• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.4
• /
• pp.404-409
• /
• 2004

We fabricated photo-sensor for fluorescence detection in LOC. LOC is high throughput screening system. Our LOC screens biochemical reaction of protein using the immunoassay, and converts biochemical reaction into electrical signal using LIF(Laser Induced Fluorescence) detection method. Protein is labeled with rhodamine intercalating dye and finger PIN photodiode is used as photo-sensor We measured fluorescence emission of rhodamine dye and analyzed tendency of fluorescence detection, according to photo-sensor size, light intensity, and rhodamine concentration. Detection current was almost linearly proportional to two parameters, intensity and concentration, and was inversely proportional to photo-sensor size. Integrated LOC consists of optical-filter deposited photo-sensor and PDMS microchannel detected 50 (pg/${mu}ell$) rhodamine. For integrated LOC including light source, we used green LED as the light source and measured emitted fluorescence.

• Proceedings of the KIEE Conference
• /
• 1995.07b
• /
• pp.833-836
• /
• 1995

The Position Sensitive Detector(PSD) is an useful which can be used to measurement the position of an incidence light in detail and in real-time. In this paper, light sources, to be predefinded positions, are used as landmarks and the 2-D PSD signals are used to compensate the position of a running mobile robot. To induce the position compensation algorithm, first, we inspect the error factor, make the error model, and evaluate the error covariance matrix between the real position and estimated position in dead reckoning system. Next we obtain an optimal position compensation algorithm to update the estimated position using extended Kalman filler by the relation of the external light position and it's PSD signal. Through the simulation of navigating a robot the effectiveness of the proposed method is confirmed.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.1
• /
• pp.101-105
• /
• 2004

The laser ablation/ionization time-of-flight mass spectrometry is applied to the isotopic analysis of solid samples using a home-made instrument. The technique is convenient for solid sample analysis due to the onestep process of vaporization and ionization of the samples. The analyzed samples were lead, cadmium, molybdenum, and ytterbium. To optimize the analytical conditions of the technique, several parameters, such as laser energy, laser wavelength, size of the laser beam on the samples surface, and high voltages applied on the ion source electrodes were varied. Low energy of laser light was necessary to obtain the optimal mass resolution of spectra. The 532 nm light generated mass spectra with the higher signal-to-noise ratio compared with the 355 nm light. The best mass resolution obtained in the present study is ~1,500 for the ytterbium.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11a
• /
• pp.505-508
• /
• 2001

Currently there is much interested in removing latent charge that is caused to latent image effect and blurring of obtained image as well as reduction of x-ray conversion efficiency in digital radiography system. To remove latent charge a-Se film is irradiated by light with 3500 lux using halogen lamp and optical fiber. We measured dark current and photosensitivity to analyze removing effect of latent charge, then compared with and without light erasing method. The reduction of measured signal due to latent charge effect was 32.3%, and the removal effect of latent charge by using light erase method was its 95.5%.

• Journal of Satellite, Information and Communications
• /
• v.7 no.1
• /
• pp.59-64
• /
• 2012

Visible light communication is a novel way of green communication. In this paper, we present the novel idea of wireless communication services such as indoor navigation systems, where users can tell where they are by detecting a signal from LED lights.

• Proceedings of the KIEE Conference
• /
• 1994.11a
• /
• pp.382-384
• /
• 1994

Wireless communication has become a hot issue for its simplicity. Using light wave instead of micro wave has many advantages. It is simple to design a circuit because we can make a circuit with discrete components such as photo diode, photo detector, OP Amp[2]. And we can have many communication channels for we can use every frequency domain. In this paper, we design the wireless communication system and analyze the pulse signal. Then using ray tracing technology we simulate the distribution of light beam.

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

• International Journal of Highway Engineering
• /
• v.18 no.5
• /
• pp.63-73
• /
• 2016

PURPOSES : The objective of this study was to analyze variations in the vehicle driving behavior characteristics on signalized intersections according to the use of traffic enforcement camera (red light camera). METHODS : In order to analyze the driving behavior characteristics on signalized intersections when red light camera are installed, the target sites for investigation were selected depending on whether the red light camera is installed and accident rates increased after the installation. In particular, to analyze the characteristics of dilemma zones in signalized intersections, approach speed and deceleration speed of 3 type vehicles (passing vehicles during a yellow light, stopping at a yellow light, passing vehicles during a green light) were examined. Based on these data, the starting point, ending point, and distance of the dilemma zones were calculated. Also, the locations of increased traffic accidents and decreased accidents after the installation of the equipment were distinguished when analyzing the traffic accident characteristics. RESULTS : Analysis results revealed that there was a tendency for the dilemma zone distance to decrease after the installation of equipment(red light camera) in most sites. This tendency was found to be due to the decrease in the approaching speed of vehicles at intersections after the installation of equipment, resulting in the starting and ending points of dilemma zone to become closer to the stop line. Moreover, analysis showed that the number of traffic accidents decreased for most intersections after the installation of equipment and safety of the intersections increased somewhat. CONCLUSIONS : In general, installation of equipment(red light camera) caused the intersections approaching speed and dilemma zone distance to decrease. Decision-making is difficult for drivers in the dilemma zone, so the decrease in the dilemma zone distance implies an improvement in traffic safety. Furthermore, the number of accidents within intersections significantly decreased after the equipment was installed, leading to the conclusion that installation of the equipment affected the decrease in traffic accidents.

• Particle and aerosol research
• /
• v.12 no.1
• /
• pp.21-26
• /
• 2016

In order to realize In-line and convenient measurement for solid-gas two phase flows, Light Transmission Fluctuation (LTF) based on the random variation of transmitted light intensity, light scattering theory and cross-correlation method was presented for online measurement of particle size, concentration and velocity. The statistical relationship among transmitted light intensity, particle size and particle number in measurement zone was described by Beer-Lambert Law. Accordingly, the particle size and concentration were determined from the fluctuation signal of transmitted light intensity. Simultaneously, the particle velocity was calculated by cross-correlation analysis of two neighboring light beams. By considering the influence of concentration variation in industrial applications, the improved algorithm based on spectral analysis of transmitted light intensity was proposed to improve measurement accuracy and stability. Therefore, the online measurement system based on LTF was developed and applied to measure pulverized coal in power station and raw material in cement plant. The particle size, concentration and velocity of powder were monitored in real-time. It can provide important references for optimal control, energy saving and emission reduction of energy-intensive industries.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.05a
• /
• pp.741-743
• /
• 2017

The visible light communication is a communication method of outputting binary data based on the illumination threshold value at the light receiving diode of the receiving unit, when the LED of the transmitting unit transmits light. However, separate receiver is necessary to receive the optical signal, there is a problem that a device not equipped with such a receiver can not utilize visible light communication. To solve this problem, this paper proposes a portable visible light receiver applicable to devices using USB OTG. Implemented portable visible light receiver converts the binary data received from the LED into a character string of ASCII code and transmits it to another device. Through data transmission experiments using smart phone confirmed that it is possible to transmit ASCII codes in the proposed method.