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A solution method for the optimistic linear semivectorial bilevel optimization problem

JOURNAL OF INEQUALITIES AND APPLICATIONS 2014年第1期2014卷 1-10页

作者： Lv, Yibing Wan, Zhongping Yangtze Univ Sch Informat & Math Jinzhou 434023 Peoples R China Wuhan Univ Sch Math & Stat Wuhan 430072 Peoples R China

In this paper, the linear semivectorial bilevel programming problem is our concern. Based on the optimal value function reformulation approach, the linear semivectorial bilevel programming problem is transformed into a nonsmooth optimization problem, and a solution algorithm is proposed. We analyze the global and local convergence of the algorithm and give an example to illustrate the algorithm proposed in this paper.

关键词： linear semivectorial bilevel programming problem optimal value function solution algorithm

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solution for a class of closed-loop leader-follower games with convexity conditions on the payoffs

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ANNALS OF OPERATIONS RESEARCH 2017年第1期253卷 405-429页

作者： Kicsiny, Richard Szent Istvan Univ Inst Math & Informat Dept Math Pater K U 1 H-2100 Godollo Hungary

In the present paper, a recent deterministic continuum-strategy two-player discrete-time dynamic leader-follower game with fixed finite time duration and closed-loop information structure is studied. The types of the considered payoff functions can be widely used in different applications (mainly in conflicts of consuming a limited resource, where one player, called the leader, is a superior authority choosing a strategy choice first, and another player, called the follower, chooses after). In case of certain payoff convexity, explicit conditions are given, when it can be known in advance that an equilibrium exists and consists of only two possible choices of both players at each step. The sub-game equilibrium from a given step may depend on the former selections of the players. Thus the continuum-strategy problem has been reduced to a general finite game of two possible choices corresponding to both players. Such type of games could be solved in a standard way with dynamic programming using a computer. Nevertheless, the game can be further simplified, and then an equilibrium can be directly determined, such decreasing the computational demand to a great extent. A solution algorithm and practical examples are also given to support the real-life application of the results.

关键词： Closed-loop leader-follower game Payoff convexity Game reduction Leader-follower equilibrium solution algorithm

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A modular mixed-integer non-linear programming algorithm for synthesis of chemical processes

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CANADIAN JOURNAL OF CHEMICAL ENGINEERING 2004年第5期82卷 1029-1036页

作者： Li, HH Qian, Y Zheng, SQ Cheng, HN S China Univ Technol Sch Chem Engn Guangzhou 510640 Peoples R China Qingdao Univ Sci & Technol Qingdao 266042 Peoples R China

A modular approach to the formulation and a solution of mixed-integer non-linear programming (MINLP) problems are presented, which reduce the size of MINLP and the computational expenses effectively. The method decomposes the synthesis task into three hierarchical levels-the superstructure, the structure, and the modules, with the layer of modules being the most critical to the problem solution. The strategy has been implemented in a simulation environment in which the variables of interest are defined as implicit functions of the optimization variables. The implicit relationships are handled using a data-oriented process simulation technique (DOPS) that significantly simplify the simulation. The method has been effectively applied to two case studies, one from literature for the synthesis of hydrodesalkylation, and another from industrial process manufacturing methylene diphenylene diisocyanates.

关键词： process synthesis modular simulator environment MINLP solution algorithm

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INVERSE RADIATION PROBLEM IN AXISYMMETRICAL CYLINDRICAL SCATTERING MEDIA

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JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER 1993年第3期7卷 479-486页

作者： MENGUC, MP MANICKAVASAGAM, S University of Kentucky Lexington Kentucky 40506

A semianalytical technique has been developed to solve the inverse radiation problem in absorbing and scattering cylindrical media. The radiative properties in the medium are allowed to vary radially. Isotropic, linearly anisotropic, and Rayleigh scattering phase functions are considered, and both the first- and second-order scattering or radiation are accounted for in the analysis. The angular radiosity distribution obtained from the solution of the forward problem is employed as input to the inverse analysis. A numerical inversion scheme is followed to determine the profiles of extinction coefficient and the single-scattering albedo. For an anisotropically scattering medium, the asymmetry factor is also recovered. It is shown that the method is simple and accurate, even though the inversion is limited to three- or four-layer media. This inversion procedure can easily be used in experiments to determine the effective radiative property distributions in cylindrical systems.

关键词： Scattering Media Absorption Coefficient Inverse Problems Albedo Single Scattering Albedo Radiative Transfer solution algorithm Radiative Heat Transfer Concentric Cylinders Gaussian Quadrature

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DISTURBANCE MODEL FOR CONTROL STRUCTURE OPTIMIZATION WITH FULL STATE FEEDBACK

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1993年第3期16卷 523-533页

作者： SLATER, GL MCLAREN, MD LORAL SPACE SYSTPALO ALTOCA 94303

This paper deals with a technique for the integrated optimization of structure and control in the design of flexible spacecraft and other flexible systems. This current approach uses the concept of response to dynamic constraints to establish tradeoffs between control energy and structural mass. This approach gives a concise variational methodology to total system optimization and eliminates the need to specify rather arbitrary tradeoffs between control energy and structural mass. Results give an explicit dependency between structural stiffness (hence mass), disturbance magnitude, control energy available, and deflection constraints. For the special case of linear controls and quadratic constraints the problem reduces to a standard linear quadratic regulator problem plus a structure optimization. The method is general, however, and can be extended to more general problems such as output feedback, nonlinear controls, and slew optimization.

关键词： Linear Quadratic Regulator Full State Feedback Nonlinear Control Flexible Spacecrafts Structural Optimization Numerical Optimization Lagrange Multipliers Linear Quadratic Gaussian solution algorithm Finite Element Modeling

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AERODYNAMIC COMPUTATIONS FOR A TRANSONIC PROJECTILE AT ANGLE-OF-ATTACK BY TOTAL VARIATION DIMINISHING SCHEMES

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JOURNAL OF SPACECRAFT AND ROCKETS 1993年第3期30卷 304-315页

作者： LIN, HN CHIENG, CC Natl Tsing Hua Univ Hsinchu Taiwan

Several total variation diminishing (TVD) schemes and the Beam-Warming solution algorithm have been incorporated in a computer code for solving three-dimensional time-dependent, Reynold's averaged Navier-Stokes equations in generalized coordinates. A finite-volume fully implicit, approximately factored scheme is employed with a time-step convergence acceleration. Transonic turbulent flows past a scant ogive cylinder boat tail projectile at Mach numbers 0.94 and 0.97 including base now region were studied. Conditions at 0- and 4-deg angle of attack were computed. Results of zero angle of attack showed that third-order TVD schemes gave little improvements over the second-order TVD schemes. Van Leer's third-order MUSCL-type TVD scheme yields somewhat better results and faster convergence than Chakravarthy's upwind-biased TVD scheme. The convergence mte of the Beam-Warming scheme is similar to that of the second-order TVD schemes. The Beam-Warming scheme gives comparative results over most of the projectile except regions of coarse grids because the scheme is very sensitive to grid resolution. For angle-of-attack computations, Van Leer's third-order MUSCL-type TVD scheme still gives better agreement with measurement.

关键词： Angle of Attack Projectiles Total Variation Diminishing Ogive Cylinder Beam and Warming Scheme Transonic Flow Navier Stokes Equations solution algorithm Velocity Profiles Pressure Coefficient

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APPROXIMATE FACTORIZATION algorithm FOR 3-DIMENSIONAL TRANSONIC NACELLE INLET FLOWFIELD COMPUTATIONS

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JOURNAL OF PROPULSION AND POWER 1985年第1期1卷 58-64页

作者： VADYAK, J ATTA, EH Lockheed-Georgia Co. Advanced Flight Sciences Dept. Marietta GA

A highly efficient computer analysis has been developed for predicting transonic nacelle/inlet flowfields. This algorithm can compute the three-dimensional transonic flowfield about axisymmetric or asymmetric nacelle/inlet configurations at zero or nonzero incidence. The flowfield is determined by solving the fullpotential equation in conservative form on a body-fitted curvilinear computational mesh. The difference equations are solved using the AF2 approximate factorization scheme. The effects of boundary-layer viscous entrainment are approximated in the inviscid algorithm by applying a surface transpiration velocity determined from the calculated boundary-layer growth. Computed results and correlations with existing methods and experiment are presented to illustrate application of the analysis. © 1985 American Institute of Aeronautics and Astronautics, Inc.

关键词： Nacelles Boundary Layer Analysis Freestream Mach Number Supercritical Flow Angle of Attack Pressure Coefficient Viscosity solution algorithm Numerical Stability Computing

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Unsteady Preconditioned Characteristic Boundary Conditions for Direct Numerical Simulation of Incompressible Flows

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AIAA JOURNAL 2020年第4期58卷 1476-1489页

作者： Parseh, Kaveh Hejranfar, Kazem Sharif Univ Technol Dept Aerosp Engn Tehran 11365 Iran

The unsteady preconditioned characteristic boundary conditions (UPCBCs) based on the artificial compressibility (AC) method are formulated and applied at artificial boundaries for the direct numerical simulation (DNS) of incompressible flows. The compatibility equations including the unsteady terms are mathematically derived in the generalized curvilinear coordinates and then incorporated as boundary conditions (BCs) in a high-order accurate incompressible flow solver. The spatial derivative terms of the system of equations are discretized using the fourth-order compact finite difference (FD) scheme, consistent with the high-order accuracy required for the DNS. The time integration is carried out using an implicit dual time-stepping method, and the robustness and performance of the numerical algorithm are enhanced by applying the preconditioning technique and calculating the automated AC parameter based on the local flow conditions. At first, the steady viscous incompressible flow for a two-dimensional plane jet is computed to assess the accuracy and performance of the solution method by applying the UPCBCs in comparison with the simplified BCs. Then, the simulation of the unsteady incompressible viscous flow around a two-dimensional NACA0012 airfoil at the Reynolds number 800 and the angle of attack 20 degrees is performed, and it is indicated that the computational cost of the solution is considerably decreased by implementing the UPCBCs at the artificial far-field boundary compared with the simplified BCs, which is remarkably valuable for the DNSs. Finally, the computation of the transition to unsteady for the incompressible flow around a three-dimensional NACA0012 wing at the same conditions of the two-dimensional case is successfully performed, and the results obtained are compared with those of previous studies that exhibit good agreement. Indications are that the present solution method by applying the UPCBCs at the artificial far-field boundary can be effect

关键词： Incompressible Viscous Flow Direct Numerical Simulation Lift Coefficient Airfoil Freestream Conditions Flow Characteristics Numerical algorithms Curvilinear Coordinates Strouhal Number solution algorithm

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APPLICATION OF A VARIATIONAL METHOD FOR GENERATING ADAPTIVE GRIDS

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AIAA JOURNAL 1986年第3期24卷 404-410页

作者： KREIS, RI THAMES, FC HASSAN, HA NASA LANGLEY RES CTRDIV TRANSON AERODYNAMTHEORET AERODYNAM BRANCHHAMPTONVA 23665

Application of variational methods for generating adaptive grids is not as straightforward as one is led to believe. Proper scaling, suitable weight functions, and appropriate clustering on boundaries must be employed to obtain a satisfactory grid. This work, which is based on the framework developed by Brackbill and Salt/man, provides simple methods for determining scaling and investigates possible options for selecting the weight function and clustering points on the boundaries. The concepts developed here are applied to 2 two-dimensional problems: a model problem based on Burger's equation containing two length scales and transonic flow past airfoils using the Euler equations. © 1986 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.

关键词： Euler Equations Transonic Flow NACA 0012 Airfoil Flow solution algorithm Gasdynamics

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ADMISSIBLE LARGE PERTURBATIONS IN STRUCTURAL REDESIGN

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AIAA JOURNAL 1991年第1期29卷 104-113页

作者： BERNITSAS, MM KANG, B University of Michigan Ann Arbor Michigan 48109

A new algorithm for structural redesign by perturbation is developed. It allows for large changes between baseline and objective structures and can satisfy both modal and static displacement objectives. It is faster and more accurate than previously developed pertubation resizing methods because it advances incrementally to the objective structure using large admissible perturbations. The computer code developed is used as postprocessor to general or special purpose finite element codes, to improve upon the design of structures with unacceptable modal and/or static displacement response. Depending on the relation between the number of redesign goals, allowable structural changes, and admissibility constraints, the desired redesign may be feasible-either locally optimal or unique-or may not exist. In the latter case, a minimum-error inadmissible design is produced. Several numerical examples are used to study the effects of definition and relaxation of the redesign admissible domain and demonstrate the accuracy of the new redesign algorithm. An offshore tower with repeated eigen-values and 192 degrees of freedom is also redesigned subject to frequency, static displacement goals, and admissibility constraints.

关键词： Finite Element Analysis Nastran Hinged Beam Fluid Structure Interaction Perturbation Method Structural Design Structural Response Young's Modulus Quadratic Programming solution algorithm

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