Operational flood control of a low-lying delta system using large time step Model Predictive Control

The safety of low-lying deltas is threatened not only by riverine flooding but by storm-induced coastal flooding as well. For the purpose of flood control, these deltas are mostly protected in a man-made environment, where dikes, dams and other adjustable infrastructures, such as gates, barriers and pumps are widely constructed. Instead of always reinforcing and heightening these structures, it is worth considering making the most of the existing infrastructure to reduce the damage and manage the delta in an operational and overall way. In this study, an advanced real-time control approach, Model Predictive Control, is proposed to operate these structures in the Dutch delta system (the Rhine–Meuse delta). The application covers non-linearity in the dynamic behavior of the water system and the structures. To deal with the non-linearity, a linearization scheme is applied which directly uses the gate height instead of the structure flow as the control variable. Given the fact that MPC needs to compute control actions in real-time, we address issues regarding computational time. A new large time step scheme is proposed in order to save computation time, in which different control variables can have different control time steps. Simulation experiments demonstrate that Model Predictive Control with the large time step setting is able to control a delta system better and much more efficiently than the conventional operational schemes.     

汉石桥湿地南部核心区富营养化成因及防治对策

为查明汉石桥湿地南部核心区的富营养化现状和成因,于2019年3—9月对该区域水体的温度、pH值、溶解氧、透明度、光照强度、化学需氧量、高锰酸盐指数、总氮、总磷、叶绿素a等指标进行定期检测分析。采用综合营养状态指数法评价南部核心区富营养化程度,采用Pearson相关性分析叶绿素a与各项水质指标之间的关系,采用主成分分析法研究水体富营养化的驱动因子。结果表明:南部核心区处于轻度-中度富营养状态;叶绿素a与透明度、pH值、溶解氧呈显著负相关,与光照强度、水温、化学需氧量、总氮等呈显著正相关,总氮是藻类生长的限制因子;水体富营养化的主要驱动因子为光照强度、水温、叶绿素a,其次为总氮与总磷。提出再生水利用、水动力条件改善、水生生物调控等防治对策,为汉石桥湿地的水生态保护和修复工作提供科学依据。     

钟房控温的一种方法及结果分析

环境温度对原子钟特性的影响已经得到了人们的重视。现对陕西天文台守时钟房的一种温控实验作一介绍,并对温控的结果进行了评价。     

中国沿海地区持续发展隐患浅论

根据作者实地考察,发现中国沿海地区经济势头迅猛增长中隐含不少重大问题,包括重复建设、急功近利、追求自我完善体系,与当代国际经济一体化的走势相背。由于防灾意识淡薄,环境问题突出,资金浪费严重,许多重大项目建设布局不合理。本文探讨了隐患形成机制及其防范对策。     

提高房地产测绘单位质量管理水平的思考

房地产测绘管理部门的主要职责是管理房地产测绘市场 ,规范市场行为 ,对房地产测绘机构进行资质审查 ,控制市场准入 ;而房地产测绘单位要抓质量意识教育 ,抓技术培训工作 ,加强技术创新 ,建立科学的质量体系 ,以进一步提高信誉 ,适应市场竞争的需要     

Algorithm design of an hybrid system embedding influence of soil for dynamic vibration control

The paper outlines an approach for improving the effectiveness and reliability of base isolation devices in civil engineering structures that undergo exceptional dynamic conditions.The strategy consists of designing the passive device in such a way to take into account the not-negligible soil–structure interaction effects. At this stage, the isolator is, then, designed in such a way to be optimally tuned on the basis of the characteristics of the structure and of the soil at the site. Anyway limits intrinsic in the effectiveness of the passive device cannot be completely overcome even when embedding in the design the influence of the soil filtering on the structural response. Therefore, at the second stage, an active vibration device is coupled to the basic isolator, which is, in turn, optimally designed for minimizing the structural response and control costs. The overall presented approach definitively produces an effective hybrid control base isolation, already optimized for the specific structure and soil in its passive component, and able to concentrate the active control effort only on the frequency ranges where it is required.     

A soil temperature control system for sapling study in alpine region

A soil temperature control system was designed for sapling study in alpine region and tested in summer, 2009. The system consisted of a power switch, voltage regulator, microcomputer timer, safety relays, temperature control device, temperature sensors, heating cables, fireproofing plastic pipes (PVC), 108 heavy-duty plastic containers and seedlings. The heating cables were held in six 2-layer PVC frames with 25 cm wide, 320 cm long and 25 cm high and three 1-layer frames with 25 cm wide and 320 cm long for 15°C soil temperature treatment, half of the 2-layer frames were used for 20°C and 25°C soil temperature treatments, respectively. Each of the frames was installed at each of ditches with 30 cm wide, 330 cm long and 30 cm deep in size. 12 seedling containers with 20 cm top diameter, 18cm bottom diameter and 25 cm high were homogenously placed at each of the ditches, and spaces between the containers were filled with natural soil. The system was economic, and could increase soil temperatures obviously and uniformly, the maximal and minimal standard errors of soil temperatures were ±0.28 and ±0.05°C at 10cm depth in the containers within each of all the ditches. In the system, aboveground environment was natural, diurnal and monthly soil temperatures varied with changing air temperature, the research results may be better to know the eco-physiological and growth responses of alpine saplings/seedlings to soil warming than that in greenhouse, laboratory, infrared heat lamp and open top chamber.     

China’s radical birth control policy and implications for India

China has been firmly carried out her birth control policy for over 2 decades, and this has been very srccessful in practice. India is the second populous country in the world. Although overpopulation problem was identified in the 1950s, and birth control policy was implemented since then, the situation has not yet been improved. The aim of this paper is to make comparisons between these two countries, in terms of social and cultural background, geographical distribution of population, national minority structure, in order to reveal the reasons behind the China’s success, and implications for India.     

电子地图印刷出版的规范化数据化控制

根据《军用地图印刷规范》和《军用地图色标》的规定要求 ,结合现有的印刷设备 ,印刷工艺条件和印刷材料 ,着重对电子地图印刷出版的规范化数据化控制进行了讨论 ,提出了质量控制参数 ,确定了相应的质量指标 ,并选择一定的信号条、测试条和控制条控制整个印刷工艺过程。     

水泥配料集散式控制系统

介绍以16位单片机8096为核心的集散式水泥配料自动控制系统的硬件电路结构和工作原理以及软件设计方法，给 出了部分单元电路及其结构参数。实际应用表明，该系统控制效果良好，可靠性高，取得了较好的社会效益和经济效益。