Maximal elements and generalized games involving condensing mappings in locally FC-uniform spaces and applications （I）

First, the notions of the measure of noncompactness and condensing set-valued mappings are introduced in locally FC-uniform spaces without convexity structure. A new existence theorem of maximal elements of a family of set-valued mappings involving condensing mappings is proved in locally FC-uniform spaces. As applications, some new equilibrium existence theorems of generalized game involving condensing mappings are established in locally FC-uniform spaces. These results improve and generalize some known results in literature to locally FC-uniform spaces. Some further applications of our results to the systems of generalized vector quasi-equilibrium problems will be given in a follow-up paper. Project supported by the Natural Science Foundation of Sichuan Education Department of China (Nos. 2003A081 and SZD0406)     

基于机动目标滤波估计的航天器主动规避策略

随着空间操控技术的发展, 航天器在轨安全问题日益受到重视.具有主动机动能力的航天器对目标航天器的自主接近严重威胁航天器的在轨安全.航天器近距离追逃博弈时,相对位置、速度、加速度等状态获取是追逃双方博弈策略形成的基础.本文在追逃双方信息获取不完全的情况下,提出了基于机动目标滤波估计与最大化视线偏转率的主动规避逃脱策略.追逃双方航天器基于当前统计模型滤波算法获得对方的相对位置、速度、加速度等导航信息.追踪航天器采用比例导引律自主接近逃逸航天器.逃逸航天器计算相对于追踪航天器的视线方向及视线偏转率,采用基于最大化视线偏转率的主动规避策略进行逃脱.对不同规避策略及不同工况进行仿真分析, 结果表明:逃逸航天器的机动能力达到追踪航天器的60%以上时,所提出的规避策略可有效规避追踪航天器的自主接近;规避策略对观测设备的测量精度和工作频率不敏感;规避效果与规避策略的响应时间有关, 逃逸航天器收到预警信息越早, 规避效果越好.      

基于混合行为博弈的多目标仿生设计方法

将多个设计目标视为不同的博弈方，通过计算设计变量对目标函数的影响因子和模糊聚类， 将设计变量集合分割为各博弈方拥有的策略空间. 对蜥蜴种群的繁衍生存机理进行仿生，将 3种蜥蜴的行为方式分别定义为利己主义、集体主义和投机主义，并赋予相应的博弈方， 各博弈方根据所仿生蜥蜴的行为特点，建立自身博弈得益函数与目标函数之间的映射关系. 各博弈方分别以自身博弈得益函数为目标，在各自的策略空间中进行单目标优化，获得本博 弈方对其余博弈方的最佳对策，所有博弈方的最佳对策形成一轮博弈的策略组合，并根据收 敛判别，通过多轮博弈，获得最终的博弈解. 以白鹤滩拱坝体型的三目标优化设计为例，设 计结果显示坝体体积方量减少了16.412万方，或2.38%; 最大主拉应力降低 了0.036MPa, 或0.31%; 整体应变能下降了0.167GJ 或4.47% 体现了基 于混合行为博弈方式的多目标仿生设计方法的有效性.     

SYSTEM OF VECTOR QUASI-EQUILIBRIUM PROBLEMS AND ITS APPLICATIONS

A new system of vector quasi-equilibrium problems is introduced and its existence of solution is proved. As applications, some existence results of weak Pareto equilibrium for both constrained multicriteria games and multicriteria games without constrained correspondences are also shown.     

混合少数者博弈模型中的模仿效应研究

我们研究了混合记忆经纪人争当少数者博弈模型中的模仿效应。我们将模仿引入混合少数者博弈模型,经纪人可以模仿邻近的更成功的经纪人,采用其最佳邻居的策略来作为自己的决策,模拟结果表明当单一社群经纪人处于拥挤区域时,模拟的引入可以明显改善经纪人之间的合作行为。     

拱坝体型的多目标博弈设计

提出基于博弈理论的多目标求解方法,给出多目标问题的博弈描述和各博弈方策略空间的计算方法,研究:1)利用Nash均衡模型求解无目标偏好的多目标竞争问题;2)利用Stackelberg寡头模型求解有目标偏好的多目标竞争问题;3)利用合作竞争模型求解关注整体得益的多目标设计问题;并给出相应的技术步骤.以白鹤滩拱坝体型的三目标博弈设计为例,取体积目标、坝体最大主拉应力目标和坝体应变能目标为博弈方,分别采用Nash均衡模型、Stackelberg寡头模型和合作竞争模型进行博弈求解,设计结果显示拱坝的体积方量、应力、应变能和位移等较初始体型的变化改善情况,实现了各博弈模型的设计目的,表明了多目标博弈设计方法的有效性.     

Tailoring particle shape for enhancing the homogeneity of powder mixtures:Experimental study and DEM modelling

The effect of particle shape modification on the segregation reduction of enzyme granules in laundry detergent powder mixtures was investigated,both experimentally and computationally using Deseret Element Method(DEM).The shape of modified enzyme particles was in such a way that the large and dense enzyme particles were layered by other fine particles in the detergent powder,by means of a process known in the literature as“seeded granulation”.It is found that the homogeneity of modified enzyme particles could be improved significantly comparing to the original spherical enzyme particles in powder mixtures.Overall,the results of this research demonstrated that the segregation-induced properties of the dense/spherical enzyme particles could be lowered by altering their shape,which could enable the enzyme particles to behave almost similar to other ingredients during the pile formation process.     

Improving the hydrodynamic performance of the SUBOFF bare hull model: a CFD approach

The main aims of this study are to investigate the hydrodynamic performance of an autonomous underwater vehicle(AUV),calculate its hydrodynamic coefficients,and consider the flow characteristics of underwater bodies.In addition,three important parts of the SUBOFF bare hull,namely the main body,nose,and tail,are modified and redesigned to improve its hydrodynamic performance.A three-dimensional(3D)simulation is carried out using the computational fluid dynamics(CFD)method.To simulate turbulence,the k-ωshear stress transport(SST)model is employed,due to its good prediction capability at reasonable computational cost.Considering the effects of the length-to-diameter ratio(LTDR)and the nose and tail shapes on the hydrodynamic coefficients,it is concluded that a hull shape with bullet nose and sharp tail with LTDR equal to 7.14 performs better than the SUBOFF model.The final proposed model shows lower drag by about 14.9%at u=1.5 m·s^-1.Moreover,it produces 8 times more lift than the SUBOFF model at u=6.1 m·s^-1.These effects are due to the attachment of the fluid flow at the tail area of the hull,which weakens the wake region.     

Analysis of a two-grid method for semiconductor device problem

The mathematical model of a semiconductor device is governed by a system of quasi-linear partial differential equations.The electric potential equation is approximated by a mixed finite element method,and the concentration equations are approximated by a standard Galerkin method.We estimate the error of the numerical solutions in the sense of the Lqnorm.To linearize the full discrete scheme of the problem,we present an efficient two-grid method based on the idea of Newton iteration.The main procedures are to solve the small scaled nonlinear equations on the coarse grid and then deal with the linear equations on the fine grid.Error estimation for the two-grid solutions is analyzed in detail.It is shown that this method still achieves asymptotically optimal approximations as long as a mesh size satisfies H=O(h^1/2).Numerical experiments are given to illustrate the efficiency of the two-grid method.     

ELASTIC CALCULATION OF STRESSES IN RINGS USING AIRY STRESS FUNCTION

Stress calculation formulae for a ring have been obtained by using Airy stress function of the plane strain field with the decomposition of the solutions for normal stresses of Airy biharmonic equation into two parts when it is loaded under two opposite inside forces along a diameter. One part should fulfill a constraint condition about normal stress distribution along the circumference at an energy valley to do the minimum work. Other part is a stress residue constant. In order to verify these formulae and the computed results, the computed contour lines of equi-maximal shear stresses were plotted and quite compared with that of photo-elasticity test results. This constraint condition about normal stress distribution along circumference is confirmed by using Greens’ theorem. An additional compression exists along the circumference of the loaded ring, explaining the divorcement and displacement of singularity points at inner and outer boundaries.     

Two‐objective optimization strategies using the adjoint method and game theory in inverse natural convection problems

This paper considers the problem of estimating the strengths of two time‐varying heat sources simultaneously, from measurements of the temperature inside the square domain in a porous medium, when prior knowledge of the source functions is not available. This problem is an inverse natural convection problem. In order to circumvent this problem, we define several optimization criteria (objective functionals) that measure discrepancies between model and measured data, where objective functionals depend on two heat sources and use multi‐criteria optimization to identify Nash equilibria, which are solutions to the non‐cooperative game according to game theory. Two non‐cooperative game strategies are considered: competitive (Nash) game and hierarchical (modified Stackelberg) game. The methodology that we employ relies on a combination of mixed finite element space approximations, finite difference time discretizations, adjoint equation and sensitivity equation techniques, and nonlinear conjugate gradient algorithms for the solutions of estimating two heat sources. Applying the Sobolev gradient for the noise removal is investigated. The performance of the present technique of inverse analysis is evaluated, by means of several numerical experiments, and is found to be very accurate as well as efficient. Copyright © 2012 John Wiley & Sons, Ltd.     

Constrained multiobjective games in locally convex<Emphasis Type="Italic">H</Emphasis>-spaces

A new class of constrained multiobjective games with infinite players in noncompact locally convex H-spaces without linear structure are introduced and studied. By applying a Fan-Glicksberg type fixed point theorem for upper semicontinuous set-valued mappings with closed acyclic values and a maximum theorem, several existence theorems of weighted Nath-equilibria and Pareto equilibria for the constrained multiobjective games are proved in noncompact locally convex H-spaces. These theorems improve, unify and generalize the corresponding results of the multiobjective games in recent literatures. Contributed by Ding Xie-ping Foundation items: the National Natural Science Foundation of China (19871059); the Natural Science Foundation of Education Department of Sichuan Province ([2000]25) Biography: Ding Xie-ping (1938-)     

Quasi-Equilibrium Problems and Constrained Multiobjective Games in Generalized Convex Space

ＩｎｔｒｏｄｕｃｔｉｏｎＬｅｔＸａｎｄＹｂｅｎｏｎｅｍｐｔｙｓｅｔｓａｎｄ2 ＸｂｅｔｈｅｆａｍｉｌｙｏｆａｌｌｓｕｂｓｅｔｓｏｆＸ .ＬｅｔＴ :Ｘ→Ｙｂｅａｓｉｎｇｌｅ＿ｖａｌｕｅｄｍａｐｐｉｎｇ ,Ａ :Ｘ→ 2 Ｘｂｅａｓｅｔ＿ｖａｌｕｅｄｍａｐｐｉｎｇ ,ψ :Ｘ×Ｙ×Ｘ→Ｒ∪ ±∞ ａｎｄｆ:Ｘ×Ｙ→Ｒ∪ ±∞ ｂｅｔｗｏｆｕｎｃｔｉｏｎｓ.Ｔｈｅｇｅｎｅｒａｌｑｕａｓｉ＿ｅｑｕｉｌｉｂｒｉｕｍｐｒｏｂｌｅｍＧＱＥＰ (Ｔ ,Ａ ,ψ)ｉｓｔｏｆｉｎｄ ^ｘ∈Ｘｓｕｃｈｔｈａｔ^ｘ∈Ａ( ^ｘ) ,ψ( ^ｘ ,Ｔ^ｘ ,ｙ)≤ 0…     

Enhanced multi‐objective optimization of a dimpled channel through evolutionary algorithms and multiple surrogate methods

Using a multi‐objective evolutionary algorithm (MOEA) and enhanced surrogate approximations, the present study demonstrates the numerical analysis and optimization of staggered‐dimple channels. Two surrogates, the response surface approximation (RSA) model and the Kriging (KRG) model, are applied in light of the surrogate fidelity of the approximate analysis. An enhanced Pareto‐optimal front is obtained by performing local resampling of the Pareto‐optimal front, which provides relatively more accurate Pareto‐optimal solutions in the design space for each surrogate model. Three dimensionless design variables are selected, which are related to geometric parameters, namely, the channel height, dimple print diameter, dimple spacing, and dimple depth. Two objective functions are selected that are related to the heat transfer and pressure loss, respectively. The objective‐function values are numerically evaluated through Reynolds‐averaged Navier–Stokes analysis at the design points that are selected through the Latin hypercube sampling method. Using these numerical simulations two surrogates, viz, the RSA and Kriging models, are constructed for each objective function and a hybrid MOEA is applied to obtain the Pareto‐optimal front. For the particular implementation of surrogate models, it is observed that Pareto‐optimal predictions of the RSA model are better than those of the KRG model, whereas the KRG model predicts equally well at the off‐Pareto‐region (region away from the Pareto‐optimal solutions), which is not the case with the RSA model. The local resampling of the Pareto‐optimal front increases the fidelity of the approximate solutions near the Pareto‐optimal region. The ratios of the channel height to the dimple print diameter and of the dimple print diameter to the dimple pitch are found to be more sensitive along the Pareto‐optimal front than the ratio of the dimple depth to the print diameter. The decrease of the ratio of the channel height to the dimple diameter and the increase of the ratio of the dimple print diameter to the pitch lead to greater heat transfer at the expense of the pressure loss, whereas the ratio of the dimple depth to the print diameter is rather insensitive to Pareto‐optimal solutions. Pareto‐optimal solutions at higher values of the Nusselt number are associated with higher values of the pressure loss due to the increased recirculation, mixing of fluid and vorticity generation. Copyright © 2010 John Wiley & Sons, Ltd.     

进化算法与确定性算法在优化控制问题中的收敛性对比

对比了进化算法(基因算法)与确定性算法(共轭梯度法)在优化控制问题中的优化效率．两种方法都与分散武优化策略-Nash对策进行了结合，并成功地应用于优化控制问题。计算模型采用绕NACA0012翼型的位流流场．区域分裂技术的引用使得全局流场被分裂为多个带有重叠区的子流场，使用4种不同的方法进行当地流场解的耦合，这些算法可以通过当地的流场解求得全局流场解。数值计算结果的对比表明．进化算法可以得到与共轭梯度法相同的计算结果．并且进化算法的不依赖梯度信息的特性使其在复杂问题及非线性问题中具有广泛的应用前景。     

CONSTRAINED MULTIOBJECTIVE GAMES IN LOCALLY CONVEX H-SPACES

IntroductionTheconceptofanequilibriumpointforann_persongamewasfirstintroducedbyNash[1,2 ],whoestablishedtheexistenceoftheequilibriumpointundercertainassumptions.Sincethen ,theNashequilibriumproblemforn_persongameshavebeenintensivelystudiedandextendedbyanumberofauthorsundervariousassumptionsanddifferentdirections.Theconstrainedgameswithfiniteorinfiniteplayersisanimportantgeneralizationofn_persongameswhichhavebeenwidelystudiedbymanyauthors.Recently ,muchattentionhasbeenfocusedonthegameproblemsw…     

Generalized constrained multiobjective games in locally <Emphasis Type="Italic">FC</Emphasis>-uniform spaces

A new class of generalized constrained multiobjective games is introduced and studied in locally FC-uniform spaces without convexity structure where the number of players may be finite or infinite and all payoff functions get their values in an infinite-dimensional space. By using a Himmelberg type fixed point theorem in locally FC-uniform spaces due to author, some existence theorems of weak Paxeto equilibria for the generalized constrained multiobjective games are established in locally FC-uniform spaces. These theorems improve, unify and generalize the corresponding results in recent literatures.     

PARETO EQUILIBRIA OF MULTICRITERIA GAMES WITHOUT COMPACTNESS，CONTINUITY AND CONCAVITY

ＰＡＲＥＴＯＥＱＵＩＬＩＢＲＩＡＯＦＭＵＬＴＩＣＲＩＴＥＲＩＡＧＡＭＥＳＷＩＴＨＯＵＴＣＯＭＰＡＣＴＮＥＳＳ,ＣＯＮＴＩＮＵＩＴＹＡＮＤＣＯＮＣＡＶＩＴＹＤｉｎｇＸｉｅｐｉｎｇ（丁协平）Ａｂｓｔｒａｃｔ：Ｉｎｔｈｉｓｐａｐｅｒ．ｂｙｕｓｉｎｇａｍｉｎ...     

LINEAR QUADRATIC NONZERO-SUM DIFFERENTIAL GAMES WITH RANDOM JUMPS

IntroductionFully coupled forward-backward stochastic differential equations with Brownian motioncan be encountered in the optimization problem when we apply stochastic maximum principleand in mathematics finance when we consider large investor in securit…