• Tribology and Lubricants
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• 제18권3호
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• pp.187-193
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• 2002

The half-value breadth off-ray diffraction profile line is generally used for a factor in nondestructive hardness measuring method of steel. In this paper, the problem in using the half-value breadth for the hardness measuring method is evaluated in strain hardened steel. And new hardness measuring method using residual stress is proposed X-ray diffraction test after rolling contact fatigue test of ball bearing with inner race of various hardness are carried out to measure the distribution of residual stress and half-value breadth from surface. The result of this study shows that there is little correlation between half-value breadth and hardness in the higher strength region and in the region increasing the hardness by strain hardening. But the magnitude of residual stress on/under race after rolling contact fatigue test becomes clearly to be correlative with hardness. Thus, it is concluded that the hardness of strain hardened steel can be estimated by this relationship between residual stress and hardness.

• 방사선산업학회지
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• 제9권3호
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• pp.153-159
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• 2015

Reliability of printed circuit board (PCB), which is based on high integrated circuit technology, is having been important because of development of electric and self-driving car. In order to answer these demand, automated X-ray inspection (AXI) is best solution for PCB non-destructive test. PCB is consist of plastic, copper, and, lead, which have low to high Z-number materials. By using dual energy X-ray imaging, these materials can be inspected accurately and efficiently. Dual energy X-ray imaging, that have the advantage of separating materials, however, need some solution such as energy separation method and enhancing efficiency because PCB has materials that has wide range of Z-number. In this work, we found out several things by analysis of X-ray energy spectrum. Separating between lead and combination of plastic and copper is only possible with energy range not dose. On the other hand, separating between plastic and copper is only with dose not energy range. Moreover the copper filter of high energy part of dual X-ray imaging and 50 kVp of low energy part of dual X-ray imaging is best for efficiency.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 춘계 학술발표대회 개요집
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• pp.302-304
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• 2004

Nuclear fuel elements containing dry recycling nuclear fuel pellets for the irradiation test in a reactor were remotely fabricated from spent PWR fuel materials in a hot cell. End closure welding as well as seal tube welding for thermal sensor of the elements was performed by Nd:YAG laser. The soundness of the end closure welds and seal tube welds for the elements were evaluated by a precise X-ray inspection system composed of a micro-focus X-ray generator with an image intensifier and a real time camera system. Then, helium leak test was performed for the elements. The soundness of the welds of the fuel elements was confirmed by the X-ray inspection and helium leak test. The irradiation test for the fuel elements were successfully completed at the HANARO research reactor.

• 한국전기전자재료학회논문지
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• 제22권6호
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• pp.516-521
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• 2009

X-ray system which is usefully used in diagnosis of the patient, 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 research 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.

• 대한방사선기술학회지:방사선기술과학
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• 제18권2호
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• pp.61-73
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• 1995

For the managements of the diagnostic X-ray equipments, the authors examined the output of single phase rectification assembly, Three phase rectification assembly and serial radiographic appartus, and got the following conclusions. 1. When the tube voltages in X-ray control panels ware compared to the measured values on the kVp pulse meter, only little differences were detected in all the X-ray equipments. And most of the equipments were all well managed within the internationally permitted limits, excepting the 12.02 % error at 120 kVp in three phase rectifying assembly. 2. As for the X-ray qualities affecting the X-ray images, the serial radiographic apparatus showed excellence, while the single phase rectification assembly were somewhat inferior to the others only maining the internationally recommended limits. 3. The tube voltage ranges where the X-ray output showed excellence were $100{\sim}200\;mA$ in serial radiographic apparatus, $200{\sim}350\;mA$ in three phase rectification assembly and $350{\sim}400\;mA$ in single phase rectification assembly respectively. 4. In the repeatability test of the X-ray equipments, CVs were in the range of $0.0029{\sim}0.049$, which is within the HEW or KS standards. Consequently all the equipments are thought to be well-manage. 5. This study on characteristics and output of the X-ray equipments was accomplished within a limited short time. Long-time researches on the function managements for the X-ray equipments should be followed along with the periodical checking the output for reduction of X-ray exposures to the patients or radio-technologists, and for maintanance and prediction of trouble of the equipments.

• 미래기술융합논문지
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• 제2권1호
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• pp.17-21
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• 2023

본 연구에서는 X-ray장치(Drgem사 TS-CSP)와 foot phantom(SFT-1556)을 이용하여 발꿈치뼈 후전 축방향 촬영에서 X-ray 튜브의 각도를 30°, 35°, 40°, 45°, 50°로 변화를 주어 각 각도에 해당하는 영상을 흭득한 뒤 정량적 평가와 정성적 평가로 나누어 영상을 평가하였다. 블라인드 테스트에서는 40°에서 4.34점으로 가장 높았으며 Image J 프로그램을 이용한 면적 계산에서는 각도가 50°에서 1750으로 가장 큰 값으로 나타났다. 또한 겹치는 부위를 제외한 면적 평가에서는 X-ray 튜브가 40°일 때 가장 큰 값을 보였다. 그러므로 발꿈치뼈를 관찰하기 위한 촬영법으로는 X-ray tube 각도가 40°일 때가 적합하다는 결과를 얻었다.

• 한국방사선학회논문지
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• 제12권5호
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• pp.651-658
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• 2018

방사선사는 일반촬영 시에 다양한 환자를 만나게 된다. 노령환자, 유아 등 몸이 불편한 환자를 검사하게 된다. 소규모의 병 의원에는 방사선사가 혼자 업무를 보는 경우가 자주 발생한다. 이러한 경우 방사선사의 두 손은 환자의 자세를 유지하는데 사용되어지기 때문에 촬영에 있어서 어려움을 느끼게 된다. 본 연구는 이러한 문제점을 극복하고자 진단용 방사선 발생 발판 스위치를 고안하여 실험하였다. 제작한 발판 스위치를 진단용 엑스선 촬영장치에 장착하여 조사선량 재현성 시험, kVp, mAs, 백분율평균오차와 같은 정량적 평가를 실시하였다. 결과적으로 발판 스위치 사용에 대한 정량적 평가는 조사선량 재현성 시험에서 변동계수가 0.05이하로 측정되었고 kVp 시험에서는 백분율 평균오차가 ${\pm}10%$ 이내로 측정되었다. mAs 시험에서도 백분율 평균오차가 ${\pm}20%$ 이내로 측정되었다. 이는 진단용 방사선 발생장치의 검사기준 범위에 모두 부합하여 사용상 문제점은 제시되지 않았다. 또한 현재 근무 중인 방사선사를 상대로 유용성에 관한 정성적 평가를 실시하였다. 결론적으로 발판스위치의 엑스선 발생효율의 정량적 평가에서는 실험된 검사가 엑스선 발생장치 장비 기준 범위에 부합하였으며 설문을 통한 평가에서도 먼저 병 의원에서 근무하는 방사선사를 상대로 발판 스위치를 사용한 이후 설문을 통해 발판 스위치에 대한 편리성과 활용성에 대해 설문 실시한 결과는 발판스위치 사용은 임상에서 많은 도움을 줄 수 있는 긍정적인 결과로 나타내었다. 그러므로 진단용 엑스선 촬영용 발판 스위치를 사용하면 방사선 기술자 작업의 신속성과 정확성을 효과적으로 향상시킬 수 있으므로 의료 서비스 만족도를 높이는 데 효과적으로 사용할 수 있을 것이다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.499-499
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• 2008

High voltage transformer of Diagnostic X-ray system has been contributed to wiping out disease to get a good quality images from patients. High voltage transformer of diagnostic X-ray system has been usefully used for diagnostic purpose but if high voltage transformer performances are deteriorated, low quality image will be archived. In this case, operator has to exposure to get a more good quality images. In this case, unexpected radiation could be exposed to patient and it is very harmful to the patient. And I would like to design and make equipment to checkable high voltage transformer performance after that I wish to test and study what it is most influences in radiation output quality.

• Journal of Ginseng Research
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• 제8권2호
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• pp.167-171
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• 1984

Soft X-ray is useful to identify the quality of fresh ginseng causing the inside cavity or white pan of red ginseng. The portion of low mass density identified by the difference in absorption of soft X-ray showed lower dry matter density and less or no response to iodine test indicating less accumulation or excess consumption of starch. The inside white part of red ginseng absorbed less X-ray than the normal part did. Probability for identification of the inside cavity or white at fresh ginseng was rather high (80-90%) in screen observation than f'3m reading and seemed to be increased further by using the developed screen and with training. The inside white of red ginseng appeared to be due to starch deficiency. Dry matter density appeared to be better than fresh weight density for the quality criterion.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2007년 가을학술발표회
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• pp.514-527
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• 2007

Earth reinforcement techniques are used worldwide and offer proven solutions to a wide range of geotechnical engineering problems. Here in this paper, recent developments of three major reinforced soil retaining wall methods in Japan were introduced in order to show how the current situation of this technique in Japan is. And the statistical data for the volume of the use was also shown, such as the total volume of the use, the scales of the structures, layout of the earth reinforcement, fill materials, and foundation conditions. Some of the case histories were also introduced with photographs and figures. And then, as one of recent research activity by the author, the study on the application of X-ray CT for the problem of earth reinforcement method combined with other method such as piling and soil improvement was introduced. In this study, a series of model test for several reinforced ground with geogrids was conducted using a newly developed test apparatus. Then, the behavior in the soil box was scanned after settlement using X-ray CT scanner. Based on these test results, the reinforcing effect by the geogrids and the soil arching effect over the pile heads was discussed precisely and those are done in 3-D with nondestructive condition. Finally, the effectiveness of the use of X-ray CT scanner in geotechnical engineering was promised.