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Luminaire Dirt Depreciation (LDD): Field Data from Several Exterior Lighting Projects
摘要： Luminaire dirt depreciation (LDD) data were evaluated for seven luminaires from three different project sites in Philadelphia, Pennsylvania, Minneapolis, Minnesota, and Yuma, Arizona. In each case, the luminaires were removed from the installation, carefully packaged and transported to a photometric testing laboratory, and then tested in the “as-is” or dirty condition, cleaned, and retested. In terms of light output, the results showed that the IES RP-36-15 method for estimating LDD was applicable to the light emitting diode (LED) luminaires evaluated. General claims of lower levels of dirt deprecation (or higher LDD values) for LED luminaires than for luminaires using conventional light sources were not supported by the test data for the LED luminaires in these three projects. Though the overall measured lumen depreciation due to accumulated dirt closely matched IES estimates for LDD, the data indicated that the accumulated dirt on the luminaires dramatically altered the luminous intensity distribution of the luminaires, with reductions in intensity of more than 25% at peak angles. These effects on luminous intensity distribution are not accounted for in IES LDD estimates.
关键词： optics and luminaire design,LED sources and systems,luminaires,roadway lighting,maintenance
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE 2nd International Conference on Circuits, System and Simulation (ICCSS) - Guangzhou, China (2018.7.14-2018.7.16)] 2018 IEEE 2nd International Conference on Circuits, System and Simulation (ICCSS) - Application of an Infinite Gain Multiple Feedback Filter in VLC Link Range Extension
摘要： This paper presents a visible light communication (VLC) link range extension, achieved by establishing a VLC system using simple, low-cost, and reliable electronic circuitry, and employing a design of a highly resonant frequency selective active band pass filter (infinite gain multiple feedback filter) at the receiver section of the system. The filter was designed for a specific center (resonant) frequency with high Quality factor and gain. An outline of the relationship between Signal-to-Noise ratio (SNR) and transmission distance for three different center frequencies was presented. Results show that by utilizing an IGMF filter at the receiver, a signal-to- noise ratio above 10dB at a distance beyond 1.5 meters can be achieved without any form of lensing at either the transmitter or receiver.
关键词： Signal-to-Noise Ratio (SNR),Infinite Gain Multiple Feedback (IGMF),Visible Light Communications (VLC),LED,Trans-Impedance Amplifier (TIA)
更新于2025-09-10 09:29:36
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Artificial Light at Night of Different Spectral Compositions Differentially Affects Tumor Growth in Mice: Interaction With Melatonin and Epigenetic Pathways
摘要： Lighting technology is rapidly advancing toward shorter wavelength illuminations that offer energy-efficient properties. Along with this advantage, the increased use of such illuminations also poses some health challenges, particularly breast cancer progression. Here, we evaluated the effects of artificial light at night (ALAN) of 4 different spectral compositions (500-595 nm) at 350 Lux on melatonin suppression by measuring its urine metabolite 6-sulfatoxymelatonin, global DNA methylation, tumor growth, metastases formation, and urinary corticosterone levels in 4T1 breast cancer cell-inoculated female BALB/c mice. The results revealed an inverse dose-dependent relationship between wavelength and melatonin suppression. Short wavelength increased tumor growth, promoted lung metastases formation, and advanced DNA hypomethylation, while long wavelength lessened these effects. Melatonin treatment counteracted these effects and resulted in reduced cancer burden. The wavelength suppression threshold for melatonin-induced tumor growth was 500 nm. These results suggest that short wavelength increases cancer burden by inducing aberrant DNA methylation mediated by the suppression of melatonin. Additionally, melatonin suppression and global DNA methylation are suggested as promising biomarkers for early diagnosis and therapy of breast cancer. Finally, ALAN may manifest other physiological responses such as stress responses that may challenge the survival fitness of the animal under natural environments.
关键词： body mass,EE-halogen,corticosterone,yellow-LED,light at night,carbon,6-SMT,GDM-levels,cosinor analysis,CFL
更新于2025-09-10 09:29:36
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Effects of UVB and UVC irradiation on cariogenic bacteria in vitro
摘要： The aim of this study was to evaluate the bactericidal effect of ultraviolet (UV) light at 265-nm (UVC) and 310-nm (UVB) wavelengths from a newly developed UV light-emitting diode (LED) device against cariogenic bacteria in vitro. Suspensions of Streptococcus mutans (S. mutans) and Streptococcus sobrinus were directly irradiated by UVB or UVC for 2.5 min or 5 min. Numbers of colonies were counted and calculated as colony forming units (CFU) per milliliter. Fluorescence microscopy (FM) and optical density measurements at 490 nm (OD490) were also taken after irradiation. In addition, the bactericidal effects of irradiation against S. mutans under 0.5 mm-thick dentin were compared using culture tests and OD490 measurements. Direct UV-LED irradiation with both UVB and UVC showed strong bactericidal effects. UVB showed superior bactericidal effect through 0.5-mm-thick dentin than did UVC, especially after demineralization. These results suggest that UVB irradiation could be utilized for the prevention and management of dental caries.
关键词： UVB,UVC,Demineralized dentin,Streptococcus sobrinus,Streptococcus mutans,UV-LED
更新于2025-09-10 09:29:36
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[ACM Press the 17th ACM Workshop - Redmond, WA, USA (2018.11.15-2018.11.16)] Proceedings of the 17th ACM Workshop on Hot Topics in Networks - HotNets '18 - Connecting Battery-free IoT Tags Using LED Bulbs
摘要： We introduce BackVLC, a system to connect battery-free IoT tags using LED bulbs. We make use of bulbs beyond illumination. We send data to the tags with visible light communication (VLC), and retrofit the bulbs with simple circuitry to enable the uplink channel current VLC systems lack, using Radio Frequency (RF) backscatter communication from the tags. Tags process and send data, harvesting energy from light and radio. We present our system design and implementation, evaluate it in preliminary simulation studies and experiments, and discuss the research challenges to develop a complete network architecture. BackVLC is the first work that combines VLC with RF backscatter.
关键词： RF backscatter,LED bulbs,visible light communication,battery-free IoT tags,BackVLC
更新于2025-09-10 09:29:36
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Smart Plant Factory (The Next Generation Indoor Vertical Farms) || Plant Factories with Artificial Lighting (PFALs): Benefits, Problems, and Challenges
摘要： The bene?ts, unsolved problems, and challenges for plant factories with arti?cial lighting (PFALs) are discussed. The remarkable bene?ts are high resource use ef?ciency, high annual productivity per unit land area, and production of high-quality plants without using pesticides. Major unsolved problems are high initial investment, electricity cost, and labor cost. A major challenge for the next-generation smart PFAL is the introduction of advanced technologies such as arti?cial intelligence with the use of big data, genomics, and phenomics (or methodologies and protocols for noninvasive measurement of plant-speci?c traits related to plant structure and function).
关键词： Smart LED lighting system,Cultivation system module (CSM),Phenotyping,Annual productivity,Standardization,Arti?cial intelligence,Resource use ef?ciency (RUE)
更新于2025-09-10 09:29:36
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[IEEE 2018 7th International Conference on Computer and Communication Engineering (ICCCE) - Kuala Lumpur, Malaysia (2018.9.19-2018.9.20)] 2018 7th International Conference on Computer and Communication Engineering (ICCCE) - Smart Street Light Using Intensity Controller
摘要： Smart street light is an intelligent control of street lights to optimize the problem of power consumption of the street, late in night. Currently, usual street lights are automatically turn on when it becomes dark and turn off when it becomes bright. This is huge waste of energy in the entire world as it is an essential community service, but current implementation is not efficient. Conventional street lights are being replaced by Light Emitting Diode (LED) street lighting system, which reduces the power consumption. The focus of this project is to design a system of street lights controller to provide a reduction in power consumption. The prototype is design by using Light Dependent Resistor (LDR), Infrared sensor (IR), battery and LED. All this component was controlled by Arduino UNO as the microcontroller. The brightness of the lamps is being controlled in this project to reduce the power consumption. The dimming of the lamps depends on the speed of object motion detected such as pedestrians, cyclists and cars. The higher speed of moving object, the greater the level of intensity. For this idea, the innovation of street lights is not quite the same as conventional street lights that are controlled by timer switch or light sensor which automatically turns the street lights on during sunset and off during sunrise. According to the study, motion detection devices may help to save up to 40% of energy per month.
关键词： power consumption,Smart street light system,sensor detection,LED street lights.
更新于2025-09-10 09:29:36
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Structure characterization and photoluminescence of sol-gel synthesized Ag-Dy-codoped silica phosphor
摘要： Bulk samples of single Ag-, Dy-doped and Ag-Dy-codoped silica matrices were synthesized using the sol-gel processing. These matrices were characterized using X-ray di?ractometry, ultraviolet-visible-near infrared (UV-VIS-NIR), Fourier transform infrared, photoluminescence (PL) excitation and emission spectroscopic techniques. High resolution transmission electron microscope con?rmed the presence of ?ne spherical Ag nanoparticles (NPs), whose average size is approximately 10–15 nm, in the Ag-doped and Ag-Dy-codoped silica matrices. UV-VIS-NIR spectra revealed absorption peaks due to Dy3+ active centers in addition to the surface plasmon resonance bands of Ag NPs centered at 410 and 452 nm in these matrices, respectively. UV-excited PL of the materials was studied and compared. Near-white light emission, which was assessed by the calculated CIE chromaticity coordinates, could be observed under UV excitation at 365 nm in the Ag-Dy-codoped silica matrix. This white light was realized by appropriate combination of prominent yellow and blue emissions. Electron spin resonance spectra revealed paramagnetic spin states for Ag which can be attributed to the quantum size e?ect of very ?ne Ag NPs dispersed in the silica network. The obtained results indicate that the Ag-Dy-codoped silica phosphor could be a promising candidate for application as white light emitting phosphor for UV LED chips.
关键词： Sol-gel,TEM,Surface plasmon resonance,Phosphors,White LED,Optical band gap
更新于2025-09-10 09:29:36
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[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Public Lighting, Public Health
摘要： Impact of artificial light at night on sleep and health of humans and other living species is discussed among scientists. This paper analyses the properties of several commercially available light sources with regards to their effects on wildlife, human sleep, and health. A novel, environmentally considerate LED light source is introduced. Further, integration of this light source into the pilot biodynamic street lighting system is described. Based on the season and time of day, a control system changes the spectral composition of the light in lighting without compromising on safety, psychological needs or energy savings.
关键词： advanced control system,spectral power distribution,light at night,LED,biodynamic lighting,non-image forming light perception,Circadian rhythm
更新于2025-09-10 09:29:36
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<i>(Invited)</i> Monolithic Integration of Si-CMOS and III-V-on-Si through Direct Wafer Bonding Process
摘要： Integration of Si-CMOS and III-V compound semiconductors (with device structures of either InGaAs HEMT, InGaP LED, GaAs HBT, GaN HEMT or InGaN LED) on a common Si substrate is demonstrated. The Si-CMOS layer is temporarily bonded on a Si handle wafer. Another III-V/Si substrate is then bonded to the Si-CMOS containing handle wafer. Finally, the handle wafer is released to realize the Si-CMOS on III-V/Si substrate. For GaN LED or HEMT on Si substrate, additional wafer bonding step is required to replace the fragile Si (111) substrate after high temperature GaN growth with a new Si (001) wafer to improve the robustness of the GaN/Si wafers. Through this substrate replacement step, the bonded wafer pair can survive the subsequent processing steps. The monolithic integration of Si-CMOS + III-V devices on a common Si platform enables new generation of systems with more functionality, better energy efficiency, and smaller form factor.
关键词： III-V compound semiconductors,Si-CMOS,wafer bonding,HEMT,GaN LED,monolithic integration
更新于2025-09-10 09:29:36