Transformer ~ Attention is All You Need

Christian Lin
4 min readOct 7, 2023

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In the groundbreaking paper “Attention is All You Need,” researchers from Google introduced the Transformer architecture, a novel approach to handling sequential data in machine learning. Departing from traditional recurrent models like LSTMs and GRUs, the Transformer solely relies on attention mechanisms, effectively allowing it to weigh the significance of different parts of an input sequence without the constraints of their order. This innovative design has paved the way for unparalleled performance in tasks like translation, outperforming the then state-of-the-art models. Furthermore, the Transformer’s architecture has since become foundational, spawning successors such as BERT, GPT, and more that dominate today’s natural language processing landscape. The paper is a testament to the transformative power of attention mechanisms in deep learning.

Preliminary

The Landscape of Sequence-to-Sequence Learning:

Before the arrival of the Transformer model, sequence-to-sequence learning was largely dominated by models like RNNs, LSTMs, and GRUs. These recurrent architectures processed input sequences step by step, maintaining an internal state from one step to the next. While effective, they had limitations in handling long-term dependencies and were computationally intensive.

A sequence-to-sequence model using an LSTM

The Rise of Attention Mechanisms:

The attention mechanism emerged as a solution to enhance the capabilities of recurrent models. By allowing a model to focus on different parts of the input for different tasks, attention offered a way to capture context more effectively. Early integration of attention into RNNs and LSTMs showcased promising improvements, particularly in tasks like machine translation.

The Limitations of Existing Paradigms:

Despite the advancements brought by attention, challenges persisted. Recurrent models, even with attention, were limited by their inherent sequential processing nature. The sequentiality posed both computational challenges, as parallelization was constrained, and representational challenges, as capturing very long-term dependencies remained tricky.

A Glimpse into the Paper’s Contribution:

“Attention is All You Need” is not just a title; it’s a statement of the paper’s primary thesis. Instead of combining attention with recurrent structures, the researchers proposed an architecture where attention stands alone at the center stage. This paper elucidates this novel design, illustrating how it not only overcomes the limitations of its predecessors but also sets new benchmarks in sequence modeling tasks.

Significance in the AI Landscape:

The Transformer model, introduced in this paper, has had reverberating impacts on the world of AI. As readers will discover, its design principles have become foundational, giving rise to several state-of-the-art models in Natural Language Processing and beyond.

Methodology

Overview:

The Transformer model, unveiled in this paper, offers a fresh perspective on handling sequence transduction tasks. Instead of banking on the recurring structures found in previous models, the Transformer harnesses the unbridled power of attention mechanisms. This architectural nuance facilitates increased parallel processing and exhibits robust efficiency when grappling with dependencies over long sequences.

An overview of Transformer Architecture

Self-Attention Mechanism:

Central to the Transformer’s prowess is the self-attention mechanism. In a marked departure from traditional methods, this mechanism facilitates interactions between any given word and every other word in a sequence. The result is a richer, more context-aware representation that adeptly captures the sequence’s semantic nuances.

An infographic illustrating the self-attention process

Multi-Head Attention:

The Transformer’s design philosophy champions the diversity of attention. It doesn’t remain confined to one attention perspective; instead, it employs multiple heads that attend to distinct portions of the input in tandem. This facilitates the capture of varied relationships and nuances within the data.

A depiction of multiple attention heads module

Positional Encoding:

In the Transformer’s architecture, there’s no inherent sense of position in a sequence, making positional encodings a necessity. These encodings, when combined with the input embeddings at the foundational layers of the encoder and decoder, equip the model with indispensable positional information.

To give the model a sense of the order of the words, we add positional encoding vectors — the values of which follow a specific pattern.

In this section we provide the big picture of Transformer model. If you want to know more detail about Transformer, you can follow the links shown as follow to further understand the related foundation and knowledge.

Introduction to Transformer from Carnegie Mellon University

In this article, I briefly share my viewpoints on the paper. I hope you can learn more about it after reading it. I also offer the video link about the paper, hope you guys like it!!!!

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Christian Lin

A master CS student used to work at ShangShing as an iOS full-end developer. Now, I dive into AI field, especially Multi-agent RL and Bio-inspired intelligence.