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Bio-medical Ontologies Maintenance and Change Management

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192 I.R. Godínez et al.<br />

The ij-thentryisgivenas:vij = p �<br />

μ=1<br />

B, ∀i ∈{1, 2,...,n} , ∀j ∈{1, 2,...,n}.<br />

α � x μ<br />

i ,xμ<br />

�<br />

j .Itisobviousthatvij ∈<br />

RECALLING PHASE<br />

A pattern x ω , that could be or not a fundamental pattern, with ω ∈<br />

{1, 2, ..., p} is presented to the alpha-beta autoassociative memory of kind<br />

∨ <strong>and</strong> the following operation is done: VΔβx ω . The result is a column vector<br />

of dimension n, withthei-th component given as:<br />

(VΔβx ϖ ) i =<br />

n�<br />

j=1<br />

β � vij,x ϖ j<br />

Remark 1. Note that alpha-beta autoassociative memories of kind ∧ are built<br />

by duality from alpha-beta autoassociative memories of kind ∨. Inorderto<br />

do so, the following changes are made:<br />

• Use operator ∨ instead of operator ∧.<br />

• Use operator ∧ instead of operator ∨.<br />

• Use operator ∇β instead of operator Δβ; operator∇β is defined as:<br />

(Λ∇βx ϖ ) i =<br />

n�<br />

j=1<br />

�<br />

β(λij,x ϖ j )<br />

The greatest limitation of alpha-beta associative memories is perhaps that<br />

they only work with binary data, being unable to manipulate integer or real<br />

numbers. However, there have been numerous efforts to extend the original<br />

model [25]-[28]. With these advances, alpha-beta memories can be applied to<br />

binary <strong>and</strong> integer pattern recognition, as well as gray-level <strong>and</strong> color image<br />

processing, <strong>and</strong> all the different fields these imply.<br />

3 Proposed Solution<br />

This section is dedicated to the main contribution presented in this chapter,<br />

the Alpha-Beta MultiMemories Classifier, used to broach the subjects of promoter<br />

identification <strong>and</strong> splice-junction zone localization. First, an extension<br />

to the heteroassociative kind of the original alpha-beta associative memory<br />

model is introduced, followed by a new model of associative memory based<br />

in the former extension: the alpha-beta heteroassociative multimemories. Finally,<br />

the concepts presented in the model of multimememories are applied<br />

to build the proposed classifier.<br />

3.1 New Alpha-Beta Heteroassociative Memory<br />

The alpha-beta associative memories model guarantee, through theorems 4.28<br />

<strong>and</strong> 4.32 from [22], the complete recall of the fundamental set, but only for

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