Aiming at the disadvantages of the basic ant colony algorithm, this paper proposes an improved ant colony algorithm for robot global path planning. First, adjust the pheromone evaporation rate dynamically to enhance the global search ability and convergence speed, and then modify the heuristic function to improve the state transition probabilities in order to find the optimal solution as quickl...

Al-Mg alloys are normally prone to lose part of their yield and tensile strength at high temperatures due insufficient thermal stability the microstructure. Here, we present a Ca-modified Al–Mg–Sc alloy demonstrating elevated temperatures. The microstructure contains Al4Ca phases distributed as network along grain boundary Al3(Sc,Zr) nano-particles dispersed within grains. evolution age-hardeni...

A loading-unloading-reloading strategy via atomistic simulations is proposed to reveal the strengthening mechanisms of rhenium in nickel-based superalloys at ambient temperature. Simulations reproduce experimentally observed increased flow stress with addition rhenium. Besides usual solid solution strengthening, two novel are uncovered. One that facilitates dislocation nucleation and, thus, inc...

Multigrid methods provide a means with which to accelerate the solution of many problems derived from multidimensional linear and nonlinear Partial Differential Equations. A multigrid approach is applied to anisotropic diffusion, a process that is useful for image smoothing and edge strengthening. It is demonstrated to improve the response of the diffusion process by smoothing stubborn low-freq...

We investigate a mixed 0 − 1 conic quadratic optimization problem with indicator variables arising in mean-risk optimization. The indicator variables are often used to model non-convexities such as fixed charges or cardinality constraints. Observing that the problem reduces to a submodular function minimization for its binary restriction, we derive three classes of strong convex valid inequalit...

We propose an algorithm for the strengthening of the Generalized Set Covering formulation of the MAX-SAT Problem. Unlike the standard approach, our procedure does not rely on the solution of the linear relaxation to generate the cuts used to strengthen the formulation. On the contrary, it computes a La-grangian bound and uses the Lagrangian multipliers to guide the generation of cutting planes....

We propose an algorithm for the strengthening of the Generalized Set Covering formulation of the MAX-SAT Problem. Unlike the standard approach, our procedure does not rely on the solution of the linear relaxation to generate the cuts used to strengthen the formulation. On the contrary, it computes a La-grangian bound and uses the Lagrangian multipliers to guide the generation of cutting planes....

This paper discusses important shortcomings of current approaches to systems security engineering. The value and limitations of perimeter security designs are examined. An architectural approach to systems security engineering is introduced as a complementary means for strengthening current approaches. Accordingly, this paper outlines a methodology to identify classes of new reusable system sec...

Population balance modeling has received an unprecedented amount of attention during the past few years from both academic and industrial quarters because of its applicability to a wide variety of particulate processes. In this article, a fresh look is taken of the basic issues of the application of population balances towards strengthening the approach as well as widening the scope of their ap...