• 품질경영학회지
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• 제49권1호
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• pp.47-60
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• 2021

Purpose: This study proposes methods and procedures for evaluating imaging security systems quality of cabinet x-ray screening system to enhance performance certification technology. Also, conducted a comparative analysis of the literature of test-kit for imaging security quality evaluation. Methods: Comparative analysis of the test-kits and related documents for image quality assessment of cabinet x-ray screening equipment. This allows assessment items were selected and the methods for each assessment item were proposed. In addition, the configuration method of the assessment team was established by applying the technology readiness assessment(TRA). Results: Four of the assessment items were selected when estimate image quality by a comparative analysis of literature. For each assessment item, the evaluation method and minimum level of availability were determined. Finally, this paper proposes an imaging quality assessment of cabinet X-ray imaging security systems. Conclusion: Development of imaging security systems evaluation procedures for cabinet X-ray screening systems can be help improve performance certification of aviation security equipment.

• 대한방사선기술학회지:방사선기술과학
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• 제44권5호
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• pp.435-441
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• 2021

The purpose of this study was to evaluate the quality of images and to quantitatively measure and analyze the dose of scattered ray to the organs, which were highly sensitive to radiation according to the use of cylinder cone in mastoid process radiography. When the cylinder cone was not used, the SID was 100cm and the field size was 24 × 36 cm(864 cm²). When using the cylinder cone which was a circle, the SID was 70 cm, the radius was 10.5 cm and field size was 86.59 cm². As a result of the study, SNR of the image quality evaluation was measured to be 2.58 for Law method and 3.90 for Stenver's method when not using cylinder cone, and 2.87 for Law method and 14.67 for Stenver's method when using cylinder cone. CNR was measured to be 0.03 for Law method and 0.04 for Stenver's method when cylinder cone was not used, and 0.04 for Law method and 0.05 for Stenver's method when using cylinder cone. When the cylinder cone was not used, the scattered ray dose was measured to be 0.10 mGy in the right eyeball, 0.30 mGy in the left eyeball, 2.02 mGy in the parotid gland, and 0.29 mGy in the thyroid gland for Law method and to be 0.03 mGy in the right eyeball, 0.12 mGy in the left eyeball, 1.43 mGy in the parotid gland, and 0.09 mGy in the thyroid gland for Stenver's method. When the cylinder cone was used, the scattered ray dose was measured to be 0.05 mGy in the right eyeball, 0.03 mGy in the left eyeball and the parotid and thyroid gland were below the measurable values for Law method and all areas were below the measurable values for Stenver's method. This was found to be statistically significant(p<0.000).

• 광물과 암석
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• 제34권4호
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• pp.227-239
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• 2021

자연산 시료의 광물함량을 X-선 분말회절분석에 의하여 실용적이고 효과적으로 정량분석하는 방법에 대하여 연구하였다. 이를 위하여 무작위 배향된 분말시료 마운트(randomly oriented powder sample mount)를 최적으로 제작하는 실험을 하였으며, 단일 피크강도를 표준물질과 비교하여 정량분석하는 레퍼런스 강도비(RIR) 방법과 X-선 회절도의 전패턴을 계산하는 리트벨드 방법의 효율성을 비교하는 실험을 수행 하였다. 또한, 비정질 광물이 포함된 시료를 리트벨드 방법에 의하여 정량분석하고 효율성을 검토하였다. 연구결과, 측면 마운팅(side mounting) 방법에 의하여 최적의 무작위 배향(random orientation)에 도달할 수 있었다. 또한, 특정 피크를 사용하는 RIR방법보다는 X-선 회절도의 전패턴을 사용하는 리트벨드 방법이 정량분석에 더 적합하였다. 그러나 어느 방법이든 분석기술 뿐만 아니라 분석자의 숙련된 경험을 필요로 한다. 리트벨드 방법에 의해 비정질 광물도 정량분석할 수 있었으며 분석결과는 지질해석을 가능하게 하였다.

• 한국작물학회지
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• 제59권2호
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• pp.188-193
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• 2014

Seed viability testing provides valuable information for assessing seed lot germinability. However, most testing methods require destruction of seed prior to test. Because the dissected seeds for viability test cannot be used further evaluation, the nondestructively X-ray photography technique that can be applied for the evaluation of seed quality has been developed. In order to know the validity and accuracy of X-ray photography technique in seed evaluation test that conducted to remove the abnormal seed from a seed lot, we have compared the results from tetrazolium viability test, germination test and X-ray contrast method in cotton. Metallic salts treatment increased the efficiency of X-ray photographic method by enhancing the penetration of X-ray in abnormal or damaged seeds rather than normal seeds that have strong and well-organized tissues in seed. Cotton seeds presoaked for 16 hr in distilled water followed by soaking into metallic salt solution (5% NaI in water) for 60 min were easily classified seeds into dead seed and viable seed based on the radiography images obtained by X-ray radiation. We concluded that soft X-ray photography was reliable to find out the various defective characters due to heat and mechanical damage of seeds.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.514-522
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• 2022

Non-destructive testing (NDT) technology is a widely used inspection method for agricultural products. Compared with the conventional inspection method, there is no extensive sample preparation for NDT technology, and the sample is not damaged. In particular, NDT technology is used to inspect the internal structure of agricultural products infested by pests. The introduction and spread of pests during the import and export process can cause significant damage to the agricultural environment. Until now, pest detection in agricultural products and quarantine processes have been challenging because they used external inspection methods. However, NDT technology is advantageous in these inspection situations. In this pilot study, we investigated the feasibility of X-ray computed tomography (X-ray CT) and magnetic resonance imaging (MRI) to identify pest infestation in agricultural products. Three kinds of artificially pest-infested fruits (mango, tangerine, and chestnut) were non-destructively inspected using X-ray CT and MRI. X-ray CT was able to identify all pest infestations in fruits, while MRI could not detect the pest-infested chestnut. In addition, X-ray CT was superior to the quarantine process than MRI based on the contrast-to-noise ratio (CNR), image acquisition time, and cost. Therefore, X-ray CT is more appropriate for the pest quarantine process of fruits than MRI.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.55-62
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• 2000

In constructing a synthetic seismogram using ray-tracing method a suite of ray-code is required to obtain a realistic seismogram which is similar to the actual seismogram or earthquake record under consideration. An infinite number of rays exist for any arbitrarily located source and receiver. One select only a finite number of such rays in computing a synthetic seismogram so their selection becomes important to the validity of the seismogram being generated. Missing certain important rays or an inappropriate selection of ray-codes in tracing rays may result in wrong interpretation of the earthquake record or seismogram. Automatic ray-code generation will eliminate such problems. In this study we have developed an efficient algorithm, with which one can generate systemastically all the ray-codes connecting source and receiver arbitrarily located. The result of this work will helpful in analysing multiple reflections in seismic data processing as well as simulating Lg wave and multiply reflected or converted phases in earthquake study.

• 한국전기전자재료학회논문지
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• 제24권8호
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• pp.647-653
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• 2011

In this study, a method to measure the thickness of thin film by EDS (energy dispersive spectroscopy) is suggested. We have developed a model which calculates the thickness of thin film from the characteristic x-ray intensity ratio of the elements in thin film and substrate by considering incident electron beam energy, x-ray generation curve, backscattering and absorption of x-ray, take-off angle of x-ray and tilt angle of the sample. We obtained the relation curve between the film thickness measured experimentally and the x-ray intensity ratio of elements. The film thicknesses calculated from the model agrees quite well with those measured experimentally. Therefore, the thin film thickness can be measured rapidly and accurately by using the model developed in this study and the x-ray intensity ratio obtained in EDS analysis.

• 한국정밀공학회지
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• 제32권4호
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• pp.387-394
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• 2015

We analyze heat generation as well as temperature distribution induced by accelerated electron impact on a target in a closed x-ray tube. For the sake of accuracy, we use Monte carlo analysis. This method gives accurate energy deposit in a medium with additional information such as secondary and backscattered electron as well as their paths. A Tungsten coated layer is divided by small rectangular cell which accumulate energy loss of primary electron beam. The cells and their accumulated energy datum are used for the input of finite element analysis. The Maximum temperature rising and temperature distribution were analyzed by transient heat analysis. Some temperature parameters such as target size and coating thickness were varied to investigate temperature sensitivity. Temperatures were compared each other to find primary variable that affect temperature rising on the x-ray target. The results will be helpful in development highresolution x-ray tube and related industries.

• 대한방사선기술학회지:방사선기술과학
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• 제22권1호
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• pp.13-20
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• 1999

This study is to calculate the exposed radiation dose using Bit method, NDD calculation method and monogram method without dosimeter. In addition, we can calculate the radiation dose from x-ray film density as a film badge. The authors examined the entrance skin dose from $2{\sim}3$ intercostal chest x-ray film density. We also studied the relationship between film density and equivalent dose in the each screen film system under the different radiation quality and the poor geometry condition of grid ratio. As results, we established the deductive method to define the entrance skindose from chest x-ray film density. The error range was found in the range $-13%{\sim}+l7%$ for between deductive entrance skindose and the $2{\sim}3$ intercostal chest x-ray film density to actual detective radiation dose with dosimeter.

• 지질공학
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• 제4권3호
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• pp.333-341
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• 1994

Ray Method와 관측지진 자료에 의해서 지각구조 상부 Mantle을 연구하면서 저속도층이 탐지되었다. 우리는 한반도에서 부곡 온천 지역과 추가령 지구대를 통과하는 P파와 S의 도착 시간 지연을 관측했다. 현재 지열 탐사는 이 지역이 심부 저속도 물체는 "지연 암영"이라고 불리우는 높은 지열이상을 설명 해주고 있다. 우리는 하부지각의 부분 용융에 기인한 저속도 물체의 가설을 하부지각의 이차원 비등질 모델의 속도변화가 있음을 Ray Method(Cerveny and Psencik, 1983)에 의해서 분석 하였다.