Unit quaternion is an ideal parameterization for joint rotations. However, due to the complexity of the geometry of S group, it’s hard to specify meaningful joint constraints with unit quaternion. In this paper, we have proposed an effective and accurate method to specify the rotation limits for joints parameterized with the unit quaternion. Joint constrains constructed with our method are adeq...

Dynamic response of a structure is a remarkable characteristic which can be optimized (controlled) by imposing constraints on natural frequencies. But it is mentionable that size and shape optimization of trusses with multiple frequency constraints is a very non-linear and non-convex problem that may be converged to local optima when using meta-heuristic algorithms. To concur this problem, rese...

We have examined the Mg–σ relation for early-type galaxies in the EFAR sample and its dependence on cluster properties. A comprehensive maximum likelihood treatment of the sample selection and measurement errors gives fits to the global Mg–σ relation of Mgb = 0.131 logσ− 0.131 and Mg2 = 0.257 logσ− 0.305. The slope of these relations is 25% steeper than that obtained by most other authors due t...

In a typical wireless telecommunication network, large number of communication links is established with limited available frequencies. The problem that addresses assigning frequencies to transmitters such interference avoided as far possible called the frequency assignment problem. usually modeled graph coloring (labeling) We study in this paper ( s , t )-relaxed L (2, 1)-labeling which consid...

This paper is concerned with some feasibility issues in mathematical programs with equilibrium constraints (MPECs) where additional joint constraints are present that must be satis ed by the state and design variables of the problems. We introduce su cient conditions that guarantee the feasibility of these MPECs. It turns out that these conditions also guarantee the feasibility of the quadratic...