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
What are the main features of UML Defined system structure for the object modelling Support for all different model organization Strong modelling for behaviour an

what are the output deice

Q. Determine the statement for array? Determine the statement ALIGN A[i] WITH B[i] This statement aligns every A[i] with B[i] as displayed in Figure below. Figure

How to get an output: Please enter a number between 0 and 6 (Enter to stop): 2 The Day of Week is Tuesday Please enter a number between 0 and 6 (Enter to stop): 9 Input Invalid Ple

Explain MDR and MAR. The data and address lines of the external memory bus linked to the internal processor bus by the memory data register, MDR and the memory address register

a. What are the activities included during the process of developing a formal specification of a sub-system interface? b. Explain the Pair Programming? What are the benefits of

What are the different layers of TCP/IP protocol stack? Layers in the TCP/IP protocol architecture are:- o  Application Layer o   Host-to-Host Transport Layer,  o  Net

Cache-Only Memory Access Model (COMA) As we have considered earlier, shared memory multiprocessor systems can use cache memories with each processor for decreasing the execution

Q. Define Keyword and Identifiers? Keyword:   A keyword is a statement which defines nature of that statement. If statement is a directive then keyword would be the title of t

Q. Show the MIPS Addressing Modes? MIPS Addressing Modes MIPS employs various addressing modes: 1. Uses Register as well asimmediate addressing modes for operations.