Measurement of burning velocity for bare strand casted with a frozen mixture of nano/micro-aluminum particles and water

Jinyong Jun,Byeong-Jun Lee,DongJooSong 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.5

Combustion characteristics of a mixture of nano- and micron-sized aluminum powder in ice were experimentally studied. Round barshaped bare strand was casted with a frozen mixture of aluminum and water and then electrically ignited in the air or argon environment. Propagating flame was recorded using a camcorder with an optical filter. Burning rate, defined as the slope in the graph of average flame position movement versus time, was also evaluated. The burning velocity peaked at equivalence ratio (f) of 0.8. Flame propagation velocity increased with a pressure exponent of 0.61 for f = 0.8 and pressure range of 0.1–0.8 MPa. For nano/micro-mixture at f = 0.8, flame propagation was not feasible if the mass fraction of micron-sized particles in fuel is higher than 0.5.

Analysis of Electroencephalogram and Electrocardiogram at an Acupoint PC9 during Pulsed Magnetic Field Stimulus

Jinyong Lee,Do Gwen Hwang,Jun Sang Yoo,Hyun Sook Lee 한국자기학회 2012 Journal of Magnetics Vol.17 No.2

We investigated the effects of pulsed magnetic fields (PMF) stimulus on electroencephalogram (EEG) alpha activity and heart rate variability (HRV) from electrocardiogram (ECG) measurements with various stimulus durations at acupoint PC9. The alpha activity in the EEG and the ratio of low frequency power and high frequency power (LHR) in the HRV, a reflection of sympathovagal activity, were increased and decreased, respectively, after PMF stimulus of 3 min. Our spectral analysis quantitatively proved that the changes in the EEG alpha activity were consistent with an autonomic function in the ECG. These findings suggest that appropriate PMF stimulus results in the same effect as that of acupuncture applied to the acupoint PC9, which is closely related to the parasympathetic activity of the autonomic nervous system.

KoreEffects of Psychiatric Symptoms on Attention in North Korean Refugees

YuJin Lee,JinYong Jun,Juhyun Park,Soohyun Kim,AhReum Gwak,SoHee Lee,SoYoung Yoo,SeogJu Kim 대한신경정신의학회 2016 PSYCHIATRY INVESTIGATION Vol.13 No.5

Objective-We investigated the performance of North Korean refugees on attention tasks, and the relationship between that performance and psychiatric symptoms. Methods-Sustained and divided attention was assessed using the computerized Comprehensive Attention Test in North Korean refugees and in South Koreans. All participants also completed the Beck Depression Inventory, the Beck Anxiety Inventory, the Impact of Event Scale-Revised and the Dissociative Experiences Scale-II (DES-II). Results-The North Korean refugees showed slower reaction times (RTs) on the visual sustained attention task compared to the South Koreans after controlling for age and sex. North Korean refugees had a greater number of omission errors (OEs) on the divided attention task and a higher standard deviation (SD) of RT. Total DES-II scores of the North Korean refugees were associated with the number of OEs and the SD of RT on the sustained attention task, and with the number of OEs on the divided attention task. Conclusion-North Korean refugees showed poorer performance on computerized attention tasks. In addition, attention deficit among North Korean refugees was associated with their dissociative experiences. Our results suggest that refugees may have attention deficits, which may be related to their psychiatric symptoms, particularly dissociation.

Psychiatry in Former Socialist Countries: Implications for North Korean Psychiatry

YoungSu Park,SangMin Park,JinYong Jun,SeogJu Kim 대한신경정신의학회 2014 PSYCHIATRY INVESTIGATION Vol.11 No.4

Very little information is available regarding psychiatry in North Korea, which is based on the legacy of Soviet psychiatry. This paper reviews the characteristics of psychiatry in former socialist countries and discusses its implications for North Korean psychiatry. Under socialism, psychiatric disorders were attributed primarily to neurophysiologic or neurobiological origins. Psychosocial or psychodynamic etiology was denied or distorted in line with the political ideology of the Communist Party. Psychiatry was primarily concerned with psychotic disorders, and this diagnostic category was sometimes applied based on political considerations. Neurotic disorders were ignored by psychiatry or were regarded as the remnants of capitalism. Several neurotic disorders characterized by high levels of somatization were considered to be neurological or physical in nature. The majority of “mental patients” were institutionalized for a long periods in large-scale psychiatric hospitals. Treatment of psychiatric disorders depended largely on a few outdated biological therapies. In former socialist countries, psychodynamic psychotherapy was not common, and psychiatric patients were likely to experience social stigma. According to North Korean doctors living in South Korea, North Korean psychiatry is heavily influenced by the aforementioned traditions of psychiatry. During the post-socialist transition, the suicide rate in many of these countries dramatically increased. Given such mental health crises in post-socialist transitional societies, the field of psychiatry may face major challenges in a future unified Korea.

잡음 분산 추정을 위한 개선된 Partial Sample Average 알고리즘

박정준(Park Jung-Jun),이진용(Lee Jinyong),임태민(Lim Taemin),김영록(Kim Younglok) 한국방송·미디어공학회 2010 한국방송공학회 학술발표대회 논문집 Vol.2010 No.11

잡음 분산 값은 SNR(signal-to-noise ratio) 추정이나 MMSE(minimum mean square error) 계산, 채널 임펄스 응답의 추정 등에 사용되는 중요한 파라미터이다. 채널이 시간에 따라 변하는 무선 통신 환경에서, 신호와 섞여 있는 잡음과 간섭 신호의 정확한 추정에는 그 한계가 있으며 이로 인해 발생하는 추정 오차는 수신기의 데이터 검출 성능을 저하시킨다. 훈련열을 이용하여 채널을 추정하였을 경우 추정된 채널 임펄스 응답 신호 중 다중 경로 신호는 소수에 불과하고 나머지 대부분의 계수는 잡음 성분만을 포함하는 신호이다. 이러한 특징을 이용하여 채널의 추정 계수로 잡음 분산을 추정하는 방법이 기존에 제시되어 있다. 여기서 제안하는 알고리즘은 기존 알고리즘인 PSA(partial sample average)와 비교해 연산량에서 차이가 거의 없이 구현되며, 3GPP TDD[1]에서의 모의 실험을 통하여 기존 알고리즘보다 더 정확한 분산 값을 찾아냄을 확인하였다.

Insomnia in North Korean Refugees: Association with Depression and Post-Traumatic Stress Symptoms

YuJin G. Lee,JinYong Jun,YuJin Lee,Juhyun Park,Soohyun Kim,SoHee Lee,SoYoung Yu,SeogJu Kim 대한신경정신의학회 2016 PSYCHIATRY INVESTIGATION Vol.13 No.1

Objective-We investigated the prevalence of insomnia and its clinical characteristics in North Korean refugees. Methods-North Korean refugees living in South Korea (48 males, 129 females; mean age 38.22±12.24 years) and South Koreans (112 males, 203 females; mean age 39.48±10.32 years) completed the following questionnaires: the Self-reported Questionnaire on Insomnia, Center for Epidemiological Studies-Depression Scale (CES-D), Trauma Exposure Check List for North Korean Refugees, and the Impact of Event Scale-Revised (IES-R). Results-North Korean refugees had insomnia more often than South Koreans did (38.42% vs. 8.89%). Depression combined with insomnia was also more prevalent in North Korean refugees (28.25% vs. 3.17%). Compared with South Koreans with insomnia, North Korean refugees with insomnia showed higher CES-D scores. The North Korean refugees with insomnia had experienced a larger number of traumatic events, and had higher CES-D and IES-R scores compared to North Korean refugees without insomnia. Insomnia in North Korean refugees was also associated with the presence of significant depressive and post-traumatic stress disorder (PTSD) symptoms. Conclusion-Insomnia was common in North Korean refugees and was closely associated with depressive and PTSD symptoms. Our study suggests that complaints of insomnia may indicate more severe psychopathology, especially in refugees.

Emotional Instability and Harm Avoidance for Childhood Obesity are Related to the Motivation for Weight Loss: A Pilot Study in Korea

KeunAh Cheon,DongHwan Lee,JinYong Jun,Kee Namkoong 대한신경정신의학회 2006 PSYCHIATRY INVESTIGATION Vol.3 No.1

Objective: The aim of this study was to evaluate the relationship between such psychosocial variables as the emotional and characteristic factors, and the motivation for weight loss in children with obesity. Methods: Thirty-seven children (mean age: 9.4±1.2 years) between the ages of 7 and 12 who had entered a summer camp for childhood obesity and their parents participated in this study. A questionnaire on the eating habits and life style of the child, the Child Behavioral Checklist (CBCL), and the Child Character Inventory (CCI) were completed by the parents of the subjects. The obese children completed the Child Depression Inventory (CDI) and the Parental Bonding Instrument (PBI) by themselves. We evaluated the motivation of the obese children to lose weight by having them take the Weight Loss Readiness Test (WLRT). Then, we analyzed the correlation between the psychological variables and the WLRT items. Results: The emotional instability scale on the CBCL was correlated with the WLRT item of emotional eating (r=0.336, p=0.042). The harm avoidance scale of the CCI was negatively correlated with the WLRT item on exercise patterns and attitudes (r=-0.047, p=0.014). However, no significant correlation was found between each of the severity scores of the CDI depressive symptoms and the other psychological variables and each of the six WLRT items. Conclusion: Our findings suggest that emotional instability and harm avoidance, as measured by the CCI, are related to the motivation for weight loss in obese children.

Somatic Symptoms as Mediating Factors between the Perceived Social Support and the Health-Related Quality of Life in North Korean Defectors

SungDoo Won,SoHee Lee,SeogJu Kim,JinYong Jun,SangSoo Shin 대한신경정신의학회 2017 PSYCHIATRY INVESTIGATION Vol.14 No.4

Objective-This study was conducted to examine the mediating effect of somatic symptoms between perceived social support and health-related quality of life among North Korean defectors living in South Korea. Methods-A total of 200 North Korean defectors were assessed using the Multidimensional Scale of Perceived Social Support, the Short-Form 8-Item Health Survey, the Patient Health Questionnaire 15, the PTSD Checklist Civilian Version and the Patient Health Questionnaire 9. Results-Somatic symptoms accounted for physical health-related quality of life after controlling for PTSD and depressive symptoms, but did not for mental health-related quality of life. Moreover, somatic symptoms mediated the relationship between perceived social support and physical and mental health-related quality of life, indicating that perceived social support indirectly affects physical and mental health-related quality of life through somatic symptoms in North Korean defectors. Conclusion-The results of this study suggest that not only intervention for PTSD or depressive symptoms but also for somatic symptoms might be effective to improve physical and mental health-related quality of life for North Korean defectors, especially those who have a lack of perceived social support.

사회적 불안이 해석수준과 중심부(vs. 주변부) 속성 강조 제품 만족도에 미치는 영향

고진용 ( Ko¸ Jin Yong ),여준상 ( Yeo¸ Jun Sang ) 한국소비자학회 2020 소비자학연구 Vol.31 No.6

일반적으로 불안은 주관적 감정으로 다가오는 어떤 사건에 대한 부정적 결과가 예측될 때 느끼는 구체적인 정서반응을 의미한다. 그동안 불안에 대한 연구는 주로 개인의 정서 이상 증상을 치료하기 위한 정신병리학적 접근이 주를 이뤘고 ‘불안’이 사회 속에서 소비자의 행동 변화를 예측하는 연구는 드물었다. 이 연구는 사회 속에서 개인이 느끼는 불안에 대한 개념을 우선 탐색하여, 일상적인 불안이 해석수준과 제품 속성 강조에 따라 만족도에 어떤 영향을 미칠 수 있는지를 탐구하는 것이 목표다. 실험1에서는 개인의 사회적 불안과 해석수준의 관계를 알아보았고 실험2에서는 지각된 사회적 불안이 제품 속성(중심부 vs. 주변부) 강조에 따른 만족도에 미치는 영향과 해석수준의 매개효과를 검증하였다. 실험1 결과, 측정된 개인의 사회적 불안이 높을수록 해석수준이 낮아지는 부적 관계가 확인되었다. 실험2에서는 중심부 속성을 강조한 제품 만족도에는 지각된 사회적 불안이 해석수준을 매개하는 간접효과가 유의미하였다. 주변부 속성을 강조한 경우에는 불안이 제품만족도에 직접효과를 미치는 것으로 나타났다. 본 연구의 시사점은 현대사회가 만들어 낸 불안이 해석수준과 특정 소비행동에 영향을 준다는 점을 밝힌 것이다. 따라서 이 연구는 최근의 일부 소비 트렌드가 불안, 또는 불안이 만들어 낸 낮은 해석수준의 영향이라는 설명을 제공할 수 있다. In general, anxiety refers to the specific emotional response by which a person feels when a negative outcome is predicted for an event to take place. However, researches on anxiety have mainly focused on psychopathological approaches to treat individual’s emotional disorders and there has been less interest in ‘anxiety’ as an indicator to predict consumers’ behavioral changes in the society. This research aims to figure out the effect of individual’s social anxiety on construal level and consumer preferences with the concept of anxiety that an individual feels in the society. In study 1, the relationship between individual's social anxiety and construal level was examined. In study 2, the effect of perceived social anxiety on the satisfaction for product attributes(emphasis on central attribute vs. peripheral attribute) and the mediating effect of construal level were examined. The result of study 1 shows the negative relationship between individual's social anxiety and constual level since construal level becomes lower when individual’s social anxiety is higher. Study 2 unveils that the indirect effect of peceived social anxiety on product satisfaction mediated by construal level is statistically significant for the product emphasizing on central attribute. In the case of emphasizing the peripheral attribute, anxiety shows only a direct effect on product satisfaction. Implication of this study is that anxiety in the modern society drives the low level construal which triggers the specific consumer behavior(e.g., preference for product emphasizing on peripheral attributes). So this research could provide the argument that some recent consumption trends might be caused by anxiety or lower construal level driven by precedented anxiety.