Why does a filter need to be applied to the output of the input gate before cell state is added to?
$begingroup$
In a neural network there are 4 gates: input, output, forget and a gate whose output performs element wise multiplication with the output of the input gate, which is added to the cell state (I don't know the name of this gate, but it's the one in the below picture with the output C_tilde
).
Why is the addition of the C_tilde
gate required in the model? In order to allow the input gate to subtract from the cell state, we could change the activation function that results in i_t
from sigmoid
to tanh
and remove the C_tilde
gate.
My reasoning is that the input gate already has a weight matrix W_i
that can is being multiplied to the input gate's input, hence it already does filtering. However, when C_tilde
is multiplied with i_t
that seems to be another unnecessary filter.
My proposed input gate would then be i_t = tanh(W_i * [h_t-1, x_t] + b_i)
and i_t
would directly be added to C_t
(C_t = f_t * C_t + i_t
rather than C_t = f_t * C_t + i_t * C_tilde_t
).
machine-learning neural-network deep-learning lstm recurrent-neural-net
$endgroup$
bumped to the homepage by Community♦ 12 mins ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
add a comment |
$begingroup$
In a neural network there are 4 gates: input, output, forget and a gate whose output performs element wise multiplication with the output of the input gate, which is added to the cell state (I don't know the name of this gate, but it's the one in the below picture with the output C_tilde
).
Why is the addition of the C_tilde
gate required in the model? In order to allow the input gate to subtract from the cell state, we could change the activation function that results in i_t
from sigmoid
to tanh
and remove the C_tilde
gate.
My reasoning is that the input gate already has a weight matrix W_i
that can is being multiplied to the input gate's input, hence it already does filtering. However, when C_tilde
is multiplied with i_t
that seems to be another unnecessary filter.
My proposed input gate would then be i_t = tanh(W_i * [h_t-1, x_t] + b_i)
and i_t
would directly be added to C_t
(C_t = f_t * C_t + i_t
rather than C_t = f_t * C_t + i_t * C_tilde_t
).
machine-learning neural-network deep-learning lstm recurrent-neural-net
$endgroup$
bumped to the homepage by Community♦ 12 mins ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
add a comment |
$begingroup$
In a neural network there are 4 gates: input, output, forget and a gate whose output performs element wise multiplication with the output of the input gate, which is added to the cell state (I don't know the name of this gate, but it's the one in the below picture with the output C_tilde
).
Why is the addition of the C_tilde
gate required in the model? In order to allow the input gate to subtract from the cell state, we could change the activation function that results in i_t
from sigmoid
to tanh
and remove the C_tilde
gate.
My reasoning is that the input gate already has a weight matrix W_i
that can is being multiplied to the input gate's input, hence it already does filtering. However, when C_tilde
is multiplied with i_t
that seems to be another unnecessary filter.
My proposed input gate would then be i_t = tanh(W_i * [h_t-1, x_t] + b_i)
and i_t
would directly be added to C_t
(C_t = f_t * C_t + i_t
rather than C_t = f_t * C_t + i_t * C_tilde_t
).
machine-learning neural-network deep-learning lstm recurrent-neural-net
$endgroup$
In a neural network there are 4 gates: input, output, forget and a gate whose output performs element wise multiplication with the output of the input gate, which is added to the cell state (I don't know the name of this gate, but it's the one in the below picture with the output C_tilde
).
Why is the addition of the C_tilde
gate required in the model? In order to allow the input gate to subtract from the cell state, we could change the activation function that results in i_t
from sigmoid
to tanh
and remove the C_tilde
gate.
My reasoning is that the input gate already has a weight matrix W_i
that can is being multiplied to the input gate's input, hence it already does filtering. However, when C_tilde
is multiplied with i_t
that seems to be another unnecessary filter.
My proposed input gate would then be i_t = tanh(W_i * [h_t-1, x_t] + b_i)
and i_t
would directly be added to C_t
(C_t = f_t * C_t + i_t
rather than C_t = f_t * C_t + i_t * C_tilde_t
).
machine-learning neural-network deep-learning lstm recurrent-neural-net
machine-learning neural-network deep-learning lstm recurrent-neural-net
asked Jul 13 '18 at 0:26
Mar DevMar Dev
1061
1061
bumped to the homepage by Community♦ 12 mins ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
bumped to the homepage by Community♦ 12 mins ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
Here is my hypothesis : The $i_t$ can add explainability to the model, as the value of the sigmoid function can give an idea as to how important a particular word is to altering the cell state $C$. This is because $i_t$ lies between 0 and 1. Having single $W$ do both filtering as well as a feature transform of $[h_{t-1},x_t]$ not only puts more stress on the matrix (has to do two things at once), but also no longer has this explainability factor.
Example: 2 vectors may require the same transformation $W*v$, but unless you allow seperate sigmoid function to give each an importance, their contribution to the cell state will remain same.
$endgroup$
add a comment |
Your Answer
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "557"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fdatascience.stackexchange.com%2fquestions%2f34401%2fwhy-does-a-filter-need-to-be-applied-to-the-output-of-the-input-gate-before-cell%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Here is my hypothesis : The $i_t$ can add explainability to the model, as the value of the sigmoid function can give an idea as to how important a particular word is to altering the cell state $C$. This is because $i_t$ lies between 0 and 1. Having single $W$ do both filtering as well as a feature transform of $[h_{t-1},x_t]$ not only puts more stress on the matrix (has to do two things at once), but also no longer has this explainability factor.
Example: 2 vectors may require the same transformation $W*v$, but unless you allow seperate sigmoid function to give each an importance, their contribution to the cell state will remain same.
$endgroup$
add a comment |
$begingroup$
Here is my hypothesis : The $i_t$ can add explainability to the model, as the value of the sigmoid function can give an idea as to how important a particular word is to altering the cell state $C$. This is because $i_t$ lies between 0 and 1. Having single $W$ do both filtering as well as a feature transform of $[h_{t-1},x_t]$ not only puts more stress on the matrix (has to do two things at once), but also no longer has this explainability factor.
Example: 2 vectors may require the same transformation $W*v$, but unless you allow seperate sigmoid function to give each an importance, their contribution to the cell state will remain same.
$endgroup$
add a comment |
$begingroup$
Here is my hypothesis : The $i_t$ can add explainability to the model, as the value of the sigmoid function can give an idea as to how important a particular word is to altering the cell state $C$. This is because $i_t$ lies between 0 and 1. Having single $W$ do both filtering as well as a feature transform of $[h_{t-1},x_t]$ not only puts more stress on the matrix (has to do two things at once), but also no longer has this explainability factor.
Example: 2 vectors may require the same transformation $W*v$, but unless you allow seperate sigmoid function to give each an importance, their contribution to the cell state will remain same.
$endgroup$
Here is my hypothesis : The $i_t$ can add explainability to the model, as the value of the sigmoid function can give an idea as to how important a particular word is to altering the cell state $C$. This is because $i_t$ lies between 0 and 1. Having single $W$ do both filtering as well as a feature transform of $[h_{t-1},x_t]$ not only puts more stress on the matrix (has to do two things at once), but also no longer has this explainability factor.
Example: 2 vectors may require the same transformation $W*v$, but unless you allow seperate sigmoid function to give each an importance, their contribution to the cell state will remain same.
answered Jul 16 '18 at 6:08
Sridhar ThiagarajanSridhar Thiagarajan
2816
2816
add a comment |
add a comment |
Thanks for contributing an answer to Data Science Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fdatascience.stackexchange.com%2fquestions%2f34401%2fwhy-does-a-filter-need-to-be-applied-to-the-output-of-the-input-gate-before-cell%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown