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情報基礎 B Lecture 3
Takeshi TokuyamaTohoku University Graduate School of Information
SciencesSystem 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 Architecture operates those transaction– Operating System shares those devices
Main MemoryMain Memory
I/O DeviceI/O Device
I/O ControllerI/O ControllerControl UnitControl Unit
Processing Unit
Processing Unit
Program Container
DataRead & Write
InstructionLoad
ProcessingInstruction
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
File Structure
//
usrusr systemsystemwwwwww
homehome locallocal binbin
b1vb1v b1cb1c b0b0
b1cb123?b1cb123?/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 IIINTERNET
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.
InternetInternet
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
Web ServerWeb Server
Enter URL
Send Web page
http://www.google.co.jp/http://www.google.co.jp/
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
– MUA(Mail User Agent)• Mailer
– MTA(Mail Transport Agent)• Program on mail server
– SMTP(Simple Mail Transport Protocol)
MUA MUAMTA MTA
SMTP SMTPInternetInternet
• Mail Address– Consists of user name and domain name
– Domain• Indicates address of mail server• Usually, name of university or company in which user
belongs
Fifth Level Domain
Third Level Domain
Second Level Domain
Top Level Domain
Fourth Level Domain
Japan
Academic
University domain name
Center for the Advancement of Higher Education
Computer System for Education of Infomatics
• Mail Address and IP Address
– Mailer sends message to IP address converted from mail address
– POP server(works as post office) receives e-mail
130.34.129.xxx
• Example of mail transport– Prof. Aronov(NYIT) to Tokuyama
ac.jp ac.jp
poly.edupoly.edu
[email protected]@cis.poly.edu
US Academic Network
JP Academic Network
Graduate school of Information Sciences
Tokuyama Lab
Mail Server: masamune130.34.233.xx
Mail Server: ziggy 128.238.32.77
NY Institute of Technology tohoku.ac.jptohoku.ac.jp
is.tohoku.ac.jpis.tohoku.ac.jp
dais.is.tohoku.ac.jpdais.is.tohoku.ac.jp
[email protected]@dais.is.tohoku.ac.jp
eduedu
Tohoku University
• 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 Received: from 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 <[email protected]>;
Fri, 2 Apr 2004 16:53:20 +0900 (JST) Received: (from aronov@localhost) by ziggy.poly.edu (8.9.0/8.9.0) id CAA17696;
Fri, 2 Apr 2004 02:53:17 -0500 (EST) Date: Fri, 2 Apr 2004 02:53:17 -0500 (EST) Message-Id: <[email protected]> From: Boris Aronov <[email protected]> To: Takeshi Tokuyama <[email protected]>
• Search Engine on the internet• Founder
– Sergey Brin, Larry Page
http://www.google.co.jp/intl/ja/about/corporate/company/execs.html
