• 대한기계학회논문집A
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• 제30권10호
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• pp.1314-1319
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• 2006

This paper describes the novel fabrication method of the high-aspect-ratio nano structure which is impossible by conventional method using a shadow mask and a Deep X-ray Lithography (DXRL). The shadow mask with $1{\mu}m-sized$ apertures is fabricated on the silicon membrane using a conventional UV-lithography. The size of aperture is reduced to 200nm by accumulated low stress silicon nitride using a LPCVD (low pressure chemical vapor deposition) process. The X-ray mask is fabricated by depositing absorber layer (Au, $3{\mu}m$) on the back side of nano shadow mask. The thickness of an absorber layer must deposit dozens micrometers to obtain contrast more than 100 for a conventional DXRL process. The thickness of $3{\mu}m-absorber$ layer can get sufficient contrast using a central beam stop method, blocking high energy X-rays. The nano circle and nano line, 200nm in diameter in width, respectively, were demonstrated 700nm in height with a negative photoresist of SU-8.

• 한국세라믹학회지
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• 제23권2호
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• pp.64-70
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• 1986

In this investigation x-ray diffraction method was mainly studied for quantitative analysis of clinker mineral composition. And also optical microscopic observation and Bogue calculation method were applied to compare with the x-ray diffraction method. In the procedure of x-ray diffraction analysis graphite monochromator automatic divergence slit and spinner for sample holder were used for minimizing the error due to the operation of the equipment. Especially the separation of overlapped peaks were proceeded by micro-processor automatically. The results of x-ray diffraction method for synthesized clinker were consistent with the Bogue value and the results of optical microscopic observation. However the results of quantitative analysis of mineral composition or commercial clinker containing solid solution of minor component were different from the Bogue value. On the other hand they agreed reasonably well with results of the optical mic-roscopic observation.

• 지질공학
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• 제28권3호
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• pp.455-463
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• 2018

본 연구에서는 치핑작업중에 콘크리트에 발생할 수 있는 손상균열을 정량분석하기 위해 X-ray CT 이미지를 이용하는 방법을 제안하고자 한다. 이를 위해 치핑작업을 수행한 후, 균열이 발생한 콘크리트 블록을 코어링하여 직경 50 mm, 길이 100 mm의 시편을 준비하였다. 그 후 마이크로 포커스 X-ray CT 촬영을 하여 얻은 이미지를 3D 이미지로 재구성(reconstruction)하였다. 이렇게 얻어진 3D CT 이미지에 3DMA (3 Dimensional Medial axis Analysis)법을 적용하여, 손상 평가 파라메타로 시편의 위치에 따라 균열의 성질을 평가하여 손상을 분석하였다. 분석결과 치핑에 의한 손상은 치핑 표면으로부터 3 cm 깊이까지 발생한 것으로 나타났다. 또한 CT이미지 공간분석법에서 사용되는 여러 파라메타 중 공극률 지표(Porosity index), Burn number 그리고 Medial axis 의 파라메타를 이용해 치핑표면 근처의 손상 분석이 가능하다는 것이 확인되었다. 이 방법은 내부구조에 변화가 발생한 암석을 대상으로 한 연구에서도 비파괴 상태로 내부의 균열 평가, 가시화에 적용가능하다.

• 한국정보통신학회논문지
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• 제24권12호
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• pp.1618-1624
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• 2020

X-ray를 기반으로 하는 장 폐색 진단 방법은 검사자의 주관적인 요소가 포함되기 때문에 객관적 진단에 영향을 미칠 수 있다. 따라서 본 논문에서는 허프 변환과 PCM 클러스터링 기법을 적용하여 장폐색 영역을 추출하는 방법을 제안한다. 제안된 방법은 X-ray 장폐색 영상에서 ROI 영역을 추출한 후, 허프 변환 기법을 이용하여 ROI 영역에서 직선을 검출하고, 검출된 직선을 이용하여 공기 액체층의 형태학적 특징을 이용하여 대장 폐색을 추출한다. 그리고 추출된 ROI 영역을 PCM 클러스터링을 적용하여 ROI 영역을 양자화 한다. 양자화된 ROI 영역 중에서 대장 폐색의 특징이 포함된 클러스터의 그룹을 선정하고, 선정된 클러스터의 그룹에서 객체를 탐색하여 소장 장폐색 영역을 추출한다. 장폐색 환자의 X-ray 영상 30개를 대상으로 PCM 클러스터링을 적용한 결과, PCM의 초기 클러스터의 수를 4개로 설정한 경우가 장폐색 검출 성능이 우수하였고 TPR은 81.47%로 나타났다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1684-1688
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• 2005

In this paper, authentication technologies for X-ray inspection images in container merchandises are introduced and a method of authentication for X-ray inspection images is proposed. Until now, X-ray images of container merchandises have been managed without any authentication of inspection results and environments, it means that there was no any action for protection of illegal copy and counterfeiting of X-ray images from inspection results. Here, authentication identifies that who did inspect container X-ray images and, whether the container X-ray images were counterfeited or not. Our proposed algorithm indicates to put important information about X-ray inspection results on an X-ray image without affecting quality of the original image. Therefore, this paper will be useful in determining an appropriate technology and system specification for authentication of X-ray inspection images. As a result of experiment, we find that the information can be embedded to X-ray image without large degradation of image quality. Our proposed algorithm has high detection ratio by Quality 20 of JPEG attack.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2002년도 추계학술대회 논문집
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• pp.31-34
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• 2002

Imaging techniques using x-ray beam at high energies (>6KeV) such as contact radiography, projection microscopy, and tomography have been used to nondestructively discern internal structure of objects in material science, biology, and medicine. This paper introduces the x-ray micro-imaging method using 1B2 micro-probe line of PAL (Pohang Accelerator Laboratory). Cross-sectional information on low electron density materials can be obtained by probing a sample with coherent synchrotron x-ray beam in an in-line holography setup. Living organism such as plants, insects are practically transparent to high energy x-rays and create phase shift images of x-ray wave front. X-ray micro-images of micro-bubbles of $20\~120\;{\mu}m$ diameter in an opaque tube were recorded. Clear phase contrast images were obtained at Interfaces between bubbles and surrounding liquid due to different decrements of refractive index.

• 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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• 제7권1호
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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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.853-856
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• 2002

Present. direct method x-ray conversion detector is studied by abroad medical instrument and country with amorphous Selenium. And we search the method for large area x-ray detector. Amorphous-Selenium based photoreceptor is widely used on the X-ray conversion materials. But amorphous-selenium based x-ray conversion detector is broken by high voltage and leakage defect point. In this paper, We investigated top-electrode distance rate to improve defect point and high voltage broken. The result to appoint to made large area x-ray conversion detector with base data.

• 전기의세계
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• 제13권3호
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• pp.13-20
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• 1964

The measurements of X-ray and Gamma-ray Dose Rate have been successfully made by measuring the short circuit current of the Silicon P-N Junction Diode being irradiated. The short circuit current flows when a silicon P-N Junction Diode is irradiated by X-ray of Gammaray radiations due to photovoltaic effect. A brief analysis is given in order to verify the proportionality of a short circuit current to the Dose Rate. Using this method, measurements of X-ray Dose Rate were carried out in the range of 0.05-1600 r/m successfully. The calibration was made by comparing with Victoreen condenser r-meter. Some advantages in this Dose Rate meter over a condenser r-meter were found. One can measure a continous variation of X-ray Dose Rate with this rate meter at the control console of X-ray device.