• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.53-57
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• 2004

The stabilization of fiber-optic current sensor has been achieved by using a broadband light source and a Faraday Rotator Glass fiber sensor coil. The very low Photo-elastic constant of the fiber suppressed output variations within ${\pm}0.4[%]$ when mechanical disturbance was applied to the sensor coil. Noise characteristics, with different light sources, have also been analyzed, which experimentally proved that the wider bandwidth source showed the better noise performance.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3156-3158
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• 1999

Occupancy sensor is a efficient light control system which light on/off automatically and reduces the unnecessary power waste. From now the research on occupancy sensor is restricted to the selection of the appropriate place or sensor. Exist occupancy sensor changes the delay time by manually to the place or situation, so it is unreliable. The delay time can been changed by the average time of the occupied and the preset time, but it is not enough to reliable. In this paper, so to acquire the reliance the average and the standard deviation of the occupied time change the delay time automatically and protect the malfunction from the detector. And to embody it, AT89C52 microcontroller is adopted to the control circuit. It is verified by simulation and experiment results of output characteristic for randomized input.

• Journal of the Korean Society of Industry Convergence
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• v.20 no.2
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• pp.89-95
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• 2017

In this paper, we suggest the method for a mobile robot to move safely from an initial position to a goal position in the wide environment like a building. There is a problem using odometry encoder sensor to estimate the position of a mobile robot in the wide environment like a building. Because of the phenomenon of wheel's slipping, a encoder sensor has the accumulated error of a sensor measurement as time. Therefore the error must be compensated with using other sensor. A vision sensor is used to compensate the position of a mobile robot as using the regularly attached light's panel on a building's ceiling. The method to create global path planning for a mobile robot model a building's map as a graph data type. Consequently, we can apply floyd's shortest path algorithm to find the path planning. The effectiveness of the method is verified through simulations and experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.2065-2067
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• 2015

In this paper, we analyze the performance of visible light communication system using rolling shutter CMOS sensor. For analysis, the effect of ISI (Inter-symbol Interference) on visible communication has been formulated. We validate our analysis through computer simulations.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.540-542
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• 1998

The Position Sensitive Detector(PSD) is an useful device which can be used to measure the position of an incidence light in accuracy and in real-time. In this paper, 2-D PSD sensor is used to measure the 2-D position of moving object with light source. To get the position of light source from PSD sensor exactly, we propose two position computation methods ; the parameter calibration and neural network. Experimental data is presented that offer the comparision between two methods and demonstrates the effectiveness of proposed approach.

• ETRI Journal
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• v.35 no.4
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• pp.566-570
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• 2013

In this paper, we demonstrate the capabilities of 380-nm ultraviolet (UV) light-emitting diodes (LEDs) using metal organic chemical vapor deposition. The epi-structure of these LEDs consists of InGaN/AlGaN multiple quantum wells on a patterned sapphire substrate, and the devices are fabricated using a conventional LED process. The LEDs are packaged with a type of surface mount device with Al-metal. A UV LED can emit light at 383.3 nm, and its maximum output power is 118.4 mW at 350 mA.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.8
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• pp.678-687
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• 2005

This paper describes a relative localization algorithm using odometry data and consecutive local maps. The purpose of this paper is the odometry error correction using the area matching of two consecutive local maps. The local map is built up using a sensor module with dual laser beams and USB camera. The range data form the sensor module is measured using the structured lighting technique (active stereo method). The advantage in using the sensor module is to be able to get a local map at once within the camera view angle. With this advantage, we propose the AVS (Aligned View Sector) matching algorithm for. correction of the pose error (translational and rotational error). In order to evaluate the proposed algorithm, experiments are performed in real environment.

• Korean Journal of Optics and Photonics
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• v.16 no.5
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• pp.433-439
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• 2005

We have developed a biosensor reading system using a white light source and a color-sensor. To reduce the environmental effect, we used the ratio of specific color intensity to the entire white light intensity. Also we could improve the responsibility of the system by controlling the amplification of the color sensor output.

• Smart Media Journal
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• v.8 no.3
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• pp.47-52
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• 2019

In this paper, we designed HW / SW interfaces for processing the signals of capacitive sensors like Electric Potential Sensor (EPS) to detect the surrounding electric field disturbance as feature signals in motion recognition systems. We implemented a smart light control system with those interfaces. In the system, the on/off switch and brightness adjustment are controlled by hand gestures using the designed and fabricated interface circuits. PWM (Pulse Width Modulation) signals of the controller with a driver IC are used to drive the LED and to control the brightness and on/off operation. Using the hand-gesture signals obtained through EPS sensors and the interface HW/SW, we can not only construct a gesture instructing system but also accomplish the faster recognition speed by developing dedicated interface hardware including control circuitry. Finally, using the proposed hand-gesture recognition and signal processing methods, the light control module was also designed and implemented. The experimental result shows that the smart light control system can control the LED module properly by accurate motion detection and gesture classification.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.953-956
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• 2009

We have investigated the effect of light on amorphous silicon thin film transistors based photo-sensor applications. We have analyzed the instability caused by electrical gate bias stresses under the light illumination and the effect of photo-induced quasi-annealing on the instability. Threshold voltage ($V_{TH}$) under the negative gate bias stress with light illumination was more decreased than that under the negative gate bias stress without light illumination even though $V_{TH}$ caused by the light-induced stress without negative gate bias was shifted positively. These results are because the increase of carrier density in a channel region caused by the light illumination has the enhanced effect on the instability caused by negative gate bias stress. The prolonged light illumination led to the recovery of shifted VTH caused by negative gate bias stress under the light illumination due to the recombination of trapped hole charges.