3,877 research outputs found
Integrating Social Media in the Development of a Special Event Population Dynamics Model
With society’s increasing participation in social media, scientists now have access to new sources of data that reflect our daily activities in space and in time. Such data are plentiful and, more notably, at an unprecedented granular level. The ability for users to capture and express their geolocation through their phones’ global positioning system (GPS) or through a particular location’s hashtag or Facebook Page provides a great opportunity for modeling spatiotemporal population dynamics. High resolution population models and databases for episodic special events can be extremely useful for enhancing emergency management and response. This research assesses the feasibility of improving a special event population distribution and dynamics model, namely Oak Ridge National Laboratory’s LandScan USA, using data from social media. Specifically, analysis is across a 24 hour period for a number of football game days associated with the University of Tennessee, Knoxville during the 2013-2014 season. Data from two popular social media platforms, namely Twitter and Facebook, were used to analyze possible patterns of population distributions around the university’s football stadium. Spatial autocorrelation was measured and calculated using Global Moran’s I and the Local Indicator of Spatial Association (LISA) test to support and build confidence of the tweet and check-in data. Overall, data from social media were found to be beneficial for improving high-resolution population distribution datasets, such as LandScan USA. However, long term collection and analysis of social media data are necessary for ensuring sustainability and predictive capacity of such data in modeling near real-time population dynamics for special events
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Analysis of spatio-social relations in a photographic archive (Flickr)
This thesis aims to study and analyse the complex spatio-social relations among social entities who interact together in a spatially structured social group. This aim is approached in three steps:
1. Collecting and classifying spatio-social data,
2. Disambiguating place names that people use to refer to their homes and
3. Analysis of data of this kind (numerical and visual).
The source of spatio-social data used in this work is Flickr. Flickr is a yahoo photo sharing site. Users have a social network of friends and a collection of photos on their profiles. According to available statistics1 the Flickr database contains more than three billion photos, out of which a hundred million are geo-tagged. In retrieving data from Flickr database two different samples have been explored. Initially a random collection of photos that have been uploaded in Flickr during the examined periods has been collected on a daily basis. This is followed by much narrower and more precise criteria for the second data sampling that resulted in Flickr sample GB data.
The thesis concludes that location dominates a significant pattern in online behavior of social entities who interact together via internet. The core contributions of this thesis are in the areas of:
1. Extracting indicative sample from very large data sets,
2. Disambiguation of place names that people use in their natural language to refer to their home locations and
3. Proposing potential new insights into behaviors of social entities with spatio-social relations.
Overall, the popularity of social networking sites and availability of data that can be obtained from the web (whether people provide voluntarily or can be retrieve as a consequence of online interactions) are likely to continue the increasing trend in future. In addition, the realm of spatio-social data analysis and its visualization also continue to expand, as do the types of maps that are achievable, the visualization packages that the maps can be built with, the number of map users and improved gazetteers with more comprehensive coverage of vague terms. Therefore, the developed methods, algorithm and applications in this study can be beneficial to researchers in social and e-social sciences, those who are interested in developing and maintaining social networking sites, geographers who work on disambiguation of fuzzy vernacular geographic terms, visualization and spatial data analysts in general and those who are looking for development and accommodation of better business strategies (i.e. localization and personalization).
1 (http://www.Flickr.com, retrieved 20/07/09
Doctor of Philosophy
dissertationRecent advancements in mobile devices - such as Global Positioning System (GPS), cellular phones, car navigation system, and radio-frequency identification (RFID) - have greatly influenced the nature and volume of data about individual-based movement in space and time. Due to the prevalence of mobile devices, vast amounts of mobile objects data are being produced and stored in databases, overwhelming the capacity of traditional spatial analytical methods. There is a growing need for discovering unexpected patterns, trends, and relationships that are hidden in the massive mobile objects data. Geographic visualization (GVis) and knowledge discovery in databases (KDD) are two major research fields that are associated with knowledge discovery and construction. Their major research challenges are the integration of GVis and KDD, enhancing the ability to handle large volume mobile objects data, and high interactivity between the computer and users of GVis and KDD tools. This dissertation proposes a visualization toolkit to enable highly interactive visual data exploration for mobile objects datasets. Vector algebraic representation and online analytical processing (OLAP) are utilized for managing and querying the mobile object data to accomplish high interactivity of the visualization tool. In addition, reconstructing trajectories at user-defined levels of temporal granularity with time aggregation methods allows exploration of the individual objects at different levels of movement generality. At a given level of generality, individual paths can be combined into synthetic summary paths based on three similarity measures, namely, locational similarity, directional similarity, and geometric similarity functions. A visualization toolkit based on the space-time cube concept exploits these functionalities to create a user-interactive environment for exploring mobile objects data. Furthermore, the characteristics of visualized trajectories are exported to be utilized for data mining, which leads to the integration of GVis and KDD. Case studies using three movement datasets (personal travel data survey in Lexington, Kentucky, wild chicken movement data in Thailand, and self-tracking data in Utah) demonstrate the potential of the system to extract meaningful patterns from the otherwise difficult to comprehend collections of space-time trajectories
CHORUS Deliverable 2.2: Second report - identification of multi-disciplinary key issues for gap analysis toward EU multimedia search engines roadmap
After addressing the state-of-the-art during the first year of Chorus and establishing the existing landscape in
multimedia search engines, we have identified and analyzed gaps within European research effort during our second year.
In this period we focused on three directions, notably technological issues, user-centred issues and use-cases and socio-
economic and legal aspects. These were assessed by two central studies: firstly, a concerted vision of functional breakdown
of generic multimedia search engine, and secondly, a representative use-cases descriptions with the related discussion on
requirement for technological challenges. Both studies have been carried out in cooperation and consultation with the
community at large through EC concertation meetings (multimedia search engines cluster), several meetings with our
Think-Tank, presentations in international conferences, and surveys addressed to EU projects coordinators as well as
National initiatives coordinators. Based on the obtained feedback we identified two types of gaps, namely core
technological gaps that involve research challenges, and “enablers”, which are not necessarily technical research
challenges, but have impact on innovation progress. New socio-economic trends are presented as well as emerging legal
challenges
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Crowdsourced Data Mining for Urban Activity: A Review of Data Sources, Applications and Methods
The penetration of devices integrated with location-based services and internet services has generated massive data about the everyday life of citizens and tracked their activities happening in cities. Crowdsourced data, such as social media data, POIs data and collaborative websites, generated by the crowd, has become fine-grained proxy data of urban activity and widely used in research in urban studies. However, due to the heterogeneity of data types of crowdsourced data and the limitation of previous studies mainly focusing on a specific application, a systematic review of crowdsourced data mining for urban activity is still lacking. In order to fill the gap, this paper conducts a literature search in the Web of Science database, selecting 226 highly related papers published between 2013 and 2019. Based on those papers, the review firstly conducts a bibliometric analysis identifying underpinning domains, pivot scholars and papers around this topic. The review also synthesises previous research into three parts: main applications of different data sources and data fusion; application of spatial analysis in mobility patterns, functional areas and event detection; application of socio-demographic and perception analysis in city attractiveness, demographic characteristics and sentiment analysis. The challenges of this type of data are also discussed in the end. This study provides a systematic and current review for both researchers and practitioners interested in the applications of crowdsourced data mining for urban activity.This research is funded by a scholarship from the China Scholarship Counci
Local Law Enforcement Jumps on the Big Data Bandwagon: Automated License Plate Recognition Systems, Infomation Privacy, and Access to Government Information
As government agencies and law enforcement departments increasingly adopt big-data surveillance technologies as part of their routine investigatory practice, personal information privacy concerns are becoming progressively more palpable. On the other hand, advancing technologies and data-mining potentially offer law enforcement greater ability to detect, investigate, and prosecute criminal activity. These concerns (for personal information privacy and the efficacy of law enforcement) are both very important in contemporary society. On one view, American privacy law has not kept up with advancing technological capabilities, and government agencies have arguably begun to overstep the acceptable boundaries of information access, violating the privacy of their citizens and decreasing the relevancy of the Fourth Amendment. On another, crime has decreased significantly over the past few decades, thanks in part to more effective and efficient policing, and criminal activity has become more technologically advanced as well; to unduly limit police would hamper legitimate efforts to keep our communities safe from serious crime. Despite decades of increasingly safer streets and fewer instances of serious police-citizen violence in America, the police continue to hold a highly criticized role in society. Indeed, most recent press about police use of big data technologies has focused on the negative implications that these developments have on citizen privacy—which is a very important concnern –but less attention has been given to balancing these privacy interests with the important societal interest in promoting effective and efficient police work. The tensions between these competing, equally legitimate aims is substantial and, in the context of police use of automated license plate recognition (ALPR) systems, limiting the scope of law enforcement data retention to protect citizen privacy (one option that has begun to find traction in Canada and in some U.S. states) might also protect the privacy of the police officers using these systems, as disclosure of these databases to the public under freedom of information (FOI) laws can allow citizens to track the historical policing patterns of individual officers
Spatial Big Data Analytics: The New Boundaries of Retail Location Decision-Making
This dissertation examines the current state and evolution of retail location decision-making (RLDM) in Canada. The major objectives are: (i) To explore the type and scale of location decisions that retail firms are currently undertaking; (ii) To identify the availability and use of technology and Spatial Big Data (SBD) within the decision-making process; (iii) To identify the awareness, availability, use, adoption and development of SBD; and, (iv) To assess the implications of SBD in RLDM. These objectives were investigated by using a three stage multi-method research process. First, an online survey of retail location decision makers across a range of sizes and sub-sectors was administered. Secondly, structured interviews were conducted with 24 retail location decision makers, and lastly, three in-depth cases studies were undertaken in order to highlight the changes to RLDM over the last decade and to develop a deeper understanding of RLDM.
This dissertation found that within the last decade RLDM changed in three main ways: (i) There has been an increase in the availability and use of technology and SBD within the decision-making process; (ii) The type and scale of location decisions that a firm undertakes remain relatively unchanged even with the growth of new data; and, (iii) The range of location research methods that are employed within retail firms is only just beginning to change given the presence of new data sources and data analytics technology.
Traditional practices still dominate the RLDM process. While the adoption of SBD applications is starting to appear within retail planning, they are not widespread. Traditional data sources, such as those highlighted in past studies by Hernandez and Emmons (2012) and Byrom et al. (2001) are still the most commonly used data sources. It was evident that at the heart of SBD adoption is a data environment that promotes transparency and a clear corporate strategy. While most retailers are aware of the new SBD techniques that exist, they are not often adopted and routinized
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