In signal approximation, classical wavelet synthesis are known to produce Gibbs-like phenomenon around discontinuities when wavelet coefficients in the cone of influence of the discontinuities are quantized. By analyzing a function in a piecewise manner, filtering across discontinuities can be avoided. Using this principle, the interval wavelet transform can generate sparser representations in the vicinity of discontinuities than classical wavelet transforms. This work introduces two new constructions of interval wavelets and shows how they can be used for image compression and upscaling.
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http://dx.doi.org/10.1109/tip.2006.884950 | DOI Listing |
BMC Med Imaging
December 2024
Department of Radiology, Peking University First Hospital, 8, Xishiku Street, Xicheng District, Beijing, 100034, China.
Background: The apparent diffusion coefficient (ADC) has been reported as a quantitative biomarker for assessing the aggressiveness of upper urinary tract urothelial carcinoma (UTUC), but it has typically been used only with mean ADC values. This study aims to develop a radiomics model using ADC maps to differentiate UTUC grades by incorporating texture features and to compare its performance with that of mean ADC values.
Methods: A total of 215 patients with histopathologically confirmed UTUC were enrolled retrospectively and divided into training and test sets.
Sci Rep
December 2024
Henan University of Engineering, Zhengzhou, 451191, China.
Social media generates vast amounts of spatio-temporal sequential data. However, current methods often ignore the complex spatio-temporal correlations within these data. This oversight makes it difficult to fully capture the dynamic features of the data.
View Article and Find Full Text PDFJ Sports Sci
December 2024
Faculty of Kinesiology and Health Studies, University of Regina, Regina, SK, Canada.
Assessment of cerebral oxygenation during repeated squat stands following an acute sport-related concussion (SRC) has the potential to identify physiological changes following SRC. All varsity university athletes completed a pre-season assessment and 53 were followed up within 5-days of suffering an SRC. Of the 53 participants, 29 had continuous beat-to-beat blood pressure (BP; sampled at 200 hz) collected by finger photoplethysmography, and 53 had right prefrontal cortex oxygenation collected by near-infrared spectroscopy (NIRS; sampled at 10 hz).
View Article and Find Full Text PDFRapid and precise forecasting of dynamical systems is critical to ensuring safe aerospace missions. Previous forecasting research has primarily concentrated on global trend analysis using full-scale inputs. However, time series arising from real-world applications such as aerospace propulsion, exhibit a distinct dynamical periodicity over a limited timeframe.
View Article and Find Full Text PDFWater Sci Technol
November 2024
College of Economics and Management, Shanghai Ocean University, Shanghai 201306, China.
This study proposes a novel approach for predicting variations in water quality at wastewater treatment plants (WWTPs), which is crucial for optimizing process management and pollution control. The model combines convolutional bi-directional gated recursive units (CBGRUs) with adaptive bandwidth kernel function density estimation (ABKDE) to address the challenge of multivariate time series interval prediction of WWTP water quality. Initially, wavelet transform (WT) was employed to smooth the water quality data, reducing noise and fluctuations.
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