Information Technology Reference
In-Depth Information
Principle
Virtual reality systems can reshape the interface
between people and information technology by
offering new ways to communicate information,
visualize processes, and express ideas creatively.
The inference engine processes the rules, data, and
relationships stored in the knowledge base to provide
answers, predictions, and suggestions the way a human
expert would. Two common methods for processing include
backward and forward chaining. Backward chaining starts
with a conclusion, then searches for facts to support it;
forward chaining starts with a fact, then searches for a
conclusion to support it.
The explanation facility of an expert system allows the
user to understand what rules were used in arriving at a deci-
sion. The knowledge acquisition facility helps the user add or
update knowledge in the knowledge base. The user interface
makes it easier to develop and use the expert system.
The people involved in the development of an expert sys-
tem include the domain expert, the knowledge engineer, and
the knowledge users. The domain expert is the person or
group who has the expertise or knowledge being captured for
the system. The knowledge engineer is the developer whose
job is to extract the expertise from the domain expert. The
knowledge user is the person who benefits from the use of
the developed system.
The steps involved in the development of an expert system
include determining requirements, identifying experts, con-
structing expert system components, implementing results,
and maintaining and reviewing the system.
Expert systems can be implemented in several ways. Pre-
viously, traditional high-level languages, including Pascal,
FORTRAN, and COBOL, were used. LISP and PROLOG are two
languages specifically developed for creating expert systems
from scratch. A faster and less-expensive way to acquire an
expert system is to purchase an expert system shell or exist-
ing package. The shell program is a collection of software
packages and tools used to design, develop, implement, and
maintain expert systems.
The benefits of using an expert system go beyond the typ-
ical reasons for using a computerized processing solution.
Expert systems display “intelligent” behavior, manipulate
symbolic information and draw conclusions, provide portable
knowledge, and can deal with uncertainty. Expert systems can
be used to solve problems in many fields or disciplines and
can assist in all stages of the problem-solving process. Past
successes have shown that expert systems are good at strate-
gic goal setting, planning, design, decision making, quality
control and monitoring, and diagnosis.
Applications of expert systems and artificial intelligence
include credit granting and loan analysis, catching cheats
and terrorists, budgeting, games, information management
and retrieval, AI and expert systems embedded in products,
plant layout, hospitals and medical facilities, help desks and
assistance, employee performance evaluation, virus detec-
tion, repair and maintenance, shipping, and warehouse
optimization.
A virtual reality system enables one or more users to move
and react in a computer-simulated environment. Virtual real-
ity simulations require special interface devices that transmit
the sights, sounds, and sensations of the simulated world to
the user. These devices can also record and send the speech
and movements of the participants to the simulation program.
Thus, users can sense and manipulate virtual objects much
as they would real objects. This natural style of interaction
gives the participants the feeling that they are immersed in
the simulated world.
Virtual reality can also refer to applications that are not
fully immersive, such as mouse-controlled navigation
through a three-dimensional environment on a graphics
monitor, stereo viewing from the monitor via stereo glasses,
stereo projection systems, and others. Some virtual reality
applications allow views of real environments with superim-
posed virtual objects. Virtual reality applications are found in
medicine, education and training, real estate and tourism, and
entertainment.
Principle
Specialized systems can help organizations and
individuals achieve their goals.
A number of specialized systems have recently appeared to
assist organizations and individuals in new and exciting ways.
Segway, for example, is an electric scooter that uses sophis-
ticated software, sensors, and gyro motors to transport peo-
ple through warehouses, offices, downtown sidewalks, and
other spaces. Originally designed to transport people around
a factory or around town, more recent versions are being
tested by the military for gathering intelligence and trans-
porting wounded soldiers to safety. Radio Frequency Identi-
fication (RFID) tags are used in a variety of settings. Game
theory involves the use of information systems to develop
competitive strategies for people, organizations, and even
countries. Informatics combines traditional disciplines, such
as science and medicine, with computer science. Bioinfor-
matics and medical informatics are examples. A number of
special-purpose telecommunications systems can be placed
in products for varied uses.
