We present a resource management algorithm based upon guided “walks” within a system state space. Walks are guided via simple predictions of optimum behavior whose accuracy increases as system state approaches a predicted optimum. Optimum behavior is defined as maximizing payoff, which is the difference between value of provided service and cost of providing the service. Feedback between predic...

This paper extends a recently proposed model for combinatorial landscapes: Local Optima Networks (LON), to incorporate a first-improvement (greedyascent) hill-climbing algorithm, instead of a best-improvement (steepest-ascent) one, for the definition and extraction of the basins of attraction of the landscape optima. A statistical analysis comparing best and first improvement network models for...

Abstract: The modelling, optimization issues and stiffness for several types of three degrees-of-freedom parallel robotic manipulators, i.e., 3-DOF pure translational, 3-DOF pure rotational and 3-DOF mixed motion types, are studied in this paper. First of all, the kinematics and Jacobian for the robotic manipulators are determined through different approaches; secondly, objective functions mode...

We describe a code transformation technique that, given code for a vector function F , produces code suitable for computing collections of Jacobian-vector products F (x)ẋ or Jacobiantranspose-vector products F (x) ȳ. Exploitation of scarcity a measure of the degrees of freedom in the Jacobian matrix means solving a combinatorial optimization problem that is believed to be hard. Our heuristics t...

The purpose of this research paper is to present a three-stage method using mathematicalprogramming techniques that finds high-quality solutions to the multi-floor facility layout problem. The first stage is a linear mixed-integer program that assigns departments to floors such that the total of the departmental interaction costs between floors is globally minimized. Subsequent stages find a lo...

The existence of locally optimal solutions to optimal power flow (OPF) problems has been a question of interest for decades. This paper presents examples of local optima on very simple power system networks. Usually local optima occur when the network is stressed, and the resulting voltage profiles are infeasible in practice; however, we present examples where the voltage is within practical li...

This paper deals with second order necessary conditions for optimal solution of optimal control problems governed by semilinear elliptic partial differential equations with pointwise state-control constraints.

Hard problems for metaheuristic search can be a source of insight for developing better methods. We examine a challenging instance of such a problem that has exactly two local optima, with the novel property that these two solutions are separated by a maximum possible number of moves in the feasible space. Once a descent method based on flipping 0-1 variables reaches the first local optimum, al...

While the task of answering queries from an arbitrary propositional theory is intractable in general, it can typically be performed eeciently if the theory is Horn. This suggests that it may be more eecient to answer queries using a \Horn approximation"; i.e., a horn theory that is semantically similar to the original theory. The utility of any such approximation depends on how often it produce...

Genetic algorithms are efficient global optimizers, but they are weak in performing fine-grained local searches. In this paper, the local search capability of genetic algorithm is improved by hybridizing real coded genetic algorithm with 'uniform random' local search to form a hybrid real coded genetic algorithm termed 'RCGAu'. The incorporated local technique is applied to all newly created of...