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See detailTopology-based Clusterhead Candidate Selection in Wireless Ad-hoc and Sensor Networks
Brust, Matthias R. UL; Andronache, Adrian; Rothkugel, Steffen UL et al

in Abstract book of 2nd IEEE/ACM International Workshop on Software for Sensor Networks (SensorWare 2007) (2007)

Detailed reference viewed: 84 (4 UL)
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See detail« Le topos de la lettre anonyme (de Laclos à Klossowski) »
Roelens, Nathalie UL

in Le topos du manuscrit trouvé (1999)

Detailed reference viewed: 53 (1 UL)
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See detailTorn Between Study and Leisure: How Motivational Conflicts Relate to Students' Academic and Social Adaptation
Grund, Axel UL; Brassler, Nina K.; Fries, Stefan

in Journal of Educational Psychology (2014), 106(1), 242-257

Research on motivational conflicts indicates that students' difficulties during studying may result from tempting alternatives in the leisure domain. In the present set of studies, we addressed the ... [more ▼]

Research on motivational conflicts indicates that students' difficulties during studying may result from tempting alternatives in the leisure domain. In the present set of studies, we addressed the question of whether academic motivation inversely has negative spillover effects on students' leisure-related functioning, too. In the first 2 studies (N = 169 and N = 206), the self-regulatory impairment students reported after the decision for studying or socializing in a predefined study-leisure conflict was related to their general academic and social adaptation. Results provide 1st evidence for domain-specific drawbacks in students' functioning, depending on which activity is interfered in situations of motivational conflict. In a 3rd study (N = 358), we replicated these findings based on idiographic conflicts. Furthermore, motivational interference is introduced as a crucial process that may underlie such adverse effects. It is demonstrated that after the decision for a focal action, the motivational strength of foregone alternatives continues to influence students' self-regulation during both study and leisure activities. Findings are discussed with regard to the connection between study and leisure strivings, motivational conflicts, and academic motivation. [less ▲]

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See detailTorn between want and should: An experience-sampling study on motivational conflict, well-being, self-control, and mindfulness
Grund, Axel UL; Grunschel, Carola; Bruhn, Dominik et al

in Motivation and Emotion (2015), 39(4), 506-520

We assumed that situations of motivational want conflict (i.e., feeling that one wants to do something else) and should conflict (i.e., thinking that one should do something else) show differential ... [more ▼]

We assumed that situations of motivational want conflict (i.e., feeling that one wants to do something else) and should conflict (i.e., thinking that one should do something else) show differential relationships to different components of well-being because more affective or more cognitive motivational aspects are ignored, respectively. Moreover, we assumed that these differences contribute to the understanding of different self-regulatory styles. Using an experience-sampling approach, 58 university students indicated their current affect, the underlying form of motivation, and whether they experienced a want or a should conflict regarding their daily activities (N = 2376). Furthermore, we assessed participants' self-control and mindfulness before and life satisfaction after the experience-sampling period. As expected, want conflicts came along with lower affective well-being, but were unrelated to cognitive life satisfaction. Although should conflicts also yielded a small, negative association with some aspects of affective well-being, overall, their negative relation with life satisfaction was more pronounced. Positive paths of self-control on affective well-being were mediated via less want and should conflicts, whereas positive paths of both mindfulness and self-control on life satisfaction were mediated via less should conflicts. The relative importance of want and should conflicts in daily self-regulation and well-being is discussed. [less ▲]

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See detailTOrPEDO: Witnessing Model Correctness with Topological Proofs
Menghi, Claudio UL; Rizzi, Alessandro Maria; Bernasconi, Anna et al

in Formal Aspects of Computing (in press)

Model design is not a linear, one-shot process. It proceeds through refinements and revisions. To effectively support developers in generating model refinements and revisions, it is desirable to have some ... [more ▼]

Model design is not a linear, one-shot process. It proceeds through refinements and revisions. To effectively support developers in generating model refinements and revisions, it is desirable to have some automated-support to verify evolvable models. To address this problem, we recently proposed to adopt topological proofs, which are slices of the original model that witness property satisfaction. We implemented TOrPEDO, a framework that provides automated support for using topological proofs during model design. Our results showed that topological proofs are significantly smaller than the original models, and that, in most of the cases, they allow the property to be re-verified by relying only on a simple syntactic check. However, our results also show that the procedure that computes topological proofs, which requires extracting unsatisfiable cores of LTL formulae, is computationally expensive. For this reason, TOrPEDO currently handles models with a small dimension. With the intent of providing practical and efficient support for flexible model design and wider adoption of our framework, in this paper, we propose an enhanced – re-engineered – version of TOrPEDO. The new version of TOrPEDO relies on a novel procedure to extract topological proofs, which has so far represented the bottleneck of TOrPEDO performances. We implemented our procedure within TOrPEDO by considering Partial Kripke Structures (PKSs) and Linear-time Temporal Logic (LTL): two widely used formalisms to express models with uncertain parts and their properties. To extract topological proofs, the new version of TOrPEDO converts the LTL formulae into an SMT instance and reuses an existing SMT solver (e.g., Microsoft Z3) to compute an unsatisfiable core. Then, the unsatisfiable core returned by the SMT solver is automatically processed to generate the topological proof. We evaluated TOrPEDO by assessing (i) how does the size of the proofs generated by TOrPEDO compares to the size of the models being analyzed; and (ii) how frequently the use of the topological proof returned by TOrPEDO avoids re-executing the model checker. Our results show that TOrPEDO provides proofs that are smaller (≈60%) than their respective initial models effectively supporting designers in creating model revisions. In a significant number of cases (≈79%), the topological proofs returned by TOrPEDO enable assessing the property satisfaction without re-running the model checker. We evaluated our new version of TOrPEDO by assessing (i) how it compares to the previous one; and (ii) how useful it is in supporting the evaluation of alternative design choices of (small) model instances in applied domains. The results show that the new version of TOrPEDO is significantly more efficient than the previous one and can compute topological proofs for models with less than 40 states within two hours. The topological proofs and counterexamples provided by TOrPEDO are useful to support the development of alternative design choices of (small) model instances in applied domains. [less ▲]

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See detailTorScan: Deanonymizing Connections Using Topology Leaks
Biryukov, Alex UL; Pustogarov, Ivan UL; Weinmann, Ralf-Philipp UL

in ERCIM News (2012), (90), 29-29

Tor is one of the most widely used tools for providing anonymity on the Internet. We have devised novel attacks against the Tor network that can compromise the anonymity of users accessing services that ... [more ▼]

Tor is one of the most widely used tools for providing anonymity on the Internet. We have devised novel attacks against the Tor network that can compromise the anonymity of users accessing services that exhibit frequent and predictable communication patterns and users establishing long-lived connections. [less ▲]

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See detailTorScan: Tracing Long-Lived Connections and Differential Scanning Attacks
Biryukov, Alex UL; Pustogarov, Ivan UL; Weinmann, Ralf-Philipp UL

in Computer Security - ESORICS 2012 - 17th European Symposium on Research in Computer Security (2012)

Tor is a widely used anonymity network providing low-latency communication capabilities. The anonymity provided by Tor heavily relies on the hardness of linking a user’s entry and exit nodes. If an ... [more ▼]

Tor is a widely used anonymity network providing low-latency communication capabilities. The anonymity provided by Tor heavily relies on the hardness of linking a user’s entry and exit nodes. If an attacker gains access to the topological information about the Tor network instead of having to consider the network as a fully connected graph, this anonymity may be reduced. In fact, we have found ways to probe the connectivity of a Tor relay. We demonstrate how the resulting leakage of the Tor network topology can be used in attacks which trace back a user from an exit relay to a small set of potential entry nodes. [less ▲]

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See detailTorsion and purity on non-integral schemes and singular sheaves in the fine Simpson moduli spaces of one-dimensional sheaves on the projective plane
Leytem, Alain UL

Doctoral thesis (2016)

This thesis consists of two individual parts, each one having an interest in itself, but which are also related to each other. In Part I we analyze the general notions of the torsion of a module over a ... [more ▼]

This thesis consists of two individual parts, each one having an interest in itself, but which are also related to each other. In Part I we analyze the general notions of the torsion of a module over a non-integral ring and the torsion of a sheaf on a non-integral scheme. We give an explicit definition of the torsion subsheaf of a quasi-coherent O_X-module and prove a condition under which it is also quasi-coherent. Using the associated primes of a module and the primary decomposition of ideals in Noetherian rings, we review the main criteria for torsion-freeness and purity of a sheaf that have been established by Grothendieck and Huybrechts-Lehn. These allow to study the relations between both concepts. It turns out that they are equivalent in "nice" situations, but they can be quite different as soon as the scheme does not have equidimensional components. We illustrate the main differences on various examples. We also discuss some properties of the restriction of a coherent sheaf to its annihilator and its Fitting support and finally prove that sheaves of pure dimension are torsion-free on their support, no matter which closed subscheme structure it is given. Part II deals with the problem of determining "how many" sheaves in the fine Simpson moduli spaces M = M_{dm-1}(P2) of stable sheaves on the projective plane P2 with linear Hilbert polynomial dm-1 for d\geq 4 are not locally free on their support. Such sheaves are called singular and form a closed subvariety M' in M. Using results of Maican and Drézet, the open subset M0 of sheaves in M without global sections may be identified with an open subvariety of a projective bundle over a variety of Kronecker modules N. By the Theorem of Hilbert-Burch we can describe sheaves in an open subvariety of M0 as twisted ideal sheaves of curves of degree d. In order to determine the singular ones, we look at ideals of points on planar curves. In the case of simple and fat curvilinear points, we characterize free ideals in terms of the absence of two coeffcients in the polynomial defining the curve. This allows to show that a generic fiber of M0\cap M' over N is a union of projective subspaces of codimension 2 and finally that M' is singular of codimension 2. [less ▲]

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See detailTorsion sur des familles de courbes de genre g
Leprévost, Franck UL

in Manuscripta Mathematica (1992), 75

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See detailTortos, emprestados e do coração: os avós por aliança
Ramos, Anne Carolina UL

in Copque, Bárbara; Peixoto, Clarice Ehlers; Luz, Gleice Mattos (Eds.) Famílias em imagens (2013)

Com o crescente número de divórcios e recomposições familiares, muitas crianças têm vivido em famílias reconstituídas ou presenciado a reconstituição do casamento de seus próprios avós. Nesses contextos ... [more ▼]

Com o crescente número de divórcios e recomposições familiares, muitas crianças têm vivido em famílias reconstituídas ou presenciado a reconstituição do casamento de seus próprios avós. Nesses contextos, entram em cena os avós sociais, que reconfiguram e redesenham as relações familiares, ampliando o leque de contato intergeracional das crianças. O relacionamento entre netos e avós sociais tende a se diferenciar amplamente daquele vivido com os avós naturais: enquanto esses últimos são biologicamente insubstituíveis, ocupando um lugar singular na história biográfica de cada criança, os avós por aliança refletem um elo que, longe de ser durável, depende das relações para existir. Neste artigo, as crianças nos mostram, por meio de suas falas e desenhos, como essas relações são significadas por elas e quais são os fatores que se atravessam na criação desses vínculos. [less ▲]

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See detailToshiaki Miyazaki: Pestalozzi und seine Lektüre. Entfaltung des Bewusstseins über Bildung, Schule und Gesellschaft
Tröhler, Daniel UL

in Zeitschrift für Pädagogik. Beiheft (1993), 39(6), 1030-1033

Detailed reference viewed: 60 (0 UL)
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See detailTotal degradation analysis of precoded signals onto non-linear satellite channels
Spano, Danilo UL; Christopoulos, Dimitrios UL; Andrenacci, Stefano UL et al

in 21st Ka Conference (2015, October)

Linear precoding exploits the spatial degrees of freedom offered by multi-antenna transmitters to manage interferences between multiple co-channel users. The adoption of precoding in practical systems ... [more ▼]

Linear precoding exploits the spatial degrees of freedom offered by multi-antenna transmitters to manage interferences between multiple co-channel users. The adoption of precoding in practical systems, however, entails a series of practical barriers. Amongst several issues, the focus herein is on the non-linear dependence of the input versus the output power of the efficient and reliable amplifiers that drive each transmit antenna, which limits the system performance. As a first step, the present work studies the impact of linear precoding on the peak-to-average power ratio (PAPR) of precoded waveforms in multibeam satellite systems using a finite alphabet. In this context, a sensitivity analysis of the PAPR at the input of each amplifier with respect to intrinsic system level parameters, such as the number of transmit feeds, is performed. Next, the performance of the whole non-linear satellite chain is analyzed with respect to the symbol-error-rate (SER) and the total degradation (TD) of the channel. Furthermore, two low-complexity solutions are considered for counteracting the effects of the non-linearities of the satellite channel on the precoded waveforms, namely an automatic gain control (AGC) operation and a non-linear equalization performed at the receiver side. [less ▲]

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See detailTotal Impact of Periodic Terms and Coloured Noise on Velocity Estimates
Klos, Anna; Olivares, German; Teferle, Felix Norman UL et al

Poster (2016, February 05)

The uncertainties of velocity estimates for position time series of Global Navigation Satellite System (GNSS) stations are mainly affected by a misfit of the deterministic model applied to this data ... [more ▼]

The uncertainties of velocity estimates for position time series of Global Navigation Satellite System (GNSS) stations are mainly affected by a misfit of the deterministic model applied to this data. Insufficiently modelled seasonal signals will propagate into the stochastic model and falsify the results of the noise analysis besides the velocity estimates and their uncertainties. In this presentation we derived the General Dilution of Precision (GDP) of velocity uncertainties. We define this dilution as the ratio between the uncertainties of velocities determined when different deterministic and stochastic models are applied. In this way we discuss, referring to previously published results, how insufficiently modelled seasonal signals influence station velocity uncertainties with white and coloured noise. Using simulated and real data from selected (115) IGS (International GNSS Service) stations we show that the noise character affects GNSS data more than seasonals for time series longer than 9 years. [less ▲]

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See detailTote leben länger Sakralisierung, Vergemeinschaftung und Gesellschaftskritik durch Monumente
Kmec, Sonja UL

in Mein, Georg; Sieburg, Heinz (Eds.) Medien des Wissens. Interdisziplinäre Aspekte von Medialität (2011)

Detailed reference viewed: 148 (14 UL)
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See detailTote Soldaten und ihre Gräber: Kriegs- und Militärfriedhöfe des Ersten Weltkrieges in Luxemburg
Kolnberger, Thomas UL

Article for general public (2018)

Während des Ersten Weltkrieges gehörte Luxemburg weder in die Gruppe der kriegsführenden Nationen noch war sein Territorium Teil der Kampffront gewesen. Trotzdem wurden hier hunderte deutsche ... [more ▼]

Während des Ersten Weltkrieges gehörte Luxemburg weder in die Gruppe der kriegsführenden Nationen noch war sein Territorium Teil der Kampffront gewesen. Trotzdem wurden hier hunderte deutsche, französische und US-amerikanische Soldaten begraben. Die meisten von ihnen wurden in der Nachkriegszeit exhumiert und innerhalb oder außerhalb des Großherzogtums ein zweites Mal bestattet. Dieser Artikel zeichnet die geschichtliche Entwicklung dieser Soldatengräberstätten in Luxemburg nach. Zitierung: Kolnberger, Thomas. "Tote Soldaten und ihre Gräber: Kriegs- und Militärfriedhöfe des Ersten Weltkrieges in Luxemburg" (2018). Éischte Weltkrich: https://ww1.lu [less ▲]

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See detailTotemic Immimanence
Van Der Walt, Johan Willem Gous UL

in Motha, Stewart (Ed.) Reading Modern Law (2012)

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See detailTotenhügel und Waldfriedhof - die Gräber und Friedhöfe für gefallene Wehrmachtssoldaten während des Zweiten Weltkriegs zwischen individueller Gräberfürsorge und nationalsozialistischem Totenkult
Janz, Nina UL

in RIHA Journal (2017)

The German soldiers who fell during the Second World War were buried in large cemetery complexes throughout Europe. Construction and design guidelines drawn up by the Wehrmacht itself put national ... [more ▼]

The German soldiers who fell during the Second World War were buried in large cemetery complexes throughout Europe. Construction and design guidelines drawn up by the Wehrmacht itself put national socialist ideology into a concrete form, furthering the myth of sacrifice for the fatherland. Hitler appointed a special architect, Wilhelm Kreis, to design gigantic memorials. In the course of the war both the Wehrmacht and the architect had to adjust their plans to the realities of war; the "heroic" plans could not be realized. [less ▲]

Detailed reference viewed: 91 (4 UL)
See detailTotes Lernen für das Leben? Zur Krise und geplanten Reformierung des taiwanesischen Bildungssystems.
Hu, Adelheid UL

in Schneider, A.; Schubert, G. (Eds.) Taiwan an der Schwelle zum 21. Jahrhundert - Gesellschaftlicher Wandel, Probleme und Perspektiven eines asiatischen Schwellenlandes. (1996)

Detailed reference viewed: 57 (0 UL)