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

Explain about disk caching scheme, Q. Explain about disk caching scheme? ...

Q. Explain about disk caching scheme? The disk caching scheme can be used to speed up performance of disk drive system. A set (cache) of buffers is assigned to hold some disk b

How to attain 180 degree precise phase shift, How to attain 180 degree prec...

How to attain 180 degree precise phase shift? Never tell using inverter: a. DCM an inbuilt resource into most of FPGA can be arranged to get 180 degree phase shift. b. BU

What is gimps native graphics file format, XCF is GIMP's "native" format. T...

XCF is GIMP's "native" format. This will preserve all information about an image, having the layers.

What are the types of pipeline hazards, What are the types of pipeline haza...

What are the types of pipeline hazards? The various pipeline hazards are:  1. Data hazard  2. Structural Hazard  3. Control Hazard.

What is input - output interface, The I/O interface provides a technique fo...

The I/O interface provides a technique for transferring information between external I/O devices and internal storage. Peripherals linked to a computer require special communicatio

Define about exe programs, Q. Define about EXE Programs? An EXE program...

Q. Define about EXE Programs? An EXE program is stored on disk with extension .exe. EXE programs are longer than COM programs as every EXE program is related with an EXE header

What is batch processing, What is Batch processing In this process, a n...

What is Batch processing In this process, a number of tasks (or jobs) are all collected together over a set period of time. They are then all loaded into the computer system (i

Explain i/o buffer and advantage of buffering, What is an I/O buffer? What ...

What is an I/O buffer? What is the advantage of buffering? Is buffering always effective? Justify your answer with help of an example.   One type of I/O requirement arises from

Network properties, Network Properties There are many properties are as...

Network Properties There are many properties are associated with interconnection networks:- 1) Topology: It signify how the nodes a network are organised. A variety of top

How can we use / display table in a screen, How can we use / display table ...

How can we use / display table in a screen? ABAP/4 offers two mechanisms for showing and using table data in a screen.  These mechanisms are TABLE CONTROLS and STEP LOOPS.

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