- 标题
- 摘要
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- 实验方案
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[IEEE 2019 Eleventh International Conference on Ubiquitous and Future Networks (ICUFN) - Zagreb, Croatia (2019.7.2-2019.7.5)] 2019 Eleventh International Conference on Ubiquitous and Future Networks (ICUFN) - Fault Monitoring in Passive Optical Networks Using Burst-Mode FBG Optical Sensor
摘要： This paper presents a fault monitoring method in passive optical networks (PON) using Burst-mode uniform FBG optical sensors. The proposed monitoring method detects physical layer faults between optical line terminal (OLT) and optical network units (ONUs). The FBG interrogation subsystem located in central office (CO) near OLT transmits FBG monitoring signal to every ONU. Each ONU branch contains an FBG sensor subsystem. The proposed system provides Burst mode upstream data transmission using time division multiple access (TDMA). We show that the proposed system is a cost- effective solution that has ability to monitor faults of any ONU branches in PON.
关键词： Fiber Bragg Grating,Fault Monitoring in PON,Burst-Mode uniform FBGs
更新于2025-09-16 10:30:52
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[IEEE 2019 41st Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC) - Berlin, Germany (2019.7.23-2019.7.27)] 2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - A wearable phototherapy device utilizing micro-LEDs
摘要： A conformable device for wearable phototherapy applications is presented. The device consists of a 1mm thick elastomeric membrane edge-lit by specially fabricated micro-sized LEDs. Nanoparticle based scattering films are utilized to extract light and a uniform emission of 15μW/cm2 is reported over an area of 2cm2.
关键词： micro-LEDs,elastomeric membrane,light extraction,wearable phototherapy,uniform emission
更新于2025-09-16 10:30:52
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Concentration Measurement of Uniform Particles Based on Backscatter Sensing of Optical Fibers
摘要： A set of miniature optical fiber particle concentration measuring instruments is designed and applied to develop a unified expression for the concentration measurement of uniform particles in tap water. By measuring the concentrations of six uniform silicon carbide particles in the size range of 38–250 μm, the unified relationship between particle size, particle concentration, and optical scattering intensity is proposed. The unified expression is verified by the concentration measurements of silicon carbide particles with three other sizes. The results show that the measurement error is less than 10%, and the unified expression is satisfactory considering the large measuring range of 0–50 kg/m3. The effects of light intensity on the concentration measurement are discussed based on the results of 150 μm silicon carbide particles under three different light intensities. It is shown that a low light intensity can be applied for high-concentration measurement with relatively low accuracy, while a high light intensity can be adopted for low-concentration measurement with higher accuracy.
关键词： unified expression,optical backscatter,optical fiber,uniform particles,silicon carbide,particle concentration
更新于2025-09-16 10:30:52
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[IEEE 2019 Chinese Control And Decision Conference (CCDC) - Nanchang, China (2019.6.3-2019.6.5)] 2019 Chinese Control And Decision Conference (CCDC) - A Kind of Digital Controlled Electro-Optical Switch Power Source with Variable Voltage and Variable Frequency
摘要： This paper suggests a real-valued sparse representation method using a unitary transformation that can convert complex-valued manifold matrices from uniform circular array into real ones. Because of this transformation, the computational complexity is modi?ed. Simulation results con?rmed the effectiveness of the proposed method with a circular array radar.
关键词： array signal processing,Angle of arrival (AOA),uniform circular array (UCA)
更新于2025-09-16 10:30:52
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Design of Curved Fresnel Lens with High Performance Creating Competitive Price Concentrator Photovoltaic
摘要： In this paper, the design of a curved Fresnel lens applying to the concentrator photovoltaic system is proposed by using the edge ray theorem, the Snell’s law, and the conservation of optical path length. The new structure of the curved Fresnel lens can improve significantly the uniformity of sunlight distribution over the solar cell while the concentration ratio can reach a high value of 900 times. The good uniform distribution can be obtained by using the novel idea. The novel idea is based on the uniform sunlight distribution of every groove of the lens so that the whole lens also distributes uniformly the sunlight beam over the receiver. The structure of the lens is built by two surfaces: input surface (or upper surface) as a part of spherical surface and output surface (or lower surface) that consists all grooves of the lens. Matlab program is used to design the input and the output surfaces of the lens. The input surface and the output surface are independent to each other in construction in Matlab. LighttoolsTM software is used to optimize the structure of the novel lens. Furthermore, LighttoolsTM is also used to perform a simulation to examine the efficiency of the lens in concentrator photovoltaic (CPV) system by using the light source with a wide spectrum of 380 – 1600 nm. The results show that the lens has an acceptance angle of 0.80 and good optical efficiency (>85%).
关键词： concentrator photovoltaic (CPV),Fresnel lens,solar energy,high concentration ratio,multi-junction solar cells,uniform irradiance distribution,CPV without secondary optical element (SOE)
更新于2025-09-12 10:27:22
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Environmental Factors for Non-uniform Dynamic Mechanical Load Test due to Wind Actions on Photovoltaic Modules
摘要： The issue of typhoons has received considerable critical attention since the associated strong winds generally damaged photovoltaic (PV) modules severely. Previous IEC standards examined the effect of static uniform-loads (IEC 61215-2:2016) or dynamic uniform-loads (IEC TS 62782:2016) on PV module in low wind velocity, but overlooked the moment effect of non-uniform loads due to wind actions in high wind velocity. Therefore, the challenge is how to improve the current mechanical loads system to meet the test requirements due to strong wind such as typhoon’s action on PV module. This work has successfully developed a new test capacity named non-uniform dynamic mechanic loads (NUDML) system, which owns eighteen (3x6) independent pneumatic cylinders with maximum loading up to ±12000 Pa (pressure load “+” or suction load “-”). NUDML system can simulate the different wind actions on PV module by the test data named mean surface pressure pattern (MSPP). All MSPPs can be evaluated directly by wind-tunnel experiment and CFD simulation. Results of this study revealed that such severity wind-test for PV module strongly relied on the choices of major environmental factors such as wind velocity (V), wind direction angle (β) and module tilt (α). In addition, the failures of test modules and its fixtures, after NUDML test, are closely related to the external forces such as MSPP (V, α, β).
关键词： Photovoltaic module,mechanical load,non-uniform,wind load,mean surface pressure pattern
更新于2025-09-12 10:27:22
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Multi-physics effects on the performance of Dense-array Concentrator Photovoltaic System
摘要： In this paper, the multi-physics effects on the performance of dense array concentrator photovoltaic (DA-CPV) system are investigated in detail by considering CPV module connections, non-uniform illumination, and temperature distribution. It is observed that the optimized module configuration can significantly reduce the overall cells temperature and then improve the efficiency and stability. We also analyze the effects of temperature uniformity on output performance. When the illumination, configuration and mean temperature are certain, the temperature distribution can affect the output performance of the DA-CPV system. In the case of non-uniform illumination, the maximum power of the module will be achieved with an inverse Gaussian temperature distribution, instead of uniform temperature. Through this comprehensive understanding the temperature effects of the DA-CPV module, a suitable cooling system can be designed to reduce power loss.
关键词： Non-uniform illumination,Concentrator photovoltaic,Multi-physics,Dense-array,Temperature
更新于2025-09-12 10:27:22
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Surgical Lamp Design Based on LED Diffuse Transmission Illumination System
摘要： In this article, we have designed a surgical light lens especially for oral surgical illumination. It provides a uniform and wide field of view for illumination during oral surgery. The support system, a set of LEDs and a double free-form surface constituted the lighting system. The double free-form surface is composed of traditional free-form surface, designed total internal reflection lens and diffuse transmission plate, which improves the optical performance of the LED. When the light keeps dispersing the pupil constriction, it eventually causes our eyes to fatigue. The purpose of increasing diffuse transmission is to make the emitted light softer, thus making peoples’ eyes feel more comfortable. Based on the problems mentioned above, a numerical method is proposed as the basis for designing the double free-form surface. First, establishing a mathematical model based on the characteristics of the transmissive surface and the property of the LED. Henceforth, the nonlinear equations for the illumination distribution of the outside surface can be deduced. By solving the equation, the contour of the free-form surface is obtained. Later, we imported the contour into the 3D modeling software Solidworks to rotate so as to get the corresponding model. Finally, the simulation results suggest that the optical uniformity of the double free-form surface is able to reach as much as 86.18%.
关键词： free-form surface,uniform illumination,the total internal reflection (TIR),optical design,Diffuse transmission
更新于2025-09-12 10:27:22
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[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - Performance of Indoor Visible Light Communication System Under Random Placement of LEDs
摘要： In this paper, the performance of indoor visible light communication (VLC) system with randomly deployed light-emitting-diodes (LED) using Matern hardcore point process (MHCP) is analyzed and compared with existing random geometries like binomial point process (BPP) and fixed geometries such as circular and square. It is well known fact that the signal-to-noise-ratio (SNR) profile inside the room changes with respect to LED placement as well as receiver’s position. In order to achieve uniform SNR across the room, the proposed work uses MHCP based LED placement at the transmitter and a single photodiode (PD) at the receiver. Simulation results show that random placement of LED using MHCP configuration results in a much more uniform SNR profile inside the room than the random BPP and conventional circular and square LED placements. Further, our results also show that by deploying MHCP based LED placement, the average SNR across the room increases.
关键词： uniform signal-to-noise-ratio,Matern hardcore point process,visible light communications
更新于2025-09-12 10:27:22
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Uniform and smooth molybdenum film produced through picosecond pulsed laser deposition
摘要： An approach to achieve uniform and smooth molybdenum (Mo) ?lm on a BK7 glass plate at room temperature is proposed through picosecond pulsed laser deposition, with the pulsed laser radiating the target along a linear track. A numerical model is established to analyze the in?uence of linear scanning offsets on the thickness homogeneity of the deposited thin ?lm. Through an appropriate choice of radiation intensity and scanning parameters, a uniform and smooth layer of Mo thin ?lm is prepared with its maximum thickness variation and root-mean-square roughness better than 5% and 1.2 nm, respectively.
关键词： picosecond pulsed laser deposition,smooth,numerical model,molybdenum film,uniform
更新于2025-09-11 14:15:04