https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/191 Fri, 24 Jul 2026 06:34:52 GMT 2026-07-24T06:34:52Z https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/213215 Title: In-situ vehicular soot sensor optimization based on quartz-enhanced photoacoustic spectroscopy Authors: Han, Jeongwoon; Hong, Joonhyeok; Rajasegar, Rajavasanth; Lee, Tonghun; Lim, Myung-Seop; Yoo, Jihyung Abstract: A quartz-enhanced photoacoustic spectroscopy (QEPAS)-based soot sensor was optimized for rapid and in-situ vehicular emission measurements. To mitigate vibration-induced interference and enhance the sensor's signal intensity, hardware refinements such as off-line transducer coupling and acoustic micro-resonators were implemented. Additionally, a method for tracking changes in transducer resonance frequency was implemented to minimize measurement uncertainty, particularly under prolonged exposure to high temperatures and heavy sooting conditions. Consequently, experimental results demonstrated a four-fold increase in signal level and a reduction in measurement uncertainty exceeding 67%. The total measurement duration was maintained within 3 s, including data processing, to ensure high temporal resolution. Sat, 01 Aug 2026 00:00:00 GMT https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/213215 2026-08-01T00:00:00Z https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/219041 Title: Energy-Optimal Control with Intelligent Crossing Decisions for Dilemma Zones at Signalized Intersections Authors: Kim, Dongryul; Han, Kyoungseok Abstract: Connected automated vehicles (CAVs) can improve energy efficiency through eco-driving at signalized intersections by avoiding energy-wasting stop-and-go patterns. However, when a lead vehicle's behavior prevents safe non-stop passage, energy-optimal crossing may conflict with rear-end collision avoidance, creating a CAV-specific dilemma zone problem. This paper presents a novel control framework that couples energy-optimal trajectory planning with collision avoidance constraints. Using pontryagin's minimum principle, we derive analytical solutions that minimize energy while satisfying both green phase passage and rear-end safety constraints. The framework provides real-time feasibility verification to establish explicit go-or-stop decision criteria, transitioning to safe fallback modes when energy-optimal intersection crossing is infeasible. Simulation results demonstrate that the proposed approach achieves energy-efficient operation while ensuring collision-free fallback mode transitions across various dilemma zone scenarios. Wed, 01 Jul 2026 00:00:00 GMT https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/219041 2026-07-01T00:00:00Z https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/219108 Title: Neural Network-Based MTPA Control Strategy for IPMSMs under Temperature Variations Authors: Lee, Jun-hyeok; Woo, Tae-gyeom; Jin, Dong-sup; Yoon, Young-doo Abstract: This paper proposes a control algorithm for the Maximum Torque per Ampere (MTPA) operation of Interior Permanent Magnet Synchronous Motors (IPMSMs) that consider temperature variations using an Artificial Neural Network (ANN). As the temperature increases, the residual magnetic flux density of the permanent magnets decreases, leading to a reduction in the magnitude of the magnetic flux. Furthermore, even at the same temperature, the d-q axis fluxes vary depending on the current operating points due to magnetic flux saturation. These nonlinear d-q axis flux variations result in nonlinear torque variations at current operating points. ANNs are well-suited for modeling nonlinear correlations and have been widely applied across various fields. Hence, ANN is applied to MTPA operation, effectively representing the nonlinear relationship between the d axis flux and MTPA operating point variations. The proposed method utilizes a Frequency-Adaptive Observer (FAO) to estimate the d-axis flux under the present temperature. Using the ANN, the MTPA operating point is adjusted by accounting for the d-axis flux variations caused by temperature changes and magnetic flux saturation. The proposed algorithm was validated through experiments on an 11 kW IPMSM. Wed, 01 Jul 2026 00:00:00 GMT https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/219108 2026-07-01T00:00:00Z https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/219109 Title: Comparison of Coaxial Magnetic Gears Using Rare Earth and Nonrare Earth Permanent Magnets Authors: Bae, Byeong-Cheol; Lee, Seung-Hun; Im, So-Yeon; Lim, Myung-Seop Abstract: Coaxial magnetic gears (CMGs) enable contactless torque transmission, addressing the noise and maintenance drawbacks of mechanical gears. However, the heavy reliance on rare earth permanent magnets (PMs) presents a challenge owing to their unstable supply and fluctuating costs. To mitigate dependence on rare earth PMs, this study proposes and evaluates four CMG configurations combining NdFeB and Ferrite. Each configuration is optimized using two-dimensional finite element analysis (FEA), with axial leakage considered by an equivalent magnetic circuit model instead of three-dimensional (3D) FEA. The suitability of bridge geometry for each PM combination is first assessed, revealing that irrespective of the PM material, the inner bridge provides superior torque density. Comparative analyses of the electromagnetic performance and active material costs were then conducted to evaluate the feasibility of each PM configuration. The results indicate that the difference in residual flux density between the inner and outer rotor PMs influences torque density, material costs, peak-to-peak torque, and efficiency. This difference was also observed in an appropriate gap between the active part and the end cover, at which end cover loss becomes negligible. Ferrite-Nd CMG showed the highest efficiency and lowest price among the combinations of nonrare earth PMs. Finally, electromagnetic performance comparisons of NdFeB-based and Ferrite-Nd CMGs using 3D FEA and experimental validation show that while the Ferrite-Nd CMG has a lower torque density than the NdFeB-based CMG, it offers promising advantages in terms of reduced rare earth dependency, negligible housing loss, and high efficiency. Wed, 01 Jul 2026 00:00:00 GMT https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/219109 2026-07-01T00:00:00Z