Enclosure 2 to COMDTINST 16478.12
III. Clustering and prioritization
(A) A clustering algorithm, described below, was used to partition the set of the
approximately 12,000 fixed lighted AtoNs into smaller groups, or clusters.
The
partitioning was based on geographic proximity, and the prioritization of
clusters was based on potential environmental effects (see Table II in the
text). The algorithm performs as follows:
Step 1: The distance from each AtoN in the set of 12,000 to its nearest
neighboring AtoN is obtained;
Step 2: All these nearest distance from step 1 are added and then divided by
the number of AtoNs in the set (12,000);
Step 3: The quotient from Step 2, the average of the nearest designated as
the 'mean of the nearest paths', M, of the set;
Step 4: One considers each individual AtoN in the set and draws a circle
with a radius equal to the mean path M around M around it;
Step 5: A cluster' is then defined by either a group of circles from Step 4
that touch (a chain-like assembly), or a single circle if it does not touch
other circles;
Step 6: From a separate computation, obtain the potential environmental
effect index, R, for each AtoN (this index is based on the attributes given
in the text of this document);
Step 7: For each cluster a score S, is computed which is equal to the sum of
the indices, or Rs, of all the AtoNs within the cluster,
Step 8:
List the scores from Step 7 in descending order.
It is noted that if the value of R for an AtoN within a cluster was not known it was
assumed to be equal to zero.
The list that results from Step 8 provides prioritization on the basis of cluster
which includes the chained circles mentioned above.
(B) Another ranking was obtained by proceeding from Step 4 in (A) above as follows:
Around each AtoN a circle of radius M was drawn. The values of R of all the within
this circle, including the value of R of subject AtoN, were summed. This sum was
then defined as the score for this AtoN. The range of values thus obtained were
partitioned into five categories on a logarithmic scale. Each AtoN was then assigned
into one of these
______________________________________
Volpe National Transportation Systems Center
Priority Ranking Plan for Aton Battery Recovery
Previous Page
