Staining Time and Space for Data
Analysis
Southern Illinois University
VAST 2008 Challenge
Mini Challenge 4: Evacuation Traces
Authors and Affiliations:
Dennis J. Bouvier,
Southern Illinois University Edwardsville, dbouvie@siue.edu [PRIMARY contact]
Britian T. Oates, Southern Illinois University Edwardsville
Student team: NO
Tool(s):
Staining is a technique for allowing time-varying
spatial data to be identified by its movement. A research prototype was developed to
demonstrate the use of staining for the evacuation traces mini-challenge.
Staining can be applied in either
the spatial or time dimensions. In spatial staining, stains are applied to
fixed locations. Any object that moves through the area becomes stained. This
allows easy categorization of data that moved through the area of
interest. A great example is the
counting and listing of the people who exited the building through a particular
doorway. By staining the path through a
doorway, everyone who moves through it becomes stained and listed for easy data
collection.
Time-staining works by indicating a
period of time during which stain should be applied. Any person who moved
during the time period stained becomes stained.
This tool was designed specifically for the mini-challenge
data set, but the technique could be applied to similar time-varying spatial
data.
This
application was programmed by Britian Oates during a
course at Southern Illinois University Edwardsville during the Summer 2008
semester. It is based on a discussion
between Britian Oates and Dr. Dennis Bouvier.
Two Page
Summary: YES
ANSWERS:
Traces-1
Where was the device set off?
Grid
cell number of where the device went off:
66x32
Short
Answer:
At tick 370, approximately 10 people are in motion. By tick
390 approximately 55 of the 81 people are in motion indicating that the explosion
occurred shortly before that time. The first people who cease movement after
tick 390 are probably closest to the blast.
As you can see in Figure 1.1, at tick 382, several people are very close
to (66, 32) (stained red on the map) and in Figure 1.2, the last frame of the
data many of those people did not make it very far. More evidence pointing to this location is
the suspicious behavior of ID 21, Roman Katalanow, He steps through the doorway into the room
containing (66, 32), then immediately leaves after entering this square, goes
around a corner, and then returns to the hall adjoining that room before
exiting the building.
Figure 1.1. The
“Time Marked People” list includes people who moved during time indicated by
the blue highlight on the time bar. The markers for these people are also
highlighted on the map. The suspected bomb location (66, 32) is stained with
red on the map. ID 21 is also stained red and appears in the Stained List at
the right of the map, as this person has visited the red stain at (66, 32) by
this point in the animation. The full path of this person is highlighted in the
map.
Figure 1.2. The
Stained People list (at the right of the map) indicates those people who
visited the suspected blast site. In particular, the path of ID 21 is
highlighted.
The “Time Marked People” list includes people who DID NOT MOVE
during time indicated by the dark highlight on the time bar. These markers are
also highlighted on the map.
Traces-2
Identify potential suspects and/or witnesses to the event.
Note: Potential
suspects and/or witnesses are people who were near the area just prior to the
explosion and exhibit suspicious behavior
List of
RFID tag numbers :
18, 21, 50, 56
Short
Answer:
To identify people who were near the area just prior to the
explosion (based on the RFID data), an area with line of sight to the room
containing the suspected blast site is stained in red beginning at tick 270
(see Figure 2.1). Then the animation is played until tick 382, just after the
explosion. Any person entering the stained area is stained. Figure 2.2 shows those persons stained in the Stained People list, with
#21 highlighted.
Number 21, Ramon Katalanow,
behaves suspiciously in this time and space, first moving away from the blast
site, then back toward it.
If “witness” is defined as
someone who could have seen ID 21 before or after the blast, the list should
also include: 01, 27, 30, 81
Another
suspicious ID is number 36. His RFID tag is the only one that does not move
after tick 250.
Figure 2.1. Area around blast site
stained in red at tick 270, before the explosion.
Figure 2.2. People stained by the red
stain from the blast site. These are the witnesses / suspects.
Traces-3
Identify any suspects and/or witnesses who managed to escape the building.
List of
RFID tag numbers :
21
Short
Answer:
Of the people on the list of suspects and witnesses (answer to
the previous question), only ID 21 escapes the building. The stained persons
list in Figure 3.1 shows those persons stained by the red blast area stain at
the end of the time data, with #21 highlighted. It can be seen that of the four
people on the list, only #21 is out of the building.
Figure 3.1. People stained by the red
stain from the blast site. These are the witnesses / suspects at the end of the
time data. Only ID #21 is out of the building.
Traces-4
Identify any casualties.
List
of RFID tag numbers :
18, 19, 36, 39, 47,
50, 56, 59, 60, 65, 69, 76, 78
Short
Answer:
We count people who did not exit the building as casualties.
To determine those people who did not exit, we begin by finding those that did.
By placing a stain at each building exit, people who exit the building are
stained. Figure 4.1. shows
the map with the stained exits with people having been stained by exiting.
Inverting this list, we get the list of people who did not exit. This list is
show in Figure 4.2. Figure 4.2. show
people who did not exit the building in their initial locations (tick = 1).
Figure 4.1. People stained by the
stains placed at each of the building exits.
Figure 4.2. Inverting the “people who
exited” stained list (from Figure 4.1.) yields the list of people who did not
exit the building. This image shows tick = 1.
Traces-5
Describe the evacuation
Detailed
Answer:
Almost everyone left of x = 30 went toward the same door at
the time of the explosion, causing a large crowd of people trying to reach the
door in the hallways around it. 13 and
59 began running for another door, resulting in one more dead as 59 stops moving
about halfway. 13 turns
around and goes back to the original door and is second to last to leave the
building.
A person of
note is number 39 who must have had an error being tracked or was somehow on
the roof or basement because he was unaffected by the walls in the data. He stops before reaching the door.
Number 36 barely moves, and this could be significant. The reasons why he hadn’t moved might known by number 28, 73, or 80.
The evacuation was a mild success, with about 13 casualties.
The immediate area around the explosive device had 5 immediate casualties. Soon after that, while people were fleeing
the area from the door south of where the bomb went off the exit became cut off
and 6 more people died. There was one
final casualty in the northern corridor without obvious cause, but it could
have been the result of a collapse or smoke.
The
evacuation would have gotten a lot worse if the bomb had been set off in the
north western side of the building or a second bomb had been placed there. In Figure 5.2, you can see just how crowded that
door and the hallway leading to it had become.
Figure 5.1. People stained by the
stains placed at each of the building exits indicating the exit they eventually
use, and people who do not exit stained in red, at tick = 1. At the bottom of
this window is also a list of the 27 people in motion during the time
highlighted on the time bar. The path of ID 21 is highlighted as well.
Figure 5.2. People stained by the
stains placed at each of the building exits indicating the exit they eventually
use, and people who do not exit stained in red, at tick = 458. In this image,
it can be seen that most people exit orderly. However, ID 39, whose path is
highlighted in this image, seems to walk through walls. It seems he is on a
different level and returns to the level everyone else is one before becoming a
casualty.