National Repository of Grey Literature 25 records found  beginprevious16 - 25  jump to record: Search took 0.00 seconds. 
Analysis of impact of noise in recordings on the automated detection of hypokinetic dysarthria
Havelková, Nikola ; Galáž, Zoltán (referee) ; Kováč, Daniel (advisor)
This thesis deals with the automated detection of hypokinetic dysarthria by analysing the influence of noise present in recordings. Appropriate single-channel methods, specifically the spectral subtraction and Kalman filter, are selected and implemented in the MATLAB R2022a to enhance speech. These methods are also used for noise-free recordings, to which additive white noise was added. Afterwards, the effectiveness of these methods is objectively evaluated by using signal-to-noise ratio values. After enhancing of speech, interferences are extracted from the recordings. The effect of the presence of noise, as well as its subsequent suppression by individual methods, is then evaluated by statistical analysis, specifically using the Kruskal-Wallis test and the post hoc Dunn’s test. The probability of distributing parameters of clean, noisy and enhanced recordings, for which the effect of noise is significant, according to statistical tests, are plotted using violin and box graphs. Finally, the classification was done by logistic regression with the help of machine learning, where the effect of the presence of noise and subsequent speech enhancement on automated detection of hypokinetic dysarthria was described according to the area values under the ROC curve.
Multilingual Analysis Of Hypokinetic Dysarthria In Patients With Parkinson’s Disease
Kováč, Daniel
This article deals with the multilingual analysis of hypokinetic dysarthria (HD) in patientswith Parkinson’s disease (PD). The goal is to identify acoustic features that have high discriminationpower and that are independent of the language of a speaker. The speech corpus contains 59 PD patientsand 44 healthy controls (HC) speaking in Czech (cs) and American English (en-US). Based onnon-parametric statistical tests and logistic regression, we observed the best discrimination power hasthe speech index of rhythmicity (extracted from a reading text) and harmonic-to-noise ratio (extractedfrom a sustained vowel). We were able to identify PD with 67% sensitivity and 79% specificity inthe Czech corpus and with 78% sensitivity and 67% specificity in the English one. The performanceof the model was significantly lower when combining both datasets, thus suggesting language playsa significant role during the automatic assessment of HD.
Automatic speech recordings segmentation tool
Santa, Roman ; Zvončák, Vojtěch (referee) ; Kováč, Daniel (advisor)
Nástroj pre automatickú segmentáciu spracováva nahrávky reči a extrahuje hovorené slovo z nahrávok. Je dôležité, aby pokročilá analýza pracovala iba s rečovými časťami z nahrávky. Nástroj na segmentáciu má ulahčiť spracovanie nahrávok pre analýzu rozdielov medzi hláskami pacientov s parkinsonovou chorobou a tými zdravými. Cieľ tejto práce je navrhnúť a otestovať detektory reči s Google WebRTC detektorom a vybrať ten najvhodnejší detektor reči s minimálnym počtom chýb. Ďalej, vytvoriť nástroj na segmentáciu nahrávok a otestovať rozpoznávanie reči pomocou dynamic time warping. Bola použitá databáza poskytnutá laboratóriom pre analýzu mozgových ochorení. Obsahuje české a maďarské nahrávky s rovnakým počtom mužských a ženských pacientov a aj rovnakým počtom zdravých pacientov a pacientov s parkinsonovou chorobou. Najlepšie výsledky v testoch dosiahol detektor na základe energie reči. Nebol zistený žiaden rozdiel v presnosti detektoru pri spracovaní mužských a ženských nahrávok alebo nahrávok zdravých či chorých pacientov. Nahrávky s nízkym odstupom signálu od šumu boli náročnejšie na spracovanie s frekvenciou chýb od 12%. Na základe výsledkov, bol navrhnutý nový detektor pre spracovanie úplnej nahrávky. Na záver bol testovaný algoritmus pre rozpoznávanie podobnosti reči na základe melovských kepstrálnych koeficientov.
Differential analysis of multilingual corpus in patients with neurodegenerative diseases
Kováč, Daniel ; Zvončák, Vojtěch (referee) ; Mekyska, Jiří (advisor)
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 %.
Predicting light use efficiency using optical vegetation indices at various time scales and environmental conditions
Kováč, Daniel ; Ač, Alexander ; Veselovská, Petra ; Dreveňáková, Petra ; Rapantová, Barbora ; Klem, Karel
This study presents data points acquired during 2 years of measuring optical properties and gas-exchange\ncharacteristics of European beech (Fagus sylvatica) and Norway spruce (Picea abies) tree species in controlled\nenvironments. The observed statistical relationships between 105 pairs of selected optical parameters\n(i.e. photochemical reflectance index [PRI], ΔPRI, and normalized difference between wavebands R690\nand R630 [where R is a reflectance at a subscripted wavelength]) and light use efficiency (LUE) were considered\nat assumed different canopy leaf area index, changing pigments stoichiometrics, and daily changing\ndynamics of environmental conditions. Our measurements suggested that consistency of the LUE estimation\nusing PRI may be disrupted by acclimation responses of plants that reduce energetic carriers for\nuse in photosynthetic CO2 uptake and the xanthophyll cycle. Also, a changing chlorophylls-to-carotenoids\nratio tends to interrupt the PRI–LUE relationship. ΔPRI showed sensitivity to leaf area index of the measured\ntrees that complicated leaf-level estimation of LUE. The most consistent assessment of LUE was\nachieved using the chlorophyll fluorescence detecting ratio (R690 – R630)/(R690 + R630).
Influence of the chlorophylls-to-carotenoids ratio on light use efficiency estimation by optical parameters
Ač, Alexander ; Kováč, Daniel ; Veselovská, Petra ; Večeřová, Kristýna ; Klem, Karel
The influence is examined of changing leaf photosynthetic pigments concentrations on sensitivity of the\nphotochemical reflectance index (PRI) and ΔPRI optical parameters in relation to light use efficiency\n(LUE). Photosynthetic and leaf chlorophylls-to-carotenoids (Chl/Car) ratio changes during the growth of\nEuropean Beech (Fagus sylvatica) and Norway spruce (Picea abies) saplings were induced by altering the\nliving environment inside growth chambers. Point reflectance measurements of each individual tree were\nrecording changes in optical properties while measurements were being taken simultaneously of altering\nphotosynthesis. Based on the evaluation of 45 pairs of measurements conducted on six individual saplings,\nthe observed variability in the strength of the PRI and ΔPRI versus LUE relationships was compared to the\nresulting leaf Chl/Car ratio of each tree. Data were used to explain the influence of changing pigments on\nthe sensitivity of each individual optical parameter with regards to the LUE estimation.
3D Audio Standards in Home Theatre Environment
Kováč, Daniel ; Schimmel, Jiří (referee) ; Balík, Miroslav (advisor)
This work deals with object-based sound. There is a description of the difference between channel-based and object-based sound and the development of this sound to today's form. Subsequently, formats that work with objects are described, and they are compared with each other. MPEGH-3D Audio format is specified here, which is a standard today, and also the method of positioning the virtual audio source by vector-base amplitude panning. It also describes how an encoder and decoder supporting speaker configurations 5.1.2, 5.1.4 and 7.1.4 has been developed according to the MPEG-H 3D Audio specification. Lastly, the work deals with the problem of panning the object sound to the standard configuration and there is also a mention of the listening test.
Bridge over a local road
Kováč, Daniel ; Mojzík, Petr (referee) ; Nečas, Radim (advisor)
This master thesis is focused for design, respectively for creating counterproposal of existing structure of Motorway Bridge located at D1 motorway between Jánovce and Jablonov in district Levoča in Slovakia. This bridge is over a local road. The main aim of this thesis is design, analysis and assessment of bearing elements of bridge deck. For purposes of this thesis was created three variants of bridge deck. Detailed analysis was performed on bearing construction from post-tensioned precast beam with monolithing concrete slab. Two mathematic models were used for analysis of chosen variant. First model was spatial 3D shell construction. The purpose of this model was determinate cross spreading line of other constant load and live load. Second, flat 2D model, was for determination creep and shrinkage appeared from long-term load. These effects were observed in at advanced defined time nodes. Outcomes from upper mentioned model were used from design and assessment of bearing elements of bridge deck, design prestressed reinforcement cables and concrete reinforcement rods.
Bridge over drain channel
Kováč, Daniel ; Nečas, Radim (referee) ; Panáček, Josef (advisor)
This bachelor thesis is foucused on design monolithic road bridge. The bridge is situated on Road R1 between Žarnovica and Šášovské Pdhradie. The primary funkcion of bridge is crossing open drain channel, secondary it is biocorridor. There are three preliminary versions designed, two of them are using monolitic prestressed concreate beams. One version is using precast beams. The project includes statical analysis drawing documentation.

National Repository of Grey Literature : 25 records found   beginprevious16 - 25  jump to record:
See also: similar author names
6 KOVÁČ, David
1 Kovač, D.
1 Kovač, Dejan
1 Kováč, Dan
13 Kováč, Daniel
4 Kováč, Dominik
6 Kováč, Dávid
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