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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.
71

Predikce tvaru čela šířící se únavové trhliny / Fatigue crack front shape estimation

Zouhar, Petr January 2016 (has links)
The presented master’s thesis deals with fatigue crack front shape estimation. The aim of this thesis is to create an iterative process leading to the real fatigue crack front shape. Thesis is solved using finite element method. The work is divided into two logical parts. The first part of the thesis describes the basic concepts of linear elastic fracture mechanic (LEFM), methods used for estimation of stress intensity factor and stress singularity exponent. The first part further describes some phenomenon’s accompanying the mechanism of fatigue crack growth as for example crack tip curving and crack closure. In the second part of the thesis there is studied an affect of the free surface on the fracture parameters, especially the affected distance from the free surface is determined. Based on the assumption of a constant stress intensity factor and stress singularity exponent along the crack front, an iterative process leading to fatigue crack front shape is presented. The accuracy of the result is discussed by comparing of obtained crack front shapes with experimental data at the end of the thesis.
72

3D morfometrická analýza obličeje pacientů s Williamsovým, Noonanové a DiGeorgeovým syndromem / 3D morphometric facial analysis in Williams, Noonan and DiGeorge syndrome patients

Čaplovičová, Martina January 2016 (has links)
The aim of the thesis was to evaluate facial dysmorphism in Williams (WBS), Noonan (NS) and DiGeorge syndrome (DGS) patients and also to evaluate changes in the morphology of the face during growth. In total 57 3D facial scans of patients of all ages were analysed, including 12 WBS, 20 NS, 25 DGS and 31 scans of control subjects. The evaluation has been carried out using methods of geometric morphometry, namely by coherent point drift - dense correspondence analysis, superprojection of mean faces, per vertex t-test and principal component analysis. Statistically significant differences in the facial morphology were shown for all the syndromes vs. control. Observed dysmorphies in WBS (narrow forehead, bitemporal narrowing, periorbital fullness, bulbous and anteverted nasal tip, malar flattening, protrusion of both lips, pointed chin) mostly confirmed existing knowledge of the typical phenotype. The morphology in WBS is thus strongly specific and manifested in most of the patients. During ontogeny, the dysmorphic features associated with increased facial convexity become pronounced, while the other typical features remain relatively stable. In contrast to the control, the retrusion of the chin occurs during the development. Observed dysmorphic traits in NS (less prominent supraorbital ridges,...
73

Tvar, velikost a proporce dlouhých kostí dolních končetin u lidských populací od pozdní doby kamenné po novověk. / Shape, size and proportions of lower limb long bones among human populations from Eneolithic to the Modern Era.

Šídová, Markéta January 2011 (has links)
Differences in the lifestyle of various populations may lead to changes in the shape of the long limb bones. This involves a reaction to the degree of mechanical and environmental stress acting upon these bones. Our work examined changes in the shape, proportions and size of the lower limb long bones (femur, tibia) over roughly the past five thousand years, or more precisely from the later phase of the Early Stone Age up to the 20th century. We studied the femurs and tibias of a total 520 adult individuals − 313 males and 207 females − from seven different periods or rather archaeological cultures. Our evaluation was based on the external, linear dimensions of the bones studied. Biological parameters were evaluated in relation to sexual dimorphism and lateral asymmetry. We paid special attention to the degree of flattening of the proximal third of the femoral and tibial shafts. Sexual dimorphism differed in individual populations. We found the least statistically significant parameters of sexual dimorphism in the oldest, Eneolithic, samples. In contrast, both sexes differed in the greatest number of parameters in the Early Middle Ages. Lateral asymmetry was most frequently demonstrated for the width dimensions in the case of the femoral and tibial diaphyses, which are in complete concurrence with...
74

Dynamická analýza konstrukce zatížené seismickým zatížením / Dynamic analysis of structure loaded seismic loads

Havlíková, Ivana January 2012 (has links)
The purpose of my master’s thesis is the solution steel hall with concrete columns, that is loaded by an earthquake. This simulation program was used RFEM. To calculate was used the spectral and temporal analysis, and that on models of structures with several combinations of materials. The analysis was performed for both the general direction of the earthquake, so for combinations of directions according to standard procedures in EC8.
75

Paralela mezi konceptem díla v architektuře a hudbě / The parallel between the concept of work in architecture and music

Lukačovič, Markéta January 2012 (has links)
The doctoral thesis preliminary focuses on the comparison of concepts of creation in music and architecture and to explore the connection and possible blending of both arts. The main focus of the dissertation is the research of the parallel between the composition of music and architecture, in their characters, means of composition and methods. The methods of approaching the topic were the analysis's of music and architectural materials such as dedicated books, magazines, internet articles, as well as audio recordings, realisations of architectonic works, printed materials on acoustics, psychology of perception and aesthetics as well as own experience and knowledge in the field of music and architecture and the experiment in composition. Results of the dissertation are theoretical conclusions enlightening the given topic and the practical experiment in the form of the analysis of the music composition and the application of its compositional methods into the architectonic design.
76

Hledání tvaru skořepinových konstrukcí / Form finding of shell structures

Musil, Jiří January 2017 (has links)
The theme of this doctoral thesis is the design of concrete shell structures with the focus on finding their optimal shape. The optimal shape of a concrete shell is the shape in which for a given load (usually the dead weight of the structure) no significant bending moments are generated in the shell and the structure is in the so-called membrane state. The inspiration for this thesis is the work of Swiss engineer Heinz Isler, who developed the shapes of shell structures using model tests of appropriately loaded flexible membranes. He developed the shell structure for large spans by inverting the resultant shape, which carried its weight almost entirely via membrane forces. The numerical solution of the above experiments using Midas Civil is presented herein. The basic principles of the method are demonstrated on the example of sagged cable. The numerically found shapes are compared with the analytical solution. A shell is designed based on the numerically found shapes and its stress response to dead load is described, particularly in relation to the membrane action. In the next part, the acquired knowledge and methods were used to design three relatively complicated shell structures. Each structure was statically analysed and its static behaviour was described. Structures with perfectly rigid or flexible supports, which simulate real behaviour of the supports, were studied. In the final phase, the results of static analysis of the selected shell were experimentally verified on a physical model in a scale of 1: 55.56. The model has been built using 3D printing. The thesis describes the use of a modelling similarity, the model design, the production process, and the experiment. The load test confirmed the optimal design of the shell structure and the validity of the numerical method for finding their shapes.
77

Význam grafických symbolů v procesu formování regionu: příklad Libereckého kraje / The Importance of Graphical Symbols in the Region Formation Process: the Case of the Liberec Region

Šifta, Miroslav January 2014 (has links)
The Importance of Graphical Symbols in the Region Formation Process: the Case of the Liberec Region The thesis analyzes the role of symbols and graphic symbolism in the process of regional and spatial identity formation in the context of the theory of institutionalization of regions by A. Paasi. The goal of the thesis is to contribute to a scientific discussion of this topic using the example of a specific region - the Liberec Region. In the theoretical part of the thesis, general studies of spatial identities, mainly with regard to creating the symbolic shape of region, are discussed, and the importance of symbolism in forming the region, its spatial identity and power relations is assessed. This section aims to define the key concepts, terms and also types of symbols used in this study. In the research part of thesis, first, the selection of the studied area is justified (region with intensively changed landscape), and, second, its situational analysis is presented, focusing mainly on the social phenomena and elements which could play role of regional symbols. Next, the actual symbolism of the region, as presented in various sources and media, is evaluated. Subsequently, it is compared with the graphic symbols of regional and local institutions, classified and analyzed according to the form...
78

Vyhodnocení hydrodynamického zatížení přelévané mostovky / Evaluation of hydrodinamic load on a brdge deck

Řezník, Jindřich January 2018 (has links)
The subject of this thesis is the evaluation of hydrodinamic load on a physical model of a bridge deck, especially to find the relation between the median and extreme quantiles of each hydrodanamic load part and to evaluate the influence, which has the shape of the bridge deck on the size of this load. Relations, that was found may be used to determine characteristic values of loads, caused by water flow, for example, when designing the bridge bearings.
79

Lávka pro pěší přes lagunu / Pedestrian bridge across the lagoon

Bezručová, Kristína January 2018 (has links)
The aim of this thesis is the design and analysis of pedestrian bridge across the lagoon. Three variants were designed. The variant of structure, which combines stress ribbon with steel arches, was chosen for analysis. There is a chapter in this thesis which deals with an ideal shape of arches for different types of loads. The calculation of load effects was made in software Ansys 17.0, considering scnstruction stages. Ultimate limit state and state limit state are evaluated. For evaluation of concrete cross sections was used MS Excel. Steel cross sections were evaluated in software Ansys 17.0. d Dynamic behaviour of construction was assessed. The mode shapes and natural frequencies were calculated. The harmonic excitation response was studied. The loss of stability was checked. The design and assessment are according to the european standards.
80

Experimentální stanovení hydrodynamického zatížení modelu přelévané mostovky / Experimental determination of the hydrodynamic load of the flooded bridge model

Naiser, Dominik January 2020 (has links)
The diploma thesis deals with experimental determination of hydrodynamic load on the overflowed bridge deck model. In the first part of the thesis the author describes the analysis of the problem together with the basic physical laws and principles that are used or assumed in the measurement itself. In the second part the author describes the measurements in the laboratory of the Faculty of Civil Engineering and its gradual processing. At the end of the work are described the results of measurement, their comparison with numerical modeling, other authors and their possible use in practice.

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