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πŸ€– AI & Machine Learning Portfolio

Professional implementation of 15+ AI/ML projects spanning classical algorithms, supervised learning, neural networks, and advanced deep learning architectures (CNN, RNN, VAE, GAN).

Portfolio by: Matheus Ferreira TeixeiraEducation: Advanced Diploma in Software Engineering - AI, Centennial College (2022-2024)GPA: 4.45/4.5 (High Honors) | Ex-NASA Intern πŸš€


🎯 Portfolio Highlights

Key Achievements:

  • πŸ€– 15+ Production-Quality Implementations - From search algorithms to generative AI
  • πŸ“Š 91.8% RΒ² Regression - Feature engineering for e-commerce prediction
  • 🎨 Generative Models - VAE latent space + DCGAN image synthesis
  • 🧠 88% Image Classification - CNN architecture for Fashion MNIST
  • πŸ’¬ 92% NLP Accuracy - YouTube spam detection with Naive Bayes
  • πŸ”¬ 11 Custom Neural Architectures - CNNs, RNNs, Autoencoders, VAE, GAN

Technical Depth:

  • 5,000+ lines of Python code
  • Complete ML pipelines (preprocessing β†’ training β†’ evaluation)
  • Advanced techniques: Transfer learning, adversarial training, Ξ²-weighting
  • Production-ready implementations with comprehensive documentation

πŸ“š Project Collections

πŸŽ“ 00_AI_Fundamentals - Classical AI & Machine Learning

6 comprehensive projects covering core AI algorithms and supervised learning fundamentals.

Projects:

  1. Simple Reflex Agent - Environment simulation with percept-action mapping
  2. Graph Search Algorithms - BFS, UCS, Greedy, A* with visual tree exploration
  3. Linear Regression - Feature engineering (RΒ² 0.195 β†’ 0.918 improvement)
  4. Logistic Regression - Binary classification (83% accuracy, threshold tuning)
  5. Neural Networks - Architecture experiments, overfitting analysis
  6. NLP Spam Detection - Text classification with TF-IDF + Naive Bayes (92% accuracy)

Skills: Search algorithms, regression, classification, neural networks, NLP, feature engineering, model evaluation

View AI Fundamentals Portfolio β†’


🧠 01_DeepLearning - Advanced Neural Architectures

4 cutting-edge projects implementing modern deep learning architectures for computer vision and generative AI.

Projects:

  1. CNN vs RNN Image Classification - Architecture comparison (88% vs 86.2% accuracy)
  2. Transfer Learning with Denoising Autoencoder - Semi-supervised learning (72.2% with 1,800 samples)
  3. Variational Autoencoder (VAE) - Probabilistic latent space (2D visualization, Ξ²-weighting)
  4. Deep Convolutional GAN (DCGAN) - Image synthesis (adversarial training, 35s GPU training)

Skills: CNNs, RNNs/LSTM, autoencoders, VAE, GANs, transfer learning, adversarial training, custom layers, convergence analysis

View Deep Learning Portfolio β†’


πŸ› οΈ Technical Stack

Core Technologies

Programming & Computation:

  • Python 3.10/3.11 - Primary language
  • NumPy 1.23.5 - Numerical computing
  • Pandas 1.5.3 - Data manipulation and analysis

Machine Learning:

  • Scikit-learn - Classical ML algorithms and preprocessing
  • Neurolab - Neural network experiments

Deep Learning:

  • TensorFlow 2.10.0 / Keras - Deep neural networks
  • TensorFlow Probability 0.18.0 - Probabilistic modeling (VAE)

Visualization & Analysis:

  • Matplotlib 3.7.2 - Plotting and visualization
  • Seaborn - Statistical visualization
  • Graphviz/Pydot - Algorithm tree visualization

Natural Language Processing:

  • NLTK - Text preprocessing
  • CountVectorizer / TfidfTransformer - Feature extraction

Development Environment:

  • Conda - Environment management
  • Git/GitHub - Version control
  • VS Code / Spyder - IDEs
  • Google Colab - GPU training (T4 GPUs)

Advanced Techniques Implemented

Algorithms:

  • Graph search (BFS, UCS, Greedy, A*)
  • Linear/Logistic regression with gradient descent
  • Feedforward neural networks with backpropagation
  • Convolutional Neural Networks (CNNs)
  • Recurrent Neural Networks (RNNs/LSTM)
  • Autoencoders (standard + denoising)
  • Variational Autoencoders (VAE)
  • Generative Adversarial Networks (GAN)

Training Strategies:

  • Transfer learning with frozen encoder layers
  • Unsupervised pre-training for semi-supervised learning
  • Adversarial training with Nash equilibrium monitoring
  • Ξ²-weighting for VAE loss balancing
  • Custom early stopping (GAN-specific heuristics)
  • Reparameterization trick for gradient flow

Data Engineering:

  • Feature engineering and selection
  • Categorical encoding (one-hot)
  • Normalization (min-max, z-score)
  • Text preprocessing (tokenization, TF-IDF)
  • Train-validation-test splits
  • Cross-validation

🌍 Real-World Applications

AI & Autonomous Systems

  • Robotics navigation - Search algorithms for pathfinding
  • Game AI - NPC behavior, decision-making agents
  • Resource optimization - Scheduling and planning

Computer Vision

  • Image classification - Fashion item categorization (88% accuracy)
  • Generative models - Synthetic image generation (VAE, GAN)
  • Transfer learning - Pre-trained encoders for feature extraction
  • Anomaly detection - Reconstruction error analysis (VAE)

Business Intelligence

  • Customer analytics - Spending prediction (RΒ² 0.918)
  • Survival prediction - Risk assessment (83% accuracy)
  • Fraud detection - Anomaly detection techniques
  • Marketing optimization - Customer lifetime value modeling

Natural Language Processing

  • Spam detection - YouTube comment classification (92% accuracy)
  • Text classification - Sentiment analysis, content moderation
  • Feature extraction - TF-IDF, Bag of Words

πŸ“Š Key Technical Achievements

1. Feature Engineering Impact

Linear Regression Project: Adding single feature ('Record' - purchase history) improved model from RΒ² 0.195 β†’ 0.918 (+72% improvement)

Lesson: Domain knowledge and feature engineering can matter more than algorithm choice.


2. Architectural Validation Through Theory

DCGAN Project: Identified Conv2DTranspose in discriminator violated DCGAN standard (Radford et al., 2015)

  • Impact: Removed 211K parameters (50% reduction: 424K β†’ 213K)
  • Result: Restored adversarial balance (discriminator accuracy: 91% β†’ 57%)

Lesson: Always validate architectures against established standards before implementation.


3. Transfer Learning Effectiveness

Autoencoder Project: Pre-trained encoder on 57,000 unlabeled images improved classifier trained on only 1,800 labeled samples

  • Baseline: 70.33% validation accuracy
  • Pre-trained: 72.17% validation accuracy
  • Hardest class improvement: 8.8% β†’ 32.4% (4x improvement)

Lesson: Unsupervised pre-training highly effective in low-data scenarios.


4. Ξ²-Weighting Derivation for VAE

VAE Project: Principled Ξ² calculation via loss magnitude analysis (not trial-and-error)

  • Problem: KL loss 100-1000x larger than reconstruction loss
  • Solution: Ξ² = 0.001 targeting 15% KL contribution
  • Result: Balanced training with sharp reconstructions + regularized latent space

Lesson: Analyze loss magnitudes to set hyperparameters systematically.


5. Data Quality > Model Complexity

Neural Network Project: Simple architecture + 100 samples (test error: 0.0020) outperformed complex 2-layer + same data (test error: 0.0257)

Lesson: Focus on data quality before adding architectural complexity.


πŸ“ Repository Structure

AI_Python_Projects/
β”œβ”€β”€ README.md                           # This file
β”‚
β”œβ”€β”€ 00_AI_Fundamentals/                 # Classical AI & ML (6 projects)
β”‚   β”œβ”€β”€ README.md                       # Fundamentals portfolio overview
β”‚   β”œβ”€β”€ 00_Agents/                      # Simple Reflex Agent
β”‚   β”œβ”€β”€ 01_Search/                      # BFS, UCS, Greedy, A*
β”‚   β”œβ”€β”€ 02_LinearRegression/            # E-commerce prediction
β”‚   β”œβ”€β”€ 03_LogisticRegression/          # Titanic classification
β”‚   β”œβ”€β”€ 04_NeuralNetwork/               # Architecture experiments
β”‚   └── 05_NPL/                         # YouTube spam detection
β”‚
└── 01_DeepLearning/                    # Advanced DL (4 projects)
    β”œβ”€β”€ README.md                       # Deep learning portfolio overview
    β”œβ”€β”€ 00_CNN_RNN_ImageClassification/ # CNN vs RNN comparison
    β”œβ”€β”€ 01_AutoencoderTransferLearning/ # Transfer learning pipeline
    β”œβ”€β”€ 02_VAE_FashionMNIST/            # Variational autoencoder
    └── 03_ConvolutionalGAN/            # DCGAN image synthesis

Each project folder contains:

  • README.md - Comprehensive documentation
  • environment.yml - Conda environment specification
  • requirements.txt - pip dependencies
  • Source code (.py files)
  • Results (visualizations, plots)

πŸš€ Getting Started

Prerequisites

  • Python 3.10+ (3.11 for AI Fundamentals, 3.10 for Deep Learning)
  • Conda (recommended) or pip
  • GPU (optional, but recommended for Deep Learning projects)

Quick Start

1. Clone the repository:

git clone https://github.com/domvito55/AI_Python_Projects.git
cd AI_Python_Projects

2. Navigate to any project:

cd 00_AI_Fundamentals/02_LinearRegression
# or
cd 01_DeepLearning/00_CNN_RNN_ImageClassification

3. Create environment:

# Option A: Conda (recommended)
conda env create -f environment.yml
conda activate [environment-name]

# Option B: pip
python -m venv venv
source venv/bin/activate  # Linux/Mac
# or
venv\Scripts\activate     # Windows
pip install -r requirements.txt

4. Run the project:

python [main_script].py

Hardware Requirements

Project Category CPU GPU Recommended
AI Fundamentals 5-15 min CPU sufficient
CNN/RNN 5-10 min CPU acceptable
Autoencoder 10-15 min CPU acceptable
VAE 30-35 min GPU recommended
GAN Hours/Days 35 seconds GPU required

Free GPU Access: Google Colab provides free T4 GPU (sufficient for all projects)


πŸ’‘ Key Learnings & Insights

Algorithm Selection

From Search Algorithms: A* optimal for pathfinding, Greedy fast but risky, BFS simple for unweighted graphs, UCS for cost optimization.

Takeaway: No universal "best" algorithm - match algorithm to problem characteristics.


Model Evaluation

From Logistic Regression: Threshold tuning creates precision-recall trade-offs

  • 0.5 threshold: 83% accuracy
  • 0.75 threshold: 81% accuracy, 100% recall

Takeaway: Business context determines optimal metrics beyond accuracy.


Overfitting Detection

From Neural Networks: Training error 6.74Γ—10⁻⁢ looked excellent, test error 0.0826 revealed overfitting.

Takeaway: Always validate on separate test data; training error alone is deceiving.


Adversarial Training Dynamics

From GAN: Oscillating losses are healthy in GANs (not training failure)

  • Generator loss: 0.6-0.9
  • Discriminator loss: 1.2-1.6
  • Discriminator accuracy: 55-60% (balanced equilibrium)

Takeaway: GAN convergence requires multi-metric monitoring, not single loss minimization.


Custom Layer Implementation

From VAE: Reparameterization trick (z = ΞΌ + Οƒ βŠ™ Ξ΅) enables gradient flow through stochastic sampling.

Takeaway: Probabilistic modeling in neural networks requires careful gradient flow design.


πŸŽ“ Academic Context

Program: Advanced Diploma in Software Engineering - Artificial IntelligenceInstitution: Centennial College, Toronto, CanadaDuration: 2022-2024 (3-year intensive program)GPA: 4.45/4.5 (High Honors)

Key Courses:

  • COMP 237: Artificial Intelligence (AI Fundamentals projects)
  • COMP 263: Deep Learning (Deep Learning projects)
  • Additional: Software Engineering, Data Structures, Algorithms

Industry Experience:

  • 8-month Co-op: TD Bank (2x terms, 2023-2024)
  • Multiple research projects with industry partners
  • Ex-NASA Intern (2012, Python development for BOBCATT project)

πŸ“« Contact & Links

Matheus Ferreira Teixeira

Live Demos:

Available for:

  • Full-time software engineering positions (AI/ML focus)
  • Freelance AI/ML consulting projects
  • Collaborative research opportunities
  • Technical writing and documentation

πŸ† Professional Highlights

Ex-NASA Intern (2012)

  • Developed Python code for BOBCATT satellite project
  • First professional experience demonstrating technical excellence from day one

Mensa Member

  • Top 2.14% IQ globally
  • Demonstrates analytical and problem-solving capabilities

Academic Excellence

  • GPA 4.45/4.5 (High Honors)
  • Consistent top performer throughout program
  • Multiple research projects and industry collaborations

12+ Years Experience

  • Engineering automation (2013-2017)
  • Entrepreneurship and business management (2017-2023)
  • Software engineering and AI/ML (2022-present)

πŸ“„ License

Educational projects completed at Centennial College (2022-2024). Code available for learning purposes and portfolio demonstration with proper attribution.


πŸ™ Acknowledgments

Centennial College Faculty:

  • Artificial Intelligence instructors
  • Deep Learning instructors
  • Co-op coordinators

Industry Partners:

  • TD Bank (Co-op opportunities)
  • Various research collaboration partners

Last Updated: November 2025

Comprehensive, production-ready implementations with professional documentation. Each project demonstrates end-to-end ML/DL pipeline development with real-world applicability.

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