• Korean Journal of Animal Reproduction
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• v.26 no.1
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• pp.79-85
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• 2002

We investigated the optimal concentration and exposure time of cycloheximide(CHX) on development of activated porcine oocytes following electrical pulse(EP). After 42~44 h maturation, oocytes were treated with 0.1% hyaluronidase, and denuded cumulus cells by pipetting. Oocytes were stimulated by electric pulse (1.2 kV/cm, 30 $\mu$sec, 1 pulse) or incubated for 3, 5 and 7 h in cycloheximide (1, 5 and 10 $\mu\textrm{g}$/$m\ell$, respectively) following electric pulse, and cultured for 8 days. Cleavage rate of oocytes activated with 10 $\mu\textrm{g}$/$m\ell$ CHX following EP was significantly (P＜0.05) higher than those of 1 $\mu\textrm{g}$/$m\ell$ (86.8% vs. 74.4%). The developmental competence of oocytes incubated to 5 $\mu\textrm{g}$/$m\ell$ of CHX was significantly (P＜0.05) higher development to blastocysts (13.3%), compared with 10 $\mu\textrm{g}$/$m\ell$ of CHX (5.6%). When the oocytes were activated with 5$\mu\textrm{g}$/$m\ell$ CHX for 3, 5, and 7 h following EP, the cleavage rate of oocytes in 5 h group(86.6%) was significantly (P＜0.05) higher than that in 3 h group(73.2%). The developmental rate of oocytes to morula in 5 and 7 h groups(26.7% and 16.4%) were significantly (P＜0.05) high than that in 3 h group(14.5%). Matured oocytes were activated with electric pulse (EP) or electric pulse combined with cycloheximide (EP + CHX) and cultured for 8 days. The rate of cleavage and development to blastocyst (80.1% and 11.6%) of activated with EP group were similar to EP combined with CHX group. When activated with EP or EP combined with CHX, the mean cell number of blastocysts were less in the activated with EP (18.67$\pm$5.53) than in the activated EP combined CHX (20.71$\pm$6.16), but not significantly different. This results suggest that, when the porcine oocytes were activated with CHX following EP, the developmental rate of activated oocytes can be improved by treated with a concentration of 5 $\mu\textrm{g}$/$m\ell$ CHX for 5 h exposure time.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.4
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• pp.44-51
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• 2002

• Prospectives of Industrial Chemistry
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• v.21 no.1
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• pp.3-18
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• 2018

전자피부(Electronic skin)는 외부 환경과의 상호작용하는 인간 피부의 기능을 대체하여 외부 자극 신호를 전기적 신호로 변환하는 센서들로 이루어진 인공피부로써, 최근 인간과 전자기기 간의 인터페이스에 대한 관심이 급증하면서 이에 대한 많은 연구들이 진행되고 있다. 그중에서도 피부의 주된 기능인 외부 물리적 자극을 인지하는 촉각을 모방하는 촉각센서는 많은 발전을 거쳐 왔으며, 한계를 극복하고자 다양한 연구들이 진행되고 있다. 촉각센서는 압력, 인장, 굽힘과 같은 물리적 자극에 반응하며, 물리적 자극 신호를 아날로그 및 디지털 신호로 변환하여 인지하는 연구들이 폭넓게 개발되고 있다. 또한, 소자의 구조에 따라 물리적 자극을 전달하는 다양한 변환 방식들이 있으며, 최근에는 각 신호 변환 방식의 민감도, 반응속도, 자극 인지 범위 등의 한계점을 극복하고, 소재의 기계적 물성을 향상시키기 위해 소재의 변형을 주거나 생체의 기관 구조 및 외부 자극 인지 원리 등을 모사한 연구들이 많은 관심을 받고 있다. 본 기고에서는 이러한 촉각센서의 물리적 자극 신호 변환 방식과 소재 변형 및 생체 모사를 통한 다양한 연구들을 소개하고자 하며, 이를 통하여 촉각센서의 나아갈 방향을 제시하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4045-4052
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• 2012

The aim of this single blind intervation study was to compare the analgesic effects of transcutaneous electrical nerve stimulation (TENS) and interferential currents (IFC) on cold-induced pain in healthy volunteers. Sixteen subjects completed six cycles of the cold-induced pain test. During each cycle pain threshold was recorded as the time from immersion of the subject is hand in cold water to the first sensation of pain and pain intensity and unpleasantness ratings were recorded using visual analogue scales. Subjects were randomly allocated to receive each 50 Hz-TENS, 50 Hz-IFC, 100 Hz-TENS and 100 Hz-IFC. Statistical analysis showed that four interventions elevated the cold pain threshold significantly and the difference between interventions was not simply significant. But, no significant differences were identified in pain intensity and unpleasantness ratings. We conclude that there were no differences in the analgesic effects of the four interventions under the present experimental conditions. But, 50 Hz-IFC has been shown to be more comfortable than other interventions.

• Progress in Medical Physics
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• v.19 no.1
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• pp.73-79
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• 2008

Retinal prosthesis is regarded as the most feasible method for the blind caused by retinal diseases such as retinitis pigmentosa (RP) or age related macular degeneration (AMD). Recently Korean consortium launched for developing retinal prosthesis. One of the prerequisites for the success of retinal prosthesis is the optimization of the electrical stimuli applied through the prosthesis. Since electrical characteristics of degenerate retina are expected to differ from those of normal retina, we performed voltage stimulation experiment both in normal and degenerate retina to provide a guideline for the optimization of electrical stimulation for the upcoming prosthesis. After isolation of retina, retinal patch was attached with the ganglion cell side facing the surface of microelectrode arrays (MEA). $8{\times}8$ grid layout MEA (electrode diameter: $30{\mu}m$, electrode spacing: $200{\mu}m$, and impedance: $50k{\Omega}$ at 1 kHz) was used to record in-vitro retinal ganglion cell activity. Mono-polar electrical stimulation was applied through one of the 60 MEA channel, and the remaining channels were used for recording. The electrical stimulus was a constant voltage, charge-balanced biphasic, anodic-first square wave pulse without interphase delay, and 50 trains of pulse was applied with a period of 2 sec. Different electrical stimuli were applied. First, pulse amplitude was varied (voltage: $0.5{\sim}3.0V$). Second, pulse duration was varied $(100{\sim}1,200{\mu}s)$. Evoked responses were analyzed by PSTH from averaged data with 50 trials. Charge density was calculated with Ohm's and Coulomb's law. In normal retina, by varying the pulse amplitude from 0.5 to 3V with fixed duration of $500{\mu}s$, the threshold level for reliable ganglion cell response was found at 1.5V. The calculated threshold of charge density was $2.123mC/cm^2$. By varying the pulse duration from 100 to $1,200{\mu}s$ with fixed amplitude of 2V, the threshold level was found at $300{\mu}s$. The calculated threhold of charge density was $1.698mC/cm^2$. Even after the block of ON-pathway with L-(1)-2-amino-4-phosphonobutyric acid (APB), electrical stimulus evoked ganglion cell activities. In this APB-induced degenerate retina, by varying the pulse duration from 100 to $1200{\mu}s$ with fixed voltage of 2 V, the threshold level was found at $300{\mu}s$, which is the same with normal retina. More experiment with APB-induced degenerate retina is needed to make a clear comparison of threshold of charge density between normal and degenerate retina.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.05a
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• pp.476-479
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• 2020

본 논문은 전기 자극 장치에 관한 것으로서, 운동상황에 맞게 인공지능 기능이 음악을 선별해 주고 음악의 BPM(beats per minute)에 맞게 전기 자극 장치에서의 PWM(pulse width modulation)신호가 동기화 되어 재활 기능과 더불어 헬스 케어와 관련된 추가적인 기능 및 효과를 제공할 수 있는 개선된 전기 자극 장치에 관한 것이다. 언제 어디서나 간편하게 셀프 운동케어와 할 수 있도록 AR기술을 이용한 카메라가 있는 디지털 디바이스를 활용하며, 해당 신체의 운동부위를 지정하게 되면 이에 맞는 운동방법을 AI기술을 이용하여 적용할 수 있다. 수행자가 잘못 운동을 하는 것을 올바르게 개선시키기 위하여 실시간 AI 음성기능과 텍스트 코칭을 통해서 올바르게 운동할 수 있게 제안하며, 이에 대한 과정과 결과를 시각적으로 보여주면, 결과에 대해서는 리포팅을 하여 사용자가 올바르게 운동을 하고 효과적으로 운동을 했는지에 대해서 정량적인 수치의 운동횟수와 운동량에 대해서 표현해준다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.373-376
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• 2005

본 연구에서는 뇌의 반응과 말초신경계의 변화를 통하여 유머와 기쁨의 긍정적인 정서의 구분이 가능한가를 밝히고자 하였다. fMRI와 말초신경계 반응 측정 실험 각각을 수행하는 동안, 유머와 기쁨정서를 유발하는 동영상 자극(2분)이 제시되었고, 실험이 끝난 후 심리적인 평가도 함께 수행되었다. fURI 실험은 boxcar design으로 한 session 내에 두 block으로 구성되었다. 말초신경계 반응실험에서는 안정상태와 정서상태에서의 피부전기 반응을 측정하였다. fMRI 결과, 유머자극과 기쁨자극 제시 시 공통적으로 precentral Cortex, temporal Cortex, precuneus 가 활성화 되었고, 유머자극은 기쁨자극에 비하여 우측 middle temporal cortex, 우측 inferior frontal cortex, 좌측 middle frontal cortex 에서 큰 활성화를 보였다. 피부전기 반응(EDA) 분석 결과 두 정서 모두 안정상태에 비하여 유의하게 증가하였고, 유머자극은 기쁨자극에 비하여 피부전도수준(SCL)과 피부전도반응의 수(NSCR)에서 유의하게 증가하는 것으로 나타났다.

• Food Science of Animal Resources
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• v.22 no.3
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• pp.234-239
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• 2002

The use of electrical stimulation in the red meat processing has been inconsistent and the mechanism(s) associated with the improvement of meat quality in electrically stimulated carcass has been disputed. This may reflect an incomplete knowledge of how to optimise the technology and also mirrors the existence of unknown factors. Although it is well established that the stimulation treatment increases the rate of post-mortem glycolysis, other biochemical and biophysical effects have been implicated with the use of this technology. The classical view that stimulation prevents muscle from shortening excessively during rigor development has been expanded to include the possibility that it also results in physical disruption of muscle structure and early 'turn-on' of tenderizing process. However, the interaction of these effects with the acceleration of the rate of proteolysis through activation of the calpain pretense system has not been comprehensively unravelled. This mini-review attempts to examine the current theories about the effect of stimulation on post-mortem muscle.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.491-494
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• 2009

본 논문에서는 비우세 팔굽관절 굽힘근육에 원심성운동을 실시하여, 지연성근육통을 유발시킨 후, 자연치유과 경피신경전기자극치료, 그리고 냉치료의 효과를 조사하는데 그 목적이 있다. 자연치유군과 경피신경 전기자극치료군, 그리고 냉치료군의 평가를 위해 팔꿉관절의 운동시에 시상통증척도(VAS), 최대 염력, 실 효치 값을 측정하여 평가하였다. 대상자는 신체적 결함이 없는 30명의 성인을 대상으로 하였고, 대상자들은 지연성근육통 유발 후, 3개의 군인 자연치유군, 경피신경전기자극치료군, 냉치료군으로 나누었고, $60^{\circ}$/초의 등속성 각속도에서 최대 근력으로 운동시에 최대 연력과 실효치 값, 그리고 시상통증척도를 측정하여 평가하였다. 1. 시상통증척도는 경피신경전기자극치료군의 치료3일차에서 다른 군과 다른 기간에 비해 가장 낮은 수치를 나타내었고, 통계적으로 유의하였다(p<.05). 2. 최대 염력은 경피신경전기자극치료군의 치료3일차에서 다른 군과 다른 기간에 비해 가장 높은 수치를 나타내었고, 통계적으로 유의하였다(p<.05).3. 실효치 값은 경피신경전기자극치료군의 치료3일차에서 다른 군과 다른 기간에 비해 가장 높은 수치를 나타내었고, 통계적으로 유의하였다(p<.05). 이상의 연구 결과로 보아 경피신경전기자극치료는 지연성근육통에 대하여 자연 치유나 냉치료에 비해 더욱 효과적인 치료 방법임을 알 수 있다. 그러므로, 지연성근육통을 가진 환자의 치료 시에 경피신경전기자극치료의 적용은 권장되어야 한다.

• Journal of Periodontal and Implant Science
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• v.34 no.3
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• pp.551-562
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• 2004

The purpose of this study was to evaluate the effects of negatively electric field on bone healing in rabbit segmental long bone defects using negatively charged PTFE membrane. Ten millimeter segmental defects in the rabbit radius were used as the experimental model. After membranes were then charge injected using a corona-charging apparatus, the left defects were covered with non charged PTFE membranes as control groups, whereas the right defect was covered with negatively charged PTFE membranes as test group. The animals were divided into 4 groups of 2 rabbits each, and sacrificed at 2, 4, 6, and 8 weeks. Histomorphometric analysis showed a more newly formed bone in negatively charged membrane at early healing period. At 2 weeks, the proportion of new bone formation to total defect area was 0.32% in control group, 1.10% in experimental group. At 4 weeks, the proportion of new bone formation to total defect area was 6.86% in control, and 13.75% in experimental. At 6 and 8 weeks, no obvious difference was found between the two groups but newly formed bone in test groups were slightly more than that in control groups. In conclusion, negatively charged membranes showed more newly bone tissue than noncharged membranes at an early healing period. Although the number of samples was small, this study showed that the combination of negatively electrical stimulation and P1FE membrane may be of value in long bone healing.