• 대한핵의학회지
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• 제9권1호
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• pp.59-71
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• 1975

53 patients with hyperthyroidism have been analyzed with special reference to therapeutic response to radioactive iodine ($^{131}I$) treatment. Mean effective half-life, 24 hour uptake rate and radiation dose of $^{131}I$ in hyperthyroid patients included in this study were respectively. 1. Mean effective half-life of $^{131}I\;was\;4.7{\pm}1.5$ days in the tracer dose and $5.0{\pm}1.5$ days in the therapeutic dose. 2. Mean 24 hour uptake rate of $^{131}I\;was\;72.7{\pm}11.1%$ in the tracer dose and $73.4{\pm}12.3%$ in the theapeutic dose. 3. Mean radiation dose of $^{131}I\;was\;5,319{\pm}2,648$ RAD as predicted and $5,692{\pm}2,843$ RAD as actual. A single dose of radioactive iodine treatment was satisfactory in 34 patients (radioiodine sensitive) and multiple doses of radioactive iodine treatments were required in 19 patients (radioiodine resistant). A radioiodine resistant group of patients with hyperthyroidism was distinctively characteristic in the following aspects. 1. Mean thyroid weight calculated in the resistant group ($63.9{\pm}14.0gm$) was significantly (p<0.01) greater than that of the sensitive group ($46.6{\pm}13.3gm$). 2. Mean 24 hour uptake rate of the tracer dose in the resistant group ($67.3{\pm}10.7%$) was significantly (p<0.01) lower than that of the sensitive group ($75.7{\pm}10.5%$). 3. Mean 24 hour uptake rate of the therapeutic dose in the resistant group ($68.5{\pm}13.7%$) was significantly (p<0.05) lower than that of the sensitive group ($76.1{\pm}10.9%$). 4. Mean predicted radiation dose, of $^{131}I$ in the resistant group ($3,684{\pm}1,745$ RAD) was significantly (p<0.01) lower than that of the sensitive group ($6,232{\pm}2,683$ RAD). 5. Mean actual radiation dose of $^{131}I$ in the resistant group ($4,100{\pm}1,691$ RAD) was significantly (p<0.01) lower than that of the sensitive group ($6,582{\pm}3,024$ RAD). 6. No significant difference was detected in terms of effective half-life of $^{131}I$ among the groups (p>0.05). 7. The average mean % difference of effective half-life, uptake rate and radiation dose measured following the tracer and therapeutic dose of $^{131}I$ were not statistically significant (p>0.05). Therefore effective half-life, uptake rate and radiation dose of the therapeutic dose of $^{131}I$ were readily predictable following the tracer dose of $^{131}I$. 8. It is concluded that the possibility of resistance to radioactive iodine treatment may be anticipated in patients with thyroid gland large in size and compromised $^{131}I$ uptake rate.

• Journal of Radiation Protection and Research
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• 제30권4호
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• pp.161-165
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• 2005

The gamma-ray dose rates in air at 233 locations in Korea have been determined. The contribution to the gamma-ray dose rates in air due to the presence of $^{232}Th-series,\;^{238}U-series\;and\;^{40}K$ is as follows: 47.3% $(36\;nGyh^{-1})\;^{232}Th-series$ 14.5% $(11\;nGyh^{-1})\;^{238}U-series$ and 38.2% $(29\;nGyh^{-1})\;^{40}K$. The mean gamma-ray dose rate theoretically derived from $^{232}Th-series,\;^{238}U-series\;and\;^{40}K\;was\;76{\pm}17\;nGyh^{-1}$. This corresponds to an annual effective dose of $410\;{\mu}Sv$ and an annual collective dose of 18900 person-Sv for all provinces under study. The results have been compared with other global radiation dose.

• Communications for Statistical Applications and Methods
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• 제9권3호
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• pp.693-701
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• 2002

When the lowest dose level compared with zero-dose control has significant difference in effect, it is referred as minimum effective dose (MED). In this paper, we discuss several nonparametric methods for finding MED using updated rank at each sequential test step in small sample size and suggest new nonparametric procedures based on placement. Monte Carlo Simulation is adapted to compare power and Familywise Error Rate(FWE) of the new procedures with those of discussed nonparametric tests for finding MED.

• Radiation Oncology Journal
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• 제16권4호
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• pp.357-366
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• 1998

Brachytherapy is an essential part of radiotherapy for uterine cervical cancer. The low dose rate (LDR) regimen has been the major technique of intracavitary therapy for cervical cancer. However, there has been an expansion in the last 20 years of high dose rate (HDR) machines using Ir-192 sources. Since 1979, HDR brachytherapy has been used for the treatment of uterine cervical cancer in Korea. The number of institutions employing HDR has been increasing, while the number of low dose rate system has been constant. In 1995, there was a total 27 HDR brachytherapy units installed and 1258 cases of patients with cervical cancer were treated with HDR Most common regimens of HDR brachytherapy are total dose of 30-39 Gy at point A with 10-13 fractions in three fractions per week. 24-32 Gy with 6-8 fractions in two fractions per week, and 30-35 Gy with 6-7 fractions in two fractions per week. The average fractionation regimen of HDR brachytherapy is about 8 fractions of 4.1 Gy each to Point A. In Korea, treatment results for HDR brachytherapy are comparable with the LDR series and appears to be a safe and effective alternative to LDR therapy for the treatment of cervical carcinoma. Studies from the major centers report the five-year survival rate of cervical cancer as. 78-86$\%$ for Stage 1, 68-85$\%$ for stage 11, and 38-56$\%$ for Stage III. World-wide questionnaire study and Japanese questionnaire survey of multiple institutions showed no survival difference in any stages and dose-rate effect ratio (HDR/LDR) was calculated to be 0.54 to 0.58. However the optimum treatment doses and fractionation schemes appropriate to generate clinical results comparable to conventional LDR schemes have yet to be standardized. In conclusion, HDR intracavitary radiotherapy is increasingly practiced in Korea and an effective treatment modality for cervical cancer. To determine the optimum radiotherapy dose and fractionation schedule, a nation-wide prospective study is necessary in Korea. In addition, standardization of HDR application (clinical, computer algorithms, and dosimetric aspects) is necessary.

• Journal of Radiation Protection and Research
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• 제31권1호
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• pp.1-7
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• 2006

The measured mean activities of $^{226}Ra,\;^{232}Th,\;^{40}K\;and\;^{137}Cs$ in the soil of Bahawalpur, Bahawalnagar and Rahimyar Khan Bistricts were 32.9, 53.6, 647.4 and 1.8 Bq $kg^{-1}$. The average absorbed dose rate calculated from these activities was 74.3 nGy $h^{-1}$ and the mean annual effective dose rate was found to be 0.46 mSv $y^{-1}$. Absorbed doses to different body organs were derived from annual effective doses using tissue weighting factors. Radiation induced fatal cancer risks were assessed by using ICRP 60 Model. Estimations incurred 184deaths per year due to cancer.

• Communications for Statistical Applications and Methods
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• 제19권1호
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• pp.33-45
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• 2012

신약 개발 연구 또는 임상시험에서 개발된 약이 0용량 대조군과 비교해 효과 차이가 있는 가장 작은 용량을 최소 효과 용량(MED)이라 한다. 본 논문에서는 다중 그룹 상황에서 동시적(simultaneous)으로 각 각 그룹의 최소 효과 용량을 확인하기 위하여 위치(placement)에 기초한 비모수적 방법을 제시하였다. 또한 Monte Carlo 모의실험을 통하여 기존에 제시된 검정법과 본 논문에서 제안한 검정법의 검정력(power)과 FWE(Family-wise Error Rate)를비교하였다.

• 지질공학
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• 제30권4호
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• pp.577-588
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• 2020

일부 암석의 우라늄 함량이 높은 것으로 알려진 옥천층군 지역의 유효선량을 파악하기 위하여 휴대용 감마선분광분석기를 이용하여 421개 지점에서 지표방사능(40K, eU, eTh)을 측정하였다. 연구지역을 5개의 지질(og1, og2, og3, og4, 화성암)로 구분했을 때 지질별 지표방사능 강도에는 큰 차이가 없었다. 전체 421 암석의 40K, eU, eTh의 함량은 각각 0.7~10.3% (평균 5.2%), 0.6~287.0 ppm (평균 8.5 ppm), 4.0~102.4 ppm (평균 31.3 ppm) 을 보였다. 방사능강도로부터 구한 연구지역의 흡수선량은 28.84~1,714.5 nGy/h의 범위로서(평균 195.4 nGy/h) 지질별 평균값 최저는 og1의 166.3 nGy/h, 최고는 og2의 233.3 nGy/h(중앙값은 198.1 nGy/h였다. 흡수선량으로부터 구한 연구지역의 옥외 유효선량은 0.04~2.10 mSv/y (평균 0.24 mSv/y)의 범위이며 함 우라늄층이 협재된 og2에 위치한 4개 지점을 제외하면 옥외 유효선량이 1 mSv/y를 넘는 지점은 없었다.

• 한국환경과학회지
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• 제11권12호
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• pp.1195-1204
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• 2002

We calculated dose rate using radiative transfer equations to consider radiative processes distinctly. The dose rate at Pohang(36°02'N, 129°23'E) was calculated using measured ozone and meteorological data and two-stream approximations(quadrature, Eddington, delta Eddington, PIFM(practical improved flux method), discrete ordinate, delta discrete ordinate) are used in solving equation. The purpose of this study is to determine the most compatible radiative transfer approximation for simulating the radiative and photochemical processes of atmosphere through comparision between calculated and measured values. Dose rate of the biologically effective irradiance in the region 0.28-0.32 U m showed the highest value when quadrature and Eddington was used and lower value on condition that delta scaling was applied. Correlation coefficient between dose rate at surface using radiation transfer equation and measured UV-B at Pohang was 0.78, 0.79 and 0.81 when delta Eddington, PIFM and delta discrete ordinate were used. Also, in case of above approximations were used, MBE(Mean Bias Error) was within -0.3MED/30min and RMBE(Relative Mean Bias Error) was below 10% between 1200 LST and 1400 LST Approximations which are compatible in estimating radiative process are delta Eddington, PIFM and delta discrete ordinate. Especially, in case that radiative process is considered more detail, delta discrete ordinate increased the number of stream is proper.

• 대한방사선기술학회지:방사선기술과학
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• 제47권2호
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• pp.107-116
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• 2024

In this study, we analyzed the use of general radiography imaging and effective dose in inpatients. Our aim is to help reduce national medical radiation exposure doses and develop rational health-care financial policies. The effective dose for each general radiography was calculated using the ALARA-GR program for 53 types (total: 260 codes) general radiography codes selected from 'National Health Insurance Care Benefit Cost'. The usage of general radiography was analyzed in the 2018 inpatient patient data of the Health Insurance Review and Assessment Service, and the effective dose for each general radiography was analyzed. 89.00% of inpatients undergo general radiography imaging at least once, with an average of 12.63 scans per person and an effective dose of 1.00 mSv. Those who received support from Medical Aid showed a higher value compared to those who were insured by National Health Insurance, with 17.39 cases and 1.43 mSv (p<.001). Chest had the highest usage rate at 23.12% for general radiography imaging, while L-spine had the highest effective dose at 24.53%. It is estimated that 420 inpatients patients undergo 121 to 820 general radiography imaging procedures per year, and 233 inpatients are estimated to have an annual effective dose of >20.00~58.25 mSv. Rational use of health-care finances and the practice of medical radiation safety management are essential for the well-being of individuals, the enhancement of quality of life, and the improvement of health-care quality.

• The Korean Journal of Physiology
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• 제3권1호
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• pp.45-49
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• 1969

The effects of water extracts and powder of Korean ginseng on the division of Saccharomyces cerevisiae were studied. 1. The addition of several doses of water extracts and powder of ginseng to the yeast medium of Moyer and Coghill showed various promoted division of Saccharomyces. 2. The optimal dose of ginseng on tile division of Saccharomyces (0.08% dry ginseng medium solution per $10\;cells/mm^3$) could be recognized. 3. On the culture for 24 hours at $18^{\circ}C$, the cell number of control group was $13.25{\times}10^3\;cells/mm^3$ and that of the optimal dose group of water extracts of ginseng was $23.20{\times}10^3\;cells/mm^3$. On the culture, for 24 hours at $25^{\circ}C$, the cell number of control group was $16.85{\times}10^3\;cells/mm^3$ and that of the optimal dose group was $30.20{\times}10^3\;cells/mm^3$. The increasing rate of cell divison by the ginseng was about twice than that of control group. The optimal dose treatment of ginseng at $18^{\circ}C$ was more effective than control group at $25^{\circ}C$. 4. On the culture for 24 hours at $18^{\circ}C$, the increasing rate of water extracts of ginseng was 75.1%, and the rate of ginseng powder was 7.6%. On the culture for 24 hours at $25^{\circ}C$, the rate of water extracts of ginseng was 79.8%, and the rate of ginseng powder was 57.2%. Therefore water extracts of ginseng was more effective than ginseng powder of same dry weight, and the promoted effect of ginseng powder at $25^{\circ}C$ was more effective than at $18^{\circ}C$.