Transcript Takeshi Tokuyama ・ Jinhee Chun Tohoku University Graduate
情報基礎
B Lecture 3
Takeshi Tokuyama
Tohoku University Graduate School of Information Sciences System Information Sciences Design and Analysis of Information Systems
HISTORY AND CONCEPT OF INFORMATION
History of Computer
• Computer – A machine that carries out arithmetic and logical operation – Supercomputer, mainframe, server, personal computer, word processor, calculator and etc
Early Computers
• • • B. Pascal(1640?) “Pascalina” C. Babbage(1822) Differnce engine ABC (Atanasoff-Berry 1942) – First electronic computing device http://www.infonet.co.jp/ueyama/ip/history/eniac.html
(Japanese)
Ideas by mathematicians
• • • • George Boole (1815-1864): Boolean Algebra Alan Turing(1912-1954): Turing machine: Basic idea of logical process by a computer – Charch-Turing thesis: Computable functions • Turing decoded the famous Enigma crypto of Nazis John Von Neumann (1903-1957) – Idea of “computer program” (stored program) Claude Shannon(1916-2001) – Information theory and switching circuit
• • • •
Boolean algebra and computing
Boolean algebra: Algebra on 0 and 1 – 0 ⊕ 0 = 0, 0 ⊕ 1=1 ⊕ 0=1, 1 ⊕ 1= 1 (AND operation) – 0 ⊗ 0=0, 0 ⊗ 1=1 ⊗ 0=0, 1 ⊗ 1= 1 (OR operation) – NOT(0) = 1, NOT(1)=0 (NOT operation) Every computation can be represented AND, OR, NOT can be realized electronically – Relay, transistor, etc Information coding (Shannon) : Transform every information by sequences of 0 and 1 (bit sequences)
The first computer in use
• ENIAC (Electronic Numerical Integrator and Computer) – First general purpose electronic computer – Invented by John William Mauchly and John Presper Eckert in 1942 http://www.infonet.co.jp/ueyama/ip/history/eniac.html
(Japanese)
• ENIAC (Electronic Numerical Integrator and Computer) – Floor area: 100 ㎡ , Length: 30m, Weight: 30t, Power Consumption 150kW – Developed secretly on military purpose such as trajectory calculation and Cryptanalysis http://www.infonet.co.jp/ueyama/ip/history/eniac.html
(Japanese)
Hardware Architecture
Control Unit Instruction Load Processing Instruction Program Container Main Memory I/O Controller Processing Unit I/O Device Data Read & Write – – Control Architecture operates those transaction Operating System shares those devices
File and Folder
• File – A block of information • Document file • Program file • Image file (a picture from a digital camera) • Audio file (ex: a song in CD) – File Size • KB: KiloByte • MB: MegaByte …etc
File and Folder
• Folder (“Directory” in Linux) – A virtual container which groups files and other folders – ex) • Music folder which contains audio files • “My Document” or “Home Directory” in your account at Tohoku University – Common file system in almost all operating systems
OS
• Operating System – Multi Task • Internet browser, music player, text editor and mailer are available at the same time – Share storages for various purpose – Required to use storage efficiently and keep in order
OS
• History of OS – MVS/CMS: OS for IBM Mainframe • Multiple Virtual Storage • Conversational Monitor System • System/360(1964) has established Mainframe features – UNIX: Typical workstation OS – MS-DOS: De facto standard of OS on early PC – Windows, MacOS: Main OSs on current PC – TRON: Japanese OS used inn cellphone – LINUX: UNIX for PC – Android
UNIX System
• • • • • MULTICS -> UNIX 1983 Published by AT&T Bell Labs 1985 UC Berkley distributed lite edition Features – Tree structure file system • Epoc making idea • Adopted in Windows, MacOS and etc – Open source – Various tools and free software – Many excellent algorithms • Data search, data checking, etc Linux for PC – Developed by Linux Torvalds
home usr
File Structure
/ www local system bin b1v b1c b1cb123?
b0 /usr/home/b1c/b1cb123?
Home directory for a student
Why tree structures?
• Tree structure is magic to handle large data – I have more than 1000,000 files in my own PC – We have more than 1000,000,000 web pages in the world – How to organize them?? Tree is the solution.
• www.dais.is.tohoku.ac.jp/~tokuyama/profile.htm
– By using a tree with 6 layers with 20 branches at each node, how many information can be represented?
Windows
• • • • • The name comes from “WindowSystem” Bill Gates: DOS and Windows, a software business magnate Mouse click and icons – So as MacOS Easy operation targeting personal users – Simple installation – Highly functional software(ex.Microsoft Office) Maintenance and version up by Microsoft – Win 95 -> 98 -> … -> XP -> Vista -> 7 (not free)
What is file name?
• • • File name consists of name and extension – Doc1 .
txt Extension is a type of file Some applications use their own extensions – mytext.txt (text file) – – mydocument.doc (MS Word 97-2003 document file) mydocument.docx (MS Word 2007- document file) – myweb.html (html file: for web design) – mypicture.jpg (picture file)
File Operation
• • • • Open “MyDocument” from icon Create folders below – practice – assignment – handout Move files from folder to another folder Create file and copy them
COMPUTER BASICS II
INTERNET
Internet
• History of the Internet – 1970s: Development on packet communication and TCP/IP(Transmission Control Protocol / Internet Protocol) – 1980s: ARPANET(Pentagon and UC Berkley) • Academic, Military, Aviation, Space Development • IBM VNET: Corporate network – 1990s: Practical Internet based on e-mail • Alternative communication method to mail and phone • For hearing-impaired person (MCI VIntonCerf) – 1990s latter half: www(world wide web) • one-to-many multimedia information service on web page • Development exceeding TV – 2000s: mobilization(cellphone)
Internet
• WWW(World Wide Web) – Multicasting information service • Open to everybody: one-to-many • User select information he/she need – Search Engine • i.e. google – Links between texts with Hypertext – Visualization on Internet Browser
Internet
• • The result of interconnecting computer networks Networks in home, office and School are connected to the internet via internet provider.
Internet Internet Provider LAN: Office, University
Internet
• Server – Provides services across network – Each server provides essential service on demand • Mail Server • Web Server…etc – Those server enables • E-mail • Web browsing • File transferring…etc
Internet
• IP address(Internet Protocol Address) – Number to identify a machine on network – Each computer has different ones – Numbers and dots • Ex) 192.168.0.1
– Provided by agency in each country • JPNIC(Japan Network Information Center)
Internet
• • Domain name – cs.he.tohoku.ac.jp
– http://www.ise.he.tohoku.ac.jp
Domain name is converted to IP address in DNS server so that to send information to receiver
website
• • Collection of related web pages on the internet Internet Browser is used to visit website – URL(Uniform Resource Locator) • A sort of address, indicates a place of information
Website
http://www.google.co.jp/
Enter URL Send Web page Web Server
Web Browser look for the web server on the internet and display web site
Website
• • HTTP – HyperText Transfer Protocol – Protocol between web browser and web server to send and receive contents HTML – HyperText Markup Language – Language for website – Links between web pages, photos, movies
SMTP SMTP Internet MTA MTA MUA – MUA(Mail User Agent) • Mailer – MTA(Mail Transport Agent) • Program on mail server – SMTP(Simple Mail Transport Protocol) MUA
• Mail Address – Consists of user name and domain name
b1xxxxx @ cs
.
he
.
tohoku
.
ac
.
jp
– Domain • Indicates address of mail server • Usually, name of university or company in which user belongs
E-mail b1xxxxx @
cs .
he
.
tohoku
.
ac .
jp Computer System for Education of Infomatics Fifth Level Domain Center for the Advancement of Higher Education Fourth Level Domain University domain name Third Level Domain Academic Second Level Domain Japan Top Level Domain
• Mail Address and IP Address
b1xxxxx @
cs .
he
.
tohoku
.
ac .
jp – Mailer sends message to IP address converted from mail address
130.34.129.xxx
– POP server(works as post office) receives e-mail
• Example of mail transport – Prof. Aronov(NYIT) to Tokuyama edu US Academic Network ac.jp
poly.edu
NY Institute of Technology JP Academic Network tohoku.ac.jp
Tohoku University is.tohoku.ac.jp
Graduate school of Information Sciences Mail Server: ziggy 128.238.32.77
dais.is.tohoku.ac.jp
Tokuyama Lab Mail Server: masamune 130.34.233.xx
• Writing e-mail – Write in an appropriate format • Sender and Title should be clear • Not a chat • There is log • Never tell a bad thing
From Fri Apr 02 16:59:09 2004 ziggy.poly.edu (ziggy.poly.edu [128.238.32.77]) by masamune.dais.is.tohoku.ac.jp (8.12.10+Sun/0000) with ESMTP id i327rKmU014249 for
• • Search Engine on the internet Founder – Sergey Brin, Larry Page http://www.google.co.jp/intl/ja/about/corporate/company/execs.html