دانلود رایگان مقاله محیط تجزیه و تحلیل دینامیکی برای آنالیز هسته ای

Abstract

A Dynamic Analysis Environment (DAE) software package is introduced to facilitate group inclusion/exclusion method testing, evaluation and comparison for pre-detonation nuclear forensics applications. Employing DAE, the multivariate signatures of a questioned material can be compared to the signatures for different, known groups, enabling the linking of the questioned material to its potential process, location, or fabrication facility. Advantages of using DAE for group inclusion/exclusion include built-in query tools for retrieving data of interest from a database, the recording and documentation of all analysis steps, a clear visualization of the analysis steps intelligible to a non-expert, and the ability to integrate analysis tools developed in different programming languages. Two group inclusion/exclusion methods are implemented in DAE: principal component analysis, a parametric feature extraction method, and k nearest neighbors, a nonparametric pattern recognition method. Spent Fuel Isotopic Composition (SFCOMPO), an open source international database of isotopic compositions for spent nuclear fuels (SNF) from 14 reactors, is used to construct PCA and KNN models for known reactor groups, and 20 simulated SNF samples are utilized in evaluating the performance of these group inclusion/exclusion models. For all 20 simulated samples, PCA in conjunction with the Q statistic correctly excludes a large percentage of reactor groups and correctly includes the true reactor of origination. Employing KNN, 14 of the 20 simulated samples are classified to their true reactor of origination.

6. Conclusions and future work

The DAE software package is a powerful tool for systematic nuclear forensic analyses. The capability for interfacing via a variety of programming languages and the modular work flow provides a platform for future development of advanced group inclusion/exclusion methods. The design of DAE yields an extensible software framework that allows for the straightforward integration of new scientific modules. The integration of these new modules involves a basic four-step process that includes: (1) the schema design of the database tables required to store all output information, (2) the specification of existing database information required as input to the new modules, (3) the design of the visual module layout that presents the control parameters to the user for manipulation, and (4) the incorporation of new mathematical routines required for the transformation of input data into output data. The new output data is stored within the internal database for use by other downstream DAE network modules. DAE modules do not interact directly with each other; rather they interact indirectly via access to the common database of stored information. This architectural feature allows for parallel module development efforts by various contributors without the need for constant coordination. The database schema itself provides all necessary interface information. New modules can selectively use only the existing database information required for operation, and each developer can independently design the table schemas for output from their new module. Once the new table schemata are finalized and shared, other developers can design modules to utilize the newly created data.