Information Technology Reference
In-Depth Information
Within the database server, four functional units are built: relational database, data
preprocessing unit, data mart (DMT) and operational data store (ODS). The main task of the
relational database is to store data and metadata of all measurements and allows users to
display information about the measurements and the measurements results in the form of
graphs and charts. The data represent a set of measured values. The metadata contain
information about particular measurement, such as the date and time of measurement, code
of specimen, measurement conditions, used equipment, etc.
The data preprocessing unit, commonly known as ETL (Extract, Transform, and Load), is
responsible for collecting and retrieving data from the relational database, their cleaning
and adjusting into the desired form, and their subsequent loading into the data scheme of
the data mart. The data have to be preprocessed for two reasons. First, the data have to be
aggregated for further analysis, for instance using OLAP; second, the data have to be refined
and consolidate for use in the neural network system.
Data preprocessing unit can be, with advantage, built using PL/SQL procedures. However,
there are a lot of freeware ETL applications, such as Clove ETL, Pentago, Spago BI, KNIME,
and more. In the case of using some of the open source applications, this functional unit will
be move from the database server to the application server. It largely depends on the
technology, respectively on the programming language of the application. This is also the
cause of the unit overlapping between the database and application server in the diagram of
the proposed DSS architecture, shown in Figure 7.
Data mart is a single subject data warehouse. Using a data warehouse technology allows
performing quick ad hoc analysis, e.g. displaying data from different perspectives and in
different contexts, such as used organic material, method of specimen preparation,
measurement method, measurement conditions, etc. Operational data store (ODS) is the last
functional unit of the database server. Its task is to store the data from the output of the
neural network system and allows users to executing queries on these data.
5.1.2 Application server
The application server is a software framework designed for the effective implementation of
procedures (programs, routines, scripts) to support building of applications. The task of
application servers is to integrate heterogeneous environment when using multilayer
architecture, and fully support the access to the various data sources. Major part of the
application servers is based on the Java 2 Platform Enterprise Edition (J2EE) standard. The
most popular open source application servers are Zope, JBoss, JOnAS, and GlassFish server
OSE, which is a free version of the application server directly supported by Oracle.
Integration of the application server into the proposed DSS architecture mainly depends on
the types and technologies of tools integrated in the neural networks system. The possibility
of omitting the application server is strengthened by the fact that today's web and database
servers taking over the function of application servers and allow direct integration of
applications.
The main function of neural networks system is generation, preparation and application of
neural networks for classification of measured data and prediction of their parameters and
trends. For this purpose, it is necessary to choose a tool or tools that contain appropriate
types of artificial neural networks, and are open-source enough to allow the modification of
learning algorithms. There are many open source tools for creating neural networks, such as
Fanny NuClass7, Joon, Encog, Neuroph, NNDef and more. Many of these are in the form of
a library of some programming languages, like C + +, Perl, Python, .NET, or PHP.
Search WWH ::
Custom Search