Matching Items (481)
Filtering by
- Creators: College of Health Solutions
- Resource Type: Text
Description
New OpenFlow switches support a wide range of network applications, such as firewalls, load balancers, routers, and traffic monitoring. While ternary content addressable memory (TCAM) allows switches to process packets at high speed based on multiple header fields, today's commodity switches support just thousands to tens of thousands of forwarding rules. To allow for finer-grained policies on this hardware, efficient ways to support the abstraction of a switch are needed with arbitrarily large rule tables. To do so, a hardware-software hybrid switch is designed that relies on rule caching to provide large rule tables at low cost. Unlike traditional caching solutions, neither individual rules are cached (to respect rule dependencies) nor compressed (to preserve the per-rule traffic counts). Instead long dependency chains are ``spliced'' to cache smaller groups of rules while preserving the semantics of the network policy. The proposed hybrid switch design satisfies three criteria: (1) responsiveness, to allow rapid changes to the cache with minimal effect on traffic throughput; (2) transparency, to faithfully support native OpenFlow semantics; (3) correctness, to cache rules while preserving the semantics of the original policy. The evaluation of the hybrid switch on large rule tables suggest that it can effectively expose the benefits of both hardware and software switches to the controller and to applications running on top of it.
ContributorsAlipourfard, Omid (Author) / Syrotiuk, Violet R. (Thesis advisor) / Richa, Andréa W. (Committee member) / Xue, Guoliang (Committee member) / Arizona State University (Publisher)
Created2014
Description
Interference constitutes a major challenge for communication networks operating over a shared medium where availability is imperative. This dissertation studies the problem of designing and analyzing efficient medium access protocols which are robust against strong adversarial jamming. More specifically, four medium access (MAC) protocols (i.e., JADE, ANTIJAM, COMAC, and SINRMAC) which aim to achieve high throughput despite jamming activities under a variety of network and adversary models are presented. We also propose a self-stabilizing leader election protocol, SELECT, that can effectively elect a leader in the network with the existence of a strong adversary. Our protocols can not only deal with internal interference without the exact knowledge on the number of participants in the network, but they are also robust to unintentional or intentional external interference, e.g., due to co-existing networks or jammers. We model the external interference by a powerful adaptive and/or reactive adversary which can jam a (1 − ε)-portion of the time steps, where 0 < ε ≤ 1 is an arbitrary constant. We allow the adversary to be adaptive and to have complete knowledge of the entire protocol history. Moreover, in case the adversary is also reactive, it uses carrier sensing to make informed decisions to disrupt communications. Among the proposed protocols, JADE, ANTIJAM and COMAC are able to achieve Θ(1)-competitive throughput with the presence of the strong adversary; while SINRMAC is the first attempt to apply SINR model (i.e., Signal to Interference plus Noise Ratio), in robust medium access protocols design; the derived principles are also useful to build applications on top of the MAC layer, and we present SELECT, which is an exemplary study for leader election, which is one of the most fundamental tasks in distributed computing.
ContributorsZhang, Jin (Author) / Richa, Andréa W. (Thesis advisor) / Scheideler, Christian (Committee member) / Sen, Arunabha (Committee member) / Xue, Guoliang (Committee member) / Arizona State University (Publisher)
Created2012
Description
Exhaustive testing is generally infeasible except in the smallest of systems. Research
has shown that testing the interactions among fewer (up to 6) components is generally
sufficient while retaining the capability to detect up to 99% of defects. This leads to a
substantial decrease in the number of tests. Covering arrays are combinatorial objects
that guarantee that every interaction is tested at least once.
In the absence of direct constructions, forming small covering arrays is generally
an expensive computational task. Algorithms to generate covering arrays have been
extensively studied yet no single algorithm provides the smallest solution. More
recently research has been directed towards a new technique called post-optimization.
These algorithms take an existing covering array and attempt to reduce its size.
This thesis presents a new idea for post-optimization by representing covering
arrays as graphs. Some properties of these graphs are established and the results are
contrasted with existing post-optimization algorithms. The idea is then generalized to
close variants of covering arrays with surprising results which in some cases reduce
the size by 30%. Applications of the method to generation and test prioritization are
studied and some interesting results are reported.
has shown that testing the interactions among fewer (up to 6) components is generally
sufficient while retaining the capability to detect up to 99% of defects. This leads to a
substantial decrease in the number of tests. Covering arrays are combinatorial objects
that guarantee that every interaction is tested at least once.
In the absence of direct constructions, forming small covering arrays is generally
an expensive computational task. Algorithms to generate covering arrays have been
extensively studied yet no single algorithm provides the smallest solution. More
recently research has been directed towards a new technique called post-optimization.
These algorithms take an existing covering array and attempt to reduce its size.
This thesis presents a new idea for post-optimization by representing covering
arrays as graphs. Some properties of these graphs are established and the results are
contrasted with existing post-optimization algorithms. The idea is then generalized to
close variants of covering arrays with surprising results which in some cases reduce
the size by 30%. Applications of the method to generation and test prioritization are
studied and some interesting results are reported.
ContributorsKaria, Rushang Vinod (Author) / Colbourn, Charles J (Thesis advisor) / Syrotiuk, Violet (Committee member) / Richa, Andréa W. (Committee member) / Arizona State University (Publisher)
Created2015
Description
Many applications require efficient data routing and dissemination in Delay Tolerant Networks (DTNs) in order to maximize the throughput of data in the network, such as providing healthcare to remote communities, and spreading related information in Mobile Social Networks (MSNs). In this thesis, the feasibility of using boats in the Amazon Delta Riverine region as data mule nodes is investigated and a robust data routing algorithm based on a fountain code approach is designed to ensure fast and timely data delivery considering unpredictable boat delays, break-downs, and high transmission failures. Then, the scenario of providing healthcare in Amazon Delta Region is extended to a general All-or-Nothing (Splittable) Multicommodity Flow (ANF) problem and a polynomial time constant approximation algorithm is designed for the maximum throughput routing problem based on a randomized rounding scheme with applications to DTNs. In an MSN, message content is closely related to users’ preferences, and can be used to significantly impact the performance of data dissemination. An interest- and content-based algorithm is developed where the contents of the messages, along with the network structural information are taken into consideration when making message relay decisions in order to maximize data throughput in an MSN. Extensive experiments show the effectiveness of the above proposed data dissemination algorithm by comparing it with state-of-the-art techniques.
ContributorsLiu, Mengxue (Author) / Richa, Andréa W. (Thesis advisor) / Johnson, Thienne (Committee member) / Syrotiuk, Violet R. (Committee member) / Xue, Guoliang (Committee member) / Arizona State University (Publisher)
Created2018
Description
High childhood obesity rates have resulted in many interventions to attempt to lower these rates. Interventions such as day camps, residential camps, therapy-based interventions and family-based interventions lead to changes in weight and self-esteem but family-based intervention leads to the longest-term success for children ages nine to 17. Analysis of the interventions was measured using tools such as BMI, BMI-percentiles, and weight. Psychological measures such as self-esteem, happiness, and quality of life analysis was preferred, however were not measured in all studies. While most interventions resulted in weight loss and increased self-esteem, results were often not long-term. Studies provided evidence that family-based therapy has potential to last long-term, however there is a lack of research. To determine the most effective childhood nutrition intervention research must conduct follow-ups for many years after the initial intervention to ensure they provide long-term results.
ContributorsAnderson, Megan Lee (Author) / McCoy, Maureen (Thesis director) / Kniskern, Megan (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The purpose of this study was to develop proposal lesson plans for 4th-6th graders based on active learning to integrate movement physical activity into the curriculum. The 4th-6th graders were chosen, as this is the age where teaching typically transitions from active learning to sedentary/lecture style teaching. Research compiled indicated positive effects of active based learning on children such as increased attention span, retention, and general focus. A survey was created to not only assess the perception of active versus didactic learners, but to also assess the effects of movement-based learning on the variables that research claimed to change. The lesson plans developed here should be transferable to a classroom lesson to evaluate the hypothesized results.
ContributorsTanna, Nimisha (Author) / Hyatt, JP (Thesis director) / Ainsworth, Barbara (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
About 75% of men and 66.58% of women are considered overweight or obese (BMI ≥25). $117 billion dollars is spent each year in medical costs due to physical inactivity. Aerobic exercise has been well defined in its’ benefits to cardiovascular health; however, the effects of resistance training are still not well defined. The purpose of this preliminary analysis was to evaluate the vascular health effects (central and peripheral blood pressure and VO2 max) of two different types of resistance training programs: high load, low repetitions resistance training and low load, high repetitions resistance training. Fourteen participants aged 18-55 years (6 males, 8 females) were involved in this preliminary analysis. Data were collected before and after the 12-week long exercise program (36 training sessions) via pulse wave analysis and VO2peak testing. Multivariate regression analysis of training program effects, while adjusting for body mass index and time, did not result in significant training effects on central and peripheral diastolic blood pressure, nor VO2peak. A statistical trend was observed between the different training programs for systolic blood pressure, suggesting that subjects partaking in the high load, low repetitions program exhibited higher systolic blood pressures than the low load, high repetitions group. With a larger sample size, the difference in systolic blood pressure may increase between training program groups and indicate that greater loads with minimal repetitions may increase lead to clinically significant elevations in blood pressure. Further work is needed to uncover the relationship between different types of resistance training and blood pressure, especially if these lifting regimens are continued for longer lengths of time.
ContributorsHill, Cody Alan (Co-author) / Hill, Cody (Co-author) / Whisner, Corrie (Thesis director) / Angadi, Siddhartha (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Introduction: Individuals with rotator cuff tears have been found to compensate in their movement patterns by using lower thoracohumeral elevation angles during certain tasks, as well as increased internal rotation of the shoulder (Vidt et al., 2016). Leading joint hypothesis suggests there is one leading joint that creates the foundation for the entire limb motion, and there are other subordinate joints which monitor the passive interaction torque and create a net torque aiding to limb motions required for the task. This experiment seeks to establish a better understanding of joint control strategies during a wide range of arm movements. Based on the leading joint hypothesis, we hypothesize that when a subject has a rotator cuff tear, their performance of planar and three-dimensional motions should be altered not only at the shoulder, which is often the leading joint, but also at other joints on the arm, such as the elbow and wrist. This paper will focus on the effect of normal aging on the control of the joints of the arm.
Methods: There were 4 groups of participants: healthy younger adults (n=14)(21.74 ± 1.97), healthy older adults (n=12)(55-75), older adults (n=4)(55-75) with a partial-thickness rotator cuff tear, and older adults (n=4)(55-75) with a full-thickness rotator cuff tear (RCT). All four groups completed strength testing, horizontal drawing and pointing tasks, and three dimensional (3D) activities of daily living. Kinematic and kinetic variables of the arm were obtained during horizontal and 3D tasks using data from 12 reflective markers placed on the arm, 8 motion capture cameras, and Cortex motion capture software (Motion Analysis Corp., Santa Rosa, CA). Strength testing tasks were measured using a dynamometer. All strength testing and 3D tasks were completed for three trials and horizontal tasks were completed for two trials.
Results: Results of the younger adult participants showed that during the forward portion of seven 3D tasks, there were four phases of different joint control mechanics seen in a majority of the movements. These phases included active rotation of both the shoulder and the elbow joint, active rotation of the shoulder with passive rotation of the elbow, passive rotation of the shoulder with active rotation of the elbow, and passive rotation of both the shoulder and the elbow. Passive rotation during movements was a result of gravitational torque on the different segments of the arm and interaction torque caused as a result of the multi-joint structure of human limbs. The number of tested participants for the minor RCT, and RCT older adults groups is not yet high enough to produce significant results and because of this their results are not reported in this article. Between the older adult control group and the young adult control group in the tasks upward reach to eye height and hair comb there were significant differences found between the groups. The differences were found in shorter overall time and distance between the two groups in the upward eye task.
Discussion: Through the available results, multiple phases were found where one or both of the joints of the arm moved passively which further supports the LJH and extends it to include 3D movements. With available data, it can be concluded that healthy older adults use movement control strategies, such as shortening distance covered, decreasing time percentage in active joint phases, and increasing time percentage in passive joint phases, to account for atrophy along with other age-related declines in performance, such as a decrease in range of motion. This article is a part of a bigger project which aims to better understand how older adults with RCTs compensate for the decreased strength, the decreased range of motion, and the pain that accompany this type of injury. It is anticipated that the results of this experiment will lead to more research toward better understanding how to treat patients with RCTs.
Methods: There were 4 groups of participants: healthy younger adults (n=14)(21.74 ± 1.97), healthy older adults (n=12)(55-75), older adults (n=4)(55-75) with a partial-thickness rotator cuff tear, and older adults (n=4)(55-75) with a full-thickness rotator cuff tear (RCT). All four groups completed strength testing, horizontal drawing and pointing tasks, and three dimensional (3D) activities of daily living. Kinematic and kinetic variables of the arm were obtained during horizontal and 3D tasks using data from 12 reflective markers placed on the arm, 8 motion capture cameras, and Cortex motion capture software (Motion Analysis Corp., Santa Rosa, CA). Strength testing tasks were measured using a dynamometer. All strength testing and 3D tasks were completed for three trials and horizontal tasks were completed for two trials.
Results: Results of the younger adult participants showed that during the forward portion of seven 3D tasks, there were four phases of different joint control mechanics seen in a majority of the movements. These phases included active rotation of both the shoulder and the elbow joint, active rotation of the shoulder with passive rotation of the elbow, passive rotation of the shoulder with active rotation of the elbow, and passive rotation of both the shoulder and the elbow. Passive rotation during movements was a result of gravitational torque on the different segments of the arm and interaction torque caused as a result of the multi-joint structure of human limbs. The number of tested participants for the minor RCT, and RCT older adults groups is not yet high enough to produce significant results and because of this their results are not reported in this article. Between the older adult control group and the young adult control group in the tasks upward reach to eye height and hair comb there were significant differences found between the groups. The differences were found in shorter overall time and distance between the two groups in the upward eye task.
Discussion: Through the available results, multiple phases were found where one or both of the joints of the arm moved passively which further supports the LJH and extends it to include 3D movements. With available data, it can be concluded that healthy older adults use movement control strategies, such as shortening distance covered, decreasing time percentage in active joint phases, and increasing time percentage in passive joint phases, to account for atrophy along with other age-related declines in performance, such as a decrease in range of motion. This article is a part of a bigger project which aims to better understand how older adults with RCTs compensate for the decreased strength, the decreased range of motion, and the pain that accompany this type of injury. It is anticipated that the results of this experiment will lead to more research toward better understanding how to treat patients with RCTs.
ContributorsFlores, Noah Mateo (Author) / Dounskaia, Natalia (Thesis director) / Vidt, Meghan (Committee member) / College of Health Solutions (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
There has been a rise in the prevalence of mental health disorders among western industrialized populations.1 By 2020, depression will be second to heart disease in its contribution to the global burden of disease as measured by disability-adjusted life years.2 Anxiety disorders are the most common mental illness in the U.S., affecting 40 million adults in the United States ages 18 and older, or 18.1% of the U.S population every year.3
Mental disorders are prevalent in young adults and frequently present between 12-24 years of age.4 The top five sources of stress reported by college students were changes in sleeping routines, changes in eating habits, increased amount of work, new responsibilities, and breaks/vacations.5 Overall, a total of 73% of college students report occasional difficulties sleeping, and 48% of students suffer from sleep deprivation, as self-reported.6,7
Lifestyle factors such as diet, exercise and sleep may influence symptoms related to stress and depression.8 Symptoms of depression include but are not limited to, persistent anxious or sad moods, feeling guilty or helpless, loss of interest in hobbies, irritability, and other behaviors that may interrupt daily living.9 Inadequate intake of folic acid from fruits and vegetables, and essential fatty acids in fish, may increase symptoms of depression.10 Unhealthy eating habits may be associated with increases in depression-like symptoms in women, supporting the notion that healthier eating habits may decrease major depression.11 Diet is only one component of how lifestyle may influence depression and stress in adults. Exercise may be another important component in decreasing depression-related symptoms due to the release of endorphins.12 It has been found that participating in regular physical activity may decrease tension levels, increase and stabilize mood, improve self-esteem, and lead to better sleeping patterns.13 It has been concluded that individuals who consume a healthy diet are less likely to experience depression whereas people eating unhealthy and processed diets are more likely to be depressed.14
Poor sleep quality as well as unstable sleeping patterns may lead to poor psychological and physical health.15 Poor sleep includes longer duration of sleep onset latency, which is defined as the amount of time it takes to fall asleep, waking up multiple times throughout the night, and not getting a restful sleep because of tossing and turning.16 In healthy adults, the short-term consequences of sleep disruption consist of somatic pain, emotional destress and mood disorders, reduced quality of life, and increased stress responsivity.17 Irregular sleep-wake patterns, defined as taking numerous naps within a 24 hour span and not having a main nighttime sleep experience, are present at alarming levels (more than a quarter) among college students.18 A study done with 2,000 college students concluded that more than a quarter of the students were at risk of a sleeping disorder.19 Therefore, college students who were classified as poor-quality sleepers, reported experiencing more psychological and physical health problems compared to their healthy counterparts. Perceived stress was also found to be a factor in lower sleep quality of young adults.20
The link between depression-like symptoms and sleep remains poorly understood. It is mentioned that there are risk factors of poor sleep, depression and anxiety among college students but this topic has not yet been heavily studied within this population.
Mental disorders are prevalent in young adults and frequently present between 12-24 years of age.4 The top five sources of stress reported by college students were changes in sleeping routines, changes in eating habits, increased amount of work, new responsibilities, and breaks/vacations.5 Overall, a total of 73% of college students report occasional difficulties sleeping, and 48% of students suffer from sleep deprivation, as self-reported.6,7
Lifestyle factors such as diet, exercise and sleep may influence symptoms related to stress and depression.8 Symptoms of depression include but are not limited to, persistent anxious or sad moods, feeling guilty or helpless, loss of interest in hobbies, irritability, and other behaviors that may interrupt daily living.9 Inadequate intake of folic acid from fruits and vegetables, and essential fatty acids in fish, may increase symptoms of depression.10 Unhealthy eating habits may be associated with increases in depression-like symptoms in women, supporting the notion that healthier eating habits may decrease major depression.11 Diet is only one component of how lifestyle may influence depression and stress in adults. Exercise may be another important component in decreasing depression-related symptoms due to the release of endorphins.12 It has been found that participating in regular physical activity may decrease tension levels, increase and stabilize mood, improve self-esteem, and lead to better sleeping patterns.13 It has been concluded that individuals who consume a healthy diet are less likely to experience depression whereas people eating unhealthy and processed diets are more likely to be depressed.14
Poor sleep quality as well as unstable sleeping patterns may lead to poor psychological and physical health.15 Poor sleep includes longer duration of sleep onset latency, which is defined as the amount of time it takes to fall asleep, waking up multiple times throughout the night, and not getting a restful sleep because of tossing and turning.16 In healthy adults, the short-term consequences of sleep disruption consist of somatic pain, emotional destress and mood disorders, reduced quality of life, and increased stress responsivity.17 Irregular sleep-wake patterns, defined as taking numerous naps within a 24 hour span and not having a main nighttime sleep experience, are present at alarming levels (more than a quarter) among college students.18 A study done with 2,000 college students concluded that more than a quarter of the students were at risk of a sleeping disorder.19 Therefore, college students who were classified as poor-quality sleepers, reported experiencing more psychological and physical health problems compared to their healthy counterparts. Perceived stress was also found to be a factor in lower sleep quality of young adults.20
The link between depression-like symptoms and sleep remains poorly understood. It is mentioned that there are risk factors of poor sleep, depression and anxiety among college students but this topic has not yet been heavily studied within this population.
ContributorsBosnino, Jasmine (Co-author, Co-author) / Whisner, Corrie (Thesis director) / Petrov, Megan (Committee member) / Mahmood, Tara (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Patients face tremendous challenges when attempting to navigate the United States health care system. This difficulty to navigate the system creates a burden that is placed on the patient and caregiver, in turn affecting the health outcomes of the patient, resulting in higher health care costs, less than desirable outcomes, and a large strain on the patient and caregiver's daily lives. There are several ways that people have tried to create a comprehensive theoretical framework to understand the system from multiple perspectives. This work will expand existing theoretical frameworks that observes the relationship between the patient, their social networks, and health care services such as the Burden of Treatment Theory. Consisting of a comprehensive, multidisciplinary literature review, research was derived from the disciplines of medicine, informatics, management, and ethics. In this paper, I attempt to identify key contributing factors and then develop and categorize these stressors into a typology. Since there are many contributing factors that affect the burden of work at multiple levels, a nested typology will be used which will link micro- and macro-leveled pressures to a single system while also showcasing how each level interacts and is influenced by the others. For the categorization of the contributing factors, they will be sorted into individual actors, organizational level, and macro-level factors. The implications of this work suggest that a combination of historical shifts, structural design, and secondary effects of policy contribute to patients' burden of work.
ContributorsTomlinson, Rachel Laiku (Author) / Pine, Katie (Thesis director) / Trinh, Mai (Committee member) / School for the Science of Health Care Delivery (Contributor) / Barrett, The Honors College (Contributor) / College of Health Solutions (Contributor)
Created2017-05