Inheritance (OOP programming)

The reliability function, R(t), defines the probability that a system or component will perform its required function without failure for a specified time 't'. For systems with a constant failure rate (λ), it is described by the exponential distribution: \(R(t) = e^{-\lambda t}\). This function is fundamental to predicting the longevity and performance of a product.

A classic illustration of the Monte Carlo method is estimating the value of \(\pi\). By inscribing a circle of radius \(r\) within a square of side length \(2r\), the ratio of their areas is \(\frac{\pi r^2}{(2r)^2} = \frac{\pi}{4}\). Randomly scattering points within the square and counting the fraction \(p\) that fall inside the circle provides an estimate: \(\pi \approx 4p\).

G-code, formally known as RS-274, is the most prevalent programming language for controlling CNC machines. It consists of sequential commands that instruct the machine on positioning, speed, and specific actions. Commands begin with a letter address; 'G' denotes preparatory commands for motion (e.g., G01 for linear feed), while 'M' signifies miscellaneous functions (e.g., M03 for spindle start).

Verification techniques are broadly classified as static or dynamic. Static verification (or static analysis) examines the system's code or design without executing it. Examples include code reviews, inspections, and automated static analysis tools. Dynamic verification (or testing) involves executing the system with a set of inputs and observing its behavior to find defects. Both are complementary for comprehensive quality assurance.

Abstraction in OOP is the concept of hiding complex implementation details and showing only the essential features of the object. It focuses on what an object does instead of how it does it. This is achieved through abstract classes and interfaces, which define a blueprint for other classes without providing a complete implementation, simplifying complex systems.

The Finite Volume Method (FVM) is a dominant numerical technique in CFD for solving partial differential equations. It discretizes the domain into a mesh of control volumes and applies the governing equations in their integral form to each volume. By converting volume integrals to surface integrals using the divergence theorem, it focuses on calculating the flux of conserved properties across cell faces.

The Finite Element Method (FEM) is a powerful numerical technique for solving complex engineering and physics problems described by partial differential equations. It works by discretizing a continuous domain into a set of smaller, simpler subdomains called 'finite elements'. This allows for the approximate numerical solution of problems in structural analysis, heat transfer, fluid flow, and electromagnetism.

Interpolation is the computational process within a CNC controller that generates a sequence of intermediate coordinate points to create a smooth path between programmed endpoints. The most fundamental types are linear interpolation (G01) for straight lines and circular interpolation (G02/G03) for arcs. This allows complex profiles to be machined from simple geometric commands in the G-code program.

The Risk Priority Number (RPN) is a quantitative measure used in FMEA to prioritize risks. It is calculated as the product of three ranked factors: Severity (S), Occurrence (O), and Detection (D). The formula is \(RPN = S times O times D\). Each factor is typically rated on a scale from 1 to 10, allowing teams to focus on the highest-scoring risks first.

Verification and validation (V&V) are distinct processes. Verification ensures a product meets its specified requirements ("Are you building it right?"). Validation ensures the product meets the user's actual needs and intended use ("Are you building the right thing?"). They are complementary activities within quality management, often performed sequentially or in parallel to ensure both correctness and usefulness.