In BAsCET, the activation value is propagated from a semantic node to another.

Let's start from the example shown in the link explanation.

/----------------\                             /--------------\
|   S: birthday  |                             |    S: cake   |
+----------------+                             +--------------+
| CI:  80        |     /-----------------\     | CI: 70       |
| AV: 100 %      +-----+ T: eat | W: 95% +-----+ AV:  0%      |
| DR:   2        |     \-----------------/     | DR:  5       |
| Ag: ComputeDay |                             | Ag: CookCake |
\----------------/                             \--------------/

Propagating the activation value of birthday through the link eat to the node cake will give the following Concept Network:

/----------------\                             /--------------\
|   S: birthday  |                             |    S: cake   |
+----------------+                             +--------------+
| CI:  80        |     /-----------------\     | CI: 70       |
| AV:  98 %      +-----+ T: eat | W: 95% +-----+ AV: 86%      |
| DR:   2        |     \-----------------/     | DR:  5       |
| Ag: ComputeDay |                             | Ag: CookCake |
\----------------/                             \--------------/

The activation value AVt+1i of a node i at the instant t + 1, after propagation, is expressed as the sum of its old activation value AVti and the other nodes' influence Ii, minus a deactivation Di, depending on its decay rate DRi.

AVt+1i = AVti + Ii - Di

The influence of other nodes could be given by this classical formula:

Ii = (Σj≠i Aj x Wij) / 100

but it lets an unbalanced influence between nodes with many neighbours (influencing them) and nodes with almost none.

That's the reason why BAsCET use a little more complicated influence, with a logarithmic behaviour.

As the birthday node has no incoming link, Ibirthday is null.

Dbirthday = 100 x 2 / 100 = 2

So, its new activation value AV1 = AV0 + I - D = 100 + 0 - 2 = 98.

As far as the cake node is concerned, it is different: its activation value is null, and so is its deactivation. However, it is influenced by birthday:

Icake = (A0birthday x Wbirthday,cake) / ( 100 x Divcake ) = 100 x 95 / ( 100 x Divcake ) = 95 / Divcake

Divcake = ln 4 / ln 3 ~ 1.0986, so Icake ~ 86.

At last, A1birthday = 0 + 86 - 0 = 86

In this example, one could add a candle node, that would be associated to the cake and birthday symbols. One could add a link from cake to candle labeled by birthday; so, when birthday and cake are both activated, this link activate candle.

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