• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.426-426
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• 2009

Diagnostic X-ray system is general and basic medical equipment to be used in mostly medical organizations, but being bombed of radioactivity is a big weak point when irradiates a X-ray to the human body so that ICRP restricted the radiation exposure tolerance of the human body. In order to reduce being bombed, the many research and development is now advanced. A lots of diagnostic X-ray machines have currently used due to the increase of occurrence efficiency of X-ray and precisely the output control by using the inverter which is a high speed switching semiconductors. For getting the confidence of the X-ray machine, the same radiation occurrence, same evaluation, and same irradiation condition are necessary when evaluates X-ray irradiation. It is the most important part for the accuracy of the test result and the patient safety. This paper has produced the high voltage occurrence system of full-wave rectification method by using the LC resonance inverter, and evaluated the irradiation reproducibility in order to use it in diagnosis of the patient.

• Journal of Korean Medicine Rehabilitation
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• v.30 no.2
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• pp.125-137
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• 2020

Objectives The purpose of this study was to examine how changes in the cervical spine correlate with body posture changes in the whole body, and to find out the significance of complementary clinical application X-ray and Chuna posture analysis. Methods From January 1, 2019 to October 31, 2019, the results of 27 patients with pain in the vertebral region were analysed in accordance with the results of cervical X-ray and Chuna posture analysis. In order to confirm the significance of Chuna posture analysis results, the survey of 187 Chuna standard curriculum instruction qualification certifiers was conducted and the responses of 47 of them were analyzed. Results The occiput-atlas cline angle increases in both hypolordosis/hyperlordosis groups based on cervical lordosis angle, and increases further than in the hyperlordosis group. There were significant correlations between the changes in the cervical spine and the body posture changes in the whole body. There were no significant differences between cervical X-ray sagittal parameters and the body posture analysis parameters based on the patient's major disease codes. Conclusions As a result of conducting a survey on the clinical importance of the body posture analysis parameters, the importance of cervical parameters was verified. Changes in the cervical spine may not only cause other changes in the cervical region, but also affect the body posture changes in the whole body. The complementary application of X-ray and Chuna posture analysis results is helpful in clinical diagnosis and treatment of musculoskeletal disorders.

• Korean Journal of Crystallography
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• v.12 no.4
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• pp.233-238
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• 2001

X-ray microdiffraction which uses x-ray beam focused down to a micron size from synchrotron radiation sources allow precision measurements of local orientation and strain variations in polycrystalline materials. Using x-ray microdiffraction setup at Pohang Light Source, we investigated the tex-ture of Cu interconnects with various widths on Si wafer by collecting Laue images and focused to about 2×3㎛ ² in size. Our results show that 1㎛ wide Cu interconnect had grains in rather ran- dom orientation. On the other hand the 20㎛ wide interconnects showed a 〈111〉fiber texture near the center. The grains were 2∼5㎛ long at the 1㎛ wide interconnect and 6∼8㎛ in size at the 20㎛ wide interconnect.

• Progress in Medical Physics
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• v.4 no.2
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• pp.37-47
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• 1993

The quality of radiation for a high energy x-ray beam can be specified by its attenuation curve in a selected material. The inverse Laplace transform of the attenuation curve can be used as an approximate indication of the energy spectrum of the beam. We have made a comparative investigation of the estimated spectrum obtained by the Laplace transform analysis of the transmitted exposure data measured in an absorption study of a 6MV x-ray beam. Two of existing transform pair models have been investicated and discussed.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.32-34
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• 2007

The X-ray projection system has long been used for steel-tube inspection and weld monitoring. The thickness of tubes and welded areas is based on the evaluation of radiographic shadow projections. The traditional tangential measurement estimates the distance of border lines of the projected wall shadows of a tube onto a radiographic image detector. The detected image in which although there is a variety of noise may be sectioned into several partitions according to its specific blocks. Imaging noise originates from most of elements of the system, such as shielding CCD camera, imaging screen, X-ray source, inspected object, electronic circuits and etc. The tangential projection incorrectness and noise influence on imaging quality. In this paper we first sectionalize the X-ray image on the basis of vertical contrast difference. And next functional and statistic analysis are carried on at each region. Geometrical distance and unsharpness of the edge caused by visual evaluation uncertainties are also discussed.

• Journal of Ocean Engineering and Technology
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• v.7 no.2
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• pp.103-113
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• 1993

X-ray diffraction analysis technique was used for the fatigue damage analysis and fatigue life prediction in Al 7075-T651 alloy. The tensile test, fatigue strength and fatigue crack propagation test with change of stress ratio were carried out. As a result, half-value breadth was increased with the plastic deformation in the specimen increasint at all test conditions. In particular, half-value breadth at the surface of the specimens fractured by fatigue was increased as stress intensity factor range and effective stress intensity factor range were increased. In addition, the good relationship between half-value breadty and diffraction pattern was shown.

• Journal of the Korean Ceramic Society
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• v.35 no.10
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• pp.1113-1119
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• 1998

Crystal structure of needle-shaped maghemite(${\gamma}$-{{{{ { {Fe }_{2 }O }_{3 } }}) has been studied by the Rieveld analysis of powder X-ray diffraction patterns. The tetragonal space group P41,.3212 and cubic space group P41,.32 have been have been used for the refinement of X-ray diffraction patterns. The crystal system of maghemite is closed to tetragonal more than cubic. The tetragonal lattice parameters are a=8.3460$\AA$ and c=25.034$\AA$ The standard X-ray diffraction pattern of the tetragonal maghemite analyzed with space group P41,.3212 is proposed.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.20 no.2
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• pp.289-297
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• 1990

The purpose of this study was to assess the resolution and focal spot size of dental X-ray machines. Fifty dental X-ray machines were selected for measuring resolution and focal spot size. These machines were used in general dental clinics. The time of installation of the X-ray machine varies from 1 year to 10 years. The resolution of these machines was measured with the test pattern. The focal spot size of these machines was measured with the star test pattern. The following results were obtained: 1. The resolution of dental intraoral X-ray machines was not significantly changed in ten years. 2. The focal spot size of dental intraoral X-ray machines was not significantly increased in ten years. The statistical analysis between the mean focal spot size and nominal focal spot size was significant at the 0.05 level about the more than 3 years used machines.

• The Journal of Engineering Geology
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• v.28 no.3
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• pp.455-463
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• 2018

This study developed a method to quantitatively measure the size of cracks in concrete using X-ray CT images. We prepared samples with a diameter of 50 mm and a length of 100 mm by coring cracked concrete block that was obtained by chipping. We used a micro-focus X-ray CT, then applied the 3DMA method (3 Dimensional Medial axis Analysis) to the 3D CT images to find effective parameters for damage assessment. Finally, we quantitatively assessed the damage based on sample locations, using the damage assessment parameter. Results clearly show that the area near the chipping surface was damaged to a depth of 3 cm. Furthermore, X-ray methods can be used to evaluate the porosity index, burn number, and medial axis, which are used to estimate the damage to the area near the chipping surface.

• Journal of the Korean Arthroscopy Society
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• v.1 no.1
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• pp.102-107
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• 1997

Discoid meniscus has been well known to a frequent anomaly of meniscus and much reported in diagnosis and treatment. But, associated X-ray findings have not been known well. We reported its significance of X-ray findings in discoid meniscus. From May 1995 to May 1997, 31 cases of discoid meniscus were compared with 51 cases of nondiseoid meniscus both confirmed by arthroscopy, with simple X-my findings. Both groups were evaluated by X-ray findings in view of lateral joint space widening, peripheral spur of lateral joint space, sclerotic change of lateral tibial plateau, concave lateral tibial plateau, flattening of lateral femoral condyle, hypoplasia of lateral femoral condyle and high riding fibula. The results of analysis were as follows: 1. Widening of lateral joint space, sclerotic change of lateral tibial plateau and cupping of lateral tibial plateau were statistically significant in discoid meniscus. 2. X-ray findings in discoid meniscus were not associated with patient's injury history and symptom duration. 3. Other X-ray findings were not related in discoid meniscus significantly. X-ray findings with patient's history and physical examination arc helpful in the diagnosis of discoid meniscus.