A quadratic bilevel programming problem is transformed into a single level complementarity slackness problem by applying Karush-Kuhn-Tucker（KKT） conditions.To cope with the complementarity constraints,a binary encod...A quadratic bilevel programming problem is transformed into a single level complementarity slackness problem by applying Karush-Kuhn-Tucker（KKT） conditions.To cope with the complementarity constraints,a binary encoding scheme is adopted for KKT multipliers,and then the complementarity slackness problem is simplified to successive quadratic programming problems,which can be solved by many algorithms available.Based on 0-1 binary encoding,an orthogonal genetic algorithm,in which the orthogonal experimental design with both two-level orthogonal array and factor analysis is used as crossover operator,is proposed.Numerical experiments on 10 benchmark examples show that the orthogonal genetic algorithm can find global optimal solutions of quadratic bilevel programming problems with high accuracy in a small number of iterations.展开更多
通信感知一体化(Integrated Sensing and Communication,ISAC)系统可以将通信感知功能有机融合,以取得更高的频谱效率和硬件利用率,但传统的大规模集中式天线阵列在平面波假设下无法提供距离维增益,且其混合波束赋形设计为非凸优化问题...通信感知一体化(Integrated Sensing and Communication,ISAC)系统可以将通信感知功能有机融合,以取得更高的频谱效率和硬件利用率,但传统的大规模集中式天线阵列在平面波假设下无法提供距离维增益,且其混合波束赋形设计为非凸优化问题,仍是具有挑战性的难题。为此,提出了一种基于子阵列的混合波束赋形设计方案,在较低的硬件复杂度下通过扩展球面波区域范围提供距离维增益,以在满足感知性能约束和发射功率预算的前提下最大化通信速率。首先提出了一种基于分式规划和最优化最小化方法的算法,将非凸优化问题转化为凸问题后迭代求解得到一个联合波束赋形矩阵;进而提出一种基于流形优化和最小二乘法的算法,迭代求解后将其分解为数字/模拟波束赋形矩阵。仿真结果表明,基于子阵列的算法相较于集中式阵列能够获得更多的距离维信息和感知自由度,通信性能提升40%,且流形优化后混合波束赋形方案能够很好地逼近联合优化的数字波束赋形方案的性能。展开更多
为获得具有优良气动性能且兼具结构强度及轻量化的复合材料飞机机翼,提出考虑气动分析和结构分析多目标多工况优化方法。分别对机翼进行气动分析及结构强度分析,以机翼展弦比、锥度比、后掠角为几何优化变量,以机翼上下机翼蒙皮的-45...为获得具有优良气动性能且兼具结构强度及轻量化的复合材料飞机机翼,提出考虑气动分析和结构分析多目标多工况优化方法。分别对机翼进行气动分析及结构强度分析,以机翼展弦比、锥度比、后掠角为几何优化变量,以机翼上下机翼蒙皮的-45°、90°、45°、0°层厚度和夹芯厚度为结构优化变量,建立以应力、位移为约束,以升阻比最大化和质量最小化为目标的协同优化模型。针对复合材料机翼多目标优化设计存在的计算量大难以取舍的问题,提出基于多准则和物理规划的自适应约束Kriging模型多目标优化算法(adaptive constraint kriging model multi-objective optimization algorithm based on multi-criteria and physical programming,AKBCP)。该算法引入了物理规划法和多准则加点,通过测试算例对比分析表明该算法具有较好的优化效果。将该算法应用到机翼多目标优化中,与初始机翼相比,优化后机翼升阻比提高3.12%,质量减轻31%,研究结果可为复合材料机翼优化设计提供参考。展开更多
基金supported by the National Natural Science Foundation of China (60873099)
文摘A quadratic bilevel programming problem is transformed into a single level complementarity slackness problem by applying Karush-Kuhn-Tucker（KKT） conditions.To cope with the complementarity constraints,a binary encoding scheme is adopted for KKT multipliers,and then the complementarity slackness problem is simplified to successive quadratic programming problems,which can be solved by many algorithms available.Based on 0-1 binary encoding,an orthogonal genetic algorithm,in which the orthogonal experimental design with both two-level orthogonal array and factor analysis is used as crossover operator,is proposed.Numerical experiments on 10 benchmark examples show that the orthogonal genetic algorithm can find global optimal solutions of quadratic bilevel programming problems with high accuracy in a small number of iterations.
文摘通信感知一体化(Integrated Sensing and Communication,ISAC)系统可以将通信感知功能有机融合,以取得更高的频谱效率和硬件利用率,但传统的大规模集中式天线阵列在平面波假设下无法提供距离维增益,且其混合波束赋形设计为非凸优化问题,仍是具有挑战性的难题。为此,提出了一种基于子阵列的混合波束赋形设计方案,在较低的硬件复杂度下通过扩展球面波区域范围提供距离维增益,以在满足感知性能约束和发射功率预算的前提下最大化通信速率。首先提出了一种基于分式规划和最优化最小化方法的算法,将非凸优化问题转化为凸问题后迭代求解得到一个联合波束赋形矩阵;进而提出一种基于流形优化和最小二乘法的算法,迭代求解后将其分解为数字/模拟波束赋形矩阵。仿真结果表明,基于子阵列的算法相较于集中式阵列能够获得更多的距离维信息和感知自由度,通信性能提升40%,且流形优化后混合波束赋形方案能够很好地逼近联合优化的数字波束赋形方案的性能。
文摘为获得具有优良气动性能且兼具结构强度及轻量化的复合材料飞机机翼,提出考虑气动分析和结构分析多目标多工况优化方法。分别对机翼进行气动分析及结构强度分析,以机翼展弦比、锥度比、后掠角为几何优化变量,以机翼上下机翼蒙皮的-45°、90°、45°、0°层厚度和夹芯厚度为结构优化变量,建立以应力、位移为约束,以升阻比最大化和质量最小化为目标的协同优化模型。针对复合材料机翼多目标优化设计存在的计算量大难以取舍的问题,提出基于多准则和物理规划的自适应约束Kriging模型多目标优化算法(adaptive constraint kriging model multi-objective optimization algorithm based on multi-criteria and physical programming,AKBCP)。该算法引入了物理规划法和多准则加点,通过测试算例对比分析表明该算法具有较好的优化效果。将该算法应用到机翼多目标优化中,与初始机翼相比,优化后机翼升阻比提高3.12%,质量减轻31%,研究结果可为复合材料机翼优化设计提供参考。
