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1.
GM(1.1)模型与矿床深部评价   总被引:1,自引:0,他引:1  
本文应用GM(1.1)模型建立矿床深评模型,并引进淡化常数ρ,从而提高了拟合精度,降低了拟合差ζ。  相似文献   

2.
参数累积估计灰色模型及地面沉降预测   总被引:6,自引:0,他引:6  
李洪然  张阿根  叶为民 《岩土力学》2008,29(12):3417-3421
基于传统GM(1,1)地面沉降预测模型的非稳定性,引入参数累积估计方法来代替最小二乘法,构建了参数累积估计的灰色沉降预测模型。通过对上海市地面沉降的预测,证实模型降低了矩阵条件数,提高了沉降预测的稳定性,进而对上海市分层沉降进行了预测,并给出相应的模型稳定性判别,预测结果给出了上海沉降的发展趋势,为地面沉降的合理防治提供了帮助。  相似文献   

3.
地面沉降的模拟计算属于灰色问题,建立一个有效的灰色预测模型是十分重要的,在分析灰色线性回归组合模型模拟序列特点的基础上,建立了以原始数据直接建模的离散GM(1,1)模型(称为ODGM(1,1)模型),将某沉降实例数据建立ODGM(1,1)模型,并与灰色线性回归组合预测模型进行比较,结果证明离散GM(1,1)模型优于灰色线性回归组合预测模型。  相似文献   

4.
Nick Bingham 《Geoforum》2008,39(1):111-122
This paper stages an encounter between one strand of the controversy around genetically modified food crops and some conceptual resources from the field of science and technology studies, with the aim of illuminating the relationship between science and politics. Contrary to some suggestions, it is argued that the spatial, temporal and material imagination encapsulated in the figure of Progress remains central to their contemporary articulation. Best described as an ‘anti-political’ strategy, Progress does not leave room for anything else but one story of the world. Through following the attempts of both scientists in the field and protestors on the streets to make public some of the trajectories which this story leaves out, what emerges is the possibility of an alternative to Progress that is not based simply on its rejection. Instead, such efforts offer resources for inventing another way of collectively going forward which chime with some more theoretical attempts to elaborate how things might be productively ‘slowed down’. An example of how government was forced to construct a way of dealing with things that is more adequate and appropriate to life in a full world is compared with Bruno Latour’s model of due process for nonhumans, before some conclusions are drawn about whether we should be depressed or hopeful about our ability to move on in the lights of such attempts.  相似文献   

5.
改进的GM(1,1)模型及其在地下水环境预测中的应用   总被引:4,自引:0,他引:4  
地下水环境评价和预测是地下水资源规划管理的重要内容之一,地下水环境的评价和预测对促进地下水资源可持续利用具有重要的现实意义。地下水环境评价和预测模型的建立以及在实际中的运用是近年来受到广泛重视的研究领域。本文基于灰色理论、数值积分公式和相邻最近插值构造了一类改进的灰色预测模型,使得灰色预测的基本模型成为特例。以实际地下水环境数据为基础,应用本文构造的几种灰色预测模型进行了预测,并进行了分析比较。计算结果表明,构造出的几种预测模型算法简单、精度较高,比基本灰色预测模型效果更好。  相似文献   

6.
近年来,地热资源作为一种绿色清洁能源越来越受到国家重视,开采利用的规模也越来越大。如何对地下热水水位的变化趋势进行准确预测,为政府决策提供技术依据显得尤为重要。由于水位监测数据有限,尝试采用灰色系统GM(1,1)模型,对廊坊市不同热储层地热井的地下热水水位进行了预测。通过对原始数据进行"一次累加,均值处理,构建预测模型,得出时间响应函数,求解预测值"等计算过程处理,结果显示预测值与实际值基本吻合,这也验证了采用灰色系统GM(1,1)模型对廊坊市地下热水水位进行预测具有良好的效果。模型预测结果表明廊坊市地下热水水位呈逐年下降趋势,建议政府采取"推广地热资源的梯级利用,限制开采量、采补结合"等措施,合理开发利用地热资源,遏制地下热水水位不断下降的趋势,使地热资源得到可持续利用。  相似文献   

7.
基于灰色模型的城市用水量预测   总被引:3,自引:0,他引:3  
邓丽娟  魏光辉 《地下水》2011,(1):100-101
介绍灰色理论建模原理和模型参数辨识方法,并结合实例建立灰色GM(1,1)预测模型,运用残差检验与后验差检验2种方法对模型进行精度检验,其模型拟合精度达99%.用所建立的模型对某市2010-2013年城市用水量进行外推预测.结果表明,该灰色模型用于城市用水量预测,符合其灰色特性,通用性好,并且所需数据少,计算量适中,预测...  相似文献   

8.
本文以灰色系统理论为基础,建立了矿井地下水涌出的GM(1,1)动态预测模型,并用该模型进行了实际预测。  相似文献   

9.
Terry Marsden 《Geoforum》2008,39(1):191-203
Why are genetic technologies necessary in the agri-food sector and why have they created such opposition in the rural domain? The paper attempts to place GM in its contested regulatory context, situated as part of three different and competing paradigms of agri-food and rural development: the agri-industrial, post-productivist and rural development models. Conceptually, it is argued that GM is currently positioned as a relatively new variant and component of the mutating and dominant agri-industrial paradigm. This sets the context and development of GM at a global level. The paper explores in its first part how the spread of GM relates to the maintenance of the unsustainable. Whilst this remains a driving force we see, in the second part, with reference to the unfolding nature of European regulation since 2000, the ways in which this agri-industrial imperative is shaped by particular State actions which blend this agri-industrial model with a wider set of consumer, private sector and environmental concerns. Overall, the EU has managed to translate a global agri-industrial imperative, despite significant external pressure, into a highly regulated ‘post-productionist’ framework in which both private and public interests are given responsibility for delivering consumer rights. This may, or may not allow room for rural sustainable development alternatives to take hold. At least it provides something of an opportunity.  相似文献   

10.
应用灰色模型对滑坡变形进行预测,目前常用灰色GM(1,1)模型,而灰色GM(2,1)模型应用较少.在实际建模中发现,取不同长度的数据序列,建立的模型也不一样,所得的预测结果也有所不同.针对上述问题,本文基于统计的方法,得出白店子滑坡灰色预测模型最佳数据序列长度,在此基础上建立GM(2,1)模型对该滑坡深部位移进行预测,并与GM(1,1)模型预测结果进行了对比.结果表明,总体精度上GM(2,1)模型略高,预测误差较小,有很好的应用价值.  相似文献   

11.
改进的GM(1,1)模型在滑坡变形预测中的应用   总被引:4,自引:1,他引:3       下载免费PDF全文
为了提高GM(1,1)模型在滑坡变形预测中的预测精度和普遍适用性,论文首先分析了GM(1,1)模型的数学特点,并根据建模机理所存在的固有缺陷探讨了几种合理实用的改进方法。在此基础上,结合呈对数型曲线的链子崖危岩体变形监测数据和呈指数型曲线的黄龙西村滑坡变形监测数据,分别了建立了传统GM(1,1)、无偏GM(1,1)、中心逼近式GM(1,1)、重构背景值的GM(1,1)和灰色神经网络组合等预测模型。预测结果表明:针对不同数学特点的滑坡变形数据,特定改进的GM(1,1)模型较传统模型预测精度更高,适用性更强。  相似文献   

12.
灰色GM(1,1)模型最优维数的研究   总被引:2,自引:1,他引:2  
灰色GM(1,1)模型的维数对模型的预测精度有很大的影响,本文通过自编的FORTRAN程序,在合适的范围内对GM(1,1)模型的维数进行自动优化,通过对宁波市地面沉降数据的计算分析,得到了C和P的定性关系,确定了优化的评价标准,维数最优化后的模型能反映预测数列变化幅度的大小。  相似文献   

13.
基于灰色GM(1,1)模型的城市生活用水量预测   总被引:1,自引:0,他引:1  
王勇 《地下水》2010,32(2):104-106
介绍灰色理论建模原理和模型参数辨识方法,并以上海市为实例建立灰色GM(1,1)预测模型,运用残差检验、后验差检验以及关联度检验3种方法对模型进行精度检验,其模型拟合精度达97.25%。用所建立的模型对上海市2003~2007年城市生活用水量进行预测。结果表明,该灰色模型用于城市生活用水量预测,符合其灰色特性,通用性好,并且所需数据少,计算量适中,预测结果与实际情况比较吻合。  相似文献   

14.
Helena Valve 《Geoforum》2011,42(2):222-230
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.  相似文献   

15.
基于GM(1,1)优化模型的岩石边坡变形预测   总被引:7,自引:0,他引:7  
岩石边坡系统是一典型灰色系统。其变形发展过程可以用灰色预测模型完成。尽管传统GM(1,1)模型预测有很多成功的实例,但是也存在一些预测偏差过大的情况,必须对其进行优化。逐步迭代法GM(1,1)模型不仅收敛速度快,而且与原始数据序列的凹凸性保持一致。利用自编的计算程序对马步坎边坡观测点G1沉降和开裂进行预测分析,结果表明逐步迭代法GM(1,1)优化模型计算精度较传统GM(1,1)模型和背景构造法GM(1,1)优化模型高,较好地反映了岩石边坡的变形趋势。  相似文献   

16.
通过对季节性冻土区铁路路基冻胀量与地层温度的监测,可以了解监测段的冻胀变化过程,但无法对未来的发展趋势作出有效预测。本文采用GM(1,1)模型对监测段落路基的冻胀变形及冻结深度的变化情况进行预测。结果表明,此预测方法可以在现有监测数据的基础上有效预测短期内路基冻胀的发展趋势。根据模型预测结果,可以提前采取有效整治措施,便于决策者对轨道检验周期、维修周期、限速周期等作出合理调整。  相似文献   

17.
郭法强 《地下水》2010,32(3):108-110
介绍灰色理论建模原理和模型参数辨识方法,并以实例(抚顺地区1994~2004年工业用水资料)建立灰色GM(1,1)预测模型,运用残差检验与后验差检验2种方法对模型进行精度检验,其模型拟合精度达98.72%。用所建立的模型对抚顺2001~2004年工业用水量进行外推预测。结果表明,该灰色模型用于工业用水量预测,符合其灰色特性,通用性好,并且所需数据少,计算量适中,预测结果与当地实际情况比较吻合。  相似文献   

18.
采用灰色理论中的GM( 1 ,1 )模型对修河高填土河堤分别在填土期和静载期的沉降量进行了预测 ,通过同实测值的比较 ,证明灰色理论运用于高填土工程中的沉降预测是可行的 ,在实际运用中应不断代入最新的实测数据 ,以便获得更准确的结果  相似文献   

19.
A. Wendy Russell 《Geoforum》2008,39(1):213-222
In this paper, I argue that genetically modified organisms (GMOs) have inherent potential to contribute to socially and environmentally sustainable agriculture by virtue of their ‘biological embeddedness’. Their actual ‘performance’ and how this contributes to sustainability depends on the ‘mutual shaping’ of technology and context. While much attention has been given to the design context of GMOs, this paper considers the influence of the application context and of users. A case study investigating the use of insect-resistant and herbicide-tolerant GM cotton in the cotton-growing region of New South Wales in Australia is presented. The study was based on focus groups with farmers and other stakeholders in a cotton-growing community. It demonstrated a range of direct and indirect effects of GM cotton use, both positive and negative for sustainability, and the ways in which these effects were influenced by the local social context. The influences of the biotechnology industry context, in limiting the contributions that gene technologies can make to sustainability, were also considered, and remedies suggested. I argue that the polarity of the GM debate is hindering progress on these issues, and that a more balanced approach to our analysis of GMOs is necessary in order to fully understand, and to influence, their role in the future of rural spaces.  相似文献   

20.
谢正文  胡汉华  胡毅夫 《岩土力学》2005,26(Z2):227-230
GM(1,1)模型是沉降预测中应用较为广泛的模型之一,在实际应用当中发现其预测效果有时候较差甚至完全失效。为此从传统GM(1,1)预测模型建模原理出发,分析存在的理论缺陷,指出在形成预测公式时规定 , 0.5为已知条件是不合理的,应当根据实际情况选用其他数据。通过引入平均斜率来计算 序列,并利用MATLAB程序进行数据处理,寻找最合适的 以及最佳维数区。某高速公路实测沉降数据计算表明,新方法有满意的拟合和预测效果,为提高建模精度提供了新的途径。  相似文献   

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