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Non-transatlantic submarine telegraph cables
Non-transatlantic submarine telegraph cables are the undersea telegraph lines that linked Britain to India and the Far East, beginning with the commercially successful England-to-France cable of 1851.
Non-uniform memory access
Non-uniform memory access (NUMA), or Cc-NUMA, is a multiprocessor memory design in which each CPU accesses its local memory node faster than memory attached to distant nodes.
Non-volatile memory
Non-volatile memory (NVM) is electronic storage that retains its data even after losing power, unlike volatile DRAM and SRAM; flash, commercially introduced in 1987, dominates, with emerging types like phase-change and magnetic memory.
Non-zero dispersion-shifted fiber
Non-zero dispersion-shifted fiber (NZDSF) is single-mode optical fiber, standardized as ITU-T G.655, whose zero-dispersion wavelength is shifted outside the 1550-nm window to suppress four-wave mixing in dense WDM systems.
Noncircular gear
A noncircular gear is a gear whose pitch curve is not a circle, so its transmission ratio varies continuously within each revolution; common shapes include ellipses and ovals.
Noncollocated control
Noncollocated control is a control arrangement for flexible structures and robots in which the actuator and sensor sit at different locations, sacrificing easy stability for better tip performance.
Nondestructive testing
Nondestructive testing (NDT), also called nondestructive evaluation (NDE), is the evaluation of materials, components, and structures for flaws without damaging them, essential for pipelines, power plants, and safety parts.
Nondeterministic algorithm
A nondeterministic algorithm, also called nondeterministic computation, is a theoretical algorithm with multiple possible steps that always takes the right or best one, underlying the class NP.
Nonfullerene tandem organic solar cells
Nonfullerene tandem organic solar cells are stacked photovoltaic devices whose organic sub-cells use non-fullerene acceptors to harvest complementary parts of the solar spectrum, reaching over 21% efficiency.
Nong Saeng power station
Nong Saeng power station (โรงไฟฟ้าหนองแซง) is a 1,600 MW natural gas-fired combined cycle power plant in Saraburi Province, Thailand, operating since 2014 and selling all output to EGAT.
Nong Yao Oil and Gas Field
Nong Yao (นงเยาว์) is an offshore oil field in the shallow waters of the Gulf of Thailand, producing sweet crude since June 2015 under Valeura Energy.
Nong-Yeganskoye Oil Field
Nong-Yeganskoye Oil Field (Нонг-Еганское) is an operating onshore oil field in the Khanty-Mansi Autonomous Okrug of western Siberia, Russia, discovered in 1974, producing since 1978, and operated by LUKOIL.
Nonholonomic constraints
Nonholonomic constraints are velocity constraints on a mechanical system that cannot be integrated into position constraints; they arise from rolling without slipping and from sliding contact, such as a skate on ice.
Nonlinear digital self-interference cancellation
Nonlinear digital self-interference cancellation is a signal-processing technique used in full-duplex wireless radios, digitally reconstructing and subtracting their own transmitter's nonlinear distortion, chiefly from power amplifier saturation, to enable simultaneous same-frequency transmission and reception.
Nonlinear dimensionality reduction
Nonlinear dimensionality reduction is a family of machine learning methods that convert high-dimensional data into low-dimensional representations while preserving curved manifolds and neighborhoods, used for visualization and clustering.
Nonlinear dynamic inversion
Nonlinear dynamic inversion (NDI) is a flight control method that cancels a vehicle's nonlinear dynamics through feedback; its incremental variant, INDI, is among the most active approaches in flight control law design.
Nonlinear filtering
Nonlinear filtering, or nonlinear filtering theory, is the recursive Bayesian estimation of a hidden system state from noisy, partial observations, solved approximately by methods like the particle filter.
Nonlinear finite element analysis
Nonlinear finite element analysis (nonlinear FEA) is a computational method for structures whose stiffness, geometry, or boundary conditions change during loading, so a linear solution cannot be scaled.
Nonlinear Fourier transform
The nonlinear Fourier transform, also called the inverse scattering transform, decomposes a nonlinear signal into spectral components that evolve simply, much like the ordinary Fourier transform.
Nonlinear frequency-division multiplexing
Nonlinear frequency-division multiplexing (NFDM) is an optical fiber technique that encodes data on the nonlinear Fourier spectrum, making fiber nonlinearity part of the signal design rather than a distortion to compensate.
Nonlinear guidance law
The nonlinear guidance law (NLGL) is a geometric path-following algorithm introduced by Park, Deyst, and How in 2007, computing lateral acceleration from a look-ahead point on the desired path.
Nonlinear interference noise
Nonlinear interference noise (NLIN) is noise-like signal distortion in wavelength-division multiplexed optical fiber systems caused by the fiber's Kerr nonlinearity, commonly modeled with the Gaussian noise model.
Nonlinear metamaterials
Nonlinear metamaterials are artificially structured composites whose response to a wave depends on its intensity, spanning optical, acoustic, and mechanical designs for frequency conversion, nonreciprocity, and vibration control.
Nonlinear model predictive control
Nonlinear model predictive control is a control strategy that solves a constrained optimization online at each sampling instant using a nonlinear plant model over a prediction horizon.
Nonlinear model reduction
Nonlinear model reduction is a family of computational methods that builds low-dimensional approximate models of high-dimensional nonlinear dynamical systems, typically by projecting the full model onto a low-dimensional subspace, enabling fast simulation, optimization, and real-time control.
Nonlinear optical loop mirror
The nonlinear optical loop mirror (NOLM) is an all-optical switching device made of a fiber loop and coupler, where a Kerr-effect asymmetry makes transmission depend on light power.
Nonlinear phase noise
Nonlinear phase noise, or the Gordon–Mollenauer effect, is phase noise in optical fiber communication that arises when amplifier noise interacts with the Kerr nonlinearity, converting amplitude fluctuations into phase fluctuations.
Nonlinear static analysis
Nonlinear static analysis, widely known as pushover analysis, is a structural analysis method that applies an incrementally increasing lateral load to a structural model until a target displacement is reached.
Nonlinear system identification
Nonlinear system identification is the construction of mathematical models of nonlinear dynamical systems from measured input and output data, using structures such as NARMAX, block-oriented, and neural state-space models.
Nonlinear time history analysis
Nonlinear time history analysis (NTHA) is a structural engineering method that integrates earthquake ground motion records through a nonlinear model to compute displacements, forces, and damage.