• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 C
• /
• pp.1954-1956
• /
• 2004

Nowadays, $CO_2$ lasers are used widely in many applications such as materials fabrication, communications, remote sensing and military purpose etc. Especially, $CO_2$ lasers are in the spotlight at surface handling and heat processing. It is important to control the laser output power and beam Quality in those fields. And those are studied the important parameters deciding the fluctuation of laser beam are smoothing capacitor, frequency and the characteristics of laser resonator. But the study of plasma parameters of $CO_2$ lasers are little. So we detect the $CO_2$ laser from emitted $CO_2$ laser discharge plasma using a non-contact photo tansistor sensor and Low pass filter. In this study, The relativity of the emitted light of discharge plasma and CO2 laser output.

• Current Photovoltaic Research
• /
• 제10권4호
• /
• pp.111-115
• /
• 2022

For the high efficiency of the photovoltaic module, a high-output solar cell, which is the basis of photovoltaic power generation, is required. As the light receiving area of the solar cell increases, the light receiving area of the photovoltaic module also increases. Accordingly, recent trend is to use large-area solar cells such as M6 and M8 instead of M2-based solar cells for manufacturing the photovoltaic module and a study on the mechanical stiffness of the module with increased size is required. In this study, a mechanical load test corresponding to IEC-61215 was performed among the reliability tests of large-area photovoltaic modules. In order to confirm the degree to which the mechanical load test affects the photovoltaic module, the output and EL images were checked by sequentially increasing the pressure by 600 Pa at a pressure of 2400 Pa. Also, factors such as output and efficiency of large-area photovoltaic modules were verified through mechanical load testing of actual large-area photovoltaic modules and the rate of change was very small at 1%.

• International journal of advanced smart convergence
• /
• 제2권2호
• /
• pp.16-18
• /
• 2013

In this paper, we develop a method to design a flexible thin film audio systems utilizing Polyvinylidene fluoride. The system we designed showed the properties of increased transparency and sound pressure levels. As an input terminal transparent oxide thin film is adopted. In order to provide dielectric insulation, a transparent insulating oxide thin film is coated to obtain double -layered structure. In the range of visible light, the output from the output of the system showed an increased and improved sound pressure level. The piezoelectric polymer film of polyvinylidene fluoride (PVDF) is used to produce mechanical vibration due to the applied electrical voltage signal. An analog electric voltage signal is transformed into sound waves in the audio system.

• 한국전기전자재료학회논문지
• /
• 제22권12호
• /
• pp.1078-1083
• /
• 2009

Generally Lighting system consists of lamp and luminaire. When a fluorescent lamp is installed in luminaire, power and light output is changed by ambient temperature. Particularly electrodeless lamp depends on the changes that are mercury pressure with amalgam temperature and magnetic properties with ferrite temperature. It has finally influence on optical efficiency. In this study, the temperature change of ferrite and cold spot, vessel are measured at transitional state and then same characteristics are measured with increase of ambient temperature. At transitional state, luminous flux is related to temperature change of cold spot that compare with behavior of mercury pressure and light output. At increase of ambient temperature, we analyzed change that efficiency and electrical, optical characteristics of elecrodeless lamp are related to ferrite core and cold spot temperature.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2011년도 춘계학술발표대회
• /
• pp.22.2-22.2
• /
• 2011

Reliability and degradation mechanism of conventional phosphor-converted white GaN-based light-emitting diodes (LEDs) were investigated. Under electro-thermal stress condition, the optical output degraded rapidly at the initial stress time accompanied by the change of chromatic properties. This could be attributed to the optical degradation of packaged materials, in particular, the browning of encapsulants and the darkening of reflective packages. At longer stress times, the optical output gradually decreased according to the degree of the reverse leakage currents, namely, the generation ofnonradiative recombination defects. This indicates that the optical degradation of white LEDs are dominated by the darkening of packaged materials and the generation of defects depending on the injection current and ambient temperatures. Using analyses of electroluminescence spectra, optical microscopy, electrical, optical, and thermal properties, optical degradations of white LEDs are discussed.

• 한국전기전자재료학회논문지
• /
• 제19권12호
• /
• pp.1149-1153
• /
• 2006

We developed the equipment palpating cell proliferation using a high brightness LED. This equipment was fabricated using a micro-controller and a high brightness LED, and designed to enable us to control light irradiation time, intensity, frequency and so on. Especially, to control the light irradiation frequency, FPGA was used, and to control the change of output value, TLC5941 was used. Control stage is divided into 30 levels by program. Consequently, the current value could be controlled by the change of level in Continue Wave(CW) and Pulse Width Modulation(PWM), and the output of a high brightness LED could be controlled stage by stage.

• 전기전자학회논문지
• /
• 제23권4호
• /
• pp.1465-1468
• /
• 2019

The image noise improvement algorithm proposed in this paper extracts the boundary line by using the window of the binarized image to detect the gesture motion. Boundary line blurring is prevented by improving Gaussian noise generated during video output. To improve gesture recognition in low-light environments, an image noise enhancement algorithm has been designed to provide an output image close to the base image. Analyzing the experimental results, we found almost 10% improvement in the results compared to the results of the existing Median filter.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 춘계학술대회 논문집
• /
• pp.1722-1728
• /
• 2007

This study analysed testing method for performance verification in the phase of signalling system development for application in the Light Rail Transit(LRT). The main focus in this study therefore includes development of vehicle location detection system by first GPS and analysis of performance verification method by field testing. The comprehensive testing method has been analysed for the signalling system for LRT high speed operation. The signalling system for LRT high speed operation deals with vehicle location identification through vehicle location information using the second GPS and decision for whether the high speed proceed signal and departure inhibition output is feasible or not and for signalling output to the corresponding vehicle.

• 한국전자통신학회논문지
• /
• 제4권2호
• /
• pp.123-129
• /
• 2009

본 연구에서는 철도 및 공항 등 대형 교통수단의 표시등으로 사용하기 위한 LED 신호등 구동회로를 설계하고 제작된 SMPS의 전기적 특성을 측정하였다. 입력전압 8~12VAC 및 8~16VDC에 대하여 출력전압, 출력전류 및 전력효율은 각각 6VDC, 1.85ADC 및 >70%이었다. 또한 규정한 AC 입력전압에 대하여 측정한 역률은 모두 0.75 이상의 값을 얻었다.

• 대한전자공학회논문지
• /
• 제7권2호
• /
• pp.1-12
• /
• 1970

본 논문에서는 선형전기광효과(Pockel 효과)를 이용하여 X대역 마이크로파(9375 MHz)를 광변조하는데 관하여 이론적인 해석과 실험적인 연구를 했다. 전기광 결정체 KDP를 공진형 변조기로 설계하여 z축으로 광선과 평행하게 마이크로파 전계를 인가하여 변조했다. 변조파 출력을 가변단락판의 위치변화에 따라 관찰했으며 /2에서 변조가 잘 개폐되는 것을 알았다. 또한 출력변조의 세기를 인가 전계의 세기를 변화시켜 측정하여 이론곡선과 비교해서 약 5%의 오차를 얻었다. 결과적으로 아직 해결되어야 할 문제는 많이 있지만 비교적 만족스러운 광변조기를 얻었다.