Questions tagged [segmentation]

In marketing/economics, the task of dividing some population such as customers into sub-groups based on some type of shared characteristics or demands. Statistically, various unsupervised and supervised methods may be used for that (clustering, conjoint analysis, tree, etc.).

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14
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3answers
1k views

How can I programmatically detect segments of a data series to fit with different curves?

Are there any documented algorithms to separate sections of a given dataset into different curves of best fit? For example, most humans looking at this chart of data would readily divide it into 3 ...
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3answers
15k views

Loss function for semantic segmentation

Appologizes for misuse of technical terms. I am working on a project of semantic segmentation via convolutional neural networks (CNNs) ; trying to implement an architecture of type Encoder-Decoder, ...
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1answer
9k views

What are the difference between Dice, Jaccard, and overlap coefficients? [closed]

I come across three different statistical measures to compare two sets, in particular to segmentation on images (e.g., comparing the similarity between the ground truth and the segmented result). ...
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3answers
2k views

Strategies for time series forecasting for 2000 different products?

First of all, I realise that my question is very broad and that it may be hard to answer this question because of it. Do you have any advice on how to approach a 'problem' where you need to make ...
7
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2answers
4k views

Differences between clustering and segmentation

I have read about piecewise aggregate approximation (PAA) mining time series data, sliding window, top down and bottom up approaches for time series segmentation but these are applicable to single ...
6
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1answer
243 views

Use a clustering as a segmentation

I ran a cluster analysis on a population of customers. I used variables like: Lifetime Spent amount etc. Now I'd like to use these clusters ('Little buyer', 'Regular fan of the brand A', ...) for ...
6
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1answer
518 views

Segmentation of employees

I am working on a determining why certain employees cause errors in a company's process and why others do not. I have the employee information, information about the errors they have made and the ...
5
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1answer
1k views

Hidden Markov Model segmentation of different proportions of binary data

I need to segment a sequence of 0s and 1s by their proportion at relatively large scales. As an example, let's define 5 different states that represent 5 different ratios of 1s & 0s. ...
5
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1answer
1k views

Clustering data into bins of variable sizes

I'd like to build a model (in R or excel) that takes in large amount of linear data and segments it into "bins". The linear data is an attribute that reflects what condition that section/record is at. ...
5
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2answers
1k views

CRF or MRF energy functions for image segmentation

I am currently working on image segmentation for the purposes of computer vision. I have read many papers and a few books dealing with MRFs and CRFs for computer vision. All of them define an energy ...
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5answers
3k views

is K-Means clustering suited to real time applications?

I want to segment a sequence of RGB images (basically it's a video) based on their colors in real time. KMeans is an easy and intuitive algorithm to use in this case, but it's execution time is very ...
4
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1answer
7k views

User segmentation by clustering with sparse data

Imagine that I have 100k users and 1k categories. For each user, up to 5 categories, I know how much money they have spent. Obviously my data is very sparse. Now I want to group users by the money ...
4
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1answer
3k views

SVM for Image Segmentation?

I turn to this forum for advice with the following problem. If you could please shed some light on any aspect of this question I'd be very grateful. Problem decription: I'm trying to use an SVM to ...
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1answer
2k views

Identify region of interest in image

I'm currently trying to work on the challenge https://www.kaggle.com/c/noaa-right-whale-recognition; I've done basic image recognition work before (Identifying plankton), but this particular challenge ...
4
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1answer
1k views

Building separate logistic regression models for each categorical variable

I am building a binary logistic regression model. I am not sure if using the variables as interactions is a better choice than building separate models for level of a categorical variable. Is there a ...
4
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0answers
694 views

BatchNorm after ReLU

I am currently experimenting with different settings for a U-Net (https://lmb.informatik.uni-freiburg.de/people/ronneber/u-net/) based image segmentation and I was unable to find out if it makes any ...
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1answer
1k views

Best method to assign new customers to existing clusters after segmentation?

After segmenting customer base using k means algorithm into 5 clusters , how to assign a new customer to one of the existing 5 clusters? Matching just the mean of clusters with values of new ...
3
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3answers
304 views

How to classify customers by those who use quite a lot of shops vs. mostly one specific shop

I would be interested in how to approach the following problem: A supermarket chain has 1 million customers in a region and 10 shops. For each of the customers we know the distribution for all the ...
3
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1answer
2k views

Estimating the best length of n-gram

I have a long sequence of words or letters {word1 word2 word3 word1 word1 word2 ..etc}. Lets say we extract all the ngrams (unigrams, bigrams, trigrams, 4-gram, 5-gram ....) along with their frequency ...
3
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1answer
415 views

Optimal classifier or optimal threshold for scoring

In practice, there can be a classifier that gives far better performance at a specific acceptable threshold than an "optimal" classifier with better average performance across range of thresholds (...
3
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2answers
180 views

Controling segmentation process in order to get usable segments

My aim is to create segments based on survey data. This in it self is quite straight forward: I use PCA to extract information from the survey answers, and then ...
3
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1answer
259 views

Market segmentation based on a time of consumption

I'm an almost graduated applied math student. I do some sporadic work in marketing. I have done a few market segmentation projects. I am soon going to do one which is important to me. I usually ...
3
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0answers
173 views

Potts model and model selection

Suppose to have two vectors of random variables $\mathbf{x}=(x_1,\dots,x_n)^{\prime}$ and $\mathbf{y}=(y_i,\dots,y_n)^{\prime}$, observed over a two dimensional space domain. Let $\boldsymbol{\xi}_{...
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0answers
102 views

Profiling survey respondents with both categorical and ordinal variables

I have a mixture of categorical and ordinal variables from a survey that I am trying to use to create "profiles" or segments that differ from one another with respect to a dependent variable (the ...
3
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1answer
4k views

3-4-5 Rule How to partition the sets?

In Data Mining course, we are taking 3-4-5 Rule to segments the data uniformly. I'm trying to understand these lines below, and how they are linked to the graph below too. If an interval covers 3, ...
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3answers
3k views

segmentation of univariate irregular time series

this is my first post. I have an irregular time series that exhibits large shifts in both mean and in the direction of the trend. It looks something like this (though this is far cleaner than ...
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4answers
680 views

Hints on this computer vision / machine learning problem

I've been working for a while on a pet problem. The task is to identify and segment out the dark lines and possibly the wiggly ones too. I'm not looking for anyone to solve this problem for me...I'm ...
2
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2answers
458 views

What are the advantages of segmentation?

Suppose you want to fit a regression model. You have a data set with multiple attributes. What would be the advantages of segmenting the data set and fitting a regression model to each of the segments?...
2
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1answer
39 views

any difference between randomly selecting before or after an event?

Is there a mathematical difference between randomly selecting a population of users before an event vs after an event, for the purposes of experimentation? For example, let's say we want to split all ...
2
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1answer
3k views

how can my loss suddenly increase while training a CNN for image segmentation?

I work with keras 1.2.2 with a tensorflow 1.4.0 backend. I'm using a unet architecture, I have 708 images of 650x650 pixels and 6 chanels. I augmented the dataset with mirrorings and rotations, for a ...
2
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1answer
2k views

Fully Convolutional Neural Network Exploding Logits and Loss

I am trying to train a fully convolutional neural network for 3D medical image segmentation, I have started from the architecture of this paper with the differences being that I have images of varying ...
2
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1answer
1k views

Why is k-medians typically used with Manhattan rather than Euclidean distance?

K-medians is typically used with Manhattan distance rather than Euclidean distance. Why is this?
2
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2answers
175 views

Detection of music note sequence in audio signal

I have an audio signal which contains the combination of different western music notes(I know this combination in advance) and I want to identify the sequence of the music notes present in it. For ...
2
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1answer
719 views

Machine learning to find an optimal set of parameters for a segmentation algorithm

Using machine learning to find an optimal set of parameters for a given segmentation algorithm. In the "classical" case of machine learning, in the training phase, the data set is constant and the ...
2
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1answer
1k views

R clustering using mclust: BIC are often NA

I'm working on segmentation/clustering and trying to use Gaussian Mixture Modelling for Model-Based Clustering. I'm using the R package Mclust in order to come up with the best fit for my data. All ...
2
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1answer
601 views

Market / Customer Segmentation - Merging two different segmentations

I have a database where each observation is a person. They were questioned on their attitude towards the consumption of X category of product. I have being using K-means to segment this data. I have ...
2
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1answer
36 views

Using pretrained segmantation network for unseen motives

For a research project, I need to do a segmentation on images. Since the motivation is nothing any of the big networks was ever trained on, I would ask if it still makes sense to use pretrained ...
2
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0answers
307 views

Evaluate image segmentation with the absence of ground truth

Motivation: - Evaluate the computerised image segmentation against manual segmentation; - Evaluate the difference between difference manual segmentation. Background: Given a raw medical image (...
2
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0answers
31 views

What are good / simple techniques available for segmenting non-cursive handwriting images?

I need to process English hand-written form fields. So the hand-writings are expected to be mostly non-cursive but the letters may occasionally overlap with each other slightly, with some punctuation ...
2
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0answers
36 views

Clustering stream of new customers based on future potential

I need to cluster new customer according to their future potential, but I have only information about their first transaction. I have access to all transactions for the other customers. So I can do ...
2
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1answer
146 views

Clustering Consumer data with over 100 variables and 50000 rows each

I am tasked with performing a clustering exercise for a consumer survey dataset with the hopes of finding distinct consumer segments. In the past, I've done it using a variety of techniques- ...
2
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0answers
158 views

What form of analysis should be used for loss given default estimates?

I am working on BASEL II IRB models and we have to estimate loss based on historic defaults. There are different outcomes/scenarios we have identified that a default can encounter that will affect ...
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2answers
2k views

Clustering Survey Responses Based on Dichotomous Responses

I have a set of about ten questions that I would like to use to create groupings from. The responses are all dichotomous (responses are in the form of 1 or 2 where 1 and 2 represent differences in ...
1
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1answer
4k views

Cross cluster analysis of categorical data in R [closed]

How do we perform cross cluster analysis in R. Most of my data has categorical variables {variable Marital Status (married, single, divorced); variable Education (tertiary, secondary, primary, etc.); ...
1
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3answers
234 views

Repeating k-means, is it helpful?

I'm working with k-means algorithm, and I'm proceeding in this way: I've run k-means from 2 to n clusters, I plotted the k-means result of the variance, to get the "elbow", to decide the best trade-...
1
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1answer
67 views

Quantify whether a set of binary segmentation models (experts) have diversity on a fixed dataset?

I have a set of models for binary segmentation task (M=10), and a set of images (N=1000). I also can collect the prediction map for all these N=1000 images, resulting in 10,000 grayscale maps. Now, ...
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1answer
436 views

What is the best way to deal with missing data in latent class models?

What is the best way to deal with missing data in latent class models? For example, Latent GOLD can estimate models with missing data (LG technical manual page 51). Simply put, the likelihood ...
1
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1answer
18 views

Experimental data segmentation using trees based on means - could single trial estimates improve reliability?

I have some categorical data and measures of participants accuracy. Let's say that it is a quiz and we have 8 different categories: History, Geography, Physics and so forth. Each participant is ...
1
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1answer
17 views

Using k-means to segment customers in the positive class

I have some labeled data (0=didn’t cancel, 1=canceled) that I am creating a model for in my marketing class. On top of predicting who is likely to cancel, I’d like to explore the possibility of ...
1
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1answer
60 views

deciles in skewed distributions [closed]

Does it make sense to use deciles for distribution that are skewed. For example, consider the exponential distribution with lambda >= 1.5 or lambda distribution ...