This study deals with replacement analysis of deteriorated equipment for improving productivity of production system. Frequent breakdown of the deteriorated equipment causes a situation that reduces productivity such as low product quality, process delay, and repair cost. However, the replacement of new equipment will be required a high initial investment cost, so it is important to analysis the economic feasibility. Therefore, we analyze the effect of the production system due to the aging effect of the equipment and the feasibility of equipment replacement based on the economic analysis. The process flow, working time, logistics movement, etc. are analyzed in order to build the simulation modeling for a ship and land switchboard production system. Using numerical examples, the economic feasibility analysis of equipment replacement through replacement of existing deteriorated equipment and additional arrangement of new facilities is performed.

This study was carried out to compare the DMY (dry matter yield) of IRG (Italian ryegrass) in the southern coastal regions of Korea due to seasonal climate scenarios such as the Kaul-Changma (late monsoon) in autumn, extreme winter cold, and drought in the next spring. The IRG data (n = 203) were collected from various Reports for Collaborative Research Program to Develop New Cultivars of Summer Crops in Jeju, 203 Namwon, and Yeungam from the Rural Development Administration (1993 – 2013). In order to define the seasonal climate scenarios, climate variables including temperature, humidity, wind, sunshine were used by collected from the Korean Meteorological Administration. The discriminant analysis based on 5% significance level was performed to distinguish normal and abnormal climate scenarios. Furthermore, the DMY comparison was simulated based on the information of sample distribution of IRG. As a result, in the southern coastal regions, only the impact of next spring drought on DMY of IRG was critical. Although the severe winter cold was clearly classified from the normal, there was no difference in DMY. Thus, the DMY comparison was simulated only for the next spring drought. Under the yield comparison simulation, DMY (kg/ha) in the normal and drought was 14,743.83 and 12,707.97 respectively. It implies that the expected damage caused by the spring drought was about 2,000 kg/ha. Furthermore, the predicted DMY of spring drought was wider and slower than that of normal, indicating on high variability. This study is meaningful in confirming the predictive DMY damage and its possibility by spring drought for IRG via statistical simulation considering seasonal climate scenarios.

In view of the growing need for clean energy, supercapacitors (SC), especially those based on activated carbon (AC) and organic electrolyte are attracting great attention for their theoretically infinite life span. However, they still age much faster than expected due to certain mechanisms. Several researches is being conducted to understand these mechanisms, but so far, the chemical reactions at the phase boundary of the activated carbon electrodes and organic electrolyte have been very unclear. Some pathways have not yet been investigated; there is no research on the reactions that can take place between acetonitrile in the vapor phase and the oxides presented on the surface of activated carbons. For this reason, in this study, divided into two parts, the first based on a thermal simulation and the second based on an experimental study, we have systematically described the ageing mechanisms by determining the gas-phase reactions that can occur at the electrode–electrolyte interface. On the one hand, a thermal model of a supercapacitor cell using activated carbon and organic electrolyte technology has been developed. This model allowed us to study the temperature distribution of supercapacitors, and thus to determine the thermodynamic parameters related to the phenomena produced at the electrode–electrolyte interface. On the other hand, a thermo-gravimetric analysis coupled with gas phase infrared spectroscopy on the activated carbons of an aged supercapacitor of the same technology as that used in the simulation was carried out. The results obtained made it possible to identify the chemical groups produced by ageing.

최근 자기공명영상 획득을 위한 시뮬레이션 도구가 개발되어 오랜 시간이 소요되는 임상 연구를 대체할 수 있게 되었다. 이에 본 연구에서는 MRiLab 시뮬레이션을 사용하여 부가인자인 에코 시간의 변화에 따라 경사에코 펄스 시퀀스가 적용된 뇌 T2 강조 영상을 획득하여 영상의 신호 및 노이즈의 변화를 정량적으로 평가하고 경향성을 파악하고자 한다. 이를 위해 실제 MRI 장비를 기반으로 새롭게 개발된 MRiLab simulation tool을 사용하여 모든 파라미터를 같게 고정한 후 TE만을 20~95 ms범위에서 5 ms 간격으로 각각 설정하여 경사에코 펄스 시퀀스가 적용된 뇌 T2 강조 영상을 획득하였다. 획득된 영상들의 신호 및 노이즈 특성 변화를 정량적으로 평가하기 위해 신호대잡음비 및 대조대잡음비를 측정하였다. 결과적으로, TE가 증가할수록 SNR은 감소하고 CNR은 증가하는 경향을 보였다. 이는 TE가 증가할수록 관심 영역으로 설정된 뇌척 수액 신호는 일정하게 유지되는 반면 노이즈는 증가하였으며, 백그라운드로 설정된 백질의 경우 신호가 감소함과 동시에 노이즈가 증가한 것이 원인으로 분석된다. 결론적으로, 진단에 용이한 경사에코 펄스 시퀀스가 적용된 뇌 T2 강조 영상을 획득하기 위해서는 그 목적에 따라 적합한 TE를 설정하는 것이 중요함을 확인하였다.

본 연구는 DML(Debriefing for Meaning Learning[이하 DML])를 적용한 응급 시뮬레이션 실 습이 간호대학생의 비판적 사고능력, 문제해결 능력, 의사소통 능력에 미치는 효과를 확인하고자 시도되었 다. 연구는 비동등성 대조군 전후 실험설계의 유사실험연구로, D 시에 소재한 간호대학생 중 중재군 38명, 대조군 35명, 총 73명을 대상으로 하였다. 연구결과, 비판적 사고능력(t=-3.144, p=.002), 문제해결 능력 (t=-3.248, p=.002), 의사소통 능력(t=-4.051, p<.001)은 실험군이 대조군에 비해 유의하게 향상된 것으로 나타났다. 본 연구를 통해 DML은 간호대학생의 비판적사고, 문제해결능력, 의사소통능력을 향상시키는 방 법임을 확인하였다.

도로협곡에서의 수목식재에 따른 보도 내 교통유발 대기오염도 변화를 살펴보기 위해 오픈소스 전산유체역학 코드 FDS(Fire Dynamics Simulator)를 사용하여 수목 투과지수, 식재 위치 및 유형에 따른 영향을 조사하였다. 광범위한 시뮬레이션을 통해 1) 관목층 만으로만 구성된 사례, 2) 관목층과 아교목층으로 구성된 사례 및 3) 관목층과 교목층으로 구성된 사례를 포함하는 400개의 시나리오 사례 중 399개 사례에 대해 유효한 데이터를 생성하였다. 분석결과, 보도 위에서 관찰되는 평균화된 정상상태 대기오염 농도는 식재유 형과는 무관하게 수목식재 후 약 10% 이상 감소하는 것으로 나타났다. 가장 큰 대기오염 감소효과는 관목층만으로 구성된 사례에서 관찰되었는데 대략 45%까지 감소하는 것으로 나타났다. 이러한 감소효과는 차선에서 인도로 대기오염물질을 직접 수송하는 선회류가 관목층에 의해 유리한 방향으로 변형되는 물리적 과정에 기초한다.

Purpose: Personal protective equipment (PPE) is critical for protecting healthcare workers from COVID-19 outbreaks. Therefore, this study examined the effects of a nursing simulation education program on PPE use for COVID-19 among nursing students. Methods: We employed a non-equivalent control group post-test design. The experimental group (n=38) engaged in a nursing simulation education program on PPE use. The control group (n=36) received PPE and the opportunity to participate in the same program after the intervention. Further, data were analyzed using descriptive statistics and independent t-test. Results: The experimental group showed significant differences in attitude toward PPE (t=3.21, p=.002) and efficacy of PPE use (t=9.92, p<.001), but not in the intention to care for patients with COVID-19 (t=0.95, p=.343). Conclusion: Nursing simulation education for PPE significantly improved attitude and increased self-efficacy toward PPE among nursing students. However, the intention to care for COVID-19 patients was not changed. Thus, it is necessary to find a way to improve the nursing intention toward COVID-19 patients.

Purpose: This study developed an educational program for structured discussion-based learning, problem-based learning (PBL), and simulation for nursing students. Its effects on learning attitude, problem-solving process, and clinical competence were then analyzed. Methods: This study used a one-group pretest–posttest experimental method among 135 fourth-year nursing students taking the simulation course at a university in D city. We operated the PBL by applying the structured discussion method and simulation education based on four modules covering major diseases among adults. The data collected before and after the program were analyzed using descriptive statistics and paired t-tests. Results: The program significantly improved nursing students’ learning attitude, problem-solving process, and clinical competence. Conclusions: We verified the effects of the simulation education program for structured discussion-based learning and PBL. Further studies are needed to develop and apply simulation educational programs utilizing various devices that can improve learners’ participation and professors’ operational protocols by systematically combining them with different teaching/learning methods.