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Video / Animation

A Better Hearing Aid Using Artificial Intelligence

Neuroengineer Nima Mesgarani is using a form of artificial intelligence called neural network models to a develop improved hearing aids. If successful, hearing impaired individuals will be better able to identify and focus on a speaker of…

Video / Animation

The Biochemistry of Redheads

Do you know someone with red hair? Perhaps you have those fiery locks yourself. This video takes a close biochemical look into what makes redheads stand out from the crowd. It's not just the color of their hair. Credit: Reactions/American…

Video / Animation

Compact Disk

This animation explains how a compact disk stores recorded information.

Video / Animation

A Company Named Carbon is Changing 3D Printing

Joe DeSimone cofounded a company called Carbon (formerly Carbon3D) to bring chemistry to bear on 3D printing. This video shows how Joe enabled the company to print at unprecedented speeds, and churn out materials that have never been printed…

Video / Animation

Radar

This animation shows how radar (radio detection and ranging) works.

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from article Transmission lines

Two common transmission lines for communication. (a) Coaxial cable. (b) Strip line.

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from article Transmission lines

Equivalent circuit that represents three sections of a lossless transmission line. Each section is of length Δz, and has an inductor (L) and capacitor (C). Voltages (V ) and currents (I ), and their differences (ΔV and ΔI ) between successive…

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from article Transmission lines

Signal detection on an oscilloscope. (a) Oscilloscope pictures of voltage pulses at three locations, z1, z2, and z3, on a transmission line, successively more distant from the signal generator. (b) Oscilloscope pictures of a periodic voltage sine…

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from article Transmission lines

Transmission line with characteristic impedance Zc, terminated in a load impedance ZL. A change of coordinate system (from z to ζ) is indicated.

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from article Transmission lines

Envelope of the voltage standing wave consisting of a wave propagating from z = −∞ and being reflected at z = 0. The wavelength, λ, and the maximum and minimum voltages, Vmax and Vmin, are indicated.

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from article Transmission lines

Two waveguides, with conventional coordinates. (a) Rectangular waveguide. (b) Cylindrical waveguide.

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from article Transmission lines

Dispersion curve for a rectangular waveguide of width a, showing relationship between the propagation constant, β, and the angular frequency, ω. Here, n specifies the mode of propagation, and c is the speed of light.

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from article Transmission lines

Equivalent circuit of a power transmission line. The single-phase circuit is used to represent balanced three-phase lines. Here, R and X are the resistance and reactance (at the operational frequency), and C is the capacitance of the entire…

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from article Crosstalk

Crosstalk in a space-division system. Z1, Z2, Z3, and Z4 designate impedances.

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from article Computer-aided circuit design

Four phases in creating a microelectronic chip. (a) Design. (b) Fabrication. (c) Testing. (d) Packaging. (After G. De Micheli, Synthesis and Optimization of Digital Circuits, McGraw-Hill, 1994)

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from article Computer-aided circuit design

Three abstraction levels of a circuit representation. (a) Architectural level. (b) Logic level. (c) Geometrical level. (After G. De Micheli, Synthesis and Optimization of Digital Circuits, McGraw-Hill, 1994)

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from article Computer security

Applications such as power generation, stock trading, airplane navigation, and medical care have become so dependent on computing that loss of availability becomes a serious threat to life or society. Even on a less dramatic level, people have…

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from article Computer security

Smartphone with fingerprint identification. (Credit: Anatoliy Babiy/Getty Images)

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from article Programmable controllers

Functional architecture of a typical high-performance single-chip microcontroller used for control and signal processing. (National Semiconductor Corp.)

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from article Ultrawideband (UWB) systems

Relationships between various UWB systems.

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from article Ultrawideband (UWB) systems

Frequency-modulated continuous-wave (FMCW) swept-frequency signaling. (a) Plot of the amplitude of the continuous wave against time, showing it gradually changing frequency. (b) Frequency-versus-time plot.

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from article Ultrawideband (UWB) systems

Spectrum of WiMedia UWB, which uses 14 RF carriers coordinated for maximum data throughput.

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from article Ultrawideband (UWB) systems

Plots of a pulsed radio or pulsed radar transmission. (a) Time plot. (b) Frequency plot.

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from article Ultrawideband (UWB) systems

Coherent pulse integration values of (a) 16 through (b) 512 pulses per symbol increase signal-to-noise ratio with limited transmit power.

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from article Ultrawideband (UWB) systems

Time difference of arrival (TDOA) tracking, which combines multiple time-of-arrival (TOA) measurements to localize pulse origin.

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from article Ultrawideband (UWB) systems

Timing diagram of a two-way time-of-flight (TW TOF) ranging conversation.

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from article Directional coupler

Four-port directional waveguide coupler.

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from article Directional coupler

Two-hole directional coupler.

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from article Directional coupler

Single-mode fiber-optic directional coupler.

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from article Calculators

Electromechanical calculator manufactured in the 1960s. (Hewlett-Packard)

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from article Calculators

Modern programmable electronic calculator. (a) Front of calculator, featuring liquid-crystal display, qwerty-style keyboard, cursor key, and function keys. The display is composed of 128 rows of 240 pixels each, and here shows a three-dimensional…

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from article Communications satellite

Artist impression of TDRS-L, the 11th member of NASA's Tracking and Data Relay Satellite System, orbiting Earth at 36,000 km (22,300 mi). TDRS-L sends signals, information, and commands from ground controllers to the International Space Station and…

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from article Communications satellite

Communications to and from a satellite.

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from article Communications satellite

Typical communications satellite. TWTA = traveling-wave–tube amplifier. (Credit: Space Systems/Loral)

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from article Communications satellite

Orbit periods of circular orbits.

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from article Anthropology

Fossil skulls of four different species of Homo (clockwise from upper left): Homo neanderthalensis, Homo antecessor, Homo erectus, and Homo sapiens. Each skull shows different anatomical variations. (Credit: creativemarc/Shutterstock)

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from article Anthropology

The indigenous inhabitants of Siberut Island (West Sumatra, Indonesia) are known as the Mentawai people. They live a seminomadic hunter-gatherer life in the coastal and rainforest environments of the island. (Credit: Chanwit Whanset/Shutterstock)

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from article Data structure

Linear array of integers.

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from article Data structure

A stack, a linear list in which elements are inserted or deleted only at one end.

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from article Data structure

A queue, a linear list that permits insertion at one end and deletion at the other.

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from article Data structure

Singly linked list or one-way chain.

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from article Data structure

Diagram representing a directed graph.

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from article Data structure

Example of a tree.

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from article Data structure

Linked storage representation for a binary tree.

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from article Machine learning

Machine-learning algorithms will help self-driving cars reliably handle unexpected situations they encounter on the road. (Credit: Karsten Neglia/Shutterstock)

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from article Programming languages