Archive for June, 2016

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Introduction To Expert Systems…

June 4, 2016

expert system

Introduction To Expert Systems. 

Borrowed this book from National Library – PNM – last month. An expert system can be distinguished from a more conventional applications program in that : It simulates human reasoning about a problem domain , rather than simulating the domain itself. This distinguishes expert systems from more familiar programs that involve mathematical modeling or computer animation. It performs reasoning over representations of human knowledge , in addition to doing numerical calculations or data retrieval. The knowledge in the program is normally expressed in some special-purpose language and kept separate from the code that performs the reasoning. These distinct program modules are referred to as the knowledge base and inference engine , respectively.

Expert systems encode the domain-dependent knowledge of everyday practitioners in some field , and use this knowledge to solve problems , instead of using comparatively domain-independent methods derived from computer science or mathematics. The process of constructing an expert systems is often called knowledge engineering , and is considered to be ‘applied artificial intelligence’.

In the field of expert systems , knowledge representation implies that we have some systematic way of codifying what  an expert knows about some domain.However , it would be a mistake to suppose that representation is the same thing as encoding , in the sense of encryption. If one encodes a message by transposing its constituent symbols in some regular fashion , the resultant piece of code would not be a representation of the contents of the message from an artificial intelligence point of view , even if the code were machine-readable and easy to store in the memory of the machine.

The notion of a symbol is so pervasive in the current theory and practice of artificial intelligence that its importance is easily overlooked. It is this notion that forms the crucial link between artificial intelligence and formal systems of logic and mathematics. In the simplest possible terms , a symbol is something that stands for something else. This ‘something else’ is usually called the designation of the symbol. It is the thing that the symbol refers to or represent. The designation may be a physical object or it may be a concept , but the symbol itself is physical. The idea behind symbolic computation is that we want to allow symbols to stand for anything at all. Programming languages based on this paradigm provide a number of primitive data structures for associating symbols with other symbols , as well as primitive operations for manipulating symbols and their associated structures.

p/s:- Some of the article above is an excerpt from the book Introduction to Expert Systems , written by Peter Jackson and published by Addison Wesley.

 

Programming Engineering Computations in Java.

Programming engineering computations in java

Borrowed this book from National Library (PNM) last month . It’s quite an interesting book to read for those who taken Java language as one of the programming language as a subject to study..The basic module of a Java program is referred to as the class. The definition of the module is the class. A class contain the information (data) and the functionality (method). The Java libraries have several classes.

A Java program contains the definition of the classes. The statements in a Java program are written in the body of the method in a class. The variables and the methods in a Java program are written in the body of the class. This makes Java , a structured language.

The compilation of the Java source code file is performed by typing the statement, javac filename.java in the command prompt of the Java bin folder. The CLASS_NAME.java program is compiled by typing javac CLASS_NAME.java in the command prompt of the Java bin folder. If the program compiles without error message , the java compiler creates a class file in the name of the Java source code file and the command prompt will be displayed as j2sdk1.4.1>bin>  in the console window.

The java class file is executed by typing java filename in the command prompt of the Java bin folder , without the class extension. The output of the java program is displayed in the console window. The compiled CLASS_NAME.java program is executed by typing java CLASS_NAME in the command prompt of the Java bin folder.

The data type  used in the numerical computations in engineering are: 1. Integer 2. Floating Point 3. Double Precision. 4. Character. 5. Boolean. An integer variable in Java is declared using the syntax, int variable_name;  . The initialization of the variable is performed as int variable_name = initial_value ;

The Java compiler has the java.lang.String class for the creation of the instances of the String class. The String class has several methods to process the instances of the String class. The instances of the String class can be created by reading the text from the console window or the input file , and using statements in the program.

Error messages can be obtained from the methods performing the tasks in the Java programs using exceptions. An exception in Java is performed by using a try block , catch block , and finally block. A try block enclosed in the curly braces performs a task. If a statement in the try block throws an exception , a catch block can be written to receive a specific type of exception. The statements in catch block instruct the computer to perform a specific task after receiving a specific  type of error message from the try block. A finally block is written to specify the task to be performed after the try and the catch blocks.

In summary , this book covers topics about File Processing in Java , Matrix Computations in Java , Exceptions in Numerical Computations in Java , Classes , Inheritance and Polymorphism , Graphical User Interface , Graphics , Java Applet and Programming Threads in Java.

p/s:- Some of the article above is an excerpt from the book – Programming Engineering Computations in Java – written by Dr. Raja Subramaniam and published by Firewall Media.