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        검색결과 1,459

        1.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The arrival of the 5G era has made electromagnetic pollution a problem that needs to be addressed, and flexible carbon-based materials have become a good choice. In this study, wet continuous papermaking technology was used to prepare carbon fiber paper (CFP) with a three-dimensional conductive skeleton network; Molybdenum disulfide ( MOS2)/ iron (Fe) @ carbon fiber paper-based shielding material was prepared by impregnating and blending molybdenum disulfide/iron ( MOS2/Fe) phenolic resin MOS2/ Fe@ CFP. The morphology, structure, electrical conductivity, mechanical properties, hydrophobicity, and electromagnetic shielding properties of the composite were characterized. The results show that the three-dimensional network structure based on a short carbon fiber paper-based conductive skeleton and the synergistic effect of the MOS2 dielectric wave absorbing agent and Fe magnetic wave absorbing agent have good electromagnetic shielding performance. Conduct electromagnetic shielding simulation using HFSS software to provide options for the structural design of CFP. The electromagnetic shielding performance of CFP reaches 70 dB, and the tensile strength reaches 34.39 MPa. Based on the mechanical properties, the compactness of carbon fiber paper is ensured. The lightning damage model test using CST software expands the direction for the use of carbon fiber paper. In summary, MOS2/ Fe @CFP with excellent shielding performance has great application prospects in thinner and lighter shielding materials, as well as high sensitivity, defense and military equipment.
        4,500원
        2.
        2024.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Disposal cover as an engineered barrier of a near-surface disposal facility for low and very low-level radioactive waste is composed of a multi-layer to isolate radioactive waste from environmental influences for the long term. To acquire a realistic forecast for the post-closure period of the disposal facility, it is essential to carry out long-term experimental research in a similar condition to the actual disposal environment. Hence, a performance test facility of the disposal cover was constructed in Gyeongju low and intermediate level radioactive waste disposal center in 2022. The constructed performance test facility has differences from the material properties presented in the design. These differences are factors that affect the prevent rainfall infiltration, which is one of the important roles of the disposal cover. Therefore, in this study, a numerical simulation of rainfall infiltration into the performance test facility was performed for the designed case and the actual constructed case. To simulate the behavior of water infiltration, the FEFLOW software based on the finite element method is used. Through the analysis of numerical simulation results, it is confirmed that the hydraulic conductivity of the material constituting the multi-layer of the disposal cover greatly influences the amount of water infiltration.
        4,800원
        3.
        2024.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To non-destructively determine the burnup of a spent nuclear fuel assembly, it is essential to analyze the nuclear isotopes present in the assembly and detect the neutrons and gamma rays emitted from these isotopes. Specifically, gamma-ray measurement methods can utilize a single radiation measurement value of 137Cs or measure based on the energy peak ratio of Cs isotopes such as 134Cs/137Cs and 154Eu/137Cs. In this study, we validated the extent to which the results of gamma-ray measurements using cadmium zinc telluride (CZT) sensors based on 137Cs could be accurately simulated by implementing identical conditions on MCNP. To simulate measurement scenarios using a lead collimator, we propose equations that represent radiation behavior that reaches the detector by assuming “Direct hit” and “Penetration with attenuation” situations. The results obtained from MCNP confirmed an increase in measurement efficiency by 0.47 times when using the CZT detector, demonstrating the efficacy of the measurement system.
        4,000원
        4.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the manufacturing industry, dispatching systems play a crucial role in enhancing production efficiency and optimizing production volume. However, in dynamic production environments, conventional static dispatching methods struggle to adapt to various environmental conditions and constraints, leading to problems such as reduced production volume, delays, and resource wastage. Therefore, there is a need for dynamic dispatching methods that can quickly adapt to changes in the environment. In this study, we aim to develop an agent-based model that considers dynamic situations through interaction between agents. Additionally, we intend to utilize the Q-learning algorithm, which possesses the characteristics of temporal difference (TD) learning, to automatically update and adapt to dynamic situations. This means that Q-learning can effectively consider dynamic environments by sensitively responding to changes in the state space and selecting optimal dispatching rules accordingly. The state space includes information such as inventory and work-in-process levels, order fulfilment status, and machine status, which are used to select the optimal dispatching rules. Furthermore, we aim to minimize total tardiness and the number of setup changes using reinforcement learning. Finally, we will develop a dynamic dispatching system using Q-learning and compare its performance with conventional static dispatching methods.
        4,000원
        5.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purpose: Improving students’ self-confidence is an important strategy in simulation learning. This study aimed to identify the factors influencing students’ self-confidence in simulation learning based on the Jeffries Simulation Framework. Method: A cross-sectional survey was conducted with 140 senior nursing students’ at a university, and data were collected through self-reported questionnaires. Data on students’ self-confidence were collected for student/ facilitator factors (satisfaction on major, overall grade average, and facilitator satisfaction), educational practice factors (active learning, collaboration, diverse ways of learning and educational goals), and simulation design characteristics factors (objectives/information, support, problem solving, feedback, and fidelity). Data were analyzed using an independent t-test, one-way ANOVA, Pearson’s correlation, and hierarchical multiple regression analysis. Results: The regression model had an adjusted R2 of .61, indicating that education goal, active learning, facilitator satisfaction, and fidelity were significant predictors of students’ self-confidence in simulation learning. Conclusion: To increase students' self-confidence with simulation learning strategies, it is necessary to design lessons that include educational goals, active learning, improved student satisfaction with the facilitator and fidelity based on the Jeffries Simulation Framework.
        4,600원
        6.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purpose: Nursing students' competence in virtual simulation-based learning is a key factor in its success. This study explored the validity and reliability of a virtual-simulation-based learning competency self-evaluation tool for nursing students. Methods: Data were collected from a web-based survey. First, 11 nursing professors participated in a focus group interview, and 7 simulation education experts participated in the preliminary item content validity. The participants in these two aspects were not the same. Then, a preliminary survey was conducted with 15 fourth-year nursing students in I City. Next, based on these three efforts, a final survey comprising 20 evaluation items was developed. This survey was administered to third- and fourth-year nursing students at four nursing colleges in Korean provinces (Seoul, Gyeonggi, Gangwon, and Gyeongsan-do); 222 complete questionnaires were used for the final analysis. Further, Kirkpatrick’s evaluation model was used for four steps each of tool development and verification processes of the associated psychometric aspects, for a total of eight steps. An exploratory factor analysis was performed on the collected survey data, and verify the tool's validity and reliability. Results: Four factors comprising 15 items explained 66.59% of the variance: learning preparation and start-up (4 items), nursing assessment (3 items), data interpretation (3 items), and problem solving (5 items). The Cronbach's α of the tool was 0.74, and that of the factors ranged from 0.72 to 0.80. Conclusions: The tool's validity and reliability were demonstrated using established methodologies. This tool can be useful for evaluating Korean nursing students' virtual simulation learning competence.
        4,900원
        7.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purpose: This study aimed to develop a program using the Room of Errors (ROE) technique to enhance the patient nursing student’s safety competencies and determine the effectiveness of simulation-based education. Methods: We conducted a methodological study using the ADDIE model for program development (Molenda, 2003). During the ROE activities, students identified errors that threatened patient safety. The program's effectiveness was evaluated in the implementation phase by measuring students' confidence in patient safety using a one-group pretest-posttest design. Results: Participants' satisfaction with the ROE program was 4.90 ± 0.36 on a 5-point Likert scale. The pre- and post-ROE program patient safety confidence scores (H-PEPSS) were statistically significant, increasing from 3.62 ± 0.54 to 4.19 ± 0.60. Participants' subjective evaluations were generally positive, indicating increased insight, confidence, and vigilance in error prevention. Conclusion: Based on this study’s significant findings, it would be beneficial to encourage students and healthcare providers to utilize ROE programs to enhance patient safety competencies.
        4,900원
        8.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purpose: The global emphasis on preventing and systematically managing acute cardiac arrest necessitates improved education in cardiovascular emergencies. This study aims to provide foundational data on the effectiveness of simulation-based cardiovascular emergency management education, applying the think-aloud method for nurses. Method: A one-group pre-posttest experimental design was used from July 29 to August 15, 2022. Twenty-eight nurses participated in this study. Data were analyzed using descriptive statistics and the Wilcoxon signed-rank test with SPSS/WIN 25.0. Results: The educational intervention showed statistically significant improvements in outcomes: knowledge of cardiovascular emergency management (Z=-4.24, p<.001), confidence in cardiovascular emergency management (Z=-4.63, p<.001), clinical reasoning competence (Z=-4.16, p<.001), and self-efficacy for group work (Z=-3.47, p=.001), and selfregulation for group work (Z=-2.29, p=.022). Conclusion: This study indicates that the use of the think-aloud method in simulation-based learning can effectively enhance cardiovascular emergency management training by reducing learners’ cognitive load. Cardiovascular emergency management competencies can be strengthened through the development of diverse educational strategies and the expansion of training support.
        4,600원
        9.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purpose: This study examined the influence of nursing students’ competencies in assessment, communication, clinical judgment, and patient safety on evidence-based practice (EBP) competency through simulation training. Methods: Data were collected from in December 11 in 2023 to January 30 in 2024, using a self-report questionnaire. The final participants were 230 nursing students in two universities. Multiple regression, t-test, ANOVA were used for data analysis. Results: The competencies of nursing students who participated in simulation training significantly influenced their EBP competency. The most influential factor on nursing students’ competency of EBP was Clinical Judgment, followed by Communication. Assessment and Patient safety competencies did not have a statistically significant impact on EBP competency. Conclusion: It is crucial for nurses to implement EBP to provide high-quality nursing and advance nursing as a science. However, since EBP competency is difficult to acquire in a short period, education on EBP is necessary from nursing school. Simulation training is considered an effective means to enhance nursing students' competency in EBP. Our study suggests incorporating elements that strengthen competencies in clinical judgment and communication when establishing a simulationbased training program to enhance the EBP competency of nursing students.
        4,200원
        16.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        실감형 콘텐츠 관련 연구가 활발히 진행되고 있다. AR을 중심으로 한 실감형 콘텐츠의 발전은 스마트 폰을 이용하여 실세계에 3D 가상 콘텐츠를 추가하는 것을 넘어, 대형 건축물에 Projection Mapping을 하는 Media Facade 콘텐츠로 발전되었다. 최근 Projection Mapping을 이용한 Media Facade를 활용한 광고 콘텐츠의 수요가 증가하면서 Projection Mapping콘텐츠에 대한 교육과 시스템개발이 요구 되고 있다. Projection Mapping을 처음 배우는 교육생의 경우, 투사할 사물 및 건축물을 만드는 것부터 큰 어려움으로 작용된다. 사물 및 건축물을 구축하기 위해서는 그만한 자원과 재원이 요구되며, 한번 만들고 나면 다시 자원 을 활용하여 바꾸기 쉽지 않다. 본 논문에서는 Projection Mapping 교육을 위한 Unity 3D Engine 기반 Projection Mapping Simulation을 제안한다. 제안된 Projection Mapping Simulation는 Unity 3D Engine을 기반하였기 때문에 무료로 교육생들이 사용이 가능하며, 다양한 3D Object File를 활용하여 사물 및 건축물을 나타내고 조작할 수 있다. 또한, Projection Mapping에 쓰이는 영상을 Video 뿐 아니라, 실시간 3D Rendering으로 사용할 수도 있다. 본 논문에서 제안한 Projection Mapping Simulation는 교육생들에게 공간과 사 물 및 건축물의 이해를 돋기 위한 실험의 장이 될 것이며, Projection Mapping 콘텐츠 연구 자들에게는 여러 Projection Mapping 기법을 실험 및 연구할 수 있는 장이 되길 희망한다.
        4,000원
        17.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Determining the number of operators who set up the machines in a human-machine system is crucial for maximizing the benefits of automated production machines. A man-machine chart is an effective tool for identifying bottlenecks, improving process efficiency, and determining the optimal number of machines per operator. However, traditional man-machine charts are lacking in accounting for idle times, such as interruptions caused by other material handling equipment. We present an adjusted man-machine chart that determines the number of machines per operator, incorporating idleness as a penalty term. The adjusted man-machine chart efficiently deploys and schedules operators for the hole machining process to enhance productivity, where operators have various idle times, such as break times and waiting times by forklifts or trailers. Further, we conduct a simulation validation of traditional and proposed charts under various operational environments of operators’ fixed and flexible break times. The simulation results indicate that the adjusted man-machine chart is better suited for real-world work environments and significantly improves productivity.
        4,000원
        18.
        2024.03 구독 인증기관·개인회원 무료
        자율주행차량의 첨단 운전자 보조 시스템(ADAS)의 발전은 자율주행차량의 상용화를 가속화하고 있지만, 그 안전성을 입증하기 위한 충분한 테스트와 검증이 필요하다. 실제 차량을 이용한 대규모 테스트는 비용과 시간뿐만 아니라 다양한 시나리오를 구현하고 평가하 는 데 어려움이 있어, 다수의 연구자들은 시뮬레이션을 활용하고 있다. 이러한 문제를 해결하기 위해, 본 연구에서는 차량 시뮬레이션 소프트웨어인 CarMaker와 교통 흐름 시뮬레이션인 VISSIM을 결합하여 공동으로 시뮬레이션을 진행한다. 또한 두 시뮬레이션의 장점 을 결합하여 자율주행차량의 데이터를 보다 포괄적으로 분석할 수 있는 프레임워크를 제안한다. 시뮬레이션 결과, 각각의 시뮬레이션 에서 얻은 Ego Vehicle의 속도 값은 미세한 차이를 보였으며, 이는 실시간 시뮬레이션의 통신 과정에서 발생하는 오류로 해석된다. 또 한, 특정 시나리오에서는 차량이 급정지 후 출발하는 형태를 보였으며, 이는 자율주행차량이 주변 차량의 주행을 인식하여 주행 패턴 에 변화를 주는 것으로 해석된다. 향후에는 도심 도로에서의 자율주행 평가를 통해 복잡한 교통 상황과 불확실한 요소들로 인해 어려 운 문제를 겪는 상황을 분석할 수 있을 것으로 기대된다.
        19.
        2024.03 구독 인증기관·개인회원 무료
        정보통신기술(Information and Communication Technology)과 기존 교통수단의 융복합으로 수소자동차, 자율주행자동차 등과 같은 새로운 교통수단 등장으로 광역 이동과 같은 이동성이 향상될 것으로 기대되고 있다. 또한, 보다 빠른 광역 이동성 확보를 위해 BRT 전용차로 도입에 대한 논의가 계속되고 있으므로 본 연구는 BRT 전용차로 구간에서 자율주행자동차의 혼입률 및 대중교통 전환율에 따른 시나리오를 설정해 서비스수준 분석을 기반으로 잉여차로 발생 가능성을 확인하였다. 더불어, 미래교통량 증가와 자율주행 기술 의 발전이 BRT 전용차로 운영 구간에 미치는 변화를 분석해 도로의 자산가치 산정을 목적으로 하고 있다. 설정한 시나리오에서 도로 가 기능을 발휘할 수 있는 일정한 서비스수준(Level of Service, LOS)를 유지하는 자율주행자동차 혼입률 수준을 파악하였으며, A~F 의 6단계로 구분하여 결과를 도출하였다. 도로의 자산가치 산정방법은 국가회계기준에서 제시하고 있는 토지의 대체적 평가방법 4가 지 방법과 보다 객관성을 확보한 새로운 자산가치 평가방법을 준용하여 도로의 자산가치를 산정하였다. 분석 결과, 간선도로 서비스수 준을 통해 BRT 전용차로를 시행하면서 연속류 구간에서는 자율주행자동차 혼입률이 75%되는 경우 편도 3차로에서 편도 2차로로 1차 로 감소가 이루어져도 현재의 서비스수준을 유지할 수 있으며, 단속류에서는 자율주행자동차의 혼입률이 50%되는 시점에 편도 4차로 에서 편도3차로 1차로 감소 시 동일한 효과를 발휘할 수 있음을 확인하였다. 즉, 연속류 구간에서 자율주행자동차 비율이 75% 및 단 속류 구간에서는 자율주행자동차의 비율이 50%되는 시점에서 1차로에 대한 도로 자산가치가 발생할 수 있음을 알 수 있었다. 이와 같은 잉여차로는 보행약자를 위한 보행 공간 및 자전거도로, 개인형이동장치((Personal Mobility, PM)전용도로, 완충녹지 등의 완전도 로로 활용될 수 있음을 시사하고 있다.
        20.
        2024.03 구독 인증기관 무료, 개인회원 유료
        전 세계적으로 실도로에서의 자율주행차 안전성능을 검증하고 자율주행 시스템 기술의 개발을 위해 다양한 실증을 수행하고 있다. 미국의 경우 캘리포니아, 오하이오, 애리조나 등 다양한 주에서 자율주행차의 실도로 테스트를 진행하고 있으며, 독일의 경우 페가수 스 및 이매진 프로젝트 등을 통해 자율주행 성능 및 협력 운행 테스트를 수행하였다. 그러나, 자율주행차의 주행 성능 측면의 평가에 국한되어 실증이 진행되고 있다는 한계가 존재한다. 실도로 환경에서 자율주행차는 비자율주행차, 보행자 및 자전거 등과 상호작용하 며, 다양한 도로 기하구조에서 주행안전성 저하 문제가 발생할 수 있다. 따라서, 본 연구에서는 혼재교통상황에서 자율주행차의 주행 안전성을 저하시키는 도로 기하구조를 도출하였다. 또한, 캘리포니아 Department of Motor Vehicles (DMV)에서 제시한 자율주행차 관련 사고자료 검토를 통해 유사한 도로 기하구조에서 발생할 수 있는 사고 유형을 검토함으로써 선제적인 대안을 마련하고자 한다. 시뮬 레이션 분석을 위한 자율주행차 거동구현의 경우 real-world automated vehicle data (AVD) 기반 주행행태 분석을 통해 VISSIM 파라미 터를 조정하였다. 위험구간 도출을 위해 평가지표를 선정하고 주행안전성 분석을 수행하였으며, 위험 구간의 도로 기하구조의 특성을 도출하였다. 마지막으로 위험구간의 도로 기하구조와 유사한 구간에서 발생한 실제 자율주행차 관련 사고 보고서를 검토함으로써 본 연구에서 도출된 위험구간의 도로 기하구조에서 발생할 수 있는 잠재적 사고 원인을 제시하였다. 본 연구의 결과를 통해 향후 자율주 행차의 실도로 도입을 위해 선제적인 대책을 마려하는데 기초자료로 활용될 수 있으며, 나아가 자율주행차 안전성 향상을 위한 경고 정보 서비스 개발, 정보 제공 인프라 설치 우선순위, 도로 기하구조 개선 사업에 활용할 수 있을 것으로 기대된다.
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