Quality of Information in Mobile Crowdsensing: Survey and Research Challenges

Smartphones have become the most pervasive devices in people's lives, and are clearly transforming the way we live and perceive technology. Today's smartphones benefit from almost ubiquitous Internet connectivity and come equipped with a plethora of inexpensive yet powerful embedded sensors, such as accelerometer, gyroscope, microphone, and camera. This unique combination has enabled revolutionary applications based on the mobile crowdsensing paradigm, such as real-time road traffic monitoring, air and noise pollution, crime control, and wildlife monitoring, just to name a few. Differently from prior sensing paradigms, humans are now the primary actors of the sensing process, since they become fundamental in retrieving reliable and up-to-date information about the event being monitored. As humans may behave unreliably or maliciously, assessing and guaranteeing Quality of Information (QoI) becomes more important than ever. In this paper, we provide a new framework for defining and enforcing the QoI in mobile crowdsensing, and analyze in depth the current state-of-the-art on the topic. We also outline novel research challenges, along with possible directions of future work.Comment: To appear in ACM Transactions on Sensor Networks (TOSN

Framing Leader Messages for Highly Reliable Organizing

This dissertation tests high-reliability organization (HRO) theory's claim that strategic leadership messages can direct followers’ sensemaking in adaptive ways (Weick & Sutcliffe, 2015). Specifically, two experiments tested whether mindfulness-based leader language choice enhanced followers' performance during a planning task. The experiments also tested the relationship between leader language choice and followers' willingness to speak up with dissent—an outcome known to be prominent in mindful, learning organizations (Kassing, 2011). In the first experiment, working adults (N = 197) in a single high-reliability organization (i.e., U.S. Army) read one of four leader message conditions prior to engaging in a scenario planning task. Leader message conditions varied by framing density, mindfulness language, and optimism. Results indicated no significant differences between leader message treatments for any of the predicted outcomes—self-reported feelings of mindfulness, participants’ performance during a planning task, and willingness to speak up with dissent. A second experiment was conducted to answer whether mindfulness-based leader messages are influential in the case of a general working adults sample (N = 481). Results did, indeed, indicate statistically significant differences in participants' performance during a planning task. Specifically, participants generated more numerous contingencies during planning when exposed to the framing- and mindfulness-dense leader message as compared with an optimistic leader message. Furthermore, participants generated significantly higher quality contingencies during planning when exposed to a mindfulness-based leader message dense with metaphors as compared with participants who received a leader message with few or no metaphors to reinforce the need for mindfulness. Finally, consistent with HRO theorizing, participants exposed to an optimistic leader message produced significantly lower quality contingencies during planning as compared with participants who received a mindfulness-based leader message. Results indicated no significant differences between leader message treatments for self-reported feelings of mindfulness or willingness to speak up with dissent. A post-hoc analysis was conducted to compare the two samples. Again, consistent with HRO theorizing, results indicated that participants drawn from a single high-reliability organization performed better on the planning task than participants sampled from a general working adult population, regardless of leader message condition. This dissertation contributes to organizational communication literature in three primary ways: First, results confirmed leadership communication can, indeed, stimulate followers’ adaptive sensemaking, which can be seen in improved performance during a planning task. Second, this research is consistent with HRO theorists' claim that lessons drawn from HROs are transferable for improving the performance of working adults outside the HRO context. Third, the observation that participants from the single HRO outperformed their general working adult counterparts on the planning task supported the notion that mindfulness is, in fact, being routinized by their HRO culture. The dissertation concludes with practical recommendations for leadership communication practice

Race Logic: Measuring Stereotyped Mental Representations of Football Player Positions

This preregistered research sought to capture the mental images associated with the quarterback and wide receiver positions to understand race logic prevalent in the NFL using the two phase, reverse correlation image classification paradigm. Participants in phase one were randomly assigned to the quarterback or wide receiver group and responded to 300 forced choice side by side images, indicating which image appears most like the target position. From these responses, four images were created based on position (quarterback or wide receiver) and participant exposure to football related media content (high or low). These images were used as stimuli in phase two where 237 additional participants rated the images on race, intelligence, and athleticism. It was hypothesized that the images created from phase one participants of quarterbacks would be rated as “more white” and the images of wide receivers would be rated as “more black,” consistent with racial stacking research. Additionally, football consumption was expected to have a polarizing effect on the ratings of the images. That is, the higher consumption participants would produce an image for quarterbacks that appears more white (black for wide receivers) than participants who have lower consumption. Finally, it was hypothesized that quarterbacks would be rated as more intelligent whereas wide receivers would be rated as more athletic. Contrary to predictions for consumption, participants with lower levels of exposure created images that were rated more consistently with race logic- the quarterback was rated as more white whereas the wide receiver was rated as more black. However, there were no significant differences in how each position was rated in terms of intelligence and athleticism. In general, quarterback images were rated higher in both intelligence and athleticism. Implications of current research findings are discussed as well as the race logic construct. Future research is needed to explore how players, coaches, and staff respond using various techniques including implicit measures

Exploration and visualization of design spaces with applications to negative stiffness metamaterials

Engineering design problems are commonly hierarchical and multilevel which requires coordination between models at each scale. If the models are computationally expensive or highly nonlinear, such as many materials design applications, identification of an optimal design may be exceptionally difficult. Alternatives to optimization-based methods include set-based methods that classify and track sets or ensembles of high performance designs. By relaxing the requirement for an optimal design, it is often possible to identify promising, high performance regions of the design space efficiently. Bayesian network classifiers (BNCs) are such an approach that can identify these regions of promising designs in the presence of nonlinear relationships and mixed variables. When manufacturing the promising designs identified by the BNC approach, the intended design may not match the physical embodiment due to manufacturing variations. These variations may alter the performance of the design leading to unsatisfactory results and products. To facilitate selection of not only high performance but reliably manufacturable designs, a method for incorporating manufacturing variation, modeled as a joint probability distribution is presented for the BNC approach. The approach utilizes a dual classification strategy that identifies regions of design that are likely to perform well within statistical confidence. These design regions can be high dimensional in which it becomes very difficult to identify and visualize clusters of promising designs. This leads to a lack of understanding of the design space. To enhance the designer’s knowledge of the design space, this work presents a method, based on spectral clustering, that can identify high performance regions in a high dimensional space. Furthermore, a method for visualizing each individual design region is presented that is accomplished by incorporating t-Distributed Stochastic Neighbor Embedding. Through the accomplishment of these three tasks—incorporating manufacturing variation, clustering, and visualizing—a novel design methodology will be developed which will then be applied to identify satisfactory designs for a negative stiffness metamaterials design problem which will be manufactured and tested.Mechanical Engineerin

Physical Function During Performance-Based Tasks and Throughout Daily Life. Is It Different Across Levels of Frailty?

The overall aim of this thesis was to provide a more focused understanding about the physical function of older women across levels of frailty. The specific aims were: 1) Examine the physical function of older women across levels of frailty during performance-based tasks and throughout their normal daily life; and 2) Review the effectiveness of current exercise interventions for the management of frailty. To answer these aims an observational study of community-dwelling older women (63-100 years) from rural Greece and a comprehensive systematic review on the impact of exercise on frail older adults were conducted. The performance-based measures that had the strongest association with frailty were ambulatory mobility, lower body muscular endurance, and non-dominant handgrip strength. Walking at a preferred pace was more related to frailty than walking at maximal pace and grip strength of the non-dominant hand had a stronger association with frailty compared to the dominant hand. In addition, accelerometers showed good agreement with the other physical activity tools, had the strongest association with frailty, and could be used to dissociate levels of frailty. This thesis showed that multiple methods can be used to accurately determine the duration and intensity of physical activity in older adults across levels of frailty since each method examined in this thesis had limitations but provided useful information about different aspects of physical activity. Muscle activity and quiescence, as measured with portable electromyography, may add insight to the dissociation of frailty since they differ across levels of frailty and may also be used to indicate differences between the upper and lower body muscles. Finally, the systematic review indicated that structured exercise training can have a positive effect on frail older adults and thus can be helpful for the management of frailty. Multicomponent training interventions, of long duration (≥ 5 months), performed three times per week, for 30-45 minutes per session, generally had superior outcomes than other exercise programs. The findings from this thesis indicated that the criteria selected to define frailty and the measurement protocols for these criteria are important. Future investigations will help classify the potential role of these measures in preventing further functional decline

Techniques for Aging, Soft Errors and Temperature to Increase the Reliability of Embedded On-Chip Systems

This thesis investigates the challenge of providing an abstracted, yet sufficiently accurate reliability estimation for embedded on-chip systems. In addition, it also proposes new techniques to increase the reliability of register files within processors against aging effects and soft errors. It also introduces a novel thermal measurement setup that perspicuously captures the infrared images of modern multi-core processors