混沌自适应水波算法在包装配送问题中的应用

追求高效的启发式算法是包装配送问题的重要研究方向。对此,设计一种求解包装配送问题的混沌自适应水波算法(CAWWA)。根据包装配送问题特征设计水波算法(WWA)个体表达式;利用混沌系统生成WWA算法初始种群,并提出一种自适应调整的碎波系数,根据进化代数调整算法搜索范围;利用包装配送实例和6个国际算例进行仿真实验。结果表明,该算法能够适用于包装配送问题求解,且与GA算法、TS算法和ACO算法相比,其全局搜索能力更强、收敛速度更快。     

协同免疫量子粒子群算法求非合作博弈Nash均衡解

考虑n人非合作博弈Nash均衡求解问题。将混合策略意义下的Nash均衡转化为最优化问题;把免疫记忆、自我进化、信息共享机制加入量子粒子群算法,通过概率浓度选择公式来保持种群的多样性,提出协同免疫量子粒子群算法。4个经典的数值算例说明,该算法优于免疫粒子群算法,具有较强的寻优能力和收敛性能。     

一种改进的K-means算法在城市通勤研究中的应用

针对K-means算法初始聚类中心选择困难、易受噪声影响等缺点,通过选择所有样本的中心和离中心最远距离的点优化初始化聚类中心;采用类间相异度迭代计算确定k值;通过计算每一个样本与其他样本的距离和,如果大于所有样本的距离均和,则认为是噪声点予以删除。随机选取100个手机定位样本进行职住地聚类实验,结果显示改进的K-means算法经过3次迭代快速实现收敛,避免了局部最优,同时聚类中心未受到噪声影响而产生偏移。采用该算法分析杭州市通勤特征,杭州市总体达到职住平衡,但在主要商圈和主干道上通勤压力较大。与杭州市第六次人口普查数据和杭州交通运行分析报告进行分析比对,结果基本一致。     

A compositional model for CO2 flooding including CO2 equilibria between water and oil using the Peng–Robinson equation of state with the Wong–Sandler mixing rule

This paper presents a three-dimensional, three-phase compositional model considering CO₂ phase equilibrium between water and oil. In this model, CO₂ is mutually soluble in aqueous and hydrocarbon phases, while other components, except water, exist in hydrocarbon phase. The Peng–Robinson (PR) equation of state and the Wong–Sandler mixing rule with non-random two-liquid parameters are used to calculate CO₂ fugacity in the aqueous phase. One-dimensional and three-dimensional CO₂ flooding examples show that a significant amount of injected CO₂ is dissolved in water. Our simulation shows 7% of injected CO₂ can be dissolved in the aqueous phase, which delays oil recovery by 4%. The gas rate predicted by the model is smaller than the conventional model as long as water is undersaturated by CO₂, which can be considered as “lost” in the aqueous phase. The model also predicts that the delayed oil can be recovered after the gas breakthrough, indicating that delayed oil is hard to recover in field applications. A three-dimensional example reveals that a highly stratified reservoir causes uneven displacement and serious CO₂ breakthrough. If mobility control measures like water alternating gas are undertaken, the solubility effects will be more pronounced than this example.     

一种用于电力终端的BDS定位漂移校正算法

文中提出了一种用于电力终端的北斗系统(BDS)静态定位漂移的校正算法,并进行了实验验证。文中首先简要介绍了定位原理和精密单点定位(PPP),分析了影响定位和定位漂移的误差源;然后,根据经验设定了一些阈值判断电力终端状态,提出了一种移动平均校正算法,以减少后期建模误差,随后通过微处理器实现该算法;最后,通过实验验证了该算法的可行性。     

一种超宽带多模喇叭的设计

采用模式匹配法结合优化算法，为新疆天文台110 m天线研制出一种工作频带为4~12 GHz的三倍频多模喇叭.该喇叭由225个圆波导台阶组成，除了加工制造易于实现之外，与常规多模喇叭以及波纹喇叭相比，最突出的优点是在超宽频带内具有等化的辐射方向图，非常适合用作超宽频带射电天文观测天线的高效率馈源或者用于其他需要超宽频带设计的天线.