Transcript The World Wide Web

Internet Programming with Logic
Programming Languages and
Constraint Solvers
• Paul Tarau
• University of North Texas & BinNet
Corporation
• http://www.cs.unt.edu/~tarau
• http://www.binnetcorp.com
• [email protected], [email protected]
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PART I: An Overview of Internet
Development Trends
• A Goal Oriented view:
– WHY to develop for the Internet?
– WHAT to develop for the Internet?
– HOW to develop for the Internet?
• Emphasizing: from the public library to the
shopping mall - the new focus on ECommerce 2
Internet Growth: driven by ECommerce
• Critical mass needed: ~20% online
• from random graphs: sudden emergence of
a big component
• Growth of E-commerce (US)
1998 -> $29 billion
1999 -> $98.4 billion
2003 -> $1.2 trillion (source: eMarketer)
3
Buying over the Internet
• Initial markets: software, travel, books, CDs
- MP3
• online stock trading: Schwab, E-Trade,
Suretrade
• online grocery: back to the future:-)
HomeGrocer, NetGrocer, Peapod
• online drugstores?
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Auctioning systems/electronic
markets
• eBay, priceline
• price comparison/item matching agents:
– EBay's Personal Shopper
– Amazon’s book recommandations
• more conventional shopping chart?
• refereal programs: Amazon, priceline
5
Trends in E-Commerce
• Integration of e-commerce and corporate
data processing systems
– backend databases: DB2, Oracle
• Complete e-commerce solutions vs.
component based e-commerce systems
– complete solution offerings: IBM
– CGI scripts (Perl), servelets, SSI, Active
Server Processes (ASP)
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Internet based e-commerce
infrastructure
• WWW - still in exponential growth for the
next few years
• payment is just Information Exhange subject to automation!
• Shopping by features: search, online
browsing can do it better than asking a (not
always) knowledgeable salesperson
• place for LP/CP: the need for intelligent7
Encryption, digital signatures
• conventional cryptography: DES, BlueFish
• public key cryptography: RSA, PGP
• confidentiality: PGP only a given group can
decode, no need for key exchange
• authentication
– digital signature, certificates - VeriSign
etc.
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• virgin territory for LP/CP: cryptography!
Secure transactions
• SSL basic security built in most browsers,
alternative: SHTTP
– still much better than conventional paper
based security
• DES: is it good for business transactions?
(40 bit ok, 128bit - truly secure)
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Forms of electronic payment
• Electronic Money
– anonymus, unforgeable, “sound” - a place
for LL?
• smart cards - downloadable from online
account
• is third party certification needed?
• E-checks vs. credit cards vs. e-cash
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Predictions/Trends?
• E-commerce will completely reshape
financial institutions
• it is likely to replace various forms of
catalog and mail order businesses
• successful in information based (books,
CDs), high margin/low volume, expensive
to keep in inventory products
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Search Engines, Portals, Service
Sites
• Trend: from Information to Knowledge - a
place for LP/CP
• Search engines: AltaVista, Snap,
NorthernLight
• Portals: Yahoo, Lycos
• Specialized service sites:
– books: www.amazon.com
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– travel: www.itn.com
Basics of Internet Infrastructure:
TCP/IP
• packet switching vs. dedicated point-topoint link
• Post Office (small packets ) vs. Phone
Center (point-to-point link)
• IP header: address 129.120.44.123 vs.
• domain based naming: www.cs.unt.edu
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Static vs. Dynamic IP addresses
• self contained server and web site: static IP
• connecting through an ISP: dynamic IP:-(
– in fact, this comes from running out of
available IP addresses - upcoming
extended IP numbers might solve this - it
is quite humiliating for users to be:
cust007.my_isp.com instead of being
www.JamesBond.com :-)
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How to create and register a new
domain?
• www.internic.net: (not a NSI monopoly
anymore!)
• new agency: http://www.icann.org/
• http://www.networksolutions.com/
• Whois service: http://www.nsiregistry.com/
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How to create a Web Site?
• Dedicated server
– T1 (large volume, high cost) or ISDN
(metered, slow, starts to look outdated)
– new: DSL from GTE (in Dallas-FW area)
– What OS? Linux+Apache (more flexible)
NT (compatible with other MSoft tools)
• Through Web hosting (inexpensive and
reliable but less flexible)
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Web Site Design Issues
• Usability issues (quick access to frequently
visited pages)
• Artistic issues (colors, layout, style)
• Designing for speed (*.mid *.jpg vs. *.wav,
animated *.gif)
• Good and bad business web sites - ratings!
• Style: look at major media companies:
www.cnn.com, www.disney.com!
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Hypertext Markup Language
(HTML) basics
•
•
•
•
<HTML>
<HEAD>
<TITLE> Welcome To My Page </TITLE>
</HEAD> <BODY>
– other html code
• </BODY>
• </HTML>
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Adding Links
• <A HREF=
• “http://www.mycompany.com”>
• My Company
• </A>
• In the Web page it looks like this:
– … My Company …
• <A HREF="mailto:[email protected]">my
email</A>
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Including Images and Sound
• <IMG SRC=pictures/me_and_my_dog.gif>
• good compression: JPG
• animated GIFs - easy to make - size can be
a problem
• Sound: MID (small) WAV, AU (older
formats) MP3 (high quality)
• static (tag: EMBED, BGSOUND) vs.
streaming audio/video: RealAudio
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Including CGI scripts
• <form method="post”
• action="http://a.b.c.d/cgibin/myscript.exe?query=who" >>
• <input type="submit" size="40"
value="Search">
• </form>
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Including Java Applets
• <applet
• code=”myapplet.class"
• height="200" width="600” >
– <param
• value=”999”
• name=”default_price" >
• </applet>
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Tools for Building Web Sites
• HTML, tables, forms, CGI scripts
• server side tools: SSI, ASP, servlets
• Media formats: GIF, JPEG, MPEG, real
audio
• Executable content: Java
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Design tools
• Composer, Microsoft Word, FrontPage
– Generating HTML
• Generating Java applets: Symantec, J++ 6.0
• Generating 3D content: VR Creator,
TrueSpace
• LP/CP tools need to interoperate with them!
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Alternative Content Formats
• VRML - now supported also by Java3D
– has links like in HTML
– has superior navigation
– has higher information density
• The future is 3D - the Nintendo generation
grows up:-)
• LP/CP tools should interoperate with the
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emerging 3D Web
Conclusion
• LP/CP comes late into the Internet Business
• it should get into fast growing or still
emerging areas
– e-commerce
– intelligent search, knowledge processing,
agents
– 3D Web, new Internet infrastructure
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