1,721,035 research outputs found
Performance of layout algorithms: Comprehension, not computation
No full textMany algorithms address the problem of rendering an abstract graph structure as a diagram in as efficient and as elegant a manner as possible. The criteria for judging the worth of these algorithms are typically the extent to which they conform to common aesthetic criteria (e.g. minimising the number of crossings, maximising symmetry), or their computational efficiency. The algorithms are not usually judged on their ability to produce diagrams that maximise humans' performance on tasks which require their use. This paper presents an example experimental methodology for considering the relative worth of eight layout algorithms with respect to human performance, together with details of an experiment using a single graph. The results indicate that, with the exception of one algorithm, there is no statistical difference between the performance data of the algorithms when applied to this graph, indicating that they produce drawings of comparable difficulty. This result is despite the different aesthetic bases for the algorithms
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
Defining multimedia
No full textMultimedia is variously and often ambiguously defined. While most people might accept a mix of voice, text and graphics, they might resist calling a live lecture on a titled work of art a multimedia presentation. On the other hand, many definitions focus entirely on technology: multimedia seems to be defined by the hardware required rather than by the user's experience. For example, despite the statement that any computer application that employs a video disk, images from a CD-ROM, uses high-quality sound, or uses high-quality video images on a screen may be termed a multimedia application, the author doubts that anyone would use the term multimedia for a computer application that merely plays a piece of music. She suggests a model of media objects that does not refer to technology or interactivity, but rather concentrates on the nature of the text. This model provides a useful basis for defining multimedia communication securely and unambiguously
Multidimensional tactons for non-visual information presentation in mobile devices
Full text linkTactons are structured vibrotactile messages which can be used for non-visual information presentation when visual displays are limited, unavailable or inappropriate, such as in mobile phones and other mobile devices. Little is yet known about how to design them effectively. Previous studies have investigated the perception of Tactons which encode two dimensions of information using two different vibrotactile parameters (rhythm and roughness) and found recognition rates of around 70. When more dimensions of information are required it may be necessary to extend the parameter-space of these Tactons. Therefore this study investigates recognition rates for Tactons which encode a third dimension of information using spatial location. The results show that identification rate for three-parameter Tactons is just 48, but that this can be increased to 81 by reducing the number of values of one of the parameters. These results will aid designers to select suitable Tactons for use when designing mobile displays
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
Metrics for Graph Drawing Aesthetics
No full textGraph layout algorithms typically conform to one or more aesthetic criteria (e.g. minimizing the number of bends, maximizing othrogonality). Determining the extent to which a graph drawing conforms to an aesthetic criterion tends to be done informally, and varies between different algorithms. This paper presents formal metrics for measuring the aesthetic presence in a graph drawing for seven common aesthetic criteria, applicable to any graph drawing of anysize. The metrics are useful for determining the aesthetic quality of a given graph drawing, or for defining a cost function for genetic algorithms or simulated annealing programs. The metrics are continous, so that aesthetic quality is not stated as a binary conformance decision (i.e. the drawing either conforms to the aesthetic or not), but can be stated as the extent of aesthetic conformance using a number between 0 and 1. The paper presents the seven metric formulae. The application of these metrics is demonstrated through the aesthetic analysis of example graph drawings produced by common layout algorithms
Tactile crescendos and sforzandos: applying musical techniques to tactile icon design
Full text linkTactile icons (Tactons) are structured vibrotactile messages which can be used for non visual information display. Information is encoded in Tactons by manipulating vibrotactile parameters. This research investigates the possibilities of applying musical techniques to tactile icon design in order to define such parameters. Tactile versions of musical dynamics were created by manipulating the amplitude of vibrations to create increasing, decreasing, and level stimuli and an experiment was carried out to test perception of these stimuli. Identification rates of 92%-100% indicate that these tactile dynamics can be identified and distinguished from each other, and that tactile dynamics could be used in Tacton design
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