Sharif Digital Repository

Remote sensing satellites propulsion subsystem preliminary design based on performance sizing is discussed. The process is a fairly complicated one considering a variety of operational as well as performance requirements. This research aims to reduce the number of iterations required by the current practice to reach a compromise. It is based on a rapid-sizing method that helps lessen lengthy iteration cycles. The proposed technique, similar to such class of preliminary design processes, leads to an acceptable approximation that must be properly conveyed to other disciplines involved for further elaborations. With proper selection of design and performance parameters together with fundamental... 

Remote sensing satellites propulsion subsystem preliminary design based on performance sizing is discussed. The process is a fairly complicated one considering a variety of operational as well as performance requirements. This research aims to reduce the number of iterations required by the current practice to reach a compromise. It is based on a rapid-sizing method that helps lessen lengthy iteration cycles. The proposed technique, similar to such class of preliminary design processes, leads to an acceptable approximation that must be properly conveyed to other disciplines involved for further elaborations. With proper selection of design and performance parameters together with fundamental... 

The assessment of existing platforms under past environmental (wave, wind, current and etc.) loads and probable future loads (earthquake) is a relatively new process and has not yet been standardized as the design has. This lack of standardization creates some difficulty in establishing performance requirements which must be developed depending upon the risks (i.e., hazards, exposures and consequences) associated with the future operation of the platform. The present criteria of the offshore structure standards for seismic assessment can be improved using Building prestandards. Recently some documents such as FEMA-356 and ATC-40 are developed for seismic assessment of buildings. However... 

This article uses gap metric method to design a multi-model controller for nonlinear systems. In order to decompose the nonlinear system into a reduced nominal local models bank as much as possible, and assure the closed-loop robust stability and performance, the decomposition and designing of local controllers are integrated. To this end, robust stability, performance, and gap metric are incorporated to build a binary distance matrix that supports defining the driving and dependence powers for each local model. Then a best–worst analysis is employed considering the driving and dependence powers to find out the nominal local models. The proposed approach screens the value of all local models... 

This work presents results on the development of robust H∞ control strategy for Networked Control Systems (NCSs) by involving uncertainties in both communication and controlled plant subsystems. The network-induced delays in both communication links (to and from the controller) are assumed to behave as Markov chains. An analytical approach is presented to calculate the transition probabilities of the Markovian network-induced delays. By employing the augmentation method, the resultant system is converted into a delay-free uncertain singular Markovian jump system with bounded transition probabilities. New conditions are established to assure that the uncertain NCS satisfies an H∞ performance...