1. CSE115: Introduction to Computer Science I Dr. Carl Alphonce 219 Bell Hall alphonce@buffalo.edu 1

2. Announcements First class? Pick up a syllabus. No recitations this week – they begin next week. Reminder: make your name signs (if you have yours, put it out!) And… 2

3. cell phones off 3

4. Today Web site tour UBLearns and Syllabus acknowledgement Lesson 1: Preliminaries –field/course overview Lesson 2: Representing things –information encoding –symbol interpretation 4

5. Lesson 1 – CSE Spectrum Why is CS/CEN cool? 5

6. 6

7. 7 ←Suzanne Vega ←Tom’s Diner ←MP3 player

8. 8 ←digital camera ←Cell phone ←Camera phone ←2D barcode

9. 9 GPS

10. 10 Payment methods –Pay-at-the-pump –Cell-phone payment

11. 11 ←Saab JAS39 Gripen ←Inherently unstable ←Can only fly under computer control ←Very agile, short take-off and landing ←Fly-by-wire commercial aircraft

12. 12 →Software development environment →Teamwork

13. Photo Credits 13 Tom's Restaurant photo. Date: 2000. Author: Rick Dikeman Suzanne Vega photo. Date: 2006. Author: Michal Maňas GPS photo. Date: 2006. Author: Vijverln, Modified: Emmanuel Boutet 2007. The teamwork photo is from: http://www.flickr.com/photos/znachor/2475763317/in/pool-agile All photos, except for the teamwork photo, are from Wikimedia Commons under the Creative Commons license. Aside from the ones noted below, all from the Wikimedia Commons are in the public domain.

14. Lesson 1 – CSE Spectrum Why is CS/CEN cool? 14 Computer Engineering (“Hardware”) Computer Science (“Software”) cell phones pay-at-pump electronic voting fly-by-wire / drive-by-wire electronic health records robotic surgery smile-sensing cameras social networking mapquest/google maps/gps games privacy mp3 / Suzanne VegaSuzanne Vega etc.

15. Software development CSE115 Introduction to Computer Science I CSE116 Introduction to Computer Science 2 CSE250 Data Structures CSE305 Intro to Programming Languages CSE442 Software Engineering 15

16. Software systems CSE321 Real-Time & Embedded Operating Systems CSE411 Intro to Computer Systems Administration CSE421 Intro to Operating Systems CSE422 Operating Systems Internals CSE451 Program Development CSE462 Database Concepts CSE486 Distributed Systems CSE489 Modern Networking Concepts 16

17. Artificial Intelligence CSE435 Information Retrieval CSE463 Knowledge Representation CSE467 Computational Linguistics CSE473 Intro to Computer Vision & Image Processing CSE474 Intro to Machine Learning 17

18. Theory CSE191 Discrete Structures CSE331 Intro to Algorithm Analysis & Design CSE396 Intro to the Theory of Computation CSE431 Algorithm Analysis & Design 18

19. Hardware/Architecture CSE241 Digital Systems CSE341 Computer Organization CSE379 Intro to Microprocessors and Microcomputers CSE452 VLSI Testing CSE453 Hardware/Software Integrated Systems Design CSE490 Computer Architecture CSE493 Intro to VLSI Electronics 19

20. Information encoding/decoding Text (ASCII, EBCDIC, Unicode, Morse code…) Images (GIF, JPG, …) Music (mp3, …) Video (MPG, …) Quantity (decimal, binary,…) 20

21. Images 21 Each pixel encodes the amount of RED, GREEN and BLUE (RGB). This is an additive color scheme. Printing uses CYAN, MAGENTA, YELLOW and BLACK (CMYK). This is a subtractive color scheme.

22. Morse Code Dots, dashes and spaces used to represent letters/digits http://www.planetofnoise.com/midi /morse2mid.phphttp://www.planetofnoise.com/midi /morse2mid.php Two features: –variable length encodings –not a prefix code 22

23. 23 Spaces of different lengths is needed to decode unambiguously. Without spaces, how many ways can six dots in a row be decoded?

24. 24 5 five cinq

25. Counting Decimal (base 10) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 etc. Binary (base 2) 0 1 10 11 100 101 110 111 1000 1001 1010 1011 1100 1101 etc. 25

26. Number systems Decimal (base 10) Each position is weighted by a power of 10. E.g. 734 = –7*100 + 3*10 + 4*1 –7*10 2 + 3*10 1 + 4*10 0 E.g. 1101 = –1*1000 + 1*100 + 0*10 + 1*1 –1*10 3 + 1*10 2 + 0*10 1 + 1*10 0 Binary (base 2) Each position is weighted by a power of 2. E.g. 111 = –1*4 + 1*2 + 1*1 = “seven” –1*2 2 + 1*2 1 + 1*2 0 E.g. 1101 = –1*8 + 1*4 + 0*2 + 1*1 = “thirteen” –1*2 3 + 1*2 2 + 0*2 1 + 1*2 0 26