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The Analysis of mutes on trombone and trumpet timbre
Košař, Vojtěch ; Mojdl, Edgar (referee) ; Jirásek, Ondřej (advisor)
This work deals with the sound mute issues, specifically how they affect the timbre of a trombone and a trumpet, their sound spectrum, levels of individual harmonic tones, the presence of formants and the directional characteristics of individual tones played in various dynamics. A part of this work is also focused on the theoretical description of a trombone and a trumpet, including their brief history, their classification, the parts they are consisting of and the timbre. The theoretical part is further dealing with the description of mathematic functions like FFT or LPC analysis, which have been implemented in the MATLAB environment when creating the graphic dependents for this theme.
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The Analysis of impedance properties of the bridge in string instruments
Němec, Petr ; Nop, Patrik (referee) ; Jirásek, Ondřej (advisor)
It is a known fact that stringed instruments bridge makes an important part of "acoustic circuit" of their bodies. Bridge acts as an acoustic filter which has the biggest impact on 2 – 6 kHz band and high frequency bands. To find the connection between the impact of a specific acoustic and mechanical properties of a bridge and acoustical behavior of the entire instrument remains as a matter of further exploration. Aim of this thesis is to find the mentioned relations of a chosen materials in an accordance to their mechanical properties within a full range of materials with common bridge properties. The experiments are designed to determine mechanical and acoustic properties of chosen materials which are then used to fabricate bridges. Subsequently the acoustical behavior of instruments with chosen bridges is determined. Based upon these findings we propose specific solutions and suggest further research.
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Analysis of Specific Cutting Forces for New Materials and CNC Machining
Fiala, Zdeněk ; Bach, Pavel (referee) ; Petrů,, Jana (referee) ; Píška, Miroslav (advisor)
This dissertation thesis is focused on the analysis of specific cutting forces and accompanying effects during machining of the new materials, composite materials. The experimental part is split up to two main chapters. In the first chapter, the development of specific cutting forces is analyzed in detail when cutting conditions are changing. The experimental machining of glass/polyester and carbon/epoxy composites is described for fibers orientations 0 a 90 (ie, the orientation of the fibers in the feed rate direction and perpendicular to the feed rate direction). The influence of the cutting tool flank wear on the specific cutting force is investigated further. The last section compares the values of specific cutting forces when machining with carbide milling tools deposited by different types of coating. The second chapter describes the measurement of sound spectrums generated by cutting process, sound maps creating and finding possible correlations between dominant frequencies of the sound and the specific cutting forces, or the cutting tool flank wear. The measurements are described for the cases of machining steel 15 260.7 and glass-polyester composite material.
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Spectrum analysis of the violin
Hanzálek, Pavel ; Smékal, Zdeněk (referee) ; Jirásek, Ondřej (advisor)
This work focuses on the problems of sound spectrum analysis and directional characteristics of the violin. The beginning of the work deals with the development of the violin, generally about timbre and directional characteristics. The theoretical part also deals with different types of sound spectra and LPC analysis on general. The practical part deals with practical tasks of work such as a description of the application created in MATLAB for examination of the time spectrum of tones, FFT spectra, formants by LPC analysis and display of directional characteristics. It also deals with the describing the methods, the process of sensing and measuring two different violins with different types of strings and age of corpus.
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The Analysis of impedance properties of the bridge in string instruments
Němec, Petr ; Nop, Patrik (referee) ; Jirásek, Ondřej (advisor)
It is a known fact that stringed instruments bridge makes an important part of "acoustic circuit" of their bodies. Bridge acts as an acoustic filter which has the biggest impact on 2 – 6 kHz band and high frequency bands. To find the connection between the impact of a specific acoustic and mechanical properties of a bridge and acoustical behavior of the entire instrument remains as a matter of further exploration. Aim of this thesis is to find the mentioned relations of a chosen materials in an accordance to their mechanical properties within a full range of materials with common bridge properties. The experiments are designed to determine mechanical and acoustic properties of chosen materials which are then used to fabricate bridges. Subsequently the acoustical behavior of instruments with chosen bridges is determined. Based upon these findings we propose specific solutions and suggest further research.
|
|
|
The Analysis of mutes on trombone and trumpet timbre
Košař, Vojtěch ; Mojdl, Edgar (referee) ; Jirásek, Ondřej (advisor)
This work deals with the sound mute issues, specifically how they affect the timbre of a trombone and a trumpet, their sound spectrum, levels of individual harmonic tones, the presence of formants and the directional characteristics of individual tones played in various dynamics. A part of this work is also focused on the theoretical description of a trombone and a trumpet, including their brief history, their classification, the parts they are consisting of and the timbre. The theoretical part is further dealing with the description of mathematic functions like FFT or LPC analysis, which have been implemented in the MATLAB environment when creating the graphic dependents for this theme.
|
|
|
Spectrum analysis of the violin
Hanzálek, Pavel ; Smékal, Zdeněk (referee) ; Jirásek, Ondřej (advisor)
This work focuses on the problems of sound spectrum analysis and directional characteristics of the violin. The beginning of the work deals with the development of the violin, generally about timbre and directional characteristics. The theoretical part also deals with different types of sound spectra and LPC analysis on general. The practical part deals with practical tasks of work such as a description of the application created in MATLAB for examination of the time spectrum of tones, FFT spectra, formants by LPC analysis and display of directional characteristics. It also deals with the describing the methods, the process of sensing and measuring two different violins with different types of strings and age of corpus.
|
|
|
Analysis of Specific Cutting Forces for New Materials and CNC Machining
Fiala, Zdeněk ; Bach, Pavel (referee) ; Petrů,, Jana (referee) ; Píška, Miroslav (advisor)
This dissertation thesis is focused on the analysis of specific cutting forces and accompanying effects during machining of the new materials, composite materials. The experimental part is split up to two main chapters. In the first chapter, the development of specific cutting forces is analyzed in detail when cutting conditions are changing. The experimental machining of glass/polyester and carbon/epoxy composites is described for fibers orientations 0 a 90 (ie, the orientation of the fibers in the feed rate direction and perpendicular to the feed rate direction). The influence of the cutting tool flank wear on the specific cutting force is investigated further. The last section compares the values of specific cutting forces when machining with carbide milling tools deposited by different types of coating. The second chapter describes the measurement of sound spectrums generated by cutting process, sound maps creating and finding possible correlations between dominant frequencies of the sound and the specific cutting forces, or the cutting tool flank wear. The measurements are described for the cases of machining steel 15 260.7 and glass-polyester composite material.
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