Tubular structural systems are one of the most common types of systems in high-rise structures. In the early days of this system, there were imperfections in its design which were overcome over time. The most important modification to rectify these defects is the use of a series of internal frames in addition to the peripheral frames and new systems in the center of the plan to eliminate design...

in this article a graph theoretical approach is employed to study some specifications of dynamic systems with time delay in the inputs and states, such as structural controllability and observability. first, the zero and non-zero parameters of a proposed system have been determined, next the general structure of the system is presented by a graph which is constructed by non-zero parameters. the...

nanocomposite materials have recently attracted increasing interests in the field of modelling. finite element modelling can be used for computation of bulk properties of polymer/clay nanocomposites. in this study, by   considering the structure of a nano-composite material, a quasi real model is proposed. the model has been used to predict the elastic constants by selection of suitable element...