https://scholar.dgist.ac.kr/handle/20.500.11750/15725 2026-04-04T10:35:42Z https://scholar.dgist.ac.kr/handle/20.500.11750/60154 Title: 타켓 위치 결정 장치 및 방법 Author(s): 이종훈; 김봉석; 김상동 Abstract: 타켓 위치 결정 장치가 개시된다. 본 타켓 위치 결정 장치는 레이더 신호를 방출하고, 복수의 채널을 통하여 타켓으로부터 반사된 레이더 신호를 수신하는 레이더 장치, 및 수신된 레이더 신호에 기초하여 타켓의 위치를 결정하는 프로세서를 포함하며, 프로세서는 복수의 채널을 통하여 수신된 레이더 신호를 이산 푸리에 변환(DFT : Discrete Fourier Transform)을 적용하고, 이산 푸리에 변환이 적용된 레이더 신호에 기초하여 타켓의 각도를 예측하고, 예측된 타켓의 각도가 기설정된 각도 범위 내이면, 복수의 채널 중 홀수 채널 또는 짝수 채널을 통하여 수신된 레이더 신호 및 기설정된 고해상도 알고리즘을 이용하여 타켓의 위치를 결정하고, 예측된 타겟의 각도가 기설정된 각도 범위를 벗어나면, 복수의 채널을 통하여 수신된 레이더 신호 및 고해상도 알고리즘을 이용하여 타켓의 위치를 결정한다. https://scholar.dgist.ac.kr/handle/20.500.11750/59983 Title: YOLO 및 회귀 모델을 활용한 GPR B-scan 영상 기반 공동 크기 및 위치 추정 Author(s): 김세경; 양경택; 송승언; 이종훈 Abstract: Ground Penetrating Radar (GPR) is a non-destructive technique used to detect subsurface voids. In this studypaper, synthetic B-scan data hiddenwithwith spherical voids were generated using gprMax, and a YOLOv8-s model was trained to detect hyperbolic patterns. Since YOLO provides bounding boxes in pixel-level coordinates, regression mapping to ground-truth (GT) labels was applied to enable real-world size estimation. The predicted bounding boxes were mapped to Ground Truth (GT) labels through regression to evaluate void size inference.Since YOLO provides bounding boxes in pixel-level coordinates, a regression-based mapping was developed to convert detection results into real-world metric (m) coordinates, enabling direct estimation of void size and position. Results show that the predicted center coordinates (X, Y) exhibited linearity with GT values (R²>0.99). The bounding box height correlated with GT (R²=0.98). Also, the bounding box width and depth (Y), the estimation of GT width shows (R²≈ 0.98). These results demonstrate that YOLOv8-s based detection can reliably support both void localization and quantitative size estimation in GPR B-scan images.These results demonstrate that the proposed method can reliably support both void localization and real-size estimation in GPR B-scan images. Thus, the proposed approach provides an automated pixel-to-meter translation framework for quantitative GPR interpretation. 2025-11-05T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59897 Title: Enhancing photoelectrochemical CO2 reduction with CuBi2O4-cellulose nanofiber hybrid photocathodes Author(s): Cho, A. Young; Yoon, Ji Hyun; Lee, Sangwoo; Yun, Heeseo; Ma, Joonhee; Park, Jun-Young; Kim, Soo Young; Lee, Jonghun; Choi, Taekjib Abstract: The photoelectrochemical (PEC) conversion of carbon dioxide (CO2) into valuable chemicals and fuels offers a promising strategy to address global challenges such as climate change and glacier retreat. However, developing high-performance photocathodes for the CO2 reduction reaction (CO2RR) is challenging, particularly in optimizing the surface morphology and active site distribution of the electrodes. In this study, we propose a CuBi2O4 (CBO)-based photocathode capable of gas-phase CO2RR through hybridization with cellulose nanofiber (CNF). Our results reveal that the CBO-CNF membrane exhibits inherent hydrophilicity and significantly larger active sites compared to a CBO film prepared with a Nafion binder, leading to reduced charge transfer resistance on the photocathode surface. Moreover, the simultaneous hydrothermal synthesis of the CBO-CNF composite precursor solution effectively inhibits the formation of undesirable CuO nanoparticles on the surface, which would otherwise increase charge transport resistance within the photocathode bulk. Consequently, the CBO-CNF membrane demonstrates superior PEC activities for CO2RR, achieving a photocurrent density of - 5.69 mA/cm2 at - 0.4 VRHE and an onset potential of 0.015 VRHE. Furthermore, the incorporation of CNF improves the long-term PEC stability of the photocathode by promoting charge carrier participation in CO2RR rather than undesired self-reduction reaction. This enhanced stability, coupled with the improved PEC performance, highlights the potential of CNF to replace existing polymer binder materials. These results suggest the feasibility of developing a new type of CBO photocathode with a porous membrane structure suitable for gas-phase PEC cells, marking a significant step forward in PEC technology for CO2 conversion. 2026-01-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59390 Title: A Multi-template Correlation Time Delay Estimation in GPR System under a Building Collapse Model Author(s): Yang, Gyeongtaeg; Kim, Sekyung; Song, Seungeon; Han, Seonho; Koo, Bontae; Lee, Jonghun Abstract: This paper proposes a multi-template correlationbased time delay estimation method that enhances the accuracy and robustness of ground-penetrating radar (GPR) signal interpretation in noisy environments. Unlike conventional approaches that rely on a single reference waveform, the proposed method utilizes the original signal along with its higher-order derivatives to better match diverse echo patterns. Simulation experiments using a four-layer collapse model generated in gprMax confirm that the proposed method achieves lower mean percentage error (MPE) than traditional techniques under low signal-to-noise ratio (SNR) conditions. By addressing the challenges of echo distortion and environmental noise, the proposed approach demonstrates strong potential for reliable subsurface detection in post-disaster search and rescue scenarios. 2025-10-03T15:00:00Z