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.

Displaying 1 - 2 of 2
Filtering by

Clear all filters

153269-Thumbnail Image.png
Description
Social media platforms such as Twitter, Facebook, and blogs have emerged as valuable

- in fact, the de facto - virtual town halls for people to discover, report, share and

communicate with others about various types of events. These events range from

widely-known events such as the U.S Presidential debate to smaller scale,

Social media platforms such as Twitter, Facebook, and blogs have emerged as valuable

- in fact, the de facto - virtual town halls for people to discover, report, share and

communicate with others about various types of events. These events range from

widely-known events such as the U.S Presidential debate to smaller scale, local events

such as a local Halloween block party. During these events, we often witness a large

amount of commentary contributed by crowds on social media. This burst of social

media responses surges with the "second-screen" behavior and greatly enriches the

user experience when interacting with the event and people's awareness of an event.

Monitoring and analyzing this rich and continuous flow of user-generated content can

yield unprecedentedly valuable information about the event, since these responses

usually offer far more rich and powerful views about the event that mainstream news

simply could not achieve. Despite these benefits, social media also tends to be noisy,

chaotic, and overwhelming, posing challenges to users in seeking and distilling high

quality content from that noise.

In this dissertation, I explore ways to leverage social media as a source of information and analyze events based on their social media responses collectively. I develop, implement and evaluate EventRadar, an event analysis toolbox which is able to identify, enrich, and characterize events using the massive amounts of social media responses. EventRadar contains three automated, scalable tools to handle three core event analysis tasks: Event Characterization, Event Recognition, and Event Enrichment. More specifically, I develop ET-LDA, a Bayesian model and SocSent, a matrix factorization framework for handling the Event Characterization task, i.e., modeling characterizing an event in terms of its topics and its audience's response behavior (via ET-LDA), and the sentiments regarding its topics (via SocSent). I also develop DeMa, an unsupervised event detection algorithm for handling the Event Recognition task, i.e., detecting trending events from a stream of noisy social media posts. Last, I develop CrowdX, a spatial crowdsourcing system for handling the Event Enrichment task, i.e., gathering additional first hand information (e.g., photos) from the field to enrich the given event's context.

Enabled by EventRadar, it is more feasible to uncover patterns that have not been

explored previously and re-validating existing social theories with new evidence. As a

result, I am able to gain deep insights into how people respond to the event that they

are engaged in. The results reveal several key insights into people's various responding

behavior over the event's timeline such the topical context of people's tweets does not

always correlate with the timeline of the event. In addition, I also explore the factors

that affect a person's engagement with real-world events on Twitter and find that

people engage in an event because they are interested in the topics pertaining to

that event; and while engaging, their engagement is largely affected by their friends'

behavior.
ContributorsHu, Yuheng (Author) / Kambhampati, Subbarao (Thesis advisor) / Horvitz, Eric (Committee member) / Krumm, John (Committee member) / Liu, Huan (Committee member) / Sundaram, Hari (Committee member) / Arizona State University (Publisher)
Created2014
153858-Thumbnail Image.png
Description
Browsing Twitter users, or browsers, often find it increasingly cumbersome to attach meaning to tweets that are displayed on their timeline as they follow more and more users or pages. The tweets being browsed are created by Twitter users called originators, and are of some significance to the browser who

Browsing Twitter users, or browsers, often find it increasingly cumbersome to attach meaning to tweets that are displayed on their timeline as they follow more and more users or pages. The tweets being browsed are created by Twitter users called originators, and are of some significance to the browser who has chosen to subscribe to the tweets from the originator by following the originator. Although, hashtags are used to tag tweets in an effort to attach context to the tweets, many tweets do not have a hashtag. Such tweets are called orphan tweets and they adversely affect the experience of a browser.

A hashtag is a type of label or meta-data tag used in social networks and micro-blogging services which makes it easier for users to find messages with a specific theme or content. The context of a tweet can be defined as a set of one or more hashtags. Users often do not use hashtags to tag their tweets. This leads to the problem of missing context for tweets. To address the problem of missing hashtags, a statistical method was proposed which predicts most likely hashtags based on the social circle of an originator.

In this thesis, we propose to improve on the existing context recovery system by selectively limiting the candidate set of hashtags to be derived from the intimate circle of the originator rather than from every user in the social network of the originator. This helps in reducing the computation, increasing speed of prediction, scaling the system to originators with large social networks while still preserving most of the accuracy of the predictions. We also propose to not only derive the candidate hashtags from the social network of the originator but also derive the candidate hashtags based on the content of the tweet. We further propose to learn personalized statistical models according to the adoption patterns of different originators. This helps in not only identifying the personalized candidate set of hashtags based on the social circle and content of the tweets but also in customizing the hashtag adoption pattern to the originator of the tweet.
ContributorsMallapura Umamaheshwar, Tejas (Author) / Kambhampati, Subbarao (Thesis advisor) / Liu, Huan (Committee member) / Davulcu, Hasan (Committee member) / Arizona State University (Publisher)
Created2015