This paper compares three methods of item calibration—concurrent calibration, separate calibration with linking, and fixed item parameter calibration—that are frequently used for linking item parameters to a base scale. Concurrent and separate calibrations were implemented using BILOG-MG. The Stocking and Lord (1983) characteristic curve method of parameter linking was used in conjunction with ...

Safety in highway geometric design is one of the main goals to be achieved. However, deterministic criteria do not provide information concerning risk associated with outputs proposed. To yield consistent safety levels, sag vertical curve model on undivided highways was calibrated using a reliability-based framework, which allows incorporate uncertainty variables. The contemplates features vehi...

Common streamflow gauging procedures require assumptions about the stage-discharge relationship (the ‘rating curve’) that can introduce considerable uncertainties in streamflow records. These rating uncertainties are not usually considered fully in hydrological model calibration and evaluation yet can have potentially important impacts. We analysed streamflow gauge data and conducted two modell...

We describe a quantitative assay of dsDNA based on real-time PCR measurement of fluorescence due to the interaction of PicoGreen dye with dsDNA. An aliquot of 1 to 5 ml of the sample is mixed with 45 ml of diluted PicoGreen reagent within an optical PCR tube. This is placed into the real-time apparatus set to read SYBR Green I dye at the end of three cycles of 94 degrees C for 30 s and 65 degre...

A summary of the development of a method of measuring fluid temperature with a laser is presented. The method is based on molecular tagging velocimetry (MTV), an established technique of obtaining spatiallyresolved fluid velocity profiles by analysis of laserinduced molecular phosphorescence emitted by photoluminescent chemicals. In aqueous solutions the intensity of the phosphorescent emission...