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131.
煤矿地理信息系统数据模型的研究   总被引:25,自引:0,他引:25  
毛善君 《测绘学报》1998,27(4):331-337
地下煤矿开采所面对的空间目标具有灰色、动态变化的特征。本文在分析煤矿空间信息特点的基础上,提出了实用于煤矿的地理信息系统数据模型。这些数据模型包括全要素的结构化不规则三角网(TIN)与GIS一体化数据模型以及网状模型。  相似文献   
132.
自动制图综合人工神经元网络方法的研究   总被引:1,自引:1,他引:0  
现代神经生理学研究表明 ,人脑的大量神经元构成有所分工而又紧密联系的神经元网络 ,它的结构和功能可以采用物理可实现的系统人工神经元网络来模拟。制图综合是人脑神经元网络获取、处理、输出地理信息的复杂视觉思维过程 ,可以用人工神经元网络来模拟。文中探讨了制图综合的人工神经元网络的设计 ,并对用于实现自动制图综合的结果进行分析 ,指出其应用前景。  相似文献   
133.
研究了复平面上 ,广义 Hermite-Fejer插值多项式的收敛性。得到了其在空间 lp(| z| =1 ) (0 相似文献   
134.
The neural network system has been developing very fast recently. It has been widely used in many industries such as automation, nuclear power plant, chemical industry, etc. Neural network systems have a great advantage in dealing with problems in which many factors influence the process and result, and the understanding of this process is poor, and there are experimental data or field data. In rock engineering, many problems are of this nature. In this paper, a brief introduction to neural network systems is given. Problems such as what is a neural network, how it works and what kind of advantages it has are discussed. After this, several applications in rock engineering, made by us, are presented. Case 1 is ore boundary delineation. In this case, the rock are divided into three classes, i.e.: (1) waste rock; (2) semi-ore; and (3) ore for mining purposes. The neural network system built can judge whether it is ore, semi-ore or waste rock along the borehole according its corresponding geophysical logging data, such as gamma-ray, gamma-gamma, neutron and resistivity. Case 2 is aggregate quality prediction. In this case, the quality parameters: (1) impact value; (2) abrasion value I; and (3) abrasion value II are predicted by using a neural network system based on density, point load, content of quarts and content of brittle minerals. Case 3 is rock indentation depth prediction. In this case, the rock indentation depth under indentation load is predicted by the established neural network system based on the indentation load on rock, indenter type and rock mechanical properties, such as uniaxial compressive strength, Young's modulus. Poisson's ratio, critical energy release rate and density. In all these cases, the neural network systems have been applied successfully. The testing results are satisfactory and better than the existing techniques.  相似文献   
135.
二滩水电站地震遥测台网持续时间震级的研制   总被引:2,自引:0,他引:2  
利用二滩水电站地震遥测台网的速度量和位移量观测记录,收集了震级ML为0.4 ̄5.4的460次地震(Δ〈210km)的振动持续时间3500多条,制作了该台网的持续时间震级公式和便查表。在方法上,不同于通常的按一次或两次曲线拟合,而采取计算机自动分段按折线拟合的方法,以阻尼最小二乘法完成其计算;在资料上,先分台制作8个子台的持续时间震级公式,在此基础上选择仪器、台基及公式中参数相近的子台,制作了适用于  相似文献   
136.
由于数字地震记录仪具有记录频带宽,分辨率高,动态范围大以及易于用计算机处理等优点,所以数字地震台网产出的数字地震资料成为地震活动性,震源机制,地球内部研究,地震监测及预报等的最基本数据源。  相似文献   
137.
The Upper Himenoura Subgroup exposed in the island of Amakusa-Shimojima, Kyushu, Japan shows an example of the terminal Cretaceous stratigraphic record in the circum Pacific region. This sequence is a part of the Upper Cretaceous intra-arc basins of southwest Japan. Four cycles of upward coarse-graded facies are recognized. Each cycle consists of a basinal mud facies in the lower part and a tide-dominated shallow marine to brackish coarse clastic facies in the upper part. Biostratigraphic correlation chiefly based on ammonites, inocerami and trigoniids indicates that this sequence is Campanian to Maastrichtian in age. The occurrence of the above three fossils decreases upward and is terminated at the top of the sequence, being replaced by a molluscan assemblage similar to the Danian. This suggests that the sedimentation may have continued to the very end of the Cretaceous period and possibly to the beginning of the Tertiary.  相似文献   
138.
This paper is a brief explanation of the diagrams of the Cretaceous transgressions and regressions on the Russian Platform, in the Crimea (Figures 1–3) and some regions of central Asia—the western flanks of the Tien Shan mountains, the Fergana basin, the Zeravshan-Gissar and Alaj mountains, and the Northern Pamirs (Figures 5–7).Internationally recognized stages are employed. They are interpreted by Sasonova (1967) for the Lower Cretaceous (K1) of the Russian Platform, by Naidin (1977) for the Upper Cretaceous (K2) of the Platform and the Crimea, by Djalilov (1971) and Pojarkova (1976) for the Upper Cretaceous of central Asia. General data on the stratigraphy of the Cretaceous of central Asia may be found in Anon 1977.  相似文献   
139.
It is shown how the generalized Laplace coefficients can be employed to deduce explicit formulas for ordinary and Newcomb derivatives of the Laplace coefficients.   相似文献   
140.
Concentration–discharge relationships have been widely used as clues to the hydrochemical processes that control runoff chemistry. Here we examine concentration–discharge relationships for solutes produced primarily by mineral weathering in 59 geochemically diverse US catchments. We show that these catchments exhibit nearly chemostatic behaviour; their stream concentrations of weathering products such as Ca, Mg, Na, and Si typically vary by factors of only 3 to 20 while discharge varies by several orders of magnitude. Similar patterns are observed at the inter‐annual time scale. This behaviour implies that solute concentrations in stream water are not determined by simple dilution of a fixed solute flux by a variable flux of water, and that rates of solute production and/or mobilization must be nearly proportional to water fluxes, both on storm and inter‐annual timescales. We compared these catchments' concentration–discharge relationships to the predictions of several simple hydrological and geochemical models. Most of these models can be forced to approximately fit the observed concentration–discharge relationships, but often only by assuming unrealistic or internally inconsistent parameter values. We propose a new model that also fits the data and may be more robust. We suggest possible tests of the new model for future studies. The relative stability of concentration under widely varying discharge may help make aquatic environments habitable. It also implies that fluxes of weathering solutes in streams, and thus fluxes of alkalinity to the oceans, are determined primarily by water fluxes. Thus, hydrology may be a major driver of the ocean‐alkalinity feedback regulating climate change. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
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