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Additional file 1: Figure S1. Associations between L-carnitine and the risk of gestational diabetes mellitus (GDM) in Chinese women.

We report a deep learning-based virtual image refocusing method that utilizes double-helix point-spread-function (DH-PSF) engineering and a cascaded neural network model, termed W-Net. This method can virtually refocus a defocused fluorescence image onto an arbitrary axial plane within the sample volume, enhancing the imaging depth-of-field and lateral resolution at the same time. We demonstrated the efficacy of our method by imaging fluorescent nano-beads at various defocus distances, and also quantified the nano-particle localization performance achieved with our virtually-refocused images, demonstrating ~20-fold improvement in image depth-of-field over wide-field microscopy, enabled by the combination of DH-PSF and W-Net inference.

This paper proposes a nonlinear H_infinity controller for stabilization of velocities, attitudes and angular rates of a fixed-wing unmanned aerial vehicle (UAV) in a windy environment. The suggested controller aims to achieve a steady-state flight condition in the presence of wind gusts such that the host UAV can be maneuvered to avoid collision with other UAVs during cruise flight with safety guarantees. This paper begins with building a proper model capturing flight aerodynamics of UAVs. Then a nonlinear controller is developed with gust attenuation and rapid response properties. Simulations are conducted for the Shadow UAV to verify performance of the proposed con- troller. Comparative studies with the proportional-integral-derivative (PID) controllers demonstrate that the proposed controller exhibits great performance improvement in a gusty environment, making it suitable for integration into the design of flight control systems for cruise flight of UAVs.

This paper outlines a feasible scheme to extract deck trend when a rotary-wing unmanned aerial vehicle (RUAV)approaches an oscillating deck. An extended Kalman filter (EKF) is de- veloped to fuse measurements from multiple sensors for effective estimation of the unknown deck heave motion. Also, a recursive Prony Analysis (PA) procedure is proposed to implement online curve-fitting of the estimated heave mo- tion. The proposed PA constructs an appropriate model with parameters identified using the forgetting factor recursive least square (FFRLS)method. The deck trend is then extracted by separating dominant modes. Performance of the proposed procedure is evaluated using real ship motion data, and simulation results justify the suitability of the proposed method into safe landing of RUAVs operating in a maritime environment.

This paper presents a nonlinear gust-attenuation controller to stabilize velocities, attitudes and angular rates of a fixed-wing unmanned aerial vehicle (UAV) in the presence of wind gusts. The proposed controller aims to achieve a steady-state flight condition such that the host UAV can avoid airspace collision with other UAVs during the cruise flight. Based on the typical UAV model capturing flight aerodynamics, a nonlinear Hinf controller is developed with rapid response property in consideration of actuator constraints. Simulations are conducted for the Shadow UAV to verify performance of the proposed controller. Comparative studies with the proportional-integral derivative (PID) controllers demonstrate that the proposed controller exhibits great performance improvement in a gusty environment, making it suitable for integration into the design of flight control systems for cruise flight with safety guarantees.

Rotary-wing unmanned aerial vehicles (RUAVs) have created extensive interest in the past few decades due to their unique manoeuverability and because of their suitability in a variety of flight missions ranging from traffic inspection to surveillance and reconnaissance. The ability of a RUAV to operate from a ship in the presence of adverse winds and deck motion could greatly extend its applications in both military and civilian roles. This requires the design of a flight control system to achieve safe and reliable automatic landings. Although ground-based landings in various scenarios have been investigated and some satisfactory flight test results are obtained, automatic shipboard recovery is still a dangerous and challenging task. Also, the highly coupled and inherently unstable flight dynamics of the helicopter exacerbate the difficulty in designing a flight control system which would enable the RUAV to attenuate the gust effect. This thesis makes both theoretical and technical contributions to the shipboard recovery problem of the RUAV operating in rough seas. The first main contribution involves a novel automatic landing scheme which reduces time, cost and experimental resources in the design and testing of the RUAV/ship landing system. The novelty of the proposed landing system enables the RUAV to track slow-varying mean deck height instead of instantaneous deck motion to reduce vertical oscillations. This is achieved by estimating the mean deck height through extracting dominant modes from the estimated deck displacement using the recursive Prony Analysis procedure. The second main contribution is the design of a flight control system with gust-attenuation and rapid position tracking capabilities. A feedback-feedforward controller has been devised for height stabilization in a windy environment based on the construction of an effective gust estimator. Flight tests have been conducted to verify its performance, and they demonstrate improved gust-attenuation capability in the RUAV. The proposed feedback-feedforward controller can dynamically and synchronously compensate for the gust effect. In addition, a nonlinear H1 controller has been designed for horizontal position tracking which shows rapid position tracking performance and gust-attenuation capability when gusts occur. This thesis also contains a description of technical contributions necessary for a real-time evaluation of the landing system. A high-infedlity simulation framework has been developed with the goal of minimizing the number of iterations required for theoretical analysis, simulation verification and flight validation. The real-time performance of the landing system is assessed in simulations using the C-code, which can be easily transferred to the autopilot for flight tests. All the subsystems are parameterized and can be extended to different RUAV platforms. The integration of helicopter flight dynamics, flapping dynamics, ship motion, gust effect, the flight control system and servo dynamics justifies the reliability of the simulation results. Also, practical constraints are imposed on the simulation to check the robustness of the flight control system. The feasibility of the landing procedure is confimed for the Vario helicopter using real-time ship motion data.

In order to achieve the objective and exact classification of the traditional Chinese medicine pulse- conditions, a pulse-condition recognition method based on BP neural network has been successfully developed. The influence of concealed layer node number on convergent speed and recognition accuracy and the influence of learning rate on convergent speed are considered. The BP network-training algorithm is improved, which obtains satisfactory network convergent error and recognition effect. The recognition tests of many pulse-condition samples indicate that our method works well in classifying the traditional Chinese medicine pulse- conditions accurately and quickly.

In this paper a new type of shape meter to measure the flatness of hot strip steel at the exit of the finishing mill is introduced. The meter consists of 7/spl times/3 laser diodes, a TV camera and an image processing system operated by a 486 microprocessor. The seven groups of three beams incident on the hot strip forming 21 bright spots captured by a CCD camera construct the measuring system. With the help of the detecting model developed by the writers, the values of height and flatness are then obtained. The accuracy of height measurement is identified to be /spl plusmn/1 mm. The flatness measured online by the meter has been calibrated by the Steel Plate Co. Ltd, of Pangang.

An image processing system of a shape meter for a hot strip mill is developed. The image processing system consists of a TV camera and its related software. The system can process the projected image illuminated by n/spl times/3 bright spots on the strip captured by the camera. The processing includes image enhancement, image window collection, binarization, image edge detection, distinguishing of laser spots, and the calculation of the spot positions. The values of height and flatness (elongation index) are then obtained online by the computer.