Current wideband frequency-modulated continuous-wave (FMCW) radar fails in detecting long-distance target, since only the target whose echo is temporally close to the reference linear frequency modulation (LFM) chirp can be detected. We propose a long-distance target detection method for the wideband FMCW radar based on photonic chirp pulse stitching. The stitching photonic chirp pulse that is generated through optical up- and downconversion of the LFM is employed as local signal for the de-chirping process instead of the LFM itself, as currently used.
View Article and Find Full Text PDFIn this work, a series of thermosensitive ionic liquid functionalized polymers, PN(IL), with controllable morphology and particle size were prepared by free radical polymerization. Then, using the polymer PN(IL) with uniform morphology as a templating agent, the ZnO composite photocatalytic materials doped with rare earth metal Ce were prepared in combination with a microwave-assisted and templated hydrothermal reaction method. Series different Ce-doping amount photocatalytic materials ZnO-Ce-x‱ were characterized by XRD, SEM, TEM, XPS, and other methods.
View Article and Find Full Text PDFSci Total Environ
September 2024
Spatially explicit population data is critical to investigating human-nature interactions, identifying at-risk populations, and informing sustainable management and policy decisions. Most long-term global population data have three main limitations: 1) they were estimated with simple scaling or trend extrapolation methods which are not able to capture detailed population variation spatially and temporally; 2) the rate of urbanization and the spatial patterns of settlement changes were not fully considered; and 3) the spatial resolution is generally coarse. To address these limitations, we proposed a framework for large-scale spatially explicit downscaling of populations from census data and projecting future population distributions under different Shared Socio-economic Pathways (SSP) scenarios with the consideration of distinctive changes in urban extent.
View Article and Find Full Text PDFWe propose an ultra-wideband photonic compressive receiver based on random codes shifting with image-frequency distinction. By shifting the center frequencies of two random codes in large frequency range, the receiving bandwidth is flexibly expanded. Simultaneously, the center frequencies of two random codes are slightly different.
View Article and Find Full Text PDFInfluenza A virus (IAV) is an endemic respiratory pathogen affecting swine worldwide and is a public health concern as a zoonotic pathogen. Veterinarians may respond to IAV infection in swine with varied approaches depending on their perception of its economic impact on human and animal health. This study considered three primary veterinary practice categories: swine exclusive veterinary practitioner, large animal practitioner, which corresponds to veterinarians that work predominantly with food animals including but not exclusively porcine, and mixed animal practitioner, which corresponds to veterinarians working with companion and food animals.
View Article and Find Full Text PDFPurpose: Harmonization of assessment methods represents an ongoing challenge in physical activity research. Previous research has demonstrated the utility of calibration approaches to enhance agreement between measures of physical activity. The present study utilizes a calibration methodology to add behavioral context from the Global Physical Activity Questionnaire (GPAQ), an established report-based measure, to enhance interpretations of monitor-based data scored using the novel Monitor Independent Movement Summary (MIMS) methodology.
View Article and Find Full Text PDFExisting photonic compressive receivers have the problem of resolution deterioration when applied in wide-range radar detection. In this study, we propose a photonic-assisted space-frequency two-dimensional (2D) compressive radar receiver capable of achieving high-resolution detection in wide-range scenarios. For the space dimension, the compression process is realized by employing a spatially adaptive photonic projection basis, which guarantees complete mapping of arbitrarily delayed echoes-the key to high-resolution wide-range detection.
View Article and Find Full Text PDFBackground: Although it is recognized that dynamic stereopsis is vital in daily life, there is still room for improvement in assessment methods. A novel clinical dynamic stereopsis assessment method was created based on an autostereoscopic display system that did not require additional auxiliary glasses. This study evaluated the optical parameters and clinical performance of the autostereoscopic display system for clinical dynamic stereopsis assessment.
View Article and Find Full Text PDFMany large-scale surveys collect both discrete and continuous variables. Small-area estimates may be desired for means of continuous variables, proportions in each level of a categorical variable, or for domain means defined as the mean of the continuous variable for each level of the categorical variable. In this paper, we introduce a conditionally specified bivariate mixed-effects model for small-area estimation, and provide a necessary and sufficient condition under which the conditional distributions render a valid joint distribution.
View Article and Find Full Text PDFSpatial generalized linear mixed models (SGLMMs) are popular models for spatial data with a non-Gaussian response. Binomial SGLMMs with logit or probit link functions are often used to model spatially dependent binomial random variables. It is known that for independent binomial data, the robit regression model provides a more robust (against extreme observations) alternative to the more popular logistic and probit models.
View Article and Find Full Text PDFBackground: Synoptic circulation patterns (large-scale tropospheric motion systems) affect air pollution and, potentially, air-pollution-morbidity associations. We evaluated the effect of synoptic circulation patterns (air masses) on the association between ozone and hospital admissions for asthma and myocardial infarction (MI) among adults in North Carolina.
Methods: Daily surface meteorology data (including precipitation, wind speed, and dew point) for five selected cities in North Carolina were obtained from the U.