• 제목/요약/키워드: Chang-Ki(張機)

검색결과 419건 처리시간 0.027초

MODIS 위성 자료를 이용한 동아시아 에어로졸-구름의 통계적 특성 (Investigating Statistical Characteristics of Aerosol-Cloud Interactions over East Asia retrieved from MODIS Satellite Data)

  • 정운선;성현민;이동인;차주완;장기호;이철규
    • 한국환경과학회지
    • /
    • 제29권11호
    • /
    • pp.1065-1078
    • /
    • 2020
  • The statistical characteristics of aerosol-cloud interactions over East Asia were investigated using Moderate Resolution Imaging Spectroradiometer satellite data. The long-term relationship between various aerosol and cloud parameters was estimated using correlation analysis, principle component analysis, and Aerosol Indirect Effect (AIE) estimation. In correlation analysis, Aerosol Optical Depth (AOD) was positively Correlated with Cloud Condensation Nuclei (CCN) and Cloud Fraction (CF), but negatively correlated with Cloud Top Temperature (CTT) and Cloud Top Pressure (CTP). Fine Mode Fraction (FMF) and CCN were positively correlated over the ocean because of sea spray. In principle component analysis, AOD and FMF were influenced by water vapor. In particular, AOD was positively influenced by CF, and negatively by CTT and CTP over the ocean. In AIE estimation, the AIE value in each cloud layer and type was mostly negative (Twomey effect) but sometimes positive (anti-Twomey effect). This is related to regional, environmental, seasonal, and meteorological effects. Rigorous and extensive studies on aerosol-cloud interactions over East Asia should be conducted via micro- and macro-scale investigations, to determine chemical characteristics using various meteorological instruments.

실시간 이상거래 탐지 기법에 관한 연구 (A Design of Mobile Fitness Recommendation System Based on Data Sharing Mechanism)

  • 장기만;김경환;최광남;김창수;정회경
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국정보통신학회 2015년도 추계학술대회
    • /
    • pp.763-765
    • /
    • 2015
  • 연구개발비의 투명성 확보를 위하여 진행되고 있는 연구들은 현재 제도의 문제점을 파악하고 개선해 나가는 방식이다. 이와 같은 연구는 제도권 밖에 있거나 제도를 따르지 않는 대상에 대해서는 대비가 이루어지지 않는 단점이 있다. 연구개발비 오용 및 부정 집행을 방지하기 위해서는 연구기관과 신용카드사 간의 거래 중에서 발생하는 이상거래를 실시간으로 탐지해야한다. 본 논문에서는 실시간 이상거래 탐지 기법에 대해 제시한다. 이상거래 탐지시스템에 업무규칙 도출을 통해 얻은 데이터를 추가함으로써 다양한 환경에서 발생할 수 있는 부정거래를 탐지 및 대응할 수 있게 된다.

  • PDF

두경부 굴곡 운동이 만성 경부통 근로자의 통증 및 경장근 단면적에 미치는 영향 (Effect of Craniocervical Flexion Exercise on Pain and Cross Sectional Area of Longus Colli Muscle in Workers with Chronic Neck Pain)

  • 천승철;장기연
    • 대한인간공학회지
    • /
    • 제29권6호
    • /
    • pp.889-895
    • /
    • 2010
  • This study compared the effects of craniocervical flexion exercise with conservative cervical flexion exercise in workers with chronic neck pain. Subjects were randomly allocated to two groups: control (n=20) and experimental group (n=20), respectively. The conservative exercise for the control group consisted of cervical flexion exercise, whereas the experimental group performed a craniocervical flexion exercise. To compare the two groups, the visual analogue scale (VAS) for a pain, neck disability index (NDI) for a neck disability scale, and cross sectional area (CSA) of longus colli muscle using ultrasound image were assessed on pre-intervention, post-intervention, and 2 weeks follow-up. 2-way repeated ANOVA was used with Bonferroni post-hoc test. (1) There were significant main effects (within and between groups) (p<0.05) and interaction effect (p<0.05) in VAS. Post-hoc test revealed that there were significant differences in all pair-wise comparisons. (2) There were significant main effects (within and between groups) (p<0.05) and interaction effect (p<0.05) in NDI. Post-hoc test revealed that there were significant differences between pre-intervention and post-intervention, pre-intervention and 2 weeks follow-up. (3) There were significant main effects (within and between groups) (p<0.05) and interaction effect (p<0.05) in CSA of longus colli muscle. Post-hoc test revealed that there were significant differences in all pair-wise comparisons. The findings indicate that craniocervical flexion exercise are more effective for improving pain, neck disability, and CSA of longus colli muscle than cervical flexion exercise in workers with chronic neck pain.

인간의 착상 기전을 연구하기 위한 3차원적 자궁내막 모델 확립 (3-Dimensional Culture System of Endometrial Cells for Studying the Human Implantation Mechanism)

  • 박동욱;양현원;권혁찬;장기홍;김세광;조동제;오기석
    • Clinical and Experimental Reproductive Medicine
    • /
    • 제26권1호
    • /
    • pp.1-8
    • /
    • 1999
  • In order to study the implantation mechanism various methods for culture of endometrial cells in vitro have been attempted. However, a disadvantage is that primary cultures of stromal and epithelial cells do not have the ability to differentiate, and therefore cannot be reproduced in the same manner as in vivo endometrium. The object of this study is to establish a three dimensional culture of endometrial cells which are both morphologically and functionally identical to in vivo endometrium. Endometrial tissues obtained after hysterectomies were cut into thin slices and treated with collagenase and trypsin-EDTA. The stromal cells and the epithelial cells were separated by centrifugation and cultured for 24 hours in DMEM media containing 10% FCS, 100 nM progesterone, and 1 nM estradiol. The cultured stromal cells were mixed with collagen gel and solidified, after which it was covered with matrigel. Epithelial cells were inoculated on the top and then cultured for 3 days. The three dimensionally cultured endometrial cells were stained for integrin ${\alpha}1,\;{\alpha}4,\;{\beta}3$, and cyclooxygenase-l, -2 by immunohistochemistry, which all showed strong expression. The cultured epithelial cells showed the formation of microvilli, tight junctions and pinopodes by electron microscopy. Studies are currently under way utilizing this three dimensional culture model to ascertain the interaction between the embryo and human endometrial cells at the time of implantation, and it is thought that further studies into a new culture environment which would allow longer periods of culture will be necessary.

  • PDF

흰쥐 기관지평활근에 대한 황련류의 이완효능 (Bronchodilatory Effects of Coptidis Rhizomas in Isolated Rat Trachea)

  • 이동웅;장기철
    • 약학회지
    • /
    • 제41권6호
    • /
    • pp.797-801
    • /
    • 1997
  • Recently we reported that water extracts of Coptidis Rhizomas showed calcium antagonistic action and alpha-adrenoceptor inhibitory action in the vascular smooth muscle. Since ca lcium antagonistic properties are important in the treatment of various diseases including asthma. In the present study, the bronchodilatory effects of crude extract of three kinds of Coptidis Rhizoma (Coptidis chinensis, Coptis japonica and root hair of Coptis japonica) was investigated using rat isolated trachea. The result showed that all extracts relaxed carbachol-contracted tracheal smooth muscle. Concentration-dependently, in which the root hair of Coptis japonica was the least potent. The inhibitory potency expressed in terms of $IC_{50}$ against carbachol contraction was 1.8${\mu}$g/ml and 2.7${\mu}$g/ml for Coptidis chinensis and Coptis japonica, respectively. These extracts also inhibited KCI-contracted tracheal smooth muscle. But the relative potency ($IC_{50}$) was 3.5 and 4.1 folds weaker than carbachol-induced contraction for Coptidics chinenesis and Coptis japonica, respectively. Pretreatment of crude extracts also inhibited carbachol- or KCI-induced contraction, non-competitively. These findings indicate that the extracts have muscarinic blocking as well as $Ca^{2+}$ channel blocking action. When provoked intracellular stored $Ca^{2+}$ release by carbachol in $Ca^{2+}$-free conditions, initial phasic contraction due to $Ca^{2+}$ release was significantly inhibited by the extracts. As taken together, we conclude that water extracts of Coptidis Rhizoma may be beneficial in bronchospasm or other broncheal tube narrowing conditions such as asthma.

  • PDF

체외수정시술을 위한 성선자극호르몬 과배란유도에 Limited Ovarian Reserve를 갖는 환자에서 성장호르몬의 사용 (Cotreatment with Growth Hormone in Controlled Ovarian Hyperstimulation for IVF in Women with Limited Ovarian Reserve)

  • 김선행;장기훈;구병삼
    • Clinical and Experimental Reproductive Medicine
    • /
    • 제21권3호
    • /
    • pp.241-245
    • /
    • 1994
  • Despite increasing success rate of IVF, poor response to ovarian stimulation remains a problem. So, attempts to improve ovarian responses, for example, by using combined gonadotropin-releasing hormone analogue(GnRH-a) and human menopausal gonadotropin(hMG) have shown limited success. It is reported that response of granulosa cells in vitro to FSH is stimulated by co-incubation with IGF-l, and IGF-l production can be increased by growth hormone. This suggest that combination regimen of G.H. and hMG may augment follicle recruitment. In fifteen patients who had previous history of poor ovarian response to gonadotropin stimulation after pituitary suppression with mid -luteal GnRH-a, the effectiveness of cotreatment with G.H. in IVF program was evaluated using a combination regimen of G.R. and hMG at Korea University Hospital IVF Clinic. Ovarian responses to gonadotropin stimulation in control and GH-treated cycles assessed by total dose and duration of hMG treatment, follicular development and peak $E_2$ level, number of eggs retrieved, and fertilization rates were also assessed. In each group, serum and follicular fluid IGF-1 concentrations on day of egg collection were measured by RIA after acidification and extraction by reveresed phase chromatography. Patients receiving G.H. required fewer days and ampules of gonadotropins, developed more oocytes, and more embryos transferred. But, the differences were not statistically significant, except the duration of hMG treatment. Our data showed a significantly higher concentration of IGF-l in the serum, not in the follicular fluid, of patients treated with G.H. compared with control group. These data suggest that growth hormone treatment does not improve the ovarian response in women with limited ovarian reserve to gonadotropin stimulation for IVF.

  • PDF

소국주(小麴酒)와 시판약주(市販藥酒)의 성분(成分)에 관(關)한 연구(硏究) (Studies on the Components of Sokokju, and Commercial Yakju)

  • 장기중;유태종
    • 한국식품과학회지
    • /
    • 제13권4호
    • /
    • pp.307-313
    • /
    • 1981
  • 한국(韓國) 고래주(古來酒)인 소국주(小麴酒)와 시판약주(市販藥酒)의 성분(成分)이 품질(品質)에 미치는 영향을 연구한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 1차 담금에 찹쌀 반숙미(半熟米)를 사용(使用)하여 양조(釀造)한 소국주(小麴酒)에 있어서 알코올과 추출물(抽出物)의 함유량(含有量)이 높았으며 다량(多量)의 pyruvic acid가 검출(檢出)되 었다. 2. 타르타르산과 시트르산은 시판(市販) 약주(藥酒)에서만 검출(檢出)되었으며 소국주(小麴酒)의 주된 유기산(有機酸)은 락트산$(7{\sim}10\;mg/ml)$ 및 푸마르신과 숙신산$(0.3{\sim}0.65\;mg/ml)$이였다. 3. 소국주용(小麴酒用) 누룩에는 락트산이 7.8 mg/g 함유(含有)되어 있었으며 시판(市販) 약주용(藥酒用) 누룩에서는 말산이 0.47 mg/g으로 다량(多量) 함유(含有)되어 있었다. 4. 관능(官能) 검사(檢査) 결과(結果) 참쌀 반숙미(半熟米)를 사용(使用)하여 양조(釀造)한 소국주(小麴酒)가 다른 약주(藥酒)보다 품질(品質)이 우수하였다.

  • PDF

구기자 부위별 추출물이 흰쥐 비장세포의 증식에 미치는 영향 (Effects of Extracts from Various Parts of Lycium chinense Mill. on the Proliferation of Mouse Spleen Cells)

  • 박종상;박종대;이봉춘;최강주;라상욱;장기운
    • 한국약용작물학회지
    • /
    • 제8권4호
    • /
    • pp.291-296
    • /
    • 2000
  • 구기자나무의 부위별 물추출물이 LPS (lipopolysaccharide) 및 Con A (concanavalin A)에 의한 마우스의 비장세포 증식능에 미치는 영향을 시험한 결과 부위별 면역 활성중 과실에서 의 No mil 처리구에서는 $0.1mg/ml{\sim}0.5mg/ml$ 농도에서, LPS 처리구에서는 $0.01mg/ml{\sim}0.1mg/ml$의 농도에서 B-cell (체액성 면역)의 분열증식을 촉진시켰다. 잎과 뿌리는 LPS 처리구에서 0.1mg/ml 까지 비장세포의 분열증식을 촉진시켰으며 Con A 처리구에서는 T-cell (세포성 면역)의 증식효과가 없었다.

  • PDF

인공지반 녹화시스템 활용을 위한 일체형 방수·방근 시트의 성능평가 (Assessment of Evaluation by Hybrid Waterproof-Roof Barrier Layer for Green System on Artificial Ground)

  • 오창원;홍종철;박기봉
    • 한국건축시공학회지
    • /
    • 제15권4호
    • /
    • pp.391-396
    • /
    • 2015
  • 도심지 건물의 증가는 친환경 공간에 대한 요구를 발생시키고, 이에 따라 옥상 및 인공지반 녹화의 보급이 급속히 증가되고 있다. 녹화시공은 방수층, 방근층, 보호콘크리트 등과 같이 다양한 재료를 시공하므로 시공시간이 길고, 하자 발생가능성이 높아진다. 본 연구는 기존의 녹화시스템 시공단계를 단축, 시공성을 향상시킨 새로운 녹화시스템에 사용하는 일체화된 방수 방근 하이브리드 시트의 물리적성능, 내구성, 방수성, 방근성을 평가함으로써 성능수준을 확인하고, 현장 적용 여부를 판단하고자 하였다. 시험결과, 우수한 물리적 성능 및 내구성, 방수성, 방근성을 확인하였으며, 향후 mock-up 시험을 수행하여 장기성능을 검증 중이다.

데이터 품질진단 기법을 이용한 연구개발비 이상거래 실시간 탐지 (Real-Time Fraud Detection using Data Quality Diagnosis Techniques for R&D Grant)

  • 장기만;김창수;정회경
    • 한국정보통신학회논문지
    • /
    • 제19권11호
    • /
    • pp.2609-2614
    • /
    • 2015
  • 국가연구개발 사업을 계획하고 관리하는 기관에서는 연구개발비 오 남용 및 부정 집행을 방지하기 위하여 다양한 대책을 마련하여 시행하고 있으나 연구개발비의 오 남용을 방지하는 데는 한계를 드러내고 있다[1,2]. 본 논문에서는 이상거래에 대한 사후 적발로 인한 연구개발비 오 남용을 방지하고자 연구개발비 집행계획 단계부터 정보를 수집하여 이상거래를 탐지할 뿐만 아니라 그 결과를 주관연구기관, 전문기관, 신용카드사 간의 상호 실시간 연동으로 공유하여 활용하도록 하였다. 이를 위해 데이터 품질진단 기법 중 연구개발 관련 규정 및 매뉴얼, Q&A, FAQ, 담당자 인터뷰 결과 등과 같은 다양한 정보로부터 업무규칙을 도출하는 아웃사이드인(Outside-In) 분석 방법을 이용하였다.