Follow these steps to change permissions for your home directory and then create a new user account to test these permissions: 1. Create a new user account named charlie. Log in to Ubuntu Server as charlie and try to copy a file to your own home directory. For example, you can use this command to make a new copy of the my memo file you created earlier:
cp mymemo mymemo. charlie
When you do so, permission is denied.
2. Log back in to Ubuntu Server with your own account.
3. To install the chmod command, use this command:
sudo apt-get install coreutils
4. Use the chmod command to give full read, write, and execute permissions to everyone for your home directory.
5. Log out and log back in to the system as charlie and verify that the user charlie can now copy a file to your home directory.

Some of your friends have gotten into the burgeoning field of time-series data mining, in which one looks for patterns in sequences of events that occur over time. purchases at stock exchanges--what’s being bought-- are one source of data with a natural ordering in time. given a long sequence s of such events, your friends want an efficient way to detect certain "patterns" in them--for example, they may want to know if the four events buy yahoo, buy ebay, buy yahoo, buy oracle occur in this sequence s, in order but not necessarily consecutively. they begin with a collection of possible events (e.g., the possible’ transactions) and a sequence s of n of these events. a given event may occur multiple times in s (e.g., yahoo stock may be bought many times in a single sequence s). we will say that a sequence s’ is a subsequence of s if there is a way to delete certain of the events from s so that the remaining events, in order, are equal to the sequence s’. so, for example, the sequence of four events above is a subsequence of the sequence buy amazon, buy yahoo, buy ebay, buy yahoo, buy yahoo, buy oracle their goal is to be able to dream up short sequences and quickly detect whether they are subsequences of s. so this is the problem they pose to you: give an algorithm that takes two sequences of even~s--s’ of length m and s of length n, each possibly containing an event more than once--and decides in time o(m n) whether s’ is a subsequence of s

10. when you create a pivottable, you need to specify where to find the data for the pivottable. is it true

Allison and her group have completed the data entry for their spreadsheet project. they are in the process of formatting the data to make it easier to read and understand. the title is located in cell a5. the group has decided to merge cells a3: a7 to attempt to center the title over the data. after the merge, allison points out that it is not centered and looks bad. where would the title appear if allison unmerged the cells in an attempt to fix the title problem?