Research models used by software engineers to design and analyse ML, including:
neural networks
While decision trees mimic human logical reasoning, neural networks draw inspiration from the structure of the human brain. They consist of interconnected "neurons" organized in layers that process information collaboratively.
A neural network typically has:
An input layer that receives the initial data
One or more hidden layers that perform computations
An output layer that produces the final prediction
Each connection between neurons has a weight that strengthens or weakens the signal, and each neuron applies an activation function to determine whether and how strongly to fire.
Internal weightings and threshold values for each node are determined in the initial training cycle for each neural network. The system is exposed to a series of inputs with known responses. Linear regression with backward chaining is used to iteratively determine the set of unique values required for output. Regular exposure to the training cycle results in improved accuracy and pattern matching.
In the diagram, signal strength between nodes with the strongest weightings are thicker representing a higher priority in determining the final output. The execution cycle follows the training cycle and utilises the internal values developed during the training cycle to determine the output.
The best way to understand neural networks is to see one in action! The TensorFlow Playground lets you build and train neural networks right in your browser. You can adjust the network architecture, change parameters, and watch how it learns: Neural Network Playground.
Also, another cool Neural Network Playground.
As you experiment, try:
Changing the number of hidden layers
Adding or removing neurons in each layer
Adjusting the learning rate
Switching between different datasets (especially the spiral one!)
Observing how the decision boundary changes as the network learns
Designing neural networks is both an art and a science. Here's how software engineers approach it:
Problem Analysis: First, they determine what type of problem they're solving - classification, regression, pattern recognition, etc.
Architecture Design: Based on the problem, they design the structure of the network:
How many layers?
How many neurons per layer?
What type of connections between layers?
What activation functions to use?
Data Preparation: Neural networks typically require large amounts of data, which needs to be:
Cleaned to remove errors
Normalized to a common scale
Split into training, validation, and testing sets
Training Process: The network learns by:
Forward propagation: Running data through the network to get predictions
Comparing predictions to actual values to calculate error
Backpropagation: Adjusting weights to reduce error
Repeating this process many times
Hyperparameter Tuning: Engineers optimize settings like learning rate, batch size, and regularization parameters to improve performance.
Validation and Testing: The model is evaluated on unseen data to ensure it generalizes well.
There's not just one type of neural network - there's a whole family of architectures designed for different tasks:
The simplest type, where information flows in one direction
Used for straightforward classification and regression tasks
Specialized for processing grid-like data such as images
Use convolutional filters to detect features regardless of position
Widely used in computer vision for tasks like object detection
Have connections that form loops, creating a "memory" effect
Well-suited for sequential data like text, speech, or time series
Used in language translation, speech recognition, and text generation
A newer architecture that revolutionized natural language processing
Uses attention mechanisms to focus on relevant parts of the input
Powers modern large language models like GPT and BERT
Neural networks have transformed numerous fields:
Facial recognition systems used in security and social media
Medical image analysis for detecting diseases
Autonomous vehicle perception systems
Object detection in satellite imagery
Machine translation services like Google Translate
Voice assistants like Siri and Alexa
Text summarization and sentiment analysis
Chatbots and conversational AI
Speech recognition for transcription
Music generation and remixing
Noise cancellation in hearing aids
AlphaGo and AlphaZero, which mastered Go and chess
Game NPCs with more natural behaviors
Procedural content generation for games
Pattern Recognition: Extraordinary ability to find complex patterns in data
Adaptability: Can be applied to a wide range of problems
Performance: State-of-the-art results on many perceptual tasks
Feature Learning: Automatically extract relevant features from raw data
Black Box Nature: Difficult to interpret how they arrive at decisions
Data Hungry: Typically require large amounts of training data
Computational Intensity: Training can be resource-intensive and expensive
Hyperparameter Sensitivity: Performance depends on careful tuning
Overfitting Risk: Can memorize training data rather than generalizing