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

How control functions help in signalling and control, How different control...

How different control function categories help in signalling and control. Events happening outside the exchange on the line units, trunk junctions and inter exchange signalin

What is the function of a data element, What is the function of a data elem...

What is the function of a data element? A data element defines the role played by a domain in a technical context.  A data element having of semantic information.

Instruction-execution cycle, Problem (a) Using a labelled diagram of ...

Problem (a) Using a labelled diagram of an Instruction-Execution cycle, describe how a CPU executes single machine instructions by referring to the five main operations.

What is a null object in c++, It is an object of a number of classes whose ...

It is an object of a number of classes whose purpose is to indicate that a real object of that class does not exist. One common use for a null object is a return value from a membe

What are the disadvantages of linux, What are the disadvantages of Linux? ...

What are the disadvantages of Linux? Learning Lack of comparable programs More technical skill required

Define how ptrace is used by debuggers, State how Shared Memory is used for...

State how Shared Memory is used for inter process communication. Define how ptrace is used by debuggers.  What are modules? Explain how data mapping takes place among modules

Find blocking probably in 100-line strowger switching system, Calculate the...

Calculate the blocking probably Pb in 100 line strowger switching system where 10 calls are in progress and 11th one arrives, probably that there is a call in a given decade = 1/10

Explain step by step switching system with neat diagram, With the help of a...

With the help of a neat diagram explain a step by step switching system. Configuration of a step by step switching system: A step by step switching system may be constr

Define critical mass and critical volume, Q. Define critical mass and criti...

Q. Define critical mass and critical volume? The minimum size in which at least one neutron is available for further fission reaction. The throng of the fissile material at the

Define side tone is essential in telephone communication, A certain amount ...

A certain amount of side tone is essential in telephone communication. Ans: It is true that a specific amount of side tone is necessary in telephone communication.

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