https://scholar.dgist.ac.kr/handle/20.500.11750/15726 2026-10-28T00:20:27Z https://scholar.dgist.ac.kr/handle/20.500.11750/60987 Title: TPGS Analog-Mediated Intracellular ROS-Amplifying Strategy Potentiates the In Vitro Anticancer Activity of a Dual-Thioketal-Linked Polymeric Drug Conjugate in A549 Lung Cancer Cells Author(s): Kim, Hyun-Chul; 이경민; Hwang Yeo Jin; Lee, Jonghun; 한화승 Abstract: Background/Objectives: Reactive oxygen species (ROS)-responsive polymeric drug conjugates (PDCs) can enable oxidative stress-triggered drug release, but their activation may be limited by heterogeneous or insufficient intracellular ROS. Herein, we synthesized a dual-thioketal-linked PDC bearing two ROS-cleavable thioketal (TK) units in series and combined it with D-alpha-Tocopheryl polyethylene glycol succinate analog (TPGSa) as a soluble ROS-modulating co-treatment. Methods: PDC was synthesized through stepwise construction of the TK linker and subsequent carbonate coupling with camptothecin (CPT). TPGSa was prepared by esterifying mPEG with tocopheryl succinate. PDC nanoassembly formation, colloidal stability, peroxide-induced structural changes, thiol generation, and CPT release behaviors were evaluated under oxidative conditions. Cytotoxicity was examined in A549 and BEAS-2B cells with intracellular ROS- and CPT-associated fluorescence. Results: PDC formed spherical nanoassemblies with a hydrodynamic diameter of 98.6 +/- 2.6 nm and a zeta potential of -13.3 +/- 1.2 mV. The PDC remained colloidally dispersed in 10% FBS-containing PBS and after lyophilized storage. Peroxide exposure produced concentration-dependent thiol generation, molecular size change, and CPT release. The PDC + TPGSa reduced A549 viability more than PDC alone, produced the most pronounced dead-cell staining, and yielded the highest intracellular ROS and CPT fluorescence signals. In contrast, BEAS-2B viability remained substantially higher under matched conditions. Conclusions: These findings support an A549-focused in vitro proof of concept in which TPGSa-associated redox perturbation is paired with a dual TK PDC to enhance CPT-associated cytotoxicity. 2026-06-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60621 Title: Low-Complexity Single-Chain ISAC Receiver via Beat-Signal Domain FRFT Author(s): Kim, Bong-Seok; Lee, Jonghun; Kim, Sangdong Abstract: This letter introduces a single-chain Fractional Fourier Transform (FRFT)-based receiver for integrated sensing and communication (ISAC) that eliminates the need for matched-filter banks. While Slope-Shift Keying (SSK) is a promising modulation technique for automotive FMCW radar, conventional coherent receivers require a bank of matched filters, making the receiver processing complexity scale linearly with the modulation order. To overcome this limitation, we apply the FRFT in the beat-signal domain. By exploiting the chirp-rate-dependent energy focusing property, this approach converts slope discrimination into a fractional-domain peak detection problem. Consequently, it enables efficient high-order symbol detection using only a single standard receive processing chain. Simulation results demonstrate that the proposed scheme reduces the modulation-order-dependent digital processing burden while maintaining stable bit error rate (BER) performance and radar sensing performance under high-mobility Rician multipath V2V conditions. 2025-12-31T15:00:00Z 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/20.500.11750/59387 Title: Radar Foot Gesture Recognition with Hybrid Pruned Lightweight Deep Models Author(s): Son, Eungang; Song, Seungeon; Kim, Bong-Seok; Kim, Sangdong; Lee, Jonghun Abstract: Foot gesture recognition using a continuous-wave (CW) radar requires implementation on edge hardware with strict latency and memory budgets. Existing structured and unstructured pruning pipelines rely on iterative training–pruning–retraining cycles, increasing search costs and making them significantly time-consuming. We propose a NAS-guided bisection hybrid pruning framework on foot gesture recognition from a continuous-wave (CW) radar, which employs a weighted shared supernet encompassing both block and channel options. The method consists of three major steps. In the bisection-guided NAS structured pruning stage, the algorithm identifies the minimum number of retained blocks—or equivalently, the maximum achievable sparsity—that satisfies the target accuracy under specified FLOPs and latency constraints. Next, during the hybrid compression phase, a global L1 percentile-based unstructured pruning and channel repacking are applied to further reduce memory usage. Finally, in the low-cost decision protocol stage, each pruning decision is evaluated using short fine-tuning (1–3 epochs) and partial validation (10–30% of dataset) to avoid repeated full retraining. We further provide a unified theory for hybrid pruning—formulating a resource-aware objective, a logit-perturbation invariance bound for unstructured pruning/INT8/repacking, a Hoeffding-based bisection decision margin, and a compression (code-length) generalization bound—explaining when the compressed models match baseline accuracy while meeting edge budgets. Radar return signals are processed with a short-time Fourier transform (STFT) to generate unique time–frequency spectrograms for each gesture (kick, swing, slide, tap). The proposed pruning method achieves 20–57% reductions in floating-point operations (FLOPs) and approximately 86% reductions in parameters, while preserving equivalent recognition accuracy. Experimental results demonstrate that the pruned model maintains high gesture recognition performance with substantially lower computational cost, making it suitable for real-time deployment on edge devices. 2025-10-31T15:00:00Z