Emerging Scholars Program - Week 1

## Introduction

Who am I?

• Alexei Czeskis
• aczeskis@purdue.edu
• Senior, majoring in CS and Math
• cs177, cs190, ESP, Research
• Karate, volleyball, books

Purpose of this class

Work in teams to solve fun, interesting problems.

## What we're actually doing today

*Split up into teams and come up with cool team names!

Consider the re-design of existing mp3 (iPod-like) players. Look at both the user interface and particularly memory requirements.
1. Assume each song is 4MB, artwork is 9MB, and you need 60MB for the Operating System. Reminder: MB = megabyte, 1MB = 1024 KB,1KB (kilobyte) = 1024 bytes, 1 byte = 1 character.
2. Now consider what information and how much of it your group wants to store for each song: song title, CD name, song length, composer, etc.
3. Decide how much space all this would take and what size memory you would need to store a reasonable number of songs.
4. Furthermore, assume each MB costs you 14 cents, and the enclosure for the mp3 player costs you \$5. At 1GB this should put you at about \$150 (the price of a 1GB ipod nano). Estimate how much your mp3 player will cost to make.
5. The interface is important, because there is no use storing information if it cannot appear anywhere in the interface. Furthermore, assume that you're making an mp3 player for an alien species in which everyone has only 4 fingers (no thumb). Sketch an interface and be able to verbally describe it.
6. Pick 2 members of your team to go up to the board and present

## A challenge for next time

Suppose you have 9 coins. They are all identical (look, feel, smell, taste, etc.), except one of them is fake and weighs a little more. You also have a binary scale. That is, it can only tell if one side is heavier than the other, but cannot quantify the difference (see picture below). Using the scale only 2 times, how can you find the fake coin? Using scale = putting coins on it and seing which side is heavier.