Computer Science Introduction PDF

Chapter 0: Introduction © 2015 Pearson Education Limited 2015.  Chapter 0: Introduction 0.1 The Role of Algorithms 0.2 The History of Computing 0.3 An Outline of Our Study 0.4 The Overarching Themes of Computer S...

Chapter 0: Introduction © 2015 Pearson Education Limited 2015.  Chapter 0: Introduction 0.1 The Role of Algorithms 0.2 The History of Computing 0.3 An Outline of Our Study 0.4 The Overarching Themes of Computer Science – Algorithms – Programming – Abstraction – Internet – Creativity – Impact – Data © 2015 Pearson Education Limited 2015 0-2  Terminology Algorithm: A set of steps that defines how a task is performed Program: A representation of an algorithm Programming: The process of developing a program Software: Programs and algorithms Hardware: Equipment / Machinery © 2015 Pearson Education Limited 2015 0-3  Figure 0.1 An algorithm for a magic trick © 2015 Pearson Education Limited 2015 0-4  History of Algorithms The study of algorithms was originally a subject in mathematics. Early examples of algorithms – Long division algorithm – Euclidean Algorithm Gödel's Incompleteness Theorem: Some problems cannot be solved by algorithms. © 2015 Pearson Education Limited 2015 0-5  Figure 0.2 The Euclidean algorithm © 2015 Pearson Education Limited 2015 0-6  History of Computing Early computing devices – Abacus: positions of beads represent numbers – Gear-based machines (1600s-1800s) Positions of gears represent numbers Blaise Pascal, Wilhelm Leibniz, Charles Babbage © 2015 Pearson Education Limited 2015 0-7  Figure 0.3 Chinese Wooden Abacus © 2015 Pearson Education Limited 2015 0-8  Early Data Storage Punched cards – First used in Jacquard Loom (1801) to store patterns for weaving cloth – Storage of programs in Babbage’s Analytical Engine – Popular through the 1970’s Gear positions © 2015 Pearson Education Limited 2015 0-9  Early Computers Based on mechanical relays – 1940: Stibitz at Bell Laboratories – 1944: Mark I: Howard Aiken and IBM at Harvard Based on vacuum tubes – 1937-1941: Atanasoff-Berry at Iowa State – 1940s: Colossus: secret German code-breaker – 1940s: ENIAC: Mauchly & Eckert at U. of Penn. © 2015 Pearson Education Limited 2015 0-10  Figure 0.4 The ENIAC computer © 2015 Pearson Education Limited 2015 0-11  Personal Computers – First used by hobbyists – IBM introduced the PC in 1981. Accepted by business Became the standard hardware design for most desktop computers Most PCs use software from Microsoft © 2015 Pearson Education Limited 2015 0-12  Into the Millennium Internet revolutionized communications – World Wide Web – Search Engines (Google, Yahoo, and Microsoft) Miniaturization of computing machines – Embedded (GPS, in automobiles, household devices, etc.) – Smartphones © 2015 Pearson Education Limited 2015 0-13  Outline of Our Study Chapter 1: Data Storage Chapter 2: Data Manipulation Chapter 3: Operating Systems Chapter 4: Networks and the Internet Chapter 5: Algorithms Chapter 6: Programming Languages © 2015 Pearson Education Limited 2015 0-14  Outline of Our Study (continued) Chapter 7: Software Engineering Chapter 8: Data Abstractions Chapter 9: Database Systems Chapter 10: Computer Graphics Chapter 11: Artificial Intelligence Chapter 12: Theory of Computation © 2015 Pearson Education Limited 2015 0-15  The Overarching Themes of Computer Science Computing technology effects: – Governments, economics, scientific research, role of data, communication, … Seven “Big Ideas” that unite computer science: – Algorithms, Abstraction, Creativity, Data, Programming, Internet and Impact © 2015 Pearson Education Limited 2015 0-16  Algorithms The science of algorithms Draws from other subjects, including – Mathematics – Engineering – Psychology – Business Administration © 2015 Pearson Education Limited 2015 0-17  Figure 0.5 The central role of algorithms in computer science © 2015 Pearson Education Limited 2015 0-18  Given the Central Role of Algorithms Which problems can be solved by algorithmic processes? How can algorithm discovery be made easier? How can techniques of representing and communicating algorithms be improved? How can characteristics of different algorithms be analyzed and compared? © 2015 Pearson Education Limited 2015 0-19  Given the Central Role of Algorithms (continued) How can algorithms be used to manipulate information? How can algorithms be applied to produce intelligent behavior? How does the application of algorithms affect society? © 2015 Pearson Education Limited 2015 0-20  Abstraction Abstraction: The distinction between the external properties of an entity and the details of the entity’s internal composition Abstract tool: A “component” that can be used without concern for the component’s internal properties © 2015 Pearson Education Limited 2015 0-21  Creativity Computer science is inherently creative – Discovering and applying algorithms is a human activity – Extends forms of expression in many ways Creating large software systems is like conceiving a grand new sculpture © 2015 Pearson Education Limited 2015 0-22  Data Computers can represent any information – That can be discretized and digitized Algorithms process and transform data Massive storage capacities High speed networks © 2015 Pearson Education Limited 2015 0-23  Questions about Data How do computers store data about common digital artifacts? – Numbers, text, images, sounds, and video How do computers approximate data about analog artifacts in the real world? How do computers detect and prevent errors in data? What are the ramifications or an ever-growing and interconnected universe of digital data? © 2015 Pearson Education Limited 2015 0-24  Programming Programming is broadly referred to as: – Translating human intentions into executable algorithms Computer hardware is capable of only simple algorithmic steps Abstractions in a programming language allow humans to reason and encode solutions to complex problems © 2015 Pearson Education Limited 2015 0-25  Questions about Programming How are programs built? What kind of errors can occur in programs? How are errors in programs found and repaired? What are the effects of errors in modern programs? How are programs documented and evaluated? © 2015 Pearson Education Limited 2015 0-26  Internet Profound impact in the way information is: – Stored – Retrieved – Shared Privacy Security © 2015 Pearson Education Limited 2015 0-27  Impact (1/2) Social, ethical, legal impacts including: – Security concerns – Issues of software ownership and liabilities – Social impact of database technology – Consequences of artificial intelligence © 2015 Pearson Education Limited 2015 0-28  Impact (2/2) No “Correct” answers, instead increase awareness of: – Various stakeholders – Alternatives – Short term and long term consequences Character-based ethics – “Good Behavior” is a consequence of “Good Character” © 2015 Pearson Education Limited 2015 0-29  End of Chapter © 2015 Pearson Education Limited 2015.