30,650 research outputs found
Recommended from our members
Types, Granularities and Combinations of Geographic Objects in the Haiti Crisis Map
Recommended from our members
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
Recommended from our members
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)
Recommended from our members
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 ‘intrinsic’ 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
Recommended from our members
Exploring Patterns of Uncertainty in Crowdsourced Crisis Information
Material flow during the extrusion of simple and complex cross-sections using FEM
This paper deals with the extrusion of rod and shape sections and uses a 3D finite element model analysis (FEM) to predict the effect of die geometry on maximum extrusion load. A description of material flow in the container is considered in more detail for rod and shape sections in order to fully comprehend the transient conditions occurring during the process cycle. A comparison with experiments is made to assess the relative importance of some extrusion parameters in the extrusion process and to ensure that the numerical discretisation yields a realistic simulation of the process. The usefulness and the limitation of FEM are discussed when modelling complex shapes. Results are presented for velocity contours and shear stress distribution during the extrusion process. It is shown that for most of the shapes investigated, the material making up
the extrudate cross-sections originates from differing regions of virgin material within the billet. The outside surface of the extrudate originates from the material moving along the dead metal zone (DMZ) and the core of the extrudate from the central deformation zone. The FE program
appears to predict all the major characteristics of the flow observed macroscopically
Exoplanet Transit Variability: Bow Shocks and Winds Around HD 189733b
By analogy with the solar system, it is believed that stellar winds will form
bow shocks around exoplanets. For hot Jupiters the bow shock will not form
directly between the planet and the star, causing an asymmetric distribution of
mass around the exoplanet and hence an asymmetric transit. As the planet orbits
thorough varying wind conditions, the strength and geometry of its bow shock
will change, thus producing transits of varying shape. We model this process
using magnetic maps of HD 189733 taken one year apart, coupled with a 3D
stellar wind model, to determine the local stellar wind conditions throughout
the orbital path of the planet. We predict the time-varying geometry and
density of the bow shock that forms around the magnetosphere of the planet and
simulate transit light curves. Depending on the nature of the stellar magnetic
field, and hence its wind, we find that both the transit duration and ingress
time can vary when compared to optical light curves. We conclude that
consecutive near-UV transit light curves may vary significantly and can
therefore provide an insight into the structure and evolution of the stellar
wind.Comment: 9 Pages, 7 figures. Accepted for publication in Monthly Notices of
The Royal Astronomical Societ
Material flow during the extrusion of simple and complex cross-sections using FEM
This paper deals with the extrusion of rod and shape sections and uses a 3D finite element model analysis (FEM) to predict the effect of die geometry on maximum extrusion load. A description of material flow in the container is considered in more detail for rod and shape sections in order to fully comprehend the transient conditions occurring during the process cycle. A comparison with experiments is made to assess the relative importance of some extrusion parameters in the extrusion process and to ensure that the numerical discretisation yields a realistic simulation of the process. The usefulness and the limitation of FEM are discussed when modelling complex shapes. Results are presented for velocity contours and shear stress distribution during the extrusion process. It is shown that for most of the shapes investigated, the material making up
the extrudate cross-sections originates from differing regions of virgin material within the billet. The outside surface of the extrudate originates from the material moving along the dead metal zone (DMZ) and the core of the extrudate from the central deformation zone. The FE program
appears to predict all the major characteristics of the flow observed macroscopically
Vergleich dreier Ringversuche zur radioimmunologischen Thyrotropin-Bestimmung nach dem "Münchner Modell"
Peer Reviewe
- …