• Applied Biological Chemistry
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• 제44권3호
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• pp.202-205
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• 2001

건강을 80% MeOH수용액으로 추출하고, 얻어진 추출물을 EtOAc, n-BuOH및 $H_2O$로 용매 분획하였다. 그 중에서 뚜렷한 활성을 보인 EtOAc 분획으로부터 DPPH(1-diphenyl-2-picryl hydrazyl) radical 포획법으로 항산화 활성을 추적하여 항산화 활성을 갖는 화합물 2종을 분리하였다. 각각을 NMR 및 MS 데이터의 해석과 문헌 자료를 조사하여 6-shogaol 및 12-shogaol로 구조를 결정하였다. 각 화합물의 $EC_{50}$값은 26.4 ${\mu}M$과 22.5 ${\mu}M$로 상용항산화제인 BHA, BHT 및 ${\alpha}-tocopherol$보다 뚜렷이 높은 활성을 나타내었다.

• Structural Engineering and Mechanics
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• 제49권1호
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• pp.95-110
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• 2014

The study deals with physical modeling of space frame-pile foundation and soil system using finite element models. The superstructure frame is analyzed using complete three-dimensional finite element method where the component of the frame such as slab, beam and columns are descretized using 20 node isoparametric continuum elements. Initially, the frame is analyzed assuming the fixed column bases. Later the pile foundation is worked out separately wherein the simplified models of finite elements such as beam and plate element are used for pile and pile cap, respectively. The non-linear behaviour of soil mass is incorporated by idealizing the soil as non-linear springs using p-y curve along the lines similar to that by Georgiadis et al. (1992). For analysis of pile foundation, the non-linearity of soil via p-y curve approach is incorporated using the incremental approach. The interaction analysis is conducted for the parametric study. The non-linearity of soil is further incorporated using iterative approach, i.e., secant modulus approach, in the interaction analysis. The effect the various parameters of the pile foundation such as spacing in a group and configuration of the pile group is evaluated on the response of superstructure owing to non-linearity of the soil. The response included the displacement at the top of the frame and bending moment in columns. The non-linearity of soil increases the top displacement in the range of 7.8%-16.7%. However, its effect is found very marginal on the absolute maximum moment in columns. The hogging moment decreases by 0.005% while sagging moment increases by 0.02%.

• 국제초고층학회논문집
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• 제5권3호
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• pp.233-241
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• 2016

This paper describes the structural solution for the design of a 29-story high-rise tower, which features a large office space above the Kabukiza Theatre. Kabuki is a type of Japanese traditional drama, and Kabukiza is the home building of Kabuki. GINZA KABUKIZA is the fifth generation of the Kabukiza Theatre, the first of which was built in 1889. In order to support 23 stories of office space above the theater - featuring a large void in plan - two 13-meter-deep mega-trusses, spanning 38.4 meters, are installed at the fifth floor of the building. Steelwork is used as a primary material for the structure above-ground, and a hybrid response control system using a buckling-restrained brace and oil damper is adopted in order to achieve a high seismic performance. This paper also describes the erection process of installing hydraulic jacks directly above the mega-truss at column bases, in order to keep the structure above the truss level during construction. The temple architecture of the previous Kabukiza is carefully restored by incorporating contemporary light-weight materials supported by steelwork.

• 전자공학회논문지
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• 제50권8호
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• pp.196-202
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• 2013

기저 세포암은 가장 일반적인 피부암이고 그 발병이 급속도로 증가하고 있다. 본 연구에서는 피부 조직에서 측정한 라만 스펙트럼에서 기저 세포암 진단을 위해 NMF(non-negative matrix factorization) 알고리즘을 사용하는 방법을 제안하였다. 측정된 라만 스펙트럼은 영역 선택과 정규화 등의 몇 가지 전처리 과정을 거쳐 분류 실험에 사용한다. 전처리 과정을 수행한 라만 스펙트럼은 NMF 알고리즘을 이용하여 분해된 행렬의 열벡터를 기저로 사용한다. 이 기저들을 선형 결합하여 각 클래스의 평균 스펙트럼에 근사하기 위한 가중치는 행렬 연산으로 결정한다. 분류 실험은 스펙트럼과 NMF에 의한 기저와 가중치의 선형 결합 스펙트럼의 차에 대한 제곱평균제곱근을 최소로 하는 클래스를 선택하는 것으로 수행한다. 기저 세포암의 진단을 위한 분류 실험에서 제안한 방법을 사용하는 경우가 약 99.1%의 평균 분류율로 이전의 BCC 진단에 사용한 방법보다 약 2-3% 정도의 향상된 성능을 보였다.

• Interaction and multiscale mechanics
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• 제3권1호
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• pp.55-79
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• 2010

The effect of soil-structure interaction on a single-storey, two-bay space frame resting on a pile group embedded in the cohesive soil (clay) with flexible cap is examined in this paper. For this purpose, a more rational approach is resorted to using the finite element analysis with realistic assumptions. Initially, a 3-D FEA is carried out independently for the frame on the premise of fixed column bases in which members of the superstructure are discretized using the 20-node isoparametric continuum elements. Later, a model is worked out separately for the pile foundation, by using the beam elements, plate elements and spring elements to model the pile, pile cap and soil, respectively. The stiffness obtained for the foundation is used in the interaction analysis of the frame to quantify the effect of soil-structure interaction on the response of the superstructure. In the parametric study using the substructure approach (uncoupled analysis), the effects of pile spacing, pile configuration, and pile diameter of the pile group on the response of superstructure are evaluated. The responses of the superstructure considered include the displacement at top of the frame and moments in the columns. The effect of soil-structure interaction is found to be quite significant for the type of foundation considered in the study. Fair agreement is observed between the results obtained herein using the simplified models for the pile foundation and those existing in the literature based on a complete three dimensional analysis of the building frame - pile foundation - soil system.

• 국제초고층학회논문집
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• 제4권3호
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• pp.171-180
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• 2015

A shaking table test was conducted at the E-Defense shaking table facility to investigate the damage and collapse behavior of a steel high-rise building under exceedingly large ground motions. The specimen is a one-third scale 18-story steel moment frame designed and constructed according to design specifications and practices used in the 1980s and 1990s. The shaking table tests used a long-duration, long-period ground motion simulated for a sequential Tokai, Nankai, and Nankai earthquake scenario. The building specimen was subjected to a series of progressively increasing scaled motions until it completely collapsed. The damage to the steel frame began through the yielding of beams along lower stories and column bases of the first story. After several excitations by increasing scaled motions, cracks initiated at the welded moment connections and fractures in the beam flanges spread to the lower stories. As the shear strength of each story decreased, the drifts of lower stories increased and the frame finally collapsed and settled on the supporting frame. From the test, a typical progression of collapse for a tall steel moment frame was obtained, and the hysteretic behavior of steel structural members including deterioration due to local buckling and fracture were observed. The results provide important information for further understanding and an accurate numerical simulation of collapse behavior.

• 분석과학
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• 제7권4호
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• pp.547-554
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• 1994

국내 자생 담자균, Phellinus ribis부터 ceramide 성분들이 존재함을 확인하고 실리카 컬럼크로마토그래피를 이용하여 분리하고 prep.-TLC로 재차 정제한 다음, 그 구조 및 조성을 검토하였다. FAB-MS 및 GC-MS를 이용하여 그 구성성분을 분석한 결과 지방산 주성분은 hydroxy fatty acid($C_{22:0}$, $C_{25:0}$, $C_{24:0}$, $C_{23:0}$)이고 sphingoid 염기는 (tri-hydroxy-sphinganine 및 동족계열의 아민으로 확인되었다.

• 한국토양비료학회지
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• 제31권4호
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• pp.400-406
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• 1998

사양토, 양토, 식양토의 3 가지의 토양을 $2^{{\prime}{\prime}}{\times}30cm(D{\times}L)$ column에 충진한 후 인공 산성비(pH 2.0, 4.0, 6.0) 1,200mm를 처리하여 산성비의 토양내 침투수량에 따른 토양의 산성화 경향, 토양 중 무기양분의 용탈과 이동양상과 산성비 토양투입에 따른 석회 중화양을 비교검토한 결과, 산성비 처리에 따른 각 토양의 pH 변화는 산성비의 pH가 4.0과 6.0에서는 별 차이가 없었으나, pH 2.0에서는 토심별로 큰 차이를 보였으며 pH감소는 사양토>양토>식양토의 순이었고, 치환산도(치환성 Al+H)는 식양토>양토>사양토의 순위였다. 산성비에 따른 각 토양의 토심별 양분 용탈량은 산성비의 pH 2.0에서 많았으며, 사양토, 양토와 식양토의 경우, 각토양 공히 Ca>K>Mg 순위였다. 토양의 pH감소와 치환산도(치환성 Al+치환성 H)는 사양토 > 양토 > 식양토의 순위였으나, pH감소에 따라 증가되는 치환산도는 그 토양의 CEC범위내 이었다. 토양내의 치환성 Al는 토양의 pH가 5이하에서는 거의 없었다. pH 3.0인 산성비(황산:질산=2:1, $1,200mm\;year^{-1}$)의 유입에 따른 H이온의 유입은 $12kg\;ha^{-1}\;year^{-1}$, 산성비의 토양유입은 S와 N가 각각 128과 $56kg\;ha^{-1}{\cdot}year^{-1}$이었으며, 이를 중화할 수 있는 소석회의 양은 $444kg\;ha^{-1}\;year^{-1}$이지만 실제로 용탈된 염기는 소석회로 사양토 923, 양토 1,731, 식양토 $1,608kg\;ha^{-1}\;year^{-1}$로 추정되었다.