• 한국작물학회지
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• 제38권1호
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• pp.60-65
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• 1993

7개 재배지역산 참당귀의 decursin 함량변이를 조사하였으며, 각 재배지의 기상요인들과의 상관분석을 통하여 기상환경이 당귀 근의 decursin 함량에 미치는 영향을 파악하고자 수행된 실험결과는 다음과 같다. 1. 참당귀 근의 유효성분인 decursin과 decursinol angelate의 정량은 순상컬럼을 사용한 HPLC법이나 GC법이 양호하였다. 2. 참당귀 뿌리의 decursin 함량은 봉화산 4. 86%, 영천산 4.75%이며 수원산은 2.33%로 재배지역에 따른 함량변이가 비교적 컸다. 3. 생육기간별 각 기상요인들과 decursin 함량과의 상관분석 결과 통계적 유의상관은 보이지 않았으나, 평균기온과 강수량은 대체적으로 부의 상관을 보였으며 일교차, 일사량, 일조시수등은 정의 상관을 나타냈다.

• Nuclear Engineering and Technology
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• 제38권5호
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• pp.411-416
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• 2006

The Advanced Test Reactor (ATR), at the Idaho National Laboratory (INL), is one of the world's premier test reactors for providing the capability for studying the effects of intense neutron and gamma radiation on reactor materials and fuels. The physical configuration of the ATR, a 4-leaf clover shape, allows the reactor to be operated at different power levels in the comer 'lobes' to allow for different testing conditions for multiple simultaneous experiments. The combination of high flux (maximum thermal neutron fluxes of 1E15 neutrons per square centimeter per second and maximum fast [E>1.0 MeV] neutron fluxes of 5E14 neutrons per square centimeter per second) and large test volumes (up to 122 cm long and 12.7 cm diameter) provide unique testing opportunities. The current experiments in the ATR are for a variety of test sponsors - US government, foreign governments, private researchers, and commercial companies needing neutron irradiation services. There are three basic types of test configurations in the ATR. The simplest configuration is the sealed static capsule, which places the capsule in direct contact with the primary coolant. The next level of experiment complexity is an instrumented lead experiment, which allows for active control of experiment conditions during the irradiation. The most complex experiment is the pressurized water loop, in which the test sample can be subjected to the exact environment of a pressurized water reactor. For future research, some ATR modifications and enhancements are currently planned. This paper provides more details on some of the ATR capabilities, key design features, experiments, and future plans.

• 한국의류학회지
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• 제23권7호
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• pp.980-986
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• 1999

This study was done to ivestigate the fabrics thatminimized harmfulness of UVB(ultraviolet B) and that might product Vit. {{{{ {D }`_{3 } ^{ } }} by UVB. Twelve female subjects wearing in three different types i.e fabric A(UVB 100% protection) fabric B(UVB 50% protection) and bikinii were exposed to outdoor environment (Air Temp : 25℃, 42% R,H Air velocity : 0.13m/s UV does :6KJ/m2) Blood samples were taken 24 hours before the after the experiment in order to examine concentration of vit.{{{{ {D }`_{3 } ^{ } }} in the blood. During the experiment axillary temperature skin temperature of 7 areas(forehead Chest Upper arm, Hand Thigh Lower leg, Foot) were measured. The more irradiated areas by UVB were the more the concentration of serum 25(OH){{{{ {D }`_{3 } ^{ } }} were significantly. Mean skin temperature was significantly low levekl in wearing the fabric of UVB 50% protection (p<0.001) Axillary temperature was significantly high level in wearing the fabric of UVB 50% protection (p<0.001). Therefore the fabric of UVB 50% protection intercepts the radiation and has advantage to give off body heat over other fabrics

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 Proceedings of the 4th Korea-China Joint Workshop on Nuclear Waste Management
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• pp.205-219
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• 2004

The remote operation of the Advanced Spent Fuel Conditioning Process (ACP) is analyzed by using the 3D graphic simulation tools. The ACP equipment operates in intense radiation fields as well as in a high temperature. Thus, the equipment should be designed in consideration of the remote handling and maintenance. As well as suitable remote handling and maintenance technology needs to be developed along with the design of the process concepts. To develop such remote operation technology, we developed the graphic simulator which provides the capability of verifying the remote operability of the ACP without fabrication of the process equipment. In other words, by applying virtual reality to the remote maintenance operation, a remote operation task can be simulated in the graphic simulator, not in the real environment. The graphic simulator will substantially reduce the cost of the development of the remote handling and maintenance procedure as well as the process equipment, while at the same time developing a remote maintenance concept that is more reliable, easier to implement, and easier to understand.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 Proceedings of The 6th korea-china joint workshop on nuclear waste management
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• pp.60-75
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• 2005

The remote operation of the Advanced Spent Fuel Conditioning Process (ACP) is analyzed by using the 3D graphic simulation tools. The ACP equipment operates in intense radiation fields as well as in a high temperature. Thus, the equipment should be designed in consideration of the remote handling and maintenance. As well as suitable remote handling and maintenance method needs to be provided. To provide such remote operation technology, we developed the graphic simulator which provides the capability of verifying the remote operability of the ACP without fabrication of the process equipment. In other words, by applying virtual reality to the remote maintenance operation, a remote operation task can be simulated in a computer, not in a real environment. In this way the graphic simulator can substantially reduce the design cost of the remote operation process and the equipment. Also it can provide new operation concept that is more reliable, easier to implement, and easier to understand.

• Journal of Communications and Networks
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• 제13권2호
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• pp.160-166
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• 2011

In u-healthcare services based on wireless body sensor networks, reliable connection is very important as many types of information, including vital signals, are transmitted through the networks. The transmit power requirements are very stringent in the case of in-body networks for implant communication. Furthermore, the wireless link in an in-body environment has a high degree of path loss (e.g., the path loss exponent is around 6.2 for deep tissue). Because of such inherently bad settings of the communication nodes, a multi-hop network topology is preferred in order to meet the transmit power requirements and to increase the battery lifetime of sensor nodes. This will ensure that the live body of a patient receiving the healthcare service has a reduced level of specific absorption ratio (SAR) when exposed to long-lasting radiation. We propose an efficientmethod for delivering delay-intolerant data packets over multiple hops. We consider forward error correction (FEC) in an erasure correction mode and develop a mathematical formulation for packet-level scheduling of delay-intolerant FEC packets over multiple hops. The proposed method can be used as a simple guideline for applications to setting up a topology for a medical body sensor network of each individual patient, which is connected to a remote server for u-healthcare service applications.

• 대한안전경영과학회지
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• 제19권4호
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• pp.25-34
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• 2017

Offshore plants should be managed at a high level of safety condition. Because the offshore plant has cramped space and has difficult access when a fire occurred, a fire can be critical to the plants. LED lighting can reduce the risk of fire by its lower energy consume suitable to intrinsic safety and lower heat radiation that can reduce the possibility of ignition. Also LED has a long lifetime. Though LED luminaire has various advantages for offshore plants, an international standard for the luminaire has not provided because it is new technology. Because there is no international and domestic standard specially provided for the LED luminaire, a guideline is required for developing the LED light and for the future establishment of an international standard. This study was conducted to develop the guideline for LED luminaire for offshore plants. Firstly, relevant standards were analyzed for the guideline. Then we found that there are editorial differences between international standards and domestic standards. So the guideline was developed based on international version and the differences between the domestic and international standard were provided to let Korean developers recognize the differences.

• Nuclear Engineering and Technology
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• 제52권5호
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• pp.1043-1050
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• 2020

Radioactive aerosols are produced during the cutting of contaminated and activated metals. They must be collected and removed by a high-performing filtration system before releasing to the environment from the decommissioning workplace. The filtration system requires regular replacement to ensure the sufficient removal of radioactive aerosols because its filtration efficiency gradually decreases. This study evaluates the efficiency and lifetime of filters while cutting metals by using a plasma arc cutter. Particularly, this study considers the aerodynamic diameter distribution of number and mass concentrations for aerosols from 6 nm to 10 ㎛ when evaluating the performance of filters. After 20 time reuses for cutting operation performed in a cutting chamber, the removal efficiency is reduced from over 99 to below 93% at 2 ㎛. The results are used to analyze the lifetime of filters, the frequencies of their replacements, and impact on internal radiation dose.

• Nuclear Engineering and Technology
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• 제51권7호
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• pp.1749-1757
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• 2019

Predicting lower flammability limits (LFL) of hydrogen has become an ever-important task for safety of nuclear industry. While numerous experimental studies have been conducted, LFL results applicable for the harsh environment are still lack of information. Our aim is to develop a calculated non-adiabatic flame temperature (CNAFT) model to better predict LFL of hydrogen mixtures in nuclear power plant. The developed model is unique for incorporating radiative heat loss during flame propagation using the CNAFT coefficient derived through previous studies of flame propagation. Our new model is more consistent with the experimental results for various mixtures compared to the previous model, which relied on calculated adiabatic flame temperature (CAFT) to predict the LFL without any consideration of heat loss. Limitation of the previous model could be explained clearly based on the CNAFT coefficient magnitude. The prediction accuracy for hydrogen mixtures at elevated initial temperatures and high helium content was improved substantially. The model reliability was confirmed for $H_2-air$ mixtures up to $300^{\circ}C$ and $H_2-air-He$ mixtures up to 50 vol % helium concentration. Therefore, the CNAFT model developed based on radiation heat loss is expected as the practical method for predicting LFL in hydrogen risk analysis.

• 항공우주시스템공학회지
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• 제13권3호
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• pp.87-94
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• 2019

본 논문에서는 무인항공기가 수명주기 동안 노출될 수 있는 운용 환경조건 입증을 위한 시험절차를 제안한다. 시험절차는 국방과학연구소 초대형 기후환경 챔버에서 시스템 요구조건을 입증할 수 있도록 수립되었다. 다양한 환경조건 중 비행체 단위에서 요구받는 강우, 습도 및 온도(저온 저장, 저온 운용, 고온 운용 및 일광(고온 저장)) 환경조건에 대하여 MIL-STD-810G w/Change 1을 기반으로 수립된 시험단계와 상세 프로파일에 대해 제안하였다.