الحاسب الآلي

This paper describes a new method of simulation for inverter circuits by using the interpreted Petri-nets (IPN). This method begins with a formalization stage which culminates in a set of IPN and mathematical equations which translate the requirements of the performance specifications sheet pertinent both to the control strategies to be guaranteed in relation to the status of the process, and to characteristics of these specifications and requirements. The algorithms of the simulation are written directly from these sets of IPN. This method facilitates and organizes writing the simulation algorithms. A single-phase half-bridge inverter circuit is used to validate this method.

This paper introduces a simple method in measuring small inductances ( in nanohenery) not usually measurable in conventional measuring instruments The idea is summarized by the slight change in the frequency of oscillation of a Colpitts oscillator caused by the unknown inductance Analogue and digital circuits have been designed for implementing this project together with a PC which calculates and displays the measured inductance value

The trend in world economy is towards Knowledge-Based Economy. Knowledge is becoming more and more a major factor in the economy of the 21st century. Technology is the type of knowledge most related to economic and social development. Technology market has been undergoing several changes during the last two decades. Technology is perceived as an intangible assets and is traded internationally either in embodied or disembodied form. Technology generation is concentrated in few developed countries and is protected more and more by Intellectual Property Rights. The world is also witnessing an evolution of new core technologies e.g. ICT (Information and Communication Technologies), biotechnologies, advanced materials and space. Their widespread application in different industries highlighted their commercial potential and prompted a wave of techno-nationalism and technological protectionism in the industrialized world. On the other hand, Management of Technology (MOT) is becoming an important aspect of world economy. Technology generation, transfer, and application are changing. Countries are more concerned with Science and Technology policies and strategies. Implementation mechanisms of these strategies are essential for the economic and human development. Indicators show that technology generation is mostly concentrated in ten developed countries. These countries have 95% of patents ownership in the US, they cover 84% of the world expenditure or R&D, and they receive 91% of the royalties and technologies fees of disembodied technology export. On the other hand, few developing countries are emerging as exporters of technology such as Korea, Taiwan, South Africa, Mexico, Brazil, Argentina, Venezuela, and others. Technology transfer has also gone important changes in the type of technologies transferred and in the mode of this transfer. These changes could reduce more the effectiveness of technology transfer to developing countries if they do not show responsive or aggressive local entrepreneurship willing to complement imported knowledge with extensive in-house technological effort on absorption, adaptation, continuous updating and eventually on innovation. Several Arab countries are formulating National Science and Technology policies and strategies to implement these policies. The primordial importance of technology absorption and not only the transfer of production facilities have been understood. The role of technology in dealing with the important challenges to Arab countries in the beginning of the 21st century is clear. Technology can help in facing the essential problems such as achieving economic diversity, improving productivity and competitiveness, managing water resources, reducing youth unemployment, and improving the real Arab capacity in defense and security. The Arab countries are more aware of the need to improve their S&T system and transfer it to a National System of Innovation: a necessity for development in the 21st century.

The 21st century is approaching , and with it the world economy is moving towards a 'knowledge based economy’ The knowledge component in the value added has been increasing continuously. Knowledge, in the form of information products or services, is becoming more important. Advances in information technology (IT) is promoting these tendencies. Arabization of IT is a key issue in this process. These changes offer vast new opportunities to the Arab world, but they also present many challenges.