AI Concepts for Software Engineers
1. Machine Learning
Machine Learning (ML) is the study of algorithms that improve automatically through experience. Core components include:
- Supervised, unsupervised, and reinforcement learning
- Regression, classification, and clustering algorithms
- Gradient descent and backpropagation
- Cross-validation and performance metrics
Example: Linear Regression
from sklearn.linear_model import LinearRegression
model = LinearRegression()
model.fit(X_train, y_train)
predictions = model.predict(X_test)
2. Deep Learning
Deep Learning is a subset of ML that uses neural networks with multiple layers (deep architectures) to model complex representations.
- Uses GPUs for training efficiency
- Excels in image, audio, and NLP tasks
- Learns hierarchically from raw data
Example: Simple Deep Neural Network with Keras
from keras.models import Sequential
from keras.layers import Dense
model = Sequential([
Dense(64, activation='relu', input_shape=(input_dim,)),
Dense(64, activation='relu'),
Dense(1)
])
model.compile(optimizer='adam', loss='mse')
model.fit(X_train, y_train, epochs=10)
3. Neural Networks
Artificial Neural Networks (ANNs) consist of layers of neurons that transform input data using weights and activation functions.
- Input, hidden, and output layers
- Activation functions: ReLU, sigmoid, softmax
- Feedforward and backpropagation process
Example: Manual forward pass
import numpy as np
def relu(x):
return np.maximum(0, x)
def forward_pass(x, weights):
return relu(np.dot(x, weights))
4. Natural Language Processing (NLP)
NLP focuses on enabling machines to understand and generate human language.
- Tokenization, stemming, lemmatization
- POS tagging, named entity recognition
- Transformers like BERT, GPT
Example: Tokenizing and stemming
from nltk.tokenize import word_tokenize
from nltk.stem import PorterStemmer
tokens = word_tokenize("ChatGPT is amazing!")
stems = [PorterStemmer().stem(word) for word in tokens]
5. Computer Vision
Computer Vision (CV) enables machines to interpret and process visual data like images and video.
- Object detection, segmentation, classification
- CNNs (Convolutional Neural Networks)
- OpenCV, TensorFlow, PyTorch support
Example: Image classification with OpenCV and CNN
import cv2
image = cv2.imread('cat.jpg')
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
6. Reinforcement Learning
RL involves agents learning optimal behavior through rewards and penalties by interacting with environments.
- Markov Decision Processes
- Q-learning, DQN, PPO
- Exploration vs. exploitation tradeoff
Example: Q-Learning algorithm sketch
Q[state, action] = reward + gamma * max(Q[next_state])
7. Generative Models
Generative models learn data distributions and can create new, similar data.
- GANs (Generative Adversarial Networks)
- VAEs (Variational Autoencoders)
- Applications: image synthesis, text generation
Example: GAN architecture outline
# Generator and Discriminator models are trained in a loop
# Generator tries to fool the Discriminator
8. Large Language Models (LLMs)
LLMs are deep neural networks trained on massive text corpora to generate human-like language.
- Examples: GPT, PaLM, LLaMA
- Used in chatbots, summarization, code generation
- Can be fine-tuned for specific domains
Example: Generate text with HuggingFace Transformers
from transformers import pipeline
generator = pipeline("text-generation", model="gpt2")
print(generator("Once upon a time", max_length=30))
9. Transformers
Transformers use self-attention to weigh importance of input tokens, allowing for parallel processing.
- Encoder-decoder architecture
- Used in LLMs, translation, vision
- Highly scalable and performant
Example: Self-attention mechanism
Attention(Q, K, V) = softmax(QK^T / sqrt(d_k)) * V
10. Feature Engineering
The process of selecting, transforming, and creating variables that help ML models perform better.
- Domain knowledge crucial
- Scaling, encoding, polynomial features
- Automated Feature Engineering tools exist
Example: Feature scaling
from sklearn.preprocessing import StandardScaler
scaler = StandardScaler()
X_scaled = scaler.fit_transform(X)
11. Supervised Learning
Training models using labeled data to learn input-output mappings.
- Regression, classification
- Requires large labeled datasets
- Clear performance metrics
Example: Classification with Decision Tree
from sklearn.tree import DecisionTreeClassifier
clf = DecisionTreeClassifier()
clf.fit(X_train, y_train)
12. Bayesian Learning
Incorporates probability distributions and uncertainty into modeling.
- Bayes’ Theorem
- Probabilistic graphical models
- Useful in low-data scenarios
Example: Naive Bayes classifier
from sklearn.naive_bayes import GaussianNB
model = GaussianNB()
model.fit(X_train, y_train)
13. Prompt Engineering
Designing effective inputs (prompts) to guide generative AI models.
- Few-shot or zero-shot learning
- Prompt templates improve performance
- Useful in LLMs like GPT
Example: Prompt template
prompt = "Translate the following English text to French: '{}'"
14. AI Agents
Autonomous software systems that perceive environments, make decisions, and act.
- Use planning, reasoning, learning
- Embodied agents (robots) or digital agents (bots)
- Popular in games, virtual assistants
Example: Simple rule-based agent
def agent(state):
if state == "hungry":
return "eat"
return "wait"
15. Fine-Tuning Models
Customizing a pre-trained model on domain-specific data to improve accuracy.
- Few epochs on new data
- Requires less data than training from scratch
- Common in NLP, CV tasks
Example: Fine-tuning BERT for classification
from transformers import BertForSequenceClassification
model = BertForSequenceClassification.from_pretrained("bert-base-uncased", num_labels=2)
16. Multimodal Models
Models that process multiple data types simultaneously (e.g., text + image).
- CLIP, Flamingo, GPT-4 (multimodal)
- Better understanding of real-world inputs
Example: Multimodal input sketch
# Inputs: image and caption
# Output: relevant tag or response
17. Embeddings
Dense vector representations of data (text, image, audio) for ML models.
- Text: word2vec, BERT embeddings
- Useful in similarity, clustering
Example: Sentence embedding
from sentence_transformers import SentenceTransformer
model = SentenceTransformer('all-MiniLM-L6-v2')
embedding = model.encode("AI is transforming software engineering.")
18. Vector Search
Search using vector embeddings to find semantically similar items.
- Used in semantic search, recommendations
- Libraries: FAISS, Pinecone
Example: FAISS search
import faiss
index = faiss.IndexFlatL2(embedding_dim)
index.add(vectors)
D, I = index.search(query_vector, k)
19. Model Evaluation
Assess model performance using metrics and validation techniques.
- Accuracy, precision, recall, F1
- Cross-validation, confusion matrix
- AUC-ROC for classifiers
Example: Evaluation metrics
from sklearn.metrics import accuracy_score, classification_report
print(accuracy_score(y_test, y_pred))
print(classification_report(y_test, y_pred))
20. AI Infrastructure
Systems and tools that support development, deployment, and scaling of AI models.
- Model training on distributed hardware
- Deployment: Docker, Kubernetes, CI/CD
- Monitoring and retraining pipelines
Example: Model deployment with Flask
from flask import Flask, request
app = Flask(__name__)
@app.route('/predict', methods=['POST'])
def predict():
data = request.json
prediction = model.predict([data['features']])
return {'prediction': prediction.tolist()}
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