• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.1
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• pp.61-69
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• 2004

A long-term growth simulation was performed at 99 land units in Yeoncheon county to test the potential adaptability of each land unit for growing soybean cultivars. The land units for soybean cultivation(CZU), each represented by a geographically referenced land patch, were selected based on land use, soil characteristics, and minimum arable land area. Monthly climatic normals for daily maximum and minimum temperature, precipitation, number of rain days and solar radiation were extracted for each CZU from digital climate models(DCM). The DCM grid cells falling within a same CZU were aggregated to make spatially explicit climatic normals relevant to the CZU. A daily weather dataset for 30 years was randomly generated from the monthly climatic normals of each CZU. Growth and development parameters of CROPGRO-soybean model suitable for 2 domestic soybean cultivars were derived from long-term field observations. Three foreign cultivars with well established parameters were also added to this study, representing maturity groups 3, 4, and 5. Each treatment was simulated with the randomly generated 30 years' daily weather data(from planting to physiological maturity) for 99 land units in Yeoncheon to simulate the growth and yield responses to the inter-annual climate variation. The same model was run with input data from the Crop Experiment Station in Suwon to obtain a 30 year normal performance of each cultivar, which was used as a "reference" for evaluation. Results were analyzed with respect to spatial and temporal variation in yield and maturity, and used to evaluate the suitability of each land unit for growing a specific cultivar. A computer program(MAPSOY) was written to help utilize the results in a decision-making procedure for agrotechnology transfer. transfer.

• Journal of radiological science and technology
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• v.29 no.3
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• pp.185-195
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• 2006

Purpose: This study investigated the status of radiation exposure doses since the establishment of the "Regulations on Safety Management of Diagnostic Radiation Generation Device" in January 6, 1995. Method: The level of radiation exposure in people engaged or having been engaged in radiation-related industries of inspection organizations, educational organizations, military units, hospitals, public health centers, businesses, research organizations or clinics over a 5 year period from Jan. 1, 2000 to Dec. 31, 2004 was measured. The 149,205 measurement data of 57,136 workers registered in a measurement organization were analysed in this study. Frequency analysis, a Chi-square test, Chi-square trend test, and ANOVA was used for data analysis. Results: Among 57,136, men were 40,870(71.5%). 50.3% of them were radiologic technologists, otherwise medical doctors(22.7%), nurse(2.9%) and others(24.1%). The average of depth radiation and surface radiation during the 5-year period were found to decrease each year. Both the depth radiation and surface radiation exposure were significantly higher in males, in older age groups, in radiological technologists of occupation. The departments of nuclear medicine had the highest exposure of both depth and surface radiation of the divisions of labor. There were 1.98 and 2.57 per 1,000 person-year were exposed more than 20 mSv(limit recommended by International Commission on Radiological Protection) in depth and surface radiation consequently. Conclusion: The total exposure per worker was siginifcantly decreased by year. But Careful awareness is needed for the workers who exposed over 20 mSv per year. In order to minimize exposure to radiation, each person engaged in a radiation-related industry must adhere to the individual safety management guidelines more thoroughly. In addition, systematic education and continuous guidance aimed at increasing the awareness of safety must be provided.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.555-561
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• 2014

For five diagnostic X-ray generators (DR), four units turned out to be appropriate in tests on the reproducibility of radiation output suggested in the IEC 60601-2-54 standard, but in one unit of the X-ray equipment, an item measured in a combination of 50% of the highest tube voltage of the diagnostic X-ray equipment, the test setting of Group C with authorized output doses between $1{\mu}Gy$ and $5{\mu}Gy$ of mAs turned out to be inappropriate. As a result, the radiation dose to the IEC 60601-2-54 standard for quantification standards proposed by the radiation output from diagnostic X-ray imaging device reproducibility of performance management should be aware that an important evaluation factor.

• Radiation Oncology Journal
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• v.15 no.2
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• pp.167-174
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• 1997

Purpose : The main Purpose of this study is to develop new payment rates for services of Radiation Oncology, considering costs of treating patients. Material and Methods : A survey of forty hospitals has been conducted in order to analyze the costs of treating patients. Before conducting the survey, we evaluated and reclassified the individual service items currently using as Payments units on the fee-for-service reimbursement system. This study embodies the analysis of replies received from the twenty four hospitals. The survey contains informations about the hospitals' costs of 1995 for the reclassified service items on Radiation Oncology. After we adjust the hospital costs by the operating rate of medical equipment, we compare the adjusted costs with the current Payment rates of individual services. Results : The current payment rates were 5.05-6.58 times lower than the adjusted costs in treatment planning services, 2.22 times lower in block making service, 1.57-2.86 times lower in external beam irradiation services, 3.82-5.01 times lower in intracavitary and interstitial irradiation and 1.12-2.55 times lower in total body irradiation. Conclusion : We could conclude that the current payment system on Radiation Oncology does not only reflect the costs of treating patients appropriately but also classify the service items correctly. For an example, when the appropriate costs and classification are applied to TBI, the payment rates of TBI should be increased five times more than current level.

• Journal of radiological science and technology
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• v.45 no.4
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• pp.347-353
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• 2022

In this study, the radiation dose rate was measured by time and distance and evaluated whether radiation dose rate was suitable for domestic and international discharge criteria. In addition, the radiation dose emitted from the patient was measured with a glass dosimeter to evaluate the exposure dose if the caregiver stays in the isolated ward by placing a humanoid phantom instead of the caregiver at a distance of 1 m from the patient, on the second day of treatment. After 23 hours of isolation, the radiation dose rates at a distance of 1 m were 20.54 ± 6.21 µSv/h at 2.96 GBq administration and 27.94 ± 12.33 µSv/h at 3.70 GBq administration. The radiation dose rates at a distance of 1 m were 25.90 ± 2.21 µSv/h when 2.96 GBq was administered and 34.22 ± 10.06 µSv/h when 3.70 GBq was administered after 18 hours of isolation. However, if the isolation period is short may cause unnecessary radiation exposure to the third person. The reading of the attached dosimeter from the morning of the second day of treatment until removal was 0.01 to 0.95 mSv, which is a surface dose determined by the International Commission on Radiation Units and Measurements. And the depth dose was 0.01 to 0.99 mSv. On the second day of treatment, even if the patient caregivers stayed in the isolation ward, the exposure dose of the patient family did not exceed the effective dose limit of 5 mSv recommended by the ICRP and NCRP.

• Journal of radiological science and technology
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• v.38 no.3
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• pp.277-286
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• 2015

Diagnostic radiation devices that is used in the country has reached to 78,000 units. When used for human subjects diagnostic purposes, it is subject to Medical Service Act, when used in diagnostic purposes in animal subjects, the subject to Veterinarians Act. When used for other purposes are subject to the Nuclear Safety Act. Even the same radiation devices varies the legislation that is applied depending on the intended use and object. Diversified been p rovisions a re necessary compared to t he analysis o f l egal content in o rder t o prevent confusion of the legislation is a matter to be applied. It is a qualitative study that Nuclear Safety Act, Medical Service Act and Veterinarians Act administrative procedures for the introduction of the applied diagnostic radiation devices, safety inspection, human resources management, area management and the content related to administrative punishment. The Nuclear Safety Act sub-provisions, the introduction of diagnostic radiation generating devices, there are many complex and complete requirements administrative procedures on the concept of a permit. Inspection of safety associated with the use, would be subject to periodic inspection auditing characteristics over the entire field of radiation safety management. It must receive court regular education for the safety administrator and workers. Unlike the reference of the radiation dose rate to specify the radiation controlled area there is a measurement obligation of radiation dose rate. Unlike the reference of the radiation dose rate to specify the radiation controlled area there is a measurement obligation of radiation dose rate. Quantitative difference of administrative punishment that is imposed when legislation violation has reached up to 10 times, over the entire field, the largest burden of radiation safety management at the time of application of the Nuclear Safety Act sub provisions. And it is applied differently depending on the purpose and the imaging target using the same diagnostic radiation devices. Depending on the use mainly under the current legal system, radiation can be lacking in fairness of the contents of the legislation for safety management, there is a risk of confusion. Alternatives such as centralized and standardization of legislation by diagnostic radiation devices use is expected to be necessary.

• Korean Journal of Plant Tissue Culture
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• v.26 no.1
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• pp.53-58
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• 1999

The gamma radiation-induced changes of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in callus cultures of cassava (Manihot esculenta Crantz) selected as a high yield of cell line for SOD were investigated. In normal cultures, the cell growth reached a maximum at 30 days after subculture (DAS), followed by a rapid decrease with further cultures. The SOD and POD specific activities (units/mg protein) showed the highest at the immediately after subculture and subsequently decreased to 20 DAS, and then increased to 30 DAS, whereas the CAT activity showed the lowest at just after subculture, and it continuously increased from 15 DAS to 30 DAS, showing a good correlation with the cell growth. Irradiation of gamma-ray of 50 and 70 Gy on 7 DAS inhibited significantly the cell growth by 50% and 80% at 14 days after treatment (DAT), respectively. In the cells irradiated with 70 Gy, SOD and POD specific activities increased by 4 and 2.5 folds at 14 DAT, respectively, whereas CAT activity was not affected. The results indicate that SOD and POD may be involved in the antioxidative mechanism in relation to oxidative stresses induced by subcultures and by gamma radiation in callus cultures of cassava.

• The Journal of Engineering Geology
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• v.30 no.4
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• pp.577-588
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• 2020

We evaluated the distributions of primordial radionuclides and effective dose rate of the Ogcheon Group, which includes rocks with high uranium content. Terrestrial gamma radiation was measured at 421 points using a portable gamma ray spectrometer. Dividing the study area into five geological units (og1, og2, og3, og4, and igneous rocks) revealed no significant difference in the concentration of surface radioactivity among the types. The concentrations of 40K, eU, and eTh for all samples ranged from 0.7% to 10.3% (average 5.2%), 0.6 to 287.0 ppm (average 8.5 ppm), and 4.0 to 102.4 ppm (average 31.3 ppm), respectively. The absorbed dose rate in the study area (calculated from the activity concentrations of 40K, eU, and eTh) was in the range of 28.84 to 1,714.5 nGy/h (average 195.4 nGy/h). Among the five geological units, the lowest average was 166.3 nGy/h (for og1) and the highest average was 233.3 nGy/h (for og2; median 198.1 nGy/h). The outdoor effective dose rate for the area obtained from the absorbed dose rate was in the range of 0.04 to 2.10 mSv/y (average 0.24 mSv/y). Except for the four sites located in the uranium-bearing coal bed of og2, none of the studied sites exceeded 1 mSv/y.

• Journal of radiological science and technology
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• v.43 no.5
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• pp.353-357
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• 2020

IVR procedures are on the rise, and patient doses are on the rise. It is necessary to evaluate fluoroscopy dose in IVR procedure. Evaluate ESD on IVR equipment as a reference to DRL settings, I would like to present the direction of improvement in the ESD rate test criteria for fluoroscopy dose. The experimental method is measured with 6cc ionization chamber under the 20cm PMMA Phantom. Radiation is subject to abdominal procedure. The average dose rate of the incident surface was 21.6 ± 11.4 mGy/min. The highest dose equipment was 58.5 mGy/min, and there was no equipment exceeding the domestic standard of 100 mGy/min. However, there were five units above 50 mGy/min. To reduce fluoroscopy dose, it is recommended to reduce pulse rate, The dose increases as the image receptor ages. It is recommended to modify the domestic inspection criteria to 50 mGy/min.

• Imaging Science in Dentistry
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• v.37 no.2
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• pp.93-102
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• 2007

Purpose: Cone beam computed tomography (CBCT) provides a lower dose and cost alternative to conventional CT, promising to revolutionize the practice of oral and maxillofacial radiology. The purpose of this study was to evaluate the absorbed and effective doses of Implagraphy and VCT (Vatech Co., Hwasung, Korea) and compare them with those of panoramic radiography. Materials and Methods: Thermoluminescent dosimeter (TLD) chips were placed at 27 sites throughout the layers of Female ART Head and Neck Phantom for dosimetry. Implagraphy, VCT units, and Planmeca Proline XC panoramic unit were used for radiation exposures. Radiation weighted doses and effective doses were measured and calculated using 1990 and 2005 ICRP tissue weighting factors. Results: Effective doses in Sv (ICRP 2005, ICRP 1990) were 90.19, 61.62 for Implagraphy at maxillay molar area, 123.20, 90.02 for Implagraphy at mandibular molar area, 183.55, 139.26 for VCT and 40.92, 27.16 for panoramic radiography. Conclusion: Effective doses for VCT and Implagraphy were only about 2.2 to 4.5 times greater than those for panoramic radiography. VCT and Implagraphy, CBCT machines recently developed in Korea, showed moderately low effective doses.