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See detailVeryVote: A Voter Verifiable Code Voting System
Joaquim, Rui UL; Ribeiro, Carlos; Ferreira, Paulo

in Ryan, Petery A.; Schoenmakers, Berry (Eds.) E-Voting and Identity (2009)

Code voting is a technique used to address the secure platform problem of remote voting. A code voting system consists in secretly sending, e.g. by mail, code sheets to voters that map their choices to ... [more ▼]

Code voting is a technique used to address the secure platform problem of remote voting. A code voting system consists in secretly sending, e.g. by mail, code sheets to voters that map their choices to entry codes in their ballot. While voting, the voter uses the code sheet to know what code to enter in order to vote for a particular candidate. In effect, the voter does the vote encryption and, since no malicious software on the PC has access to the code sheet it is not able to change the voter’s intention. However, without compromising the voter’s privacy, the vote codes are not enough to prove that the vote is recorded and counted as cast by the election server. We present a voter verifiable code voting solution which, without revealing the voter’s vote, allows the voter to verify, at the end of the election, that her vote was cast and counted as intended by just performing the match of a few small strings. Moreover, w.r.t. a general code voting system, our solution comes with only a minor change in the voting interaction. [less ▲]

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See detailVerzerrte Aufmerksamkeitslenkung auf Heroinreize bei opioidsubstituierten Patienten
Degen, B.; Schächinger, H.; Albrich, J. et al

in Sucht (2008), 54(3), 155-155

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See detailVerzerrte Aufmerksamkeitslenkung auf Heroinreize bei opioidsubstituierten Patienten
Degen, B.; Schächinger, H.; Albrich, J. et al

in Nervenarzt (2008), 79(Supplement 4), 300-300

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See detailVesicle dynamics in confined steady and harmonically modulated Poiseuille flows
Boujja, Z.; Misbah, C.; Ez-Zahraouy, H. et al

in Physics Reviews (2018)

Detailed reference viewed: 90 (0 UL)
See detailThe viability of C-tests: Which place do they have among other language tests?
Reichert, Monique UL

Presentation (2018, November 17)

C-tests are language tests that consist of a small number of short texts. In each one of those texts, and starting with the second sentence, the second half of each second word is omitted, and test takers ... [more ▼]

C-tests are language tests that consist of a small number of short texts. In each one of those texts, and starting with the second sentence, the second half of each second word is omitted, and test takers are asked to provide the missing word parts. In addition to their appealing characteristic as language measurement instruments which are easy to create, administer and score, they generally yield highly objective and reliable results. These features might explain why C-tests have in the meantime been used for a multitude of purposes and languages. However, the recurrent question about the validity of C-tests makes aware that caution needs to be exercised with regard to the contexts in which these language tests can ideally be used. The presentation will give an introduction about the process(es) of c-test development, and highlight different purposes for which C-tests can be used by placing them in the context of other, more “classical” language tests. [less ▲]

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See detailEl viaje peripatético de la educación en un mundo globalizado y "educacionalizado”
Bruno-Jofré, Rosa; Tröhler, Daniel UL

in Pensamiento Educativo : Revista de Investigación Educacional Latinoamericana = Pensamiento Educativo : Journal of Latinamerican Educational Research (2014), 51(1), 1-102

Detailed reference viewed: 370 (1 UL)
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See detailVianden
Margue, Michel UL

in Paravicini, Werner (Ed.) Höfe und Residenzen im spätmittelalterlichen Reich. Grafen und Herren (2012)

Detailed reference viewed: 95 (7 UL)
See detailVianden - Funktionen einer Burg im Wandel der Geschichte
Kreutz, Bernhard René UL

in Wagener, Olaf (Ed.) Burgen und Befestigungen in der Eifel. Von der Antike bis ins 20. Jahrhundert. Akten der 8. wissenschaftlichen Tagung in Oberfell (2013)

Detailed reference viewed: 108 (12 UL)
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See detailVianden 1308. Der Viandener "Freiheitsbrief" in seinem historischen Kontext
Margue, Michel UL

in 700 Joor Veinen (2009)

Detailed reference viewed: 123 (4 UL)
See detailVianden – Funktionen einer Burg im Wandel.
Kreutz, Bernhard René UL

Scientific Conference (2012, June 12)

Detailed reference viewed: 41 (3 UL)
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See detailVibration of functionally graded material plates with cutouts & cracks in thermal environment
Rahimabadi, A. A.; Natarajan, S.; Bordas, Stéphane UL

in Key Engineering Materials (2013), 560

In this paper, the effect of a centrally located cutout (circular and elliptical) and cracks emanating from the cutout on the free flexural vibration behaviour of functionally graded material plates in ... [more ▼]

In this paper, the effect of a centrally located cutout (circular and elliptical) and cracks emanating from the cutout on the free flexural vibration behaviour of functionally graded material plates in thermal environment is studied. The discontinuity surface is represented independent of the mesh by exploiting the partition of unity method framework. A Heaviside function is used to capture the jump in the displacement across the discontinuity surface and asymptotic branch functions are used to capture the singularity around the crack tip. An enriched shear flexible 4-noded quadrilateral element is used for the spatial discretization. The properties are assumed to vary only in the thickness direction. The effective properties of the functionally graded material are estimated using the Mori-Tanaka homogenization scheme and the plate kinematics is based on the first order shear deformation theory. The influence of the plate geometry, the geometry of the cutout, the crack length, the thermal gradient and the boundary conditions on the free flexural vibration is numerically studied. © (2013) Trans Tech Publications, Switzerland. [less ▲]

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See detailVibrational and optical properties of MoS2: From monolayer to bulk
Molina-Sanchez, Alejandro UL; Hummer, Kerstin; Wirtz, Ludger UL

in Surface Science Reports (2015), 70(4), 554-586

Molybdenum disulfide, MoS2, has recently gained considerable attention as a layered material where neighboring layers are only weakly interacting and can easily slide against each other. Therefore ... [more ▼]

Molybdenum disulfide, MoS2, has recently gained considerable attention as a layered material where neighboring layers are only weakly interacting and can easily slide against each other. Therefore, mechanical exfoliation allows the fabrication of single and multi-layers and opens the possibility to generate atomically thin crystals with outstanding properties. In contrast to graphene, it has an optical gap of ~1.9 eV. This makes it a prominent candidate for transistor and opto-electronic applications. Single-layer MoS2 exhibits remarkably different physical properties compared to bulk MoS2 due to the absence of interlayer hybridization. For instance, while the band gap of bulk and multi-layer MoS2 is indirect, it becomes direct with decreasing number of layers. In this review, we analyze from a theoretical point of view the electronic, optical, and vibrational properties of single-layer, few-layer and bulk MoS2. In particular, we focus on the effects of spin–orbit interaction, number of layers, and applied tensile strain on the vibrational and optical properties. We examine the results obtained by different methodologies, mainly ab initio approaches. We also discuss which approximations are suitable for MoS2 and layered materials. The effect of external strain on the band gap of single-layer MoS2 and the crossover from indirect to direct band gap is investigated. We analyze the excitonic effects on the absorption spectra. The main features, such as the double peak at the absorption threshold and the high-energy exciton are presented. Furthermore, we report on the the phonon dispersion relations of single-layer, few-layer and bulk MoS2. Based on the latter, we explain the behavior of the Raman-active A1gA1g and View the MathML sourceE2g1 modes as a function of the number of layers. Finally, we compare theoretical and experimental results of Raman, photoluminescence, and optical-absorption spectroscopy. [less ▲]

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See detailVibrational properties of boron nitride nanotubes: Effects of finite length and bundling
Wirtz, Ludger UL; Rubio, A.

in IEEE Transactions on Nanotechnology (2003), 2

We present ab initio calculations of phonons in single-wall. boron nitride nanotubes. Raman and infrared active modes of isolated and infinitely long tubes are evaluated according to the non-symmorphic ... [more ▼]

We present ab initio calculations of phonons in single-wall. boron nitride nanotubes. Raman and infrared active modes of isolated and infinitely long tubes are evaluated according to the non-symmorphic rod groups of BN nanotubes. For tubes of finite length, the selection rules are less restrictive and give rise to additional modes which may be observed in Raman and IR spectroscopy with an intensity depending on the tube length. Bundling of tubes is shown to have little effect on the phonon frequencies. However, arranging tubes in a large periodic array (larger than the wave-length of incoming light) gives rise to a strong frequency shift (LO-TO splitting) of some modes due to the establishing of a macroscopic electric field. Modes of A(1) symmetry experience a shift for laser light along the tube axis and E-1 modes are split for light incidence in the perpendicular direction. [less ▲]

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See detailVibrational properties of hexagonal boron nitride: Inelastic X-ray scattering and ab initio calculations
Serrano, J.; Bosak, A.; Arenal, R. et al

in Physical Review Letters (2007), 98(9), 095503

The phonon dispersion relations of bulk hexagonal boron nitride have been determined from inelastic x-ray scattering measurements and analyzed by ab initio calculations. Experimental data and calculations ... [more ▼]

The phonon dispersion relations of bulk hexagonal boron nitride have been determined from inelastic x-ray scattering measurements and analyzed by ab initio calculations. Experimental data and calculations show an outstanding agreement and reconcile the controversies raised by recent experimental data obtained by electron-energy loss spectroscopy and second-order Raman scattering. [less ▲]

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See detailVibrational properties of LaNiO3 films in the ultrathin regime
Schober, Alexander; Fowlie, Jennifer; Guennou, Mael UL et al

in APL Materials (2020)

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See detailVibrational properties of LaNiO3 films in the ultrathin regime
Schober, Alexander; Fowlie, Jennifer; Guennou, Mael UL et al

in APL MATERIALS (2020), 8(6),

Collective rotations and tilts of oxygen polyhedra play a crucial role in the physical properties of complex oxides such as magnetism and conductivity. Such rotations can be tuned by preparing thin films ... [more ▼]

Collective rotations and tilts of oxygen polyhedra play a crucial role in the physical properties of complex oxides such as magnetism and conductivity. Such rotations can be tuned by preparing thin films in which dimensionality, strain, and interface effects come into play. However, little is known of the tilt and rotational distortions in films a few unit cells thick including the question of if coherent tilt patterns survive at all in this ultrathin limit. Here, a series of films of perovskite LaNiO3 is studied and it is shown that the phonon mode related to oxygen octahedral tilts can be followed by Raman spectroscopy down to a film thickness of three pseudocubic perovskite unit cells (similar to 1.2 nm). To push the limits of resolution to the ultrathin regime, a statistical analysis method is introduced to separate the Raman signals of the film and substrate. Most interestingly, these analyses reveal a pronounced hardening of the tilt vibrational mode in the thinnest films. A comparison between the experimental results, first principles simulations of the atomic structure, and the standing wave model, which accounts for size effects on the phononic properties, reveals that in the ultrathin regime, the Raman spectra are a hybrid entity of both the bulk and surface phononic behavior. These results showcase Raman spectroscopy as a powerful tool to probe the behavior of perovskite films down to the ultrathin limit. [less ▲]

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See detailVibrations due to hydroshield tunnelling
Van Baars, Stefan UL

in Proceedings of the 9th International Conference on Structural Dynamics, EURODYN 2014 (2014, June)

The Hubertus tunnel in Den Hague, the Netherlands, is a 1.5 km long bored tunnel, mostly below groundwater level, constructed with a hydro-shield Tunnel Boring Machine in 2006 and 2007. The vibrations due ... [more ▼]

The Hubertus tunnel in Den Hague, the Netherlands, is a 1.5 km long bored tunnel, mostly below groundwater level, constructed with a hydro-shield Tunnel Boring Machine in 2006 and 2007. The vibrations due to the tunnelling have been recorded both inside the tunnel and at ground surface. No harmful vibrations were observed while the Hubertus tunnel was being bored, although unexpected vibration nuisance did occur. This is an effect that is widely known when tunnelling in rock, but was not expected when tunnelling in beach sand. Analyses of the recorded vibrations showed that the vibrations were mainly caused by the trembling motion of the TBM in the sand as a result of the stick-slip effect. This creates shear waves along the TBM shaft and pressure waves at the bore front. Both waves travel in an axial direction. [less ▲]

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See detailVicarious pain while observing another in pain: an experimental approach.
Vandenbroucke, S.; Crombez, G.; Van Ryckeghem, Dimitri UL et al

in Frontiers in human neuroscience (2013), 7

OBJECTIVE: This study aimed at developing an experimental paradigm to assess vicarious pain experiences. We further explored the putative moderating role of observer's characteristics such as ... [more ▼]

OBJECTIVE: This study aimed at developing an experimental paradigm to assess vicarious pain experiences. We further explored the putative moderating role of observer's characteristics such as hypervigilance for pain and dispositional empathy. METHODS: Two experiments are reported using a similar procedure. Undergraduate students were selected based upon whether they reported vicarious pain in daily life, and categorized into a pain responder group or a comparison group. Participants were presented a series of videos showing hands being pricked whilst receiving occasionally pricking (electrocutaneous) stimuli themselves. In congruent trials, pricking and visual stimuli were applied to the same spatial location. In incongruent trials, pricking and visual stimuli were in the opposite spatial location. Participants were required to report on which location they felt a pricking sensation. Of primary interest was the effect of viewing another in pain upon vicarious pain errors, i.e., the number of trials in which an illusionary sensation was reported. Furthermore, we explored the effect of individual differences in hypervigilance to pain, dispositional empathy and the rubber hand illusion (RHI) upon vicarious pain errors. RESULTS: RESULTS of both experiments indicated that the number of vicarious pain errors was overall low. In line with expectations, the number of vicarious pain errors was higher in the pain responder group than in the comparison group. Self-reported hypervigilance for pain lowered the probability of reporting vicarious pain errors in the pain responder group, but dispositional empathy and the RHI did not. CONCLUSION: Our paradigm allows measuring vicarious pain experiences in students. However, the prevalence of vicarious experiences of pain is low, and only a small percentage of participants display the phenomenon. It remains however unknown which variables affect its occurrence. [less ▲]

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See detailVicarious Viewing Time: Prolonged Response Latencies for Sexually Attractive Targets as a Function of Task- or Stimulus-Specific Processing
Imhoff, Roland; Schmidt, Alexander F. UL; Weiss, Simone et al

in ARCHIVES OF SEXUAL BEHAVIOR (2012), 41(6), 1389-1401

The amount of time an individual spends gazing at images is longer if the depicted person is sexually appealing. Despite an increasing use of such response latencies as a diagnostic tool in applied ... [more ▼]

The amount of time an individual spends gazing at images is longer if the depicted person is sexually appealing. Despite an increasing use of such response latencies as a diagnostic tool in applied forensic settings, the underlying processes that drive the seemingly robust effect of longer response latencies for sexually attractive targets remain unknown. In the current study, two alternative explanations are presented and tested using an adapted viewing time paradigm that disentangled task- and stimulus-specific processes. Heterosexual and homosexual male participants were instructed to rate the sexual attractiveness of target persons differing in sex and sexual maturation from four experimentally assigned perspectives-heterosexual and homosexual perspectives for both sexes. This vicarious viewing time paradigm facilitated the estimation of the independent contributions of task (assigned perspective) and stimuli to viewing time effects. Results showed a large task-based effect as well as a relatively smaller stimulus-based effect. This pattern suggests that, when viewing time measures are used for the assessment of sexual interest, it should be taken into consideration that response latency patterns can be biased by judging images from a selected perspective. [less ▲]

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