1,721,265 research outputs found
Evaluating the Influence of Haptic Force-Feedback on 3D Selection Tasks using Natural Egocentric Gestures
Full text linkImmersive Virtual Environments (IVEs) allow participants to interact with their 3D surroundings using natural hand gestures. Previous work shows that the addition of haptic feedback cues improves performance on certain 3D tasks. However, we believe this is not true for all situations. Depending on the difficulty of the task, we suggest that we should expect differences in the ballistic movement of our hands when presented with different types of haptic force-feedback conditions. We investigated how hard, soft and no haptic force-feedback responses, experienced when in contact with the surface of an object, affected user performance on a task involving selection of multiple targets. To do this, we implemented a natural egocentric selection interaction technique by integrating a two-handed large-scale force-feedback device in to a CAVE (TM)-like IVE system. With this, we performed a user study where we show that participants perform selection tasks best when interacting with targets that exert soft haptic force-feedback cues. For targets that have hard and no force-feedback properties, we highlight certain associated hand movement that participants make under these conditions, that we hypothesise reduce their performance
The influence of body movement on presence in virtual environments
No full textWe describe an experiment to assess the influence of body movements on presence in a virtual environment. In the experiment 20 participants were to walk through a virtual field of trees and count the trees with diseased leaves. A 2 x 2 between-subjects design was used to assess the influence of two factors on presence: tree height variation and task complexity. The field with greater variation in tree height required participants to bend down and look up more than in the lower variation tree height field. In the higher complexity task participants were told to remember the distribution of diseased trees in the field as well as to count them. The results showed a significant positive association between reported presence and the amount of body movement - in particular, head yaw - and the extent to which participants bent down and stood up. There was also a strong interaction effect between task complexity and gender: Women in the more-complex task reported a much lower sense of presence than in the simpler task. For applications in which presence is an important requirement, the research in this paper suggests that presence will be increased when interaction techniques are employed that permit the user to engage in whole-body movement
Translocation of deoxynivalenol to the head of soft wheat following infection of the stem base by Fusarium culmorum.
No full textGoing 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
Using tracked mobile sensors to make maps of environmental effects
No full textWe present a study the results of a study of environmental carbon monoxide pollution that has uses a set of
tracked, mobile pollution sensors. The motivating concept is that we will be able to map pollution and other
properties of the real world a fine scale if we can deploy a large set of sensors with members of the general public
who would carry them as they go about their normal everyday activities. To prove the viability of this concept
we have to demonstrate that data gathered in an ad-hoc manner is reliable enough in order to allow us to
build interesting geo-temporal maps.
We present a trial using a small number of global positioning system-tracked CO sensors. From analysis of raw
GPS logs we find some well-known spatial and temporal properties of CO. Further, by processing the GPS logs
we can find fine-grained variations in pollution readings such as when crossing roads. We then discuss the space
of possibilities that may be enabled by tracking sensors around the urban environment – both in getting at personal
experience of properties of the environment and in making summative maps to predict future conditions.
Although we present a study of CO, the techniques will be applicable to other environmental properties such as
radio signal strength, noise, weather and so on
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
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