Self-adaptive Green-Ampt infiltration parameters obtained from measured moisture processes

The Green-Ampt(G-A) infiltration model(i.e., the G-A model) is often used to characterize the infiltration process in hydrology. The parameters of the G-A model are critical in applications for the prediction of infiltration and associated rainfall-runoff processes. Previous approaches to determining the G-A parameters have depended on pedotransfer functions(PTFs) or estimates from experimental results, usually without providing optimum values. In this study, rainfall simulators with soil moisture measurements were used to generate rainfall in various experimental plots. Observed runoff data and soil moisture dynamic data were jointly used to yield the infiltration processes, and an improved self-adaptive method was used to optimize the G-A parameters for various types of soil under different rainfall conditions. The two G-A parameters, i.e., the effective hydraulic conductivity and the effective capillary drive at the wetting front, were determined simultaneously to describe the relationships between rainfall, runoff, and infiltration processes. Through a designed experiment, the method for determining the GA parameters was proved to be reliable in reflecting the effects of pedologic background in G-A type infiltration cases and deriving the optimum G-A parameters. Unlike PTF methods, this approach estimates the G-A parameters directly from infiltration curves obtained from rainfall simulation experiments so that it can be used to determine site-specific parameters. This study provides a self-adaptive method of optimizing the G-A parameters through designed field experiments. The parameters derived from field-measured rainfall-infiltration processes are more reliable and applicable to hydrological models.     

引导交叉——一种新的遗传交叉策略

介绍了遗传算法的优化方法,在已经存在的交叉算子上提出了一种新的交叉算子——引导交叉,它结合了异位交叉和等位交叉的特点,并加入个体反码表示形式,在执行交叉操作前有一个自适应的选择交叉方式的判断,给出了5组不同的测试函数的仿真实验。实验结果表明,引导交叉算子可比其他交叉算子更有效地提高遗传算法的收敛性,且易于找到全局最优解。     

栅极式相浓度传感器的设计与仿真优化

研究一种用于圆形封闭管道内气固两相流实时截面相浓度测量传感器。该传感器采用新型栅极式电容电极设计,有效地均化了空间敏感电场分布,减小了因截面流型变化而导致的测量值波动,提高了测量精度;同时,栅极轴向检测特性的优化,提高了传感器对圆管截面相浓度信号的实时跟踪及瞬态检测能力。     

OPTIMIZING LAYOUT OF URBAN STREET CANYON USING NUMERICAL SIMULATION COUPLING WITH MATHEMATICAL OPTIMIZATION

1. INTRODUCTION Vehicular emissions have become one of thmain sources of urban atmospheric pollution in Chinwith the development of the urban construction andthe increase in the number of vehicles. There are lots of factors influencing the transport and dispersion of vehicular exhausted pollutants and further influencing the local air quality, among which the gas dynamical effect due to the mechanical turbulence from huge buildings and street canyons is especially remarkable. Previous stu…     

基于知识的广义优化方法

传统的优化方法在描述能力、建模方法、方法实现和模型数据的分析等方面都存在着局限性,需要引入新的思路.针对上述问题,提出了基于知识的广义优化方法,给出了广义优化中知识概念、优化问题的描述,以及基于知识的广义优化方法的一般求解过程.其基本方法是在优化问题知识模型的基础上,建立基于知识的广义优化算法,通过知识系统的约简,得到用于制定优化方案的决策规则.同时给出了基于知识的广义优化方法在在锅炉燃烧优化问题中的应用示例,说明了方法的有效性.     

东海西湖井身结构深度优化技术及其应用

东海西湖地区深部地层具有研磨性强,可钻性差,机械钻速低,且存在异常高温高压等特点。通过不断探索、实践井身结构优化技术,形成了东海近几年较为固定的探井井身结构。但表层?444.5 mm井眼再加速遭遇“瓶颈”,常压深井井身结构仍有优化空间。随着东海钻井技术的不断进步及油气资源勘探开发的需求,水平井及大斜度井的数量在不断增多,而开发井?215.9 mm井眼水平段?177.8 mm尾管下入困难。因此,需要进一步对东海西湖凹陷区域井身结构进行深度优化。针对以上难点,研究形成了表层井眼尺寸优化技术、深井井身结构简化技术及开发井尾管尺寸优化技术。现场试验应用表明,钻井提速效果明显,为后续井的井身结构继续优化奠定了基础。同时也降低了深部井段复杂情况出现的概率,增大了探井套管和井眼环空间隙,为后续作业提供了便利,也为复杂地质条件下深井和超深井的井身结构的设计提供了新的思路。     

燃煤机组的供热改造项目实例分析

目的 为了提高燃煤机组的运行效率和经济效益,以珠海发电厂的供热改造项目为对象进行实例分析,探索煤电机组经营困境的破局之路。 方法 通过剖析珠海发电厂供热改造项目,从可行性、控制策略、改造效果等几个方面综合探讨。 结果 分析结果表明,供热改造后机组煤耗明显降低,同时供热量的增加提高热电比,可争取更多的计划电量,增加发电基数。 结论 供热改造对于条件合适的燃煤机组是一个值得参考的优化途径,具有非常重要的指导意义和经济价值。     

螺带几何参数对反应釜内混合性能的影响

为提高螺带式搅拌器的混合性能,基于均匀试验设计方法对偏心式和对心式螺带搅拌器进行方案设计,通过数值模拟对各方案进行计算和分析,选取最优方案并与原始方案的混合时间、混合效果、功率以及单位体积混合能进行对比。结果表明：偏心式螺带搅拌器相较于对心式的混合时间减少1.25~17.5 min,但其混合效果降低2.1%~9.1%;对心式螺带搅拌器相较于偏心式消耗功率高0.02~0.53 kW,单位体积混合能高120~931 kJ/m³;螺带数5条、螺距1200 mm、转速35 rad/min的对心式螺带搅拌器为最优方案,其混合效果与原始方案相比提升8.5%,混合时间减少20 min,消耗功率增加4.43 kW,单位体积混合能减少54.09 kJ/m³。     

Multi-Objective Optimization for an Industrial Grinding and Classification Process Based on PBM and RSM

The grinding and classification process is one of the key sub-processes in mineral processing, which influences the final process indexes significantly and determines energy and ball consumption of the whole plant. Therefore, optimal control of the process has been very important in practice. In order to stabilize the grinding index and improve grinding capacity in the process,a process model based on population balance model(PBM) is calibrated in this study. The correlation between the mill pow...     

云边端架构下边缘智能计算关键问题综述：计算优化与计算卸载

近年来,随着入网设备数量与数据体量的急剧增加,以云计算为代表的中心式计算模式的缺点越来越显露出来。边缘计算,即让计算尽量靠近数据源,以减少数据传输时间和网络延迟,作为云计算的补充,已经成为学术界和工业界关注的焦点。该文面向边缘计算中应用较广的实例架构—云边端架构,以及边缘计算的典型应用—边缘智能计算,讨论云边端架构下边缘智能计算的两大关键问题：计算优化和计算卸载。首先分析和梳理了云边端架构下边缘智能计算优化的应用与研究现状。然后讨论了云边端架构下计算卸载的研究思路和现状。最后,总结提出了目前云边端架构下边缘智能计算业务所面临的挑战和未来研究趋势。