1,720,958 research outputs found
Modeling of the EMS VCS3 voltage-controlled filter as a nonlinear filter network
No full textA previously developed nonlinear differential equation system, representative of the diode-based voltage-controlled filter on board of the EMS VCS3 analog synthesizer, can be modeled in terms of a filter network. The properties of this network can be converted block-by-block into a discrete-time version of the same model, in which the relationships existing between the system variables take the form of delay-free loops. In the presence of such loops, the discrete-time filter network is solved by iterating over a fixed-point scheme. Simulations running at 176.4 kHz show reasonable fidelity of the model in the regimes of interest, as well as shorter computation time compared to previous implementations of the same system. While reducing aliasing, such a sampling rate optimizes also the computation time as it requires fewer fixed-point iterations. The new model represents an improved alternative to previously developed voltage-controlled filter designs in the field of virtual analog
A nonlinear digital model of the EMS VCS3 voltage-controlled filter
Full text linkThis article presents a nonlinear discrete-time model of the EMS VCS3 voltage-controlled filters. The development of the model is based on the study of the filter circuitry and its behavior in the time domain. From this circuitry a system of nonlinear differential equations has been derived describing the dynamics in regime of large signals. The digital implementation of the filter is based on a numerical approximation of those equations. The resulting Matlab model has been compared with a structurally identical simulation running under PSpice. Finally, a real-time realization of the VCF has been implemented under the Pure Data processing environment
A shoe-based interface for ecological ground augmentation
No full textThe prototype of a wearable shoe-based interface is presented, which provides the user with auditory cues of ground. Data supplied by sensors embedded in the shoes drive a set of physics-based synthesis models running on a laptop, whose audio output is sent to a pair of shoe-mounted loudspeakers. By informing the synthesis models with ecological properties of grounds, neutral floors can be
interactively augmented so as to react like they were made of a different
material
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
An exploration on the influence of vibrotactile cues during digital piano playing
No full textAn exploratory experiment was carried out in which subjects with different musical skills were asked to play a digital piano keyboard, first by following a specific key sequence and style of execution, and then performing freely. Judgments of perceived sound quality were recorded in three different settings, including standard use of the digital piano with its own internal loudspeakers, and conversely use of the same keyboard for controlling a physics-based piano sound synthesis model running on a laptop in real time. Through its audio card, the laptop drove a couple of external loudspeakers, and occasionally a couple of shakers screwed to the bottom of the keyboard. The experiment showed that subjects prefer the combination of sonic and vibrotactile feedback provided by the synthesis model when playing the key sequences, whereas they promote the quality of the original instrument when performing free. However springing out of a preliminary evaluation, these results were in good accordance with the development stage of the synthesis software at the time of the experiment. They suggest that vibrotactile feedback modifies, and potentially improves the performer's experience when playing on a digital piano keyboard
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