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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66 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 ...
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2answers
82 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 ...
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3answers
98 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 ...
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1answer
60 views

Why is there more than one way of calculating the accuracy?

Some sources consider the true negatives (TN) when computing the accuracy, while some don't. Source 1: https://medium.com/greyatom/performance-metrics-for-classification-problems-in-machine-learning-...
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1answer
109 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 ...
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1answer
3k views

How to calculate entropy for an ID3 decision tree?

$$H(S)=-\sum_{x \in X} p(x) \log _{2} p(x)$$ Wikipedia's description of entropy breaks down the formula, but I still don't know how to determine the values of X and p(x), defined as "The proportion ...
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2answers
58 views

Why are the terms classification and prediction used as synonyms in the context of deep learning?

Why are the terms classification and prediction used as synonyms especially when it comes to deep learning? For example, a CNN predicts the handwritten digit. To me, a prediction is telling the next ...
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1answer
144 views

How can I minimise the false positives?

I have 50,000 samples. Of these 23,000 belong to the desired class $A$. I can sacrifice the number of instances that are classified as belonging to the desired class $A$. It will be enough for me to ...
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1answer
59 views

Should I use Monte Carlo or a classifier for this Decision Making problem?

I want to build a model to support decision making for loan insurance proposal. There are three actors in the problem: a bank, a loaner applicant (someone who ask for a loan) and a counselor. The ...
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1answer
166 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 ...
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3answers
133 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 ...
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1answer
493 views

Training a Yes/No NN for Image Classes

I am fairly a newbie to Neural Networks. I wanted to ask if it is possible to train a NN to identify only one type object? For instance, a table from a large set of images, where the NN should be ...
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1answer
50 views

Creating a classifier for simpler classifiers trained on few training samples

Suppose I have a classification problem with a stream of training-samples constantly arriving over time. I cannot keep all training-samples in memory, but I still want to train a classifier that will ...
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2answers
904 views

Perceptron learning algorithm: different accuracies for different training methods

So, my question is a bit theoretical. I have been trying to implement a perceptron based classifier with outputs 1 and 0 depending on the category. I have used 2 methods: The ...
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1answer
105 views

Extracting multiple softmax values from image

I am currently in the pre-process of starting an image classification and extraction project which needs to output multiple softmax and absolute values from a single image like such: ...
3
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1answer
2k views

Multi-label Classification with non-binary outputs

I am looking to train a dataset that would output a sequence of letters (I'm using this for peptide sequences). Since I have 22 different possibilities of amino acids, I need to output a vector that ...
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3answers
8k views

How to “combine” two images for CNN input (classification task)?

For a classification task (I'm showing a pair of exactly two images to a CNN that should answer with 0 -> fake pair or 1 -> real pair) I am struggling to figure out how to design the input. At the ...
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1answer
256 views

How do Google cars recognize the traffic signs?

The paper Multi-column Deep Neural Networks for Image Classification (pages 7-8) shows an attempt at recognizing the traffic signs, with lower error rates, by using multi-column deep neural networks. ...
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1answer
53 views

How do I determine the most appropriate classifier for a certain problem?

Consider a Bayesian classifier used in spam e-mail filtering. It converts an e-mail to a vector, most of the time using the bag-of-words method. Although it learns first before getting employed, it ...
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1answer
55 views

Video engagement analysis with deep learning

I am trying to rank video scenes/frames based on how appealing they are for a viewer. Basically, how "interesting" or "attractive" a scene inside a video can be for a viewer. My final goal is to ...
3
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1answer
43 views

Decreasing Loss, Constant Accuracy

Problem Statement I've built a classifier to classify a dataset consisting of n samples and four classes of data. To this end, I've used pretrained VGG-19, pretrained Alexnet and even lenet (with ...
3
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1answer
35 views

How much the dialects recognition and speech recognition are relevant?

In this tutorial, they build a speech recognition model to classify a one-second audio clip as one of ten predefined words. Suppose that we modified this problem as the following: Given an Arabic ...
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1answer
99 views

Why is the last layer of a DBN or DBM used for classification task?

I understand why deep generative models like DBN ( deep belief nets ) or DBM ( deep boltzmann machines ) are able to capture underlying structures in data and use it for various tasks ( ...
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1answer
90 views

Machine Learning - Is selected models combination good?

I've selected more than 10 discriminative (Classification) models, each wrapped with a BaggingClassifier object, optimized with a GridSearchCV, and all of them placed within a VotingClassifier object. ...
3
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1answer
560 views

Multi-Label Image Classification using KNN

I'm not quite sure how I should go about creating a multi-label image KNN classifier using python as a lot of the literature I have read does not explicitly explain this methodology. Specifically, I ...
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1answer
89 views

What are examples of AI that use philosophy derived ontologies?

I'm looking for AI systems or natural language processors that use, in the classification and interrelation of notions/objects, some philosophical system, like basic laws of logic, Kantian or ...
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1answer
79 views

Using AI to interpret the nature a specific input and use the correct model

How would one go about building an AI that is capable to look at any kind of input and then identify what is the nature of this data? For example, an AI that is able to do image classification, NLP ...
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1answer
120 views

What is the most effective way to build a classifier?

At the moment, I am working on a project which requires me to build a naive Bayes classifier. Right now, I have a form online asking for people to submit a sentence and the subject of the sentence, in ...
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1answer
42 views

How to classify human actions?

I'm quite new to machine learning (I followed the Coursera course of Andrew Ng and now starting deeplearning.ai courses). I want to classify human actions real-time like: Left-arm bended Arm above ...
3
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1answer
38 views

How to draw bounding boxes for gender classification?

I wonder what is the better way of drawing rectangles on images for gender classification. My task is to create a classifier (CNN based) to detect gender from pictures of entire bodies (not just faces)...
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1answer
44 views

Can a model, retrained on images classified previously by itself, increase its accuracy?

Let's assume I have a CNN model trained to categorize some objects on the images. By using this model I find more categorized images. If I now retrain this model on data set that consists old set and ...
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2answers
63 views

Which online machine learning technique to use for multi-class classification problem with multiple inputs?

I have the following problem. We have $4$ separate discrete inputs, which can take any integer value between $-63$ and $63$. The output is also supposed to be a discrete value between $-63$ and $63$. ...
3
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2answers
95 views

How do we know the classification boundaries of the data?

Consider an image classification problem. Conceptually, we then have some high dimensional space where all the images can be represented as points, and having large enough labeled data set we can ...
3
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1answer
319 views

Alternative to sliding window neural network (was: Object detect (or) image classification at specific locations in the frame)

Recent advances in Deeplearning and dedicated hardware has made it possible to detect images with a much better accuracy than ever. Neural networks are the gold standard for computer vision ...
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1answer
77 views

What are causative and exploratory attacks in Adversarial Machine Learning?

I've been researching Adversarial Machine Learning and I know that causative attacks are when an attacker manipulates training data. An exploratory attack is when the attacker wants to find out about ...
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1answer
59 views

How do I classify measurements into only two classes?

I am a member of a robotics team that is measuring the amount of reflected IR light to determine the lightness/darkness of a given material. We eventually hope to be able to use this to follow a line ...
2
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1answer
99 views

Facial recognition and classifying unknowns with neural networks

As far as I understand, neural networks aren't good at classifying 'unknowns', i.e. objects that do not belong to a learned class. But how do face detection/recognition approaches usually determine ...
2
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2answers
66 views

Can we train the model to detect real users with only positive labels?

We have hundreds of thousands of customers records, and we need to take the benefits of our data to train a model that will recognize fake entries or unrealistic ones for our platform, where customers ...
2
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1answer
44 views

What make a CNN suitable for image classification or for semantic segmentation?

I've just started with CNN and there is something that I haven't understood yet: How do you "ask" a network: "classify me these images" or "do semantic segmentation"? I think it must be something on ...
2
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1answer
37 views

Feature extraction timeseries, model compatibility

I've got a timeseries with sensor data (e.g. accelerometer and gyroscope). I now want to extract the activity out of it (e.g. walking, standing, driving, ...). I Followed this Jupyter Notebook. But ...
2
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1answer
179 views

Text classification task chatbot

I'm building a customer assistant chatbot in Python, so a text classification task, and I have available more or less 7 hundred sentences of average length 15 words (unbalanced class). What do you ...
2
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2answers
79 views

Finding the right questions to increase accuracy in classification

Lets say I have a list of 100k medical cases from my hospital, each row = patient with symptoms (such as fever , funny smell, pain etc.. ) and my labels are medical conditions such as Head trauma, ...
2
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2answers
146 views

Question classification according to chapters

I have a corpus, say an instruction manual. The text in this manual is grouped into chapters and each chapter is split up into sections. For example, Chapter 1/Section 1, Chapter 1/Section 2 and so on....
2
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1answer
83 views

Decision tree: more than 2 classes, how to represent elements that are in a class vs ones that aren't?

I'm building a decision tree and would like to separate (for example) the elements that are in class 0 from those in classes 1 and 2, case in point: ...
2
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1answer
111 views

Is it possible to classify songs by genres based on spectrograms?

Is it possible to categories songs based on their spectrograms using image recognition or would there need to more features? I was thinking that the spectrograms might also run into problems with EDM ...
2
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1answer
1k views

Why is the hyperbolic tangent with MSE better than the sigmoid with cross-entropy?

Usually, in binary classification problems, we use sigmoid as the activation function of the last layer plus the binary cross-entropy as cost function. However, I have already experienced (more than ...
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3answers
122 views

Feature Selection algorithm for a high featured data

I have a cancer patient database from mass spectrometry on patients which consists of more than half million features. My task is to apply a feature selection algorithm to extract the most relevant ...
2
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1answer
316 views

confusion matrix is useful to be applied to the result of fuzzy c means clustering or not

After obtaining the result of algorithm fuzzy c means on the iris flower data set. Results are to be checked for their correctness. So, how to derive it in matlab. I mean code for that. please suggest....
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1answer
500 views

Bag-of-Words (BoW) model in image detection

Any good example for Bag-of-Words (BoW) model in image retrieving? I want a simple example to understand the whole process of BoW.
2
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1answer
362 views

Can ConvNets be used for real-time object recognition from video feed?

Convolutional neural network are leading type of feed-forward artificial neural network for image recognition. Can they be used for real-time image recognition for videos (frame by frame), or it takes ...