https://research-explorer.ista.ac.at
2000-01-01T00:00+00:001monthlyExpression-invariant 3D face recognition
https://research-explorer.ista.ac.at/record/18324
Bronstein, AlexanderBronstein, Michael M.Kimmel, Ron2003We present a novel 3D face recognition approach based on geometric invariants introduced by Elad and Kimmel. The key idea of the proposed algorithm is a representation of the facial surface, invariant to isometric deformations, such as those resulting from different expressions and postures of the face. The obtained geometric invariants allow mapping 2D facial texture images into special images that incorporate the 3D geometry of the face. These signature images are then decomposed into their principal components. The result is an efficient and accurate face recognition algorithm that is robust to facial expressions. We demonstrate the results of our method and compare it to existing 2D and 3D face recognition algorithms.https://research-explorer.ista.ac.at/record/18324engSpringer Natureinfo:eu-repo/semantics/altIdentifier/doi/10.1007/3-540-44887-x_8info:eu-repo/semantics/altIdentifier/issn/0302-9743info:eu-repo/semantics/altIdentifier/issn/1611-3349info:eu-repo/semantics/altIdentifier/isbn/9783540403029info:eu-repo/semantics/closedAccessBronstein AM, Bronstein MM, Kimmel R. Expression-invariant 3D face recognition. In: <i>4th International Conference on Audio- and Video-Based Biometric Person Authentication</i>. Vol 2688. Springer Nature; 2003:62-70. doi:<a href="https://doi.org/10.1007/3-540-44887-x_8">10.1007/3-540-44887-x_8</a>Expression-invariant 3D face recognitionLNCSinfo:eu-repo/semantics/conferenceObjectdoc-type:conferenceObjecttexthttp://purl.org/coar/resource_type/c_5794A unified framework of direct and indirect reciprocity
https://research-explorer.ista.ac.at/record/9402
Schmid, LauraChatterjee, KrishnenduHilbe, ChristianNowak, Martin A.2021Direct and indirect reciprocity are key mechanisms for the evolution of cooperation. Direct reciprocity means that individuals use their own experience to decide whether to cooperate with another person. Indirect reciprocity means that they also consider the experiences of others. Although these two mechanisms are intertwined, they are typically studied in isolation. Here, we introduce a mathematical framework that allows us to explore both kinds of reciprocity simultaneously. We show that the well-known ‘generous tit-for-tat’ strategy of direct reciprocity has a natural analogue in indirect reciprocity, which we call ‘generous scoring’. Using an equilibrium analysis, we characterize under which conditions either of the two strategies can maintain cooperation. With simulations, we additionally explore which kind of reciprocity evolves when members of a population engage in social learning to adapt to their environment. Our results draw unexpected connections between direct and indirect reciprocity while highlighting important differences regarding their evolvability.https://research-explorer.ista.ac.at/record/9402https://research-explorer.ista.ac.at/download/9402/14496engSpringer Natureinfo:eu-repo/semantics/altIdentifier/doi/10.1038/s41562-021-01114-8info:eu-repo/semantics/altIdentifier/issn/2397-3374info:eu-repo/semantics/altIdentifier/wos/000650304000002info:eu-repo/semantics/altIdentifier/pmid/33986519info:eu-repo/grantAgreement/EC/H2020/863818info:eu-repo/grantAgreement/EC/FP7/279307info:eu-repo/semantics/openAccessSchmid L, Chatterjee K, Hilbe C, Nowak MA. A unified framework of direct and indirect reciprocity. <i>Nature Human Behaviour</i>. 2021;5(10):1292–1302. doi:<a href="https://doi.org/10.1038/s41562-021-01114-8">10.1038/s41562-021-01114-8</a>ddc:000A unified framework of direct and indirect reciprocityinfo:eu-repo/semantics/articledoc-type:articletexthttp://purl.org/coar/resource_type/c_6501Lamellipodin tunes cell migration by stabilizing protrusions and promoting adhesion formation
https://research-explorer.ista.ac.at/record/8434
Dimchev, Georgi AAmiri, BehnamHumphries, Ashley C.Schaks, MatthiasDimchev, VanessaStradal, Theresia E. B.Faix, JanKrause, MatthiasWay, MichaelFalcke, MartinRottner, Klemens2020Efficient migration on adhesive surfaces involves the protrusion of lamellipodial actin networks and their subsequent stabilization by nascent adhesions. The actin-binding protein lamellipodin (Lpd) is thought to play a critical role in lamellipodium protrusion, by delivering Ena/VASP proteins onto the growing plus ends of actin filaments and by interacting with the WAVE regulatory complex, an activator of the Arp2/3 complex, at the leading edge. Using B16-F1 melanoma cell lines, we demonstrate that genetic ablation of Lpd compromises protrusion efficiency and coincident cell migration without altering essential parameters of lamellipodia, including their maximal rate of forward advancement and actin polymerization. We also confirmed lamellipodia and migration phenotypes with CRISPR/Cas9-mediated Lpd knockout Rat2 fibroblasts, excluding cell type-specific effects. Moreover, computer-aided analysis of cell-edge morphodynamics on B16-F1 cell lamellipodia revealed that loss of Lpd correlates with reduced temporal protrusion maintenance as a prerequisite of nascent adhesion formation. We conclude that Lpd optimizes protrusion and nascent adhesion formation by counteracting frequent, chaotic retraction and membrane ruffling.This article has an associated First Person interview with the first author of the paper. https://research-explorer.ista.ac.at/record/8434https://research-explorer.ista.ac.at/download/8434/8435engThe Company of Biologistsinfo:eu-repo/semantics/altIdentifier/doi/10.1242/jcs.239020info:eu-repo/semantics/altIdentifier/issn/0021-9533info:eu-repo/semantics/altIdentifier/issn/1477-9137info:eu-repo/semantics/altIdentifier/wos/000534387800005info:eu-repo/semantics/altIdentifier/pmid/ 32094266info:eu-repo/grantAgreement/FWF//M02495info:eu-repo/semantics/openAccessDimchev GA, Amiri B, Humphries AC, et al. Lamellipodin tunes cell migration by stabilizing protrusions and promoting adhesion formation. <i>Journal of Cell Science</i>. 2020;133(7). doi:<a href="https://doi.org/10.1242/jcs.239020">10.1242/jcs.239020</a>Cell Biologyddc:570Lamellipodin tunes cell migration by stabilizing protrusions and promoting adhesion formationinfo:eu-repo/semantics/articledoc-type:articletexthttp://purl.org/coar/resource_type/c_6501Inverse-Sybil attacks in automated contact tracing
https://research-explorer.ista.ac.at/record/9826
Auerbach, BenediktChakraborty, SuvradipKlein, KarenPascual Perez, GuillermoPietrzak, Krzysztof ZWalter, MichaelYeo, Michelle X2021Automated contract tracing aims at supporting manual contact tracing during pandemics by alerting users of encounters with infected people. There are currently many proposals for protocols (like the “decentralized” DP-3T and PACT or the “centralized” ROBERT and DESIRE) to be run on mobile phones, where the basic idea is to regularly broadcast (using low energy Bluetooth) some values, and at the same time store (a function of) incoming messages broadcasted by users in their proximity. In the existing proposals one can trigger false positives on a massive scale by an “inverse-Sybil” attack, where a large number of devices (malicious users or hacked phones) pretend to be the same user, such that later, just a single person needs to be diagnosed (and allowed to upload) to trigger an alert for all users who were in proximity to any of this large group of devices.
We propose the first protocols that do not succumb to such attacks assuming the devices involved in the attack do not constantly communicate, which we observe is a necessary assumption. The high level idea of the protocols is to derive the values to be broadcasted by a hash chain, so that two (or more) devices who want to launch an inverse-Sybil attack will not be able to connect their respective chains and thus only one of them will be able to upload. Our protocols also achieve security against replay, belated replay, and one of them even against relay attacks.https://research-explorer.ista.ac.at/record/9826engSpringer Natureinfo:eu-repo/semantics/altIdentifier/doi/10.1007/978-3-030-75539-3_17info:eu-repo/semantics/altIdentifier/issn/03029743info:eu-repo/semantics/altIdentifier/issn/16113349info:eu-repo/semantics/altIdentifier/isbn/9783030755386info:eu-repo/grantAgreement/EC/H2020/665385info:eu-repo/grantAgreement/EC/H2020/682815info:eu-repo/semantics/openAccessAuerbach B, Chakraborty S, Klein K, et al. Inverse-Sybil attacks in automated contact tracing. In: <i>Topics in Cryptology – CT-RSA 2021</i>. Vol 12704. Springer Nature; 2021:399-421. doi:<a href="https://doi.org/10.1007/978-3-030-75539-3_17">10.1007/978-3-030-75539-3_17</a>Inverse-Sybil attacks in automated contact tracingLNCSinfo:eu-repo/semantics/conferenceObjectdoc-type:conferenceObjecttexthttp://purl.org/coar/resource_type/c_5794