Examples of artificial neural networks, Computer Engineering

Examples of artificial neural networks:

Now here as an example consider a ANN that has been trained to learn the following rule categorising the brightness of 2x2 black and white pixel images also as: if it contains 3 or 4 black pixels then it is dark; but if it contains 2, 3 or 4 white pixels then it is bright. So here we can model this with a perceptron through sa pixel then they output +1 if the pixel is white and  if -1 then the pixel is black. But here also if the input example is to be categorised as bright when the output unit produces a 1and if the example is dark when the output unit produces a 1. In fact if we choose the weights as in the following diagram where the perceptron will perfectly categorise any image of four pixels by dark or light according to our rule: as there are 4 input units and one for each pixel then they output +1 if the pixel is white and for -1 if the pixel is black. Here also the output unit produces a 1 if the input example is to be categorised as bright and if the example is dark then -1. Whether we choose the weights as in the following diagram then the perceptron will perfectly categorise any image of four pixels through dark or light according to our rule: 

2194_Examples of artificial neural networks.png

Furthermore details we see that in this case there the output unit has a step function through the threshold set to -0.1. But note there the weights in this network are all the same that is not true in the practical case. So now here it is convenient to make the weights going in to a node add up to 1 also, means it is possible to compare them easily. Thus the reason this network perfectly captures our notion of darkness and lightness is it means that if three white pixels are input so then three of the input units produce +1 and one input unit produces  -1. Hence this goes into the weighted sum that giving a value of S = 0.25*1 + 0.25*1 + 0.25*1 + 0.25*(-1) = 0.5. As we seen this is greater than the threshold of  -0.1, the output node produces +1 that relates to our notion of a bright image. Furthermore details we see that four white pixels will produce a weighted sum of 1 that is greater than the threshold so then two white pixels will produce a sum of 0 and also greater than the threshold. In fact if there are three black pixels then S will be -0.5 that is below the threshold thus the output node will output -1 so the image will be categorised as dark. Actually an image with four black pixels will be categorised as dark.

Posted Date: 1/11/2013 6:57:27 AM | Location : United States







Related Discussions:- Examples of artificial neural networks, Assignment Help, Ask Question on Examples of artificial neural networks, Get Answer, Expert's Help, Examples of artificial neural networks Discussions

Write discussion on Examples of artificial neural networks
Your posts are moderated
Related Questions
Name the concepts of Object oriented There are various concepts of object oriented analysis Abstraction, Encapsulation, Identity, Modularity, Hierarchy, Typin

Explain CGI standard. The CGI Standard: Technology utilized for building dynamic web documents is termed as Common Gateway Interface (CGI). The CGI standard gives how a serv

Communication by Message Passing You will agree that a single object alone is generally not very helpful. Objects usually emerge as components of a system or a larger program.

Q. Structure of Input - Output Interface? Due to complexity and number of external devices that I/O interface control, there is not any standard structure of I/O interface. Let

What is skew? Clock Skew: In circuit design, clock skew is a phenomenon within synchronous circuits wherein the clock signal (sent through the clock circuit) arrives at dive

The method(s) of payment for online consumers are A) Electronic cash    (B) Credit/debit C) Electronic checks

Execution of a program in CPU is completed employing different set of registers and their individual circuitry. As CPU registers are used for execution of interrupt service routine

Benefits of implementing ERP

What is a Service in SAP terminology? A service refers to something offered by an s/w component.

Q. Average data transfer rate in floppy? A floppy is about 0.64 mm thick and is available in diameters 5.25 inch and 3.5 inch. Data are arranged in form of tracks and sectors.