In South Korea, the replacement of steam generators began with Kori Unit 1 in 1995, and to date, 20 steam generators have been replaced and are currently stored in intermediate storage facilities. In the future, additional decommissioned steam generators may arise due to measures like the extension of the lifespan of nuclear power plants. In Korea, technological development for dismantling steam generators is underway, and there is no track record of actual dismantling. Although the replaced decommissioned steam generators are stored in intermediate facilities, for site recycling purposes, steam generators, which have relatively lower radiation doses compared to reactor heads and other primary equipment, should be prioritized for dismantling. While there are various specifications for steam generators, those dismantled and stored domestically are of the Recirculation Type. They can be classified into three types: the Westinghouse type WH-51 used in Kori Unit 1, the Fra-51B used in Han-ul Units 1 and 2, and the OPR-1000 used in Han-ul Units 3 and 4. The quantity of U-Tubes varies depending on the specification, but the radiation is concentrated in the primary side components, the U-Tube and Chamber. Since the parts related to the secondary side are not contaminated, they can be disposed of independently after classification. To dismantle a steam generator, it is of utmost importance to first create a scenario regarding where and how the dismantling will take place. Through the analysis of the advantages and disadvantages of each scenario, the optimal timing, location, and cutting method for dismantling should be researched. Furthermore, based on those findings, the best scenario should be derived through an analysis of worker radiation exposure and dismantling costs. To achieve this, a 3D simulation software developed by Cyclelife Digital Solutions under the French EDF was utilized to conduct simulations based on different dismantling schedules and methods. As a result, the optimal scenario for dismantling the steam generator was derived.

Nuclear Material Accountancy (NMA) system quantitatively evaluates whether nuclear material is diverted or not. Material balance is evaluated based on nuclear material measurements based on this system and these processes are based on statistical techniques. Therefore, it is possible to evaluate the performance based on modeling and simulation technique from the development stage. In the performance evaluation, several diversion scenarios are established, nuclear material diversion is attempted in a virtual simulation environment according to these scenarios, and the detection probability is evaluated. Therefore, one of the important things is to derive vulnerable diversion scenario in advance. However, in actual facilities, it is not easy to manually derive weak scenario because there are numerous factors that affect detection performance. In this study, reinforcement learning has been applied to automatically derive vulnerable diversion scenarios from virtual NMA system. Reinforcement learning trains agents to take optimal actions in a virtual environment, and based on this, it is possible to develop an agent that attempt to divert nuclear materials according to optimal weak scenario in the NMA system. A somewhat simple NMA system model has been considered to confirm the applicability of reinforcement learning in this study. The simple model performs 10 consecutive material balance evaluations per year and has the characteristic of increasing MUF uncertainty according to balance period. The expected vulnerable diversion scenario is a case where the amount of diverted nuclear material increases in proportion to the size of the MUF uncertainty, and total amount of diverted nuclear material was assumed to be 8 kg, which corresponds to one significant quantity of plutonium. Virtual NMA system model (environment) and a divertor (agent) attempting to divert nuclear material were modeled to apply reinforcement learning. The agent is designed to receive a negative reward if an action attempting to divert is detected by the NMA system. Reinforcement learning automatically trains the agent to receive the maximum reward, and through this, the weakest diversion scenario can be derived. As a result of the study, it was confirmed that the agent was trained to attempt to divert nuclear material in a direction with a low detection probability in this system model. Through these results, it is found that it was possible to sufficiently derive weak scenarios based on reinforcement learning. This technique considered in this study can suggest methods to derive and supplement weak diversion scenarios in NMA system in advance. However, in order to apply this technology smoothly, there are still issues to be solved, and further research will be needed in the future.

In order to solve the rapidly increasing domestic delivery volume and various problems in the recent metropolitan area, domestic researchers are conducting research on the development of “Urban Logistics System Using Underground Space” using existing urban railway facilities in the city. Safety analysis and scenario analysis should be performed for the safe system design of the new concept logistics system, but the scenario analysis techniques performed in previous studies so far do not have standards and are defined differently depending on the domain, subject, or purpose. In addition, it is necessary to improve the difficulty of clearly defining the control structure and the omission of UCA in the existing STPA safety analysis. In this study, an improved scenario table is proposed for the AGV horizontal transport device, which is a key equipment of an urban logistics system using underground space, and a process model is proposed by linking systematic STPA safety analysis and scenario analysis, and UCA and Control Structure Guidelines are provided to create a safety analysis.

This study introduces the Three-Memory-Model (Cherry, 2019) in education into Maritime Simulator- based training in Sri Lanka and conducts empirical research. In simulator-based education what is disseminated as knowledge during the Briefing, Scenario and Debriefing phases must be transferred from short-term, across working memory to long-term-memory. Working memory gained during the scenario phase, could be encoded into long-term-memory through rehearsal probes. But the number of probes which could be tolerated by the participants of simulator-based training has not undergone empirical investigation. Thus, selecting the Open Sea scenario phase as its setting the research questions aim to identify tolerance limits in the participants for the number of freezes and the number of probes introduced during each freeze. The methodology selects a population of seafarers (n = 60). Through stratified random sampling this population was subdivided based on experience at sea as Group A (n = 30): Mean of 2 years and Group B (n = 30): Mean of 13.6 years of sea experience. The duration of the open sea scenario phase is 35 minutes with freezes at 10-minute intervals. The number of probes were given a range of 7 to. Data analysis utilized SPSS. The highest percentage mean value was obtained for three freezes for the Open Sea scenario phase while two freezes had the next highest percentage mean value. The mean value of the tolerance limits for questions during one freeze is approximately 9 and 6 probes for Group A and B respectively. Citing prior research on working memory, visuo-spatial vs. verbal working memory, reaction time and age this study raises a counter argument against the findings: the self-declared tolerance limits of the number of questions the participants feel comfortable to answer during each freeze. The findings of this research are valuable to maritime Simulator-based instructional designers outside and within Sri Lanka.

고령운전자의 인지 및 신체 기능 저하로 인한 교통사고 증가는 점점 심각한 사회적 문제가 되고 있으며, 이 로 인해 면허증을 자진하여 반납하는 제도가 운영되고 있으나 보다 객관적인 평가 방법이 필요하다. 본 연 구에서는 다양한 주행 상황에서 발생하는 정적 및 동적 시각 자극에 대하여 운전자의 시각적 행동을 평가 할 수 있는 운전 시뮬레이션 주행 환경과 시나리오를 구현하는 것이 목표이다. 이를 위해 고령운전자의 주 행 특성 분석에 활용된 운전 시뮬레이션 시나리오를 기존의 연구 문헌들로부터 수집하였고, 정적 및 동적으 로 구분된 표적 자극에 따른 텍스트 네트워크 분석을 통해 주행환경과 시나리오를 재분류하였다. 또한, 유 사한 유형의 시나리오들은 보다 발생 빈도가 높고 표적 자극이 다양한 주행환경으로 병합하였다. 연구 결과 로 신호교차로, 비신호 교차로, 왕복 2차로, 왕복 4차로 주행환경에서의 전체 12종의 시나리오로 구성된 운 전 시뮬레이션 콘텐츠가 구현되었다. 신호등, 정차된 차량, 표지판 등으로 구성된 정적 시각 자극과 주행 중 인 차량, 무단 횡단하는 보행자 등의 동적인 시각 자극이 제시되며, 이에 대한 시선 탐색(Visual Detection), 시지각(Visual Perception), 시각운동기능(Visuomotor Function)의 정량적 측정을 통해 운전자의 시각 행동 평가가 이루어진다. 본 연구에서 제안하는 시나리오 구성 방법은 운전 시뮬레이션 콘텐츠를 구현하기 위한 새로운 접근 방식으로써 시각 자극에 따른 운전 능력 검사 환경 구축에 관한 기초 자료로 활용될 수 있을 것으로 기대된다.

Purpose: This study aims to develop a simulation module equipped with scenario-based core nursing skills and test the effects after applying the simulation education based on a developed scenario. Method: This was a nonequivalent control group pre-/posttest design study, and 114 nursing students participated from April 1 to August 30, 2018. The applied scenario-based core nursing skills simulation module was developed in the order of planning, development, application, and evaluation according to the Dick and Carye Model’s program development process. Knowledge, self-efficacy, stress, and nursing practice were measured before and after intervention in two groups: an experimental group that performed a simulation after applying the scenario-based core nursing skills, and a control group that performed a simulation after applying core nursing skills. Results: Knowledge (F=23.19, p<.001), self-efficacy (F=25.83, p<.001), and nursing practice (t=9.51 p<.001) increased in the group that performed a simulation after applying the scenario-based core nursing skills, whereas stress (F=40.41, p<.001) decreased. Conclusion: Various education methods should be applied to increase the education effect of the simulation, Simulation performance can be used as an alternative to improve nursing practice during simulation education.

Purpose: This study was conducted to explore Virtual Reality (VR) utilization strategies in scenario-based nursing simulation training. Method: This was an integrative review for the identification of scenario-based VR simulation training applied to nursing undergraduates. The existing literature was searched in electronic databases using RISS, PubMed, and Pro-Quest and the key words were “Scenario based,” “Simulation,” “Virtual reality,” “Virtual training,” and “Nursing.” Finally, five studies were analyzed. Results: All the studies were conducted from 2016 to 2019. One RCT, two quasi-experimental studies, and two mixed method studies were identified. The topics of the scenarios were all different; acute myocardial infarction, management of respiratory system disease with hypoxia, postoperative nursing with appendicitis, teamwork and communication in outpatient and emergency situations, and disaster situation training . The outcome variables that were significant statistically were performance, self-confidence, and learning satisfaction. Conclusion: The findings suggest that virtual simulation in nursing education can potentially improve knowledge, performance, and learning confidence and can increase satisfaction with learning experience among nursing undergraduates. Multidisciplinary cooperation and investment are needed to develop diverse content applying VR in nursing simulation education. The review of the side effects also needs to be performed.

The paper presents the damage estimation of bridge structures in Daegu city based on the scenario-based earthquakes. Since the fragility curves for domestic bridge strucures are limited, the Hazus methodology is employed to derive the fragility curves and estimate the damage. A total of four earthuquake scenarios near Daegu city are assumed and structure damage is investigated for 81 bridge structures. The seismic fragility function and damage level of each bridge had adopted from the analytical method in HAZUS and then, the damage probability using seismic fragility function for each bridge was evaluated. It was concluded that the seismic damage to bridges was higher when the magnitude of the earthquake was large or nearer to the epicenter.

Recently, most of the information system use environment is changing to GUI environment based on windows and web. Most of the development tools for building such a GUI-based information system support object-oriented and event-driven programming concepts. However, there is still a lack of a development methodology that systematically supports event-based information system construction. From a business perspective, an information system is one that supports business processes efficiently and effectively to improve business performance. These business processes are composed of business activities which involve a series of business events. A business event is executed according to a business scenario. Therefore, it is necessary to grasp these events in the requirements analysis stage and to apply it on the system development methodology. However, information systems development methodology which systematically reflect the event processing concept still is insufficient. From this viewpoint, this paper proposes an event-driven scenario-based development methodology that can meet the recent development environment of information systems, and applies the proposed methodology to a small scale information system development case.