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47 results on '"Urbanova, Petra"'

2. EDITORIAL

Author

Králík, Miroslav and Urbanová, Petra

Published
2022

8. Head poses and grimaces: Challenges for automated face identification algorithms?

Author

Urbanova, Petra, Goldmann, Tomas, Cerny, Dominik, and Drahansky, Martin

Subjects
FACIAL expression, ARTIFICIAL intelligence, IMAGE processing, ALGORITHMS, FACIAL muscles, HEAD, MACHINE learning
Abstract

• The performance of identification algorithms is susceptible to many factors. • Head rotation beyond a 15-degree angle pose challenges to automated systems. • An upward tilt of 10° and higher leads to a notable degradation in performance. • Only a smiling face produced consistently positive log-likelihood ratios. • There is evidence of sex-related bias favoring males in image processing. In today's biometric and commercial settings, state-of-the-art image processing relies solely on artificial intelligence and machine learning which provides a high level of accuracy. However, these principles are deeply rooted in abstract, complex "black-box systems". When applied to forensic image identification, concerns about transparency and accountability emerge. This study explores the impact of two challenging factors in automated facial identification: facial expressions and head poses. The sample comprised 3D faces with nine prototype expressions, collected from 41 participants (13 males, 28 females) of European descent aged 19.96 to 50.89 years. Pre-processing involved converting 3D models to 2D color images (256 × 256 px). Probes included a set of 9 images per individual with head poses varying by 5° in both left-to-right (yaw) and up-and-down (pitch) directions for neutral expressions. A second set of 3,610 images per individual covered viewpoints in 5° increments from −45° to 45° for head movements and different facial expressions, forming the targets. Pair-wise comparisons using ArcFace, a state-of-the-art face identification algorithm yielded 54,615,690 dissimilarity scores. Results indicate that minor head deviations in probes have minimal impact. However, the performance diminished as targets deviated from the frontal position. Right-to-left movements were less influential than up and down, with downward pitch showing less impact than upward movements. The lowest accuracy was for upward pitch at 45°. Dissimilarity scores were consistently higher for males than for females across all studied factors. The performance particularly diverged in upward movements, starting at 15°. Among tested facial expressions, happiness and contempt performed best, while disgust exhibited the lowest AUC values. [ABSTRACT FROM AUTHOR]

Published
2024
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9. Morphometric Sex Estimation from the Hip Bone by Means of the HIP 1.1 Software

Author

Králík, Miroslav, Klíma, Ondřej, Urbanová, Petra, Polcerová, Lenka, Čuta, Martin, Hutchison, David, Series Editor, Kanade, Takeo, Series Editor, Kittler, Josef, Series Editor, Kleinberg, Jon M., Series Editor, Mattern, Friedemann, Series Editor, Mitchell, John C., Series Editor, Naor, Moni, Series Editor, Pandu Rangan, C., Series Editor, Steffen, Bernhard, Series Editor, Terzopoulos, Demetri, Series Editor, Tygar, Doug, Series Editor, Reuter, Martin, editor, Wachinger, Christian, editor, Lombaert, Hervé, editor, Paniagua, Beatriz, editor, Lüthi, Marcel, editor, and Egger, Bernhard, editor

Published
2018
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13. Imaging and 3D Analysis Based on Two or More Three-Dimensional CBCT Recordings before and after Orthodontic Treatment and Maxillofacial Therapy.

Author

Dostalova, Tatjana, Eliasova, Hana, Prochazka, Ales, Nocar, Adam, and Urbanova, Petra

Subjects
CONE beam computed tomography, THREE-dimensional imaging, CORRECTIVE orthodontics, IMAGE analysis, ORTHODONTIC diagnosis
Abstract

Cone beam computed tomography (CBCT) has emerged as a crucial radiographic technique for orthodontic diagnosis and treatment planning, particularly for cases requiring the assessment of complex anatomical relationships. In the first part of the study, we examined metric characteristics measured on 3D cranial models of patients before and after surgery. In the second part, we conducted more complex data processing, analyzing a set of 12 cranial feature points using Procrustes analysis to quantify and visually represent surgical modifications. The third part involved comparing 3D facial surfaces using Iterative Closest Point (ICP) alignment and nearest point-to-point distances. Additionally, we tested point configurations in the facial soft tissues. The study included a group of orthodontic patients from whom CBCT data and 3D facial scans were obtained during treatment. The results demonstrated that each method could assess preoperative and postoperative changes to varying degrees. They also highlighted potential gender differences in surgical modifications that warrant further investigation and consideration during surgical planning. The aim of our study was to compare 3D visualizations of skull and facial models before and after surgery, to assess the degree of relative agreement or similarity, and to identify any morphological differences. [ABSTRACT FROM AUTHOR]

Published
2024
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25. Towards an improvement of optically stimulated luminescence (OSL) age uncertainties:modelling OSL ages with systematic errors, stratigraphic constraints and radiocarbon ages using the R package BayLum

Author

Guérin, Guillaume, Lahaye, Christelle, Heydari, Maryam, Autzen, Martin, Buylaert, Jan-Pieter, Guibert, Pierre, Jain, Mayank, Kreutzer, Sebastian, Lebrun, Brice, Murray, Andrew S., Thomsen, Kristina J., Urbanova, Petra, Philippe, Anne, Guérin, Guillaume, Lahaye, Christelle, Heydari, Maryam, Autzen, Martin, Buylaert, Jan-Pieter, Guibert, Pierre, Jain, Mayank, Kreutzer, Sebastian, Lebrun, Brice, Murray, Andrew S., Thomsen, Kristina J., Urbanova, Petra, and Philippe, Anne

Abstract

Statistical analysis has become increasingly important in optically stimulated luminescence (OSL) dating since it has become possible to measure signals at the single-grain scale. The accuracy of large chronological datasets can benefit from the inclusion, in chronological modelling, of stratigraphic constraints and shared systematic errors. Recently, a number of Bayesian models have been developed for OSL age calculation; the R package “BayLum” presented herein allows different models of this type to be implemented, particularly for samples in stratigraphic order which share systematic errors. We first show how to introduce stratigraphic constraints in BayLum; then, we focus on the construction, based on measurement uncertainties, of dose covariance matrices to account for systematic errors specific to OSL dating. The nature (systematic versus random) of errors affecting OSL ages is discussed, based – as an example – on the dose rate determination procedure at the IRAMAT-CRP2A laboratory (Bordeaux). The effects of the stratigraphic constraints and dose covariance matrices are illustrated on example datasets. In particular, the benefit of combining the modelling of systematic errors with independent ages, unaffected by these errors, is demonstrated. Finally, we discuss other common ways of estimating dose rates and how they may be taken into account in the covariance matrix by other potential users and laboratories. Test datasets are provided as a Supplement to the reader, together with an R markdown tutorial allowing the reproduction of all calculations and figures presented in this study.

Published
2021

26. Towards an improvement of optically stimulated luminescence (OSL) age uncertainties: modelling OSL ages with systematic errors, stratigraphic constraints and radiocarbon ages using the R package BayLum

Author

Guérin, Guillaume, primary, Lahaye, Christelle, additional, Heydari, Maryam, additional, Autzen, Martin, additional, Buylaert, Jan-Pieter, additional, Guibert, Pierre, additional, Jain, Mayank, additional, Kreutzer, Sebastian, additional, Lebrun, Brice, additional, Murray, Andrew S., additional, Thomsen, Kristina J., additional, Urbanova, Petra, additional, and Philippe, Anne, additional

Published
2021
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28. Towards an improvement of OSL age uncertainties: modelling OSL ages with systematic errors, stratigraphic constraints and radiocarbon ages using the R package BayLum

Author

Guérin, Guillaume, primary, Lahaye, Christelle, additional, Heydari, Maryam, additional, Autzen, Martin, additional, Buylaert, Jan-Pieter, additional, Guibert, Pierre, additional, Jain, Mayank, additional, Kreutzer, Sebastian, additional, Murray, Andrew S., additional, Thomsen, Kristina J., additional, Urbanova, Petra, additional, and Philippe, Anne, additional

Published
2020
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29. Supplementary material to "Towards an improvement of OSL age uncertainties: modelling OSL ages with systematic errors, stratigraphic constraints and radiocarbon ages using the R package BayLum"

Author

Guérin, Guillaume, primary, Lahaye, Christelle, additional, Heydari, Maryam, additional, Autzen, Martin, additional, Buylaert, Jan-Pieter, additional, Guibert, Pierre, additional, Jain, Mayank, additional, Kreutzer, Sebastian, additional, Murray, Andrew S., additional, Thomsen, Kristina J., additional, Urbanova, Petra, additional, and Philippe, Anne, additional

Published
2020
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31. A novel interdisciplianry approach for building Archaeology: the inegration of mortar 'single grain' luminescence dating into archaeological research, the example of the Saint Seurin Basilica, Bordeaux'

Author

Michel, Anne, Urbanova, Petra, CANTIN, Nadia, Guibert, Pierre, Lanos, Philippe, Dufresne, Philippe, Garnier, L, Ausonius-Institut de recherche sur l'Antiquité et le Moyen âge, Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), IRAMAT-Centre de recherche en physique appliquée à l’archéologie (IRAMAT-CRP2A), Institut de Recherches sur les Archéomatériaux (IRAMAT), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), Géosciences Rennes (GR), Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
ComputingMilieux_MISCELLANEOUS, [SHS]Humanities and Social Sciences
Abstract

International audience

Published
2018

33. Dating of archaeological mortars by Optically Stimulated Luminescence: a novel approach for dating the construction of historical buildings

Author

Urbanova, Petra, Guibert, Pierre, IRAMAT-Centre de recherche en physique appliquée à l’archéologie (IRAMAT-CRP2A), Institut de Recherches sur les Archéomatériaux (IRAMAT), and Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2016

34. Mortar Dating Methodology: Assessing Recurrent Issues and Needs for Further Research

Author

Hayen, Roald, primary, Van Strydonck, Mark, additional, Fontaine, Laurent, additional, Boudin, Mathieu, additional, Lindroos, Alf, additional, Heinemeier, Jan, additional, Ringbom, Åsa, additional, Michalska, Danuta, additional, Hajdas, Irka, additional, Hueglin, Sophie, additional, Marzaioli, Fabio, additional, Terrasi, Filippo, additional, Passariello, Isabella, additional, Capano, Manuela, additional, Maspero, Francesco, additional, Panzeri, Laura, additional, Galli, Anna, additional, Artioli, Gilberto, additional, Addis, Anna, additional, Secco, Michele, additional, Boaretto, Elisabetta, additional, Moreau, Christophe, additional, Guibert, Pierre, additional, Urbanova, Petra, additional, Czernik, Justyna, additional, Goslar, Tomasz, additional, and Caroselli, Marta, additional

Published
2017
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36. Absorbed dose, equivalent dose, measured dose rates, and implications for OSL age estimates: Introducing the Average Dose Model

Author

Guerin, Guillaume, Christophe, C., Philippe, A., Murray, Andrew Sean, Thomsen, Kristina Jørkov, Tribolo, Chantal, Urbanova, Petra, Jain, Mayank, Guibert, Pierre, Mercier, Norbert, Kreutzer, Sebastian, Lahaye, Christelle, Guerin, Guillaume, Christophe, C., Philippe, A., Murray, Andrew Sean, Thomsen, Kristina Jørkov, Tribolo, Chantal, Urbanova, Petra, Jain, Mayank, Guibert, Pierre, Mercier, Norbert, Kreutzer, Sebastian, and Lahaye, Christelle

Abstract

Luminescence ages are calculated by dividing an absorbed dose by the dose rate to which the natural dosimeter has been exposed. In practice, one measures an equivalent dose, De; in the absence of an alpha dose contribution, this should be indistinguishable from the dose absorbed in nature. Here we first review the relationship between absorbed dose, equivalent dose and dose rate, and the measurements that lead to their estimation; we restate that, in contrast to recent suggestions, an equivalent dose is not a physically different quantity from a beta or gamma dose absorbed by quartz grains. Statistical analysis of OSL data is of great importance when dealing with single grain data, since such data commonly exhibit significant scatter. However, dose rate measurements provide an arithmetic mean of dose rates absorbed by individual grains; in this article, we propose a new model to estimate the average dose absorbed by the grains. We thus introduce a new model for OSL age estimates: the Average Dose Model (ADM). We argue that ADM ages should be more accurate than Central Age Model (CAM) based ages, and we provide experimental evidence supporting this expectation. We also argue that the use of the Finite Mixture Model should be avoided. Finally, we discuss the implications for multi-grain age estimates derived from well-bleached samples.

Published
2017

44. Quenching of 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole-modified Na +/K +-ATPase reveals a higher accessibility of the low-affinity ATP-binding site

Author

Linnertz, Holger, Urbanova, Petra, and Amler, Evzen

Abstract

7-Chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) labeled Na +/K +-ATPase covalently with two different inactivation constants ( Ki=2.5 μM; Ki′=10 μM). It apparently modified the two different ATP-binding sites of the enzyme since it decreased the activity of the E 2ATP site, i.e. the K +-activated para-nitrophenylphosphatase activity, in an enzyme whose high-affinity E 1ATP site had been blocked by fluorescein 5′isothiocyanate (FITC). It also reduced the activity of the E 1ATP site, i.e. the Na +-activated protein phosphorylation, in an enzyme whose low-affinity E 2ATP site had been blocked by Co(NH 3) 4PO 4. Fluorescence quenching experiments with KI, CsCl and MnCl 2of the NBD-Cl-labeled Na +/K +-ATPase revealed two differently accessible types of fluorophores depending on the ATP site: The E 2ATP site apparently differs from the E 1ATP site in that it is more open because the fluorophore labeling in the E 2ATP site was sterically better accessible for quenchers.

Published
1997
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47. Mortar Dating Methodology: Assessing Recurrent Issues and Needs for Further Research

Author

Mark Van Strydonck, Laura Panzeri, Petra Urbanová, Christophe Moreau, Anna Galli, Marta Caroselli, Sophie Hueglin, Tomasz Goslar, Justyna Czernik, F. Maspero, Pierre Guibert, Danuta Michalska, Isabella Passariello, Laurent Fontaine, Manuela Capano, Åsa Ringbom, Fabio Marzaioli, Alf Lindroos, Mathieu Boudin, Anna Addis, Roald Hayen, Irka Hajdas, Elisabetta Boaretto, Gilberto Artioli, Jan Heinemeier, Michele Secco, Filippo Terrasi, Hayen, Roald, Van Strydonck, Mark, Fontaine, Laurent, Boudin, Mathieu, Lindroos, Alf, Heinemeier, Jan, Ringbom, Ã sa, Michalska, Danuta, Hajdas, Irka, Hueglin, Sophie, Marzaioli, Fabio, Terrasi, Filippo, Passariello, Isabella, Capano, Manuela, Maspero, Francesco, Panzeri, Laura, Galli, Anna, Artioli, Gilberto, Addis, Anna, Secco, Michele, Boaretto, Elisabetta, Moreau, Christophe, Guibert, Pierre, Urbanova, Petra, Czernik, Justyna, Goslar, Tomasz, Caroselli, Marta, Unité de chimie organique moléculaire et macromoléculaire (UCO2M), Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), CNR Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Max Planck Weizmann Center for Integrative Archaeology and Anthropology (WPWC), Max Planck Institute for Evolutionary Anthropology, Max-Planck-Gesellschaft-Max-Planck-Gesellschaft-Weizmann Institute of Science, Laboratoire de Recherche en Sciences Humaines (Lares-Las), Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), IRAMAT-Centre de recherche en physique appliquée à l’archéologie (IRAMAT-CRP2A), Institut de Recherches sur les Archéomatériaux (IRAMAT), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), Faculty of Physics, Adam Mickiewicz University in Poznań (UAM), Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Weizmann Institute of Science [Rehovot, Israël]-Max Planck Institute for Evolutionary Anthropology [Leipzig], Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM), Institut Royal du Patrimoine Artistique | Royal Institute for Cultural Heritage (KIK-IRPA), Åbo Akademi University [Turku], Aarhus University [Aarhus], Newcastle University [Newcastle], Seconda Università degli studi di Napoli, Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), Universita degli Studi di Padova, Max Planck Institute for Evolutionary Anthropology [Leipzig], Max-Planck-Gesellschaft-Max-Planck-Gesellschaft-Weizmann Institute of Science [Rehovot, Israël], CEA- Saclay (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Poznań Radiocarbon Laboratory | Poznańskie Laboratorium Radiowęglowe, Scuola universitaria professionale della Svizzera italiana = University of Applied Sciences and Arts of Southern Switzerland [Manno] (SUPSI), Seconda Università degli Studi di Napoli = Second University of Naples, Università degli Studi di Milano-Bicocca = University of Milano-Bicocca (UNIMIB), Università degli Studi di Padova = University of Padua (Unipd), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), Hayen, R, Van Strydonck, M, Fontaine, L, Boudin, M, Lindroos, A, Heinemeier, J, Ringbom, Å, Michalska, D, Hajdas, I, Hueglin, S, Marzaioli, F, Terrasi, F, Passariello, I, Capano, M, Maspero, F, Panzeri, L, Galli, A, Artioli, G, Addis, A, Secco, M, Boaretto, E, Moreau, C, Guibert, P, Urbanova, P, Czernik, J, Goslar, T, and Caroselli, M

Subjects
010506 paleontology, Archeology, Optically stimulated luminescence, 01 natural sciences, Civil engineering, law.invention, law, Absolute dating, [CHIM]Chemical Sciences, 0601 history and archaeology, CARBONATE, Radiocarbon dating, lime, OSL, 0105 earth and related environmental sciences, 060102 archaeology, Archeology (arts and humanities), Dating methodologies in archaeology, 06 humanities and the arts, AMS C-14, LIME MORTARS, radiocarbon AMS dating, mortar dating, General Earth and Planetary Sciences, Environmental science, Mortar, Earth and Planetary Sciences (all)
Abstract

Absolute dating of mortars is crucial when trying to pin down construction phases of archaeological sites and historic stone buildings to a certain point in time or to confirm, but possibly also challenge, existing chronologies. To evaluate various sample preparation methods for radiocarbon (14C) dating of mortars as well as to compare different dating methods, i.e.14C and optically stimulated luminescence (OSL), a mortar dating intercomparison study (MODIS) was set up, exploring existing limits and needs for further research. Four mortar samples were selected and distributed among the participating laboratories: one of which was expected not to present any problem related to the sample preparation methodologies for anthropogenic lime extraction, whereas all others addressed specific known sample preparation issues. Data obtained from the various mortar dating approaches are evaluated relative to the historical framework of the mortar samples and any deviation observed is contextualized to the composition and specific mineralogy of the sampled material.

Published
2017
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