Reflector Design Method for Rotational Uniform Illuminance System with LED

Based on nonimaging design method, uniform illuminance systems with LED source were developed to create a uniform illuminated circular region with a desired size in a screen at a prescribed place. By using ray-tracing software based on Monte-Carlo method, the simulation results show that in the illuminated region the luminous uniformity is higher than 90%.

Distributed Intelligent Lighting System by Performing New Model for Illuminance and Color Temperature in the Workplace

A new approach has been proposed to improve the performance of the in-telligent lighting system by estimating personal illuminance and desired color temperature at the workplace. We are considering the problem of using the sensing devices manually for the intelligent lighting system. The lighting control system has not become useful without sensing devices to measure the provided illuminance and color temperature. In this paper, we have used the property of light for the color temperature to estimate the level of color temperature for each user at the workplace. The new method will give personal illuminance for each user at the workplace and decrease the power consumption of the environment as well. As a result, the proposed method of the intelligent lighting system has realized the target of illuminance and color temperature for each user at the workplace by adapting dimming levels using illuminance sensing information for each user. Thus, the energy of the workplace has reduced by using a distributed luminance to realize the target for each user.

Comparison of Illuminance in Different Environments: A Case Study on Subway Stations

With urbanization and the rapid development of social economy,China’s rail transit industry has developed rapidly in recent years.In order to alleviate the pressure of road network,subways provide convenience as they are fast and space-saving.Subway stations are major energy consumers of urban power grid due to their large traffic volume and long operation time.On the premise of ensuring operation safety,reducing the energy consumption of subway helps in energy conservation and emission reduction as proposed in the 13th Five-Year Plan.According to the statistics of the energy-saving evaluation report of rail transit engineering,the lighting system accounts for 20%-30%of the total power consumption of the subway station.Due to the single lighting control mode of the lighting system in the subway station,the actual station illumination cannot be reported and adjusted in time,resulting in the waste of lighting energy and high power consumption of the system.Through in-depth research on the intelligent lighting system of subway station,this paper improves the system control,and finally summarizes the optimization scheme of subway station lighting design which can effectively save the power consumption of lighting system.The main contents of this paper are as follows:The research results of this paper can provide effective measures for energy saving of electric lighting in subway stations and reduce electric energy consumption;on the other hand,as an integral part of building lighting energy-saving system,it also has certain guiding significance for the research of building lighting energy-saving.

Influence of Illuminance on the Observed Order of Reaction of Photodegradation of Nitrofurazone Solution

The relationship between the observed order of reaction of photodegradation of nitrofurazone solution and the illuminance of incident light as well as the concentration of the solution was studied, In the studies, the solutions of three concentrations were exposed to light with three different illuminance values, respectively, The results indicated that the observed order of reaction was increased with the decrease of concentration, when the illuminance was kept constant, and with the increase of illuminance when the concentration was kept constant. The observed order of reaction of photodegradation of nitrofurazone solution depended on both the concentration of the drug and the illuminance of the incident light.

Design optimisation of mean room surface exitance and total corneal illuminance using Monte Carlo simulation

In lighting design,mean room surface exitance(MRSE)has been known as an indicator of the adequacy of illumination in an indoor space.Recent studies have suggested an exponential model relating MRSE and the observer’s retinal response.This is particularly applicable in a room with homogenous room surface reflectance and a constant total corneal illuminance,which is the total illuminance received at the eye.However,accuracy of the exponential model is yet to be assessed in detail.Furthermore,the implication on interior lighting design is also yet to be quantified.This study thus aims to assess the accuracy of the exponential model and to optimise the output variables.Random computations using Monte Carlo simulation are performed for various input variables,followed with sensitivity and uncertainty analyses and optimisation.Prediction errors of the exponential model are found between-10%and 6%.The MRSE is highly influenced by surface reflectance,whereas the total corneal illuminance is influenced by the source luminous flux.Optimum design parameters are obtained by minimising the ratio between total corneal illuminance and MRSE.Overall,this study provides guidelines in lighting design practice for enhancing room spatial brightness while minimising energy use.

The effects of light illuminance and correlated color temperature on mood and creativity

The lighting environment is one of the indoor environmental factors that may influence creativity.The combined effects of illumination(300 lx vs.2000 lx)and color temperature(3000 K vs.6000 K)on mood and creativity were investigated in 24 participants.During exposure,participants completed questionnaires to assess their mood and lighting perceptions,performed creative and analytical tasks,and collected saliva samples for analysis of melatonin concentration.An interactive effect of illuminance and color temperature on the mood was observed.The participants performed better on the performance of Flexibility,Fluency and Originality in the verbal creative task when they expressed higher positive mood(at 2000 lx,6000 K and 300 lx,3000 K)and performed better on the performance of Resistance to closure in the figural creative task when they reported the lowest positive mood(at 2000 lx,3000 K).Analytical thinking,including calculation and echoic memory skills,was facilitated at the lighting setting(300 lx,6000 K)that induced the least affective intensity.No significant difference in melatonin concentration was observed.This evidence implies that the affective state of the occupants was influenced by light and that their creative performance was altered accordingly.These findings will help to elaborate a design guideline on the lighting environment according to the specific needs of different tasks.

Effects of unit size on current density and illuminance of micro-LED-array

A 300 μm×300 μm light emitting diode(LED) chip is divided into nine 80 μm×80 μm units with 30 μm spacing between adjacent ones. After arraying, the total saturation light output power and the maximum injection current are enhanced by 5.19 times and nearly 7 times, respectively. In addition, the test results demonstrate that the illuminance uniformity on the receiving surface reaches the optimum when the spacing between the arrays is equal to the maximum flat condition. The larger the number of arrays, the greater the area with uniform illuminance on the receiving surface.

Estimation-free spatial-domain image reconstruction of structured illumination microscopy

Structured illumination microscopy(SIM)achieves super-resolution(SR)by modulating the high-frequency information of the sample into the passband of the optical system and subsequent image reconstruction.The traditional Wiener-filtering-based reconstruction algorithm operates in the Fourier domain,it requires prior knowledge of the sinusoidal illumination patterns which makes the time-consuming procedure of parameter estimation to raw datasets necessary,besides,the parameter estimation is sensitive to noise or aberration-induced pattern distortion which leads to reconstruction artifacts.Here,we propose a spatial-domain image reconstruction method that does not require parameter estimation but calculates patterns from raw datasets,and a reconstructed image can be obtained just by calculating the spatial covariance of differential calculated patterns and differential filtered datasets(the notch filtering operation is performed to the raw datasets for attenuating and compensating the optical transfer function(OTF)).Experiments on reconstructing raw datasets including nonbiological,biological,and simulated samples demonstrate that our method has SR capability,high reconstruction speed,and high robustness to aberration and noise.

High-speed autopolarization synchronization modulation three-dimensional structured illumination microscopy

In recent years,notable progress has been achieved in both the hardware and algorithms of structured illumination microscopy(SIM).Nevertheless,the advancement of three-dimensional structured illumination microscopy(3DSIM)has been impeded by challenges arising from the speed and intricacy of polarization modulation.We introduce a high-speed modulation 3DSIM system,leveraging the polarizationmaintaining and modulation capabilities of a digital micromirror device(DMD)in conjunction with an electrooptic modulator.The DMD-3DSIM system yields a twofold enhancement in both lateral(133 nm)and axial(300 nm)resolution compared to wide-field imaging and can acquire a data set comprising 29 sections of 1024 pixels×1024 pixels,with 15 ms exposure time and 6.75 s per volume.The versatility of the DMD-3DSIM approach was exemplified through the imaging of various specimens,including fluorescent beads,nuclear pores,microtubules,actin filaments,and mitochondria within cells,as well as plant and animal tissues.Notably,polarized 3DSIM elucidated the orientation of actin filaments.Furthermore,the implementation of diverse deconvolution algorithms further enhances 3D resolution.The DMD-based 3DSIM system presents a rapid and reliable methodology for investigating biomedical phenomena,boasting capabilities encompassing 3D superresolution,fast temporal resolution,and polarization imaging.

Tomato detection method using domain adaptive learning for dense planting environments

This study aimed to address the challenge of accurately and reliably detecting tomatoes in dense planting environments,a critical prerequisite for the automation implementation of robotic harvesting.However,the heavy reliance on extensive manually annotated datasets for training deep learning models still poses significant limitations to their application in real-world agricultural production environments.To overcome these limitations,we employed domain adaptive learning approach combined with the YOLOv5 model to develop a novel tomato detection model called as TDA-YOLO(tomato detection domain adaptation).We designated the normal illumination scenes in dense planting environments as the source domain and utilized various other illumination scenes as the target domain.To construct bridge mechanism between source and target domains,neural preset for color style transfer is introduced to generate a pseudo-dataset,which served to deal with domain discrepancy.Furthermore,this study combines the semi-supervised learning method to enable the model to extract domain-invariant features more fully,and uses knowledge distillation to improve the model's ability to adapt to the target domain.Additionally,for purpose of promoting inference speed and low computational demand,the lightweight FasterNet network was integrated into the YOLOv5's C3 module,creating a modified C3_Faster module.The experimental results demonstrated that the proposed TDA-YOLO model significantly outperformed original YOLOv5s model,achieving a mAP(mean average precision)of 96.80%for tomato detection across diverse scenarios in dense planting environments,increasing by 7.19 percentage points;Compared with the latest YOLOv8 and YOLOv9,it is also 2.17 and 1.19 percentage points higher,respectively.The model's average detection time per image was an impressive 15 milliseconds,with a FLOPs(floating point operations per second)count of 13.8 G.After acceleration processing,the detection accuracy of the TDA-YOLO model on the Jetson Xavier NX development board is 90.95%,the mAP value is 91.35%,and the detection time of each image is 21 ms,which can still meet the requirements of real-time detection of tomatoes in dense planting environment.The experimental results show that the proposed TDA-YOLO model can accurately and quickly detect tomatoes in dense planting environment,and at the same time avoid the use of a large number of annotated data,which provides technical support for the development of automatic harvesting systems for tomatoes and other fruits.

Ultracompact and high-efficiency liquid-crystalon-silicon light engines for augmented reality glasses

In lightweight augmented reality(AR)glasses,the light engines must be very compact while keeping a high optical efficiency to enable longtime comfortable wearing and high ambient contrast ratio.“Liquid-crystal-on-silicon(LCoS)or micro-LED,who wins?”is recently a heated debate question.Conventional LCoS system is facing tremendous challenges due to its bulky illumination systems;it often incorporates a bulky polarizing beam splitter(PBS)cube.To minimize the formfactor of an LCoS system,here we demonstrate an ultracompact illumination system consisting of an in-coupling prism,and a light guide plate with multiple parallelepiped extraction prisms.The overall module volume including the illumination optics and an LCoS panel(4.4-μm pixel pitch and 1024x1024 resolution elements),but excluding the projection optics,is merely 0.25 cc(cm3).Yet,our system exhibits an excellent illuminance uniformity and an impressive optical efficiency(36%–41%for a polarized input light).Such an ultracompact and high-efficiency LCoS illumination system is expected to revolutionize the next-generation AR glasses.

ED-Ged:Nighttime Image Semantic Segmentation Based on Enhanced Detail and Bidirectional Guidance

Semantic segmentation of driving scene images is crucial for autonomous driving.While deep learning technology has significantly improved daytime image semantic segmentation,nighttime images pose challenges due to factors like poor lighting and overexposure,making it difficult to recognize small objects.To address this,we propose an Image Adaptive Enhancement(IAEN)module comprising a parameter predictor(Edip),multiple image processing filters(Mdif),and a Detail Processing Module(DPM).Edip combines image processing filters to predict parameters like exposure and hue,optimizing image quality.We adopt a novel image encoder to enhance parameter prediction accuracy by enabling Edip to handle features at different scales.DPM strengthens overlooked image details,extending the IAEN module’s functionality.After the segmentation network,we integrate a Depth Guided Filter(DGF)to refine segmentation outputs.The entire network is trained end-to-end,with segmentation results guiding parameter prediction optimization,promoting self-learning and network improvement.This lightweight and efficient network architecture is particularly suitable for addressing challenges in nighttime image segmentation.Extensive experiments validate significant performance improvements of our approach on the ACDC-night and Nightcity datasets.

Efficacy and safety of Usights UC100 illuminated microcatheter in microcatheter-assisted trabeculotomy

AIM:To evaluate the efficacy and safety of Usights UC100 illuminated microcatheter in microcatheter-assisted trabeculotomy(MAT).METHODS:Totally 10 eyes of 10 patients with primary open angle glaucoma(POAG)who underwent MAT facilitated by Usights UC100(5 eyes)or iTrack(5 eyes)were reviewed.The success of this surgery was defined as intraocular pressure(IOP)<22 mm Hg with>30%reduction,without oral glaucoma medications,or additional glaucoma surgery.RESULTS:The mean pre-operative IOP was 25.38±10.22 mm Hg in the Usights UC100 group and 19.98±3.87 mm Hg in the iTrack group.MAT was achieved in all eyes in both groups.The success rates for the Usights UC100 group and iTrack groups were in all and 4 eyes,respectively.Both microcatheters produced a statistically significant reduction in IOP,and eyes using Usights UC100 achieved a lower IOP than the iTrack group at 3mo followup(12.58±1.52 and 14.84±1.89 mm Hg,respectively),but no statistical significance was there.No severe side effects were observed in either group.CONCLUSION:MAT using Usights UC100 or iTrack both achieve significant pressure reduction in cases of POAG,and Usights UC100 is as safe as iTrack.

Numerical Simulation of Super-Resolution Structured Illumination Microscopy (SIM) Using Heintzmann-Cremer Algorithm with Non-Continuous Spatial Frequency Support

We report a comprehensive numerical study of super resolution (SR) structured illumination microscopy (SIM) utilizing the classic Heintzmann-Cremer SIM process and algorithm. In particular, we investigated the impact of the diffraction limit of the underlying imaging system on the optimal SIM grating frequency that can be used to obtain the highest SR enhancement with non-continuous spatial frequency support. Besides confirming the previous theoretical and experimental work that SR-SIM can achieve an enhancement close to 3 times the diffraction limit with grating pattern illuminations, we also observe and report a series of more subtle effects of SR-SIM with non-continuous spatial frequency support. Our simulations show that when the SIM grating frequency exceeds twice that of the diffraction limit, the higher SIM grating frequency can help achieve a higher SR enhancement for the underlying imaging systems whose diffraction limit is low, though this enhancement is obtained at the cost of losing resolution at some lower resolution targets. Our simulations also show that, for underlying imaging systems with high diffraction limits, however, SR-SIM grating frequencies above twice the diffraction limits tend to bring no significant extra enhancement. Furthermore, we observed that there exists a limit grating frequency above which the SR enhancement effect is lost, and the reconstructed images essentially have the same resolution as the one obtained directly from the underlying imaging system without using the SIM process.

Night Vision Characteristics and Application of MTV 2821CB CCD Camera

Aim To describe accumulating frames characteristics of CCD camera as a night vision detector. Methods Utilizing CCD external trigger, computer video capture card and image processing software, the image accumulation was made. Results The detection of the static object image whose illuminance on the CCD FPA(focal plane array) was less than 3 7×10 -5 lx was realized and the image's resolution of 300?TV lines was achieved. Conclusion This experimental system can provide a kind of night vision device capable of detecting the static object at low light level and with low cost compared to an image intensifier.

A COMPARISON OF FOUR DAYLIGHTING METRICS IN ASSESSING THE DAYLIGHTING PERFORMANCE OF THREE SHADING SYSTEMS

The assessment of the daylighting performance of a design solution is a complex task due to the changing nature of daylight.A few quantitative metrics are available to designers to assess such a performance,among them are the mean hourly illuminance(MHI),the daylight factor(DF),the daylight autonomy(DA)and the useful daylight illuminance(UDI).Each of these metrics has a purpose,a set of criteria and limitations that affect the outcome of the evaluation.When to use one metric instead of another depends largely on the design goals to be achieved.Using Design Iterate Validate Adapt(DIVA)daylighting simulation program,we set out to examine the performance behavior of these four metrics with the changing dimensions of three shading devices:a horizontal overhang,a horizontal louver system,and a vertical fin system,and compare their performance behavior as the orientation changes of the window to which these devices are attached.The context is a typical classroom of a prototypical elementary school.Our results indicate that not all four metrics behave similarly as we vary the size of each shading device and as orientation changes.The lesson learned is that not all daylighting metrics lead to the same conclusions and that it is important to use the metric that corresponds to the specific goals and objectives of the design and of the daylighting solution.The UDI is the metric that leads to outcomes most different than the other three metrics investigated in this paper.

CCD视频信号处理电路设计

针对e2v公司的CCD67 Back Illuminated NIMO型CCD,设计其视频信号处理电路,包括:前置放大电路、相关双采样(CDS)电路以及低通滤波电路等。实验结果表明,设计的CCD视频信号处理电路能够达到去除噪声、提取有用信号的目的。

Controlled illumination and seismic acquisition geometry for target-oriented imaging

The conventional method of seismic data acquisition geometry design is based on the assumption of horizontal subsurface reflectors, which often is not suitable for complex structure. We start from a controlled illumination analysis and put forward a method of seismic survey geometry design for target-oriented imaging. The method needs a velocity model obtained by a preliminary seismic interpretation. The one-way Fourier finite-difference wave propagator is used to extrapolate plane wave sources on the target layer to the surface. By analyzing the wave energy distribution at the surface extrapolated from the target layer, the shot or receiver locations needed for target layer imaging can be determined. Numerical tests using the SEG-EAGE salt model suggest that this method is useful for confirming the special seismic acquisition geometry layout for target-oriented imaging.

Intelligent emergency service system based on wireless sensor and actuator networks

An intelligent emergency service（ IES） system is designed for indoor environments based on a wireless sensor and actuator network（ WSAN） composed of a gateway, sensor nodes, and a multi-robot system（ MRS）. If the MRS receives accident alarm information, the group of robots will navigate to the accident sites and provide corresponding emergency services.According to the characteristics of the MRS, a distributed consensus formation protocol is designed, which can assure that the multiple robots arrive at the accident site in a specified formation. The prototype emergency service system was designed and implemented, and some relevant simulations and experiments were carried out. The results showthat the MRS can successfully provide emergency lighting and failure node replacement services when accidents happen. The effectiveness of the algorithm and the feasibility of the system are verified.

Alerting effects of light in healthy individuals: a systematic review and meta-analysis

Light plays an essential role in psychobiological and psychophysiological processes,such as alertness.The alerting effect is influenced by light characteristics and the timing of interventions.This meta-analysis is the first to systematically review the effect of light intervention on alertness and to discuss the optimal protocol for light intervention.In this meta-analysis,registered at PROSPERO(Registration ID:CRD42020181485),we conducted a systematic search of the Web of Science,PubMed,and PsycINFO databases for studies published in English prior to August 2021.The outcomes included both subjective and objective alertness.Subgroup analyses considered a variety of factors,such as wavelength,correlated color temperature(CCT),light illuminance,and timing of interventions(daytime,night-time,or all day).Twenty-seven crossover studies and two parallel-group studies were included in this meta-analysis,with a total of 1210 healthy participants(636(52%)male,mean age 25.62 years).The results revealed that light intervention had a positive effect on both subjective alertness(standardized mean difference(SMD)=-0.28,95%confidence interval(CI):-0.49 to-0.06,P=0.01)and objective alertness in healthy subjects(SMD=-0.34,95%CI:-0.68 to-0.01,P=0.04).The subgroup analysis revealed that cold light was better than warm light in improving subjective alertness(SMD=-0.37,95%CI:-0.65 to-0.10,P=0.007,I2=26%)and objective alertness(SMD=-0.36,95%CI:-0.66 to-0.07,P=0.02,I2=0).Both daytime(SMD=-0.22,95%CI:-0.37 to-0.07,P=0.005,I2=74%)and night-time(SMD=-0.32,95%CI:-0.61 to-0.02,P=0.04,I2=0)light exposure improved subjective alertness.The results of this meta-analysis and systematic review indicate that light exposure is associated with significant improvement in subjective and objective alertness.In addition,light exposure with a higher CCT was more effective in improving alertness than light exposure with a lower CCT.Our results also suggest that both daytime and night-time light exposure can improve subjective alertness.