基于Oracle的文献资料库全文检索技术

介绍使用0racle Text对文献资料库进行全文检索的技术。     

SOFTWARE REVIEWS

software reviews are in this article BMDP/PC CONCEPTS COMPUTERIZED ATLAS EVALUATION OF ALTERNATE PROPOSALS (EAP) EXTRA: EXPRESS TRANSIT ANALYSIS MATC CAD MOTORS TRANSPORTATION PACKAGE PCMAP: Thematic Mapping Software for the IBM Personal Computer, Version 2.3 PLACE TRANPLAN . US-ATLAS     

Stochastic geometry in petroleum geology

Many aspects of the generation, migration, trapping, and discovery of petroleum, as well as its primary and enhanced recovery, depend upon geometry. The scale of the relevant geometric features varies all the way from that of continental margins and basins down to the pores and fissures in reservoir rocks. Because the spatial complexity is so great for each of these processes, it is reasonable to describe them statistically. The primary purpose of this paper is to survey possible ways in which statistical or stochastic geometry enters and might be used in petroleum geology and engineering. While it offers some new theory, this paper does not directly suggest any specific new methods for the estimation of hydrocarbon resources or reserves. This deficiency is mainly due to the current lack of relevant data. When data are available the point of view explained herein will be fruitful. The survey ties together many topics in a novel way.     

Probabilistic seismic response and reliability assessment of isolated bridges

Bridge seismic isolation strategy is based on the reduction of shear forces transmitted from the superstructure to the piers by two means: shifting natural period and earthquake input energy reduction by dissipation concentrated in protection devices. In this paper, a stochastic analysis of a simple isolated bridge model for different bridge and device parameters is conducted to assess the efficiency of this seismic protection strategy. To achieve this aim, a simple nonlinear softening constitutive law is adopted to model a wide range of isolation devices, characterized by only three essential mechanical parameters. As a consequence of the random nature of seismic motion, a probabilistic analysis is carried out and the time modulated Kanai-Tajimi stochastic process is adopted to represent the seismic action. The response covariance in the state space is obtained by solving the Lyapunov equation for a stochastic linearized system. After a sensitivity analysis, the failure probability referred to extreme displacement and the mean value of dissipated energy are assessed by using the introduced stochastic indices of seismic bridge protection efficiency. A parametric analysis for protective devices with different mechanical parameters is developed for a proper selection of parameters of isolation devices under different situations.     

Stochastic Hill's equations for the study of errant rocket burns in orbit

The problem of errant rocket burns in low Earth orbit is of growing interest, especially in the area of safety analysis of nuclear powered spacecraft. The development of stochastic Hill's equations provides a rigorous mathematical tool for the study of such errant rocket maneuvers. These equations are analyzed within the context of a theory of linear dynamical systems driven by a random white noise. It is established that the trajectories of an errant rocket are realizations of a Gauss-Markov process, whose mean vector is given by the solution of a deterministic rocket problem. The time-dependent covariance matrix of the process is derived in an explicit form.     

A simplified method for simulation of strong ground motion using finite rupture model of the earthquake source

We present a simplified method to simulate strong ground motion for a realistic representation of a finite earthquake source burried in a layered earth. This method is based on the stochastic simulation method of Boore (Boore, D. M., 1983, Bull. Seism. Soc. Am. 73, 1865–1894) and the Empirical Greens Function (EFG) method of Irikura (Irikura, K., 1986, Proceedings of the 7th Japan Earthquake symposium, pp. 151–156). The rupture responsible for an earthquake is represented by several subfaults. The geometry of subfaults and their number is decided by the similarity relationships. For simulation of ground motion using the stochastic simulation technique we used the shapping window based on the kinetic source model of the rupture plane. The shaping window deepens on the geometry of the earthquake source and the propagation characteristics of the energy released by various subfaults. The division of large fault into small subfaults and the method for accounting their contribution at the surface is identical to the EGF. The shapping window has been modified to take into account the effect of the transmission of energy released form the finite fault at various boundaries of the layered earth model above the source. In the present method we have applied the correction factor to adjust slip time function of small and large earthquakes. The correction factor is used to simulate strong motion records having basic spectral shape of ² source model in broad frequency range. To test this method we have used the strong motion data of the Geiyo earthquake of 24th March 2001, Japan recorded by KiK network. The source of this earthquake is modelled by a simple rectangular rupture of size 24 × 15 km, burried at a depth of 31 km in a multilayered earth model. This rupture plane is divided into 16 rectangular subfaults of size 6.0 × 3.75 km each. Strong motion records at eight selected near-field stations were simulated and compared with the observed records in terms of the acceleration and velocity records and their response spectrum. The comparison confirms the suitability of proposed rupture model responsible for this earthquake and the efficacy of the approach in predicting the strong motion scenario of earthquakes in the subduction zone. Using the same rupture model of the Geiyo earthquake, we compared the simulated records from our and the EGF techniques at one near-field station. The comparison shows that this technique gives records which matches in a wide frequency range and that too from simple and easily accessible parameters of burried rupture.     

Pattern classification using tabu search to identify the spatial distribution of groundwater pumping

Pattern classification and Tabu Search are integrated to optimize the zonation and associated average groundwater pumping rates. A simulated problem analogous to the Choushui Creek Alluvial in Janghauh county of Taiwan is used to examine the proposed method. Three problems are tested including (1) optimizing zonation patterns with known pumping rates and number of zones, (2) optimizing pumping rates and zonation patterns with a predetermined number of zones, and (3) optimizing all pumping rates, number of zones, and zonation. The results indicate that the proposed method successfully identifies spatial patterns of groundwater pumping for all three cases. However, some initial zonations result only in local optimums. Thus, using more than one initial zonation to increase search diversification is recommended. Application to different problems such as the spatial distribution of hydraulic conductivity values and area weighting of rainfall stations, is encouraged.

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Resumen El patrón de clasificación y la búsqueda tabú están integrados para optimizar la zonificación y las tasas promedio de bombeo de aguas subterráneas asociadas. Se ha utilizado un área diseñada análoga al arroyo aluvial Choushui en la provincia Janghauh en Taiwan para examinar el método propuesto. Se han probado tres problemas que incluyen (1) la zonificación únicamente con las tasas de bombeo y número de zonas dadas, (2) tasa de bombeo y zonificación con un número predeterminado de zonas, y (3) todas las tasa de bombeo, número de zonas y zonificaciones. Los resultados indican que el método propuesto identifica exitosamente los patrones espaciales de bombeo de las aguas subterráneas en los tres casos. Sin embargo, Algunas zonificaciones iniciales solamente resultan en óptimos locales. Por esta razón se recomienda utilizar más de una zonificación inicial para incrementar la diversificación de la búsqueda. Se sugiere la aplicación a problemas diferentes tales como la distribución espacial de conductividades hidraúlicas y la ponderación de áreas de estaciones de monitoreo de precipitación.

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Résumé La classification des patrons et la recherche Tabu sont intégrés pour optimiser la zonation et la moyenne associée du taux de pompage de leau souterraine. Une région analogue à lalluvion du ruisseau Choushui de la région Janghauh en Taiwan a été recrée afin dexaminer la méthode proposée. Trois problèmes sont évalués, incluant loptimisation de (1) la zonation avec seulement un taux de pompage et un nombre de zones donnés, (2) le taux de pompage et la zonation avec un nombre prédéterminé de zones, et (3) tous les taux de pompage, nombre de zones et la zonation. Les résultats indiquent que la méthode proposée identifie avec succès les patrons de pompage de leau souterraine dans les trois cas. Toutefois, certaines zonations initiales résultent seulement en optimums locaux. Par conséquent, lutilisation de plus dune zonation initiale afin daugmenter la diversification de la recherche est recommandée. Lutilisation de la méthode est suggérée pour la résolution de différents problèmes tels que la distribution spatiale de la conductivité hydraulique et la pondération des stations de mesure de précipitations.

     

Selection of environmental conditions for nearshore structure design

1　Introduction　InChina ,coastalcitiesaremostlyregionaleconomicdevelopmentcenters.Becauseoftheirspecialgeogra phiclocations ,typhoonsandassociatedstormsurgescauseheavylossesoflivesandproperties.In 1 992 Qing daowasfloodedduetothecoincidenceoftheastrono m…     

GPS／GLoNASS组合定位的抗差Helmert方差分量估计模型

GPS和GLONASS存在系统差异,组合定位时,采用Helmert方差分量估计可得到更加准确的结果。但GNSS观测值常受到衍射信号和多路径效应的影响,使观测值存有粗差,从而导致Helmert方差分量估计的失真。为此,将抗差Helmert方差分量估计应用于GPS／GLONASS组合单点定位,实验结果表明：抗差Helmert方差分量估计可以有效地抑制组合系统粗差观测值的影响。     

宁津县国土数字档案管理信息系统的设计与实现

传统县级国土资源档案管理方式落后,条目式管理不能适应国土资源档案管理的要求,现有的地籍系统、土地利用系统和土地交易系统的数据分散于三个独立系统中,数据格式多样,给土地归档工作带来不便,需把各个部门各个系统的相关数据进行统一归档管理.本文结合宁津县国土数字档案管理信息系统的设计与实现过程,阐述了整个系统的总体设计思想,系统的功能模块划分、数据整理建库以及系统功能模块的设计实现,为县(市)级档案管理系统的建设提供了参考方案.