Recently, there has been significant interest in the study of the community search problem in social and information networks: given one or more query nodes, find densely connected communities containing the query nodes. However, most existing studies do not address the “free rider” issue, that is, nodes far away from query nodes and irrelevant to them are included in the detected community. So...

This thesis addresses the application of nonlinear optimization to three different problems in computer graphics: the generation of gait cycles for legged creatures, the generation of models of truss structures, and the generation of models of constant mean curvature structures. We first present work on the automatic motion generation for legged creatures. Our technique is a reformulation of sp...

the aim of this paper is to present four strategies to increase the accuracy and speed of optimization of truss structures under the constraint of structural system failure probability (ssfp). in the first strategy based on the probability rules, a criterion is defined to avoid producing many correlated paths and obtain more accurate upper bound of ssfp. in the second strategy, the force method...

1. Abstract Swarm algorithms such as Particle Swarm Optimization (PSO) are non-gradient probabilistic optimization algorithms that have been successfully applied to obtain global optimal solutions for complex problems such as multi-peak problems. However these algorithms have not been applied to complicated structural and mechanical optimization problems since local optimization capability is s...

Metaheuristic algorithms have successfully been used to solve any type of optimization problem in the field structural engineering. The newly proposed Arithmetic Optimization Algorithm (AOA) has recently presented for mathematical problems. AOA is a metaheuristic that uses main arithmetic operators’ distribution behavior, such as multiplication, division, subtraction, and addition mathematics. ...

Sizing and shape structural optimization problems are normally stated in terms of a minimum weight approach with constraints that limit the maximum allowable stresses and displacements. However, topology structural optimization problems have been usually stated in terms of a maximum stiffness (minimum compliance) approach. In this kind of formulations, the aim is to distribute a given amount of...

In this paper we describe an optimal reconfiguration planning algorithm that morphs a grounded truss structure of known geometry into a new geometry. The plan consists of a sequence of paths to move truss elements to their new locations that generate the new truss geometry. The trusses are grounded and remain connected at all time. Intuitively, the algorithm grows gradually the new truss struct...

This paper presents the optimization of the location and feedback gains of active bar in a closed loop control system for stochastic piezoelectric smart truss structures under stationary random excitation. The mathematical model with reliability constraints on the mean square value of the structural random dynamic displacement and stress response is developed based on maximization of dissipatio...