• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.6
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• pp.582-590
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• 2020

This paper presents the results of new error analysis on the veering of marine target with the concept of frequency of occurrence, and shows how to apply the midcourse guidance errors of anti-ship missile. The veering error would be a dominant factor in the midcourse guidance errors with flight time increase. This study suggests the reasonable application method of the veering error based on the characteristics of abnormal error, and describes the tailoring method including trade-off between the midcourse guidance range of veering target and the value of frequency of occurrence on veering error.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.331-335
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• 2016

When a boating accident, such as a January number three, the customer's risk management issues emerged. Ships and accident risk in confined spaces such as risk management to locate the customer and dangers of probation is available. In this paper, aboard after consent to obtain information for customers to wrist to customers, webbing or portable device embedded in devices and Wireless sensor information Input was attached, disposable consumer information. Customer on board the ship setting for location analysis and positioning according to information communication protocol, ships, each customer's real-time location information on the screen, 3 the foundation of d customers on the floor Can be designed to inform. Threshold designed to reduce the error of the information to analyze the position in current position and errors. Also, to system attacks would control the situation of accident and emergency jaenanguk server with real-time information transmission of information outside the emergency during a disaster, search and Disaster relief to be possible.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.6
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• pp.1-13
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• 2020

In this paper, the author proposed a nuclear power plant (NPP) instrumentation signal faults identification algorithm. A variational autoencoder (VAE)-based model is trained by using only normal dataset as same as existing anomaly detection method, and trained model predicts which signal within the entire signal set is anomalous. Classification of anomalous signals is performed based on the reconstruction error for each kind of signal and partial derivatives of reconstruction error with respect to the specific part of an input. Simulation was conducted to acquire the data for the experiments. Through the experiments, it was identified that the proposed signal fault identification method can specify the anomalous signals within acceptable range of error.

• Journal of Radiation Protection and Research
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• v.29 no.3
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• pp.157-163
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• 2004

Atmospheric dispersion modelling has been widely used to predict the fate and transport of radioactive or toxic materials released from nuclear facilities which is an unlikely accidental event. To improve the forecasting performance of the dispersion model, it is required that source rate and dispersion characteristics must be defined appropriately. Generally, source term of the radioactive materials is much uncertain at the early phase of an accidental event. In this study, we computed the source rate with the experimental field data monitored at the Yeoung-Kwang nuclear site and obtained the optimal source rate to minimize the errors between the measured concentrations and the computed ones by the Gaussian plume model. Computed source term showed a good result within 24% of the artificially released source rate.

• Journal of Radiation Protection and Research
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• v.39 no.2
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• pp.96-102
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• 2014

Urine bioassay has been widely used for internal dosimetry due to simple process of sampling and measurement. In this paper, we participated in the NRIP (NIST Radiochemistry Intercomparison Program) hosted by US NIST to carry out a reliable performance test of urine bioassay and introduced the measurement method and results of NRIP-2013. In customary exercise with 60 days of reporting time, bioassay results of 12 radionuclides in the synthetic urine samples were acceptable based on the performance criteria of ANSI N13.30. In emergency preparedness exercise with 8 hours of reporting time, bioassay results of 9 radionuclides showed that differences ranged from -35% to 45%. However, we concluded that urine bioassay applied for emergency preparedness exercise would be applicable for rapid screening and estimation of internal exposure within a difference of ${\pm}45%$ in the event of radiological accidents.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.468-468
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• 2023

최근 급격한 기후변화에 의한 이상가뭄 발생 등을 대비하기 위한 비상용수 또는 대체 수자원으로서의 지하수 개발수요가 증가함에 따라 기저유량 확보 및 수질개선 방안을 수립하는 것은 지속가능한 수자원 이용 관리 측면에 있어서 매우 중요하다. 국내 지하수 사용에 따른 하천유량의 변동에 관한 연구는 활발히 진행되었으나, 실질적으로 적용가능한 지하수 저감 방안 및 지하 수질개선방안에 대한 연구는 미비한 실정이다. 이에 본 연구에서는 바이오차를 이용하여 시험포를 설계 및 시공하였으며, 실내 인공강우 실험을 통해 지하 침투수 확보 능력 및 수질개선 효과를 평가하였다. 대조구는 폭 1 m × 길이 1 m × 깊이 0.60 m로 시공하였으며, 바이오차 시험포는 폭 1 m × 길이 1 m, 시험포 상단과 하단 각 0.10 m씩 대조구와 동일한 흙으로 채웠으며, 그 사이 0.40 m만큼은 바이오차를 채워서 시공하였다. 시험의 정밀도를 높이기 위해 동일한 조건으로 대조구와 바이오차 시험포 각 2개씩, 총 4개의 시험포를 시공하여 실내 인공강우 실험을 진행하였으며, 시험포에서 발생한 직접유출수와 기저유출수를 이용하여 바이오차의 지하 침투량 확보 및 수질개선효과를 분석하였다. 시험포 완공 후 총 2번의 실내인공강우 실험 결과 대조구에서 발생한 직접유출량은 총 0.214 m³, 바이오차 시험포에서는 총 0.194 m³로 대조구 대비 총 직접유출량 저감효과는 9.4%로 나타났다. 기저유출의 경우 바이오차 시험포(0.036 m³)에서 대조구(0.003 m³) 대비 약13배 많은 양의 기저유출수가 발생한 것으로 나타났다. 각 시험포에서 발생한 유출수의 오염부하를 산정해 대조구 시험포 대비 바이오차 시험포에서 발생한 직접유출수의 오염부하 저감효과를 분석한 결과 BOD₅ 항목과 COD_Mn 항목, 그리고 TOC 항목의 경우 26.3%과 22.0%, 그리고 27.6%로 저감 된 것으로 나타났으나, SS 항목과 T-N 항목, 그리고 T-P 항목의 경우 저감효과가 없는 것으로 나타났다. 이와 같이 바이오차는 지하 침투수 확보 능력은 효과적인 것으로 나타났으나, 직접유출수의 수질개선 효과는 미비한 것으로 나타났다. 그러나 바이오차의 지하 침투량 및 수질개선 효과는 바이오차 생산 시 사용된 열분해 방식, 사용된 바이오차의 양 등에 따라 편차가 클것으로 판단되며, 바이오차의 생산 방법, 토양 흡착 기간, 바이오차의 양 등 다양한 조건에서의 모니터링을 통해 정량화 되어야 할 것으로 판단된다.

• Tunnel and Underground Space
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• v.9 no.4
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• pp.306-314
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• 1999

In underground spaces including nuclear waste repository, prediction of air quantity, temperature/humidity and pollutant concentration is utmost important for space construction and management during the normal state as well as for determining the measures in emergency cases such as underground fires. This study aims at developing a model for underground space environment which has capabilities to take into account the effects of autocompression for the natural ventilation head calculation, to find the optimal location and size of fans and regulators, to predict the temperature and humidity by calculating the convective heat transfer coefficient and the sensible and latent heat transfer rates, and to estimate the pollutant levels throughout the network. The temperature/humidity prediction model was applied to a military storage underground space and the relative differences of dry and wet temperatures were 1.5 ~ 2.9% and 0.6 ~ 6.1%, respectively. The convection-based pollutant transport model was applied to two different vehicle tunnels. Coefficients of turbulent diffusion due to the atmospheric turbulence were found to be 9.78 and 17.35$m^2$/s, but measurements of smoke and CO concentrations in a tunnel with high traffic density and under operation of ventilation equipment showed relative differences of 5.88 and 6.62% compared with estimates from the convection-based model. These findings indicate convection is the governing mechanism for pollutant diffusion in most of the tunnel-type spaces.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1105-1111
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• 2010

The Korea Atomic Energy Research Institutes has been developing the SMART (System integrated Modular Advanced ReacTor), an environment-friendly nuclear reactor for the generation of electricity and to perform desalination. SMART reactors can be exposed to various external and internal loads caused by seismic and coolant flows. The CRDM(control rod drive mechanism), one of structures of the SMART, is a component which is adjusting inserting amount of a control rod, controlling output of reactor power and in an emergency situation, inserting a control rod to stop the reactor. The purpose of this research is performing the analysis of dynamic characteristic to ensure safety and integrity of structure of CRDM. This paper presents two FE-models, 3-D solid model and simplified Beam model of the CRDM in the coolant, and then compared the results of the dynamic characteristic about the two FE-models using a commercial Finite Element tool, ABAQUS CAE V6.8 and ANSYS V12. Beam 4 and beam 188 of simplified-model were also compared each other. And simplified model is updated for accuracy compare to 3-D solid.

• Journal of Aerospace System Engineering
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• v.16 no.1
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• pp.104-109
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• 2022

The bomb rack unit (BRU) installed inside the pylon serves to fix external attachments such as external fuel tank or external weapon, and also serves to separate external attachments in case of emergency. In particular, the load generated when the external attachment is separated from the BRU is called the punching load. In this study, we present the results of a structural static test performed to verify the structural integrity of the pylon under the BRU punching condition acting on it. In the structural static test report, we present the implementation method for the separation load of the external attachment and the test profile for the BRU punching load condition, and compared the error between the load input signal and the feed-back signal to determine the appropriateness of load control in each test. Furthermore, we compared the strain results obtained in the numerical analysis and structural test at the main positions of the specimen. As a result, it was shown that the load of the actuators were properly controlled within the allowable error range in each test, and the numerical analysis effectively predicted the test result. Finally, through structural static tests conducted by design limit load and design ultimate load, we verified that the aircraft pylon dealt with in this study has sufficient structural strength for external attachment separation condition.

• Journal of Korean Society for Geospatial Information Science
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• v.6 no.2 s.12
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• pp.21-34
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• 1998

SAR is an active imaging sensor emitting its own energy source and can be operated in all weather conditions. Thus SAR provides data which can not be obtained by an optical sensor. In this study, the potentials and problems of the techniques for DEM extraction from the SAR imagery were evaluated through theoretical researches and practical experiments. And then the accuracy was tested by RMS error between the digitized map contour and the results from this experiment. Here, two types of DEM extraction method were evaluated. One was an analytical photogrammetric technique, and the other was a SAR interferometric processing. From the experiment, we found that the photogrammetric technique is currently the most suitable method considering topographic conditions of Korea. In the SAR interferometry technique, we also conclude that the problems caused by decorrelations due to the temporal reasons and due to the scattering effects from vegetation should be solved.