Validation of computational methods

The goal of any quality assurance program in criticality safety is to ensure that limits have been accurately established and will contribute to a safe operation. Computers are relied on to a great extent in most criticality safety programs and consequently are a key element in quality assurance programs in criticality safety. Computers are used at the Lawrence Livermore Laboratory (LLL) not only directly in criticality safety analysis but also in management of numerical and bibliographic criticality data that are needed for the validation of computational methods. 

American National, Standard, Validation of Computational Methods for Nuclear Criticality Safety, ANSI N16.9-1975. 

Gas-phase chemistry studies of atomic and molecular rare-earth and actinide ions have a deep-rooted history of more than three decades. In gas phase, physical and chemical properties of elementary and molecular species can be studied in absence of external perturbations. Due to the relative simplicity of gas-phase systems compared to condensed-phase systems, solutions or solids, it is possible to probe in detail the relationships between electronic structure, reactivity, and energetics. Most of this research involves the use of a variety of mass spectrometry techniques, which allows one exerting precise control over reactants and products. Many new rare earth and actinide molecular and cluster species have been identified that have expanded knowledge of the basic chemistry of these elements and provided clues for understanding condensed-phase processes. Key thermodynamic parameters have been obtained for numerous atomic and molecular ions. Such fundamental physicochemical studies have provided opportunities for the refinement and validation of computational methods as applied to the particularly challenging lanthanide and actinide elements. Among other applications, the roles of... 

The results of numerical simulation of bluff-body stabilized premixed flames by the PPDF method are presented in section 12.2. This method was developed to conduct parametric studies before applying a more sophisticated and CPU time consuming PC JVS PDF method. The adequate boundary conditions (ABC) at open boundaries derived in section 12.3 play an essential role in the analysis. Section 12.4 deals with testing and validating the computational method and discussing the mechanism of flame stabilization and blow-off. 

In the range of validity of our method, integral molar entropies were easily computed by the appropriate equations and showed a loss of freedom for the adsorbed phase with respect to the compressed phase of same density. 

The process for implementation and prospective validation of computer systems outlined in Figure 3 depicts the system application activities within each life-cycle phase and identifies key issues and considerations for each step. The process includes for evaluation of both the computer system product and the system supplier s working methods. The same life-cycle approach may be applied to validate the associated control and monitoring instrumentation [9]. 

Design and qualification of critical support utilities Validation of computer systems, methods, manufacturing, and cleaning processes Labeling controls... 

One key issue is the requirement for animal testing. The report and recommendations of the European Centre for the Validation of Alternative Methods (ECVAM) workshop (Leahy et al., 1997) clearly state that a major priority is to reduce the number of animals used in pharmacokinetic studies in drug development. As much information as possible should be obtained from alternative sources, such as computer modeling or using data already generated for similar compounds. 

The first section of this thesis deals with development and validation of analytical biotechnological methods for qualitative and quantitative analysis (papers I-II). The second section (papers III- VI) concerns the issue of isotherm parameters determination for preparative purposes. More particularly, this section deals with the validated characterization of phase systems through the determination of isotherm parameters and computer simulations (paper III) and with the development and validation of methods to determinate adsorption isotherm parameters directly from component mixtures (papers IV-VI). The two sections together have one important feature in common the development and validation of chromatographic methods for analytical and preparative purposes (papers I-VI). The intention of this summary is to give readers who are new in the area a general introduction to the fields described above. For a more detailed discussion, see papers I-VI. 

The validation of analytical methods is a well-known problem in the analytical community [1], The international guidance for equipment qualification (EQ) of analytical instruments and their validation is in the development stage [2-4], At this time validation of computer systems for analytical instruments is less elaborated [5-7], The term computer system comprises computer hardware, peripherals, and software that includes application programs and operating environments (MS-DOS, MS-Windows and others) [5, 6], Since programs, software and the whole computer system are elements of the instrument used by the analyst according to the analytical method, successful validation of the method as a black box [8] means successful validation of the instrument, computer system, software and programs. On the other hand, the same instrument may also be calibrated and validated as a smaller (in-... 

Abstract Validation of analytical methods of well-characterised systems, such as are found in the pharmaceutical industry, is based on a series of experimental procedures to establish selectivity, sensitivity, repeatability, reproducibility, linearity of calibration, detection limit and limit of determination, and robustness. It is argued that these headings become more difficult to apply as the complexity of the analysis increases. Analysis of environmental samples is given as an example. Modern methods of analysis that use arrays of sensors challenge validation. The output may be a classification rather than a concentration of analyte, it may have been established by imprecise methods such as the responses of human taste panels, and the state space of possible responses is too large to cover in any experimental-design procedure. Moreover the process of data analysis may be done by non-linear methods such as neural networks. Validation of systems that rely on computer software is well established. 

This book is unique in that to date no textbook on chemical process deign and simulation using microcomputers and the FORTRAN programming language has been published. FORTRAN 90 is a major development of the FORTRAN language and includes all the computer programs in this text as a subset. To assist the user and to demonstrate the validity of the methods, worked examples of practical industrial relevance are provided throughout the text. 

It is difficult to determine these thermochemical parameters from experiment, because it is hard to monitor the precursor hydrocarbon radical and the formed peroxy radical. The experiment is further complicated by the presence of reactions to new products by the energized peroxy radicals which can prevent the monitoring of equilibrium. Experiments on ion methods using proton affinity or basicity, often with mass spectrometric analysis, are also utilized to determine enthalpies of formation of radicals. Our methods rely heavily on experimentally determined thermochemical data and we would like to point out that this data is very valuable to validate the computational methods. 

In Sect. 1.4, we will demonstrate the validity of the method by analysing the relativistic Kepler problem by computing the perihelion motion of the planet Mercury, followed by Sect. 1.5, displaying the explicit connection between the Schwarzschild singularity and Gddel s theorem. The final conclusion summarises the modus operandi and its subsequent consequences. 

To validate the computational methods used to determine the sulfonamide geometrical parameters, six sulfonamide derivatives stored in the CSD were chosen for the test set because they contain three types of sulfonamide nitrogen atoms, non-, mono-, and disubstituted (Fig. 17.2). These sulfonamide derivatives were... 

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