Position Root Mean Square Error Research Articles

FTIR/ATR Spectroscopy Applied to the Rapid Determination of Chemical Oxygen Demand of Wastewater

A directly rapid quantification method for chemical oxygen demand (COD) of wastewater was established by Fourier transform infrared (FTIR) spectroscopy combined with attenuated total reflection (ATR) technology and moving window partial least squares (MWPLS) method with changeable parameters. All samples were firstly divided into the calibration set and the prediction set. And then according to the predicion effect, the optimal model was selected, and the corresponding waveband, number of adopted wavenumbers, PLS factor, root mean squared error of predication (RMSEP), correlation coefficient of predication (RP) were 3152-1109 cm-1, 1060, 8, 21.5 mg/L, and 0.981 respectively, which was obviously superior to the optimal PLS model on the whole spectral collecting region. The result shows that FTIR/ATR spectroscopy can be applied to the rapid determination of COD of wastewater, and the waveband selected by MWPLS method with changeable parameters has higher signal to noise ratio, which can effectively improve the precision of the predictive model.

Model Optimization for near-Infrared Spectroscopy Analysis of Chemical Oxygen Demand of Wastewater

A directly rapid quantitative analysis method for chemical oxygen demand (COD) of wastewater samples was established by near-infrared (NIR) spectroscopy and partial least square (PLS) method. The optimization of Savitzky-Golay (SG) smoothing modes combined with PLS factor was applied to optimize the model of NIR spectroscopy analysis here. The waveband used for modeling was the combination of 400-1878 nm and 2088-2338 nm. The optimal smoothing parameters were the 5thderivative smoothing, 5thdegree polynomial, 17 smoothing points, the optimal PLS factor, root mean squared error of predication (RMSEP) and correlation coefficient of predication (RP) were 7, 33.2 (mg/L) and 0.929 respectively, which was obviously superior to the direct PLS model without SG smoothing and ones based on the whole spectral collecting region 400-2500 nm. This demonstrated that NIR spectroscopy can be applied to the rapid determination of COD of wastewater, large-scale simultaneous optimization selection of SG smoothing parameters and PLS factor can be effectively applied to the model optimization of NIR analysis.

FTIR/ATR Spectroscopy Analysis of COD in Wastewater Based on Combination Optimization of SG Smoothing Modes and PLS Factor

A directly rapid quantitative analysis method for chemical oxygen demand (COD) of wastewater was established by Fourier transform infrared (FTIR) spectroscopy and attenuated total reflection (ATR) technology. The combination selection of Savitzky-Golay (SG) smoothing modes combined with partial least squares (PLS) factor was applied to the model optimization here. The optimal smoothing parameters were 2ndorder derivative smoothing, 6thdegree polynomial and 51 smoothing points. The corresponding optimal PLS factor, root mean squared error of predication (RMSEP) and correlation coefficient of predication (RP) were 11, 24.4 (mg/L) and 0.968 respectively, which was obviously superior to the direct PLS model without SG smoothing. This demonstrated that the combination selection of SG smoothing parameters and PLS factor can be effectively applied to the model optimization for FTIR/ATR analysis of COD in wastewater.

On-orbit performance of Gravity Probe B drag-free translation control and orbit determination

The Gravity Probe B (GP-B) Relativity Mission is a fundamental physics experiment to test Einstein’s theory of General Relativity based on observations of spinning gyroscopes onboard a satellite in a near-polar, near-circular orbit at an altitude of about 640 km around the Earth. The GP-B mission was designed to test two predictions of Einstein’s theory, the geodetic effect and the frame-dragging effect, to an accuracy better than 5 × 10 −4 arcsec/yr. Drag-free control technology is implemented in the GP-B translation control system to minimize support forces and support induced torques on the gyroscopes. A Global Positioning System (GPS) receiver onboard the GP-B satellite provides real-time position, velocity and timing data. The GP-B orbit is determined on the ground based on the 3-axis GPS position data and verified independently with ground-based laser ranging measurements. This paper describes the design and implementation of the drag-free translation control and orbit determination system of the GP-B satellite. The on-orbit performance of the drag-free translation control system satisfies the requirements of the GP-B science experiment. The residual accelerations from the gyroscope control efforts are less than 4 × 10 −11 m/s 2 (along the satellite roll axis) and less than 2 × 10 −10 m/s 2 (transverse to the satellite roll axis) between 0.01 mHz and 10 mHz in inertial space. The non-gravitational acceleration along the satellite roll axis, including a nearly constant component (which is kept below 1 × 10 −7 m/s 2) and a sinusoidal component (whose amplitude varies from about 5 × 10 −7 m/s 2 to less than 1 × 10 −8 m/s 2), causes the gyroscope spin axis to drift less than 9 × 10 −5 arcsec/yr. The orbit determination system is found to provide overlapping orbit solution segments having RMS (root mean square) position and velocity errors of a few meters and a few mm/s, well within the RMS mission requirements of 25 m and 7.5 cm/s.

Erratic eye tracking in schizophrenic patients as revealed by high-resolution techniques

Using high-resolution infrared oculography with digital recording and analysis techniques, we tested several types of eye movements in 19 schizophrenic patients and 11 normal controls. Abnormal slow pursuit eye movements, seen in about half of the patients, were characterized by erratic inaccuracies in position, velocity, and phase. Tracking errors were quantitatively assessed by their root mean square (RMS) error. Position RMS errors fell into two clearly separated groups, with 10 of 19 patients clustering about the normal controls and the remaining 9 having much higher errors than normal. Although several of these poor trackers had an excess of saccades or low pursuit gain, these abnormalities were not primarily responsible for the large erratic tracking errors. Saccades in response to unpredictable target jumps had normal latencies (reaction times) and velocities, but were more hypometric and variable in accuracy than those of controls. These saccadic abnormalities did not correlate with the patients' position RMS errors during slow pursuit.