• 한국지반공학회논문집
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• 제27권12호
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• pp.53-68
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• 2011

본 연구에서는 기존 NATM 터널공법의 문제점을 개선한 신개념의 NATM Composite 라이닝 공법 개발에 대한 기초 연구를 수행하였다. 먼저 NATM Composite 라이닝 공법의 개요 대하여 소개하고 시공성에 대한 검토를 수행하였다. 그리고 NATM Composite 라이닝 공법의 개발을 위한 기초 연구로서 고성능 PC 패널 라이닝의 개발을 위해 다양한 혼화재료의 영향을 검토하고, PC 패널 설치 위치별 최적 배합을 도출하였다. 또한 PC 패널 배면 뒤채움재로 경량기포 모르타르 재료를 개발하였으며 실대형 하중재하 실험을 통해 NATM Composite 라이닝 공법의 거동 특성을 규명하였다. NATM Composite 라이닝 공법은 기존 현장타설 라이닝 공법에 비해 안정성과 시공성을 크게 향상 시킬 수 있을 것으로 판단된다.

• 마이크로전자및패키징학회지
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• 제13권4호
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• pp.37-43
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• 2006

플립칩 공정에 Sn 범프를 적용하기 위해 도금전류밀도와 전류모드에 따른 Sn 도금막의 표면 거칠기와 경도를 측정하였다. 전류밀도 $5{\sim}50\;ma/cm^{2}$에서 전기도금한 Sn 도금막은 $2.0{\sim}2.4{\mu}m$의 표면 거칠기를 나타내었으며, 직류모드보다 펄스모드로 형성한 Sn 도금막에서 표면 거칠기가 감소하였다 할로겐 램프를 사용하여 $300^{\circ}C$에서 3초간 유지하는 표면 열처리에 의해 Sn 도금의 표면 거칠기가 $1\;{\mu}m$ 정도로 현저히 저하되었다. 전류밀도 $5{\sim}50mA/cm^{2}$에서 전기도금한 Sn 도금막은 10 Hv의 경도를 나타내었다. Sn 범프들을 이용하여 플립칩 본딩한 시편들은 $33{\sim}17m{\Omega}$의 낮은 접속저항을 나타내었다.

• Nuclear Engineering and Technology
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• 제51권8호
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• pp.1897-1904
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• 2019

Three-layer back propagation network (BPN) and genetic neural network (GNN) were developed in this study to predict the flow boiling heat transfer coefficient (HTC) in conventional and small-diameter channels. The GNN has higher precision than BPN (with root mean square errors of 17.16% and 20.50%, respectively) and other correlations. The inputs include vapor quality x, mass flux G, heat flux q, diameter D and physical parameter φ, and the predicted flow boiling HTC is set as the outputs. Influences of input parameters on the flow boiling HTC are discussed based on the trained GNN: nucleate boiling promoted by a larger saturated pressure, a larger heat flux and a smaller diameter is dominant in small channels; convective boiling improved by a larger mass flux and a larger vapor quality is more significant in conventional channels. The HTC increases with pressure both in conventional and small channels. The HTC in conventional channels rises when mass flux increases but remains almost unaffected in small channels. A larger heat flux leads to the HTC growth in small channels and an increase of HTC was observed in conventional channels at a higher vapor quality. HTC increases inversely with diameter before dry out.

• Journal of the Korean Data and Information Science Society
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• 제21권6호
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• pp.1101-1108
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• 2010

본 연구는 요추 추간판 탈출증 환자 30명을 대상으로 전신냉기치료와 감압치료를 병행한 그룹과 감압치료를 적용한 그룹으로 나누어 2주간 실시한 후 통증과 요추 굴곡 관절가동범위, 그리고 전반적 인지효과에 미치는 효과에 대해 알아보기 위해 실시하였다. 본 연구의 측정은 시각적 상사 척도 검사와 수정판 쇼버 검사, 그리고 전반적 인지효과척도를 검사하였다. 대응표본 T검사에서 두 그룹 모두 효과적이었다. 그러나 독립표본 T검정과 공분산분석 결과 전신냉기치료와 감압치료를 병행한 그룹에서 더욱 효과적이었다. 요추 추간판 탈출증의 통증과 관절가동범위, 그리고 전반적 인지효과를 개선시키기 위해 전신냉기치료와 감압치료 병용 시 효과적이란 것을 검증하였다.

• 대한예방한의학회지
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• 제14권3호
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• pp.27-35
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• 2010

Objective : This study was carried out to investigate the acute toxicity and safety of Insampaedok-san extract in ICR Mice. Methods : SPF ICR male and female mice were administered orally with Insampaedok-san extract of 0 (control group), 1250, 2500 and 5000 mg/kg. After single administration, we daily examined number of deaths, clinical signs, gross findings and changes of body weight for 14 days. Hematological parameters and isolated organ weights were determined after 14 days of administration. Results : No dead animal and no significant changes of body weights were found during experimental period. In addition, no differences were found between control and all of treated groups in clinical signs, organ weights and hematology, and other findings. Conclusions : Insampaedok-san extract did not show any toxic effects and oral LD50 values of the extracts was over 5000 mg/kg in ICR mice.

• 한국한의학연구원논문집
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• 제17권3호
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• pp.115-121
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• 2011

Objective : The purpose of this study was to investigate the changes in the contents of constituents in Socheongryong-tang (CY) and its fermentations (FCY) with 10 species of lactic acid bacteria. Methods : Ten strains of lactic acid bacteria, Lactobacillus casei 127, L. acidophilus 128, L. casei 129, L. plantarum 144, L. amylophilus 161, L. curvatus 166, L. delbruekil subsp. lactis 442, L. casei 693, B. breve 744, and B. thermophilum 748, were used for the fermentation of Socheongryong-tang. The increased and decreased constituents were identified using HPLC/DAD and various liquid chromatographic techniques, and the structure was elucidated using NMR and MS. These compounds were quantitatively analyzed using an HPLC/DAD system. Results : The increased constituents were identified to be liquiritigenin (1) and cinnamyl alcohol (2), and the decreased constituent was determined to be liquiritin (3). Liquiritigenin (1) and cinnamyl alcohol (2) were increased in all of the FCYs, while liquiritin (3) was decreased. The fermentation of the ten lactic acid bacteria demonstrated that the decomposable rate of these three compounds in FCYs were different. Socheongryong-tang fermented by L. plantarum 144 and L. amylophilus 161 showed the most remarkable changes. Conclusions : CY could be increased antibacterial, neuroprotective, or antiinflammatory effect by fermentation with lactic acid bacteria, especially with L. plantarum and L. amylophilus, considering their known biological activities. In addition, it is expected that this study will help to establish quality control parameters for FCY.

• 한국지능시스템학회논문지
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• 제22권6호
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• pp.748-753
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• 2012

본 논문에서는 최적 pRBFNNs 패턴분류기 기반 3차원 스캐너를 이용한 얼굴인식 알고리즘을 설계한다. 일반적으로 2차원 영상을 이용한 얼굴인식 시스템은 사진의 명암도를 이용하여 얼굴의 특징을 추출하게 된다. 그렇기 때문에 빛이나 조명, 또는 얼굴 포즈와 같은 환경 변화들은 시스템의 성능을 저하시킨다. 따라서 본 논문에서 제안된 얼굴인식 알고리즘은 2차원 얼굴인식 시스템의 한계를 극복하기 위하여 3차원 스캐너를 사용하여 설계한다. 먼저 3차원 스캐너를 이용하여 얼굴 형상을 스캔하고 스캔된 얼굴 형상은 포즈 보상 과정을 통하여 정면으로 변환된다. 그 후에 Point Signature 기법을 사용하여 얼굴의 깊이 정보를 추출하고 마지막으로 고차원 패턴인식 문제에 대한 해결을 위하여 최적화된 pRBFNNs (Polynomial-based Radial Basis Function Neural Networks) 모델을 사용하여 인식성능을 확인한다.

• 한국환경보건학회지
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• 제44권6호
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• pp.539-547
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• 2018

Objectives: Ozone ($O_3$) advisories are issued by provincial/prefectural and city governments in Korea and Japan when oxidant concentrations exceed the criteria of the related country. Advisories issued only after exposure to high $O_3$ concentrations cannot be considered ideal measures. Forecasts of $O_3$ would be more beneficial to citizens' health and daily life than real-time advisories. The present study was undertaken to present a simplified forecasting model that can predict surface $O_3$ concentrations for the afternoon of the day of the forecast. Methods: For the construction of a simple and practical model, a multivariate regression model was applied. The monitored data on gases and climate variables from Japan's air quality networks that were recorded over nearly one year starting from April 2016 were applied as the subject for our model. Results: A well-known inverse correlation between $NO_2$ and $O_3$ was confirmed by the monitored data for Iksan, Korea and Fukuoka, Japan. Typical time fluctuations for $O_3$ and $NO_x$ were also found. Our model suggests that insolation is the most influential factor in determining the concentration of $O_3$. $CH_4$ also plays a major role in our model. It was possible to visually check for the fit of a theoretical distribution to the observed data by examining the probability-probability (P-P) scatter plot. The goodness of fit of the model in this study was also successfully validated through a comparison (r=0.8, p<0.05) of the measured and predicted $O_3$ concentrations. Conclusions: The advantage of our model is that it is capable of immediate forecasting of surface $O_3$ for the afternoon of the day from the routinely measured values of the precursor and meteorological parameters. Although a comparison to other approaches for $O_3$ forecasting was not carried out, the model suggested in this study would be very helpful for the citizens of Korea and Japan, especially during the $O_3$ season from May to June.

• Geomechanics and Engineering
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• 제18권4호
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• pp.439-448
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• 2019

The bearing capacity of roadside support is the key problem in gob-side entry retaining technology. To study the cooperative bearing characteristics of the roof-roadside support-floor along the gob-side entry retaining, a mechanical model of the composite structure of the roof-roadside support-floor was first established. A method for determining the structural parameters of gob-side entry retaining was then proposed. Based on this model, adaptability analysis of roadside support was carried out. The results showed that the reasonable width of the gob-side entry roadway was inversely proportional to the mining height, and directly proportional to the bearing strength of the roof and floor. And the reasonable width of the "flexible-hard" roadside support was directly proportional to its own strength, and inversely proportional to the width of the gob-side entry retaining. When determining the position and size of the roadside support along the gob-side entry retaining, the surrounding rock environment should be fully considered. Measured results from case study also show the rationality of the model and calculation method.

• Journal of Ginseng Research
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• 제43권3호
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• pp.368-376
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• 2019

Background: In the current phytochemical research on ginseng, the differentiation and structural identification of ginsenosides isomers remain challenging. In this paper, a two-dimensional mass spectrometry (2D-MS) method was developed and combined with statistical analysis for the direct differentiation, identification, and relative quantification of protopanaxadiol (PPD)-type ginsenoside isomers. Methods: Collision-induced dissociation was performed at successive collision energy values to produce distinct profiles of the intensity fraction (IF) and ratio of intensity (RI) of the fragment ions. To amplify the differences in tandem mass spectra between isomers, IF and RI were plotted against collision energy. The resulting data distributions were then used to obtain the parameters of the fitted curves, which were used to evaluate the statistical significance of the differences between these distributions via the unpaired t test. Results: A triplet and two pairs of PPD-type ginsenoside isomers were differentiated and identified by their distinct IF and RI distributions. In addition, the fragmentation preference of PPD-type ginsenosides was determined on the basis of the activation energy. The developed 2D-MS method was also extended to quantitatively determine the molar composition of ginsenoside isomers in mixtures of biotransformation products. Conclusion: In comparison with conventional mass spectrometry methods, 2D-MS provides more direct insights into the subtle structural differences between isomers and can be used as an alternative approach for the differentiation of isomeric ginsenosides and natural products.