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from article Digital object identifier system
Digital Object Identifier components.
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from article Radio broadcasting
Predicted daytime and nighttime interference-free field strength coverage contours of the AM station KLOK in San Jose, California.
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from article Radio broadcasting
FM broadcast baseband frequency spectrum.
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from article Radio broadcasting
Predicted 3.16-mV/m coverage contour for the 100-kW station KUGN in Eugene, Oregon. The broken line represents coverage based on FCC field strength curves. The solid lines and “islands” represent a more realistic depiction of coverage that…
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from article Internet of things
Smart cities use IoT devices to improve communication, transportation, and services. (Credit: Shutterstock/Anucha Maneechote)
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from article Geometrization theorem
Making a 2-D torus.
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from article Geometrization theorem
Life in Seifert-Weber dodecahedral space. (Courtesy of Geometry Center, University of Minnesota)
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from article Geometrization theorem
Hyperbolic dodecahedron of infinite diameter. The infinite spikes are rounded off “chimneys,” which are here triangular rather than rectangular. (Courtesy of Paul Nylander from http://bugman123.com/)
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from article Geometrization theorem
Neck pinching, resulting in infinite curvature.
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from article Geometrization theorem
Ricci flow with surgery.
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from article Doppler VOR
Collocation of Doppler VOR and TACAN beacons installed on 100-foot high (30-m) tower with a counterpoise of 119-ft (36-m) diameter in forest near Frankfurt, Germany. Circular array consists of 39 loop antennas fed by solid-state commutator. Center…
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from article Doppler VOR
Principle of Doppler VOR beacon. Reference signal R and bearing signal V which is generated by dipole d are shown as they would be measured in aircraft to the north, east, south, and west of the beacon. (a) Dipole d at 180°. (b) Dipole d at 270°.…
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from article Doppler VOR
Comparison of radial flight recordings. (a) From VOR installation. (b) From DVOR installation. Both experimental beacons were located at same unfavorable site. Plane is flying constant course at bearing of 133° from beacons at 4000-ft (1.2-km)…
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from article Matrix theory
Vector rotation that rotates any vector v in the plane counterclockwise through 45° to a new vector Tv.
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from article Boolean algebra
A portrait of George Boole.
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from article Calculus of variations
Weierstrass condition. Symbols explained in text.
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from article Calculus of variations
Example of an area-minimizing surface that cannot be written as the graph of a single function. (a) Nonconvex domain C. (b) Minimal graph over C that is not area-minimizing. (c) Second surface over C that has less area. (After F. Morgan, Geometric…
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from article Calculus of variations
Comparison of surfaces. (a) Surface with no handles. (b) Surface with one handle and less area. (c) Surface with two handles and still less area. (d, e, f) These three surfaces are deformed to show that they do have zero, one, and two handles,…
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from article Calculus of variations
Examples of surfaces minimizing the integral of a nonelliptic integrand among all bodies having the same volume (the surface at upper left) and among all surfaces having the same boundary (the saddle-shaped surface). Surfaces were computed as part…
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from article Linear algebra
Geometric representation of a vector OP.
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from article Radian measure
Diagrams showing radian measurement. Symbols are explained in the text.
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from article Z transform
Extraction of discrete-time sample values from a continuous signal.
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from article Analog computer
Special-purpose pneumatic analog computer, model Foxboro 556. (Foxboro Co.)
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from article Analog computer
Multiprocessor analog computer. (a) Exterior. (b) Organization. (Applied Dynamics International)
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from article Analog computer
Addition of electric currents by using a passive network of resistors. (a) Individual voltages and resistors. (b) Voltages and corresponding currents summed into a common resistor.
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from article Analog computer
Symbol for a high-gain direct-current amplifier, with one inverting input referenced to ground.
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from article Analog computer
High-gain amplifier which has been made into an operational amplifier through the inclusion of an input resistor and a feedback resistor tied together at the amplifier's summing junction (SJ).
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from article Analog computer
Summing junction currents into an operational amplifier create the fixed gain function, determined by resistor values, as indicated in the box.
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from article Analog computer
Operational amplifier which has been made into a summer through the use of several input resistors connected to the summing junction. Output is equal to the inverted weighted sum of the inputs.
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from article Analog computer
Block diagram representation of a hybrid analog-to-digital computer.
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from article Inertial navigation system
Elementary accelerometer.
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from article Inertial navigation system
Computation of distance by two integrations. Integration of acceleration gives velocity; integration of velocity gives distance.
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from article Inertial navigation system
Schematic of a three-gimbal platform.
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from article Inertial navigation system
Strap-down inertial navigation system. (After A. Lawrence, Modern Inertial Technology, 2d ed., Springer, New York, 1998)
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from article Inertial navigation system
Inertial navigation process. The inertial sensor assembly (ISA) and inertial measurement unit (IMU) are defined in Table 2.
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from article Inertial navigation system
Strap-down inertial navigation systems. (a) Mock-up of system based on laser gyro technology. The three laser gyros, hermetically sealed, are on the left (Honeywell). (b) 130-cm3 (8-in.3) system that uses silicon MEMS technology (Draper Laboratory).
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from article Inertial navigation system
Automobile navigation system.
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from article Automatic gain control (AGC)
Block diagram of a typical automatic gain control (AGC) circuit. (From J. R. Smith, Modern Communication Circuits, 2d ed., WCB/McGraw-Hill, Boston, 1998)
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from article Synthetic aperture radar (SAR)
The basic idea of synthetic aperture radar (SAR); a side-looking case is illustrated. Two example scatterers, A and B, are shown in the ground scene. Le = maximum flight path length for effective SAR processing.
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from article Synthetic aperture radar (SAR)
The range-dependent Doppler-time function of surface objects (reference objects A and B of Fig. 1), as the synthetic aperture radar passes by, for (a) A and B close to the flight path and (b) A and B at greater range.
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from article Synthetic aperture radar (SAR)
Synthetic aperture radar image of an office building in Lincoln, Massachusetts. (Lincoln Laboratory, Massachusetts Institute of Technology)
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from article Synthetic aperture radar (SAR)
Example of inverse synthetic aperture radar (ISAR). (a) Outline of YAK-42 aircraft. (b, c) ISAR images of the aircraft for two different focusing methods. (Xidian University of China)
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from article Umami taste receptor
Schematic drawing of a taste bud. (Copyright © McGraw Hill)
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from article Umami taste receptor
Schematics of umami, sweet, and chimeric T1R receptors. The T1R1/T1R3 umami taste receptor and the T1R1-2/T1R3 chimeric receptor recognize umami ligands, whereas the T1R2/T1R3 sweet taste receptor and the T1R2-1/T1R3 chimeric receptor recognize…
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from article Circle
A circle, with radius, diameter, and circumference indicated. (Credit: McGraw-Hill Education)
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from article Circle
Nine-point circle and Euler line PMH.
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from article Sonobuoy
Launch of a sonobuoy from an antisubmarine warfare (ASW) aircraft. (a) In flight. (b) Buoy strikes the water in a nearly vertical attitude. (c) Antenna and hydrophone are positioned automatically.
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from article Trihedron
Trihedron and trihedral angles.
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from article Trihedron
Spherical triangle ABC formed by intersection of sphere with a trihedron. The center of the sphere is at the vertex of the trihedron.
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from article Electric filter
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from article Electric filter
Passive, lumped-element filters. (a) RC low-pass filter. (b) LC band-pass filter.
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from article Electric filter
Ladder structure. (a) Overall structure with alternating series and shunt arms. (b) LC circuit whose impedance contains both a finite-frequency pole and a zero. Such circuits are used in the series and shunt arms of the ladder structure.
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from article Electric filter
Mechanical filter.
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from article Electric filter
Single-amplifier filters. (a) Low-pass Sallen-Key filter. (b) Low-pass, infinite-gain, single-amplifier filter. (c) Cascade of second-order filter realizations.
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from article Electric filter
Multiple-amplifier filters. (a) State-variable (KHN) filter. (b) Tow-Thomas filter.
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from article Electric filter
Simulated-inductor realization of fifth-order high-pass filter. (a) RLC prototype, normalized for cutoff frequency of 1 rad/s (0.159 Hz). (b) Direct active-RC realization.
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from article Satellite television broadcasting
Direct broadcasting television satellite system.
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from article Gamma function
Depiction of gamma function Γ(z) for real values of z.
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from article Yeast
Colorized scanning electron micrograph (SEM) of Schizosaccharomyces pombe yeast. This single-celled fungus is studied widely as a model organism for eukaryotic cell division. It is a rod-shaped yeast that grows by elongation at its ends, and it…
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from article Yeast
Cell shapes of yeasts are extremely varied: (a) rectangular; (b) pear-shaped; (c) apiculate; (d) ogival; (e) spherical; (f) globose; (g) ellipsoidal (oval); (h) elongate; (i) tetrahedral. (Copyright © McGraw Hill)
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from article Yeast
Colorized scanning electron micrograph (SEM) of cells of brewer's yeast (Saccharomyces cerevisiae). This yeast consists of single vegetative cells. Small daughter cells can be seen budding off from the larger cells. Saccharomyces cerevisiae ferments…
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from article Yeast
Yeast mycelia: (a) a true septate mycelium showing a break to form an arthrospore; (b) a pseudomycelium. (Copyright © McGraw Hill)
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from article Yeast
Heterothallic (bifactorial) life cycle of a basidiomycetous yeast, Leucosporidium scottii. (Copyright © McGraw Hill)
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from article Yeast
A fluorescent antibody stain reveals the oval budding yeast cells of Candida albicans. This yeast is the most common human fungal pathogen. (Credit: Maxine Jalbert and Leo Kaufman/Centers for Disease Control and Prevention)
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from article Beer
Grains of (a) barley before malting and (b) hop plant. (Credit: U.S. Department of Agriculture)
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from article Beer
Fermentation tanks. (Credit: ClarkandCompany/Getty Images)
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from article Peppermint
Peppermint (Mentha piperita). (Credit: Michael Thompson/Agricultural Research Service, U.S. Department of Agriculture)
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from article Citron
Citron (Citrus medica), including cross sections of the fruit. (Photo courtesy of California Citrus Clonal Protection Program)
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from article Foodborne disease
Trichrome-stained photomicrograph of a Giardia lamblia trophozoite (a growing stage in the life cycle of certain protozoan parasites). This microorganism often causes giardiasis (a diarrheal foodborne illness). (Credit: Melanie Moser/Centers for…
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from article Foodborne disease
A cluster of norovirus particles. (Credit: Charles D. Humphrey/Centers for Disease Control and Prevention)
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from article Foodborne disease
Colored scanning electron micrograph showing Salmonella enterica bacteria (serotype Typhimurium; colorized red) invading an immune cell (colorized yellow). This bacterial species commonly causes food-associated gastroenteritis. (Credit: National…
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from article Foodborne disease
Close-up view of Campylobacter jejuni bacteria. This scanning electron microscope image shows the characteristic spiral (or corkscrew) shape of C. jejuni cells. (Credit: De Wood and Chris Pooley/Agricultural Research Service, U.S. Department of…
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from article Modeling language
Systems engineering work space.
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from article Modeling language
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from article Modeling language
Component diagram for car window control. The small rectangles signify that this is a component diagram.
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from article Modeling language
Example of deep dependency structure.
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from article Hyperbolic navigation system
Typical grid of hyperbolic lines of position formed by a master (M) and two secondary stations (W and X).
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from article Hyperbolic navigation system
Individual lines of position from a master and two secondaries at location P. γ =LOP crossing angle.
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from article Hyperbolic navigation system
Typical curves of constant horizontal dilution of precision (HDOP) for a master (X) and two secondary stations (X and Y). Numbers give HDOP values of contours.
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from article Taste
Taste buds in a circumvallate papilla in a mouse tongue with taste cells visualized in color by cell-type-specific fluorescent antibodies. (Credit: Aki Taruno/Perelman School of Medicine, University of Pennsylvania)
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from article Taste
Illustration of the internal structures of a taste bud, which is composed of basal stem cells and three types of taste cells (dark, light, and intermediate). Taste cells extend from the base of the taste bud to the taste pore, where microvilli…
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from article Taste
Lemons and lemonade taste sour because they are very acidic and have a high concentration of hydrogen (H+) ions. (Credit: Mad Circles/Getty Images)
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from article Taste
Taste quality changes when spatial arrangements within a molecule are altered. (Copyright © McGraw-Hill Education)
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from article Milk
Dairy cow milking operation. (Credit: Yadamons/Getty Images)
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from article Milk
Milk and milk products yogurt and mozzarella. (Credit: Lilyana Vynogradova/iStockphoto/Getty Images)
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from article Telemetering
Functions of a generic aerospace telemetry system.
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from article Telemetering
Functions of a supervisory control and data acquisition (SCADA) system.
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from article Telemetering
Functions of a spacecraft telemetry and command system, using packet telemetry.
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from article Pythagorean theorem
Proof of Pythagorean theorem based on comparison of areas of squares.
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from article Pythagorean theorem
Three-dimensional Pythagorean theorem.
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from article Artificial intelligence
A Google self-driving car in Mountain View, California, USA. (Credit: Grendelkhan: CC BY-SA 4.0)
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from article Spread spectrum communication
Equipment for a basic direct-sequence (pseudonoise-encoded), binary phase-shift keyed, spread spectrum system. (a) Transmitter. (b) Receiver.
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from article Spread spectrum communication
Example of how a narrow-band jammer is despread in the front end of a receiver. (a) System model. (b) Transmitted signal and jammer. (c) Despread signal and jammer.
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from article Spread spectrum communication
Example of a frequency-hopped signal pattern.
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from article Spread spectrum communication
Frequency-hopping equipment for (a) transmitter and (b) receiver.
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from article Agricultural machinery
A tractor pulling a multipurpose machine used for precision tillage and planting. (Credit: Scott Bauer/U.S. Department of Agriculture)
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from article Agricultural machinery
Agricultural aircraft applying a chemical pesticide on a field. (Credit: jupiterimages/Getty Images)
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from article Agricultural machinery
A combine harvester hopper filling up with corn kernels as the machine harvests the field. (Credit: Glow Images)
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from article Agricultural machinery
A harvester machine is used to drop tomatoes into a container. (Credit: Phil Schermeister/National Geographic RF/Getty Images)
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from article Saffron
Saffron (Crocus sativus) with its three red-colored stigmas. These distinctive stigmas (“saffron threads”) are dried to obtain the spice. (Photo copyright © Joanna Baron, used with permission)
