189 research outputs found
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Characterising Locality Descriptions in Crowdsourced Crisis Information
Humanitarian organisations are reluctant to use information from social media when responding to crises or conflicts, identifying trust and accuracy as principal concerns. However, the Geographic Information Science literature contains significant research into uncertainty, research we draw upon here to characterise locality descriptions in incident reports related to the 2010 earthquake in Haiti. We do so using a classification developed to georeference locality descriptions in MaNIS, the Mammal Networked Information System. We found that although there are similarities between the datasets, crowdsourced crisis information presents significant challenges with respect to vagueness, ambiguity and precision (resolution)
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A Design, Analysis and Evaluation Model to Support the Visualization Designer-User
Existing visualization design and evaluation frameworks rest on a distinction between the designer and the user. However, there is little explicit guidance on design, analysis and evaluation when the designer is the user. A simple solution to this problem is for the researcher (who combines the designer and user roles) to be clear about which activity they are conducting at which point in time. To support the researcher, we propose a design, analysis and evaluation model. This model complements existing visualization design and evaluation frameworks. We have adopted this model in our ongoing research into uncertainty in crowdsourced crisis information
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Types, Granularities and Combinations of Geographic Objects in the Haiti Crisis Map
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Exploring Road Incident Data with Heat Maps
This research seeks to determine whether heat mapping is an effective technique for the visual exploration of road incident data. Four software prototypes, which adopted map, treemap and spatial treemap layouts, were developed using open source software. Whilst the visualization process described by Fry (2007) informed the development effort, the evaluation methodology was based on the Nested Process Model (Munzner, 2009). The results of two evaluation methods-a design study and the presentation and discussion of results with domain experts-confirm heat mapping's validity and provide requirements for further software development
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Visual Analytical Approaches to Evaluating Uncertainty and Bias in Crowdsourced Crisis Information
Concerns about verification mean the humanitarian community are reluctant to use information collected during crisis events, even though such information could potentially enhance the response effort. Consequently, a program of research is presented that aims to evaluate the degree to which uncertainty and bias are found in public collections of incident reports gathered during crisis events. These datasets exemplify a class whose members have spatial and
temporal attributes, are gathered from heterogeneous sources, and do not have readily available attribution information. An interactive software prototype, and existing software, are applied to a dataset related to the current armed conflict in Libya to identify βintrinsicβ characteristics against which uncertainty and bias can be evaluated. Requirements on the prototype are identified, which in time will be expanded into full research objectives
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Visual Analytical Approaches to Evaluate Uncertainty and Bias in Crowdsourced Crisis Information
Increasing numbers of people are using social media to exchange information during crisis and conflict events. On the one hand, the humanitarian community is reluctant to use this information in the response effort as it fears the cost of untrustworthy and inaccurate information. On the other, the volunteer and technical communities have attempted to resolve this impasse by crowdsourcing crisis information; for example, by asking volunteers to ascertain whether a crisis report is trustworthy and accurate. Trust and accuracy are two characteristics of uncertainty: The fact that each is likely to have spatial, temporal and thematic aspects is supported by research, which suggests that geography characterises crisis information. Consequently, a research programme grounded in geographic information science, (geo)visualization and (geo)visual analytics is presented that seeks to evaluate the degree to which uncertainty and bias (systematic variation) are found in crowdsourced crisis information; and seeks to provide heuristics to help manage these factors. This programme consists of a methodology for undertaking interactive, analysis-guided software development that is informed by action research, scenario-based design and Munzner's model of visualization validation; and a prototype software application that combines interactive visual representations with spatial statistical functions to explore two datasets of crowdsourced crisis information. Following a review of the literature and a description of the data, the methodology and its implementation are placed within an appropriate work plan. Three supporting publications are included, as well as supporting statements regarding the author's skills and engagement with the academic community
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Monitoring the Health of Computer Networks with Visualization - VAST 2012 Mini Challenge 1 Award: "Efficient Use of Visualization"
The complex computer networks of large organisations contain many machines of many types, used in many geographic locations. Although system administrators should monitor the health of each machine, they need to do so within the context of the whole computer network. Our visualization presents the health of a fictitious financial institution's computer network at a snapshot in time and over a time range, and preserves the important aspects of each facility's administrative and geographic context. Using the "Bank of Money" VAST Challenge dataset, our visualization allowed us to correctly identify several areas of concern, as well as hypothesise about their causes
Monomeric PcrA helicase processively unwinds plasmid lengths of DNA in the presence of the initiator protein RepD
The helicase PcrA unwinds DNA during asymmetric replication of plasmids, acting with an initiator protein, in our case RepD. Detailed kinetics of PcrA activity were measured using bulk solution and a single-molecule imaging technique to investigate the oligomeric state of the active helicase complex, its processivity and the mechanism of unwinding. By tethering either DNA or PcrA to a microscope coverslip surface, unwinding of both linear and natural circular plasmid DNA by PcrA/RepD was followed in real-time using total internal reflection fluorescence microscopy. Visualization was achieved using a fluorescent single-stranded DNA-binding protein. The single-molecule data show that PcrA, in combination with RepD, can unwind plasmid lengths of DNA in a single run, and that PcrA is active as a monomer. Although the average rate of unwinding was similar in single-molecule and bulk solution assays, the single-molecule experiments revealed a wide distribution of unwinding speeds by different molecules. The average rate of unwinding was several-fold slower than the PcrA translocation rate on single-stranded DNA, suggesting that DNA unwinding may proceed via a partially passive mechanism. However, the fastest dsDNA unwinding rates measured in the single-molecule unwinding assays approached the PcrA translocation speed measured on ssDNA
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Exploring the geographic uncertainty associated with crowdsourced crisis information: a geovisualisation approach
New information and communications technologies, such as mobile phones and social media, have presented the humanitarian community with a dilemma: how should humanitarian organisations integrate information from crisis-affected communities into their decision-making processes whilst guarding against inaccurate information from untrustworthy sources? Advocates of crisis mapping claim that, under certain circumstances, crowdsourcing can increase the accuracy of crisis information. However, whilst previous research has studied the geography of crisis information, the motivations of people who create crisis map mashups, and the motivations of people who crowdsource crisis information, the geography of, and the uncertainty associated with, crowdsourced crisis information has been ignored. As such, the current research is motivated by the desire to explore the geographic uncertainty associated with, and to contribute a better understanding of, crowdsourced crisis information.
The current research contributes to the fields of GISc (Geographic Information Science) and crisis informatics; crisis mapping; and geovisualisation specifically and information visualisation more generally. These contributions can be summarised as an approach to, and an understanding of, the geographic uncertainty associated with crowdsourced crisis information; three geovisualisation software prototypes that can be used to identify meaningful patterns in crisis information; and the design, analysis, and evaluation model, which situates the activities associated with designing a software artefact-and using it to undertake analysis-within an evaluative framework. The approach to the geographic uncertainty associated with crowdsourced crisis information synthesised techniques from GISc, geovisualisation, and natural language processing. By following this approach, it was found that location descriptions from the Haiti crisis map did not 'fit' an existing conceptual model, and, consequently, that there is a need for new or enhanced georeferencing methods that attempt to estimate the uncertainty associated with free-text location descriptions from sources of crowdsourced crisis information
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