2,548 research outputs found

    Improving and Scaling Mobile Learning via Emotion and Cognitive-state Aware Interfaces

    Get PDF
    Massive Open Online Courses (MOOCs) provide high-quality learning materials at low cost to millions of learners. Current MOOC designs, however, have minimal learner-instructor communication channels. This limitation restricts MOOCs from addressing major challenges: low retention rates, frequent distractions, and little personalization in instruction. Previous work enriched learner-instructor communication with physiological signals but was not scalable because of the additional hardware requirement. Large MOOC providers, such as Coursera, have released mobile apps providing more flexibility with “on-the-go” learning environments. This thesis reports an iterative process for the design of mobile intelligent interfaces that can run on unmodified smartphones, implicitly sense multiple modalities from learners, infer learner emotions and cognitive states, and intervene to provide gains in learning. The first part of this research explores the usage of photoplethysmogram (PPG) signals collected implicitly on the back-camera of unmodified smartphones. I explore different deep neural networks, DeepHeart, to improve the accuracy (+2.2%) and robustness of heart rate sensing from noisy PPG signals. The second project, AttentiveLearner, infers mind-wandering events via the collected PPG signals at a performance comparable to systems relying on dedicated physiological sensors (Kappa = 0.22). By leveraging the fine-grained cognitive states, the third project, AttentiveReview, achieves significant (+17.4%) learning gains by providing personalized interventions based on learners’ perceived difficulty. The latter part of this research adds real-time facial analysis from the front camera in addition to the PPG sensing from the back camera. AttentiveLearner2 achieves more robust emotion inference (average accuracy = 84.4%) in mobile MOOC learning. According to a longitudinal study with 28 subjects for three weeks, AttentiveReview2, with the multimodal sensing component, improves learning gain by 28.0% with high usability ratings (average System Usability Scale = 80.5). Finally, I show that technologies in this dissertation not only benefit MOOC learning, but also other emerging areas such as computational advertising and behavior targeting. AttentiveVideo, building on top of the sensing architecture in AttentiveLearner2, quantifies emotional responses to mobile video advertisements. In a 24-participant study, AttentiveVideo achieved good accuracy on a wide range of emotional measures (best accuracy = 82.6% across 9 measures)

    Video Quality Prediction for Video over Wireless Access Networks (UMTS and WLAN)

    Get PDF
    Transmission of video content over wireless access networks (in particular, Wireless Local Area Networks (WLAN) and Third Generation Universal Mobile Telecommunication System (3G UMTS)) is growing exponentially and gaining popularity, and is predicted to expose new revenue streams for mobile network operators. However, the success of these video applications over wireless access networks very much depend on meeting the user’s Quality of Service (QoS) requirements. Thus, it is highly desirable to be able to predict and, if appropriate, to control video quality to meet user’s QoS requirements. Video quality is affected by distortions caused by the encoder and the wireless access network. The impact of these distortions is content dependent, but this feature has not been widely used in existing video quality prediction models. The main aim of the project is the development of novel and efficient models for video quality prediction in a non-intrusive way for low bitrate and resolution videos and to demonstrate their application in QoS-driven adaptation schemes for mobile video streaming applications. This led to five main contributions of the thesis as follows:(1) A thorough understanding of the relationships between video quality, wireless access network (UMTS and WLAN) parameters (e.g. packet/block loss, mean burst length and link bandwidth), encoder parameters (e.g. sender bitrate, frame rate) and content type is provided. An understanding of the relationships and interactions between them and their impact on video quality is important as it provides a basis for the development of non-intrusive video quality prediction models.(2) A new content classification method was proposed based on statistical tools as content type was found to be the most important parameter. (3) Efficient regression-based and artificial neural network-based learning models were developed for video quality prediction over WLAN and UMTS access networks. The models are light weight (can be implemented in real time monitoring), provide a measure for user perceived quality, without time consuming subjective tests. The models have potential applications in several other areas, including QoS control and optimization in network planning and content provisioning for network/service providers.(4) The applications of the proposed regression-based models were investigated in (i) optimization of content provisioning and network resource utilization and (ii) A new fuzzy sender bitrate adaptation scheme was presented at the sender side over WLAN and UMTS access networks. (5) Finally, Internet-based subjective tests that captured distortions caused by the encoder and the wireless access network for different types of contents were designed. The database of subjective results has been made available to research community as there is a lack of subjective video quality assessment databases.Partially sponsored by EU FP7 ADAMANTIUM Project (EU Contract 214751

    Sports Content Viewership Motivations Across Digital Devices

    Get PDF
    U.S. advertisers spent over $2 billion on sporting events in 2014 directing advertisements towards consumers through digital devices used such as televisions, computers, smartphones, and tablets. The purpose of this cross-sectional study was to identify motivation factors that predict the intention to view sports content on digital devices. Knowing such factors is important for advertisers to prioritize distribution channels. Uses and gratification theory formed the theoretical framework for the study. The methodology adapted a survey that encapsulated 9 motives. The research questions examined what motives influenced sports viewership, what motives predicted the intention to view specific sports content, and the differences in viewing intention across sports content types. Data were collected through a survey administered to a qualified random sample of U.S. respondents with 525 responses received. Data were analyzed using exploratory factor analysis to group the questions into motivation factors, multiple linear regression to determine the significance of these factors in predicting viewership intent, and nonparametric Friedman testing to determine what demographics influenced viewership. Findings included: (a) 8 factors explained 76% of the variance; (b) 8 motives were significant in predicting viewership intention, with Escape (β = .714) ranking the highest; and (c) younger viewers had a greater intent to consume content on digital devices other than television, with smartphones (M = .73) ranking the highest. Social change benefits include: (a) sports content providers and advertisers could target the right content and advertisement to maximize viewership retention and revenue, and (b) users could view their desired sports content on their chosen device

    An Exploratory Study of Patient Falls

    Get PDF
    Debate continues between the contribution of education level and clinical expertise in the nursing practice environment. Research suggests a link between Baccalaureate of Science in Nursing (BSN) nurses and positive patient outcomes such as lower mortality, decreased falls, and fewer medication errors. Purpose: To examine if there a negative correlation between patient falls and the level of nurse education at an urban hospital located in Midwest Illinois during the years 2010-2014? Methods: A retrospective crosssectional cohort analysis was conducted using data from the National Database of Nursing Quality Indicators (NDNQI) from the years 2010-2014. Sample: Inpatients aged ≥ 18 years who experienced a unintentional sudden descent, with or without injury that resulted in the patient striking the floor or object and occurred on inpatient nursing units. Results: The regression model was constructed with annual patient falls as the dependent variable and formal education and a log transformed variable for percentage of certified nurses as the independent variables. The model overall is a good fit, F (2,22) = 9.014, p = .001, adj. R2 = .40. Conclusion: Annual patient falls will decrease by increasing the number of nurses with baccalaureate degrees and/or certifications from a professional nursing board-governing body

    Error propagation

    Get PDF

    Image synthesis based on a model of human vision

    Get PDF
    Modern computer graphics systems are able to construct renderings of such high quality that viewers are deceived into regarding the images as coming from a photographic source. Large amounts of computing resources are expended in this rendering process, using complex mathematical models of lighting and shading. However, psychophysical experiments have revealed that viewers only regard certain informative regions within a presented image. Furthermore, it has been shown that these visually important regions contain low-level visual feature differences that attract the attention of the viewer. This thesis will present a new approach to image synthesis that exploits these experimental findings by modulating the spatial quality of image regions by their visual importance. Efficiency gains are therefore reaped, without sacrificing much of the perceived quality of the image. Two tasks must be undertaken to achieve this goal. Firstly, the design of an appropriate region-based model of visual importance, and secondly, the modification of progressive rendering techniques to effect an importance-based rendering approach. A rule-based fuzzy logic model is presented that computes, using spatial feature differences, the relative visual importance of regions in an image. This model improves upon previous work by incorporating threshold effects induced by global feature difference distributions and by using texture concentration measures. A modified approach to progressive ray-tracing is also presented. This new approach uses the visual importance model to guide the progressive refinement of an image. In addition, this concept of visual importance has been incorporated into supersampling, texture mapping and computer animation techniques. Experimental results are presented, illustrating the efficiency gains reaped from using this method of progressive rendering. This visual importance-based rendering approach is expected to have applications in the entertainment industry, where image fidelity may be sacrificed for efficiency purposes, as long as the overall visual impression of the scene is maintained. Different aspects of the approach should find many other applications in image compression, image retrieval, progressive data transmission and active robotic vision

    Children\u27s Susceptibility to Television Advertising: A Behavioral Test of Cognition and Attitude

    Get PDF
    Television\u27s alleged effects on children have been the object of considerable debate since the early 1950\u27s. The effects of television commercials, however, have been the focus of only a handful of studies. According to recent FCC figures, television commercials now comprise 20 percent--12 minutes or more per hour--of television broadcast content (Johnson, 1973). Earlier figures reported by Steiner (1963) placed commercials as the third largest content category on television, following movies and comedy-variety, but ahead of action dramas and eight other programming categories. Although content emphasis may have changed over the decade, e.g. an increase in action dramas, advertising is still a paramount content category occupying one-fifth of air time. At today\u27s viewing levels, this means the average child is exposed to approximately 100 television commercials per day (Action for Children\u27s Television, 1971)

    Full Issue 14(4)

    Get PDF

    Full Issue 14(4)

    Get PDF
    il saggio esamina compiutamente la disciplina dell'art. 19 d.lgs. n. 5/200
    • …
    corecore