Adding momentum - sigmoid units, Computer Engineering

Assignment Help:

Adding Momentum - Sigmoid units:

However imagine a ball rolling down a hill as it does so then it gains momentum in which its speed increases and it becomes more difficult to stop. Alternatively as it rolls down the hill towards the valley floor as the global minimum, then it might occasionally wander into local hollows. Moreover,, there it may be that the momentum it has obtained stays it rolling up and out of the hollow and back on track to the valley floor. 

Hence the crude analogy describes one heuristic technique for avoiding local minima that called adding momentum, funnily enough. Thus the method is simple as: now for each weight remember as the previous value of Δ that was added on to the weight in the last epoch. Rather then, where updating that weight for the current epoch, add on a little of the previous Δ. Now how small to make the additional extra is controlled through a parameter α that's called the momentum which is set to a value between 0 and 1. 

Alternatively to see why this might help bypass local minima so note there that if the weight change carries on in the direction it was going in the previous epoch and then the movement will be a little much more pronounced in the current epoch. Thus this effect will be compounded as the search continues in the same direction. Where the trend finally reverses so then the search may be at the global minimum case there it is hoped that the momentum won't be enough to take it anywhere other than where it is belongs. Conversely the search may be at a fairly narrow local minimum. So next there in this case, even though the back propagation algorithm which dictates Δ will change direction then it may be that the additional extra from the previous epoch as the momentum may be enough to  counteract this effect for a few steps. Then we can saythese few steps may be all that is utilised to bypass the local minimum.


Related Discussions:- Adding momentum - sigmoid units

What do you mean by supercomputers, Q. What do you mean by Supercomputers? ...

Q. What do you mean by Supercomputers? The upper end of state of art mainframe machine is supercomputers. These are among the fastest machines in terms of processing speed and

#title.sequential circuit, design modulo 12 up synchronous counter using t ...

design modulo 12 up synchronous counter using t flip flop

Difference between field-group header and other field groups, What is the d...

What is the difference between field-group header and other field groups? The header field group is a particular field group for the sort criteria.  The system automatically p

Benefits of device controllers, Q. Benefits of Device controllers? Usin...

Q. Benefits of Device controllers? Using device controllers for attaching I/O devices to a computer system in place of connecting them directly to system bus has subsequent ben

IA-32 support, In order to support IA-32 Itanium can switch in 32-bit mode ...

In order to support IA-32 Itanium can switch in 32-bit mode with special jump escape instructions. IA-32 instructions have been mapped to Itanium's functional units. But as Itanium

Explain abstract class, What is an interface and what is an abstract class?...

What is an interface and what is an abstract class? Please, expand by examples of using both. Explain why?   Abstract classes are closely related to interfaces. They are classe

Pseudocode, 1 1 1 1 2 1 1 3 3 1 1 4 6 4 1

1 1 1 1 2 1 1 3 3 1 1 4 6 4 1

What is static timing, What is Static timing a. Delays over all paths a...

What is Static timing a. Delays over all paths are added up. b. All possibilities, including false paths, verified without the need for test vectors. c. Faster than simul

What is race-around problem and how can you rectify this, What is Race-arou...

What is Race-around problem? How can you rectify this? The clock pulse which remains into the 1 state whereas both J and K are equal to 1 will reason the output to complement a

What is a disk drive, What is a disk drive? The electro mechanical mech...

What is a disk drive? The electro mechanical mechanism that spins the disk and moves the read/write heads known as disk drive.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd