Investigation of Relationship between Reflection Resonance and Applied Current Density in Bragg Photonic Crystal

Bumseok Kim 조선대학교 기초과학연구원 2012 조선자연과학논문집 Vol.5 No.1

Hepatotoxicity Induced by Microcystin-LR in Rat

Bumseok Kim,Jae Woo Cho,Hyuk Nyun Kwon,Ivar Blank,Irina Borisova,Sohail Ejaz,Irina Chekarova,Jungkee Kwon,Chae Woong Lim 한국독성학회 2006 Toxicological Research Vol.22 No.4

Microcystin-LR (MC-LR) is a cyanobacterial hepatotoxin mainly produced by Microcystis aeruginosa. The current study examined the effects of a single intraperitoneal dose of MC-LR in rats. Female Sprague-Dawley rats were intraperitoneally injected with MC-LR (100 ㎍/㎏ body weight) and they were sacrificed at 0, 20, 40, 80, 160 min, or 12 h after injection. Clinically, animals showed lethargy and had ruffled hair beginning at 40 min post injection. In the gross findings, liver was enlarged and its color was changed into dark red beginning at 40 min post injection. Microscopically, dissociation of centrilobular hepatocytes and hemorrhage was observed in the hepatic central regions and such pathological changes were then extended to the portal regions of liver by time course manner. Interestingly at 80 min after MC-LR injection, the entrapped eosinophilic materials that may be necrotic fragments of dissociated hepatocytes were found in the capillaries of lung and renal glomerulus. Ultrastructurally, microvilli of the hepatocytes were disrupted or lost at all time points. Furthermore, the Disse space and gap junctions were widened beginning at 40 min post injection. These results suggest that liver is the major target organ of MC-LR and isolated hepatocytes by the effects of such hepatotoxin may secondarily reduce the physiological function of lung and kidney.

The Psychometric Properties of the Korean Version of the Verbal Abuse Questionnaire in University Students

Bumseok Jeong,SangWon Lee,JongSun Lee,JaeHyun Yoo,KoWoon Kim,Sooyun Cho,JeeYoung Ahn,Jeewook Choi 대한신경정신의학회 2015 PSYCHIATRY INVESTIGATION Vol.12 No.2

Objective-The aim of the present study was to examine the psychometric properties of the Korean Verbal Abuse Questionnaire (K-VAQ) that consists of 15 items related with life-time verbal aggression exposure. Methods-A total of 5814 university students who agreed to take part in the study completed the K-VAQ, the Korean version of the Life Event CheckList (LEC-K) and Impact of Event Scale-Revised (K-IES-R). Internal consistency was checked by using item-total item correlation and Cronbach’s alpha coefficient. Exploratory and confirmatory factor analyses were performed, and convergent and concurrent validity levels were examined. Finally, a cluster analysis was conducted to verify the validity of the cutoff point of the K-VAQ. Results-The Cronbach’s alpha correlation coefficient was 0.9. The K-VAQ showed a single factor structure which explained 55.34% of the total variance. The K-VAQ was significantly associated with the LEC-K (r=0.24) and K-IES-R (r=0.28), indicating good convergent validity and concurrent validity. The cluster analysis provided four clusters of trauma experiences: high, moderate, low, and minimal, with K-VAQ ranges of 43–81, 20–42, 7–19, and 0–6, respectively. In a further investigation, a K-VAQ score of 40 was found to be the appropriate cutoff point to delineate the highly verbally abused group, as used in the previous studies. A sum of 36.5% of the highly verbally abused group reported to show substantial symptoms of PTSD (K-IES-R score >22). Conclusion-The present findings suggest that the K-VAQ has good psychometric properties for assessing verbal aggression among the Korean population.

Pecci-Quinn Extension of the Natural Hybrid Inflation Model

Bumseok Kyae 한국물리학회 2012 새물리 Vol.62 No.7

The "natural hybrid inflation model," which combines the supersymmetric hybrid model and the natural inflation model, was proposed to achieve the spectral index of 0.96, and an axion decay constant of intermediate scale. By introducing both the U(1)_R and a shift symmetry and employing the minimal Kahler potential, we were able to avoid the eta-problem. The two inflaton fields in this model can admit a large non-Gaussianity. For a full realization of the idea of the natural inflation, the shift symmetry in the model should be embedded in a U(1)_(PQ) symmetry.

Detection of Nitroaromatic Compounds Based on Fluorescent Silafluorene Chemosensors

Bumseok Kim 조선대학교 기초과학연구원 2010 조선자연과학논문집 Vol.3 No.1

Functional and anatomical connectivity abnormalities in left inferior frontal gyrus in schizophrenia

Bumseok, J,Wible, Cynthia G.,Ryu-Ichiro, H,Marek, K Wiley Subscription Services, Inc., A Wiley Company 2009 Human brain mapping Vol.30 No.12

<P><B>Abstract</B></P><P>Functional studies in schizophrenia demonstrate prominent abnormalities within the left inferior frontal gyrus (IFG) and also suggest the functional connectivity abnormalities in language network including left IFG and superior temporal gyrus during semantic processing. White matter connections between regions involved in the semantic network have also been indicated in schizophrenia. However, an association between functional and anatomical connectivity disruptions within the semantic network in schizophrenia has not been established. Functional (using levels of processing paradigm) as well as diffusion tensor imaging data from 10 controls and 10 chronic schizophrenics were acquired and analyzed. First, semantic encoding specific activation was estimated, showing decreased activation within the left IFG in schizophrenia. Second, functional time series were extracted from this area, and left IFG specific functional connectivity maps were produced for each subject. In an independent analysis, tract‐based spatial statistics (TBSS) was used to compare fractional anisotropy (FA) values between groups, and to correlate these values with functional connectivity maps. Schizophrenia patients showed weaker functional connectivity within the language network that includes left IFG and left superior temporal sulcus/middle temporal gyrus. FA was reduced in several white matter regions including left inferior frontal and left internal capsule. Finally, left inferior frontal white matter FA was positively correlated with connectivity measures of the semantic network in schizophrenics, but not in controls. Our results indicate an association between anatomical and functional connectivity abnormalities within the semantic network in schizophrenia, suggesting further that the functional abnormalities observed in this disorder might be directly related to white matter disruptions. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.</P>

Precise focus point scenario for a natural Higgs boson in the MSSM

Kyae, Bumseok,Shin, Chang Sub American Physical Society 2014 PHYSICAL REVIEW D - Vol.90 No.3

Sentinel-1 위성을 이용한 북한 지역의 고해상도 토양수분 산정

천범석 ( Bumseok Chun ),김상우 ( Sangwoo Kim ),이태화 ( Taehwa Lee ),신용철 ( Yongchul Shin ) 한국농공학회 2019 한국농공학회 학술대회초록집 Vol.2019 No.-

토양수분은 지하수와 지표수 산정, 자연재해 예측 및 농작물의 생장과 같은 다양한 분야에서 중요한 역할을 한다. 최근 토양수분을 이용한 가뭄평가지수 제시와 토양수분이 다양한 작물에 주는 영향 등 다양한 분야에서 토양수분에 대한 관심이 증가하고 있다. 토양수분의 측정 방법 중 TDR(Time Domain Reflectometry)을 이용한 토양수분 직접 측정방법은 지점단위의 토양수분을 빠른 시간 내 정확한 측정이 가능한 장점이 있다. 하지만 직접 측정 방법은 토양수분의 공간분포를 나타내지 못하는 한계가 있다. 이러한 한계를 극복하기 위하여 원격탐사자료를 이용한 토양수분 간접측정방법이 제시되어 최근 이를 이용한 남한 지역의 토양수분 산정에 관한 연구가 진행되고 있다. 그러나 현재 북한 지역의 토양수분 산정에 관련된 연구는 미비한 상황이다. 따라서 본 연구에서는 북한 지역을 대상으로 고해상도의 Sentinel-1 SAR(Synthetic Aperture Radar) 센서 기반 후방산란계수를 이용하여 토양수분 공간분포를 산정하였다. Sentinel-1 SAR 센서 기반 토양수분과 GPM(Global Precipitation Measurement) 위성강우 이미지자료를 비교하였으며, 전체적으로 강우 변화에 따른 모의 토양수분 공간분포의 변화가 잘 반영하는 것으로 나타났다. 본 연구는 향후 북한 지역 홍수, 가뭄, 산불, 농업 등 다양한 분야에서 기초자료로 활용 될 수 있을 것으로 사료된다.

자료포괄분석(DEA)을 이용한 주식의 가치 평가

김범석(BumSeok Kim),김명석(Myung S. Kim),민재형(Jae H. Min) 한국경영과학회 2011 經營 科學 Vol.28 No.3

This study suggests a DEA(Data Envelopment Analysis) based model to evaluate the value of corporate stock. The model integrating PER(Price-Earning Ratio), PBR(Price-BookValue Ratio), PSR(Price-Sales Ratio) and volatility in DEA structure has an advantage of overcome the limitation of traditional financial ratio based models. In order to show the effectiveness of the suggested model. we compare the performance of portfolio composed by DEA approach with those of portfolios made by traditional approaches such as PER, PBR, and PSR in terms of stock return and volatility. Specifically, we use the data of all the enterprises listed on the S&P 500 in the U.S. in 2007 and 2009 as the sample data for the experiments. The results of the experiments show that the performance of the DEA approach is clearly better than those of other approaches. Particularly, in sharply plummeting market, the performance of the DEA approach is shown to be prominently better than those of other approaches as the DEA approach reflects investment risk as well as profitability and growth. The DEA score combining the existing investment indices may serve as a useful barometer for selecting a stable and profitable portfolio.

Investigation of Relationship between Reflection Resonance and Applied Current Density in Bragg Photonic Crystal

Kim, Bumseok The Basic Science Institute Chosun University 2012 조선자연과학논문집 Vol.5 No.1

Relationship between reflection resonance and applied current density in Bragg photonic crystal has been investigated. Multiple bit encodes of distributed Bragg reflector features have been prepared by electrochemical etching of crystalline silicon by using various square wave current densities. Optical characterization of multi-encoding of distributed Bragg reflectors on porous silicon was achieved by Ocean optics 2000 spectrometer for the search of possible applications of multiple bit encoding of distributed Bragg reflectors such as multiplexed assays and chemical sensors. The morphology and cross-sectional structure of multi-encoded distributed Bragg reflectors was investigated by field emission scanning electron micrograph.