intersection

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intersection

Maths
a. a point or set of points common to two or more geometric configurations
b. the set of elements that are common to two sets
c. the operation that yields that set from a pair of given sets. Symbol: ∩, as in AB

intersection

[‚in·tər′sek·shən]
(civil engineering)
A point of junction or crossing of two or more roadways.
A surveying method in which a plane table is used alternately at each end of a measured baseline.
(mathematics)
The point, or set of points, that is common to two or more geometric configurations.
For two sets, the set consisting of all elements common to both of the sets. Also known as meet.
For two fuzzy sets A and B, the fuzzy set whose membership function has a value at any element x that is the minimum of the values of the membership functions of A and B at x.
The intersection of two Boolean matrices A and B, with the same number of rows and columns, is the Boolean matrix whose element cij in row i and column j is the intersection of corresponding elements aij in A and bij in B.

intersection

intersectionclick for a larger image
i. A point where the centerlines of runways cross each other. See intersecting runways.
ii. A point defined by any combination of courses, radials, or bearings of two or more navigational aids.
iii. The point on the earth vertically above which the centerlines of airways cross.
iv. Used to describe the point where two runways, a runway and a taxiway, or two taxiways cross or meet.
References in classic literature ?
The few he passed gave him no heed, and he had almost reached the nearest intersection when he saw several men wearing yellow tunics identical to that which he had taken from his prisoner.
They were coming directly toward him and the ape-man saw that should he continue on he would meet them directly at the intersection of the two streets in the full light of the flare.
Like the others he had passed they paid no attention to him and the moment they were behind him he continued upon his way, turning to the right at the intersection of the two streets.
He had proceeded for some little distance and had about reached a point where he judged he would find the street which led up from the city gate when, at an intersection of two streets, his nostrils caught the scent spoor of the girl.
We must suppose the Melipona to arrange her cells in level layers, as she already does her cylindrical cells; and we must further suppose, and this is the greatest difficulty, that she can somehow judge accurately at what distance to stand from her fellow-labourers when several are making their spheres; but she is already so far enabled to judge of distance, that she always describes her spheres so as to intersect largely; and then she unites the points of intersection by perfectly flat surfaces.
As soon as this occurred, the bees ceased to excavate, and began to build up flat walls of wax on the lines of intersection between the basins, so that each hexagonal prism was built upon the festooned edge of a smooth basin, instead of on the straight edges of a three-sided pyramid as in the case of ordinary cells.
The bees, however, did not suffer this to happen, and they stopped their excavations in due time; so that the basins, as soon as they had been a little deepened, came to have flat bottoms; and these flat bottoms, formed by thin little plates of the vermilion wax having been left ungnawed, were situated, as far as the eye could judge, exactly along the planes of imaginary intersection between the basins on the opposite sides of the ridge of wax.
We see how important a part excavation plays in the construction of the cells; but it would be a great error to suppose that the bees cannot build up a rough wall of wax in the proper position--that is, along the plane of intersection between two adjoining spheres.
The work of construction seems to be a sort of balance struck between many bees, all instinctively standing at the same relative distance from each other, all trying to sweep equal spheres, and then building up, or leaving ungnawed, the planes of intersection between these spheres.
It is even conceivable that an insect might, by fixing on a point at which to commence a cell, and then moving outside, first to one point, and then to five other points, at the proper relative distances from the central point and from each other, strike the planes of intersection, and so make an isolated hexagon: but I am not aware that any such case has been observed; nor would any good be derived from a single hexagon being built, as in its construction more materials would be required than for a cylinder.
Thus, as I believe, the most wonderful of all known instincts, that of the hive-bee, can be explained by natural selection having taken advantage of numerous, successive, slight modifications of simpler instincts; natural selection having by slow degrees, more and more perfectly, led the bees to sweep equal spheres at a given distance from each other in a double layer, and to build up and excavate the wax along the planes of intersection.
But even if I had had the free disposition of the boudoir, I should have held to the plan I had formed; because any other plan of attack would have separated us at the moment of the struggle with the man, while my plan united us all for the attack, at a spot which I had selected with almost mathematical precision,--the intersection of the two galleries.

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