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- Creators: Turaga, Pavan
- Member of: ASU Electronic Theses and Dissertations
Description
Advancements in computer vision and machine learning have added a new dimension to remote sensing applications with the aid of imagery analysis techniques. Applications such as autonomous navigation and terrain classification which make use of image classification techniques are challenging problems and research is still being carried out to find better solutions. In this thesis, a novel method is proposed which uses image registration techniques to provide better image classification. This method reduces the error rate of classification by performing image registration of the images with the previously obtained images before performing classification. The motivation behind this is the fact that images that are obtained in the same region which need to be classified will not differ significantly in characteristics. Hence, registration will provide an image that matches closer to the previously obtained image, thus providing better classification. To illustrate that the proposed method works, naïve Bayes and iterative closest point (ICP) algorithms are used for the image classification and registration stages respectively. This implementation was tested extensively in simulation using synthetic images and using a real life data set called the Defense Advanced Research Project Agency (DARPA) Learning Applied to Ground Robots (LAGR) dataset. The results show that the ICP algorithm does help in better classification with Naïve Bayes by reducing the error rate by an average of about 10% in the synthetic data and by about 7% on the actual datasets used.
ContributorsMuralidhar, Ashwini (Author) / Saripalli, Srikanth (Thesis advisor) / Papandreou-Suppappola, Antonia (Committee member) / Turaga, Pavan (Committee member) / Arizona State University (Publisher)
Created2011
Description
Playing tennis professionally is a stressful profession. However, it has the potential to be even more stressful for players who must move from their home country in order to train. If not dealt with, these stresses have the potential of causing many negative outcomes, including increasing levels of distress, in these professional tennis players. It is known that resources play a role in reducing or buffering levels of stress and distress among individuals, but there are competing theories as to how this occurs. Using Ensel and Lin's models of stress processes, this is an exploratory study that identifies the stresses and distresses professional Taiwanese tennis players face and the resources they use to cope. Participants included in this study are professional Taiwanese tennis players (2 males and 2 females) who continuously attend national and international tennis competitions and have both domestic and world ranks. Results from the semi-structured interviews revealed that challenges, frustration, resources, and toughness were four general themes to describe stresses and distresses professional Taiwanese tennis players face and the resources they use to cope. Future research for professional tennis players is also discussed.
ContributorsHung, Wei-Hsia (Author) / Rodriguez, Ariel (Thesis advisor) / Chuang, Shu-Tzu (Committee member) / Budruk, Megha (Committee member) / Hager, Mark A. (Committee member) / Arizona State University (Publisher)
Created2011
Description
The objective of this study was to understand domestic and foreign-born housekeeper's individual perceptions of labor mobility and job satisfaction related to their jobs within the hospitality industry. Literature regarding the bridging of tourism, immigration, and labor supply was addressed to expose broad conceptual frameworks that lead to the development of this study. More specifically, literature regarding labor mobility within tourism industries, migrant decision making, and barriers to mobility and immigration helped to construct a narrowed conceptual framework specific to hospitality labor in Phoenix, Arizona. Similar and previous studies focused on perceived labor mobility during significant economic or industry shifts. This study included the addition of a policy factor to help determine to what degree state policy change effected hospitality workers' perceived labor mobility. Arizona's recently passed and implemented legislative act SB1070 regards immigrant identification and employment, and enforcement of the act in the state of Arizona; this serves as the implicated policy change. Data were collected via on-site survey administered February to May 2011. An overall score was created for the five motivational dimensions: 1 — Status; 2 — Economic; 3 — Refugee; 4 — Entrepreneurial; and, 5 — Political using principle component factor analysis using a varimax rotation with Kaiser normalization. Theory and literature suggest that the economic advancement, status advancement, and the refugee orientation are effective explanatory variables for motivating a career move into the tourism industry. A total of 82 questionnaires were delivered and completed (N = 82), and none were eliminated. The statistically-determined Economic Dimension was characterized by eleven statements explained 51% of the variation and was the overwhelming motivational force. The average coded response for change in job satisfaction was very positive at .75. Ten features of changes in job satisfaction were used as the basis of the second measure of change in job satisfaction. The first Principle Component of the ten features of job satisfaction change explained 45% of the variation in these features and loadings were positive near or above 0.60 for all items. The relationship between variations in each of the measurements of change in job satisfaction and motivating factors was explored using regression analysis. The two dependent variables were Overall Change and First Principle Component, and the independent variables for both regressions included the four motivating factors as measured by the rotated factors scores to represent dimensions of Economic, Status, Refugee and Entrepreneurial. In addition to the motivational factors, four demographic variables were included as independent variables to account for personal and situational differences. None of the regression coefficients were significant at even the 10% level. Although this result was expected, the positive sign of regression coefficients suggest that expectations of working as a housekeepers results in a positive outcome. Understanding this relationship further is necessary, and seeking larger sample sizes over a longer period of time would be most beneficial to this field of research.
ContributorsCasson, Mallory (Author) / Tyrrell, Timothy (Thesis advisor) / Budruk, Megha (Committee member) / Li, Wei (Committee member) / Arizona State University (Publisher)
Created2011
Description
Numerous studies have examined the attachments individuals have to the places they visit, and that those attachments are formed through experiencing a place in person. This study is unique in that it examines pre-trip place attachment formation via the use of mobile technology and social media. It proposes that media experienced through the use of a participant's smartphone can foster the development of positive emotions, which in turn, facilitates greater mental imagery processing that ultimately influences pre-trip place attachment formation. An experimental design was constructed to examine how text and video on a destination's Facebook page influences an individual's emotions, mental imagery, and subsequently attachment to that destination. Specifically, a 2 (narrative text vs. descriptive text) x 2 (short, fast-paced video vs. long, slow-paced video) between-subjects design was used. A total of 343 usable participant responses were included in the analysis. The data was then analyzed through a two-step process using structural equation modeling. Results revealed no significant influence of textual or video media on emotions although the choice in text has a greater influence on emotions than choice in video. Additionally, emotions had a significant impact on mental imagery. Finally, mental imagery processing had a significant impact on only the social bonding dimension of place attachment. In conclusion, while media had no significant impact on emotions, the effect of previous traveler's retelling of personal accounts on the emotions of potential travelers researching a destination should be examined more closely. Further, the study participants had no prior experience with the destination, yet emotions influenced mental imagery, which also influenced social bonding. Thus further research should be conducted to better understand how potential traveler's image of a destination can be affected by the stories or others.
ContributorsPlunkett, Daniel (Author) / Budruk, Megha (Thesis advisor) / Lee, Woojin (Thesis advisor) / Wetmore, Jameson (Committee member) / Wise, Greg (Committee member) / Arizona State University (Publisher)
Created2013
Description
Advancements in mobile technologies have significantly enhanced the capabilities of mobile devices to serve as powerful platforms for sensing, processing, and visualization. Surges in the sensing technology and the abundance of data have enabled the use of these portable devices for real-time data analysis and decision-making in digital signal processing (DSP) applications. Most of the current efforts in DSP education focus on building tools to facilitate understanding of the mathematical principles. However, there is a disconnect between real-world data processing problems and the material presented in a DSP course. Sophisticated mobile interfaces and apps can potentially play a crucial role in providing a hands-on-experience with modern DSP applications to students. In this work, a new paradigm of DSP learning is explored by building an interactive easy-to-use health monitoring application for use in DSP courses. This is motivated by the increasing commercial interest in employing mobile phones for real-time health monitoring tasks. The idea is to exploit the computational abilities of the Android platform to build m-Health modules with sensor interfaces. In particular, appropriate sensing modalities have been identified, and a suite of software functionalities have been developed. Within the existing framework of the AJDSP app, a graphical programming environment, interfaces to on-board and external sensor hardware have also been developed to acquire and process physiological data. The set of sensor signals that can be monitored include electrocardiogram (ECG), photoplethysmogram (PPG), accelerometer signal, and galvanic skin response (GSR). The proposed m-Health modules can be used to estimate parameters such as heart rate, oxygen saturation, step count, and heart rate variability. A set of laboratory exercises have been designed to demonstrate the use of these modules in DSP courses. The app was evaluated through several workshops involving graduate and undergraduate students in signal processing majors at Arizona State University. The usefulness of the software modules in enhancing student understanding of signals, sensors and DSP systems were analyzed. Student opinions about the app and the proposed m-health modules evidenced the merits of integrating tools for mobile sensing and processing in a DSP curriculum, and familiarizing students with challenges in modern data-driven applications.
ContributorsRajan, Deepta (Author) / Spanias, Andreas (Thesis advisor) / Frakes, David (Committee member) / Turaga, Pavan (Committee member) / Arizona State University (Publisher)
Created2013
Description
With robots being used extensively in various areas, a certain degree of robot autonomy has always been found desirable. In applications like planetary exploration, autonomous path planning and navigation are considered essential. But every now and then, a need to modify the robot's operation arises, a need for a human to provide it some supervisory parameters that modify the degree of autonomy or allocate extra tasks to the robot. In this regard, this thesis presents an approach to include a provision to accept and incorporate such human inputs and modify the navigation functions of the robot accordingly. Concepts such as applying kinematical constraints while planning paths, traversing of unknown areas with an intent of maximizing field of view, performing complex tasks on command etc. have been examined and implemented. The approaches have been tested in Robot Operating System (ROS), using robots such as the iRobot Create, Personal Robotics (PR2) etc. Simulations and experimental demonstrations have proved that this approach is feasible for solving some of the existing problems and that it certainly can pave way to further research for enhancing functionality.
ContributorsVemprala, Sai Hemachandra (Author) / Saripalli, Srikanth (Thesis advisor) / Fainekos, Georgios (Committee member) / Turaga, Pavan (Committee member) / Arizona State University (Publisher)
Created2013
Description
In contemporary society, sustainability and public well-being have been pressing challenges. Some of the important questions are:how can sustainable practices, such as reducing carbon emission, be encouraged? , How can a healthy lifestyle be maintained?Even though individuals are interested, they are unable to adopt these behaviors due to resource constraints. Developing a framework to enable cooperative behavior adoption and to sustain it for a long period of time is a major challenge. As a part of developing this framework, I am focusing on methods to understand behavior diffusion over time. Facilitating behavior diffusion with resource constraints in a large population is qualitatively different from promoting cooperation in small groups. Previous work in social sciences has derived conditions for sustainable cooperative behavior in small homogeneous groups. However, how groups of individuals having resource constraint co-operate over extended periods of time is not well understood, and is the focus of my thesis. I develop models to analyze behavior diffusion over time through the lens of epidemic models with the condition that individuals have resource constraint. I introduce an epidemic model SVRS ( Susceptible-Volatile-Recovered-Susceptible) to accommodate multiple behavior adoption. I investigate the longitudinal effects of behavior diffusion by varying different properties of an individual such as resources,threshold and cost of behavior adoption. I also consider how behavior adoption of an individual varies with her knowledge of global adoption. I evaluate my models on several synthetic topologies like complete regular graph, preferential attachment and small-world and make some interesting observations. Periodic injection of early adopters can help in boosting the spread of behaviors and sustain it for a longer period of time. Also, behavior propagation for the classical epidemic model SIRS (Susceptible-Infected-Recovered-Susceptible) does not continue for an infinite period of time as per conventional wisdom. One interesting future direction is to investigate how behavior adoption is affected when number of individuals in a network changes. The affects on behavior adoption when availability of behavior changes with time can also be examined.
ContributorsDey, Anindita (Author) / Sundaram, Hari (Thesis advisor) / Turaga, Pavan (Committee member) / Davulcu, Hasan (Committee member) / Arizona State University (Publisher)
Created2013
Description
Empirical and theoretical gaps exist on the subject matter of attendee experiential behavior at community festivals as this action occurs in real time. To acquire knowledge and begin to build theory, attendee behavior was investigated through an interpretive lens to give rise to a socially constructed understanding of this phenomenon in contrast to typical positivist inquiry designs found in the field of event studies used to test theory and determine universal explanations. This ontology was deemed appropriate as human experience at community festivals is multifaceted, relative to social interactions, highly variable with complex meanings, and has a wide variety of consequential implications; all views representative of social constructivism. A grounded theory approach was used in conjunction with a participant observation method to collect data on attendee behavior during fieldwork undertaken at community festivals. Prior to fieldwork, literature was not reviewed nor specific theory pre-selected to serve as a basis for research, with the researcher's only intent to record attendee's on-site actions with an open mind. Fieldwork notes were systematically expanded into descriptive narratives that were broken down into initial codes to establish robust analytic directions, which were synthesized into categories and subcategories through focused coding. Relationships between categories and subcategories were reassembled with axial coding bringing into view a strong emergent theme on social capital bonding and bridging at community festivals and a second theme that considers the aspirations of event management to program festive experiences. To strengthen the second theme event manager interviews and content analysis of event association newsletters were conducted as theoretical sampling to move data towards saturation. From emergent themes it was theorized, while social capital bonding is profusely exhibited at community festivals, social capital bridging is minimally displayed unless augmented with programmed festivity to increase physical, emotional, and social engagement of attendees. Literature reviewed in relation to this theory revealed that spirituality, dance, music, the arts, and wild abandonment were important elements of festivity. An implication arising from this study indicates that if community festivals consciously enhance programmed festivity then correspondingly increased social capital impacts within community development might also be achieved.
ContributorsBiaett, Vernon (Author) / Phillips, Rhonda (Thesis advisor) / Budruk, Megha (Committee member) / Hultsman, Wendy (Committee member) / De La Garza, Sarah (Committee member) / Arizona State University (Publisher)
Created2013
Description
Digital sound synthesis allows the creation of a great variety of sounds. Focusing on interesting or ecologically valid sounds for music, simulation, aesthetics, or other purposes limits the otherwise vast digital audio palette. Tools for creating such sounds vary from arbitrary methods of altering recordings to precise simulations of vibrating objects. In this work, methods of sound synthesis by re-sonification are considered. Re-sonification, herein, refers to the general process of analyzing, possibly transforming, and resynthesizing or reusing recorded sounds in meaningful ways, to convey information. Applied to soundscapes, re-sonification is presented as a means of conveying activity within an environment. Applied to the sounds of objects, this work examines modeling the perception of objects as well as their physical properties and the ability to simulate interactive events with such objects. To create soundscapes to re-sonify geographic environments, a method of automated soundscape design is presented. Using recorded sounds that are classified based on acoustic, social, semantic, and geographic information, this method produces stochastically generated soundscapes to re-sonify selected geographic areas. Drawing on prior knowledge, local sounds and those deemed similar comprise a locale's soundscape. In the context of re-sonifying events, this work examines processes for modeling and estimating the excitations of sounding objects. These include plucking, striking, rubbing, and any interaction that imparts energy into a system, affecting the resultant sound. A method of estimating a linear system's input, constrained to a signal-subspace, is presented and applied toward improving the estimation of percussive excitations for re-sonification. To work toward robust recording-based modeling and re-sonification of objects, new implementations of banded waveguide (BWG) models are proposed for object modeling and sound synthesis. Previous implementations of BWGs use arbitrary model parameters and may produce a range of simulations that do not match digital waveguide or modal models of the same design. Subject to linear excitations, some models proposed here behave identically to other equivalently designed physical models. Under nonlinear interactions, such as bowing, many of the proposed implementations exhibit improvements in the attack characteristics of synthesized sounds.
ContributorsFink, Alex M (Author) / Spanias, Andreas S (Thesis advisor) / Cook, Perry R. (Committee member) / Turaga, Pavan (Committee member) / Tsakalis, Konstantinos (Committee member) / Arizona State University (Publisher)
Created2013
Description
One of the main challenges in planetary robotics is to traverse the shortest path through a set of waypoints. The shortest distance between any two waypoints is a direct linear traversal. Often times, there are physical restrictions that prevent a rover form traversing straight to a waypoint. Thus, knowledge of the terrain is needed prior to traversal. The Digital Terrain Model (DTM) provides information about the terrain along with waypoints for the rover to traverse. However, traversing a set of waypoints linearly is burdensome, as the rovers would constantly need to modify their orientation as they successively approach waypoints. Although there are various solutions to this problem, this research paper proposes the smooth traversability of the rover using splines as a quick and easy implementation to traverse a set of waypoints. In addition, a rover was used to compare the smoothness of the linear traversal along with the spline interpolations. The data collected illustrated that spline traversals had a less rate of change in the velocity over time, indicating that the rover performed smoother than with linear paths.
ContributorsKamasamudram, Anurag (Author) / Saripalli, Srikanth (Thesis advisor) / Fainekos, Georgios (Thesis advisor) / Turaga, Pavan (Committee member) / Arizona State University (Publisher)
Created2013