Nowadays, a lot of time and resources are used to determine the quality of goods and services. As a consequence, the quality of measurements themselves, e.g., the metrological traceability of the measured quantity values is essential to allow a proper evaluation of the results with regard to specifications and regulatory limits. This requires knowledge of the measurement uncertainties of all qu...

A two-step process is commonly used to evaluate data–model fit of latent variable path models, the first step addressing the measurement portion of the model and the second addressing the structural portion of the model. Unfortunately, even if the fit of the measurement portion of the model is perfect, the ability to assess the fit within the structural portion is affected by the quality of the...

We consider chemical reaction networks taken with mass-action kinetics. The steady states of such a system are solutions to a system of polynomial equations. Even for small systems the task of finding the solutions is daunting. We develop an algebraic framework and procedure for linear elimination of variables. The procedure reduces the variables in the system to a set of “core” variables by el...

The selective measurement of aldosterone in biological fluids has been handicapped by the lack of specific and sensitive assays. Bioassay methods (l-4) have been limited by the variation inherent in animal response. Chemical methods (5-9) require extensive purification procedures to remove contaminants, and are therefore subject to variable recoveries of the steroid. Furthermore, the quantity o...

In a continuous chemical process, the accuracy and reliability of process and analytical measurements creates the basis for control system performance and ultimately for product uniformity. Measurement results, whether from fast on-line measurement devices or from sample-based laboratory analyses, is the key for selecting the method for process control and analysis. Intelligent and advanced con...