An introduction to the NSPCG software package

NSPCG is the most recent research-oriented software package developed as part of the ITPACK Project at the Center for Numerical Analysis of The University of Texas at Austin. It is designed to solve large sparse systems of linear equations by a variety of different non-symmetric preconditioned conjugate gradient methods. Several different sparse data storage schemes are available for storing the coefficient matrix of the linear system. Matrices with a wide range of structures from highly structured to completely unstructured can be accommodated. To limit memory requirements, the accelerators in the package can be called directly with the matrix stored in a user-defined sparse data storage format (for example, from a particular application) by supplying some user-written routines for certain matrix–vector operations. The main entry point into the package is through a single subroutine call. The various methods are accessed by using a particular naming convention for the first two parameters that in turn selects a preconditioner, an accelerator and a data storage scheme. Some of the basic preconditioners that are available are Jacobi, Incomplete LU Decomposition and Symmetric Successive Overrelaxation as well as block preconditioners. The user can select from a large collection of accelerators such as Conjugate Gradient (CG), Chebyshev (SI, for semi-iterative), Generalized Minimal Residual (GMRES), Biconjugate Gradient Squared (BCGS) and many others. The package is modular so that almost any accelerator can be used with almost any preconditioner. One of the main purposes for the development of the package was to provide a common modular structure for research on iterative methods. The entire package is written in Fortran 77 with vectorization in mind for applications on supercomputers.     

Application of generic risk assessment software to radioactive waste disposal

Monte Carlo methods are used in a variety of applications such as risk assessment, probabilistic safety assessment and reliability analysis. While Monte Carlo methods are simple to use, their application can be laborious. A new microcomputer software package has been developed that substantially reduces the effort required to conduct Monte Carlo analyses. The Sensitivity and Uncertainty Analysis Shell (SUNS) is a software shell in the sense that a wide variety of application models can be incorporated into it. SUNS offers several useful features including a menu-driven environment, a flexible input editor, both Monte Carlo and Latin Hypercube sampling, the ability to perform both repeated trials and parametric studies in a single run, and both statistical and graphical output. SUNS also performs all required file management functions.     

The FLOWMETRIKA software package

The FLOWMETRIKA software package is described. The purpose of the package is to design and check systems for measuring liquid and gas flow rates using the variable pressure drop method in orifices. Standard programs for calculating the physical properties of fluid media are employed in the software and the calculations are carried out in accordance with the State Standard GOST 8.563.1.2-97. The design is based on the optimality criterion taking constraints into account. Translated from Izmeritel'naya Tekhnika, No. 1, pp. 33–34, January, 2000.     

A framework to integrate software behavior into dynamic probabilistic risk assessment

Software plays an increasingly important role in modern safety-critical systems. Although, research has been done to integrate software into the classical probabilistic risk assessment (PRA) framework, current PRA practice overwhelmingly neglects the contribution of software to system risk. Dynamic probabilistic risk assessment (DPRA) is considered to be the next generation of PRA techniques. DPRA is a set of methods and techniques in which simulation models that represent the behavior of the elements of a system are exercised in order to identify risks and vulnerabilities of the system. The fact remains, however, that modeling software for use in the DPRA framework is also quite complex and very little has been done to address the question directly and comprehensively. This paper develops a methodology to integrate software contributions in the DPRA environment. The framework includes a software representation, and an approach to incorporate the software representation into the DPRA environment SimPRA. The software representation is based on multi-level objects and the paper also proposes a framework to simulate the multi-level objects in the simulation-based DPRA environment. This is a new methodology to address the state explosion problem in the DPRA environment. This study is the first systematic effort to integrate software risk contributions into DPRA environments.     

DSD: a generic software package for model-based fault diagnosis in dynamic systems

A user-friendly, interactive software package is described that can be used for fault diagnosis in dynamic systems. The methodology is based on the representation of system evolution in time as probability of transitions between sets of magnitude intervals in the state/parameter space. The software is developed in C++ for Windows NT platform. The display capabilities of the software and its implementation are illustrated using a second order system.     

Comprehensive risk assessment for rail transportation of dangerous goods: a validated platform for decision support

Currently, the most advanced and well documented risk assessments for the transportation of dangerous goods by railway take into account:

(i) statistics-based loss of containment frequencies,

(ii) specification of potential consequences for a given release situations using event tree methodology as an organisational tool and

(iii) consequence calculation models to determine a risk figure known as CCDF (Complementary Cumulative Distribution Function).

Such procedures for the risk assessment (including for example decision-making on preventive measures) may offer only a limited insight into the causes and sequences leading to an accident and do not allow for any kind of predictive analysis. The present work introduces an enhanced solution, and a related software platform, which attempts to integrate loss of containment causes and consequences with system's infrastructure and its environment. The solution features:

(i) the use of a detailed Master Logical Diagram, including fault/event tree analysis to determine a loss of containment frequency based on different initiating events, scenarios and specific basic data,

(ii) the characterization of a resulting source term following a release situation, and

(iii) the calculation of various potential impacts on the neighbouring site.

Results are wrapped into a CCDF format for each selected traffic segment. The risk-related results are integrated on a software platform, structured as a decision support system using intelligent maps and a variety of GIS (Geographical Information System) data processing procedures. The introduction of the hot spot approach, allows us to focus on the most risk-relevant areas and to use information on various railway infrastructure elements (e.g. points, tunnels), are the basis of the new models employed. The software is applicable to any railway transportation system, comprising its technical infrastructure, rolling stock, human actions, regulation and management procedures. It provides the determination of the annual societal risk due to potential accident scenarios, while also revealing information on the potential causes of an accident taking into account spatial parameters. The approach and software have been validated by a case study done for a particular traffic segment of the Swiss Federal Railway company.     

PRDC--a software package for personnel radiation dose calculation

To determine effective dose, we usually need to use a very complicated human body model and a sophisticated computer code to transport radiations in the body model and surrounding medium, which is not very easy to practicing health physicists in the field. This study develops and tests a software package, called PRDC (Personnel Radiation Dose Calculation), which calculates effective dose and radiation doses to various organs/tissues and personal dosemeters based on a series of interpolations.     

Thermophysical property predictions from the software package EOSMIX

A two-fluid corresponding-states model for predicting the thermodynamic properties of mixtures has been developed, which uses accurate equations of state for the reference substances of the components. A new mixing parameter has been introduced, which takes account of the differences in molecular sizes in binary fluid mixtures. The three mixing parameters for methane-ethane and methane-propane have been optimized using different types of experimental data. Comparisons of predictions with data are given for experimental densities and speed of sound.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado, U.S.A.     

A software package for evaluating results by regression analysis

Translated from Izmeritel'naya Tekhnika, No. 4, pp. 27–29, April, 1992.     

Hardware/software package for research on surface impedance

We present relationships between the real and imaginary parts of the surface impedance of the ceramic YBA₂Cu₃O_7−x and a static external magnetic field over a scanned range of −8 to 8 kA/m and, conversely, for a varying field with an amplitude of 80 A/m and a frequency of 163 Hz; these relationships were obtained with a hardware/software package. Translated from Izmeritel'naya Tekhnika, No. 4, pp. 23–26, April, 1999.     

A modular and innovative software package for multichannel dataacquisition

A software package called Acquire is described which can control multichannel data acquisition equipment, collect and archive the data, analyze and present results in user-defined plot formats, and link together the individual tasks of a repetitive experiment to produce a fully automated turn-key solution. It is concluded that the modular structure of the described software can be customized quickly and easily. The customization is further simplified by incorporating many high-level functions like comprehensive plotting facilities, integrated data software package routines, etc. into this general-purpose software package. Examples of plot picture formats are presented     

The development of a decision support framework for a quantitative risk assessment in multimodal green logistics: an empirical study

The objective of this research was to develop a decision support framework (DSF) to assess quantitative risk in multimodal green logistics. This risk assessment is the combination of a number of models, the failure mode and effects analysis, the risk contour plot, the quantitative risk assessment, the analytic hierarchy process and the data envelopment analysis which can support a user to perform risk assessment in various decisions. The contribution of this research is that the risk assessment model can generate an optimal green logistics route in accordance with weight from the user. The highlight of this DSF is that the quantitative assessment model can reduce bias on risk assessment of logistics route. An in-depth case study, recommendations, limitations and further research are also provided.     

The assessment of software reliability

This paper is concerned with actual and potential uses of statistical methods in the assessment of software reliability. The aim is to provide a statistical audience with an understanding of the issues involved, and to generate interest in some of the current outstanding problems. The paper identifies reasons for software reliability assessment, outlines why special methods are needed to deal with the software aspect of systems, and discusses the role of statistics.     

Quality assessment of software prototypes

This paper introduces a concept for the assessment of prototypes. On the basis of the international standard ISO/IEC CD 12119 it shows that there are differences as well as similarities between traditional methods of software testing and the assessment of software prototypes. Prototype assessments consist mainly of user-driven and ergonomic (usability related) assessments. The degree to which user requirements are realised is also an important assessment item. To perform correctness assessments a proper installation is essential. Without this errors cannot be assigned properly. Furthermore, it is also vital to have reliable documentation available for correctness assessments. Verbal information is insufficient, especially where no or poor general documentation is available. The assessment should be outlined on a black-box basis because the final implementation of the program will normally use a different program language. To maintain the advantage of short reaction times during prototype development it is also important to avoid too long assessment intervals.     

STRRAP system—A software for hazardous materials risk assessment and safe distances calculation

This work presents a powerful computational tool (Stochastic Toxic Release Risk Assessment Package, STRRAP) useful in risk assessment and emergency planning (safe distance calculation), which allows to handle the stochastic uncertainty of atmospheric parameters, critical for risk calculation when diffusion of hazardous gases or particulate matter occur as a consequence of an emission or accidental release. In fact, the random behaviour of wind intensity, wind direction, atmospheric stability and temperature, given a time horizon, (a season or a complete year), is taken into account considering also the day or night condition.STRRAP can be used for releases or emissions from static sources (for example a stack or a fixed tank in a facility) or from transportation accidents (road, rail, maritime and pipeline transport) involving different scenarios.After a stochastic simulation based on well-known diffusion models (dense and light gases, particulate matter) is carried out, the downwind pollutant concentrations are obtained, in order to compute safe distances and/or individual and societal risks.Some study cases are analyzed to show STRRAP capabilities.     

Risk assessment and optimization of a safety system using the maros simulation package

The performance of a pressure-surge relief system which acts as a safety mechanism within the export facility of an oil terminal is analysed in detail. Dynamic simulation methods are integrated with failure mode effects analysis to establish the risk of catastrophic failure of the terminal. An optimization procedure is presented which demonstrates the use of simulation to establish suitable inspection, testing and preventive maintenance schedules which maximize the effectiveness of the surge relief system over its design life. The importance of such activities is evident — left unattended the surge-relief system will not meet minimum safety standards, whereas planned maintenance and testing is shown to improve safety standards above the minimum required.     

Classification of queueing models for a workstation with interruptions: a review

Queueing theory is commonly used to evaluate the performance of production systems. Due to the complexity of practical production lines, choosing correct queueing models under the existence of interruptions can be intricate, but is critical to the evaluation of system performance. This paper gives a review of research in this area, proposes a systematic way to classify different types of interruptions in manufacturing systems and suggests proper queueing models for each category. The operational definition of service time is given and the decomposition properties for the run-based state-induced and time-based preemptive events are explained. The corresponding G/G/1 approximate models are proposed.     

基于MCM的不确定度评定软件开发

蒙特卡洛法(MCM)是基于对输入量的概率分布进行统计模拟的一种不确定度评定方法,主要应用于不适合使用GUM法评定测量不确定度的场合,并可对GUM法评定结果进行验证。提出一种用VB6实现自适应蒙特卡洛试验的软件实现方法,根据用户录入的输入量参数生成符合相应分布规律的伪随机数,代入用户录入的测量模型,得到一组输出量的蒙特卡洛试验数据,对这些数据进行统计处理得到输出量的测量不确定度评定结果及其概率密度分布曲线。该文简要介绍了软件的系统架构、测量不确定评定中常见分布的伪随机数算法及统计试验关键算法。     

Radon risk in Alpine regions in Austria: risk assessment as a settlement planning strategy

Soil gas radon measurements complement indispensable and well-established radon indoor measurements in Austria. Radon in soil gas is a result of geochemical conditions as well as of geology, mineralogy, geophysics and meteorology. Therefore, geological factors can help to predict potential indoor radon concentrations via soil gas. Soil gas radon measurements in well-defined geological units give an estimate of local and regional radon hazards and build the basis for radon risk maps, which could be used for land-use planning and urban development. The creation of maps makes an important contribution to health care. For this purpose, several research projects were carried out in Austria. On the one hand, a study was already conducted in Lower Austria to determine the influence of meteorological and soil physical parameters on radon concentrations in soil gas and to evaluate soil gas radon concentrations with a radon emanation and migration model. On the other hand, radon measurements on different geomorphologic formations in the Austrian Alps, which are potential settlement areas, are of special interest.