Search results for "FREQUENCY"
showing 10 items of 2158 documents
Squeezing in Kerr-like cavities: optomechanics, polariton microcavities and superconducting circuits
2017
Aquesta tesi està dedicada fonamentalment a l’estudi teòric de la generació d’estats comprimits de la llum mitjançant cavitats òptiques tipus Kerr amb un bombeig bicromàtic. Bàsicament amb aquest tipus d’injecció fem que la usual corba de biestabilitiat observada en la dinàmica no lineal d’aquests sistemes amb injecció monocromàtica, canvie a una bifurcació tipus forca, degut a un fenòmen de mescla de quatre ones. A prop de l’esmentada bifurcació les fluctuacions quàntiques del camp electromagnètic són modificades de forma que l’estat quàntic de la llum a l’eixida de la cavitat és d’un buit comprimit. En aquesta introducció explicarem breument que és aquesta compressió de la llum, que són l…
Rotation-invariant optical recognition of three-dimensional objects.
2008
An automatic method for rotation-invariant three-dimensional (3-D) object recognition is proposed. The method is based on the use of 3-D information contained in the deformed fringe pattern obtained when a grating is projected onto an object’s surface. The proposed method was optically implemented by means of a two-cycle joint transform correlator. The rotation invariance is achieved by means of encoding with the fringe pattern a single component of the circular-harmonic expansion derived from the target. Thus the method is invariant for rotations around the line of sight. The whole experimental setup can be constructed with simple equipment. Experimental results show the utility of the pro…
Predicting Word Maturity from Frequency and Semantic Diversity: A Computational Study
2016
Semantic word representation changes over different ages of childhood until it reaches its adult form. One method to formally model this change is the word maturity paradigm. This method uses a text sample for each age, including adult age, and transforms the samples into a semantic space by means of Latent Semantic Analysis. The representation of a word at every age is then compared with its adult representation via computational maturity indices. The present study used this paradigm to explore to the impact of word frequency and semantic diversity on maturation indices. To do this, word maturity indices were extracted from a Spanish incremental corpus and validated, using correlation scor…
Consistency and word-frequency effects on spelling among first- to fifth-grade French children : A regression-based study.
2008
We describe a large-scale regression study that examines the influence of lexical (word frequency, lexical neighborhood) and sublexical (feedforward and feedback consistency) variables on spelling accuracy among first, second, and third- to fifth-graders. The wordset analyzed contained 3430 French words. Predictors in the stepwise regression analyses were grade-level-based and compiled from child-directed written materials. In all grades, feedforward consistency and word frequency had independent effects. However, whereas the feedforward-consistency contribution remained high and did not vary across grades, the impact of word frequency exhibited a massive jump between first and second grade…
Two ways to reformulate: a contrastive analysis of reformulation markers
2003
The aim of this paper is to present a contrastive analysis of reformulation markers in English, Spanish and Catalan. The study is based on a corpus of expository prose (mainly academic writing). The analysis shows coincidences in the sources of the markers and differences in the variety of forms expressing reformulation as well as in their frequency of use. Assuming that grammaticalization processes such as those leading to the creation of connectives have their roots in discourse, parallel differences are expected to be found in text construction. The present paper argues that the differences identified in the grammar of English vs. those of Spanish and Catalan can be associated with two d…
Transposed-letter effects: Consonants, vowels and letter frequency
2008
There is now considerable evidence (e.g., Perea & Lupker, 2003a, 2003b) that transposed-letter nonword primes (e.g., jugde for JUDGE) are more effective primes than replacement-letter nonword primes (e.g., jupte for JUDGE). Recently, Perea and Lupker (2004) demonstrated that, in Spanish, this transposed-letter prime advantage exists only when the transposed letters are consonants (C-C transpositions) and not when they are vowels (V-V transpositions). This vowel-consonant difference causes problems even for models that can successfully explain transposed-letter effects (e.g., SOLAR, Davis, 1999). In Experiment 1 in the present paper, we demonstrated a parallel result in a language with a dif…
Naming pseudowords in Spanish: effects of syllable frequency.
2003
Three naming experiments were conducted to examine the role of the first and the second syllable during speech production in Spanish. Facilitative effects of syllable frequency with disyllabic words have been reported in Dutch and Spanish (Levelt & Wheeldon, 1994; Perea & Carreiras, 1998). In both cases, the syllable frequency effect was independent of-and additive to-the effect of word frequency. However, Levelt and Wheeldon (1994) found that words ending in a high-frequency syllable were named faster than words ending in a low-frequency syllable, whereas Perea and Carreiras (1998) found a facilitative effect of syllable frequency for the initial syllable. In Experiments 1-2, we manipulate…
Can parafoveal-on-foveal effects be obtained when reading an unspaced alphasyllabic script (Thai)?
2013
One controversial question in the field of eye movements and reading is whether there is evidence of parafoveal-on-foveal effects. This is an important issue because some models of eye movements in reading make quite different predictions in this respect (e.g., E-Z Reader vs. SWIFT models). The aim of the current study was to investigate if parafoveal-on-foveal effects occur when reading Thai, an unspaced, alphasyllabic orthography. Word frequency (high and low) of the word to the right of the currently fixated word was manipulated to examine if it would influence processing of the fixated word. Thirty-six participants read single sentences while having their eye movements monitored. There …
Is perception a two-way street ?The case of feedback consistency in visual word recognition
1998
It is generally assumed that during reading, the activation produced over orthographic units feeds forward to phonological units. Supporting interactive models of word recognition, Stone, Vanhoy, and Van Orden (1997) recently claimed that phonological activation reverberates to orthographic processing units and consequently constrains orthographic encoding. They found that the consistency of the relations between phonology and orthography (feedback consistency) influenced lexical decision performance. We explored the effect in five experiments conducted with French words. Although feedback consistency affected writing performance, no significant effect was observed in lexical decision even …
Dual-stage and dual-deficit? Word recognition processes during text reading across the reading fluency continuum
2021
AbstractCentral questions in the study of visual word recognition and developmental dyslexia are whether early lexical activation precedes and supports decoding (a dual-stage view) or not (dual-route view), and the locus of deficits in dysfluent reading. The dual-route view predicts early word frequency and length interaction, whereas the dual-stage view predicts word frequency effect to precede the interaction effect. These predictions were tested on eye movements data collected from (n = 152) children aged 9–10 among whom reading dysfluency was overrepresented. In line with the dual-stage view, the results revealed an early word frequency effect in first fixation duration followed by robu…