Semanlink - Artificial Intelligence AND Similarity queries / Vector search

> for each unseen instance, its K nearest neighbors in the training set are firstly identified. After that, based on statistical information gained from the label sets of these neighboring instances, i.e. the number of neighboring instances belonging to each possible class, [Maximum a posteriori (MAP)](tag:maximum_a_posteriori_estimation) principle is utilized to determine the label set for the unseen instance.

Implemented in [scikit-multilearn](http://scikit.ml/api/skmultilearn.adapt.mlknn.html), in [java](https://github.com/lefman/mulan-extended/blob/master/mulan/src/mulan/classifier/lazy/MLkNN.java)

> the first lazy approach proposed specifically for multi-label classification. This is also a binary relevance approach which considers each label independently as a binary classification problem. Instead of a standard k-NN method, however, MLkNN uses the maximum a-posteriori (MAP) (Kelleher et al., 2015) approach combined with k-NN. [src](https://pdfs.semanticscholar.org/af9b/33da37d290c063cd826ab5923d96892a9767.pdf)

2018-03-18 A propos

Learning Deep Structured Semantic Models for Web Search using Clickthrough Data - Microsoft Research (2013)

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2017-12-30 A propos

DSSM ("Deep Semantic Similarity Model") - Microsoft Research

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DSSM (Deep Semantic Similarity Model)

2017-12-30 A propos

[1712.01208] The Case for Learned Index Structures

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2017-12-11 A propos

(fastText) Euclidean distance instead of cosine-similarity?

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2017-12-07 A propos

Semantic Hashing [9 mins] - Université de Toronto | Coursera

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2017-11-07 A propos

Semantic hashing (2008) - Ruslan Salakhutdinov, Geoffrey Hinton

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> We show how to learn a deep graphical model of the word-count vectors obtained from a
large set of documents. The values of the latent variables in the deepest layer are easy to
infer and give a much better representation of each document than Latent Semantic Analysis.
When the deepest layer is forced to use a small number of binary variables (e.g. 32),
the graphical model performs ‘‘semantic hashing”: Documents are mapped to memory
addresses in such a way that semantically similar documents are located at nearby
addresses. Documents similar to a query document can then be found by simply accessing
all the addresses that differ by only a few bits from the address of the query document. This
way of extending the efficiency of hash-coding to approximate matching is much faster
than locality sensitive hashing, which is the fastest current method. By using semantic
hashing to filter the documents given to TF-IDF, we achieve higher accuracy than applying
TF-IDF to the entire document set.

Indexing is implemented in the following manner: a document is mapped to a word-count vector and then this vector is passed through a [#Restricted Boltzmann Machine](/tag/restricted_boltzmann_machine) autoencoder and encoded to 32-bit address.

2017-11-07 A propos

[1004.5370] Self-Taught Hashing for Fast Similarity Search

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2017-11-07 A propos

Finding Similar Items

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**Jaccard similarity**: similarity of sets, based on the relative size of their intersection -> **finding textually similar documents in a large corpus, near duplicates**. [Collaborative Filtering](/tag/collaborative_filtering) as a Similar-Sets Problem (cf. online purchases, movie ratings)

**Shingling** turns the problem of textual similarity of documents into a pb of similarity of sets

k-shingle: substring of length k found within a document. k: 5 for emails. Hashing shingles. Shingles built from words (stop word + 2 following words)

Similarity-Preserving Summaries of Sets: shingles sets are large -> compress large sets into small representations (“signatures”) that preserve similarity: **[Minhashing](/tag/minhash)** - related to Jaccard similarity (good explanation in [wikipedia](https://en.wikipedia.org/wiki/MinHash))

It still may be impossible to find the pairs of docs with greatest similarity efficiently -> **[Locality-Sensitive Hashing](/tag/locality_sensitive_hashing)** for Documents

Distance measures

Theory of Locality-Sensitive Functions

LSH famiies for other distance measures

Applications of Locality-Sensitive Hashing:

- entity resolution
- matching fingerprints
- matching newpapers articles

Methods for High Degrees of Similarity: LSH-based methods most effective when the degree of similarity we
accept is relatively low. When we want to find sets that are almost identical, other methods can be faster.

2017-07-26 A propos

How to spot first stories on Twitter using Storm | Michael Vogiatzis

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2017-07-26 A propos

Effective measures for inter-document similarity

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2017-07-21 A propos

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2017-07-10 A propos

How to reduce dimension for TfIdf / BOW vector? : MachineLearning

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2017-06-26 A propos