Klausenwong7461

We aim to develop a nonintrusive, reliable, convenient flow rate measurement and leak detection method. The flow rate is known to be related to the vibration excited by the turbulent internal flow, but there exists some scatter in the vibration data at low flow speeds ( less then 2m/s) due to the resolution limits of the sensor. A customized fiber Bragg grating acceleration sensor is designed and applied to measure the low flow rate and detect leakage in the pipeline. Experimental tests show the relationship between the standard deviation of vibration data and flow rate at low velocity is quadratic; the R2 of quadratic curve fitting is 0.990. Moreover, for leak detection, selected features are used as the input of support vector machine classifiers to identify the leak in the pipeline. The results demonstrate that the proposed method achieves a high accuracy of 99.00% to determine the leak state and nonleak state.A liquid crystal variable retarder (LCVR) enables fast, automated control of retardance that can be used as a variable waveplate in polarimetric instruments. However, precise control of the polarization state requires calibration of the LCVR. A manufacturer calibration curve is typically supplied for a single specific wavelength and temperature, but for applications under different conditions, additional calibration is needed. Calibration is typically performed with crossed polarizers to generate an intensity curve that is converted to retardance, but this method is prone to noise when retardance is close to zero. Here, we demonstrate a simple common-path Sagnac interferometer to measure retardance and provide open source software for automated generation of calibration curves for retardance as a function of wavelength and voltage. We also provide a curve fitting method and closed-form functional representation that outputs the voltage needed to achieve a desired retardance given a specified wavelength.In order to provide accurate altitude information autonomously for land navigation, a self-developed one-dimensional reference-beam laser Doppler velocimeter (1D LDV) with light weight, small volume, and low cost is integrated with a strapdown inertial navigation system (SINS). The velocity sensed by the 1D LDV and the altitude output by the SINS are fused by the dead reckoning algorithm. Dynamic vehicle tests are carried out in an urban area with the altitude difference of 28 m and a mountainous area with the altitude difference of 1363 m. The horizontal positioning error and the altitude error are 10.8 m and 0.5 m in the urban area and 45.9 m and 3.6 m in the mountainous area. The experimental results illustrate that the developed SINS/1D LDV integrated navigation system is viable to provide highly accurate altitude as well as horizontal parameters in practical application.To overcome the diffraction barrier, super-resolution microscopy is contrived and has witnessed scientific developments in varying fields, especially in last few decades, such as stochastic optical reconstruction microscopy, stimulated emission depletion microscopy (STED), mirror-enhanced super-resolution microscopy (MEANS), and fluorescence emission difference microscopy (FED). Recently, saturated competition microscopy (SAC) was developed to realize high sub-diffraction resolution in either fluorescent or non-fluorescent imaging. Compared with STED, SAC features non-constraint in fluorescent dye selection. Nevertheless, the lateral resolution is limited in consideration of photobleaching side effects. Also, the axial resolution enhancement of SAC has not been demonstrated. In this study, a method, combining FED, MEANS, and SAC, is presented to improve the three-dimensional (3D) resolution. The numerical study reveals that the lateral resolution is close to 0.085λ and axial resolution can be enhanced to 0.184λ. In addition, the SNR is improved simultaneously. The availability to improve 3D resolution of SAC is believed to be significant for biological imaging in the future.We report the development of a three-dimensional optical model to predict the propagation of light through multilayer optical fluorescence sensors employing total internal reflection. The ray-tracing-based model visualizes the propagation of light from a light source through the optical sensor allowing optimization of the optical path, optical properties of the materials, and the coupling strategy. The model demonstrates how light can be guided through different layers of the sensor structure by controlling the incident angle of light and the relationship between the incident angle and the relative sensitivity. Simulation results are compared against experimental data to validate the model in a fluorescence-based dissolved oxygen sensor. Customization of the light source parameters, coupling optics, sensor optical properties, and sensor dimensions could allow developers to refine and optimize sensor prototypes before conducting bench testing.The error-diffusion dithering technique is widely used in three-dimensional (3D) measurement. The sinusoid similarity of dithering fringe patterns greatly affects measurement accuracy, while the traditional dithering methods lack this quality. In this paper, we present a kernel-optimized dithering technique based on the Floyd-Steinberg dithering method and establish an optimization strategy considering both intensity and phase aspects to generate high-quality sinusoidal fringes for 3D measurement by utilizing the binary defocusing technique. Both simulations and experiments demonstrate that the proposed method could improve the performance of 3D measurement effectively under different defocusing amounts, especially in narrow strips.Aiming at the problem of uneven distribution of receiving illuminance and optical power on the receiving plane of the visible light communication (VLC) system, this paper proposes a light source optimization method based on an improved bat algorithm (IBA). Taking the rectangular and hybrid layouts with 16 light-emitting diodes (LEDs), as examples, we set the variance of received light power on the receiving plane as the fitness function. By redesigning the speed update method and local search method of the traditional bat algorithm (BA), the IBA is used to optimize the LED half-power angle and LED position that affect the system performance. check details The simulation results show that, considering the primary reflection of the wall, the method can reduce the received illumination and optical power fluctuation of the receiving plane within a limited number of iterations under different light source layout schemes.