Search the repository

A+ | A- | | SLO | ENG

Keywords: gradbeništvo, digitalna proizvodnja, ekskurzijski tiskalnik
Published in DiRROS: 01.04.2025; Views: 2; Downloads: 0
This document has many files! More...

Abstract: Objectives: Pupil dilation can serve as a measure of auditory attention. It has been proposed as an objective measure for adjusting hearing aid configurations, and as a measure of hearing threshold in the pediatric population. Here we explore (1) whether the pupillary dilation response (PDR) to audible sounds can be reliably measured in normally hearing infants within their average attention span, and in normally hearing adults, (2) how accurate within-participant models are in classifying PDR based on the stimulus type at various intensity levels, (3) whether the amount of analyzed data affects the model reliability, and (4) whether we can observe systematic differences in the PDR between speech and nonspeech sounds, and between the discrimination and detection paradigms. Design: In experiment 1, we measured the PDR to target warble tones at 500 to 4000 Hz compared with a standard tone (250 Hz) using an oddball discrimination test. A group of normally hearing infants was tested in experiment 1a (n = 36, mean [ME] = 21 months), and a group of young adults in experiment 1b (n = 12, ME = 29 years). The test was divided into five intensity blocks (30 to 70 dB SPL). In experiment 2a (n = 11, ME = 24 years), the task from experiment 1 was transformed into a detection task by removing the standard warble tone, and in experiment 2b (n = 12, ME = 29 years), participants listened to linguistic (Ling-6) sounds instead of tones. Results: In all experiments, the increased PDR was significantly associated with target sound stimuli on a group level. Although we found no overall effect of intensity on the response amplitude, the results were most clearly visible at the highest tested intensity level (70 dB SPL). The nonlinear classification models, run for each participant separately, yielded above-chance classification accuracy (sensitivity, specificity, and positive predictive value above 0.5) in 76% of infants and in 75% of adults. Accuracy further improved when only the first six trials at each intensity level were analyzed. However, accuracy was similar when pupil data were randomly attributed to the target or standard categories, indicating over-sensitivity of the proposed algorithms to the regularities in the PDR at the individual level. No differences in the classification accuracy were found between infants and adults at the group level, nor between the discrimination and detection paradigms (experiment 2a versus 1b), whereas the results in experiment 2b (speech stimuli) outperformed those in experiment 1b (tone stimuli). Conclusions: The study confirms that PDR is elicited in both infants and adults across different stimulus types and task paradigms and may thus serve as an indicator of auditory attention. However, for the estimation of the hearing (or comfortable listening) threshold at the individual level, the most efficient and time-effective protocol with the most appropriate type and number of stimuli and a reliable signal to noise ratio is yet to be defined. Future research should explore the application of pupillometry in diverse populations to validate its effectiveness as a supplementary or confirmatory measure within the standard audiological evaluation procedures.
Keywords: adults, audiometry, auditory attention, infants, pupillometry
Published in DiRROS: 31.03.2025; Views: 28; Downloads: 10
Full text (2,02 MB)
This document has many files! More...

Abstract: Let $(E,h)$ be a semipositive hermitian holomorphic line bundle on a compact complex manifold $X$ with $\dim >1$. Assume that for each point $x\in X$ there exists a divisor $D \in |E|$ in the complete linear system determined by $E$ whose complement $X\setminus D$ is a Stein neighbourhood of $x$ with the density property. Then, the disc bundle $\Delta_h(E)=\{e\in E:|e|_h<1\}$ is an Oka manifold while $D_h(E)=\{e\in E:|e|_h>1\}$ is a Kobayashi hyperbolic domain. In particular, the zero section of $E$ admits a basis of Oka neighbourhoods $\{|e|_h < c\}$ with $c >0$. We show that this holds if $X$ is a rational homogeneous manifold of dimension $>1$. This class of manifolds includes complex projective spaces, Grassmannians, and flag manifolds. This phenomenon contributes to the heuristic principle that Oka properties are related to metric positivity of complex manifolds.
Keywords: Oka manifolds, holomorphic line bundles, hermitian metric, polarised manifold
Published in DiRROS: 31.03.2025; Views: 29; Downloads: 16
Full text (515,39 KB)
This document has many files! More...

Abstract: The morphology-adaptive multifield two-fluid model MultiMorph focuses on the reliable and robust simulation of interfacial multiphase flows in industrial applications. The idea is to combine the Volume-of-Fluid approach with the Euler-Euler approach to model both large and small scale interfacial structures efficiently. The choice of the local representation of interfacial structures, such as bubbles or droplets, by either the first or the second of the aforementioned basic method strongly depends on the ratio of the length scale of the interface feature to the grid spacing. In case the computational grid gets too coarse to locally resolve an interfacial structure, a morphology transfer is required. Such a transfer process allows to convert resolved fluid into non-resolved one, i.e. changing from a continuous description to a disperse one. A formulation for such a numerically motivated morphology transfer process is presented. It is validated with a case of a two-dimensional single rising bubble on a grid with gradually varying cell size. The model is then applied to two further cases: an oil–water phase inversion and a water jet plunging into a free water surface. Hereby, functionality, robustness and feasibility of the proposed morphology transfer mechanism are demonstrated. This work contributes to a hybrid modelling approach for the simulation of two-phase flows adapting the numerical representation depending on local flow morphology and on available computational resources
Published in DiRROS: 28.03.2025; Views: 123; Downloads: 19
Full text (2,23 MB)

Keywords: manjšine, Hrvaška, slovenščina, raba jezika, jezikovna politika, učenje jezika, šolstvo
Published in DiRROS: 28.03.2025; Views: 71; Downloads: 20
Full text (822,46 KB)