Computer technology Standards

NAA is a quantitative method. Quantification can be performed by comparison to standards or by computation from basic principles (parametric analysis). A certified reference material specifically for trace impurities in silicon is not currently available. Since neutron and y rays are penetrating radiations (free from absorption problems, such as those found in X-ray fluorescence), matrix matching between the sample and the comparator standard is not critical. Biological trace impurities standards (e.g., the National Institute of Standards and Technology Standard Rference Material, SRM 1572 Citrus Leaves) can be used as reference materials. For the parametric analysis many instrumental fiictors, such as the neutron flux density and the efficiency of the detector, must be well known. The activation equation can be used to determine concentrations ... 

N.Chapin, An Introduction to Automatic Computers, Technology Center,Chicago, 111(1955) 6)US National Bureau of Standards, "Computer Development(SEAC DYSEAC) at the NBS, Govt PrntgOff, Washington... 

Procedural controls (1) Measures taken to ensure the trustworthiness of records and signatures established through the implementation of standard operating procedures (SOPs). (2) Written and approved procedures providing appropriate instmctions for each aspect of the development, operations, maintenance, and security applicable to computer technologies. In the context of regulated operations, procedural controls should have QA/QC controls equivalent to the applicable predicate regulations. 

Adopting a standard approach also allows the impact of new and developing regulations and computer technology on the nsnal GxP validation protocol to be more easily assessed and necessary corrective actions taken in a consistent and timely manner. 

The UNIVAC was not the only computer project the National Bureau of Standards was involved in, nor was it the only such project in which it was working with the military. The NBS established its National Applied Mathematics Laboratories in 1945 because the U.S. Navy wanted there to be a single national body to provide leadership in the development of new computational technology. Additionally, the National Bureau of Standards wanted to obtain a copy of the UNIVAC because the Office of the Air Comptroller of the U.S. Air Force was interested in using the machine in operations research techniques in military administration. ... 

Due to the large number of observables in an atomic resolution refinement, the inversion of the normal matrix of the refinement can be used to estimate standard uncertainties for the refined parameters (Cruickshank, 1970 Press et al., 2(X)2). The corresponding calculations are enormous and until recently could only performed on large mainframe-type computers. However, with the rapid progress in computing technology, the matrix inversion can now be done on standard crystallographic workstations in a couple of hours. ... 

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