Computer Science An Overview PDF

Computer Science An Overview 13th Edition, Global Edition Chapter 0 Introduction Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Chapter 0: Introduction 0.1...

Computer Science An Overview 13th Edition, Global Edition Chapter 0 Introduction Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Chapter 0: Introduction 0.1 The Role of Algorithms (terminology + mattebas) 0.2 The History of Computing 0.3 An Outline of Our Study (bokens uppbyggnad) 0.4 The Overarching Themes of Computer Science – Algorithms – Programming – Abstraction – Internet – Creativity – Impact – Data Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. 0.1 The Role of Algorithms 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 the algorithms they represent Hardware: The machinery Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Figure 0.1 An algorithm for a magic trick Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Figure 0.2 The Euclidean algorithm for finding the greatest common divisor of two positive integers Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. 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. Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. 0.2 The 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 & Lady Ada Lovelace Mer moderna namn: Alan Turing och Margaret Hamilton (se våra porträtt i korridoren på plan 5 hus 99 Exakta årtal eller memorering av alla namn är inte nödvändigt. Ni bör känna igen företeelser och namn men behöver inte kunna rabbla upp allt själva. Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Figure 0.3 Chinese Wooden Abacus Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. 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 https://en.wikipedia.org/wiki/Punched_card Gear positions https://en.wikipedia.org/wiki/Mechanical_computer Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Early Computers Based on mechanical relays – 1940: Stibitz at Bell Laboratories https://en.wikichip.org/wiki/relay_computer – 1944: Mark I: Howard Aiken and IBM at Harvard Based on vacuum tubes https://en.wikipedia.org/wiki/Vacuum_tube – 1937-1941: Atanasoff-Berry at Iowa State – 1940s: Colossus: secret German code-breaker – 1940s: ENIAC: Mauchly & Eckert at U. of Penn. Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Figure 0.4 Three women operating the ENIAC’s main control panel Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Här ligger en kort sammanfattning av utvecklingen mellan 50-tal och 80-tal Transistorn – 1950-tal, mindre, strömsnål, mkt längre livslängd, en transistor i en komponent Integrerade kretsar – Slutet av 50-tal till slutet av1970-tal (VLSI), fler och fler transistorkretsar på ett enda kiselchip – 1979 och framåt: Mikrochip –> mikroprocessorer -> CPU’er Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. 0-12 Personal Computers – Hobbyists built homemade computers – Apple Computer established in 1976. – IBM introduced the PC in 1981. ▪ Accepted by business ▪ Became the standard hardware design for most desktop computers ▪ Most PCs use software from Microsoft Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. End of the 20th Century Internet revolutionized communications – World Wide Web – Search Engines Miniaturization of computing machines – Embedded (GPS, in automobile engines) – Smartphones Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. 0.3 An Outline of Our Study Detta är alltså endast en Chapter 1: Data Storage beskrivning av Chapter 2: Data Manipulation bokens kapitel Chapter 3: Operating Systems Chapter 4: Networks and the Internet Chapter 5: Algorithms Chapter 6: Programming Languages Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. An 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 Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. 0.4 The Overarching Themes of Computer Science Computing technology is fundamental to being a part of the modern world This book will include applications and consequences of computer science Seven “Big Ideas” that unite computer science: – Algorithms, Abstraction, Creativity, Data, Programing, Internet and Impact Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Algorithms Computer Science is the science of algorithms Draws from other subjects, including – Mathematics – Engineering – Psychology – Business Administration – Linguistics Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Figure 0.5 The central role of algorithms in computer science Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Given the Central Role of Algorithms Which problems can be solved by algorithmic processes? How can characteristics of different algorithms be analyzed and compared? How can algorithms be applied to produce intelligent behavior? How does the application of algorithms affect society? Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. 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 Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Creativity Computer science is inherently creative – Discovering and applying algorithms is a human activity – Extends existing forms of expression – Enables new modes of digital expression Creating large software systems is like conceiving a grand new sculpture Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Data Computers can represent any information that can be discretized and digitized Algorithms process and transform data – Search for patterns – Create simulations – Generate knowledge and insight Data is driving modern discovery Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. 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? Dessa frågor ger kursen svar på.. Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. 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 Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. 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? Dessa frågor ger kursen i många fall svar på.. Tidigare kurs är också till hjälp.. Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Internet Profound impact in the way information is: – Stored – Retrieved – Shared Privacy Security Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Impact Social, ethical, legal impacts including: – Security concerns – Issues of software ownership and liabilities – Social impact of database technology – Consequences of artificial intelligence Copyright © 2019 Pearson Education, Ltd. All Rights Reserved. Impact explored through “Social Issues” questions Social Issues questions are meant to increase awareness of: – Various stakeholders – Alternatives – Short term and long term consequences Character-based ethics – “Who do I want to be?” – Become more aware, insightful, and sensitive to the issues involved Copyright © 2019 Pearson Education, Ltd. All Rights Reserved.