• 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 Korean Academy of Oral and Maxillofacial Radiology
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• v.18 no.1
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• pp.213-225
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• 1988

This study was to compare the quality of image by different screen and film combinations. Using the sensitometer measured the speed and average gradient of blue sensitive films and orthochromatic films. The films was combined with rare earth screen LR, LM, LF and conventional screen OM, OH, XOR, OKa and exposed the step wedge to impulse 2, 3, 4, 6, 10, 15, 24,3 8, 60 and measured the density. The following results were obtained: 1. The density of film and film-screen combinations showed significant difference, then in film-screen combinations was significantly different by the screens than films. 2. The speed of blue sensitive films was little different, the TMG of orthochromatic films produced high speed, and the AX film was high average gradient. 3. The relative speed of film-screen combinations showed significant difference, and was high in the OKa of the conventional screens and in the LR of the rare earth screens, especially that of LR screen in the combination with blue sensitive films was high. 4. The average gradient of film-screen combinations showed no significant difference, and was high in the OKa screen and LR/OG combination, and that of OKa/AX combination was highest. 5. The latitude of film-screen combinations showed significant difference by screens, and was high in the LM screen in combination with blue sensitive films and in the OM screen in combination with orthochromatic films. 6. The subject contrast of film-screen combinations showed significant difference by screen, and was high in the LR screen in combination with blue sensitive AX film and orthochromatic TMG film.

• Journal of radiological science and technology
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• v.16 no.1
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• pp.67-80
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• 1993

Recently, a large number of new screen-film systems have become available for use in diagnostic radiology. These new screens are made of materials generally known as rare-earth phosphors which have high x-ray absorption and high x-ray to light conversion efficiency compared to calcium tungstate phosphors. The major advantage of these new systesms is reduction of patient exposure due to their high speed or high sensitivity. However, a system with excessively high speed can result in a significant degradation of radiographic image quality. Therefore, th speed is important parameters for users of these system. Our aim of in this was to determine accurately and precisely the absolute speed and relative speeds of both new and conventional screen-film system. We determined the absolute speed in condition of BRH phantom beam qulity and the relative speed were measured by a split-screen technique in condition of BRH and ANSI phantom beam qulity. The absolute and the relative speed were determined for 8 kinds of screen-4 kinds of film in regular system and 7 kinds of screen-7 kinds of film in ortho system. In this study we could know the New Rx, T-MAT G has the highest film speed, also know Green system's stndard deviation of relative speed larger than blue system. It was realized that there were no relationship between the absolute speed and the blue system. It was realized that there were no relationship between the absolute speed and the relative speed in ortho or regular system.

• Journal of radiological science and technology
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• v.13 no.2
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• pp.15-20
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• 1990

In clinical fields, single screen-film system will be generalized according to high speed and high image qualify of intensifying screen film system in future. In single screen-film system, for imaging the best image, we must choice good film according to speed and gredient. Double screen-film system will be replaced single screen film system in general radiography. Author has thought that single screen film system will be developed new diagnosis area according to X-Ray films.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.1
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• pp.75-83
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• 2011

As screen printing is changed by automation recently, could print more exactly. However, must suffer great many trial and error to have still gotten perfect result. By the way, at this step, fair time and money should be invested. Therefore, if search for optimum condition in early time visualizing screen printing process using simulator program before progress printing, is judged that may be correct and gets printing result efficiently. In this paper, searched optimum printing speed and ink viscosity using FLOW-3D program. Also, the result could confirm truth that is agreeing almost with experiment contents. Through this, is thought that may expect extension of screen printing wide application that vivify advantage of screen print if use simulation program.

• Journal of radiological science and technology
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• v.1 no.1
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• pp.15-24
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• 1978

The characteristics of the rare earth phosphors intensifying screen (LM-6, Grenex-8) as compared with $CaWO_4$ intensifying screen had been studied utilizing several common x-ray films, and found the following results. 1. Compared with the conventional CaWO4 intensifying screen, the rare earth phosphors intensifying screen was found to be more sensitive over to 1.26-3.47 times. So the radiation exposure could be reduced to 1/1.26 -1/3.47. 2. Sharpness as well as the film speed were both increased. So the motion blurring and geometrical unsharpness could be decreased. 3. In spite of that the film speed was increased, photographic contrast was kept up. Therefore, the more ideal film of greater latitude could be obtained. 4. The effects of the rare earth phosphors intensifying screen would be much increased as using with orthochromatic x-ray films.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.138-141
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• 2008

The screen doors installed in the station of subway are subject to the train-wind pressure caused by the operation of trains. The train-wind pressure has to be correctly estimated for the design of safe structure of screen doors. As three-dimensional numerical flow analysis technology has been significantly developed, the analysis on the train-wind pressure with diverse variables such as train specifications, train speed, tunnel and station configurations, and blockage ratio can be effectively carried out with three-dimensional numerical method. In this study, computational analysis of train-induced wind in a subway tunnel employing the screen doors are carried out by using the three-dimensional numerical method with the model of the moving boundary for the run of trains. While the numerical analysis of train-wind pressure was applied on the one island-type station in the Seoul Subway Line 2, maximum pressure of 494 Pa was estimated on the screen door when two trains pass each other at the speed of 80km/h in the platform.

• Journal of Korea Game Society
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• v.20 no.5
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• pp.41-52
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• 2020

This study aimed to address whether the varying degree of screen speed in the context of a Virtual reality exergame will interact with users' intrinsic motivation in influencing user perceptions. Results from our experiment (N = 40), showed that screen speed and intrinsic motivation have significantly interacted in influencing players' feeling of flow, attitude, and intention to replay the game (i.e., the 7km/h and 9km/h speeds have induced more favorable user perceptions than the 5km/h speed). Further implications of the findings are discussed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.5
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• pp.355-359
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• 2020

In this study, image analysis and surface roughness measurements using an optical microscope are presented as a method to quantitatively evaluate the results of screen printing. Using this method, the squeegee speed, which is the printing process condition, and the printability of the electrode according to the screen mesh were evaluated. Increasing the squeegee speed in the printing process acts as a process element that increases the line width precision of the printed electrode and lowers the surface roughness of the printed surface. Furthermore, the edge roughness, which indicates the clarity of printing, was not significantly affected by the speed of the squeegee during printing. The print thickness increases in proportion to the squeegee speed, but is largely dependent on the screen thickness.

• International Journal of Railway
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• v.2 no.2
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• pp.93-97
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• 2009

The experiments for aerodynamic characteristics of railway acoustic screen are performed using 1/61 scaled-down moving model rig facility which employs an axis symmetry and one wire guidance method. The launching mechanism is an air-gun type. The train model for the experiment is the high speed train (Korea Train Express: KTX) and the tested speed is about 300 km/h. The tested train length is 61 em which is corresponding to two units of KTX train. The cross sectional area and weight of train model are 0.00264 $m^2$ and 287 g, respectively. The Reynolds number based on the model train length is $1.2{\times}10^7$. The strength of pressure wave is measured using piezo typed pressure sensor. The measured pick value of pressure was as high as 365 Pa in the shortest gap between the acoustic screen and model train. The measured pressure is well compared with the field test data of mc 779-1 [2] values. However, the experimental data were slightly lower than the mc 779-1 values. The results show the model test can be used as a substitute for the field test.