• Journal of Sensor Science and Technology
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• v.18 no.5
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• pp.385-392
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• 2009

This paper describes the algorithm development of a new body pressure detection sensor for occupant classification system. U.S. Government has required that advanced airbag system should be installed to every automobiles after 2006 according to FMVSS 208 regulation. Therefore, Occupant Classification System should be provided the passenger with safety in order to protect the infants or children that sit in the front passenger seat. When an occupant sits on the chair of the vehicle, deployment of the airbag depends on passenger's weigh distribution and postures. Authors have been developed a new pattern recognition of passenger and weight distribution at the same time by Force Sensing Resistor for the safety.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.4042-4051
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• 2021

In this work, we applied a multilevel modeling technique to estimate the diametral creep in the pressure tubes of Korean Canada Deuterium Uranium (CANDU) units. Data accumulated from in-service inspections were used to develop the model. To confirm the strength of the multilevel models, a 2-level multilevel model considering the relationship between channels for a CANDU unit was compared with existing linear models. The multilevel model exhibited a very robust prediction accuracy compared to the linear models with different data pooling methods. A 3-level multilevel model, which considered individual bundles, channels, and units, was also implemented. The influence of the channel installation direction was incorporated into the three-stage multilevel model. For channels that were previously measured, the developed 3-level multilevel model exhibited a very good predictive power, and the prediction interval was very narrow. However, for channels that had never been measured before, the prediction interval widened considerably. This model can be sufficiently improved by the accumulation of more data and can be applied to other CANDU units.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.431-432
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• 2004

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.140.2-140
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• 1999

• Journal of the Korean Society for Railway
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• v.15 no.6
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• pp.537-542
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• 2012

Rolling stocks are often subjected to the effects of natural strong wind or wind pressure caused by the crossing train. These wind pressure cause the falling-off in running stability and overturn safety. It is sometimes reported that trains are blown over by a gust of wind. So, many countries enact regulations to secure the overturn safety for wind speed. In this study, theoretical equations of overturn safety based on multi-body model are derived and analyzed the difference between the result of the solid model and that of multi-body model. In case of multi-body model, it is assumed that the degrees of freedom for carbody and bogie are assigned an independent values respectively. The results show that the latter approach based on multi-body model can access the overturn safety of train and replace the conventional method by using commercial software which is accessing with decrement of wheel load.

• Journal of the Korean Institute of Gas
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• v.21 no.6
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• pp.30-38
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• 2017

Established in the 1960s, high pressure underground pipelines in Ulsan and Yeosu industrial estate are underground as toxic gas as well as combustible gas that is heavier than city gas and low combustion range. Especially, industrial pipelines occupy more than 20 years old pipes. In this way, the industrial estate pipeline was installed before the introduction of the supervision of construction, However, unlike the city gas pipeline, the pipeline is managed without any legal obligation. In this study, the safety management status of high pressure underground pipelines and urban gas underground pipelines in the industrial estate is analyzed and comparison of laws, extent of damage impact, using the pipe inspection model for pipe inspection of high pressure piping system with the existing piping system. it is intended to cuntribute to improving the safety of industrial estate are underground pipeline.

• Journal of the Korean Institute of Gas
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• v.19 no.5
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• pp.36-40
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• 2015

To evaluate the safety of propane cylinder, the flame test was performed by the flame exposure scenario of propane cylinder. The cylinder which was exposed in a flame was rapidly occurred to increase the internal pressure by liquid expansion, if so it cause of physical explosion. Therefore, the cylinder which was applied with thermal pressure relief device sholud be not bursted and the propane should be discharged to outside safely. The flame average temperature that was around of cylinder is $600^{\circ}C$, and then it increased $700^{\circ}C$ by discharged propane. The result of flame test, the cylinder was deformed, but it was not bursted. The regulations of flame exposure test for propane cylinder were not restricted, this paper can be applied to restrict the flame test if the cylinder is possible to expose the flame. Also, the results is expected as reference for estimation of the pressure cylinder performance.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.35-40
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• 2023

In order to prevent an ammonia container from bursting under conditions such as overcharging and abnormal temperature rise, it is necessary to prepare accident prevention measures through analysis of the operating mechanism of the Thermally Activated Pressure Relief Devices (TPRD) attached to the container. In this study, stress analysis acting on the ammonia container under pressurized conditions, density change analysis according to temperature change, and correlation between container filling amount and temperature and pressure change were presented. In addition, the maximum filling amount of the ammonia container was calculated, and the temperature and pressure at the filling amount were calculated through the phase equilibrium diagram. Based on this, the appropriate melting point of the Thermally Activated Pressure Relief Devices was derived and verified through a melting temperature experiment. Based on the results of this study, conditions for preventing ammonia container rupture accidents were suggested.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.132-140
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• 2024

In the event of a severe accident in Sodium Cooled Fast Reactors (SFR), the sodium combustion aerosols along with fission product aerosols would migrate to the environment through leak paths of the Reactor Containment Building (RCB) concrete wall under positive pressure. Understanding the characteristics of sodium aerosol transport through concrete leak paths is important as it governs the environmental source term. In this context, experiments are conducted to study the influence of various parameters like pressure, initial mass concentration, leak path diameter, humidity etc., on the transport and deposition of sodium aerosols in straight leak paths of concrete. The leak paths in concrete specimens are prepared by casting and the diameter of the leak path is measured using thermography technique. Aerosol transport experiments are conducted to measure the transported and plugged aerosol mass in the leak paths and corresponding plugging times. The values of differential pressure, aerosol concentration and relative humidity taken for the study are in the ranges 10-15 kPa, 0.65-3.04 g/m³ and 30-90% respectively. These observations are numerically simulated using 1-Dimensional transport equation. The simulated values are compared with the experimental results and reasonable agreement among them is observed. From the safety assessment view of reactor, the approach presented here is conservative as it is with straight leak paths.

• Journal of the Korean Society of Safety
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• v.22 no.4
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• pp.7-12
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• 2007

In order to evaluate the integrity of Zr-2.5Nb pressure tubes, probabilistic fracture mechanics(PFM) approach was employed. Failure assessment diagram(FAD), plastic collapses, and critical crack lengths(CCL) were used for evaluating the failure probability as failure criteria. The Kr-FAD as failure assessment diagram was used because fracture of pressure tubes occurred in brittle manner due to hydrogen embrittlement of material by deuterium fluence. The probabilistic integrity evaluation observed AECL procedures and used fracture toughness parameters of EPRI and recently announced theory. In conclusion, the probabilistic approach using the Kr-FAD made it possible to determine major failure criterion in the pressure tube integrity evaluation.