• Design & Manufacturing
• /
• v.14 no.2
• /
• pp.42-48
• /
• 2020

This study is on the injection molding analysis for the LED outdoor lighting top cover of one heat sink body type structure. Thermoplastic and thermosetting resins were applied to compare the thermal properties during the injection molding process. The thermoplastic resin is used in this study due to special characteristics that it is light, good strength and dose long not transmute quality even if pass long time. The thermosetting resin is applied to this study due to good in strength, lightweight and excellent etc, thermal conductivity. This study presented a preliminary analysis of fill time, weld line, air trap etc. for the injection molding process of LED lamp cover and body through simulation using Moldflow. As a result of the study, it was selected HTM-102 material because the thermosetting resin has excellent strength and heat conductivity.

• Journal of Mushroom
• /
• v.11 no.1
• /
• pp.24-31
• /
• 2013

As a result of advenced research, Penicillium growth inhibition effect in media of cauliflower mushroom by different LED lighting color inhibited all treated groups, but blue wavelength treatment group was unfitted for culture of cauliflower mushroom due to lots of spore of penicillium. So, to investigated characteristics of mycelial growth of cauliflower mushroom according to different LED wavelength and LED wavelength color. As a results, all red wavelength treatment groups found highest mycelial growth tendency. Thus, mycelial growth investigated different quantity of red lighting wavelength conditions. The quantity of lighting wavelength was low intention, 1.41 ${\mu}mol/m^2S$ treatment group found highest mycelial growth. Effects of mycelial growth by subculture found difference of statistical in one time to carry out a subculture treatment group. Mycelial growth by different quantity of LED lighting in different media composition of wood chip media indicated highest trend in the Korean pine treatment groups. To cultured treatment group for 84th days found difference of statistical, when a quantity of LED lighting red wavelength 2.11 ${\mu}mol/m^2S$ treated in wood chip of the Korean pine media. In conclusion, good culture condition of cauliflower mushroom estimated quantity of red lighting wavelength 2.11 ${\mu}mol/m^2S$ in wood chip media of the Korean pine for 84th days.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.11
• /
• pp.1550-1559
• /
• 2013

Light emitting diode(LED) lighting has been applied various industry fields because of its high efficiency, low power consumption, long life time, and environment friendly characteristics. Generally, LED lighting needs a driver to maintain constant current. Most popular driver is the switching converter. In the converter, there are several electrolytic capacitors. However the lifespan of the electrolytic capacitor is much shorter than LED. Therefore the lifespan of LED lighting with electrolytic capacitor is decreased. Also, LED lighting needs dimming control because of various needs and energy saving. This paper presents the dimmable single-stage PFC DCM flyback converter without electrolytic capacitor and parallel LC resonant filter for reducing 120[Hz] ripple on the output. The type 2 controller is used to maintain constant current and the analog dimming control is used. The proposed converter is verified through simulation and experimental works.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.37 no.5
• /
• pp.486-493
• /
• 2024

Lighting has been used for a long time as a medium to convey brightness from darkness, and through incandescent lamps and fluorescent lamps, LED light sources have now become the standard in the lighting industry. Recently, the lighting equipment industry has been undergoing rapid digital transformation, starting with smart lighting, and is evolving into smart lighting customized for individuals and spaces through the development of IoT technology, cloud-based services, and data analysis. However, the blue light emitted from digital devices (computers, smartphones, tablets, etc.) or LED lights stimulates the melanopsin in the optic ganglion cells in the retina of the eye, which in turn stimulates the secretion of melatonin through the pineal gland, which regulates the secretion of melatonin. This can reduce sleep quality or disrupt biological rhythms. This interaction between blue light and melatonin has such a significant impact on human sleep patterns and overall health that it is essential to reduce exposure to blue light, especially in the evening. Human-centered lighting refers to lighting that takes into account the effects of light on the physical and mental areas, such as human activity and awakening, improvement of sleep quality, and health management. Many research institutes study the effects in the visible area and the non-visible area. By studying the impact, it is expected to improve the quality of human life. In this study, we plan to study ways to implement human-centered lighting by collecting sunrise and sunset data and linking commercialized LED packages and control devices with open-source hardware.

• Journal of Bio-Environment Control
• /
• v.25 no.1
• /
• pp.57-62
• /
• 2016

This study was conducted to find out the influence of red LED (Light Emitting Diode) lighting on the photosynthesis, vegetative growth and fruit quality of 'Fuji'/M.26 adult apple tree during night after sunset. The photosynthetic rate, stomatal conductance and transpiration rate at daytime of red LED treatments was not different to those of the control. However, the stomatal conductance and transpiration rate at the nighttime of red LED treatments were lower than those of the control, and the red LED lighting during night after sunset was not induce to photosynthesize at nighttime. In the leaf characteristics, the red LED lighting seemed to increase leaf area and C/N ratio, but decrease SPAD value. The bourse shoot length of the red LED treatments was shorter than that of the control. In the fruit quality, the red LED lighting seemed to increase ethylene production, respiration rate, soluble solid content and fruit red color, and especially the fruit red color tend to increase as the red LED lighting time was longer. In conclusion, the red LED lighting during night after sunset of 'Fuji'/M.26 apple tree promoted the fruit maturation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.10a
• /
• pp.324-327
• /
• 2014

This paper describes a study on the intelligent LED lighting system implementation applicated environmental reservation setting. The environment variables are preset by ON and OFF time of illuminator and brightness data. The setting data enables to be changed by personal preferences on the selecting menu. It is possible to reduce unnecessary consumption and operation for the lighting system. The system customized by user's environment is convenient for disability by using bluetooth. Thus the system results in cost effective and energy savings. The system performances are examined for convenient operation and energy saving for practicality in implemented system.

• Journal of Information Processing Systems
• /
• v.11 no.1
• /
• pp.125-133
• /
• 2015

The Remote Device Management (RDM) protocol is used to manage the devices in the lighting control networks. RDM provides bi-directional communications between a controller and many lighting devices over the DMX512-A network. In RDM, using a simple binary search scheme, which is based on the 48-bit unique ID (UID) of each device, discovers the lighting devices. However, the existing binary search scheme tends to require a large delay in the device discovery process. In this paper, we propose a novel partition-based discovery scheme for fast device discovery in RDM. In the proposed scheme, all devices are divided into several partitions as per the device UID, and the controller performs device discovery for each partition by configuring a response timer that each device will use. From numerical simulations, we can see that there is an optimal number of partitions to minimize the device discovery time for a given number of devices in the proposed scheme, and also that the proposed partition-based scheme can reduce the device discovery time, as compared to the existing binary search scheme.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.3
• /
• pp.66-72
• /
• 2016

An LED lighting control system was developed to combine information technology and LED lights for efficient management and energy savings. The system can monitor and control the status of an LED luminaire using Bluetooth wireless communication, sensor technology, and smart phones. An LED lighting control circuit was designed using a temperature sensor, illumination sensor, and Bluetooth module with a fuzzy constant-current control circuit. We extended the lifetime and prevented damage to the LED by optimizing the supply current of the LED luminaire based on the heat-generation temperature of $70^{\circ}C$ of an LED heat sink. We also automatically adjusted the ON/OFF time depending on the ambient illumination of the LED luminaire. By allowing easy control of the LED luminaires on a smartphone, we improved the efficiency and achieved energy savings. The control system was validated through experiments for normal operation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.4
• /
• pp.1419-1426
• /
• 2012

The heating and cooling energy load of the KNU plant factory was analyzed using the DesignBuilder. Indoor temperature set-point, LED supplemental lighting schedule, LED heat gain, and type of double skin window were selected as simulation parameters. For the cases without LED supplemental lighting, the proper growth temperature of lettuce $20^{\circ}C$ was selected as indoor temperature set-point together with $15^{\circ}C$ and $25^{\circ}C$. The annual heating and cooling loads which are required to maintain a constant indoor temperature were calculated for all the given temperatures. The cooling load was highest for $15^{\circ}C$ and heating load was highest for $25^{\circ}C$. For the cases with LED supplemental lighting, the heating load was decreased and the cooling load was 6 times higher than the case without LED. In addition, night time lighting schedule gave better result as compared to day time lighting schedule. To investigate the effect of window type on annual energy load, 5 different double skin window types were selected. As the U-value of double skin window decreases, the heating load decreases and the cooling load increases. To optimize the total energy consumption in the plant factory, it is required to set a proper indoor temperature for the selected plantation crop, to select a suitable window type depending on LED heat gain, and to apply passive and active energy saving technology.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.3
• /
• pp.16-25
• /
• 2013

Now it's a trend to install a series of white fluorescent light and orange high pressure sodium lamps because tunnel lighting should be opaque to the safety of drivers from soot, dust, humidity, and fog. Also fluorescent lighting is replaced to LED due to the fact that it improves amenity and object recognition and LED lighting has gradually been improved its nature. In this paper, we have implemented the circuits of the yellow series of high-pressure sodium lamps and white series of LED lights at one board to improve the transparency and recognition of objects. It is possible for inductive high-pressure sodium lamps and the capacitive LED drivers to circuit without power factor compensation. Two circuit parts share only a small number of parts, so low cost LED drivers compared to conventional ones are possible. Therefore, the implementation of the hybrid lighting with high-pressure sodium lamps and LED lights that can be driven at the same time by one driving circuit is possible. The LED capacitive power factor was 0.91 while individually implemented the sodium lamp power factor was 0.98. It shows not only the 2% improvement of hybrid forms but also the efficiency and THD.