Decision Support Systems

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23 févr. 2014 (il y a 3 années et 10 mois)

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Decision Support
Systems

And

Multimedia Databases



Decision Support System


Problem and Solution types


Characteristics of Decision support system


Capabilities of a DSS


Levels and components of DSS


Conclusion



Multimedia Systems


Why multimedia is a problem for databases ?


Support for searching


Types of Databases


Relational Databases and Multimedia, Example
-

Access


Object Relational Databases and Multimedia , Example
-

Oracle


Object Oriented Databases and Multimedia , Example


Jasmine


Conclusion





Decision support systems (DSS)


Offer potential to assist in solving both semi
-
structured and unstructured problems


Intelligence

Design

Choice

Implementation

Monitoring

Problem

solving

Decision

making


Optimization model


Finding the best solution


Satisfying
model


Finding a good
--

but not necessarily the best
--

solution to a problem


Heuristics


Commonly accepted guidelines or procedures that
usually find a good solution


Multiple decision objectives


Increased alternatives


Increased competition


The need for creativity


Social and political actions


International aspects


Technology


Time


Handles large amounts of data from different
sources


Provides report and presentation flexibility


Offers both textual and graphical orientation



Supports
top
down analysis


Performs complex, sophisticated analysis and
comparisons using advanced software
packages


Supports optimization,

satisficing
”,
and
heuristic approaches


Performs different types of analyses


“What
-
if” analysis


Makes hypothetical changes to problem and observes
impact on the results


Simulation


Duplicates features of a real system


Goal
-
seeking analysis


Determines problem data required for a given result


You know the desired result


You want to know the required input(s)


Example:


Microsoft Excel’s “Goal Seek” and “Solver” functions

Excel

demo


Supports


Problem solving phases


Different decision frequencies


Frequency

low

high

Merge with

another
company?

How many
widgets

should I order?


Highly structured problems


Straightforward problems, requiring known facts
and relationships.


Semi
-
structured or unstructured problems


Complex problems wherein relationships among
data are not always clear, the data may be in a
variety of formats, and are often difficult to
manipulate or obtain

Operational
-
level

managers involved with

daily decisions

Strategic
-
level managers

involved with long
-
term

decisions

Low

High

Decision Frequency

Strategic


Tactical


Operational


Web
-
based decision support systems


Decision support system software provides
business intelligence through web browser clients
that access databases either through the Internet or
a corporate intranet



Model management software (MMS)


Coordinates the use of models in the DSS


Model base


Provides decision makers with access to a variety of
models


Dialogue manager


Allows decision makers to easily access and
manipulate the DSS

Database

Model base

External database

access

Access to the

internet, networks,

and other computer

systems

Dialogue manager

DBMS

MMS

External

databases



Decision Support systems
inherit
characteristics of drill down analysis
for
complex problems that range in various
domains.



Historic and current change patterns

can be
studied analytically by utilizing long term
Databases maintained to aid in decision
support system.


Why multimedia is a problem for databases


Support for searching


Types of
Databases


Relational Databases and Multimedia


Example
-

Access


Object Relational Databases and Multimedia


Example
-

Oracle


Object Oriented Databases and Multimedia


Example
-

Jasmine



Data increasingly means not just numbers and
small strings but multimedia data as well


structured (text, images, video, audio, VR, etc.)


Databases promise:


well structured data organisation


efficient storage of large amounts of data


querying


transactional support for concurrent users


If you include multimedia data


multimedia is large and may swamp other data


multimedia data structures are completely different from
standard database structures


multimedia data structures do not easily lend themselves
to content
-
based searching



Databases already integrate various kinds of
data, numbers, dates, small text strings.


They do this by the use of
domains


i.e. each atomic value in the database belongs to
one of a small number of types


each type has two aspects:


a range of values which are acceptable


some operations which are available




the schema indicates a domain for each part
of the database and the DBMS enforces the
domain constraint


e.g. in a Relational Database, each column is
assigned a domain


Therefore a DBMS must provide domain types
for any kind of data that they wish to house
and theoverall structure will deal with the
integration


TEXT


GRAPHICS


MPEG


ANIMATION


VIDEO


AUDIO



There are numerous different types of
multimedia databases, including:


The
Authentication Multimedia Database



The
Identification Multimedia Database
is a
data comparison of one
-
to
-
many


A newly
-
emerging type of multimedia
database, is the
Biometrics Multimedia
Database
;


DBMS typically provide three different kinds of
domain for multimedia data:


Large
object domains, sequences of data often of
two kinds


Binary Large Objects


BLOBs



which are an
unstructured sequence of bytes


Character Large Objects


CLOBs



which are an
unstructured sequence of characters


File
references


instead of holding the data, a file
reference contains a link to the data (OLE in Access)


Genuine
multimedia data types


(Oracle and
Jasmine)



There is an important difference between the
last of these and the first two:


multimedia data types present the possibility of
exploiting the structure of the data for querying
and manipulation


large objects at best allow you to extract sections
or to concatenate them


file references mean that the DBMS has no
data
at
all



A DBMS permits a user to search the database
by
content
e.g. give the name of the student with
matriculation number 0123456

We would like to do
the same with multimedia data
e.g. give the
pictures painted by Picasso
or

sound files with
female singer hitting top
C



With standard data this is easy


numeric and
string operators are well understood With
multimedia data this is more difficult and requires
some method of identifying contents of which
there are two kinds:



Automatic
identification


an algorithm takes the data and returns a measure
which can be compared


e.g. of blackness


Manual
identification


a person examines the data and catalogues it


e.g.
in a table of pictures, there is a column for the
picture and another for the painter



There are three kinds of DBMS that might
be used for housing multimedia data.


Relational DBMS
store everything as First
Normal Form tables


all data items are
atomic
and are held in
rectangular
tables


data can only be related if they are in one or in
two records connected by a common value
(foreign key)


records are identified only by content


it is difficult (if not impossible) to extend the set
of domains



Object
-
oriented DBMS
store everything as
classes of objects


all data is held as components of objects (like
Java variables)


data is related by object reference (i.e. one class
variable has a type which is another class and the
values of that variable are instances of that class)


the set of classes is extensible and so you can
freely create domains



Object
-
relational DBMS
are fundamentally
relations but are not First Normal Form


the values in cells can be object references as well
as atomic values


new types can be defined



In a relational database, you can have:


domain types for large objects


using a string type for file names


extra file types as in OLE in Access


In an object
-
oriented database, you can
have:


specially designed classes for multimedia


In an object
-
relational database, you can
have:


specially designed types for multimedia



Oracle and SQL3

support three large object
types:


BLOB
-

The BLOB domain type stores
unstructured binary data in the database.
BLOBs

can store up to four gigabytes of binary data.


CLOB


The CLOB domain type stores up to four
gigabytes of single
-
byte character set data


NCLOB
-

The NCLOB domain type stores up to
four gigabytes of fixed
-
width and varying width
multi
-
byte national character set data


* SQL3 is a significant extension to standard SQL which turns into a full object
-
based language



Oracle interMedia supports multimedia storage,
retrieval, and management of:


BLOBs
stored locally in Oracle8i onwards and containing
audio, image, or video data


BFILEs,

stored locally in operating system
-
specific file
systems and containing audio, image or video data


URLs
containing audio, image, or video data stored on any
HTTP server such as Oracle Application Server, Netscape
Application Server, Microsoft Internet Information Server,
Apache HTTPD server, and Spyglass servers


Streaming audio

or
video

data stored on specialized media
servers such as the Oracle Video Server



Jasmine is an Object
-
Oriented database and
has an application known as Studio is its
development environment


It comes with a number of built in classes
include four multimedia classes:


Picture
-


Image



Video



Audio
-


These come with manipulation and
compression facilities They also have been
made to fit well with Java Media Framework



At present you can not do much with MM data
,



there are two reasons for this:

1. It is
very large


indexing on multimedia data is not reasonable nor is
storing a default value


other retrieval may be slowed down


transactions may be
compromised


2. The
properties are not well understood
or
implementable


At the moment, there is no reason for
putting multimedia data into a relational
database


it just slows everything down


and you can’t do very much


You could use an object relational or object
oriented database


now you can do more


but the products are immature


and everything will be slow



There are three main reasons for
integrating multimedia data with a
database:


1. Cataloguing the data


a column for file names is good enough


2. Decorating Reports


The OLE approach works well here Otherwise a
file name column and a simple application for
generating the reports would do


3. Web Applications


Again a file name column is good enough



What is a Decision Support System ?


What type of problems DSS address ?


Explain components of DSS system ?


What makes Multimedia databases different
from traditional databases ?


Name different types of MM database.


Compare, contrast and provide examples
for :


Relational Databases and Multimedia


Object Relational Databases and Multimedia


Object Oriented Databases and Multimedia


1.
http://www.peterindia.net/MultimediaDatabase.html

2.
http://www.tech
-
faq.com/multimedia
-
database.html

3.
http://www.docstoc.com/docs/7641273/Multimedia
-
Database
-
Content
-
and
-
Structure

4.
http://ftp.it.murdoch.edu.au/units/ICT219/Papers%20for%2
0transfer/papers%20on%20IR/IR15_MM%20Database.pdf





Thanks !