• Journal of radiological science and technology
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• v.3 no.1
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• pp.29-35
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• 1980

The tube voltage in radiographic technique factors of the extremities was studied to use the acryl phantom and aluminum step wedge. It was the proper tube voltage that was over 55-60kV in the finger, over 65kV in the forearm and over 75kV in the knee joint.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1193-1195
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• 1995

The superconducting properties of YBaCuO thin films prepared by pulsed laser deposition(PLD) have been investigated. The x-ray diffraction patterns of the films are substantially different from one another. The YBaCuO thin films manufactured at the 20% of Argon mixture ratio were indicated $T_c$(zero)=88.2 K, $T_c$(onset)=92.1 K, and $J_c=9.0{\times}10^4A/cm^2$(at 77.3K).

• Journal of radiological science and technology
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• v.7 no.1
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• pp.41-46
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• 1984

Authors investigated an influence of x-ray tube voltage on x-ray quality and dose with using objects of various thickness, and obtained the results as follows: 1. Radiographic effects were influenced by tube voltages and objects. 2. Dose decrement rates hade more influence upon primary-rays than total x-rays at lower tube voltages. 3. The quality of transmitted x-rays was affected by tube voltages and thickness of objects. 4. Scattered-ray contents were proportional to tube voltages with using grid.

• Journal of radiological science and technology
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• v.7 no.1
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• pp.67-70
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• 1984

Radiographic units have changeable factors in x-ray outputs, Therefore, an exposure factor by basic experimental study must be made out about each x-ray installation, but this is very intricate methods and not a practical business. Authors tried out a new method to make simple exposure factors. The first, we had a experimental object radiograph taken to find the output of each radiographic unit. The second, by obtained x-ray density we found the difference in x-ray output. and lastly, we made a new and simple correction method to use the obtained output and x-ray density.

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.15 no.1
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• pp.159-172
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• 2004

The goal of junior colleges is to conduct professional education. But that purpose itself has faded for the distortion of goal. This study is geared to present solution to the problems facing tourism majors of junior colleges. What cause these problems is, first, imprudent increase of recruitments in the popular area, second, tourism companies tendency not to give them proper career opportunities, finally, lack of professional consciousness. To solve these problems, improvement of educational circumstance of junior colleges enlargement of the career opportunities of tourism companies are necessary and on the part of students, they need to receive enough education for personality and the enhancement of ability.

• Journal of radiological science and technology
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• v.2 no.1
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• pp.51-54
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• 1979

Research and Analisis for the qualities of chest films of emergency cases were completed in order to produce a valuable one of diagnostic necessity. It is resulted as follows; 1. Among the 3,505 cases of chest films, 47% of them was poor conditioned the reason was fowned as of unsuitable exposure. 2. It become the same condition when we increased 11.4% of KVp in full exhalation compare with the full inhalation of erect position and 20% after full exhalation and 4.3% after full inhalation in supine position. The result was that no difference between prone position and supine position was fowned. 3. When respiration volume is different, proper control of KVp is extremely needed.

• Journal of radiological science and technology
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• v.6 no.1
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• pp.35-41
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• 1983

Boot-Strap method is used to measure the sensitivity of X-ray film, but it is too complicated to design the plot and this method is generally a falling-off in the accuracy and the reproducibility. Authors made an attempt a new method to obtain the stable H-D curve, that is to say; Boot-Strap method used in combination with distance-change method, and the accuracy and the reproducibility.

• Journal of radiological science and technology
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• v.13 no.2
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• pp.27-30
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• 1990

It is an experimental report about object contrast according to the Kinds of screen and obtained results as follows : 1. In the same object radiography, use acquired the difference of the object contrast between LT-II ($CaWO_{4}\;system$) and G4 (Gd system) screens. 2. object contrast more decreased in Gd system screen than $CaWO_{4}$, and object contrast controlled by X-ray tube voltage. 3. The difference of object contrast seen clearly in 80 kVp.

• Journal of radiological science and technology
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• v.13 no.2
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• pp.21-25
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• 1990

This report is study about difference of H-D curve in regular film and ortho type film, and obtained results as follows : 1. In the blue-color emission intensifying screen, ortho type films and in the green-color emission intensifying screens, regular type are decreased in their gradient. 2. When joint use of regular type film and ortho type film, the gradient difference not seen in blue color screen. 3. The gradient difference seen clearly in G4, KM screens(green color emission intensifying). Especially, in part of high film density, the gradient difference are great. So we have to right use of screen and film because not matched used of theare the sensitivity and gradient are decrease.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1355-1357
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• 1997

In this study, the ferrite/rubber composite microwave absorbers mixed Ni-Zn ferrite and $Ni_2Y$ ferroxplana were prepared in order to control matching condion. The variation of the material constants($\dot{\varepsilon}$, $\dot{\mu}$) and microwave absorbing characteristics were investigated with various ferrite mixing ratio. The material constants of ferrite/rubber composite microwave absorber could be controlled by variation ferrite mixing radio. The matching frequency and thickness could be controlled with various ferrite mixing ratio.