Information Technology Reference
In-Depth Information
1
SIM
=
1
d
∈
[
0
∞
)
or
if
(5.6)
ij
ij
+
d
ij
In addition, ReMind system developed by Cognitive System Company
employ the following definition to calculate similar degrees among cases:
n
n
Ã
Ã
w
×
(
f
l
,
f
R
) /
w
Sim
(5.7)
i
i
i
i
i
=
1
i
=
1
w
is the weight of i-th feature of the case, Sim is the similarity
function, and f
li
f
R
i are the values of i-t
h
feature of the target case and the
potential base cases in case base.
where
5.8 Case Reuse
The case reuse can be classified into two types in terms of the information
reused: result reuse and method reuse. To the former, the adaptation is applied
directly to the solution stored in cases. The system looks for prominent
differences between the base case and the target one and then applies a set of
adaptation rules to suggest a solution. Instead of the solutions stored, the
method reuse reuses the algorithms, or rules employed in the problem solving
in the base cases to produce a new solution to the target case, while the choice
of adaptation methods are dependent on the concrete problems.
Case revise happens when the proposed solution is regarded as not good,
so the first step in case revise is the evaluation on the proposed solution. Only
in the cases that the solution is evaluated to be not good, a revise process is
evoked. The evaluation on a proposed solution can fulfilled on the basis of
feedbacks after the solution's application, or by consulting domain experts. It
takes some time to wait a feedback, e.g., patient's therapeutic effects, while
some kinds of real-time feedbacks are required in some situations.
Generally speaking, there is no existing case that exactly matches the new
case, so in problem solving CBR systems, it is necessary to transform or adapt
the solutions to the retrieved cases to the new problem. The revise process use
the description of the current problem and a suggested solution gotten in the
reuse process to output a better solution.
The revision may be just simple replacement to some components of the
suggested solution, or very complex to revise the whole structure of the
suggested solution. Revision can take place in the process that the suggested
