Database Reference
In-Depth Information
Moreover, concerning the needs of the user
for queries about particular sensors, mining the
whole set of information from all the sensors may
not always be necessary and effective. Connecting
the sensors' domain information with reported
values will make it easy when the mining task
only associated with part of potential sensors.
It will also save computing power and memory
spaces, which consequently provide higher quality
of service in the wireless sensor networks. More
data warehousing and mining issues in the sensor
stream application domain will be discussed in
the following subsection.
to the server or multiple servers for centralized
or distributed processing and computing through
single-hop or multiple-hop routing. Different data
warehousing and mining techniques need to be
considered regarding to the different computing
models, for example, the centralized computing,
distributed or parallel computing, etc. In this topic
chapter, we focus our discussion to the central-
ized computing, in which there is one server to
collect and process all the delivered data from
multiple sensors.
Data Preprocessing Issues
data Warehousing and Mining Issues
After the data is delivered to the server, before it
can be processed, several data preprocess steps
need to be performed to get the data ready for
the processing unit and connect it with domain
information. We discuss each of the steps in the
following paragraphs.
As shown in Figure 2, there are several stages in the
sensor stream processing infrastructure, namely
the data collecting stage, the data preprocessing
stage, the data storage and processing stage,
and the data reporting and analysis stage. In this
subsection, we discuss the data warehousing and
mining issues needed to be considered in each of
these stages, respectively.
Data Extraction
The first step of the data preprocessing stage is
data extraction. In this step, the package sent from
a particular sensor is extracted and information
associated with the data warehousing and mining
tasks is collected.
Data Collecting Issues
In the sensor stream application domain, data is
gathered through wireless sensors and is delivered
Figure 2. Sensor stream processing infrastructure
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