http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Nam, Kyungmin,Park, Kook Jin,Shin, SangJoon,Kim, Seung Jo,Choi, Ik-Hyeon The Korean Society for Aeronautical and Space Scie 2015 International Journal of Aeronautical and Space Sc Vol.16 No.3
A methodology for determining the design allowables of composite laminates by using lamina level test data and finite element analysis (FEA) is proposed and verified in this paper. An existing method that yields the laminate design allowables by using the complete test results for laminates was improved to reduce the expensive and time-consuming tests. Input property samples for FEA were generated after considering the statistical distribution characteristics of lamina level test data., and design allowables were derived from several FEA analyses of laminates. To apply and verify the proposed method, Hexcel 8552 IM7 test data were used. For both un-notched and open-hole laminate configurations, it was found that the design allowables obtained from the analysis correctly predicted the laminate test data within the confidence interval. The potential of the present simulation to substitute the laminate tests was demonstrated well.
Kyungmin Nam,Kook Jin Park,SangJoon Shin,Seung Jo Kim,Ik-Hyeon Choi 한국항공우주학회 2015 International Journal of Aeronautical and Space Sc Vol.16 No.3
A methodology for determining the design allowables of composite laminates by using lamina level test data and finite element analysis (FEA) is proposed and verified in this paper. An existing method that yields the laminate design allowables by using the complete test results for laminates was improved to reduce the expensive and time-consuming tests. Input property samples for FEA were generated after considering the statistical distribution characteristics of lamina level test data. , and design allowables were derived from several FEA analyses of laminates. To apply and verify the proposed method, Hexcel 8552 IM7 test data were used. For both un-notched and open-hole laminate configurations, it was found that the design allowables obtained from the analysis correctly predicted the laminate test data within the confidence interval. The potential of the present simulation to substitute the laminate tests was demonstrated well.
Improvement of Gamma-ray Analysis Procedures for Reducing Human Error and Workload Using Automation
Kyungmin Kim,Jong Soo Nam,Sang-Mo Hwang,Hyo-Jong Kim,Duckha kim,Cheongyeon Cho,Hongrae Jeon 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1
Radioactive waste can be classified according to the concentration level for radionuclides, and the disposal method is different through the level. Gamma analysis is inevitably performed to determine the concentration of radioactive waste, and when a large amount of radioactive waste is generated, such as decommissioning nuclear facilities, it takes a lot of time to analyze samples. The performance of a lot of analysis can cause human errors and workload. In general, gamma analysis is performed using by HPGe detector. Recently, for convenience of analysis, commercial automatic sample changers applicable to the HPGe detectors were developed. The automatic sample changers generate individual analysis reports for each sample. In this study, gamma analysis procedure was improved using the application of the automatic sample changer and the automated data parsing using by Python. The application of automatic sample changers and data parsing technique can solve the problems. The human errors were reduced to 0% compared to the previous method by improving the gamma analysis procedure, and working time were also dramatically reduced. This automation of analysis procedure will contribute to reducing the burden of analysis work and reducing human errors through various improvements.
Kyungmin Noh,Seyed Amir Arsalan Shams,Wooyeol Kim,Jae Nam Kim,Chong Soo Lee 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.10
The goals of this study were to quantify and explain the effects of microstructure on the resistance of low-carbon steels tolow-cycle fatigue and to extremely low-cycle fatigue (ELCF). Three different microstructures (ferrite–pearlite, ferrite–martensite,and ferrite–bainite–martensite) were tested, and their fatigue properties were analyzed using the strain-based Coffin–Manson model and an energy-based model. According to the Coffin–Manson model, ferrite–pearlite showed the bestELCF resistance, whereas in the energy-based model that considers the effect of tensile strength ferrite–bainite–martensiterevealed the highest ELCF resistance. At similar tensile strength, ferrite–bainite–martensite had longer ELCF life than ferrite–martensite; the difference may be a result of the smaller strain incompatibility between bainite and ferrite than betweenferrite and martensite. In all three microstructures, cracks initiated at the surface and propagated into the interior; this resultindicates that fracture mode was not altered during cyclic loading at high strain amplitudes. Ferrite–martensite microstructuredeveloped many sub-cracks surrounding a main crack; they could facilitate propagation of a main crack, and thereby degradefatigue life at high strain amplitudes.
Kyungmin Kim,Jeongwook Moon,Dong-Ju Lee,Il-Sik Kang,Dae Seong Nam,Jong Hwa Pack,Sung Jin Han,Yun Gun Jung,Heung-Ju Cho,Hongrae Jeon,Tack-Jin Kim 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1
Natural uranium-contaminated soil in Korea Atomic Energy Research Institute (KAERI) was generated by decommissioning of the natural uranium conversion facility in 2010. Some of the contaminated soil was expected to be clearance level, however the disposal cost burden is increasing because it is not classified in advance. In this study, pre-classification method is presented according to the ratio of naturally occurring radioactive material (NORM) and contaminated uranium in the soil. To verify the validity of the method, the verification of the uranium radioactivity concentration estimation method through γ-ray analysis results corrected by self-absorption using MCNP6.2, and the validity of the pre-classification method according to the net peak area ratio were evaluated. Estimating concentration for 238U and 235U with γ-ray analysis using HPGe (GC3018) and MCNP6.2 was verified by ?-spectrometry. The analysis results of different methods were within the deviation range. Clearance screening factors (CSFs) were derived through MCNP6.2, and net peak area ratio were calculated at 295.21 keV, 351.92 keV(214Pb), 609.31 keV, 1120.28 keV, 1764.49 keV(214Bi) of to the 92.59 keV. CSFs for contaminated soil and natural soil were compared with U/Pb ratio. CSFs and radioactivity concentrations were measured, and the deviation from the 60 minute measurement results was compared in natural soil. Pre-classification is possible using by CSFs measured for more than 5 minutes to the average concentration of 214Pb or 214Bi in contaminated soil. In this study, the pre-classification method of clearance determination in contaminated soil was evaluated, and it was relatively accurate in a shorter measurement time than the method using the concentrations. This method is expected to be used as a simple pre-classification method through additional research.
Analysis of temperature-dependent abnormal bursting patterns of neurons in Aplysia
Nam Gyu Hyun,Kwangho Hyun,Saecheol Oh,Kyungmin Lee 대한생리학회-대한약리학회 2020 The Korean Journal of Physiology & Pharmacology Vol.24 No.4
Temperature affects the firing pattern and electrical activity of neurons in animals, eliciting diverse responses depending on neuronal cell type. However, the mechanisms underlying such diverse responses are not well understood. In the present study, we performed in vitro recording of abdominal ganglia cells of Aplysia juliana , and analyzed their burst firing patterns. We identified atypical bursting patterns dependent on temperature that were totally different from classical bursting patterns observed in R15 neurons of A. juliana . We classified these abnormal bursting patterns into type 1 and type 2; type 1 abnormal single bursts are composed of two kinds of spikes with a long interspike interval (ISI) followed by short ISI regular firing, while type 2 abnormal single bursts are composed of complex multiplets. To investigate the mechanism underlying the temperature dependence of abnormal bursting, we employed simulations using a modified Plant model and determined that the temperature dependence of type 2 abnormal bursting is related to temperaturedependent scaling factors and activation or inactivation of potassium or sodium channels.
Temperature Dependence of Action Potential Parameters in <b><i>Aplysia</i></b> Neurons
Hyun, Nam Gyu,Hyun, Kwang-Ho,Lee, Kyungmin,Kaang, Bong-Kiun S. Karger AG 2012 Neuro-Signals Vol.20 No.4
<P>Abstract</P><P>Although the effects of temperature changes on the activity of neurons have been studied in <I>Aplysia</I>, the reproducibility of the temperature dependence of the action potential (AP) parameters has not been verified. To this end, we performed experiments using <I>Aplysia </I>neurons. Fourteen AP parameters were analyzed using the long-term data series recorded during the experiments. Our analysis showed that nine of the AP parameters decreased as the temperature increased: the AP amplitude (A<SUB>AP</SUB>), membrane potential at the positive peak (V<SUB>pp</SUB>), interspike interval, first half (Δt<SUB>r1</SUB>) and last half (Δt<SUB>r2</SUB>) of the temperature rising phase, first half (Δt<SUB>f1</SUB>) and last half (Δt<SUB>f2</SUB>) of the temperature falling phase, AP (Δt<SUB>AP, 1/2</SUB>), and differentiated signal (Δt<SUB>DS, 1/2</SUB>) half-width durations. Five of the AP parameters increased with temperature: the differentiated signal amplitude (A<SUB>DS</SUB>), absolute value of the membrane potential at negative peak (∣ V<SUB>np</SUB> ∣), absolute value of the maximum slope of the AP during the temperature rising (∣ –MSR ∣) and falling (∣–MSF∣) phases, and spiking frequency (Frequency). This work could provide the basis for a better understanding of the elementary processes underlying the temperature-dependent neuronal activity in <I>Aplysia.</I></P><P>Copyright © 2012 S. Karger AG, Basel</P>