We describe a simple method for high-precision rotary angle encoder calibration for longrange angular errors. By using a redesigned electronic nulling autocollimator, an opticalpolygon artifact is calibrated simultaneously with determining the encoder error function over a rotation of 2π rad. The technique is applied to the NIST vacuum double crystal spectrometer, which depends on precise measu...

The COMPTEL instrument onboard the Compton Gamma{Ray Observatory imaged the bright gamma{ray burst GRB 940301 within 1.6 hours of the event, with a mean 1 error radius of 1.5. The error region was subsequently reened by combining the COMPTEL location with the arc derived from diierences in the event arrival time at the Ulysses and BATSE detectors. Westerbork observations of the COMPTEL error re...

As a simple and compelling approach for estimating outof-sample prediction error, cross-validation naturally lends itself to the task of model comparison. However, even with moderate sample size, it can be surprisingly difficult to compare multilevel models based on predictive accuracy. Using a hierarchical model fit to large survey data with a battery of questions, we demonstrate that even tho...

Ratiometric fluorescence-imaging technique is commonly used to measure extracellular pH in tumors and surrounding tissue within a dorsal skin-fold window chamber. Using a pH-sensitive fluorophore such as carboxy SNARF-1 one can measure pH distributions with high precision. However, it is often observed that the measured pH is lower than expected, with a bias that varies from one image to anothe...

This paper presents a method for computing position and attitude of an instrument attached to the human body such as a handheld or head-mounted video camera. The system uses two Inertial Measurement Units (IMUs). One IMU is part of our earlier-developed Personal Dead-Reckoning (PDR) system, which tracks the position and heading of a walking person relative to a known starting position. The othe...

Introduction: Interior heat flow provides essential constraints on the thermal and chemical evolution of planetary bodies. On the moon, heat flow instrument designs typically have to reach depths below the annual solar thermal wave for the Moon (2-3 m), or alternatively methods must be applied to be able to decouple the influence of the relatively large temperature gradients associated with the...

An instrument for intraoperative sensing of surgeons’ hand tremor during vitreoretina l microsurgery has been developed. Real-time monitoring of tremor is useful to surgeons for purposes of training, adjustment of technique, monitoring of fatigue, and deciding when or whether to perform certain procedures. The instrument incorporates six inertial sensors (three accelerometers and three rate gyr...

Objective: The objective of the study was to determine whether health care aides (HCAs) could safely assist in medication administration in long-term care (LTC). Method: We obtained medication error reports from LTC facilities that involve HCAs in oral medication assistance and we analyzed Resident Assessment Instrument (RAI) data from these facilities. Standard ratings of error severity were "...

We have used high spectral resolution spectroscopic measurements from the MIPAS instrument on the Envisat satellite to simultaneously retrieve vertical profiles of H2O and HDO in the stratosphere and uppermost troposphere. A thorough error analysis of the retrievals confirms that reliable δD data can be obtained up to an altitude of 45 km. Averaging over multiple orbits and thus over longitudes...

We consider nonlinear models with an independent variable that is measured with error. The measurement error can be correlated with the true value, i.e. the measurement error is allowed to be nonclassical. We show that we can use a control variate estimator to estimate the parameters of interest. If we are prepared to make an assumption of the joint distribution of the first-stage and measureme...