1,720,985 research outputs found
Evaluation of an Eye Tracking Selection Technique with Progressive Refinement
No full textWe designed a novel eye tracking selection technique with progressive refinement - eye-controlled sphere-casting refined by quad-menu (EyeSQUAD) selection technique. Through a user study, we evaluated the performance of this technique with comparison of two previous selection techniques - ray-casting and SQUAD under different target size and distractor density scenarios. Results show that the EyeSQUAD technique can achieve similar selection speed as ray-casting and SQUAD and is more accurate than ray-casting although less precise than SQUAD. Finally, we summarized several insights for designing interaction techniques with eye tracking.</p
The effect of rest frames on simulator sickness reduction
No full textWith increasing prevalence and capabilities of Virtual Reality (VR) as a part of education, entertainment, data analysis and industrial applications, the consideration of constructing a more user-friendly virtual environment becomes more important, which requires the reduction or elimination of simulator sickness (SS) -- a discomfort caused in simulated environment. As a form of motion sickness (MS) -- caused by movement in travel, some signs and symptoms of SS are the same as those of MS's, such as pallor, cold sweating, nausea, and vomiting. Several convincing theories or hypothesis to explain the cause of SS have been advanced, such as Sensory Conflict Theory, Postural Instability Theory and Rest Frames Hypothesis. Based on the first two theories aforementioned, high-quality tracking systems and modification of field of view (FOV) have been proposed to reduce the mismatch between visual perception and vestibular system in virtual environment (VE). Two main drawbacks exist in these techniques: (1) They will make uses weary in VE needs long distance physical navigation; (2) Modifying the field of view will decrease immersion.To this end, inspired by the rest frame hypothesis and previous study on field of view, the goal of this research is to evaluate the effect of rest frames -- portions of the virtual environment that remain fixed in relation to the real world and do not move as the user moves around -- on SS reduction. A study was performed in this research, in which all participants experienced two different VR sessions: one with rest frames and the other without rest frames. The rest frames were developed by using a transparent cockpit attached with a black metal net in our experimental environment. A questionnaire asking users' discomfort was shown periodically in the VE during the study, which allowed us to record the level of participants' comfort in real time. Participants were required to finish a Simulator Sickness Questionnaire (SSQ) and a presence questionnaire after completing either session, to analyze the influence of rest frames on presence and their overall sickness induced by VR. Through comparing the time spent in VE, the real-time subjects' discomfort levels and scores of SSQ and presence questionnaire from both sessions, we found that rest frames have advantages as follows:(1) Users could experience VEs without physical navigation;(2) Rest frames significantly helped users acclimate to VR;(3) The level of discomfort in VR was reduced;(4) The level of presence was not impacted.</p
Granulated rest frames as a technique to mitigate visually-induced motion sickness and their application
No full textAs a visual cue, rest-frames are isotropically vertical and relatively stationary to subjects; they are used to alleviate visually induced motion sickness in the virtual reality experience. However, the use of rest-frames as a visually induced motion sickness–alleviation technique poses several challenges for the user. This is primarily because the existing design is content-based, not graphics-driver-level, so it cannot be seamlessly applied to various platforms. The design also blocks some peripheral vision, sacrificing the user’s spatial-recognition ability.This dissertation aims to understand and improve rest-frames’ design, making their use a viable technique to reduce visually induced motion sickness. This technique is graphics-driver-level, so it can run seamlessly in any environment. With this goal, the dissertation proposes and validates a novel design of rest-frames inspired by amodal completion: granulated rest-frames. A generic method to process stereoscopic videos to study user-experience is also presented. The new design implements rest-frames as visual noise with changeable settings to maintain the user’s spatial-recognition ability and provide more flexibility at the graphics-driver level.This study finds the optimal size and sparsity of granulated rest-frames by investigating the user’s visual-search performance at different settings. It also validates the effect of granulated rest-frames in alleviating visually induced motion sickness in interactive virtual environments. The main finding is that granulated rest-frames can help first-time users adapt to a virtual environment more quickly without affecting the spatial-recognition ability of their peripheral vision. This dissertation also demonstrates the applicability of granulated rest-frames in stereoscopic videos in a preliminary study, as part of which a generic method to investigate users’ reactions to 360° videos is proposed. The dissertation also offers an experimental design to explore the utilization of granulated rest-frames’ effects in general-purpose interaction techniques in a future study.</p
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
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