All articles A–Z

Dynamic pressure

Dynamic pressure, also known as velocity pressure or wind pressure, is half the fluid density times flow velocity squared, equal to the kinetic energy per unit volume of the flow.

Dynamic pricing

Dynamic pricing is the practice of adjusting prices frequently in response to market conditions, using demand forecasting and optimization, as pioneered by American Airlines' yield management.

Dynamic program analysis is a software analysis method that examines a program while it executes, using runtime information from instrumentation to detect bugs, performance problems, and security vulnerabilities.

Dynamic programming

Dynamic programming is an algorithm design method, developed by Richard Bellman at RAND in the early 1950s, that solves optimization problems by breaking them into overlapping subproblems and reusing stored results.

Dynamic random-access memory

Dynamic random-access memory, or DRAM, is a volatile semiconductor memory storing each bit as charge on a single transistor and capacitor; its density makes it the main memory of most computers.

Dynamic range

Dynamic range is the ratio between the largest and smallest signal a system can detect or reproduce without distortion, expressed in decibels and spanning audio, radar, imaging, and scientific instruments.

Dynamic range compression

Dynamic range compression (DRC), also called audio level compression, is an audio signal processing technique that narrows the difference between loud and quiet passages of a signal.

Dynamic relaxation

Dynamic relaxation is an iterative numerical method that solves a structure's static equilibrium equations by simulating a damped dynamic process, used mainly for form-finding of tension structures.

Dynamic rupture simulation

Dynamic rupture simulation is a computational seismology method that numerically models spontaneous earthquake fault rupture by solving for stress, friction, and wave propagation, unlike kinematic models.

Dynamic semantics

Dynamic semantics is a view of natural language meaning in which a sentence's meaning is an instruction to update the conversational context, not a set of truth conditions.

Dynamic shear rheometer

A dynamic shear rheometer (DSR) is a laboratory instrument that measures viscoelastic properties by oscillating a thin sample between parallel plates, standard for asphalt binders.

Dynamic soaring

Dynamic soaring is a flight technique in which an unpowered glider or bird gains energy from wind shear by repeatedly climbing and descending across the shear layer while turning.

Dynamic Source Routing

Dynamic Source Routing (DSR) is a reactive routing protocol for wireless ad hoc networks in which each packet carries its complete route, standardized as RFC 4728.

Dynamic stall

Dynamic stall is an unsteady flow separation process on an airfoil during rapid motion past its static stall limit, briefly increasing lift before a leading-edge vortex sheds.

Dynamic state estimation

Dynamic state estimation is a family of filtering methods that estimate the time-varying hidden state of a dynamic system from noisy measurements, one time step at a time.

Dynamic stochastic general equilibrium model

A dynamic stochastic general equilibrium (DSGE) model is a macroeconomic model in which optimizing households, firms, and policymakers face random shocks, used widely in central banks.

Dynamic structure factor

The dynamic structure factor, S(Q,ω), gives the probability that a particle such as a neutron scatters from a sample with given momentum and energy transfer.

Dynamic Structures (company)

Dynamic Structures is a Canadian engineering and heavy-fabrication company in Port Coquitlam, British Columbia, founded in 1926, that builds theme park ride systems for Disney and Universal and telescope enclosures.

Dynamic Systems Development Method

The Dynamic Systems Development Method (DSDM) is an Agile project delivery framework created in 1994 by a consortium seeking to add quality and control to Rapid Application Development, now maintained by the Agile Business Consortium.

Dynamic testing

Dynamic testing is software testing in which a test item is evaluated by executing it with selected inputs and observing its runtime behavior, as defined by ISO/IEC/IEEE 29119.

Dynamic time warping

Dynamic time warping, or DTW, is a similarity measure for time series that finds the optimal nonlinear alignment between two sequences, developed by Sakoe and Chiba for speech recognition.

Dynamic topography

Dynamic topography is the height of the sea surface relative to the geoid, produced by ocean currents, or the solid-Earth deformation caused by flow in the convecting mantle.

Dynamic topology optimization

Dynamic topology optimization is a structural design method that distributes material within a design domain to maximize stiffness or dynamic performance under vibration, harmonic, or transient loads.

Dynamic treatment regime

A dynamic treatment regime, also called an adaptive treatment strategy, is a sequence of decision rules for tailoring treatment to a patient's changing status over time.

Dynamic typing

Dynamic typing is a property of programming languages where type checks happen at run time rather than before the program runs, as in Python and JavaScript.

Dynamic vapor sorption

Dynamic vapor sorption (DVS) is a gravimetric analytical technique measuring a sample's mass change as humidity or temperature is varied, most commonly to construct water vapor sorption isotherms.

Dynamic voltage and frequency scaling

Dynamic voltage and frequency scaling (DVFS) is a power management technique that adjusts a processor's supply voltage and clock frequency at runtime to match the current workload and save energy.

Dynamic voltage restorer

A dynamic voltage restorer (DVR) is a series-connected custom power device that injects corrective voltage to protect sensitive loads from sags, swells, and other disturbances, but not outages.

Dynamic wake meandering

Dynamic wake meandering (DWM) is a mid-fidelity engineering wake model developed at the Technical University of Denmark that treats a turbine wake deficit as a passive tracer carried by large-scale turbulence.