Artificial Intelligence Stack Exchange
Artificial Intelligence Stack Exchange

Questions tagged [hidden-markov-model]

For questions related to the hidden Markov model and related algorithms such as the forward algorithm.

See e.g. https://en.wikipedia.org/wiki/Hidden_Markov_model.

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Can hidden Markov models be used to model any time series data?

Can HMMs be used to model any time series data? Or does the data have to be that of a Markov process? In HTK documentation, I see that the first few lines state that it can model any time series HTK is a toolkit for building Hidden Markov Models…
vinjk
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How can I use a Hidden Markov Model to recognize images?

How could I use a 16x16 image as an input in a HMM? And at the same time how would I train it? Can I use backpropagation?
david david
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What are the differences between CRF and HMM?

What I know about CRF is that they are discriminative models, while HMM are generative models, but, in the inference method, both use the same algorithm, that is, the Viterbi algorithm, and forward and backward algorithms. Does CRF use the same…
Faris Dewantoro
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Is there an equivalent model to the Hidden Markov Model for continuous hidden variables?

I understand that Hidden Markov Models are used to learn about hidden variables $z_i$ with the help of observable variables $\xi_i$. On Wikipedia, I read that while the $\xi_i$'s can be continuous (say Gaussian), the $z_i$'s are discrete. Is this…
stoic-santiago
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How do multiple coordinate systems help in capturing invariant features?

I've been reading this paper that formulates invariant task-parametrized HSMMs. The task parameters are represented in $F$ coordinate systems defined by $\{A_j,b_j\}_{j=1}^F$, where $A_j$ denotes the rotation of the frame as an orientation matrix…
stoic-santiago
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Expected duration in a state

I am going through Rabiner 1989 and he writes that the discrete probability density function of duration $d$ in state $i$ (that is, staying in a state for duration $d$, conditioned on starting in that state) is $$p_i(d) =…
jstycrpsc
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Is the Markov property assumed in the forward algorithm?

I'm majoring in pure linguistics (not computational), and I don't have any basic knowledge regarding computational science or mathematics. But I happen to take the "Automatic Speech Recognition" course in my graduate school and struggling with it. I…
Jeeyoung Jeon
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What is meant by decoding in a Hidden Markov Model?

HMM contains two types of states: observable and hidden. Let $\{ h_1,h_2,h_3,\cdots,h_n\}$ be hidden states and $\{o_1,o_2,o_3,\cdots, o_m\}$ be the observable states. Suppose the $n^2$ transition probabilities $p(h_j|h_i)$ and the $mn$ emission…
hanugm
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Looking for help on initializing continuous HMM model for word level ASR

I have been studying HMM implementation approaches on ASR for the last couple of weeks. This probabilistic model is very new to me. I am currently using a Python package called Pomegranate to implement an ASR model of my own for the Librispeech…
Zander
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How to deal with very, very small time-series?

I have an ensemble of 231 time series, the largest among them being 14 lines long. The task at hand is to try to predict these time-series. But I'm finding this difficult due to the very small size of the data. Any suggestions about what algorithm…
Ons Bouarada
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What is a Hidden Markov Model - Artificial Neural Network (HMM-ANN)?

As far as I know, neural networks have hidden computational units and HMM has hidden states. Hidden Markov Models can be used to generate a language, that is, list elements from a family of strings. For example, if you have an HMM that models a set…
Pluviophile
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Predicting Hot Categories In a Reference Manager

Reference managers like Zotero or Mendeley allow researchers to categorize papers into hierarchical categories called collections. The User navigates through a listing of these collections when filing a new item. The retrieval time grows something…
Max Suica
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Can HMM, MRF, or CRF be used to classify the state of a single observation, not the entire observation sequence?

I learn that the Viterbi algorithm used for Hidden Markov Model (HMM) can classify a sequence of hidden states from the corresponding observations; Markov Random Field (MRF) and Conditional Random Field (CRF) can also do it. Can these algorithms be…
drerD
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What is the role of self loop in Hidden Markov Models(HMM)?

What actually does the self-loop (within the single hidden state ) in the Hidden Markov model helpful for? I learn that one of the use cases concerning Natural language Understanding is that it helps a model to stay within the current state in case…
Pam Cesar
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Determining observation and state spaces for viterbi algorithm in a simple word recognition system using HMM

The system I'm trying to implement is a microcontroller with a connected microphone which have to recognise single words. the feature extraction is done using MFCC (and is working). the system have to recognise [predefined, up to 20] single words…
Tirdad Sadri Nejad
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