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Questions tagged [classification]

For questions related to the placement of individual cases into categories, such as is essential in fraud detection, spam detection, quality control, prediction of user or market responses, automated organizing or indexing, assigning objects in view to types of obstacles or risks, writing or typing recognition, phonic recognition, .

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15
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2answers
3k views

Why has cross entropy become the classification standard loss function and not Kullbeck Leibler divergence?

Cross entropy is identical to the KL divergence plus entropy of target distribution. KL equals to zero when the two distributions are the same, which seems more intuitive to me than the entropy of the ...
14
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2answers
915 views

When is deep learning overkill?

For example, for classifying emails as spam, is it worthwhile - from a time/accuracy perspective - to apply deep learning (if possible) instead of another machine learning algorithm? Will deep ...
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4answers
1k views

What makes neural networks so good at predictions?

I am new to neural-network and I am trying to understand mathematically what makes neural networks so good at classification problems. By taking the example of a small neural network (for example, ...
9
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4answers
7k views

How to classify data which is spiral in shape?

I have been messing around in tensorflow playground. One of the input data sets is a spiral. No matter what input parameters I choose, no matter how wide and deep the neural network I make, I cannot ...
9
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3answers
581 views

Do I need classification or regression to predict the availability of a user given some features?

While studying data mining methods I have come to understand that there are two main categories: Predictive methods: Classification Regression Descriptive methods: Clustering Association rules ...
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2answers
123 views

Can machine learning algorithms (CNNs?) be used/trained to differentiate between small differences in details between images?

I was wondering if machine learning algorithms (CNNs?) can be used/trained to differentiate between small differences in details between images (such as slight differences in shades of red or other ...
7
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1answer
152 views

Classification with different approaches

A few days ago I asked the question, if a NN with linear activation function can produce a function concatenated of linear functions, what actually is impossible (Can a NN with linear activation ...
7
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1answer
107 views

What algorithms are used for segmentation and classification of non solid regions in an image?

In the process of segmentation, pixels are assigned to regions based on features that distinguishes them from the rest of the image. Value Similarity and Spatial Proximity, for example, are two ...
7
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1answer
494 views

Loss function for Hierarchical Multi-label classification

I am looking to try different loss functions for a hierarchical multi-label classification problem. So far, I have been training different models or submodels like multilayer perceptron ( MLP )branch ...
6
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3answers
4k views

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, ...
6
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2answers
417 views

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 ...
6
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2answers
3k views

How to implement an “unknown” class in NN classification?

For example I need to detect classes for MNIST data. But I want to have not 10 classes for digits but also I want to have 11th class "not a digit". So that any letter (except "O" of course:) ), any ...
6
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3answers
151 views

Is it better to make neural network to have hierchical output?

i'm quite new to neural network and i recently built neural network for number classification in vehicle license plate. It has 3 layers: 1 input layer for 16*24(382 neurons) number image with 150 dpi ,...
6
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2answers
2k views

Does data skew matter in classification problem?

I'm working on a image classification problem using 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% ...
6
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1answer
234 views

How to add more features to the input of a machine learning algorithm?

I am trying to perform a binary classification of tweets using machine learning. The usual way of doing this seems to be putting a hand-classified tweet's words into a big vector, then use that ...
6
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2answers
98 views

Why are documents kept separated when training a text classifier?

Most of bibliography consider text classification as the classification of documents. When using bag of words and bayesian classification, they usually use the statistic TFIDF, where TF normalizes the ...
6
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0answers
107 views

Why does my NN not classify these tic tac toe pattern correctly? [closed]

I'm trying to teach an AI different pattern of tic tac toe to recognize wether a given pattern represents a win or not. Unfortunately it's not learning to recognize them correctly and I think may way ...
5
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2answers
492 views

How does text classification reduce manpower costs?

(I apologize for the title being too broad and the question being not 'technical') Suppose that my task is to label news articles. This means that given a news article, I am supposed to classify ...
5
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2answers
92 views

How do I improve accuracy and know when to stop training?

I am training a modified VGG-16 to classify crowd density (empty, low, moderate, high). 2 dropout layers were added at the end on the network each one after one of the last 2 FC layers. network ...
5
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3answers
75 views

Do specific units exists for measuring the intelligence of a machine?

We can measure the power of the machine with the number of operation per second or the frequency of the processor. But does units similar of IQ for humans exist for a AI? I'm asking for a unit which ...
5
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2answers
865 views

Deep Learning – Classification or Regression Approach?

I am fairly new to deep learning in general and I am currently facing a problem I want to solve using neural networks and I am unsure if it is a classification or regression problem. I am aware that ...
5
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2answers
1k views

Is it possible to classify data using a genetic algorithm?

Is it possible to classify data using a genetic algorithm? For example, would it be possible to sort this database? Any example in Matlab?
5
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3answers
204 views

How to make convnets aware what the image actually is, not what is depicted on it?

I've uploaded a picture to Wolfram's ImageIdentify of graffiti on the wall, but it recognized it as 'monocle'. Secondary guesses were 'primate', 'hominid', and 'person', so not even close to 'graffiti'...
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2answers
185 views

Can neural networks learn to ignore an input datum?

Disclaimer: I'm not a student in computer science and most of my knowledge about ML/NN comes from YouTube, so please bear with me! Let's say we have a classification neural network, that takes some ...
5
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3answers
267 views

How does neural network classifier classify from just drawing a decision plane?

I understand that a neural network basically distorts(non-linear transformation) and changes the perspective(linear transformations) of input space to draw a plane to classify data. How does the ...
5
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1answer
120 views

How do I statistically evaluate a ML model?

I have a model that predicts sentiment of tweets. Are there any standard procedures to evaluate such a model in terms of its output? I could sample the output, work out which are correctly predicted ...
5
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2answers
69 views

What should the range of the output layer be when performing classification?

I am working on a MLP neural networks, using supervised learning (2 classes and multi-class classification problems). For the hidden layers, I am using $\tanh$ (which produces an output in the range $[...
5
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1answer
132 views

Methods to tell if a question can be answered from a paragraph

I'm working on a project related to machine Q&A, using the SQuAD dataset. I've implemented a neural-net solution for finding answers in the provided context paragraph, but the system (obviously) ...
5
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1answer
190 views

Detect patterns in sequences of actions

I have to analyse sequences of actions that look more or less like this JSON blob. The question I'm trying to answer is whether there are recurring (sub)patterns that different users adopt when asked ...
5
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2answers
2k views

Spam Detection using Recurrent Neural Networks

I am working on this code for spam detection using recurrent neural networks. Question 1. I am wondering whether this field (using RNNs for email spam detection) worths more researches or it is a ...
5
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2answers
69 views

Two data classes for a convolutional neural network, can one have a LOT more images for training than the other?

I have two classes in the training set: one that has images with a feature and the other of images without that feature. Can there be a LOT more images with "no feature" so I can fit in all possible ...
5
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1answer
52 views

Which marketing-related classification challenges is a feed forward neural network suited to solve?

I am trying to think of some marketing-related classification challenges that a feed-forward neural network would be suited for. Any ideas?
4
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4answers
115 views

How to classify language as friendly or aggressive with AI?

Just for the purpose of learning I'd like to classify the likeliness of a tweet being in aggressive language or not. I was wondering how to approach the problem. I guess I need first train my neural ...
4
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3answers
96 views

What kind of neural network architecture do I use to classify images into one hundred thousand classes?

I have an image dataset where objects may belong to one of the hundred thousand classes. I want to know what kind of neural network architecture should I use in order to achieve this.
4
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1answer
36 views

Is there any measure of separability of classes?

I want to know if there is a measure of how well two classes in Y are separable (linearly or not) based on their features in X. Easiest way of explaining this is to compare it to correlation ...
4
votes
1answer
49 views

Class Restriction in Generative Adversarial Networks

this is my first post here. Our problem setting: We have to do a binary classification of data given a training-dataset D, where the majority of items belongs to class A and some items belong to ...
4
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1answer
46 views

Why does the binary cross-entropy work better than categorical cross-entropy in a multi-class single label problem?

I was just doing a simple NN example with the fashion MNIST dataset, where I was getting 97% accuracy, when I noticed that I was using Binary cross-entropy instead of categorical cross-entropy by ...
4
votes
1answer
52 views

How to define a loss function for a classifier where the confusion between some classes is more important than the confusion between others?

I have a dataset of images belonging to $N$ classes, $A_1, A_2...A_n,B_1,B_2...B_m$ and I want to train a CNN to classify them. The classes can be considered as subclasses of two broader classes $A$ ...
4
votes
1answer
31 views

Looking to build, compile, and/or find dataset for serial-parallelized code examples

I'm looking to perform two tasks: Train a classifier to classify code as serial or parallel Train a generative algorithm to generate parallel code from serial For the first task a simple scraper ...
4
votes
1answer
67 views

Can I combine two classifiers that make different kinds of errors to get a better classifier?

I have a dataset with 2,23,586 samples out of which i used 60% for training and 40% for testing. I used 5 classifiers individually, SVM, LR, decision tree, random forest and boosted decision trees. ...
4
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2answers
140 views

Measuring and Classifying human intelligence?

I have a dataset of millions of chat messages from different discussions. Some of the messages are written by people who lack understanding or relevant language skills. These messages almost always ...
4
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0answers
102 views

Supervised K-means clustering doesn't appear to work

I have a data set containing actions taken by customers (e.g., view a product, add a product to cart, purchase product), the product bought (if any) and times of said actions. I am attempting to use K-...
3
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2answers
132 views

Why not use the MSE instead of the current logistic regression?

When watching the machine learning course on Coursera by Andrew Ng, in the logistic regression week, the cost function was a bit more complex than the one for linear regression, but definitely not ...
3
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2answers
60 views

Are there tools to help labelling images?

I need to manually classify thousands of pictures into discrete categories, say, where each picture is to be tagged either A, B, or C. Edit: I want to do this work myself, not outsource / crowdsource ...
3
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2answers
70 views

Will a neural network always predict the correct label if it sees the exact same input during training and testing?

If I'm performing a text classification task using a model built in Keras, and for example, am attempting to predict the appropriate tag given a Stack Overflow question: "how to subtract 1 from an ...
3
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3answers
95 views

Method for Multi-class/category?

I am having issues getting started with a multi class problem with multiple features and hoping someone could please point me in the right direction. I have data that is structured like this for ...
3
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1answer
106 views

How many training example text classifier needs to be trained?

I want to train text classifier (using https://www.uclassify.com) with 12 classes/categories. I will be training it to classify news/articles (I know that there are existing classifier but I want to ...
3
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1answer
19 views

Natural language recommendation system: to pre-classify inputs or not?

Does it help to "pre-classify" natural language inputs using labeled input fields? E.g., "Who," "What," "Where," "When," "Why," "How," and "How much?" Or is a single, monolithic, free-form, long-text ...
3
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1answer
100 views

K-means using only certain dataframe columns [closed]

I'm using the k-means algorithm from the scikit-learn library, and the values I want to cluster are in a pandas dataframe with 3 columns: ID ...
3
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3answers
126 views

Can this problem be solved by AI?

I am looking in to building a kind of troubleshooting web application. It would be a form that starts with a first question. Depending on the answer, you get a follow up question and so on until the ...