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Deriving backpropagation equations "natively" in tensor form

Image shows a typical layer somewhere in a feed forward network: $a_i^{(k)}$ is the activation value of the $i^{th}$ neuron in the $k^{th}$ layer. $W_{ij}^{(k)}$ is the weight connecting $i^{th}$ neuron in the $k^{th}$ layer to the $j^{th}$ neuron…
Neil Slater
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Why don't tree ensembles require one-hot-encoding?

I know that models such as random forest and boosted trees don't require one-hot encoding for predictor levels, but I don't really get why. If the tree is making a split in the feature space, then isn't there an inherent ordering involved? There…
moefasa
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Why do we use a Gaussian kernel as a similarity metric?

In graph-based clustering, why is it preferred to use the Gaussian kernel rather than the distance between two points as the similarity metric?
zfb
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Why use convolutional NNs for a visual inspection task over classic CV template matching?

I had an interesting discussion come up based on a project we were working on: why use a CNN visual inspection system over a template matching algorithm? Background: I had shown a demo of a simple CNN vision system (webcam + laptop) that detected if…
JDS
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NLP: What are some popular packages for multi-word tokenization?

I intend to tokenize a number of job description texts. I have tried the standard tokenization using whitespace as the delimiter. However I noticed that there are some multi-word expressions that are splitted by whitespace, which may well cause…
CyberPlayerOne
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How does a convolutional ply differ from an ordinary convolutional network?

I am currently working on recreating the results of this paper. In the paper they describe a method for using CNN for features extraction, and have a acoustic model that is Dnn-hmm and pretrained using RBM. Section III subsection A states…
Carlton Banks
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Perceptron learning rate

Today I've seen many Perceptron implementations with learning rates. According to Wikipedia: there is no need for a learning rate in the perceptron algorithm. This is because multiplying the update by any constant simply rescales the weights…
bkoodaa
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Is there a C library for machine learning algorithms?

Are there any machine learning libraries for C. Specifically interested in unsupervised learning.
Chandan Venkatesh
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feature extraction for a pretrained model in keras

Keras has a way to extract the features of a pretrained model, described here https://keras.io/applications/ from keras.applications.vgg16 import VGG16 from keras.preprocessing import image from keras.applications.vgg16 import…
spore234
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What is the memory cost of a CNN?

I was recently thinking about the memory cost of (a) training a CNN and (b) inference with a CNN. Please note, that I am not talking about the storage (which is simply the number of parameters). How much memory does a given CNN (e.g. VGG-16 D) need…
Martin Thoma
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Why do popular search engines not follow the usual AND, OR logic for queries?

I am teaching myself Information Retrieval from Christopher Manning's book (PDF link: http://nlp.stanford.edu/IR-book/pdf/01bool.pdf). I tried Exercise 1.13: "Try using the Boolean search features on a couple of major web search engines.…
user21595
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3 answers

What is the correct way to compute Mean F1 score?

I have a set of 10 experiments that compute precision, recall and f1-score for each experiment. Now, average precision & average recall is easy to compute. I have some confusion regarding average f1-score. There are 2 ways on how i can compute mean…
Pinkesh Badjatiya
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Algorithms and techniques for spell checking

Can anyone suggest any algorithm and technique for spell checking? After some googling, I found some interesting ones such as this one from Peter Norvig, http://norvig.com/spell-correct.html and few others. However, most of them were written many…
edwin
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Which book is a standard for introduction to genetic algorithms?

I have heard of genetic algorithms, but I have never seen practical examples and I've never got a systematic introduction to them. I am now looking for a textbook which introduces genetic algorithms in detail and gives practical examples how they…
Martin Thoma
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What knowledge do I need in order to write a simple AI program to play a game?

I'm a B.Sc graduate. One of my courses was 'Introduction to Machine Learning', and I always wanted to do a personal project in this subject. I recently heard about different AI training to play games such as Mario, Go, etc. What knowledge do I need…
Niv Hoffman
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