digital preservation refers to an important aspect that most iranian digital library initiatives lack. this component is security. while a digital library may be misconceived as an information supply space without a physical form, the same security concerns in force for operation of physical library are valid. unlike the analog materials, all digital copies of digital materials are original. a ...

supply security of energy is one of the main challenges of industrialized countries in recent decades. also, it has been noted that in recent years other countries like new emergence asian countries and latin american countries, have understood the role and importance of energy. however, oil and gas have more importance for numerous reasons such as convenience availability, high thermal value a...

Until recently, computer security was an obscure discipline that seemed to have little relevance to everyday life. With the rapid growth of the Internet, e-commerce, and the widespread use of computers, computer security touches almost all aspects of daily life and all parts of society. Even those who do not use computers have information about them stored on computers. This paper reviews some ...