• 한국산학기술학회논문지
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• 제15권1호
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• pp.547-554
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• 2014

본 논문에서는 3가지 음원의 a지수가 피험자에게 미치는 영향과 피험자의 안정성, 집중력 및 생산성을 향상 시킬 수 있는 최적의 음원의 a지수를 찾기 위한 연구를 하였다. 피험자는 건강상태를 점검하여 남자 5명과 여자 5명의 대학생 10명으로 선별하였고 실험기간은 약 2달간 진행되었다. 뇌파(EEG), 심박동변이(HRV) 및 진동이미지를 측정하여 안정성, 집중력, 스트레스 및 심장박동의 변화를 분석하였다. 온도 $25[^{\circ}C]$, 상대습도 50[%], 조도 1.000[lux] 및 기류속도 0.02[m/sec]의 인공기후실 에서 음원의 a지수 a=1.106, a=1.749 및 a=2.227의 음원을 이용하여 측정하였다. 연구결과 a=1.106에서 음원에 노출되기 전에 비하여 상대 $S{\alpha}$파, 상대 $L{\beta}$ 및 상대 $M{\beta}$파가 활성화 되었으며 비대칭지수, 스트레스지수 및 심박변이도는 감소하였다. 따라서 변동리듬 a=1.106의 음원이 안정성, 집중력 및 생산성 향상과 스트레스 감소에 가장 효과적인 것을 알 수 있었다.

• 천문학논총
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• 제12권1호
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• pp.35-45
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• 1997

SOFT($\underline{So}lar\;\underline{F}lare\;\underline{T}elescope$) installed at BOAO(Bohyunsan Optical Astronomy Observatory) is purposed for observing solar active regions using four refractors on single mount with a $400"\times300"$ field of view: Two refractors with a diameter of 15cm(f15) are observe the white light and $H\alpha$, and the other two refractors with a diameter of 20cm(f8) are observe the magnetic field distribution and Doppler shifts at the solar chromosphere. Three Lyot filters, one of the most important observational instruments, are installed on the optical rails for VMG, LMG, and $H\alpha$ that possible to very narrow pass band observation under high precision stability of temperature. From the combination of KD*P and quarter wave plate in the Lyot filter possible observe the magnetic fields strength and doppler shifts by using the characteristics of polarization components. In this paper, we introduce the basic characteristics, optical system, and monitor system of the SOFT.

• 디지털융복합연구
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• 제10권9호
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• pp.289-295
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• 2012

기존 연구에서 에너지 소비의 효율성을 향상하기 위해 제시된 무선 센서 네트워크의 라우팅 기법은 다양하게 존재하지만 라우팅을 위해서는 자신의 위치 정보와 1 홉(hop) 거리에 인접한 주변 노드들의 위치 정보를 유지해야 한다. 그리고 BS 노드로 데이터를 전송하기 위하여 여러 노드를 경유하여 목적지까지 전송하는 다중 홉(Multi-hop) 전송 방식을 사용한다. 이러한 기법은 네트워크의 전체적인 에너지 소모와 센서 노드의 전력 소모를 발생시켜 효율적인 에너지 관리에 문제가 발생한다. 따라서 본 논문에서는 센서 노드의 전파 범위와 RSSI를 이용하여 소스 노드와 거리 $d{\pm}{\alpha}$를 만족하는 BS 노드의 위치 기반 1-홉 라우팅 기법을 제안한다.

• Perspectives in Nursing Science
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• 제14권2호
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• pp.64-69
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• 2017

Purpose: Breathing can be controlled either unconsciously or consciously. In Asian countries, various conscious breathing-control techniques have been practiced for many years to promote health and wellbeing. However, the exact mechanism underlying these techniques has not yet been established. The purpose of this study is to explore the physiological mechanism explaining how conscious breathing control could affect the autonomic nervous system, brain activity, and mental changes. Methods: The coupling phenomenon among breathing rhythm, heart rate variability, and brain waves was explored theoretically based on the research hypothesis and a review of the literature. Results: Respiratory sinus arrhythmia is a well-known phenomenon in which heart rate changes to become synchronized with breathing: inhalation increases heart rate and exhalation decreases it. HRV BFB training depends on conscious breathing control. During coherent sinusoidal heart rate changes, brain ${\alpha}$ waves could be enhanced. An increase in ${\alpha}$ waves was also found and the synchronicity between heart beat rhythm and brain wave became strengthened during meditation. Conclusion: In addition to the effect of emotion on breathing patterns, conscious breathing could change heart beat rhythms and brainwaves, and subsequently affect emotional status.

• 감성과학
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• 제7권4호
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• pp.51-56
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• 2004

본 연구의 목적은 각각의 색채 자극 하에서의 생리신호를 측정하고자 하였다. 실험에 사용된 색채는 빨강, 노랑, 녹색, 파랑, 보라, 그리고 백색을 사용하였다. 실험은 방음 암실에서 이루어졌으며, 건강한 성인 남, 여 30명을 대상으로 하였다. 생리신호의 측정은 뇌파와 심전도를 측정하였다. 뇌파의 실험결과는 차가운 색 계통의 색채에서 $\alpha$파의 상대 전력비가 증가한 것을 볼 수 있었다. 또한 심전도의 HRV 분석 결과도 차가운 색 계통에서 HF/LF의 비가 증가한 것을 볼 수 있었으며, 이 결과로서 색채 조명이 인체의 감성변화에 영향을 미치는 것을 알 수 있었으며, 이 결과를 활용하여 색채 환경 설계에 도움을 줄 수 있으리라 사료된다.

• 전기학회논문지
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• 제57권10호
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• pp.1822-1828
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• 2008

This paper presents design parameter calculation methodology and its realization to construction for the 10/350${\mu}s$ lightning impulse current generator(ICG) modelled as double exponential function waveform with characteristic parameters ${\alpha},{\beta}$. Matlab internal function, "fzero" was applied to find ${\lambda}={\alpha}/{\beta}$ which is solution of nonlinear equation linearly related with two wave parameter $T_1$ and $T_2$. The calculation results for 10/350${\mu}s$ lightning impulse current show very good accuracy with error less 0.03%. Two type of 10/350${\mu}s$ ICGs based on the calculated design circuit parameters were fabricated by considering the load variation. One is applicable to the MOV based Surge protective device(SPD) for less 15 kA and the other is to test small resistive devices such as spark gap arrester and bonding device with maximum current capability 30 kA. The tested waveforms show error within 10% in comparison with the designed estimation and the waveform tolerance recommended in the IEC 61643-1 and IEC 60060-1.

• The Korean Journal of Physiology and Pharmacology
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• 제22권1호
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• pp.17-21
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• 2018

Our previous studies have confirmed that morroniside has neuroprotective effects. However, the effects of morroniside on cardiac myocardium remain unknown. Rats were anaesthetized with 10% chloral hydrate (0.35~0.4 mL/kg) and an acute myocardial infarction (AMI) was induced by ligating the anterior descending coronary artery (LAD). Following AMI, morroniside was administered intragastrically for 3 consecutive days at doses of 45, 90 and 180 mg/kg, respectively. Lactate dehydrogenase (LDH) and cardiac troponin T (cTnT) activities in AMI rats in the serum were detected with commercial kits. The expression of IL-6, $IL-1{\beta}$ and $TNF-{\alpha}$ in myocardium was detected by Western blotting analysis. We observed a significant decline in the Q(q) wave amplitude in morroniside-treated rats after 72 h. Additionally, treatment of morroniside decreased the levels of LDH and cTnT in AMI rats. We also observed that morroniside reduced the expression of IL-6, $IL-1{\beta}$ and $TNF-{\alpha}$ in myocardium. Taken together, our findings demonstrate that morroniside had effective anti-inflammatory properties in AMI rats.

• 약학회지
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• 제30권6호
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• pp.311-316
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• 1986

A new UV labeling reagent was developed and used in HPLC for the determination of prostaglandin $E_2$ which have weak UV light-absorbing property. This reagent, 2-bromoacetyltriphenylene, was synthesized by the bromination of 2-acetyltriphenylene which was obtained from triphenylene by Friedel-Crafts reaction. The wave length maximum (${\lambda}_{max}^{CH_3CN}$ of this reagent was 268nm. Prostaglandin E$_2$ was extracted from prostaglandin E$_2$-$\beta$-cyclodextrin using a Sep-pak $C_{18}$ cartridge. The prostaglandin E$_2$ was labeled with 2-bromoacetyl-triphenylene in aectonitrite using 18-crown-6-ether as catalyst. Derivatized prostaglandins were separated on a reversed-phase column (Radial-pak) $\mu$-Bondapak $C_{18}$ using acetonitrile: water=60:40 as mobile phase. The effluent was monitored by UV detector at 254nm filter kit. Linearity of calibration curve was obtained between 30ng and 140ng, and the lower limit of detection was 5ng.

• 대한인간공학회지
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• 제32권5호
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• pp.421-427
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• 2013

Objective: This paper is to analyze the impact of musical training to the fast ${\alpha}$ wave activation of the EEG. Background: EEG is neurological research method that can observe the brain function in real time. EEG can be used to determine the nervousness and relaxedness of a person who receives stimuli in a structured environment. Therefore, it is possible to interpret the functional state of human brain by the analysis of EEG. Method: The brain activities of two groups of university students in the point of RFA(Relative Fast Alpha) caused by different music are analyzed in this paper. One is the group of music majors and the other is the group of non-majors. Results: Music major and non-major groups show meaningful differences in RFA during exposed to classic and metal music. Conclusion: Learning experience on music affects RFA increment of music majors. Application: The result of this study will be used as basic data to evaluate the learning effects of students who want to study music.

• 한국재료학회지
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• 제12권1호
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• pp.44-47
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• 2002

DV(Discrete Variation)-X${\alpha}$ cluster calculation was employed to calculate the electronic states of ${\gamma}'- Fe_4N$ which was one of iron nitride phases synthesized from plasma ion nitriding to improve surface hardness and wear resistance. The result of calculated electron density of states for Fe was similar to the result of band calculation. The cluster used for calculation of electronic states of ${\gamma}'-Fe_4N$ was based on $Fe_{14}N$ cluster which comprises 15 atoms. Finally the electronic states of ${\gamma}'- Fe_4N$ such as net-charge, band order, energy level, electron wave-function, and contour map for electron density were derived by the calculation.