1,721,093 research outputs found
Effects of carrier and phase on the pitch of long-duration vibrato tones
No full textPrevious studies on the pitch of long-duration vibrato tones, where the modulator is a symmetric function (e.g. sine or triangular wave) have shown that the pitch perceived corresponds to either the arithmetic or geometric mean fundamental frequency of the vibrato tone. In one study the pitch of a vibrato tone consisting of a square wave modulated by a triangular wave was found to be inexplicably lower than that of a sine wave modulated by a triangular wave. An investigation into the pitch of short-duration vibrato tones also revealed an effect of phase on vibrato pitch. An experiment was undertaken with the aim of exploring the effects of carrier and phase on the pitch of long-duration vibrato tones. Six musically trained participants made matches between modulated and unmodulated tones using a method of adjustment and free response paradigm. The following carriers were investigated: a sinusoid, a complex tone with 4 resolved harmonics, a complex tone with 12 harmonics and a complex tone containing harmonics 10 to 15 (all of equal amplitude). Initial phases of 0 and p radians were also explored and the carrier frequency was set to 500 Hz for all conditions. A repeated measures analysis of variance with factors carrier, phase and adjustment tone starting frequency revealed a statistically significant main effect of phase (F (1, 5) = 24.747, p < 0.005), but no significant main effect of carrier. The effect of phase was found to be in opposition with previous findings for short-duration vibrato tones and possible reasons are discussed
Range of tuning for tones with and without vibrato
No full textPrevious studies on vibrato pitch attempted to determine the "principal pitch" of vibrato tones and not the range of tuning for such tones in a melodic context. This study investigates the range of acceptable tuning (RAT) for tones with and without vibrato, using repeating ascending and descending three-tone arpeggios. The second tone in each sequence was modulated or unmodulated with an initial pitch that was flat or sharp. With each repetition the pitch of the second tone increased or decreased by 3 cents depending upon the initial pitch condition. Participants indicated when they perceived the second tone to be in tune and out of tune. The RAT for vibrato tones was approximately 10 cents greater than for unmodulated tones. This is largely due to the lower RAT limit, indicating that the carrier frequency of vibrato tones can be 10 cents flatter than the fundamental frequency of an unmodulated tone
Effect of carrier on the pitch of long duration vibrato tones
No full textBackground Previous studies on the pitch perceived for long-duration vibrato tones, where the modulator is a symmetric function (e.g. sine or triangular wave) have shown that the pitch perceived is generally the mean. For sinusoidal carriers modulated using a triangular wave is has been suggested that the pitch perceived is closer to the geometric mean than the arithmetic mean.Aims A pilot study was undertaken with the aim of exploring the effect of carrier on the perceived pitch and pitch strength of vibrato tones. The following carriers were investigated: a sinusoid, an impulse with four resolved harmonics of equal amplitude (including f0), an impulse with twelve harmonics and an impulse containing the fundamental plus unresolved harmonics nine to twelve (all of equal amplitude).Method Pitch matches were obtained between modulated and unmodulated tones using a two-interval two-alternative adaptive procedure. The modulated tone was presented first, followed by one second of silence and then the unmodulated tone. Subjects indicated which of the tones was higher in pitch. Three carrier frequencies (fc = ERBN no. 4 (123.2Hz), 10 (442.3Hz) and 16 (1051.1Hz)) were investigated for each of the four carriers resulting in twelve experimental conditions. In addition subjects were required to make unmodulated tone matches for all carriers at fc = ERBN no. 10. Tone length was one second including 40ms raised cosine onset and offset ramps. The modulator in all cases was a sinusoid with an initial phase of 0 degrees, a rate of 6Hz and extent of .s 6% of fc. All stimuli were presented at 45dBA.Results A two-way repeated measures ANOVA revealed a significant main effect of carrier, F(3, 39) =4.01, p < .05 and interaction between carrier and frequency. Overall there was much variation in the subjects’ responses and this variation tended to increase with fc.Conclusions The results of this pilot study suggest that carrier type may affect the perceived pitch of tonesvibrato; however there was large variance in subject responses and so a long term study using fewer, highly trained subjects is currently being undertaken to corroborate these results.<br/
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
