• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1233-1234
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• 2006

A simple new method to fabricate transparent carbon nanotube field emission devices was developed. The highly graphitized single wall carbon nanotubes were attached on Sn/ITO glass by arc discharge method. Post heat treatments below the deformation temperature of soda-lime glass guaranteed a good mechanical adhesion and electrical contact of the nanotubes. The Sn layer was oxidized below $400^{\circ}C$ and became transparent. As increasing the oxidation temperatures, the emission properties became stable and life time of emitter has been increased.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.258-263
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• 1989

The configuration of Brushless DC moter is similar to the permanent magnet Synchronous moter. Power transistors are oftenly used to supply the switching by feedback signals of rotor positioning sensors. Brushless DC moter have been used in Aerospace and Robotics where the electromagnetic noise or the sparking of the commutator contact can not be tolerated and long - lived maintenance - free operation is required. This paper describes the design of the microprocessor - based controller for the Brushless DC moter. The controller is designed to operate for the constant torque generation and variable speed control using sinusoidal PWM inverters and resolvers as rotor positioning sensors.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1457-1459
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• 2001

This paper deals with the change of surface Potential decay, surface resistivity, contact an91e and XPS of ultraviolet-treated PET films. From the experimental results on the surface Potential decay of UV degraded-samples, it was found that the accumulation of charge is decreased and the surface potential decay time is shortened. Also, from the result of XPS, it was found that the changes affected by the surface degradation of PET film were caused by the generation of carboxyl groups through the chain decomposition and recombination with oxygen molecules in the air.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1276-1278
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• 1998

In this paper, aging characteristics of silicone rubber used for outdoor insulation have been investigated with regards to sunlight effect. For this purpose, silicone rubbers were aged under the artificial sunlight by use of xenon arc lamp(1500W) and various tests were performed such as tracking, breakdown, contact angle, stress, strain. And then, in order to elucidate the changes of material, analysis have been followed as follows; FT-IR, SEM and EDS. Regarding the effect of the sunlight, it was obs that the surface of test samples are severely da with decreased hydrophobicity, tracking resistan breakdown strength.

• Carbon letters
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• v.14 no.4
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• pp.243-246
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• 2013

In this work, electroless Ni-plating on polyethylene terephthalate (PET) ultra-fine fibers surfaces was carried out to improve the electric conductivity of the fiber. The surface properties of PET ultra-fine fibers were characterized using scanning electron microscopy, X-ray diffraction, and contact angle analyses. The electric conductivity of the fibers was measured using a 4-point testing method. The experimental results revealed the presence of island-like nickel clusters on the PET ultra-fine fibers surfaces in the initial plating state, and the electric conductivity of the Ni-plated fibers was enhanced with increasing plating time and thickness of the Ni-layers on the PET ultra-fine fibers.

• The Korean Journal of Ceramics
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• v.4 no.1
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• pp.43-46
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• 1998

We have investigated the formation and thermal stability of cobalt aluminide(CoAl) thin films on GaAs. In order to obtain cobalt-aluminide thin films, we deposited a multilayer of Co/Al on GaAs, and subsequently annealed the samples at 80$0^{\circ}C$ for 30 min. After annealing, single-phase cobalt aluminide was produced showing a flat and uniform interface with GaAs. which indicates that cobalt aluminide (CoAl) is thermally stable with GaAs. In addition, the adherence and mechanical properties of the as-deposited, and annealed Co/Al multilayer structure on GaAs are compatible with those required for device fabrication processes. The electrical property of the CoAl/GaAs contact shows rectifying characteristics, indicating that the diodes were usable as rectifying gate electrodes.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1404-1406
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• 1998

The outdoor polymeric insulating materials such as silicone rubber, ethylene propylene diene monomer(EPDM), ethylene vinyl acetate(EVA) and epoxy are aged by various natural environment with the long-term performance in outdoor. In this paper, the effects of UV-ray on surface of silicone rubber were investigated by using the weather-Ometer. The accelerated aging stresses were simulated by UV radiation. high temperature and humidity as well as water spray. These the aging characteristics were examined through contact angle measurements, tracking resistance test, FT-IR and SEM/EDS analysis. the experimental results showed that tracking resistance decreases with increase in the UV-ray irradiation period. But the surface of silicone rubber kept hydrophobicity. It is found that the inorganic filler such as $Al(OH)_3$ improves tracking resistance and the $TiO_2$ is very effective in preventing degradation of silicone rubber surface from UV-ray.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.600-602
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• 2005

Recently image display devices have become large and high quality. To control the qualities of the component, measurements of the shape and thickness of a plate glass has been required. In order to measure the shape of the specular objects, Non-Contact Optical Sensor using Hologram laser unit was proposed. The sensor has a optical system that is composed of a Hologram laser and objective lens used for CD Player, and the sensor showed high performance for measuring the shape and thickness of transparent plates. In the sensor, the temperature of the sensor body is controlled by TEC(Thermoelectric Cooler). In this paper, we proposed the measuring method to make better performance of sensor using focus error signal of a hologram laser unit. It can measure the shape and the thickness of transparent objects with the s-type focus error signal which is generated by the sensor while it goes to the object.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2167-2169
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• 2004

The main concern for a displacement measurement is the performance of a sensor such as speed, resolution, accuracy and so on. The mainly used sensors are a linear CCD(charge coupled device) and a PSD(position sensitive detection) as a non-contact type. The output value of a linear CCD is so sensitive to a temperature change that it needs a cooling device. Additionally, because of its structural problem, there are some limits in resolution and speed, and it needs a complex image processing algorithm. Also, PSD has some disadvantages like sensitivity to environmental lights and nonlinearities. Like this, a linear CCD and PSD have their own characteristics and if we know them well, we can choose the one of the two sensors properly in some applications according to purposes. In this paper, I performed which one is superior to the other among the two sensors in terms of accuracy, resolution, measurement speed, signal to noise ratio.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2474-2476
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• 2004

지폐 인식 자동화기기가 여러 분야에 보편화되면서 다양한 지폐를 고속으로 처리할 수 있는 고속지폐 인식 자동화 기기가 요구되고 있다. 하지만 대부분의 지폐 인식 자동화 기기가 고속화에 적합하지 않은 구조로 설계되어 있고 신권 추가가 용이하지 않다. 본 논문은 고속 Paper Currency 인식 시스템에 적합한 범용 하드웨어 시스템과 Bayes Rule 기반의 고속 인식 알고리즘을 제안한다. 제안된 범용 하드웨어 구조는 고속의 CIS(Contact Image Sensor)와 DSP(Digital Signal Processor) 그리고 Dual Memory System으로 구성되었다. Bayes Rule에 기초한 고속 인식 알고리즘은 기존의 Paper Currency 인식 시스템에 사용되었던 기계학습 방법에 비해 신권 추가가 쉽고 적은 연산으로 권종을 판별할 수 있어 고속 지폐 인식 자동화기기에 적합하다. 본 논문에서는 제안된 방법들을 실제 자동화기기로 구현하여 그 유용성을 검증한다.