Reconstructing normalized difference vegetation index (NDVI) time series datasets is essential for monitoring long-term changes in terrestrial vegetation. Here, a temporal–spatial iteration (TSI) method was developed to estimate the NDVIs of contaminated pixels, based on reliable data. The NDVIs of contaminated pixels were first computed through linear interpolation of adjacent high-quality pix...

Many time-series smoothing methods can be used for reducing noise and extracting plant phenological parameters from remotely-sensed data, but there is still no conclusive evidence in favor of one method over others. Here we use moderate-resolution imaging spectroradiometer (MODIS) derived normalized difference vegetation index (NDVI) to investigate five smoothing methods: Savitzky-Golay fitting...

Different ensemble strategies were compared in online near-infrared models for monitoring active pharmaceutical ingredients of Traditional Chinese Medicine. Bagging partial least square regression and boosting partial least square regression were adopted to near-infrared models, to determine hesperidin and nobiletin content during the extraction process of Pericarpium Citri Reticulatae in a pil...

The efficacy of smoothing first-order data as a preprocessing method for multivariate calibration is discussed. In particular, the use of symmetric smoothing filters (such as Savitzky–Golay filters) is examined from the perspective of calibration performance, in contrast with past studies based on univariate signal-to-noise improvement. It is shown mathematically that in the limit of a perfect ...

A novel method for the rapid determination of chrysin and galangin in Chinese propolis of poplar origin by means of visible and near infrared spectroscopy (Vis-NIR) was developed. Spectral data of 114 Chinese propolis samples were acquired in the 325 to 1,075 nm wavelength range using a Vis-NIR spectroradiometer. The reference values of chrysin and galangin of the samples were determined by hig...

Extraction of scaffolds, such as the meiotic spindles, a 3D tubular framework consisting of the microtubules, from conforcal laser scanning microscopy (CLSM) data of a cell is a challenge in biological image processing. It is of major importance in the research of microtubule anchor proteins, and molecular motor mechanics. However, the scaffold is hidden within CLSM data due to the nature of li...

BACKGROUND We describe online optical measurements of urea in the effluent dialysate line during regular hemodialysis treatment of several patients. Monitoring urea removal can provide valuable information about dialysis efficiency. METHODS Spectral measurements were performed with a Fourier-transform infrared spectrometer equipped with a flow-through cell. Spectra were recorded across the 50...

Golay sequences have been used extensively for constructing base sequences, Yang numbers, T-sequences, Hadamard matrices, SBIBDs and Hadamard matrices with maximum possible sums. The possibility of obtaining new Golay sequences is diminishing and only non-existence results are appearing nowadays. We introduce block Golay sequences. It turns out that every result on Golay sequences could be exte...

Five Balkan paprika varieties at physiological maturity were investigated by means of Raman spectroscopy in order to discriminate the differences which stemmed from their genetic variability since plants grown under same experimental conditions. The spectra obtained using 532 nm wavelength. In an effort find best classification power, several pre-processing methods applied: 1) baseline correcti...

Gliomas, one of the most severe malignant tumors central nervous system, have a high mortality rate and an increased risk recurrence. Therefore, early glioma diagnosis control treatment great significance. The blood plasma samples patients, patients with skull craniectomy defects, healthy donors were studied using terahertz time-domain spectroscopy (THz-TDS). An analysis experimental THz data w...