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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.
11

Percepční citlivost ve frekvenční a temporální doméně u hudebních a řečových stimulů / Perceptual sensitivity to music and speech stimuli in the frequency and temporal domains

Lukeš, David January 2014 (has links)
The subject of this thesis is perceptual sensitivity with respect to subtle frequency-based and temporal manipulations in speech, music and mixed stimuli. We hypothesize that an individual's sensitivity to variation in all three types of stimuli should be similar (i.e. a correlation should exist), seeing that findings in evolutionary biology, neurosciences, psy- chology and experimental phonetics are pointing towards a relatively strong link between the mechanisms of perception in speech and music. Our listening experiment revealed mostly intermediate correlations; additionally, we argue that by employing syntactically less complicated stimuli, which would target specifically fundamental sensitivity without requiring a complex syntactic analysis in parallel, even more robust correlations could be obtained. While the influence of prior formal linguistic education on performance in the test was negligible, the influence of musical experience was considerable, which lends further support to the idea of simplifying especially the music stimuli in future research. Key words: music, speech, perception, sensitivity, correlation
12

Spatial distribution of fish in reservoirs and lakes / Spatial distribution of fish in reservoirs and lakes

MUŠKA, Milan January 2013 (has links)
This thesis is focused on the fish spatial distribution and its changes mainly during the diel cycle. In the first part, I described the fish spatial distribution in the tropical lake ecosystem of Lake Turkana. The second part deals with the fish spatial distribution in a temperate reservoir on the different spatial scales from in/offshore habitats over the fine-scale to the level of individuals. The linkage of fish distribution patterns with selected environmental variables was also evaluated.
13

Teplotní závislost elektronického šumu piezokeramických snímačů / Electronic noise temperature characteristics of piezoceramic sensors

Shromáždil, Petr January 2009 (has links)
The main objective of the thesis „Electronic noise temperature dependence of piezoceramic sensors“ is to design the measuring set-up for the measurement of the piezoceramic sensor noise temperature dependence. The application for the control of the measurement process is realized. The theoretic chapter is focused on the properties of materials for the production of piezoceramic sensors. The basic effects related to the piezoceramic properties and the material structure is described in this part. Next chapter is focused on the technology of production of used piezoceramic. The properties of solid solutions as PbZrO3 – PbTiO3, and the non-destructive methods of the material testing are discussed. Our attention is concentrated to methods of acoustic emission. The next chapter is concerned on the realization of the measuring set-up and program equipment. The tested sample is the acoustic emission sensor made of piezoceramic material PCM-51. It is placed in the cylinder chest which is heated by the DC current source. The temperature measurement is realized by the data acquisition switch unit. The results of measurements are saved in PC and they are analyzed using MATLAB program. As a result we receive the frequency spectra of the electric noise voltage spectral density SU. The temperature dependencies of resonant peak value and frequency are determined from these spectra.
14

Akustické vlastnosti slovního přízvuku ve čtené české anglictině / Acoustic properties of word stress in read Czech English

Liska, Jan January 2011 (has links)
key words: Czech English, foreign accent, word stress, word accent, stressed syllable, duration, f0, acoustic cues. This study investigates the acoustic properties of word stress in Czech English. The notion of foreign accent is introduced and its drawbacks are presented. Further on the various influences on the perceived degree, or strength, of foreign accent are discussed. Faulty realization of word stress is identified as one of the factors that contribute to unintelligibility of non-native speech (Benrabah, 1997; Hahn, 2004; Cutler, 1984). In Chapter 2 we compare the results of studies that used speakers of a variety of languages and form a basic theory on the acquisition of acoustic cues to word stress. We are mostly interested in f0 and duration. This theory, based on the feature hypothesis (McAllister et al., 2002 in Lee, Guion & Harada, 2006), states that languages that have a similar stress system to that of English (Dutch, Arabic) use their native cues to signal word stress, while non-contrastive languages (Vietnamese, Czech) prefer cue/s that are phonologically active on segmental level in their native language. Speakers of Vietnamese, a tone language, were found to prefer f0 over duration (Nguyen, 2003), so for Czech, a language that uses phonological vowel duration, it is expected that...
15

Influence of wood structure on wood properties of tropical species

Baar, Jan January 2014 (has links)
The presented thesis is focused on aesthetical and acoustic properties of tropical wood. The discussed tropical species are utilized in Europe mainly for their unusual appearance and colour in joinery and furniture production. The irreplacable acoustic properties like low internal friction predestine specific species for production of musical instruments. The colour of six selected tropical species - jatoba (Hymenea courbaril L.), massaranduba (Manilkara bidentata A. Chev.), muiracatiara (Astronium graveolens Jacq.), angelim amargoso (Vatairea spp.), angelim pedra (Hymenolobium spp.) and angelim vermelho (Dinizia excelsa Ducke) - were analyzed and expressed in CIEL*a*b* colour space. Subsequently the samples were exposed to artificial sunlight and the light-induced discolouration rate and progress was evaluated. The colour change was rapid in zhe first hours of exposure and all species showed a similar trend in lightness (L*) change - initial darkening replaced by gradual fading. The change in chromatic parameters (a* and b*) change was specific for individual species and probably related to the chemical composition of the extractives. The overall discolouration of lighter coloured wood samples is more distinctive. The extractive content of tropical species is usually high and determines wood colour. The wood of African Padauk (Pterocarpus soyauxii Taub) and Jatoba (Hymenaea courbaril L.) was extracted in a mixture of methanol, water and acetone. The total extractives and total phenolic content was measured. Extractive content was related to colour parameters and above all to lightness in both species. The increase in extractive content leads to a lighter and more yellow colouration of Jatoba wood while African Padauk was darker with a higher amount of extractives. In Jatoba, a positive correlation was found between extractive content and the rate of discolouration. The extractives are responsible for intensive discolouration of tropical woods in contrast to light coloured woods from the temperate zone, where the yellowing is primarily caused by lignin photodegradation. The sound velocity was measured by ultrasound and resonance longitudinal method in heartwood of doussie (Afzelia bipindensis), merbau (Intsia bijuga), wengé (Millettia stuhlmannii Taub.), muiracatiara (Astronium graveolens Jacq.) and zebrano (Microberlinia brazzavillensis). The sound velocity was not related to the density in any case. Although anatomical structural characteristics as fiber length or ray ratio positively influenced it. With longer fibers and slender rays the sound velocity increased. Other acoustic properties like dynamic young modulus of elasticity, specific modulus of elasticity, internal friction and acoustic conversion efficiency (ACE) were determined and were related to measured anatomical features. The differences in composition of wood tissue of individual species were the main source of departure between the assessed relationships. The wood with longer fibers and lower frequency of rays reached lower values of internal friction. The stiffness of wood characterized by the dynamic modulus of elasticity was correlated with fiber and ray tissue. A higher volume of fibers influenced the stiffness positively, while ray volume had the opposite effect on stiffness. Positive effects of fiber length and ray ratio were found for dynamic modulus of elasticity and for acoustic conversion efficiency as well. Both values increased with longer fibers and higher ray ratio. The sound velocity is the basis of some nondestructive techniques for determination of wood mechanical properties. The comparison of density and three dynamic moduli of elasticity (longitudinal and flexural resonance method and ultrasound method) in prediction of mechanical properties was carried out. The density was evaluated as a poor predictor when the samples are not straight-grained and defect free. The interlocked grain often occurred in tropical species and its presence influences the mechanical properties of wood but not wood density. The dynamic moduli of elasticity showed strong correlation with the static modulus of elasticity. Among nondestructive techniques, the weakest correlation was found for the ultrasound method, which is probably partially explained by different measuring mechanism. The prediction of the modulus of rupture is less accurate when the dynamic modulus of elasticity is compared with the static modulus of elasticity; however, it was still good in comparison with the density model.
16

Trh s akustickými piany ve vybraných zemích Jižní Ameriky na příkladu společnosti PETROF / The market for acoustic pianos in selected countries of South America on the example of PETROF company

Ceralová, Anna January 2014 (has links)
The thesis examines a potential of markets in Peru, Chile, Uruguay, Argentina and Brazil for trade with acoustic pianos PETROF. The first chapter contains an overview of piano manufacturers and terms associated with that field. Characteristic of protectionism and its effects on trade are mentioned in the first chapter as well, since some countries apply trade barriers frequently. An economic analysis of these states together with a market analysis follows. The market potential investigation is based on field research in the countries of South America.
17

Diferenční analýza multilingválního řečového korpusu pacientů s neurodegenerativními onemocněními / Differential analysis of multilingual corpus in patients with neurodegenerative diseases

Kováč, Daniel January 2020 (has links)
This diploma thesis focuses on the automated diagnosis of hypokinetic dysarthria in the multilingual speech corpus, which is a motor speech disorder that occurs in patients with neurodegenerative diseases such as Parkinson’s disease. The automatic speech recognition approach to diagnosis is based on the acoustic analysis of speech and subsequent use of mathematical models. The popularity of this method is on the rise due to its objectivity and the possibility of working simultaneously on different languages. The aim of this work is to find out which acoustic parameters have high discriminative power and are universal for multiple languages. To achieve this, a statistical analysis of parameterized speech tasks and subsequent modelling by machine learning methods was used. The analyses were performed for Czech, American English, Hungarian and all languages together. It was found that only some parameters enable the diagnosis of the hypokinetic disorder and are, at the same time, universal for multiple languages. The relF2SD parameter shows the best results, followed by the NST parameter. When classifying speakers of all the languages together, the model achieves accuracy of 59 % and sensitivity of 72 %.
18

University Residential Centre / University Residential Centre

Weyr, Jan January 2014 (has links)
This diploma thesis is aimed on solution of a three-storey object for residential and commercial purposes of a university. In the ground floor there is canteen with canteen kitchen, café, shops and fitness. The first and second floors are designed as an accommodation for students with different types of room layouts. Reinforced concrete skeleton was chosen as a load-bearing system of the building and acoustic masonry is used as an infill material. The roof is designed as a green flat roof with extensive type of flora. The object is founded on piles.
19

Integrace civilních bezpilotních prostředků do neřízeného vzdušného prostoru / Integration of unmanned air vehicles to uncontrolled airspace

Kohutek, Jakub January 2011 (has links)
The master’s thesis expresses an opinion on trends in UAV integration into non-segregated airspace issue. In the beginning, barriers to integration are characterized and a broader context is shown. Since necessity of the technical realization of the “see and be seen” principle exists, requirements for so called Sense and Avoid systems are presented. Various methods of Sense and Avoid are briefly described, highlighting their contribution to air safety and their potential for future development. The UAV communication topic is described in the last chapter, providing a list of the volume of transmitted messages, analyzing data link frequencies and selecting appropriate means of UAV operations.
20

Vývoj a výzkum environmentálně úsporných izolačních materiálů / Development of environmental friendly materials

Peterková, Jitka January 2013 (has links)
Increasing demand for new progressive construction materials requires development of modern environmentally friendly materials with excellent end-use properties and reasonable price. One of the main objectives of material research in building industry is using renewable resources of raw materials of industrial waste for development of new construction materials. Current trend of thermal insulation of building constructions results in development of environmentally friendly insulation materials based on renewable material resources from agriculture and stock farming, which could became alternative for current common use insulation materials in the future. The thesis describes research and development of insulation materials based on natural fibres of agricultural origin; in particular fibres of hemp, flax and jute. Hydrothermal behavior of developed materials is studied including computational simulation of behavior of researched materials after building in the construction.

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