Matching Items (479)
Description
Distributed wireless sensor networks (WSNs) have attracted researchers recently due to their advantages such as low power consumption, scalability and robustness to link failures. In sensor networks with no fusion center, consensus is a process where
all the sensors in the network achieve global agreement using only local transmissions. In this dissertation, several consensus and consensus-based algorithms in WSNs are studied.
Firstly, a distributed consensus algorithm for estimating the maximum and minimum value of the initial measurements in a sensor network in the presence of communication noise is proposed. In the proposed algorithm, a soft-max approximation together with a non-linear average consensus algorithm is used. A design parameter controls the trade-off between the soft-max error and convergence speed. An analysis of this trade-off gives guidelines towards how to choose the design parameter for the max estimate. It is also shown that if some prior knowledge of the initial measurements is available, the consensus process can be accelerated.
Secondly, a distributed system size estimation algorithm is proposed. The proposed algorithm is based on distributed average consensus and L2 norm estimation. Different sources of error are explicitly discussed, and the distribution of the final estimate is derived. The CRBs for system size estimator with average and max consensus strategies are also considered, and different consensus based system size estimation approaches are compared.
Then, a consensus-based network center and radius estimation algorithm is described. The center localization problem is formulated as a convex optimization problem with a summation form by using soft-max approximation with exponential functions. Distributed optimization methods such as stochastic gradient descent and diffusion adaptation are used to estimate the center. Then, max consensus is used to compute the radius of the network area.
Finally, two average consensus based distributed estimation algorithms are introduced: distributed degree distribution estimation algorithm and algorithm for tracking the dynamics of the desired parameter. Simulation results for all proposed algorithms are provided.
all the sensors in the network achieve global agreement using only local transmissions. In this dissertation, several consensus and consensus-based algorithms in WSNs are studied.
Firstly, a distributed consensus algorithm for estimating the maximum and minimum value of the initial measurements in a sensor network in the presence of communication noise is proposed. In the proposed algorithm, a soft-max approximation together with a non-linear average consensus algorithm is used. A design parameter controls the trade-off between the soft-max error and convergence speed. An analysis of this trade-off gives guidelines towards how to choose the design parameter for the max estimate. It is also shown that if some prior knowledge of the initial measurements is available, the consensus process can be accelerated.
Secondly, a distributed system size estimation algorithm is proposed. The proposed algorithm is based on distributed average consensus and L2 norm estimation. Different sources of error are explicitly discussed, and the distribution of the final estimate is derived. The CRBs for system size estimator with average and max consensus strategies are also considered, and different consensus based system size estimation approaches are compared.
Then, a consensus-based network center and radius estimation algorithm is described. The center localization problem is formulated as a convex optimization problem with a summation form by using soft-max approximation with exponential functions. Distributed optimization methods such as stochastic gradient descent and diffusion adaptation are used to estimate the center. Then, max consensus is used to compute the radius of the network area.
Finally, two average consensus based distributed estimation algorithms are introduced: distributed degree distribution estimation algorithm and algorithm for tracking the dynamics of the desired parameter. Simulation results for all proposed algorithms are provided.
ContributorsZhang, Sai (Electrical engineer) (Author) / Tepedelenlioğlu, Cihan (Thesis advisor) / Spanias, Andreas (Thesis advisor) / Tsakalis, Kostas (Committee member) / Bliss, Daniel (Committee member) / Arizona State University (Publisher)
Created2017
Description
This study examined upper extremity function, including manual dexterity, in chronic stroke survivors following a 10-week high intensity interval treadmill walking intervention. Six stroke survivors completed two 35-minute high intensity interval treadmill walking sessions based on ventilatory threshold per week. In addition, each participant completed one 30-minute low-intensity walking session at home. Participants completed upper extremity and manual dexterity testing at baseline, acutely, and after the 10-week intervention. Contrary to the prediction made, significant improvements in both paretic and non-paretic upper-extremity function including manual dexterity were not found. While time to complete the Nine Hole Peg Test (9HPB) somewhat decreased and the number of blocks transferred in the Box and Blocks Test (BBT) slightly increased, results were not found to be statistically significant. The results do suggest, nonetheless, that high intensity interval treadmill training may lead to improvements in upper extremity function and potentially daily living in chronic stroke survivors.
ContributorsHatty, Laura Elizabeth (Author) / Ringenbach, Shannon (Thesis director) / Bosch, Pamela (Committee member) / Holzapfel, Simon (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Background: Physical inactivity is a major cause of obesity, hypertension, cardiovascular disease, and diabetes and has become a major public health problem. Physical inactivity is detrimental to one's health, but it has also created a significant healthcare burden. Within the past decade, many health-based interventions have been implemented to encourage physically inactive individuals to adopt a more active lifestyle. These health-based interventions have used social media websites, particularly Facebook, to establish social support between the participants of those interventions. There is currently limited research on this topic. This study aims to add to that literature by exploring strategies to encourage participants of health-based interventions to interact with a Facebook group. Purpose: An exercise and nutrition-based intervention called Athletes for Life (AFL) has been using a Facebook page over the past 2.5 years to establish social support between participants of the program, among other functions. The level of interaction that participants had with the Facebook page has declined over the past year. The objective of this study is to redesign and refine the AFL Facebook page so that it is more appealing and interactive to AFL participants. Methods: Redesigning and refining the AFL Facebook page were achieved through three strategies. The first strategy was to recruit approximately twenty participants to the new AFL Facebook group. The next strategy was to select a participant to become the group champion who would post encouraging content on the Facebook group wall. The final strategy was to maintain the consistency with which participants liked and viewed posts on the group wall. Results: The results of this study showed nine participants joined the group and these participants had a combined total of 62 likes and 110 views on the group wall over an eleven-week period. Participants interacted with the content posted by the Facebook group administrators on a consistent basis, but only one participant posted a recipe to the group wall. Measuring the level of interaction for each individual post was significant because it illustrated that the level of interaction participants had with posts depended on the identity of the posts' author. Conclusions: Future research should test the effectiveness of a Facebook group page for promoting physical activity and implementing the suggestions from study participants to increase Facebook usage.
ContributorsNasef, Amr Sherif (Author) / Crespo, Noe (Thesis director) / Hekler, Eric (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The Student Health Outreach for Wellness (SHOW) is a free, student-led interprofessional clinic and community outreach initiative that aims to serve individuals experiencing homelessness in Phoenix, AZ. Individuals experiencing homelessness face many situational and financial barriers to finding healthcare. In order to better understand these barriers, a community needs assessment (CNA) was conducted in Fall 2014 on the Human Services Campus (HSC), a hub of resources for the population. Results indicated chronic disease is moderately prevalent (37.21% and 27.91% reported obesity and hypertension, respectively, among others). Since chronic diseases can lead to more severe health issues, it is imperative to address, manage, and avoid these conditions. Health education programs are a key component of the SHOW clinic model and a means to address chronic disease. The Health Belief Model (HBM) is a theory-based behavior change model used in programs to increase patient adherence to and promotion of preventative health behaviors. SHOW health education programs will use the constructs of this model to inform program development. Since many student volunteers are not well-versed in health education literature, a SHOW Program Development Guide based on the HBM has been created. The guide will help ensure SHOW delivers high-quality and efficacious programs that have a long-lasting impact on patients now and as the organization continues to grow.
ContributorsReeve, Emma Christine (Author) / Hoffner, Kristin (Thesis director) / Harrell, Susan (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Informal caregivers to persons with Alzheimer’s disease (AD) commonly experience high levels of perceived burden, stress, and low quality of life— outcomes that negatively affect the quality of care provided. Yet to be explored are the effects of heart-focused breathing, a self-regulation deep breathing technique, on perceived caregiver burden and heart rate variability (HRV), a measure of autonomic nervous system function. Considering the high attrition rates of many previous in-person AD caregiver interventions, it may be necessary to implement an online intervention to address perceived caregiver burden. This study aimed to test the trends in effects of a 2-week online heart-focused breathing intervention using HeartMath’s Heart Lock-In® technique on perceived caregiver burden, perceived stress, quality of life, anxiety, inner haven, self-compassion, and HRV in a population of AD caregivers. Ten informal AD caregivers participated in the study with five participants randomized into the waitlist control group and five into the intervention group. The intervention group practiced a 10-minute heart-focused breathing protocol using their smart device (i.e., phone) every day for a 2-week period. Participants completed pre- and post- self-report questionnaires online via Google Forms and HRV assessments via the Welltory mobile application. The HRV assessments measured rMSSD, high frequency, and low frequency. The intervention group did not experience improvements related to perceived caregiver burden, perceived stress, anxiety, inner haven or high frequency waves. However, the study results suggest positive trends in quality of life, self-compassion, rMSSD, and low frequency waves among the AD caregivers. Additional research within a larger and more diverse population is needed.
Keywords: Informal Alzheimer’s caregivers, perceived caregiver burden, heart-focused breathing, heart rate variability
Keywords: Informal Alzheimer’s caregivers, perceived caregiver burden, heart-focused breathing, heart rate variability
ContributorsJames, Taylor Anne (Author) / Larkey, Linda K. (Thesis director) / James, Darith (Committee member) / Edson College of Nursing and Health Innovation (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The purpose of this study was to determine if there was a relationship between the constructs of motivational theories, Self-Determination Theory and Health Belief Model, and adherence to a home exercise program. The constructs of Self-Determination Theory are autonomy, competence, and social relatedness. The constructs of Health Belief Model are perceived benefits, perceived barriers, perceived severity, and perceived susceptibility. Participants were receiving therapy at two outpatient clinics located in the Phoenix metropolitan area (n=40). Autonomy was assessed with a modified Treatment Self-Regulation Questionnaire. Competence was assessed with a modified Perceived Competence Scale. Social relatedness was assessed with a modified Health Care Climate Questionnaire. Perceived benefits and barriers were measured with a modified Exercise Benefits/Barriers Scale. Perceived severity and susceptibility were measured with a modified Health Beliefs Questionnaire. Adherence was measured with one Likert-type question that was created by the researchers. The data was scored and analyzed with the scoring guidelines provided by the questionnaires and the statistics software, IBM Statistical Package for the Social Sciences. The results showed that competence was the only construct that was significantly correlated with home exercise program adherence. The results from this study should be used for further research that focuses on creating a competence-supportive environment in physical therapy settings.
ContributorsAutrey, Makenna Noelle (Co-author) / Hamilton, Marissa (Co-author) / Hoffner, Kristin (Thesis director) / Broman, Tannah (Committee member) / School of Nutrition and Health Promotion (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
According to the Center for Disease Control, 1 in every 3 individuals will fall in their lifetime. Treadmill perturbation training has been a beneficial tool to increase reactive postural control and decrease the amount of falls. This study looked at the extent of the training effects on 29 healthy young adults to evaluate if stepping improvements in one direction could generalize to improvements in the quality of stepping in other directions. Outcome variables of Margin of Stability (MOS), step length, and step latency were evaluated for all 15 participants trained with forward perturbations and 14 participants trained with backward perturbations. From the paired t-tests, there were limited significant improvements in stepping with regards to motor learning and generalization. The only significant outcome was an increase in step length for the participants who trained in the backward direction (p=0.014; p<0.05). However, this significant increase in step length for this backward group did not generalize when the participants stepped in the forward direction post training. From the correlation tests, there was a significant, moderate correlation between motor learning and generalization (rho =0.527, p= 0.043; p<0.05), thus suggesting there may be a relationship between the amount of learning and the amount of generalization observed. Further evaluation of the second step and the foot motion during stepping may reveal more information and explain the changes in stepping to describe how healthy young adults were able to regain balance with each perturbation given.
ContributorsNowak, Rachael Teresa (Author) / Peterson, Daniel (Thesis director) / Dounskaia, Natalia (Committee member) / School of Nutrition and Health Promotion (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
DescriptionThis paper explores what lifestyle choices college students can take from the six longevity hotspots of the world to increase their happiness, and in turn potentially add a few years to their lives.
ContributorsKenehan, Bryn (Author) / Giasson, Hannah (Thesis director) / Barth, Chrissy (Committee member) / Barrett, The Honors College (Contributor) / Edson College of Nursing and Health Innovation (Contributor)
Created2024-05
Description
This thesis explores the importance of preoperative patient education on peripheral nerve blocks in improving informed consent and expanding the patient's role in their care. It looks at the impact of providing patients with education on the procedure, expected outcomes and post-operative care so they fully understand what to expect during this procedure. By showcasing the importance of informed consent and shared decision-making between healthcare staff and patients, this thesis demonstrates the ability for improved health outcomes through expansion of preoperative nerve block education.
ContributorsVelez, Annasophia (Author) / Day, Kim (Thesis director) / Hagler, Debra (Committee member) / Barrett, The Honors College (Contributor) / Edson College of Nursing and Health Innovation (Contributor)
Created2024-05