GEMSFIT: a generic fitting tool for geochemical activity models

GEMSFIT, a parallelized open-source tool for fitting thermodynamic activity models has been developed. It is the first open-source implementation of a generic geochemical-thermodynamic fitting tool coupled to a chemical equilibrium solver which uses the direct Gibbs energy minimization (GEM) approach. This enables speciation-based fitting of complex solution systems such as solid solutions and mixed solvents. The extendable framework of GEMSFIT provides a generic interface for fitting geochemical activity models at varying system compositions, temperatures and pressures. GEMSFIT provides the most common tools for statistical analysis which allow thorough evaluation of the fitted parameters. The program can receive input of measured data from a PostgreSQL database server or exported spreadsheets. The fitting tool allows for bound, linear, and nonlinear (in)equality-constrained minimization of weighted squared residuals of highly nonlinear systems over a wide temperature and pressure interval only limited by user-supplied thermodynamic data. Results from parameter regression as well as from statistical analysis can be visualized and directly printed to various graphical formats. Efficient use of the code is facilitated by a graphical user interface which assists in setting up GEMSFIT input files. The usage and resulting output of GEMSFIT is demonstrated by results from parameter regression of the extended universal quasichemical aqueous activity model for geothermal brines.     

GeoPyTool:A cross-platform software solution for common geological calculations and plots

GeoPyTool is an open source application developed for geological calculations and plots,such as geochemical classification,parameter calculation,basic statistical analysis and diagrams for structural geology.More than acting as a link from raw data stored in Microsoft Excel~(?)(MS Excel)files to vector graphic files,GeoPyTool includes recently developed routines that have not been included in previous software,such as the calculation of the Ce~((Ⅳ))/Ce~((Ⅲ))ratio for zircons as a method to examine the temporal evolution of oxygen fugacity in the magmatic source for igneous rocks,and the temperature calculator with titanium in zircon and zirconium in rutile.Besides these routines,GeoPyTool also allows users to load any figure from articles or books as a base map.As a Python-based crossplatform program,GeoPyTool works on Windows~(?),MacOS X~(?)and GNU/Linux.GeoPyTool can do the whole process from data to results without the dependence of Microsoft Excel~(?),CorelDraw~(?) and other similar software.It takes Excel~(?)XLSX and CSV(Comma Separated Value)as the formats of both the input data source files and the output calculation results files.The figures generated by GeoPyTool can be saved as portable network graphics(PNG),scalable vector graphics(SVG)or portable document format(PDF).Another highlight of GeoPyTool is the multilingual support,the official versio n of GeoPyTool supports both Chinese and English,and additional languages can be loaded through interface files.GeoPyTool is still in the development stage and will be expanded with further geochemical and structural geology routines.As an open source project,all source code of GeoPyTool are accessible on Github(https://github.com/GeoPyTool/GeoPyTool).Users with Python experience can join in the development team and build more complex functions expanding the capabilities of GeoPyTool.     

FuzzyKrig: a comprehensive matlab toolbox for geostatistical estimation of imprecise information

Using kriging has been accepted today as the most common method of estimating spatial data in such different fields as the geosciences. To be able to apply kriging methods, it is necessary that the data and variogram model parameters be precise. To utilize the imprecise (fuzzy) data and parameters, use is made of fuzzy kriging methods. Although it has been 30 years since different fuzzy kriging algorithms were proposed, its use has not become as common as other kriging methods (ordinary, simple, log, universal, etc.); lack of a comprehensive software that can perform, based on different fuzzy kriging algorithms, the related calculations in a 3D space can be the main reason. This paper describes an open-source software toolbox (developed in Matlab) for running different algorithms proposed for fuzzy kriging. It also presents, besides a short presentation of the fuzzy kriging method and introduction of the functions provided by the FuzzyKrig toolbox, 3 cases of the software application under the conditions where: 1) data are hard and variogram model parameters are fuzzy, 2) data are fuzzy and variogram model parameters are hard, and 3) both data and variogram model parameters are fuzzy.     

CondMerg: an open source implementation in R language of conditional merging for weather radars and rain gauges observations

Monitoring of extreme events requires accurate measurement of rainfall intensities and merging weather radar data with ground information is a very common technique used to obtain the required precision. In order to do this, several methods exist but very few open source implementations are available. CondMerg is the first open source software developed in R language implementing the conditional merging method and some other experimental variants based on it. It is a cross-platform software, easily adaptable to different needs, optimized for batch processing of multiple events but also usable in near real time applications. For its execution it requires two inputs: a CSV file with rain gauges measurements and a geo-referred TIF file with weather radar quantitative precipitation estimations; main outputs are TIF files with merged observations although the code also returns information about cross-validation, with scatter plots and indexes. All TIF files are ready to be managed by common GIS software for easy visualization and analysis. Use of the program is very simple: execution can be interactive or non-interactive and, in both cases, it just requires to set some parameters at the beginning of the program and run it. The code has been tested on different extreme rain events occurred in the Piedmont region (northwestern Italy) showing improved accuracy of reconstructed rainfall fields.     

地震三维观测系统共中心点面元属性的并行计算方法

针对高密度地震勘探下的三维观测系统海量面元属性计算需求,基于OpenCL并行编程模型,研究并实现了适用于异构环境下面元属性的并行计算方法。根据面元分析算法特点将整个网格分成多个子区域,子区域可由不同设备以粗粒度方式并行,而子区域内部以炮检对方式细粒度并行。采用HP Z820工作站,在CPU+GPU异构混合平台下的试算结果表明,异构多核处理速度是CPU(单核)的30倍以上,数据生成速率高于300 MB/s。     

利用Delphi 6实现单桩最终沉降量计算程序的跨平台开发

本文对Delphi 6及其内部的VCL和CLX两个组件类库作了简要的论述,分析了这两个组件库的各自特点及相互之间的区别,对比了开发环境(Windows与Linux)的不同.根据CLX库完全支持跨平台的特性,说明了利用Delphi 6实现应用程序的跨平台开发的具体方法和步骤,并提出了利用Delphi 6进行跨平台开发的几点注意事项.最后,给出实现单桩承载力计算程序跨平台开发的关键源代码.     

利用中国静止气象卫星资料估算黄河源区蒸散发量

以黄河源区为研究区域,选取2009年9月该区域的中国静止气象卫星(FY-2D)观测资料,结合地面气象观测资料,基于能量平衡原理,估算了研究区域的逐时陆面蒸散发量。结果表明:在晴天条件下,利用陆表能量平衡系统模型求出蒸散发量的大小;在阴天条件下,利用FY-2D云顶反照率资料,根据太阳辐射在大气中的衰减过程,得出地表太阳辐射收支,进而求出蒸散发量的大小。卫星遥感估算的逐时蒸散发量与地面观测值相比,平均相对误差15.2%,估算误差在可接受的合理范围内,为实现陆面蒸散发量的业务化奠定了一定的基础。     

Development of python-FALL3D: a modified procedure for modelling volcanic ash dispersal in the Asia-Pacific region

Volcanic ash is the most widespread of all volcanic hazards and has the potential to affect hundreds of thousands, or even millions, of people in the densely populated islands of Indonesia. There is limited information available for this region on the hazard posed by volcanic ash, particularly from volcanoes that have not erupted in recent times. There is a need for computational models capable of accurately predicting volcanic ash dispersal at ground level when coupled with field observations of historical or ongoing eruptive activity. To maximise the effectiveness of such models, they should be readily accessible, easy to use and well tested. Geoscience Australia in collaboration with the Australia-Indonesia Facility for Disaster Reduction and the Indonesian Centre for Volcanology and Geohazard Mitigation has collaboratively adapted an existing open-source volcanic ash dispersion model for use in Indonesia. The core model is the widely used, open-source volcanic ash dispersion model FALL3D. A Python wrapper (name here python-FALL3D) has been developed, which modifies the modelling procedure of FALL3D in order to simplify its use for those with little or no background in computational modelling. The modified procedure does not alter the core functionality of FALL3D, but simplifies the modelling procedure by streamlining the installation process, automating both the pre-processing of input meteorological datasets and configuring and executing each utility program in a single-step process. An application example was presented using python-FALL3D for an active volcano in West Java, Indonesia. The example showed that communities located on the western side of Gunung Gede are always susceptible to volcanic ash ground loading regardless of the seasonal variations in wind conditions, whereas communities on the eastern side of Gunung Gede have a marked increase in susceptibility to ground loading during rainy season conditions when prevailing winds include a strong easterly component.     

地球深部探测计划中地学软件研发关键技术

针对高效率、高精度快速移动平台联合探测技术,发展由此带来的海量数据综合信息处理、解释和地质建模一体化所需的大型软件平台技术,可为实现复杂环境条件下有效实施大面积资源勘探调查、实现重大找矿突破目标提供切实可行的技术保障。采用引进和自主研发的"红蓝军"双轨路线,基于已有的地震数据处理解释基础,完善了高端软件平台地震和非震数据分析功能的联合,形成了具有跨操作平台、数据融合、二次开发、数据共享管理等功能的综合研究一体化分析软件平台,填补了国外软件产品在地震-非震数据联合分析方面的空白,为地球深部探测数据分析提供技术支撑。     

地震资料观测系统定义软件的研究与开发

地震资料处理过程中,观测系统的定义是不可或缺的关键步骤之一。在实际工作中通过对地震勘探观测系统定义的需求研究,使用Visual C++2010IDE结合Qt自主开发了一套针对陆上与海上通用的观测系统定义软件,该软件支持跨平台运行,提供了灵活多样的布设模式、直观的图形显示、面元网格划分和质量控制方式,在实际工区的使用过程中具备很强的实用性和可扩展性。     

Parallel finite element analysis of seismic soil structure interaction using a PC cluster

This paper describes an implementation of a highly scalable parallel computational facility with high speedup efficiency using relatively low-cost hardware, which consists of a cluster of desktop personal computers (PCs) connected via a 10-Gigabit Ethernet. Two-levels of parallelization were implemented. Communication between different PCs was achieved using message passing interface (MPI) protocol. Domain decomposition was automated and based on element numbering. Domain continuity was assured largely by re-numbering the elements using a “front squasher” code prior to decomposition. Within each PC, the shared memory parallelization was implemented using either the open-multiprocessing (OpenMP) or the MPI protocol. Analysis of three different problems with number of degrees-of-freedom ranging from about 129,000 to about 2,260,000 shows a speedup efficiency generally above 70%. Super-linear speedup was achieved in several of the cases examined in this study, with the hybrid MPI-OpenMP approach generally performing better compared to the pure MPI method for parallelization. The results demonstrate the feasibility of acquiring a parallel computing facility with relatively modest outlay that is within the reach of consulting or engineering offices.     

Multi-Region Boundary Element Analysis for Coupled Thermal-Fracturing Processes in Geomaterials

This paper describes a boundary element code development on coupled thermal–mechanical processes of rock fracture propagation. The code development was based on the fracture mechanics code FRACOD that has previously been developed by Shen and Stephansson (Int J Eng Fracture Mech 47:177–189, 1993) and FRACOM (A fracture propagation code—FRACOD, User’s manual. FRACOM Ltd. 2002) and simulates complex fracture propagation in rocks governed by both tensile and shear mechanisms. For the coupled thermal-fracturing analysis, an indirect boundary element method, namely the fictitious heat source method, was implemented in FRACOD to simulate the temperature change and thermal stresses in rocks. This indirect method is particularly suitable for the thermal-fracturing coupling in FRACOD where the displacement discontinuity method is used for mechanical simulation. The coupled code was also extended to simulate multiple region problems in which rock mass, concrete linings and insulation layers with different thermal and mechanical properties were present. Both verification and application cases were presented where a point heat source in a 2D infinite medium and a pilot LNG underground cavern were solved and studied using the coupled code. Good agreement was observed between the simulation results, analytical solutions and in situ measurements which validates an applicability of the developed coupled code.     

Parallel and scalable block system generation

Generating a realistic representation of a fractured rock mass is a first step in many different analyses. Field observations need to be translated into a 3-D model that will serve as the input for these analyses. The block systems can contain hundreds of thousands to millions of blocks of varying sizes and shapes; generating these large models is very computationally expensive and requires significant computing resources.By taking advantage of the advances made in big data analytics and Cloud Computing, we have a developed an open-source program—SparkRocks—that generates block systems in parallel. The application runs on Apache Spark which enables it to run locally, on a compute cluster or the Cloud. The block generation is based on a subdivision and linear programming optimization as introduced by Boon et al. (2015). SparkRocks automatically maintains load balance among parallel processes and can be scaled up on the Cloud without having to make any changes to the underlying implementation, enabling it to generate real-world scale block systems containing millions of blocks in minutes.     

隧道开挖地表移动计算软件SASMD的开发

从随机介质理论出发,简述了隧道开挖引起地表位移与变形计算所采用的理论与方法,介绍了基于随机介质理论而研制的隧道开挖引起地表位移与变形计算软件SASMD的设计思想、整体结构和主要特点,列举了若干个用SASMD软件所计算的工程实例。通过与实测值的比较,证明了基于随机介质理论而研制的SASMD软件具有精确度高、结果可靠、使用方便的特点,适于科技人员在分析隧道开挖引起地表位移与变形时使用。     

A Surface Model for Aeolian Dune Topography

A surface model for aeolian bedform topography is adapted from a surface model of subaqueous bedform topography. The aeolian bedform surface model is developed using a uniform grid with a cell-centered finite volume approximation of the sediment continuity equation. The resulting modeling framework approximates the dynamic motions of aeolian bedform topography driven by bedform field boundary conditions. The numerical model is applied to simulate bedforms growing from unimodal and bimodal transport regimes from both a fixed elevation (sediment source area) and within a domain with fully periodic boundary conditions. The rates at which modeled aeolian bedforms grow and morphologically mature are sensitive to the chosen boundary conditions. Video files of model simulations and source code for the presented aeolian bedform surface modeling framework are available in supplemental materials. The aeolian bedform surface model code is malleable and readily modified for exploratory study of dynamic bedform topography that inherits morphological traits from aeolian bedform field boundary conditions.     

New Zealand’s National Landslide Database

A New Zealand Landslide Database has been developed to hold all of New Zealand’s landslide data and provide factual data for use in landslide hazard and risk assessment, including a probabilistic landslide hazard model for New Zealand, which is currently being developed by GNS Science. Design of a national Landslide Database for New Zealand required consideration of existing landslide data stored in a variety of digital formats and future data yet to be collected. Pre-existing landslide datasets were developed and populated with data reflecting the needs of the landslide or hazard project, and the database structures of the time. Bringing these data into a single database required a new structure capable of containing landslide information at a variety of scales and accuracy, with many different attributes. A unified data model was developed to enable the landslide database to be a repository for New Zealand landslides, irrespective of scale and method of capture. Along with landslide locations, the database may contain information on the timing of landslide events, the type of landslide, the triggering event, volume and area data, and impacts (consequences) for each landslide when this information is available. Information from contributing datasets include a variety of sources including aerial photograph interpretation, field reconnaissance and media accounts. There are currently 22,575 landslide records in the database that include point locations, polygons of landslide source and deposit areas, and linear landslide features. Access to all landslide data is provided with a web application accessible via the Internet. This web application has been developed in-house and is based on open-source software such as the underlying relational database (PostGIS) and the map generating Web Map Server (GeoServer). Future work is to develop automated data-upload routines and mobile applications to allow people to report landslides, adopting a consistent framework.     

基于GIS的中国西南地区覆冰气象条件评估

采用中国西南地区(95°~110° E、 25°~35° N) 96个常规气象观测站1961年1月1日至2009年12月31日逐日气象要素资料提取覆冰相关要素, 利用1 km×1 km DEM资料通过GIS技术建立经度、 纬度、 海拔高度3个宏观地形因子以及坡度、 坡向和开放度3个微观地形因子的数据库, 通过三维二次趋势面的逐步回归方法, 在ArcMap/Info中进行与覆冰有关的气象要素栅格空间化, 在此基础上按照轻、 中、 重三个级别建立了各级覆冰模型并划分了覆冰风险分布. 结果表明: 满足覆冰条件日数序列在2000年以来呈显著上升趋势, 覆冰灾害发生的可能性增大. 一般来说, 宏观地形因子对气象要素的分布影响较大, 相对湿度模型和日照时数模型通过微观地形因子订正后, 精度有所提高. 通过模型得到的西南地区覆冰风险分布图能够较为精确的模拟出西南地区覆冰的风险分布, 与实际情况相符.     

Window 9X下利用VtoolsD开发硬件中断设备驱动程序

作者在本文中介绍了基于PC和Windows 9X平台下用中断方式实现数据采集的方法；并对虚拟设备驱动程序（VxD）和VtoolsD工具箱进行了简要介绍，通过对源代码的分析，说明了实时硬件中断VxD的实现过程。     

A 2D,fully-coupled,hydro-mechanical,FDEM formulation for modelling fracturing processes in discontinuous,porous rock masses

This paper presents a new, fully-coupled, hydro-mechanical (HM) formulation for a finite-discrete element method computer code. In the newly-developed, hydraulic solver, fluid flow is assumed to occur through the same triangular mesh used for the mechanical calculations. The flow of a viscous, compressible fluid is explicitly solved based on a cubic law approximation. The implementation is verified against closed-form solutions for several flow problems. The approach is then applied to a field-scale simulation of fluid injection in a jointed, porous rock mass. Results show that the proposed method can be used to obtain unique geomechanical insights into coupled HM phenomena.     

Pre-landfall evacuee perception of the meteorological hazards associated with Hurricane Gustav

In this study, evacuees from the path of Hurricane Gustav were surveyed to determine which meteorological hazards most influenced their decision to leave. Surveys were conducted along two major evacuation routes on August 30 and 31, 2008, to collect time-sensitive data on individual evacuation decisions related to the meteorological hazards from Hurricane Gustav. The regions of New Orleans, Houma, and Lafayette were represented most frequently, as determined by zip code data collected from the surveys. Responses were evaluated first by meteorological hazard for the entire dataset and then by three-digit zip code region. Overall, storm surge was the most important meteorological variable, followed by the size of the storm, wind, rain, and tornadoes. When separated into three-digit zip code regions, analyses revealed evacuees from in and around New Orleans were driven to evacuate as a result of the perceived threat from storm surge and storm size; residents in the Houma, Louisiana region were motivated to leave due to the threat from storm surge; and Lafayette and the surrounding areas were most-concerned with the threats posed by hurricane-force winds. Given the forecast track and intensity, survey respondents understood the meteorological hazards from Gustav and were motivated to leave based on personal evaluations of risk associated with the storm.