http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
SEUNGYEOB RYU,고성호 한국원자력학회 2012 Nuclear Engineering and Technology Vol.44 No.6
The volume of fluid (VOF) model of FLUENT and the lattice Boltzmann method (LBM) are used to simulate two-phase flows. Both methods are validated for static and dynamic bubble test cases and then compared to experimental results. The VOF method does not reduce the spurious currents of the static droplet test and does not satisfy the Laplace law for small droplets at the acceptable level, as compared with the LBM. For single bubble flows, simulations are executed for various Eotvos numbers, Morton numbers and Reynolds numbers, and the results of both methods agree well with the experiments in the case of low Eotvos numbers. For high Eotvos numbers, the VOF results deviated from the experiments. For multiple bubbles, the bubble flow characteristics are related by the wake of the leading bubble. The coaxial and oblique coalescence of the bubbles are simulated successfully and the subsequent results are presented. In conclusion, the LBM performs better than the VOF method.
( Seungyeob Sakong ),( Eic Ju Lim ),( Jun-min Cho ),( Nak-jun Choi ),( Jae-woo Cho ),( Jong-keon Oh ) 대한외상학회 2021 大韓外傷學會誌 Vol.34 No.2
Purpose: Open extremity fractures require prompt antibiotic medication and initial debridement surgery to reduce the infection rate and restore functional stabilization. We aimed to report the effects and positive outcomes of a trauma team approach on the management of open extremity fractures in polytrauma patients. Methods: This retrospective review included all polytrauma patients with open extremity fractures admitted between March 2009 and December 2019. Patients were divided into two groups according to whether they were treated before or after the implementation of the trauma team approach (March 2014). We analyzed the outcomes in each group with respect to the time interval until the doctor’s arrival, total length of stay in the emergency department, the time interval until initial antibiotic treatment and operation, whether the initial operation was performed within 24 hours, and the rate of deep infections. Results: A total of 123 patients met the inclusion criteria. There were no statistically significant differences in demographic characteristics. The time interval until the doctor’s arrival (64.12±49.2 minutes vs. 19.82±15.23 minutes; p=0.035) and initial antibiotic treatment (115.47±72.12 minutes vs. 48.78±30.12 minutes; p=0.023) significantly improved after implementing the trauma team approach. The union rate was not significantly different. However, the time interval until initial debridement, opportunity for initial debridement within 24 hours, and the rate of deep infections demonstrated better results. Conclusions: The reduced time interval until initial antibiotic treatment and debridement could be attributed to the positive effect of the trauma team approach on the management of open extremity fractures in polytrauma patients.
Seungyeob Baik,Arup K. George,Junghyup Lee 대한전자공학회 2018 Journal of semiconductor technology and science Vol.18 No.5
In this paper, we propose a fully-differential amplitude-shift-keying (ASK) demodulator for suppressing the effect of undesired common mode variations on the received data, In addition, the ASK demodulator is robust against power supply ripples. The proposed demodulator consists of a fully-differential envelope detector (ED), programmable gain amplifier (PGA) and a differential comparator. The ED and PGA operate in the sub-threshold region and the inverter based comparator consumes only dynamic current, making it highly power-efficient. The proposed system is implemented in a 0.18 μm CMOS process and consumes 2.5 μA from a 1 V power supply. At a data rate of 200 kbps, this leads to an FOM of 12.5 pJ/bit.