• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.95-95
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• 2014

An OLED(Organic Light-Emitting Diode) device based on the emissive electroluminescent layer a film of organic materials. OLED is used for many electronic devices such as TV, mobile phones, handheld games consoles. ULVAC's mass production systems are indispensable to the manufacturing of OLED device. ULVAC is a manufacturer and worldwide supplier of equipment and vacuum systems for the OLED, LCD, Semiconductor, Electronics, Optical device and related high technology industries. The SMD Series are single-substrate sputtering systems for deposition of films such as metal films and TCO (Transparent Conductive Oxide) films. ULVAC has delivered a large number of these systems not only Organic Evaporating systems but also LTPS CVD systems. The most important technology of thin-film encapsulation (TFE) is preventing moisture($H_2O$) and oxygen permeation into flexible OLED devices. As a polymer substrate does not offer the same barrier performance as glass substrate, the TFE should be developed on both the bottom and top side of the device layers for sufficient lifetimes. This report provides a review of promising thin-film barrier technologies as well as the WVTR(Water Vapor Transmission Rate) properties. Multilayer thin-film deposition technology of organic and inorganic layer is very effective method for increasing barrier performance of OLED device. Gases and water in the organic evaporating system is having a strong influence as impurities to OLED device. CRYO pump is one of the very useful vacuum components to reduce above impurities. There for CRYO pump is faster than conventional TMP exhaust velocity of gases and water. So, we suggest new method to make a good vacuum condition which is CRYO Trap addition on OLED evaporator. Alignment accuracy is one of the key technologies to perform high resolution OLED device. In order to reduce vibration characteristic of CRYO pump, ULVAC has developed low vibration CRYO pumps to achieve high resolution alignment performance between Metal mask and substrate. This report also includes ULVAC's approach for these issues.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.241-245
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• 2006

EEFL(External Electrode Fluorescent Lamp) for LCD displays are analyzed on electrical and optical characteristics by various electrode length. The electrodes of EEFL are coated at the outside of the glass tube. Brightness and efficiency of the EEFL are affected on lamp impedance characteristic. So, the experimental models are proposed for analysis and measurements of the brightness and efficiency of the lamps according to the electrode length. The sample of LCD backlight unit is used for these experiments, EEFL arrayed BLU of 32' for commercial TV display. The parameters of the experiments were quantised for simple result reading as the length of electrodes as 15, 23 and 30 mm. The inverter was designed and manufactured in the laboratory as the Full-Bridge switching inverter. The feature of the output were measured on voltages about 1000 - 1400V at the currents of 11 - 29 mA and the brightness $15,000\;cd/m^2-40,000\;cd/m^2$. The experiments have shown that the brightness are increased by increasing of the electrode lengths which have the lamp currents increased. But at an certain conditions, the brightness and efficiency were decreased because of unmatched between the inverter output and lamp impedance. The optimum applications of the EEFL BLU of 32' in this experiments have been shown to choose the parameters for driving frequencies of 100 kHz - 150 kHz, the brightness of $18,000-19,000\;cd/m^2$ and efficiencies of 40 - 45 lm/w.

• Progress in Medical Physics
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• v.22 no.1
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• pp.3-11
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• 2011

The purpose of this study was to evaluate feasibility of Vertical Multileaf Collimator for determination of irradiation size using Vertical Multileaf Collimator and lead block to determine 4 different irradiation shape in case of Co-60 gamma-ray and 6 MV X-ray. We chose ion chamber, glass dosimeter and EBT chromic film to compare with Vertical Multileaf Collimator results and lead block results. In case of Co-60 gamma-ray and 6 MV X-ray, the central axis point dose normalized at reference field of lead block with ion chamber results for Vertical Multileaf Collimator were estimated higher than lead block about 5.1%, 4.2%. In case of Co-60 gamma-ray, the central axis point dose normalized at reference field of lead block with glass dosimeter results for Vertical Multileaf Collimator were estimated higher than lead block about 2.2%, 7.8%, 7.2%, 4.0% for reference, circle, triangle, cross field, respectively. In case of 6 MV X-ray, the central axis point dose normalized at reference field of lead block with glass dosimeter results for Vertical Multileaf Collimator were estimated higher than lead block about 6.7%, 6.2%, 3.8%, 6.2% for reference, circle, triangle, cross field, respectively. The results of EBT chromic film, Vertical Multileaf Collimator of penumbra size for all irradiation shape was smaller than lead block of those size that 2.0~3.5 mm for Co-60 gamma-ray, 0.5~1.0 mm for 6 MV X-ray. The results from this study, radiation treatment volume that results in shielding block can be minimized. In addition, during radiation treatment for 2, 3-dimensional radiation therapy using a Vertical Multileaf Collimator of this survey can be used to determine variety of irradiation fields.

• Child Health Nursing Research
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• v.8 no.2
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• pp.183-194
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• 2002

This study was conducted to obtain a basic information related to a more systematic safety education and measures against children's accidents by a descriptive survey with regard to accidents actually experienced by elementary schoolers, their perceived safety education activities and school facilities to their safety lives. The data was collected among 1,654 pupils, belonging to the 5th and 6th grades in Pusan from Nov. 20 to Dec. 1, 2000. The data was analyzed using SPSSWIN(7.5). The results were as follows ; 1. According to the perception by elementary schoolers, they received safety life instruction at school in most cases from teachers in charge of their own class (41.0％). Such safety education was provided often during formal classes(24.4％). Traffic guidance was given by parents, highest in frequency(67.3％). 2. Matters as most often treated during safety life instruction were safety knowledge or dangerous things(37.5％). A majority of notices of school safety instruction were presented sometimes(48.4％). Source of knowledge about safety lives included teacher (35.3％), parents(32.9％), TV and newspaper (29.9％). As a source of knowledge of emergency treatment, school nurses were accounted for 41.3％ that was highest. 3.Among the 1,654 students, 91.8％ experienced at least more than one case of safety accident. The most frequent type and cause of safety accident were wound(33.7％). and self-carelessness(38.4％) respectively. In most cases, the subject experienced such accident during a break time(32.2％) and at a playgrounds. Part of body as most often damaged by accidents were arms and legs, 25.4％ higher than any other sides problem solving measures against the accident were taken by school nurse in most cases, 44.8％ in percentage point. 4. Those students' perceived safety management of school facilities showed that they considered classroom facilities as most safe (61.6％), while playground facilities as least safe(42.8％). They also responded that the treatment of glass fragments or stones at playground is the most important item of safety management.