Characteristic Curve


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characteristic curve

[‚kar·ik·tə′ris·tik ′kərv]
(graphic arts)
In photography, a graph that shows how increases in exposure increase the density of the film.
(mathematics)
One of a pair of conjugate curves in a surface with the property that the directions of the tangents through any point of the curve are the characteristic directions of the surface.
A curve plotted on graph paper to show the relation between two changing values.
A characteristic curve of a one-parameter family of surfaces is the limit of the curve of intersection of two neighboring surfaces of the family as those surfaces approach coincidence.

Characteristic Curve

 

one of the most important indexes of a photographic material. It expresses (for specified exposure and developing conditions) the optical density obtained from photographic darkening of the material as a function of the common logarithm of the exposure that produced the darkening. (SeeSENSITOMETRY.)

Characteristic curve

A graphical display depicting complex nonlinear relationships in electronic circuits. A typical use is to show voltage-current relationships in semiconductor devices. Device amplification capabilities, for example, are exhibited by a characteristic plot which traces output current versus output voltage with a third controlling variable as a parameter. This control variable could be the base current of a bipolar junction transistor (BJT) or the gate-to-source voltage of a metal-oxide-semiconductor (MOS) transistor.

Other characteristics often included in transistor data sheets are displays of current gain versus bias current, gain versus frequency, and input and output impedances versus frequency. Less commonly, other graphical nonlinear relationships, such as the variation of thermocouple voltage with temperature or the dependence of electrical motor torque with current, also are known as characteristic curves.

In the past, characteristic curves were used as tools in the graphical solution of nonlinear circuit equations that are followed by relationships of this type. In current practice, this analysis is performed using computer packages for circuit simulation. Designers still use characteristic curves from data sheets, however, to evaluate relative performance capabilities when selecting devices, and to provide the information needed for a preliminary pencil-and-paper circuit design. See Amplifier, Transistor

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References in periodicals archive ?
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Lee, "Relationship between the soil-water characteristic curve and the suction stress characteristic curve: experimental evidence from residual soils," Geotechnical and Geological Engineering, vol.
Soil-Water Characteristic Curve of Residual Soil from a Flysch Rock Mass
Tian, "Influence of drying-wetting cycles on soil-water characteristic curve of undisturbed granite residual soils and microstructure mechanism by nuclear magnetic resonance (NMR) spin-spin relaxation time (T2) relaxometry," Canadian Geotechnical Journal, vol.
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Caption: Figure 6: Response characteristic curves of simulation verification.
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Specifically, we compared FIT results with subsequent biopsy results to produce receiver operating characteristic curves for FIT and biopsy-proven neoplasias (colorectal carcinoma and colonic adenoma).
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Key statement: A rubber composition having a reinforcing filler of activated carbon having a pore volume of 0.15 cc/g or more, a weight average particle size of less than 140 microns, and a differential characteristic curve of pore volume versus adsorption potential by the GAED or equivalent method having a peak value at less than 5 cal/cc.
Method of reinforcing rubber and rubber composition
This curve, called an item characteristic curve (ICC), is assumed to graphically depict the true relationship between the trait and the responses to the item.
Item response theory for measurement validity

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