Popular Name | Standard Name | Speed | Media | Maximum Segment Length |
Orange Hose Ethernet | 10Base5 | 10Mbps | ThickCOAX | 500 m |
CheapNET ThinNET | 10Base2 | 10Mbps | ThinCOAX | 185 m |
10BaseT, CAT-3, CAT-5 | 10BaseT | 10Mbps, 100Mbps | Unshielded Twisted Pair | 100 m |
Fiber | 10BaseF | 10Mbps, 100Mbps | Fiber-optic cable | 2 km |
Wireless (infrared) | Wireless (infrared) | 10 Mbps | infrared waves | 500 feet |
Wireless (radio) | cellular | 1.25 - 5 Mbps | radio waves | varies |
Introduction to Internet Resources
Selected Resources on the Internet
Internet Protocols - TCP/IP
begin game display instructions pick a number between 1 and 100 set counter to 0 repeat turn until number is guessed or counter = 7 get guess from user if guess = number then say so and quit; else if guessControl structures:
- sequence statements
- selection(decision) statements
- repetition(looping) statement
Testing the algorithm From Algorithm to Program
program Game; (*Programmed by Clay Cowgill 6/1/93 *) (*******************************************) var Number, Guess, Counter : integer; (*******************************************) begin writeln('Welcome to the guessing game. I''ll pick a number'); writeln(' between 1 and 100 and you try to guess what it is'); writeln(' You get 7 tries.'); (*Calculate a random number between 1 and 100 *) Number := abs (Random mod 100) + 1; Counter := 0; repeat (*turn*) writeln('What''s your guess'); readln(Guess); if Guess = Number then writeln('You got it!') else if GuessNumber then writeln('I fooled you 7 times!') end. Pascal programs - heading, declaratations, body; comments Source Code----->Compiler/Interpreter------>Object Code (Machine Language) syntax errors, logic errors The Languages of Computers
- 1rst Generation - Machine Language (1s & 0s)
- 2nd Generation - Assembly Language (mneumonics)
- 3rd Generation - High-level Languages (FORTRAN, COBOL, BASIC)
- Structured programming: GOTO less, logically cohesive modules (Pascal)
- Efficiency: C
- Object-oriented: C++, Smalltalk
- Others: Ada, Modula-2, LISP, PROLOG, LOGO
- Macro languages (scripting languages): Lotus, WordPerfect, Linkway
- 4th Generation - 4GLs - nonprocedural languages: SQL
- Visual Programming: Visual BASIC, Delphi
The Future of Programming
- Natural languages
- Users become "programmers"
- More programming tools including visual programming
Programs in Perspective: Systems Analysis and Systems Life Cycle
information system - hardware, software, data, people, procedures system life cycle - investigation (problem?), analysis, design (top-down / prototype), development (testing), implementation, maintenance, retirement
The Science of Computing
software engineering database management graphics artificial intelligence computer theory networks & telecommunications computer architecture algorithms & data structures Management info systems programming concepts & languages The State of Software
"hardware is soft, software is hard"
- Software Problems - cost (75% not completed or used), reliablity
- Software Solutions - structured programming & OOPs, Programming environments, program verification techniques, human management
Chapter 11 Exercises
- Discussion Questions - 1, 2, 3
- Projects - 1
Chapter 12: Artificial Intelligence Alan Turing - Turing Machine, Collosus, Turing Test; "Can machines think?" Thinking About Thinking Machines
"What is intelligence?"Can Machines Think? - Turing Test What is Artificial Intelligence?
"Artificial intelligence is the study of ideas which enable computers to do the things that make people seem intelligent."
Patrick Henry Winston"Artificial intelligence is the study of how to make computers do things at which, at the moment, people are better."
Elaine Rich"Artificial intelligence is the study of the computations that make it possible to perceive, reason, and act."
Patrick Henry Winston"Computers are very powerful, but very dumb. Artificial intelligence just makes them less dumb."
An Wang
Artificial Intelligence
Expert Systems Robotics Natural Language Processing Voice Recognition Voice Synthesis Computer Vision Fuzzy Logic Neural Networks - self teaching Games: Searching algorithms, Hueristic (rules of thumb), pattern recognition, machine learning Natural-Language Communication
Machine Translation Traps (automatic translation using parsing programs)
- "The spirit is willing, but the flesh is weak" --> "The wine is agreeable, but the meat is rotten"
- "out of sight, out of mind" --> "blind and insane" or "invisible idiot"
ELIZA Nonsense and Common Sense
- syntax - set of rules for constructing sentences from words
- semantics - underlying meaning of words and phrases (context)
Knowledge Bases and Expert Systems
- data -> information -> knowledge
- knowledge base - facts & system for determining & changing relationships between facts
Artificial Experts
- expert system - software designed to replicate the decision making process of a human expert
- knowledge engineer - specialist who interviews and observes experts and converts their "knowledge" into a knowledge base
Expert system (Knowledge base system) - collection of if-then rules
- MYCIN - diagnose diseases
- AMEX - credit checks
- XCON - DEC, configure computer systems
- AARON - automated artist
- grammar checkers
Expert systems
- help train new employees
- reduce number of human errors
- take care of routine tasks
- provide expertise when no experts are available
- preserve knowledge of experts
- combine knowledge of several experts
- make knowledge available to more people
- Expert system shells
- Pattern Recognition: Making Sense of the World
- identifying recurring patterns in input data with the goal of understanding or categorizing that input
Image Analysis - process of identifying objects & shapes
colorizing movies, piloting cruise missles Optical Character Recognition (OCR)
- POS devices, mail sorting, scanners
- handwriting recognition (Pentop computers)
Automatic Speech Recognition
digitized voice - speaker independence, limited vocabulary, continuous speech Talking Computers
- speech synthesis
- digitized speech and sound
Neural Networks
- distributed, parallel computing systems
- requires training
The Robot Revolution
What is a Robot?
- robota - forced labor
- robot - computer-controlled machine designed to perform specific manual tasks
- input: vision, auditory, touch, heat, external control sensors
- output: mechanical motion, voice
Advantages - save labor costs, improve quality and increase production, hazardous / uncomfortable jobs AI Implications
- ELIZA
- embedded AI
Chapter 12 Exercises
- Discussion Questions - 2, 3, 6
Steve Roberts: Winebiko --> BEHEMOTH (True Telecomputing) Chapter 13: Computers at Work
Into the Information Age
paradigm shift - change in thinking that results in a new way of seeing the world agricultural economy -> industrial economy -> information economy Computers and Change
- "By the year 2000, anybody in western civilization [will] be able to get the answer to any question that has an answer." Jerry Pournelle
- "An age rich in electronic information may achieve wonderful social conveniences at the cost of placing freedom in a deep chill." Langdon Winner
Where Computers Work
- Entertainment - TV, movies, sound, graphics
- Publishing - graphic arts, DTP
- Medicine - medical databases, CAT
- Airlines - CAD, air traffic control, reservations
- Science -
The Automated Factory
robotics, CAD-CAM, CIM
The Automated Office
centralized computing --> enterprise computing (distributed / integrated computing)
Workgroup computing
paperless office
The Electronic Cottage
- telecommuting
- satellite offices
- regional work centers
Management by Computer
- Transaction Processing Systems - traditional DP
- Management Information Systems - computerized system that includes procedures for collecting data, a database for storing data, and software tools for analyzing data and producing reports for different levels of management
- Decision Support System - nonroutine decision-making tool (what if?)
- Executive Support Systems - including expert systems
Other Management Tools
- Project Management Software - needed to overcome information overload
Computers and Jobs
The Productivity Problem
- Productivity and Profits - "software crisis"
- Productivity and PCs - distractions, reliablity of computer system, rapid changes
- Productivity and People - lack of training and support
Computers and Job Quality
- De-skilling and up-skilling - fast-food cashiers; training & support
- Monitoring and surveillence - privacy, morale, devalued skills, loss of quality
- The electronic sweatshop - international telecommuting
Rules of Thumb - Ergonomics and Health
- Choose equipment that's ergonomically designed
- Create a healthy workspace
- Rest your eyes
- Build flexibility into your work environment
- Listen to your body
Employment and Unemployment
- Workers against machines
- Cautiously optomistic forecasts
- Will we need a new economy
Rules of Thumb - Considering Computer Careers
- Learn touch-typing
- Use computers regularly
- Don't forsake the basics (math & communications skills)
- Combine your passions
- Ask questions
- If you can't find your dream job, build it yourself
- Prepare for change
Chapter 13 Exercises
- Discussion Questions - 1, 2, 6
- Projects - 2
Jobs & Wozniak Chapter 14: Computers at School and at Home
Education in the Information Age
Information Age Education
- Technological familiarity - technophobia
- Literacy
- Mathematics
- Culture
- Communications
- Learning how to learn
Computers Go to School
Computer Aided Instruction
- drill-and-practice software
- tutorial software
- simulation software
courseware
- individualized learning
- motivation (entertaining)
- confidence
Programming Tools
"In many schools today, the phrase 'computer-aided instruction' means making the computer teach the child. One might say the computer is being used to program the child. In my vision, the child programs the computer and, in doing so, both acquire a mastery over a piece of the most modern and powerful technology and establishes an intimate contact with some of the deepest ideas from science, from mathematics, and from the art of intellectual model building." Seymour Papert, Mindstorms
LOGO Simulation and Games
- Virtual Frog Dissection Kit, Carmen San Diego, Sim CityProductivity Tools
- lab sensing hardware (LabView)
- groupware
- music synthesizers
Computer-Controlled Media
"I hear and I forget, I see and I remember, I do and I understand." Chinese ProverbComputers at School: Midterm Grades
- Presentation Aids
- Hypermedia and Interactive Multimedia (encyclopedias)
- Authoring Tools for Students (Authorware)
High Marks
- improved problem-solving skills
- more motivated
- higher self-esteem
- cooperative learning
Room for Improvement
- "state of art"
- teacher training
- restructuring (How does it fit?)
The Classroom of Tomorrow
- Internet, multimedia, ACOT schools
The Campus of Tomorrow
"The further one pursues knowledge, the less one knows" Lao Tse
- Project 2000 - UIUC's Tablet, Plato
- Distance Education: Virtual Schools
- Classes on the Internet
- University of Phoenix
- University of Nova
Computers Come Home
"There is no reason for any individual to have a computer in the home" Ken Olsen, 1977
Home Automation SystemHousehold Business
Business Applications at Home
- Wordprocessing,
- Spreadsheets,
- Database Programs,
- Personal Information Management Programs,
- Accounting & Income Tax Programs
Smart Cards Communication, Education, and Information
- AOL, CompuServe, Prodigy, etc.
- CD-ROM Encyclopedia
- custom newspapers & newscasts
Home Entertainment Redefined
- computer & video games
- interactive fiction & movies
- VR
Creativity and Leisure Rules of Thumb - Concise Computer Consumer's Guide
- Cost
- Capability
- Capacity
- Customizability
- Compatibility
- Connectivity
- Convenience
- Company
- Curve
Chapter 14 Exercises
- Discussion Questions - 1, 3, 6
- Projects - 5
Chapter 15: Computer Security and Risks
Kempelen's Amazing Chess-Playing Machine
- On-line Outlaws: Computer Crime
- FBI's National Crime Information Center
The Computer Crime Dossier
- Computer Crime - crime accomplished through the knowledge or use of computer technology
- average computer crime = $600,000
Theft by Computer
money, phone time, computer time Software Piracy and Intellectual Property Laws
- software piracy - illegal duplication of copyrighted software
- 20% loss worldwide
"look-and-feel" lawsuits Software Sabotage
- Trojan horse
- Virus
- Worms
- Logic and Time Bombs
Hacking and Electronic Trespassing
Clifford Stoll's - The Cuckoo's Egg Computer Security: Reducing Risks
Computer Security - protecting computer systems and the information they contain against unwanted access, damage, modification, or destruction.
A computer will do exactly what it is programmed to do! A computer can do only what it it programmed to do!
Physical Access Restrictions
- smart card
- password
- signature
- biometrics
Passwords
- access control software
- call-back systems
Encryption audit-control software BACKUPS
Human Security Controls
Security, Privacy, and Freedom: The Delicate Balance
- monitor e-mail???
- active badge (smart badge)
Justice on the Electronic Frontier
- Are BBS sysops responsible for software on their BBS?
- Are Universities responsible for e-mail messages sent by students?
Security and Reliability
Bugs and Breakdowns
- It's impossible to eliminate all bugs
- Even programs that appear to work can contain dangerous bugs
- The bigger the system, the bigger the problem
Computers at War
"Knowledge is power and permits the wise to conquer without bloodshed and to accomplish deeds surpassing all others." Sun Tzu, The Art of War
- smart weapons
- autonomous systems
- SDI
IS SECURITY POSSIBLE?
Computer Crime, Security, and Computer Viruses
Chapter 13 Exercises
- Discussion Questions - 2, 5
Chapter 16: Inventing the Future
Alan Kay - Xerox PARC(Palo Alto Research Center), PC, DynaBook
Tomorrow Never Knows
The Hazards of Predicting the Future
- "Everything that can be invented has been invented." Charles Duell, 1899
- "Who the hell wants to hear actors talk?" Henry Warner, 1927
- 1900 Mercedes-Benz study - worldwide demand for cars = 1 million
Four ways to Predict the Future
- 1) Invent it
- 2) look at current research
- 3) look at past products & see what made them sucessful
- 4) look at four phases of technology
- harware software
- service way of life
From Research to Reality: 21st-Century Information Technology
Tomorrow's Hardware: Trends and Innovations
- Speed
- Size
- Efficiency
- Capacity
- Cost - performance / price - doubles every 2 years
New Ripples
- flat-panel displays
- solid-state storage devices
- RISC processors
- parallel processing
- alternative chip technologies - GaAs, superconductors, optical computers
- fiber-optic & wireless networks
The expanding information infrastructure Tomorrow's Software: Evolving Applications and Interfaces
- OOPs, CASE tools, visual programming environments
Software Currents
- cross-platform communications
- customizable applications
- converging user interfaces
From WIMP to SILK (speech, image, language, knowledge capabilities)
- Speech & language - voice mail & voice annotation
- Imaging - graphics --> VR
- Knowledge - software agents
Tomorrow's Service: Agents on the Network
- Intelligent agents: NewsPeek, Knowbots, Disclosure's "angels"
Cyberspace Services
- Personal telephone numbers
- Videophones
- Electronic yellow pages
- Open electronic markets
- On-demand automobiles
- Customized clothes
- Movies on demand
- Customizable TV & textbooks
Tomorrow's Way of Life: Transparent Technology
- Embedded intelligence - appliances smart toilets
- Ubiquitous computers - active badges, automated house, car, office
The Day After Tomorrow: Information Technology Meets Biology
- Microtechnology - micromachines: microsensors, smart pill
- Nanotechonlogy - nanomachines, scanning tunneling microscope
- Artificial Life
Human Questions for a Computer Age
- Will computers be democratic?
- Will the Global Village be a community? (haves vs. have-nots)
- Will we become information slaves?
Chapter 16 Exercises
- Discussion Questions - 2, 3
- Projects - 2