In this paper, the effectiveness of the fuzzy sliding mode control strategy on three-dimensional benchmark building with smart base isolation under seismic excitation has been examined. One of the appropriate control theories for such this nonlinear system is the sliding mode control theory; discontinuous sliding mode theory has weakness such as chattering phenomena. In this paper, we used a combination of fuzzy logic and sliding mode theory for the deletion of this defect. The proposed control theory has been scrutinized by applying on lately developed nonlinear three-dimensional base-isolated benchmark building. This building because of the three-dimensional nature, coalescing of lateral and torsional responses, continuity of responses of the superstructure, and base is modeled with three degrees of freedom on every floor. In this building eight actuators assigned only at the base level and in the two directions (x, y). In other words, 16 actuators are located underneath the structure. Furthermore, the base isolation system has been modeled by considering lateral coupled equations for a better examination of the performance of the system.The results indicate that reduction of control performance is remarkable. Also, utilizing proposed control theory can decrease the responses of building in two main directions and, particularly, in the rotational degree of freedom. KEYWORDS 3D building modeling, Bouc-Wen model, earthquake excitation, fuzzy logic, sliding mode, smart base isolation

Summary The aim of this paper is reducing the responses of structures under the mine blast‐induced ground motion by using semi‐active tools. In other words, the objective of this study is to provide a method to reduce the destructive effects of underground mine‐blast excitation. Investigating the behavior of structures under the mine blast excitation is essential because some buildings are subjected to the blast load of mines due to the rapid urbanization in different regions. Also, the importance of studying this excitation, based on the distinctive nature of mine blast‐induced underground motion, becomes more apparent. For proper investigation and comparison of responses, a seismic excitation is considered. To reduce the responses of two proposed shear structures, magnetorheological (MR) and orifice dampers are utilized. The optimum location for these dampers is investigated. To generate the optimal force each time step the clipped‐optimal algorithm is used based on the input force. The control force can be changed by adjusting the input voltage and magnetic field of dampers. In this research, structural responses based on optimal and maximum voltage are scrutinized. The results indicated that the proposed method is appropriate for reducing the responses of structures under the mine blast‐induced ground motion and seismic excitation.

Till now, various models of the motion of nanobots have been submitted; the pioneer models, in spite of being exact in mathematics, had their own kind of problems. The most recent challenge is to describe a model whose attitude can be practical so that these motions can be estimated. Considering the massive uses of nanobots, the kinds of motions and velocities of these very small robots need to be studied in a more accurate way. In this essay, we tried to develop a three-dimensional model. The three dimensional model is based on 7 spheres and 6 arms and describes a kind of movement requiring 2 spheres at each arm. The velocity of each kind has also been evaluated. Furthermore, two kinds of three-dimensional movements have been issued and compared as well. That will result in the simplicity of the equations. By applying Oseen's approximation in the Stokes' equation, the velocity in various media has been calculated and modulated.