Application of Ultrasonic Wet-Magnetic Separation Method to Prepare Nano-sized Mg<SUB>x</SUB>Ni<SUB>y</SUB>Zn<SUB>1-x-y</SUB>Feu₂O₄

구문선,최용 한국표면공학회 2016 한국표면공학회 학술발표회 초록집 Vol.2016 No.11

Finite Element Analysis of Combustion Reaction on Iron and Metal Oxides Interface

구문선,최용 한국표면공학회 2017 한국표면공학회 학술발표회 초록집 Vol.2017 No.5

기분과 성격특성이 정신생리적 반응에 미치는 영향

구문선,유범희,Koo, Moon-Sun,Yu, Bum-Hee 대한수면의학회 2001 수면·정신생리 Vol.8 No.1

목 적 : 본 연구는 정상인에서 바이오피드백 시스템으로 측정된 정신생리적 변인들과 기분 및 성격 특성에 미치는 영향을 알아보고자 하였다. 방 법 : 광고를 통해 모집한 내과적, 정신과적 질환의 병력이 없는 건강한 성인남녀 50명을 대상으로 스필버거 특성불안척도, 베크 우울척도, 성인용 아이젱크 성격검사를 측정하였다. 정신생리학적 변인은 J & J 바이오피드백 시스템을 이용하여 말초피부 온도, 피부전도 반응, 전완 근전도, 전두근 근전도의 수준을 기저기, 스트레스기, 회복기의 3시기로 나누어서 측정하였다. 또한 각 심리척도의 상위 10명, 하위 10명을 고집단(고불안, 고우울, 외향성, 고신경증)과 저집단(저불안, 저우울, 내향성, 저신경증)으로 분류하여 고/저 집단간의 정신생리적 반응의 차이를 t-test, repeated measures ANOVA, Pearson 상관분석을 통해 살펴보았다. 결 과 : 특성불안과 정신생리적 반응과의 관계를 살펴보았을 때, 전완 근전도의 스트레스 반응만이 특성불안과 유의한 상관관계를 나타냈을 뿐(r=0.282, p<0.05), 다른 정신생리적 반응과 연관성은 관찰되지 않았다. 우울감은 기저기와 회복기의 전완 근전도에서 각각 부적 상관관계를 나타냈다(r=-0.299, p<0.05;r=-0.314, p<0.05). 고우울 집단과 저우울 집단을 비교한 결과 전두근 근전도가 스트레스와 회복반응에서 유의한 상호작용 효과를 나타냈다 (F=4.26, p<.05). 외향적인 집단은 내향적인 집단에 비해 스트레스기에 측정된 전완 근전도가 높은 것으로 나타났다. 결 론:본 연구를 통해 정상인에게서 기분과 성격 특성은 바이오피드백 시스템으로 측정한 정신생리적 반응과 연관이 있음을 확인했다. 이는 각종 정신과적 장애에서 동반되는 정신생리적 변인의 이상소견을 해석하는데 있어 반드시 고려해야 할 점으로 생각된다. Objectives: This study examined the effect of mood and personality characteristics on psychophysiological responses measured by a biofeedback system in a normal population. Methods: Fifty healthy volunteers without any history of medical or psychiatric illnesses participated in this study. We measured the Spielberger trait anxiety inventory, Beck depression inventory, and Eysenck personality questionnaires in these subjects. Using the J & J biofeedback system, we also measured skin temperature, electrodermal response, forearm and frontal electromyography (EMG)s in 3 experimental conditions of baseline, stress, and recovery phases. Results: Trait anxiety did not show any significant correlation with psychophysiological responses except stress response in forearm EMG levels(r=0.282, p<0.05). Depressed mood was negatively correlated with forearm EMG levels in baseline (r=-0.299, p<0.05) and recovery phases(r=-0.314, p<0.05). Subjects with relatively high levels of depressed mood showed different stress and recovery responses in frontal EMG levels compared with those with relatively low levels of depressed mood (F=4.26, p<0.05). Extroverted subjects showed higher levels of forearm EMG than introverted ones in stress phase. Conclusion: Mood and personality characteristics in healthy subjects are closely related with psychophysiological responses measured by a biofeedback system. We suggest that mood and personality characteristics should be considered as important variables in analyzing abnormal psychophysiological responses in some psychiatric patients.

불면증의 바이오피드백 치료

구문선,유범희,Koo, Moon-Sun,Yu, Bum-Hee 한국정신신체의학회 2006 정신신체의학 Vol.14 No.1

불면증은 다양한 신체적, 정신적 원인에 의해 생기는데, 특히 과잉각성은 불면증에 중요한 영향을 미친다고 알려져 있다. 불면증 환자에서 약물치료에 한계가 있으며 심리적 요인이 불면증의 발생과 경과에 큰 영향을 미친다는 사실이 알려지면서, 여러 가지 비약물치료적 방법이 도입되었다. 바이오피드백을 포함한 비약물치료는 불면증 치료에 효과적이며 치료 효과도 오래 유지되는 것으로 보고되었다. 바이오피드백은 이완요법과 함께 사용 시 불면증 환자의 각성 수준을 낮춰 수면의 시작 및 유지에 도움이 되므로, 각성 수준이 높거나 약물 사용에 제한이 따르는 불면증 환자에게 매우 유용할 수 있다. Insomnia is associated with numerous psychiatric and physical conditions, and hyperarousal is known to play an important role in the development of insomnia. There are a lot of limitations to use hypnotic medications for the treatment of insomnia. As psychological factors can greatly affect the development and progress of insomnia, several non-pharmacological treatment methods have been used for insomnia. Biofeedback is effective in the treatment of insomnia and its treatment effect lasts considerably long. Biofeedback together with relaxation techniques can reduce levels of arousal in insomnia patients so that they are effective for induction and maintenance of sleep. In conclusion, biofeedback treatment seems to be very helpful for insomnia patients who show high levels of arousal and have limitations in the use of hypnotic medications.

울릉도와 독도 생성시기의 동해 퇴적물의 광물학적 연구 (Site U1430, IODP Expedition 346)

구문선(Moonseon Koo),박한범(Hanbeom Park),김진욱(Jinwook Kim) 한국암석학회 2021 한국암석학회 학술발표회 논문집 Vol.2021 No.8

초음파 습식 자기분류법을 이용한 Mg<SUB>x</SUB>Ni<SUB>y</SUB>Zn<SUB>1-x-y</SUB>Fe<SUB>2</SUB>O<SUB>4</SUB> 나노입자 제조

구문선(Moon Sun Gua),권혁주(Hyuk Joo Kwon),최용(Yong Choi) 한국표면공학회 2017 한국표면공학회지 Vol.50 No.3

MgxNiyZn1-x-yFe2O4 ferrite powders were prepared by self-propagating high temperature synthesis followed by classifying with an ultrasonic wet-magnetic separation unit to get high pure nano-sized particles. The MgxNiyZn1-x-yFe2O4 ferrites were well formed by using several powders like iron, nickel oxide, zinc oxide and magnesium oxide at 0.1 MPa of oxygen pressure. The ultrasonic wet-magnetic separation of pre-mechanical milled ferrite powders resulted in producing the powders with average size of 800 nm. The addition of a surfactant during the wet-magnetic separation process improved productivity more than twice. The coercive force, maximum magnetization and residual magnetization of the MgxNiyZn1-x-yFe2O4 nano-powders with 800 nm size were 3651 A/m, 53.92 Am<SUP>2</SUP>/kg and 4.0 Am<SUP>2</SUP>/kg, respectively.

유한요소법에 의한 수학적 모델링을 활용한 준-나노 Cu_xNi_yZn_1-x-yFe₂O₄ 페라이트 연소합성

구문선 ( Moon Sun Gu ),최용 ( Yong Choi ) 대한금속ㆍ재료학회 2017 대한금속·재료학회지 Vol.55 No.11

Numerical modeling of the self-propagating high temperature synthesis (SHS) of Cu_xNi_yZn_1-x-y Fe₂O₄ ferrites was carried out using the finite element method, to control the combustion synthesis behaviors of the ferrites. Additional pre-heating above 300 ℃ caused the combustion temperature at the inner surface of the reactant compact to completely propagate the SHS reaction. The porous Cu_xNi_yZn_1-x-yFe₂O₄ ferrites formed by the SHS were ball-milled and then magnetically separated and classified to obtain quasi-nano-sized powders. The reitveld refinement estimated that the SHS product formed at room temperature was about 64% ternary ferrites, while that formed with 598 K preheating was about 85% ternary ferrites. (Received May 12, 2017; Accepted July 19, 2017)

정상인에서 측정한 바이오피드백의 정신생리학적 특징

김율리,구문선,김의정,유범희,Kim, Youl-Li,Koo, Moon-Sun,Kim, Eui-Jung,Yu, Bum-Hee 대한수면의학회 2002 수면·정신생리 Vol.9 No.1

본 연구는 정상인을 대상으로 바이오피드백 시스템으로 측정된 정신생리적 반응의 특징을 파악하는 것을 목적으로 시행되었다. 연구 결과 20대에서 피부전도반응이 다른 연령대에 비해 유의하게 높았으며, 여성에서 전두부 근전도가 남성에 비해 유의하게 높았다. 한편 정상인에서 바이오피드백 측정치와 자가 평가한 기분 변수와는 관련이 없는 것으로 나타났다. 본 연구의 결과는 향후 바이오피드백 시스템 기기를 이용하여 평가를 할 때 성별, 연령별 특징을 고려해야 함을 시사한다. 본 연구에서 제시된 정신생리변수에 관한 중요한 특징들은 향후 동종의 바이오피드백 시스템을 이용한 연구결과를 비교하는 데 도움이 될 것으로 기대된다. Objectives: This study is aimed at measuring psychophysiological responses using a biofeedback system in healthy people to obtain basic normative data for biofeedback research and treatment. Methods: Ninety-six healthy volunteers (55 males and 41 females : average age $30.4{\pm}8.0$) without any history of major medical or psychiatric illnesses participated in this study. Psychophysiological responses were assessed using the ProComp+ and BioGraph program (ver. 2.1) with regard to forearm and frontal electromyography (EMG), electrodermal response (EDR), and skin temperature. They were measured in 3 phases (baseline, stress, and recovery phases), respectively. Beck depression inventory and Spielberger state and trait anxiety inventory were used to measure mood states. We compared psychophysiological responses according to age and gender differences, respectively and examined the relationship between mood states and psychophysiological measures. Results: People in their twenties showed higher EDR levels in the 3 phases than those of other age groups. Female subjects showed higher frontal EMG levels in the 3 phases compared with male subjects. There was no significant correlation between biofeedback measures and mood states in these subjects. Conclusion: We present normative data of psychophysiological responses measured by a biofeedback system in healthy people. These results suggest that gender and age should be considered as important variables in assessing psychophysiological responses using a biofeedback system.

공황장애 환자에서 파록세틴 약물 치료가 바이오피드백 측정 변수들에 미치는 영향

류한욱,구문선,유범희 대한정신약물학회 2004 대한정신약물학회지 Vol.15 No.4

Objective There have been much effort to find reliable indicators predicting treatment response in panic disorder. This study aimed to find the effect of pharmacotherapy on biofeedback measurement variables in panic disorder patients. Method We recruited 38 panic disorder patients(M;25, F;13) in the Samsung Medical Center, who were diagnosed by the ADIS-IV(Anxiety Disorder Interview Schedule-IV), and 33 normal control subjects (M;21 F;12 ). Panic patients were treated with paroxetine for 3 months. All subjects were assessed on forearm and frontal electromyography(EMG), electrodermal response(EDR), and skin temperature in baseline, stress, recovery phases using the Procomp & Biograph biofeedback instrument. Psychological measures such as Hamilton anxiety rating scale(HAM-A), Hamilton depression rating scale(HAM-D), Beck depression inventory( BDI), Spielberger state-trait anxiety inventory(STAI-S, STAI-T), and Anxiety sensitivity index(ASI) were also assessed. All measurements were performed at the beginning of the study and after 3 months of paroxetine treatment. Result Panic patients had significantly higher scores on psychological measures such as HAM-A, HAM-D, BDI, STAI-S, STAI-T, and ASI(all p values<0.001) before treatment. After 3months of treatment, panic patients showed significant improvement on baseline EDR(z=-2.824, p=0.005), stress EDR(z=-2.691, p=0.007), and recovery EDR (z=-3.416, p=0.001). They also showed significant improvement on HAM-A, HAM-D, BDI, STAI-S, STAI-T, and ASI(all p values <0.001) after treatment. Conclusion Electrodermal response, one of the biofeedback measurement variables, was suggested to be the possible indicator predicting treatment response in panic disorder.

한국인 만성 긴장형두통 환자에서 바이오피드백을 활용한 자율적 이완훈련의 효과

강은호,안주연,구문선,박주언,유범희 大韓神經精神醫學會 2008 신경정신의학 Vol.47 No.3

Objectives : We aimed to evaluate the efficacy of biofeedback-assisted autogenic training for chronic tension-type headache, and to determine the relationship among the changes in electromyography (EMG) activity, headache activity, and mood states according to the psychophysiological treatment. Methods : Chronic tension-type headache patients aged from 20 to 40 years (n=35) were randomized to the treatment group receiving biofeedback-assisted autogenic training (8 sessions) or the monitoring-only control group. EMG activities, headache index, and various psychological variables were examined. Results : We found greater treatment response rate (≥50% reduction in headache index) in patients with biofeedback-assisted autogenic training than in the monitoring group (61% vs. 18% ; χ²=6.882, df=1, p=0.01). There were no significant changes in the mean values of the pretreatment EMG activities across the sessions m either group (all p’s>0.1). Mood states including anxiety and depression improved over time in the both groups, with the improvements being more prominent in the treatment group. Moreover, the reduction in depression level predicted treatment outcome in terms of headache index (95% confidence interval : 0.272-0.966, p=0.039). Conclusion : These results show that biofeedback-assisted autogenic training is effective for the treatment of chronic tension-type headache in a Korean population. Changes in mood states may be closely associated with the clinical outcome in the treatment of chronic tension-type headache using biofeedback-assisted autogenic training.