A piezoelectric tube of the type typically used for actuation in Scanning Tunneling Microscopes (STMs) and Atomic Force Microscopes (AFMs) is considered. Actuation of this piezoelectric tube is hampered by the presence of a lightly damped low frequency resonant mode. This resonant mode is first identified and then damped using a Positive Velocity and Position Feedback (PVPF) controller, a contr...

We describe the design principles of a photometric flatbed scanner with a scan area of 250 X 250 mm2, a dynamic range of 4000 gray levels, a signal/noise ratio of 2000/1, a step size of 0.1 mm, and a step frequency of 2000 steps per second. It is controlled by a microcomputer and used to acquire data for quantitative evaluation of gels or chromatograms. The performance of the instrument is demo...

A systematic procedure for designing a high-speed, compact serial-kinematic XYZ scanner for atomic force microscopy is presented in this Letter. Analytical stiffness calculations are used to estimate the first natural frequency and travel range of the scanner. Design and characterisation of the scanner are presented. Results of finite-element analysis and experimentation on the scanner revealed...

Objectives To develop a mathematical model for multi-category patient scheduling decisions in computed tomography (CT), and to investigate associated tradeoffs from economic and operational perspectives. Methods We modeled this decision-problem as a finite-horizon Markov decision process (MDP) with expected net CT revenue as the performance metric. The performance of optimal policies was compar...

OBJECTIVES To develop a mathematical model for multi-category patient scheduling decisions in computed tomography (CT), and to investigate associated tradeoffs from economic and operational perspectives. METHODS We modeled this decision-problem as a finite-horizon Markov decision process (MDP) with expected net CT revenue as the performance metric. The performance of optimal policies was comp...

To investigate scanner performance and guide development of an instrument qualification method, slides with replicates of successive dilutions of cyanine 5 (Cy5) and cyanine 3 (Cy3) dyes (referred to as dye slides) were scanned. The successive dilutions form a dose-response curve from which performance can be assessed. The effects of a variety of factors, including the number of scans and slide...

As a critical component of any microarray experiment, scanner performance has the potential to contribute variability and bias, the magnitude of which is usually not quantified. Using Standard Reference Material (SRM) 2,242, which is certified for Raman spectral correction, for monitoring the microarray fluorescence at the two most commonly used wavelengths, our team at the National Institute o...