No (20983)
Yes (2657)
Number of found documents:
23640
Published from
to
Infants' learning of novel segments is modulated by prosody
Chládková, Kateřina; Podlipský, V.J.; Nudga, Natalia; Paillereau, Nikola; Kynčlová, Kateřina; Šimáčková, Š.
2023 - English
Young infants recognize atypical realisations of native-language speech. Later they learn words better from native-accented talkers. However, 6-month-olds preferentially listen to unfamiliar speech. We tested whether the learning of new vowels matches 6-month-olds’ listening preferences, being more effective from nonnative-accented speech. We exposed Czech six-month-olds to delexicalised utterances with consonants replaced by [f] and vowels by 405 tokens sampled from a bimodal [ɛ]-[æ] distribution, a contrast absent from Czech, and with either native or atypical rhythm. Discrimination of [ɛ]-[æ] was then tested in an alternating/non-alternating paradigm. Longer first-look duration to non-alternating than to alternating trials – indicating a learning effect – was found in infants familiarised with the novel contrast in atypical rhythm, such effect was not\ndetected after familiarisation with native rhythm. Six-month-olds thus more effectively exploit distributional information about novel vowels from non-native rhythm, which matches their previously reported preferences for listening to novel over familiar accents.
Keywords:
distributional learning; selective learning; non-native rhythm; vowels; infancy
Available on request at various institutes of the ASCR
Infants' learning of novel segments is modulated by prosody
Young infants recognize atypical realisations of native-language speech. Later they learn words better from native-accented talkers. However, 6-month-olds preferentially listen to unfamiliar speech. ...
TESTING THE METHOD OF MULTIPLE SCALES AND THE AVERAGING PRINCIPLE FOR MODEL PARAMETER ESTIMATION OF QUASIPERIODIC TWO TIME-SCALE MODELS
Papáček, Štěpán; Matonoha, Ctirad
2023 - English
Some dynamical systems are characterized by more than one timescale, e.g. two well separated time-scales are typical for quasiperiodic systems. The aim of this paper is to show how singular perturbation methods based on the slow-fast decomposition can serve for an enhanced parameter estimation when the slowly changing features are rigorously treated. Although the ultimate goal is to reduce the standard error for the estimated parameters, here we test two methods for numerical approximations of the solution of associated forward problem: (i) the multiple time-scales method, and (ii) the method of averaging. On a case study, being an under-damped harmonic oscillator containing two state variables and two parameters, the method of averaging gives well (theoretically predicted) results, while the use of multiple time-scales method is not suitable for our purposes.
Keywords:
Dynamical system; Singular perturbation; Averaging; Parameter estimation; Slow-fast decomposition; Damped oscillations
Fulltext is available at external website.
TESTING THE METHOD OF MULTIPLE SCALES AND THE AVERAGING PRINCIPLE FOR MODEL PARAMETER ESTIMATION OF QUASIPERIODIC TWO TIME-SCALE MODELS
Some dynamical systems are characterized by more than one timescale, e.g. two well separated time-scales are typical for quasiperiodic systems. The aim of this paper is to show how singular ...
Different Boundary Conditions For LES Solver PALM 6.0 Used for ABL in Tunnel Experiment
Řezníček, Hynek; Geletič, Jan; Bureš, Martin; Krč, Pavel; Resler, Jaroslav; Vrbová, Kateřina; Trush, Arsenii; Michálek, Petr; Beneš, L.; Sühring, M.
2023 - English
We tried to reproduce results measured in the wind tunnel experiment with a CFD simulation provided by numerical model PALM. A realistic buildings layout from the Prague-Dejvice quarter has been chosen as a testing domain because solid validation campaign for PALM simulation of Atmospheric Boundary Layer (ABL) over this quarter was documented in the past. The question of input data needed for such simulation and capability of the model to capture correctly the inlet profile and its turbulence structure provided by the wind-tunnel is discussed in the study The PALM dynamical core contains a solver for the Navier-Stokes equations. By default, the model uses the Large Eddy Simulation (LES) approach in which the bulk of the turbulent motions is explicitly resolved. It is well validated tool for simulations of the complex air-flow within the real urban canopy and also within its reduced scale provided by wind tunnel experiments. However the computed flow field between the testing buildings did not correspond well to the measured wind velocity in some points. Different setting of the inlet boundary condition was tested but none of them gave completely developed turbulent flow generated by vortex generators and castellated barrier wall place at the entrance of the aerodynamic section of the wind tunnel.
Keywords:
large eddy simulation; wind tunnel; atmospheric boundary layer; PALM model; turbulence
Fulltext is available at external website.
Different Boundary Conditions For LES Solver PALM 6.0 Used for ABL in Tunnel Experiment
We tried to reproduce results measured in the wind tunnel experiment with a CFD simulation provided by numerical model PALM. A realistic buildings layout from the Prague-Dejvice quarter has been ...
Room temperature ethanol detection using carbon materials
Kočí, Michal
2023 - English
Allotropic forms of carbon, in particular graphene oxide (GO) or nanocrystalline diamond (NCD), attracted the attention of many research groups due to their unique electronic structures and extraordinary physical and chemical properties, preferable for many different applications, including sensor devices. This work focuses on responses of various sensing layers (NCD with hydrogen termination (H-NCD), graphene oxide (GO), reduced graphene oxide (rGO), thiol-functionalized graphene oxide (GO-SH) and their hybrid structures to ethanol vapor with concentrations up to 100 ppm in synthetic air at room temperature. The measured parameters of the tested sensors, especially stability, reproducibility and regeneration, are compared and critically evaluated. The high sensitivity of tested sensors achieved at room temperature makes them very promising for monitoring ethanol vapor as well as other volatile substances (e.g., isopropyl-alcohol or acetone).
Keywords:
gas sensor; nanocrystalline diamond (NCD); graphene oxide (GO); reduced graphene oxide (rGO); thiol-functionalized graphene oxide (GO-SH)
Available at various institutes of the ASCR
Room temperature ethanol detection using carbon materials
Allotropic forms of carbon, in particular graphene oxide (GO) or nanocrystalline diamond (NCD), attracted the attention of many research groups due to their unique electronic structures and ...
Výzkum zříceniny hradu Štamberk v kontextu regionu
Novotný, Jakub; Ramešová, Michaela
2023 - Czech
Příspěvek přibližuje dosavadní výsledky výzkumu hradu Štamberk realizovaného dle nově definovaných zásad pro výzkum, správu a prezentaci historických zřícenin, jehož cílem je podpořit nová řešení jak zvýšit využitelnost hradu pro cestovní ruch a integrovat památku do regionálních struktur lokalit s potenciálem cestovního ruchu. Hrad byl významným panstvím v rámci území dnešní Vysočiny. Předmětem řešení projektu, na kterém od roku 2020 spolupracuje ÚTAM AV ČR s Mikroregionem Telčsko, je výzkum historie hradu se zaměřením na technologická hlediska jeho výstavby, stavebních změn i zániku. Součástí je vytvoření 3D modelu zříceniny v krajinném kontextu. Projekt se soustředí na dějiny výroby vápna a související inventarizaci geologických lokalit. Tento výzkum přináší nové informace důležité nejen pro poznání historie hradu či pro studium analogických situací, ale také pro zvýšení atraktivity památky pro cestovní ruch. Příspěvek nejprve představí aktuální standardy výzkumu a managementu zřícenin, následně se bude zabývat nástinem potenciálu výzkumu Štamberka pro oblast cestovního ruchu s důrazem na historii hradu, mapování krajinného rámce a identifikace vazeb na regionální prostředí. Na závěr zrekapituluje dosavadní výsledky využitelné k prezentaci historického, kulturního i přírodního bohatství regionu se specifickou vazbou na cestovní ruch. The paper provides an overview of the research results of the Štamberk castle carried out according to newly defined principles for the research, management and presentation of historical ruins, the aim of which is to support new solutions to increase the usability of the castle for tourism and to integrate the monument into the regional structures of localities with tourism potential. The castle was an important place within the territory of today's Highlands. The subject of the project, on which ITAM CAS has been collaborating with the Telčsko Microregion since 2020, is research into the history of the castle with a focus on the technological aspects of its construction, structural changes and demise. It includes the creation of a 3D model of the ruins in a landscape context. The project focuses on the history of lime production and the related inventory of geological sites. This research brings new information important not only for learning about the history of the castle or for studying analogous situations, but also for increasing the attractiveness of the monument for tourism. The paper first presents the current standards of research and management of ruins, then it deals with an outline of the research potential of Štamberk for the field of tourism with an emphasis on the history of the castle, mapping the landscape framework and identifying links to the regional environment. At the end, it summarizes the results so far that can be used to present the historical, cultural and natural wealth of the region with a specific link to tourism.
Keywords:
Štamberk; ruin; technological research; presentation of monuments; tourism
Available at various institutes of the ASCR
Výzkum zříceniny hradu Štamberk v kontextu regionu
Příspěvek přibližuje dosavadní výsledky výzkumu hradu Štamberk realizovaného dle nově definovaných zásad pro výzkum, správu a prezentaci historických zřícenin, jehož cílem je podpořit nová řešení jak ...
Mechanical properties of basalt: a study on compressive loading at different strain rates using SHPB
Falta, J.; Krčmářová, N.; Fíla, T.; Vavro, Martin; Vavro, Leona
2023 - English
This article focuses on the mechanical properties of basalt in compressive loading at different strain-rates. The study employs advanced instrumentation for the evaluation of the results in dynamic conditions, while standard uni-axial loading device is used for evaluation in quasi-static conditions. Basalt specimens were subjected to four different loading-rates from 200–600 s−1 on which the stress-strain dependence was evaluated together with DIC analysis of crack initiation and disintegration process. Understanding the mechanical properties of basalt can provide insights for engineers and designers in creating structures that are durable and able to withstand different loading conditions. The findings of this study can have implications for a wide range of industries, including aerospace, automotive, and construction, among others.
Keywords:
SHPB; basalt; compressive loading; dynamic loading
Available at various institutes of the ASCR
Mechanical properties of basalt: a study on compressive loading at different strain rates using SHPB
This article focuses on the mechanical properties of basalt in compressive loading at different strain-rates. The study employs advanced instrumentation for the evaluation of the results in dynamic ...
Asynchronous time integration while achieving zero interface energy
Dvořák, Radim; Kolman, Radek; Falta, J.; Neühauserová, M.
2023 - English
This contribution deals with an asynchronous direct time integration of the finite-element model. The proposed method is applied to the phenomenon of wave propagation through an elastic linear continuum. The numerical model is partitioned into individual subdomains using the domain decomposition method by means of localized Lagrange multipliers. For each subdomain, different time discretizations are used. No restrictions for relation between subdomain’s time steps are imposed. The coupling of the subdomains is forced by an acceleration continuity condition. Additionally, we use the a posteriori technique to also provide the displacement and velocity continuity at the interfaces, and hence we obtain exact continuity of all three kinematic fields. The proposed method is experimentally validated using the modified SHPB (split Hopkinson pressure bar) setup.
Keywords:
finite element method; direct time integration; asynchronous integration; domain decomposition; localized lagrange multipliers
Available at various institutes of the ASCR
Asynchronous time integration while achieving zero interface energy
This contribution deals with an asynchronous direct time integration of the finite-element model. The proposed method is applied to the phenomenon of wave propagation through an elastic linear ...
Skryté kulturní hodnoty chráněných území
Fišer, J.; Novák, David; Šmejda, L.
2023 - Czech
Kulturní charakter krajiny vyplývá nejen z její současné hospodářské struktury, ale také z antropogenní minulosti, která se odráží v četných památkách, jež ukazují, že lidé v minulosti využívali i tu část krajiny, která je nyní chráněna pro své přírodní hodnoty. Intenzita těchto činností však byla spojena s obecnými strategiemi osídlení, které výrazně respektovaly geomorfologické charakteristiky krajiny. Velkoplošná chráněná přírodní území se vyznačují výjimečnými krajinnými prvky nebo významnými přírodními hodnotami. I v těchto částech krajiny byl minulý vliv člověka významný a zanechal zde své stopy. Intenzita a specifika tohoto vlivu jsou v článku prezentovány na základě archeologických dat. Archeologická data byla zpracována do rastru, jehož hodnoty jsou vztaženy k počtu archeologických období přítomných v daném území. Chráněná krajina byla lidmi využívána spíše sporadicky a nárůst aktivity lze spojit až s obdobím středověku a novověku. Plochy nechráněné krajiny byly v minulosti využívány intenzivněji. Vysvětlení tohoto rozdílu však není založeno na sociálních preferencích, ale na geomorfologické struktuře chráněné krajiny a s ní spojené historii osídlení. The cultural character of the landscape stems not only from its current economic structure but also from the anthropogenic past reflected in numerous relics, which show that people in the past also used the part of the landscape that is now protected for its natural values. However, the intensity of these activities was linked to general settlement strategies with a strong respect to the geomorphological characteristics of the landscape. Large-scale protected natural areas are characterised by exceptional landscape features or significant natural values. Even in these parts of the landscape, past human influence was significant and left its traces. The intensity and specifics of this influence are presented in the paper on the basis of archaeological data. The archaeological data were processed into a grid whose values are related to the number of archaeological periods present in the given area. The protected landscape was used by people rather sporadically and the increase in activity can only be associated with the mediaeval and modern periods. Areas of the unprotected landscape were more intensively used in the past. However, the explanation for the difference is not based on social preferences but on the geomorphological structure of the protected landscape and its associated settlement history.
Keywords:
past human activities; archaeology; protected natural sites; landscape history; land use
Available at various institutes of the ASCR
Skryté kulturní hodnoty chráněných území
Kulturní charakter krajiny vyplývá nejen z její současné hospodářské struktury, ale také z antropogenní minulosti, která se odráží v četných památkách, jež ukazují, že lidé v minulosti využívali i tu ...
Laserová ablace atomů vápníku a hliníku jako zdroj částic pro iontovou past
Grim, Jakub; Pekař, Zdeněk; Pham, Minh Tuan; Číp, Ondřej
2023 - Czech
Laserová ablace je účinnou metodou pro generování částic z různých materiálů, včetně těch s vysokou teplotou vypařování, jako je hliník. Využití vysokoenergetických laserových pulsů umožňuje kontrolované odpaření materiálu a vytvoření ablačního kráteru. V pilotní sestavě pro generování neutrálních atomů vápníku a hliníku pomocí laserové ablace byly dosaženy úspěšné výsledky. Metoda je porovnávána s tepelnou píckou s cílem optimalizovat proces generování těchto částic. Následná spektroskopická měření na generovaných atomech jsou prováděna s cílem optimalizace absorpce a emise fotonů pro následnou ionizaci v iontové pasti. Studie přechodů neutrálních atomů Ca a Al ukazuje, že laserová ablace poskytuje efektivnější generaci atomů s možností větší kontroly nad tímto procesem. Laser ablation is an effective method for generating particles from a variety of materials, including those with high evaporation temperatures such as aluminum. The use of high-energy laser pulses enables controlled evaporation of the material and the creation of an ablation crater. Successful results have been obtained in a pilot setup for the generation of neutral calcium and aluminium atoms by laser ablation. The method is being compared with thermal resistance oven in order to optimize the prosec generation of these particles. Subsequent spectroscopic measurements on the generated atoms are performed to optimize the absorption and emission of photons for subsequent ionization in the ion trap. A study of the transitions of neutral Ca and Al atoms shows that laser ablation provides a more efficient generation of atoms with the possibility of greater control over the process.
Keywords:
laser ablation; ion trap; particle generation; fluorescence spectroscopy
Available at various institutes of the ASCR
Laserová ablace atomů vápníku a hliníku jako zdroj částic pro iontovou past
Laserová ablace je účinnou metodou pro generování částic z různých materiálů, včetně těch s vysokou teplotou vypařování, jako je hliník. Využití vysokoenergetických laserových pulsů umožňuje ...
Comparison of finite element simulation of tungsten nanoindentation with Berkovich and conical indenter
Fiala, L.; Ballo, I.; Kovář, J.; Fuis, Vladimír
2023 - English
Finite Element Method (FEM) was used to study the difference between using Berkovich and conical indenters in nanoindentation test of tungsten specimen. The study was aimed to determine the\nmodulus of elasticity of a tested specimen and how it changes with different indenter. The FEM analysis also revealed that the modulus of elasticity was sensitive to the dimensions of both specimen and the indenter for which were made several numerical calculations with different dimensions.
Keywords:
nanoindentation; FEM; Berkovich indenter; conical indenter; tungsten
Available at various institutes of the ASCR
Comparison of finite element simulation of tungsten nanoindentation with Berkovich and conical indenter
Finite Element Method (FEM) was used to study the difference between using Berkovich and conical indenters in nanoindentation test of tungsten specimen. The study was aimed to determine the\nmodulus ...
NRGL provides central access to information on grey literature produced in the Czech Republic in the fields of science, research and education. You can find more information about grey literature and NRGL at service web
Send your suggestions and comments to nusl@techlib.cz
Provider
Other bases