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- Genre: Doctoral Dissertation
- Creators: Arizona State University
- Member of: ASU Electronic Theses and Dissertations
Description
The rapid advancement of wireless technology has instigated the broad deployment of wireless networks. Different types of networks have been developed, including wireless sensor networks, mobile ad hoc networks, wireless local area networks, and cellular networks. These networks have different structures and applications, and require different control algorithms. The focus of this thesis is to design scheduling and power control algorithms in wireless networks, and analyze their performances. In this thesis, we first study the multicast capacity of wireless ad hoc networks. Gupta and Kumar studied the scaling law of the unicast capacity of wireless ad hoc networks. They derived the order of the unicast throughput, as the number of nodes in the network goes to infinity. In our work, we characterize the scaling of the multicast capacity of large-scale MANETs under a delay constraint D. We first derive an upper bound on the multicast throughput, and then propose a lower bound on the multicast capacity by proposing a joint coding-scheduling algorithm that achieves a throughput within logarithmic factor of the upper bound. We then study the power control problem in ad-hoc wireless networks. We propose a distributed power control algorithm based on the Gibbs sampler, and prove that the algorithm is throughput optimal. Finally, we consider the scheduling algorithm in collocated wireless networks with flow-level dynamics. Specifically, we study the delay performance of workload-based scheduling algorithm with SRPT as a tie-breaking rule. We demonstrate the superior flow-level delay performance of the proposed algorithm using simulations.
ContributorsZhou, Shan (Author) / Ying, Lei (Thesis advisor) / Zhang, Yanchao (Committee member) / Zhang, Junshan (Committee member) / Xue, Guoliang (Committee member) / Arizona State University (Publisher)
Created2013
Description
"Romantic Cyber-Engagement" offers a new type of dissertation organized around three projects that combine the core values of the Digital Humanities with the hypertext tradition of scholarly pursuits in the field of Romanticism. The first of the three Digital Humanities contributions is to the profession. "A Resource for the Future: The ICR Template and Template Guide" articulates a template for the construction and operation of an advanced conference in Romantic studies. This part of the project includes the conference web site template and guide, which is publicly available to all interested organizations; the template guide includes instructions, tutorials, and advice to govern modification of the template for easier adaptation for future conferences. The second project, "Collaborative Literature Projects in the Digital Age: The Frankenstein Project" is a functional pedagogical example of one way to incorporate Digital Humanities praxis as an interactive part of a college course. This part of the dissertation explains the "Frankenstein Project," a web site that I created for an undergraduate critical theory course where the students contributed various critical approaches for sections of the novel Frankenstein; or, The Modern Prometheus. The final project, "'[W]hat they half-create, / And what perceive': The Creation of a Hypertext Scholarly Edition of 'Tintern Abbey;'" is a critical approaches section in which I created an interactive web site that focused on the primary work, "Lines Written a Few Miles above Tintern Abbey: On Revisiting the Banks of the Wye during a Tour, July 13, 1798." This advanced, multimodal site allows viewers to examine various critical approaches to each section of the primary work, and the viewer/reader can interactively engage the text in dialogue by contributing their own interpretation or critical approach. In addition to the three products and analysis generated from this dissertation, the project as a whole offers an initial Digital Humanities model for future dissertations in discipline of English Literature.
ContributorsMatsunaga, Bruce (Author) / Lussier, Mark S (Thesis advisor) / Broglio, Ronald (Committee member) / Wright, Johnson K (Committee member) / Arizona State University (Publisher)
Created2013
Description
Answer Set Programming (ASP) is one of the most prominent and successful knowledge representation paradigms. The success of ASP is due to its expressive non-monotonic modeling language and its efficient computational methods originating from building propositional satisfiability solvers. The wide adoption of ASP has motivated several extensions to its modeling language in order to enhance expressivity, such as incorporating aggregates and interfaces with ontologies. Also, in order to overcome the grounding bottleneck of computation in ASP, there are increasing interests in integrating ASP with other computing paradigms, such as Constraint Programming (CP) and Satisfiability Modulo Theories (SMT). Due to the non-monotonic nature of the ASP semantics, such enhancements turned out to be non-trivial and the existing extensions are not fully satisfactory. We observe that one main reason for the difficulties rooted in the propositional semantics of ASP, which is limited in handling first-order constructs (such as aggregates and ontologies) and functions (such as constraint variables in CP and SMT) in natural ways. This dissertation presents a unifying view on these extensions by viewing them as instances of formulas with generalized quantifiers and intensional functions. We extend the first-order stable model semantics by by Ferraris, Lee, and Lifschitz to allow generalized quantifiers, which cover aggregate, DL-atoms, constraints and SMT theory atoms as special cases. Using this unifying framework, we study and relate different extensions of ASP. We also present a tight integration of ASP with SMT, based on which we enhance action language C+ to handle reasoning about continuous changes. Our framework yields a systematic approach to study and extend non-monotonic languages.
ContributorsMeng, Yunsong (Author) / Lee, Joohyung (Thesis advisor) / Ahn, Gail-Joon (Committee member) / Baral, Chitta (Committee member) / Fainekos, Georgios (Committee member) / Lifschitz, Vladimir (Committee member) / Arizona State University (Publisher)
Created2013
Description
This dissertation addresses the research challenge of developing efficient new methods for discovering useful patterns and knowledge in large volumes of electronically collected spatiotemporal activity data. I propose to analyze three types of such spatiotemporal activity data in a methodological framework that integrates spatial analysis, data mining, machine learning, and geovisualization techniques. Three different types of spatiotemporal activity data were collected through different data collection approaches: (1) crowd sourced geo-tagged digital photos, representing people's travel activity, were retrieved from the website Panoramio.com through information retrieval techniques; (2) the same techniques were used to crawl crowd sourced GPS trajectory data and related metadata of their daily activities from the website OpenStreetMap.org; and finally (3) preschool children's daily activities and interactions tagged with time and geographical location were collected with a novel TabletPC-based behavioral coding system. The proposed methodology is applied to these data to (1) automatically recommend optimal multi-day and multi-stay travel itineraries for travelers based on discovered attractions from geo-tagged photos, (2) automatically detect movement types of unknown moving objects from GPS trajectories, and (3) explore dynamic social and socio-spatial patterns of preschool children's behavior from both geographic and social perspectives.
ContributorsLi, Xun (Author) / Anselin, Luc (Thesis advisor) / Koschinsky, Julia (Committee member) / Maciejewski, Ross (Committee member) / Rey, Sergio (Committee member) / Griffin, William (Committee member) / Arizona State University (Publisher)
Created2012
Description
Forrest Research estimated that revenues derived from mobile devices will grow at an annual rate of 39% to reach $31 billion by 2016. With the tremendous market growth, mobile banking, mobile marketing, and mobile retailing have been recently introduced to satisfy customer needs. Academic and practical articles have widely discussed unique features of m-commerce. For instance, hardware constraints such as small screens have led to the discussion of tradeoff between usability and mobility. Needs for personalization and entertainment foster the development of new mobile data services. Given distinct features of mobile data services, existing empirical literature on m-commerce is mostly from the consumer side and focuses on consumer perceptions toward these features and their adoption intentions. From the supply side, limited data availability in early years explains the lack of firm-level studies on m-commerce. Prior studies have shown that unclear market demand is a major reason that hinders firms' adoption of m-commerce. Given the advances of smart phones, especially the introduction of the iPhone in 2007, firms recently have started to incorporate various mobile information systems in their business operations. The study uses mobile retailing as the context and empirically assesses firms' migration to this new sales venue with a unique cross-sectional dataset. Despite the distinct features of m-commerce, m-Retailing is essentially an extended arm of e-Retailing. Thus, a dependency perspective is used to explore the link between a firm's e-Retail characteristics and the migration to m-Retailing. Rooted in the innovation diffusion theory, the first stage of my study assesses the decision of adoption that indicates whether a firm moves to m-Retailing and the extent of adoption that shows a firm's commitment to m-Retailing in terms of system implementation choices. In this first stage, I take a dependency perspective to examine the impacts of e-Retail characteristics on m-Retailing adoption. The second stage of my study analyzes conditions that affect business value of the m-Retail channel. I examine the association between system implementation choices and m-Retail performance while analyzing the effects of e-Retail characteristics on value realization. The two-stage analysis provides an exploratory assessment of firm's migration from e-Retailing to m-Retailing.
ContributorsChou, Yen-Chun (Author) / Shao, Benjamin (Thesis advisor) / St. Louis, Robert (Committee member) / Goul, Michael (Committee member) / Arizona State University (Publisher)
Created2013
Description
Medical students acquire and enhance their clinical skills using various available techniques and resources. As the health care profession has move towards team-based practice, students and trainees need to practice team-based procedures that involve timely management of clinical tasks and adequate communication with other members of the team. Such team-based procedures include surgical and clinical procedures, some of which are protocol-driven. Cost and time required for individual team-based training sessions, along with other factors, contribute to making the training complex and challenging. A great deal of research has been done on medically-focused collaborative virtual reality (VR)-based training for protocol-driven procedures as a cost-effective as well as time-efficient solution. Most VR-based simulators focus on training of individual personnel. The ones which focus on providing team training provide an interactive simulation for only a few scenarios in a collaborative virtual environment (CVE). These simulators are suited for didactic training for cognitive skills development. The training sessions in the simulators require the physical presence of mentors. The problem with this kind of system is that the mentor must be present at the training location (either physically or virtually) to evaluate the performance of the team (or an individual). Another issue is that there is no efficient methodology that exists to provide feedback to the trainees during the training session itself (formative feedback). Furthermore, they lack the ability to provide training in acquisition or improvement of psychomotor skills for the tasks that require force or touch feedback such as cardiopulmonary resuscitation (CPR). To find a potential solution to overcome some of these concerns, a novel training system was designed and developed that utilizes the integration of sensors into a CVE for time-critical medical procedures. The system allows the participants to simultaneously access the CVE and receive training from geographically diverse locations. The system is also able to provide real-time feedback and is also able to store important data during each training/testing session. Finally, this study also presents a generalizable collaborative team-training system that can be used across various team-based procedures in medical as well as non-medical domains.
ContributorsKhanal, Prabal (Author) / Greenes, Robert (Thesis advisor) / Patel, Vimla (Thesis advisor) / Smith, Marshall (Committee member) / Gupta, Ashish (Committee member) / Kaufman, David (Committee member) / Arizona State University (Publisher)
Created2014
Description
ABSTRACT Recent studies indicate that top-performing companies have higher-performing work environments than average companies. They receive higher scores for worker satisfaction with their overall physical work environment as well as higher effectiveness ratings for their workspaces (Gensler, 2008; Harter et al., 2003). While these studies indicate a relationship between effective office design and satisfaction they have not explored which specific space types may contribute to workers' overall satisfaction with their physical work environment. Therefore, the purpose of this study is to explore the relationship between workers' overall satisfaction with their physical work environments and their perception of the effectiveness of spaces designed for Conceptual Age work including learning, focusing, collaborating, and socializing tasks. This research is designed to identify which workspace types are related to workers' satisfaction with their overall work environment and which are perceived to be most and least effective. To accomplish this two primary and four secondary research questions were developed for this study. The first primary question considers overall workers' satisfaction with their overall physical work environments (offices, workstations, hallways, common areas, reception, waiting areas, etc.) related to the effective use of work mode workspaces (learning, focusing, collaborating, socializing). The second primary research question was developed to identify which of the four work mode space types had the greatest and least relationship to workers' satisfaction with the overall physical work environment. Secondary research questions were developed to address workers' perceptions of effectiveness of each space type. This research project used data from a previous study collected from 2007 to 2012. Responses were from all staff levels of US office-based office workers and resulted in a blind sample of approximately 48,000 respondents. The data for this study were developed from SPSS data reports that included descriptive data and Pearson correlations. Findings were developed from those statistics using coefficient of determination.
ContributorsHarmon-Vaughan, Elizabeth (Author) / Kroelinger, Michael D. (Thesis advisor) / Bernardi, Jose (Committee member) / Ozel, Filiz (Committee member) / Arizona State University (Publisher)
Created2013
Description
Children are five times more likely to be overweight at the age of 12 years if they are overweight during the preschool period, and 60% of overweight preschoolers are overweight at the age of 12 years (Matusik & Malecka-Tendera, 2011). Primary care interventions are urgently needed to improve healthy lifestyle behaviors in families. Parental influence plays an important factor in the development of healthy behaviors in children. Cognitive behavioral interventions have demonstrated preliminary success in promoting healthy lifestyle behaviors in both adults and children. Mobile technology used to supplement interventions aimed at behavior change offers an outlet to bridge gaps in health disparities and generate innovative evidence. Therefore, the purpose of this research was to establish the feasibility, acceptability, and preliminary effects of a cognitive-behavioral intervention (TEXT2COPE) synergized with mobile technology on the healthy lifestyle behaviors of parents of overweight and obese preschoolers. Primary aims of the proposed pilot study were to (a) examine the feasibility and acceptability of the TEXT2COPE program among parents of overweight or obese preschoolers with mobile phones; (b) evaluate the preliminary effects of the TEXT2COPE program on healthy lifestyle behaviors in families with overweight or obese preschoolers; and (c) evaluate the relationship among the study variables (i.e., cognitive beliefs, perceived difficulty, and healthy lifestyle behaviors). Findings indicate that this program is feasible and acceptable in this population. The intervention improved healthy lifestyle beliefs and behaviors in parents. Further supported are the interconnected relationships between parental beliefs, thoughts, and behaviors.
ContributorsMilitello, Lisa K (Author) / Melnyk, Bernadette M (Thesis advisor) / Small, Leigh (Committee member) / Hekler, Eric (Committee member) / Jacobson, Diana (Committee member) / Arizona State University (Publisher)
Created2014
Description
Attack of the Fake Geek Girls: Challenging Gendered Harassment and Marginalization in Online Spaces applies feminist, gender, and rhetorical theories and methods, along with critical discourse analysis, to case studies of the popular online social media platforms of Jezebel, Pinterest, and Facebook. This project makes visible the structural inequities that underpin the design and development of internet technologies, as well as commonplace assumptions about who is an online user, who is an active maker of internet technologies, and who is a passive consumer of internet technologies. Applying these critical lenses to these inequities and assumptions enables a re-seeing of commonplace understandings of the relationship between gender performativity and digital cultures and practices. Together, these lenses provide a useful set of tools for methodically resisting the mystique of technologies that are, simultaneously, represented as so highly technical as to be opaque to scrutiny, and as ubiquitous to everyday life as to be beneath critical examination.
Through a close reading of the discourses surrounding these popular social media platforms and a rhetorical analysis of their technological affordances, I documented the transference of gender-biased assumptions about women's roles, interests, and competencies, which have historically been found in face-to-face contexts, to these digital spaces. For example, cultural assumptions about the frivolity of women's interests, endeavors, issues, and labors make their way into digital discourse that situates the online practices of women as those of passive consumers who use the internet only to shop and socialize, rather than to go about the serious, masculine business of making original digital content.
This project expands on existing digital identity and performativity research, while applying a sorely needed feminist critique to online discourses and discursive practices that assume maleness and masculinity as the default positionality. These methods are one approach to addressing the pressing problems of online harassment, the gender gap in the technology sector, and the gender gap in digital literacies that have pedagogical, political, and structural implications for the classroom, workplace, economic markets, and civic sphere.
Through a close reading of the discourses surrounding these popular social media platforms and a rhetorical analysis of their technological affordances, I documented the transference of gender-biased assumptions about women's roles, interests, and competencies, which have historically been found in face-to-face contexts, to these digital spaces. For example, cultural assumptions about the frivolity of women's interests, endeavors, issues, and labors make their way into digital discourse that situates the online practices of women as those of passive consumers who use the internet only to shop and socialize, rather than to go about the serious, masculine business of making original digital content.
This project expands on existing digital identity and performativity research, while applying a sorely needed feminist critique to online discourses and discursive practices that assume maleness and masculinity as the default positionality. These methods are one approach to addressing the pressing problems of online harassment, the gender gap in the technology sector, and the gender gap in digital literacies that have pedagogical, political, and structural implications for the classroom, workplace, economic markets, and civic sphere.
ContributorsTekobbe, Cindy (Author) / Miller, Keith D. (Thesis advisor) / Rose, Shirley K. (Committee member) / Boyd, Patricia (Committee member) / Arizona State University (Publisher)
Created2015
Description
Mobile applications (Apps) markets with App stores have introduced a new approach to define and sell software applications with access to a large body of heterogeneous consumer population. Several distinctive features of mobile App store markets including – (a) highly heterogeneous consumer preferences and values, (b) high consumer cognitive burden of searching a large selection of similar Apps, and (c) continuously updateable product features and price – present a unique opportunity for IS researchers to investigate theoretically motivated research questions in this area. The aim of this dissertation research is to investigate the key determinants of mobile Apps success in App store markets. The dissertation is organized into three distinct and related studies. First, using the key tenets of product portfolio management theory and theory of economies of scope, this study empirically investigates how sellers’ App portfolio strategies are associated with sales performance over time. Second, the sale performance impacts of App product cues, generated from App product descriptions and offered from market formats, are examined using the theories of market signaling and cue utilization. Third, the role of App updates in stimulating consumer demands in the presence of strong ranking effects is appraised. The findings of this dissertation work highlight the impacts of sellers’ App assortment, strategic product description formulation, and long-term App management with price/feature updates on success in App market. The dissertation studies make key contributions to the IS literature by highlighting three key managerially and theoretically important findings related to mobile Apps: (1) diversification across selling categories is a key driver of high survival probability in the top charts, (2) product cues strategically presented in the descriptions have complementary relationships with market cues in influencing App sales, and (3) continuous quality improvements have long-term effects on App success in the presence of strong ranking effects.
ContributorsLee, Gun Woong (Author) / Santanam, Raghu (Thesis advisor) / Gu, Bin (Committee member) / Park, Sungho (Committee member) / Arizona State University (Publisher)
Created2015