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排序方式: 共有126条查询结果,搜索用时 15 毫秒
101.
Risk-based environmental decision-making using fuzzy analytic hierarchy process (F-AHP) 总被引:1,自引:4,他引:1
Solomon Tesfamariam Rehan Sadiq 《Stochastic Environmental Research and Risk Assessment (SERRA)》2006,21(1):35-50
Environmental risk management is an integral part of risk analyses. The selection of different mitigating or preventive alternatives often involve competing and conflicting criteria, which requires sophisticated multi-criteria decision-making (MCDM) methods. Analytic hierarchy process (AHP) is one of the most commonly used MCDM methods, which integrates subjective and personal preferences in performing analyses. AHP works on a premise that decision-making of complex problems can be handled by structuring the complex problem into a simple and comprehensible hierarchical structure. However, AHP involves human subjectivity, which introduces vagueness type uncertainty and necessitates the use of decision-making under uncertainty. In this paper, vagueness type uncertainty is considered using fuzzy-based techniques. The traditional AHP is modified to fuzzy AHP using fuzzy arithmetic operations. The concept of risk attitude and associated confidence of a decision maker on the estimates of pairwise comparisons are also discussed. The methodology of the proposed technique is built on a hypothetical example and its efficacy is demonstrated through an application dealing with the selection of drilling fluid/mud for offshore oil and gas operations. 相似文献
102.
103.
基于MapX控件实现线切割区域功能 总被引:1,自引:0,他引:1
“线切割区域”是地图编辑中一种非常有用的功能,文中在对规则凸多边形、不规则凹多边形、多连通区域3种最基本的区域线切割分析的基础上,给出了一种在MapInfo公司Mapx控件基础上实现线切割区域功能的算法。通过实例可以发现,算法具有实现切割效率高、适应性强的优点。 相似文献
104.
GPS非线性数据处理的同伦最小二乘模型 总被引:4,自引:1,他引:4
基于非线性同伦思想 ,提出了非线性最小二乘同伦方法 ,并推导出相应的GPS同伦非线性模型和算法。算例表明 ,对于精度较差的初始值 ,采用同伦非线性GPS伪距定位模型较线性最小二乘求解精度要好。 相似文献
105.
利用时域中的卷积积分法求解测温传感器响应方程,对其响应特性尤其是自动平均能力进行了数学描述,发现每个时刻测温传感器输出值,是此时刻之前一段时间内外界温度输入值的不等权平均值,其权重随着与输出时刻的接近呈指数增加。进一步应用这个结论讨论了不同来源温度资料的同化问题,对资料同化技术的提高有一定的指导意义。 相似文献
106.
Guidance for petroleum prospecting is provided by authentic geochemical anomalies, obtained after interference has been eliminated in the original data from a geochemical survey for hydrocarbons. However, this elimination is a complicated process. Few working models or effective methods for interference elimination have been proposed, hampering a wider acceptance of geochemical prospecting as a viable tool for hydrocarbon exploration. This study focuses on the models for different types of interference and developing techniques for interference elimination. We first restudied the geometric nature of hydrocarbon anomalies and interference on the basis of Zhang, L., and Lia, Z. (J. China Univ. Geosci., v. 9, no. 1, p. 72–80, 1998). From this, we determined that at least two types of interference are present in the data of a surface geochemical survey for hydrocarbons. One is the superimposition type originating mainly from microorganisms and contamination, and the other is the multiplication type resulting from variations in soil mineral components. We then established digital conceptual models for both types of interference based on the geometry of anomalies and interference. Finally, we used wavelet analysis to eliminate both types of interference in the models for testing. As Morlet wavelet and symmetric border treatment fit the geometric characteristics of the anomalies and interference, they were used in this study. We found that pre-wavelet analysis treatment is different for different types of interference. For the multiplication type, log-transformation and normalization are needed before wavelet analysis whereas only normalization is needed for the superimposition type. In practice, one needs to identify the type of interference. Therefore, the criteria for determining the interference type were first established geochemically in this study. The newly developed techniques were then applied to the data of acid-extractable hydrocarbons of soils in the Eastern Anan Sag, Inner Mongolia where traditional techniques had failed to eliminate the interference in these data. Using our new techniques, we determined the interference was the multiplication type. This new approach enabled us to satisfactorily eliminate the interference in the original data. It should be noted that our study indicates that the multiplication type of interference is much more common and severe than previously thought. 相似文献
107.
108.
流形群运动目标自动识别与跟踪模型结构及参数的最优配置 总被引:1,自引:0,他引:1
探讨了用流形群运动目标的形状、纹理特征,以及它们的空间面积的重叠度来构建多种适合流形群运动目标自动识别与跟踪的匹配模板的方法。通过最大欧几里得贴近度的择近原则,实现模板匹配,完成目标识别;通过对匹配模板的交替更新和交叉匹配算法,实现目标跟踪。为了提高识别与跟踪的准确度和效率,对识别与跟踪模型结构及参数进行了优化组合,建立了一种适合计算机自动识别和跟踪类似中尺度对流系统(MCSs)的流形群运动目标的优化模型,即多级串行和多级并行模板匹配的识别与跟踪模型,并提出了基于此模型的快速识别与跟踪算法及技巧。用优化了的多级串行识别与跟踪模型及快速跟踪算法,对1998、1999、2000、2002年6~8月的青藏高原上空MCSs进行了识别与跟踪试验。试验结果表明,其准确率高达90%。 相似文献
109.
强污染单历元GPS形变信号的提取和粗差识别 总被引:6,自引:0,他引:6
阐述了小波分析技术用于强污染GPS单历元形变信号处理的基本原理及其实现方法。以含少量粗差的低信噪比形变信号为例 ,研究了基于Mallat分解和合成算法 ,分离信号趋势项并进行粗差识别的技术。采用小波软阈值降噪的方法去除强污染数据中的随机噪声 ,降噪效果远好于中值滤波。最后对识别的粗差信息进行线性修复 ,获得了令人满意的形变信号 相似文献
110.
提出了一种新的小波系数分类算法,基于该分类算法,提出了一种更为合理的无损编码算法。实验结果显示,此方法优于其他基于小波的无损编码算法。 相似文献