Tagged Questions

Refers to techniques for classifying data into categories based on similarities (which can either be known previously, or learned).

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22 views

New research ideas [on hold]

I am pursuing a project on Tracking learning and detection in a video stream. For that, I have read the paper titled Tracking-Learning-Detection. But as this paper was written in 2011, most of the ...
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0answers
17 views

why pretraining for convolutional neural networks

Usually Back propagation NN has the problem of vanishing gradients. I found that Convolutional NN (CNN) some how get rid of this vanishing gradient problems (why?). Also in some papers some ...
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41 views

Change in objective function optimization - Regularization in Logistic Regression

If I have the objective function of Logistic Regression to optimize by maximizing it, would it change to a minimization problem when I add regularization term to it? Or can I still solve the ...
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37 views

Prediction for new data using trained Gaussian Mixture Model

I am not sure how to do the prediction for some new data using trained Gaussian Mixture Model (GMM). For example, I have got some labelled data drawn from 3 different classes (clusters). For each ...
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0answers
12 views

Kalman filter before or after outlier removal?

I am getting radar data points in form of (x,y) coordinate system relative to my position every ms.[around 10-15 data points]. Now, inorder to have better position estimate of the points, I would like ...
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0answers
14 views

How can I validate if a pattern is meaningful?

I am a financial analyst for a construction company. My goal is to develop an accurate sales model that is correctly reflects prior sales history (back testing) so I can then predict future sales. I ...
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2answers
188 views

Pattern recognition with time series analysis

I'm looking for some good pointers to pattern recognition with time series. Possibly something practical that can be easily understood. As a toy example, think about collecting data from an ...
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0answers
34 views

What is the next step after acquiring the parameters(means, covar, priors) from GMM via EM

I am comparing the results achieved from clustering via K-means and GMM. For comparison I have accumulated a dataset of images. The training set consists of 359 images. I used SIFT to extract the ...
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1answer
26 views

How well do Convolutional neural networks in other image domains?

I was recently trying out caffe and learning about CNN. So far I have seen that the model used by Krizhevsky performs really well in natural images. However I wanted to know how these models or CNN ...
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31 views

find group of rows in a matrix with pattern similar to another matrix

I've been scratching my head about this problem for some time: I have a big gene expression dataset (20k genes x 200 samples) in matrix A and i have a subset of this dataset (i.e. 40 genes x 200 ...
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27 views

Dirichlet process mixture model in Python

My question is concerned with the practical issues of using this model. I've tried to use Dirichlet process mixture model from Scikit learn python package to find a number of clusters in my data (1D ...
3
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1answer
56 views

Excluding the scatter points from a feature

I have a set of data points that are supposed to sit on a locus and follow a pattern, but there are some scatter points from the main locus that cause uncertainty in my final analysis. I would like to ...
2
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0answers
187 views

Finding best neural network structure and inputs using optimization algorithm and cross-validation

I'm using optimization algorithm to find best structure+inputs of a patternnet neural network in MATLAB R2014a using ...
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0answers
29 views

Find linear subsets in a 2D point (xy) data [duplicate]

My problem is the very idea of how to start the analysis of 2D point patterns, specifically how to find linear trends within their spatial pattern. I have XY data points which are organized like in ...
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1answer
19 views

Supervised Pattern Recognition with Probabilistic Labels

I am interested in supervised pattern recognition problems where the the label associated with each pattern gives the probability of membership for each of the $c$ classes, rather than assigning each ...
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25 views

breakpoint analyses on multiple series: how to detect common points

I have 20 time series that span the same period (100 days each), from 4 species sampled at 5 different location. I made a loop to perform a breakpoint analysis on all of them, resulting in 0 to 3 ...
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1answer
62 views

detect line in geocoordinates

I have repeated samples of geocoordinates of activities in a city. In most of these samples positions will simply be random. In some samples, however, some percentage of the data will be arranged -- ...
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0answers
55 views

Order and similarity measurement

Let's say I have 10 different groups, and each group has its own string sequence. So, it should be like: ...
2
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3answers
287 views

Pattern mining on a small data set

I have a small data set 30 features/predictors and 30 observations. My target variable is Oil production and my predictors are well & reservoir properties (depth, trajectory, temperature, pressure ...
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37 views

Neural-Net style pattern recognition with an unknown/varying number of inputs?

Say for example I had a weighted graph such that each node had an associated value. The nodes' values are given by some function of the edge weights and the number of edges as well as the node's ...
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24 views

Walking recognition

I have walking samples from 20 different people. My aim is to detect which walking samples are from which person. I'm trying to achieve this by extracting "walking cycles" from each person's dataset ...
3
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1answer
103 views

detect line in scatter

I have repeated samples from the following process: Most samples will only contain points that are randomly distributed on a 2-dimensional plane. Sometimes, however, the sample will contain not only ...
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0answers
24 views

how to handle occlusion for face recognition?

If there some occlusion on face (such as sunglasses, mask, scarf), the recognition rate will decrease steeply? How to handle this case? I have do a survey, the PCA reconstruction method have been ...
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0answers
34 views

Anomaly detection of web browsing sequences

Please consider that I'm quite new to machine learning. I need to create models based on browsing patterns of web users and find deviations from that model. I'm using web server access log files. For ...
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1answer
24 views

missing value patterns

I am doing some data preparation with Python using Pandas and I am working with a dataset that has about 80 variables with missing values and I want to capture any patterns of missingness to cut down ...
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0answers
32 views

How many features to overfit the classification?

Recently, I have got some 'strange' comments from the reviewer of my paper. In my paper, I discussed a novel feature extraction method, and then I compared three classification methods for my binary ...
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3answers
68 views

Recognition of simple patterns and prediction

I have been doing supervised learning and classification with multilayer perceptron for some time. But now I need to use unsupervised learning to infer the presence of a pattern and I would need some ...
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0answers
29 views

Conceptual question on image pattern representation

I have a basic question regarding pattern learning, or pattern representation. Assume I have a complex pattern of this form, could you please provide me with some research directions or concepts that ...
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0answers
30 views

What is the simplest way to classify airplan manuvers?

Suppose we have declared four motion types for air-plane. If we represent each maneuver with a trajectory line, what is the best classification method to retrieve the trajectory pattern with a similar ...
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0answers
63 views

visualize the naive bayes with k-fold cv

I have done the classification using naive Bayes as a classifier, and applied 10-fold CV.I know that I can get the mean and variance of the result. However, how can I plot the classifier performance? ...
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0answers
24 views

Benchmarking model in speech recognition with different language

My supervisor asked me to benchmark my method in classifying speech signal with other language. I am doing Malay language speech recognition. To benchmark my method/feature used, I need to test ...
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0answers
41 views

Multiple Discriminant Analysis, Linear Discriminant Analysis, and Multidimensional scaling - how are they related?

Some time ago when I took a Pattern Classification class, the "concept" was introduced as Multiple Discriminant Analysis: You want to project your data onto a subspace (if you are interested in ...
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1answer
70 views

Testing a 2D point cloud for banana shape

I have many point clouds of a small size (say <200 points) in 2D. Some of them are isotropic and can be modelled as a single point. Others are elongated and curved so that they can reasonably be ...
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0answers
26 views

How Sensitive Are Neural Networks?

CrossPost: https://stackoverflow.com/questions/24301472/how-sensitive-are-ff-neural-networks I am aware of pruning, and am not sure if it removes the actual neuron or makes its weight zero, but I am ...
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0answers
27 views

Recognize spatio-temporal patterns correlating with events

I am trying to recognize a spatio-temporal pattern in my spatio-temporal input sequence X. The occurrence of the pattern is roughly temporally correlated with another event E1. For example I have ...
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0answers
18 views

Time series pattern identification - SVD/SSA?

I've looked over other posts regarding time series data, and am unsure if the mentioned methods would apply to what I'm trying to do, since I'm not familiar with pattern analysis methods: I have time ...
2
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1answer
45 views

Having a Neural Network recreate what it's learned

I've created a basic Neural Network that learns from basic information and can verify whether or not a piece of information matches it's parameters from a match percentage. Conceptually however, I ...
2
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1answer
78 views

Finding all largest sequences

What would be a good / efficient algorithm or approach to find all the largest sequences within a list of chains with varying lengths? For instance these chains: ...
2
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0answers
29 views

How can you use HMMs and ANNs for on-line handwriting recognition?

I've asked this question on cs.stackexchange before. It has a 20-hours remaining bounty there. On-line handwriting recognition is the task of converting a series of $(x(t),y(t))$ coordinates to ...
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0answers
36 views

HIdden Markov model training Baum Welch, concavity log likelihood

Hi i'm developing an hidden markov model algorithm training with multiple sequences. The recognition rate is good but i have doubts about the shape of the curve of log likelihood obtained from the ...
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0answers
32 views

Subtracting mahalanobis distance in one direction from total

Sincere appologies for what may be a stupid question, I'm new to pattern recognition and have exhausted all the textbooks which are aproachable to a beginner. I have substantially reworded this post ...
2
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2answers
138 views

Does fastICA require PCA to run at first?

I reviewed an application based paper saying that applying PCA before applying ICA (using fastICA package). My question is that does ICA (fastICA) requires PCA to run at first? This paper mentioned ...
3
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2answers
229 views

Confused about sensitivity, specificity and area under ROC curve (AUC)

Just read a unpublished paper for review purpose. The reported results like Leave-one-out cross validation sensitivity is 95%. Leave-one-out cross validation specificity is 100%. Leave-one-out cross ...
2
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1answer
42 views

Face Recognition approach DCT features

Face Recognition approach based on entropy estimate of the nonlinear DCT features proposes to use maximum entropy estimate of the DCT of the pixels. My question is maximizing entropy would mean ...
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0answers
40 views

Time series image data classification / video image classification

I am working on classifying video frames into two classes, positive and negative. e.g. if a particular pattern appears in a frame that frame will be classified into positive, otherwise negative. But ...
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0answers
27 views

Smart application of transformations in digit recognition

So I'm working on some machine learning code to recognize the digits 0-9 using singular value decomposition, followed by a least squares comparison with the first 15 or so singular vectors as my ...
0
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0answers
37 views

Methods for temporal patterns extraction

For example a video or series of images, or usage patterns data on a website, or a univariate time series, is there some flexible methods for extracting patterns of any length, such as head ...
2
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2answers
97 views

Comparison of close data sets

I'm studying around 100 sets of temperature ($N_{sample}=500$), which depends $4$ explicative variables such as power or speed. The dependency is always the same in each set, but sometimes the mean ...
0
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1answer
41 views

Which type neural networks for time series classification

I would like to use neural networks to classification of time series ( I have some Patterns and I want to adjust input time series to an appropriate class) -ist it possible to do this job with ...
0
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0answers
109 views

What's wrong with my Kernel algorithm (Kernel SVD)?

I have a user-item matrix $A$ as data input, which is a sparse matrix containing a large number of missing values (as zeros). Each row is a user, and each column is an item. Generally, I am conducting ...