Page 142 - DCAP601_SIMULATION_AND_MODELING

Simulation and Modelling

Notes  From our observations, one reason is that in a multiple-channels queue the customers can
hop from one queue to another.
 Another reason is the impression of shorter waiting time but our simulation result has
proven it wrong. While hopping queues may seem to allow customers to get to the server
faster, it is not always true.

 A customer can hop to a shorter queue but the service time needed by the customers in the
queue may be longer thus resulting in an even longer waiting time. Another side effect is
that it can lead to disorder during the crowded hours and the most recent incident is the
fight at McDonalds during their Hello Kitty promotion.

8.3 Keywords

Feature: The object which is being mapped for use in a GIS system. Features may be points, lines
or areas.
Geographic Information System (GIS): A mapping system which combines positional data with
descriptive information to form a layered map.
Residual: A quality indicator for a GPS position that is determined during the differential
correction process indicates uncorrectable error. High residuals are not desirable.

Value: Descriptive information about a Feature. Values can be thought of as the answers to the
questions posed by Attributes.

8.4 Self Assessment

Fill in the blanks:

1. In the queuing model two types of events are used, namely arrival and .............................
2. Constant Service Time Model shows a ............................. Queue leading to a single Service
Facility which, in turn, handles each consumer in the precise same quantity of time.

3. A typical plot of ............................. number of arrivals and departures on an over-saturated,
uniform arrival rate approach to a signalized intersection.
4. The primary purpose of doing a queuing analysis at a signalized intersection is to be able
to determine the ............................. of queues that form.
5. The ............................. is a method that demonstrates dynamically the structure and the
behaviors of a system with computer in order to evaluate and predict the effect of the
behaviors of some system and provide information for decision.
6. Time-averaged statistics is defined by area under a ............................. (integration)

7. In terms of the sequence of event, the system arranges the sequence of event executing
with a table called “............................. ”.
8. The arrival corresponds to the ............................. event when a customer reaches a service
station
9. The abscissa is time and the ............................. is the cumulative number of arrivals as well
as the cumulative number of departures for a given stream (or approach) at an intersection.
10. In the queuing model, data units are often considered as ............................. and CPUs,
transmission lines, channels and terminals are thought as .............................

11. In FIFO, the ............................. of arrival and departure are the same

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