Artificial Intelligence Unfolded - Article 1: A Comprehensive Guide to ML, Neural Networks, and Deep Learning
Hrishi Kulkarni
Chief Technology Officer (CTO), Executive Director, Board Member, Innovation and Change Catalyst, Strategic Technologist, Product & Data Engineering, Cloud Computing, AI/ML, GenAI, MLOps, Programme Management
In the ever-evolving landscape of technology, terms such as Artificial Intelligence (AI), Machine Learning (ML), Neural Networks (NN), Deep Learning (DL), and Generative AI are far more than mere buzzwords; they epitomise the cutting edge of innovative solutions across a multitude of sectors.
Currently, I'm attending an extensive course at the University of Oxford, which covers a broad range of topics. These include core Machine Learning and Deep Learning algorithms, the mathematics underpinning them, and power of Python. It starts getting more interesting though. The coverage extends to advanced topics such as LLMs, Generative AI, OpenAI, Prompt Engineering, Retrieval Augmented Generation (RAG), GraphRAG, Cloud platforms such as Azure OpenAI, AWS as well as exploring MLOps, Co-pilots, LlamaIndex, and notably, Autonomous AI Agents.
Course Director, Ajit Jaokar , a Visiting Fellow of the Department of Engineering Science at 英国牛津大学 and an influential industry figure himself, has lined up impressive leaders, Christoffer Noring, Jerry Liu, Alfredo Deza, Anthony Alcaraz, David Stevens, Wenqi Glantz, Dr Erika Tajra, Dr. Kakasaheb Nandiwale, Andy McMahon , Anjali Jain , Amita Kapoor to name a few, for discussion sessions on AI. The knowledge gained through these discussions with the group of notable and influential leaders in the field of artificial intelligence involves deep diving to understand the power of what we can achieve if AI is used ethically and carefully,?and it just blows the mind. Having said that though, it is also very easy to feel inundated with the plethora of jargons, technologies, models, tools, use cases, and the constant stream of evolving news encountered daily as everyone wants to onboard the journey of adopting AI.
So I thought, why not start consolidating the knowledge in a methodical order and put pen to paper to help me and possibly others who are embarking on the journey towards AI, implementing it carefully to make a difference in the business world. With this article, the first in a series to come, my goal is to lay down my thoughts and foundations of AI. This piece dives into the core concepts and applications of AI and ML, and distinguishes between these technologies, offering a comprehensive overview and insights into their key algorithms.
I'll post on other interesting topics in coming weeks, mainly those which have interested me the most and will try and keep it simple!
Artificial Intelligence: The Foundation of Future Technologies
AI represents the capability of software—or more broadly, systems—to carry out tasks that typically necessitate human intelligence. This encompasses a wide array of functionalities, from understanding natural language to recognising patterns in data.
AI applications are often driven by machine learning and deep learning algorithms, which allow these systems to learn from data and improve over time. These technologies are crucial in addressing stochastic problems, where outcomes are influenced by randomness, unlike deterministic problems that have predictable outcomes based on input parameters, conditions, and rules.
The Spectrum of AI: From Narrow AI to AGI
The realm of AI spans from Narrow AI, systems designed to perform specific tasks within a limited domain—like adjusting a thermostat based on environmental data or algorithmic trading in financial markets—to Artificial General Intelligence (AGI). AGI envisions highly autonomous systems capable of outperforming humans across most tasks of economic value, embodying or even exceeding human-level intelligence across a broad spectrum of intellectual activities. This includes:
Machine Learning: The Engine of AI
Machine Learning, a critical subset of AI, empowers systems with the capability to autonomously learn from data and enhance their performance over time. This involves uncovering hidden patterns within data without being explicitly programmed to make specific predictions or decisions.
Supervised Learning
At the heart of Machine Learning lies Supervised Learning, a methodology where the model is trained on a labeled dataset, which means that each training example is paired with an output label. This approach facilitates models in predicting outcomes for unforeseen data, making it foundational for numerous applications such as spam detection, sentiment analysis, risk assessment, and price prediction.
Key Concepts in Supervised Learning
Classification
Classification, a pivotal type of supervised learning, aims to categorise data points into predefined classes. This method is foundational to applications such as email spam detection, customer segmentation, and sentiment analysis of user reviews.
Classification Algorithms
The objective of the algorithm is to find the finest line or decision boundary that can separate n-dimensional space into classes such that one can put the new data points in the right class in the future. This decision boundary is called a hyperplane. In most of the cases, SVMs have a cut above precision than Decision Trees, KNNs, Naive Bayes Classifiers, logistic regressions, etc. In addition to this SVMs have been well known to outmatch neural networks on a few occasions. SVMs are highly recommended due to their easier implementation, and higher accuracy with less computation.
The evolution from traditional algorithms like Logistic Regression and Decision Trees to more complex models such as Support Vector Machines and Neural Networks illustrates the rapid advancement and diversification of machine learning techniques. Each algorithm has its unique strengths and is suited to specific types of problems, highlighting the importance of understanding the underlying principles to effectively apply them to real-world challenges.
As we delve deeper into the realms of AI and ML, it becomes apparent that the field is not just about selecting the right algorithm but also about understanding data, crafting features, and fine-tuning parameters to coax the best performance from models. The journey through Supervised Learning and Classification offers a glimpse into the meticulous and nuanced process of developing intelligent systems capable of making sense of vast and complex datasets.
In the table below I list various Classification algorithms and their use cases.
Algorithm
Logistic Regression
Use Cases
- Binary classification
- Probabilistic outcomes
When to Use
- When the outcome is binary or dichotomous (e.g., spam or not spam)
- Useful for understanding the impact of independent variables on the outcome due to its interpretability
Algorithm
Decision Trees
Use Cases
- Classification and regression
- Feature importance
When to Use
- When data has a hierarchical structure
- Easy to interpret and explain to non-technical stakeholders
- Handles both numerical and categorical data
Algorithm
Random Forest
Use Cases
- Multiclass classification
- Feature importance
When to Use
- When dealing with overfitting in decision trees
- For improving accuracy through ensemble learning
- Handles large datasets with higher dimensionality well
Algorithm
Support Vector Machines (SVM)
Use Cases
- Binary classification
- Multiclass classification
When to Use
- When there is a clear margin of separation in high-dimensional space
- Effective in cases where the number of dimensions exceeds the number of samples
Algorithm
Naive Bayes
Use Cases
- Text classification
- Spam filtering
When to Use
- When assumptions of feature independence hold
- Efficient with large datasets
- Good baseline for text-related tasks
Algorithm
K-Nearest Neighbors (K-NN)
Use Cases
- Classification
- Regression
- Recommender systems
When to Use
- When data is labeled and the dataset is not too large (to avoid performance issues)
- Useful in applications like recommendation systems where similarity to neighbours is a strong indicator
Regression
Moving beyond classification, Regression represents another cornerstone of Supervised Learning. Unlike classification, which deals with discrete outcomes, regression focuses on predicting continuous variables. It's instrumental in establishing a relationship between a dependent (target) variable and one or more independent (predictor) variables. Through regression models, we can fit a line, curve, or surface that best represents the data, providing a quantitative assessment of relationships among variables.
Key Concepts in Regression Analysis
Regression models excel in forecasting and predicting outcomes, making them indispensable in fields such as economics, finance, and the biological sciences. They enable us to understand and quantify the relationship between variables, paving the way for informed decision-making and predictive analytics.
Regression Algorithms
Other notable regression algorithms include:
The exploration of regression, alongside classification, underscores the versatility and depth of Supervised Learning. By understanding both discrete and continuous prediction models, practitioners can apply these techniques across a broad spectrum of real-world problems, from predicting stock prices to estimating medical outcomes.
Unsupervised Learning
Diverging from the supervised learning models discussed previously, Unsupervised Learning involves analysing and clustering unlabeled datasets. This approach allows us to discover hidden patterns or data groupings without the need for prior training on labeled data. Clustering, a key unsupervised learning technique, exemplifies this by grouping data points into clusters based on similarity measures.
Clustering
Clustering algorithms aim to segregate sets of objects into groups, such that objects within the same cluster exhibit higher similarity to each other than those in different clusters. This technique is invaluable for exploratory data analysis, revealing natural groupings, anomaly detection, and customer segmentation among others. It provides insights into data structure without predefined labels, driven by the intrinsic characteristics of the data itself.
Types of Clustering
Clustering Algorithms
The exploration of clustering within Unsupervised Learning underscores the methodology's ability to provide deep insights into the structure of datasets without relying on pre-labeled outcomes. This aspect of machine learning opens up possibilities for discovering new patterns and relationships in data, showcasing the versatility and depth of machine learning techniques.
Evaluation of Clustering
The evaluation of clustering algorithms presents unique challenges, distinct from those encountered in supervised learning. Without ground truth labels for comparison, traditional metrics like accuracy or precision are not applicable. Nevertheless, various metrics have been developed to assess the quality of clustering, providing insights into how well an algorithm has performed in grouping similar items together.
Silhouette Score
One of the most insightful metrics for evaluating clustering performance is the Silhouette Score. This measure calculates how similar an object is to its own cluster compared to other clusters. The score ranges from -1 to 1, where:
The Silhouette Score provides a concise, yet powerful indication of the effectiveness of the clustering. High average scores across all data points suggest that the clustering configuration is appropriate and distinct, while low scores may indicate overlapping clusters or inappropriate cluster definitions.
The evaluation of clustering, through metrics such as the Silhouette Score, is crucial for validating the results of unsupervised learning algorithms. It guides data scientists in refining their models and selecting the most appropriate clustering techniques for their specific data and objectives.
In the table below I list various Clustering algorithms and their use cases.
Algorithm
K-means Clustering
Use Cases
- Market segmentation
- Document clustering
- Image segmentation
When to Use
- For large datasets due to its efficiency
- When instances can be clearly separated into non-overlapping clusters
Algorithm
Hierarchical Clustering
领英推荐
Use Cases
- Taxonomy generation
- Organisational chart creation
When to Use
- When the number of clusters is not known in advance
- For smaller datasets due to higher computational cost
- When a hierarchy of clusters is more informative than flat clusters
Algorithm
DBSCAN (Density-Based Spatial Clustering of Applications with Noise)
Use Cases
- Anomaly detection
- Spatial data clustering
- Identifying clusters of arbitrary shapes
When to Use
- When there is noise in the data and outliers are present
- For datasets where cluster density varies
- When the number of clusters is unknown and clusters have arbitrary shapes
Algorithm
Gaussian Mixture Models (GMM)
Use Cases
- Image segmentation
- Speech recognition
- Customer profiling
When to Use
- When clusters are assumed to have different sizes and covariance structures
- For datasets where clusters can overlap
- When a probabilistic cluster assignment is preferred
Neural Networks (NN)
Neural Networks stand at the core of deep learning, drawing inspiration from the human brain to mimic how biological neurons communicate. These networks comprise input and output layers, along with one or more hidden layers, where the actual processing occurs. The interconnected nodes, or neurons, within these layers apply activation functions to process inputs and generate outputs, enabling the network to learn from data patterns.
Types of Neural Networks
Components of Neural Networks
The Learning Process in Neural Networks
The learning process involves several key steps:
The weights for each input to an artificial neuron in a neural network are determined through a learning process. Initially, weights are usually set to small random values. Then, as the network is trained on a dataset, these weights are incrementally adjusted based on the error of the network's output compared to the expected result. The goal of this training process is to minimise the error across all outputs, thereby allowing the network to learn the underlying patterns in the data. The process of adjusting the weights is achieved through several key steps:
1. Initialisation
2. Forward Propagation
3. Loss Calculation
4. Backpropagation
5. Weight Update
6. Iterative Optimisation
Through this iterative process of adjusting weights based on the back propagated error gradients, the network learns to map inputs to the correct outputs, effectively "deciding" the importance (weight) of each input in making predictions.
Through the intricacies of neural networks, from their structure inspired by the human brain to the sophisticated learning mechanisms they employ, we delve deeper into the essence of what makes deep learning so powerful. Neural Networks, with their diverse architectures and components, underscore the capacity of machines to not just process data, but to learn and interpret the world in ways that mimic human cognition.
Deep Learning
Deep Learning, a subfield of machine learning, leverages neural networks with multiple layers—hence "deep"—to learn from vast amounts of unstructured or unlabeled data. This approach is inspired by the structure and function of the human brain, specifically the interconnectedness and layered nature of neurons.
Deep learning models, through their depth, are adept at learning hierarchies of information, enabling them to tackle complex tasks that are beyond the reach of more traditional algorithms.
Deep Learning Models
Multi-Layer Perceptrons (MLPs)
Multi-Layer Perceptrons (MLPs) are a class of feedforward artificial neural networks, which consist of at least three layers of nodes: an input layer, one or more hidden layers, and an output layer. Each node, or neuron, in one layer connects with a certain weight to every node in the following layer, making the network fully connected. MLPs are a foundational model in deep learning, used for solving both regression and classification problems by learning complex patterns in data.
Training MLPs
Training MLP involves adjusting its weights and biases to minimise the loss function. This is typically done using gradient descent or variations thereof (e.g., stochastic gradient descent). The training process involves repeatedly:
Convolutional Neural Networks (CNNs)
CNN is a type of forwarded neural network that excel in processing visual data, drawing inspiration from the biological visual cortex. They are particularly effective in image and video recognition, object detection, and other tasks requiring the analysis of visual content.
Key Components of CNNs
How CNNs Work
Training CNNs
CNNs are trained using a large set of labeled images. The training process involves:
Recurrent Neural Networks (RNNs)
Designed for sequential data, RNNs can remember information from earlier inputs using loops within the network, making them ideal for time series analysis, natural language processing, and other domains where context matters
Long Short-Term Memory (LSTM)
LSTMs are an advanced form of RNNs capable of learning long-term dependencies, addressing the challenge of remembering information over extended sequences. This makes them particularly powerful for tasks in natural language processing and complex time series analysis.
How Deep Learning Works
Deep Learning models undergo a training process where they learn to identify patterns and features in data.
Feature Learning: Through layers of processing, the model learns to identify important features, starting from simple ones in early layers to more complex features in deeper layers.
Classification and Prediction: Utilising the features learned, the model makes predictions or classifies data, often through fully connected layers at the end of the network.
These models are trained on large datasets, using backpropagation and optimisation algorithms to adjust weights and minimise loss, allowing them to improve over time and handle tasks of increasing complexity.
And finally, in the below table I have listed the Deep Learning models and their use cases.
Algorithm
Multi-Layer Perceptron (MLP)
Use Cases
- Classification tasks
- Regression tasks
- For datasets with a high number of features
When to Use
- When the relationship between inputs and outputs is complex but does not involve temporal or sequential data
Algorithm
Convolutional Neural Networks (CNN)
Use Cases
- Image recognition
- Video analysis
- Image classification
- For tasks involving image or video data where spatial hierarchies in the data are relevant
When to Use
- When performance and accuracy in visual tasks are critical
Algorithm
Recurrent Neural Networks (RNN)
Use Cases
- Language modeling
- Speech recognition
- For sequential data such as text or time series
When to Use
- When context or the sequence of data points is important for prediction
Algorithm
Long Short-Term Memory (LSTM)
Use Cases
- Sequence prediction
- Time series forecasting
- Natural language processing
- For tasks that require learning long-term dependencies in sequential data
When to Use
- When RNN performance is limited by vanishing or exploding gradient problems
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8 个月Hrishi Kulkarni In the inaugural article of this enlightening series, the author embarks on a journey into the intricate world of artificial intelligence, shedding light on the foundational concepts of Machine Learning, Neural Networks, and Deep Learning. By unraveling the complexities of these technologies, the article not only equips readers with a deeper understanding of AI but also unveils the transformative potential they hold for shaping future business systems. As we stand on the cusp of a new era defined by intelligent automation, mastering these fundamental principles becomes imperative for navigating the evolving landscape of technology and innovation. Dive into this comprehensive guide to embark on a quest towards unlocking the limitless possibilities of Artificial Intelligence.
Exciting journey ahead! Can't wait to read more about it. ??
Author | Co-founder@Erdos Research | AI & machine learning Senior Tutor at University of Oxford| Data architect at Metro Bank
8 个月Very informative Hrishi Kulkarni
Data Analyst (Insight Navigator), Freelance Recruiter (Bringing together skilled individuals with exceptional companies.)
8 个月Excited to delve into this AI journey with you! ?? Hrishi Kulkarni