Polarization optical properties of suspended particles measurement in water by a polarized Scheimpflug lidar system.

The polarization optical properties of suspended particles in water play a pivotal role in numerical simulation or real water medium detection. Polarized multi-wavelength oceanic lidar provides an effective method for characterizing the size, shape, and concentration of suspended particles. In this paper, we present a concise and effective optical approach to measure the information in the polarization of the lidar signal with 0°, 45°, 90°, and 135° polarization angles of suspended particles by laboratory experiments based on polarized Scheimpflug lidar system.

The individualized treatment for minimally invasive repair of pectus carinatum in adolescent: a single center' s retrospective study.

Background: Pectus carinatum (PC) mainly present at the growth spurt time of the early teenage years or the puberty. Poor outer appearance is a major reason for seeking help for surgeons to increase self-confidence and self-esteem. At present, minimally invasive repair (MIR) is one of effective ways to correct the chest wall deformity.

Tunable single frequency Hz-magnitude narrow linewidth Brillouin fiber laser based on parity-time symmetry.

An Hz-magnitude ultra-narrow linewidth single-frequency Brillouin fiber laser (BFL) is proposed and experimentally demonstrated. The single frequency of the laser is selected by parity-time (PT) symmetry, which consists of a stimulated Brillouin scatter (SBS) gain path excited by a 24 km single-mode fiber (SMF) and an approximately equal length loss path tuned with a variable optical attenuator (VOA). These paths are coupled through a fiber Bragg grating (FBG) into a wavelength space.

A Time-Consistency Curriculum for Learning From Instance-Dependent Noisy Labels.

Many machine learning algorithms are known to be fragile on simple instance-independent noisy labels. However, noisy labels in real-world data are more devastating since they are produced by more complicated mechanisms in an instance-dependent manner. In this paper, we target this practical challenge of Instance-Dependent Noisy Labels by jointly training (1) a model reversely engineering the noise generating mechanism, which produces an instance-dependent mapping between the clean label posterior and the observed noisy label and (2) a robust classifier that produces clean label posteriors.

Validation of the polarized Monte Carlo model of shipborne oceanic lidar returns.

The polarized Monte Carlo (PMC) model has been applied to study the backscattering measurement of oceanic lidar. This study proposes a PMC model for shipborne oceanic lidar simulation. This model is validated by the Rayleigh scattering experiment, lidar equation, and in-situ lidar LOOP (Lidar for Ocean Optics Profiler) returns [Opt.

Research on Simultaneous Measurement of Magnetic Field and Temperature Based on Petaloid Photonic Crystal Fiber Sensor.

In this paper, we propose and design a magnetic field and temperature sensor using a novel petaloid photonic crystal fiber filled with magnetic fluid. The PCF achieves a high birefringence of more than 1.43 × 10 at the wavelength of 1550 nm via the design of material parameters, air hole shape and the distribution of the photonic crystal fiber.

Scattering direction sampling methods for polarized Monte Carlo simulation of oceanic lidar.

Monte Carlo techniques have been widely applied in polarized light simulation. Based on different preconditions, there are two main types of sampling strategies for scattering direction: one is the scalar sampling method; the others are polarized sampling approaches, including the one- and two-point rejection methods. The polarized simulation of oceanic lidar involves a variety of mediums, and an efficient scattering sampling method is the basis for the coupling simulation of the atmosphere and ocean.

A Parametrical Model for Instance-Dependent Label Noise.

In label-noise learning, estimating the transition matrix is a hot topic as the matrix plays an important role in building statistically consistent classifiers. Traditionally, the transition from clean labels to noisy labels (i.e.

Overcoming cohort heterogeneity for the prediction of subclinical cardiovascular disease risk.

Cardiovascular disease remains a leading cause of mortality with an estimated half a billion people affected in 2019. However, detecting signals between specific pathophysiology and coronary plaque phenotypes using complex multi-omic discovery datasets remains challenging due to the diversity of individuals and their risk factors. Given the complex cohort heterogeneity present in those with coronary artery disease (CAD), we illustrate several different methods, both knowledge-guided and data-driven approaches, for identifying subcohorts of individuals with subclinical CAD and distinct metabolomic signatures.

Coherent high-spectral-resolution lidar for the measurement of the atmospheric Mie-Rayleigh-Brillouin backscatter spectrum.

In this study, a 1550 nm coherent high-spectral-resolution lidar (CHSRL) is developed to measure the optical properties of aerosols and atmospheric wind profiles in the atmospheric boundary layer. To determine the optical properties, a coherent frequency discriminator based on the fast Fourier transform is designed in the CHSRL to separate the Mie and the Rayleigh-Brillouin backscatter spectra to fulfill the needs of high-spectral measurements. The atmospheric wind velocity is retrieved using the simultaneously measured Doppler shift.

Shipborne variable-FOV, dual-wavelength, polarized ocean lidar: design and measurements in the Western Pacific.

For the requirement of high-precision vertical profile of the polarization and optical properties of natural seawater, a ship-borne variable-FOV, dual-wavelength, polarized ocean lidar system is designed to obtain the volume linear depolarization ratio (VDR), color ratio and optical parameter profiles of seawater. With the high signal-to-noise ratio, which benefits from the high power (355 nm with 120 mJ, 532 nm with 200 mJ) solid-state laser and a photon counting recorder with a sampling rate of 1 GHz, the attenuated backscattered signal of seawater in the western Pacific campaign reaches to the depth of 50 m, where a plankton layer presents. The receiver of lidar is capable of switching to wide and narrow field of view (FOV), respectively, to obtain the lidar attenuation coefficient K, which is in good agreement with the beam attenuation coefficient of seawater c with a narrow FOV and diffuse attenuation coefficient K with a wide FOV.

Bridging the Gap Between Few-Shot and Many-Shot Learning via Distribution Calibration.

A major gap between few-shot and many-shot learning is the data distribution empirically oserved by the model during training. In few-shot learning, the learned model can easily become over-fitted based on the biased distribution formed by only a few training examples, while the ground-truth data distribution is more accurately uncovered in many-shot learning to learn a well-generalized model. In this paper, we propose to calibrate the distribution of these few-sample classes to be more unbiased to alleviate such an over-fitting problem.

Temperature self-calibrated pH sensor based on GO/PVA-coated MZI cascading FBG.

A temperature self-calibrated potential of hydrogen (pH) sensor based on the single mode fiber-tapered dual core photonic crystal fiber-single mode fiber (SMF-TDCPCF-SMF) structure cascaded with a fiber Bragg grating (FBG) is proposed and demonstrated. The TDCPCF structure formed Mach-Zehnder interferometer (MZI) is modified with a coating of graphene oxide/polyvinyl alcohol (GO/PVA) hybrid hydrogel to realize the measurement of pH, and the uncoated FBG is used to calibrate temperature. In our experiment, the sensitivity coefficient of 0.

Active and passive optical remote sensing of the aquatic environment: introduction to the feature issue.

Through decades of efforts and practices, we have achieved great progress in understanding ocean biology and biogeochemistry through satellite measurements of ocean (water) color, or passive remote sensing. These include detailed global maps of the distribution of surface phytoplankton, the production of newly formed particulate organic matter through photosynthesis (i.e.

Self-assisted membrane-penetrating helical polypeptides mediate anti-inflammatory RNAi against myocardial ischemic reperfusion (IR) injury.

Anti-inflammatory RNA interference (RNAi) provides a promising paradigm for the treatment of myocardial ischemia reperfusion (IR) injury. To overcome the membrane barriers against intracardial siRNA delivery, various guanidinated helical polypeptides with potent and aromaticity-assisted membrane activities were herein developed and used for the delivery of siRNA against RAGE (siRAGE), a critical regulator of the pro-inflammatory cascade. Aromatic modification of the polypeptide led to notably enhanced trans-membrane siRNA delivery efficiencies, and more importantly, allowed more siRNA cargoes to get internalized via non-endocytosis, an effective pathway toward gene transfection.

Aircraft wake vortex and turbulence measurement under near-ground effect using coherent Doppler lidar.

This paper evaluates the wake vortex characteristics using pulsed coherent Doppler lidar (PCDL) under near-ground effect (NGE). A wake vortex visualization demonstrator (V2D) is developed in order to visualize wake vortex in real-time. The combination of radial velocity distribution and FFT spectrum characterization are used to identify the core position of wake vortex.

High-sensitivity refractive index and temperature sensor based on cascaded dual-wavelength fiber laser and SNHNS interferometer.

A novel differential intensity-measurement high-sensitivity refractive index (RI) sensor based on cascaded dual-wavelength fiber laser and single-mode-no-core-hollow-core-no-core-single-mode (SNHNS) structure is proposed and demonstrated. The sensing unit consists of one uniform fiber Bragg grating (FBG) and an SNHNS structure as all-fiber interferometer filter. The dual-wavelength fiber laser has a ring cavity composed of two FBGs with central wavelengths of 1550.

Fiber ring laser based on MMF-PMFBG-MMF filter for three parameters sensing.

A dual-wavelength fiber ring laser based on multimode fiber-polarization maintaining fiber Bragg grating-multimode fiber (MMF-PMFBG-MMF) filter for simultaneously axial strain, temperature and refractive index (RI) sensing is proposed and experimentally demonstrated. In the ring laser, stable dual-wavelength lasing is determined by the MMF-PMFBG-MMF filter with two polarization states. The fiber birefringence affected by axial strain is far less than the effect of the temperature.

High sensitivity axial strain and temperature sensor based on dual-frequency optoelectronic oscillator using PMFBG Fabry-Perot filter.

A dual-frequency optoelectronic oscillator (OEO) incorporating a polarization-maintaining fiber Bragg grating (PMFBG) Fabry-Perot filter for high-sensitivity and high-speed axial strain and temperature sensing is proposed and experimentally demonstrated. In the OEO loop, two oscillation frequencies are determined by a PMFBG Fabry-Perot filter with two ultra-narrow notches and two laser sources which operate as a dual-passband microwave photonic filter. The fiber birefringence affected by axial strain is far less than the temperature.

Doppler lidar investigation of wind turbine wake characteristics and atmospheric turbulence under different surface roughness.

Four field experiments based on Pulsed Coherent Doppler Lidar with different surface roughness have been carried out in 2013-2015 to study the turbulent wind field in the vicinity of operating wind turbine in the onshore and offshore wind parks. The turbulence characteristics in ambient atmosphere and wake area was analyzed using transverse structure function based on Plane Position Indicator scanning mode. An automatic wake processing procedure was developed to determine the wake velocity deficit by considering the effect of ambient velocity disturbance and wake meandering with the mean wind direction.

Wind turbine wake visualization and characteristics analysis by Doppler lidar.

Wind power generation is growing fast as one of the most promising renewable energy sources that can serve as an alternative to fossil fuel-generated electricity. When the wind turbine generator (WTG) extracts power from the wind, the wake evolves and leads to a considerable reduction in the efficiency of the actual power generation. Furthermore, the wake effect can lead to the increase of turbulence induced fatigue loads that reduce the life time of WTGs.

Mobile multi-wavelength polarization Raman lidar for water vapor, cloud and aerosol measurement.

Aiming at the detection of atmospheric water vapor mixing ratio, depolarization ratio, backscatter coefficient, extinction coefficient and cloud information, the Water vapor, Cloud and Aerosol Lidar (WACAL) is developed by the lidar group at Ocean University of China. The lidar consists of transmitter, receiver, data acquisition and auxiliary system. For the measurement of various atmospheric physical properties, three channels including Raman channel, polarization channel and infrared channel are integrated in WACAL.

Decreased serum CA19-9 is associated with improvement of insulin resistance and metabolic control in patients with obesity and type 2 diabetes after Roux-en-Y gastric bypass.

Aims/introduction: Patients with type 2 diabetes are known to show elevated serum levels of carbohydrate antigen 19-9 (CA19-9). The aim of the present study was to investigate the possible relationships of CA19-9 with metabolic control, insulin resistance (IR), and pancreatic β-cell function in patients with obesity and type 2 diabetes who underwent Roux-En-Y gastric bypass (RYGB).

Materials And Methods: The present study included 81 healthy volunteers, and 33 patients diagnosed with obesity and type 2 diabetes who underwent RYGB.