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- Genre: Doctoral Dissertation
Description
There has been a vast increase in applications of Unmanned Aerial Vehicles (UAVs) in civilian domains. To operate in the civilian airspace, a UAV must be able to sense and avoid both static and moving obstacles for flight safety. While indoor and low-altitude environments are mainly occupied by static obstacles, risks in space of higher altitude primarily come from moving obstacles such as other aircraft or flying vehicles in the airspace. Therefore, the ability to avoid moving obstacles becomes a necessity
for Unmanned Aerial Vehicles.
Towards enabling a UAV to autonomously sense and avoid moving obstacles, this thesis makes the following contributions. Initially, an image-based reactive motion planner is developed for a quadrotor to avoid a fast approaching obstacle. Furthermore, A Dubin’s curve based geometry method is developed as a global path planner for a fixed-wing UAV to avoid collisions with aircraft. The image-based method is unable to produce an optimal path and the geometry method uses a simplified UAV model. To compensate
these two disadvantages, a series of algorithms built upon the Closed-Loop Rapid Exploratory Random Tree are developed as global path planners to generate collision avoidance paths in real time. The algorithms are validated in Software-In-the-Loop (SITL) and Hardware-In-the-Loop (HIL) simulations using a fixed-wing UAV model and in real flight experiments using quadrotors. It is observed that the algorithm enables a UAV to avoid moving obstacles approaching to it with different directions and speeds.
for Unmanned Aerial Vehicles.
Towards enabling a UAV to autonomously sense and avoid moving obstacles, this thesis makes the following contributions. Initially, an image-based reactive motion planner is developed for a quadrotor to avoid a fast approaching obstacle. Furthermore, A Dubin’s curve based geometry method is developed as a global path planner for a fixed-wing UAV to avoid collisions with aircraft. The image-based method is unable to produce an optimal path and the geometry method uses a simplified UAV model. To compensate
these two disadvantages, a series of algorithms built upon the Closed-Loop Rapid Exploratory Random Tree are developed as global path planners to generate collision avoidance paths in real time. The algorithms are validated in Software-In-the-Loop (SITL) and Hardware-In-the-Loop (HIL) simulations using a fixed-wing UAV model and in real flight experiments using quadrotors. It is observed that the algorithm enables a UAV to avoid moving obstacles approaching to it with different directions and speeds.
ContributorsLin, Yucong (Author) / Saripalli, Srikanth (Thesis advisor) / Scowen, Paul (Committee member) / Fainekos, Georgios (Committee member) / Thangavelautham, Jekanthan (Committee member) / Youngbull, Cody (Committee member) / Arizona State University (Publisher)
Created2015
Description
Opioid use rates and related deaths continue to be a public health crisis; while there are many contributing factors to opioid use disorders, criteria for diagnosis include problems related to social functioning. Previous research indicates that laboratory rats, which are frequently used as animal models of addiction-related behaviors, are capable of prosocial behavior. The following collection of studies were performed to determine the effects of heroin on prosocial behavior in rats, as well as the role of the insula in both self-administration of heroin and prosocial behaviors. All of the experiments were conducted utilizing an established model of prosocial behavior in rats in which a performing rat releases a cagemate from a restrainer. The occurrence of and latency to free the confined rat was recorded. After baseline rescuing behavior was established, rats were allowed to self-administer heroin (0.06 mg/kg/infusion i.v.), and subsequent experimental conditions were imposed.
Experimental conditions, in a series of different studies, included comparing heroin reinforcers with sucrose, chemogenetically modulating the insular cortex (both stimulatory and inhibitory processes) and administering excitotoxic lesions in the insula. There were significant differences in saving behaviors between heroin and sucrose groups demonstrating an opioid induced loss of prosocial behavior. Modulating the insula chemogenetically resulted in some restoration of these opioid related deficits, and insular lesions did not significantly impact prosocial behaviors, however, there were significant differences between rates of heroin intake in lesioned animals versus non-lesioned controls. Taken together, these results demonstrate the deleterious effects of heroin on prosocial behaviors and offer further support for the role of the insula in both addiction and social constructs.
Experimental conditions, in a series of different studies, included comparing heroin reinforcers with sucrose, chemogenetically modulating the insular cortex (both stimulatory and inhibitory processes) and administering excitotoxic lesions in the insula. There were significant differences in saving behaviors between heroin and sucrose groups demonstrating an opioid induced loss of prosocial behavior. Modulating the insula chemogenetically resulted in some restoration of these opioid related deficits, and insular lesions did not significantly impact prosocial behaviors, however, there were significant differences between rates of heroin intake in lesioned animals versus non-lesioned controls. Taken together, these results demonstrate the deleterious effects of heroin on prosocial behaviors and offer further support for the role of the insula in both addiction and social constructs.
ContributorsTomek, Seven Eli (Author) / Olive, Michael F (Thesis advisor) / Neisewander, Janet (Committee member) / Wynne, Clive (Committee member) / Comer, Sandra (Committee member) / Arizona State University (Publisher)
Created2020
Description
Within a positive youth development framework, Lerner and colleagues posited that youth and young adults are societal assets that support the pillars of democracy and incite community contribution through the development of individual character strengths. Strengths might include hope and civic attitudes, which researchers have linked to numerous positive outcomes; however, connections to civic behaviors are largely unknown. Developmentally, shifting identities, excitement about the future, and an introduction into formal citizenship within U.S. society characterize the emerging adulthood period. Emerging adulthood is also characterized by burgeoning relationships and service opportunities, particularly on college campuses. These factors make emerging adulthood a prime context in which to investigate the aims of the current study, which centered on investigation of the development of hope and civic attitudes, and how each contributed to civic engagement including interpersonal prosocial behavior, community volunteering, and political behaviors. Effortful control was hypothesized to play a role in relations as an intrapersonal factor that implicated relations between hope and civic attitudes and outcomes, and was therefore included as a moderator. Sample consisted of 217 emerging adults (~ 67% female, 58% White, 30% Pell-grant eligible, 19-20 years old) across three time points at a major university in the southwest U.S. from spring 2019 to spring 2020. Path models, structural equation models, and moderation analyses evidenced direct relations between hope and interpersonal prosocial behavior. Civic attitudes directly related to community volunteering and political engagement. Transactional relations between hope and civic engagement were not apparent. Similarly, moderation analyses showed no interactive effects between hope and civic attitudes and effortful control on study outcomes. Findings evidenced stability in hope and civic attitudes across early emerging adulthood and invited future work investigating the development of each in early adolescence and later emerging adulthood. Future interventions might prioritize the development of hope in efforts to increase interpersonal prosociality and civic attitudes to increase volunteering and political engagement among emerging adults, where civic engagement has been historically low. Overall, findings supported hope and civic attitudes as hallmarks of positive youth development with the potential to uniquely contribute to community enhancement in emerging adulthood.
ContributorsFraser, Ashley Michelle (Author) / Spinrad, Tracy L (Thesis advisor) / Bryce, Crystal I (Committee member) / Eisenberg, Nancy (Committee member) / Morris, Stacy L (Committee member) / Arizona State University (Publisher)
Created2021
Description
Prosocial behavior refers to voluntary acts done to benefit another. To date, there is little work examining children’s prosocial behavior toward outgroup members. Across several multi-method multi-informant data sets, I used various statistical methods (e.g., latent change score analysis, mediation and moderation analyses) to examine the predictors, correlates, and development of children’s prosocial behavior toward various outgroup members (e.g., gender, race). In Study 1, I examined the relation between preschoolers’ other-gender friendships and their prosocial behavior toward other-gender peers. Findings showed support for the hypothesis that cross-gender friendships are positively associated with children’s prosocial behavior toward other-gender peers over time. Further, children’s prosocial behavior toward other-gender peers positively predicted children’s later gender attitudes suggesting that fostering intergroup prosocial behavior could be a potentially effective solution to reduce intergroup prejudice. To capture the multifaceted nature of social identities, in Study 2, I examined children’s prosocial behavior toward various ingroup and outgroup members with the intention of exploring the degree of ingroup-ness and testing the transfer effect of intergroup contact. Findings showed that cross-gender friendships were positively predictive of school-age children’s prosocial behavior toward diverse others. Further, cross-race friendships are related to children’s diverse prosocial behavior indirectly through children’s race-based sympathy. Study 3 extended the previous two studies by testing both Intergroup Contact Theory and Social Identity Theory and taking into consideration the social identity of oneself (versus the targets of prosocial behavior). Specifically, I examined the central component of gender identity: children’s perceived same-gender similarity and other-gender similarity, as well as children’s same- and other-gender friendships. Results showed that only intergroup friendships, but not children’s gender identity, were related to children’s prosocial behavior toward same- and other-gender peers. In sum, this basic research has potential to shed light on ways to promote equity and inclusion across various social groups early in development.
ContributorsXIAO, XINYUE (Author) / Spinrad, Tracy L (Thesis advisor) / Martin, Carol Lynn (Thesis advisor) / Eisenberg, Nancy (Committee member) / DeLay, Dawn (Committee member) / Arizona State University (Publisher)
Created2020