Database Reference
In-Depth Information
A strong connection exists between the
event-condition-action
(ECA)
paradigm [64] and event processing (EP). EP applies three basic ECA
concepts, i.e., events, conditions and actions. However, EP considers
more complex events, conditions, and actions, and traditional ECA rules
are insucient for more complex conditions and actions. The differences
between
stream processing
(SP) [65] and event processing (EP) are
some blurry. Both SP and EP have the ability to to eciently process
long-running continuous queries over sequences of events. SP tends to
place a higher emphasis on managing large volumes of data with rela-
tively fewer queries; whereas EP tends to consider the effect of sharing
across many queries or many patterns and focus on response generation
[63].
Complex event processing
(CEP) [66] refers to effective detection
and evaluation of the specified meaningful event patterns such as op-
portunities, exceptions, or threats over event streams. It is also often
referred to as complex pattern matching. The goal of CEP is to identify
meaningful events such as opportunities or threats and generate timely
responses. Based on Mythbusters [67], EP is analogous to signal process-
ing and CEP is more aligned with higher level situational inferencing.
1.3 Applications of Sensor Event Processing
In the era of smart planet, a variety of sensors including RFID have
been widely deployed within wired or wireless networks to produce mea-
surements and observations. The sensor data can be viewed as events
(i.e.,
sensor events
) and can be utilized for the purposes of probing and
monitoring. Sensor network applications can be categorized into areas
such as military intelligence, environment monitoring, municipal admin-
istration, industry production, health-care assistance, smart home and
so on. Next we summarize some common event-driven sensor-enabled
example applications, which generates huge volume of observing events
to be handled with EP mechanisms.
Military Intelligence Applications
: Military intelligence is inher-
ently based on an information-rich environment. Nowadays, the number
of sensors, satellites, and soldiers is pervasive, and the need to present
a timely, correct, aggregated and integrated view based on the multiple
sensing information sources is critical for effective and precise decision
making.
Environment Monitoring Applications
: Multiple sensors can be
deployed at different sites on the mountain-side for the prediction of geo-
logical disasters such as avalanche at the monitored mountain. There are
several influential parameters including static ones such as the steepness
