I thought that there was no particular article on graphical modeling in Qiita, Here's a quick overview of graphical modeling.
"Introduction to graphical modeling that I can't hear anymore" http://www.slideshare.net/Kawamoto_Kazuhiko/ss-35483453
Roughly, it is a model for Bayesian inference.
(Additionally…) A graphical representation of the conditional independence between random variables. Conditional independence is the key to modeling and efficient algorithms. (There is a connection, but there is no combinatorial explosion)
For the observable observable variable x By defining an unobservable latent variable z, It is possible to express values that are not originally observed.
Markov random field: Graphical graph with undirected graph Bayesian network: Graphical modeling with valid graphs
-Supplement- Intuitively, the Bayesian network is easier to understand, ・ Markov random field: Adjacent nodes should be given ・ Basic network: Dependencies are occurring between children Therefore, it is complicated to determine whether it is conditional independence. The Markov random field is a simpler model than the Bayesian network.
The latent variable of the Markov random field is ・ Discrete probability: Hidden Markov model ・ For continuous probability: Kalman filter (normal distribution), Particle filter (other than normal distribution) is.
If the graph has a loop structure An approximate solution can be derived by using the belief propagation method (sum of products algorithm).
↓ The commentary article is easy to understand. "Implementing Markov Random Field / Belief Propagation with Python networkx" http://sinhrks.hatenablog.com/entry/2014/12/27/232506
As the title suggests, implement using the networkx module in Python It is built on the subject of image processing.
Visual modeling is possible by using graphs It is said to be the strength of graphical modeling, I feel that skill is required to actually demonstrate our strengths.
Since I wrote a description of graphical modeling and latent variables, How Graphical Modeling is Used in the Advertising Industry Now An example of using it in the current trend of native ads, I would like to write based on the article and thesis (Yahoo!).
paper Paper title: Search for content-linked advertising using a topic model Author: Hiroshi Yamamoto Masaki Noguchi Shingo Ono Koji Tsukamoto (Yahoo Japan Corporation) http://www.anlp.jp/proceedings/annual_meeting/2014/pdf_dir/P2-14.pdf
Topic Model made it possible to summarize sentences quickly and easily, To read potential interests from the list of feature words included in Topic Human analog work such as prior knowledge and imagination will occur, so improvement is necessary.
Uses word vec2 (state-of-the-art natural language processing technology developed and published by Google).
Fusion with native advertising platform
It becomes necessary to use a dynamic learning model.
Due to the omni-channelization of purchasing information and the evolution of behavior prediction by machine learning Highly accurate targeted advertising is possible.
Criteria for ad selection ・ Words in the content ・ Similarity of words in advertisement sentences There is.
Even if you have ads that are suitable for your content If the words used in the content and the advertisement are different The ad is not a candidate for display.
To solve the problem that appropriate advertisements cannot be displayed as candidates due to word mismatch Convert words from both the page content and the ad text into topics. ⇒Proposed a method to search for advertisements in the converted topic space.
By combining word search and topic search, It was shown that the accuracy of ad search is improved compared to the case where both are used alone.
・ Natural language processing: What is "natural language processing" that is also used for smartphones? (http://logmi.jp/45207)
・ Topic model: Beginning of topic model (https://speakerdeck.com/yamano357/tokyowebmining46th) I think you can understand it somehow by reading.
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