Chapter 9 13 a) What must the code distance be to detect five errors? b) What must the code distance to be to correct five errors? 15 a) How many data bits are required to store one of the decimal digits 0 through 9? b) How many parity bits are required to correct a single error? c) Write a single-error correction code using even parity. Underline the parity bits? d) What is the code distance of your code? 16) A set of eight data bits is transmitted with the single-error correction code of figure 9.25. For each of the received bit patterns below, state whether an error occurred. If it did, correct the Figure 9.25 4 10 b)1101 00110010 d) 1011 00100100 a)1001 10101001 c)0 00010110100 18 a) Figure 9.28 shows the RAID level 01 and RAID level 10 systems with eight physical disks Draw the equivalent systems for level 01 and level 10 with four physical disks b) Assume that two disks go bad. The sequence BBGG means that the first and second disks are bad and the third and fourth disks are good. With this scenario, the RAID level 01 disk is good because the two bad disks are in the same first striped disk, but the RAID level 10 disk is bad because the two bad disks are in the same first mirrored disk. How many permutations of four letters with two B's and two G's are there? c) Tabulate each permutation, and for each one determine whether the RAID disk is good or bad for level 01 and 10 Figure 9.28