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See detailCustomization of System Software for Large-scale Embedded Applications
Nehmer, Jürgen; Sturm, Peter; Baentsch, Michael et al

in Computer Communications (1997), 20

Detailed reference viewed: 88 (3 UL)
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See detailA cut finite element method for spatially resolved energy metabolism models in complex neuro-cell morphologies with minimal remeshing
Farina, Sofia UL; Claus, Susanne; Hale, Jack UL et al

in Advanced Modeling and Simulation in Engineering Sciences (2021), 8

A thorough understanding of brain metabolism is essential to tackle neurodegenerative diseases. Astrocytes are glial cells which play an important metabolic role by supplying neurons with energy. In ... [more ▼]

A thorough understanding of brain metabolism is essential to tackle neurodegenerative diseases. Astrocytes are glial cells which play an important metabolic role by supplying neurons with energy. In addition, astrocytes provide scaffolding and homeostatic functions to neighboring neurons and contribute to the blood–brain barrier. Recent investigations indicate that the complex morphology of astrocytes impacts upon their function and in particular the efficiency with which these cells metabolize nutrients and provide neurons with energy, but a systematic understanding is still elusive. Modelling and simulation represent an effective framework to address this challenge and to deepen our understanding of brain energy metabolism. This requires solving a set of metabolic partial differential equations on complex domains and remains a challenge. In this paper, we propose, test and verify a simple numerical method to solve a simplified model of metabolic pathways in astrocytes. The method can deal with arbitrarily complex cell morphologies and enables the rapid and simple modification of the model equations by users also without a deep knowledge in the numerical methods involved. The results obtained with the new method (CutFEM) are as accurate as the finite element method (FEM) whilst CutFEM disentangles the cell morphology from its discretisation, enabling us to deal with arbitrarily complex morphologies in two and three dimensions. [less ▲]

Detailed reference viewed: 108 (7 UL)
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See detailCut-and-Mouse and Ghost Control: Exploiting Antivirus Software with Synthesized Inputs
Genç, Ziya Alper UL; Lenzini, Gabriele UL; Sgandurra, Daniele

in Digital Threats: Research and Practice (2021), 2(1),

To protect their digital assets from malware attacks, most users and companies rely on antivirus (AV) software. AVs' protection is a full-time task against malware: This is similar to a game where malware ... [more ▼]

To protect their digital assets from malware attacks, most users and companies rely on antivirus (AV) software. AVs' protection is a full-time task against malware: This is similar to a game where malware, e.g., through obfuscation and polymorphism, denial of service attacks, and malformed packets and parameters, tries to circumvent AV defences or make them crash. However, AVs react by complementing signature-based detection with anomaly or behavioral analysis, and by using OS protection, standard code, and binary protection techniques. Further, malware counter-acts, for instance, by using adversarial inputs to avoid detection, and so on. In this cat-and-mouse game, a winning strategy is trying to anticipate the move of the adversary by looking into one's own weaknesses, seeing how the adversary can penetrate them, and building up appropriate defences or attacks. In this article, we play the role of malware developers and anticipate two novel moves for the malware side to demonstrate the weakness in the AVs and to improve the defences in AVs' side. The first one consists in simulating mouse events to control AVs, namely, to send them mouse "clicks" to deactivate their protection. We prove that many AVs can be disabled in this way, and we call this class of attacks Ghost Control. The second one consists in controlling whitelisted applications, such as Notepad, by sending them keyboard events (such as "copy-and-paste") to perform malicious operations on behalf of the malware. We prove that the anti-ransomware protection feature of AVs can be bypassed if we use Notepad as a "puppet" to rewrite the content of protected files as a ransomware would do. Playing with the words, and recalling the cat-and-mouse game, we call this class of attacks Cut-and-Mouse. We tested these two attacks on 29 AVs, and the results show that 14 AVs are vulnerable to Ghost Control attack while all 29 AV programs tested are found vulnerable to Cut-and-Mouse. Furthermore, we also show some weaknesses in additional protection mechanisms of AVs, such as sandboxing and CAPTCHA verification. We have engaged with the affected AV companies, and we reported the disclosure communication with them and their responses. [less ▲]

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See detailCut-Based Abduction
D'Agostino, G.-C.; Gabbay, Dov M. UL

in Journal of Logic and Computation (2008), 16(6), 537560

In this paper we explore a generalization of traditional abduction which can simultaneously perform two different tasks: (i) given an unprovable sequent G, find a sentence H such that, H G is provable ... [more ▼]

In this paper we explore a generalization of traditional abduction which can simultaneously perform two different tasks: (i) given an unprovable sequent G, find a sentence H such that, H G is provable (hypothesis generation); (ii) given a provable sequent G, find a sentence H such that H and the proof of , H G is simpler than the proof of G (lemma generation). We argue that the two tasks should not be distinguished,and present a general procedure for indingsuitable hypotheses or lemmas. When the original sequent is provable, the abduced formula can be seen asa cut formula with respect to Gentzen's sequent calculus, so the abduction method is cut-based. Our method is based on the tableau-like system KE and we argue for its advantages over existing abduction methods based on traditional Smullyan-styleTableaux. [less ▲]

Detailed reference viewed: 34 (1 UL)
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See detailCut-Elimination for Quantified Conditional Logic
Benzmüller, Christoph UL

in Journal of Philosophical Logic (2017), 46(3), 333353

A semantic embedding of quantified conditional logic in classical higher-order logic is utilized for reducing cut-elimination in the former logic to existing results for the latter logic. The presented ... [more ▼]

A semantic embedding of quantified conditional logic in classical higher-order logic is utilized for reducing cut-elimination in the former logic to existing results for the latter logic. The presented embedding approach is adaptable to a wide range of other logics, for many of which cut-elimination is still open. However, special attention has to be payed to cut-simulation, which may render cut-elimination as a pointless criterion. [less ▲]

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See detailA CutFEM Method for a spatial resolved energy metabolism model in complex cellular geometries
Farina, Sofia UL

Scientific Conference (2021, January)

Computational techniques have been widely used to tackle problems in the biological sciences. A com- promise between high quality simulations and simple but accurate models can help to understand un ... [more ▼]

Computational techniques have been widely used to tackle problems in the biological sciences. A com- promise between high quality simulations and simple but accurate models can help to understand un- known aspects of this field. In this work, we will show how the Cut Finite Element Method (CutFEM) [1] can be a powerful tool to solve a reaction diffusion PDE system that models the energy metabolism of a cell. The main difficulty to approach this problem is dealing with the morphology of the cell that can have sharp edges and evolves over time. While classical FEM requires the mesh conform to the domain boundary, CutFEM allows a non-conforming discretisation of the domain, and thus is especially suited for modeling complex and evolving cellular geometries. First, we introduce our simplified model for metabolic pathways taking place in a region small enough to consider the material property as homogeneous. The results obtained with FEM (FENICS Project [2][3]) and CutFEM suggest that the two methods are equivalent. This allows us to use CutFEM to increase the complexity of the domain, from a spherical shaped cell to an irregular astrocyte. We conclude that CutFEM is a robust method for tackling biological problems with complex geometries, opening the possibility to extend the complexity of our mathematical model including more features and to consider real cellular shapes that evolve in time in future work. [less ▲]

Detailed reference viewed: 96 (8 UL)
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See detailCutting in real time in corotational elasticity and perspectives on simulating cuts
Courtecuisse, H.; Kerfriden, P.; Bordas, Stéphane UL

Book published by Springer (2013)

We focus here on the simulation of surgical acts of types similar to cutting and needle insertion in soft tissue, in real time (500 Hz), where the scale of the surgical instrument is several orders of ... [more ▼]

We focus here on the simulation of surgical acts of types similar to cutting and needle insertion in soft tissue, in real time (500 Hz), where the scale of the surgical instrument is several orders of magnitude smaller than that of the organ. [less ▲]

Detailed reference viewed: 95 (0 UL)
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See detailCu–Zn disorder and band gap fluctuations in Cu2ZnSn(S,Se)4: Theoretical and experimental investigations
Scragg, Jonathan J. S.; Larsen, Jes K. UL; Kumar, Mukesh et al

in Physica Status Solidi B. Basic Research (2016), 253(2), 247-254

Detailed reference viewed: 166 (1 UL)
See detailLe Cvce.eu, une infrastructure numérique
Gabellini, Marco UL

Presentation (2017, December 18)

Présentation des publications numériques sur le processus de la construction européenne analysé dans une perspective transnationale et multidimensionnelle sur le site cvce.eu. Les collections de ... [more ▼]

Présentation des publications numériques sur le processus de la construction européenne analysé dans une perspective transnationale et multidimensionnelle sur le site cvce.eu. Les collections de publications thématiques et le programme d’histoire orale, comprenant près de 100 interviews de personnalités européennes, constituent une approche innovante de la construction européenne. [less ▲]

Detailed reference viewed: 46 (5 UL)
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See detailCVH Malach – Centrum vizuální historie Konference a workshop o novém přístupu a využití video databáze Fortunoff
Bronec, Jakub UL

in Marginalia Historica : Časopis pro Dějiny Vzdělanosti a Kultury (2020), 10(1/2019), 164-167

On May 18, I took part in a very interesting workshop organized by the Malach Centre for Visual History at the Faculty of Mathematics and Physics of the Charles University in Prague. This exceptional ... [more ▼]

On May 18, I took part in a very interesting workshop organized by the Malach Centre for Visual History at the Faculty of Mathematics and Physics of the Charles University in Prague. This exceptional association provides local access to the extensive digital archives of the USC Shoah Foundation - the Institute for Visual history and Education (USC), the Refugee Voices archive of the Association of Jewish Refugees and the testimony collection of the Jewish Holocaust Centre in Melbourne. Nevertheless, the workshop focused on the newly incorporated Fortunoff Video Archive (FVA) that belongs to the category of long-awaited ingestion, and the path to get a licence was more than difficult. The archive represents a new source for all scholars including me, but in this short comment, I would like to critically point out to several minor drawbacks. [less ▲]

Detailed reference viewed: 85 (10 UL)
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See detailCyber bullying among school aged children in Luxembourg
Steffgen, Georges UL; Pfetsch, Jan UL; König, Andreas UL et al

Scientific Conference (2009, August)

Detailed reference viewed: 92 (6 UL)
See detailCyber bullying in Luxemburg: Aus nationaler Sicht
Steffgen, Georges UL

Presentation (2007, November)

Detailed reference viewed: 65 (1 UL)
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See detailCyber bullying: Current research findings
Steffgen, Georges UL

Scientific Conference (2009, April)

Detailed reference viewed: 47 (0 UL)
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See detailCyber bullying: The role of empathy
Steffgen, Georges UL

Scientific Conference (2009, April)

Detailed reference viewed: 72 (0 UL)
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See detailCyber bullying: The role of traditional bullying and empathy
Steffgen, Georges UL; König, Andreas UL

in Sapeo, B.; Haddon, L.; Mante-Meijer, E. (Eds.) et al The good, the bad and the challenging. Conference Proceedings (Vol. II) (2009)

Detailed reference viewed: 397 (2 UL)
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See detailCyber Security and Vulnerability Analysis of Networked Control System subject to False-Data injection
Gerard, Benjamin; Bezzaoucha, Souad UL; Voos, Holger UL et al

in Proceedings of the 2018 American Control Conference (2018, June 27)

In the present paper, the problem of networked control system (NCS) cyber security is considered. The geometric approach is used to evaluate the security and vulnerability level of the controlled system ... [more ▼]

In the present paper, the problem of networked control system (NCS) cyber security is considered. The geometric approach is used to evaluate the security and vulnerability level of the controlled system. The proposed results are about the so-called false data injection attacks and show how imperfectly known disturbances can be used to perform undetectable, or at least stealthy, attacks that can make the NCS vulnerable to attacks from malicious outsiders. A numerical example is given to illustrate the approach. [less ▲]

Detailed reference viewed: 207 (9 UL)
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See detailCyber-attack detection based on controlled invariant sets
Rosich, Albert; Voos, Holger UL; Darouach, Mohamed

in European Control Conference (ECC), Strasbourg, France, 24-27 June 2014 (2014, June)

This paper explores a new method for detecting cyber-attacks on a controller. Specifically, the proposed detector is based on invariant sets in order to determine whether an attacker has hijacked the ... [more ▼]

This paper explores a new method for detecting cyber-attacks on a controller. Specifically, the proposed detector is based on invariant sets in order to determine whether an attacker has hijacked the controller and perpetrated a cyber-attack. One particularity of this detection method is that few information about the controller is required. Thus, the detector becomes useful for a large range of control laws and its vulnerability can be reduced by limiting its accessibility. Finally, a simple but significant example is presented in order to show the benefits and the flaws of the proposed methodology. [less ▲]

Detailed reference viewed: 152 (2 UL)
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See detailCyberbullying as an act of revenge?
König, Andreas UL; Gollwitzer, Mario; Steffgen, Georges UL

in Australian Journal of Guidance & Counselling (2010), 20(2), 210-224

Despite significant overlaps between victim status in traditional forms of bullying and cyberbullying, and qualitative results about self-reported reasons for cyberbullying, the role of revenge and ... [more ▼]

Despite significant overlaps between victim status in traditional forms of bullying and cyberbullying, and qualitative results about self-reported reasons for cyberbullying, the role of revenge and retaliation as a motive to engage in acts of cyberbullying has not yet been examined systematically. As a first step, this study investigates whether and to what extent traditional victims, when they become cyberbullies, actually choose their former (traditional) perpetrators as targets of their own cyberbullying behavior. Furthermore, the impact of individual differences in relevant traits, such as vengefulness and justice sensitivity, on the choice of cybervictims is examined. Data from 473 students were collected via an online survey. Of these, 149 were identified as traditional victims/cyberbullies. Results show that traditionally bullied students indeed tend to choose their former perpetrators as cybervictims, and that individual differences play a role in the choice of their victims. Implications for further research, as well as for interventions and prevention programmes, are discussed. [less ▲]

Detailed reference viewed: 292 (3 UL)
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See detailCyberbullying in the Benelux-Countries: First findings and ways to address the problem
Steffgen, Georges UL; Vandebosch, Heidi; Völlink, Trijntje et al

in Mora-Merchan, J.; Jäger, T. (Eds.) Cyberbullying: a cross-national comparison (2010)

Detailed reference viewed: 119 (3 UL)
See detailCyberbullying through the new media: Findings from an international network
Smith, Peter K.; Steffgen, Georges UL

Book published by Psychology Press (2013)

Detailed reference viewed: 460 (14 UL)