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The comptometer-type calculator was the first machine to receive an all-electronic calculator engine in 1961 (the ANITA mark VII released by Sumlock comptometer of the UK). In 1890 W. T. Odhner got the rights to manufacture his calculator back from Königsberger & C , which had held them since it was first patented in 1878, but had not really ...
Because operators are applied one-at-a-time, the user must work out which operator key to use at each stage, and this can lead to problems. [ 9 ] [ 10 ] When discussing these problems, Harold W. Thimbleby has pointed out that button-operated calculators "require numbers and operation signs to be punched in a certain order, and mistakes are easy ...
The operator in its use probably is more mathematical than physical, the unit function more physical than mathematical. The operator p in the Heaviside calculus initially is to represent the time differentiator d / dt . Further, it is desired for this operator to bear the reciprocal relation such that p −1 denotes the operation of ...
The fractional part function has Fourier series expansion [19] {} = = for x not an integer. At points of discontinuity, a Fourier series converges to a value that is the average of its limits on the left and the right, unlike the floor, ceiling and fractional part functions: for y fixed and x a multiple of y the Fourier series given ...
The Comptometer was the first commercially successful key-driven mechanical calculator, patented in the United States by Dorr Felt in 1887.. A key-driven calculator is extremely fast because each key adds or subtracts its value to the accumulator as soon as it is pressed and a skilled operator can enter all of the digits of a number simultaneously, using as many fingers as required, making ...
In industrial engineering, the standard time is the time required by an average skilled operator, working at a normal pace, to perform a specified task using a prescribed method. [1] It includes appropriate allowances to allow the person to recover from fatigue and, where necessary, an additional allowance to cover contingent elements which may ...
Pascal's calculator (also known as the arithmetic machine or Pascaline) is a mechanical calculator invented by Blaise Pascal in 1642. Pascal was led to develop a calculator by the laborious arithmetical calculations required by his father's work as the supervisor of taxes in Rouen . [ 2 ]
An adjoint operator of the conjugate-linear operator A on a complex Hilbert space H is an conjugate-linear operator A ∗ : H → H with the property: A x , y = x , A ∗ y ¯ for all x , y ∈ H . {\displaystyle \langle Ax,y\rangle ={\overline {\left\langle x,A^{*}y\right\rangle }}\quad {\text{for all }}x,y\in H.}