In this study, global climate change scenario by Hadley Centre Global Environmental Model version 2-Atmosphere and Ocean (HadGEM2-AO) is dynamically downscaled using four regional climate models (RCMs). All RCMs with 12.5-km and 50-km resolution are integrated for continuous 27 years (1979-2005). In general, RCMs with higher horizontal resolution more reasonably capture the spatial distribution of precipitation over South Korea compared to those with lower resolution. In particular, heavy precipitation regions related to complex mountain ranges are well simulated due to detailed topography in RCMs with higher resolution. Difference between RCMs with dissimilar resolutions is relatively robust in summer compared to other seasons. This could be associated with that higher resolution and detailed topography lead to more realistic simulation of heavy summer precipitation related to mesoscale phenomena.
Sensitivity analysis of the WRF model according to the impact of nudging (e.g., nudging techniques and application domains) was conducted during high nocturnal ozone episode to improve the prediction of the regional ozone concentration in the southeastern coastal area of the Korean peninsula. The analysis was performed by six simulation experiments: (1) without nudging (e.g., CNTL case), (2) with observation nudging (ONE case) to all domains (domain 1∼4), (3) with grid nudging (GNE case) to all domains, (4)∼(6) with grid nudging to domain 1, domain 1∼2 and domain 1∼3, respectively (GNE-1, GNE-2, GNE-3 case). The results for nudging techniques showed that the GNE case was in very good agreement with those observed during all analysis periods (e.g., daytime, nighttime, and total), as compared to the ONE case. In particular, the large effect of grid nudging on the near-surface meteorological factors (temperature, relative humidity, and wind fields) was predicted at the coastline and nearby sea during daytime. The results for application domains showed that the effects of nudging were distinguished between the meteorological factors and between the time periods. When applied grid nudging until subdomain, the improvement effects of temperature and relative humidity had differential tendencies. Temperature was increased for all time, but relative humidity was increased in daytime and was decreased in nighttime. Thus, GNE case showed better result than other cases.
An electro-hydraulic actuator (EHA) is widely used in industrial motion systems and the increasing bandwidth of EHA position control is important issue. The model-inverse feedforward controller is known to extend the bandwidth of system. When the system has non-minimum phase (NMP) zeros, direct model inversion makes system unstable. To overcome this problem, an approximate model-inverse method is used. A representative approximate model inversion method is zero phase error tracking control (ZPETC). However, if zeros locate right half plane of z-plane, the approximate inverse model amplifies the high-frequency response. In this paper, to solve the problem of ZPETC, an adaptive model-inverse control is proposed. The adaptive algorithm updates feedforward term in real-time. The effectiveness of the proposed adaptive model-inverse position control strategy is verified by comparison with typical proportional-integral (PI) control and feedforward control by experiments. As a result, the proposed adaptive controller extends the bandwidth of EHA position control.
Background : Korean Red Ginseng has been reported to have various anti-virus, anti-tumor, anti-inflammation and immune-regulating activity. However, Korean Red Ginseng Crude Saponin (KRGCS) effect on Pulmonary inflammation has been insufficient research. We have investigated the effect of KRGCS on pulmonary inflammation in mouse model. Methods and Results : Pulmonary inflammation induced by cigarette smoke condensates (CSC) and lipopolysaccharide (LPS) in BALB/c mice. 100uL (ratio 1:1) of CSC (4mg/mL) and LPS (100ug/mL) solution instilled with intratracheal injection once per a week for 3 weeks in mice. KRGCS was also administered orally a dose of 10mg/kg and 25mg/kg for 3 weeks. KRGCS treatment groups decreased the number of inflammatory total cells in lung tissues and bronchoalveolar lavage fluid (BALF) and the number of neutrophils in BALF dropped more than negative control groups. Additionally, KRGCS reduced the absolute number of CD4+ and CD8+ cells in BALF, and the number of CD11b+ Gr-1+cells in the lung and BALF. Furthermore, we found that KRGCS declined significantly the level of the cytokine chemokine (C-X-C motif)-1 (CXCL-1), Macrophage inflammatory protein-2 (MIP-2), and tumor necrosis factor alpha (TNF-α) in BALF. Conclusion : These results that KRGCS has an inhibitory effects on pulmonary inflammation such as COPD, may be a candidate of effective herbal pharmaceuticals for the cure of lung diseases.
본 연구는 단경간 교량의 정적하중입력/변위출력관계를 이용한 새로운 교량 유한요소모델 개선 방법을 제안하였고, 실내 모형교량 실험을 통해 검증하였다. 기존의 유한요소모델개선기법은 실험으로부터 얻어진 모드계수와 유한요소모델로부터 예측된 모드계수가 유사해 지도록 유한요소모델을 개선하는데, 이 과정에서 구조계의 질량행렬에 대한 가정을 필요로 한다. 제안된 기법은 질량행렬을 가정하지 않고, 오 히려 질량행렬 추정을 가능하게 하는 장점을 가진다. 제안된 기법은 두 단계로 구성된다. 첫째, 정적 하중입력-변위응답으로부터 강성행렬을 개선하고, 둘째, 실측된 고유진동수를 이용하여 질량행렬을 개선한다. 실험검증을 위하여 실내 모형교량을 제작하였고, 제안된 기법을 이용하 여 모형교량의 탄성계수를 추정하였으며, Universal Testing Machine으로 부터 얻어진 탄성계수와 비교하였다. 또한 기존의 유한요소모델개 선기법으로 추정된 탄성계수와 비교하였다. 실험의 결과들로부터 제안된 기법이 합리적으로 탄성계수와 질량밀도를 추정하는 것이 관찰되었 고, 기존의 유한요소모델개선기법은 고차모드를 사용했을 때 상대적으로 큰 오차를 주는 것이 관찰되었다. 추가적으로 유한요소모델링 오차 에 대하여 토의하였다.
Background: Sanguisorba officinalis has been used in traditional Asian medicine owing to its beneficial effects on various diseases. The purpose of this study was to evaluate the effect of S. officinalis on the antioxidant system of Streptozotocin (STZ) and Alloxan (ALL) induced diabetic rats. Methods and Results: Triglyceride and Low-Density Lipoprotein (LDL)-cholesterol levels decreased in the STZ-induced diabetic groups treated with S. officinalis extract (SOE) compared to the corresponding levels in the control groups. Moreover, in the ALLinduced diabetic groups, SOE reduced triglyceride, LDL-cholesterol, and High-Density Lipoprotein (HDL)-cholesterol levels. Malondialdehyde (MDA) levels decreased significantly in the STZ and ALL-induced groups treated with SOE compared to the corresponding levels in the control group. Further, Glutathione (GSH) levels increased but did not reach statistical significance. The levels of Superoxide Dismutase (SOD) and Glutathione-S-Transferase (GST) showed a tendency to recover with SOE treatment in the STZ and ALL-induced diabetic groups. In addition, Catalase (CAT) levels in the SOE treatment group decreased significantly compared to those in the control group. Conclusions: These results suggest that SOE might be an effective agent in attenuating oxidative stress in diabetic patients by improving blood lipid profiles and inducing the anti-oxidative enzyme systems.
본 연구는 학생 중심의 음악과 수행평가를 구현하기 위한 방안을 모색하고, 핵심역량을 토대 로 피드백 전략이 강화된 학생 성장을 위한 음악과 평가 모델을 개발하는 데 목적을 두었다. 평가모델은 초·중·고등학생을 대상으로 한 5개 주제에 대해 3차시씩 총 15차시로 개발하였다. 이 평가모델에서는 평가의 개념을 학습 결과인 동시에 학습 과정으로 접근한 수시평가의 형태 를 적용하였고, 성취기준에 근거하여 현장 활용도를 고려한 수행과제와 평가방법을 개발하였으 며, 평가요소를 추출하고 평가척도를 제시하였다. 평가 결과에 따라 피드백과 심화·보충학습 자료를 4개 수준으로 구성하였다. 이렇게 개발한 평가모델은 시범학교의 현장 적용과 전문가들 의 검토를 통해 타당성과 적합성을 검증하고 수정‧보완하여 완성하였다.
In this study, the intensity change of a crack and concrete surface as light condition was estimated by using a reflection model. The result shaw that the concrete surface intensity was proportional to the light incident degree and the crack intensity was affected by the geometry of the crack.
In this paper, the tensile stiffness and deformation of laminated rubber bearing is investigated based on the research and test results. ISO 22762 and JIS K 6410 are not providing the tensile characteristics of rubber bearings. Besides, the tensile stiffness and deformation models are proposed by several researchers by quite different methods. Proper models are recommended for nonlinear deformation state in order to propose the tensile model and build up base data.
This study was conducted for the development of degradation model for the coated steel member in the atmospheric environment. Field inspection data was assessed against the existing evaluation factors which were proposed by the related research process. A correlation between evaluated degradation score and service life of coated steel member was plotted on the graph, and degradation of the coated steel member could be evaluated by quantitative analysis method.
Interest in seismic performance evaluation is increased due to various earthquake in the world. Many studies about fragility analysis of structure are performing which is based on probability analysis of failure for infrastructures maintenance. In this study, probability of failure for a numerical model of prototype square-shape reinforced concrete column was calculated in accordance with amplitude of seismic ground motion. The numerical model was updated based on results from shake table tests. The probability of failure will be used for comparing with that for scaled models. The difference of fragilities from prototype and scaled model can be confirmed by the comparing in a further study.
High speed railway bridges should be strictly maintained due to its social importance. However, There are many problems to execute loading test for precision safety diagnosis. A numerical experiment with a numerical model which is updated for reflecting characteristics of an existing bridge can be useful for high speed railway bridge maintenance. Moreover, more efficient maintenance can be possible if only ambient vibration is needed for numerical model updating process. In this study, a numerical model updating process is introduced in which only ambient vibration is enough to execute the process. Also, the usability of updated numerical model is verified by comparing measured and analyzed acceleration.
The bridges with damage can be a huge threat to human society. However, AASHTO (2012) and Korean Highway Bridge Design Code (2012) do not account for dynamic impacts for bridge column design under the impact loading. It recommends static force for bridge column design due to high computational cost and analysis time. In this study, in order to reduce the computational cost and time for the dynamic analysis, low dimensional model for the dynamic analysis was developed and residual displacements were compared with direct impact analysis.
Recently, an indirect displacement estimation method using data fusion of acceleration and strain (i.e., acceleration-strain-based method) has been developed. This paper proposes an improved displacement estimation method that can be applied to more general types of bridges by building the mapping using the finite element model of the structure. An experimental validation of the proposed method was carried out on a prestressed concrete girder bridge, and the method provides the best estimate for dynamic displacements.
This paper considers a homogeneous multiple regression (HMR) model and a non-homogeneous multiple regression model, that is, ensemble model output statistics (EMOS), which are easy to implement postprocessing techniques to calibrate probabilistic forecasts that take the form of Gaussian probability density functions for continuous weather variables. The HMR and EMOS predictive means are biascorrected weighted averages of the ensemble member forecasts and the EMOS predictive variance is a linear function of the ensemble variance. We also consider the alternative implementations of HMR and EMOS which constrains the coefficients to be non-negative and we call these techniques as HMR+ and EMOS+, respectively. These techniques are applied to the forecasts of surface temperature over Pyeongchang area using 24-member Ensemble Prediction System for Global (EPSG). The performances are evaluated by rank histogram, residual quantile-quantile plot, means absolute error, root mean square error and continuous ranked probability score (CRPS). The results showed that HMR+ and EMOS+ models perform better than the raw ensemble mean, HMR and EMOS models. In the comparison of HMR+ and EMOS+ models, HMR+ performs slightly better than EMOS+ model in terms of CRPS, however they had a very similar CRPS and if there exists a ensemble spread-skill relationship, it is seen that EMOS is slightly better calibrated than the homogeneous multiple regression model.
빛은 피부에서 개개인마다 상이한 반사, 흡수 및 산란 등의 광학적 거동을 보여준다. 특히, 피부에서 빛의 반사는 분광반사율이라는 물리량 측정을 통해 개인의 피부 밝기지표로 널리 활용되어 왔다. 따라서 피부에서 빛의 반사 거동 연구는 개인 맞춤형 화장품, 특히 메이크업 제품 개발에 있어 좀 더 효율적인 처방 개선에 기여하 거나 새로운 평가법에 활용될 수 있다. 본 연구에서는 Kubelka-Munk 모델을 이용하여 개인의 피부 특성에 따 른 빛의 분광반사율 거동에 대해 다각적인 분석을 수행하였다. 또한, 상기 모델과 기존에 알려진 문헌 정보를 이용하여 개인의 피부 분광반사율에 영향을 줄 수 있는 피부 두께 및 헤모글로빈 등의 다양한 파라미터들에 대한 기여도 분석을 수행하였다. 이를 통해, 일반적인 여성의 피부에서의 분광반사율 이론치를 계산하였고, 분광반사 율 실측을 통해 이론치와 실측치 간의 유사성을 확인하였다. Kubelka-Munk 모델을 이용한 피부 분광반사율 연구는 향후 새로운 개인 맞춤형 메이크업 화장품 개발에 유용하게 이용될 수 있을 것으로 사료된다.