The scientific and technical information system in Saudi Higher Education: a systems approach

Continuing change in the provision of, and access to, scientific and technical information has stimulated the interest of researchers to study current information provision and usage in different work environments. The aim of this thesis is to study the current operation of the STI system in the Saudi higher education environment. A systems approach was adopted in order to have a holistic view of the requirements of this study. Since the systems approach is a concept, rather than a specific methodology, a number of framework research models that take the systems approach into consideration were developed to guide the investigation of both the information systems and the users. [Continues.

Robustness enhancement study of augmented positive identification controller by a sigmoid function

The dissolved oxygen concentration in the wastewater treatment process (WWTP) must remain in a specific range while the factory operates. The augmented positive identification (PID) controller with a nonlinear element (sigmoid function) is proposed to assure stability and reduce uncertainties in the wastewater direct reuse/recycling model. The nonlinear controller gains (PID controller with sigmoid function) for uncertain wastewater treatment processes are tuned using the particle swarm optimization (PSO) technique. The proposed robust method for controlling wastewater treatment processes has good robustness during model mismatching, reduces treatment time compared to traditional positive identification (PID) controllers tuned by PSO, is easy to apply, and has good performance, according to simulation results

Five-phase travelling wave induction heater for continuous heating of flat material

This study proposed a novel travelling wave induction heating system with five-phase exciting current. The proposed system used special exciting current to obtain a homogeneous eddy current density, which affects the temperature pattern over the material surface. Five-phase system has been attracted from many industrial applications due to its inherent features compared to the three-phase system. An even number of phases is not preferred because the poles exchange with each other. A comparison investigation with other traditional methods is represented to realise the features of the proposed method. A finite-element method simulation is represented by using ANSYS 15^®; the simulation results show that the proposed system gives superior performance of energy transferred, uniform heat distribution and higher power factor over that of the traditional three-phase system. Moreover, it performs identical eddy current, power densities, temperature and efficiency to that of the six-phase system with profits of reduction in size, weight, cost and winding copper losses