• Journal of the Korean Society for Railway
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• v.17 no.4
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• pp.260-269
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• 2014

Transition tracks are an alternative for enhancing the long-term serviceability and durability of concrete track components in railway bridges. The goal of this paper is to investigate the structural behavior for transition track systems of railway bridge deck ends. In this study, the structural behavior of transition tracks such as the variations in static, dynamic, and fatigue behaviors and dynamic properties (natural frequency and damping ratio) are assessed and compared through performing loading tests and finite element analyses using actual vehicle impact loadings. As a result, it is found that the structural behavior of the transition track system is expected to satisfy the actual vehicle impact loading, and the variation in the neutral axis and dynamic characteristics are not affected by the fatigue loading. Therefore, it is inferred that the structural capacity and long-term durability of the transition track system is proven.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.11
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• pp.1055-1065
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• 2009

In this study, stability analysis of boundary layers on airfoils is performed by using parabolized stability equations(PSE). Boundary layer edge conditions are obtained by compressible inviscid flow calculations. Mean velocity and temperature profiles of the laminar boundary layer are obtained by solving compressible boundary layer equations in generalized curvilinear coordinates with fourth order accuracy in the wall normal direction. Laminar mean flow profiles are used as input data for PSE to investigate growth rates of disturbances and stability characteristics. For the cases of boundary layer on NACA0012 and HSNLF(1)-0213 airfoils at Mach number 0.5, growth rates with respect to disturbance frequencies and profiles of disturbance amplitude are investigated. The effect of angle of attack on stability characteristics are examined at both upper and lower surfaces. The neutral stability curves, effect of Mach number and effect of airfoil section shapes are also analyzed.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.50-50
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• 2001

혈액형을 지배하는 유전자는 진화에 대하여 중립적인 작용을 하고 있어서 집단의 유전적 구조의 특성 파악, 계통분류학 등에 많이 응용되고 있다. 본 연구는 칡소에 대한 유전학적 특성을 구명하고자 혈액형 분석기술을 응용하여 실시하였다. 공시동물은 (주)한경게놈텍 목장에서 사육중인 외모적으로 칡소의 특징을 보이는 25두를 이용하였다. 혈액은 경정맥에서 헤파린 처리된 진공 채혈관에 무균적으로 채취하여 혈장, 백혈구 및 적혈구로 원심분리한 후 냉동 혹은 냉장 보관하여 각 실험에 이용하였다. 적혈구 항원형의 검출은 2% 적혈구 부유액과 축산기술연구소에서 생산된 항혈청 11종을 이용하여 용혈반응으로 실시하였고, 혈액단백·효소를 지배하고 있는 6개의 유전자 좌위에 대하여 전분 혹은 포리아크릴 아미드겔 전기영동으로 다형 검출을 실시하였다. 용혈반응으로 검출한 적혈구 항원형의 반응양상은 검사한 11종의 항체에 대하여 6종은 50%이상의 개체에서 양성반응을 보였다. 이와 같은 결과는 일반 한우에서 보이는 양성반응율보다는 높은 것으로 판단되어진다. 전기영동법으로 분석한 6개의 혈액단백·효소 지배 유전자 좌위 중 ALB좌위을 제외한 5개 유전자 좌위에서 다형이 관찰되었다. HB, AMY-1, GC 및 PTF-2 유전자 좌위는 2개의 대립유전자가 관찰되었고, TF 유전자 좌위는 4개의 대립유전자가 관찰되었다. 표 1에서 같이 칡소에서 관찰된 각 유전자 좌위의 대립유전자 빈도의 구성은 일반적인 한우와는 상이한 결과를 보였으나 평균 이형접합도는 칡소가 0.438, 일반한우가 0.442로 계산되어 유전적 변이성은 유사한 것으로 추정되었다. 이상의 결과로 본 연구에서 분석한 칡소는 다른 한우집단과는 상이한 유전적 구조를 가지고 있으나, 유전적 다형성은 비교적 높은 것으로 시사되었다. 보다 정확하고 많은 량의 유전정보 수집을 위하여 Microsatellite DNA 및 모색 관련 유전자를 분석할 필요성이 있을 것으로 사료된다.(Table Omitted)

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.2
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• pp.211-215
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• 1983

Thirty eight varieties with high uniformity and clearance in grain quality among 70 colored soybeans collected from nation-wide provinces were investigated for their seed morphological and agronomic traits. As for seed morphological traits, grain volumetric size, grain weight, grain length, grain thickness, . hilum length and width were studied on the tendency of statistical dispersion and variations. As a result, four groups could be classified on the basis of 100 grains weight, so as small, medium, large, and super large groups, Also, as for agronomic traits, among others, the tendency of setting in flowering date, maturing date, yield components, and stem weight, stem length were studied on the basis of statistical inter-relationships between above mentioned characteristics. From the above, bigger variations were detected in weighing characters of soybean plants than in duration characters. And the flowering and maturing days showed significant relationships to the stem length, stem weight, also stem length and stem weight to the grain yield.

• Journal of the Korean earth science society
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• v.22 no.5
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• pp.405-414
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• 2001

Jecheon granite can be divided into two types; porphyritic granite (K-feldspar megacryst bearing) and medium-grained biotite granite. Porphyritic granite, host body of feldspar deposits, is 8${\sim}$11 km in diameter and about 80 $km^{2}$ in area. It mainly contains K-feldspar, plagioclase, biotite and quartz, and magnetite, zircon, sphene and apatite are accessary minerals. Enclosed minerals in K-feldspar megacryst with 3${\sim}$10 cm in diameter are hornblende, plagioclase, quartz, magnetite, apatite, sphene and zircon. Mafic enclaves mainly consisting of hornblende, plagioclase and quartz are frequently observed in porphrytic granite. Medium-grained biotite granite consists of K-feldspar, plagioclase, biotite and hornblende as main, and hematite, muscovite, apatite and zircon as accessary minerals. Core and rim An contents of plagioclase from porphyritic granite, medium biotite granite, K-feldspar megacryst, and mafic enclave are 36 and 21, 40 and 32, 37 and 32, and 43 and 36, respectively. $X_{Fe}$ values of hornblende are 0.57 at biotite granite, 0.51 at K-feldspar mehacryst and 0.45 at mafic enclave. $X_{Fe}$ values of biotite and hornblende are homogeneous without chemical zonation. K-feldspar megacryst shows end member of pure composition with exsolved thin lamellar pure albites. Characteristics of mineral compositions and petrography indicate porphyritic granite is igneous origin and medium-grained biotite granite comes from the same source of magma; biotite granite is initiated to solidly and from residual melt porphyritic granite can be formed. Possibly K-feldspar megacrysts are formde under H$_{2}$O undersaturation condition and near K-feldspar solidus curve temperature; growth rate is faster than nucleation rate. Mafic enclaves are thought to be mingled mafic magma in felsic magma, which is formed from compositional stratigraphy. Estimated equilibrium temperature and pressure for medium-grained biotite granite are about $800^{\circ}C$ and 4.83${\sim}$5.27 Kb, respectively.

• The Journal of Engineering Geology
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• v.14 no.2
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• pp.147-168
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• 2004

Purpose of this study is to quantitatively characterize the fracture roughness which was measured with a confocal laser scanning microscope. The roughness discrete data measured by confocal laser microscope were analyzed by spectral analysis and fast Fourier transform (FFT).The roughness data by used noise reduction filter were applied for fractal analysis to describe roughness features quantitatively. Artificial fractures created by Brazilian test on granites were used to measure fracture roughness under the confocal laser scanning microscope. Measurements were performed along three scan lines on each fracture surface. 36 scan lines were determined on 12 specimens in total. Features of roughness showed that coarse and medium grained granites tend to more rough features than those of fine grained granites. Continuous analog data of roughness is possible to described as discrete data of measure roughness with a fixed interval under the confocal laser microscope. Results of FFT with the measured data showed the highest values on the second harmonics. Distribution of average amplitude of second harmonics was observed 0.9853 in coarse grained granite, 1.0792 in medium grained granite and 0.6794 in fine grained granite. This indicates that the larger roughness has the higher energy of harmonics as the result of fractal analysis in low frequency zone.

• Journal of Korean Society of Steel Construction
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• v.28 no.5
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• pp.365-371
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• 2016

In the case of the superstructure which is consist of two I girders and slab, the section can behave as II section, so that the neutral axis with respect to out of plane direction flexure can be regarded as major axis. Therefore in-plane flexural mode might govern the free vibration mode. Meanwhile, horizontally curved girders always experience not only bending moments but also torsional moments although the primary load is usually supposed to be gravitational load. The interaction due to bending and torsional moments make the behavior complicated and torsional mode may govern the free vibration mode. In other words, structure can have different dynamic characteristic due to its initial curvature. In this research, using 3-dimensional sell elements, free-vibration analyses are carried out due to initial curvature. The analysis models are assumed to be composite and non-composite and finally natural frequency and eigen mode are discussed.

• Journal of Korean Society of Steel Construction
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• v.15 no.5 s.66
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• pp.509-518
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• 2003

In this study, we carried out nonlinear analysis according to various interface nonlinear models by interaction magnitude, and analyzed interface behavior such as distribution of tangential traction and relative slip in steel-concrete composite structure. As a result of this study, tangential traction and relative slip of interface is rapidly increased at the steel plate-concrete interface, especially at the neutral region, rather than tensile, as opposed to the T beam-concrete interface. In transverse direction, it has gradually reduced to go outside from loading position. In longitudinal direction, it was minimum at the central region near the loading point, maximum at 0.6-0.7L from support and gradually reduced as it nears support. Moreover, as the load is increased, the failure of interface gradually expands from the maximum tangential traction position to the entire region. It is expected to provide fundamentality for interface behavior and load-carrying mechanism, and for the design of bending and shear connection of steel-concrete composite structure.

• Journal of Conservation Science
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• v.32 no.1
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• pp.75-88
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• 2016

In this study, 5 mural paintings in the Buddhist temples of Joseon era were researched for component analysis on the soil contained in the walls. The results of particle size analysis showed that the ratio of particle contents were different in each layer. In the finishing layer, the distribution of the middle sand fraction is higher than that of the middle layer. The results of XRD analysis showed that quartz, feldspar, and clay mineral are the main components of sand, suggesting similar mineral composition to that of ordinary soil component. It seems weathered rocks were used for construction of the walls. The main chemical components detected from EDX analysis were Si, Al, Fe, and K. Also the SEM images showed sand or clay sized minerals. In conclusion, the walls of the buddhist mural paintings in Joseon Dynasty had been constructed by using the loess, and had been produced by using mixture of clay and sand particles of different sizes for each layer. This study identified the characteristics of the materials and the manufacturing technologies used on the walls of mural paintings of Buddhist temples in Joseon era.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.365-365
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• 2023

우리나라는 지리, 지형 및 기상특성으로 인해 집중호우와 태풍 등으로 자연재해 피해를 입고 있으며, 재해예방사업의 일환으로 1998년부터 자연재해위험개선지구 정비사업을 통해 자연재해로부터 침수, 유실, 붕괴위험 등 피해예방을 위해 노력하고 있다. 서울특별시는 도시화로 인한 우수침투 가능지역 감소와 유역경사 부족에 따른 충분한 관거 경사확보의 어려움으로 저지대에 노면수가 집중되면서 대규모 침수피해(2010. 09, 2011. 07)가 발생되었으며, 신월·신정지구 및 화곡2지구가 자연재해위험개선지구로 선정(2011. 04), 침수방지를 위한 대책으로 국내 최초의 대규모 터널형 빗물저류배수시설(신월빗물저류배수시설)을 준공(2020. 05)하였다. 본 연구에서는 신월빗물저류배수시설 설치에 따른 상습침수구역의 사업 전·후 침수피해 저감효과 검증을 위해 도시유출모형을 구축하여 서울시 방재성능목표 확보여부를 판단하고자 하였다. 기존 설계 당시 서울시 방재성능목표(30년 빈도, 95mm/hr)는 확보되었으나 이를 초과하는 강우(2010. 09, 98.5mm/hr)가 발생함에 따라 수행된 추가 분석(100mm/hr) 결과, 유역의 침수 완전해소를 위해서는 빗물저류배수시설과 더불어 국부적인 간선관거 개량의 필요성이 제시되었다. 이에 따라 본 연구에서는 도시유출모형 구축 시 최근 개선된 하수관로, 지형특성, 홍수량산정표준침(2019, 환경부)등에 따른 수리·수문특성을 반영하고, 신일펌프장(간이)을 추가적으로 고려하여 현재 기준에서의 침수피해 저감 효과를 면밀이 분석하였으며, 그 결과 서울시 방재성능목표 뿐만 아니라 100mm/hr에도 침수가 완전 해소되는 것으로 나타났다. 신월빗물저류배수터널 설치에 따른 침수피해 저감효과 평가 및 분석결과를 통해 자연재해위험개선지구의 해제가 가능할 것으로 판단되며, 지역안전·환경효과, 주민만족도 등 다양한 항목에 대하여 상습침수구역 내 주민설문조사를 수행한 결과 신월빗물저류배수터널에 대한 만족도가 충분히 제고된 만큼 향후 시설의 기능적, 운영적 측면에서의 유지관리가 잘 이루어진다면 침수로부터 안전한 도시를 구현하는데 큰 역할을 할 것으로 기대된다.