Knowledge representation scheme

Organic chemistry is a unique theater for AI research because over the past 150 years organic chemists have created a powerful graphical knowledge representation scheme. This representation... 

Expert System Shells are software packages that facilitate the building of knowledge-based systems by providing a knowledge representation scheme and an inference engine. The developer adds domain knowledge. 

Knowledge Representation for IQAP. Three knowledge representation schemes, i.e., relational, rule-based and frame-based, and constraint-based, were examined for developing IQAP s knowledge base. For a general description of some knowledge representation schemes (4). 

Figure 5 Simplified View of the Knowledge Representation Scheme in GEOTOX...

On the surface, these two definitions are similar both describe a knowledge representation scheme. However, the difference is in the context. The first one describes a theoretical, abstract concept, while the second one, proposed 25 years later, describes the same concept as used in a computer system. Today, ontologies (based on the concept of a semantic network) are widely used in information technology but also in engineering to represent and store in computers complex knowledge systems, which can be continually updated and which can contain definitions of various concepts, their relationships, pictures, and even audio and video materials (Ogujejofor et al. 2004). 

The SOM is a model that emphasizes particular aspects of biological neural nets, especially those ordered maps found experimentally in the cortex. The SOM captures some of the fundamental processing principles of the brain. The SOM is a model of unsupervised machine learning and also an adaptive knowledge representation scheme. The SOM is a tool for statistical analysis and visualization. The SOM is both a projection method that maps high-dimensional data space into low-dimensional space, and a clustering method in which similar data samples tend to be mapped to nearby neurons. 

Relationships Between Objects, Processes, and Events. Relationships can be causal, eg, if there is water in the reactor feed, then an explosion can take place. Relationships can also be stmctural, eg, a distiUation tower is a vessel containing trays that have sieves in them or relationships can be taxonomic, eg, a boiler is a type of heat exchanger. Knowledge in the form of relationships connects facts and descriptions that are already represented in some way in a system. Relational knowledge is also subject to uncertainty, especiaUy in the case of causal relationships. The representation scheme has to be able to express this uncertainty in some way. 

The most popular representation scheme in expert systems is the mle-based scheme. In a rule-based system the knowledge consists of a number of variables, also called attributes, to which a number of possible values are assigned. The rules are the functions that relate the different attributes with each other. A mle base consists of a number of If... Then... mles. The IF part contains the conditions that must be satisfied for the actions or conclusions in the THEN part to be valid. As an example, suppose we want to express in a mle that a compound is unstable in an alkaline solution if it contains an ester function. In a semi-formal way the mle can be written ... 

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