Neighborhood discontinuities in bivariate interpolation of scattered observations

Because of the need for computational efficiency, bivariate interpolation methods applied to scattered observations often involve two stages. Initially the variable is estimated at regular grid nodes using a running subset of data (usually of fixed number). This, however, will produce discontinuities in the interpolated surface. Thus a second stage, curvilinear interpolation technique, is applied to estimated values to smooth out the effect of discontinuities. Such problems can be overcome efficiently in processing large data sets by interpolating over natural neighbor subsets. Interpolation procedures that generate discontinuities in the interpolated surface are inappropriate for geological applications, where dislocations due to structural complications may be present.     

NUCLEAR POWER IMPACTS: A CONVERGENCE/DIVERGENCE SCHEMA

Impacts of nuclear power plants are generally considered on a local scale only. A schema that considers local and interstate convergence and divergence is found useful in identifying the widespread nature of the impacts, especially those associated with a local decision to build a nuclear facility. Of the four possible subdivisions within this schema, three apply to the Palo Verde power plant near Phoenix, AZ.     

Seismic regime of the west Bohemian earthquake swarm region: Preliminary results

Summary The western part of the Bohemian Massif located between two tectonic units, the Moldanubian and the Saxo-Thuringian, is characterized by the re-occurrence of earthquake swarms. The focal region for these swarms includes the territory of West Bohemia and the adjacent territory of SE Saxony and NE Bavaria. During the most recent swarm in December 1985 – January 1986, more than 8000 small earthquakes were recorded; the two largest earthquakes with local magnitudes (M_L) of 4·6 and 4·1. This paper presents a summary of the seismic energy release in space and time for the western part of the Bohemian Massif, based on seismic observations of permanent seismic stations established in West Bohemia since 1986. It was found out that microearthquake activity, mostly of a swarm-like character, persisted between two macroseismically observed swarms. The foci of the microearthquakes predominantly cluster in six main epicentral zones, four of which are located in West Bohemia or in its immediate vicinity in Saxony. The remaining two are in Saxony and in Bavaria. The four epicentral zones in West Bohemia were studied in detail. It was found that the individual zones differ in size, in depth of hypocentres, in geometry, as well as in temporal activity. Moreover, it was found that the seismicity in the most active epicentral zone is closely related to the system of principal tectonic faults referred to as the Kruné Hory fault and the Mariánské Lázn fault.     

Towards realistic flow modelling. Creation and evaluation of two-dimensional simulated porous media: An image analysis approach

This work is part of an attempt to quantify the relationship between the permeability tensor (K) and the micro-structure of natural porous media. A brief account is first provided of popular theories used to relate the micro-structure toK. Reasons for the lack of predictive power and restricted generality of current models are discussed. An alternative is an empirically based implicit model whereinK is expressed as a consequence of a few pore-types arising from the dynamics of depositional processes. The analytical form of that implicit model arises from evidence of universal association between pore-type and throat size in sandstones and carbonates. An explicit model, relying on the local change of scale technique is then addressed. That explicit model allows, from knowledge of the three-dimensional micro-geometry to calculateK explicitly without having recourse to any constitutive assumptions. The predictive and general character of the explicit model is underlined. The relevance of the change of scale technique is recalled to be contingent on the availability of rock-like three-dimensional synthetic media. A random stationary ergodic process is developed, that allows us to generate three-dimensional synthetic media from a two-dimensional autocorrelation functionr( _x , _y ) and associated probability density function measured on a single binary image. The focus of this work is to ensure the rock-like character of those synthetic media. This is done first through a direct approach:n two-dimensional synthetic media, derived from single set ( ,r( _x , _y )) yieldn permeability tensorsK _i-1,n ⁱ (calculated by the local change of scale) of the same order. This is a necessary condition to ensure thatr( _x , _y ) and carry all structural information relevant toK. The limits of this direct approach, in terms of required Central Process Unit time and Memory is underlined, raising the need for an alternative. This is done by comparing the pore-type content of a sandstone sample andn synthetic media derived fromr( _x , _y ) and measured on that sandstone-sample. Achievement of a good match ensures that the synthetic media comprise the fundamental structural level of all natural sandstones, that is a domainal structure of well-packed clusters of grains bounded by loose-packed pores.     

具有简单约束非线性规划的Hermite插值法

讨论具有简单约束非线性规划的求解方法 ,通过构造特殊结构的 Hermite插值公式 ,利用有效集的技巧 ,给出了求解这类问题的 Hermite插值算法。在通常的假设条件下 ,证明了算法具有全局收敛性。在严格互补松驰条件下 ,证明了算法在有限次迭代后有效约束集保持不变 ,从而使算法简化为求解无约束最优化的算法 ,有关收敛速度的结论相应成立     

Macroseismic evidence and site effects for the Lunigiana (Italy) 1995 Earthquake

On October 10, 1995, an M_L= 4.8 (ING) earthquake occurred in the region of Lunigiana (northwestern Italy). The shock was felt over a large area and produced significant damage. We performed a macroseismic survey and damage zonation and assessed a maximum intensity VII MCS in the epicentral area. The damage pattern, that we investigated in detail for some of the villages in the most heavily damaged area, emphasises the role of surface geology in amplifying the effects. Topographic effects and near-surface geology are largely responsible for broadening the damage area. Given the moderate size of the earthquake, many of the macroseismic observations, including rotations of objects and the propagation of visible waves in the ground, are suggestive of amplification phenomena.     

江苏里下河平原局地温度的计算

应用气候学温度方程,在求出江苏里下河平原地理因素对局地温度影响的同时,着重分析下垫面环境条件对局地温度的贡献。最后建立的局地温度计算方程,由于增加了下垫面的影响项,因而计算值更接近实际。经检验,效果极为显著。     

合肥地区超压密粉土-砂层的性状与地基评价

本文论述了合肥地区超压密粉土—砂层的分布及其物理力这性质。通过多种方法计算对比,综合确定了地基承载力与桩的端阻力。认为可以作为中高层建筑的桩基或箱（筏）基持力层。并对地层时代归属作了探讨。     

Conditional LAS stochastic simulation of regionalized variables in random fields

Ore reserves forecasts are required to aid in investment decisions, mine design and valuation, short and long term production plans and proper and efficient mill design. In random multivariable fields with limited data and high levels of uncertainty, the kriged block estimates produce a smoothing effect resulting in underestimating high values and overestimating low values. The modified conditional simulation (MCS) methodology solves these problems by simulating the random field to preserve its mean and the variance structure. The simulation model is conditioned to reproduce the data at known sample points to minimize the variability between the simulated data and the true field data. In this study, the authors develop the MCS methodology to simulate ore reserve grades using the best linear unbiased estimation (BLUE) and the local average subdivision (LAS) techniques. The MCS methodology is applied to simulate block grades in a section of the Sabi Gold Project in Zimbabwe. The results are compared with the kriged estimates for this section. Analysis of the results shows that the MCS methodology reproduces the known sample grades with minimum estimation error of 0.001 while the estimation error associated with the kriged estimates is 1.104, a 100% efficiency of the MCS method over the kriging technique.     

南秦岭隆滑构造

在南秦岭,发生于加里东─—海西期的隆滑构造,由基底杂岩、滑覆层状岩系和其之间的滑脱构造带组成。它是主选山期前,在盆地演化过程中,由地慢上隆,导致基底减压深熔,并局部隆起,并引起上覆层状岩系分层滑脱所形成的一套地质要素组合。它与形成于主造山以后的“变反核条岩”在造山带演化过程的动力学意义有着本质的区别。