Prediction of overland flow and seepage zones associated with the interaction of multiple infiltration devices (cascading infiltration devices)     

David D. J. Antia 《水文研究》2008,22(14):2595-2614

Infiltration devices are traditionally evaluated as standalone entities that do not interact with each other. A model is outlined that will allow interactions between proposed infiltration devices to be predicted prior to a development commencing. The model allows prediction of seepage into downslope devices and the assessment of the locations where the combined ground‐water mound will reach the surface and result in overland flow. The volume of overland flow discharged by the seepage zone may exceed the overland and piped flow received by the infiltration devices. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

模糊控制在直流变频空调器中的应用     

邓金强  王晓平 《成都信息工程学院学报》2004,19(4):490-495

从直流型变频空调器的特点及控制要求出发,提出了模糊控制系统的结构,讨论了直流变频空调器的模糊控制算法.对控制器的性能(主要是鲁棒性)进行了详细的分析,对所采用的模糊控制算法在Matlab平台下进行了仿真,作为比较同时给出了其他常用算法的仿真结果.  相似文献   

Cross-Correlation Detection of Point Sources in the WMAP First Year Data     

Jian-Yin Nie  Shuang-Nan Zhang  Department of Physics  Center for Astrophysics  Tsinghua University  Beijing  Key Laboratory of Particle Astrophysics  Institute of High Energy Physics  Chinese Academy of Sciences  Beijing 《中国天文和天体物理学报》2007,7(2):199-208

We apply a Cross-Correlation (CC) method developed previously for detecting gamma-ray point sources to the WMAP first year data by using the Point-Spread Function of WMAP and obtain a full sky CC coefficient map. We find that the CC method is a pow- erful tool to examine the WMAP foreground residuals which can be further cleaned accord- ingly. Evident foreground signals are found in the WMAP foreground cleaned maps and the Tegmark cleaned map. In this process 101 point sources are detected, and 26 of them are new sources additional to the originally listed WMAP 208 sources. We estimate the ?ux of these new sources and verify them by another method. As a result, a revised mask file based on the WMAP first year data is produced by including these new sources.  相似文献   

Quality control and homogeneity of Turkish precipitation data     

Ozan Mert Göktürk  Deniz Bozkurt  Ömer Lütfi Şen  Mehmet Karaca 《水文研究》2008,22(16):3210-3218

Outlier trimming and homogeneity checking/correction were performed on the monthly precipitation time series of various lengths from 267 stations in Turkey. Outlier values are usually found during dry summer months, and are concentrated mostly over the southern parts of the country, where the dry period is most pronounced, implying natural extremes rather than wrong measurements. Homogeneity analysis was done using the Standard Normal Homogeneity Test, on an individual monthly basis, which led to many non‐testable series due to lack of reference stations, especially during summer months. Yet, remaining testable months were usually helpful for the assessment of homogenity, revealing a well distributed set of stations that proved to be homogeneous. There were still a number of stations which either could not be tested efficiently, or were classified as inhomogeneous. Lack of metadata is argued to be largely responsible for inefficient homogeneity testing. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Statistical characterization of impact of system variables on temporal dynamics of groundwater in highly weathered regoliths     

V. Rasiah  J. D. Armour  A. L. Cogle 《水文研究》2007,21(18):2435-2446

In situations where the water table fluctuates during the rainy season the characterization of the impact of system variables on the temporal dynamics of the groundwater (GW) is essential to improve the understanding at catchment or regional scale behaviour of GW. In this study the appropriateness of the statistical parameters; mean, median, the 80^th percentile (PC80), coefficient of variation (CV), correlation coefficient (r), and multiple regression models were assessed to characterize the impact of system variables on the temporal dynamics of hydraulic head relative to ground surface (HH) during rainy seasons. The study was conducted from 1999 to 2003 in the wet tropical Johnstone River catchment (JRC) in north‐east Queensland, Australia. Piezometer wells were installed at 32 sites under cropping to 5–90 m depth on different soil types, landscape positions, and varying proximity to surface water bodies (i.e. four system variables). The HH was measured, at least at 10–15 day intervals during 1–5 consecutive rainy seasons. The HH in the 32 wells fluctuated throughout each of the five rainy seasons. The mean HH averaged over the seasons ranged from 1·1 to 17·2 m across the wells, the median from 0·9 to 17·3 m, and the PC80 from 0·3 to 16·1 m. The temporal behaviour of HH characterization by mean of means of HH, the mean of medians of HH, and the mean of PC80 of HH, indicated the HH can be classified to belong to three different groups for each one of these parameters. The impact of the system variables on temporal dynamics, explored using multiple regression procedure, indicated that the model for median was marginally better than mean. The CV was found to be most appropriate parameter to characterize the impact of GW system variable (aquifer type), a component of the system variables, on temporal dynamics. The interactions of GW (i) belonging to different GW system and (ii) at shoulder with footslope in a landscape were best characterized by simple linear correlations. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

交流数字伺服系统的智能PID控制律研究     

唐红雨  陈迅 《成都信息工程学院学报》2007,22(1):60-63

智能PID是在结合传统的PID控制和人工智能的基础上形成的，针对交流伺服系统的要求，提出智能PID控制算法，旨在提高系统控制的精度，并从理论上对控制律进行了详细地分析。然后，在Matlab的环境下进行了系统仿真实验，从结果来看，控制策略用于交流伺服系统，能够得到一个较好的系统动、静态性能，从而获得一个较好的控制品质。  相似文献   

基于Atmega16的多点温湿度测控系统设计     

权伟  蔡淮  于小娟 《成都信息工程学院学报》2007,22(4):503-508

介绍了基于Atmega16单片机为检测和控制核心,并同多个数字温度传感器DS18B20及模拟湿度传感器HS1101构成温度与湿度的测控系统.给出了系统的总体设计方案、硬件设计及软件框图.所设计的粮情测控系统具有优良的性价比,通过系统软硬件的联合调试说明,该系统可以满足对温湿度及烟雾进行实时监控的需要,具有稳定性好、精度高等特点,有一定的应用价值.  相似文献   

The prevention of cracking and water leakage in the concrete inner lining of frozen shafts     

Yu Gongchun 《Geotechnical and Geological Engineering》1986,4(3):247-251

  相似文献   

地下水位对定点形变观测干扰的抽水实验   总被引：5，自引：2，他引：3  

陈鹏  李正媛  刘妙龙  董洪军  陈嵩 《大地测量与地球动力学》2004,24(3):79-83

抽水所造成的地下水位的变化会即时在局部范围内造成地表的形变，干扰定点地壳形变观测。在蓟县地震台进行的抽水实验表明：这种干扰的幅度与抽水水井到形变监测仪器的距离有关，也和抽水水井水位的最大降深有关。根据实验数据得到了抽水对定点形变观测的影响范围的经验公式。  相似文献   

Streamflow estimation using optimal regional dependency function     

Abdüsselam Altunkaynak 《水文研究》2009,23(25):3525-3533

The determination of spatial dependency of regionalized variable (ReV) is important in engineering studies. Regional dependency function that leads to calculation of weighting coefficients is required in order to make regional or point‐wise estimations. After obtaining this dependency function, it is possible to complete missing records in the time series and locate new measurement station. Also determination of regional dependency function is also useful to understand the regional variation of ReV. Point Cumulative Semi‐Variogram (PCSV) is another methodology to understand the regional dependency of ReV related to the magnitude and the location. However, this methodology is not useful to determine the weighting coefficient, which is required to make regional and point‐wise estimations. However, in Point Semi‐Variogram (PSV) proposed here, weighting coefficient depends on both magnitude and location. Although the regional dependency function has a fluctuating structure in PSV approach, this function gradually increases with distance in PCSV. The study area is selected in Mississippi river basin with 38 streamflow stations used for PCSV application before. It is aimed to compare two different geostatistical models for the same data set. PSV method has an ability to determine the value of variable along with optimum number of neighbour stations and influence radius. PSV and slope PSV approaches are compared with the PCSV. It was shown that slope slope point semi‐variogram (SPSV) approaches had relative error below 5%, and PSV and PCSV methods revealed relative errors below 10%. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献