• Fire Science and Engineering
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• v.25 no.1
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• pp.1-6
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• 2011

An evacuation simulation was carried out to confirm evacuation efficiency for stair width and problems in calculation of occupant load for high-rise buildings. The evacuation time and number of evacuated persons from a 39 story condominium-mercantile building were calculated by using Simulex for stair widths of 1.2 m, 1.5 m, and 1.8 m. The total occupant load based on the Korean code was higher than the number of actual residents by 2.3 times, and that based on the NFPA 101 Life Safety Code by 2.6 times, respectively. For the occupant load based on the Korean code, smaller stair width resulted in lower evacuation efficiencies due to bottlenecks in egress. For the actual residents and NFPA code-based occupant load, a high evacuation efficiency and negligible effects of the stair width on evacuation efficiency were confirmed. It was shown that there was a bottleneck even at the stair width of 1.8 m for the Korean code-based occupants, while the stair width of 1.2 m provided safe egress to the actual residents or NFPA code-based occupants. This recommended further studies on possibility of lowering the level of the Korean code in calculation of the occupant load.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.6
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• pp.1139-1150
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• 2022

With the rapid development of SW Industry, softwares are everywhere in our daily life. The number of vulnerabilities are also increasing with a large amount of newly developed code. Vulnerabilities can be exploited by hackers, resulting the disclosure of privacy and threats to the safety of property and life. In particular, since the large numbers of increasing code, manually analyzed by expert is not enough anymore. Machine learning has shown high performance in object identification or classification task. Vulnerability detection is also suitable for machine learning, as a reuslt, many studies tried to use RNN-based model to detect vulnerability. However, the RNN model is also has limitation that as the code is longer, the earlier can not be learned well. In this paper, we proposed a novel method which applied BERT to detect vulnerability. The accuracy was 97.5%, which increased by 1.5%, and the efficiency also increased by 69% than Vuldeepecker.

• Journal of the Society of Disaster Information
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• v.5 no.1
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• pp.66-74
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• 2009

As building heights increase, so do these challenges in Korea. High-rise buildings present a variety of challenges to fire safety and protection. The fire protection technology in our country is still on a weak situation which is mainly due to the lack of concerns by the government, companies and citizen. This paper provides general guidance regarding fire-related property protection system for high-rise building performance based design. The importance of high-rise building in of the number of occupants, the value of property, and the a catastrophic loss would have on the community all warrant an increased level of protection and life safety. Because, We have to prepare a new spacial code and standard guidance for fire protection at the stage of the high-rise building design.

• Earthquakes and Structures
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• v.9 no.4
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• pp.893-910
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• 2015

Earthquake safety of existing buildings has gained considerable importance after earthquakes which have occurred in our country especially in the last 30 years. Performance based assessment methods have been widely used for existing reinforced concrete structures. This study aims to investigate the earthquake performances of the building stock located in Van Lake basin in Eastern Anatolia of Turkey. The case study of buildings has been modeled on and the structural performances have been determined by employing the non-linear methods described in the latest Turkish Earthquake Code published in 2007. The Van lake basin is located on the very seismically active in a region. On October 23, 2011, a magnitude of Mw 7.2 earthquake struck the Van province in eastern Turkey. The earthquake ground motion was recorded as about 0.1g in Bitlis province. Performance evaluations have been performed by taking samples from each district consisting urban building stocks of Bitlis. A total of 16 reinforced concrete buildings have been evaluated. Among them, 53% of those buildings were determined in the Fully Operational performance level; 13% of them in the Life Safety performance and 34% of them could not be evaluated because of the ratio of the effective mass of first mode to the total mass of the buildings was smaller than 0.70. Therefore, incremental equivalent seismic load methods, which are a part of Turkish Earthquake Code -2007, cannot be used.

• Journal of the Korean Society of Safety
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• v.21 no.6 s.78
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• pp.20-25
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• 2006

In the design of class 1 components to apply ASME code section III NB, a fatigue is considered as one of the important failure mechanisms. Fatigue analysis procedure and standard fatigue design curve(S-N curve) is suggested in ASME code, which had to be performed to meet the integrity of components at the design step. As the plant life extension for operating power plants and the long-lived plant design, however, are being progressed, the fact which the existing ASME fatigue design curve can not consider fatigue effects sufficiently comes to the fore. To find the technical solution for these problems, a number of researches and discussion are continued up to now. In this study, the detailed fatigue analyses using the 3 dimensional modeling for the fatigue-weakened components were performed to develop the optimized fatigue analysis procedure and their results are compared with other reference solutions.

• Korean Institute of Interior Design Journal
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• v.15 no.5 s.58
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• pp.202-208
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• 2006

The purpose of this study is to suggest architectural planning guideline for the improvement of the evacuation environment in a ward. To suggest of guideline, the problem of irrational domestic criteria is searched according to compare National fire code (NFPA101, Life safety code) with Korea building law. This study includes stairs, corridors and exit door etc. but excludes fire facilities. To verify effectiveness of suggested guideline, egress simulation is run that based on databases according to literature survey. The results of this study could be summarized as follow: Suggested guidelines are subdivision(fire partition), evacuation by elevator, secure useful waiting space of elevator hall and smokeproof enclosures, the corridor is divided by fire or smoke barriers corridor from hazardous room, only wheeled items are arranged in corridors of a ward story. The result of computer simulation for suggested guidelines verify that egress time can be decreased 20% or above.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.795-801
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• 1998

Metallic fatigue of Pressurized Water Reactor(PWR) materials is a generic safety issue for commercial nuclear power plants. It is very important to obtain the fatigue usage factor for component integrity and life extension. In this paper, fatigue usage was obtained at the inside surface of Kori unit 2, 3 and 4 RCP casing weld, based on the design transient. And it was intended to establish the procedure and the detailed method of fatigue evaluation in accordance with ASME Section III Code. According to this code rule, two methods to determine the stress cycle and the number of cycles could be applied. One method is the superposition of cycles of various design transients and the other is based on the assumption that a stress cycle correspond to only one design transient. Both method showed almost same fatigue usage in the RCP casing weld.

• Structural Engineering and Mechanics
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• v.59 no.1
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• pp.123-132
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• 2016

Many military and commercial aging aircrafts flying beyond their design life may experience severe crack and corrosion damage, and thus lead to catastrophic failures. In this paper, were used in a finite element model to evaluate the effect of corrosion on the adhesive damage in bonded composite repair of aircraft structures. The damage zone theory was implemented in the finite element code in order to achieve this objective. In addition, the effect of the corrosion, on the repair efficiency. Four different patch shapes were chosen to analyze the adhesive damage: rectangular, trapezoidal, circular and elliptical. The modified damage zone theory was implemented in the FE code to evaluate the adhesive damage. The obtained results show that the adhesive damage localized on the level of corrosion and in the sides of patch, and the rectangular patch offers high safety it reduces considerably the risk of the adhesive failure.

• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.269-274
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• 2019

$^{64}Cu$ is a favorable radionuclide in nuclear medicine applications because of its unique characteristics such as three types of decay (electron capture, ${\beta}^-$ and ${\beta}^+$) and 12.7 h half-life. Production of $^{64}Cu$ by irradiation $^{nat}Cu$ and $^{nat}CuNPs$ in Tehran Research Reactor was investigated. The characteristics of copper nanoparticles were investigated with SEM, TEM and XRD analysis. The cross section of $^{63}Cu(n,{\gamma})^{64}Cu$ reaction was done with TALYS-1.8 code. The activity value of $^{64}Cu$ was calculated with theoretical approach and MCNPX-2.6 code. The results were compared with related experimental results which showed good adaptations between them.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.923-931
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• 2008

Coupling rubber pad are important components in railway vehicles. It can be used for reduce shock, vibration and noise. Simple tension, equi-biaxial tension and pure shear test were performed to acquire the coefficient of rubber material which were Mooney-Rivlin and Ogden model. The finite element analysis was executed to evaluate the behavior of deformation and stress distribution by using the commercial finite element analysis code. Useful life evaluation are very important in design procedure to assure the safety and reliability of the rubber components. In this paper, useful life prediction of rubber pad for railway vehicle were experimentally investigated. Accelerated heat-aging test for rubber material were carried. Compression set results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot.