基于麻雀搜索算法优化Elman残差自校正地面沉降预测模型

地面沉降是一种常见的地质灾害,严重阻碍当地居民的生产生活,如何对地面沉降进行准确预测已经成为相关专家学者讨论的热点话题,但常规数学模型难以对地面沉降量做出准确预测。提出了麻雀搜索算法(sparrow search algorithm,SSA)优化Elman的地面沉降量预测方法,同时根据组合模型原理提出了SSA-Elman残差自校正(SSA-Elman residual self-correction,SSA-Elman-RSC)模型的策略,通过残差校正的方式降低神经网络预测误差,成功地将地面沉降量预测模型应用于山西省大同市潇河产业园,将预测结果与未进行残差修正的模型预测结果进行比较分析。结果表明,对于均方根误差(root mean squared error,RMSE)、平均绝对误差(mean absolute error,MAE)、均方误差(mean square error,MSE)3个指标,SSA-Elman-RSC拥有更高的精度。该模型的提出为山西地区地面沉降量预测提供了一种新方法,并且组合模型的建立提供了一种新思路。

Evaluation of Treated Municipal Wastewater Quality for Irrigation

Wastewater reuse is a useful tool in minimizing the amount of wastewater in the environment. Therefore, evaluation of the suitability of Al-Rustamiyah WWTP municipal treated wastewater for irrigation was made according to its compo-sition and the international irrigation water quality standards. In addition, to classify water quality and to evaluate its suitability for irrigation purposes, Sodium Adsorption Ratio (SAR), Soluble Sodium Percentage (SSP) and Residual Sodium Carbonate (RSC) were calculated following standard equations and found experimentally as (2.11), (35.67) and (–12.75) respectively. Plotting the values of conductivity (EC) and sodium absorption ratio (SAR) on the US salinity diagram illustrated that most of the samples fall in the field of C3-S1, indicating high salinity and low sodium water which can be used for irrigation on almost all types of soil without danger of exchangeable sodium. Furthermore, the data indicate slight to moderate degree of restriction on the use of this treated wastewater in irrigation due to chloride hazard. RSC value is negative at all sampling sites, indicating that there is no complete precipitation of calcium and magnesium. Overall, the treated wastewater can be classified with few exceptions as suitable for irrigation use.

高压配电网剩余供电能力计算及应用

传统最大供电能力模型未计及电网现有负荷变化规律,计算结果偏理想化,剩余供电能力概念的提出解决了这一问题,但未考虑高压配电网对负荷增长的影响,因此本文提出高压配电网剩余供电能力计算模型。首先对高压配电网的正常运行方式和故障后运行方式进行总结和等效处理,定义独立供电区域的概念,然后在N-1安全准则的基础上,建立剩余供电能力计算模型,用以评估高压配电网在当前的网架结构和负荷水平下的剩余供电能力,最后通过实际电网算例验证了本文所提方法的有效性和实用性。