• Journal of Korean Ophthalmic Optics Society
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• v.1 no.1
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• pp.53-56
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• 1996

In testing visual acuity of kindergarten's children, single Landolt's ring in chart projector was used under proper intensity of illumination. According to the result of 218 eyes' test, 0.6 V.A. forms 8.5 % at the age of 3, 0.7 V.A. forms 84.7 % at the age of 4, and 1.0 V.A. forms 6.8 % at the age of 5. However, children's visual acuity has been gradually developed with their growth. None of emmetropia can be found through the test. All of the children have ametropic eyes.

• Journal of radiological science and technology
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• v.15 no.1
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• pp.79-87
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• 1992

It is a matter of common knowledge that madical radiation is most accented for of radiation is doses applied to the whole of people, and of them the radation dose by radiography diagnosis is mainly prevalent. In applying X-rays to a certain man for radiography diagnosis a radiologyist will have to have an absolute sense of mission concerning the reduction and prevention of the patient's radiation dose as the radiologyist obligation. Accordingly, the radiography conditions of the patient's chest employed 197 medical facilites were surveyed and skin dose was computated by the IPH Bit system and examined. As a result, it was shown that the average skin dose was $288\;{\mu}Sv$, its minimum value was $1600\;{\mu}Sv$, which was over 32 times its minimum value. This shows that the appropriate radiography method has not been applied at applying X-ray to the patient. It comes from the performance of X-ray equipment, the choice of auxiliary equipment materials etc. But the most important thing is to master the appropriate radiography condition, and therefore this point will have to be kept in mind.

• Journal of radiological science and technology
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• v.2 no.1
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• pp.59-69
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• 1979

For the clearer visualization of the lung apices in the routine chest P-A view, we have analysed the films at the different positions and different directions of the central X-ray beams. The brief results are as the follows. 1. Best visualization of the lung apices are made with the following position of the patient and central ray. Central ray is directed to the median sagittal plane at the level of the 5th thoracic vertebra with the palms of the hands placing at the greater trochanteric area of the both femurs. 2. The position of the sterno-clavicular joint shows no alteration between the radiographs with the central beam to the film center and to the 5th thoracic vertebra, and position of the hands at the greater trochanters or iliac crests. 3. No relationship exists between the center of the film and the position of the hand. The central beam is projected more inferiorly when the beam is centered to the film center than to the 5th thoracic vertebra. 4. The scapulae are rotated sufficiently anteriorly and more inferiorly, with placing the palms at the greater trochanters, directing central ray to the 5th thoracic vertebra, and with close contact the lung apices to the cassette.

• Journal of radiological science and technology
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• v.2 no.1
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• pp.15-22
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• 1979

Author made a experiment on the exposure dose with various intensifying screens in taking chest roentgenogram and obtained the results as follows; 1. Special speed type was the most sensitive intensifying screen, the r(gamma) value of this screen was distributed from 2.6 to 2.9. 2. The resolution activity of intensifying screen was inversely proportional to its sensitivity. If, the sensitivity and detail of the fine detail speed type intensifying screen at 100 KV were 100, those of the special speed type were 549 and 54.44 respectively. 3. If the exposure dose of the fine detail type intensifying screen was 1.0 at 60 KV, that of the special speed type intensifying screen was 0.1 at 80KV, and the skin dose of patient was as follows; it was 64.8 mRad at 60KV in mid speed type, 8.1 mRad at 80KV in super high speed type, and 7.2 mRad at 80KV in special speed type intensifying screen respectively.

• Journal of Nutrition and Health
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• v.11 no.3
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• pp.37-42
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• 1978

Actomyosin and myofibril were extracted from Korean native Goat muscle with the Weber-Edsall solution. ATPase activities and physiochemical properties were measured. The results obtained were as follows; 1) Mg-activitied ATPase activity of actomyosin and myofibrill from Korean native Goat muscle exhibited a common biphasic response, a typical ATPase pattern, that is high at a low ionic strength and low at a high ionic strength. Actomyosin showed high activity than myofibrill. 2) Mg-activited ATPase activity of actomyosin from muscle increased extraction time 24 hours. 3) EDTA-enhanced ATPase activity of actomyosin was greater than myofibrill and low at the low ionic strength, high at the high ionic strength. The difference of the activity were shown great broad pattern at the after 0.3M KCI concentration. 4) Effect of EGTA on-ATPase activity of myofibrill and actomyosin from muscle was measured, the Mg-ATPase activity was markedly depressed. 5) Solubility of actomyosin from muscle began to solubilize at KCI concentration of 0.28M and solubilized completely at the KCI concentration of 0.3M.

• Journal of radiological science and technology
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• v.10 no.1
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• pp.49-53
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• 1987

This thesis compared and analyzed the characteristics, centered on a characteristic curve, about X-ray computerized tomographic film generally used in Korea recently. The results were as follows: 1. Maximum gradient (gamma) was film A-2.19, film B-2.00, film C-1.92. 2. Latitude was confined within the limits of density 0.6-2.0 in all. 3. When we changed window center from 0 to 40, the difference of density, which was in 1.0, was film A-0.12, film B-0.16, fil m C-0.14. 4. When we changed window width from 0 to 500, the difference of density, which was in 1.0, was film A-0.06, film B-0.08, film C-0.05. 5. In the case of window width 50 and window center 20, latitude was 0.5-2.0, 0.5-2.2, 0.5-1.9 and gamma value was 1.74, 1.82, 1.72 respectively, 6. In the case of window width 80 and window center 30, latitude was 0.6-2.2, 0.6-2.3, 0.8-2.2 and gamma value was 2.0, 2.13, 1.95 respectively.

• Journal of radiological science and technology
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• v.1 no.1
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• pp.61-67
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• 1978

Recently, Demands of automatic X-ray film processors are increasing more and more at general hospitals and private clinics, but various troubles because of incorrect control were found out. Authors have researched to find out the function and activity of automatic X-ray film processor for 70 days with Kodak X-OMAT processor, and results obtained were as follows; 1. Automatic X-ray film processor have an advantage to conduct the rapid treatment of X-ray film processing, but incorrect handling of developing and fixing agents were brought about a great change in contrast and optical density of X-ray film pictures. 2. About 10,000 X-ray films could be finished by same developing and fixing solution without exchanging any other solutions in automatic X-ray film processor.

• Applied Chemistry for Engineering
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• v.5 no.6
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• pp.957-966
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• 1994

The transformation of butanes and 1-butene into aromatic compounds was performed over HZSM-5 catalyst and its Ag ion-exchanged form. The yield of aromatic hydrocarbons appreciably increased by incorporating silver cations into HZSM-5. The silver cations serve as catalysts for dehydrogenation of the starting hydrocarbons. $Ag^+$ ions could be reduced to $Ag^0$ metals with resulting in the formation of acidic OH grops by hydrogen produced during the dehydrogenation of butanes and 1-butene. The reaction of 1-butene over ZSM-5 with different loading of Ag was carried out to investigate the effect of acidic properties of these catalysts.

• Journal of Technologic Dentistry
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• v.5 no.1
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• pp.5-11
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• 1983

In order to ascertain the aspects of the dental technicians training system which require improvement, and also to provide important data for use in setting up dental technicians manpower planning, our country's dental technicians training and employment status has been studied and analyzed. The objects of the survey are 1896896 dental and Social Affairs from 1965 to 1982. The results were as follows; 1. Education organs for dental technicians are education system such as health junior college and service training systems. About 965 dental technicians have come from the service training systems and 931 technicians have come from health junior college in our country. 2. Total number of employment of dental technicians employed in our country are 820, and 292 of them are engaged in Seoul, So unbalanced employment of dental technicians will be troubled in a future. 3. All registrated to government are 1,896 till 1982 and 820 of them engaged are that is, we can suppose about employment of dental technicians in a future, 3,746 dental technicians will registrate to Health and Social Administration an 1992, and 1,482 of them will be able to take their job in Korea.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1747-1749
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• 2001

This paper simulated discharge progress and partial discharge using needle-plan electrodes system in $SF_6$, studied the distribution of frequency spectrum of the radiated electromagnetic waves using biconical antenna and spectrum analyzer. From results of this study, a method was introduced for measurement and analysis of the radiated electromagnetic waves in accordance with discharge progress in $SF_6$. Besides, according to the consideration of the mutual relation between frequency spectrum of the radiated electromagnetic waves and discharge progress, it was confirmed that detecting partial discharge and estimating discharge progress in $SF_6$ can be possible.