What is a Neural Network?

7/1/2026beginner

Source: AI Learning Hub

この記事の要約

ニューラルネットワークは、生物の神経系からヒントを得た計算システムで、相互につながった多数のニューロン(処理単位)によって情報を処理し、予測を行います。現代のAI技術の基礎となっており、訓練によって重みを調整することで、複雑なパターンを学習できるようになります。

話のネタ・雑談に

ニューラルネットワークについて話す際のポイント:「実は人間の脳の仕組みをコンピュータで再現したものなんです。データを与えて学習させると、自動的に判断能力が高まっていく、まさにAIの心臓部です。」

英語本文

A neural network is a computational system inspired by biological nervous systems found in animals. It consists of interconnected units called neurons that work together to process information and make predictions. Neural networks form the foundation of modern artificial intelligence and machine learning.

The basic building block of a neural network is the neuron, which receives input signals, processes them, and sends output to other neurons. Each connection between neurons has a weight that determines how strongly one neuron influences another. During training, these weights are adjusted using an algorithm called backpropagation, which allows the network to learn from data and improve its accuracy over time.

Neural networks are organized into layers: an input layer that receives data, one or more hidden layers that perform computations, and an output layer that produces the final result. The depth and complexity of these layers determine the network's ability to learn complex patterns. activation functions are used in each neuron to introduce non-linearity, allowing the network to learn more sophisticated relationships in the data. This is why deep neural networks with many layers can solve some of the most challenging problems in artificial intelligence.

Vocabulary

neuron

Meaning: ニューロン、神経細胞(AIでは処理の最小単位)

Example: Each neuron receives input and passes a signal forward.

network

Meaning: ネットワーク、相互につながったシステム

Example: A neural network consists of many interconnected neurons.

training

Meaning: 学習(モデルにデータを与えて調整すること)

Example: The model improves through training on large datasets.

weight

Meaning: 重み、パラメータの強度

Example: Each connection has a weight that determines its importance.

activation

Meaning: 活性化関数、ニューロンを活性化するための関数

Example: The activation function decides if a neuron fires.

gradient

Meaning: 勾配、変化の傾き

Example: Gradient descent helps optimize the model's parameters.

layer

Meaning: 層、ニューロンのグループ

Example: A neural network can have multiple hidden layers.

algorithm

Meaning: アルゴリズム、計算手順

Example: Backpropagation is the main training algorithm.

Quiz

1. What does a neuron do in a neural network?

2. Which of the following is a key component of neural networks?

3. What improves a neural network's performance?

4. What is the purpose of weights in neural networks?

← Back to articles