• Journal of Radiation Protection and Research
• /
• v.47 no.2
• /
• pp.93-98
• /
• 2022

Background: This study aims to derive the characteristics of each work type for industrial radiography based on empirical evidence through expert advice and a survey of radiation workers of various types of industrial radiography. Materials and Methods: According to a Korean report, work types of industrial radiography are classified into indoor tests, underground pipe tests, tests in a shielded room (radiographic testing [RT] room test), outdoor field tests, and outdoor large structure tests. For each work type, exposure geometry and radiation sources were mainly identified through the expert advice and workers' survey as reliable empirical evidence. Results and Discussion: The expert advice and survey results were consistent as the proportion of the work types were high in the order of RT room test, outdoor large structure test, underground pipe test, outdoor field test, and indoor test. The outdoor large structure test is the highest exposure risk work type in the industrial radiography. In most types of industrial radiography, radiation workers generally used ¹⁹²Ir as the main source. In the results of the survey, the portion of sources was high in the order of ¹⁹²Ir, X-ray generator, ⁶⁰Co, and ⁷⁵Se. As the exposure geometry, the antero-posterior geometry is dominant, and the rotational and isotropic geometry should be also considered with the work type. Conclusion: In this study, through expert advice and a survey, the external exposure characteristics for each work type of industrial radiography workers were derived. This information will be used in the reconstruction of organ dose for health effects assessment of Korean radiation workers.

• Journal of Radiation Protection and Research
• /
• v.37 no.4
• /
• pp.177-180
• /
• 2012

Industrial radiography practice is usually employed in public domain. Over the years there are several radiation accidents reported in this practice. The accidents often result in severe or fatal exposures to occupational workers and public. The number of radiation accidents is also significant when compared with other industrial accidents. This paper describes practice specific training as one of the measures to the improve radiation safety and reduce the accidents. The efforts by International Atomic Energy Agency (IAEA) to disseminate information and to improve the radiation safety status in industrial radiography are also discussed.

• Quality Improvement in Health Care
• /
• v.9 no.1
• /
• pp.90-100
• /
• 2002

Background : This study was attempted to provide us with basic data on how to environmental improvement with patients for examination, and to offer them better treatment. This study was performed to compare the patients, perception between before and after improvement in the diagnostic radiography room. Methods : The data was collected by interviewing 75 patients who underwent the radiography under the diagnostic radiology at Seoul National University Hospital in Korea. The interview ran from August 9 to October 18, 1999. Data were analyzed by percentage and paired t-test. SD(Semantic Differential) method was composed of adjective 13 words. Results : Patients were attending the elementary schools in the Seoul residents. There was no significant difference in kindness unkindness dimension and were significant differences in other dimensions. The mean score of response level to present room was 3.67 and that of improvement room was 2.16. Conclusions : The results of this study suggest a radiography room plan which is considering emotional aspect of children.

• Journal of the Korean Society of Radiology
• /
• v.16 no.5
• /
• pp.585-594
• /
• 2022

The detector for digital radiography testing, which is currently mainly used, consists of a detector with a flat structure, making it impossible to fully adhere to the digital radiography testing of the test object with curvature. In this study, a curved panel detector capable of adhering to curvature was fabricated to improve the quality of the digital image during the digital radiography testing of piping welds at industrial sites, and digital radiography images using flat and curved panel detectors were obtained for 6in pipes with different nominal thickness. As a result of the experiment, it was confirmed that the flat panel detector does not fully adhere to the pipe, resulting in a gap between the outer part of the pipe and the detector, resulting in a difference in the unsharpness and diffusion of the digital image. On the other hand, it was confirmed that the curved panel detector minimizes the gap between the pipe outer part and the detector, so that digital image diffusion is less than that of the flat panel detector. The higher the confidence of the image, the lower the quality and error in reading, so it is believed that higher quality images can be obtained than conventional flat panel detectors when using detectors that can be closely attached to the inspection object.

• Imaging Science in Dentistry
• /
• v.40 no.1
• /
• pp.9-14
• /
• 2010

Purpose : We evaluated the absorbed doses to the organs and calculated the effective doses when using the digital panoramic radiography. Materials and Methods : The absorbed dose averages in major organs of oral and maxillofacial region were measured using the Dental head phantom (CIRS Co., USA), $^nLi_2B_4O_7$ TLD chip and UD-716AGL dosimeter (Matsushita Electric Industrial Co., JPN) when performing indirect and direct digital panoramic radiography. Effective doses were calculated from correspond to ICRP 2007 recommendations for two panoramic radiography. Results : The absorbed dose average on indirect and direct digital panoramic radiography was highest in parotid glands as measured 1259.6 mGy and 680.7 mGy respectively. Absorbed dose average in another organs were high in order of esophagus, submandibular gland, tongue and thyroid gland on both types of digital panoramic radiography. The absorbed dose average was higher on indirect type than direct one (p<0.05). The effective dose was higher on indirect type than direct one as measured 13.28 mSv and 8.70 mSv respectively. Conclusion : The absorbed doses in salivary gland and oral mucosa were high. However, thyroid gland also demands the attention on radiography due to high tissue weighting factor in spite of the low absorbed dose.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.9
• /
• pp.3347-3352
• /
• 2010

It is recommended that the door of control room is closed during radiography to protect a radiologic technologist. However, for those patients such as of emergency or pediatrics, the door must be kept open unavoidably to apply immediate medical administration and treatment on the potential case of emergency which could be happened through the course of radiography. In addition, it could be efficient by reducing patients waiting time when the door is open for a general case. This study was conducted to evaluate practical exposure rate to a radiologic technologist when the door is open during the radiography, and to find out the ways to minimize radiation exposure and to increase the efficiency simultaneously. Measuring practical exposure rate was fulfilled with glass dosimeter, and it was 2.02 mGy/week at the location of radiologic technologist under the condition that the door is open during the radiography, which was about 2.3 times higher than the 100 mR/week. It means that the considerable amount of scattered rays through the door opening, and increase exposure rate at the radiologic technologist. Hence we confirmed that a radiologic technologist probably overexposed if the door is open during the radiography. It was also confirmed by the Monte Carlo simulation that the exposure rate could be reduced up to approximately 1/100 by change only the door opening direction. In conclusion, since the proper door opening direction provides same shielding effect whether it is open or close, the door opening direction need to be considered when it is installed at radiography facilities.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.45 no.5
• /
• pp.103-110
• /
• 2008

A reliable extraction of welded area is the precedent task before the detection of weld defects in industrial radiography. This paper describes an attempt to detect and extract the welded features of steel tubes from the computed radiography(CR) images. The statistical properties are first analyzed on over 160 sample radiographic images which represent either weld or non-weld area to identify the differences between them. The analysis is then proceeded by pattern classification to determine the clustering parameters. These parameters are the width, the functional match, and continuity. The observed weld image is processed line by line to calculate these parameters for each flexible moving window in line image pixel set. The local statistic line-clustering method is used as the classifier to recognize each window data as weld or non-weld cluster. The sequential procedure is to track the edge lines between two distinct regions by iterative calculation of threshold, and it results in extracting the weld feature. Our methodology is concluded to be effective after experiment with CR weld images.

• Journal of Korea Foundry Society
• /
• v.30 no.3
• /
• pp.100-110
• /
• 2010

The solidification sequence and formation of intermetallic phase of Fe-rich Al-Si-Cu alloy were investigated by using real-time imaging of synchrotron X-ray radiation. Effects of cooling rate during uni-directional solidification on the resultant solidification behavior was also studied in a specially constructed vacuum chamber in the SPring-8 facility. The series of radiographic images were complementarily analyzed with conventional analysis of OM and SEM/EDX for phase identification. Detailed solidification sequence and formation mechanisms of various phases were discussed based on real-time image analysis. The growth rates of $\alpha$-AlFeMnSi and ${\beta}-Al_5FeSi$ were measured in order to understand the growth behavior of each phase. It is suggested that real-time imaging technique can be a powerful tool for the precise understanding of solidification behavior of various industrial materials.

• Nuclear Engineering and Technology
• /
• v.52 no.7
• /
• pp.1597-1601
• /
• 2020

Background: Non-destructive evaluation of defects in metals or composites specimens is a regular method in radiographic imaging. The maintenance examination of metallic structures is a relatively difficult effort that requires robust techniques for use in industrial environments. Methods: In this research, iron plate, lead marker and tungsten defect with a 0.1 cm radius in spherical shape were separately simulated by MCNP code and SuperMC software. By ¹⁹²Ir radiation source, two exposures were considered to determine the depth of the actual defined defect in the software. Also by the code, displacement shift of the defect were computed derived from changing the source location along the x- or y-axis. Results: The computed defect depth was identified 0.71 cm in comparison to the actual one with accuracy of 13%. Meanwhile, the defect position was recognized by disorder and reduction in obtained gamma flux. The flux amount along the x-axis was approximately 0.5E+11 units greater than the y-axis. Conclusion: This study provides a method for detecting the depth and position of the defect in a particular sample by combining code and software simulators.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.45 no.4
• /
• pp.71-77
• /
• 2008

This paper presents a methodology for recovering the industrial radiographic images from the effects of nonlinear distortion. Analytical approach based on the inverse square law and Beer's law is developed in order to improve a mathematic model of nonlinear type. The geometric effect due to dimensions of the radioactive source appeals on the digitized images. The relation that expresses parameters values(angle, position, absorption coefficient, length, width and pixel account) is defined in this model, matching with the sample image. To perform the search for image recovery most similar to the model, a correction procedure is designed. The application of this method on the radiographic images of steel tubes is shown and recovered results are discussed.