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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

Cosmologie et science de la nature chez Francis Bacon et Galilée / Cosmology and science of nature in Francis Bacon and Galileo

Boulier, Philippe 10 December 2010 (has links)
Aux XVIIIe et XIXe siècles, les historiens des sciences associaient généralement Francis Bacon et Galilée pour leur rôle dans l’émergence de la science moderne, mais, à la fin du XIXe et au début du XXe siècle, la Révolution scientifique fut identifiée de manière stricte à la construction de la physique mathématique, ce qui eut souvent pour conséquence de rejeter Bacon hors de l’histoire des sciences. Nous reprenons l’étude conjointe de ces deux auteurs pour mesurer quelle est exactement la nature de leur divergence. Dans la première partie de notre travail, nous abordons les questions cosmologiques. Sur quels arguments Galilée fonde-t-il sa défense publique du copernicianisme entre 1610 et 1616, jusqu’à la première condamnation de l’opinion copernicienne par l’Eglise Catholique ? Pour quelles raisons Bacon, qui suit cette campagne copernicienne, rejette-t-il la plupart des découvertes astronomiques de Galilée ? Pourquoi Bacon, tout en réussissant à percevoir le caractère (trop peu) systématique du géocentrisme, refuse-t-il l’héliocentrisme ? Dans la deuxième partie de notre travail, nous abordons les questions relatives à la méthode, ainsi que les théories de la matière et du mouvement. Quel est le rôle de la perception sensible et la fonction des mathématiques dans les théories de Bacon ? Quelle est la signification de sa théorie du mouvement, qui multiplie les objets d’étude en proposant une typologie des différents mouvements concrets, alors que la physique mathématique tend à réduire tout déplacement au seul mouvement linéaire inertiel ? Quelle est la fonction de l’atomisme mathématique de Galilée ? Dans quelle mesure sa science du mouvement se distingue-t-elle de l’approche baconienne ? La différence fondamentale entre la science galiléenne et la démarche de Bacon consiste, selon nous, dans la nature des expériences et des observations qui sont convoquées, ainsi que dans le type d’abstraction que ces deux auteurs veulent conférer à la philosophie naturelle. / During the eighteenth and nineteenth centuries, historians of science usually considered that Francis Bacon and Galileo had respectively played their role in the merging of modern science, but, at the end of the nineteenth and the beginning of the twentieth century, Scientific Revolution has been strictly reduced to the elaboration of mathematical physics, which had for consequence to exclude Bacon from the history of science. Our aim is to underline the exact nature of the difference between those two authors. In the first part, we deal with the cosmological problems. What arguments did Galileo produce to sustain his public commitment for the Copernican system, from 1610 to 1616, until the first condemnation of copernicanism by the Roman Church ? For what reasons did Bacon reject most of Galileo’s astronomical discoveries ? Why Bacon, who clearly perceived the fact that the geocentric theory lacked systematic character, refused heliocentrism ? In the second part, we deal with the methodological questions, we analyse matter theories and the science of motion. What is the role of sense perception and what is the fonction of mathematics in Bacon’s theories ? What is the significance of his theory of motion, which multiplies the objects of study, proposing a typology of concrete movements, while mathematical physics aims at reducing any motion to the rectilinear inertial movement ? What is the fonction of the mathematical atomism proposed by Galileo ? In what measure does his science of motion distinguish from the baconian approach ? We think that the fondamental difference between the science of Galileo and the theories of Bacon consists in the nature of the experiments and observations used, and in the type of abstraction they are looking for in natural philosophy.
32

Fenomenologie a ekonomie / Phenomenology and Economics

Špecián, Petr January 2010 (has links)
The thesis Phenomenology and Economics is an account of methodological possibilities brought by the phenomenological method into the realm of economic thought. From the starting point of Misesian praxeology the thesis advances to the key contributions of Alfred Schütz whose concept of telescopic ideal type enables us to cross the gap between theory and history. Telescopic ideal type allows us to grasp the specific nature of economics that is, on the one hand, proud of its rigor and precision connected with the formal modelling and on the other hand deals with an interpretation of individual agents in their life-world. Methodological insights developed through this analysis are then applied to the problem of coordination and spontaneous order and to the question of the relationship between behavioral economics and rational choice theory.
33

Hydraulický čistící stroj / Hydraulic cleaner-machine

Lužný, Jan January 2020 (has links)
This diploma thesis deals with the design of hydraulic trash rack cleaning machine for waste water treatment plant. The first part of the thesis describes methods of removing coarse impurities from intake water to technological equipment. Furthermore, a specific design including calculation and choice of the drive is made. Part of the work is also solving the course of force effects and strength analysis of the most stressed parts. The work also deals with the comparison of design solution of hydraulic and mechanical drive of the machine. The attachment contains a drawing of the cleaning machine assembly and selected welded complex.
34

Centrum Ponava Brno, Královo Pole / Ponava Centre Brno, Královo Pole

Chytilová, Markéta January 2014 (has links)
The main idea in dealing with my thesis was to design a high quality public space where people will feel comfortable, safely and have a reason to come back. Furthermore, this is the place to be full of life and will serve the general public. The cultural center, that was designed, to become part of Královo Pole cultural campus, so-called K2-center, which will create a basis for free time activities, relaxation and education. A significant part of the proposed building is made up of multi-functional hall, library, restaurant, teen center and spaces for leisure time activities. On the ground floor will be located business parter and coffee bar. The aim of my project was to take into account what is most needed for inhabitants of Královo Pole for the purpose to meet the demands for quality leisure time for the widest spectrum of people. There is an effort to place the object itself as the most sensitive, given the current surrounding areas. The aim was not to design a huge object but especially a pleasant environment functioning as a center of leisure time activities.
35

Manipulátor velkorypadla KK1300 / Manipulator of bucket wheel excavator KK1300

Adamík, Jan January 2010 (has links)
The document describes a manipulator for a wheel excavator. The purpose of the manipulator is to handle with the propulsive shaft of a crushing machine and the tension cylinder of an interchanging conveyor-belt during the assembling and maintenance. The objective of the master's thesis is the strength analysis of the manipulator components and the telescopic arm with using the finite element method. The thesis also comprises the assembly drawing of the manipulator with additional devices and the propulsion system calculation. The project is carried out with the cooperation of NOEN a.s.
36

Weight reduction of reachstacker

Jönsson, Hugo, Wallman, Jakob January 2023 (has links)
This thesis has been carried out together with Kalmar Global’s Innovation Center and covers a concept study about weight reduction of the telescopic boom of the Reachstacker DRG 450.The reason for this weight reduction is to ease Kalmar’s transition from fossil fueled to electric driven vehicles since less weight reduces energy consumption and leaves more room for batteries. The main focus of the study is to test a wide array of cross sections for the boom with the aim of weight saving. During the thesis both meshless and traditional finite element calculations are used when utilising simulation-driven design to optimise the boom. The study concludes that using a narrower octagonal cross section, improved material quality and adapting the positions of the mounts can decrease the weight by 23% with also decreasing the material cost by 13%.
37

Estimation en présence de données incohérentes : étude de l'impact des biais de déclaration d'âge à l'initiation de la consommation de substances psychoactives à partir de données longitudinales

Chagra, Djamila 12 1900 (has links)
Les données d’enquêtes jouent un rôle primordial dans la production scientifique en sciences sociales. Cependant, la présence de biais dans les données au moment de la collecte, y compris les erreurs de réponse et de non-réponse, pourrait affecter la fiabilité des résultats obtenus. Bien que le problème des erreurs de réponse et de non-réponse soit largement discuté, la littérature existante s’intéresse peu aux mécanismes par lesquels ces erreurs influencent les mesures estimées. Par conséquent, l’objectif principal de cette thèse est d’apporter une contribution méthodologique à la compréhension des estimations d’enquêtes en présence de données erronées et manquantes, en déterminant leur part explicative dans les modèles estimés. À l’aide de deux mesures répétées de l’âge de la première consommation de substances psychoactives recueillies par l’ELNEJ (1994-2009) auprès de jeunes Canadiens à l’âge de 12-13 ans, puis à l’âge de 14-15 ans, cette thèse par articles visait à étudier : (1) les types d’incohérences ou de biais imputés dans la deuxième mesure comparativement à la première (mesure de référence) et ainsi déduire les caractéristiques des répondants dont les déclarations sont incohérentes (Article 1); (2) l’impact de ces biais dans la détermination des prédicteurs de la consommation précoce, c’est-à-dire à l’âge de 13 ans ou moins (Article 2); et (3) leur impact sur la prédiction de la consommation à l’âge de 16-17 ans en fonction de l’âge d’initiation (Article 3). L’impact du biais est déterminé en corrigeant (1) le biais de sélection dû à la censure des répondants ayant des déclarations incohérentes de l’échantillon de l’étude, lorsque l’âge de l’initiation est la variable dépendante dans le modèle estimé (Article 2) ou (2) le biais d’endogénéité dû à la présence de valeurs erronées et manquantes dans l’âge d’initiation, lorsque l’âge d’initiation est une variable explicative dans le modèle estimé (Article 3). Le premier article révèle qu’au deuxième passage de l’enquête, les jeunes de 14-15 ans ne fournissent pas nécessairement des âges d’initiation cohérents avec ceux fournis lorsqu’ils avaient 12-13 ans. La proportion d’incohérence enregistrée n’est pas négligeable; elle est de 43 % pour l’alcool, 33 % pour le tabac et 32 % pour la drogue. Ces jeunes sont susceptibles de déclarer des âges d’initiation plus tardifs ou d’omettre l’expérimentation antérieure (biais télescopique vers l’avant: BTA), des âges d’initiation plus hâtifs (biais télescopique vers l’arrière: BTR), et peuvent également ne pas déclarer leur initiation à au moins un des deux cycles d’enquête (Biais non-déclaré : BND). Les résultats de la régression multinomiale montrent que le risque de détecter ces biais n’est pas le fruit du hasard; il varie en fonction des caractéristiques socio-démographiques et personnelles des répondants, notamment le genre, la structure de la famille et la région de résidence. En raison du biais dans la deuxième déclaration de l'âge d'initiation, le deuxième article démontre que l'identification des groupes à risque de consommation précoce est affectée par le potentiel de biais au sein de ces groupes. En utilisant l'approche de Heckman, il a été conclu que les âges d'initiation déclarés plus hâtifs (plus tardifs) génèrent une surestimation (sous-estimation) des risques de consommation précoce (à 13 ans et moins) dans les groupes les plus susceptibles de fournir des âges biaisés vers l'arrière BTR (biaisés vers l'avant BTA). Cependant, ces risques sont sous-estimés dans les groupes qui n’ont pas déclaré leur âge d’initiation lors du premier passage de l’enquête (BND). Ceci indique que pour ces groupes, l’âge d’initiation qui n’a pas été déclaré lors du premier passage est probablement un âge précoce (autour de 12-13 ans). Le troisième article conclut que les biais attribués à l'âge de l'initiation affectent l’estimation de la relation entre l’âge d’initiation et la fréquence de consommation à l'âge de 16-17 ans. Le fait que cette relation soit surestimée ou sous-estimée dépend spécifiquement du type de biais et de sa corrélation avec la consommation ultérieure. Enfin, cette thèse tente de fournir des preuves empiriques mettant en évidence le biais de réponse et de non-réponse comme une source d'information supplémentaire qui caractérise l'échantillon de l'étude et qui sa propre part explicative dans les modèles estimés. La validité des données d'enquête est donc d'une grande utilité pour la validité des résultats des études. / Survey data play an essential role in scientific production in the social sciences. However, the presence of bias in the data at the time of collection, including response and non-response errors, could affect the reliability of the results obtained. Although the problem of response and nonresponse errors is widely discussed, little attention has been paid in the existing literature to the mechanisms by which these errors influence the estimated measures. Therefore, the main objective of this thesis is to make a methodological contribution to the understanding of survey estimates in the presence of erroneous and missing data, by determining their explanatory part in the estimated models. Using two repeated measures of age at first substance use collected by the NLSCY (1994-2009) from Canadian youth, when they were 12-13 years old and again at 14-15 years old, this article-based dissertation aimed to investigate: (1) the types of inconsistencies or biases imputed in the second measure relative to the first (baseline) measure and thus infer the characteristics of respondents whose reports are inconsistent (Paper 1); (2) the impact of these biases in determining predictors of early use, i.e., at age 13 and younger (Paper 2); and (3) their impact on predicting use at age 16-17 as a function of age of initiation (Paper 3). The impact of bias is determined by correcting for (1) selection bias due to censoring of respondents with inconsistent reports from the sample, when age of initiation is the dependent variable in the estimated model (Paper 2) and (2) endogeneity bias due to the presence of erroneous and missing values in age of initiation, when age of initiation has an explanatory variable in the estimated model (Paper 3). The first article reveals that at the second survey round, 14–15 years old do not necessarily provide ages of initiation consistent with those provided when they were 12-13 years old. The proportion of inconsistency recorded is not negligible; it is 43% for alcohol, 33% for tobacco, and 32% for drugs. These youth are likely to report later ages of initiation or omit previous experimentation (telescopic forward bias: BTA), earlier ages of initiation (telescopic backward bias: BTR) and may also fail to report initiation on at least one of the two survey rounds (unreported bias: BND). Multinomial regression results show that the risk of detecting these biases is not random; it varies with respondents' socio-demographic and personal characteristics, including gender, family structure, and region of residence. Because of the bias in the second report on age of initiation, the second article demonstrates that the identification of groups at risk for early use is affected by the potential for bias within these groups. Using Heckman's approach, it was concluded that earlier (later) reported initiation ages generate an overestimation (underestimation) of the risks of early use (at age 13 and younger) in the groups most likely to provide backward-biased (forward-biased) ages. However, this risk is underestimated in groups that did not report their age of initiation at the first survey round (BND). This indicates that for these groups, the age of initiation that was not reported in the first round is likely to be an early age (around 12-13 years). The third paper concludes that biases attributed to age of initiation affect the estimate of the relationship between age of initiation and frequency of use at age 16-17. Whether this relationship is overestimated or underestimated depends specifically on the type of bias and its correlation with later use. Finally, this thesis attempts to provide empirical evidence highlighting response and nonresponse bias as an additional source of information that characterizes the study sample and has its own explanatory part in the estimated models. The validity of survey data is thus of great benefit to the validity of studies results.
38

PRODUCT DEVELOPMENT OF WORK CHAIRS AND OFFICE CHAIR

MUKUNDAN KUMAR, ABHIJITH, THOMAS, SAM January 2020 (has links)
Work chair is considered as an important element for the users to improve comfort in work environment. An ergonomic chair design and engineering is therefore considered very important for its usability and comfort view of point for the users. The aim of the thesis is to improve the mobility and ergonomics of the existing chair in all aspects. Ergonomically designed chairs are important for long time seated workers to increase their productivity and also to reduce low back injuries which arise due to the poor design chairs in ergonomic aspects. In addition, ergonomically designed chairs help to increase the seating comfortability of the chair users. QFD and waterfall model was followed for the work execution. In this paper, we discuss a design of an ergonomically efficient chair with simple adjustments which gives more comfortability. This will give us a better likelihood to stay in a neutral position. The Ergonomics of the chair is improved in various steps. This thesis focuses on many ideas in which some of them are implemented and evaluated.
39

Návrh výsuvné manipulační platformy mobilního robotu / Design of an extensible platform for mobile robot

Šumšal, Zdeněk January 2017 (has links)
This thesis is about the design of the telescopic platform. which should be fasten on robot called Breach. Purpose of this platform is to carry another equipment like sensors, cameras or manipulator. The platform has to provide chiefly the high demands on load capacity. Another part of the thesis is design of mechanism placed on this telescopic platform, or just on the robot Breach. This mechanism has to load up small subject on the top part of the platform and then unload it on chosen place. Only thing defined for this subjekt is maximal weight of 2 kilograms, but other parameters aren´t specified. Construction is therefore focused on maximal versatility of this mechanism.
40

Konstrukční návrh kamerového jeřábu / Design of camera crane

Navrátil, Pavel January 2011 (has links)
This Master’s thesis deals with several variants construction design of camera crane. Two optimal variants are chosen with regard to practical usage. The thesis includes complete design of these variants with 3D models and strenght analyses. This analyses are processed by final element method. The first variant made based on technical documentation and it has worked for company Filmochod s.r.o..

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