• 대기
• /
• 제17권3호
• /
• pp.217-230
• /
• 2007

Using the Lorenz-95 simple model, which can simulate many atmospheric characteristics, we compare the performance of ensemble strategies such as bred vectors, the bred vectors rotated (to be orthogonal to each bred member), and the Ensemble Transform Kalman Filter (ETKF). The performance metrics used are the RMSE of ensemble means, the ratio of RMS error of ensemble mean to the spread of ensemble, rank histograms to see if the ensemble member can well represent the true probability density function (pdf), and the distribution of eigen-values of the forecast ensemble, which can provide useful information on the independence of each member. In the meantime, the orthogonal bred vectors can achieve the considerable progress comparing the bred vectors in all aspects of RMSE, spread, and independence of members. When we rotate the bred vectors for orthogonalization, the improvement rate for the spread of ensemble is almost as double as that for RMS error of ensemble mean compared to the non-rotated bred vectors on a simple model. It appears that the result is consistent with the tentative test on the operational model in KMA. In conclusion, ETKF is superior to the other two methods in all terms of the assesment ways we used when it comes to ensemble prediction. But we cannot decide which perturbation strategy is better in aspect of the structure of the background error covariance. It appears that further studies on the best perturbation way for hybrid variational data assimilation to consider an error-of-the-day(EOTD) should be needed.

• Nutrition Research and Practice
• /
• 제9권4호
• /
• pp.393-399
• /
• 2015

BACKGROUND/OBJECTIVES: Thin children may have insufficient intake of energy and nutrients, resulting in reduced immune function and growth. This study aimed to identify the effects of multiple herb formula SEC-22 supplementation on growth, dietary changes, and picky eating behaviors in thin children. SUBJECTS/METHODS: A double-blind, randomized clinical trial was conducted on 79 children aged 2-5 years with poor appetites, BMI percentile < 25, and without any illness. Subjects were given either SEC-22 (n = 35) or placebo (n = 44) for 2 months and followed for an additional 2 months. Three-day dietary records, questionnaires on picky eating behaviors, and anthropometric measures were collected. RESULTS: Energy, carbohydrate intake, and feeding difficulty improved in both groups during the intervention period. However, changes were maintained only in the SEC-22 group after 2 months of follow-up post-supplementation. 'Frequency of trying to feed' was improved in the SEC-22 group compared to the placebo group after the first month of follow-up (P < 0.05). Intakes of potassium and thiamine were improved in the SEC-22 group compared to the placebo group after the first month of intervention (P < 0.05). 'Frequency of food reward', eating amount, and intakes of carbohydrate, potassium, and vitamin C showed significant improvement compared to the placebo group after the second month of follow-up (P < 0.05). CONCLUSIONS: These results suggest that SEC-22 supplementation can improve parental feeding difficulty resulting from insufficient eating amount or picky eating as well as increase nutrient intake in thin children. Although these improvements were observable at least 2 months after supplementation, effects beyond this time frame need to be confirmed.

• 복식
• /
• 제50권2호
• /
• pp.125-140
• /
• 2000

The major findings of basic women wear in genre painting were ; 1. Due to the influence of Shill-Hak (practical science) philosophy, Jeogori became shorter and a tighter fit came to be the norm. 2,. The shortening of the Jeogori influenced a longer Chima with a wider span providing comfort in movement or at work. The end of the skirt was often held by one hand to the waist adding to comfort. This was called the Go-dul-chima(Lifted Chima). 3. Because the Geo-dul-chima exposed a portion of one underwear at the bottom of the dress this influenced the "irnamentation' of underpants and underskits. 4. Collars or lapels came in the form of Dang-ko, Kal, Mok-pan and Ban-Mokpan. Among there Dang-ko style collars were the most common which allows us to conclude that this was the most popular. 5. The most commonly used colors for Jeogori were white (39.8%) and jade(18.3%) . The most commonly used colors for CHima were deep blue(34.4%) and jade(20.4%) . The lower Chima used the darkercolors to give stability to the overall costume. 6. Clothing had the function of differentiating the classes. Only the Yang-ban were allowed to wear the Samhijang Jeogori and the Gob-Chima(double layered Chima) and the knotting of the Chima to the left. But the painting show that these rules were not adhered to in the strictest manner. With the bases of these types of chima and Jeogori can look at the characteristical beauty of the ordinary women during the late Cho-sun dynasty. First is the beauty which comes from mystery of those parts of body which can not be seen. A sense of subtle and sensual beauty as well as that coming from the enlargement of reduction of the upper body, narrow waist and abundant lower body parts creating an ideal silhouette of sexual charm. An expression of emotion through clothing by those who lived during those times.

• 한국전산구조공학회논문집
• /
• 제30권1호
• /
• pp.17-22
• /
• 2017

본 연구에서는 페이즈필드 설계법에 기반한 형상최적설계를 통해 개선된 패치안테나 금속 패치 부분의 형상 설계를 진행하였다. 설계 목적은 패치 안테나의 목적 주파수에서의 방사 효율을 최대화 하는 것으로 설정하였고, 이에 따라 목적 함수는 반사손실을 나타내는 S-파라미터 값의 최소화로 정의하였다. 패치형상의 최적화 결과는 페이즈필드 설계법을 이용하여 도출하였고, 최적화 결과의 회색영역을 제거하기 위해서 컷오프 방법을 적용하였다. 더불어 쿼터 정합기의 길이 변화를 통해 성능 개선 과정을 진행하였다. 이를 통해 도출해낸 최종 형상에 대한 해석 결과, 목표 주파수에서의 S-파라미터 값이 -1.14dB에서 -12.73dB로 개선됨을 확인하였다.

• 대한토목학회논문집
• /
• 제31권5D호
• /
• pp.671-677
• /
• 2011

최근 철도 서비스를 개선하고자 기존선을 복선 및 전철화 하는 등 철도네트워크 기능강화사업이 활발히 추진되고 있다. 이를 배경으로 본 논문에서 급행철도와 같이 새로운 철도 운영서비스가 제공될 경우 타 교통수단으로부터 얼마의 전환수요가 발생될 것이며, 철도이용형태는 어떻게 변화될 것인지? 등 앞으로 건설될 대구권 광역철도를 대상으로 SP와 RP데이터에 의한 전환수요 예측방법의 적용성을 검토하였다. 모형 구축결과, 기존 SP와 RP데이터를 결합하는 동시적 모형과 순차적 모형이 모두 유용하여 총통행시간과 통행비용의 파라미터 추정치가 충분한 설명력을 나타내고 있으며, 동시적 방법이 보다 효율적으로 분석되었다. 특히 RP+SP의 결합모형의 타당성을 더욱 높이기위해서 RP데이터를 비례적으로 적용한다면, 철도요금과 통행시간 설정에 따라 전환수요를 쉽게 파악할 수 있을 것이며, 대구권 광역철도를 비롯하여 타 지역에서도 보다 실용적으로 적용할 수 있을 것으로 판단된다.

• The Korean Journal of Physiology and Pharmacology
• /
• 제1권3호
• /
• pp.285-296
• /
• 1997

Injury to brain transforms resting astrocytes to their reactive form, the hallmark of which is an increase in glial fibrillary acidic protein (GFAP), the major intermediate filament protein of their cell type. The overall glial response after brain injury is referred to as reactive gliosis. Glial-neuronal interaction is important for neuronal migration, neurite outgrowth and axonal guidance during ontogenic development. Although much attention has been given to glial regulation of neuronal development and regeneration, evidences also suggest a neuronal influence on glial cell differentiation, maturation and function. The aim of the present study was to analyze the effects of glial-hippocampal neuronal co-culture on GFAP expression in the co-cultured astrocytes. The following antibodies were used for double immunostaining chemistry; mouse monoclonal antibodies for confirm neuronal cells, rabbit anti GFAP antibodies for confirm astrocytes. Primary cultured astrocytes showed the typical flat polygonal morphology in culture and expressed strong GFAP and vimentin. Co-cultured hippocampal neurons on astrocytes had phase bright cell body and well branched neurites. About half of co-cultured astrocytes expressed negative or weak GFAP and vimentin. After 2 hour glutamate (0.5 mM) exposure of glial-neuronal co-culture, neuronal cells lost their neurites and most of astrocytes expressed strong CFAE and vimentin. In Western blot analysis, total GFAP and vimentin contents in co-cultured astrocytes were lower than those of primary cultured astrocytes. After glutamate exposure of glial-neuronal co-culture, GFAP and vimentin contents in astrocytes were increased to the level of primary cultured astrocytes. These results suggest that neuronal cell decrease GFAP expression in co-cultured astrocytes and hippocampal neuronal-glial co-culture can be used as a reactive gliosis model in vitro for studying GFAP expression of astrocytes.

• 대한약리학회지
• /
• 제32권2호
• /
• pp.177-188
• /
• 1996

The effects of cytokines on the growth and differentiation of glial cells in culture were evaluated to confirm that cytokines could modify the number and function of glial cells. Proliferation of glial cells was determined by the $^3H-thymidine$ uptake and the double immunostain with anti-cell specific marker and anti-bromodeoxyuridine(BrdU) antibody. To check the effect on the differentiation of glial cells, the amount of glial fibrillar acidic protein(GFAP) and the activity of glutamine synthetase(GS) were measured in astrocytes. And also the amounts of myelin basic protein(MBP) and the activity of 2',3'-cyclic nucleotide phosphohydrolase(CNPase) were measured in oligodendrocytes. Among the cytokines used, only interleukin-$1{\beta}(IL-1{\beta})$ stimulated the growth of type 1 and type 2 astrocyte as well as 0-2A precursor cell. When the functional changes in these glial cells by cytokines were tested, $IL-1{\beta}$ did not increase GFAP content in type 1 and type 2 astrocyte, but $IL-1{\beta}$ increased GS activity in type 1 astrocyte, and slightly decreased this enzyme activity in type 2 astrocyte. Also interleukin-2(IL-2) and $interferon-{\gamma}$ $(IFN-{\gamma})$ inhibited the activity of GS in type 1 and type 2 astrocyte. On the other hand, all cytokines used did not modify the growth and differentiation in oligodendrocytes. From these results we could suggest that $IL-1{\beta}$ increases the growth of type 1 and type 2 astrocyte and also promotes the development for 0-2A precursor cell to type 2 astrocyte.

• Geomechanics and Engineering
• /
• 제9권5호
• /
• pp.645-667
• /
• 2015

Single treatment and staged treatments in vertical wells are widely applied in sandstone and mudstone thin interbedded (SMTI) reservoir to stimulate the reservoir. The keys and difficulties of stimulating this category of formations are to avoid hydraulic fracture propagating through the interface between shale and sand as well as control the fracture height. In this paper, the cohesive zone method was utilized to build the 3-dimensional fracture dynamic propagation model in shale and sand interbedded formation based on the cohesive damage element. Staged treatments and single treatment were simulated by single fracture propagation model and double fractures propagation model respectively. Study on the changes of fracture vicinity stress field during propagation is to compare and analyze the parameters which influence the interfacial induced stresses between two different fracturing methods. As a result, we can prejudge how difficult it is that the fracture propagates along its height direction. The induced stress increases as the pumping rate increasing and it changes as a parabolic function of the fluid viscosity. The optimized pump rate is $4.8m^3/min$ and fluid viscosity is $0.1Pa{\cdot}s$ to avoid the over extending of hydraulic fracture in height direction. The simulation outcomes were applied in the field to optimize the treatment parameters and the staged treatments was suggested to get a better production than single treatment.

• 한국광학회지
• /
• 제25권5호
• /
• pp.254-261
• /
• 2014

본 논문에서는 일반적인 코팅형 형광체와 이격 형광체 등 두 가지의 형광체 구조가 적용된 백색 LED를 제작한 후 온도변화에 따라 각 백색 LED의 발광 특성이 어떻게 변하는지 측정, 비교하였다. 상온에서 80oC 사이의 구간에서 측정된 두 백색 LED의 발광 스펙트럼을 분석하기 위해 Gaussian Lorentz-cross product 함수와 Asymmectic double sigmoidal 함수를 각각 청색 피크와 황색 피크의 곡선맞춤에 활용하였다. 이로부터 각 피크의 중심파장과 진폭, 반치폭 및 비대칭성을 온도의 함수로 구할 수 있었다. 온도에 따른 휘도와 색좌표를 측정한 결과 이격형광체 구조의 백색 LED의 온도에 따른 휘도저하율 및 색좌표 변화율이 훨씬 적었다. 이는 청색 LED 칩과 형광체가 분리됨에 따라 형광체의 온도가 일반 형광체 도포형 LED의 경우에 비해 낮아져서 효율이 상승했고 아울러 형광체에서 발생한 빛의 칩에 의한 흡수가 감소했기 때문인 것으로 해석된다.

• 한국전자파학회지:전자파기술
• /
• 제6권1호
• /
• pp.37-47
• /
• 1995

본 논문에서는 기존의 마이크로스트립 안테나가 갖는 협대역 특성과 급전선의 기생방사로 인한 방사패턴의 열화를 개선할 수 있는 슬롯결합 적충 마이크로스트립 안테나의 특성을 해석하고, 중심주파수 l1.5GHz와 12. $\alpha$}Hz에서 독립적인 공진 특성을 갖는 두 패치와 급전 슬롯의 상호결합작용에 의한 이중공진현상으로 인하여 15-20%의 대역폭을 갖는 적충안테나를 설계 제작하여 1.9-2.2GHz의 광대역 특성을 지님을 실험적으로 확인 하였다. 이에 대한 해석은 산란해석방볍을 이용하여 슬롯결합 급전구조에 대한 정확한 해석 모델을 제시하고, 제시된 모델과 함께 스펙트럼 영역에서 Green 함수를 유도하고 Galerkin 방법에 의해 수치적 계산을 하는 Full wave 해석방볍을 적용하였다. 수치해석에 사용된 기저함수는 해의 수렴도, 정확도 및 계산시간을 비교하여 패치는 3 개의 EB 모드, 급전선은5개의 PWS 모드를 사용하였다.