فريدة

• When analysing markets, a range of assumptions are made about the rationality of economic agents involved in the transactions
• The Wealth of Nations was written

  1776
• Rational


  (in classical economic theory) economic agents are able to consider the outcome of their choices and recognise the net benefits of each one
• Producers act rationally by


  Selling goods/services in a way that maximises their profits
• Workers act rationally by


  Balancing welfare at work with consideration of both pay and benefits
• Governments act rationally by

  Placing the interests of the people they serve first in order to maximise their welfare
• Rationality in classical economic theory is a flawed assumption as people usually don't act rationally
• If you add up marginal utility for each unit you get total utility
• SEIYUN UNIVERSITY
• College of Applied Science – CS department
• INFORMATION TECHNOLOGY
• Instructor: Dr. Mazin Md. Alkathiri
• Seiyun University - Yemen
• LECTURE 3:
• SOFTWARE CONCEPTS
• Types of software


  • System software
  • Application software
• System software


  • Operating systems
  • Programming languages
  • Database systems
• Application software

  • General office tasks (word processing, etc.)
  • Accounting
  • Design
  • Factory automation
• Computer program


  A series of instructions written in the language of the computer which specifies processing operations that the computer is to carry out on data
• Programming


  The process of producing a computer program, involving writing, compiling, running, and debugging the program
• Programming languages


  • Machine language
  • Assembly language
  • High-level languages
• Machine language


  The lowest-level programming language, consisting of binary code that is immediately understood by computers
• Machine language


  • Almost impossible for humans to use
  • Instructions are in the form of a Binary code also called machine code and are called machine instructions
• Assembly language


  A programming language that uses mnemonic codes and symbolic addresses, which are then translated into machine code by an assembler
• Common features of Assembly language

  • Mnemonic code
  • Symbolic Addresses
  • 1 to 1 translation to machine language
• Assembly language statements


  • INC COUNT
  • MOV TOTAL, 48
  • ADD AH, BH
  • AND MASK1, 128
  • ADD MARKS, 10
  • MOV AL, 10
• Assembler


  A program that converts assembly language into machine code
• High-level languages


  Machine independent and problem-oriented programming languages that are more abstract, easier to use, and more portable across platforms than low-level languages
• High-level languages


  • Programmer uses variables, arrays, and Boolean expressions to develop logic
  • Source programs are written in statements akin to English
  • Translated into machine language code with a compiler or interpreter
• Interpreter


  A translation program that converts each high-level language statement into the corresponding machine code, executing the program statement by statement
• Compiler


  A program that translates the entire high-level source code into executable machine code prior to execution
• Computer program compilation process

  1. Lexical analysis

  2. Syntactical analysis

  3. Type/Semantic checking

  4. Code optimization

  5. Code generation
• High-level language examples


  • Fortran
  • Basic
  • Visual Basic
  • C
  • C++
  • Java
• High-level language categories


  • Procedure-oriented languages
  • Problem-oriented languages
  • Natural languages
• Procedure-oriented languages


  High-level languages designed to solve general-purpose problems, using English-like commands that are easy to follow and portable
• Problem-oriented languages


  Also known as Fourth Generation Languages (4GL), used to solve specific problems with simple English-like syntax
• Natural languages


  Also known as Fifth Generation Languages, designed to make computers behave like experts and solve problems, where the programmer just specifies the problem and constraints