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The subject of systemic reliability assessment, allocation and optimization as well as structural reliability (SR) of a two stage solid fuel launch vehicle (LV) is investigated. In this regards, first the LV reliability block diagram is broken-down into appropriate subsystems. Subsequently the total LV system reliability is determined assuming the subsystems reliability. In addition, using a hybrid GA-PSO algorithm optimal subsystems redundancy levels, reliabilities as well their type are determined to simultaneously maximize the total reliability while minimizing the LV cost (weight) as a constraint. While the reliability and cost of subsystems are not precisely known, the total LV... 

It has been shown that there is a relationship between the topological and spectral properties of a graph and its dynamics. However, most of the studies have not considered the direction of the links, even though most of the real networks are directed. In this thesis, we study the intrinsic relationship between the graphs’ structures, the spectral characteristics of their associated matrices, and the synchronization implications for different directed random graphs by changing their link directionality. To this end we make use of Kuramoto model for modeling the synchronization dynamics of the network. We show that, in contrast to the results of studies which suggest the λ2/λN as a measure of... 

Different reasons, all structures have inside crack or surface crack when crack growth is more at the frequancy load and it is one of the main factor in the diagnosis of structural life that this sensitivity is much greater aerial parts industry. The aim of this project, designing a new structure for the auxiliary engine compartment of the aircraft with the damage tolerance theory for cargo aircraft within the country are making. In the first stage after reviewing activitation past, the evaluation design rules between each company design its obligations, standards in design and then conceptual plan to make. Then reload force plan to make. At this stage with regard to maneuver the airplane... 

Various philosophical views on scientific models, in this research, are reviewed and criticized. From a syntactic point of view, a scientific theory is nothing but its models, and this is the theory that illustrates how the model is constructed. Pragmatic view, by adopting a pluralistic view, argue that the interpretive model provides the basis for the concretization of the abstract concepts of the theory, and it is possible that representational model is incompatible with the theory itself. The model works better than theory even in functions such as prediction, explanation and representation in some places. A group of philosophers believe that with the introduction of fiction discussion,...