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See detailLa conversion de CO2, NOx et/ou SO2 en utilisant la technologie du charbon actif
Chaouni, Wafaâ

Doctoral thesis (2016)

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See detailConversion from Arithmetic to Boolean Masking with Logarithmic Complexity
Coron, Jean-Sébastien UL; Groszschädl, Johann UL; Tibouchi, Mehdi et al

in Leander, Gregor (Ed.) Fast Software Encryption, 22nd International Workshop, FSE 2015, Istanbul, Turkey, March 8-11, 2015, Revised Selected Papers (2015, March)

A general technique to protect a cryptographic algorithm against side-channel attacks consists in masking all intermediate variables with a random value. For cryptographic algorithms combining Boolean ... [more ▼]

A general technique to protect a cryptographic algorithm against side-channel attacks consists in masking all intermediate variables with a random value. For cryptographic algorithms combining Boolean operations with arithmetic operations, one must then perform conversions between Boolean masking and arithmetic masking. At CHES 2001, Goubin described a very elegant algorithm for converting from Boolean masking to arithmetic masking, with only a constant number of operations. Goubin also described an algorithm for converting from arithmetic to Boolean masking, but with O(k) operations where k is the addition bit size. In this paper we describe an improved algorithm with time complexity O(log k) only. Our new algorithm is based on the Kogge-Stone carry look-ahead adder, which computes the carry signal in O(log k) instead of O(k) for the classical ripple carry adder. We also describe an algorithm for performing arithmetic addition modulo 2^k directly on Boolean shares, with the same complexity O(log k) instead of O(k). We prove the security of our new algorithm against first-order attacks. Our algorithm performs well in practice, as for k=64 we obtain a 23% improvement compared to Goubin’s algorithm. [less ▲]

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See detailConversion of non-proliferating astrocytes into neurogenic neural stem cells: control by FGF2 and IFN-gamma
Kleiderman, Susanne; Gutbier, Simon; Tufekci, Kemal U. et al

in Stem Cells (2016), 34(12), 28612874

Conversion of astrocytes to neurons, via de-differentiation to neural stem cells (NSC), may be a new approach to treat neurodegenerative diseases and brain injuries. The signaling factors affecting such a ... [more ▼]

Conversion of astrocytes to neurons, via de-differentiation to neural stem cells (NSC), may be a new approach to treat neurodegenerative diseases and brain injuries. The signaling factors affecting such a cell conversion are poorly understood, and they are hard to identify in complex disease models or conventional cell cultures. To address this question, we developed a serum-free, strictly controlled culture system of pure and homogeneous ‘astrocytes generated form murine embryonic stem cells (ESC)’. These stem cell derived astrocytes (mAGES), as well as standard primary astrocytes resumed proliferation upon addition of FGF. The signaling of FGF receptor tyrosine kinase converted GFAP-positive mAGES to nestin-positive NSC. ERK phosphorylation was necessary, but not sufficient, for cell cycle re-entry, as EGF triggered no de-differentiation. The NSC obtained by de-differentiation of mAGES were similar to those obtained directly by differentiation of ESC, as evidenced by standard phenotyping, and also by transcriptome mapping, metabolic profiling, and by differentiation to neurons or astrocytes. The de-differentiation was negatively affected by inflammatory mediators, and in particular, interferon gamma (IFNγ) strongly impaired the formation of NSC from mAGES by a pathway involving phosphorylation of STAT1, but not the generation of nitric oxide. Thus, two antagonistic signaling pathways were identified here that affect fate conversion of astrocytes independent of genetic manipulation. The complex interplay of the respective signaling molecules that promote/inhibit astrocyte de-differentiation may explain why astrocytes do not readily form neural stem cells in most diseases. Increased knowledge of such factors may provide therapeutic opportunities to favor such conversions. [less ▲]

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See detailConversion of Security Proofs from One Leakage Model to Another: A New Issue
Coron, Jean-Sébastien UL; Christophe, Giraud; Emmanuel, Prouff et al

in Proceedings of COSADE 2012 (2012)

To guarantee the security of a cryptographic implementation against Side Channel Attacks, a common approach is to formally prove the security of the corresponding scheme in a model as pertinent as ... [more ▼]

To guarantee the security of a cryptographic implementation against Side Channel Attacks, a common approach is to formally prove the security of the corresponding scheme in a model as pertinent as possible. Nowadays, security proofs for masking schemes in the literature are usually conducted for models where only the manipulated data are assumed to leak. However in practice, the leakage is better modeled encompassing the memory transitions as e.g. the Hamming distance model. From this observation, a natural question is to decide at which extent a countermeasure proved to be secure in the first model stays secure in the second. In this paper, we look at this issue and we show that it must definitely be taken into account. Indeed, we show that a countermeasure proved to be secure against second-order side-channel attacks in the first model becomes vulnerable against a first-order side-channel attack in the second model. Our result emphasize the issue of porting an implementation from devices leaking only on the manipulated data to devices leaking on the memory transitions. [less ▲]

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See detailConversione del contratto e rapporti di lavoro. Trasformazione e sanzione nel trattamento delle invalidità dei contratti di lavoro
Ratti, Luca UL

Book published by Giappichelli (2017)

Il titolo del libro separa in endiadi un’espressione unitaria – conversione del contratto di lavoro – tanto ricorrente nel linguaggio comune e nella prassi quanto ritenuta inaccoglibile sul piano ... [more ▼]

Il titolo del libro separa in endiadi un’espressione unitaria – conversione del contratto di lavoro – tanto ricorrente nel linguaggio comune e nella prassi quanto ritenuta inaccoglibile sul piano giuridico. L’accostamento della tecnica della conversione del contratto alla disciplina dei rapporti di lavoro è volto a segnalare, almeno in ipotesi, una certa contrapposizione tra la fattispecie di cui all’art. 1424 c.c. e le norme del diritto del lavoro che implicano l’invalidazione del contratto originario e ne prospettano una proiezione futura. Sullo sfondo di tale meccanismo si registrano risultanze normative che negli anni recenti hanno mutato sensibilmente la fisionomia, l’estensione e gli equilibri interni della legislazione lavoristica. Tra queste, la progressiva individualizzazione del diritto del lavoro si è manifestata attraverso un tentativo di ridurre l’importanza della contrattazione collettiva e un ritorno al contratto individuale quale fonte di regolazione del rapporto di lavoro, fattori che hanno favorito l’accentuarsi di un’interazione più diretta fra legge e autonomia individuale. In misura crescente si sono così rilevati momenti di tensione tra uguaglianza e libertà, tra eteronomia e autonomia. Confrontandosi con tali mutamenti, il libro mira a raccogliere i diversi significati dell’espressione “conversione del contratto” impiegati nel diritto del lavoro per proporne una sistemazione ordinata, in linea con i caratteri tipici del rapporto fra norma invalidante e aspirazione ad assicurare ove possibile la continuità del rapporto di lavoro. [less ▲]

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See detailLa convertibilité des monnaies en Afrique Subsaharienne hors zone franc
Bourgain, Arnaud UL

in Mondes en Développement (1996), 24(94), 71-84

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See detailConvex Capital Requirements for Large Portfolios
Föllmer, Hans UL; Knispel, Thomas

in Stochastic Analysis and Applications to Finance. Essays in Honour of Jia-an Yan (2012)

For a large homogeneous portfolio of financial positions, we study the asymptotic behavior of the capital requirement per position defined in terms of a convex monetary risk measure. In an actuarial ... [more ▼]

For a large homogeneous portfolio of financial positions, we study the asymptotic behavior of the capital requirement per position defined in terms of a convex monetary risk measure. In an actuarial context, this capital requirement can be seen as a premium per contract. We show that the premia converge to the fair premium as the portfolio becomes large, and we give a precise description of the decay of the risk premia. The analysis is carried out first for a law-invariant convex risk measure and then in a situation of model ambiguity. [less ▲]

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See detailConvex Combination of Constraint Vectors for Set-membership Affine Projection Algorithms
Nagashima Ferreira, Tadeu; Alves Martins, Wallace UL; Lima, Markus et al

in Proc. of IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) (2019, May)

Set-membership affine projection (SM-AP) adaptive filters have been increasingly employed in the context of online data-selective learning. A key aspect for their good performance in terms of both ... [more ▼]

Set-membership affine projection (SM-AP) adaptive filters have been increasingly employed in the context of online data-selective learning. A key aspect for their good performance in terms of both convergence speed and steady-state mean-squared error is the choice of the so-called constraint vector. Optimal constraint vectors were recently proposed relying on convex optimization tools, which might some- times lead to prohibitive computational burden. This paper proposes a convex combination of simpler constraint vectors whose performance approaches the optimal solution closely, utilizing much fewer computations. Some illustrative examples confirm that the sub-optimal solution follows the accomplishments of the optimal one. [less ▲]

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See detailThe convex core of quasifuchsian manifolds with particles
Lecuire, Cyril; Schlenker, Jean-Marc UL

in Geometry & Topology (2014), 18(4), 2309--2373

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See detailConvex Optimization-based Beamforming: From Receive to Transmit and Network Designs
Gershman, Alex B.; Sidiropoulos, Nicholas D.; Shahbazpanahi, Shahram et al

in IEEE Signal Processing Magazine (2010), 27(3), 62-75

In this article, an overview of advanced convex optimization approaches to multisensor beamforming is presented, and connections are drawn between different types of optimization-based beamformers that ... [more ▼]

In this article, an overview of advanced convex optimization approaches to multisensor beamforming is presented, and connections are drawn between different types of optimization-based beamformers that apply to a broad class of receive, transmit, and network beamformer design problems. It is demonstrated that convex optimization provides an indispensable set of tools for beamforming, enabling rigorous formulation and effective solution of both long-standing and emerging design problems. [less ▲]

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See detailConvex Risk Measures: Basic Facts, Law-invariance and beyond, Asymptotics for Large Portfolios
Föllmer, Hans UL; Knispel, Thomas

in MacLean, Leonard C.; Ziemba, William T. (Eds.) Handbook of the Fundamentals of Financial Decision Making (2013)

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See detailConvexity of probit weights
Schumann, Martin; Tripathi, Gautam UL

in Statistics and Probability Letters (2018), 143

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See detailConvivial ambient technologies: Requirements, ontology, and design
Caire, Patrice UL; van der Torre, Leon UL

in The Computer Journal (2010), 53(8), 12291256

In this paper we discuss the use of the social concept ‘conviviality’ for computer science in general, and for the development of ambient technologies in particular. First, we give a survey of the use of ... [more ▼]

In this paper we discuss the use of the social concept ‘conviviality’ for computer science in general, and for the development of ambient technologies in particular. First, we give a survey of the use of the concept ‘conviviality’ in the social sciences. Conviviality is usually considered a positive concept related to sociability. However, further analysis reveals a negative side related to lack of diversity, privacy and ethical issues. Second, we argue that conviviality requirements for ambient intelligence are challenging, because ambient technologies give rise to a new virtual and social reality, and conviviality issues play a central role in applications that are concerned with the interaction of material, virtual and social realities. Conviviality highlights an important challenge that we illustrate with examples that emphasize ethical issues, such as privacy threats, surveillance of users and identity theft. Intelligent interfaces, for example, allow instant interactions and thereby create strong needs for coordination and regulation mechanisms that have to be addressed to ensure the safeguard of individuals against abuses, such as privacy intrusions and identity manipulations. Third, we propose a conviviality ontology by operationalizing the fuzzy concept of ‘conviviality,’ such that it can be used in computer science in the same way as other social concepts such as ‘service,’ ‘contract’ or ‘trust’ are used in this area. Conviviality is defined using dependence networks, and tools for conviviality are based on, what we call, conviviality masks. Fourth, we illustrate how convivial ambient intelligence applications can be designed using our operationalized concept of conviviality. We illustrate our arguments and contributions with a running example on the use of ambient technologies in digital cities, as a prototypical example where material reality such as ambient technologies interacts with virtual and social realities. [less ▲]

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See detailConviviality by Design
Caire, Patrice UL; Bikakis, Antonis; Efthymiou, Vasileios UL

in Social computing, Social cognition, social networks Acquisition, representation and reasoning with contextualized knowledge (ARCOE 2012) (2012)

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See detailConviviality masks in multiagent systems
Caire, Patrice UL; Villata, Serena; Boella, Guido et al

in Conviviality Masks in Multiagent Systems (2008)

In this paper we study tools for conviviality to develop user-friendly multiagent systems. First, we show how to use the social-cognitive concept of conviviality in multiagent system technology by ... [more ▼]

In this paper we study tools for conviviality to develop user-friendly multiagent systems. First, we show how to use the social-cognitive concept of conviviality in multiagent system technology by relating it to agent power and social dependence networks. Second, we de- fine conviviality masks as transformations of social dependencies by hiding power relations and social structures to facilitate social interactions. Third, we introduce dynamic dependence networks to model the creation of conviviality using conviviality masks. We illustrate the use of conviviality masks with a multiagent telecon- ferencing application for virtual worlds. [less ▲]

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See detailA Conviviality Measure for Early Requirement Phase of Multiagent System Design
Caire, Patrice UL; van der Torre, Leon UL

in Normative Multiagent Systems (2009)

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See detailConviviality Measures
Caire, Patrice UL; Alcalde, Baptiste UL; van der Torre, Leon UL et al

in Proc. of 10th Int. Conf. on Autonomous Agents and Multiagent Systems (AAMAS 2011) (2011)

Conviviality has been introduced as a social science concept for multiagent systems to highlight soft qualitative requirements like user friendliness of systems. In this paper we introduce formal ... [more ▼]

Conviviality has been introduced as a social science concept for multiagent systems to highlight soft qualitative requirements like user friendliness of systems. In this paper we introduce formal conviviality measures for dependence networks using a coalitional game theoretic framework, which we contrast with more traditional efficiency and stability measures. Roughly, more opportunities to work with other people increases the conviviality, whereas larger coalitions may decrease the efficiency or stability of these involved coalitions. We first introduce assumptions and requirements, then we introduce a classification, and finally we introduce the conviviality measures. We use a running example from robotics to illustrate the measures. [less ▲]

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See detailConviviality-Driven Access Control Policy
El Kateb, Donia UL; Zannone, Nicola; Moawad, Assaad UL et al

in Requirements Engineering (2014)

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See detailConviviality-driven access control policy
El Kateb, Donia UL; Zannone, N.; Moawad, Assaad UL et al

in Requirements Engineering (2015), 20(4), 363-382

Nowadays many organizations experience security incidents due to unauthorized access to information. To reduce the risk of such incidents, security policies are often employed to regulate access to ... [more ▼]

Nowadays many organizations experience security incidents due to unauthorized access to information. To reduce the risk of such incidents, security policies are often employed to regulate access to information. Such policies, however, are often too restrictive, and users do not have the rights necessary to perform assigned duties. As a consequence, access control mechanisms are perceived by users as a barrier and thus bypassed, making the system insecure. In this paper, we draw a bridge between the social concept of conviviality and access control. Conviviality has been introduced as a social science concept for ambient intelligence and multi-agent systems to highlight soft qualitative requirements like user-friendliness of systems. To bridge the gap between conviviality and security, we propose a methodological framework for updating and adapting access control policies based on conviviality recommendations. Our methodology integrates and extends existing techniques to assist system designers in the derivation of access control policies from socio-technical requirements of the system, while taking into account the conviviality of the system. We illustrate our framework using the Ambient Assisted Living use case from the HotCity of Luxembourg. © 2014, Springer-Verlag London. [less ▲]

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See detailLe coopérateur ouvrier ou la signification du principe de double qualité dans les SCOP
Hiez, David UL

in Revue Internationale de l'Economie Sociale : Recma, Revue des Etudes Coopératives, Mutualistes et Associatives (2006), (299),

Detailed reference viewed: 62 (0 UL)