Questions tagged [machine-learning]

How can we build computer systems that automatically improve with experience, and what are the fundamental laws that govern all learning processes?

From The Discipline of Machine Learning by Tom Mitchell:

The field of Machine Learning seeks to answer the question "How can we build computer systems that automatically improve with experience, and what are the fundamental laws that govern all learning processes?" This question covers a broad range of learning tasks, such as how to design autonomous mobile robots that learn to navigate from their own experience, how to data mine historical medical records to learn which future patients will respond best to which treatments, and how to build search engines that automatically customize to their user's interests. To be more precise, we say that a machine learns with respect to a particular task T, performance metric P, and type of experience E, if the system reliably improves its performance P at task T, following experience E. Depending on how we specify T, P, and E, the learning task might also be called by names such as data mining, autonomous discovery, database updating, programming by example, etc.

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Doubt in understanding GANs

I was going through original GAN paper: Goodfellow, Ian, et al. "Generative adversarial nets." Advances in neural information processing systems. 2014. Link: http://papers.nips.cc/paper/5423-generative-adversarial-nets.pdf For proving optimal D, eq…
user1953366
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Knowledge Distillation math proof

In the paper "Distilling the Knowledge in a Neural Network" by Hinton, soft target of student model is defined as cross-entropy $C$ between teacher model and student model. Assume that $i$ is an integer, $i \in [1, N]$, where $N$ is number of class…
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Could RMSprop induce unwanted oscillation?

RMSprop is a method for preventing oscillation that could potentially occur in learning. For example, see the figure below (taken from Andrew Ng's Coursera lecture): In this figure, the global optima resides at the red dot, and we have two…
gablin
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Generative Adversarial Networks - discriminator function "running away"

TLDR: I made a toy version of a GAN. During model training, I observed a feedback loop where the discriminator "runs away" from the generator, and then the generator "follows" it. How is this problem addressed in practice? I've created a toy…
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Why are the graphs for average reward vs. steps so noisy?

I am reading Reinforcement Learning: An Introduction by Sutton and Barto. They have several graphs that plot either average reward vs. number of steps or %optimal action vs. number of steps for an $n$-armed bandit problem. I don't understand why…
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Piecewise-linear activation function definition doesn't correspond to graph found in textbook

Edit: as pointed out by dcolazin in the comments, this is indeed a mistake in the 2nd version of the book. The example of the piecewise-linear function was removed completely in the 3rd edition of the book. I'm reading Simon Haykin's Neural Networks…
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bias variance tradeoff

we saw in my machine learning course the error decomposition, that decompose the error to an approximation error and estimation error. In addition, we talked a lot about the bias-variance trade-off. As far as I understand, those are two different…
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What are the most generous constraints for positive semidefiniteness in this construction?

I am asking this in the context of MultiTask Learning applied to Gaussian Processes. Suppose I have two isotropic RBF kernel functions $K^a(x,x')$ and $K^b(x,x')$ and $N$ distinct points $x_1, x_2, ..., x_N$. Consider the following $200 \times 200$…
Sean Lee
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Can I compare User and Item Matrices like for like? - Collaborative Filtering

I'm doing some collaborative filtering using this approach. I'm trying to compare the consequent user and item matrices to see where there may be users with preferences that aren't being met by the available items. In my case, despite the fact that…
Hamley
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Gradient descent stopping criteria

One criteria for gradient descent stopping is using $reltol$ - stopping gradient descent when improvement drops below a threshold. In practice, is there any difference between stopping when empirical improvement approaches zero v.s. stopping when…
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what is the detailed procedure about the likelihood can be represented as the conditional probability.

I am learning this post here is a formula about the likelihood of single data point $$ P(y_i ) = h_{\theta}(\mathbf{x}_i)^{y_i} (1 - h_{\theta}(\mathbf{x}_i))^{1-y_i}$$ $P(y_i)$ is known as the likelihood of single data point $\mathbf{x}_i$, …
JJJohn
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Expected Prediction Error for Classification

I am self-studying elements of statistical learning. I got stuck in the following equations: The expected prediction error for classification is given as: $$G(x) = argmin_{g \in G} \sum _{k=1}^K L(G_k,g) Pr (G_k|X=x) $$ where L is the loss function,…
prony
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What is the set $\{h_{w,b}(x)=[[\langle w,x\rangle >b ]]\mid w\in \mathbb{R}^d\}$

In particular to the topic, what does $h_{w,b}(x)=[[\langle w,x\rangle > b]]$ means?
Saar
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Where does the hyper-plane begin with a SVM, an how does it iterate to it's ideal positioning?

This is a little tricky for me to word and have been studying support vectors. I understand where the hyper-plane should should sit on a graph, but I can't seem to find how this process starts out. Based on some initial classification data, where…
WillacyMe
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Machine learning: PAC-learnability

Would love your help (even a clue or a direction) with this question from hw assignment. Let $\mathcal{C}$ denote the class of all possible target concepts defined over a set of instances $\mathcal{X}$. Suppose that $\mathcal{H}$ is a space of…
Noam
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