ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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- Creators: Shen, Wei
- Creators: Sugar, Thomas
Description
Entrepreneurship entails a transition from status quo to a founder/leader of a new organization, and the dominant view in the literature focuses on opportunities in a hypothetical situation, namely an entrepreneurial option. This study shifts the attention from an entrepreneurial option to a current situation and proposes that a perception of costliness in status quo as a driver of entrepreneurial decisions and strategies. Specifically, I propose that a perception of inequality due to the local hierarchy of an organization engenders motivation of disadvantaged employees to become a leader of his/her own entrepreneurial organization. Utilizing hierarchy-based power dynamics and attribution biases, I theorize that i) status gap between a leader and a member and ii) status distinctiveness of a leader in the current organization affect an entrepreneurial decision because of inequality perception. Furthermore, I hypothesize that entrepreneurial organizations driven by such status inequality are more likely to replicate the local structure of the previous employer in terms of status hierarchy to compensate for the perceived disadvantages in the previous employer. The empirical analyses of this study investigate entrepreneurial decisions and entrepreneurial team formation of jazz musicians from jazz discographies between 1950 and 2018, and I found supportive results. This study contributes to the entrepreneurship and inequality literature by bridging two research spaces. It first uncovers the roles of a negative perception of the status quo in entrepreneurship, in addition to the established idea of a positive perception of an alternative option. It also suggests a novel explanation of the long-standing question of inequality reproduction by looking at whether and how inequality spreads via entrepreneurship.
ContributorsJeon, Chunhu (Author) / Shen, Wei (Thesis advisor) / Bundy, Jonathan N (Thesis advisor) / Certo, S. Trevis (Committee member) / Arizona State University (Publisher)
Created2022
Description
While pulse oximeter technology is not necessarily an area of new technology, advancements in performance and package of pulse sensors have been opening up the opportunities to use these sensors in locations other than the traditional finger monitoring location. This research report examines the full potential of creating a minimally invasive physiological and environmental observance method from the ear location. With the use of a pulse oximeter and accelerometer located within the ear, there is the opportunity to provide a more in-depth means to monitor a pilot for a Gravity-Induced Loss of Consciousness (GLOC) scenario while not adding any new restriction to the pilot's movement while in flight. Additionally, building from the GLOC scenario system, other safety monitoring systems for military and first responders are explored by alternating the physiological and environmental sensors. This work presents the design and development of hardware, signal processing algorithms, prototype development, and testing results of an in-ear wearable physiological sensor.
ContributorsNichols, Kevin (Author) / Redkar, Sangram (Thesis advisor) / Tripp Jr., Llyod (Committee member) / Dwivedi, Prabha (Committee member) / Sugar, Thomas (Committee member) / Arizona State University (Publisher)
Created2021
Description人口的老龄化不仅对养老事业提出更高的要求，也对养老服务产业人才的培养提出要求。但是青年学生选择涉老服务专业的意愿却非常低。因此，为了探究职业学院如何增强涉老服务专业吸引力这一问题，本文以学生为主体视角，利用相关理论，对于影响青年学生选择涉老服务专业的因素进行全面的分析，并结合深度访谈和调查法，提出并建构了相关的理论模型。首先，通过深度访谈和焦点小组讨论，结合对现有的文献的分析，本文提出了影响青年学生选择职业院校涉老服务专业的各种因素，主要包括：个人未来风险感知、家庭经济资本、社会信息评价、校企合作水平、专业课程建设水平、学生激励水平、师资队伍建设水平。之后，本文通过调查法，基于社会认同理论构建了本文的研究模型，并通过结构方程模型对所构建的模型进行检查。
本文的研究结果表明：个人未来风险感知对学生专业认同度产生负面影响；家庭经济资本对学生专业认同度产生负面影响；社会信息评价对学生专业认同度产生正面影响；校企合作水平对学生专业认同度产生正面影；专业课程建设水平对学生专业认同度产生正面影响；学生激励水平对学生专业认同度产生正面影响；师资队伍建设水平对学生专业认同度产生正面影响；学生专业认同度对学生专业选择意愿产生正面影响。
基于上述研究结论，本文选取了个人未来风险感知、家庭经济资本、社会信息评价、校企合作水平、专业课程建设水平、学生激励水平、师资队伍建设水平等因素对于广东岭南职业技术学院涉老服务专业的现有吸引力进行了分析和评估，并从这些视角进一步了对如何提升招生吸引力问题进行探讨，为提高涉老服务专业对于青年学生的吸引力，得出了相关管理建议。
ContributorsZhou, Lanqing (Author) / Shen, Wei (Thesis advisor) / Wu, Fei (Thesis advisor) / Pei, Ker-Wei (Committee member) / Arizona State University (Publisher)
Created2021
Description
As the world moves towards faster production times, quicker shipping, and overall, more demanding schedules, the humans caught in the loop are subject to physical duress causing them to physically break down and have muscular skeletal injuries. Surprisingly, with more automation in logistics houses, the remaining workers must be quicker and do more, again resulting in muscular-skeletal injuries. To help alleviate this strain, a class of robotics and wearables has arisen wherein the human is assisted by a worn mechanical device. These devices, traditionally called exoskeletons, fall into two general categories: passive and active. Passive exoskeletons employ no electronics to activate their assistance and instead typically rely on the spring-like qualities of many materials. These are generally lighter weight than their active counterparts, but also lack the assistive power and can even interfere in other routine operations. Active exoskeletons, on the other hand, aim to avoid as much interference as possible by using electronics and power to assist the wearer. Properly executed, this can deliver power at the most opportune time and disengage from interference when not needed. However, if the tuning is mismatched from the human, it can unintentionally increase loads and possibly lead to other future injuries or harm. This dissertation investigates exoskeleton technology from two vantage points: the designer and the consumer. In the first, the creation of the Aerial Porter Exoskeleton (APEx) for the US Air Force (USAF). Testing of this first of its kind exoskeleton revealed a peak metabolic savings of 8.13% as it delivers 30 N-m of torque about each hip. It was tested extensively in live field conditions over 8 weeks to great success. The second section is an exploration of different commercially available exoskeletons and the development of a common set of standards/testing protocols is described. The results show a starting point for a set of standards to be used in a rapidly growing sector.
ContributorsMartin, William Brandon (Author) / Sugar, Thomas (Thesis advisor) / Redkar, Sangram (Thesis advisor) / Hollander, Kevin (Committee member) / Arizona State University (Publisher)
Created2021
Description
With the extensive technological progress made in the areas of drives, sensors and processing, exoskeletons and other wearable devices have become more feasible. However, the stringent requirements in regards to size and weight continue to exert a strong influence on the system-wide design of these devices and present many obstacles to a successful solution. On the other hand, while the area of controls has seen a significant amount of progress, there also remains a large potential for improvements. This dissertation approaches the design and control of wearable devices from a systems perspective and provides a framework to successfully overcome the often-encountered obstacles with optimal solutions. The electronics, drive and control system design for the HeSA hip exoskeleton project and APEx hip exoskeleton project are presented as examples of how this framework is used to design wearable devices. In the area of control algorithms, a real-time implementation of the Fast Fourier Transform (FFT) is presented as an alternative approach to extracting amplitude and frequency information of a time varying signal. In comparison to the peak search method (PSM), the FFT allows extracting basic gait signal information at a faster rate because time windows can be chosen to be less than the fundamental gait frequency. The FFT is implemented on a 16-bit processor and the results show the real-time detection of amplitude and frequency coefficients at an update rate of 50Hz. Finally, a novel neural networks based approach to detecting human gait activities is presented. Existing neural networks often require vast amounts of data along with significant computer resources. Using Neural Ordinary Differential Equations (Neural ODEs) it is possible to distinguish between seven different daily activities using a significantly smaller data set, lower system resources and a time window of only 0.1 seconds.
ContributorsBoehler, Alexander (Author) / Sugar, Thomas (Thesis advisor) / Redkar, Sangram (Committee member) / Hollander, Kevin (Committee member) / Arizona State University (Publisher)
Created2021
Description
There has been a decrease in the fertility rate over the years due to today’s younger generation facing more pressure in the workplace and their personal lives. With an aging population, more and more older people with limited mobility will require nursing care for their daily activities. There are several applications for wearable sensor networks presented in this paper. The study will also present a motion capture system using inertial measurement units (IMUs) and a pressure-sensing insole with a control system for gait assistance using wearable sensors. This presentation will provide details on the implementation and calibration of the pressure-sensitive insole, the IMU-based motion capture system, as well as the hip exoskeleton robot. Furthermore, the estimation of the Ground Reaction Force (GRF) from the insole design and implementation of the motion tracking using quaternion will be discussed in this document.
ContributorsLi, Xunguang (Author) / Redkar, Sangram (Thesis advisor) / Sugar, Thomas (Committee member) / Subramanian, Susheelkumar (Committee member) / Arizona State University (Publisher)
Created2022
Description
In nature, some animals have an exoskeleton that provides protection, strength, and stability to the organism, but in engineering, an exoskeleton refers to a device that augments or aids human ability. However, the method of controlling these devices has been a challenge historically. Depending on the objective, control systems for exoskeletons have ranged from devices as simple spring-loaded systems to using sensors such as electromyography (EMG). Despite EMGs being very common, force sensing resistors (FSRs) can be used instead. There are multiple types of exoskeletons that target different areas of the human body, and the targeted area depends on the need of the device. Usually, the devices are developed for either medical or military usage; for this project, the focus is on medical development of an automated elbow joint to assist in rehabilitation. This thesis is a continuation of my ASU Barrett honors thesis, Upper-Extremity Exoskeleton. While working on my honors thesis, I helped develop a design for an upper extremity exoskeleton based on the Wilmer orthosis design for Mayo Clinic. Building upon the design of an orthosis, for the master’s thesis, I developed an FSR control system that is designed using a Wheatstone bridge circuit that can provide a clean reliable signal as compared to the current EMG setup.
ContributorsCarlton, Bryan (Author) / Sugar, Thomas (Thesis advisor) / Aukes, Daniel (Committee member) / Hollander, Kevin (Committee member) / Arizona State University (Publisher)
Created2023
Description
This research proposes some new data-driven control methods to control a nonlinear dynamic model. The nonlinear dynamic model linearizes by using the Koopman theory. The Koopman operator is the most important part of designing the Koopman theory. The data mode decomposition (DMD) is used to obtain the Koopman operator. The proposed data-driven control method applies to different nonlinear systems such as microelectromechanical systems (MEMS), Worm robots, and 2 degrees of freedom (2 DoF) robot manipulators to verify the performance of the proposed method. For the MEMS gyroscope, three control methods are applied to the linearized dynamic model by the Koopman theory: linear quadratic regulator (LQR), compound fractional PID sliding mode control, and fractional order PID controller tuned with bat algorithm. For the Worm robot, an LQR controller is proposed to control the linearized dynamic model by the Koopman theory. A new fractional sliding mode control is proposed to control the 2 DoF arm robot. All the proposed controllers applied to the linearized dynamic model by the Kooman theory are compared with some conventional proposed controllers such as PID, sliding mode control, and conventional fractional sliding mode control to verify the performance of the proposed controllers. Simulation results validate their performance in high tracking performance, low tracking error, low frequency, and low maximum overshoot.
ContributorsRahmani, Mehran (Author) / Redkar, Sangram (Thesis advisor) / Sugar, Thomas (Committee member) / C. Subramanian, Susheelkumar (Committee member) / Arizona State University (Publisher)
Created2023
Description
This thesis presents the design and testing of a soft robotic device for water utility pipeline inspection. The preliminary findings of this new approach to conventional methods of pipe inspection demonstrate that a soft inflatable robot can successfully traverse the interior space of a range of diameter pipes using pneumatic and without the need to adjust rigid, mechanical components. The robot utilizes inflatable soft actuators with an adjustable radius which, when pressurized, can provide a radial force, effectively anchoring the device in place. Additional soft inflatable actuators translate forces along the center axis of the device which creates forward locomotion when used in conjunction with the radial actuation. Furthermore, a bio-inspired control algorithm for locomotion allows the robot to maneuver through a pipe by mimicking the peristaltic gait of an inchworm. This thesis provides an examination and evaluation of the structure and behavior of the inflatable actuators through computational modeling of the material and design, as well as the experimental data of the forces and displacements generated by the actuators. The theoretical results are contrasted with/against experimental data utilizing a physical prototype of the soft robot. The design is anticipated to enable compliant robots to conform to the space offered to them and overcome occlusions from accumulated solids found in pipes. The intent of the device is to be used for inspecting existing pipelines owned and operated by Salt River Project, a Phoenix-area water and electricity utility provider.
ContributorsAdams, Wade Silas (Author) / Aukes, Daniel (Thesis advisor) / Sugar, Thomas (Committee member) / Zhang, Wenlong (Committee member) / Arizona State University (Publisher)
Created2019
Description
In this study I investigate the organizational strategies that Chinese power generation companies may use to reduce the impact of coal price increases on their profits. Organizations are open systems in that no organization possesses all the resources that it needs and all organizations must obtain resources from their external environments in order to survive. Resource dependent theory suggests that the most important goal of an organization is to find effective mechanisms to cope with its dependence on the external environments for resources that are critical to its survival. Chinese power generation companies traditionally rely heavily on coal as their raw materials, and an increase in coal price can have a significant negative impact on their profits. To address this issue, I first provide a systematic review of the resource dependence theory and research, with a focus on the strategies such as vertical integration, diversification, and hedging that organizations can undertake to reduce their dependence on the external environment as well as their respective benefits and costs. Next, I conduct a qualitative case analysis of the primary strategies the largest Chinese power generation companies have used to reduce their dependence on coal. I then explore a new approach that Chinese power generation companies may use to cope with increases in coal price, namely, by investing in an index of coal companies in the stock market. My regression analysis shows that coal price has a strong positive relation with the price of the coal company index. This finding suggests that it is possible for firms to reduce the negative impact of raw material price increase on their profits by investing in a stock market index of the companies that supply the raw materials that they depend on.
ContributorsSun, Min (Author) / Shen, Wei (Thesis advisor) / Liu, Jun (Committee member) / Pei, Ker-Wei (Committee member) / Arizona State University (Publisher)
Created2015