用数值遗传算法改进非线性PLS法进行构效关系研究

将数值遗传算法同非线性ＰＬＳ结合，改进和完善了非线性ＰＬＳ，推导了指数，对数，倒数和Ｓｉｇｍｏｉｄ函数的公式，构造了可以处理多种非线性函数关系的算法，可用于解决复杂的结构与性能相互关系。     

A genetic algorithm for structure-based de novo design

Genetic algorithms have properties which make them attractive in de novo drug design. Like other de novo design programs, genetic algorithms require a method to reduce the enormous search space of possible compounds. Most often this is done using information from known ligands. We have developed the ADAPT program, a genetic algorithm which uses molecular interactions evaluated with docking calculations as a fitness function to reduce the search space. ADAPT does not require information about known ligands. The program takes an initial set of compounds and iteratively builds new compounds based on the fitness scores of the previous set of compounds. We describe the particulars of the ADAPT algorithm and its application to three well-studied target systems. We also show that the strategies of enhanced local sampling and re-introducing diversity to the compound population during the design cycle provide better results than conventional genetic algorithm protocols.     

Simple algorithm for isothermal-isobaric molecular dynamics

We review principles of non-Hamiltonian statistical mechanics and present a new set of equations and integration algorithm for isothermal-isobaric dynamics. The chief advantage of the present scheme is that it is somewhat simpler than previous methods. We perform numerical simulations to test the accuracy of the algorithm and compare its stability to that of a "gold standard," a symplectic integrator for Hamiltonian dynamics of the same system. The stability of the isothermal-isobaric algorithm is comparable to the stability of the symplectic integrator.     

两种计算吸光光度法同时测定钙镁

研究了在pH10．5的硼砂-氢氧化钾缓冲溶液和乙醇的增敏作用条件下，偶氮氯膦Ⅰ与钙、镁的吸收特性，建立了多波长光度法同时测定钙和镁的方法。采用两种矩阵算法对试验数据进行处理，并对结果进行比较和分析。钙和镁含量在0～25μg／25ml范围内用计算法Ⅱ能得到准确结果。     

人类A3腺苷受体拮抗剂1,2,4-三唑并[1,5-α]喹喔啉衍生物的QSAR研究

采用遗传算法构建了27种人类腺苷受体拮抗剂1,2,4-三唑并[1,5-α]喹喔啉衍生物与受体之间的亲和性的QSAR模型.为得到理想模型,计算了拓扑学、热力学、空间、电子拓扑状态和量子化学描述符.结合这些参数得到最终模型:ENpKi=13.407-0.027*FC-8-0.033*FC-8 0.845*Atype_C_28-19.493*Shadow_XYfrac.计算得到的统计学指标为:LOF=0.291,r2=0.766,ra2dj=0.723,F-test=17.974,PRESS=3.469,CV-r2=0.791.通过对模型进行分析,得到如下结论:降低C-8位亲电、亲核原子的前线电子密度的权重和分子在XY平面的投影分数,增加疏水性原子类型描述符Atpye_C_28的值,都对增加化合物分子与受体的亲和性有利.利用此模型合理的设计了两个新的化合物,并预测具有较高的结合活性.该研究为喹喔啉衍生物作为人类A3腺苷受体拮抗剂的结构改造提供理论指导,并为进一步研究受体与配体亲和性机理奠定理论基础.     

Extrapolated Smoothing Descent Algorithm for Constrained Nonconvex and Nonsmooth Composite Problems*

In this paper, the authors propose a novel smoothing descent type algorithm with extrapolation for solving a class of constrained nonsmooth and nonconvex problems,where the nonconvex term is possibly nonsmooth. Their algorithm adopts the proximal gradient algorithm with extrapolation and a safe-guarding policy to minimize the smoothed objective function for better practical and theoretical performance. Moreover, the algorithm uses a easily checking rule to update the smoothing parameter to ensure that any accumulation point of the generated sequence is an (affine-scaled) Clarke stationary point of the original nonsmooth and nonconvex problem. Their experimental results indicate the effectiveness of the proposed algorithm.     

Lamination Design Optimization for Continuous Fiber Reinforced Composites of Variable Thicknesses北大核心CSCD

由于具备高的比强度、比刚度,利用连续纤维增强复合材料代替传统金属材料以实现结构轻量化正受到设计者们的广泛关注。然而,结构的复杂性给复合材料的铺层设计与优化带来了很大的挑战。针对航空用复合材料铺层设计约束多的问题,通过逐步构建设计变量准确表达结构的铺层信息。基于经典遗传算法框架,结合各设计变量特点,定义了铺层优化算法中的遗传算子,通过引入“修复”策略保证了每一代解都能满足设计约束,分布在可行域区间内。最后利用精英保留策略提高了算法的局部寻优能力,可以降低复杂复合材料结构铺层设计的计算成本。通过解决经典benchmark问题并与已有优化结果的比较,验证了前述铺层优化算法的全局、局部寻优能力,为工程实际中的复合材料铺层设计优化提供了理论支撑。     

考虑罚金政策的众包物流服务质量网络均衡模型

为优化众包物流服务质量,考虑平台罚金政策,构建了包括发包方、众包平台和接包方在内的三层众包物流服务网络模型,并进行算例分析。结果表明,众包平台实施罚金政策并加大自身服务质量投入成本会促使接包方改善自身的服务质量,众包平台的服务质量和利润随之增大,但一味的增大罚金不但会使得接包方利润下降,众包平台的服务质量和利润也呈稍微下降趋势,因此平台应该选择合适的罚金区间;平台在竞争的同时也要进行一定的合作,因为平台间同步协调改进罚金政策以及质量投入会取得更大的收益和更高的平均服务质量。