• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.24 no.5
• /
• pp.433-442
• /
• 2012

The influence of outdoor sky conditions on photosensor signals were examined to determine an appropriate index that is effectively used for optimum illuminance fluctuation when a daylight dimming system is used for a small office. Field measurements were conducted under various sky conditions. Results indicate that the outdoor global and vertical illuminance fluctuated within narrow ranges under clear and overcast sky conditions. The fluctuation of sky ratio under partly-cloudy sky caused wide ranges of illumnance fluctuation. A partially-shielded photosensor at backwall produced 56% of light output from fixtures controlled by a photosensor at ceiling. This implies that the photosensor at backwall does not always guarantee target illuminance due to the less output. The fluctuation of light output from fixtures were insignificant under clear and overcast sky. The fluctuation range of photosensor illuminance under partly-cloudy sky caused wide fluctuation ranges of light output. Regression result implies that the outdoor vertical illuminance was recommended for an effective index that is used for control of light output.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.4
• /
• pp.63-69
• /
• 2014

Visible light communication is a communication method using an LED's blinking(ON/OFF), it has a feature of light because of the limit of perception by the human's optic nerve. LED' dimming control used in the VLC system is important factor needed to provide energy saving and life benefits. With advances in VLC system, MIMO technology has received much attention in that it can be obtain channel capacity proportionate to the number of antenna. Therefore, in this paper, with RC method which is one of the MIMO style in VLC system, it is compared communication performance using RZ-OOK, VPPM, MPPM and OPPM. As a result of the simulation was run against this, MPPM works well in terms of Power requirement and OPPM works well in terms of Spectral efficiency and Bandwidth requirement, also it was confirmed that there is a significant impact on the communication performance of each modulation scheme according to the dimming.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.2
• /
• pp.461-468
• /
• 2010

This paper presents a simple digital LCD backlight inverter using a single-chip microcontroller. The proposed inverter reduces the ignition voltage and eliminates the current spikes and hence improves the ignition behavior of the cold cathode fluorescent lamp(CCFL). Thus it increases the CCFL's life span. This is achieved by implementing a digital dimming control algorithm, that contains the soft-starting algorithm, all on a single-chip microcontroller. The inverter utilizes the full-bridge resonant circuit topology. The design example along with a simple analysis for the inverter is shown, and the experimental results of the designed prototype results in close agreement with the theoretical analysis and explanation. The overall system's power efficiency is approximately 85%. Compared with conventional inverters, the ignition voltage is reduced by around 30% without any lamp current spike occurring during the dimming control operation.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2018.07a
• /
• pp.521-523
• /
• 2018

본 논문은 PV시스템과 조명제어 알고리즘을 이용해 건물에너지 감소 ICT 융복합 플랫폼 개발에 관한 연구내용을 보여준다. 개발 된 ICT 플랫폼은 비 주거 건물 환경에서 전력을 절감 할 수 있으며, 건물에너지 감소를 위해 조명부하 감소에 중점을 두었다. 본 연구는 이를 위해 LED 디밍 알고리즘을 설계 및 적용하고, ESS 및 PV와의 연계를 통하여 건물에너지 절감 시스템을 제안한다. 제안 된 시스템은 ICT 융합 플랫폼과 LED제어 알고리즘으로 구성 되어 있으며 ICT 플랫폼은 계통 및 ESS 전력 제어/관리 및 모니터링을 수행하고, LED제어 알고리즘을 통해 상황인지기반 조명부하감소를 수행한다. 본 논문에서 제안 된 시스템의 연계 신뢰성을 시뮬레이터 및 에뮬레이터를 통하여 성능 분석을 하였다.

• Journal of the Korea Computer Industry Society
• /
• v.10 no.3
• /
• pp.99-104
• /
• 2009

In this paper, fluorescent lamp on/off control and luminous intensity used an power line communication and remotely will be able to control system design. Embodied the respectively illumination equipment and tools by the network using PLC. In order to remote control and on/off of illumination equipment, luminous intensity composed a server. Will convert a previous analog system with digital system and the possibility witch will reduce an error ratio was. Consequently will be able to simplify a circuit.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.17 no.5
• /
• pp.71-78
• /
• 2017

Visible light communication (VLC) offers communication function in addition to illumination. Because the signal communication capacity per cable is 1,000 times compared to the power line communication (PLC), optical fiber is being advertised as the basis of the information and communication. Also dimming control of LED is an important component needed to provide energy savings and quality of life. This study configured multi-hop VLC system model in a building using optical fiber and analyzed the power performance of two of modulations using dimming techniques. The transmission power and received power were used to compare the power performance in multi-hop VLC environments.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.4
• /
• pp.1233-1238
• /
• 2010

The lighting industry has become the bigger and more systemized using the semiconductor LED with each control R(Red), G(Green), B(Blue). The communication standard DMX512(ANSI E1.11) protocol of it basically needs the address which can be distinguished between the lighting terminals. The conventional method has to give the address of the lighting any methods like dip switch, EEROM and PROM. Then the lighting terminal can receive RGB data from DMX512 communication. According to electrical characteristics DMX512 protocol has to the splitter every 32 lighting terminals. If 512 lightings is all connected, maximum 16 splitters are needed. This paper is solved above weakness in DMX512 protocol using serial connection all lighting terminals. Also I developed the intelligent lighting terminal with auto-addressing. This was solved the inconvenience of the address assignment and the usage of the splitter. The developed products is applied and selled the semiconductor lighting terminals using ON-OFF control, dimming control, sequential control and rainbow control.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2017.11a
• /
• pp.1058-1060
• /
• 2017

본 논문에서는 고속도로에서의 방향성을 고려하여 저전력형 가로등 제어 시스템을 설계하고 구현했다. 본 연구에서 제시한 시스템은 조도 센서와 적외선 센서를 이용해 디밍이 가능하고, 차량의 이동 방향에 따라 해당 방향의 가로등이 점등되는 시스템으로 야간에서 가로등에 소비되는 전력량을 줄여 에너지 효율을 향상시킬 수 있음을 확인하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.55-57
• /
• 2022

In this study, a customized semi-passive RFID receiver module was implemented for in-VIVO deep tissue photo-therapy. A novel wireless technique is required due to a limitation of RF communication in body environment, as internal body has a complex structure such as, skin, fat, skeleton, water, and so on. Recently, coherently incoherent beamforming (CIB) based on RFID was introduced and it is able to transmit wireless signal with high reliability under the incoherent condition such as in-VIVO deep tissue. The proposed miniature photo capsule based on RFID consists of miniature controller, ultra small LED array and wireless RFID chip. RF Reader can access with standard RFID protocol (ISO 18000-6c) using UHF RFID antenna, a control command is wirelessly writtern on USER Bank memory. With received control command, therapy LED array dims with mulilevel under timer control. The signal process of designed RFID photo therapy capsule is analyzed and evaluated under the various environments in detailed.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.10
• /
• pp.235-242
• /
• 2014

LED lighting control technique is one of the ongoing research areas for efficient management of LED lighting. In this paper, we design and implementation of LED street lighting remote control system which have a wired and wireless communication function for LED street lighting remote control. The implemented system can automatically dimming and individual(or consolidated) LED street lighting via RS-485/422 or Wi-Fi. In experimental results, the implemented remote control system was satisfactory for all of the desired functions.