This study simulated strong ground motion waveforms in the southern Korean Peninsula, based on the physical earthquake modeling of the Southern California Earthquake Center (SCEC) BroadBand Platform (BBP). Characteristics of intensity attenuation were investigated for M 6.0-7.0 events, incorporating the site effects. The SCEC BBP is software generates broadband (0-10 Hz) ground-motion waveforms for earthquake scenarios. Among five available modeling methods in the v16.5 platform, we used the Song Model. Approximately 50 earthquake scenarios each were simulated for M 6.0, 6.5, and 7.0 events. Representative metrics such as peak ground acceleration (PGA) and peak ground velocity (PGV) were obtained from the synthetic waveforms that were simulated before and after the consideration of site effects (VS30). They were then empirically converted to distribution of instrumental intensity. The intensity that considers the site effects is amplified at low rather than high VS30 zones.

본 연구에서는 다공성 보와 논로컬 매개변수 사이의 관계에 대한 유한요소해석을 수행한다. 논로컬 매개변수는 다공성 보의 결함을 표현하는 변수들로 정의하여, 하중조건 및 경계조건에 대한 수치모사를 통해 계산한다. 다공성 보와는 반대 개념의 결함을 가지는 보에 대한 해석도 수행하였다. 이러한 보들의 거동은 논로컬 매개변수의 항으로 표현하였으며, 이 매개변수는 구멍의 지름의 제곱 그리고 원기둥 지름의 세제곱에 비례하는 것을 확인하였다. 특히 작은 원기둥을 가지는 보에 축하중을 가하는 경우, 예상과는 다르게 3 차원 유한요소 해석 결과와 2차원 평면응력 해석 결과는 다름을 알 수 있었다.

PURPOSES : This paper aims to summarize the findings of studies related to driving safety in long tunnels, and based on these findings, evaluate the risk in driving safety in consecutive tunnels. METHODS: After evaluating the risk in consecutive tunnels, it was verified that driving safety depends on the tunnel length of the consecutive tunnels and the interval between the tunnels. The experimental devices used in this study were a virtual driving simulator and PolyG-I system, measuring, driving speed and among driver's brain waves, theta wave that represents drowsiness or inner conscious states. RESULTS: The results of experiment I showed that, in consecutive tunnels, the variation of speed was higher and the theta wave increased at similar points in comparison with that for long tunnels, demonstrating the risk in consecutive tunnels. The results of experiment II revealed that the variation of speed was the highest in the shortest tunnel (250 m) and the risk of overspeeding was the highest in the longest tunnel (900 m). Additionally, among the consecutive tunnels, the longer tunnels significantly increased the overall theta wave in the tunnels, increasing the risk of drowsy driving. CONCLUSIONS: Of the three scenarios, it was concluded that safety was highest when the tunnel length was set to 600 m.

Purpose: The National League for Nursing/Jeffries Simulation Theory (NLN/JST) is a middle-range theory widely used in nursing simulation education. Although the NLN/JST was revised in 2015, there is still no formal critique of the theory. The purpose of this study is to present a critique of the NLN/JST. Method: This study comprehensively analyzes and evaluates the theory using Fawcett and DeSanto-Madeya’s (2013) framework. Results: The theory demonstrates positive social and theoretical significance, testability, and empirical and pragmatic adequacy. Nevertheless, semantic clarity and internal consistency need to be made clearer. Conclusion: The NLN/JST is a suitable framework for nursing simulation education. The theory considers not only participants but also patients and systems as outcomes of simulation education, and is able to incorporate situation-specific backgrounds. That said, it is still necessary to develop a systematic nursing curriculum for clinical reasoning competence of both nursing students and nurses, given the wide range of clinical situations they may encounter.

Purpose: The purpose of this study was to analyze trends in articles published in the Journal of Korean Society for Simulation in Nursing (KSSN) and to provide future directions for improvement. Method: The study analyzed data collected from 57 research articles published in KSSN between 2013 and 2018. A descriptive analysis was conducted with a focus on frequency and percentage for quantitative data. Results: The proportion of articles on quantitative research was 80.7%, while the proportion of articles on qualitative research was 15.8%. The majority of the quantitative research was focused on experimental study (47.4%). The prevailing data collection settings were school (75.4%), and for the data analysis, descriptive statistics (71.9%), t-test (50.1%), ANOVA (19.3%) and chi-square test (17.5%). The analysis results based on the simulation education research showed that the most frequently used scenario topics were delivery care and postpartum hemorrhage. The most frequently used variables measured were clinical performance (43.8%), problem-solving process (31.3%), self-confidence (31.3%), and self-efficacy (28.1%). Conclusion: Especially in the case of simulation nursing, there is a need to encourage research into utilizing a variety of research methodologies and simulations.

The concept of carsharing involves sharing a small number of reserved cars to be used individually by a larger number of people as required. This study examines the operating parameters of one-way carsharing systems in order to determine the appropriate operating conditions that minimizes the lost sales rate. Five operating parameters are tested in this study: the number of stations, the average number of vehicles per station, the rate of one-way trip, the average number of staffs per station, and the relocation policy. The performance of round-trip carsharing systems is also compared to that of one-way carsharing systems. A simulation model is developed and simulations are performed to determine the appropriate combination of operating parameter and levels. The simulation results show that the average number of vehicles per station is the most critical parameter. Other key findings obtained from this research are as follows. First, applying the appropriate relocation policy to one-way carsharing systems can allow more customers to rent vehicles than the traditional round-trip carsharing systems. Second, the appropriate relocation policy should be selected based on the average number of vehicles per station in order to minimize the lost sales rate. Third, the number of stations does not affect the lost sales rate. This study findings will provide tools to understand impact of the carsharing system parameters on the efficiency of the carsharing operations.

PURPOSES: This study presents the results of the collection rate of various road debris dummies using Automated Road Debris Remover System(ROBOS), which is a newly developed automatic road-debris removal system. In addition, for traffic flow safety, appropriate safe deceleration distances for ROBOS are estimated using VISSIM. METHODS: A total of 12 kinds of road debris dummies were selected based on the opinions of public agencies, and randomly placed on the road. Repeated tests were performed. The road debris dummies were placed on the center of the lane, the shoulders, and the median. During the test, the ROBOS running speed was maintained at 15 km/h for an approximately 10-km-long roadway, and the collection and loading process was performed five times under the same condition. For the simulations, the road debris was assumed to be placed on Lane 1 under different traffic conditions and grades. Multiple simulations were conducted, and the average values were used to obtain appropriate safe deceleration distances for ROBOS. RESULTS: The dummies were considerably large and heavy, and the collection rate was very high for the very light dummy. The simulation results indicate that during debris collection using ROBOS, when the traffic volume is relatively low, the degree of change in traffic flow is high, and when the traffic flow rate is high, the risk of an accident is also considerable. CONCLUSIONS : We demonstrated that the debris collection efficiency of ROBOS is very high when the brush-conveyor and vacuum are used simultaneously. Further, when the exact location of road debris on specific lanes and for specific traffic volumes is known, a safe deceleration distance is recommended.

Purpose: The purpose of this study is to provide basic data for developing strategies to improve the learning effect of simulation by analyzing the reflective journaling after the simulation based learning on the nursing of patients with upper gastrointestinal (UGI) bleeding. Method: From September 19–29, 2016, we conducted a simulation of UGI bleeding patient nursing with fourth-year students in the nursing department of University B in City A, and analyzed the data using content analysis. Results: In this study, reflective journaling can be an effective educational method to strengthen nursing competence, such as the self-reflection of nursing students, evidence-based nursing practice, teamwork, and communication ability. Conclusion: Reflective journaling after practice in simulation-based education is an important process in training critical thinking, situational judgment, and reflection of nursing practice content, and needs to be extended to both on-campus practice and clinical practice.

The wakes behind a square cylinder were simulated using two-equation turbulence models, k-ε and RNG k-ε models. For comparisons between the model predictions and analytical solutions, we employed three skill assessments:, the correlation coefficient for the similarity of the wake shape, the error of maximum velocity difference (EMVD) of the accuracy of wake velocity, and the ratio of drag coefficient (RDC) for the flow patterns as in the authors’ previous study. On the basis of the calculated results, we discussed the feasibility of each model for wake simulation and suggested a suitable value for an eddy viscosity related constant in each turbulence model. The k-ε model underestimated the drag coefficient by over 40 %, and its performance was worse than that in the previous study with one-equation and mixing length models, resulting from the empirical constants in the ε-equation. In the RNG k-ε model experiments, when an eddy viscosity related constant was six times higher than the suggested value, the model results were yielded good predictions compared with the analytical solutions. Then, the values of EMVD and RDC were 3.8 % and 3.2 %, respectively. The results of the turbulence model simulations indicated that the RNG k-ε model results successfully represented wakes behind the square cylinder, and the mean error for all skill assessments was less than 4 %.

이 논문에서는 지진 하중을 받는 꼬인 삼각대 지지구조를 갖는 해상풍력발전기의 지진 신뢰성 해석 방법을 제시한다. 수 평하중에 대해서 면외 변위가 발생하는 꼬인 삼각대지지 구조의 기하학적 특성과 지반의 비선형성을 포함한 지반-말뚝 상호작용을 고려하기 위한 구조물의 3차원 동적 유한요소 모델을 제시하였다. 지진신뢰성 평가를 위해 재현주기별 인공지진파를 사용한 시간이력 해석을 통해 말뚝 두부의 수평변위로 정의된 한계 상태식에 대하여 파괴확률을 산정하였다. 비선형 시간이 력해석에 의한 한계상태식 평가를 고려하여 효율적으로 신뢰성 해석을 하기 위해 Markov Chain Monte Carlo 샘플링 방법을 적용한 부분집합 시뮬레이션 방법의 적용을 제시하였다. 제시한 방법은 2차원 모델 및 정적해석만으로는 정확한 결과를 도출할 수 없는 꼬인 삼각대 지지구조를 갖는 해상풍력발전기의 신뢰성 평가 및 설계기준 개발에 활용될 수 있음을 보였다.

본 연구에서는 미국 남캘리포니아 지진센터에서 개발한 물리적 지진모델링 기반 광대역 강지진동 모사 플랫폼( 버전 16.5)을 활용하여, 규모 6.0, 6.5, 7.0 지진에 대한 진도 감쇠 특성 분석을 수행하였다. 지진 발생 위치는 2016년 규모 5.8 경주 지진 진앙 인근을 가정하였으나 지각 전파 모델의 경우 남캘리포니아 강지진동 모사 플랫폼에서 제공하 는 미국의 대표적인 지각 모델 두 개를 사용하였다. 하나는 판 내부를 대표하는 미국 중동부 지역(Central and Eastern United States, CEUS) 모델이고 다른 하나는 판의 경계를 대표하는 미 서부 지역(LA Basin) 모델이다. 버전 16.5 플랫 폼에는 5개의 모델링 방법론이 제시되고 있으며 본 연구에서는 Song 모델과 Exsim 모델을 사용하였다. 동일 규모의 지진이라 하더라도 지진발생 환경이 다른 지역(CEUS vs LA Basin)에서는 같은 진앙 거리에서 진도 2 등급에 가까운 차이가 발생할 수 있음을 본 연구를 통해서 발견하였다. 본 연구에서 나타난 지역별 진도 감쇠 특성의 차이를 감안할 때 한반도에서 좀 더 정밀한 지진재해 평가를 위해서는 지역에 적합한 진도 감쇠 특성을 이해하는 것이 중요할 것으로 판단되며 본 연구는 지역 특화된 진도 감쇠 특성을 고려하지 않을 경우 진도 감쇠 분포의 불확실성 정도를 잘 보여준다.

The AtoN Simulator provides simulation circumstances, which include the topographical and environmental characteristics of a primary harbor, as well as the characteristics of navigating a ship and maritime traffic. The AtoN planning expert can design a safer and more efficient distribution of AtoN using the simulator. AtoN simulation system is a system that adds AtoN part such as AtoN attribute and modeling to ship handling simulation system. AtoN 3D modeling and motion characteristics implemented in existing ship handling simulations were not perfect. Therefore, there was inconvenience in 3D simulation. Therefore, AtoN attribute construction and 3D modeling are required for AtoN simulation system. This study researched the AtoN 3D modeling for AtoN simulator. The AtoN analysis surveyed the AtoN for 3D modeling. Modeling design was designed to be similar to the actual AtoN on the basis of such an analysis of the AtoN scale. Modeling was AtoN 3D modeling based on the design drawings. Each AtoN was grouped into a Main Category and Sub Category. Specific data were easily changed using the 3D tools.

Prior to the design and production stages of the center pillar, the structural analysis must be carried out at the concept stage. Commercial softwares for the structural analysis provide benefits such as performance prediction and deformation. In this study, the structural analysis using SolidWorks was performed to investigate the stress and displacement characteristics of the center pillar for two types of collision positions and velocities. As the impact velocity increased, the maximum equivalent stress and displacement of the center pillar were larger. In the case of passenger cars, the equivalent stress and displacement according to the velocity change increased by about 133% and 116% at 16.5m/s , based on 5.5m/s . Also, the equivalent stress and displacement in the SUV car increased by about 119% and 378%, respectively

For performance analysis of flood prevention projects, this study performed simulation (SWMM) for the five sites where the projects have been completed. The models were constructed using watershed and sewer information of the project sites and were verified using flood records in the past to improve accuracy. In this simulation, the design rainfall data (probability 30~50 years) and the rainfall data in the summer of 2017 were applied. When the design rainfall data was applied to the models, simulation results presented that all the sites were flooded before the projects, but after the projects all the sites were not flooded due to improve discharge capacity. And when the rainfall data in the summer of 2017 was applied to the models, simulation results presented that all the sites were flooded before the projects, but after the projects any sites did not occur flooding in this summer. So if the projects had not been completed, all the sites might be flooded in the summer of 2017. These effects were analyzed as the improvement of discharge capacity due to rehabilitation of sewer, construction of underground tunnel and pumping station, etc. As the results, ratio of sewer that water depth exceed diameter reduced from 52.3~75.8% to 17.1~39.8%.

본 연구는 4연동 벤로형 유리온실의 냉·난방 부하를 고려한 PV 시스템의 적정 패널 설치 면적을 도출하기 위하여 BES 기법을 이용하여 온실 및 PV 시스템의 에너지 모델을 설계하였으며 동적 에너지 시뮬레이션을 수행하였다. 대상 작물은 파프리카로 선정하였으며 작물의 적정생육온도를 고려하여 냉·난방장치 및 환기장치의 가동조건을 설정하였다. 2012년부터 2016년까지 총 5년 동안의 기간별 냉·난방부하 및 최대 냉·난방 부하를 환 기팬의 환기량 조건 별로 분석을 실시하였다. 온실의 냉 ·난방 부하 산정과 함께 PV 시스템의 설치 각도에 따른 전력 생산량을 분석하였으며 신재생에너지 공급의무비율을 적용하여 최적 PV 시스템 설계 방안을 도출하였다. 환기팬의 환기량 60AE·hr-1 조건에서 대상 온실의 기간 평균 냉방 부하로 인한 전력 소모량은 174,310kWh, 기간 평균 난방 부하로 인한 전력 소모량은 458,903kWh 로 총 633,213kWh의 전력 소모량이 산정되었다. PV 시스템은 설치 각도를 30o로 설정하는 조건에서 가장 높은 전력 생산량이 나타났으며 월별 최적 각도를 적용하는 조건에서는 고정형 PV 시스템보다 약 5.7% 많은 전력 을 생산하는 것으론 산정 되었다. 최종적으로 대상 온실에 적합한 PV 시스템 패널 면적을 도출한 결과, 고정형 PV 시스템은 521m2의 패널이 필요한 것으로 산정되었고, 가변형 PV 시스템의 경우 494m2의 패널이 필요한 것으로 산정되었다. 본 연구를 통하여 4연동 벤로형 유리온실의 냉·난방 부하를 고려한 PV 시스템의 필요 패널 설치 면적을 도출할 수 있었으며 PV 시스템의 온실 적용 가능성 및 경 제성 평가의 기초 자료로 활용 가능할 것으로 판단된다. 한편, 본 연구에서는 작물 특성 데이터를 확보하지 못하여 작물의 에너지 교환을 고려하지 않았다. 보다 정확한 결과를 도출하기 위해서는 현장 실험 데이터에 기반을 둔 추가 연구가 필요할 것으로 판단된다.

Recently there is a growing interest in the airborne spread of virus. In particular, there is growing interest in secondary infection through the air in the hospital. The distribution of air-born virus depends on ventilation system installed in a hospital. In this study, simulations were carried out to predict the move of air-born virus by ventilation system at hospital. Simulation results showed that pressure distribution was –372.05Pa ∼ -3.45 Pa at 1st floor incase of only used mechanical exhaust at bathroom, shower stall , storage, kitchen etc.. if ventilation switch from used mechanical exhaust to mechanical exhaust & mechanical supply. Simulation results showed that pressure distribution was -336.44Pa at stair hall < -0.2Pa at bathroom < mean 1.19Pa at other room. So simulation results showed that using all of the mechanical supply and mechanical exhaust was more effective then the mechanical exhaust for maintain the pressure distribution in hospital. It was also showed that when using the mechanical supply and mechanical exhaust more effectively prevention of air born virus diffusion.