Matching Items (500)
Description
In this thesis, we consider the problem of fast and efficient indexing techniques for time sequences which evolve on manifold-valued spaces. Using manifolds is a convenient way to work with complex features that often do not live in Euclidean spaces. However, computing standard notions of geodesic distance, mean etc. can get very involved due to the underlying non-linearity associated with the space. As a result a complex task such as manifold sequence matching would require very large number of computations making it hard to use in practice. We believe that one can device smart approximation algorithms for several classes of such problems which take into account the geometry of the manifold and maintain the favorable properties of the exact approach. This problem has several applications in areas of human activity discovery and recognition, where several features and representations are naturally studied in a non-Euclidean setting. We propose a novel solution to the problem of indexing manifold-valued sequences by proposing an intrinsic approach to map sequences to a symbolic representation. This is shown to enable the deployment of fast and accurate algorithms for activity recognition, motif discovery, and anomaly detection. Toward this end, we present generalizations of key concepts of piece-wise aggregation and symbolic approximation for the case of non-Euclidean manifolds. Experiments show that one can replace expensive geodesic computations with much faster symbolic computations with little loss of accuracy in activity recognition and discovery applications. The proposed methods are ideally suited for real-time systems and resource constrained scenarios.
ContributorsAnirudh, Rushil (Author) / Turaga, Pavan (Thesis advisor) / Spanias, Andreas (Committee member) / Li, Baoxin (Committee member) / Arizona State University (Publisher)
Created2012
Description
Diabetic retinopathy (DR) is a common cause of blindness occurring due to prolonged presence of diabetes. The risk of developing DR or having the disease progress is increasing over time. Despite advances in diabetes care over the years, DR remains a vision-threatening complication and one of the leading causes of blindness among American adults. Recent studies have shown that diagnosis based on digital retinal imaging has potential benefits over traditional face-to-face evaluation. Yet there is a dearth of computer-based systems that can match the level of performance achieved by ophthalmologists. This thesis takes a fresh perspective in developing a computer-based system aimed at improving diagnosis of DR images. These images are categorized into three classes according to their severity level. The proposed approach explores effective methods to classify new images and retrieve clinically-relevant images from a database with prior diagnosis information associated with them. Retrieval provides a novel way to utilize the vast knowledge in the archives of previously-diagnosed DR images and thereby improve a clinician's performance while classification can safely reduce the burden on DR screening programs and possibly achieve higher detection accuracy than human experts. To solve the three-class retrieval and classification problem, the approach uses a multi-class multiple-instance medical image retrieval framework that makes use of spectrally tuned color correlogram and steerable Gaussian filter response features. The results show better retrieval and classification performances than prior-art methods and are also observed to be of clinical and visual relevance.
ContributorsChandakkar, Parag Shridhar (Author) / Li, Baoxin (Thesis advisor) / Turaga, Pavan (Committee member) / Frakes, David (Committee member) / Arizona State University (Publisher)
Created2012
Description
Recent advances in camera architectures and associated mathematical representations now enable compressive acquisition of images and videos at low data-rates. While most computer vision applications of today are composed of conventional cameras, which collect a large amount redundant data and power hungry embedded systems, which compress the collected data for further processing, compressive cameras offer the advantage of direct acquisition of data in compressed domain and hence readily promise to find applicability in computer vision, particularly in environments hampered by limited communication bandwidths. However, despite the significant progress in theory and methods of compressive sensing, little headway has been made in developing systems for such applications by exploiting the merits of compressive sensing. In such a setting, we consider the problem of activity recognition, which is an important inference problem in many security and surveillance applications. Since all successful activity recognition systems involve detection of human, followed by recognition, a potential fully functioning system motivated by compressive camera would involve the tracking of human, which requires the reconstruction of atleast the initial few frames to detect the human. Once the human is tracked, the recognition part of the system requires only the features to be extracted from the tracked sequences, which can be the reconstructed images or the compressed measurements of such sequences. However, it is desirable in resource constrained environments that these features be extracted from the compressive measurements without reconstruction. Motivated by this, in this thesis, we propose a framework for understanding activities as a non-linear dynamical system, and propose a robust, generalizable feature that can be extracted directly from the compressed measurements without reconstructing the original video frames. The proposed feature is termed recurrence texture and is motivated from recurrence analysis of non-linear dynamical systems. We show that it is possible to obtain discriminative features directly from the compressed stream and show its utility in recognition of activities at very low data rates.
ContributorsKulkarni, Kuldeep Sharad (Author) / Turaga, Pavan (Thesis advisor) / Spanias, Andreas (Committee member) / Frakes, David (Committee member) / Arizona State University (Publisher)
Created2012
Description
This paper will cover a variety of stable isotope systems, both light and heavy, that are used to interpret isotopic analysis in two different disciplines: bioarchaeology and forensic anthropology. To begin, I will give short histories of both bioarchaeology and forensic anthropology, including what is considered to be the beginning of the disciplines as well as the founders of said disciplines. Following the histories of the disciplines, there will be a short background in isotopes and isotopic analysis, including an introduction to isoscapes and how isotopic data can be collected for further interpretation. There will then be an introduction to light isotopes, focusing on the ones used for this thesis, which will lead into the background of each light isotope. Following the light isotopes is an introduction to the heavy isotopes and the backgrounds of each of the heavy isotopes. Finally, this thesis will end in the conclusions section.
ContributorsFranco, Kristina Marie (Author) / Knudson, Kelly (Thesis director) / Stojanowski, Christopher (Committee member) / School of Criminology and Criminal Justice (Contributor) / School of Human Evolution & Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
This paper studies the change in social diversity and interaction space from the Classic to Postclassic periods in the Mimbres Valley and East Mimbres Area. Between the Classic and Postclassic periods the Mimbres region of the American Southwest exhibits an increase in diversity of ceramic wares. Previous research suggests that increased diversity of ceramics indicates a more diverse community, which could pose challenges to local social interaction (Nelson et al. 2011). I am interested in whether the architecture of plazas, focal points of communities' social structures, change in response to the growing social diversity. To examine this, I quantify the diversity of painted ceramics at Classic and Postclassic villages as well as the extent of the enclosure of plazas. I find that there is a definite shift towards greater plaza enclosure between the Classic and Postclassic periods. I conclude this paper with a discussion of possible interpretations of this trend regarding the social reactions of Mimbres communities to the changes which reshaped the region between the Classic and Postclassic periods.
ContributorsHarkness, Rebecca Jean (Author) / Nelson, Margaret (Thesis director) / Hegmon, Michelle (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution and Social Change (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2015-05
Description
This paper aims to investigate how the portrayal of the crusaders in twentieth and twenty-first century film has evolved and how they have become tools in serving contemporary goals, including those of individual filmmakers and broad societal ideologies. Through the analysis of five films, in both narrative and cinematography, spanning from the 1950s until 2011, themes of redemption, maturity, and the dichotomy of "good" and "bad" are discussed, as well as their chronological evolution in regards to the crusading hero. These films, widely ranging in historical subject matter and country of origin, show a greater range of evolution for the holy war hero and the important themes widely associated with them.
ContributorsBowman, Taylor Nicole (Author) / Benkert, Volker (Thesis director) / Bruhn, Karen (Committee member) / Miller, April (Committee member) / Barrett, The Honors College (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2015-05
Description
The video-on-demand marketplace in film has usually been reserved for independent distributors like Magnolia Pictures and IFC Films, who cannot secure widespread theatrical exhibition like the major studios do (which include Sony, 20th Century Fox, Warner Bros., and Disney, amongst other), therefore opting for the in-home launch of films through on-demand services. These include cable providers, iTunes, Google Play, and even Netflix and Amazon Instant Video. A drastic change to this model came with the launch of The Interview exclusively on VOD platforms and in independent cinemas, challenging the established norm in the industry of major studios releasing their films with major exhibitors like AMC and Regal. Sony's controversial film provided a breakthrough in the VOD marketplace as it became the highest-grossing film ever released on the platform. There remains mystery and secrecy in the VOD realm, though, as independent distributors fail to provide accountable data on their releases and rarely measure financial successes in public. Whereas theatrical box office are available every weekend, VOD numbers do not have to be disclosed at any time, further driving ambiguity behind just how successful the technology must be when the films are often low-key, character-driven efforts rather than the blockbusters that pervade the theatrical landscape around the world. This paper explores the ramifications of video-on-demand on the theatrical marketplace, and attempts to counter the recent claim of The Interview being the game-changing success for VOD.
ContributorsForthun, Eric Matthew (Author) / Sandler, Kevin (Thesis director) / Green, Michael (Committee member) / Barrett, The Honors College (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor) / Department of English (Contributor)
Created2015-05
Description
Society places great trust in the police to uphold and protect the law. People who have a duty to protect (vs. no duty) and violate the institution they are supposed to safeguard are often judged more harshly. I test whether people will punish an on-duty police officers more severely for committing a violent crime compared to an off-duty officer or a civilian. I hypothesized that this effect might be enhanced when a perpetrator commits a violent crime against an African-American compared to a Caucasian. Furthermore, I predicted that this effect will be exacerbated after highly publicized controversial incidents of police use-of-force. In a mock jury paradigm involving a defendant who committed a violent crime, I found that the protective role of the perpetrator and race of the victim did not affect punishment judgments. Participants did, however, punish defendants less and identified with police more after a highly publicized incident (the Ferguson grand jury decision) compared to before the incident.
ContributorsSanchez, Manuel Justin (Author) / Salerno, Jessica (Thesis director) / Schweitzer, Nicholas (Committee member) / Barrett, The Honors College (Contributor) / School of Criminology and Criminal Justice (Contributor) / School of Social and Behavioral Sciences (Contributor)
Created2015-05
Description
As the poverty level increases in Arizona, so does the opportunity gap between high- income and low-income students. We believe that all youth regardless of their zip code, the color of their skin, or their family background should see themselves as leaders and scholars in the community. Access to higher education, quite simply should be attainable for all students. The New American University charter that ASU has adopted is inspiring and groundbreaking. We believe this charter underscores the significance of equal access to education. The REACH program embraces the urgency of educational inequity, by enhancing the potential success of high school teenagers, who attend the Boys & Girls Club \u2014 Ladmo Branch in Tempe, Arizona. REACH empowers youth to develop stronger leadership skills, while becoming more involved in their community. We provide an opportunity for these teens to engage in leadership discussions, receive college mentoring/tutoring, and connect with the community and resources that Arizona State University (ASU) has to offer. It is our hope that every REACH teen is inspired to apply for college. REACH strives to provide any support the teens require to be successful throughout the college testing and admission process. REACH works with multiple communities at Arizona State University including the Pat Tillman Scholars, Devils' Advocates, Honors Devils, Changemaker Central, Barrett, The Honors College and W. P. Carey School of Business to organize and lead a group of teens through a remarkable curriculum that will shape the way they view cultural diversity, educational achievement, and leadership. The weekly meetings consist of discussions, creative team-building, critical thinking exercises, and cultural awareness experiences. Demonstrating to the teens, administrators, volunteers, mentors, and tutors the rich culture that Tempe has to offer and the skills and experience that they have to offer their community as well. In this thesis will we present our work developing and implementing the REACH program at the Ladmo Branch of the Tempe Boys and Girls Club from the Spring of 2013 through the Spring of 2015. We will describe the structure of REACH, our weekly leadership curriculum, our assessment and evaluation method, and the supplemental programs that we instituted (i.e., tutoring and mentoring). We will reflect on our successes and the challenges that we faced over the span of three years. We will conclude our thesis with a critical analysis of the program as a whole in order to provide advice for others who want to create and engage in a sustainable, student lead, community action organization.
ContributorsBurba, Monica (Co-author) / Smith, Jenna (Co-author) / Mokwa, Michael (Thesis director) / Eaton, John (Committee member) / Barrett, The Honors College (Contributor) / School of Politics and Global Studies (Contributor) / School of Sustainability (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor) / School of International Letters and Cultures (Contributor)
Created2015-05
Description
Corruption is a growing issue in China that has only worsened in recent years due to the competition for power between the two foremost factions within the Chinese Communist Party (CCP), the Tuanpai and Princelings. Based on a series of case studies of high-ranking Chinese officials, I analyze patterns of corruption employed by members of the two factions that enable them to gain power and authority within the CCP. This analysis argues that due to the high levels of intense corruption within China and the CCP, change in the form of small and gradual reform is the only way to battle this corruption without further threatening the legitimacy of the government. Small changes such as allowing the competition between factions to remain as a form of checks and balances for the government or allowing more freedom with social media will gain some trust back for the Chinese government. If drastic changes are made and all corrupt officials in the government are indicted, that may in turn destabilize the country by ruining all faith in the government and removing so many individuals who contribute to day-to-day governance. This analysis suggests that possible solutions must start small and gradually increase to maintain the stability and legitimacy of China and the CCP while also beginning to fight the corruption culture.
ContributorsLloyd, Jennifer Alexandra (Author) / Shair-Rosenfield, Sarah (Thesis director) / Bustikova-Siroky, Lenka (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / School of Politics and Global Studies (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2015-05