Why does data have to be encoded before it can be written to a disk?
What will be an ideal response?
In first?generation drives, it was necessary to encode data because a signal is received from the surface only when the magnetic flux changes; that is, if you recorded a stream of 1s as a constant signal (magnetization), you would pick nothing up when you read the data. Data encoding was used to ensure sufficient flux transitions to generate a clock to divide the data into individual bits.
Today, with very high transmission rates, the properties of rapidly changing signals become very important in terms of their bandwidth. Even aspects like intersymbol interference are important (intersymbol interference occurs when the bits are so closely packed that the signal picked up from one bit contains energy from adjacent bits). Modern recording codes have the optimum properties in terms of factors like bandwidth and intersymbol interference.
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When PowerPoint opens, it displays a default template presentation.
Answer the following statement true (T) or false (F)
What is the output after the following loop terminates?
``` int number = 25; int i; boolean isPrime = true; for (i = 2; i < number; i++) { if (number % i == 0) { isPrime = false; break; } } int number = 25; int i; boolean isPrime = true; for (i = 2; i < number; i++) { if (number % i == 0) { isPrime = false; break; } } int number = 25; int i; boolean isPrime = true; for (i = 2; i < number; i++) { if (number % i == 0) { isPrime = false; break; } } System.out.println("i is " + i + " isPrime is " + isPrime); ``` a. i is 5 isPrime is true b. i is 5 isPrime is false c. i is 6 isPrime is true d. i is 6 isPrime is false
Many programs written with inheritance could be solved with composition instead, and vice versa. Discuss the relative merits of these approaches in the context of the Point, Circle, Cylinder class hierarchy in this chapter. Rewrite the classes in Figs. 9.6–9.8 (and the supporting programs) to use composition rather than inheritance. After you do this, reassess the relative merits of the two
approaches both for the Point, Circle, Cylinder problem and for object-oriented programs in general. What will be an ideal response?
When copying information from Excel into PowerPoint, a selection of two or more adjacent or nonadjacent cells in Excel is called a(n) ________
Fill in the blank(s) with correct word