• 한국자기공명학회논문지
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• 제6권1호
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• pp.45-53
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• 2002

Objectives: This study investigated alterations in regional cerebral blood flow (rCBF) in patients with transient global amnesia (TGA) using statistical parametric mapping 99 (SPM99). Methods: Noninvasive rCBF measurements using 99mTc-ethyl cysteinate dimer (ECD) SPECT were performed on 8 patients with TGA who have ongoing symptoms and 17 age matched controls. The relative rCBF maps in patients with TGA and controls were compared. Results: In patients with TGA, significant decreased rCBF was found along the L superior temporal extending to L parietal region of the brain and L thalamus. There were areas of increased rCBF in the R temporal, R frontal region and R thalamus. Conclusion: We could demonstrate decreased perfusion in left cerebral hemisphere and increased perfusion in right cerebral hemisphere in patients with TGA using SPM99. The imbalanced change of rCBF between bilateral cerebral hemisphere in patients with TGA might suggest that imbalanced neuronal activity between the bilateral hemispheres may have strong relationship to the pathogenesis of the TGA. For quantitative SPECT analysis in TGA patients, we recommend SPM99 rather than the ROI method because of its definitive advantages.

• 지질공학
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• 제17권2호
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• pp.263-270
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• 2007

터널 시공 중 일상적으로 수행되는 계측에 의해 정량화되는 터널의 거동은 안정성 평가를 위한 주요한 항목이며, 이는 지역적인 지질학적 특성에 크게 의존한다. 본 연구에서는 지질학적 특성 차에 의한 RMR 항목별 터널 거동에 미치는 영향도를 분석하기 위하여, 터널의 face mapping 자료와 계측자료를 각각 설명변수와 종속변수로 한 수량화 분석을 실시하였다. 분석 결과, RMR 인자가 터널의 변위에 미치는 중요도의 평균은 R1, R2, R3, R4, R5 각각 17.0%, 20.4%, 20.4, 11.6%, 30.6%로서, 이는 분석지역의 지하수특성이 변위에 크게 영향을 미친 것으로 판단된다.

• 대한화장품학회지
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• 제34권2호
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• pp.109-115
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• 2008

기질 화합물로써 $3{\beta}$-hydroxy-12-oleanen-28-oic acid 유도체들의 치환기($R_1{\sim}R_4$)가 변화함에 따른 protein tyrosine phosphatase(PTP)-1B의 저해활성에 관한 비교 분자장 분석(CoMFA) 모델을 유도하고 정량적으로 검토하였다. 최적의 CoMFA F1 모델은 가장 높은 예측성과 상관성($r^2_{cv.}=0.654$ 및 $r^2_{ncv.}=0.995$)을 나타내었다. 저해활성에 관한 CoMFA장 기여비율(%)의 순서는 입체장(53.0%), 정전기장(36.2%) 및 소수성장(10.8%) 이었다. 등고도 분석 결과로부터 저해활성은 기질 분자 내 $R_4$-치환기에 의존적이었으며 특히 melanin 저해활성이 높은 새로운 화합물(P1 및 P2)이 예측되었다.

• Bulletin of the Korean Chemical Society
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• 제30권3호
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• pp.613-617
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• 2009

3D-QSARs for the inhibition activities against protox by herbicidal 2-N-phenylisoindolin-1-one derivatives were studied quantitatively using CoMFA and CoMSIA methods. The result of the statistical quality of optimized CoMSIA model 2 ($FF:\;{r^2}_{cv.};\;0.973\;&\;{r^2}_{ncv.};\;0.612$) was higher than that of CoMFA model 1 ($AF:\;{r^2}_{cv.};\;0.414\;&\;{r^2}_{ncv.};\;0.909$). Also, the relative contribution of the optimized CoMSIA model 2 showed the steric (24.6%), electrostatic (31.0%), hydrophobic (ClogP, 23.4%) and H-bond acceptor field (21.0%), respectively. From the results of the contour maps, the protox inhibition activities are expected to increase when steric favor and H-bond acceptor favor groups are substituted on $R_2$ position and positive favor group are substituted on $C_2,\;C_3,\;and\;C_5$ atom in phenyl ring of $R_2$ position. And the inhibition activities are expected to increase when hydrophobic favor group is substituted on $C_1,\;C_3$ atom in phenyl ring of $R_2$ position and $C_1$ atom of $R_2$ position and hydrophilic favor groups are substituted on $C_4$ atom in phenyl ring of $R_1$ position and the terminal group of $R_1$ position.

• 한국지리정보학회지
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• 제15권1호
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• pp.144-158
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• 2012

도시의 국지기후 분석에 충분한 공간해상도의 정확한 분석을 위해서는 이를 지원할 정밀한 공간정보가 필요하다. 1~4m 해상도의 항공 LiDAR(Light Detection And Ranging) 자료와 KOMPSAT-2(Korea Multi-Purpose Satellite-2) 위성영상 자료를 이용하여 초고해상도(5m) 입체적 지형 지면 토지피복 모델을 개선하였다. CAS(Climate Analysis Seoul)를 이용하여 도시내부의 지표면 속성비율과 건물의 밀집도 높이 면적에 따른 열적용량과 국지규모 기온을 분석하였다. 자료의 정밀도 향상 결과가 국지규모 기온 분석에 미치는 효과를 평가하기 위해, 개선이전 및 이후 국지기온 분석 결과와 ASTER 위성영상 지표면온도 및 지상 기온관측 자료를 각각 비교 분석하였다. 그 결과 개선이후 국지규모 기온분석 결과와 ASTER 지표면온도 비교시, 건물(BS)지역에서 높은(R=0.76) 상관관계가 나타났다. 지상 기온관측과의 비교에서도 그 편차가 개선이전 1.27K보다 개선되어 0.70K로 나타났다. 본 연구 결과로부터 초고해상도 공간정보가 현실을 잘 반영할 뿐만 아니라 이를 이용한 상세한 기온분석이 가능함을 알 수 있었다. 향후 도시 개발 계획 시나리오에 대한 상세도시기후 예측 및 분석에 본 연구의 정밀한 지형 지면 토지피복 모델 기술 등이 활용될 수 있을 것이다.

• 대한원격탐사학회지
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• 제21권3호
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• pp.189-211
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• 2005

This paper makes an effort to compare the recently evolved soft classification method based on Linear Spectral Mixture Modeling (LSMM) with the traditional hard classification methods based on Iterative Self-Organizing Data Analysis (ISODATA) and Maximum Likelihood Classification (MLC) algorithms in order to achieve appropriate results for mapping, monitoring and preserving valuable coastal wetland ecosystems of southern India using Indian Remote Sensing Satellite (IRS) 1C/1D LISS-III and Landsat-5 Thematic Mapper image data. ISODATA and MLC methods were attempted on these satellite image data to produce maps of 5, 10, 15 and 20 wetland classes for each of three contrast coastal wetland sites, Pitchavaram, Vedaranniyam and Rameswaram. The accuracy of the derived classes was assessed with the simplest descriptive statistic technique called overall accuracy and a discrete multivariate technique called KAPPA accuracy. ISODATA classification resulted in maps with poor accuracy compared to MLC classification that produced maps with improved accuracy. However, there was a systematic decrease in overall accuracy and KAPPA accuracy, when more number of classes was derived from IRS-1C/1D and Landsat-5 TM imagery by ISODATA and MLC. There were two principal factors for the decreased classification accuracy, namely spectral overlapping/confusion and inadequate spatial resolution of the sensors. Compared to the former, the limited instantaneous field of view (IFOV) of these sensors caused occurrence of number of mixture pixels (mixels) in the image and its effect on the classification process was a major problem to deriving accurate wetland cover types, in spite of the increasing spatial resolution of new generation Earth Observation Sensors (EOS). In order to improve the classification accuracy, a soft classification method based on Linear Spectral Mixture Modeling (LSMM) was described to calculate the spectral mixture and classify IRS-1C/1D LISS-III and Landsat-5 TM Imagery. This method considered number of reflectance end-members that form the scene spectra, followed by the determination of their nature and finally the decomposition of the spectra into their endmembers. To evaluate the LSMM areal estimates, resulted fractional end-members were compared with normalized difference vegetation index (NDVI), ground truth data, as well as those estimates derived from the traditional hard classifier (MLC). The findings revealed that NDVI values and vegetation fractions were positively correlated ($r^2$= 0.96, 0.95 and 0.92 for Rameswaram, Vedaranniyam and Pitchavaram respectively) and NDVI and soil fraction values were negatively correlated ($r^2$ =0.53, 0.39 and 0.13), indicating the reliability of the sub-pixel classification. Comparing with ground truth data, the precision of LSMM for deriving moisture fraction was 92% and 96% for soil fraction. The LSMM in general would seem well suited to locating small wetland habitats which occurred as sub-pixel inclusions, and to representing continuous gradations between different habitat types.

• 한국융합학회논문지
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• 제9권8호
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• pp.1-8
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• 2018

얼굴인식, 홍채인식과 같은 생체보안 분야에서 눈, 코, 입술 등 얼굴특징을 추출하는 과정은 필수적이다. 본 논문은 초고속(faster) R-CNN을 이용하여 얼굴영상에서 눈 및 입술영역을 검출하는 방법을 연구하였다. 초고속 R-CNN은 딥러닝을 이용한 물체검출 방법으로 기존의 특징기반 방법에 비해 성능이 우수한 것으로 알려져 있다. 본 논문에서는 얼굴영상에 콘볼루션, 선형정류과정, max pooling과정을 차례로 적용하여 특징맵을 추출하고 이로부터 제안영역(region proposal)을 검출하는 RPN(region proposal network)을 학습한다. 그리고 제안영역과 특징맵을 이용하여 눈 및 입술 검출기(detector)를 학습한다. 제안방법의 성능을 검토하기 위해 남녀한국인 얼굴영상 800장으로 실험하였다. 학습을 위해 480장을 이용했으며 테스트용으로 320장을 사용하였다. 컴퓨터모의 실험결과 눈 및 입술영역 검출의 평균정확도는 50 에포치일 때 각각 97.7%, 91.0%를 얻을 수 있었다.

• Journal of Applied Biological Chemistry
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• 제50권2호
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• pp.52-57
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• 2007

Quantitative structure-activity relationships (QSARs) on the inhibition activities by oleanolic acid analogues (1-19) as a potent inhibitor against protein tyrosine phosphatase-1B were studied quantitatively using 2D-QSAR and HQSAR methodologies. The inhibition activity was dependent on the variations of $R_{4-}$substituent, and as shown in 2D-QSAR model ($r^2=0.928$), it has a tendency to increase as the negative Randic Indice (RI) goes up. The size of the molecular fragments used in HQSAR varied from five to eight. The fragment distinctions had the best statistic value, whose predictability is $q^2=0.785$ and correlation coefficient is $r^2=0.970$, on condition of connections. From the atomic contribution maps, the factor that contributes to the inhibition activities is the $C_{15}{\sim}C_{17}$ bond in the D ring. From the analysis result of these two the models, the structural distinctions and descriptors that contribute to the inhibition activities were obtained.

• 설비공학논문집
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• 제11권4호
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• pp.499-510
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• 1999

A computer program was developed for simulating performance(capacity, power consumption and etc.) of air-conditioners using compressor, fin-tube heat exchanger and capillary tube. The program consists of five modules, condenser, evaporator, compressor, capillary tube simulation modules and properties modules of refrigerant and moist air, The present program is focused on R22 only, however can be easily extended for other refrigerants such as R407C and R410A just by adding property modules. The compressor simulation module utilizes performance maps supplied by manufacturers-map-based model. The condenser and evaporator simulation modules are modeled using tube-by-tube method. Simulation results(capacity and power consumption) were compared with calorimeter test results of actual air-conditioners of window and split types, where more than 82% of the data lied within ${\pm}5$% of the predicted results.

• International Journal of Air-Conditioning and Refrigeration
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• 제14권4호
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• pp.156-165
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• 2006

Convective boiling heat transfer coefficients were measured in a horizontal minichannel with R-l34a. The test section was made of stainless steel tube with an inner diameter of 3.0 mm and a length of 2m. It was uniformly heated by applying electric current directly to the tube. Local heat transfer coefficients were obtained for heat fluxes from 10 to $40kW/m^2$, mass fluxes from 200 to $600kgT/m^2s$, qualities up to 1.0, and the inlet saturation temperature of $10^{\circ}C$. The experimental results were mapped on Wojtan et $al.'s^(7)$ and Wang et $al.'s^(8)$ flow pattern maps. The nucleate boiling was predominant at low vapor quality whereas the convective boiling was predominant at high vapor quality. Laminar flow appeared in the flow with minichannel. The experimental results were compared with six existing two-phase heat transfer coefficient correlations. A new boiling heat transfer coefficient correlation based on the superposition model for refrigerants was developed with mean and average deviations of 10.39% and -3.66%, respectively.