In the process industries,engineers who deal with water and effluent systemsface *** include:high costs for fresh water as well as for effluent treatment anddisposal;process bottlenecks caused by water-system limitati...
详细信息
In the process industries,engineers who deal with water and effluent systemsface *** include:high costs for fresh water as well as for effluent treatment anddisposal;process bottlenecks caused by water-system limitations;requried capacity increases to,andlarge capital expendicuturs on,water-treatment facilites;and limited guidance on when and how toregenerate,recycle and reuse existing process water.
The deterministic problem of constructing synthesized control strategies from the results of available observations under unknown but bounded disturbances subjected in advance to hard bounds on the uncertain parameter...
详细信息
The deterministic problem of constructing synthesized control strategies from the results of available observations under unknown but bounded disturbances subjected in advance to hard bounds on the uncertain parameters is considered. The suggested solutions rely on methods of dynamic programming and set-valued analysis and are formulated in terms of the Hamiltonian formalism. It is shown that the problem can be separated into two - a finite-dimensional problem of estimation and an infinite-dimensional control problem. (C) 2004 Elsevier Ltd. All rights reserved.
A boundary reconstruction technique using the inverse method is proposed. The finite-element method is employed to realize the deformable grid system. An adaptive strategy for updating the grid system is suggested. Se...
详细信息
A boundary reconstruction technique using the inverse method is proposed. The finite-element method is employed to realize the deformable grid system. An adaptive strategy for updating the grid system is suggested. Sensitivity analysis is performed to obtain the derivatives required for restoration of the undetermined boundary. The boundary is sought using sequential quadratic programming. The overall performance of the method is examined by comparing the restored boundary with the original boundary.
We consider solving mathematical programs with complementarity constraints (MPCCs) as nonlinear programs (NLPs) using standard NLP solvers. This approach is appealing because it allows existing off-the-shelf NLP solve...
详细信息
We consider solving mathematical programs with complementarity constraints (MPCCs) as nonlinear programs (NLPs) using standard NLP solvers. This approach is appealing because it allows existing off-the-shelf NLP solvers to tackle large instances of MPCCs. Numerical experience on MacMPEC, a large collection of MPCC test problems is presented. Our experience indicates that sequential quadratic programming (SQP) methods are very well suited for solving MPCCs and at present outperform interior-point solvers both in terms of speed and reliability. All NLP solvers also compare very favorably to special MPCC solvers on tests published in the literature.
Free flight is an emerging paradigm in air traffic management. Conflict detection and resolution is the heart of any free-flight concept. The problem of optimal cooperative three-dimensional conflict resolution involv...
详细信息
Free flight is an emerging paradigm in air traffic management. Conflict detection and resolution is the heart of any free-flight concept. The problem of optimal cooperative three-dimensional conflict resolution involving multiple aircraft is addressed by the rigorous numerical trajectory optimization methods. The conflict problem is posed as an optimal control problem of finding trajectories that minimize a certain objective function while the safe separation between each aircraft pair is maintained. The initial and final positions of the aircraft are known and aircraft models with detailed nonlinear point-mass dynamics are considered. The protection zone around the aircraft is modeled to be cylindrical in shape. A novel formulation of the cylindrical protection zone is proposed by the use of continuous variables. The optimal control problem is converted to a finite dimensional nonlinear program (NLP) by the use of collocation on finite elements. The NLP is solved by the use of an interior point algorithm that incorporates a novel line search method. A reliable initialization strategy that yields a feasible solution on simple models is also proposed and adapted to detailed models. Several resolution scenarios are illustrated. The practical issue of flyability of the generated trajectories is addressed by the ability of our mathematical programming framework to accommodate detailed dynamic models.
This paper demonstrates the convergence stability and the actual usefulness of the gradient-based motion optimizations for manipulator arms. An optimal motion-planning problem is converted into a finite-dimensional no...
详细信息
This paper demonstrates the convergence stability and the actual usefulness of the gradient-based motion optimizations for manipulator arms. An optimal motion-planning problem is converted into a finite-dimensional nonlinear programming problem that utilizes cubic or quintic B-splines as basis functions. This study shows that the numerically calculated gradient is a useful tool in finding minimum torque, minimum energy, minimum overload, and minimum time motions for manipulator arms in the presence of static or moving obstacles. A spatial 6-link manipulator is simulated without simplifying any of the kinematic, dynamic or geometric properties of the manipulator or obstacles.
Some properties of regularized and penalized nonlinear programming formulations of mathematical programs with equilibrium constraints (MPECs) are described. The focus is on the properties of these formulations near a ...
详细信息
Some properties of regularized and penalized nonlinear programming formulations of mathematical programs with equilibrium constraints (MPECs) are described. The focus is on the properties of these formulations near a local solution of the MPEC at which strong stationarity and a second-order sufficient condition are satisfied. In the regularized formulations, the complementarity condition is replaced by a constraint involving a positive parameter that can be decreased to zero. In the penalized formulation, the complementarity constraint appears as a penalty term in the objective. The existence and uniqueness of solutions for these formulations are investigated, and estimates are obtained for the distance of these solutions to the MPEC solution under various assumptions.
This paper presents two feedback neural networks for solving a nonlinear and mixed complementarity problem. The first feedback neural network is designed to solve the strictly monotone problem. This one has no paramet...
详细信息
This paper presents two feedback neural networks for solving a nonlinear and mixed complementarity problem. The first feedback neural network is designed to solve the strictly monotone problem. This one has no parameter and possesses a very simple structure for implementation in hardware. Based on a new idea, the second feedback neural network for solving the monotone problem is constructed by using the first one as a subnetwork. This feedback neural network has the least number of state variables. The stability of a solution of the problem is proved. When the problem is strictly monotone, the unique solution is uniformly and asymptotically stable in the large. When the problem has many solutions, it is guaranteed that, for any initial point, the trajectory of the network does converge to an exact solution of the problem. Feasibility and efficiency of the proposed neural networks are supported by simulation experiments. Moreover, the feedback neural network can also be applied to solve general nonlinear convex programming and nonlinear monotone variational inequalities problems with convex constraints. (C) 2003 Elsevier Ltd. All rights reserved.
In this paper, we propose an algorithm based on basic simulated annealing (SA) to optimize unsteady chemical systems. By parametrizing the control inputs, the system described by a set of differential-algebraic equati...
详细信息
In this paper, we propose an algorithm based on basic simulated annealing (SA) to optimize unsteady chemical systems. By parametrizing the control inputs, the system described by a set of differential-algebraic equations is first transferred into a nonlinear programming (NLP) problem. By using a linear function, we furthermore convert discretized control inputs and time grids into the control profile with a variable time length to improve numerical quality. Thus, the discretized control inputs and the corresponding execution time lengths will he considered as a set of decision variables. Then, these decision variables are globally determined by our algorithm with the help of a special integrator to optimize the performance index. In order to exhibit the facility of the proposed algorithm, several typical examples are provided.
An optimization procedure for designing super-resolving filters is presented, which is to design amplitude-type and phase-only transverse super-resolving Toraldo filters by nonlinear programming at the special Strehl ...
详细信息
An optimization procedure for designing super-resolving filters is presented, which is to design amplitude-type and phase-only transverse super-resolving Toraldo filters by nonlinear programming at the special Strehl ratio (the ratio of the maximum intensity of the central core of the super-resolving pattern to that of the Airy pattern). Results of comparisons between the performance of our filters and those of the references indicate that the former is superior to the latter. The super-resolving characters of the two types of filters are also discussed and compared. (C) 2003 Elsevier B.V. All rights reserved.
暂无评论