HW3-Solution

HW3-Solution - QUESTION 1: a) What operating system are you...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
QUESTION 1: a) What operating system are you looking at, and how long have you used these files (approximately)? Ans: Windows XP Service Pack 3. I have been using these files for approximately 4 months. b) How many files did you find? Ans: 106318 files. c) What is the mean file size? Ans: 7,613,800 bytes or 7.6138 Mega Bytes (MB) d) What is the standard deviation of file sizes? Ans: 968,370,000 bytes or 968.37 MB e) What is the median file size? Ans: 7,064 bytes or 7.064 KB f) Based on mean and median, is the distribution of your files Gaussian, or are there more small files, or more large files? Ans: There are much more small files and a few large files and the distribution is skewed heavily because for my files, Median (7064) is much smaller than Mean (7613800). g) What is the mode of all file sizes, and how often does it occur? Ans: 65 bytes. It has occurred for 428 times. h) Is this file size significant (a large percentage of files)? i) If so, what do you think caused it? (i.e., is there some application that creates files of exactly this size?) Or if not, why is it not significant? Ans: This file size (65 bytes) is not significant because it is far too small. A file of this size can merely contain 65 ASCII characters which can only be good for some very small configuration
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
files. I think files of this size could have been generated by my email client which might be using each file for storing a junk/deleted email’s subject line or some identity. That would also explain wide occurrence of such files. j) What is the PDF of file sizes? k) What is the CDF of file sizes? Show the graph. 0 0.5 1 1.5 2 2.5 3 x 10 11 0 1 2 3 4 5 6 7 8 9 10 x 10 -10 File Sizes Density PDF File Size Distribution 10 0 10 2 10 4 10 6 10 8 10 10 10 12 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 File Sizes CDF CDF
Background image of page 2
l) What is the CCDF, the cumula and y axes as log-scale. m) What characteristic of a CCD Ans: If the CCDF curve decays s bounded and goes down slowly w axis). This shows that the probab So files with large sizes will be t system. n) Do the file sizes of your home Ans: Yes, it shows heavy-tailed b o) Why or why not? (Be specific Ans: As the graph shows the pro (e.g. a 1,000,000 bytes file can o can occur at greater than 1% prob p) Are you a bigger pack-rat than home directory? Ans: No, my file count has reach
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 08/05/2009 for the course CSCI 551 taught by Professor Billcheng during the Spring '08 term at USC.

Page1 / 8

HW3-Solution - QUESTION 1: a) What operating system are you...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online