• Title/Summary/Keyword: Radiological technology

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Preliminary Shielding Analysis of the Concrete Cask for Spent Nuclear Fuel Under Dry Storage Conditions (건식저장조건의 사용후핵연료 콘크리트 저장용기 예비 방사선 차폐 평가)

  • Kim, Tae-Man;Dho, Ho-Seog;Cho, Chun-Hyung;Ko, Jae-Hun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.15 no.4
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    • pp.391-402
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    • 2017
  • The Korea Radioactive Waste Agency (KORAD) has developed a concrete cask for the dry storage of spent nuclear fuel that has been generated by domestic light-water reactors. During long-term storage of spent nuclear fuel in concrete casks kept in dry conditions, the integrity of the concrete cask and spent nuclear fuel must be maintained. In addition, the radiation dose rate must not exceed the storage facility's design standards. A suitable shielding design for radiation protection must be in place for the dry storage facilities of spent nuclear fuel under normal and accident conditions. Evaluation results show that the appropriate distance to the annual dose rate of 0.25 mSv for ordinary citizens is approximately 230 m. For a $2{\times}10$ arrangement within storage facilities, rollover accidents are assumed to have occurred while transferring one additional storage cask, with the bottom of the cask facing the controlled area boundary. The dose rates of 12.81 and 1.28 mSv were calculated at 100 m and 230 m from the outermost cask in the $2{\times}10$ arrangement. Therefore, a spent nuclear fuel concrete cask and storage facilities maintain radiological safety if the distance to the appropriately assessed controlled area boundary is ensured. In the future, the results of this study will be useful for the design and operation of nuclear power plant on-site storage or intermediate storage facilities based on the spent fuel management strategy.

Appropriate image quality management method of bone mineral density measurement (골밀도 측정의 올바른 질 관리방법)

  • Kim, Ho-Sung;Dong, Kyung-Rae
    • Proceedings of the Korea Contents Association Conference
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    • 2009.05a
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    • pp.1141-1149
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    • 2009
  • In Bone Mineral Density(BMD) measurements, accuracy and precision must be superior in order to know the small changes in bone mineral density and actual biological changes. Therefore the purpose of this study is to increase the reliability of bone mineral density inspection through appropriate management of image quality from machines and inspectors. For the machine management method, the recommended phantom from each bone mineral density machine manufacturer was used to take 10~25 measurements to determine the standard amount and permitted limit. On each inspection day, measurements were taken everyday or at least three times per week to verify the whether or not change existed in the amount of actual bone mineral density. Also evaluations following Shewhart control chart and CUSUM control chart rules were made for the bone mineral density figures from the phantoms used for measurements. Various forms of management became necessary for machine installation and movement. For the management methods of inspectors, evaluation of the measurement precision was conducted by testing the reproducibility of the exact same figures without any real biological changes occurring during reinspection. There were two measurement methods followed: patients were either measured twice with 30 measurements or three times with 15 measurements. An important point to make regarding measurements is that after the first inspection and any other inspection following, the patient was required to come off the inspection table completely and then get back on for any further measurements. With a 95% confidence level, the precision error produced from the measurement bone mineral figures produced a precision error of 2.77 times the minimum of the biological bone mineral density change (Least significant change: LSC). In order to assure reliability in inspection, there needs to be good oversight of machine management and measurer for machine operation and inspection error. Accuracy error in machines needs to be reduced to under 1% for scientific development in bone mineral density machines.

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A study on the effects of scattering dose on eyes and thyroid for panoramagraphy - Focus on TLD and PLD - (파노라마 촬영시 눈과 갑상선에 미치는 표면선량에 관한 연구 - TLD, PLD 중심으로 -)

  • Dong, Kyung-Rae
    • Proceedings of the Korea Contents Association Conference
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    • 2009.05a
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    • pp.1118-1123
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    • 2009
  • Ten hospitals from the Gwangju area were used to examine shallow dose to eyes and thyroid from panoramagraphy. Thermoluminescent dosimeter (TLD) and Photoluminescent dosimeter (PLD) were used as measurement devices at each hospital. ICRP 60 and ICRP 73 set standards for acceptability for eyes at 15mSv and thyroid at 1mSv per year. Left eye measures with TLD and PLD resulted in 0.19mSv and 0.24mSv respectively. Right eye measures with TLD and PLD resulted in 0.23mSv and 0.25mSv respectively. Thyroid measures with TLD and PLD resulted in 0.08mSv and 0.25mSv respectively with both measures not exceeding standards for acceptance. There was a significant difference in comparing the left eye and thyroid for TLD and PLD (p<0.01). There was no significant difference with the right eye (p>0.05). The absorbed dose measurements for eyes and thyroid using TLD and PLD in regards to panorama devices at each hospital were within the ICRP 60 recommendations; however, with the possibility of stochastic effect, all dose levels were taken into consideration.

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Ginsenoside Rd inhibits the expressions of iNOS and COX-2 by suppressing NF-κB in LPS-stimulated RAW264.7 cells and mouse liver

  • Kim, Dae Hyun;Chung, Jae Heun;Yoon, Ji Sung;Ha, Young Mi;Bae, Sungjin;Lee, Eun Kyeong;Jung, Kyung Jin;Kim, Min Sun;Kim, You Jung;Kim, Mi Kyung;Chung, Hae Young
    • Journal of Ginseng Research
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    • v.37 no.1
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    • pp.54-63
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    • 2013
  • Ginsenoside Rd is a primary constituent of the ginseng rhizome and has been shown to participate in the regulation of diabetes and in tumor formation. Reports also show that ginsenoside Rd exerts anti-oxidative effects by activating anti-oxidant enzymes. Treatment with ginsenoside Rd decreased nitric oxide and prostaglandin $E_2$ ($PGE_2$) in lipopolysaccharides (LPS)-challenged RAW264.7 cells and in ICR mouse livers (5 mg/kg LPS; LPS + ginsenoside Rd [2, 10, and 50 mg/kg]). Furthermore, these decreases were associated with the down-regulations of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 and of nuclear factor (NF)-${\kappa}B$ activity in vitro and in vivo. Our results indicate that ginsenoside Rd treatment decreases; 1) nitric oxide production (40% inhibition); 2) $PGE_2$ synthesis (69% to 93% inhibition); 3) NF-${\kappa}B$ activity; and 4) the NF-${\kappa}B$-regulated expressions of iNOS and COX-2. Taken together, our results suggest that the anti-inflammatory effects of ginsenoside Rd are due to the down-regulation of NF-${\kappa}B$ and the consequent expressional suppressions of iNOS and COX-2.

Development of Detailed Korean Adult Eye Model for Lens Dose Calculation

  • Han, Haegin;Zhang, Xujia;Yeom, Yeon Soo;Choi, Chansoo;Nguyen, Thang Tat;Shin, Bangho;Ha, Sangseok;Moon, Sungho;Kim, Chan Hyeong
    • Journal of Radiation Protection and Research
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    • v.45 no.1
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    • pp.45-52
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    • 2020
  • Background: Recently, the International Commission on Radiological Protection (ICRP) lowered the dose limit for the eye lens from 150 mSv to 20 mSv, highlighting the importance of accurate lens dose estimation. The ICRP reference computational phantoms used for lens dose calculation are mostly based on the data of Caucasian population, and thus might be inappropriate for Korean population. Materials and Methods: In the present study, a detailed Korean eye model was constructed by determining nine ocular dimensions using the data of Korean subjects. The developed eye model was then incorporated into the adult male and female mesh-type reference Korean phantoms (MRKPs), which were then used to calculate lens doses for photons and electrons in idealized irradiation geometries. The calculated lens doses were finally compared with those calculated with the ICRP mesh-type reference computational phantoms (MRCPs) to observe the effect of ethnic difference on lens dose. Results and Discussion: The lens doses calculated with the MRKPs and the MRCPs were not much different for photons for the entire energy range considered in the present study. For electrons, the differences were generally small, but exceptionally large differences were found at a specific energy range (0.5-1 MeV), the maximum differences being about 10 times at 0.6 MeV in the anteroposterior geometry; the differences are mainly due to the difference in the depth of the lens between the MRCPs and the MRKPs. Conclusion: The MRCPs are generally considered acceptable for lens dose calculations for Korean population, except for the electrons at the energy range of 0.5-1 MeV for which it is suggested to use the MRKPs incorporating the Korean eye model developed in the present study.

A Convergence Study on the Core Competencies of students: G university (G 대학 대학생 핵심역량 설정에 관한 융합연구)

  • Kim, Chang-Gyu;Jang, Kee-Duck;Chun, Yeol-Eo
    • Journal of the Korea Convergence Society
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    • v.9 no.7
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    • pp.77-86
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    • 2018
  • This research is based on core competency in order to provide diverse educational opportunities and to train compatible human resources according to industrial change. The research set up the core competency of university students according to document research and the importance of core competency of students, professors, faculty and parents. As a result, a total of 14 competencies were deducted by importance and validation from enrolled students, graduated students and professors. A total of 5 core competencies and 14 detailed competencies were deducted. Creativity, problem solving ability, self-directed overall problem solving abilities, expertise ability, data processing ability, technology application according to industry, consideration and serving character, community service, communicational ability, self-management, inter personal relationship, foreign language ability, global, leadership and competence were the 14 elements of this research. Based on the result of this study, it is necessary to improve the competence of university students by applying them to the curriculum development and operation and to find out the extent of the students competence enhancement through the development of future capacity measuring tools.

Comparison with ABCHES and Abdomen Compression Device in Respirational Radiation Therapy on Patients in Hepatocellular Carcinoma (간세포암 환자에서 ABCHES와 복부압박장비의 적용한 호흡동조방사선 치료의 유용성 비교)

  • Cho, Yoon-Jin;Byun, Sang-Joon;Kim, Young-Jae
    • Journal of the Korean Society of Radiology
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    • v.6 no.5
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    • pp.395-402
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    • 2012
  • 4D-Radiation Therapy is the optimal treatment to track moving organs(tumor) and give the appropriate prescription dose to tumor and low radiation dose to normal tissue surrounding tumor volume. The ABCHES is a 4DRT devices maintaining shallow breathing to patients. It allows the tumor's movement was minimize. Meanwhile, Abdominal compression device is limited the breath compressing abdomen on patients. In this paper we will quantitative analysis the movement of tumor on only ABCHES versus ABCHES with Abdomal compression device and Analysis tumor dose and normal tissue's dose by Dose Volume Histogram on two parts. The result of Comparision ABCHES and ABCHES with Abdominal compression device, SI(Superior-Inferior) direction, AP(Anterior-Posterior) direction and LR(Left-Right) direction was limited 1.0 mm, 0.2 mm, 0.2 mm(average). and also reduction rate of voluume in HPTV was $16{\pm}2%$, and LPTV was $15.8{\pm}0.8%$ under only using ABCHES and ABCHES with compression. The analysis dose volume histogram was more radiation dose in ABCHES and abdominal compression device than only using ABCHES, and less normal tissue-ipsilateral lung, whole lung, kidney-dose in ABCHES and abdominal compression device than only using ABCHES. The overall analysis was ABCHES with abdominal compression better than only using ABCHES method. In hereafter it will be studies that limitation of ABCHES and abdomonal compression device. In other words, patient's discomfort on compression intensity, method of application on patient with inaccurate respiration cycle.

The Effect of Acoustic Velocity of Ultrasonographic Equipment Using an N-365 Multipurpose Phantom (N-365 다목적팬텀에서 초음파진단장치의 음속변화 효과)

  • Kim, Yon-Min;Shim, Jae-Goo;Kim, Sang-Hyun
    • Journal of the Korean Society of Radiology
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    • v.11 no.4
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    • pp.221-225
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    • 2017
  • To evaluate the performance of ultrasound imaging system, we investigated the change of spatial resolution according to changing sonic velocity change parameter provided by ultrasound equipment. Ultrasound phantom images were obtained using a 3.0 ~ 5.0 MHz convex transducer in an ultrasound diagnostic device used at a medical institution located at Iksan. N-365 multi-purpose ultrasound phantom was used to measure longitudinal distance measurement accuracy and longitudinal and transverse resolution. In the same manner, the sonic velocity of the ultrasound equipment was changed from 1580 m/sec to 1400 m/sec in six steps, and the full width at half maximum(FWHM) was measured using the image J program to determine whether the measured values were different. As a result, lateral resolution was measured from 1.91 mm to 5.3 mm according to the speed change, and the smallest FWHM was 1.91 mm at 1420 m/sec. The axial resolution was measured from 1.03 mm to 1.14 mm according to the speed change, and the smallest FWHM was 1.03 mm at 1400 m/sec. The slower the sound velocity of the ultrasound equipment, the shorter the length of longitudinal measurement.

A Study of the Characteristics of the Human External Auditory Canal Using 3-Dimensional Medical Imaging (3차원 의료영상을 이용한 인체 외이도 특징에 관한 연구)

  • Kim, Hyeong-Gyun
    • Journal of the Korean Society of Radiology
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    • v.11 no.6
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    • pp.467-473
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    • 2017
  • Using Digital Imaging and Communications in Medicine(DICOM) and a 3D medical imaging program, the characteristics of the external auditory canal(EAC) were compared. Using images of the ears of 63 different male and female subjects of varying age, this study measured and compared EAC transverse axis lengths, internal diameter circumferences, and upper and lower curvature angles. The findings of the study indicated differences in EAC shapes according not only to age and sex but also to the left and right of the same subject. A comparison between the sexes of the subjects (35 males and 28 females) indicated that, on average, the length of the EAC was 4.75mm longer in males. Based on the lower curvature angle, the interior side of the diameter circumference of the EAC was found to be reduced on average by 37.2% compared to the exterior side. Although the upper curvature angle was on average $25.7^{\circ}$ larger than the lower curvature angle, 4 subjects showed a larger lower curvature angle and large differences between the upper and lower curvature angles were observed in 8 subjects of the younger age group (4~14 years old). This indicated changes in EAC curvature shapes during growth. This study presents a method to raise safety and precision by comparing direct measurements taken through physical means and indirect measurements acquired from existing ear samples. This was possible due to technological developments in which 3D medical image representation technology creates images close to reality, and, through further development, this method is expected to be used for standardization research of EAC shapes.

Current Status of Imaging Physics & Instrumentation In Nuclear Medicine (핵의학 영상 물리 및 기기의 최신 동향)

  • Kim, Hee-Joung
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.2
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    • pp.83-87
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    • 2008
  • Diagnostic and functional imaging device have been developed independently. The recognition that combining of these two devices can provide better diagnostic outcomes by fusing anatomical and functional images. The representative examples of combining devices would be PET/CT and SPECT/CT. Development and their applications of animal imaging and instrumentation have been very active, as new drug development with advanced imaging device has been increased. The development of advanced imaging device resulted in researching and developing for detector technology and imaging systems. It also contributed to develop a new software, reconstruction algorithm, correction methods for physical factors, image quantitation, computer simulation, kinetic modeling, dosimetry, and correction for motion artifacts. Recently, development of MRI and PET by combining them together was reported. True integration of MRI and PET has been making the progress and their results were reported. The recent status of imaging and instrumentation in nuclear medicine is reported in this paper.