3,363 research outputs found

    Feedback Control of Human Stress with Music Modulation

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    Mental stress has known detrimental effects on human health, however few algorithmic methods of reducing mental stress have been widely explored. While the act of listening to music has been shown to have beneficial effects for stress reduction, and furthermore, audio players have been designed to selectively choose music and other inputs with the intent of stress reduction, limited work has been conducted for real-time stress reduction with feedback control using physiological input signals such as heart rate or Heart Rate Variability (HRV). This thesis proposes a feedback controller that uses HRV signals from wearable sensors to perform real-time (< 1 second) modulations to music through tempo changes with the goal to regulate and reduce stress levels. A standardized, stress inducing test based on the popular Stroop test is also introduced, which has been shown to induce acute stress in subjects and can be used as a testing benchmark for controller design. Ultimately, a controller is presented that when used is not only able to maintain stress levels during stress-inducing inputs to a human but even provides de-stressing effects beyond baseline performance.No embargoAcademic Major: Electrical and Computer Engineerin

    An Online Actor Critic Algorithm and a Statistical Decision Procedure for Personalizing Intervention.

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    Increasing technological sophistication and widespread use of smartphones and wearable devices provide opportunities for innovative health interventions. An Adaptive Intervention (AI) personalizes the type, mode and dose of intervention based on users' ongoing performances and changing needs. A Just-In-Time Adaptive Intervention (JITAI) employs the real-time data collection and communication capabilities that modern mobile devices provide to adapt and deliver interventions in real-time. The lack of methodological guidance in constructing data-based high quality JITAI remains a hurdle in advancing JITAI research despite its increasing popularity. In the first part of the dissertation, we make a first attempt to bridge this methodological gap by formulating the task of tailoring interventions in real-time as a contextual bandit problem. Under the linear reward assumption, we choose the reward function (the ``critic") parameterization separately from a lower dimensional parameterization of stochastic JITAIs (the ``actor"). We provide an online actor critic algorithm that guides the construction and refinement of a JITAI. Asymptotic properties of the actor critic algorithm, including consistency, asymptotic distribution and regret bound of the optimal JITAI parameters are developed and tested by numerical experiments. We also present numerical experiment to test performance of the algorithm when assumptions in the contextual bandits are broken. In the second part of the dissertation, we propose a statistical decision procedure that identifies whether a patient characteristic is useful for AI. We define a discrete-valued characteristic as useful in adaptive intervention if for some values of the characteristic, there is sufficient evidence to recommend a particular intervention, while for other values of the characteristic, either there is sufficient evidence to recommend a different intervention, or there is insufficient evidence to recommend a particular intervention.PhDStatisticsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/133223/1/ehlei_1.pd

    Proceedings of the International Workshop on EuroPLOT Persuasive Technology for Learning, Education and Teaching (IWEPLET 2013)

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    "This book contains the proceedings of the International Workshop on EuroPLOT Persuasive Technology for Learning, Education and Teaching (IWEPLET) 2013 which was held on 16.-17.September 2013 in Paphos (Cyprus) in conjunction with the EC-TEL conference. The workshop and hence the proceedings are divided in two parts: on Day 1 the EuroPLOT project and its results are introduced, with papers about the specific case studies and their evaluation. On Day 2, peer-reviewed papers are presented which address specific topics and issues going beyond the EuroPLOT scope. This workshop is one of the deliverables (D 2.6) of the EuroPLOT project, which has been funded from November 2010 – October 2013 by the Education, Audiovisual and Culture Executive Agency (EACEA) of the European Commission through the Lifelong Learning Programme (LLL) by grant #511633. The purpose of this project was to develop and evaluate Persuasive Learning Objects and Technologies (PLOTS), based on ideas of BJ Fogg. The purpose of this workshop is to summarize the findings obtained during this project and disseminate them to an interested audience. Furthermore, it shall foster discussions about the future of persuasive technology and design in the context of learning, education and teaching. The international community working in this area of research is relatively small. Nevertheless, we have received a number of high-quality submissions which went through a peer-review process before being selected for presentation and publication. We hope that the information found in this book is useful to the reader and that more interest in this novel approach of persuasive design for teaching/education/learning is stimulated. We are very grateful to the organisers of EC-TEL 2013 for allowing to host IWEPLET 2013 within their organisational facilities which helped us a lot in preparing this event. I am also very grateful to everyone in the EuroPLOT team for collaborating so effectively in these three years towards creating excellent outputs, and for being such a nice group with a very positive spirit also beyond work. And finally I would like to thank the EACEA for providing the financial resources for the EuroPLOT project and for being very helpful when needed. This funding made it possible to organise the IWEPLET workshop without charging a fee from the participants.

    On the Role of Context in the Design of Mobile Mashups

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    This paper presents a design methodology and an accompanying platform for the design and fast development of Context-Aware Mobile mashUpS (CAMUS). The approach is characterized by the role given to context as a first-class modeling dimension used to support i) the identification of the most adequate resources that can satisfy the users' situational needs and ii) the consequent tailoring at runtime of the provided data and functions. Context-based abstractions are exploited to generate models specifying how data returned by the selected services have to be merged and visualized by means of integrated views. Thanks to the adoption of Model-Driven Engineering (MDE) techniques, these models drive the flexible execution of the final mobile app on target mobile devices. A prototype of the platform, making use of novel and advanced Web and mobile technologies, is also illustrated

    Linear mixed models with endogenous covariates: modeling sequential treatment effects with application to a mobile health study

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    Mobile health is a rapidly developing field in which behavioral treatments are delivered to individuals via wearables or smartphones to facilitate health-related behavior change. Micro-randomized trials (MRT) are an experimental design for developing mobile health interventions. In an MRT the treatments are randomized numerous times for each individual over course of the trial. Along with assessing treatment effects, behavioral scientists aim to understand between-person heterogeneity in the treatment effect. A natural approach is the familiar linear mixed model. However, directly applying linear mixed models is problematic because potential moderators of the treatment effect are frequently endogenous---that is, may depend on prior treatment. We discuss model interpretation and biases that arise in the absence of additional assumptions when endogenous covariates are included in a linear mixed model. In particular, when there are endogenous covariates, the coefficients no longer have the customary marginal interpretation. However, these coefficients still have a conditional-on-the-random-effect interpretation. We provide an additional assumption that, if true, allows scientists to use standard software to fit linear mixed model with endogenous covariates, and person-specific predictions of effects can be provided. As an illustration, we assess the effect of activity suggestion in the HeartSteps MRT and analyze the between-person treatment effect heterogeneity

    Using interpreted runtime models for devising adaptive user interfaces of enterprise applications

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    Although proposed to accommodate new technologies and the continuous evolution of business processes and business rules, current model-driven approaches do not meet the flexibility and dynamic needs of feature-rich enterprise applications. This paper illustrates the use of interpreted runtime models instead of static models or generative runtime models, i.e. those that depend on code generation. The benefit of interpreting runtime models is illustrated in two enterprise user interface (UI) scenarios requiring adaptive capabilities. Concerned with devising a tool-supported methodology to accommodate such advanced adaptive user interface scenarios, we propose an adaptive UI architecture and the meta-model for such UIs. We called our architecture Custom Enterprise Development Adaptive Architecture (CEDAR). The applicability and performance of the proposed approach are evaluated by a case study
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