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Posted to user@hadoop.apache.org by unmesha sreeveni <un...@gmail.com> on 2015/02/12 11:14:19 UTC

Neural Network in hadoop

I am trying to implement Neural Network in MapReduce. Apache mahout is
reffering this paper
<http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf>

Neural Network (NN) We focus on backpropagation By defining a network
structure (we use a three layer network with two output neurons classifying
the data into two categories), each mapper propagates its set of data
through the network. For each training example, the error is back
propagated to calculate the partial gradient for each of the weights in the
network. The reducer then sums the partial gradient from each mapper and
does a batch gradient descent to update the weights of the network.

Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked out
example for gradient descent algorithm.

Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
<http://pastebin.com/6gAQv5vb>

   1. Which is the better way to parallize neural network algorithm While
   looking in MapReduce perspective? In mapper: Each Record owns a partial
   weight(from above example: w0,w1,w2),I doubt if w0 is bias. A random weight
   will be assigned initially and initial record calculates the output(o) and
   weight get updated , second record also find the output and deltaW is got
   updated with the previous deltaW value. While coming into reducer the sum
   of gradient is calculated. ie if we have 3 mappers,we will be able to get 3
   w0,w1,w2.These are summed and using batch gradient descent we will be
   updating the weights of the network.
   2. In the above method how can we ensure that which previous weight is
   taken while considering more than 1 map task.Each map task has its own
   weight updated.How can it be accurate? [image: enter image description
   here]
   3. Where can I find backward propogation in the above mentioned gradient
   descent neural network algorithm?Or is it fine with this implementation?
   4. what is the termination condition mensioned in the algorithm?

Please help me with some pointers.

Thanks in advance.

-- 
*Thanks & Regards *


*Unmesha Sreeveni U.B*
*Hadoop, Bigdata Developer*
*Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
http://www.unmeshasreeveni.blogspot.in/

Re: Neural Network in hadoop

Posted by Ted Dunning <te...@gmail.com>.
That is a really old paper that basically pre-dates all of the recent
important work in neural networks.

You should look for works on Rectified Linear Units (ReLU), drop-out
regularization, parameter servers (downpour sgd) and deep learning.

Map-reduce as you have used it will not produce interesting results because
the overhead of map-reduce will be far too high.

Here are some references:

http://www.cs.toronto.edu/~ranzato/publications/DistBeliefNIPS2012_withAppendix.pdf

http://arxiv.org/abs/1412.5567

http://arxiv.org/abs/1502.01710

http://www.comp.nus.edu.sg/~dbsystem/singa/

http://0xdata.com/product/deep-learning/


On Thu, Feb 12, 2015 at 2:14 AM, unmesha sreeveni <un...@gmail.com>
wrote:

> I am trying to implement Neural Network in MapReduce. Apache mahout is
> reffering this paper
> <
> http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf
> >
>
> Neural Network (NN) We focus on backpropagation By defining a network
> structure (we use a three layer network with two output neurons classifying
> the data into two categories), each mapper propagates its set of data
> through the network. For each training example, the error is back
> propagated to calculate the partial gradient for each of the weights in the
> network. The reducer then sums the partial gradient from each mapper and
> does a batch gradient descent to update the weights of the network.
>
> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked out
> example for gradient descent algorithm.
>
> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
> <http://pastebin.com/6gAQv5vb>
>
>    1. Which is the better way to parallize neural network algorithm While
>    looking in MapReduce perspective? In mapper: Each Record owns a partial
>    weight(from above example: w0,w1,w2),I doubt if w0 is bias. A random
> weight
>    will be assigned initially and initial record calculates the output(o)
> and
>    weight get updated , second record also find the output and deltaW is
> got
>    updated with the previous deltaW value. While coming into reducer the
> sum
>    of gradient is calculated. ie if we have 3 mappers,we will be able to
> get 3
>    w0,w1,w2.These are summed and using batch gradient descent we will be
>    updating the weights of the network.
>    2. In the above method how can we ensure that which previous weight is
>    taken while considering more than 1 map task.Each map task has its own
>    weight updated.How can it be accurate? [image: enter image description
>    here]
>    3. Where can I find backward propogation in the above mentioned gradient
>    descent neural network algorithm?Or is it fine with this implementation?
>    4. what is the termination condition mensioned in the algorithm?
>
> Please help me with some pointers.
>
> Thanks in advance.
>
> --
> *Thanks & Regards *
>
>
> *Unmesha Sreeveni U.B*
> *Hadoop, Bigdata Developer*
> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
> http://www.unmeshasreeveni.blogspot.in/
>

Re: Neural Network in hadoop

Posted by Ted Dunning <te...@gmail.com>.
That is a really old paper that basically pre-dates all of the recent
important work in neural networks.

You should look for works on Rectified Linear Units (ReLU), drop-out
regularization, parameter servers (downpour sgd) and deep learning.

Map-reduce as you have used it will not produce interesting results because
the overhead of map-reduce will be far too high.

Here are some references:

http://www.cs.toronto.edu/~ranzato/publications/DistBeliefNIPS2012_withAppendix.pdf

http://arxiv.org/abs/1412.5567

http://arxiv.org/abs/1502.01710

http://www.comp.nus.edu.sg/~dbsystem/singa/

http://0xdata.com/product/deep-learning/


On Thu, Feb 12, 2015 at 2:14 AM, unmesha sreeveni <un...@gmail.com>
wrote:

> I am trying to implement Neural Network in MapReduce. Apache mahout is
> reffering this paper
> <
> http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf
> >
>
> Neural Network (NN) We focus on backpropagation By defining a network
> structure (we use a three layer network with two output neurons classifying
> the data into two categories), each mapper propagates its set of data
> through the network. For each training example, the error is back
> propagated to calculate the partial gradient for each of the weights in the
> network. The reducer then sums the partial gradient from each mapper and
> does a batch gradient descent to update the weights of the network.
>
> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked out
> example for gradient descent algorithm.
>
> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
> <http://pastebin.com/6gAQv5vb>
>
>    1. Which is the better way to parallize neural network algorithm While
>    looking in MapReduce perspective? In mapper: Each Record owns a partial
>    weight(from above example: w0,w1,w2),I doubt if w0 is bias. A random
> weight
>    will be assigned initially and initial record calculates the output(o)
> and
>    weight get updated , second record also find the output and deltaW is
> got
>    updated with the previous deltaW value. While coming into reducer the
> sum
>    of gradient is calculated. ie if we have 3 mappers,we will be able to
> get 3
>    w0,w1,w2.These are summed and using batch gradient descent we will be
>    updating the weights of the network.
>    2. In the above method how can we ensure that which previous weight is
>    taken while considering more than 1 map task.Each map task has its own
>    weight updated.How can it be accurate? [image: enter image description
>    here]
>    3. Where can I find backward propogation in the above mentioned gradient
>    descent neural network algorithm?Or is it fine with this implementation?
>    4. what is the termination condition mensioned in the algorithm?
>
> Please help me with some pointers.
>
> Thanks in advance.
>
> --
> *Thanks & Regards *
>
>
> *Unmesha Sreeveni U.B*
> *Hadoop, Bigdata Developer*
> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
> http://www.unmeshasreeveni.blogspot.in/
>

Re: Neural Network in hadoop

Posted by Ted Dunning <te...@gmail.com>.
That is a really old paper that basically pre-dates all of the recent
important work in neural networks.

You should look for works on Rectified Linear Units (ReLU), drop-out
regularization, parameter servers (downpour sgd) and deep learning.

Map-reduce as you have used it will not produce interesting results because
the overhead of map-reduce will be far too high.

Here are some references:

http://www.cs.toronto.edu/~ranzato/publications/DistBeliefNIPS2012_withAppendix.pdf

http://arxiv.org/abs/1412.5567

http://arxiv.org/abs/1502.01710

http://www.comp.nus.edu.sg/~dbsystem/singa/

http://0xdata.com/product/deep-learning/


On Thu, Feb 12, 2015 at 2:14 AM, unmesha sreeveni <un...@gmail.com>
wrote:

> I am trying to implement Neural Network in MapReduce. Apache mahout is
> reffering this paper
> <
> http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf
> >
>
> Neural Network (NN) We focus on backpropagation By defining a network
> structure (we use a three layer network with two output neurons classifying
> the data into two categories), each mapper propagates its set of data
> through the network. For each training example, the error is back
> propagated to calculate the partial gradient for each of the weights in the
> network. The reducer then sums the partial gradient from each mapper and
> does a batch gradient descent to update the weights of the network.
>
> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked out
> example for gradient descent algorithm.
>
> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
> <http://pastebin.com/6gAQv5vb>
>
>    1. Which is the better way to parallize neural network algorithm While
>    looking in MapReduce perspective? In mapper: Each Record owns a partial
>    weight(from above example: w0,w1,w2),I doubt if w0 is bias. A random
> weight
>    will be assigned initially and initial record calculates the output(o)
> and
>    weight get updated , second record also find the output and deltaW is
> got
>    updated with the previous deltaW value. While coming into reducer the
> sum
>    of gradient is calculated. ie if we have 3 mappers,we will be able to
> get 3
>    w0,w1,w2.These are summed and using batch gradient descent we will be
>    updating the weights of the network.
>    2. In the above method how can we ensure that which previous weight is
>    taken while considering more than 1 map task.Each map task has its own
>    weight updated.How can it be accurate? [image: enter image description
>    here]
>    3. Where can I find backward propogation in the above mentioned gradient
>    descent neural network algorithm?Or is it fine with this implementation?
>    4. what is the termination condition mensioned in the algorithm?
>
> Please help me with some pointers.
>
> Thanks in advance.
>
> --
> *Thanks & Regards *
>
>
> *Unmesha Sreeveni U.B*
> *Hadoop, Bigdata Developer*
> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
> http://www.unmeshasreeveni.blogspot.in/
>

Re: Neural Network in hadoop

Posted by Grzegorz Ewald <gr...@gmail.com>.
Hi,
I don't get it - whats is idea of parallelising algorithm, that is quite
fast and in general focuses only on simple arithmetic operations. The
algorithm itself is difficult to parallelise as it requires series of
weight updates, so I believe that MapReduce payload would be bigger than
parallelisation profit. Eventually, in case of extreme big networks you
could get something but it would be rather "ars pro aprte" as extremely big
networks are not as efficient. Moreover, the algorithm used to stick in
local minimum, so you would get almost nothing... Looking further, I see
that you are using sigmoid perceptrons - you know derivative a-priori...
The only point, where i could imagine using parallel approach to calculate
gradient in neural network, is situation where you are to learn big,
unknown network (you do not know the structure and activation functions).
But it is pointless to approach such a case with NN.

Finally - the stop condition. Usual this is a learning error (if you have a
big faith) or error descent (if you are a bit smarter).


2015-02-12 11:14 GMT+01:00 unmesha sreeveni <un...@gmail.com>:

> I am trying to implement Neural Network in MapReduce. Apache mahout is
> reffering this paper
> <
> http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf
> >
>
> Neural Network (NN) We focus on backpropagation By defining a network
> structure (we use a three layer network with two output neurons classifying
> the data into two categories), each mapper propagates its set of data
> through the network. For each training example, the error is back
> propagated to calculate the partial gradient for each of the weights in the
> network. The reducer then sums the partial gradient from each mapper and
> does a batch gradient descent to update the weights of the network.
>
> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked out
> example for gradient descent algorithm.
>
> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
> <http://pastebin.com/6gAQv5vb>
>
>    1. Which is the better way to parallize neural network algorithm While
>    looking in MapReduce perspective? In mapper: Each Record owns a partial
>    weight(from above example: w0,w1,w2),I doubt if w0 is bias. A random
> weight
>    will be assigned initially and initial record calculates the output(o)
> and
>    weight get updated , second record also find the output and deltaW is
> got
>    updated with the previous deltaW value. While coming into reducer the
> sum
>    of gradient is calculated. ie if we have 3 mappers,we will be able to
> get 3
>    w0,w1,w2.These are summed and using batch gradient descent we will be
>    updating the weights of the network.
>    2. In the above method how can we ensure that which previous weight is
>    taken while considering more than 1 map task.Each map task has its own
>    weight updated.How can it be accurate? [image: enter image description
>    here]
>    3. Where can I find backward propogation in the above mentioned gradient
>    descent neural network algorithm?Or is it fine with this implementation?
>    4. what is the termination condition mensioned in the algorithm?
>
> Please help me with some pointers.
>
> Thanks in advance.
>
> --
> *Thanks & Regards *
>
>
> *Unmesha Sreeveni U.B*
> *Hadoop, Bigdata Developer*
> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
> http://www.unmeshasreeveni.blogspot.in/
>



-- 
Pozdrawiam,
Grzegorz Ewald

<ma...@gmail.com>

Re: Neural Network in hadoop

Posted by Ted Dunning <te...@gmail.com>.
That is a really old paper that basically pre-dates all of the recent
important work in neural networks.

You should look for works on Rectified Linear Units (ReLU), drop-out
regularization, parameter servers (downpour sgd) and deep learning.

Map-reduce as you have used it will not produce interesting results because
the overhead of map-reduce will be far too high.

Here are some references:

http://www.cs.toronto.edu/~ranzato/publications/DistBeliefNIPS2012_withAppendix.pdf

http://arxiv.org/abs/1412.5567

http://arxiv.org/abs/1502.01710

http://www.comp.nus.edu.sg/~dbsystem/singa/

http://0xdata.com/product/deep-learning/


On Thu, Feb 12, 2015 at 2:14 AM, unmesha sreeveni <un...@gmail.com>
wrote:

> I am trying to implement Neural Network in MapReduce. Apache mahout is
> reffering this paper
> <
> http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf
> >
>
> Neural Network (NN) We focus on backpropagation By defining a network
> structure (we use a three layer network with two output neurons classifying
> the data into two categories), each mapper propagates its set of data
> through the network. For each training example, the error is back
> propagated to calculate the partial gradient for each of the weights in the
> network. The reducer then sums the partial gradient from each mapper and
> does a batch gradient descent to update the weights of the network.
>
> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked out
> example for gradient descent algorithm.
>
> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
> <http://pastebin.com/6gAQv5vb>
>
>    1. Which is the better way to parallize neural network algorithm While
>    looking in MapReduce perspective? In mapper: Each Record owns a partial
>    weight(from above example: w0,w1,w2),I doubt if w0 is bias. A random
> weight
>    will be assigned initially and initial record calculates the output(o)
> and
>    weight get updated , second record also find the output and deltaW is
> got
>    updated with the previous deltaW value. While coming into reducer the
> sum
>    of gradient is calculated. ie if we have 3 mappers,we will be able to
> get 3
>    w0,w1,w2.These are summed and using batch gradient descent we will be
>    updating the weights of the network.
>    2. In the above method how can we ensure that which previous weight is
>    taken while considering more than 1 map task.Each map task has its own
>    weight updated.How can it be accurate? [image: enter image description
>    here]
>    3. Where can I find backward propogation in the above mentioned gradient
>    descent neural network algorithm?Or is it fine with this implementation?
>    4. what is the termination condition mensioned in the algorithm?
>
> Please help me with some pointers.
>
> Thanks in advance.
>
> --
> *Thanks & Regards *
>
>
> *Unmesha Sreeveni U.B*
> *Hadoop, Bigdata Developer*
> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
> http://www.unmeshasreeveni.blogspot.in/
>

Re: Neural Network in hadoop

Posted by unmesha sreeveni <un...@gmail.com>.
On Thu, Feb 12, 2015 at 4:13 PM, Alpha Bagus Sunggono <ba...@gmail.com>
wrote:

> In my opinion,
> - This is just for 1 iteration. Then, batch gradient means find all delta,
> then updates all weight. So , I think its improperly if each have weight
> updated. Weight updated should be after Reduced.
> - Backpropagation can be found after Reduced.
> - This iteration should be repeat and repeat again.
>
​I doubt if iteration is for each record. ie say for example we have just 5
records,so whether the iteration will be 5 ? or some other concepts.
ie from the above example
​
​
​​
∆*w**0*,∆*w**1*,∆*w*
*2​ ​*
​
will be the delta error

​.So here lets say we have a threshold value
​. so for each record we will be checking if
​
∆*w**0*,∆*w**1*,∆*w*
*2​ * is
​less
 than
​ or equal to ​

​threshold value , else continue the iteration. Is it like that . Am I
wrong ?

​Sorry I am not that much clear on the iteration part.​


> Termination condition should be measured by delta error of sigmoid output
> in the end of mapper.
> ​
> Iteration process can be terminated after we get suitable  small value
> enough of the delta error.
>

Is there any criteria in updating delta weights?
 after calculating output of perceptron lets find the error:
(oj*(1-0j)(tj-oj))
check if error is less than threshold,then delta weight is not updated else
update delta weight .
Is it like that?


>
> On Thu, Feb 12, 2015 at 5:14 PM, unmesha sreeveni <un...@gmail.com>
> wrote:
>
>> I am trying to implement Neural Network in MapReduce. Apache mahout is
>> reffering this paper
>> <http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf>
>>
>> Neural Network (NN) We focus on backpropagation By defining a network
>> structure (we use a three layer network with two output neurons classifying
>> the data into two categories), each mapper propagates its set of data
>> through the network. For each training example, the error is back
>> propagated to calculate the partial gradient for each of the weights in the
>> network. The reducer then sums the partial gradient from each mapper and
>> does a batch gradient descent to update the weights of the network.
>>
>> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked
>> out example for gradient descent algorithm.
>>
>> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
>> <http://pastebin.com/6gAQv5vb>
>>
>>    1. Which is the better way to parallize neural network algorithm
>>    While looking in MapReduce perspective? In mapper: Each Record owns a
>>    partial weight(from above example: w0,w1,w2),I doubt if w0 is bias. A
>>    random weight will be assigned initially and initial record calculates the
>>    output(o) and weight get updated , second record also find the output and
>>    deltaW is got updated with the previous deltaW value. While coming into
>>    reducer the sum of gradient is calculated. ie if we have 3 mappers,we will
>>    be able to get 3 w0,w1,w2.These are summed and using batch gradient descent
>>    we will be updating the weights of the network.
>>    2. In the above method how can we ensure that which previous weight
>>    is taken while considering more than 1 map task.Each map task has its own
>>    weight updated.How can it be accurate? [image: enter image
>>    description here]
>>    3. Where can I find backward propogation in the above mentioned
>>    gradient descent neural network algorithm?Or is it fine with this
>>    implementation?
>>    4. what is the termination condition mensioned in the algorithm?
>>
>> Please help me with some pointers.
>>
>> Thanks in advance.
>>
>> --
>> *Thanks & Regards *
>>
>>
>> *Unmesha Sreeveni U.B*
>> *Hadoop, Bigdata Developer*
>> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
>> http://www.unmeshasreeveni.blogspot.in/
>>
>>
>>
>
>
> --
> Alpha Bagus Sunggono
> http://www.dyavacs.com
>



-- 
*Thanks & Regards *


*Unmesha Sreeveni U.B*
*Hadoop, Bigdata Developer*
*Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
http://www.unmeshasreeveni.blogspot.in/

Re: Neural Network in hadoop

Posted by unmesha sreeveni <un...@gmail.com>.
On Thu, Feb 12, 2015 at 4:13 PM, Alpha Bagus Sunggono <ba...@gmail.com>
wrote:

> In my opinion,
> - This is just for 1 iteration. Then, batch gradient means find all delta,
> then updates all weight. So , I think its improperly if each have weight
> updated. Weight updated should be after Reduced.
> - Backpropagation can be found after Reduced.
> - This iteration should be repeat and repeat again.
>
​I doubt if iteration is for each record. ie say for example we have just 5
records,so whether the iteration will be 5 ? or some other concepts.
ie from the above example
​
​
​​
∆*w**0*,∆*w**1*,∆*w*
*2​ ​*
​
will be the delta error

​.So here lets say we have a threshold value
​. so for each record we will be checking if
​
∆*w**0*,∆*w**1*,∆*w*
*2​ * is
​less
 than
​ or equal to ​

​threshold value , else continue the iteration. Is it like that . Am I
wrong ?

​Sorry I am not that much clear on the iteration part.​


> Termination condition should be measured by delta error of sigmoid output
> in the end of mapper.
> ​
> Iteration process can be terminated after we get suitable  small value
> enough of the delta error.
>

Is there any criteria in updating delta weights?
 after calculating output of perceptron lets find the error:
(oj*(1-0j)(tj-oj))
check if error is less than threshold,then delta weight is not updated else
update delta weight .
Is it like that?


>
> On Thu, Feb 12, 2015 at 5:14 PM, unmesha sreeveni <un...@gmail.com>
> wrote:
>
>> I am trying to implement Neural Network in MapReduce. Apache mahout is
>> reffering this paper
>> <http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf>
>>
>> Neural Network (NN) We focus on backpropagation By defining a network
>> structure (we use a three layer network with two output neurons classifying
>> the data into two categories), each mapper propagates its set of data
>> through the network. For each training example, the error is back
>> propagated to calculate the partial gradient for each of the weights in the
>> network. The reducer then sums the partial gradient from each mapper and
>> does a batch gradient descent to update the weights of the network.
>>
>> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked
>> out example for gradient descent algorithm.
>>
>> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
>> <http://pastebin.com/6gAQv5vb>
>>
>>    1. Which is the better way to parallize neural network algorithm
>>    While looking in MapReduce perspective? In mapper: Each Record owns a
>>    partial weight(from above example: w0,w1,w2),I doubt if w0 is bias. A
>>    random weight will be assigned initially and initial record calculates the
>>    output(o) and weight get updated , second record also find the output and
>>    deltaW is got updated with the previous deltaW value. While coming into
>>    reducer the sum of gradient is calculated. ie if we have 3 mappers,we will
>>    be able to get 3 w0,w1,w2.These are summed and using batch gradient descent
>>    we will be updating the weights of the network.
>>    2. In the above method how can we ensure that which previous weight
>>    is taken while considering more than 1 map task.Each map task has its own
>>    weight updated.How can it be accurate? [image: enter image
>>    description here]
>>    3. Where can I find backward propogation in the above mentioned
>>    gradient descent neural network algorithm?Or is it fine with this
>>    implementation?
>>    4. what is the termination condition mensioned in the algorithm?
>>
>> Please help me with some pointers.
>>
>> Thanks in advance.
>>
>> --
>> *Thanks & Regards *
>>
>>
>> *Unmesha Sreeveni U.B*
>> *Hadoop, Bigdata Developer*
>> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
>> http://www.unmeshasreeveni.blogspot.in/
>>
>>
>>
>
>
> --
> Alpha Bagus Sunggono
> http://www.dyavacs.com
>



-- 
*Thanks & Regards *


*Unmesha Sreeveni U.B*
*Hadoop, Bigdata Developer*
*Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
http://www.unmeshasreeveni.blogspot.in/

Re: Neural Network in hadoop

Posted by unmesha sreeveni <un...@gmail.com>.
On Thu, Feb 12, 2015 at 4:13 PM, Alpha Bagus Sunggono <ba...@gmail.com>
wrote:

> In my opinion,
> - This is just for 1 iteration. Then, batch gradient means find all delta,
> then updates all weight. So , I think its improperly if each have weight
> updated. Weight updated should be after Reduced.
> - Backpropagation can be found after Reduced.
> - This iteration should be repeat and repeat again.
>
​I doubt if iteration is for each record. ie say for example we have just 5
records,so whether the iteration will be 5 ? or some other concepts.
ie from the above example
​
​
​​
∆*w**0*,∆*w**1*,∆*w*
*2​ ​*
​
will be the delta error

​.So here lets say we have a threshold value
​. so for each record we will be checking if
​
∆*w**0*,∆*w**1*,∆*w*
*2​ * is
​less
 than
​ or equal to ​

​threshold value , else continue the iteration. Is it like that . Am I
wrong ?

​Sorry I am not that much clear on the iteration part.​


> Termination condition should be measured by delta error of sigmoid output
> in the end of mapper.
> ​
> Iteration process can be terminated after we get suitable  small value
> enough of the delta error.
>

Is there any criteria in updating delta weights?
 after calculating output of perceptron lets find the error:
(oj*(1-0j)(tj-oj))
check if error is less than threshold,then delta weight is not updated else
update delta weight .
Is it like that?


>
> On Thu, Feb 12, 2015 at 5:14 PM, unmesha sreeveni <un...@gmail.com>
> wrote:
>
>> I am trying to implement Neural Network in MapReduce. Apache mahout is
>> reffering this paper
>> <http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf>
>>
>> Neural Network (NN) We focus on backpropagation By defining a network
>> structure (we use a three layer network with two output neurons classifying
>> the data into two categories), each mapper propagates its set of data
>> through the network. For each training example, the error is back
>> propagated to calculate the partial gradient for each of the weights in the
>> network. The reducer then sums the partial gradient from each mapper and
>> does a batch gradient descent to update the weights of the network.
>>
>> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked
>> out example for gradient descent algorithm.
>>
>> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
>> <http://pastebin.com/6gAQv5vb>
>>
>>    1. Which is the better way to parallize neural network algorithm
>>    While looking in MapReduce perspective? In mapper: Each Record owns a
>>    partial weight(from above example: w0,w1,w2),I doubt if w0 is bias. A
>>    random weight will be assigned initially and initial record calculates the
>>    output(o) and weight get updated , second record also find the output and
>>    deltaW is got updated with the previous deltaW value. While coming into
>>    reducer the sum of gradient is calculated. ie if we have 3 mappers,we will
>>    be able to get 3 w0,w1,w2.These are summed and using batch gradient descent
>>    we will be updating the weights of the network.
>>    2. In the above method how can we ensure that which previous weight
>>    is taken while considering more than 1 map task.Each map task has its own
>>    weight updated.How can it be accurate? [image: enter image
>>    description here]
>>    3. Where can I find backward propogation in the above mentioned
>>    gradient descent neural network algorithm?Or is it fine with this
>>    implementation?
>>    4. what is the termination condition mensioned in the algorithm?
>>
>> Please help me with some pointers.
>>
>> Thanks in advance.
>>
>> --
>> *Thanks & Regards *
>>
>>
>> *Unmesha Sreeveni U.B*
>> *Hadoop, Bigdata Developer*
>> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
>> http://www.unmeshasreeveni.blogspot.in/
>>
>>
>>
>
>
> --
> Alpha Bagus Sunggono
> http://www.dyavacs.com
>



-- 
*Thanks & Regards *


*Unmesha Sreeveni U.B*
*Hadoop, Bigdata Developer*
*Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
http://www.unmeshasreeveni.blogspot.in/

Re: Neural Network in hadoop

Posted by unmesha sreeveni <un...@gmail.com>.
On Thu, Feb 12, 2015 at 4:13 PM, Alpha Bagus Sunggono <ba...@gmail.com>
wrote:

> In my opinion,
> - This is just for 1 iteration. Then, batch gradient means find all delta,
> then updates all weight. So , I think its improperly if each have weight
> updated. Weight updated should be after Reduced.
> - Backpropagation can be found after Reduced.
> - This iteration should be repeat and repeat again.
>
​I doubt if iteration is for each record. ie say for example we have just 5
records,so whether the iteration will be 5 ? or some other concepts.
ie from the above example
​
​
​​
∆*w**0*,∆*w**1*,∆*w*
*2​ ​*
​
will be the delta error

​.So here lets say we have a threshold value
​. so for each record we will be checking if
​
∆*w**0*,∆*w**1*,∆*w*
*2​ * is
​less
 than
​ or equal to ​

​threshold value , else continue the iteration. Is it like that . Am I
wrong ?

​Sorry I am not that much clear on the iteration part.​


> Termination condition should be measured by delta error of sigmoid output
> in the end of mapper.
> ​
> Iteration process can be terminated after we get suitable  small value
> enough of the delta error.
>

Is there any criteria in updating delta weights?
 after calculating output of perceptron lets find the error:
(oj*(1-0j)(tj-oj))
check if error is less than threshold,then delta weight is not updated else
update delta weight .
Is it like that?


>
> On Thu, Feb 12, 2015 at 5:14 PM, unmesha sreeveni <un...@gmail.com>
> wrote:
>
>> I am trying to implement Neural Network in MapReduce. Apache mahout is
>> reffering this paper
>> <http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf>
>>
>> Neural Network (NN) We focus on backpropagation By defining a network
>> structure (we use a three layer network with two output neurons classifying
>> the data into two categories), each mapper propagates its set of data
>> through the network. For each training example, the error is back
>> propagated to calculate the partial gradient for each of the weights in the
>> network. The reducer then sums the partial gradient from each mapper and
>> does a batch gradient descent to update the weights of the network.
>>
>> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked
>> out example for gradient descent algorithm.
>>
>> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
>> <http://pastebin.com/6gAQv5vb>
>>
>>    1. Which is the better way to parallize neural network algorithm
>>    While looking in MapReduce perspective? In mapper: Each Record owns a
>>    partial weight(from above example: w0,w1,w2),I doubt if w0 is bias. A
>>    random weight will be assigned initially and initial record calculates the
>>    output(o) and weight get updated , second record also find the output and
>>    deltaW is got updated with the previous deltaW value. While coming into
>>    reducer the sum of gradient is calculated. ie if we have 3 mappers,we will
>>    be able to get 3 w0,w1,w2.These are summed and using batch gradient descent
>>    we will be updating the weights of the network.
>>    2. In the above method how can we ensure that which previous weight
>>    is taken while considering more than 1 map task.Each map task has its own
>>    weight updated.How can it be accurate? [image: enter image
>>    description here]
>>    3. Where can I find backward propogation in the above mentioned
>>    gradient descent neural network algorithm?Or is it fine with this
>>    implementation?
>>    4. what is the termination condition mensioned in the algorithm?
>>
>> Please help me with some pointers.
>>
>> Thanks in advance.
>>
>> --
>> *Thanks & Regards *
>>
>>
>> *Unmesha Sreeveni U.B*
>> *Hadoop, Bigdata Developer*
>> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
>> http://www.unmeshasreeveni.blogspot.in/
>>
>>
>>
>
>
> --
> Alpha Bagus Sunggono
> http://www.dyavacs.com
>



-- 
*Thanks & Regards *


*Unmesha Sreeveni U.B*
*Hadoop, Bigdata Developer*
*Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
http://www.unmeshasreeveni.blogspot.in/

Re: Neural Network in hadoop

Posted by unmesha sreeveni <un...@gmail.com>.
On Thu, Feb 12, 2015 at 4:13 PM, Alpha Bagus Sunggono <ba...@gmail.com>
wrote:

> In my opinion,
> - This is just for 1 iteration. Then, batch gradient means find all delta,
> then updates all weight. So , I think its improperly if each have weight
> updated. Weight updated should be after Reduced.
> - Backpropagation can be found after Reduced.
> - This iteration should be repeat and repeat again.
>
​I doubt if iteration is for each record. ie say for example we have just 5
records,so whether the iteration will be 5 ? or some other concepts.
ie from the above example
​
​
​​
∆*w**0*,∆*w**1*,∆*w*
*2​ ​*
​
will be the delta error

​.So here lets say we have a threshold value
​. so for each record we will be checking if
​
∆*w**0*,∆*w**1*,∆*w*
*2​ * is
​less
 than
​ or equal to ​

​threshold value , else continue the iteration. Is it like that . Am I
wrong ?

​Sorry I am not that much clear on the iteration part.​


> Termination condition should be measured by delta error of sigmoid output
> in the end of mapper.
> ​
> Iteration process can be terminated after we get suitable  small value
> enough of the delta error.
>

Is there any criteria in updating delta weights?
 after calculating output of perceptron lets find the error:
(oj*(1-0j)(tj-oj))
check if error is less than threshold,then delta weight is not updated else
update delta weight .
Is it like that?


>
> On Thu, Feb 12, 2015 at 5:14 PM, unmesha sreeveni <un...@gmail.com>
> wrote:
>
>> I am trying to implement Neural Network in MapReduce. Apache mahout is
>> reffering this paper
>> <http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf>
>>
>> Neural Network (NN) We focus on backpropagation By defining a network
>> structure (we use a three layer network with two output neurons classifying
>> the data into two categories), each mapper propagates its set of data
>> through the network. For each training example, the error is back
>> propagated to calculate the partial gradient for each of the weights in the
>> network. The reducer then sums the partial gradient from each mapper and
>> does a batch gradient descent to update the weights of the network.
>>
>> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked
>> out example for gradient descent algorithm.
>>
>> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
>> <http://pastebin.com/6gAQv5vb>
>>
>>    1. Which is the better way to parallize neural network algorithm
>>    While looking in MapReduce perspective? In mapper: Each Record owns a
>>    partial weight(from above example: w0,w1,w2),I doubt if w0 is bias. A
>>    random weight will be assigned initially and initial record calculates the
>>    output(o) and weight get updated , second record also find the output and
>>    deltaW is got updated with the previous deltaW value. While coming into
>>    reducer the sum of gradient is calculated. ie if we have 3 mappers,we will
>>    be able to get 3 w0,w1,w2.These are summed and using batch gradient descent
>>    we will be updating the weights of the network.
>>    2. In the above method how can we ensure that which previous weight
>>    is taken while considering more than 1 map task.Each map task has its own
>>    weight updated.How can it be accurate? [image: enter image
>>    description here]
>>    3. Where can I find backward propogation in the above mentioned
>>    gradient descent neural network algorithm?Or is it fine with this
>>    implementation?
>>    4. what is the termination condition mensioned in the algorithm?
>>
>> Please help me with some pointers.
>>
>> Thanks in advance.
>>
>> --
>> *Thanks & Regards *
>>
>>
>> *Unmesha Sreeveni U.B*
>> *Hadoop, Bigdata Developer*
>> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
>> http://www.unmeshasreeveni.blogspot.in/
>>
>>
>>
>
>
> --
> Alpha Bagus Sunggono
> http://www.dyavacs.com
>



-- 
*Thanks & Regards *


*Unmesha Sreeveni U.B*
*Hadoop, Bigdata Developer*
*Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
http://www.unmeshasreeveni.blogspot.in/

Re: Neural Network in hadoop

Posted by Alpha Bagus Sunggono <ba...@gmail.com>.
In my opinion,
- This is just for 1 iteration. Then, batch gradient means find all delta,
then updates all weight. So , I think its improperly if each have weight
updated. Weight updated should be after Reduced.
- Backpropagation can be found after Reduced.
- This iteration should be repeat and repeat again. Termination condition
should be measured by delta error of sigmoid output in the end of mapper.
Iteration process can be terminated after we get suitable  small value
enough of the delta error.


On Thu, Feb 12, 2015 at 5:14 PM, unmesha sreeveni <un...@gmail.com>
wrote:

> I am trying to implement Neural Network in MapReduce. Apache mahout is
> reffering this paper
> <http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf>
>
> Neural Network (NN) We focus on backpropagation By defining a network
> structure (we use a three layer network with two output neurons classifying
> the data into two categories), each mapper propagates its set of data
> through the network. For each training example, the error is back
> propagated to calculate the partial gradient for each of the weights in the
> network. The reducer then sums the partial gradient from each mapper and
> does a batch gradient descent to update the weights of the network.
>
> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked
> out example for gradient descent algorithm.
>
> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
> <http://pastebin.com/6gAQv5vb>
>
>    1. Which is the better way to parallize neural network algorithm While
>    looking in MapReduce perspective? In mapper: Each Record owns a partial
>    weight(from above example: w0,w1,w2),I doubt if w0 is bias. A random weight
>    will be assigned initially and initial record calculates the output(o) and
>    weight get updated , second record also find the output and deltaW is got
>    updated with the previous deltaW value. While coming into reducer the sum
>    of gradient is calculated. ie if we have 3 mappers,we will be able to get 3
>    w0,w1,w2.These are summed and using batch gradient descent we will be
>    updating the weights of the network.
>    2. In the above method how can we ensure that which previous weight is
>    taken while considering more than 1 map task.Each map task has its own
>    weight updated.How can it be accurate? [image: enter image description
>    here]
>    3. Where can I find backward propogation in the above mentioned
>    gradient descent neural network algorithm?Or is it fine with this
>    implementation?
>    4. what is the termination condition mensioned in the algorithm?
>
> Please help me with some pointers.
>
> Thanks in advance.
>
> --
> *Thanks & Regards *
>
>
> *Unmesha Sreeveni U.B*
> *Hadoop, Bigdata Developer*
> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
> http://www.unmeshasreeveni.blogspot.in/
>
>
>


-- 
Alpha Bagus Sunggono
http://www.dyavacs.com

Re: Neural Network in hadoop

Posted by Ted Dunning <te...@gmail.com>.
That is a really old paper that basically pre-dates all of the recent
important work in neural networks.

You should look for works on Rectified Linear Units (ReLU), drop-out
regularization, parameter servers (downpour sgd) and deep learning.

Map-reduce as you have used it will not produce interesting results because
the overhead of map-reduce will be far too high.

Here are some references:

http://www.cs.toronto.edu/~ranzato/publications/DistBeliefNIPS2012_withAppendix.pdf

http://arxiv.org/abs/1412.5567

http://arxiv.org/abs/1502.01710

http://www.comp.nus.edu.sg/~dbsystem/singa/

http://0xdata.com/product/deep-learning/


On Thu, Feb 12, 2015 at 2:14 AM, unmesha sreeveni <un...@gmail.com>
wrote:

> I am trying to implement Neural Network in MapReduce. Apache mahout is
> reffering this paper
> <
> http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf
> >
>
> Neural Network (NN) We focus on backpropagation By defining a network
> structure (we use a three layer network with two output neurons classifying
> the data into two categories), each mapper propagates its set of data
> through the network. For each training example, the error is back
> propagated to calculate the partial gradient for each of the weights in the
> network. The reducer then sums the partial gradient from each mapper and
> does a batch gradient descent to update the weights of the network.
>
> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked out
> example for gradient descent algorithm.
>
> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
> <http://pastebin.com/6gAQv5vb>
>
>    1. Which is the better way to parallize neural network algorithm While
>    looking in MapReduce perspective? In mapper: Each Record owns a partial
>    weight(from above example: w0,w1,w2),I doubt if w0 is bias. A random
> weight
>    will be assigned initially and initial record calculates the output(o)
> and
>    weight get updated , second record also find the output and deltaW is
> got
>    updated with the previous deltaW value. While coming into reducer the
> sum
>    of gradient is calculated. ie if we have 3 mappers,we will be able to
> get 3
>    w0,w1,w2.These are summed and using batch gradient descent we will be
>    updating the weights of the network.
>    2. In the above method how can we ensure that which previous weight is
>    taken while considering more than 1 map task.Each map task has its own
>    weight updated.How can it be accurate? [image: enter image description
>    here]
>    3. Where can I find backward propogation in the above mentioned gradient
>    descent neural network algorithm?Or is it fine with this implementation?
>    4. what is the termination condition mensioned in the algorithm?
>
> Please help me with some pointers.
>
> Thanks in advance.
>
> --
> *Thanks & Regards *
>
>
> *Unmesha Sreeveni U.B*
> *Hadoop, Bigdata Developer*
> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
> http://www.unmeshasreeveni.blogspot.in/
>

Re: Neural Network in hadoop

Posted by Alpha Bagus Sunggono <ba...@gmail.com>.
In my opinion,
- This is just for 1 iteration. Then, batch gradient means find all delta,
then updates all weight. So , I think its improperly if each have weight
updated. Weight updated should be after Reduced.
- Backpropagation can be found after Reduced.
- This iteration should be repeat and repeat again. Termination condition
should be measured by delta error of sigmoid output in the end of mapper.
Iteration process can be terminated after we get suitable  small value
enough of the delta error.


On Thu, Feb 12, 2015 at 5:14 PM, unmesha sreeveni <un...@gmail.com>
wrote:

> I am trying to implement Neural Network in MapReduce. Apache mahout is
> reffering this paper
> <http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf>
>
> Neural Network (NN) We focus on backpropagation By defining a network
> structure (we use a three layer network with two output neurons classifying
> the data into two categories), each mapper propagates its set of data
> through the network. For each training example, the error is back
> propagated to calculate the partial gradient for each of the weights in the
> network. The reducer then sums the partial gradient from each mapper and
> does a batch gradient descent to update the weights of the network.
>
> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked
> out example for gradient descent algorithm.
>
> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
> <http://pastebin.com/6gAQv5vb>
>
>    1. Which is the better way to parallize neural network algorithm While
>    looking in MapReduce perspective? In mapper: Each Record owns a partial
>    weight(from above example: w0,w1,w2),I doubt if w0 is bias. A random weight
>    will be assigned initially and initial record calculates the output(o) and
>    weight get updated , second record also find the output and deltaW is got
>    updated with the previous deltaW value. While coming into reducer the sum
>    of gradient is calculated. ie if we have 3 mappers,we will be able to get 3
>    w0,w1,w2.These are summed and using batch gradient descent we will be
>    updating the weights of the network.
>    2. In the above method how can we ensure that which previous weight is
>    taken while considering more than 1 map task.Each map task has its own
>    weight updated.How can it be accurate? [image: enter image description
>    here]
>    3. Where can I find backward propogation in the above mentioned
>    gradient descent neural network algorithm?Or is it fine with this
>    implementation?
>    4. what is the termination condition mensioned in the algorithm?
>
> Please help me with some pointers.
>
> Thanks in advance.
>
> --
> *Thanks & Regards *
>
>
> *Unmesha Sreeveni U.B*
> *Hadoop, Bigdata Developer*
> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
> http://www.unmeshasreeveni.blogspot.in/
>
>
>


-- 
Alpha Bagus Sunggono
http://www.dyavacs.com

Re: Neural Network in hadoop

Posted by Alpha Bagus Sunggono <ba...@gmail.com>.
In my opinion,
- This is just for 1 iteration. Then, batch gradient means find all delta,
then updates all weight. So , I think its improperly if each have weight
updated. Weight updated should be after Reduced.
- Backpropagation can be found after Reduced.
- This iteration should be repeat and repeat again. Termination condition
should be measured by delta error of sigmoid output in the end of mapper.
Iteration process can be terminated after we get suitable  small value
enough of the delta error.


On Thu, Feb 12, 2015 at 5:14 PM, unmesha sreeveni <un...@gmail.com>
wrote:

> I am trying to implement Neural Network in MapReduce. Apache mahout is
> reffering this paper
> <http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf>
>
> Neural Network (NN) We focus on backpropagation By defining a network
> structure (we use a three layer network with two output neurons classifying
> the data into two categories), each mapper propagates its set of data
> through the network. For each training example, the error is back
> propagated to calculate the partial gradient for each of the weights in the
> network. The reducer then sums the partial gradient from each mapper and
> does a batch gradient descent to update the weights of the network.
>
> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked
> out example for gradient descent algorithm.
>
> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
> <http://pastebin.com/6gAQv5vb>
>
>    1. Which is the better way to parallize neural network algorithm While
>    looking in MapReduce perspective? In mapper: Each Record owns a partial
>    weight(from above example: w0,w1,w2),I doubt if w0 is bias. A random weight
>    will be assigned initially and initial record calculates the output(o) and
>    weight get updated , second record also find the output and deltaW is got
>    updated with the previous deltaW value. While coming into reducer the sum
>    of gradient is calculated. ie if we have 3 mappers,we will be able to get 3
>    w0,w1,w2.These are summed and using batch gradient descent we will be
>    updating the weights of the network.
>    2. In the above method how can we ensure that which previous weight is
>    taken while considering more than 1 map task.Each map task has its own
>    weight updated.How can it be accurate? [image: enter image description
>    here]
>    3. Where can I find backward propogation in the above mentioned
>    gradient descent neural network algorithm?Or is it fine with this
>    implementation?
>    4. what is the termination condition mensioned in the algorithm?
>
> Please help me with some pointers.
>
> Thanks in advance.
>
> --
> *Thanks & Regards *
>
>
> *Unmesha Sreeveni U.B*
> *Hadoop, Bigdata Developer*
> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
> http://www.unmeshasreeveni.blogspot.in/
>
>
>


-- 
Alpha Bagus Sunggono
http://www.dyavacs.com

Re: Neural Network in hadoop

Posted by Alpha Bagus Sunggono <ba...@gmail.com>.
In my opinion,
- This is just for 1 iteration. Then, batch gradient means find all delta,
then updates all weight. So , I think its improperly if each have weight
updated. Weight updated should be after Reduced.
- Backpropagation can be found after Reduced.
- This iteration should be repeat and repeat again. Termination condition
should be measured by delta error of sigmoid output in the end of mapper.
Iteration process can be terminated after we get suitable  small value
enough of the delta error.


On Thu, Feb 12, 2015 at 5:14 PM, unmesha sreeveni <un...@gmail.com>
wrote:

> I am trying to implement Neural Network in MapReduce. Apache mahout is
> reffering this paper
> <http://www.cs.stanford.edu/people/ang/papers/nips06-mapreducemulticore.pdf>
>
> Neural Network (NN) We focus on backpropagation By defining a network
> structure (we use a three layer network with two output neurons classifying
> the data into two categories), each mapper propagates its set of data
> through the network. For each training example, the error is back
> propagated to calculate the partial gradient for each of the weights in the
> network. The reducer then sums the partial gradient from each mapper and
> does a batch gradient descent to update the weights of the network.
>
> Here <http://homepages.gold.ac.uk/nikolaev/311sperc.htm> is the worked
> out example for gradient descent algorithm.
>
> Gradient Descent Learning Algorithm for Sigmoidal Perceptrons
> <http://pastebin.com/6gAQv5vb>
>
>    1. Which is the better way to parallize neural network algorithm While
>    looking in MapReduce perspective? In mapper: Each Record owns a partial
>    weight(from above example: w0,w1,w2),I doubt if w0 is bias. A random weight
>    will be assigned initially and initial record calculates the output(o) and
>    weight get updated , second record also find the output and deltaW is got
>    updated with the previous deltaW value. While coming into reducer the sum
>    of gradient is calculated. ie if we have 3 mappers,we will be able to get 3
>    w0,w1,w2.These are summed and using batch gradient descent we will be
>    updating the weights of the network.
>    2. In the above method how can we ensure that which previous weight is
>    taken while considering more than 1 map task.Each map task has its own
>    weight updated.How can it be accurate? [image: enter image description
>    here]
>    3. Where can I find backward propogation in the above mentioned
>    gradient descent neural network algorithm?Or is it fine with this
>    implementation?
>    4. what is the termination condition mensioned in the algorithm?
>
> Please help me with some pointers.
>
> Thanks in advance.
>
> --
> *Thanks & Regards *
>
>
> *Unmesha Sreeveni U.B*
> *Hadoop, Bigdata Developer*
> *Centre for Cyber Security | Amrita Vishwa Vidyapeetham*
> http://www.unmeshasreeveni.blogspot.in/
>
>
>


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