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Intelligence, Agents and Multimedia Group
University of Southampton
Current Trends in Information
Technology
Paul Lewis
[email protected]
Intelligence, Agents and Multimedia Group
University of Southampton
Aims and Unit Synopsis:
• To develop a knowledge of some broad
issues in computing and IT which are of
current interest and of potential benefit
and to enhance the students’ skill in
applying some of the latest technology.
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Intelligence, Agents and Multimedia Group
University of Southampton
Learning Outcomes:
On successful completion of the unit the students should be
able to:
•
develop a web site using a web site authoring package
•
use scripts to develop dynamic web pages
•
understand some of the basic principles and jargon
associated with some of the following topics
information retrieval
knowledge processing
software agents
object technology
multimedia information handling
communications and networks
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Intelligence, Agents and Multimedia Group
University of Southampton
Syllabus
This course is an awareness course covering a
variety of issues in Information Technology
including such topics as :
• The World Wide Web
• AI and Knowledge Processing
• Agents and Agent technology
• Object Oriented approaches to software engineering
• Information retrieval and Multimedia information handling
• Communications and Networks
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Intelligence, Agents and Multimedia Group
University of Southampton
Assessment:
• The unit will be assessed completely by
coursework, for example by a project to
develop a modest but dynamic web site
relevant to some other aspect of the
degree course and an essay on a
particular topic in IT.
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Intelligence, Agents and Multimedia Group
University of Southampton
Format
• Each week we will have two lectures
followed by lab sessions in
Building 58 Room 1053
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Intelligence, Agents and Multimedia Group
University of Southampton
Information Technology
• Concerned with the use of computers and
communications systems for managing an
processing (storing, retrieving, converting,
processing, protecting, transmitting)
information.
• Facilitated by the convergence of
telecommunications, electronics and computing
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Intelligence, Agents and Multimedia Group
University of Southampton
Telecommunications and Networks
• World telecommunications network
Largest man-made system
Technology and services evolving
rapidly
• Facilities for linking computers
Data volumes increasing
Data transfer rates increasing
Multimedia systems
(text/images/speech/video)
require high bandwidth
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Intelligence, Agents and Multimedia Group
University of Southampton
• Early computers all stand alone
• Direct inter computer communications has led to
electronic mail
bulletin boards
news services
distributed computer systems
the web and information sharing
electronic funds transfer
e-medicine
e-commerce
e-shopping
e-banking
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Intelligence, Agents and Multimedia Group
University of Southampton
At the computer system level
New services are evolving
• Daemons to handle message passing over networks
• File systems may be distributed or single systems shared
by several processors
• Facilities for file transfer
• Facilities for remote login
• Facilities for automatic interaction between systems
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Intelligence, Agents and Multimedia Group
University of Southampton
Common Types of Network Configuration
• Broadcast networks
• Token Ring
• Point to point links
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Intelligence, Agents and Multimedia Group
University of Southampton
Broadcast Networks
e.g. Ethernet
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•
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Any computer on the net can send a message at any time
message contains destination address
Each computer checks all messages and picks up its own
messages can collide and become garbled
Sending systems detect this and rebroadcast after a random
short time
• If traffic is high, extra collision traffic may saturate the
network
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Intelligence, Agents and Multimedia Group
University of Southampton
Token Ring
e.g. Fibre distributed data interface (FDDI)
• Message token is passed around the ring
• A computer can only transmit when it has the
token
• Avoids collisions
• There is performance reduction in large rings
• Network fails totally if there is a break
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Intelligence, Agents and Multimedia Group
University of Southampton
Point to Point Links
• Only two end points involved
• Some wide area networks (WANs) are
connected this way
• One computer can typically only handle a
few links
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Intelligence, Agents and Multimedia Group
University of Southampton
Data Transfer Rates
Transfer rate
(bits/sec)
300
2,400
9,600
19,600
1,000,000
Time to transmit a 20 page report
(36000 bits/page say)
40 mins
5 mins
1.25mins
37.5 secs
0.072 secs
Eg BT Broadband 512000 bits/sec
a 512*512 colour image with24 bits/pixel is 6 million bits (uncompressed)
Compression algorithms are an important key
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Intelligence, Agents and Multimedia Group
University of Southampton
Local Area Networks (LANs)
• Typically used in a single laboratory or building
• Typically run over copper wire or fibre optic cable
• Ethernet is popular
mainly 10 or 100 Mbits/sec peak working
computers typically attached to coaxial cable at tap
points but can use twisted pair or fibre optic cable
or more recently wireless
• FDDI Fibre Distributed Data Interface
less popular than ethernet
interfacing is more difficult
peak rates 100 Mbits/sec
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Intelligence, Agents and Multimedia Group
University of Southampton
Local Area Networks (cont)
• ATM Asynchronous Transfer Mode
technology for high data rate communications
can work at rates >> 100 MBits/sec
typically used for backbone of a WAN
(Note Ethernet and FDDI are LAN technologies not appropriate for
WANs)
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Intelligence, Agents and Multimedia Group
University of Southampton
Network Protocols
• Computers communicate over networks
using protocols which determine the format
of messages
• Protocol for the internet is TCP/IP
Transmission Control Protocol/Internet Protocol
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Intelligence, Agents and Multimedia Group
University of Southampton
The Internet
• Loosely administered network of networks
• Agreed procedures for access and
intercommunication
• Internetworking uses gateways, routers and
firewalls
• Gateways: convert data traffic from one
network format to another. They link LANs
to WANs and WANs to WANs
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Intelligence, Agents and Multimedia Group
University of Southampton
Routers
• Decide which route through the network a
message should take to continue towards its
destination
- networks are now very complex
- many different paths between points
- routers communicate with each other
about network faults
- busy or broken routes can be avoided
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Intelligence, Agents and Multimedia Group
University of Southampton
• telnet provides remote logon to distant computer
• ftp
transfers files between computers on the internet
• ssh and sftp (secure shell) provides encryption
phl/40% telnet penelope.ecs.soton.ac.uk
Trying 152.78.68.135...
Connected to penelope.
Escape character is '^]'.
SunOS 5.6
login:
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Intelligence, Agents and Multimedia Group
University of Southampton
Host Addresses
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Computers on the Internet have a unique address or host number.
E.g. 140.138.30.5
First six digits typically identify company or campus
next group identifies eg a department
last group identifies a specific computer
Symbolic names can be associated with these
e.g. penelope.ecs.soton.ac.uk
• DNS Distributed name service keeps track of names and addresses
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Intelligence, Agents and Multimedia Group
University of Southampton
Firewalls
• Used to protect local networks or individual
computers by implementing access controls
to and from the internet
• all traffic coming in or going out must pass
through it
• only authorised traffic gets through
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Intelligence, Agents and Multimedia Group
University of Southampton
Firewalls
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can restrict insecure network services
restrict access to certain hosts
log activity
control use of internet
limit security effort to just one or a few
computers
• do not necessarily protect against viruses in
files transferred by ftp
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Intelligence, Agents and Multimedia Group
University of Southampton
Networks and Distributed
Computing
• Networks of computers
allow distributed access to
resources
• Files may be configured
so they may be seen by
users of several machines
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Intelligence, Agents and Multimedia Group
University of Southampton
Client Server Model
• Applications may be split between
processors
• Client/server model is a popular architecture
• Client sends request to server for a
particular service
• Server responds and may need to process
data, retrieve information or make requests
to other servers etc to service the requests
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Intelligence, Agents and Multimedia Group
University of Southampton
Client Server Model (cont)
• Clients and servers are software processes which
are really two halves of the same application
• The world wide web uses a client server model
• Browsers are clients… send request to web servers
for documents
• Remote web server software receives the request
for a document, retrieves it and sends to client
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Intelligence, Agents and Multimedia Group
University of Southampton
Client Server Model
• Clients and servers may be on the same or
different machines
• One client may access many servers
• One server can serve many clients
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Intelligence, Agents and Multimedia Group
University of Southampton
Client Server Model
• Popular as makes good use of networked
resources
• Growth in internet has increased popularity
• Single repositories of data may be
maintained more easily eg database servers
• Server typically sits on a large machine and
may be relatively expensive
• Client can run on a small, low cost platform
if necessary
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Intelligence, Agents and Multimedia Group
University of Southampton
Usenet and the World Wide Web
• Two different application which are usually
accessed via the internet
• Both are world wide information systems
but different in nature
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Intelligence, Agents and Multimedia Group
University of Southampton
Usenet
• Usenet is a distributed online bulletin board
(discussion group) system begun in 1979 - a set of
news groups hierarchically classified by subjects
• Users can read, contribute and reply to postings on
almost every conceivable subject
• Contributions are posted to the newsgroups
• Newsgroups are broadcast to sites which take
them
• Sites can choose which sites they take
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Intelligence, Agents and Multimedia Group
University of Southampton
Usenet
• Some groups are moderated
• Most are open
• Newsreaders are similar to email software and
allow you to select, read and respond to postings
• Unlike a bulk email, only one copy of the usenet
feed is kept on a particular site
• Web browsers now offer facilities for accessing
news groups without the need to receive the feed.
• Information in Usenet is mainly transient
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Intelligence, Agents and Multimedia Group
University of Southampton
The World Wide Web
• Information is less transient than in Usenet
• The web is a way of sharing access to documents
and navigating between documents using
hypertext links
• The web has become an attempt to organise the
bulk of the information on computers attached to
the internet in an easily accessible way
• Invented by Sir Tim Berners-Lee in 1989 at
CERN. He has a chair here in Southampton in the
School of Electronics and Computer Science and
at MIT.
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Intelligence, Agents and Multimedia Group
University of Southampton
The WWW
• The WWW is a client server system
• Internet Explorer and Moxzilla/Firefox are
popular web browsers (web clients)
• Web documents are held on web servers
• Web documents are usually written in HTML
(HyperText Markup Language) which specifies
the document content structure, (titles, paragraphs
etc) and any links to other documents.
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Intelligence, Agents and Multimedia Group
University of Southampton
Hypertext links and the WWW
• Hypertext systems allow non-linear reading
of information using buttons and links for
navigation
• Links in hypertext provide an association
between some text (the source anchor) and
another document (the destination of the
link)
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Intelligence, Agents and Multimedia Group
University of Southampton
Hypertext links and the WWW
• Each document on the Web is identified by a URL
(uniform resource locator) e.g.
http://www.ecs.soton.ac.uk/dir1/file3.htm
• Three parts:
- transfer protocol
- internet ddress of server where document is held
- the pathname of the file containing the document
URLs are used in browsers to specify which documents to
read
URLs are used in documents to specify destinations of links
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Intelligence, Agents and Multimedia Group
University of Southampton
Some Other Aspects of the Web
• Documents on the web involve more effort
than emailing to a usenet newsgroup for
example. Web tends to be used for more
durable information
• Search engines (Google, Yahoo, AltaVista)
• Links from non text.. image maps
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Intelligence, Agents and Multimedia Group
University of Southampton
Newer Aspects
• Blogs or web logs
a website into which text can be added easily
(typically using web based forms) and are
displayed in reverse chronological order
Blogging: - keeping a web log
• Wikis
a website that allows users to easily add and edit
content and is suitable for collaborative writing
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Intelligence, Agents and Multimedia Group
University of Southampton
The Semantic Web
"The Semantic Web is an extension of the
current web in which information is given
well-defined meaning, better enabling
computers and people to work in
cooperation." -- Tim Berners-Lee, James
Hendler, Ora Lassila, The Semantic Web,
Scientific American, May 2001
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Intelligence, Agents and Multimedia Group
University of Southampton
The Semantic Web (cont)
• provides a common framework that allows data to
be shared and reused across application, enterprise
and community boundaries.
• collaborative effort led by W3C with participation
from a large number of researchers and industrial
partners.
• based on the Resource Description Framework
(RDF), which integrates a variety of applications
using XML for syntax and URIs for naming.
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Intelligence, Agents and Multimedia Group
University of Southampton
The Grid
• Grid computing is a form of distributed computing that
involves coordinating and sharing computing, application,
data, storage, or network resources across dynamic and
geographically dispersed organizations.
• Grid technologies promise to change the way organizations
tackle complex computational problems. However, the
vision of large scale resource sharing is not yet a reality in
many areas
• Grid computing is an evolving area of computing, where
standards and technology are still being developed to
enable this new paradigm.
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Intelligence, Agents and Multimedia Group
University of Southampton
The workshop Week 1
• Building 58 Room 1053
• Creating your own web pages
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