• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.127-132
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• 2019

This study examined the change in the attention of University students after being given Transcranial Direct Current Stimulation (tDCS). The participants were divided randomly into two group (tDCS vs. Control). tDCS was applied to 37 university students ($23.08{\pm}3.33years$). The tDCS group was applied 2 mA, for 13 minutes twice over a 26 minute period ($n_1=19$). The control ($n_2=18$) was not applied after padding and was applied twice for 13 minutes over a 26 minute period. This study was conducted from September 3 to 28, 2018 and three times a week for a total of four weeks. The electroencephalogram was confirmed to affect attention. tDCS showed significant improvement in the results in the sensory motor rhythm wave (p<0.01, 95% CI: -1.955, -0.459), middle beta wave (p<0.05; 95% CI: 0.027, 0.943), and power ratio (p<0.01, 95% CI: -1.764, -0.315). The results showed that tDCS application increased the attention ability significantly. These results can be applied to attention deficit disorder (ADHD) patients and college students.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.10
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• pp.1193-1201
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• 2004

The effect of equivalence ratio and fuel/air mixing quality on the phase-resolved gas temperatures at different phases of the oscillating pressure cycle was experimentally investigated. An atmospheric pressure, optically accessible and laboratory-scale dump combustor operating on methane with heat release rate of 1.59kW was used. Temperature measurements were made using coherent anti-Stokes Raman spectroscopy (CARS) at several spatial locations fur typical unstable combustion conditions. Analysis was conducted using parameters such as phase-resolved averaged temperature, normalized standard deviation and temperature probability distribution functions (PDFs). Also the probability on the occurrence of high temperature (over 1900K) was investigated to get the information on the perturbation of equivalence ratio and NOx emission characteristics. It was shown that most of temperature histograms exhibit Gaussian profile which has short breadth of temperature fluctuation at equivalence ratio of 0.6, while beta profile was predominant for the cases of other equivalence ratios (${\Phi}$=0.55, 0.50). It was also shown that phase-resolved averaged temperature oscillated in phase with pressure cycle, while normalized standard deviations which represent temporal turbulent intensity of temperature showed nearly constant value around 0.1. The characteristics on the occurrence of high temperature also displayed periodic wave form which was very similar to the pressure signal. And the amplitude of this profile went larger as the fuel/air mixing quality became poorer. These also provided additional information on the perturbation of equivalence ratio at flame as well as NOx emission characteristics.

• Korean Journal of Biological Psychiatry
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• v.4 no.1
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• pp.54-59
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• 1997

Objects : Sanjoin, the seeds of Zizyphus vulgaris var. spinosus has been used as the most important hypnotic agent in chinese medicine to treat insomnia. This research was performed in order to examine the effect of betulinic acid and sanjoinine-A which are components of Sanjoin. Method : Sleeping time, sleep recordings of EEG, EMG, serum serotonin level, and locomotor activity were measured in rats which received betulinic acid and sanjoinine-A as sleep induction material extracted from Sanjoin. Results : 1) Groups received betulinic acid, sanjoinine-A, and lorazepam showed increased sleep time than control group with saline. 2) Groups with betulinic acid, sanjoinine-A, lorazepam and saline recorded ${\beta}$-wave in sleep recordings of EEG. In EMG, there was no significant difference among all groups. 3) No significant difference in serum serotonin level among all groups was found. 4) In autonomic activity testing, groups of betulinic acid, sanjoinine-A, and lorazepam showed significantly more decreased in activity than saline group. In comparison of groups of betulinic acid and sanjoinine-A with a group of lorazepam, there was no significant difference. Conclusion : These results suggest that betulinic acid and sanjoinine-A have the sedative effect like lorazepam rather than sleep effect.

• The Journal of Korean Physical Therapy
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• v.18 no.2
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• pp.47-58
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• 2006

Purpose: The study to pulsed ultrasound effects of diabetes mellitus fracture model in rat. Methods: We used 36 Sprague-Dawely rats which were divided into 3 groups; the animals were divided into group of 4 rats each 4th, 14th and 28th days. All animal was induced diabetes mellitus model to used streptozotocin with 45 mg/kg. Pulsed wave were divided into $50\;mW/cm^2$ and $100\;mW/cm^2$. Results: T-ALP value was significantly change from group II, III on 14th, 28th days (p<0.05). Especially T-ALP value to between groups was significantly change from group II on 14th days (p<0.05). Osteocalcin value was significantly change from group II on 28th days(p<0.05). At fracture site, osteoblast, osteoclast expression was observed from 4th days after treatment and it reached its maximum intensity at 28th days. At fracture site, $TGF-{\beta}_1$ expression was observed from 4th days after treatment and it reached maximum intensity at 14th days. Conclusion: According to this study, diabetes mellitus fracture model to the more effective is divided into $50m\;W/cm^2$ pulsed ultrasound.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.4
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• pp.505-512
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• 2013

PURPOSE: The purpose of this study applied computerized cognitive therapy and proprioception exercise to stroke patients and analyzed improvement in their changes in Electrocephalogram(EEG). METHODS: The subjects were 30 patients who were diagnosed with stroke and they were randomly selected to a proprioceptive training group(n=15), a cognitive training group(n=15). The experiment was performed for three times per week for 6 weeks and EEG was measured before and after the experiment. RESULT: Before and after the experiment in each group of experiments, the ${\alpha}$-and ${\beta}$-wave study showed significant changes but, there was no significant difference in the change between groups before and after the experiment. CONCLUSION: From the above results, the cognitive training and the proprioception training have a positive impact in stroke patients EEG changes, but it is difficult to suggest a better therapeutic interventions. However, as compared with that the cognitive training that directly involved in the cognitive and brain activation, the proprioception training have changes on brain activation. Therefore, of Clinical therapeutic interventions, the proprioception training can be presented effectively to the changes in brain activation in stroke patients.

• Journal of Acupuncture Research
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• v.28 no.2
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• pp.27-41
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• 2011

Objectives : The aim of this study was to examine the effect of manual acupuncture at the bilateral $LI_4$, $ST_{36}$ and $LR_3$ on normal human every 3 minute time interval by using power spectrum analysis. Methods : 25 healthy volunteers participated in this study. 32 channel EEG(Electroencephalogram) measurements were carried out before, during and after acupuncture treatments. In this study, power spectrum was used as a measure of complexity. Statistical analysis was performed using repeated measure ANOVA and Bonferroni method. Results : 1. In acupuncture group, Mean HRT, PSI, Normalized HF decreased significantly. SDNN, Ln(TP), Ln(LF), Ln(VLF), Normalized LF and LF/HF ratio increased significantly. RMSSD, Ln(HF) were not affected. 2. In sham acupuncture group, all indicators were not affected. 3. In control group, mean HRT, Ln(TP) decreased significantly. SDNN, RMSSD, PSI, Ln(LF), Ln(HF), Ln(VLF), normalized LF, normalized HF and LF/HF ratio were not affected. Conclusions : This results suggest that manipulation needling of 6 acupoints induced increase of delta, theta, beta waves. Both manipulation and simple needling induced decrease of alpha wave during 12~15 time intervals.

• Journal of Korean Physical Therapy Science
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• v.26 no.3
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• pp.1-7
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• 2019

Purpose: The purpose of this study was to investigate the effects of the Otago exercise combined with action observation training on changes of the brain activity of the elderly. Design: Randomized controlled trial. Methods: Thirty elderly women in the experiment were included. Participants were randomly assigned to the Otago combined with action observation training group, the Otago exercise group, and the control group (10 in each group). The Otago combined with action observation training group and the Otago exercise group performed the strength and balance exercises of the Otago exercise program for 50 minutes three times a week for 12 weeks. The Otago combined with action observation training group underwent additional action observation training for the Otago movement for 20 minutes three times a week. No intervention was performed in the control group. PolyG-1 (LAXTHA Inc., Daejeon, Korea) was used to measure the changes in the brain activity following intervention. One-way analysis of variance was used to compare the effects among the groups and a post-hoc test was performed. Results: The relative mu rhythms in the F3, C3, and C4 regions were significantly increased in the Otago combined with action observation training group. Relative beta wave activity in the Fp1, F3, F3, and C3 regions was significantly increased in the Otago combined with action observation training group (p<0.05). Conclusion: The results indicated that the Otago exercise combined with action observation training was effective for promoting the brain activity of the elderly.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.185-185
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• 2011

기존 장대레일 궤도의 안정성 평가는 궤도 매개변수에 대하여 고정된 안전측의 값을 사용하는 결정론적인 해석에 의존해서 평가되어져 왔다. 그러나 실제현장의 궤도조건은 많은 영향인자들에 의해 그 특성이 불확실하게 변하고 있다. 따라서 온도하중에 의한 궤도 좌굴에 영향을 미치는 궤도 구성인자들의 불확실성 및 임의성을 보다 합리적으로 고려하기 위해서 확률론적 기법을 적용하는 것이 필수적이다. 본 연구에서는 기존 본 연구진에 의해 개발된 장대레일 궤도의 좌굴확률 평가시스템을 이용하여 좌굴 취약도 곡선을 나타내었으며, 궤도 좌굴에 영향을 미치는 주요변수 중 하나인 도상횡저항력에 대한 영향을 분석하였다. 좌굴확률 평가시스템에서는 장대레일 궤도의 좌굴확률을 산정하기 위하여 구조물의 안정과 파괴를 판단할 수 있는 기준을 한계상태방정식으로 표현하고, 이 한계상태방정식으로부터 확률론적 기법 중 하나인 AFOSM(Advanced First Order Second Moment) 방법을 이용하여 파괴확률의 간접적인 지표인 신뢰도지수(${\beta}$)를 통해 좌굴확률을 계산한다. 한계상태방정식에서 구조물의 강도(보유성능)에 해당하는 부분은 궤도의 허용좌굴온도이고, 하중(요구성능)에 해당하는 부분은 레일온도하중으로써 현재 레일온도와 중립온도의 차로 반영된다. 허용좌굴온도 산정에 고려되는 주요변수는 곡선반경(Radius), 도상횡저항력(Lateral Ballast Resista nce), 연직도상강성(Vertical Ballast Stiffness), 궤도 틀림량(Misalignment), 틀림길이(Half Wave Length), 열차운행속도(Velocity)이다. 각 확률변수들이 갖는 확률분포는 모두 정규분포로 가정하였다. 궤도의 기하학적 특성은 곡선반경 5,000m에 대해 고려하였으며, 열차는 KTX의 제원을 사용하여 정지된 상태에서 고려하였다. 틀림량과 틀림길이는 이에 대한 통계적 특성자료가 부족하여 확률변수로 고려하지 않고 결정론적 값으로 취급하였다. 레일온도의 통계적 특성치는 본 연구진에 의해 구축된 기후요소 및 레일온도 DB를 근거로 결정하였으며, 중립온도는 선로관리지침에 따라 $25{\pm}3^{\circ}C$를 기준으로 결정하였다. 또한 도상횡저항력은 실측 데이터를 참고로 하여 평균값에서 10%의 변동량을 갖는 것으로 보고 통계적 특성치를 결정하였다. 도상횡저항력이 좌굴확률에 미치는 영향을 매우 큰 것을 알 수 있었으며, 레일온도 $60^{\circ}C$일 때 도상횡저항력이 증가하면서 감소되는 좌굴확률이 도상저항력이 커질수록 그 감소량이 작아지는 것을 알 수 있었다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.9
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• pp.1286-1293
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• 2014

Typically, studies through the simulation system have been progressed, because the evaluation of the driver's arousal state about the service of a actual train has risk of safety for the driver. When configured event same as the real in simulation system, the ability to cope with an accident situation may be the same each other. But the difference in the state of tension or arousal will occur. In this study, requested to cooperate with the railways in order to escape from these constraints, and the target of the experiment was to real engineer service. I was set about experiment when the train was stopped as safe as possible. As a result, the beta wave of EEG signals that representing complex calculations or anxiety is increased rapidly on the basis of a flag station from at the time of departure. The size of the electrodermal activity signal in response to movement of the body gave a noticeable. In terms of HRV, if the train approach a flag station gradually and the R-R interval is narrowed. So that the driver can be estimated as arousal state. In accordance with this study, if the quantitative standard of arousal state be based on the driver's biosignals will provide, it will be able to take advantage of development the system that would prevent train accidents caused by human error.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.4
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• pp.193-198
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• 2006

Many gastrointestinal muscles show electrical oscillation, so-called 'slow wave', originated from interstitial cells of Cajal (ICCs). Thus, a technique to freshly isolate the cells is indispensable to explore the electrophysiological properties of the ICCs. To apply an enzyme solution on the serosal surface for cell isolation, the intestine was inverted and 0.02% trypsin solution and 0.04% collagenase solution were applied to serosal cavity. After the enzyme treatment, mucosal layer was removed and longitudinal muscle layer was gently separated from the rest of tissue. The thin layer was stretched in the recording chamber and mounted on an inverted microscope. Using ${\beta}-escine$, perforated whole cell patch clamp technique was used. Under a microscope, the tissue showed smooth muscle cells and interstitial cells around the myenteric plexus. Under voltage clamp condition, three types of membrane potential were recorded. One group of interstitial cells, which were positive to methylene blue and CD34, showed spontaneous outward current. These cells had bipolar shape and were considered as fibroblast-like cells because of their peculiar shape and arrangement. Another group, positive to c-kit and methylene blue, showed spontaneous inward current. These cells had more rounded shape and processes and were considered as ICCs. The third, positive to c-kit and had granules containing methylene blue, showed quiet membrane potentials under the voltage-clamp mode. These cells appeared to be resident macrophages. Therefore, in the freshly isolated thin tissue preparation, methylene blue could easily identify three types of cells rather than morphological properties. Using this method, we were able to study electrical properties of fibroblast and residential macrophage as well as myenteric ICCs.