基于等式的等间隔GM(1,1)模型比较研究

本文归纳了基于等式的2种等间隔GM(1,1)模型,比较了这2种模型与常规模型的精度,算例显示:当发展系数a较小时,3种模型的后验差比值C和小误差概率P的精度一致;当发展系数较大时,基于等式的模型比常规模型的后验差比值C和小误差概率P的精度高,且基于等式的这2种模型的后验差比值C和小误差概率P精度基本相当.     

GM trees on trial in a field: Reductionism, risks and intractable biological objects

Identification of GM plants with their internal molecular-genetic qualities serves transformation of living organisms into identifiable commodities and objects of regulation. From molecular reductionist assumptions it also follows that scientific research is to be based on experiments that allow analysis of genetic influence in isolation. In this paper, I analyse molecular reductionism ‘in action’ by means of an ethnographic case study, focusing on the practices and transformations through which a field trial of transgenic trees created understanding of the risks or risklessness of the trees. The results show how the mobilisation of the field trial design, choosing of key analytical scales and formation of the research team stabilised the paths that experimentation was to follow. The scientists took the emerging inconsistencies and surprises calmly, indicating that unexpected events are an essential part of a scientific process. However, surprises could matter only in relation to the testing arrangements. Therefore, what could become visible and what could make a difference for the constitution of risk/risklessness were the fluctuations that the particular analytical assemblages defined as significant from the outset. Meanwhile, it was impossible to treat the trees and the field ecosystem as mutually constitutive. Nevertheless, there is no reason to think of knowledge production concerning transgenic organisms in deterministic terms. First, scientists are bound to be complexly engaged with the ecosystems that they are supposed to sort out. Second, consideration of the public lessons of experiments may elicit problems and limitations of molecular reductionism.     

人类活动对柳林泉域水文过程影响研究

20世纪50年代以后,柳林泉流量日益减少,人类活动成为其衰减的主要原因。通过分阶段应用灰色系统模型,定量地描述人类活动对柳林泉水文过程的影响。第一阶段(1957~1973年),柳林泉水流量只受自然条件的影响,第二阶段(1974~2009年)柳林泉水流量受自然条件和人类活动的双重影响。运用灰色关联分析和GM时滞模型,通过比较分析得到人类活动对柳林泉水文过程的影响。结果显示:人类活动导致泉水流量相对于降水量的时间滞后由0年增长到4年,即地下水压力波在传播过程中受到人类活动的干扰,强度被削弱,传播速度变缓。降水量对泉水流量的灰作用系数由第一阶段的1.127 2×10-2下降到了第二阶段的7.75×10-3,说明由于人类活动使降水量对泉水流量的补给强度减弱。     

灰色系统与神经网络组合模型在地下水水位预测中的应用

灰色GM(1,1)模型与人工BP神经网络对于预测非线性数列变化趋势都具有很好的适用性,但同其他预测方法一样也存在各自的局限性。本文采用灰色GM(1,1)模型与人工神经网络相结合的方法,对GM(1,1)模型预测结果进行了修正。以收集到的某地区1996～2006年的地下水水位埋深数据为算例,计算结果表明,经人工神经网络修正后的灰色系统的预测值比原预测值的预测精度有了很大提高。     

GM(1,1)预测效果数值试验

采用不同类型原始数据对传统GM(1，1)进行了预测效果数值试验，然后通过对预测结果及传统GM(1，1)基本思想进行深入分析提出传统GM(1，1)存在的问题，并提出了相应的改进思路。     

洱海的营养状态发展趋势的灰色预测

根据洱海多年（1990－1998）的几个主要富营养化指标的普适卡森指标TSIG值，建立了TSIG指数的灰色GM（1，1）预测模型，应用该模型对洱海1999－2004年的营养状态发展趋势进行了预测，此预测结果可为今后的治理提供一定的依据。     

大同地震监测中心站GM4-XL磁通门磁力仪观测数据漂移分析

大同地震监测中心站配备2套GM4-XL磁通门磁力仪进行地磁观测,探头置于同一地下地磁房。自2017年以来,2套仪器每年夏秋季均存在不同程度的数据漂移现象。从数据连续率、完整率及台站背景噪声、数据预处理等角度,对2017年以来观测数据进行质量评价。通过与山西省其他台站地磁数据进行差值检测,结合地磁房附近地质条件、地下地磁室及观测墩建设、降雨等因素,分析认为,大同地震监测中心站地磁观测数据漂移的原因在于,夏秋季降雨致土层渗水,玻璃钢罩密封性较差,探头室地面积水,造成观测墩基不稳,使得置于观测墩上的仪器探头水平状态改变,进而引起观测数据发生漂移。     

加权GM(1.1)模型在地铁沉降监测中的应用

GM(1,1)模型中的新数据的重要性远远大于那些陈旧的数据,然而,传统的GM(1,1)模型数据的累加并没有体现出新数据的重要性.通过对广州地铁五号线沉降监测数据进行处理,分别建立传统的GM(1,1)模型和加权GM(1,1)模型,对两种模型进行分析与预报,比较的结果验证了加权GM(1,1)模型在地铁沉降变形分析中的有效性、实用性和正确性.     

Forecasting Hourly Roadside Particulate Matter in Taipei County of Taiwan Based on First‐Order and One‐Variable Grey Model

In this study, seven types of first‐order and one‐variable grey differential equation model (abbreviated as GM (1, 1) model) were used to forecast hourly roadside particulate matter (PM) including PM₁₀ and PM_2.5 concentrations in Taipei County of Taiwan. Their forecasting performance was also compared. The results indicated that the minimum mean absolute percentage error (MAPE), mean squared error (MSE), root mean squared error (RMSE), and maximum correlation coefficient (R) was 11.70%, 60.06, 7.75, and 0.90%, respectively when forecasting PM₁₀. When forecasting PM_2.5, the minimum MAPE, MSE, RMSE, and maximum R‐value of 16.33%, 29.78, 5.46, and 0.90, respectively could be achieved. All statistical values revealed that the forecasting performance of GM (1, 1, x⁽⁰⁾), GM (1, 1, a), and GM (1, 1, b) outperformed other GM (1, 1) models. According to the results, it revealed that GM (1, 1) was an efficiently early warning tool for providing PM information to the roadside inhabitants.     

基于地面三维激光扫描技术的滑坡模型监测与预测

地面三维激光扫描技术可以高精度、高密度、高速度、非接触地测量滑坡表面三维空间坐标,从而得到滑坡模型地表的整体变形资料.文章结合滑坡模型试验,利用灰色模型GM(1,1)对模型中提取的两个监测点的三维坐标位移进行预测,经由实测值与预测值比较、误差检验、图形对比等得出结论:灰色模型可以应用于长期的滑坡控制点三维坐标位移预测中.