Session Index

We propose a non-destructive surface contour measurement system with the advantages of rapid measurement and low cost. It utilizes a uniform light source to measure the curvature of unknown lenses. By projecting fringe patterns onto a scattering screen and analyzing the reflected image, the system accurately determines the object's surface deviation (SAG). In the experimental results, we successfully reconstructed surface information, affirming the system's potential feasibility for practical applications. The system's non-destructive nature and accurate measurement capabilities make it a promising tool for enhancing surface inspection processes.

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Zirconia, commonly used in dentures, is prone to staining. In this study, we introduced specific grid patterns on zirconia surfaces using femtosecond laser texturing, aiming to enhance its hydrophobicity. While untreated zirconia exhibited hydrophilic tendencies, our laser-textured designs, especially with a 0.012 mm spacing grid, achieved contact angles up to 140°. This represents a great potential for laser texturing to enhance liquid stain resistance in zirconia-based dentures.

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This study delves into the optical and dielectric properties of the optical adhesive NOA65 impregnated with methyl red (MR) at various concentrations. Photoisomerization behavior of the azo dye MR upon ultraviolet (UV) exposure influences its optical and dielectric characteristics. By adjusting MR concentrations, control over absorption and emission spectra is achieved. Dielectric analysis reveals intriguing redshift and blueshift tendencies, impacted by temperature and MR content. Exposure to UV induces the trans-to-cis isomerization, affecting dielectric relaxation frequencies. This comprehensive exploration sheds light on the complex interplay between MR doping, UV exposure, and dielectric behavior in NOA65, offering insights into potential

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Model predictive control (MPC), a potent model-based technique for autonomous vehicle path following, often grapples with computational constraints due to model linearization. In this study, we address this challenge by introducing a long short-term memory (LSTM) approach to estimate the dynamic model of the unmanned ground vehicle (UGV). This LSTM-based formulation captures the UGV’s behavior within a state-space linear dynamic model. Integrating LSTM with MPC yields notable enhancements, particularly in S-curve and L-shape path-following scenarios. By mitigating the computational demands of traditional linearization, our approach shows promise in real-time implementations for optimized tracked vehicle trajectory tracking.

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Deep reinforcement learning relies on solid mathematical principles and fine-tunes network parameters through interactions with the environment. In this study, the trajectory tracking and obstacle avoidance of field tracked vehicles are conducted by the soft actor-critic (SAC) agent designed with the deep-neural-network-based model predictive control (MPC). The synergy between SAC and MPC enhances adaptability and performance, enabling successful navigation in demanding scenarios.

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Bistable switching is a common technique in conventional cholesteric liquid crystals (CLCs). However, our research team has previously discovered the interaction between the dielectric and the electrohydrodynamic (EHD) effects in ion-doped cholesteric liquid crystals. In this study, the influence of EHD and dielectric effects are investigated under different frequencies, electric fields and cell gaps. Based on the obtained results, the bistable optical performance of devices fabricated by ion-doped cholesteric liquid crystals can be further optimized.

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In this study, a simple manufacturing process LC grating sample is provided. The substrate of this sample is a hexagonal substrate formed by arraying microbeads, and then a vertically aligned liquid crystal grating is fabricated using this substrate. Research shows that when unpolarized light is incident, the electrically controllable grating sample can change the intensity of diffraction and change the polarization of diffraction by changing the input voltage.

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The interferometry is often adopted for optical quality inspection of high precision demand catadioptric telescopes which could be used to measure the wavefront of optical system. However, vast majority of catodioptric telescopes are comprised of plural lenses and these lenses are usually closed to the image plane which may easily produce the ghost fringes during the interferometry and affect the wavefront measurement result. In order to resolve this problem, an investigation for figuring out where the ghost fringe coming from will be illustrated and a crucial optical parameter for reducing the disturbance from ghost fringe will be discussed.

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