Example multi-layer ann with sigmoid units, Computer Engineering

Example Multi-layer ANN with Sigmoid Units - Artificial intelligence:

We will discuss ourselves here with ANNs containing only 1 hidden layer, as this makes describing the back propagation routine simpler. Notice that networks where you may feed in the input on the left and propagate it forward to get an output are known feed forward networks. Below is such an ANN, with 2 sigmoid units in the hidden layer. The weights have been set arbitrarily between all the units.


2290_Example Multi-layer ANN with Sigmoid Units.png

Notice that the sigma units have been recognized with sigma signs in the node on the graph. As we did with perceptrons, we may give this network an input and determine the output. Also we may look to see which units "fired", for example, had a value closer to 1 than to 0.

Imagine we input the values 10, 30, 20 into the 3 input units, from top to bottom. Then the weighted sum approaching into H1 will be:

SH1 = (0.2 * 10) + (-0.1 * 30) + (0.4 * 20) = 2 -3 + 8 = 7.

Then the σ function is applied to SH1 to give:

σ (SH1) = 1/(1+e-7) = 1/(1+0.000912) = 0.999

[Do not forget to -ve S]. In Simple term, the weighted sum coming into H2 will be: SH2 = (0.7 * 10) + (-1.2 * 30) + (1.2 * 20) = 7 - 36 + 24 = -5

And σ applied to SH2 gives:

σ (SH2) = 1/(1+e5) = 1/(1+148.4) = 0.0067

From this, we may see that H1 has fired, but H2 has not fired. Now we can calculate that the weighted sum put in to output unit O1 will be:

SO1 = (1.1 * 0.999) + (0.1*0.0067) = 1.0996

And the weighted sum put in to output unit O2 will be: SO2 = (3.1 * 0.999) + (1.17*0.0067) = 3.1047

Now the output sigmoid unit in O1 will calculate the output values from the network for O1:

σ (SO1) = 1/(1+e-1.0996) = 1/(1+0.333) = 0.750

and the output from the network for O2:

σ(SO2) = 1/(1+e-3.1047) = 1/(1+0.045) = 0.957

Thus, if this network represented the learned rules for a categorization problem, the input triple (10,30,20) would be categorized into the category related with O2, because this has the bigger output.

Posted Date: 10/2/2012 6:20:49 AM | Location : United States

Related Discussions:- Example multi-layer ann with sigmoid units, Assignment Help, Ask Question on Example multi-layer ann with sigmoid units, Get Answer, Expert's Help, Example multi-layer ann with sigmoid units Discussions

Write discussion on Example multi-layer ann with sigmoid units
Your posts are moderated
Related Questions
The heart of an experts systems is the powerful corups of knowledge that accumulates during system building. The knowledge is explicit and organized to simplify decisio

Interrupt vector table is always created in first 1K area of the memory. Explain why? When CPU receives an interrupt type number from PIC, it uses this number to look up corres

The Standard C Library function is removing. (This is thus one of the few questions in this section for which the answer is not ''It's system-dependent.'') On older, pre-ANSI Unix

what is the basic diff between mbr and mdr

Evaluation Functions for Cutoff Search - artificial intelligent Evaluation functions guess the score that may be guaranteed if a specific world state is reached. In chess, such

Applications Of Parallel Processing Parallel computing is an development of serial computing that effort to emulate what has always been the affirm of affairs in the natural wo

The Environment variable SCRIPT_NAME in CGI script specifies? In CGI script gives the path of URL after server name.

Conversion of Decimal Number to Binary Number: For converting a decimal number to binary integer part and fractional part are handled separately. Let's describe it with help of

explain area sub division method algorithm

A managed bean - sometimes simply referred to as an MBean - is a type of JavaBean, developed with dependency injection. Managed Beans are particularly used in the Java Management E