T. Yaku et al. intoduced octgrids that are graph expressions of multiresolution threedimensional top

1
IEEE Internat. Conf. Adv. Learning Tech.
(ICALT2007) , July 2007, Niigata, Japan
Geographical Concept Recognition with the Octgrid
Method for Learning Geology and Geography
Ryusuke Yokoyama, Akira Kureha, Tomoe
Motohashi, Hiroyasu Ogasawara, Takeo Yaku,
and Daisuke Yoshino Nihon University, Kanto
Gakuin University yaku_at_cs.chs.nihon-u.ac.jp,
ryusuke, kureha, yoshino_at_yaku.cs.chs.nihon-u.ac.
jp cspeirce_at_chs.nihon-u.ac.jp, tomoe_at_kanto-gakuin.
ac.jp  

• Introduction
• To provide learners with skills for
  recognizing geographical concepts.
• Reviw octgrid method. Our system runs on 3D maps
  in octgrid data format.
• Propose an automatic recognition system for
  ridges, valleys, and contour lines.
• Application of the above systems to an integrated
  CAI system, ggCAI.

• T. Yaku et al. intoduced octgrids that are graph
  expressions of multi-resolution
  three-dimensional topographical maps,
  intermediate
• code (H7CODE) that is a grid graph, and a
  list structures.
• figure 2 is an example of rectangle division
  and the corresponding octgrids

Background Octgrid Method
Figure 1. rectangular dissection D1 and octgrids
G1 that correspond to D1.
Geographical Concept Recognition Module
Characteristic topography extraction in this
article means that which displays general
geographical ideas a mountain, ridge, valley,
contour line, or delta based on data of meters
above sea level.
Yana river
Yumifuri river
Yachiba river
Figure 5. Example of expressing a drainage basin.
Figure 3. Ridge extraction of Mt. Fuji .
Figure 4 . Valley extraction of Mt. Fuji.
Figure 2. Contour lines near Mt. Fuji. Moving
from the outside inward, the black lines
represent the altitudes of 1000,1500,2000,2500,300
0,and 3500 meters.
Extraction of ridges and valleys operates to down
dissection of the maximum called drive line. When
we extract a valley we reverse ?the numerical
values
A drainage basin is the whole area of a region
where water from rain and snow flows into a river.
Input DEM file and a number to show a
place. Output Geographical Concept Recognition
file. The number of the steps 352. Description
language C.
Input DEM file and a number to show a
place. Output drainage basin file. The number of
the steps 387. Description language C.
Input DEM file and a number to show a
place. Output Contour line file. The number of
the steps 137. Description language C.
Application to Learning System of Geology and
Geography This section deals with the
specifications and structure of courseware Each
set of contents has a link from each
corresponding list of geography, or earth
science topics. The number of contents
Eight places (contour line, valley, and ridge per
one place) We incorporate the output of a
geographical concept recognition system in CAI.
Figure 7 is an example of applying a CAI
system.
Figure 6. Snapshot of courseware.
Conclusion We have developed a system that
provides a large number of required examples in
classrooms. Future WorkA recognition system of
delta and alluvial fan. We also provide a system
for recognizing ridges, valleys, and contours
from landform maps. Future Work A Geographical
concept recognition system corresponding to a
world topographical map. We have applied
the two systems to a CAI system for the study of
geology and geography. Future Work To
incorporate a geographical concept recognition
system in CAI.