Matching Items (939)
Description
As robots become more prevalent, the need is growing for efficient yet stable control systems for applications with humans in the loop. As such, it is a challenge for scientists and engineers to develop robust and agile systems that are capable of detecting instability in teleoperated systems. Despite how much

As robots become more prevalent, the need is growing for efficient yet stable control systems for applications with humans in the loop. As such, it is a challenge for scientists and engineers to develop robust and agile systems that are capable of detecting instability in teleoperated systems. Despite how much research has been done to characterize the spatiotemporal parameters of human arm motions for reaching and gasping, not much has been done to characterize the behavior of human arm motion in response to control errors in a system. The scope of this investigation is to investigate human corrective actions in response to error in an anthropomorphic teleoperated robot limb. Characterizing human corrective actions contributes to the development of control strategies that are capable of mitigating potential instabilities inherent in human-machine control interfaces. Characterization of human corrective actions requires the simulation of a teleoperated anthropomorphic armature and the comparison of a human subject's arm kinematics, in response to error, against the human arm kinematics without error. This was achieved using OpenGL software to simulate a teleoperated robot arm and an NDI motion tracking system to acquire the subject's arm position and orientation. Error was intermittently and programmatically introduced to the virtual robot's joints as the subject attempted to reach for several targets located around the arm. The comparison of error free human arm kinematics to error prone human arm kinematics revealed an addition of a bell shaped velocity peak into the human subject's tangential velocity profile. The size, extent, and location of the additional velocity peak depended on target location and join angle error. Some joint angle and target location combinations do not produce an additional peak but simply maintain the end effector velocity at a low value until the target is reached. Additional joint angle error parameters and degrees of freedom are needed to continue this investigation.
ContributorsBevilacqua, Vincent Frank (Author) / Artemiadis, Panagiotis (Thesis director) / Santello, Marco (Committee member) / Trimble, Steven (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2013-05
Description
It is well known that deficiencies in key chemical elements (such as phosphorus, P) can reduce animal growth; however, recent empirical data have shown that high levels of dietary nutrients can also reduce animal growth. In ecological stoichiometry, this phenomenon is known as the "stoichiometric knife edge," but its underlying

It is well known that deficiencies in key chemical elements (such as phosphorus, P) can reduce animal growth; however, recent empirical data have shown that high levels of dietary nutrients can also reduce animal growth. In ecological stoichiometry, this phenomenon is known as the "stoichiometric knife edge," but its underlying mechanisms are not well-known. Previous work has suggested that the crustacean zooplankter Daphnia reduces its feeding rates on phosphorus-rich food, causing low growth due to insufficient C (energy) intake. To test for this mechanism, feeding rates of Daphnia magna on algae (Scenedesmus acutus) differing in C:P ratio (P content) were determined. Overall, there was a significant difference among all treatments for feeding rate (p < 0.05) with generally higher feeding rates on P-rich algae. These data indicate that both high and low food C:P ratio do affect Daphnia feeding rate but are in contradiction with previous work that showed that P-rich food led to strong reductions in feeding rate. Additional experiments are needed to gain further insights.
ContributorsSchimpp, Sarah Ann (Author) / Elser, James (Thesis director) / Neuer, Susanne (Committee member) / Peace, Angela (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Sustainability (Contributor)
Created2014-05
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Description

For decades, understanding the complexity of behaviors, motivations, and values has interested researchers across various disciplines. So much so that there are numerous terms, frameworks, theories, and studies devoted to understanding these complexities and how they interact and evolve into actions. However, little research has examined how employee behaviors translate

For decades, understanding the complexity of behaviors, motivations, and values has interested researchers across various disciplines. So much so that there are numerous terms, frameworks, theories, and studies devoted to understanding these complexities and how they interact and evolve into actions. However, little research has examined how employee behaviors translate into the work environment, particularly regarding perceived organizational success. This study advances research by quantitatively assessing how a greater number of individual employees’ pro-environmental behaviors are related to the perceived success of environmentally sustainable workplace activities. We have concluded that the more pro-environmental behaviors an employee embodies, the more positively they perceive the success of their local government's sustainable purchasing policy. Additionally, other factors matter, including organizational behaviors, like training, innovation, and reduction of red tape.

ContributorsFox, Angela (Author) / Darnall, Nicole (Thesis advisor) / Bretschneider, Stuart (Committee member) / Behravesh, Shirley-Ann (Committee member) / School of Sustainability (Contributor)
Created2022-04-19
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Description

BACKGROUND: The City of Phoenix initiated the HeatReady program in 2018 to prepare for extreme heat, as there was no official tool, framework, or mechanism at the city level to manage extreme heat. The current landscape of heat safety culture in schools, which are critical community hubs, has received less

BACKGROUND: The City of Phoenix initiated the HeatReady program in 2018 to prepare for extreme heat, as there was no official tool, framework, or mechanism at the city level to manage extreme heat. The current landscape of heat safety culture in schools, which are critical community hubs, has received less illumination. HeatReady Schools—a critical component of a HeatReady City—are those that are increasingly able to identify, prepare for, mitigate, track, and respond to the negative impacts of schoolgrounds heat. However, minimal attention has been given to formalize heat preparedness in schools to mitigate high temperatures and health concerns in schoolchildren, a heat-vulnerable population. This study set out to understand heat perceptions, (re)actions, and recommendations of key stakeholders and to identify critical themes around heat readiness. METHODS: An exploratory sequential mixed-methods case study approach was used. These methods focused on acquiring new insight on heat perceptions at elementary schools through semi-structured interviews using thematic analysis and the Delphi panel. Participants included public health professionals and school community members at two elementary schools—one public charter, one public—in South Phoenix, Arizona, a region that has been burdened historically with inequitable distribution of heat resources due to environmental racism and injustices. RESULTS: Findings demonstrated that 1) current heat safety resources are available but not fully utilized within the school sites, 2) expert opinions support that extreme heat readiness plans must account for site-specific needs, particularly education as a first step, and 3) students are negatively impacted by the effects of extreme heat, whether direct or indirect, both inside and outside the classroom. CONCLUSIONS: From key informant interviews and a Delphi panel, a list of 30 final recommendations were developed as important actions to be taken to become “HeatReady.” Future work will apply these recommendations in a HeatReady School Growth Tool that schools can tailor be to their individual needs to improve heat safety and protection measures at schools.

ContributorsShortridge, Adora (Author) / Walker, William VI (Author) / White, Dave (Committee member) / Guardaro, Melissa (Committee member) / Hondula, David M. (Committee member) / Vanos, Jennifer K. (Committee member) / School of Sustainability (Contributor)
Created2022-04-18
Description
Pima was not the original name for the tribe of the Native Americans that lived along the Gila River, but their name is only one of many changes this tribe has faced due to the influence of outside sources. Pima was a name given to this tribe by the Spaniards

Pima was not the original name for the tribe of the Native Americans that lived along the Gila River, but their name is only one of many changes this tribe has faced due to the influence of outside sources. Pima was a name given to this tribe by the Spaniards during the 1600s. Throughout history the Pima have fought not only for their rights as a nation, but also for the rights of their beloved river, the Gila River. The relationship between the Pima tribe and Gila River is a very strong and deep connection. In fact, the Pima call themselves A-a'tam, which means "the people," and they identify with the Papago, a historical name for the Indians in the Sonoran Desert. A'kimult, which means "river" was added to their name as well. Being known as the River People may fit perfectly with this tribe due to their close knit and respectful relationship with the river over the decades (Russell, "The Pima Indians, 1975). Today the Pima call the Gila River Indian Community their main Tribal headquarters, which is located south of Phoenix. The Gila River Indian Community (GRIC) is part of both the Pinal and Maricopa counties and has a land area of 583.749 square miles ("Brownfields", 2010). Water deprivation and a bleak agricultural economy are challenges facing the Pima, which historically were strong in both areas. The Gila River has gone from a naturally flowing river to a restricted and nearly dried up waterbed. This research paper will examine the changes that both the Pima and the Gila River have undergone since settlers began to claim land in the late 1800's. It is my goal to look into the natural history and ecology of the Gila River and explain how this change has affected the Pima and their sustainability as a tribe. The ultimate goal is to have information easily accessible for reference for future research projects and to ] provide background information to help implement new programs and projects that will benefit the GRIC. Understanding the relationship between the Gila Valley and Pima will present areas where sustainable projects can improve the economy and society as a whole. The Native Americans who will be specifically addressed during this research are the tribes on the GRIC, which comprise the Akimel O-odham (Pima) and Pee Posh (Maricopa). These communities have a resident population of 15,084 and are located in the Maricopa and Pinal counties of central Arizona, to the south and east of metropolitan Phoenix ("Brownfields", 2010). Today the community is 372,000 acres and varies with an elevation of 935 feet to 1,450 feet ("Gila River", 2012). Literature will be the primary area of research along with informal discussions with employees of the GRIC. The Pimas' beliefs, interests, and practices will be addressed and researched; and review of the literature that deals with each problem they have faced as a result of the changing economy and society. By researching the relationship and proposing new ideas to help maintain the GRIC it will assure that the interests of the Pima are the priority. The potential that this research project can offer must encompass cultural sustainability, which is "developing, renewing and maintaining human cultures that create positive, enduring relationships with other peoples and the natural world" (Hawkes, 2001).
ContributorsRagan, McKenzie (Author) / Martinez, David (Thesis director) / Larson, Kelli (Committee member) / Manetta, Carol (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / College of Public Programs (Contributor)
Created2012-12
Description
This project aims to provide a contextualized history of the Sky Harbor Neighborhood Association‟s community collective action efforts. The Sky Harbor Neighborhood (SHN) of East Phoenix is bounded on the West by 24th St., on the East by 32nd St., on the North by Roosevelt St., and the South by

This project aims to provide a contextualized history of the Sky Harbor Neighborhood Association‟s community collective action efforts. The Sky Harbor Neighborhood (SHN) of East Phoenix is bounded on the West by 24th St., on the East by 32nd St., on the North by Roosevelt St., and the South by Washington Street. SHN is a majority Latino, low-income, working class community (U.S. Census Bureau, 2010) that faces a variety of challenges including low walkability due to inadequate pedestrian infrastructure, low tree coverage, and crime. East Van Buren St., which has a reputation for being one of Phoenix‟s red-light districts, splits the neighborhood in two. In addition, the SHN lacks some key amenities such as grocery stores and is partly considered a food desert by the United States Department of Agriculture (USDA Economic Research Service, 2012).
ContributorsPearson, Kimberly (Author) / Golub, Aaron (Thesis director) / Wiek, Arnim (Committee member) / York, Abigail (Committee member) / Barrett, The Honors College (Contributor) / College of Liberal Arts and Sciences (Contributor) / School of Sustainability (Contributor)
Created2012-12
Description
Freshwater is an essential component of life for most organisms on earth. "Civilization itself is built on a foundation of water (Fagan, 2011)," as people often congregate near water sources, and find innovative solutions to exploit these resources for food production and domestic needs. Rising demand for water due to

Freshwater is an essential component of life for most organisms on earth. "Civilization itself is built on a foundation of water (Fagan, 2011)," as people often congregate near water sources, and find innovative solutions to exploit these resources for food production and domestic needs. Rising demand for water due to altered lifestyles and population increase pose further stress on water availability. Alterations and pollution of freshwater ecosystems can dramatically compromise ecological services that many species, among them humans, depend on. Arid places are specifically vulnerable in regards to water, characterized by very low levels of precipitation, as well as many dry months, which are often followed by a short time of severe storms. Considering the interconnectedness of social and ecological systems in regards to freshwater services is crucial in order to sustainably manage freshwater resources and avoid ecological crises that in turn are likely to lead to social crises around the globe (Berkes et. al., 2003).
ContributorsHenenson, Einav (Author) / Anderies, M. John (Thesis director) / Aggarwal, Rimjhim (Committee member) / Golub, Aaron (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor)
Created2012-12
Description

Long distance travel around the globe can potentially be revolutionized with the use of an intercontinental rocket that uses low earth orbit as its medium. This transport system can increase growth in many new businesses like tourism travel between the continents. This research evaluates the technical and non-technical possibilities

Long distance travel around the globe can potentially be revolutionized with the use of an intercontinental rocket that uses low earth orbit as its medium. This transport system can increase growth in many new businesses like tourism travel between the continents. This research evaluates the technical and non-technical possibilities of using a double-stage reusable rocket, where the second stage is also a reusable, rocket-powered passenger vehicle using a low earth orbit space journey with a stabilized re-entry method that ensures passenger comfortability. A potential network of spaceports spanning the globe is postulated within a range of 4,000 km to 8,000 km(2,160 nm to 4,320 nm) of each other, and each located within an hour by any other means of ground transport to population hubs greater than four million. This will help further connect the world as the journey from one major city to another would take at most an hour, and no point on the habited continents would be more than 4,000 km(2,160 nm) from a spaceport. It is assumed that the costs of an international first class flight ticket are in the thousands of dollars range showing how there is a potential market for this type of travel network. The reasoning and analysis, through a literature review, for an intercontinental rocket vehicle is presented along with the various aspects of the possibility of this kind of travel network coming to fruition in the near future.

ContributorsRanganathan, Anirudh (Co-author) / Karthikeyan, Sayish (Co-author) / Takahashi, Timothy (Thesis director) / Niemczyk, Mary (Committee member) / Mechanical and Aerospace Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

Long distance travel around the globe can potentially be revolutionized with the use of an intercontinental rocket that uses low earth orbit as its medium. This transport system can increase growth in many new businesses like tourism travel between the continents. This research evaluates the technical and non-technical possibilities

Long distance travel around the globe can potentially be revolutionized with the use of an intercontinental rocket that uses low earth orbit as its medium. This transport system can increase growth in many new businesses like tourism travel between the continents. This research evaluates the technical and non-technical possibilities of using a double-stage reusable rocket, where the second stage is also a reusable, rocket-powered passenger vehicle using a low earth orbit space journey with a stabilized re-entry method that ensures passenger comfortability. A potential network of spaceports spanning the globe is postulated within a range of 4,000 km to 8,000 km(2,160 nm to 4,320 nm) of each other, and each located within an hour by any other means of ground transport to population hubs greater than four million. This will help further connect the world as the journey from one major city to another would take at most an hour, and no point on the habited continents would be more than 4,000 km(2,160 nm) from a spaceport. It is assumed that the costs of an international first class flight ticket are in the thousands of dollars range showing how there is a potential market for this type of travel network. The reasoning and analysis, through a literature review, for an intercontinental rocket vehicle is presented along with the various aspects of the possibility of this kind of travel network coming to fruition in the near future.

ContributorsKarthikeyan, Sayish Priya (Co-author) / Ranganathan, Anirudh (Co-author) / Takahashi, Timothy (Thesis director) / Niemczyk, Mary (Committee member) / Mechanical and Aerospace Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

Titanium has been and continues to be a popular metal across any form of manufacturing and production because of its extremely favorable properties. In important circumstances, it finds itself outclassing many metals by being lighter and less dense than comparably strong metals like steel. Relative to other metals it has

Titanium has been and continues to be a popular metal across any form of manufacturing and production because of its extremely favorable properties. In important circumstances, it finds itself outclassing many metals by being lighter and less dense than comparably strong metals like steel. Relative to other metals it has a noteworthy corrosion resistance as it is stable when it oxidizes, and due to the inert nature of the metal, it is famously hypoallergenic and as a result used in a great deal of aviation and medical fields, including being used to produce replacement joints, with the notable limitation of the material being its cost of manufacturing. Among the variants of the metal and alloys used, Ti6Al4V alloy is famous for being the most reliable and popular combination for electron beam manufacturing(EBM) as a method of additive manufacturing. <br/>Developed by the Swedish Arcam, AB, EBM is one of the more recent methods of additive manufacturing, and is notable for its lack of waste by combining most of the material into the intended product due to its precision. This method, much like the titanium it is used to print in this case, is limited mostly by time and value of production. <br/>For this thesis, nine different simulations of a dogbone model were generated and analyzed in Ansys APDL using finite element analysis at various temperature and print conditions to create a theoretical model based on experimentally produced values.

ContributorsKauffman, Jordan Michael (Author) / Ladani, Leila (Thesis director) / Razmi, Jafar (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05