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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Training and validation set

If I have a dataset of 1300 samples, is it a fair proportion to split it into 1100 for training and 200 for validation? Will I incur some sort of bias if I reduce even more the validation set? (I've noticed that with 1120/180 I get a better accuracy…
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Machine learning with Reject Option

Can any one have ideas of machine learning with Reject Option (ambiguous points)? Are there any software package for some of these algorithms? ie, how to choose the reject threshold
Gloria
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How to calculate Vapnik-Chervonenkis dimension?

I got stuck with this problem: Given just a $$X=\{1,2,3,4\}$$ and a $$C=\{\{1,3,4\},\{4\},\{2,3\},\{3\},\{1,2\},\{1\},\{2\}\}$$ how do I calculate VC dimension of C? I know that for example with $$S=\{1,2,3\}$$ given in the prior problem would…
Kromag
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What does homomorphism mean in the GLOVE paper?

It is mentioned in the GloVe: Global Vectors for Word Representation. It says: where $w_i$, $w_j$ and $\tilde{w}_k$ are all word vectors and $F$ is just an unknown function. The author then assumes $F$ as $exp$. What is homomorphism exactly? Why…
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Machine learning : Perceptron, purpose of bias and threshold

I started to study Machine Learning, but in the book I am reading there is something I don't understand. I am a total beginner in terms of Machine Learning, and I am just trying to read as much content I can. I simply don't understand the purpose of…
Scaraux
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how correlation will help me to find features of my model in machine learning?

I read articles that tells correlation is used to find features in ML. But I want to know how it's exactly working.
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Calculating a volume from a 3D matrix

There is a boundary map between a 2D image and a 3D image. Let's say the sun light shines behind you and your shadow projects in front of you - in the plane. There is a boundary match between yourself (3D object) and your shadow (2D image). Now…
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Difference between multi-task lasso regression and ridge regression

The question is: what is the difference between multi-task lasso regression and ridge regression? The optimization function of multi-task lasso regression is $$ min_w \sum_{l=1}^L1/N_t\sum_{i=1}^{N_t} J^l(w,x,y) +…
Wyatt
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why is SSE cost function convex?

In regards to Machine Learning, in the Adaline rule we say that $$ J(w)=\frac{1}{2} \sum_{i} (\mbox{target}^{(i)} - \mbox{output}^{(i)})^2, \quad \mbox{output}^{(i)} \in \mathbb{R} $$ is convex. I´d like to know how can we say that? Some proof that…
killezio
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Growth function-Number of hypothesis

I am trying to prove that $m_{h}(n)\leq min(M,2^{n})$ where M is the number of the hypotheses and $m_{h}(n)$ is the growth function. The only thing I know is that $m_{h}(n)\leq2^{n}$ from definition of growth function but I can found a relation…
p1337
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Machine learning: Characteristics of the growth function

I'm trying to prove the following: $$m_H(2n) \le m_H(n)^2$$ So far the only thing I've been able to come up with is that they both are upper bounded by $2^{2n}$ using the definition of the growth function : $$m_H(n) \le 2^n$$ Although that doesn't…
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Understanding the equation for margin in linear classification

In linear classification, the margin is the distance that the closest point is to the separating hyperplane. It is useful because not all hyperplanes are equal, so taking the hyperplane with the largest margin is an intuitive way to select the best…
jds
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Support Vector Machines: Hype or Hallelujah? - what is alfa?

I at the moment trying to understand how SVM works with the help of this paper The paper itself explains things pretty well, but there is an alfa term, which doesn't seem to be documented anywhere? could any of elaborate on what it means? and what…
Lamda
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Valid approach to generate new training data out of some existing training data

Is there any valid approach to generate new training data out of some existing training data. I ask this question only in regard of my learning problem not in a general context. My learning problem is to convert the 6 dimension acceleration and…
Saman
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Does choice of initial Theta effect Perceptron's convergence?

I am studying the Perceptron algorithm. Right now I am trying to understand if the initialization choice of $\theta$ effects the algorithm's ability to converge. I have tried experimenting by applying the algorithm to a linearly separable training…
irem
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