Technology and the built world

Fully sharded data parallelism

Fully sharded data parallelism (FSDP) is a memory-saving distributed deep learning training method that shards a model's parameters, gradients, and optimizer states across GPU workers.

Fulong converter station

Fulong converter station (复龙换流站), located at Fulong in Sichuan Province, China, is the sending-end (rectifier) station of the Xiangjiaba–Shanghai ±800 kV UHVDC link, commissioned in 2010.

Fulton surface-to-air recovery system

The Fulton surface-to-air recovery system, or Skyhook, retrieves people from the ground by aircraft without landing, used by the CIA and US military from 1958 to 1997.

Fuman Oil and Gas Field

Fuman Oil and Gas Field is an ultra-deep oil and gas field in the Tarim Basin, Xinjiang, China, operated by PetroChina and producing from Ordovician carbonates below 6,000 m.

Fumitake Yoshida (吉田文武, 1913–2007) was a Japanese chemical engineer and Kyoto University professor known for research on mass transfer, gas absorption, and bubble columns, and was elected to the US National Academy of Engineering.

Function block diagram

Function block diagram (FBD) is a graphical programming language for programmable logic controllers in which functions and blocks are wired together so control logic flows from inputs to outputs.

Function calling

Function calling is a large language model capability in which the model emits structured JSON requests to invoke external tools, established by OpenAI in June 2023.

Function Health

Function Health is an American membership-based health testing company founded in 2021 and launched in 2023, offering 160+ lab tests, at-home draws, and clinician-written interpretations.

Function key

Function keys, also called PF keys, are the programmable F1 through F12 keys in a row at the top of most keyboards, assigned to commands by each application.

Function overloading

Function overloading, or method overloading, is a form of ad hoc polymorphism where multiple functions share one name and differ in parameter lists, with the compiler selecting which one a call refers to.

Function points

A function point is a unit for measuring the functional size of software, developed by Allan Albrecht at IBM in the late 1970s and now an international standard.

Functional Airspace Block

A functional airspace block (FAB) is a volume of European airspace defined by operational requirements rather than national borders, under the EU's Single European Sky initiative.

Functional baseline

The functional baseline, called the Requirements Baseline in Air Force usage, is the first technical baseline in configuration management, documenting a system's approved performance requirements and verification.

Functional coverage

Functional coverage is a user-defined metric in hardware verification that measures how much of a design's specification has been exercised during simulation, unlike automatically extracted code coverage.

Functional decomposition

Functional decomposition is a method that breaks a complex function into simpler subfunctions computed separately and recombined by composition, fundamental in logic synthesis and FPGA design.

Functional dependency

A functional dependency in relational database theory, written X → Y, is a constraint where one set of attributes determines another, underpinning keys, Armstrong's axioms, and normalization.

Functional encryption

Functional encryption is a public-key cryptographic scheme in which a key tied to a function f lets its holder compute f(x) from an encryption of x, learning nothing else.

Functional integration (formal methods)

Functional integration in formal methods is a program-development technique in which specification, implementation, and correctness proof are produced together, so the delivered program is correct a priori.

Functional programming

Functional programming is a declarative style of programming that treats computation as evaluating mathematical functions, favoring pure functions and immutable data, with languages including LISP, ML, and Haskell.

Functional requirement

A functional requirement states what a system must do, expressed as an obligation on the product rather than how it will be built, and is typically written as a "shall" statement.

Functional resonance analysis method

The functional resonance analysis method (FRAM) is a qualitative safety analysis technique by Erik Hollnagel that models how everyday performance variability can resonate into accidents.

Functional specification

A functional specification, also called a functional spec or functional specifications document, states in precise, testable terms what a software or hardware system must do, capturing its functional requirements.

Functional testing

Functional testing is software testing that evaluates what a system should do, checking completeness, correctness, and appropriateness, typically as black-box testing derived from the specification.

Functional verification

Functional verification is the process of checking that a digital circuit design is logically correct against its specification before manufacturing, typically consuming over half of chip project time.

Functionally graded additive manufacturing

Functionally graded additive manufacturing (FGAM) is a layer-by-layer fabrication process that gradually varies a part's composition, density, or microstructure so properties are matched to function.

Functionally graded material

A functionally graded material (FGM) is a composite whose composition and microstructure vary continuously through the part, reducing thermal stress; leading uses include turbine-engine thermal barrier coatings.

Fundamental diagram of traffic flow

The fundamental diagram of traffic flow shows how flow rate, density, and speed relate on a road, rising to maximum flow at an intermediate density before congestion reduces it.

Fundamental matrix (computer vision)

The fundamental matrix is a 3 × 3 rank-2 matrix in computer vision encoding the epipolar geometry between two uncalibrated camera views, satisfying x'TFx = 0 for corresponding points.

Oct 26, 2026

Fundamentals of Data Engineering

Fundamentals of Data Engineering: Plan and Build Robust Data Systems (2022, O'Reilly), by Joe Reis and Matt Housley, a 450-page beginner book organizing data engineering around a five-stage lifecycle and six undercurrents.