Some Uses for Computers in Research

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Some Uses for Computersin Research
Dr. Darren M. Gillis, Z317 Duff Roblin,
474-9683 dgillis_at_umanitoba.ca
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OUTLINE

• The Information Machine
• The World Wide Web
• Information content and quality
• The Calculating Machine
• Statistical Packages
• Numerical Modeling
• The Working Machine
• Data recording
• Digital Measures
• Interfacing Computers with Apparatus in the Lab
  and Field

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REMEMBER It is just a tool

• Computers do
• allow more calculations to be done quickly
• provide a means of storing and accessing
  information at a greater rate than possible with
  written or printed material

• Computers do NOT
• guarantee the correct result
• sometimes less is more
• excessive analysis or numerical modeling may
  obscure the original problem

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Internet, Information Highway, and the World
Wide Web (WWW)
Where did it all come from?
The Cold War Required Information exchange
between defense researchers at Universities and
the Military with high survivability of nuclear
strikes.
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Solution Redundant, decentralized links between
institutions using leased phone lines (cables,
satellites, etc.) The Internet
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Early Internet ARPANET

• Advanced Research Projects Agency Network
  (ARPANET) of the U.S. Department of Defense
• Servers
• computers
• connects to others via telecommunication lines
• control information exchange
• routing according to traffic load
• usually UNIX operating systems

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• Early Services via Internet
• remote computer access
• rlogin
• telnet
• remote file access
• FTP - file transfer protocol
• anonymous FTP
• Gopher
• electronic mail
• personal messages
• mail lists
• news groups
• Internet bulletin boards

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Meanwhile, in Switzerland...

• At CERN (the particle physics guys)
• exchange of data and manuscripts
• desire for standard, viewable format
• created HTTP - hypertext transfer protocol

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What makes HTTP special?

• document could be non-linear
• links possible
• within the same file
• between different files
• between files on different machines
• file could contain
• text
• image
• now sound, movie, forms, etc.

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Thus, the World Wide Web

• WWW a.k.a. world wide wait
• uses an HTTP viewer or web browser
• Originally Mosaic
• Netscape
• MS Internet Explorer
• Evolution of the Internet from
• a collection of isolated files
• gtgtgt toward ltltlt
• a single, cross-referenced document

Unstructured, decentralized, dynamic i.e.
potentially very annoying
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The Homepage the fundamental WWW entity

• An HTTP document maintained by
• an individual
• a company
• a non-commercial organization
• to serve their own specific needs including
• propagation of information
• text, data, programs
• produced by maintainer
• links to related sites
• commerce
• dialogue (via forms, BBS, etc.)

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Homepage is identified by its URL (Universal
Resource Locator)
http//www.umanitoba.ca/home.html
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• Know-bots
• constantly search the Internet
• download content lists of servers
• title lines of HTTP pages
• sometimes contents
• update searchable master-index
• accessible as WWW Pages

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Quality of Information??

• No peer review for most WWW info
• follow up leads with detailed research
• Many peer reviewed journals are on-line!
• Same content, different medium
• Still reviewed, information equally reliable
• Can save paper (but often print)
• speeds distribution AFTER publication
• Software
• if shareware/freeware beware
• VIRUS scan regularly and then again!
• programs associated with publications may be
  found this way

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The Calculating Machine
Statistical Analysis
S X2/n
Numerical Modeling
dX/dt r X (1 - X/K)
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Statistical AnalysesPackages
SPSS, SAS, S-Plus, R, etc.

• Do most calculations for common statistics
• t-tests
• ANOVA, ANCOVA, MANOVA
• Factor Analysis
• Cluster Analysis
• Time Series Analysis

Do NOT chose appropriate statistics,design
experiments, or select relevanthypotheses!!!
(may have guides, but)
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For example
Tool Bar for common tasks

• Data Window
• quickly add/delete/modify

• Output Window
• Text formatted results

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Numerical Modeling of Natural Systems
Model

• a simplified representation of the real world
• qualitative or logical
• quantitative
• analytical
• differential eqns
• numerical
• difference eqns
• readily testable predictions
• answer specific questions
• how long ? how much ? how many ?

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Types of models

• Qualitative
• more people are born every year than in any
  previous year

• Quantitative
• Exponential
• N(t) N0 e r t
• Answer the question
• If we started with 2 people, how many people will
  there be in 100 years?

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How Are Model Calculations Performed?
We must translate mathematical formulas into
instructions that calculating machines can
execute

• The Programming Language
• BASIC - Beginners All-purpose Symbolic
  Instructional Code
• FORTRAN - Formula Translation Language
• Other specialized languages
• APL, Pascal, Forth, LISP, Prolog, ...
• Current Favorites C C
• Compiled Languages allow best speed
• Interpreted Languages allow easiest use

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Output of Models of Natural Systems

• Numeric output
• value of interest
• values for further analysis

• Output should match the question(s) being asked
  by the model
• frequencies - histograms
• relationships - scattergrams
• time trends - TS plots
• spatial trends - maps
• spatial - animation
• temporal

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Animated Output of GrouseDistribution With and
WithoutMilitary Training
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Modeling Emergent Behavior in Natural Systems
e.g. BOIDS http//www.geocities.com/SiliconValley/
Bay/5922/
1. Separation steer to avoid crowding local
flockmates. 2. Alignment steer towards the
average heading of local flockmates.
3. Cohesion steer to move toward the average
position of local flockmates.
Such models do not PROVE hypotheses about natural
systems, but they do test the logic of our
conceptions and provide predictions to judge
those concepts.
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Where Do I Start? The Spreadsheet
Current Spreadsheets incorporate calculating,
graphing, data analysis, and even programming
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The Lab and Field Machine
New measuring apparatus is being designed to
interface directly with computers.

• Digital
• balances
• calipers
• thermometers
• etc.

• Removes data transcription step
• increases rate of data collection
• Telemetry remote collection transmission

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With proper equipment data collection and
preliminary analysis can be done almost
simultaneously.
Example Sonogram Software
Frequency
Time
Darkness represents intensity
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And finally an example of computer aids in
presentations Powerpoint tips