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Junsuk Kim

Publications and source records attributed to Junsuk Kim.

2 recordsLinked to original sources

RoPT: Robust 6DoF Object Pose Tracking in Video

Accurate 6-DoF object pose tracking is essential for robotic interaction, yet conventional monocular pipelines frequently suffer from catastrophic divergence under rapid object motion. We present RoPT, a robust tracking framework engineered to overcome this limitation by unifying visual perception, temporal kinematics, and global re-localization into a tightly coupled closed loop. Unlike existing open-loop trackers, RoPT delivers three critical capabilities that fundamentally alter system resilience. First, the visual perception component tracks object masks to robustly handle partial and severe occlusions. Second, a kinematic factor graph regularizes frame-to-frame updates, forecasts forward pose predictions, and drives a parallel multi-hypothesis verification scheme to bypass local minima. Finally, an active re-localization module transforms the pipeline into a closed-loop system, making it failure-aware and capable of deterministic self-recovery. We demonstrate the effectiveness of our framework across challenging benchmarks alongside real-world robotic demonstrations, achieving significantly higher tracking survivability under rapid motion.

cs.CV↗

Secondary Concentration Plateau and Formation of Flow Stagnation by Ion Concentration Polarization in Microchannels

Ion transport in perm-selective media has been extensively investigated in recent years owing to its applications in advancements of fundamental understanding of nanoscale electrokinetics as well as innovative engineering applications. A key phenomenon in this context is ion concentration polarization (ICP) that occurs near perm-selective nanoporous membranes or nanochannels under dc bias. In classical settings, involving voltage-driven transport of ions through perm-selective membranes, concentration polarization is well understood as formation of steep concentration drop to reach near zero concentration (depletion layer) at the anodic side of cation-selective membranes. In contrast to this classical description, we demonstrate here that when ICP is driven in a microchannel and coupled with electroosmotic flows a long-tailed fluorescent layer in front of diffusion layer is formed, which can be characterized as an additional plateau in the concentration profile. Using a micro/nanofluidic platform, in situ visualizations, and local concentration measurements by microelectrode arrays we quantify that this plateau layer has a concentration of 60 % of bulk electrolyte concentration, regardless of the bulk concentration itself. Using a mathematical analysis of conservation laws for flow, charge, and salt, we demonstrate that this plateau region is related to the formation of a flow stagnation point due to the competition between electro-osmotic and induced pressure driven flows. Consistent with the experiments, this analysis predicts the plateau concentration to be 60% of the bulk electrolyte. Thus, this plateau concentration region completes the picture of ICP in microchannels which has drawn significant attention from the fields of electrokinetics and micro/nanofluidics.

physics.flu-dyn↗