38,475 research outputs found

    Quantifying subjective quality evaluations for mobile video watching in a semi-living lab context

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    This paper discusses results from an exploratory study in which Quality of Experience aspects related to mobile video watching were investigated in a semi-living lab setting. More specifically, we zoom in on usage patterns in a natural research context and on the subjective evaluation of high and low-resolution movie trailers that are transferred to a mobile device using two transmission protocols for video (i.e., real-time transport protocol and progressive download using HTTP). User feedback was collected by means of short questionnaires on the mobile device, combined with traditional pen and paper diaries. The subjective evaluations regarding the general technical quality, perceived distortion, fluentness of the video, and loading speed are studied and the influence of the transmission protocol and video resolution on these evaluations is analyzed. Multinomial logistic regression results in a model to estimate the subjective evaluations regarding the perceived distortion and loading speed based on objectively-measured parameters of the video session

    Evaluation in a project lifeā€cycle: The hypermedia CAMILLE project

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    In the CAL literature, the issue of integrating evaluation into the lifeā€cycle of a project has often been recommended but less frequently reported, at least for largeā€scale hypermedia environments. Indeed, CAL developers face a difficult problem because effective evaluation needs to satisfy the potentially conflicting demands of a variety of audiences (teachers, administrators, the research community, sponsors, etc.). This paper first examines some of the various forms of evaluation adopted by different kinds of audiences. It then reports on evaluations, formative as well as summative, set up by the European CAMILLE project teams in four countries during a largeā€scale courseware development project. It stresses the advantages, despite drawbacks and pitfalls, for CAL developers to systematically undertake evaluation. Lastly, it points out some general outcomes concerning learning issues of interest to teachers, trainers and educational advisers. These include topics such as the impact of multimedia, of learner variability and learner autonomy on the effectiveness of learning with respect to language skills

    Speech-based recognition of self-reported and observed emotion in a dimensional space

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    The differences between self-reported and observed emotion have only marginally been investigated in the context of speech-based automatic emotion recognition. We address this issue by comparing self-reported emotion ratings to observed emotion ratings and look at how differences between these two types of ratings affect the development and performance of automatic emotion recognizers developed with these ratings. A dimensional approach to emotion modeling is adopted: the ratings are based on continuous arousal and valence scales. We describe the TNO-Gaming Corpus that contains spontaneous vocal and facial expressions elicited via a multiplayer videogame and that includes emotion annotations obtained via self-report and observation by outside observers. Comparisons show that there are discrepancies between self-reported and observed emotion ratings which are also reflected in the performance of the emotion recognizers developed. Using Support Vector Regression in combination with acoustic and textual features, recognizers of arousal and valence are developed that can predict points in a 2-dimensional arousal-valence space. The results of these recognizers show that the self-reported emotion is much harder to recognize than the observed emotion, and that averaging ratings from multiple observers improves performance

    A cognitive approach to user perception of multimedia quality: An empirical investigation

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    Whilst multimedia technology has been one of the main contributing factors behind the Web's success, delivery of personalized multimedia content has been a desire seldom achieved in practice. Moreover, the perspective adopted is rarely viewed from a cognitive styles standpoint, notwithstanding the fact that they have significant effects on usersā€™ preferences with respect to the presentation of multimedia content. Indeed, research has thus far neglected to examine the effect of cognitive styles on usersā€™ subjective perceptions of multimedia quality. This paper aims to examine the relationships between usersā€™ cognitive styles, the multimedia quality of service delivered by the underlying network, and usersā€™ quality of perception (understood as both enjoyment and informational assimilation) associated with the viewed multimedia content. Results from the empirical study reported here show that all users, regardless of cognitive style, have higher levels of understanding of informational content in multimedia video clips (represented in our study by excerpts from television programmes) with weak dynamism, but that they enjoy moderately dynamic clips most. Additionally, multimedia content was found to significantly influence usersā€™ levels of understanding and enjoyment. Surprisingly, our study highlighted the fact that Bimodal users prefer to draw on visual sources for informational purposes, and that the presence of text in multimedia clips has a detrimental effect on the knowledge acquisition of all three cognitive style groups

    Bioart: Transgenic art and recombinant theatre

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    EEG-based mental workload neurometric to evaluate the impact of different traffic and road conditions in real driving settings

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    Car driving is considered a very complex activity, consisting of different concomitant tasks and subtasks, thus it is crucial to understand the impact of different factors, such as road complexity, traffic, dashboard devices, and external events on the driverā€™s behavior and performance. For this reason, in particular situations the cognitive demand experienced by the driver could be very high, inducing an excessive experienced mental workload and consequently an increasing of error commission probability. In this regard, it has been demonstrated that human error is the main cause of the 57% of road accidents and a contributing factor in most of them. In this study, 20 young subjects have been involved in a real driving experiment, performed under different traffic conditions (rush hour and not) and along different road types (main and secondary streets). Moreover, during the driving tasks different specific events, in particular a pedestrian crossing the road and a car entering the traffic flow just ahead of the experimental subject, have been acted. A Workload Index based on the Electroencephalographic (EEG), i.e., brain activity, of the drivers has been employed to investigate the impact of the different factors on the driverā€™s workload. Eye-Tracking (ET) technology and subjective measures have also been employed in order to have a comprehensive overview of the driverā€™s perceived workload and to investigate the different insights obtainable from the employed methodologies. The employment of such EEG-based Workload index confirmed the significant impact of both traffic and road types on the driversā€™ behavior (increasing their workload), with the advantage of being under real settings. Also, it allowed to highlight the increased workload related to external events while driving, in particular with a significant effect during those situations when the traffic was low. Finally, the comparison between methodologies revealed the higher sensitivity of neurophysiological measures with respect to ET and subjective ones. In conclusion, such an EEG-based Workload index would allow to assess objectively the mental workload experienced by the driver, standing out as a powerful tool for research aimed to investigate driversā€™ behavior and providing additional and complementary insights with respect to traditional methodologies employed within road safety research

    The simultaneity of complementary conditions:re-integrating and balancing analogue and digital matter(s) in basic architectural education

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    The actual, globally established, general digital procedures in basic architectural education,producing well-behaved, seemingly attractive up-to-date projects, spaces and first general-researchon all scale levels, apparently present a certain growing amount of deficiencies. These limitations surface only gradually, as the state of things on overall extents is generally deemed satisfactory. Some skills, such as ā€œold-fashionedā€ analogue drawing are gradually eased-out ofundergraduate curricula and overall modus-operandi, due to their apparent slow inefficiencies in regard to various digital mediaā€™s rapid readiness, malleability and unproblematic, quotidian availabilities. While this state of things is understandable, it nevertheless presents a definite challenge. The challenge of questioning how the assessment of conditions and especially their representation,is conducted, prior to contextual architectural action(s) of any kind
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