Parent frame

A typical feature of expert systems that support frames is inheritance. Frames can be organized in a hierarchical structure. They can inherit properties (attributes) from frames that are higher in the hierarchy. The latter are therefore called parent frame and the former child frame. There are many varieties of the inheritance principle. Frames can have only one parent frame (simple inheritance) or may have multiple parent frames (multiple inheritance). All attributes can be inherited (full inheritance) or only a few, selected by the knowledge engineer, may be inherited (partial inheritance) by the child frames. An example of a simple inheritance organization of frames is shown in Table 43.1. The frame Organic Compound is the parent frame. The frames Ester and Acids are child frames of Organic Compound . A typical example of inheritance is instantiation. The frame Acetic acid is a child of Acids and, since no extra attributes are added, it is also an instantiation. 

A consolidated review ofthe current-state-of-the-art on optimal damperpositioning techniques is presented in this chapter. The inherent assumptions made in previous research are discussed and substantiated with numerical studies. Earlier studies have shown that optimal distribution of dampers is sensitive to in-structure damping. In this chapter the significance of optimal distribution of dampers coupled with the necessity for the use ofa more realistic in-structure damping model is qualitatively illustrated using a comparative sensitivity study. The effect of inherent assumption of linearity of the parent frame on the optimality is also investigated. It is shown that linearity assumption imposed on the parent frame in a major seismic event may not be justified thereby raising doubts on the scope of optimality techniques proposed in literature. 

Both linear and nonlinear parent structural frames were considered in the study. The nonlinear parent frame was idealized as a yielding shear frame which also takes into account the new retrofitting techniques based on weakening and damping described in Lavan et al (2008). The other most important contribution of this work was the consideration of cost of the damper as an external constraint. Paola and Navarra (2009) discussed the stochastic responses of MDOF structures with nonlinear viscous dampers to a seismic excitation. 

Inherent assnmption of Rayleigh s vis-cons damping model for representing in-strnctnre damping of parent frame. 

Inherent assumption of linear elastic behavior of the parent frame. Except for Lavan and Levy (2005), Lavan et al (2008), Cimellaro et al (2008), and Lavan... 

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