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Supervised learning The supervised learning (SL) problem is formulated as follows. You are given a dataset $\mathcal{D} = \{(x_i, y_i)_{i=1}^N$, which is assumed to be drawn i.i.d. from an unknown joint probability distribution $p(x, y)$, where $x_i$ represents the $i$th input and $y_i$ is the corresponding label. You choose a loss function $\mathcal{L}: ...


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There is a problem with confining Artificial Intelligence to a single definition, because it has become an umbrella term encompassing many fields of science. It has come a long way from the "thinking machines" of the 50s. Actually, the term was coined in a summer workshop in 1956, whose proposal was: The study is to proceed on the basis of the conjecture ...


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I believe that the idea is to have a similar ratio of fraud/"normal transaction" as to the ones that bank encounter on real life. If you balance it you will probably have a lot of false positive once you apply your solution to real world's data and, if that may be fine for you to play with, it's not what a bank would like as they can't block too much of the ...


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The paper Fair and Unbiased Algorithmic Decision Making: Current State and Future Challenges argues that ensuring fairness is not a trivial task and that the current statistical formalizations of fairness lead to a long list of criteria that are each flawed (or even harmful) in different contexts, that is, there are trade-offs between the proposed ...


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A typical clustering algorithm is k-means (and not k-NN, i.e. k-nearest neighbours, which is primarily used for classification). There are other clustering algorithms, such as hierarchical clustering algorithms. sklearn provides functions that implement k-means (and an example), hierarchical clustering algorithms, and other clustering algorithms. To assess ...


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This is the definition of conditional probability + Total probability decomposition formula: $p(y|x) = \frac{p(y,x}{p(x)} = \frac{p(x,y)}{\sum_{y'}p(x,y')}$. The idea is to use some unsupervised learning algorithm to learn the distribution $p(x,y)$ for every possible value of $y$, and by using the previous formula you can find $p(y|x)$.


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When you say likelihood, you are invoking several other concepts like events, sample, parameters, model, probability density function (PDF), etc (it would be helpful if you learn more about these concepts). In essence, a likelihood function $l(x|\theta)$ is a PDF that quantifies how likely is that event $x$ happens out of a set of possible events, given the ...


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Yes, you could use clustering: Encode your features as a feature vector and feed it into a clustering algorithm (see Finding Groups in Data for a comprehensive description of these). You could use agglomerative clustering, which would give you groups of similar items; perhaps different level headings will be clustered together. Alternatively you could try a ...


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One problem with clustering algorithms is that they will typically find you a solution, ie they will split your data set into clusters, but it will find you a structure even if there isn't one. Your data looks like it could consist of about 5 to 7 clusters, but it could equally well just be 2 or only 1. What you need to do after the clustering is to assess ...


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There are some unsupervised learning algorithms that can be used for pattern recognition (i.e. the discovery of patterns in data). The most notable one is probably k-means, which is a clustering algorithm. In k-means, you cluster your unlabeled data into groups (or clusters) based on the distance (or similarity) between them. When a new data point arrives, ...


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In Supervised learning, the goal is to learn a mapping from points in a feature space to labels. So that for any new input data point, we are able to predict its label. whereas in Unsupervised learning data set is composed only of points in a feature space, i.e. there are no labels & here the goal is to learn some inner structure or organization in the ...


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The principal components (eigenvectors) correspond to the direction (in the original n-dimensional space) with the greatest variance in the data. The corresponding eigenvalue is a number that indicates how much variance there is in the data along that eigenvector (or principal component). Thus, feature 2 is the most important (based on ...


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How to fix the network above to auto-classify XOR data, in unsupervised manner? This cannot be done, except accidentally. Unsupervised learning cannot replace or emulate supervised learning. As a thought experiment, consider why you would expect the network to discover XOR, when simply considering outputs rounded to binary, you could equally find AND, OR, ...


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In the paper Generalization in Unsupervised Learning (2015), Abou-Moustafa and Schuurmans develop an approach to assess the generalization of an unsupervised learning algorithm $A$ on a given dataset $S$ and how to compare the generalization ability of two unsupervised learning algorithms $A_1$ and $A_2$, for the same learning task. They first provide a ...


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Yes you can use KNN algorithm to cluster (well actually its a classification not a clustering if you use KNN) the data. But, first you need to set one feature as a label because KNN is a supervised learning method, it need a labeled data to train the data first. For example you can use Gender as label to classify the data. To determine the quality of the ...


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The first place I would have directed you would be Sklearn and pydiffmap. I found this paper specifically about the problem you are doing using python the reference a package called megaman It seems like an active Github . I suggest not just looking at manifold learning papers but leaning towards a search toward non linear embedding or non linear ...


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I did an experiment, took a trained densenet121 and kept the bottom layers. I trained the FC layer to a softmax and then to a lambda layer that normalized the vector. I trained the network with imagenet to make the outputs the most far a away from (1,1,1,1,1...1) as possible, so I would get one hot vectors. I did, but the network trained to a single category ...


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