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Stereo microphone preamplifier with integrated ADC
Tóth, Péter ; Šotner, Roman (referee) ; Kratochvíl, Tomáš (advisor)
he aim of this work is to design a mobile microphone preaplifier with integrated ADC suitable for in field work. In the intruduction a general overwiev is presented about the history of sound recording and it also deals with the parameters of the devices designed in this work. In the next chapter the contruction of each module is described.
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Modelling eye movements during Multiple Object Tracking
Děchtěrenko, Filip ; Lukavský, Jiří (advisor) ; Toth, Peter Gabriel (referee)
In everyday situations people have to track several objects at once (e.g. driving or collective sports). Multiple object tracking paradigm (MOT) plausibly simulate tracking several targets in laboratory conditions. When we track targets in tasks with many other objects in scene, it becomes difficult to discriminate objects in periphery (crowding). Although tracking could be done only using attention, it is interesting question how humans plan their eye movements during tracking. In our study, we conducted a MOT experiment in which we presented participants repeatedly several trials with varied number of distractors, we recorded eye movements and we measured consistency of eye movements using Normalized scanpath saliency (NSS) metric. We created several analytical strategies employing crowding avoidance and compared them with eye data. Beside analytical models, we trained neural networks to predict eye movements in MOT trial. The performance of the proposed models and neuron networks was evaluated in a new MOT experiment. The analytical models explained variability of eye movements well (results comparable to intraindividual noise in the data); predictions based on neural networks were less successful.
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Sound Processing in an Emulator of Cochlear Implant
Tóth, Peter ; Maršálek, Petr (advisor) ; Hric, Jan (referee)
The time accuracy of the auditory neuronal pathway in its sound localization branch is high, compared to other sensory systems. The time differences in the sound arrival between the left and right ear are distinguished by the neural circuit in this branch. The accuracy achieved here is in the order of tens of microseconds. This phenomenon has not yet been definitively clarified. In this master thesis, a model of a neuron central to this neural circuit is presented. This neuron is called binaural (neuron of the two ears) and is located in the medial superior olive (MSO) neural nucleus. The properties of the MSO neuron are described. Specifically, the neuron acts as a coincidence detector, and this is necessary for the circuit functioning. Main result of the thesis is the theory explaining how the function of the coincidence detector can be described based on the interaction of the post-synaptic potentials on the spike-response model neuron. Generality and implications for the auditory pathway are then discussed.
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Bayesian models of eye movements
Lux, Erik ; Děchtěrenko, Filip (advisor) ; Toth, Peter Gabriel (referee)
Attention allows us to monitor objects or regions of visual space and extract information from them to use for report or storage. Classical theories of attention assumed a single focus of selection but many everyday activities, such as playing video games, suggest otherwise. Nonetheless, the underlying mechanism which can explain the ability to divide attention has not been well established. Numerous attempts have been made in order to clarify divided attention, including analytical strategies as well as methods working with visual phenomena, even more sophisticated predictors incorporating information about past selection decisions. Virtually all the attempts approach this problem by constructing a simplified model of attention. In this study, we develop a version of the existing Bayesian framework to propose such models, and evaluate their ability to generate eye movement trajectories. For the comparison of models, we use the eye movement trajectories generated by several analytical strategies. We measure the...
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Bayesian models of eye movements
Lux, Erik ; Děchtěrenko, Filip (advisor) ; Toth, Peter Gabriel (referee)
Attention allows us to monitor objects or regions of visual space and extract information from them to use for report or storage. Classical theories of attention assumed a single focus of selection but many everyday activities, such as playing video games, suggest otherwise. Nonetheless, the underlying mechanism which can explain the ability to divide attention has not been well established. Numerous attempts have been made in order to clarify divided attention, including analytical strategies as well as methods working with visual phenomena, even more sophisticated predictors incorporating information about past selection decisions. Virtually all the attempts approach this problem by constructing a simplified model of attention. In this study, we develop a version of the existing Bayesian framework to propose such models, and evaluate their ability to generate eye movement trajectories. For the comparison of models, we use the eye movement trajectories generated by several analytical strategies. We measure the similarity between...
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Modeling of Binaural Hearing.
Tóth, Peter ; Maršálek, Petr (advisor) ; Košťál, Lubomír (referee) ; Hromádka, Tomáš (referee)
The central theme of this thesis is a description of information processing in the sound localization circuit of the auditory pathway. The focus is on principal neurons of the medial superior olive (MSO), the first major convergence point for binaural information. Selected properties and relations of MSO neurons are derived and expressed through models. In the thesis we present three modeling studies. The first one clarifies a relation- ship between biophysical parameters of the MSO neuron and its ability to detect coincidental spikes from the left and the right ear. The second study describes the statistical behavior of spike trains on the input and output of the MSO neuron. In the third work, we studied how interaural coherence could guide localization of sound sources in complex listening situations with multiple sound sources in reverberant environments. The main results are analytical and numerical models describing the aforemen- tioned relations and behaviors. Secondary results include that inhibitory input to the MSO neuron narrows and shifts the time range of coincidence detection, that ergodic assumption from statistical physics and circular statistics are beneficial in the description of spike trains in the auditory pathway, and that interaural level difference of parts of the signal with...
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Bayesian models of eye movements
Lux, Erik ; Děchtěrenko, Filip (advisor) ; Toth, Peter Gabriel (referee)
Attention allows us to monitor objects or regions of visual space and extract information from them to use for report or storage. Classical theories of attention assumed a single focus of selection but many everyday activities, such as playing video games, suggest otherwise. Nonetheless, the underlying mechanism which can explain the ability to divide attention has not been well established. Numerous attempts have been made in order to clarify divided attention, including analytical strategies as well as methods working with visual phenomena, even more sophisticated predictors incorporating information about past selection decisions. Virtually all the attempts approach this problem by constructing a simplified model of attention. In this study, we develop a version of the existing Bayesian framework to propose such models, and evaluate their ability to generate eye movement trajectories. For the comparison of models, we use the eye movement trajectories generated by several analytical strategies. We measure the...
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Bayesian models of eye movements
Lux, Erik ; Děchtěrenko, Filip (advisor) ; Toth, Peter Gabriel (referee)
Attention allows us to monitor objects or regions of visual space and extract information from them to use for report or storage. Classical theories of attention assumed a single focus of selection but many everyday activities, such as playing video games, suggest otherwise. Nonetheless, the underlying mechanism which can explain the ability to divide attention has not been well established. Numerous attempts have been made in order to clarify divided attention, including analytical strategies as well as methods working with visual phenomena, even more sophisticated predictors incorporating information about past selection decisions. Virtually all the attempts approach this problem by constructing a simplified model of attention. In this study, we develop a version of the existing Bayesian framework to propose such models, and evaluate their ability to generate eye movement trajectories. For the comparison of models, we use the eye movement trajectories generated by several analytical strategies. We measure the similarity between...
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Essays on Foreign Capital, Extenal Finance and Trade of European Firms
Tóth, Peter ; Lízal, Lubomír (advisor) ; Lubyová, Martina (referee) ; Halpern, László (referee)
This dissertation is composed of three chapters studying empirical questions of corporate finance, European integration and international trade using firm-level data. The first chapter is focused on the macroeconomic and firm-specific determinants of attracting foreign investors to Czech firms before Czech EU membership. The second chapter tests the effect of introducing the European single currency on the likelihood of equity and corporate debt issues by firms in the eurozone. The third chapter asks to what extent cheaper imported inputs may offset the loss in export sales due to domestic currency appreciation in Czech manufacturing firms around the EU accession period. In the first chapter we study what factors attracted foreign capital to Czech firms during the mid-transition, pre-EU-accession period 1997-2002. While the foreign own- ers' influence on firm performance has been widely studied, the same is not true for the opposite direction of causality. We consider macroeconomic, industry- and firm-level indicators of a firm's attractiveness to foreign capital. Using panel data techniques, we es- timate linear models, limited dependent variable models and a hazard model with foreign ownership as the response variable. We find that foreign investors are likely to come from countries with higher corporate taxes...
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Sound Processing in an Emulator of Cochlear Implant
Tóth, Peter ; Maršálek, Petr (advisor) ; Hric, Jan (referee)
The time accuracy of the auditory neuronal pathway in its sound localization branch is high, compared to other sensory systems. The time differences in the sound arrival between the left and right ear are distinguished by the neural circuit in this branch. The accuracy achieved here is in the order of tens of microseconds. This phenomenon has not yet been definitively clarified. In this master thesis, a model of a neuron central to this neural circuit is presented. This neuron is called binaural (neuron of the two ears) and is located in the medial superior olive (MSO) neural nucleus. The properties of the MSO neuron are described. Specifically, the neuron acts as a coincidence detector, and this is necessary for the circuit functioning. Main result of the thesis is the theory explaining how the function of the coincidence detector can be described based on the interaction of the post-synaptic potentials on the spike-response model neuron. Generality and implications for the auditory pathway are then discussed.
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