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1500 questions
7
votes
5 answers
Binary classifier that minimizes false positive error
I have a binary classification problem, where a false positive error has a very big cost compared to the false negative error.
Is there a way to design a classifier for such problems (preferably, with an implementation of the algorithm)?
ayyoob imani
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7
votes
2 answers
How do I create an AI for a two-players board game?
Goal
I want to create an artificial intelligence to compete against other players in a board game.
Game explanation
I have a board game similar to 'snakes and ladders'. You have to get to a final field before your opponent does. But instead of…
po0l
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7
votes
1 answer
Why is the target $r + \gamma \max_{a'} Q(s', a'; \theta_i^-)$ in the loss function of the DQN architecture?
In the paper Human-level control through deep reinforcement learning, the DQN architecture is presented, where the loss function is as follows
$$
L_i(\theta_i) = \mathbb{E}_{(s, a, r, s') \sim U(D)} \left[ \left( r + \gamma \max_{a'} Q(s', a';…
echo
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7
votes
1 answer
How come that the addition of features can decrease the performance of a neural network?
I have a Remaining Useful Life (RUL) prediction problem that I want to solve. When I added two or more features as inputs to my ANN, the accuracy of my ANN has been decreased. More precisely, I've added features like RMS or KURTOSIS (or both). I was…
Aref.a
- 79
- 3
7
votes
1 answer
Why does 'loss' change depending on the number of epochs chosen?
I am using Keras to train different NN. I would like to know why if I increment the epochs in 1, the result until the new epoch is not the same. I am using shuffle=False, and np.random.seed(2017), and I have check that if I repeat with the same…
Pablo Ruiz Ruiz
- 179
- 3
7
votes
2 answers
How to combine backpropagation in neural nets and reinforcement learning?
I have followed a course on machine learning, where we learned about the gradient descent (GD) and back-propagation (BP) algorithms, which can be used to update the weights of neural networks, and reinforcement learning, in particular, Q-learning. I…
Yadeses
- 231
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7
votes
2 answers
Effective algorithms for OCR
I am using Google's OCR to extract text from images, like receipts and invoices.
Whare examples of techniques used to make sense of the text? For example, I would like to extract the date, name of the business, address, total amount, etc.
Before…
Abhay Naik
- 179
- 2
7
votes
4 answers
Why is my test error lower than the training error?
I am trying to train a CNN regression model using the ADAM optimizer, dropout and weight decay.
My test accuracy is better than training accuracy. But, as far as I know, usually, the training accuracy is better than test accuracy.
So I wonder how…
이희준
- 73
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- 4
7
votes
2 answers
Does data skew matter in classification problem?
I'm working on an image classification problem using a neural network. In the training data set, 90% of the samples fall into 10% of all categories, while 10% of the sample fall into the other 90% categories. So an example is not evenly distributed…
James Gan
- 173
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7
votes
4 answers
What is the purpose of the hidden layers?
Why would anybody want to use "hidden layers"? How do they enhance the learning ability of the network in comparison to the network which doesn't have them (linear models)?
kenorb
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7
votes
4 answers
Do neural network weights need to add up to one?
The idea that weights determine how much influence each input value from the current layer will have when calculating the input to the following layer reminds me of when my professors would say that our final grade for the course was broken down…
Garrett
- 181
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7
votes
4 answers
What does "e" do in the Sigmoid Activation Function?
Within the Sigmoid Squishification function,
f(x) = 1/(1 + e^(-x))
"e" is unnecessary, as it can be replaced by any other value that is not 0 or 1. Why is "e" used here?
As shown below, the function is working well without that, and in replacement,…
Jake
- 81
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7
votes
2 answers
How to determine if an Amazon review is likely to be fake using text classification
I'm currently in the research stage of building a web app in ASP.NET where the user can input a URL to an Amazon product, then the app would determine how likely its reviews are to be genuine. I need help figuring out what algorithm to use in…
user8709398
- 71
- 2
7
votes
2 answers
In this implementation of the Information Set Monte Carlo Tree Search, why can't the players see the cards of each other?
After reading this paper about Monte Carlo methods for imperfect information games with elements of uncertainty, I couldn't understand the application of the determinization step in the author's implementation of the algorithm for the Knockout…
tamirok
- 71
- 1
7
votes
4 answers
What are the reasons to belief AGI will not be dangerous?
We are in the middle of an ongoing debate about the safety of AGI and our current approach towards this technology. As summary, some quotes from a recent article from Time magazine:
Many researchers[...] expect that the most likely result of…
Martin
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