• Journal of the Earthquake Engineering Society of Korea
• /
• v.10 no.1 s.47
• /
• pp.63-74
• /
• 2006

The seismic fragility analysis method has been used as a quantitative seismic safety evaluation method for the NPP(Nuclear Power Plant) structures and equipments. The seismic fragility analysis gives a realistic seismic capacity excluding the convertism included in the design stage. The conservatism is considered as the probabilistic parameters related to the response and capacity in the seismic fragility analysis. In this study, the displacement based seismic fragility analysis method was proposed based on the nonlinear dynamic analysis results. In this study, the seismic safety of the prestressed concrete containment building of KSNP(Korean Standard Nuclear Power Plant) was evaluated for the scenario earthquakes, neat-fault, far-fault, design earthquake and probability based scenario earthquake, which can be occurred in the NPP sites.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.24 no.2
• /
• pp.59-65
• /
• 2020

The empirical Green's function method is applied to the foreshock and the mainshock of the 2016 Gyeongju earthquake to simulate strong ground motions of the mainshock and scenario earthquake at seismic stations of seven metropolises in South Korea, respectively. To identify the applicability of the method in advance, the mainshock is simulated, assuming the foreshock as the empirical Green's function. As a result of the simulation, the overall shape, the amplitude of PGA, and the duration and response spectra of the simulated seismic waveforms are similar with those of the observed seismic waveforms. Based on this result, a scenario earthquake on the causative fault of Gyeongju earthquake with a moment magnitude 6.5 is simulated, assuming that the mainshock serves as the empirical Green's function. As a result, the amplitude of PGA and the duration of simulated seismic waveforms are significantly increased and extended, and the spectral amplitude of the low frequency band is relatively increased compared with that of the high frequency band. If the empirical Green's function method is applied to several recent well-recorded moderate earthquakes, the simulated seismic waveforms can be used as not only input data for developing ground motion prediction equations, but also input data for creating the design response spectra of major facilities in South Korea.

• Journal of Biomedical Engineering Research
• /
• v.30 no.4
• /
• pp.311-317
• /
• 2009

An automatic control system is proposed and implemented for a miniaturized DNA extraction system using magnetic bead. A host-local system is employed for the accommodation of the graphical user interface and the basic control function. The functional partitioning into the local and the host system is discussed. The control functions are classified and formalized for the flexible control scenario, which is the input of the proposed system. As the proposed scenario is consists of the sequence of the user-centric actions, the user goal can be easily programmed and modified. The DNA extraction performance of the implemented system was compared with the existing silica-membrane-based method, resulting in the comparable concentration and purity of the extracted DNA. The proposed system is currently being utilized for the development of the DNA extraction system only changing scenario, without any alteration of the system.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.31 no.2
• /
• pp.25-37
• /
• 2023

The purpose of this study is to develop and technically implement the design and scenario of cabin safety contents for virtual reality (VR)-based cabin safety learning for aviation service majors. The process for developing VR cabin safety learning contents consisted of a total of four stages: learning stage, research stage, verification stage, and application stage. The cabin safety scenario items for the production of VR learning contents reflected the occurrence of an emergency, the procedure for survival from impact, and the evacuation procedure from the aircraft as the core. For the technical implementation of learning contents, modeling work is conducted by checking scenario reviews, types and numbers of objects related to equipment and facilities, and items of interaction. In addition, the connection work with the actual metaverse platform is carried out to enable the utilization of the manufactured facilities and equipment objects. Finally, application tests were carried out to reconfirm supplementary items.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.21 no.1
• /
• pp.31-39
• /
• 2017

In this study, to estimate the combination of earthquake magnitude ($M_w$) and distance (R) corresponding to the design spectrum defined in Korean Building Code (KBC) 2016, the response spectra predicted from the attenuation relationships with the variation of $M_w$ (5.0~7.0) and R (10~30km) are compared with the design spectrum in KBC 2016. Four attenuation relationships, which were developed based on local site characteristics and seismological parameters in Southern Korea and Eastern North America (ENA), are used. As a result, the scenario ground motions represented by the combinations of $M_w$ and R corresponding to the design spectrum for Seoul defined in KBC 2016 are estimated as (1) when R =10 km, $M_w=6.2{\sim}6.7$; (2) when R = 15 km, $M_w=6.5{\sim}6.9$; and (3) when R = 20 km, $M_w=6.7{\sim}7.1$.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.32 no.10
• /
• pp.882-889
• /
• 2008

A humanoid is a robot with its overall appearance based on that of the human body. When the humanoid moves or walks, dynamic forces act on the body structure. Although the humanoid keeps the balance by using a precise control, the dynamic forces generate unexpected deformation or vibration and cause difficulties on the control. Generally, the structure of the humanoid is designed by the designer's experience and intuition. Then the structure can be excessively heavy or fragile. A humanoid design scenario for a systematic design is proposed to reduce the weight of the structure while sufficient strength is kept. Lower parts of the humanoid are selected to apply the proposed design scenario. Multi-body dynamics is employed to calculate the external dynamic forces on the parts and structural optimization is carried out to design the lower parts. Because structural optimization using dynamic forces directly is fairly difficult, linear dynamic response structural optimization using equivalent static loads is utilized. Topology and shape optimizations are adopted for two steps of initial and detailed designs, respectively. Various commercial software systems are used for analysis and optimization. Improved designs are obtained and the design results are discussed.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.12 no.1
• /
• pp.241-257
• /
• 2020

The rapid proliferation of oil/gas drilling and wind turbine installations with jack-up rig-formed structures increases structural safety requirements, due to the greater risks of operational collisions during use of these structures. Therefore, current industrial practices and regulations have tended to increase the required accidental collision design loads (impact energies) for jack-up rigs. However, the existing simplified design approach tends to be limited to the design and prediction of local members due to the difficulty in applying the increased uniform impact energy to a brace member without regard for the member's position. It is therefore necessary to define accidental load estimation in terms of a reasonable collision scenario and its application to the structural response analysis. We found by a collision probabilistic approach that the kinetic energy ranged from a minimum of 9 MJ to a maximum 1049 MJ. Only 6% of these values are less than the 35 MJ recommendation of DNV-GL (2013). This study assumed and applied a representative design load of 196.2 MN for an impact load of 20,000 tons. Based on this design load, the detailed design of a leg structure was numerically verified via an FE analysis comprising three categories: linear analysis, buckling analysis and progressive collapse analysis. Based on the numerical results from this analysis, it was possible to predict the collapse mode and position of each member in relation to the collision load. This study provided a collision strength assessment between attendant vessels and a jack-up rig based on probabilistic collision scenarios and nonlinear structural analysis. The numerical results of this study also afforded reasonable evaluation criteria and specific evaluation procedures.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.42 no.4 s.304
• /
• pp.35-44
• /
• 2005

Face recognition out of biometrics is considerable interesting due to high performance and accessibility in applications to security such as access control and banking service. Therefore, a study on the protocol of the performance test is an important issue to understand the art-of state and to show a direction in future works, in addtion to developing algorithms. We present a design criterion for the performance test protocol of face recognition system and show the result of experiment executed on identification and verification scenario based on PCA algorithm and XM2VTS DB

• Nuclear Engineering and Technology
• /
• v.53 no.2
• /
• pp.677-687
• /
• 2021

The tendency to renewables is one of the consequences of changing attitudes towards energy issues. As a result, solar energy, which is the leader among renewable energies based on availability and potential, plays a crucial role in full filing global needs. Significant problems with the solar thermal power plants (STPP) are the operation time, which is limited by daylight and is approximately half of the power plants with fossil fuels, and the capital cost. Exergy analysis survey of STPP hybrid with PCM storage carried out using Engineering Equation Solver (EES) program with genetic algorithm (GA) for three different scenarios, based on eight decision variables, which led us to decrease final product cost (electricity) in optimized scenario up to 30% compare to base case scenario from 28.99 $/kWh to 20.27 $/kWh for the case study. Also, in the optimal third scenario of this plant, the inner carbon dioxide gas cycle produces 1200 kW power with a thermal efficiency of 59% and also 1000 m3/h water with an exergy efficiency of 23.4% and 79.70 kg/h with an overall exergy efficiency of 34% is produced in the tetrageneration plant.

• Journal of the Korea Safety Management & Science
• /
• v.25 no.4
• /
• pp.95-104
• /
• 2023

The purpose of this study is to propose measures to increase evacuation safety by calculating the habitable time using a fire and evacuation simulation program for the Room-escape cafe currently in operation, and comparing and analyzing it with the evacuation required time. Assuming a fire due to overheating of electric heaters in use in front of the warehouse, the habitable time was calculated through fire simulation, and the occupant's evacuation time calculated through evacuation simulation according installation of safety facilities, etc. was compared and analyzed with the habitable time. In the case of escape room cafes with safety facilities installed, evacuation safety was satisfied, but in escape room cafes without safety facilities, the evacuation safety was not secure. As a result of analyzing evacuation safety for each scenario based on the ASET analyzed in the fire simulation, it was found that in scenario 1, evacuation safety was secured and everyone successfully evacuated, while in scenario 2, no one succeeded in evacuation. These results can be said to confirm that the installation of safety facilities is very important in business establishments such as escape room cafes, which become enclosed structures when games are started.