The document discusses N-gram language models. It explains that an N-gram model predicts the next likely word based on the previous N-1 words. It provides examples of unigrams, bigrams, and trigrams. The document also describes how N-gram models are used to calculate the probability of a sequence of words by breaking it down using the chain rule of probability and conditional probabilities of word pairs. N-gram probabilities are estimated from a large training corpus.
Simply put, semantic analysis is the process of drawing meaning from text. It allows computers to understand and interpret sentences, paragraphs, or whole documents, by analyzing their grammatical structure, and identifying relationships between individual words in a particular context.
Simply put, semantic analysis is the process of drawing meaning from text. It allows computers to understand and interpret sentences, paragraphs, or whole documents, by analyzing their grammatical structure, and identifying relationships between individual words in a particular context.
This lecture talks about parsing. Briefly gives overview on lexicon, categorization, grammar rules, syntactic tree, word senses and various challenges of natural language processing
word sense disambiguation, wsd, thesaurus-based methods, dictionary-based methods, supervised methods, lesk algorithm, michael lesk, simplified lesk, corpus lesk, graph-based methods, word similarity, word relatedness, path-based similarity, information content, surprisal, resnik method, lin method, elesk, extended lesk, semcor, collocational features, bag-of-words features, the window, lexical semantics, computational semantics, semantic analysis in language technology.
Word embedding, Vector space model, language modelling, Neural language model, Word2Vec, GloVe, Fasttext, ELMo, BERT, distilBER, roBERTa, sBERT, Transformer, Attention
Introduction to Natural Language ProcessingPranav Gupta
the presentation gives a gist about the major tasks and challenges involved in natural language processing. In the second part, it talks about one technique each for Part Of Speech Tagging and Automatic Text Summarization
This lecture talks about parsing. Briefly gives overview on lexicon, categorization, grammar rules, syntactic tree, word senses and various challenges of natural language processing
word sense disambiguation, wsd, thesaurus-based methods, dictionary-based methods, supervised methods, lesk algorithm, michael lesk, simplified lesk, corpus lesk, graph-based methods, word similarity, word relatedness, path-based similarity, information content, surprisal, resnik method, lin method, elesk, extended lesk, semcor, collocational features, bag-of-words features, the window, lexical semantics, computational semantics, semantic analysis in language technology.
Word embedding, Vector space model, language modelling, Neural language model, Word2Vec, GloVe, Fasttext, ELMo, BERT, distilBER, roBERTa, sBERT, Transformer, Attention
Introduction to Natural Language ProcessingPranav Gupta
the presentation gives a gist about the major tasks and challenges involved in natural language processing. In the second part, it talks about one technique each for Part Of Speech Tagging and Automatic Text Summarization
Simulation de phénomènes naturels : Explorer comment la modélisation et la simulation sont utilisées pour simuler des phénomènes naturels tels que les catastrophes naturelles (ouragans, tremblements de terre, inondations), les phénomènes météorologiques, etc., afin de mieux comprendre leur comportement et d'améliorer les mesures de prévention et de préparation.
This lectures provides students with an introduction to natural language processing, with a specific focus on the basics of two applications: vector semantics and text classification.
(Lecture at the QUARTZ PhD Winter School (http://www.quartz-itn.eu/training/winter-school/ in Padua, Italy on February 12, 2018)
A Neural Probabilistic Language Model.pptx
Bengio, Yoshua, et al. "A neural probabilistic language model." Journal of machine learning research 3.Feb (2003): 1137-1155.
A goal of statistical language modeling is to learn the joint probability function of sequences of
words in a language. This is intrinsically difficult because of the curse of dimensionality: a word
sequence on which the model will be tested is likely to be different from all the word sequences seen
during training. Traditional but very successful approaches based on n-grams obtain generalization
by concatenating very short overlapping sequences seen in the training set. We propose to fight the
curse of dimensionality by learning a distributed representation for words which allows each
training sentence to inform the model about an exponential number of semantically neighboring
sentences. The model learns simultaneously (1) a distributed representation for each word along
with (2) the probability function for word sequences, expressed in terms of these representations.
Generalization is obtained because a sequence of words that has never been seen before gets high
probability if it is made of words that are similar (in the sense of having a nearby representation) to
words forming an already seen sentence. Training such large models (with millions of parameters)
within a reasonable time is itself a significant challenge. We report on experiments using neural
networks for the probability function, showing on two text corpora that the proposed approach
significantly improves on state-of-the-art n-gram models, and that the proposed approach allows to
take advantage of longer contexts.
Efficient Lattice Rescoring Using Recurrent Neural Network Language Models
X. Liu, Y. Wang, X. Chen, M. J. F. Gales & P. C. Woodland
ICASSP 2014
I introduced this paper at NAIST Machine Translation Study Group.
A Simple Explanation of the paper XLNet(https://arxiv.org/abs/1906.08237).
It would be helpful to get to grips with the concepts XLNet before you dive into the paper.
2137ad - Characters that live in Merindol and are at the center of main storiesluforfor
Kurgan is a russian expatriate that is secretly in love with Sonia Contado. Henry is a british soldier that took refuge in Merindol Colony in 2137ad. He is the lover of Sonia Contado.
Hadj Ounis's most notable work is his sculpture titled "Metamorphosis." This piece showcases Ounis's mastery of form and texture, as he seamlessly combines metal and wood to create a dynamic and visually striking composition. The juxtaposition of the two materials creates a sense of tension and harmony, inviting viewers to contemplate the relationship between nature and industry.
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This are the interiors of the Merindol Colony in 2137ad after the Climate Change Collapse and the Apocalipse Wars. Merindol is a small Colony in the Italian Alps where there are around 4000 humans. The Colony values mainly around meritocracy and selection by effort.
Explore the multifaceted world of Muntadher Saleh, an Iraqi polymath renowned for his expertise in visual art, writing, design, and pharmacy. This SlideShare delves into his innovative contributions across various disciplines, showcasing his unique ability to blend traditional themes with modern aesthetics. Learn about his impactful artworks, thought-provoking literary pieces, and his vision as a Neo-Pop artist dedicated to raising awareness about Iraq's cultural heritage. Discover why Muntadher Saleh is celebrated as "The Last Polymath" and how his multidisciplinary talents continue to inspire and influence.
2. N-gram
• Model probabilistik N-gram, merupakan model yang digunakan untuk
memprediksi kata berikutnya yang mungkin dari kata N-1 sebelumnya. Model
statistika dari urutan kata ini seringkali disebut juga sebagai model bahasa
(language models / LMs).
• Model estimasi seperti N-gram memberikan probabilitas kemungkinan pada
kata berikutnya yang mungkin dapat digunakan untuk melakukan
kemungkinan penggabungan pada keseluruhan kalimat. Model N-
gram merupakan model yang paling penting dalam pemrosesan suara
ataupun bahasa baik untuk memperkirakan probabilitas kata berikutnya
maupun keseluruhan sequence.
3. • N-Grams ini akan mengambil sejumlah kata yang kita butuhkan
dari sebuah kalimat. Seperti contohnya kalimat “Fahmi adalah
anak yang rajin”, maka bentuk N-Grams dari kalimat tersebut
adalah :
1.Unigram : Fahmi, adalah, anak, yang, rajin
2.Bigram : Fahmi adalah, adalah anak, anak yang, yang rajin
3.Trigram : Fahmi adalah anak, anak yang rajin
4.dst.
4. What is an N-gram?
• An n-gram is a subsequence of n items from a given sequence.
• Unigram: n-gram of size 1
• Bigram: n-gram of size 2
• Trigram: n-gram of size 3
• Item:
• Phonemes
• Syllables
• Letters
• Words
• Anything else depending on the application.
5. Example
the dog smelled like a skunk
• Bigram:
• "# the”, “the dog”, “dog smelled”, “ smelled like”, “like a”, “a skunk”, “skunk#”
• Trigram:
• "# the dog", "the dog smelled", "dog smelled like", "smelled like a", "like a
skunk" and "a skunk #".
6. How to predict the next word?
• Assume a language has T word types in its lexicon, how likely is word
x to follow word y?
• Solutions:
• Estimate likelihood of x occurring in new text, based on its general frequency
of occurrence estimated from a corpus
• popcorn is more likely to occur than unicorn
• Condition the likelihood of x occurring in the context of previous words
(bigrams, trigrams,…)
• mythical unicorn is more likely than mythical popcorn
7. Statistical View
• The task of predicting the next word can be stated as:
• attempting to estimate the probability function P:
• In other words:
• we use a classification of the previous history words, to predict the next word.
• On the basis of having looked at a lot of text, we know which words tend to
follow other words.
8. N-Gram Models
• Models Sequences using the Statistical Properties of N-Grams
• Idea: Shannon
• given a sequence of letters, what is the likelihood of the next letter?
• From training data, derive a probability distribution for the next letter given a
history of size n.
9. • Markov assumption: the probability of the next word depends only
on the previous k words.
• Common N-grams:
10. Using N-Grams
• For N-gram models
• P(w1,w2, ...,wn)
• By the Chain Rule we can decompose a joint probability, e.g. P(w1,w2,w3) as
follows:
P(w1,w2, ...,wn) = P(w1|w2,w3,...,wn) P(w2|w3, ...,wn) … P(wn-1|wn) P(wn)
n
k
wk
wk
P
wn
P
1
1
1
)
|
(
)
1
(
11. Example
• Compute the product of component conditional probabilities?
• P(the mythical unicorn) = P(the) * P(mythical | the) * P(unicorn|the mythical)
• How to calculate these probability?
12. Training and Testing
• N-Gram probabilities come from a training corpus
• overly narrow corpus: probabilities don't generalize
• overly general corpus: probabilities don't reflect task or domain
• A separate test corpus is used to evaluate the model
13. A Simple Bigram Example
• Estimate the likelihood of the sentence:
I want to eat Chinese food.
• P(I want to eat Chinese food) = P(I | <start>) P(want | I) P(to | want) P(eat |
to) P(Chinese | eat) P(food | Chinese) P(<end>|food)
• What do we need to calculate these likelihoods?
• Bigram probabilities for each word pair sequence in the sentence
• Calculated from a large corpus
14. Early Bigram Probabilities from BERP
The Berkeley Restaurant Project (BeRP) is a testbed for a speech recognition system is being developed
by the International Computer Science Institute in Berkeley, CA
15.
16. • P(I want to eat British food) =
P(I | <start>) P(want | I) P(to | want) P(eat | to)
P(British | eat) P(food | British) =
.25*.32*.65*.26*.001*.60 = .000080
• N-gram models can be trained by counting and normalization
The Berkeley Restaurant Project (BeRP) is a testbed for a speech recognition system s being developed by the International Computer Science Institute in Berkeley, CA
http://www.icsi.berkeley.edu/real/berp.html