• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.221-227
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• 2008

This paper is to show the designing for LED lights driver unit. The main purpose of driver designing is high electrical efficient performance and intelligent control LED driver. Nowadays, a lightning system with some of charactestics such as an environmentally friendly purposes with a possible reduction of electric power consumptions. We constitute a intelligent contron LED control system that helps to save an electric energy, and a communication system to control the system. This LED driver can be used for intelligent light control. This product expects to improve the light control by dimming instead of interlace on/off light control that increases the social cost such as car accidents and etc.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.2
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• pp.8-18
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• 2015

This paper proposes a dimming method and a hybrid LED driving circuit suitable for the ultra high definition (UHD) broadcasting. There are major two problems during the dimming control for traditional LED broadcast lightings; one is a flicker that occurred when camera filming to these lightings, and the other is that linear control is impossible for LED luminous intensity under 10% due to LED electrical characteristics. The proposed dimming method and the driving circuit are designed to solve two problems simultaneously. For high level dimming control region from 10 to 100%, the analog control method was applied to the switching regulator constructed by MOSFET operated in the saturation region. For low level dimming control region under 10%, the fast PWM control method with the linear regulator constructed by MOSFET in the ohmic region was used. We verified experimentally that the dimming method is able to control the luminous intensity linearly from 1 to 100% and the flicker disappears on images taken by the charge coupled device (CCD) and the complementary metal oxide semiconductor (CMOS) cameras. Therefore, the proposed method is suitable for the UHD broadcasting.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.540-549
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• 2024

Despite the acknowledged benefits by incorporating daylighting in the lighting system of office buildings to enhance energy efficiency and ensure occupants' well-being, a significant gap in understanding the integration of daylighting control system (DCS) with Building Information Modeling (BIM) exists, which can lead to improved energy efficiency and enhanced building design, specifically regarding the impact of daylight on occupant comfort. Previous studies have highlighted the potential of BIM to revolutionize both architectural design and building performance. However, an untapped potential of BIM in facilitating daylighting control in office areas is yet to be explored. The significance of this study lies in prioritizing occupants' well-being and enhancing building performance. This research identifies the feasibility of BIM-enabled DCS through a literature review from three perspectives: BIM-enabled DCS and daylight strategies, BIM-assisted façade system improvement, and user-centric daylight utilization within BIM platforms. As for results, a sensor network diagram illustrating network structure, data flow, and connections between devices of BIM enabled daylight control system for office buildings are established. Additionally, a BIM assisted daylight control strategy diagram is presented to outline user-centric control facilitated by BIM platform. In terms of contribution to the body of knowledge, this research will provide a comprehensive synthesis of existing literature in this domain. Additionally, this research could provide architects, DCS designers, and sustainable building professionals with potential advancements and inspirations to promote energy-efficient and user-centric building design in the future.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.1
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• pp.45-52
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• 2017

EEG signals that are the same as those that have the same disabled people. So, the EEG signals are becoming the next generation. In this paper, we propose an internet of things system that controls the indoor environment using EEG signal. The proposed system consists EEG measurement device, EEG simulation software and indoor environment control device. We use data as EEG signal data on emotional imagination condition in a comfortable state and logical imagination condition in concentrated state. The noise of measured signal is removed by the ICA algorithm and beta waves are extracted from it. then, it goes through learning and test process using SVM. The subjects were trained to improve the EEG signal accuracy through the EEG simulation software and the average accuracy were 87.69%. The EEG signal from the EEG measurement device is transmitted to the EEG simulation software through the serial communication. then the control command is generated by classifying emotional imagination condition and logical imagination condition. The generated control command is transmitted to the indoor environment control device through the Zigbee communication. In case of the emotional imagination condition, the soft lighting and classical music are outputted. In the logical imagination condition, the learning white noise and bright lighting are outputted. The proposed system can be applied to software and device control based BCI.

• Journal of Biosystems Engineering
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• v.24 no.2
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• pp.115-122
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• 1999

Because of their small mass, volume, solid state construction and long life, light-emitting diodes(LEDs) hold promises as a lighting source for intensive plant production system. Spectral characteristics and light intensity of LEDs were tested to investigate their feasibility as artificial lighting sources for growth and morphogenesis control in transplant production system. Blue, green, and red LEDs had a peak-emission wavelength at 442nm, 522nm, and 673nm, respectively. Their half width defined as the difference between upper and lower wavelength in the intensity equivalent to 50% of the maximum intensity showed 26nm, 41nm, and 74nm, respectively. Photosynthetic photon flux(PPE) at the distance of 9cm under the LEDs array was measured as $235{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for red, $109{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for green, and $75{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for blue LEDs. At the same distance, green LEDs had the illuminance of 13,0001x, nine to ten times higher than those of red and blue LEDs. Red, green, and blue LEDs at a distance of 9cm had the irradiance of $46W{\cdot}m^{-2},\;19W{\cdot}m^{-2},\;8W{\cdot}m^{-2}$, respectively. Light intensity of blue, green, and red LEDs increased linearly in proportion to the magnitude of the current applied to the operating circuit. Thus the light intensity of LEDs was controlled by the applied current in operating circuit.

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.292-298
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• 1997

These studies were conducted to verify the effect of the supplementary lighting by reflective film mulching and its establishment in the north side of greenhouse on the utility of light at tomato by means of investigating changes of leaf temperatures, stomatal features, transpiration rates and photosynthetic rates. Stomatal density of leaves were high in the reflective film mulching but sizes of stomata were not different. As the osmotic potential in rooting zone was low, the stomatal resistance was high, transpiration rate was low, and leaf temperature was increased by 40.62$^{\circ}C$. And also in the block of reflective film mulching photosynthetic rates were decreased hut chlorophyll contents were not different. Especially, there is an effect of controlling greenhouse whiteflies by treatment of reflective film mulching. It is thought that the reason of high quality or increasing yield at several crops by supplementary lighting, such as reflective film mulching, would be caused by influences of absorption and distribution of nutrients through high transpiration rate and photosynthesis which resulted from increase of stomata.

• Korean Journal of Organic Agriculture
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• v.24 no.1
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• pp.99-114
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• 2016

This study was conducted to evaluate effects of various eco light sources with various lighting distance in 'Viking' rose (Rosa spp.) on the growth and flowering quality to be applied for farm sites. Treatment included 10-, 20-, and 30-RL (-BL, -RBL, -FL, and -IL), which referred to red LED (blue LED, red+blue LED, fluorescent, and incandescent) lighting at 10 cm, 20 cm, 30 cm respectively, apart from flowers. NL referred to natural light as a control. Growth and flowering of 'Viking' rose were non-destructively measured at 4, 6, and 8 weeks after treatment (WAT). FL treatment increased plant height at 4, 6, and 8 WAT, regardless of lighting distance, with the shortest height observed for the NL-treated flowers. 30 RL treatment also increased plant height at 6 and 8 WAT. Stem diameter and number of leaves were not significantly different for all the treatments at 8 WAT, with the lowest values observed for RBL treated-flowers among the light source treatments. Number of root was the greatest for the 30 BL-treated flowers (10.0) but the fewest for the 30 FL (4.7). Length of flower neck at 6 WAT was the extended by 6~7 cm in the 10 FL and 20 FL treatments as well as by 5~6 cm in the 20 RL and 30 RL treatments, inducing 100% of flowering. NL increased $a^*$ (29) of flower color, with the lowest value (10) observed for 20 RL. All things considered, 30 RL would be the best interaction treatment of source and distance of eco light to improve plant height and flowering quality of 'Viking' rose.

• Architectural research
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• v.7 no.2
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• pp.47-54
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• 2005

A photoelectric dimming control system for a small private office space with a double skin envelope system was analyzed for the purpose of examining optimum control performances under a variety of daylight conditions. Computer simulations were performed for the three different photosensor types positioned at the center of ceiling in the space. They were applied in both a south and north-facing room. Daylight conditions were a fixed horizontal venetian blind on an external envelope and a retractable shading device on an internal envelope under a clear, intermediate and overcast sky at different times of a day and year. Partially-shielded photosensors provided good control performances providing the required electric light output under clear and intermediate sky conditions. Unshielded photosensors failed to provide necessary illuminance levels producing less electric output and fully-shielded photosensors generally provided excessive light output. Reasonable electric lighting energy savings were achieved except under overcast sky conditions where the control system did not contribute to energy savings due to the less daylight through envelopes. The retractable shading device covering 50% of the internal envelope reduced energy savings up to 19.62%, but the workplane illuminance levels were maintained within recommended ranges. The coefficients of determination between workplane illuminance and photosensor illuminance due to daylight ranged from 0.74 to 0.98. Partially-shielded conditions provided best correlations and the north-facing room yielded stronger correlation than the south-facing room.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.10
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• pp.1382-1387
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• 2018

There is a high demand for energy efficiency improvement of factories that make up a large part of national electric energy. Therefore, research on smart FEMS technology for monitoring, analyzing and controlling energy consumption patterns is under way, but there is still a lack of research on detailed element technology for communication and control inside the factory. In this paper, we proposed OFDM VLC system based on MODBUS protocol for communication between gateways, sensors, and devices to implement smart FEMS in indoor factory environment. Assuming a conveyor belt load control, we validated the proposed system by simulating the inverter motor control and checking the performance.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.17-21
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• 2013

A building energy-saving have been increased worldwide interest. There is continuing research on IT technology for efficient management of BEMS. Recently, It is able to control of LED and to maximize energy savings to the development of LED lighting technology. We propose the security image processing system to improve efficiency and we implement the real-time status monitoring system to surveil the object in the building energy management system. In this paper, we proposed the system of LED control using Zigbee network for connect the server. User is able to control LED light and monitering by the desktop. We implemented LED light control software on the based of Real-time monitering and LED control. Also detect human body movement.