Optimal Locations of Groundwater Extractions in Coastal Aquifers

A regional water supply management model for coastal aquifers was developed. One of its outcomes is the definition of the optimized locations for groundwater withdrawal. Such a tool permits the analysis of alternative plans for groundwater extraction and the sustainable use of water resources in a coastal aquifer subject to saltwater intrusion. The principal components are the evolutionary optimization and the analytical/numerical simulation models. The optimization technique looks for the best well locations taking into consideration the economic results and the satisfaction of the societal water demand. However these two concerns are conditioned by trying to control the saltwater intrusion, i.e., preserving the environmental equilibrium. The simulation model uses the governing mathematical equations for groundwater movement to find the interface between freshwater and saltwater. Because of the non-linearity in the system and the possibility of a jumping interface, a security distance was defined. This is a controlling variable which can be set by the decision makers. The model was applied to a typical case with interesting results. For example, diagrams showing the relationship between the location of the wells and the security distance(s) are of importance to the managers. It was also crucial to have an understanding of the tradeoffs between groundwater withdrawals, positions of the wells from the coast line, and the security distance. The model was also applied to a real case in order to relate the extractions, distances and artificial recharge (not presented in this paper).     

广义准正则格形码距离谱的计算

本文讨论了格形码距离谱的计算问题，定义了度量空间意义下的广义准正则格形码，对具有Ｉｍａｉ与Ｈｉｒａｋａｗａ［２］和Ｕｎｇｅｒｂｏｅｃｋ［３］定义的典型的时不变网格结构的广义准正则格形码，证明了其距离谱可用全零信息序列对应的码字进行计算。在理论上推广了Ｍ．Ｒｏｕａｎｃｅ与Ｄ．Ｊ．Ｃｏｓｔｅｌｏ的结果，解决了非平方欧几里德度量意义下一类ＴＣＭ信号序列的距离谱计算问题     

城市道路中的高杆照明

分析高杆照明的特点及其在城市道路中应用的实例，进而阐述高杆照明系统中主要参数的确定方法。     

The minimum squared euclidean distance of multi-h phase codes

The minimum squared Euclidean distance(MSED) of binary multi-h phase codes is presented. The signal segregation degree(SSD) has been put forward to determine MSED of multi-h phase codes. In order to maximize MSED, SSD should be as large as possible. The necessary and sufficient conditions of maximizing SSD are derived. Finally, SSD and the exact formulae for MSED of binary 2-h phase codes are also presented.     

基于参差距离的相位差变化值的解模糊方法研究

利用相位差及其变化率对辐射源进行定位是新近提出的一种快速单基无源定位方法。本文分析了利用相位干涉议得到的相位差变化值的相位模糊特点,提出了一种利用相位干涉仪的接收天线之间的参差距离对相位差变化值进行解模糊的方法,讨论了正确解模糊的条件和范围,并给出了仿真结果。     

DDS技术在数字激光相位测距仪中的应用

本文介绍了直接数字合成(DDS)技术在激光相位测距仪中的应用。使用该技术研制的数字激光相位测距仪具有操作简便、携带方便、性能可靠的特点，测相精度优于干分之一。     

离轴数字全息记录条件的研究

用振幅全息和菲涅耳衍射理论,分析离轴数字全息记录系统结构参数对数字全息再现的影响,并进行相应的实验验证。理论分析和实验研究结果都表明,如果记录物体和CCD的尺寸固定,记录物体和CCD之间的记录距离将直接影响数字全息再现像的分离状况和系统的分辨率,在保证再现像分离的前提下,缩短物体和CCD之间的距离将有利于数字全息再现像分辨率的提高。     

运用模式分类的雷达抗转发式距离欺骗干扰方法

针对雷达转发式欺骗干扰中的距离欺骗，提出了一种基于模式分类来识别目标与干扰的方法。该方法基于干扰和目标能量和起伏特性差异确定提取特征因子，再利用RBF神经网络方法进行分类。仿真结果表明，该方法具有较好的抗距离欺骗干扰性能。     

河南电力远程教育网系统安全方案开发应用

河南省电力公司远程教育平台,作为一个省内电力系统职工的再教育、技术培训、技能培训中心,访问量大,安全要求高,我们在软件设计时充分考虑到系统的安全性。