- 标题
- 摘要
- 关键词
- 实验方案
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Analysis of Thermal and Optical Characteristics of Light Emitting Diode on Various Heatsinks
摘要： Light emitting diodes (LED) are widely used in today’s world due to its less power consumption and its high luminance capacity. Around 20-30% of energy is converted to light energy and 70-80% of energy is dissipated as heat. The excessive rise in temperature causes failure to the LED. An effective thermal management is required for the proper heat dissipation in LED. In this work, the heat dissipation and the optical characteristics of the 16 W LED are studied using different types of aluminium heat sinks. The variation of case and junction temperature as well as the optical characteristic of LED is measured for different heatsink at different It was observed that heat sink with higher surface area shows the best result in terms of lower case and junction temperature. The higher luminous intensity was observed for the parallel fin type 1 heatsink due to higher surface area.
关键词： Heatsink,Case temperature,Light Emitting Diode (LED),Junction temperature
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE 3rd International Conference on Computing, Communication and Security (ICCCS) - Kathmandu, Nepal (2018.10.25-2018.10.27)] 2018 IEEE 3rd International Conference on Computing, Communication and Security (ICCCS) - Li-Fi Technology: Bridging The Radio Frequency Communication Gap
摘要： Communication in the modern day era is predominantly dependent on Information and Communication Technology (ICT). The rise in cybercrime, digital espionage and other cyber-related disturbances is one of great concerns to cyberspace users, both corporate and individual. Radio Frequency technologies and solutions been adopted for in-building, and outdoor wireless coverage solutions for the supply-chains market, including turnkey solutions for optimized communications, are been faced with security issues. This paper suggests a secure network communications route (Li-Fi Technology) alternative for users of radio frequency identification (RFID) technologies and solutions. A communication path that is resilient and resistant to disruptions by mitigating sophisticated network communication attacks such as spoofing and TCP/IP attacks (Man-In-the-middle attacks, Denial of Service attacks). This paper proposes the use of Li-Fi network for a safe and secure cyberspace communication exchange path.
关键词： LED,Wi-Fi,Li-Fi,RFID,Network,Attacks,Communication
更新于2025-09-23 15:23:52
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[IEEE 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Varna (2018.9.20-2018.9.22)] 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Color space distribution of luminaire for dynamic ?tunable white" lighting at different color temperatures
摘要： In this paper are presented the experimental results from the study of light and color distributions of specially constructed luminaire for dynamic "tunable white" lighting. They would be the base for the following study in the field of lighting effects on human health and wellbeing - Human Centric Lighting (HCL).
关键词： color,changing of color temperature,human centric lighting,LED lighting sources,dimming process of lighting
更新于2025-09-23 15:23:52
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New Dynamic Photo-Electro-Thermal Modeling of Light-Emitting Diodes with Phosphor Coating as Light Converter
摘要： Phosphor-coated light-emitting diode (PC-LED) is the dominant LED technology for public lighting. This paper presents a comprehensive theory for analyzing and modeling phosphor coating in white light-emitting diodes (LEDs) as a dynamic light converter. The new PC-LED model not only obeys the traditional diode equation, it includes the energy-storage and transient effects of the phosphor coating. Major control variables include energy storage in and the luminous flux from the phosphor coating. This new model enables the dynamic variations of luminous flux and energy storage and power loss in phosphor-coating to be accurately predicted. Part-1 of this paper provides the details of the theory and analysis leading to the new PC-LED model under the framework of the photo-electro-thermal theory. Details of the model parameter determination, model setup and experimental verification are included in Part-2. The model offers the important power loss equation of the phosphor coating which highlights the factors affecting the heat loss and the coating’s blackening effects. This equation can be used by engineers to design LED drivers in order to reduce the coating temperature and the blackening effects and to prolong LED lifetime.
关键词： Phosphor-coated light-emitting diodes (PC-LED),flux capacitor,light converter.,photo-electro-thermal (PET) theory,dynamic model of PC-LED
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference and Exposition on Electrical And Power Engineering (EPE) - Iasi, Romania (2018.10.18-2018.10.19)] 2018 International Conference and Exposition on Electrical And Power Engineering (EPE) - Aspects Regarding Disturbances Produced by Fluorescent Tubes
摘要： This paper has a strong applicative character. There is presented a modern system for monitoring dynamic states, carried out with the help of a data acquisition board. It is insisted upon an original monitoring program conceived by the paper team. There are presented then two applications of using this system: a) (experimental) analysis of disturbances produced by a fluorescent tube; b) analysis of disturbances produced by a LED tube. A special attention is paid to the experimental aspects which emphasize the waveforms of the currents corresponding to some fluorescent tubes (in a few representative operation states). Finally, there are presented conclusions, which have been obtained by finalizing the research and the afferent bibliography.
关键词： LED tube,harmonic analysis,test,fluorescent tube,disturbances
更新于2025-09-23 15:22:29
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[ACM Press the 4th ACM Workshop - Snowbird, Utah, USA (2017.10.16-2017.10.16)] Proceedings of the 4th ACM Workshop on Visible Light Communication Systems - VLCS '17 - SeedLight
摘要： With the increasing consumer demand for smart objects, LED-to-Camera communication appears as a low-cost alternative to radio to make any conventional device smart. Since LEDs are already on most electronics devices, that is achieved at the cost of negligible hardware modifications. However, as these LEDs are very different from the widely studied ceiling ones, several challenges need to be addressed to make this happen. Among these issues, we note the constrained physical layer data unit (PHY-SDU) length that complicates the use of coding strategies to cope with bits or packets erasure. To break this limitation, this paper presents SeedLight, a coding scheme designed to face the inherent packet losses and enhance line-of-sight LED-to-Camera communication goodput. SeedLight leverages random linear coding to provide an efficient redundancy mechanism that works even on PHY-SDU of tens of bits. The key idea of SeedLight is to reduce the code overhead by replacing the usual coding coefficients by a seed. Since this work addresses IoT devices with low computational resources, SeedLight encoding algorithm complexity remains low. We develop an implementation of SeedLight on a low-cost MCU and a smartphone to evaluate both the communication and algorithmic performances. Experimental results show that SeedLight introduces a negligible overhead and can be implemented even on the cheapest MCU, such as the ones used in many IoT devices. The achievable goodput can be up to 2.5kbps, while the gain compared to a trivial retransmissions scheme is up to 100%.
关键词： VLC,Random Linear Coding,IoT,LED-to-camera
更新于2025-09-23 15:22:29
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High Speed Wireless Internet Using LiFi
摘要： The internet has become a basic necessity, so with the advancement in technology, people are demanding something faster than WI-FI. Since light is the only medium that can travel fastest than any other source of data transmission else so if we use this medium for internet, it will be the best utilization of medium with a higher data transmission rate. This technology was implemented over and came out with concept of LI-FI Technology. Li-Fi in known for Light-Fidelity, Li-Fi uses an idea of visible light communication (VLC) technology that uses light as a medium to convey fast high-speed communication in a manner like Wi-Fi. Since visible light is present everywhere, the main idea of our review paper is how LI-FI technology can help in security, speed and reliability of internet and even can change our life style. This innovation is actualized utilizing white LED bulbs matched with the Downlink transmitter that can give a higher information transmission rate up to 10Gbps. The main prospective of this paper demonstrates the forthcoming routine of Li-Fi technology innovation and its highlights to expand the execution of information transmission and different applications where Li-Fi has been put to utilize.
关键词： Data utilization,Visible Light communication,Wi-Fi,server,Light-emitting diode (LED),Light-Fidelity (Li-Fi),Video LAN Client (VLC)
更新于2025-09-23 15:22:29
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Benefits, problems and challenges of plant factories with artificial lighting (PFALs): a short review
摘要： The benefits and problems to be solved and challenges for plant factories with artificial lighting (PFALs) are discussed. The benefits include high resource-use efficiency, high annual productivity per unit land area, and production of high-quality plants without using pesticides, regardless of weather. A major problem to be solved is high initial investment and operation costs. Challenges for the next-generation smart PFALs include the introduction of advanced technologies such as artificial intelligence with the use of big data, genomics and phenomics (or methodologies and protocols for noninvasive measurement of plant-specific traits related to plant structure and function).
关键词： resource-use efficiency (RUE),cultivation system module (CSM),standardization,smart LED lighting system,annual productivity,artificial intelligence,phenotyping
更新于2025-09-23 15:22:29
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A review on smart application of supplemental lighting in greenhouse fruiting vegetable production
摘要： Different spectra of light trigger different plant growth processes. Therefore, the optimum light spectrum for various plant physiological and growth processes may be different. For greenhouse fruiting vegetables, such as tomatoes, it is important to optimize light spectrum to promote canopy growth to increase light interception during the early stage of plant growth. Once the plants reach full canopy, the focus should be moved to optimizing vertical light distribution because most greenhouse fruiting vegetables are tall crops and the growth processes along the vertical profile are different; most of the canopy growth occurs in the top and middle canopy while fruit growth occurs in the middle and bottom canopy. Because the fruit, not the leaf, is the economic product, the optimized light spectral composition should enhance leaf carbon export and translocation to fruit to improve fruit yield and quality. Therefore, a research project was initiated in 2013 to identify proper light spectral composition and vertical distribution regimes for greenhouse fruiting vegetable production. Different overhead light sources (high-pressure sodium light with or without far-red light-emitting diode (LED) light, plasma light and different spectral compositions of LEDs) and several intra-canopy spectral compositions provided by LEDs were evaluated over four winters on tomatoes, mini-cucumbers and sweet peppers. The effects of light spectrum on whole-plant net carbon exchange and leaf carbon export using 14C-isotype tracing were also investigated. The vertical light regimes resulted in significant differences in leaf photosynthetic rate, leaf size, fruit yield and fruit quality in greenhouse tomatoes, mini-cucumbers and sweet peppers. Proper vertical light regimes were identified for hybrid light systems (overhead high intensity discharge light + intra-canopy LEDs) and for pure LED light systems (overhead + intra-canopy LEDs). This review clearly demonstrates that optimized vertical light regimes can be developed for improving both plant growth and fruit yield and quality in year-round greenhouse fruiting vegetable production.
关键词： far-red light,Solanum lycopersicum,Capsicum annuum,Cucumis sativus,light quality,vertical light spectral distribution,temperature,LED,lighting,spectral composition
更新于2025-09-23 15:22:29
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[IEEE 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Varna, Bulgaria (2018.9.20-2018.9.22)] 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Renewable energy sources and lighting
摘要： Photovoltaic system is one of the promising renewable energy technologies. In this paper lighting system based on renewable energy sources is developed and analysed. The proposed system in the paper is designed to power lighting in common areas of residential buildings. A block diagram and system unites are presented in paper. Calculations of the costs have been presented.
关键词： Renewable energy sources,LED,lighting
更新于2025-09-23 15:22:29