철 혼입 및 실리콘 결함점 생성에 따른 MFI형 제올라이트의 산촉매적 특성에 대한 효과 연구

학위논문(박사) - 한국과학기술원 : 화학과, 2024.2,[vi, 98 p. :]Zeolites are microporous crystalline materials, and their inherent acidity makes them versatile catalysts for various catalytic reactions. To tailor the acid-catalytic properties of zeolites to a suitable level for specific reactions, several factors affecting the acidity of zeolites are being studied. In addition to the change of aluminum content, the replacement of aluminum with heteroatoms or the utilization of functional groups such as silanol are alternative methods for modifying acidity. This thesis explores the acid catalytic properties of zeolite by the incorporation of iron or the generation of silicon defect depending on the synthesis condition changes. Both approaches result in the formation of weak acid sites, rendering them suitable for catalytic reactions where strong acid sites may pose challenges. This study investigates the consequential changes in the physicochemical properties induced by these modifications, and their applications in the methanol-to-hydrocarbon reaction and Beckmann rearrangement reaction. These findings can contribute to a deeper understanding of how these factors in the zeolite synthesis procedure influence the acid-catalyzed reactions, providing valuable insights for the design and optimization of catalysts in diverse applications.한국과학기술원 :화학과

Performance Analysis of 4G/5G C-V2X Video Transmission

차량 간 통신(Vehicle-to-Everything, V2X), 특히 셀룰러 V2X(C-V2X)는 원거리에서도 실시간 교통 상황 정보 공유가 가능하다는 점에서 자율주행차 및 스마트 교통 시스템의 발전에서 주목받고 있다. 현재 C-V2X를 활용한 협력 인식 메시지(Cooperative Awareness Messages, CAM), 안전 메시지(Basic Safety Messages, BSM)와 같은 주기적 저속 데이터 메시지 전송이 고려되고 이에 관련된 연구가 다양하게 진행되고 있지만, 원격주행 등의 서비스를 제공하기 위해서는 센서 데이터 등의 고속 데이터 메시지 공유가 필요하다. 이에 본 연구에서는 MATLAB 기반 시뮬레이션을 활용하여 차량-기지국 간의 실시간 카메라 센서 영상 공유를 위한 통신 상황을 가정하고, 4G LTE와 5G NR 환경에서의 영상 전송 성능을 분석하였다. 이 때, 영상 성능 전송 성능 평가를 위해 변조 코딩 구성(Modulation and Coding Scheme, MCS), 압축 여부, 해상도에 따른 지연 시간과 지원 가능한 초당 프레임(Frame Per Second, FPS)을 분석하였다. Vehicle-to-Everything (V2X) communication, particularly Cellular V2X (C-V2X), is gaining attention in the development of autonomous vehicles and smart transportation systems due to its ability to share real-time traffic information over long distances. While current research and applications focus on the periodic low-speed data message transmission, such as Cooperative Awareness Messages (CAM) and Basic Safety Messages (BSM), utilizing C-V2X, high-speed data message sharing, such as sensor data, is essential for providing services like remote driving. Therefore, in this study, we assumed a communication scenario for sharing real-time camera sensor footage between vehicles and base stations using MATLAB-based simulations and analyzed the video transmission performance in 4G LTE and 5G NR environments. To evaluate the video transmission performance, we analyzed the latency and available frames per second (FPS) according to the modulation and coding scheme (MCS), compression, and image resolution.FALSEkc