Knowledge management

1. KNOWLEDGE
MANAGEMENT
PRESENTED BY:
AKASH SHARMA
MBA

2. OLAP (Online
Analytical
Processing)

3. OVERVIEW
 INTRODUCTION
 OLAP CUBE
 OLAP OPERATION
 TYPES OF OLAP
 BENEFITS OF OLAP

4. INTRODUCTION TO OLAP
 OLAP (online analytical processing) is computer
processing that enables a user to easily and selectively
extract and view data from different points of view.
 OLAP allows users to analyze database information from
multiple database systems at one time.
 OLAP data is stored in multidimensional databases.

5.  Some popular OLAP server software programs include:
 Oracle Express Server
 Hyperion Solutions Essbase
 OLAP processing is often used for data mining.
 OLAP products are typically designed for multiple-user
environments, with the cost of the software based on
the number of users.

6. THE OLAP CUBE
 An OLAP Cube is a data structure that allows fast
analysis of data.
 The arrangement of data into cubes overcomes a
limitation of relational databases.
 It consists of numeric facts called measures which are
categorized by dimensions.
 The OLAP cube consists of numeric facts called
measures which are categorized by dimensions.

7. OLAP CUBE

8. OLAP OPERATIONS
 The user-initiated process of navigating by calling for
page displays interactively, through the specification of
slices via rotations and drill down/up is sometimes
called "slice and dice".
 Slice: A slice is a subset of a multi-dimensional array
corresponding to a single value for one or more
members of the dimensions not in the subset.
 Dice: The dice operation is a slice on more than two
dimensions of a data cube (or more than two
consecutive slices).

9.  Drill Down/Up: Drilling down or up is a specific analytical technique
whereby the user navigates among levels of data ranging from the most
summarized (up) to the most detailed (down).
 Roll-up: A roll-up involves computing all of the data relationships for one
or more dimensions. To do this, a computational relationship or formula
might be defined.
 Pivot: To change the dimensional orientation of a report or page display.
 The output of an OLAP query is typically displayed in a matrix (or pivot)
format. The dimensions form the row and column of the matrix; the
measures, the values.

10. TYPES OF OLAP
 Relational OLAP(ROLAP):
Extended RDBMS with multidimensional data mapping to
standard relational operation.
 Multidimensional OLAP(MOLAP): Implemented operation in
multidimensional data.
 Hybrid OnlineAnalytical Processing (HOLAP) is a hybrid
approach to the solution where the aggregated totals are
stored in a multidimensional database while thedetail data
is stored in the relational database. This is the balance
between the data efficiency of the ROLAP model and the
performance of the MOLAP model.

11. BENEFITS OF OLAP
 One main benefit of OLAP is consistency of information and
calculations.
 "What if" scenarios are some of the most popular uses of
OLAP software and are made eminently more possible by
multidimensional processing.
 It allows a manager to pull down data from an OLAP
database in broad or specific terms.
 OLAP creates a single platform for all the information and
business needs, planning, budgeting, forecasting, reporting
and analysis.

12. EXPERT SYSTEM

13. Overview
•What is an Expert System?
•History
•Components of Expert System
•Who is involved?
•Development of Expert System

14. WHAT IS AN EXPERT SYSTEM?
 An expert system is a computer program that
contains some of the subject-specific
knowledge of one or more human experts.

15. History of Expert Systems

16.  Early 70s
 Goal of AI scientists  develop computer programs that
could in some sense think .
 In 60s general purpose programs were developed for
solving the classes of problems but this strategy produced
no breakthroughs.
 In 1970 it was realized that The problem-solving power of
program comes from the knowledge it possesses.

17. To make a program
intelligent, provide it
with lots of high-quality,
specific knowledge
about some problem
area.

18. Building Blocks of Expert
System

19.  Knowledge base (facts)
 Production Rules ("if.., then..")
 Inference Engine (controls how "if.., then.." rules are
applied towards facts)
 User Interface

20. Knowledge Base
 The component of an expert system that contains the
system’s knowledge.
 Expert systems are also known as Knowledge-based systems.

21. Knowledge Representation
 Knowledge is represented in a computer in the form of
rules ( Production rule).
 Consists of an IF part and THEN part.
 IF part lists a set of conditions in some logical combination.
 If the IF part of the rule is satisfied; consequently, the THEN
part can be concluded.

22. Knowledge Representation
 If flammable liquid was spilled then call the fire department.
 If the material is acid and smells like vinegar then the spill
material is acetic acid.

23.  Chaining of IF-THEN rules to form
a line of reasoning
 Forward chaining (facts driven)
 Backward chaining (goal driven)

24. Inference Engine
 An inference engine tries to derive answers from a
knowledge base.
 It is the brain of the expert systems that provides a
methodology for reasoning about the information in the
knowledge base, and for formulating conclusions.

25. User Interface
 It enables the user to
communicate with an expert
system.

26. Other features
 Reasoning with uncertainty
 Explanation of the line of
reasoning
 Fuzzy Logic

27. Data
Visualization

28. Data Visualization
“...to convey information through visual
representations.”
“...produces (interactive) visual representations of
abstract data to reinforce human cognition; thus
enabling the viewer to gain knowledge about the
internal structure of the data and causal relationships
in it.”

29. Visualization Goals
 Answer questions (or discover them)
 Make decisions
 See data in context
 Support graphical calculation
 Find patterns
 Present argument or tell a story
 Inspire

30. Three Functions of
Visualization
 Record: store information
 Analyze: support reasoning about information
 Communicate: convey information to others