this research discusses the process of designing a conceptual model for a new information system, i.e. electronic document management system. the new system is designed for an educational institute (itvhe) whose managers are the research population. the research methodology is based on structured analysis and design methodology (ssadm). in the end, the new system proposed using a data flow diag...

Nowadays study of the industrial pollutions has become a controversial issue to reduce the risks of them in all of the world. Studding of air, water, and soil pollutions as separately may cause neglect from address to a comprehensive look in industrial pollution issue. In addition, without the exact information about quantity and quality of pollution sources, reduce or eliminate industrial poll...

Regarding the increased energy consumption of the processes at the operational units in the National Iranian Oil Company, the present study analyzed energy consumption at one of the gas refineries. In this refinery, which is the main supplier of Fajr Jam refinery for the national gas network, as well as an injection into the oil fields of the Iranian South oil company, the pressure of gas after...

It has been shown in Symanzik and Baker (1996a) that a particular subclass of Formalized Data Flow Diagrams (FDFD's) is Turing equivalent. We call this Turing equivalent subclass of FDFD's persistent flow-free Reduced Data Flow Diagrams (PFF--RDFD's). PFF--RDFD's do not contain persistent flows, reference only values whose types have finite domains, and have enabling conditions that contain no ...