Matching Items (212)
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- All Subjects: artificial intelligence
- Genre: Masters Thesis
Description
The increasing popularity of Twitter renders improved trustworthiness and relevance assessment of tweets much more important for search. However, given the limitations on the size of tweets, it is hard to extract measures for ranking from the tweet's content alone. I propose a method of ranking tweets by generating a reputation score for each tweet that is based not just on content, but also additional information from the Twitter ecosystem that consists of users, tweets, and the web pages that tweets link to. This information is obtained by modeling the Twitter ecosystem as a three-layer graph. The reputation score is used to power two novel methods of ranking tweets by propagating the reputation over an agreement graph based on tweets' content similarity. Additionally, I show how the agreement graph helps counter tweet spam. An evaluation of my method on 16~million tweets from the TREC 2011 Microblog Dataset shows that it doubles the precision over baseline Twitter Search and achieves higher precision than current state of the art method. I present a detailed internal empirical evaluation of RAProp in comparison to several alternative approaches proposed by me, as well as external evaluation in comparison to the current state of the art method.
ContributorsRavikumar, Srijith (Author) / Kambhampati, Subbarao (Thesis advisor) / Davulcu, Hasan (Committee member) / Liu, Huan (Committee member) / Arizona State University (Publisher)
Created2013
Community-based development: scaling up the correct use of misoprostol at home births in Afghanistan
Description
Globally, more than 350 000 women die annually from complications during pregnancy and childbirth (UNFPA, 2011). Nearly 99% of these, according to World Health Organization (WHO) trends (2010) occur in the developing world outside of a hospital setting with limited resources including emergency care (WHO, 2012; UNFPA, 2011). The most prevalent cause of death is postpartum hemorrhage (PPH), accounting for 25% of deaths according to WHO statistics (2012). Conditions in Afghanistan are reflective of the scope and magnitude of the problem. In Afghanistan, maternal mortality is thought to be among the highest in the world. The Afghan Mortality Survey (AMS) data implies that one Afghan woman dies about every 2 hours from pregnancy-related causes (AMS, 2010). Lack of empowerment, education and access to health care resources increase a woman's risk of dying during pregnancy (AMS, 2010). This project aims to investigate the prospects of scaling-up the correct use of misoprostol, a prostaglandin E1 analogue, to treat PPH in developing countries where skilled assistance and resources are scant. As there has been little published on the lessons learned from programs already in place, this study is experience-driven, based on the knowledge of industry experts. This study employs a concurrent triangulation approach to synthesize quantitative data obtained from previous studies with qualitative information gathered through the testimonies of key personnel who participated in pilot programs involving misoprostol. There are many obstacles to scaling-up training initiatives in Afghanistan and other low-resource areas. The analysis concludes that the most crucial factors for scaling-up community-based programs include: more studies analyzing lessons learns from community driven approaches; stronger partnerships with community health care workers; overcoming barriers like association with abortion, misuse and product issues; and a heightened global and community awareness of the severity of PPH without treatment. These results have implications for those who actively work in Afghanistan to promote maternal health and other countries that may use Afghanistan's work as a blueprint for reducing maternal mortality through community-based approaches. Keywords: Afghanistan, community-based interventions, community-driven, maternal mortality, MDG5, misoprostol, postpartum hemorrhage, reproduction, scale-up
ContributorsCristy, Candice (Author) / Grossman, Gary (Thesis advisor) / Parmentier, Mary-Jane (Committee member) / Byrd, Denise (Committee member) / Arizona State University (Publisher)
Created2013
Description
There is a popular notion that creativity is highly valued in our culture. However, those "in the trenches," people in creative endeavors that actually produce the acts of creativity, say this is not so. There is a negative correlation between the value stated and the true value placed on creativity by our contemporary culture. The primary purpose of this study was to investigate that correlation as well as a possible contributing factor to this negative correlation--the fear of risk involved in enacting and accepting creativity. The methods used in this study were literature review and interview. An extensive literature review was done, as much has been written on creativity. The review was done in four parts: 1) the difficulty in defining creativity; 2) fear and the fear of creativity; 3) solutions - ways to be, express, and accept creativity; and 4) the plethora of articles written about creativity. Six one-on-one interviews were conducted with creative individuals from a variety of commercial creative endeavors. Creatives in commercial fields were chosen specifically because of their ability to influence the culture. The results of this study showed that the hypothesis, that there is a negative correlation between the value stated and the true value placed on creativity, is true. The fear of risk involved in enacting and accepting creativity as a factor in this dichotomy was also shown to be true.
ContributorsGelman, Howard P (Author) / Heywood, Wil (Thesis advisor) / Patel, Mookesh (Committee member) / Knox, Gordon (Committee member) / Arizona State University (Publisher)
Created2013
Description
This study was done in collaboration with the Kino Border Initiative. The Kino Border Initiative is a Catholic, bi-national organization run by Missionary Sisters of the Eucharist, Jesuit priests and lay people. The organization is dedicated to providing services to recently deported migrants and migrants-in-transit through their soup kitchen, women's shelter and first aid station in Nogales, Sonora. Based on their experiences in the women's shelter, the Missionary Sisters of the Eucharist and researcher sought out to further understand migrant women's experiences of gender-based violence prior to migration. Using data collected by the Sisters, it was decided to use an analysis rooted in testimonio, and, in this way, use the women's words as a foundational basis for understanding the migration of women. The analysis is based on 62 testimonies related to women's histories of violence and their migration experiences, and the information from 74 intake questionnaires that were all analyzed retroactively. The analysis of data and testimonios has led to the realization that violence suffered by migrant women is not limited to the journey itself, and that 71% of women report having suffered some sort of violence either prior to or during migration. Often times, the first experiences of violence originated in their homes when they were children and continue to repeat itself throughout their lifetimes in varied forms. Their stories reveal how the decision to migrate is a consequence to the transnational and structural violence that pushes women to seek out ways to survive and provide for their families.
ContributorsConrad, Marla (Author) / Elenes, C. Alejandra (Thesis advisor) / Simmons, William P. (Committee member) / Téllez, Michelle (Committee member) / Arizona State University (Publisher)
Created2013
Description
The objective of this study was to investigate the generational differences among US commercial airline pilots regarding their attitudes toward safety. A survey was distributed to three different US airlines: one major commercial airline, one regional airline, and one charter airline. A total of 106 pilots participated in this study. The pilots were categorized into three groups of generations based on birth years: Baby Boomers: 1946-1964, Generation X: 1965-1980, and Generation Y: 1981-2000. Through the use of one-way Analysis of Variance (ANOVA), the results of the analyses found that there was no significant difference between the generations of pilots regarding safety attitudes. In the subcategory of self-confidence, the results indicated no significant differences between the different generations of pilots. However, in the subcategories of risk orientation and safety orientation, significant differences were detected among the three generations of pilots. Baby Boomers were found to have the lowest risk tolerance, while Generation Y had the highest. Conversely, Baby Boomers were found to have the highest safety orientation, with the lowest being that of Generation Y.
ContributorsGashgari, Emad A (Author) / Niemczyk, Mary (Thesis advisor) / Nullmeyer, Robert (Committee member) / Gibbs, Robert (Committee member) / Arizona State University (Publisher)
Created2013
Description
Objective of this thesis project is to build a prototype using Linear Temporal Logic specifications for generating a 2D motion plan commanding an iRobot to fulfill the specifications. This thesis project was created for Cyber Physical Systems Lab in Arizona State University. The end product of this thesis is creation of a software solution which can be used in the academia and industry for research in cyber physical systems related applications. The major features of the project are: creating a modular system for motion planning, use of Robot Operating System (ROS), use of triangulation for environment decomposition and using stargazer sensor for localization. The project is built on an open source software called ROS which provides an environment where it is very easy to integrate different modules be it software or hardware on a Linux based platform. Use of ROS implies the project or its modules can be adapted quickly for different applications as the need arises. The final software package created and tested takes a data file as its input which contains the LTL specifications, a symbols list used in the LTL and finally the environment polygon data containing real world coordinates for all polygons and also information on neighbors and parents of each polygon. The software package successfully ran the experiment of coverage, reachability with avoidance and sequencing.
ContributorsPandya, Parth (Author) / Fainekos, Georgios (Thesis advisor) / Dasgupta, Partha (Committee member) / Lee, Yann-Hang (Committee member) / Arizona State University (Publisher)
Created2013
Descriptionnone
ContributorsZamil, Ruaa (Author) / Parmentier, Mary J (Thesis advisor) / Chhetri, Nalini (Committee member) / Grossman, Gary (Committee member) / Arizona State University (Publisher)
Created2013
Description
Linear Temporal Logic is gaining increasing popularity as a high level specification language for robot motion planning due to its expressive power and scalability of LTL control synthesis algorithms. This formalism, however, requires expert knowledge and makes it inaccessible to non-expert users. This thesis introduces a graphical specification environment to create high level motion plans to control robots in the field by converting a visual representation of the motion/task plan into a Linear Temporal Logic (LTL) specification. The visual interface is built on the Android tablet platform and provides functionality to create task plans through a set of well defined gestures and on screen controls. It uses the notion of waypoints to quickly and efficiently describe the motion plan and enables a variety of complex Linear Temporal Logic specifications to be described succinctly and intuitively by the user without the need for the knowledge and understanding of LTL specification. Thus, it opens avenues for its use by personnel in military, warehouse management, and search and rescue missions. This thesis describes the construction of LTL for various scenarios used for robot navigation using the visual interface developed and leverages the use of existing LTL based motion planners to carry out the task plan by a robot.
ContributorsSrinivas, Shashank (Author) / Fainekos, Georgios (Thesis advisor) / Baral, Chitta (Committee member) / Burleson, Winslow (Committee member) / Arizona State University (Publisher)
Created2013
Description
This thesis introduces the Model-Based Development of Multi-iRobot Toolbox (MBDMIRT), a Simulink-based toolbox designed to provide the means to acquire and practice the Model-Based Development (MBD) skills necessary to design real-time embedded system. The toolbox was developed in the Cyber-Physical System Laboratory at Arizona State University. The MBDMIRT toolbox runs under MATLAB/Simulink to simulate the movements of multiple iRobots and to control, after verification by simulation, multiple physical iRobots accordingly. It adopts the Simulink/Stateflow, which exemplifies an approach to MBD, to program the behaviors of the iRobots. The MBDMIRT toolbox reuses and augments the open-source MATLAB-Based Simulator for the iRobot Create from Cornell University to run the simulation. Regarding the mechanism of iRobot control, the MBDMIRT toolbox applies the MATLAB Toolbox for the iRobot Create (MTIC) from United States Naval Academy to command the physical iRobots. The MBDMIRT toolbox supports a timer in both the simulation and the control, which is based on the local clock of the PC running the toolbox. In addition to the build-in sensors of an iRobot, the toolbox can simulate four user-added sensors, which are overhead localization system (OLS), sonar sensors, a camera, and Light Detection And Ranging (LIDAR). While controlling a physical iRobot, the toolbox supports the StarGazer OLS manufactured by HAGISONIC, Inc.
ContributorsSu, Shih-Kai (Author) / Fainekos, Georgios E (Thesis advisor) / Sarjoughian, Hessam S. (Committee member) / Artemiadis, Panagiotis K (Committee member) / Arizona State University (Publisher)
Created2012
Description
This is a study that tests the New Urbanist claims that neighborhood design impacts sense of community and residential habits. Through the framework provided by New Urbanist theories, a social survey is used to examine residential perception and behavior among three fringe neighborhoods in southeast Tucson, each representing a different approach to neighborhood design: New Urbanist, traditional suburban, and a hybrid variety. The primary relationships studied are between neighborhood design and use of public space, neighborhood design and travel habits, and neighborhood design and sense of community. The findings show that the New Urbanist community does support the highest levels of sense of community and use of public space, but conclusions cannot be drawn concerning the relationship between sense of community and travel behavior, especially non-vehicular travel to public space. While these results are inconclusive concerning the direct impact of the neighborhood type on certain behaviors and perceptions, the findings support the notion that a New Urbanist design does indeed enhance social interactions and use of public space. It also offers insight into the importance of residential preferences, not as much towards walkability but towards general environmental concern.
ContributorsSchwaller, Ellen (Author) / Talen, Emily (Thesis advisor) / Pijawka, K David (Committee member) / Crew, Katherine (Committee member) / Arizona State University (Publisher)
Created2012