• The Korean Journal of Pain
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• v.22 no.3
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• pp.210-215
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• 2009

Background: Several studies have indicated that a nerve injury enhances the expression of the voltage-gated calcium channel ${\alpha}2{\delta}1$ subunit (Cav ${\alpha}2{\delta}1$) in sensory neurons and the dorsal spinal cord. This study examined whether NMDA receptor activation is essential for Cav ${\alpha}2{\delta}1$-mediated tactile allodynia in Cav ${\alpha}2{\delta}1$ overexpressing transgenic mice and L5/6 spinal nerve ligated rats (SNL). These two models show similar Cav ${\alpha}2{\delta}1$ upregulation and behavioral hypersensitivity, without and with the presence of other injury factors, respectively. Methods: The transgenic (TG) mice were generated as described elsewhere (Feng et al., 2000). The left L5/6 spinal nerves in the Harlan Sprague Dawley rats were ligated tightly (SNL) to induce neuropathic pain, as described by Kim et al. (1992). Memantine 2 mg/kg (10 ul) was injected directly into the L5/6 spinal region followed by $10{\mu}l$ saline. Tactile allodynia was tested for any mechanical hypersensitivity. Results: The tactile allodynia in the SNL rats could be reversed by an intrathecal injection of memantine 2 mg/kg at 1.5 hours. The tactile allodynia in the Cav ${\alpha}2{\delta}1$ over-expressing TG mice could be reversed by an intrathecal injection of memantine 2 mg/kg at 1.5, 2.0 and 2.5 hours. Conclusions: The behavioral hypersensitivity was similar in the TG mice and nerve injury pain model, supporting the hypothesis that elevated Cav ${\alpha}2{\delta}1$ mediates similar pathways that underlie the pain states in both models. The selective activation of spinal NMDA receptors plays a key role in mediating the pain states in both the nerve-injury rats and TG mice.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.6
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• pp.1062-1068
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• 2007

In order to design and develop a ubiquitous game, it is necessary to develop a natural and flexible interface between the real world and the virtual world, based on social and physical context awareness. We design user interface model and the tactile sensing system that performs virtual interaction and collection of the sensor data. It is sensitive so the collected data should be filtered, rearranged and analyzed. This information is quite different from stylus input, keyboard, button or mouse for interaction. We detect kicked 3D force position of a ball, moment of area, moment of inertia and modified ball shape using tactile sensing system and analyzed data. The results demonstrate that the proposed approach is desirable and robust as well as the results can be used realistic actions and reactions considering attack force and to make interesting environments for ubiquitous game.

• The Korean Journal of Pain
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• v.20 no.1
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• pp.8-14
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• 2007

Background: Anticonvulsants and antidepressants are adjuvant analgesic drugs that are used widely for treating chronic neuropathic pain syndromes. The combined analgesic effect of gabapentin and milnacipran was investigated with a rat neuropathic pain model. Methods: The rat neuropathic pain model was made by ligating the spinal nerves (L5 and L6). An intrathecal catheter was inserted into the subarachnoid space. Tactile allodynia was tested with the up-down method using von Frey hair. We determined the antiallodynic effect of intraperitoneal (I.P.) and intrathecal (I.T.) gabapentin. The combined effect of I.P. gabapentin (50 mg/kg) and milnacipran (0, 10 and 30 mg/kg) was investigated. Results: Intraperitoneal and intrathecal administration of gabapentin increased the threshold for tactile allodynia (the ED50 was 60.6 mg/kg and $45.5{\mu}g$, respectively). Co-administration of I.P. milnacipran increased the antiallodynic effect of I.P. gabapentin in a dose-dependent fashion. Conclusion: The combined administration of milnacipran and gabapentin may increase the total analgesic effect during treatment of neuropathic pain.

• The Korean Journal of Pain
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• v.21 no.1
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• pp.11-17
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• 2008

Background: Peripheral nerve injury induces up-regulation of the calcium channel alpha2delta (${\alpha}2{\delta}$) subunit and TRPM8 in the dorsal root ganglion (DRG) which might contribute to allodynia development. We investigated the expression of the ${\alpha}2{\delta}$ subunit and TRPM8 in the DRG of sympathetically maintained pain (SMP) and sympathetic independent pain (SIP) rat model. Methods: For the SMP model, the L5 and L6 spinal nerves were ligated tightly distal to the DRG. For the SIP model, the tibial and sural nerves were transected, while the common peroneal nerve was spared. After a 7 day postoperative period, tactile and cold allodynia were assessed using von Frey filaments and acetone drops, respectively. Expression of the ${\alpha}2{\delta}$ subunit and TRPM8 in the L5 and L6 DRG were subsequently examined by a Western blot. Results: There were no significant differences between the two models for the thresholds of tactile and cold allodynia. Expression of the ${\alpha}2{\delta}$ subunit in the ipsilateral DRG to the injury was increased as determined on a Western blot as compared to that in the contralateral or sham-operated DRG of the SMP model, but there was no difference in expression seen with the use of the SIP model. There was no difference in the expression of TRPM8 in the ipsilateral DRG to the injury and the contralateral or sham-operated DRG of either model. Conclusions: Up-regulation of the ${\alpha}2{\delta}$ subunit in injured DRG may play a role that contributes to tactile allodynia development in SMP, but not TRPM8 to cold allodynia after peripheral nerve injury.

• Convergence Security Journal
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• v.23 no.5
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• pp.125-133
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• 2023

This paper proposes an AI model that determines parking and non-parking zones based on return authentication photos to address parking issues that may arise in shared electric scooter systems. In this study, we used a pre-trained Segformer_b0 model on ADE20K and fine-tuned it on tactile blocks and electric scooters to extract segmentation maps of objects related to parking and non-parking areas. We also presented a method to perform binary classification of parking and non-parking zones using the Swin model. Finally, after labeling a total of 1,689 images and fine-tuning the SegFomer model, it achieved an mAP of 81.26%, recognizing electric scooters and tactile blocks. The classification model, trained on a total of 2,817 images, achieved an accuracy of 92.11% and an F1-Score of 91.50% for classifying parking and non-parking areas.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.280-281
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• 2009

Piezoelectric vibrators can be good replacements of electric motors to excite touch screen of a mobile device owing to small volume and low power consumption. One problem to be solved yet for real application is larger excitation force or moment than available currently. More efficient excitation by a piezoelectric vibrator could be achieved by operating at one of resonance frequencies of the system, which must also be as close as possible to frequency range where index finger is most sensitive and increasing transmission force or moment at that frequency. In this study, dynamic models are derived for the piezoelectric exciter and an adhesive viscoelastic layer, which connect the exciter to the screen. The adhesive layer is modeled as distributed stiffness by considering its geometric shape to relative to the piezoelectric exciter. Then, equations of motion for the piezoelectric exciter and the adhesive layer are derived using Hamilton's principle. Based on this model, dynamic characteristics of the exciter will be designed to maximize the force or moment transmitted onto the screen structure.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.259-262
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• 2003

Fabric hand is ultimately a subjective response to physical stimuli, but there are clearly practical advantage in the development and commercial trading of textile fabrics to be gained from the replacement of the traditional subjective tactile assessment by an objective measurement evaluation method. Moreover, the reliable objective measurement method for warp knitted fabrics have not developed yet, despite their increasing importance. (omitted)

• The Journal of Korea Robotics Society
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• v.3 no.1
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• pp.9-15
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• 2008

Unlike robotic systems, humans excel at a variety of tasks by utilizing their intrinsic impedance, force sensation, and tactile contact clues. By examining human strategy in arm impedance control, we may be able to teach robotic manipulators human''s superior motor skills in contact tasks. This paper develops a novel method for estimating and predicting the human joint impedance using the electromyogram(EMG) signals and limb position measurements. The EMG signal is the summation of MUAPs (motor unit action potentials). Determination of the relationship between the EMG signals and joint stiffness is difficult, due to irregularities and uncertainties of the EMG signals. In this research, an artificial neural network(ANN) model was developed to model the relation between the EMG and joint stiffness. The proposed method estimates and predicts the multi joint stiffness without complex calculation and specialized apparatus. The feasibility of the developed model was confirmed by experiments and simulations.

• Journal of the Korean Chemical Society
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• v.62 no.1
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• pp.43-51
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• 2018

In this study, visually impaired secondary students' conception of "changes of state of water" was explored. Science inquiry activity for students with visual impairments was implemented to 16 middle school students and 15 high school students from school for the blind. 14 of them were totally blind, 13 had low vision and the others were not identified. Inquiry activities were conducted by communicating with the researcher while students were individually exploring the molecular models of water and ice developed for the study. After the exploration, students were asked to explain the concept of changes of state of water with the model they explored. Opinion on the need and the usability of this kind of tactile model was also asked to them. All conversations were recorded, transcribed, and analyzed. As a result, students with visual impairments answered exactly about the materials used for the model and their numbers. However, they didn't know what the model stood for. They had experiences of learning molecule of water and changes of state of water, but it was a phenomenon and superficial understanding. Students got to understand the molecular structures of water and ice, and had a positive perception on the need and the usability of the model. Based on these results, educational implications were discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.841-845
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• 1996

Reverse engineering enables a fast creation of CAD model from an existing part without any technical drawing or digital data. This method of data acquisition is necessary in several industrial applications when the modification of an existing product design has to be performed and verified afterwards. In this paper, the surface of an existing ship propeller was measured by a tactile measuring system and the acquired point data of the surface were used for modeling of a solid model in CAD system. By using LOM and casting processes, an aluminum propeller for functional test was manufactured and then its accuracy was measured by a laser scanner and compared with the origin릴 CAD data. As the results show, the use of LOM as a rapid prototyping process and casting as a secondary process delivers a functional prototype propeller which can be used for test purposes.