Deep Learning for Natural Language Processing: Word Embedding

1. Introduction

Natural Language Processing (NLP) is a field of computer science and artificial intelligence that enables computers to understand and process human natural language. The development of natural language processing has primarily been driven by advances in deep learning technology. This article aims to take a closer look at word embedding, one of the key technologies in natural language processing.

2. Basics of Natural Language Processing

To perform natural language processing, it is essential to first understand the characteristics of natural language. Human languages often contain polysemy and ambiguity, and their meanings can change depending on the context, making them challenging to process. Various techniques and models have been developed to address these issues.

Common tasks in NLP include text classification, sentiment analysis, machine translation, and conversational systems. In this process, representing text data numerically is crucial, and the technique used for this purpose is word embedding.

3. What is Word Embedding?

Word embedding is a method of mapping words into a high-dimensional vector space, where the semantic similarity between words is expressed as the distance between vectors. In other words, similar-meaning words are positioned close to each other. This vector representation allows natural language to be input into machine learning models.

Representative word embedding techniques include Word2Vec, GloVe, and FastText. While these techniques have different algorithms and structures, they fundamentally learn word vectors by utilizing the surrounding context of words.

4. Word2Vec: Basic Concepts and Algorithms

4.1 Structure of Word2Vec

Word2Vec is a word embedding technique developed by Google that uses two models: CBOW (Continuous Bag of Words) and Skip-Gram. CBOW predicts the central word from surrounding words, while Skip-Gram predicts the surrounding words from a given central word.

4.2 CBOW Model

The CBOW model takes the surrounding words of a specific word in a given sentence as input and predicts the central word. In this process, the model averages the embedding vectors of the input words to make predictions about the central word. This allows CBOW to learn the relationships between words using a sufficient amount of data.

4.3 Skip-Gram Model

The Skip-Gram model predicts surrounding words from a given central word. This structure especially helps rare words to have high-quality embeddings. By predicting the surrounding words, it can learn deeper relationships between them.

5. GloVe: Global Statistical Word Embedding

GloVe (Globally Vectors for Word Representation) is a word embedding technique developed at Stanford University that learns word vectors using statistical information from the entire corpus. GloVe utilizes the co-occurrence probabilities of words to capture semantic relationships in vector space.

The key idea behind GloVe is that the inner product of word vectors is related to the co-occurrence probabilities of the two words. This allows GloVe to precisely learn relationships between words using a large corpus.

6. FastText: A Technique Reflecting Character Information Within Words

FastText is a word embedding technique developed by Facebook that decomposes words into a set of n-grams, unlike traditional word-based models. This approach takes into account character information within words, enhancing the embedding quality of low-frequency words.

FastText can encompass various forms of words through morphological analysis, making it advantageous for expressing low-frequency words. It particularly exhibits superior performance in languages with complex structures.

7. Applications of Word Embedding

7.1 Text Classification

Word embedding shows significant effectiveness in text classification tasks. By converting words into vectors, machine learning algorithms can effectively process text data. For example, it is widely used for sentiment analysis of news articles and spam classification.

7.2 Machine Translation

In the field of machine translation, word embedding that accurately represents the semantic relationships between words is essential. By utilizing word embeddings, more accurate translation results can be achieved, ensuring that translated sentences are semantically consistent.

7.3 Conversational AI

Word embedding plays a crucial role in conversational systems as well. For instance, generating appropriate responses to user questions requires understanding context and considering semantic connections between words. Therefore, word embedding is vital for enhancing the quality of conversational AI.

8. Conclusion and Future Prospects

Word embedding is an important technology that quantifies the semantic relationships between words in natural language processing. With the development of various embedding techniques, we have laid the foundation for developing higher-quality natural language processing models.

In the future of NLP, it is expected that more sophisticated word embedding techniques will be developed. In particular, the combination with deep learning technology will contribute to efficiently processing and analyzing large amounts of unstructured data.