优化的NSGA-Ⅱ方法在马莲河流域水资源综合管理中的应用研究

根据马莲河流域水资源总量极端贫乏、年际年内分配不均、常规水资源量低、水污染问题较严重等特点,利用系统分析理论和优化技术建立了流域的大系统、多目标水资源优化配置模型,并利用优化的NSGA-Ⅱ方法进行求解,得到流域2020年期望水资源配置下的最佳分配方案为:流域总供水量57 086×104m3,工业供水量21 690×104m3(总产值约为144.6亿元),能源基地供水量4 329×104m3(总产值约为346.32万元),农业供水量20 840×104m3,生活供水量9 452×104m3,生态供水量811×104m3。对比期望方案供水量增加了6 710×104m3,综合缺水率减少了11.41%。并根据预测的流域的分配方案和预测的流域需水量,进行了流域的水资源平衡分析,通过平衡分析的结果进行流域的综合管理研究。2020年在最优水资源分配方案下,工业缺水率3.21%、减少了4.51%;能源基地缺水率0.00%;农业缺水率4.64%、缺水率增加26.17%;生活缺水率0.00%;生态缺水率1.00%、缺水率增加了1.00%。配置方案实现了流域内水资源的最佳分配,使宝贵、有限的水资源产生最大的社会、经济及环境效益,为流域经济、能源产业的快速发展提供水资源保障。     

Active control of MDOF structures with supplemental electrorheological fluid dampers

A method for design of an active control system for multistorey structures using Electrorheological (ER) dampers is presented. Incorporated at various levels of a structural frame, ER dampers are used to improve the response of the structure during earthquakes. Optimal control theory was used to design the ER devices. The aim of the design is to find the most suitable combination of the minimum required forces produced by the ER dampers to obtain the optimal structural response. The mechanical response of ER fluid dampers is regulated by an electric field, depending on the displacements and velocities of the frame. Numerical analysis of an ER damped seven-storey structure is represented as an example. Significant improvement of the structural response was obtained using optimal active controlled ER dampers compared to passive controlled and uncontrolled structures. Copyright © 1999 John Wiley & Sons, Ltd.     

带乘性噪声广义系统状态最优估计算法

针对带乘性噪声广义系统,提出1种在线性最小方差意义下的状态最优估计算法.首先,采用标准分解将系统变换为2个子系统;其次,通过估计子系统的状态,获得原系统的状态最优滤波.同时,算法还给出了动态噪声与量测噪声的估计.仿真结果表明了该算法的有效性.     

利用三频数据最优组合求解电离层延迟的方法

目的 针对利用双频观测值估计双差电离层延迟量时间长、精度低等问题,基于三频载波观测值,提出了一种适用于长距离双差电离层延迟量实时估计的方法。首先,根据不同观测值线性组合的误差特性,选择求解电离层延迟量的最优组合观测值;然后,在准确获取最优组合观测值对应模糊度的基础上求解电离层延迟量初值;最后,引入平滑思想,通过Hatch滤波进一步优化电离层延迟量初值。算例分析表明,只要利用几十甚至十几个历元,双差电离层延迟量估值精度即可有效控制在2cm之内,实现了长距离双差电离层延迟量实时、高精度估计。     

哈萨克斯坦科扎萨伊油田优快钻井技术

哈萨克斯坦科扎萨伊油田钻井地质环境复杂,储层位于盐下,钻遇的地层层系多,地层性质差异大,具多套压力系统。钻井过程中发生地层漏失、坍塌、掉块及盐膏层蠕变等复杂情况,严重影响了钻井时效和钻井安全。针对这些技术难题,开展了油田井身结构、井身质量、提速潜力、高效钻头等分析与优化,提出了预弯曲钻具高倾角地层井斜控制技术、混合钻头减震提速技术,以及PDC-孕镶块复合钻头高研磨性地层提速技术。现场应用取得了较好的效果,平均机械钻速提高50%以上,钻井周期缩短28%。     

小波多分辨率分析时变系统参数识别算法的鲁棒性研究

针对多自由度时变系统参数识别问题,基于Daubechies小波多分辨率展开的时变参数辨识方法分析影响参数识别鲁棒性的各个因素。通过数值分析针对突变、线性慢变以及谐波快变的时变参数进行识别,研究结果表明:当基函数dbN一定时,在预先确立的分解尺度范围内,识别精度随分解尺度的增加而增加;待识别参数的频率特性对分解尺度的选择有很大影响,快时变参数比慢时变参数对分解尺度更为敏感;基函数dbN并不是影响识别精度的主要因素;在分解尺度相同的情况下,可以通过提高采样频率增加快时变参数识别精度。     

Optimal Compensation and Implementation for Adaptive Optics Systems

This paper develops a compensation algorithm based on Linear–Quadratic–Gaussian (LQG) control system design whose parameters are determined (in part) by a model of the atmosphere. The model for the atmosphere is based on the open-loop statistics of the atmosphere as observed by the wavefront sensor, and is identified from these using an auto-regressive, moving average (ARMA) model. The (LQG) control design is compared with an existing compensation algorithm for a simulation developed at ESO that represents the operation of MACAO adaptive optics system on the 8.2 m telescopes at Paranal, Chile. This revised version was published online in July 2006 with corrections to the Cover Date.     

Reconstruction of eddies by assimilating satellite altimeter data into Princeton Ocean Model

An optimal interpolation assimilation model for satellite altimetry data is developed based on Princeton Ocean Model (POM), which is applied in a quasi-global domain, by the method of isotropic correlation between sea level anomaly (SLA) and sea temperature anomaly. The perfor- mance of this assimilation model is validated by the modeled results of SLA and the current patterns. Comparisons between modeling and satellite data show that both the magnitudes and distribution patterns of the simulated SLA are improved by assimilation. The most signiˉcant improvement is that meso-scale systems, e.g., eddies, are well reconstructed. The evolution of an eddy located in the northwest Paciˉc Ocean is traced by using the assimilation model. Model results show that during three months the eddy migrated southwestward for about 6 degrees before merging into the Kuroshio. The three dimensional structure of this eddy on 12 August 2001 is further analyzed. The strength of this warm, cyclonic eddy decreases with the increase of depth. The eddy shows di?erent horizontal patterns at di?erent layers, and the SLA and temperature ˉelds agree with each other well. This study suggests that this kind of data assimilation is economic and reliable for eddy reconstruction, and can be used as a promising technique in further studies of ocean eddies as well as other ˉne circulation structures.     

水下多路液压快速接头的夹头结构分析与优化

深海油气田水下生产系统装备之间的精准连接是国际公认的技术难题,对接一般通过深海连接器完成。弹性夹头是水下连接器的重要组成部分,其性能关系到海洋油气生产系统的安全性和可靠性。弹性夹头的主要作用是在水下机器人的辅助下连接和锁紧连接器的固定端和移动端。采用ABAQUS软件的显式动力学分析模块计算夹头夹紧心轴这一过程中的应力、反作用力状态。三维模型仿真结果表明,锁紧过程中弹性夹头的最大应力不超过430 MPa,小于所选取的材料屈服强度480 MPa。采用正交试验和方差分析的方法研究夹头的长度、夹头与心轴的间隙等几个关键尺寸从而分析影响夹头应力和连接所需推力的最显著因素。对夹头的结构进行优化设计,同时也为夹头心轴结构的设计提供了理论依据。最后,通过试验研究对样机进行测试,测试结果表明,夹紧动作所需的最大推力在700 N以下。     

1991年夏季持续性异常环流的共轭敏感性分析

在共轭敏感性分析的基础上发展了最敏感扰动的概念。用共轭模式对江淮流域大水1991年东亚夏季环流的持续异常特征,包括乌拉尔阻塞高压、鄂霍次克海偶极子型阻塞以及副热带高压的变动过程进行了分析,分别得到了对这些过程影响最大的初始扰动。结果从新的角度揭示了这些系统最重要的影响因子,也显示了共轭敏感性分析方法在大气环流物理过程诊断中的有效性和应用前景。