基于智能算法的多水源泵站在线优化控制技术

在供水系统实际运行过程中,调度人员往往根据实际需求,在当前水泵运行状态的基础上开启或关闭一台水泵,以调节管网中的压力和流量.人工经验的调度方式难以充分反映并结合管网中压力、流量的变化及实际需求,进而及时作出科学决策.针对此问题,提出了多水源泵站在线优化控制技术,建立了基于直接优化调度方法的在线优化控制模型,采用智能优化算法进行了求解,并确立了四项方案评价指标对在线优化控制方案进行评价.将所建立的模型,应用于南方城市供水系统在线优化控制中,验证了其实用性,并编制了相应的计算程序软件.     

Research on the frequency domain ∑△-DPCA

The frequency domain ∑A-DPCA processing （F-∑A-DPCA） is investigated in details and an improved scheme for the F-∑A-DPCA is proposed, which can significantly reduce the computational burden. In practice, because of the sum and difference beam pattern designed independently and other system errors, the clutter suppression of the time domain ∑A-DPCA processing （T-∑A-DPCA） is significantly degraded. However, the F-∑A-DPCA adaptively calculates the optimum gain ratio for motion compensation within each Doppler cells which is robust to system errors. Theoretical analysis and simulation results are presented to validate that the F-∑A-DPCA can achieve superior performance of clutter cancellation than the time domain processing, and its performance can be significantly increased if more pulses are used for the Doppler filtering. The improved approach is efficient, and feasible for real-time application.     

MEMS陀螺仪冗余配置故障检测方法

针对姿态测量系统的可靠性问题,提出了一种冗余配置方式的微机电系统(micro-electro-mechanical system,MEMS)陀螺仪故障检测方法。首先,基于三轴MEMS陀螺仪研究了冗余配置的形式,给出了相应的故障评价函数,并给出了最优配置角度的计算方法;其次,根据冗余配置建立陀螺仪故障检测数学模型,设计了MEMS陀螺仪硬故障检测方法,并进一步证明了陀螺仪的软故障和陀螺仪输出噪声的相关性,通过最大似然估计给出了软故障检测判决函数;最后,利用自主构建的故障检测硬件平台进行了实验验证,成功实现了对发生硬故障及软故障陀螺仪敏感轴的检测。该方法将MEMS陀螺仪的冗余配置扩展到了敏感轴水平,提高了MEMS陀螺仪的数据利用率,增加了系统可靠性。     

对地面动目标检测雷达的干扰技术综述

地面动目标检测(ground moving target indication, GMTI)系统能够实现对地面运动的检测、定位、测速等功能,并生成地面态势信息。由于现代战争“发现即摧毁”的特点, GMTI系统对地面运动目标构成严重的威胁。为了有效对抗GMTI系统,提升对地面运动目标的防护能力,对GMTI干扰技术进行综述。首先介绍了目前GMTI发展状况,之后介绍了GMTI干扰技术发展状况,并主要从干扰效果、干扰调制方式、干扰布站方式、干扰能量来源等角度对GMTI干扰技术进行概述和总结,最后对GMTI干扰技术发展趋势进行了分析。     

下一代密集WLAN网络干扰管理机制

在密集高效无线局域网部署场景中,针对传统802.11协议造成用户公平性差和吞吐量低的问题,提出一种以用户为中心的资源配置方法。该方法通过对用户进行识别分类,以用户为中心配置信道和功率,在保证用户公平性的前提下,最大化网络吞吐量。提出的功率控制机制和用户识别方法可以很简单的应用于现有无线局域网系统中。仿真结果表明,提出的资源配置方法平均提升单位基本服务集吞吐量47.3%,干扰最严重的基本服务集的吞吐量提升190%,每个基本服务集的边缘用户的吞吐量平均提升约74.3%。     

超启发式DE算法求解零等待发酵工艺调度

为解决具备间歇过程特点的零等待发酵工艺调度过程中易变质的难点,提出了一种超启发式差分算法,并将最小化最大完工时间设置为优化目标。此算法分为2层,高层为改进的自适应差分进化算法,来对低层的启发式操作进行选择排序。而低层组合排序成了新的算法对问题域进行操作,加入模拟退火算法避免陷入局部最优。所提出的方法具有学习的机制,对不同问题具有较强的泛化能力。通过测试算例和实际生产进行算法的比较和求解验证了此算法的有效性,结果表明所提出的算法比传统的启发式算法性能更优。     

一种基于需求景气分析和“幼稚预测”思想的需求预测模型

根据汽车生产企业和宾馆企业需求预测问题的基本特点,利用需求时间序列及其变化曲线,提出了一种基于需求景气分析和"幼稚"预测思想的定量预测模型,即首先划分产品的景气变化模式,然后寻找当前点状态的最佳历史匹配,并据此给出需求预测值.本文给出了模型的相关定义及算法,并以宾馆和汽车生产企业的实际需求数据为应用对象,检验了该模型的预测性能.试验结果表明,该方法具有较理想的预测精度.     

不完全维修下的单部件系统视情维修及更换策略

实际装备维修工程中,系统并不总能够通过维修恢复如新,并且修后工作时间和维修时间会随着系统年龄增加而分别呈现缩短和延长趋势。针对这个问题,利用连续时间马尔科夫链理论建立单部件系统在不完全维修条件下的视情维修及更换策略模型。根据马氏过程平稳状态下统计平衡原理得到状态概率方程组,并给出相应的递归求解算法。分别以系统稳态可用度最大、长期运行费用率最低以及规定可用度约束下平均故障前时间最长为目标,确定系统最优检测频率、视情维修阈值和更换策略。最后通过算例说明系统在最优维修及更换策略下达到的性能指标与系统劣化属性和维修能力水平的关系,验证了该模型的可行性。     

Novel reference range selection method in InlSAR imaging

Aiming at the reference range selection for different antennas in interferometric inverse synthetic aperture radar (InISAR) systems, this paper proposes a respective focusing (RF) method. The reference ranges for echoes of different antennas are selected respectively for RF, which is different from the traditional uniform focusing (UF) with the same reference range applied to all the antennas. First, a comparison between UF and RF for InISAR signal model considering the ranging error is given. Compared with RF, UF has an advantage in overcoming the ranging error differences between different antennas. Then the influence of ranging error upon the interferometric imaging with RF is investigated particularly, and it is found that the ranging error differences between different antennas are far smaller than the wavelength, which is advantageous to imaging. By comparing the capabilities of interferometric imaging between RF and UF, it is concluded that RF is a better choice in conquering problems such as image mismatching and phase ambiguity even with ranging errors. Simulations demonstrate the validity of the proposed method.     

Dynamic pricing and compensation on heterogeneous sales forces

In this paper, we analyze the pricing decision and the compensation strategy of a firm that relies on a heterogeneous sales force to sell its product in two periods. The sales agents’ selling abilities are their private information and will determine the effectiveness of the agents’ selling efforts. We introduce three compensation contract strategies, i.e. pooling, semi-separating and separating that the firm can adopt in period one and by applying principle-agent theory, derive the optimal compensation contracts and optimal price for the firm in two periods in each strategy. Comparing these three contract strategies, we found that the optimal strategy for the firm depends on the discount factor. We show that the firm will surely offer separating contracts in period one for some small discount factor, and for some large discount factor pooling contract is certain to be provided in period one. However, semi-separating contracts may be considered for some mediate discount factor, and also may not appear for all discount factors in period one. Our analysis also reveals that the optimal price decreases with the discount factor when pooling contract is offered in period one and increases with the discount factor when separating contracts is offered in period one.