Bayesian Networks and Probabilistic Graphical Models
1. Bayesian Networks (Directed Models)
Joint Probability Factorization:
P(X₁, X₂, ..., Xₙ) = Π P(Xᵢ | parents(Xᵢ))
Variable Types:
Observed: User inputs and sensor measurements (Uₜ, Zₜ)
Latent/Hidden: States and landmarks (Xₜ, L)
Example Factorization:
P(uₜ, l, xₜ, xₜ₊₁, zₜ, zₜ₊₁) = P(uₜ)P(l)P(xₜ|uₜ)P(xₜ₊₁|xₜ)P(zₜ|xₜ,l)P(zₜ₊₁|l,xₜ₊₁)
2. Conditional Independence and D-Separation
Blocking Rules:
Chain (A → B → C): Blocked if
Intranet Architecture, Security and Network Protocols
1. Intranet Concepts and Architecture
An intranet is a private internal network of an organization that uses Internet technologies such as TCP/IP, web browsers, and HTTP to facilitate secure communication, information sharing, and collaboration among employees. It creates a centralized digital environment where users can access internal documents, applications, and databases. The architecture of an intranet typically follows a client-server model consisting of client devices, web servers, application
Read MoreWeb Application Security Testing and Secure SDLC Practices
PART 1 – FOUNDATIONS (Week 9)
- SDLC Phases (exact order): Planning → Requirements → Architecture & Design → Coding → Testing → Release → Maintenance. Definition: SDLC (Software Development Life Cycle): a structured framework for building and maintaining software to ensure quality and efficiency. (How: sequential or iterative like Agile; why: prevents chaos and integrates security early to avoid costly rework.)
- Shift-Left Principle: Security from commit #1 → 60–100× cheaper than
EM Algorithm, K-Means, and Ensemble Methods Explained
1. Expectation-Maximization (EM) for GMMs
The Expectation-Maximization (EM) algorithm is an iterative method used to estimate parameters in statistical models that involve latent (hidden) variables, such as missing data or unobserved groupings. It is especially useful for fitting models like Gaussian Mixture Models (GMMs), where the data is assumed to come from a mixture of several Gaussian distributions, but the assignment of each data point to a specific Gaussian is unknown.
How the EM Algorithm
Read MoreEssential Cybersecurity Concepts, Threats & Best Practices
Essential Cybersecurity Concepts, Threats & Practices
1. Define Cybersecurity: Why Is It Important?
Cybersecurity is the practice of protecting computers, networks, applications, and data from unauthorized access, attacks, or damage.
Importance:
- Protects sensitive data
- Prevents financial loss
- Ensures privacy and safe online activities
2. What Is Social Engineering? Examples
Social engineering is manipulating people to steal confidential information.
Examples: Phishing emails, fake customer care calls
Read MoreCybersecurity Fundamentals: 20 Essential Concepts Defined
Cybersecurity Fundamentals: 20 Essential Concepts
1. Defining Cyber Security
Cyber Security refers to the practices, technologies, and processes designed to protect computers, networks, programs, and data from unauthorized access, attacks, and damage.
2. The CIA Triad Explained
The CIA Triad is the core model of information security and cyber defense, focusing on three critical components:
- Confidentiality: Protecting sensitive data from unauthorized access and disclosure.
- Integrity: Ensuring that data