https://scholar.dgist.ac.kr/handle/20.500.11750/185 2026-04-04T16:07:13Z https://scholar.dgist.ac.kr/handle/20.500.11750/13160 Title: Study of a Line-Patterning Process Using Impact Print-Type Hot Embossing Technology Author(s): Kim, Myeongjin; Ahn, Jaewon; Bae, Junseong; Kim, Donghyun; Kim, Jongbum; Kim, Jonghyun; Yun, Dongwon Abstract: An impact print-type hot embossing process is a method for creating arbitrary patterns on polymer film in real-time. This process can form 20–100 μm dot patterns and line patterns using an impact head and a high-precision moving stage on a polymer film such as polyester (PET) film, polymethyl methacrylate (PMMA) film, polyvinyl chloride (PVC) film without the need for the embossing stamps used for conventional hot embossing processes. This technology can also create line patterns with varying widths and depths by adjusting the positions of the impact header. Moreover, the proposed process can be used to fabricate electrical channels of various widths and depths to install ultrafine electronic devices. Because the proposed method can create ultrafine patterns in real-time, using it can reduce the cost and time required for pattern modifications and process replacements. In addition, from the result of the bending test after applying the conductive ink to the line pattern, it is known that this process is suitable for making the flexible electrical channel. The advantages of this line-patterning method will contribute significantly to the current field of hot embossing to create ultrafine patterns by enabling small-quantity production of various types of products while also facilitating mass production. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 2020-01-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/11694 Title: A Novel End-Effector Robot System Enabling to Monitor Upper-Extremity Posture during Robot-Aided Planar Reaching Movements Author(s): Hwang, Yeji; Lee, Seongpung; Hong, Jaesung; Kim, Jonghyun Abstract: End-effector type robots have been popularly applied to robot-aided therapy for rehabilitation purpose. However, those robots have a key drawback for the purpose: lack of the user's posture (joint angle) information. This letter proposes a novel end-effector rehabilitation robot system that contains a contactless motion sensor to monitor upper- extremity posture during robot-aided reaching exercise. The sensor allows the posture estimation without complicated procedures but has an inaccuracy problem such as occlusion and an unreliable segment length. Therefore, we developed a posture monitoring method, which is an analytical method without training procedure, based on the combined use of the information obtained from the sensor and the robot. Eight healthy subjects participated in the experiment with planar reaching exercise for validation. The results of joint angle estimation, high correlation coefficient (0.95 ± 0.03) and small errors (3.55 ± 0.70 deg), show that the proposed system can provide affordable upper-extremity posture estimation. © 2020 IEEE. 2020-03-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/10093 Title: A Robust Motion Control with Antiwindup Scheme for Electromagnetic Actuated Microrobot Using Time-Delay Estimation Author(s): Kim, Junyoung; Choi, Hongsoo; Kim, Jonghyun Abstract: For the safety and efficacy of in vivo therapy using electromagnetic actuated microrobots, position tracking performance is crucially important. However, it is difficult to manipulate the microrobots accurately and rapidly due to the nonlinear and complex dynamics of the microrobots and highly limited magnetic force of the actuator. In this paper, we propose a robust control law for the microrobots. It consists of a time-delay estimation to compensate for the unknown/unmodeled dynamics, an antiwindup scheme, and a forgetting factor to improve the performance. In addition, we added a switching action to the control law in order to guarantee the stability of the controller. The improved performance and stability of the proposed control law were verified through an experiment that contains 3-DOF motion. 2019-05-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/9748 Title: A Paradigm to Enhance Motor Imagery Using Rubber Hand Illusion Induced by Visuo-Tactile Stimulus Author(s): Song, Minsu; Kim, Jonghyun Abstract: Enhancing motor imagery (MI) results in amplified event-related desynchronization (ERD) and is important for MI-based rehabilitation and brain-computer interface (BCI) applications. Many attempts to enhance the MI by providing a visual guidance have been reported. We believe that the rubber hand illusion (RHI), which induces body ownership over an external object, can provide better guidance to enhance MI; thus, an RHI-based paradigm with motorized moving rubber hand was proposed. To validate the proposed MI enhancing paradigm, we conducted an experimental comparison among paradigms with 20 healthy subjects. The peak amplitude and arrival times of ERD were compared at contralateral and ipsilateral electroencephalogram channels. We found significantly amplified ERD caused by the proposed paradigm, which is similar to the ERD caused by motor execution. In addition, the arrival time suggests that the proposed paradigm is applicable for BCI. In conclusion, the proposed paradigm can significantly enhance the MI with better characteristics for use with BCI. 2019-02-28T15:00:00Z