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3 years ago

For an 18 Mbps LTE data stream with a symbol time of 66.67 μs, how many subcarriers are created?

1 answer:

8 0

1/.0000667 = 14,992.5;
18,000,000/14,992 = 1,200 subcarriers
For an 18 Mbps LTE data stream with a symbol time of 66.67 μs, 1,200 subcarriers are created.

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It takes 2 seconds to read or write one block from/to disk and it also takes 1 second of CPU time to merge one block of records.

Alexxx [7]

Answer:

Part a: For optimal 4-way merging, initiate with one dummy run of size 0 and merge this with the 3 smallest runs. Than merge the result to the remaining 3 runs to get a merged run of length 6000 records.

Part b: The optimal 4-way merging takes about 249 seconds.

Explanation:

The complete question is missing while searching for the question online, a similar question is found which is solved as below:

Part a

For optimal 4-way merging, we need one dummy run with size 0.

Merge 4 runs with size 0, 500, 800, and 1000 to produce a run with a run length of 2300. The new run length is calculated as follows $L_{mrg}=L_0+L_1+L_2+L_3=0+500+800+1000=2300$
Merge the run as made in step 1 with the remaining 3 runs bearing length 1000, 1200, 1500. The merged run length is 6000 and is calculated as follows

$L_{merged}=L_{mrg}+L_4+L_5+L_6=2300+1000+1200+1500=6000$

The resulting run has length 6000 records.

Part b

For step 1

Input Output Time

Input Output Time is given as

$T_{I.O}=\frac{L_{run}}{Size_{block}} \times Time_{I/O \, per\, block}$

Here

L_run is 2300 for step 01
Size_block is 100 as given
Time_{I/O per block} is 2 sec

$T_{I.O}=\frac{L_{run}}{Size_{block}} \times Time_{I/O \, per\, block}\\T_{I.O}=\frac{2300}{100} \times 2 sec\\T_{I.O}=46 sec$

So the input/output time is 46 seconds for step 01.

CPU Time

CPU Time is given as

$T_{CPU}=\frac{L_{run}}{Size_{block}} \times Time_{CPU \, per\, block}$

Here

L_run is 2300 for step 01
Size_block is 100 as given
Time_{CPU per block} is 1 sec

$T_{CPU}=\frac{L_{run}}{Size_{block}} \times Time_{CPU \, per\, block}\\T_{CPU}=\frac{2300}{100} \times 1 sec\\T_{CPU}=23 sec$

So the CPU time is 23 seconds for step 01.

Total time in step 01

$T_{step-01}=T_{I.O}+T_{CPU}\\T_{step-01}=46+23\\T_{step-01}=69 sec\\$

Total time in step 01 is 69 seconds.

For step 2

Input Output Time

Input Output Time is given as

$T_{I.O}=\frac{L_{run}}{Size_{block}} \times Time_{I/O \, per\, block}$

Here

L_run is 6000 for step 02
Size_block is 100 as given
Time_{I/O per block} is 2 sec

$T_{I.O}=\frac{L_{run}}{Size_{block}} \times Time_{I/O \, per\, block}\\T_{I.O}=\frac{6000}{100} \times 2 sec\\T_{I.O}=120 sec$

So the input/output time is 120 seconds for step 02.

CPU Time

CPU Time is given as

$T_{CPU}=\frac{L_{run}}{Size_{block}} \times Time_{CPU \, per\, block}$

Here

L_run is 6000 for step 02
Size_block is 100 as given
Time_{CPU per block} is 1 sec

$T_{CPU}=\frac{L_{run}}{Size_{block}} \times Time_{CPU \, per\, block}\\T_{CPU}=\frac{6000}{100} \times 1 sec\\T_{CPU}=60 sec$

So the CPU time is 60 seconds for step 02.

Total time in step 02

$T_{step-02}=T_{I.O}+T_{CPU}\\T_{step-02}=120+60\\T_{step-02}=180 sec\\$

Total time in step 02 is 180 seconds

Merging Time (Total)

Now the total time for merging is given as

$T_{merge}=T_{step-01}+T_{step-02}\\T_{merge}=69+180\\T_{merge}=249 sec\\$

Total time in merging is 249 seconds seconds

5 0

3 years ago

A seven-octet pattern of alternating 0s and 1s used by the receiver to establish bit synchronization is a _______

Licemer1 [7]

Answer: Preamble

Explanation:

Preamble is a 7- octet pattern of alternating the 0's and 1's and it allow devices in the network to easily synchronized the receiver clock. It also provide the bit level synchronization.

It basically allow the start of frame delimiter to provide the byte synchronization and assign a new frame. The bits are transmit orderly from left to right in the frame.

5 0

3 years ago

13. What is the suggested rpm on a hard drive for a laptop?

mario62 [17]

Usually it’s either 5400 or 7200RPM

3 0

3 years ago

"giga" can mean both 109 and 230. explain to what each refers. can this cause confusion when reading a computer advertisement?

inn [45]

Giga usually means 10^9

We're trying to work giba, which is 2^30 into the vocabulary to differentiate them because of the confusion and difference that they create.

7 0

3 years ago

A loop that will output only the names that come before "Thor" in the alphabet from the names list.

matrenka [14]

names = ["Kevin", "Joe", "Thor", "Adam", "Zoe"]

names.sort()

for x in names:

if x == "Thor":

break

else:

print(x)

I made up my own names for the sake of testing my code. I wrote my code in python 3.8. I hope this helps.

3 0

2 years ago