虚拟主机技术在宁夏地震应急指挥技术系统中的应用

虚拟机技术利用软件模拟硬件及系统环境,应用日益广泛。对常用虚拟机做对比分析,给出使用VMware实现宁夏地震应急指挥技术系统部署的具体实例,对应用效果做总结分析。     

虚拟技术在地震前兆技术系统中的应用

地震前兆技术系统长期稳定和可靠运行对管理人员来说至关重要,本文以山西前兆台网为例,基于VMware虚拟机搭建了地震前兆技术系统,并利用其快闪及克隆功能实现了地震前兆技术系统的快速备份及恢复,提升了地震前兆技术系统故障应急处置能力。     

基于虚拟技术的地震应急指挥技术系统应用

地震应急指挥技术系统的特殊性要求整个系统必须具有高可靠性及稳定性.基于虚拟技术的地震应急指挥技术系统可实现整个系统的容灾备份,并通过虚拟机特性将原来在多台服务器上部署的系统在一台高性能服务器上实现,节约资源的同时,使异地移植更加灵活.基于虚拟技术的地震应急指挥技术系统,可提升整个系统的稳定性、灵活性、可靠性.     

虚拟技术在地震应急指挥技术系统中的应用

利用虚拟技术,可将原来在多台服务器上部署的地震应急指挥技术系统在一台高性能服务器上实现容灾备份,在节约硬件资源的同时,虚拟机灵活部署、快速恢复的特性也能提高整个系统的灵活性、可靠性.本文对什么样的服务器可作为地震应急指挥系统的虚拟服务器,如何规划虚拟应用,虚拟部署后的系统与原系统比较有何差异等进行了研究.本文的研究结果可为全国各省区域应急指挥中心的容灾备份提供参考依据.     

基于FusionCompute的地震行业网私有云平台部署与实现

针对传统地震数据机房存在业务扩展成本高且周期长、维护繁琐、无法保障重要业务系统的无故障连续运作等问题,采用虚拟化云计算技术,实现地震行业网的私有云服务。华为FusionCompute云服务系统将主机、存储等物理资源虚拟化,并整合为统一资源,供多个虚拟机使用,行业专网内运维人员通过用户接口远程访问云平台,在虚拟机上可快速、高效地按需搭建业务系统。地震私有云平台不仅减少业务扩展运营期间的设备采购、系统搭建、运行维护等人力和物力投入,且通过FusionCompute的迁移技术,实现业务系统的"零宕机"服务。     

虚拟化技术在地震信息网络业务中的应用

根据VMware公司的虚拟机组件ESX3．5及管理组件Virtual Center2．5,结合现有硬件技术平台,在山东省地震局实现虚拟化技术的实际部署和应用。结果发现,将虚拟化技术应用到地震行业信息网络业务,可以提高工作效率,具有重要的实际意义。     

甘肃省地震应急指挥技术系统设计与实现

介绍了甘肃省地震应急指挥系统建设的必要性和意义、建设目的和原则、建设内容和系统构成,并对应急指挥技术系统7个方面的具体内容做了详细介绍.     

服务器虚拟化在数据中心的应用实践

通过虚拟化技术实现服务器整合,提高资源利用率、简化系统管理。基于四川省地震局数据中心服务器虚拟化应用,阐述了虚拟化平台的搭建过程,虚拟机部署,并介绍了虚拟化的应用经验。     

云南地震应急卫星通讯技术的系统集成与应用

根据云南地震应急工作的实际需求,提出卫星通讯技术系统的三类设计方案。实现了卫星通讯技术系统与地震现场应急技术系统和地震应急指挥中心技术系统的集成。该系统集成在多次地震现场应急工作和模拟应急演习中得到了应用和检验。最后分析了系统集成存在的问题和进一步的工作方向。     

ASP技术在湖南省内地震前兆数据日报网站体系中的应用

针对湖南省前兆台站每天报送所收集并整理后的前兆数据,向湖南省地震局传递从中遇到的问题。借助湖南省地震行业网。利用ASP技术,整合前兆数据特点,制作了一个基于ASP技术的地震前兆数据日报网站体系。本文对该系统功能及实现方法做了简要介绍。     

Imaging pre‐existing natural fractures using microseismic data

In hydraulic fracturing treatments, locating not only hydraulic fractures but also any pre‐existing natural fractures and faults in a subsurface reservoir is very important. Hydraulic fractures can be tracked by locating microseismic events, but to identify the locations of natural fractures, an additional technique is required. In this paper, we present a method to image pre‐existing fractures and faults near a borehole with virtual reverse vertical seismic profiling data or virtual single‐well profiling data (limited to seismic reflection data) created from microseismic monitoring using seismic interferometry. The virtual source data contain reflections from natural fractures and faults, and these features can be imaged by applying migration to the virtual source data. However, the imaging zone of fractures in the proposed method is strongly dependent on the geographic extent of the microseismic events and the location and direction of the fracture. To verify our method, we produced virtual reverse vertical seismic profiling and single‐well profiling data from synthetic microseismic data and compared them with data from real sources in the same relative position as the virtual sources. The results show that the reflection travel times from the fractures in the virtual source data agree well with travel times in the real‐source data. By applying pre‐stack depth migration to the virtual source data, images of the natural fractures were obtained with accurate locations. However, the migrated section of the single‐well profiling data with both real and virtual sources contained spurious fracture images on the opposite side of the borehole. In the case of virtual single‐well profiling data, we could produce correct migration images of fractures by adopting directional redatuming for which the occurrence region of microseismic events is divided into several subdivisions, and fractures located only on the opposite side of the borehole are imaged for each subdivision.     

Kirchhoff scattering series for sources and receivers located in an elastic medium: Another insight into the concept of virtual events

The convolution-type and correlation-type representation theorems are building blocks of wave-scattering theory whose usefulness expands in many seismological applications. For example, the Kirchhoff scattering series currently used for attenuating free-surface multiples has been derived from the convolution-type representation theorem. The recently introduced concept of virtual events, which allows us to put virtual sources and virtual receivers inside the subsurface based on the data collected at the sea surface, has been derived by a combined use of the convolution-type and correlation-type representation theorems. The formulation of inverse Kirchhoff scattering series and virtual events has been limited so far to the cases in which sources or receivers, or both, are located in the water. Unfortunately, this assumption is not valid, especially in the context of virtual events, in which both sources and receivers will often be located in a solid. We here redescribe the Kirchhoff scattering series and reformulate the concept of virtual events for the cases in which sources and receivers are in a solid. Moreover, we describe a new form of Kirchhoff series based on the correlation-type representation theorem and new formulae for computing virtual events which do not include the complex renormalization operation of the previous formulation.     

Retrieval of super‐virtual refraction by cross‐correlation

Topography and severe variations of near‐surface layers lead to travel‐time perturbations for the events in seismic exploration. Usually, these perturbations could be estimated and eliminated by refraction technology. The virtual refraction method is a relatively new technique for retrieval of refraction information from seismic records contaminated by noise. Based on the virtual refraction, this paper proposes super‐virtual refraction interferometry by cross‐correlation to retrieve refraction wavefields by summing the cross‐correlation of raw refraction wavefields and virtual refraction wavefields over all receivers located outside the retrieved source and receiver pair. This method can enhance refraction signal gradually as the source–receiver offset decreases. For further enhancement of refracted waves, a scheme of hybrid virtual refraction wavefields is applied by stacking of correlation‐type and convolution‐type super‐virtual refractions. Our new method does not need any information about the near‐surface velocity model, which can solve the problem of directly unmeasured virtual refraction energy from the virtual source at the surface, and extend the acquisition aperture to its maximum extent in raw seismic records. It can also reduce random noise influence in raw seismic records effectively and improve refracted waves’ signal‐to‐noise ratio by a factor proportional to the square root of the number of receivers positioned at stationary‐phase points, based on the improvement of virtual refraction's signal‐to‐noise ratio. Using results from synthetic and field data, we show that our new method is effective to retrieve refraction information from raw seismic records and improve the accuracy of first‐arrival picks.     

Generation of realistic synthetic catchments to explore fine continental surface processes

Understanding, analysing, and predicting the erosion mechanisms and sedimentary flows produced by catchments plays a key role in environmental conservation and restoration management and policies. Numerical case-testing studies are generally undertaken to analyse the sensitivity of flood and soil erosion processes to the physical characteristics of catchments. Most analyses are conducted on simple virtual catchments with physical characteristics that, unlike real catchments, are perfectly controlled. Virtual catchments generally correspond to V-shaped valley catchments. However, although these catchments are suitable for methodical analysis of the results, they do not provide a realistic representation of the spatial structures of the landscape and field conditions. They can, therefore, lead to potential modelling errors and can make it difficult to extend or generalize their results. Our proposed method bridges the gap between real and traditional virtual catchments by creating realistic virtual catchments with perfectly controllable physical characteristics. Our approach represents a real alternative to traditional test case procedures and provides a new framework for geomorphological and hydrological communities. It combines a field procedural generation approach, geographic information system processing procedures, and the CAESAR-Lisflood landscape evolution model. We illustrate how each of these components acts in the process of generating virtual catchments. Five physical parameters were adjusted and tested for each virtual catchment: drainage density, hypsometric integral, mean slope of the main channel, granulometry, and land use. One of our virtual catchments is compared with a real catchment and a virtual catchment produced by a standard method. This comparison indicates that our approach can produce more realistic virtual catchments than those produced by more traditional methods, while a high degree of controllability is maintained. This new method of generating virtual catchments therefore offers significant research potential to identify the impacts of the physical characteristics of catchments on hydro-sedimentary dynamics and responses.     

Geomagnetic field: Contribution of higher harmonics to the variations of virtual pole positions

Summary On the basis of the 1945 IGRF two sets of virtual geomagnetic poles have been computed and compared. The first set refers to a realistic model of the field; these virtual poles are all located in the north polar area. The second set refers to an artificial field containing higher harmonics only; these virtual poles are distributed over the Earth's surface as a whole. However both sets of virtual poles yield similar distributions of values of their space (and probably also time) variations.     

Virtual velocity of sand transport in water

Using the 160‐m‐long flume at Tsukuba University we undertook an experiment to provide a first estimate of the virtual velocity of sand in the size range 0.5–2.0 mm. For the flow velocity used in our experiment this sediment‐size range would conventionally be regarded as suspended sediment. The virtual velocity was found to be 37–41% of the flow velocity. Paradoxically, virtual velocity decreases as particle size decreases. Such a lower virtual velocity of finer sediment is not inconceivable. First, trapping of the sediment appears to be a function of bed roughness, and there is a probable relationship between bed roughness and trapping efficiency for particles of different sizes. Second, finer particles are more likely to find sheltered positions on a rough bed and thus experience lower mobility, relative to the more exposed coarser grains, as observed for bedload transport. Third, the virtual velocity of particles undergoing bedload transport has been found, in some instances, to be lower for finer clasts. We combine our data with previous studies of virtual velocity of bedload to develop, for the first time, a hypothesis for a holistic analysis of sediment movement in rivers. Copyright © 2017 John Wiley & Sons, Ltd.     

多层螺旋CT后处理技术对气管支气管异物的诊断价值

目的:评价多层螺旋CT三维重建及仿真内窥镜技术对气管支气管异物的诊断价值。方法:对20例支气管异物、1例气管异物、1例先天性气管性支气管发育异常、1例气管良性肿瘤患儿行多层螺旋CT检查并进行三维重建及仿真内窥镜技术显示气管支气管病变;三维重建技术包括多平面重建、最大密度投影、最小密度投影、表面遮盖显示和容积再现,CT仿真内窥镜对气管支气管异物的显示与支气管镜所见具有一致性。结果:多层螺旋CT三维重建及仿真内窥镜可准确、直观地显示气管支气管异物的位置、大小、形态、密度及阻塞程度。结论:多层螺旋CT三维重建及仿真内窥镜可准确评价气管支气管异物,是一种准确无创性诊断方法,为临床治疗提供直观的影像学资料,具有较高的临床诊断及指导价值。     

3D Marchenko applications: implementation and examples

We implement the 3D Marchenko equations to retrieve responses to virtual sources inside the subsurface. For this, we require reflection data at the surface of the Earth that contain no free-surface multiples and are densely sampled in space. The required 3D reflection data volume is very large and solving the Marchenko equations requires a significant amount of computational cost. To limit the cost, we apply floating point compression to the reflection data to reduce their volume and the loading time from disk. We apply the Marchenko implementation to numerical reflection data to retrieve accurate Green's functions inside the medium and use these reflection data to apply imaging. This requires the simulation of many virtual source points, which we circumvent using virtual plane-wave sources instead of virtual point sources. Through this method, we retrieve the angle-dependent response of a source from a depth level rather than of a point. We use these responses to obtain angle-dependent structural images of the subsurface, free of contamination from wrongly imaged internal multiples. These images have less lateral resolution than those obtained using virtual point sources, but are more efficiently retrieved.