With rapid advances of solar blind ultraviolet LED and detecting technology in recent years, communication gradually becomes a research hotspot due to its inherent advantages: low background noise, non-line-of-sight(NLOS) good secrecy. The strong scattering characteristics atmospheric render waveband the ideal choice for achieving NLOS optical communication. This paper reviews history status both China abroad, especially introduces three main issues communication: channel model, system...

Monte-Carlo models are analyzed for multiple scattering channels in optical wireless communications. It is demonstrated that the system impulse response function can be obtained by integration model. The convergence performance model and improved introducing different sampling methods. simulation results show gamma channel only applied to cases where common volume between transmitted light beam receiving field-of-view open. Numerical suggests a three-order case, computation efficiency of...

A fast computer-generated hologram (CGH) generation method for three-dimensional point cloud models is proposed. The points of the model are classified into parallel two-dimensional layers after a layer spacing δz set. Then, CGH can be calculated by layer-based method. In addition, simple approach occlusion culling introduced. computation time reduced thousands times compared to point-based Discussion results show that proposed more effective larger models, and with huge number points,...

The study on short-range ultraviolet communication (UVC) channel modeling is often based prolate-spheroidal coordinate system in the previous studies. In this letter, we propose a single scattering coplanar model spherical system, where transmitter beam and receiver field of view (FOV) can point arbitrarily under limitation that sum transceiver elevation angles half their own FOV less than 180°, are above ground. We utilize number intersections between special ray cone conical surface to...

Multimode fiber (MMF) is extensively studied for its ability to transmit light modes in parallel, potentially minimizing optical size imaging. However, current research predominantly focuses on grayscale imaging, with limited attention color studies. Existing colorization methods often involve costly white lasers or multiple sources, increasing system expenses and space. To achieve wide-field images typical monochromatic illumination MMF imaging system, we proposed a data-driven...

The resolution of a lensless on-chip microscopy system is constrained by the pixel size image sensors. This Letter introduces super-resolution based on compact array light source illumination and sub-pixel shift search. utilizes closely spaced composed four RGB LED modules, sequentially illuminating sample. A search algorithm proposed, which determines comparing frequency captured low-resolution holograms. Leveraging this shift, reconstruction introduced, building upon multi-wavelength phase...

Lens-free on-chip microscopy with RGB LEDs (LFOCM-RGB) provides a portable, cost-effective, and high-throughput imaging tool for resource-limited environments. However, the weak coherence of limits high-resolution imaging, luminous surfaces LED chips on do not overlap, making coherence-enhanced executions tend to undermine portable cost-effective implementation. Here, we propose specially designed pinhole array enhance in It modulates three-color beams from separately so that effectively...

High-resolution pixel LED headlamps are lighting devices that can produce high-resolution light distribution to adapt road and traffic conditions, intelligently illuminate areas, assist drivers. Due the complexity of roads functional diversity LEDs safety has come into question is subject in-depth research conducted by car manufacturers regulators. We summarize current possible functions analyze ways in which they could be improved. This paper also discusses prospect new technologies future.

The study on multiple scattering propagation of non-line-of-sight ultraviolet communication is based the stochastic Monte Carlo method in previous studies. In this letter, an integral model two-order and three-order deduced a narrow beam case. A prolate-spheroidal coordinates system isotropic hypothesis are used to simplify model. Compared with method, computational efficiency stability proposed much better do not decrease increase range. This letter provides new way obtain path loss long ranges.

We demonstrate a lensless imaging system with edge-enhanced constructed Fresnel zone aperture (FZA) mask placed 3 mm away from CMOS sensor. propose vortex back-propagation (vortex-BP) and amplitude vortex-BP algorithms for the FZA-based to remove noise achieve fast reconstruction of high contrast edge enhancement. Directionally controlled anisotropic enhancement can be achieved our proposed superimposed algorithm. With different algorithms, amp-vortex edge-camera in this paper 2D bright...

Controlled Environmental Agriculture (CEA) has gained a lot of attention in recent years, mainly because its ability to overcome extreme weather problems and ensure food safety. CEA can meet the full growth state monitoring crop period; however, optimization growing environment is still limited by algorithm defects. In this article, we present an method based on reinforcement learning, Q-learning time-series prediction model Informer. This approach demonstrated for first time as far know. By...

The single-scattering model for short-range ultraviolet (UV) communication is often replaced by an approximate due to its simplified calculation. However, there are certain errors associated with the existing models. To reduce errors, a spherical crown (SC) in narrow beam case derived this letter, where we assume that differential volume thin layer of SC. Meanwhile, applicable conditions and error range SC provided. calculation results indicate models from -1.4 6.0 dB while those -0.2 0.4...

Feature detection of strawberry multi-type defects and the ripeness stage faces huge challenges because color diversity visual similarity. Images from hyperspectral near-infrared (NIR) information sources are also limited by their low spatial resolution. In this study, an accurate RGB image (with a resolution 2048×1536 pixels) NIR (ranging 700–1100 nm in wavelength, covering 146 bands, with 696×700 fusion method was proposed to improve features strawberries. This based on pretrained VGG-19...

With the rapid development of computer hardware and emergence parallel calculation diffraction fields, a breakthrough has been made in terms limitation unacceptable amount computational cost to design diffractive optical elements (DOEs), more accurate global search algorithms can be introduced complex DOEs holographic projections instead traditional iterative algorithms. In this paper, hybrid algorithm which combines particle swarm optimization (PSO) with simulated annealing (SA) is proposed...

Digital holography has been widely applied in quantitative phase imaging (QPI) for monolayer objects within a limited depth. For multilayer imaging, compressive sensing is employed to eliminate defocused images but with missing information. A iteratively enhanced (PIE-CS) algorithm proposed achieve and simultaneously. Linear filtering first the off-axis hologram Fourier domain, an intermediate reconstructed complex image obtained. periodic mask then superimposed on recover object The...

In crop cultivation, particularly in controlled environmental agriculture, light quality is one of the most critical factors affecting growth and harvest. Many scholars have studied effects on strawberry traits, but they used relatively simple components considered only a small number qualities traits each experiment, results were not complete or objective. order to comprehensively investigate different from 350 nm 1000 better predict future trend strawberries under qualities, we proposed...

Unmanned aerial vehicle (UAV) ultraviolet (UV) communication has garnered significant attention due to its broad range of applications. Currently, there are few decoding algorithms specifically tailored for UAV UV multiple-input-single-output (MISO) scenarios. We propose an enhanced maximum a posteriori (MAP) and log-likelihood ratio belief propagation (LLRBP) algorithm MISO systems. This strategically ranks interference signals based on the signal-to-interference plus noise (SINR),...

A new double-layer sunlight concentration system, where each layer is divided into two regions, proposed, and the system has four volume holograms. Since holograms convert light in different directions, interlayer crosstalk reduced, a high ratio. The simulation results show that can achieve 30° operation angle range. are fabricated on photopolymer substrates, left half of implemented using characteristics assessed. agreement experimental diffraction efficiency validates proposed method....

With the rapid development and application of CRFs (Conditional Random Fields) in computer vision, many researchers have made some outstanding progress this domain because solve classical version label bias problem with respect to MEMMs (maximum entropy Markov models) HMMs (hidden models). This paper reviews research status object recognition especially introduces two main discrete optimization methods for image labeling CRFs: graph cut mean field approximation. describes briefly while it...

The existing ultraviolet (UV) single scattering models do not incorporate the applicability of transceiver geometry, which makes them have certain errors even in short-range cases. To solve this issue, we propose a model Letter, is suitable for case where field view above ground. This meets requirements general UV communication. For tractable analysis, utilize number intersections between special rays on cone to classify communication scenarios. Calculation results show that when elevation...