• 한국전자통신학회논문지
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• 제13권3호
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• pp.617-622
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• 2018

시설원예 하우스 내부의 공기 밀폐나 유동상태에 직접적인 영향을 주는 송풍기, 측창 개폐기의 동시제어는 $CO_2$ 농도 관리에 필수적이다. 현재 농업인구 감소에 따른 개인당 경작면적 증가로 자동화 시스템과 통합제어의 요구가 꾸준히 증가하고 있는 실정이다. 본 논문에서는 $CO_2$발생기의 연료 및 연소공기 혼합비(공연비), 내 외부 환경에 따른 $CO_2$ 공급량의 제어와 $CO_2$ 공급에 있어 중요한 변수인 측정 개폐기와 같은 기존 설치기기를 동시에 제어할 수 있는 통합 제어시스템을 제안한다.

• 한국전기전자재료학회논문지
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• 제22권6호
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• pp.516-521
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• 2009

X-ray system which is usefully used in diagnosis of the patient, being bombed of radioactivity is a big weak point when irradiates a X-ray to the human body so that ICRP restricted the radiation exposure tolerance of the human body. In order to reduce being bombed, the many research and development is now advanced. A lots of diagnostic X-ray machines have currently used due to the increase of occurrence efficiency of X-ray and precisely the output control by using the inverter which is a high speed switching semiconductors. For getting the confidence of the X-ray machine, the same radiation occurrence, same evaluation, and same irradiation condition are necessary when evaluates X-ray irradiation. It is the most important part for the accuracy of the test result and the patient safety. This research has produced the high voltage occurrence system of full-wave rectification method by using the LC resonance inverter, and evaluated the irradiation reproducibility in order to use it in diagnosis of the patient.

• 한국가시화정보학회지
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• 제22권2호
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• pp.20-26
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• 2024

Water management is crucial for the performance, durability, and stability of Polymer Electrolyte Membrane Fuel Cells (PEMFCs). Due to its importance, various methods for visualizing PEMFC's internal water distribution have been adapted to study and manage water within the cells. However, these methods often require large facilities, leading to high costs and significant barriers to entry. This study addresses these challenges by using a commercial Radiation (X-ray) Generator (RG) for internal water distribution visualization and comparing the results with synchrotron X-ray data from the Pohang Accelerator Laboratory (PAL) 9D beamline. Despite the lower resolution and potential beam distortion challenges, the RG shows promise for PEMFC water distribution visualization, suggesting the need for further research to refine water attenuation coefficients and build-up factors for improved measurement accuracy.

• 한국방사선학회논문지
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• 제13권2호
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• pp.297-303
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• 2019

국내 의료기관 핵 의학과에서는 환자에게 방사성 의약품을 주입하기 위해 체내검사의 80% 이상이 $^{99}Mo/^{99m}TcI$ Generator에서 방사선 핵종인 $^{99m}TcI$ 용출하여 사용한다. 사용이 종료된 Generator 중 외국으로 부터 수입한 국외용 Generator는 각 의료기관에서 자체 처분을 시행한다. 각 의료기관에서는 자체처분을 시행 할 때에는 방사성 폐기물이 자체처분 허용 농도 이하를 만족하여야 한다. 국내에 제시된 자체처분에 대한 지침은 방사선 감쇠 계산식으로 도출된 값으로 Generator 사용 후로부터 80일 이후 자체처분이 가능하다는 내용을 제시하였다. 이러한 지침이 직접 Generator를 가지고 측정한 데이터를 통해 비교 분석하여 타당성이 있는지에 대하여 연구하고자 한다. 결과적으로 1000 mCi 용량의 Generator 의 경우 Generator 구성 요소 중 반감기가 가장 길며, 방사능이 많은 $^{99}Mo$(몰리브덴) column을 가지고 실험하였을 때, 방사성 폐기물로 차체 처분 허용농도 이하가 되는 일수는 $^{99m}TcI$을 용출하여 유도한 기간은 72일, 직접 칼럼을 측정하여 도출한 처분 일은 71일이였다. 직접적으로 연구한 결과는 지침의 내용에서 제시한 자체처분 일수보다 8~9일 정도 보관 일수 차이가 있으나, 국내 차체 처분 보관 일수의 범위 안에 속하므로 국내 자체처분에 대한 지침이 타당성이 있음을 확인 하였다.

• International Journal of Advanced Culture Technology
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• 제12권2호
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• pp.368-374
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• 2024

During an X-ray examination, the beam of radiation is dispersed in many directions. We believe that managing radiation dose is about providing transparency to users and patients in the accurate investigation and analysis of radiation dose. The purpose of measuring the radiation dose as a function of location is to ensure that medical personnel using the equipment or participating in the operating room are minimally harmed by the different radiation doses depending on their location. Four mobile diagnostic X-ray units were used to analyze the radiation dose depending on the spatial location. The image intensifier and the flat panel detector type that receives the image analyzed the dose by angle to measure the distribution of the exposure dose by location. The radiation equipment used was composed of four units, and measuring devices were installed according to the location. The X-ray (C-arm) was measured by varying the position from 0 to 360 degrees, and the highest dose was measured at the center position based on the abdominal position, and the highest dose was measured at the 90° position for the head position when using the image intensifier equipment. The operator or medical staff can see that the radiation dose varies depending on the position of the diagnostic radiation generator. In the image intensifier and flat panel detector type that accepts images, the dose by angle was analyzed for the distribution of exposed dose by position, and the measurement method should be changed according to the provision of dose information that is different from the dose output from the equipment according to the position.

• Journal of Advanced Marine Engineering and Technology
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• 제18권4호
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• pp.33-42
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• 1994

The radiative heat transfer analysis in the fluidized particles layer has important application in many technological areas such as combustion chambers at high pressure and temperature, plasma generators for nuclear fusion, MHD generator using pulverized coal and the liquid droplet radiator used to reject wasted heat from a power plant operating in space. To accurately model the radiation properties of the fluidized particles layer, it is necessary to know the radiation interchange factors of particles in each layer. But the solutions are usually not possible for the equations of radiative heat transfer because it has an inherent difficulty in treating the governing intergo- differential equations, which are derived from the remote effects of radiative heat transfer. In this study, the analysis uses the Monte Carlo simulation method with optical depth model to calculate the radiation interchange factors of particles in each layer with wall and with each other.

• Journal of Radiation Protection and Research
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• 제42권1호
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• pp.21-25
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• 2017

Background: We are developing L-band and S-band microwave dielectric absorption systems aiming novel dosimetry using DNAs, such as plasmid DNA and genomic DNA, and microwave technology. Materials and Methods: Each system is composed of a cavity resonator, analog signal generator, circulator, power meter, and oscilloscope. Since the cavity resonator is sensitive to temperature change, we have made great efforts to prevent the fluctuation of temperature. We have developed software for controlling and measurement. Results and Discussion: By using this system, we can measure the resonance frequency, f, and ${\Delta}Q$ (Q is a dimensionless parameter that describes how under-damped an oscillator or resonator is, and characterizes a resonator's bandwidth relative to its center frequency) within about 3 minutes with high accuracy. Conclusion: This system will be expected to be applicable to DNAs evaluations and to novel dosimetric system.

• Journal of Pharmaceutical Investigation
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• 제33권2호
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• pp.145-149
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• 2003

Manufacturing facilities of the pharmaceuticals must meet certain level of the cleanness required so that foreign substances such as dust, moisture, heat, microorganism, or virus do not contaminate the product. In case of radiopharmaceuticals for medical treatment and diagnosis, not only should the operators and environment be protected from radiation but also need to be isolated from the foreign contaminant. Therefore, manufacturing facilities for radiopharmaceuticals must satisfy the design standards of both hot cell and clean room which are specified by GMP. However, standards of maintaining negative pressure for preventing spread of radioactive contaminant in isolated facilities conflict with the standards of maintaining positive pressure for keeping cleanness. To solve this problem, air pressure of hot cell was designed lower than in the adjacent area to meet standards of the radiation safety. To keep higher cleanness in certain part of the hot cell for filling, minimal relative positive pressure allows. In order to effectively maintain the cleanness that is required for production of Tc-99m generator, which takes 70% of whole demand of radiopharmaceuticals, the rooms placed in each side of production room are used as a buffer area and three lead hot cells are installed in production room. In this research, we established the appropriate engineered design concept for Tc-99m generator manufacturing facility, which satisfies both GMP cleanness standard for preventing particles, bacteria, other contaminants and the regulations of radiation safety for supervising and controlling the amount of radiation exposure and exhausted radioactivity. And the concept of multi-barrier buffer zones is introduced to apply negative air pressure for hot cell with first priority and to continue relative positive air pressure for clean room.

• Journal of Radiation Protection and Research
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• 제29권2호
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• pp.129-139
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• 2004

의료 및 산업체에서 중형방사선 선원의 사용증가는 정규 및 사고시 작업자와 일반인에 대해 방사선 노출의 위험을 초래한다. 본 연구에서는 중형 의료용 선원을 사용하는 $^{99m}Tc$ 발생기에 대한 위험도 평가를 수행하였다. 사건수목기법을 활용하여 국내 현실에 적합한 시나리오를 도출하였으며, 정규 및 사고시로 나누어 작업자와 일반인에 대해서 몬테칼로 기법에 의거한 불확실성 분석을 수행하였다. 아울러 위험도결과에 가장 영향을 미치는 인자를 알아보기 위해 5가지 독립변수에 대한 민감도 분석을 수행하였다. 빈도수의 기여로 인해 정규작업에 대한 위험도가 사고시 위험도보다 높게 평가되었다. $^{99m}Tc$ 발생기의 경우 정규작업 시 작업자 $0.6mSvy^{-1}$, 일반인 $0.014mSvy^{-1}$ 이며 사고시 작업자 $3.96mSvy^{-1}$, 일반인 $0.0016mSvy^{-1}$로 평가되었다. 정규작업 보다 사고시의 불확실성 범위가 10배 정도 더 높게 나타났다. 또한 민감도 분석 결과 선원의 강도, 작업거리, 작업시간이 위험도에 가장 영향을 미치는 인자로 나타났다. 이리한 위험도 평간 방법론과 결과는 중대형 선원에 대한 위험도 정보 활용 규제 (Risk-Informed Regulation)에 유용할 것으로 기대한다.

• 대한방사성의약품학회지
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• 제3권2호
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• pp.80-84
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• 2017

Re-188 is an excellent and practical radioisotope produced by W-188/Re-188-generator for therapy. We prepared Re-188-tin colloid for therapy of various diseases and tried to treat peritoneal effusion in animal model. Sarcoma-180 cells were injected into ICR mice to induce peritoneal effusion and the mice were grown for 3 d. Re-188-tin colloids (0.25, 0.5, and 1 mCi/mL per 30 g body weight) were injected into the mice and the mice were grown for 90 d. Planar gamma scintigraphy showed even distribution of Re-188-tin colloid radioactivity. Bax expression was found to be dose dependent to Re-188-tin colloid. Normal saline treated group showed the shortest survival time. Among the treated groups, 0.5 mCi dose group showed the longest survival time. In conclusion, Re-188-tin colloid was prepared successfully and showed the feasibility to use as a peritoneal effusion treatment in mice.