Database Reference
In-Depth Information
of the mountain and dynamic ones such as temperature, air pressure and
snow depth. The measurements and their history values play a critical
role for correct and timely event processing.
Municipal Administration Applications
: A tra
c monitoring
system can gather GPS data transmitted by cars, including the ID, po-
sition, and speed of cars. Besides, vast amount of sensors can also be
deployed at main routes and key junctions to collect real-time trac
conditions. Each car transmits a packet of data periodically. The mon-
itoring system can introduce event processing to correlate the data in
order to detect trac problems, recommend ideal driving routes, or send
route in real-time.
Industry Production Applications
: Subtle electronic products
such as chips should be manufactured in a finely controlled production
environment. Many conditions of the plants such as the vibration of
equipment parts need to be carefully monitored. In such case, corre-
sponding sensors which measure mechanical vibrations can be used to
avoid inecient manual measuring and patrolling. Recently, RFID has
been widely adapted for tracking the exact locations of items or tallying
the number of items in the same category in a modern warehouse.
Health-care Assistance Applications
: Sensors are often deployed
to track and monitor doctors and patients inside a hospital. We can
imagine such a scenario: Each patient can be attached a small and light
weight sensor node for detecting the heart rate or the blood pressure.
Doctors may also carry sensor nodes so their location inside the hospital
can be quickly identified. Similarly, sensors can be mounted at some
critical areas to facilitate more effective monitoring. For the sake of
reasonable diagnosis or prediction, sensor events from multiple monitors
should be correlated, and knowledge of the patient's condition and dis-
ease history should also be considered during this type of sensor event
processing.
Smart Home Applications
: For home automation, smart sensor
nodes and actuators can be embedded in appliances such as vacuum
cleaners, microwaves, ovens, refrigerators, and VCRs. Sensors for mea-
suring temperature, humidity, percentages of air components and others
can also be deployed in the home to monitor indoor conditions or actuate
adjustments through smart appliances such as air conditioners. These
sensor nodes can interact with each other, and can be conveniently mon-
itored and managed by end users through via the Internet or satellites.
To support effective, ecient, and near real-time phenomena prob-
ing and objects monitoring, streaming sensor data have to be gracefully
managed in an event processing manner. Different from the traditional
events in active databases, sensor events come with temporal or even
