• Journal of radiological science and technology
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• v.42 no.6
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• pp.423-428
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• 2019

The Precise measurement of the knee's Congruence angle is required for diagnosis of patella dislocation. The purpose of this study is to consider the distortion diagram and usefulness about the test of the bilateral side and one side through the evaluating congruence angle from Merchant view of patellofemoral joint to central X-ray. We've evaluated the sulcus angle and Congruence angle following central X-ray's changes when we took Merchant view of patellofemoral joint aimed to right lower limb from human whole body phantom. The subject of the evaluation was classified as normal group and varus group, and the varus group has experimented with External rotation of legs as 15° and 30°. When normal groups result as 0, 7.5, 15 cm, it was measured as 17.25 ± 1.34°, 19.60 ± 1.41°, 20.55 ± 1.77° each. The gap between minimal and maximum angle was 3.3°, and the value was shown as getting bigger when it further away from the centeral X-ray. When Congruence angle in 15° varus group was 0, 7.5, 15 cm, it was each 16.45 ± 1.34°, 17.10 ± 0.99°, 17.80 ± 1.13°. And when Congruence angle in 30° varus group was 0, 7.5, 15 cm, it was measured each 18.35 ± 1.63°, 18.95 ± 1.06°, 19.60 ± 1.41°. The difference between minimum and maximum of angle in 15° varus group and 30° varus group was each 1.35° and 1.25°, the angles have shown as increasing the further away from the center. The patellofemoral joint showed that the congruence angle increases as the further away from Central X-ray, and also it is judged that is possible to change the congruence angle by a degree of varus knee. Thus, accurate measurement of the congruence angle is shown to advantage that methods for examining by split each side at two times than methods for examining both sides at a time. Therefore, it is expected to helpful on the diagnostic side of patella dislocation and subluxation.

• Publications of The Korean Astronomical Society
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• v.7 no.1
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• pp.39-50
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• 1992

A velocity inhomogeneity, which is the regional preponderence of either radial or tangential orbits, is searched with the new technique proposed by Kim (1992) for Coma, Hydra I, and Abell 2256 cluster of galaxies. Conspicuous inhomogeneities are found in the Coma and A2256 which X-ray isophotes are indicative for their underlying potentials being ellipitcal in shape, Even in their central regions, zones that are dominated by radial orbits are clearly distinguishable from that of the tangential orbits, and defining the cluster 'equator' as the direction of maximum elongation of the X-ray isophotes, radial orbits dominate along this direction whereas tangential orbits dominate the 'polar' zones. Merger events that are evidenced in X-ray observations occur in the equatorial zones of Coma and A2256, suggesting preponderence of radial orbits in the zones, which is in good agreement with their velocity structures. On the other hand, the inhomogeneity in Hydra I turns out to be insignificant in the central regions and this is just what is expected from a cluster whose X-ray isophotes is nearly circular. The velocity distribution in regions further out, however, shows significant inhomogeneity and this seems to support the previous results that this cluster is likely to have substructures and velocity anisotropy.

• Journal of the Korean Society of Radiology
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• v.6 no.6
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• pp.465-471
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• 2012

In this study, three dimensional X-ray dose distribution from dental X-ray generator system was measured by ALOKA PDM-117 dosimeter. The X-ray dose distribution will be change with XCP-DS FIT in oral shot, because the distance between X-ray generator and the dosimeter. The X-ray dose change affects on patient exposure and radiograph image quality. Therefore, it is important to obtain relation between the X-ray dose and the distance. The X-ray dose at the central position was decreased with increasing the distance. Furthermore, the dose at the edge of the X-ray flux was increased with increasing the distance. The increased dose affects on the patient radiation exposure. The present results will provide for good dental radiograph image and reducing radiation over-exposure on patient.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.557-558
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• 2018

• Journal of the Korean Society of Safety
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• v.25 no.1
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• pp.27-31
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• 2010

It is a well known fact that the LCD and Semiconductor Devices are a central part of IT industry which is important in the present and the future. But the biggest problem of Semiconductor and LCD manufacturing is maintaining a cleaning room environment. For this reason, the soft X-ray type Ionizer was used as the electrostatic reducer device, which protects damage of the product against electrostatic discharge in the manufacturing process. Therefore it is a essential important factor during Semiconductor and LCD production process. But the soft X-ray has a intrinsic problem with harmful to human being in case of soft X-ray exposure. That's reason we have the research to solve above problem and made an apparatus that it was covered with shielding structure to protect X-ray radiation to outside. And besides, it has a possibility to eliminate the charged electrostatic in the narrow space through the slot for Ion emissions with dual soft X-ray sources on the both side. It is also not make the particles from itself when it has been operated.

• Journal of Information Processing Systems
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• v.18 no.3
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• pp.319-331
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• 2022

The capability to examine an X-ray image is so far a challenging task. In this work, we suggest a practical and novel algorithm based on image fusion to inspect the issues such as background noise, blurriness, or sharpness, which curbs the quality of dual-energy X-ray images. The current technology exercised for the examination of bags and baggage is "X-ray"; however, the results of the incumbent technology used show blurred and low contrast level images. This paper aims to improve the quality of X-ray images for a clearer vision of illegitimate or volatile substances. A dataset of 40 images was taken for the experiment, but for clarity, the results of only 13 images have been shown. The results were evaluated using MSE and PSNR metrics, where the average PSNR value of the proposed system compared to single X-ray images was increased by 19.3%, and the MSE value decreased by 17.3%. The results show that the proposed framework will help discern threats and the entire scanning process.

• Journal of radiological science and technology
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• v.41 no.4
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• pp.289-295
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• 2018

When using a mobile X-ray unit, primary radiation creates medical images and secondary radiation scatters in many directions, which reduces image quality and causes exposure to patients, care givers and medical personnel. The purpose of this study was to develop a radiation shielding system for effectively shielding secondary radiation and evaluate its effectiveness. Using a mobile X-ray unit, spatial dose according to presence of human equivalent phantom and spatial dose using the developed shielding device were measured, and the phantom at 80 cm equidistance from center of X-ray was compared with spatial dose according to use of a shield. Measurements were taken at intervals of 10 cm every $30^{\circ}$ from the head direction($-90^{\circ}$) to the body direction($+90^{\circ}$). In the spatial dose measurement with and without the phantom, when the human equivalent Phantom was used, the spatial dose was increased by 40% in all directions from 40 cm to 100 cm from the central X-ray, and about 88% of the space dose was reduced when using the developed shields with the phantom. The equidistance dose at 80 cm from the central X-ray was increased by 39% from $5.1{\pm}0.26{\mu}Gy$ to $7.1{\pm}0.15{\mu}Gy$ when the human equivalent phantom was used, and when phantom was used and shielding was used, the spatial dose was reduced by about 90% from $7.1{\pm}0.15{\mu}Gy$ to $0.7{\pm}0.07{\mu}Gy$. The spatial dose of natural radiation was measured to be about $0.2{\pm}0.04{\mu}Gy$ when using the developed shielding with Phantom at a distance of 1 m or more. It is expected that by using the developed shielding system, it will be possible to effectively reduce secondary radiation dose received in all directions and to ensure safe imaging.

• 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 Korean Academy of Oral and Maxillofacial Radiology
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• v.7 no.1
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• pp.27-30
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• 1977

To insure accuracy in dental roentgenographs, it is important that the patient's head position and angulation of the x-ray tube. In 1907 Cieszynski applied the rule of isometry to dental radiography and established that in the production of an accurate image of a tooth, the central ray must be porjected perpendicularly to a plane bisecting angle formed by the longitudinal axis of the tooth and the film plane. Proper exposure of the film is a part of the production of a good dental radiograph, and correct processing also makes an essential contribution to the quality of the radiograph. The author analysed the failure of exposure and processing results, and recommended followings. 1. The patient head must be positioned that occlusal plane are parallel with the horizontal floor. 2. Central ray must be projected to the objective tooth and supporting structure and projected as perpendicularly to tooth axis and film surface as possible. 3. In processing, the temperature of the solution and the processing time must be correct.

• Journal of the Korean Geotechnical Society
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• v.27 no.11
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• pp.93-101
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• 2011

High quality X-ray computed microtomography (micro-CT) imaging of internal microstructures and pore space in geomaterials is often hampered by some inherent noises embedded in the images. In this paper, we introduce image calibration techniques for removing the most common noises in X-ray micro-CT, cupping (brightness difference between the periphery and central regions) and ring artifacts (consecutive concentric circles emanating from the origin). The artifacts removal sequentially applies coordinate transformation, normalization, and low-pass filtering in 2D Fourier spectrum to raw CT-images. The applicability and performance of the techniques are showcased by describing extraction of 3D pore structures from micro-CT images of porous basalt using artifacts reductions, binarization, and volume stacking. Comparisions between calibrated and raw images indicate that the artifacts removal allows us to avoid the overestimation of porosity of imaged materials, and proper calibration of the artifacts plays a crucial role in using X-ray CT for geomaterials.