• Journal of Institute of Control, Robotics and Systems
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• v.18 no.3
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• pp.188-192
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• 2012

In this study, a carbon nanotube (CNT) flexible strain sensor was fabricated with CNT based epoxy and rubber composites for tactile sensing. The flexible strain sensor can be fabricated as a long fibrous sensor and it also may be able to measure large deformation and contact information on a structure. The long and flexible sensor can be considered to be a continuous sensor like a dendrite of a neuron in the human body and we named the sensor as a biomimetic artificial neuron. For the application of the neuron in biomimetic engineering, an ANMS (Artificial Neuron Matrix System) was developed by means of the array of the neurons with a signal processing system. Moreover, a strain positioning algorithm was also developed to find localized tactile information of the ANMS with Labview for the application of an artificial e-skin.

• PNF and Movement
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• v.13 no.1
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• pp.17-23
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• 2015

Purpose: This study aims to identify changes in the mirror neuron system in normal people through mu rhythm during action observation of occupation-based intervention, purposeful activity and prepare a method of intervention form of occupation using occupation and activity. Methods: TThis study aims to identify changes in the mirror neuron system in normal people through mu rhythm during action observation of occupation-based intervention, purposeful activity and prepare a method of intervention form of occupation using occupation and activity. The activation of the mirror neuron system was compaired among 3 condition by oneway ANOVA. Results: The result of analysis showed mu suppression in all conditions. Although all conditions showed mu suppression, there was no significant difference among the conditions. Conclusion: The results suggest that the mirror neuron system is activated during action observation to be able to occupational therapy but the mirror neuron system is not separately activated among the conditions.

• Journal of Sensor Science and Technology
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• v.28 no.5
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• pp.284-288
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• 2019

A calibration-free analog neuron circuit is proposed as a viable alternative to the power hungry digital neuron in implementing a deep neural network. The conventional analog neuron requires calibrations because a voltage-mode link is used between the soma and the synapse, which results in significant uncertainty in terms of current mapping. In this work, a current-mode link is used to establish a robust link between the soma and the synapse against the variations in the process and interconnection impedances. The increased hardware owing to the adoption of the current-mode link is estimated to be manageable because the number of neurons in each layer of the neural network is typically bounded. To demonstrate the utility of the proposed analog neuron, a simple neural network with $4{\times}7{\times}3$ architecture has been designed for classifying iris flowers. The chip is now under fabrication in 0.35 mm CMOS technology. Thus, the proposed true current-mode analog neuron can be a practical option in realizing power-efficient neural networks for edge computing.

• PNF and Movement
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• v.9 no.4
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• pp.33-40
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• 2011

Purpose : The aims of this study was to identify changes mu rhythm according to familiarity with a stimulus in people with stroke. Methods : Seventeen right-handed participants were asked to observe 2 different stimulus; a non-familiarity stimulus condition (NFSC), and a familiarity stimulus condition (FSC). Electroencephalogram (EEG) signals from electrodes on the participant's scalp were recorded during action observation. The activation of the mirror neuron system was compaired between FSC and NFSC by a paired t-test. An independent t-test was used to compare the difference between right and left hemispheres for the activation of the mirror neuron system during action observation of performing a task with the right hand. Results : The result of paired t-test showed no significantly difference between NFSC and FSC in the activation of the mirror neuron system. The Result of independent t-test also showed no significantly difference in the activation of mirror neuron system between the right and left hemispheres. Conclusion : The familiarity with a stimulus had no signigicant effect on the activation of the mirror neuron system according to the familiarity and in either the right or left hemispheres in people with chronic stroke.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.3
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• pp.361-368
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• 2011

Purpose : The aims of this study was to identify the activation of the mirror neuron system during action observation in people with stroke and the difference between left hemisphere and right hemisphere and to provide possibility of the use of action observation as a clinical method for improving motor function after stroke. Methods : Seventeen participants were asked to observe 3 different stimulation conditions for 80 seconds. A 30 second rest period was given between stimulations. Electroencephalogram(EEG) signals from electrodes on the participant's scalp were recorded during action observation. The activation of the mirror neuron system(MNS) between the picture observation condition and action observation condition was compared with a paired t-test. An independent t-test was used to compare difference between C3 and C4 on the activation of the mirror neuron system in the action observation condition. Results : Result of paired t-test showed a significantly decreased log ratio in the activation of the mirror neuron system in the action observation condition compared to the picture observation condition. Result of the independent t-test indicated no significant differences in the activation of the mirror neuron system in the right and left hemisphere. Conclusion : The mirror neuron system showed greater activation in the action observation condition than in the picture observation condition and activation in the both hemisphere during action observation. We conclude that these findings suggest that this may possibly be an efficient clinical intervention method for improving motor function.

• Biomolecules & Therapeutics
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• v.18 no.4
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• pp.386-395
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• 2010

Bone marrow-derived mesenchymal stem cells (BM-MSC) are a multipotent cell population that can differentiate into neuron-like cells. Previously it has been reported that murine BM-MSC can differentiate into neuron-like cells by co-treatment with a Rho-associated kinase (ROCK) inhibitor -Y27632 and $CoCl_2$. In this study, we compared several ROCK inhibitors for the ability to induce human BM-MSCs to differentiate into neuron-like cells in the presence of $CoCl_2$. Y27632 with high specificity for ROCK at 1-30 ${\mu}M$ was best at inducing neuronal differentiation of MSCs. Compared to HA1077 and H1152, which also effectively induced morphological change into neuron-like cells, Y27632 showed less toxicity even at 100 ${\mu}M$, and resulted in longer multiple branching processes at a wide range of concentrations at 6 h and 72 h post-induction. H89, however, which has less specificity by inhibition of protein kinase A, S6 kinase 1 and MSK1 with similar or greater potency, was less effective at inducing neuronal differentiation of MSCs. Simvastatin, which can inhibit Rho, Ras, and Rac by blocking the synthesis of isoprenoid intermediates, showed little activity for inducing morphological changes of MSCs into neuron-like cells. Accordingly, the expression patterns for neuronal cell markers,including ${\beta}$-tubulin III, neuron-specific enolase, neurofilament, and microtubule-associated protein, were consistent with the pattern of the morphological changes. The data suggest that the ROCK inhibitors with higher specificity are more effective at inducing neuronal differentiation of MSCs.

• 전자공학회논문지 IE
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• v.46 no.1
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• pp.16-22
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• 2009

Integrated circuit of a pulse-type neuron for Hodgkin-Huxley model is implemented in a $0.5{\mu}m$ 1 poly 2 metal CMOS technology. Proposed pulse-type neuron model consist of input stage with summing function and pulse generating block which make neuron pulse above threshold value. Pulse generating circuit consist of several transistors, capacitors and negative resistor with a charge supply function. SPICE simulation results show that neuron pulse is generated above threshold current of 70 nA. Measurements of the fabricated pulse type neuron chip in condition of 5 V power supply are shown and compared with the simulated results.

• Annals of Clinical Neurophysiology
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• v.8 no.1
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• pp.63-70
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• 2006

Background: Testosterone is reported to have neuroprotective effect in various neurological diseases. Recently, the mechanism involved in nitric oxide (NO)-mediated motor neuron death is under extensive investigation. The Cu/Zn-superoxide dismutase (SOD1) mutations has been implicated in selective motor neuron death of amyotrophic lateral sclerosis (ALS) and it is said to play an important role in NO-mediated motor neuron death. However, neuroprotective effect of testosterone on motor neuron exposed to NO has rarely been studied. Methods: Motor neuron-neuroblastoma hybrid cells expressing wild-type or mutant (G93A or A4V) SOD gene were treated with $200{\mu}M$ S-nitrosoglutathione. After 24 hr, cell viability was measured by MTT assay. To see the neuroprotective effect of testosterone, pretreatment with 1 nM testosterone was done 1 hr before S-nitroglutathione treatment. To study the mechanism of protective effect, $20{\mu}M$ flutamide (androgen receptor antagonist) was also pretreated with testosterone 1 hr before S-nitroglutathione treatment. Results: S-nitrosoglutathione showed significant neurotoxic effect in all three cell lines. Percentage of cell death was somewhat different in each cell line. 1 nM testosterone showed neuroprotective effect in G93A and wild-type cell line. In A4V cell line, testosterone did not showed neuroprotective effect. The neuroprotective effect of testosterone was reversed by $20{\mu}M$ flutamide. Conclusions: These results indicate that testosterone induces neuroprotection in NO-mediated motor neuron death directly through the androgen receptor. This neuroprotective effect of testosterone varies according to the types of SOD1 gene mutation. These data suggest that testosterone may be of therapeutic value against ALS.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.10a
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• pp.3-5
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• 1997

• 전자공학회논문지 IE
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• v.44 no.3
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• pp.12-22
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• 2007

In this paper, we designed of the high speed digital neuron processor in order to digital neural networks. we designed of the MAC(Multiplier and Accumulator) operation unit used residue number system without carry propagation for the high speed operation. and we implemented sigmoid active function which make it difficult to design neuron processor. The Designed circuits are descripted by VHDL and synthesized by Compass tools. we designed of MAC operation unit and sigmoid processing unit are proved that it could run time 19.6 nsec on the simulation and decreased to hardware size about 50%, each order. Designed digital neuron processor can be implementation in parallel distributed processing system with desired real time processing, In this paper.