by having a large RPA in the PBR leading to excessive absorption of photons throughout the PBR. The second part of the thesis focused on management and optimization of energy demanding units associated to the culture of solar PBRs. During this part, energetic costs linked to the biomass production where associated to the theoretical performances of different planar systems in order to compare them (with the example of an annual production in Nantes (France)), and determine the efforts necessary to implement microalgae on industrial scale in the field of energy.
2

Extensões orientadas a objetos da linguagem LISP : uma implementação do CLOS

André de Souza Mello Valente 01 August 1990 (has links)
A orientação a objetos, enquanto modelo de organização de linguagens de programação,vem tomando espaço e importância cada vez maiores a partir do início da década de 80. Entre as linguagens de programação orientadas a objetos existentes, destacam-se por seu poder de expressão as extensões orientadas a objetos da linguagem Lisp. Lisp é uma importante linguagem de programação, de características funcionais, cujas origens remontam aos primórdios da Computação. Um passo à frente nesse panorama se coloca o Common Lisp Object System(eLOS). Mais que apenas uma extensão de Lisp orientada a objetos, o CLOS se propõe a fundir os paradigma funcional à orientação a objetos em uma linguagem rica, poderosa e eficientemente implementável. Neste trabalho, apresentamos uma implementação didática, portável e extensível do CLOS, apontando as soluções dadas aos principais problemas que foram deixados em aberto na sua especificação. Além disso, propomos um framework para descrição e análise de linguagens de programação orientadas a objetos,'; que servirá. de arcabouço para uma análise comparativa das principais extensões de Lisp orientadas a objetos (Flavors, Loops, ObjVlisp, CommonObjects, CLOS) e de uma descrição de duas das mais importantes linguagens orientadas a objetos: Smalltalk e C++. Por fim, propomos uma extensão do eLOS para solução distribuída de problemas baseada na arquitetura do Quadro-Negro (Blackboard), o DCK (a Distributed CLOS Kernel). Essa proposta utiliza um kernel para solução distribuída de problemas que opera sob Unix, chamado DPSK.
3

Predicate Dispatching in the Common Lisp Object System

Ucko, Aaron Mark 01 May 2001 (has links)
I have added support for predicate dispatching, a powerful generalization of other dispatching mechanisms, to the Common Lisp Object System (CLOS). To demonstrate its utility, I used predicate dispatching to enhance Weyl, a computer algebra system which doubles as a CLOS library. My result is Dispatching-Enhanced Weyl (DEW), a computer algebra system that I have demonstrated to be well suited for both users and programmers.
4

Aspects of structure in Gabriel Fauré’s Le jardin clos and related works

Skoumal, Zdenek Denny January 1982 (has links)
Despite an ever-increasing number of specialized studies in music theory, only a limited number can be found which examine the music of Gabriel Faure. Most discussions of this music are in context of a historical overview, with emphasis on Faure's use of modality. This thesis presents detailed analyses of songs from the cycle Le Jardin Clos, Op. 106, and highlights several aspects of Faure's style. Various earlier songs are brought into the discussion in order to trace stylistic development and present evidence for views taken with regard to Le Jardin Clos. Although modality is periodically discussed (particularly in Chapters III and IV), the focus is not on this feature. Chapter I introduces the notion of ambiguity, a problem encountered commonly in the analysis of Faure's music. It then proceeds to point out one source of ambiguity--harmonic progressions derived from the implications inherent in the motions of outer voices. Particular attention is given to instances where the outer voices move "in contrary motion to create wedge-shaped structures. In this chapter, linear motion is emphasized. Chapter II turns to various structures of third-relation. The most extended portion of the chapter is devoted to a discussion of the "superchord", a tertian structure which, although heard in segments only, appears as a controlling element in larger areas of music. Distinction is made between this phenomenon and a normal progression in thirds (i-VI-iv). Other structures related to the superchord are also considered. The last example of Chapter II shows a structure based on a combination of a tertian design and a wedge shape. In Chapter III, various non-traditional ways of treating the leading tone are examined. In addition to leading tones which are lowered (in modal and tonal contexts) or avoided, the discussion concentrates on melodic lines which rise to the leading tone and retreat downward. Chapter IV reviews melodic characteristics encountered up to that point, and, with the addition of further features, presents a melody typical of Faure's later style. The major issue in this chapter concerns melodies that center around the fifth degree of the scale. The final chapter returns to the topic of ambiguity by discussing instances where two tonal centers are juxtaposed. This feature of Faure's music is distinguished from bitonality, as the latter is generally understood. / Arts, Faculty of / Music, School of / Graduate
5

The Directing Problems Involved in a Production of Jean-Paul Sarte's "No Exit"

Tolan, Robert W. January 1961 (has links)
No description available.
6

The Influence of Modern Art on Toru Takemitsu's Works for Piano

Chayama, Yuri January 2013 (has links)
This study examines the influence of Modern Art on the piano compositions of Toru Takemitsu (1930-1996) to demonstrate how he was inspired by visual art and integrated its ideas into his music. From his youth, Takemitsu was aware of the relationship between music and visual art, exploring different genres, especially Surrealist poetry and modern painting, as well as Japanese gardens, then harmonizing and incorporating these ideas within his music. In doing so, he established his own philosophy and musical structure, combining colorful sonorities with spatial effects of timelessness, which became cornerstones of his music. This document explores and identifies ideas from Modern Art - primarily visual works of Paul Klee, Odilon Redon, Kagaku Murakami, and other Surrealists - that Takemitsu adapted and wove into his compositions to create visual imagery, rich in color, within his music. The use of these ideas is discussed in an analysis of two of Takemitsu's most profound and mature solo piano works, Les Yeux Clos - In Memory of Shuzo Takiguchi (1979) and Les Yeux Clos II (1989), both inspired by Odilon Redon's series of paintings, entitled Les Yeux Clos (1890).Following Chapter I, the introduction, Chapter II discusses Takemitsu's early influences, film music, legacy, and contribution to society. Chapter III examines Takemitsu's encounter with Surrealism and the four artists– Shuzo Takiguchi, Paul Klee, Odilon Redon, and Kagaku Murakami - that influenced him the most by demonstrating the importance of breaking with convention and freely exploring one's inner world. Chapter IV identifies the principles and ideas of Modern Art and Surrealism that appealed to Takemitsu, and how he adapted them into his compositions. The ideas fall into four categories: philosophy, structure, color, and space. Chapter V presents original analyses of two solo piano works, Les Yeux Clos and Les Yeux Clos II, demonstrating how the principles and ideas of different art forms are integrated into Takemitsu's works. Concluding remarks in Chapter VI include a brief discussion of how an understanding of Takemitsu's complex artistic journey can deepen a performer's understanding and interpretation of Les Yeux Clos and Les Yeux Clos II.
7

Dante, Damnation, and The Undead: How The Conception of Hell Has Changed in Western Literature from Dante's Inferno to The Zombie Apocalypse

Whitman, Isabelle M. 15 May 2015 (has links)
Dante's Inferno defined hell in Western literature for centuries; it was a physical place for sinners, they were subjected to physical torments, and it was in the afterlife. Dante’s depiction was firmly rooted in Christian theology. However, as fears and morals change, ideas of hell evolve as well. With the popularity of the zombie and other apocalypse narratives, these ideas return to the notion of physical torment and earthly places. In poetry, novels, theater, television, and film, writers examine different interpretations of hell, punishment, and redemption as metaphors for modern sins. In Sartre’s Huis clos, hell is a windowless room, and the tortures are inflicted psychologically by other people. In Romero’s Living Dead films, hell comes to earth, and the torments are both physical and psychological. Joss Whedon’s Buffy the Vampire Slayer shows how hellish the common experiences of high school and growing up can be. Cormac McCarthy’s The Road examines hell as a lack of place, a relentless journey without end. In these and other works, the concept of hell is reinvented and replaced by new ideas, but the influence of the past iterations shapes the new landscapes.
8

Utilisation des modes directionnels dans la résolution

Oudot, Olivier 30 November 1987 (has links) (PDF)
Cette étude met en évidence l'utilité des modes directionnels pour l'optimisation de la résolution dans le langage Prolog. Ils se caractérisent essentiellement par le fait qu'ils permettent de distinguer les différentes utilisations possibles d'un même prédicat. Un algorithme de production automatique de ces modes est décrit. L'étude est concrétisée par la réalisation du compilateur Starlog, fonctionnant sur un cas particulier de modes directionnels
9

Time-Multiplexed Channel Switches for Dynamic Frequency Band Reallocation / Tidsmultiplexade Kanalswitchar för Dynamisk Frekvensbandsreallokering

Stenholm, Roland January 2016 (has links)
A partially parallel reconfigurable channel switch is constructed for use in DFBR. Its permutation can be changed while running without any interruption in the streams of data. Three approaches are tried: one based on asorting network, one based on memories and multiplexers and one based on a Clos network. Variants with the pattern stored in memories and in shift registers are tried. They are implemented in automatically generated Verilog and synthesized for an FPGA. Their cost in terms of area use, memory use and maximum clock frequency is compared and the results show that the Clos based approach is superior in all aspects and that pattern data should not be saved in shift registers. The work is open source and available for download at https://github.com/channelswitch/channelswitch. / En delvis parallel och delvis seriell kanalswitch för användning inom DFBR skapas. Dess permutation kan ändras medan den kör utan avbrott i dataströmmen. Tre alternativ undersöks: ett baserat ett sorteringsnätverk, ett baserat på minnen och multiplexrar och ett som baseras på Clos-nätverk. Versioner med mönsterdata sparad i skiftregister och i minnen prövas. De implementeras i automatiskt genererad Verilog och synthesiseras för en FPGA. Deras kostnad i areaanvändning, minnesanvändning och maximal klockfrekvens jämförs. Resultaten visar i princip att Clos-nätverken är bäst i alla avseenden och att mönsterdata ska sparas i RAM-minnen och inte i skiftregister. Arbetet är open source och kan laddas ner från https://github.com/channelswitch/channelswitch.
10

OneSwitch Data Center Architecture

Sehery, Wile Ali 13 April 2018 (has links)
In the last two-decades data center networks have evolved to become a key element in improving levels of productivity and competitiveness for different types of organizations. Traditionally data center networks have been constructed with 3 layers of switches, Edge, Aggregation, and Core. Although this Three-Tier architecture has worked well in the past, it poses a number of challenges for current and future data centers. Data centers today have evolved to support dynamic resources such as virtual machines and storage volumes from any physical location within the data center. This has led to highly volatile and unpredictable traffic patterns. Also The emergence of "Big Data" applications that exchange large volumes of information have created large persistent flows that need to coexist with other traffic flows. The Three-Tier architecture and current routing schemes are no longer sufficient for achieving high bandwidth utilization. Data center networks should be built in a way where they can adequately support virtualization and cloud computing technologies. Data center networks should provide services such as, simplified provisioning, workload mobility, dynamic routing and load balancing, equidistant bandwidth and latency. As data center networks have evolved the Three-Tier architecture has proven to be a challenge not only in terms of complexity and cost, but it also falls short of supporting many new data center applications. In this work we propose OneSwitch: A switch architecture for the data center. OneSwitch is backward compatible with current Ethernet standards and uses an OpenFlow central controller, a Location Database, a DHCP Server, and a Routing Service to build an Ethernet fabric that appears as one switch to end devices. This allows the data center to use switches in scale-out topologies to support hosts in a plug and play manner as well as provide much needed services such as dynamic load balancing, intelligent routing, seamless mobility, equidistant bandwidth and latency. / PHD

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