Abstract (from part one)
The use of Radio Frequency Identification (RFID) technology is expanding rapidly in both commercial and Department of Defense (DoD) supply chains.Many resources within the RFID research and development community have been focused on hardware and firmware components, including active and passive RFID tags, tag readers, and embedded software, yet fewer resources have been focused on exploiting the data collected by tag readers and stored in electronic databases.GeoTime visualization exploits the collection and storage of RFID data, and provides global in-transit visibility of the DoD supply chain down to the last tactical mile.
Background (from part one)
DoD recognizes the value of expanding their global RFID infrastructure and sees a RFID-capable supply chain as a critical element of defense transformation [Wynne, 2004].Beginning in January 2005, DoD has mandated the use of RFID for specific product types (packaged operational rations, clothing, individual equipment, tools, personal demand items, and weapons systems repair parts) shipped to specific defense depots (Susquehanna, PA and San Joaquin, CA).In January 2006, DoD mandates will expand to include most product types and most military service and defense depots [DoD, 2004].
Currently, the DoD's Product Manager for Joint Automatic Identification Technology (PM J-AIT) is managing over 1,500 RFID read/write stations in 25 states and 20 countries around the world.These read/write stations will provide supply chain data to five In-Transit Visibility (ITV) servers.The data contained on the ITV servers provides the basis for monitoring the entire DoD supply chain on a near real-time basis.The challenge is to create a visual display of critical data elements that provides military commanders with information such as "Where are my supplies right now?" and "When will those supplies get to my troops?"
4 Information Interaction
In addition to familiar user interface features such as selection, filtering, hide/show and grouping that operate as commonly expected, the following interactions were specifically developed or customized to work within the GeoTime environment.
4.1 Temporal Navigation
A Time and Range Slider, as shown in Figure 7, is a linear time scale that is visible underneath the visualization representation.This slider contains selectors that allow control of three independent temporal parameters: the Instant of Focus, the Past Range of Time and the Future Range of Time.Past and future ranges can be independently set by the user by clicking and dragging on handles.The time range visible in the time scale of the time slider can be expanded or contracted to show a time span from centuries to seconds.Clicking and dragging on the time slider anywhere except the three selectors will allow the entire time scale to slide to translate in time to a point further in the future or past.
7: GeoTime slider with
variable past and future time
ranges and handles.
Continuous animation of events over time and geography is provided as the time slider is moved forward and backwards in time.
4.2 Simultaneous Spatial and Temporal Navigation
Common interactions such as zoom-box selection and saved views are provided.In addition, simultaneous spatial and temporal zooming has been implemented to allow the user to quickly move to a context of interest.In any view, the user may select a subset of events and zoom to them in both time and space using the Fit Time and Fit Space functions.Within the Overlay Calendar views, these actions happen simultaneously by dragging a zoom-box on the time grid itself.The time range and the geographic extents of the selected events are used to set the bounds of the new view.
4.3 Association Analysis
Functions have been developed that take advantage of the association based connections between events, entities and locations.These functions are used to find groups of connected objects during analysis.Associations connect these basic objects into complex groups representing actual occurrences.These associations can be followed from object to object to reveal connections that are not immediately apparent.Association analysis functions are especially useful in analysis of large data sets where a quick and efficient method to find and/or filter connected groups is desirable.The association analysis function can be used to display only those locations and/or products in the visualization that pertain to critical shipments.For example, "show me all the weapon system repair parts shipped from Defense Distribution Depot, Susquehanna, PA to Baghdad within the past 72 hours".Two association analysis functions have been implemented within GeoTime: Expanding Search and Connection Search.
4.3.1 Expanding Search
As illustrated in Figure 8, the expanding search function allows the user to start with a selected object(s) and then incrementally show objects that are associated with it by increasing degrees of separation.The user selects an object or group of objects of focus and clicks on the Expanding Search button.This causes everything in the visualization representation to disappear except the selected items.The user then increments the search depth and objects connected by the specified depth are made visible in the display.In this way, sets of connected objects are revealed.
|Figure 8: Expanding search.|
4.3.2 Connection Search
The Connection Search function allows the user to connect any two objects by their web of associations.The user selects any two objects and clicks on the Connection Search tool.The connection search algorithm scans the extents of the network of associations starting from one of the objects.The search will continue until the second object is found as one of the connected objects or until there are no more connected objects.If a path of associated objects between the target objects exists, all of the objects along that path are displayed and the depth is automatically displayed showing the minimum number of links between the objects.This is illustrated in Figure 9.One application of this technique is displaying the interrelation between a pallet shipped and a pallet never delivered to determine the point of failure.
1 Object 2
|System finds common data elements between Object 1 and Object 2|
|Figure 9: Connection search|
5 Entity and Event Interactive Visualization
Icons and images are used to describe entities such as supply classes, people, organizations and objects.Icons can also be used to describe activities such as item shipped or item delivered.These icons can be standard DoD map icons or tailored icons.
As entities change location in time, their movement is animated from one location to another.Simple linear interpolation is done between individual observations.A trail or track, that traces an entity in time and geography, can be displayed for one or more selected entities.Due to the relative immaturity of RFID tag and reader technology, the assumption can be made that there will be many non-reads and false-reads as objects move throughout the supply chain.In other words, there will be gaps in data.GeoTime "connects-the-dots" and shows reliable tracks of shipments, even with gaps in data.
Mouse over drill down, shown in Figure 10, allows additional information, such as text or images, to be displayed in the visualization.
|Figure 10: Pointing at an object in the display drills down to additional information.|
Ink strokes can be placed on the map and used to annotate elements of interest with arrows, circles and freeform markings.Some examples are shown in Figure 11.Ink objects are located in geography and time and so appear and disappear as geographic and time contexts are navigated.
|Figure 11: Screen shot of GeoTime with ink annotation.|
5.3 3-D Terrain Maps
Tracking objects and events over the terrain in which they travel can be critical for military analysis.GeoTime utilizes both 2D and 3D maps as required.Figure 12 shows an example of a 3D terrain map with shipment tracks and other entity information displayed in a single scene.
|Figure 12: Screen shot of the GeoTime prototype in calendar mode, showing recent events within a localized area.|
6 Summary and Conclusions
The GeoTime prototype demonstrates that a combined spatial and temporal display is possible, and can be an effective technique when applied to analysis of complex past and future events within a geographic context.GeoTime can be used to get an instant view of military shipment status at any time/space coordinate.Standard activity reports from other DoD automated systems can be imported and translated into GeoTime elements.Over the course of time, thousands of tag-reader events can be stored and reviewed within the system.GeoTime visualization exploits the collection and storage of RFID data, and provides global in-transit visibility of the DoD supply chain down to the last tactical mile.
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For more information about GeoTime applications contact:
FC Business Systems
Oculus Info Inc.,
Portions of text, all diagrams and all images © 2005 Oculus Info Inc.Reprinted with the permission of Oculus Info Inc.