Dimensioning of an European backbone network in OPNET WDM Guru

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Effects of captioning on video comprehension and incidental vocabulary learning

This study examines how three captioning types (i.e., on-screen text in the same language as the video) can assist L2 learners in the incidental acquisition of target vocabulary words and in the comprehension of L2 video. A sample of 133 Flemish undergraduate students watched three French clips twice. The control group (n = 32) watched the clips without captioning; the second group (n = 30) watched fully captioned clips; the third group (n = 34) watched keyword captioned clips; and the fourth group (n = 37) watched fully captioned clips with highlighted keywords. Prior to the learning session, participants completed a vocabulary size test. During the learning session, they completed three comprehension tests; four vocabulary tests measuring (a) form recognition, (b) meaning recognition, (c) meaning recall, and (d) clip association, which assessed whether participants associated words with the corresponding clip; and a final questionnaire. Our findings reveal that the captioning groups scored equally well on form recognition and clip association and significantly outperformed the control group. Only the keyword captioning and full captioning with highlighted keywords groups outperformed the control group on meaning recognition. Captioning did not affect comprehension nor meaning recall. Participants' vocabulary size correlated significantly with their comprehension scores as well as with their vocabulary test scores

Differential Effects of Input-based and Output-based Tasks on L2 Vocabulary Learning

This paper reports on a quasi-experimental study that explored the differential effects of input- and output-based tasks on L2 vocabulary learning. The study adopted a pretest- posttest within-participants design, with sixty Vietnamese EFL university students. Participants in the experimental group completed four input and four output tasks in an online learning environment. The target items (ten single words and ten compounds) were counterbalanced across the tasks. The study measured vocabulary gains at four levels of sensitivity: spontaneous use of the target items, form recall, meaning recall and meaning recognition. The analyses showed that the input-based tasks resulted in higher vocabulary gains at the meaning recall level, whereas the output-based tasks resulted in better scores at the form recall level. No difference was found in the spontaneous use and meaning recognition tests.Cet article rend compte d'une étude quasi expérimentale qui a exploré les effets différentiels des tâches basées sur les entrées et les sorties sur l'apprentissage du vocabulaire L2. L'étude a adopté une conception intra-participants prétest-post-test, avec soixante étudiants universitaires vietnamiens EFL. Les participants du groupe expérimental ont effectué quatre tâches d'entrée et quatre tâches de sortie dans un environnement d'apprentissage en ligne. Les éléments cibles (dix mots simples et dix composés) ont été contrebalancés entre les tâches. L'étude a mesuré les gains de vocabulaire à quatre niveaux de sensibilité : utilisation spontanée des éléments cibles, rappel de forme, rappel de sens et reconnaissance de sens. Les analyses ont montré que les tâches basées sur les entrées entraînaient des gains de vocabulaire plus élevés au niveau du rappel de sens, tandis que les tâches basées sur les sorties entraînaient de meilleurs scores au niveau du rappel de forme. Aucune différence n'a été trouvée dans les tests d'utilisation spontanée et de reconnaissance de sens

Long-range Kondo signature of a single magnetic impurity

The Kondo effect, one of the oldest correlation phenomena known in condensed matter physics, has regained attention due to scanning tunneling spectroscopy (STS) experiments performed on single magnetic impurities. Despite the sub-nanometer resolution capability of local probe techniques one of the fundamental aspects of Kondo physics, its spatial extension, is still subject to discussion. Up to now all STS studies on single adsorbed atoms have shown that observable Kondo features rapidly vanish with increasing distance from the impurity. Here we report on a hitherto unobserved long range Kondo signature for single magnetic atoms of Fe and Co buried under a Cu(100) surface. We present a theoretical interpretation of the measured signatures using a combined approach of band structure and many-body numerical renormalization group (NRG) calculations. These are in excellent agreement with the rich spatially and spectroscopically resolved experimental data.Comment: 7 pages, 3 figures + 8 pages supplementary material; Nature Physics (Jan 2011 - advanced online publication