1. Some Research ProjectsBy
Kwok-Bun Yue
October 23, 2001
Bun Yue (©copyright 2000)
11/15/2018

2. Software Architecture Evolution (1)
What does the future look like?
Software architecture has changed rapidly during the last 40 years.
A very coarse evolution will be shown.
This is another approach to look at the importance of XML.
The phases are blurred and the boundary are not clear cut.
Bun Yue (©copyright 2000)
11/15/2018

3. Software Architecture Evolution (2)
Phase 1: Mainframe.
Highly centralized.
Very thin clients: dumb terminals.
Low connectivity
Largely disconnected to outside of the organization.
60’s & 70’s: Years of the mainframe:
Very few expensive computers.
Low system resources -> optimization is critical.
Thin clients.
Low connectivity.
Powerful centralized IT department.
Enabling technology: Enterprise mainframe.
Representative company: IBM
Bun Yue (©copyright 2000)
11/15/2018

4. Software Architecture Evolution (3)
Phase 2: Traditional 2-tiered Client and Server
Fat clients: PC.
Proprietary protocols.
Many dedicated servers.
Still largely within the organization.
Inexpensive personal computers.
Fat Clients
Better system resources.
Limited connectivity.
Resources in the departmental levels.
Enabling technologies: PC/client-server
Representative company: Microsoft.
services
clients
servers
Organization
Bun Yue (©copyright 2000)
11/15/2018

5. Software Architecture Evolution (4)
Phase 3: Web-Based N-tiered Client-Server
Internet
intranet
clients
Web Server
clients
Application
Server
Major flow of services
There are actually two major advance: Web and Middle layers.
Servers: database servers, workgroup servers, etc: backend enterprise application
Application servers are the middle layer, providing a layer for storing business logic.
Thin clients: browsers as the Universal clients
High connectivity.
High system resources.
Important paradigm changes: Web-centric application development.
Fast changing pace.
Enabling technologies: HTTP, TCP/IP, HTML, Internet standards.
services
servers
Organization
Bun Yue (©copyright 2000)
11/15/2018

6. Software Architecture Evolution (5)
Phase 3: Web-Based N-tiered Client-Server
Open protocols (because of Web).
Middle layer for definition of business logic: better software development and management.
Serving clients outside of the organization: Internet.
The browser is becoming the universal client.
Thinner clients: no need of complicated proprietary cilent software.
Thinner clients (more processing done in the server side and the middle layer).
Universal clients: Easy to develop a car. Now it is easy to get a car!
Bun Yue (©copyright 2000)
11/15/2018

7. Software Architecture Evolution (6)
Phase 4: Web-Centric Applications
intranet
Internet
clients
Web Server
clients
XML
servers
Application
Server
XML
Servers
External XML servers may be connected to backend servers, thus allowing communication between two organizations backend servers through XML.
XML servers may be parts of the application server.
Note the bi-directional flow between XML servers.
The next 10+ years?
Universal connectivity: anywhere, anywhen.
Blurred clients and servers.
PC no longer the prime connectivity tools.
Human no longer the immediate consumers of data.
Enabling technologies: connectivity standards (e.g. IP v6, XML, WAP/WML, Bluetooth, etc), highly portable tools (Java, Jini, XML, etc), network-enabled appliances.
Potential huge social and cultural
services
servers
Major flow
of services
Organization
Bun Yue (©copyright 2000)
11/15/2018

8. Software Architecture Evolution (7)
Phase 4: Web-Centric Applications
Potentially thin clients.
Clients and servers can be blurred: e.g. Napster.
Services in and out of the organization.
Data/services from many servers, inside and outside of the organization.
No single organization can provide 'everything.'
Much more personalized software.
XML is a cornerstone technology of Web-Centric architectures, e.g. .Net of Microsoft.
Client/Server blurred because of processing improvement.
E.g. AOL purchase of Time/Warner.
Even if an organization can provide everything, it may not be efficient.
Bun Yue (©copyright 2000)
11/15/2018

9. Areas of Research Interests
Internet Application Development
Databases
Concurrent Programming
Distributed Systems
Real-Time Programming
Bun Yue (©copyright 2000)
11/15/2018

10. Internet Projects Explosive growth
High potential for research projects
Areas: infrastructures, architectures, application development
Technologies: Cold Fusion, ASP, PHP, Web Application Servers, CGI-Perl, Java Servlets, JSP, XML, XSL, IMAP, LDAP, etc.
Bun Yue (©copyright 2000)
11/15/2018

11. Internet Example: WML(1)
Wireless Markup Language (WML): for delivering Internet contents to wireless device such as cellular phone.
WML is based on XML.
Relatively simple to develop.
Bun Yue (©copyright 2000)
11/15/2018

12. The <card> tag stores
A Simple WML Example
hello.wml:
<?xml version="1.0"?>
<!DOCTYPE wml PUBLIC
"-//WAPFORUM//DTD WML 1.1//EN" "
<wml>
<card id="Hello_World" title="Hello">
<p>This is my first card.</p>
<p>Thank you.</p>
</card>
</wml>
WML root element
Like HTML, each element is usually composed of a start tag and a corresponding tag.
The card element is one of the most important in WML. A card is usually displayed in a screen (scrolling allowed).
The <card> tag stores
information of a
display screen
Bun Yue (©copyright 2000)
11/15/2018

13. Hello.wml display The WML page is displayed simply as the right:
<p>This is my first card.</p>
<p>Thank you.</p>
There are two paragraphs.
Phone.com emulator is used.
The title of the card is not displayed by phone.com emulator.
The URL is artificial.
Bun Yue (©copyright 2000)
11/15/2018

14. Another WML Example (1) A simple stock quote application.
User submits one or more stock symbols and the application returns their stock quotes.
Stock quote URL:
Bun Yue (©copyright 2000)
11/15/2018

15. Another WML Example(2)
Bun Yue (©copyright 2000)
11/15/2018

16. WML Research Potentials
Potential research topics for WML:
Design patterns.
Language design issues.
Navigational architectures.
Security and privacy model.
Smart WML generators.
Bun Yue (©copyright 2000)
11/15/2018

17. Example: XML (1) XML stands for eXtensible Markup Language.
XML is a system for defining, validating, and sharing document formats.
XML is the cornerstone technology of the semantic Web, where contents have meaning beyond display information.
Web-centric architectures will become increasingly important in current and future IT infrastructures.
XML is a cornerstone technology of the Web-centric architecture.
Bun Yue (©copyright 2000)
11/15/2018

18. Example: XML (2) XML application development. Generation example:
Generation of XML documents.
Consumption of XML documents.
Generation example:
Note that, currently, you need to use Microsoft's Internet Explorer 5.0+ to view XML.
Bun Yue (©copyright 2000)
11/15/2018

19. Example: XML (3) Consumption of XML:
Viewing XML: XSL (eXtensible Stylesheet Language), XML-enabled browsers.
Transforming XML documents: XSL, DOM (Document Object Model).
Extracting XML document information: XML parsers.
Bun Yue (©copyright 2000)
11/15/2018

20. Example: XML (4) Potential Research Topics in XML:
XSL Design patterns.
Efficient storage of XML documents.
Querying XML documents.
XML transformation models and techniques comparison.
Web-centric application models and architectures.
Many more.
Bun Yue (©copyright 2000)
11/15/2018

21. Other Internet-Related Projects
Web Caching.
VoiceXML.
Web software architecture.
Others…
Bun Yue (©copyright 2000)
11/15/2018

22. Database Projects Utilization of UML in data warehouse design.
Executing relational algebra through the Web.
Executing relational calculus through the Web.
Bun Yue (©copyright 2000)
11/15/2018

23. Concurrent Programming Projects
Implementation of various mutual exclusion algorithms in Java.
Implementation of Linda-style tuple spaces in Java.
Bun Yue (©copyright 2000)
11/15/2018

24. Distributed Systems Projects
Dynamic distributed objects migration: proof of concepts done by Mr. Chris Stokes.
Dynamic distributed objects migration: criteria of migration and performance evaluation.
Enhancing the efficiency of CORBA/ODB adapters.
Bun Yue (©copyright 2000)
11/15/2018

25. Real-Time Programming Projects
Implementation of the Optimal Mutex Protocol in Ada and Java.
Implementation of the Priority Ceiling Protocol in Java.
Effects of task suspension on protocols for minimizing priority inversion.
Bun Yue (©copyright 2000)
11/15/2018

26. Conclusions
Good time to do applied computing research, especially in the area of the Internet.
Don't forget to donate a scholarship to the School if your future research leads to a windfall.
Thanks!!
Bun Yue (©copyright 2000)
11/15/2018