Jihwan Oh

Dr. Jihwan Oh

orcid

Research Focus & Metrics

Academic Career Length

2Years (2025-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 August 2025 in Journal of Institute of Control, Robotics and Systems
Verified
Journal Article
Closed access
SHSeokhwan Hwang
Seokhwan Hwang
Jihwan OhJihwan Oh
Jihwan Oh
JLJungsoo Lee
Jungsoo Lee
SHSoonwoong Hwang
Soonwoong Hwang
Wansoo KimWansoo Kim
Wansoo Kim
This paper proposes a real-time trajectory planning method using nonlinear optimization and whole-body control for cooperative transport with heterogeneous mobile manipulators. Unlike conventional approaches that rely on passive path following, the proposed method enables the follower robot to actively generate its own trajectory by laterally offsetting the leader’s path and refining it through nonlinear optimization. The optimization process simultaneously considers inter-robot distance maintenance, geometric consistency, and obstacle avoidance in cluttered environments. The optimized trajectory is executed through a generalized hierarchical control framework that integrates impedance-based coordination between the mobile base and manipulator. Experimental validation with two mobile manipulators—, featuring different locomotion and control characteristics—, demonstrates that the system maintains a consistent end-effector distance while adapting to environmental changes. The proposed method achieves high-fidelity trajectory tracking (average error: 0.037 m, standard deviation: 0.039 m) and maintains inter-robot spacing within a 1.05–1.65 m range for 96.09% of the task duration. The results demonstrate the framework’s relevance to real-world cooperative transport situations, emphasizing the need for adaptability, precision, and inter-robot coordination.

7 September 2026 in Sensors
Verified
Journal Article
Open access
PDF file
IGINHO GIL
INHO GIL
SHSeongmin Ha
Seongmin Ha
Jihwan OhJihwan Oh
Jihwan Oh
DLDonggyu Lee
Donggyu Lee
SHSoonwoong Hwang
Soonwoong Hwang
Wansoo KimWansoo Kim
Wansoo Kim
On-device Human Activity Recognition (HAR) requires balancing accuracy and deployment efficiency on constrained hardware. We present Lightweight Human Activity Recognition (L-HAR), a controlled comparison of Baseline and Lightweight Temporal Convolutional Network (TCN), Transformer, and Long Short-Term Memory (LSTM) models using data sampled at 100Hz from three inertial measurement units (IMUs) worn by one participant. Evaluations covered classification, model footprint, multiply–accumulate operations (MACs), offline CPU latency, Desktop/Raspberry Pi streaming, 8-bit integer (INT8) quantization, and software-estimated Raspberry Pi energy efficiency. Lightweighting reduced parameters by up to 95.5%, model size by 94.0%, and MACs by 87.6–95.5%, with accuracy reductions of 0.8–2.2 percentage points (pp) and sub-millisecond offline latency for all Lightweight models. Baseline and Lightweight models sustained approximately 100Hz message/inference rates on Desktop, whereas no Raspberry Pi configuration reached 100Hz inference. Among Lightweight models, Transformer achieved 9.381ms End-to-End (E2E) latency and 66.925Hz inference. INT8 quantization changed accuracy and F1-score by less than 0.13 pp; Quantized TCN achieved the best Raspberry Pi streaming result (9.066ms E2E; 69.928Hz) with an estimated 49.933mJ per inference. These results demonstrate architecture- and backend-dependent deployment behavior and the need for direct target-platform evaluation.

1 July 2026
Verified
Conference Paper
Closed access
Jihwan OhJihwan Oh
Jihwan Oh
SHSeongmin Ha
Seongmin Ha
IGInho Gil
Inho Gil
DLDonggyu Lee
Donggyu Lee
JNJoonkyu No
Joonkyu No
WKWansoo Kim
Wansoo Kim