• Earthquakes and Structures
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• 제2권4호
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• pp.337-356
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• 2011

In this paper, cable-stayed bridges with single pylon and two equal side spans, with variations in geometry and span ranging from 120 m to 240 m have been studied. 3D models of the bridges considered in this study have been analysed using ANSYS. As the first step towards a detailed seismic analysis, free vibration response of different geometries is studied for their mode shapes and frequencies. Typical pattern of free vibration responses in different frequencies with change in geometry is observed. Further, three different seismic loading histories are chosen with various characteristics to find the structural response of different geometries under seismic loading. Effect of variation in pylon shape, cable arrangement with variation in span is found to have typical characteristics with different structural response under seismic loading. From the study, it is observed that the structural response is very much dependent on the geometry of the cable-stayed bridge and the characteristics of the seismic loading as well. Further, structural responses obtained from the study would help the design engineers to take decisions on geometric shapes of the bridges to be constructed in seismic prone zones.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3183-3186
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• 2007

Taylor-Couette flow may appear when the angular velocity is different between two concentric rotating cylinders. This kind of Taylor-vortex flow can be easily seen in lots of engineering problems. In general the geometries of rotating cylinders are generally complex in these cases. In this study, we investigated Taylor-Couette flow when the outer cylinder has the slit along the annulus. The radius ratio and aspect ratio of the experimental model used was 0.825 and 48, respectively. The depth of slits is 5mm and total 18 slits are azimuthally located along the inner wall of outer cylinder. We used PIV method to measure the flow and applied index matching method to resolve the complex geometry effect. The results show the model with slit has no stable wavy vortex region above Re=143.

• 국제초고층학회논문집
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• 제4권1호
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• pp.85-90
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• 2015

Advances in the technology of computational design are giving architects and engineers the opportunity to analyze buildings with complex geometries. This study explores the optimization and automation process using the parametric design method, and uses digital tools to achieve surface representation and panelization for curved shaped office buildings. In this paper, we propose parametric algorithms of dimensional and geometric constraints using the Knowledge-ware scripts embedded in Gehry Technologies' Digital Project. The knowledge-based design methods proposed in this study can be used to systemize the knowledge possessed by experts in the form of data. Such knowledge is required to promote collaboration between designers and engineers in the process of CAD/CAE/CAM. The aim of this study is to integrate the process into design, which establishes an integrated process. This integration enables two-way feedback between design and construction data by combining the methods used in designing, engineering, and construction.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1992년도 추계학술발표회논문집
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• pp.25-29
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• 1992

In this paper, The Monte Carlo Simulation is performed in complex geometries which are composed of obstacles intercepted path of photon. Light is assumed to be particle and has particular direction and weighting value. The illuminance distribution is calculated proportional to the summation of weighting values striking area element. The result of simulation is consistent with that of experiments in a few error.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.851-857
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• 2014

Carotenoids, natural antenna pigments in photosynthesis share a symmetric backbone of conjugated polyenes. Contrary to the symmetric and almost planar geometries of carotenoids, excited state structure and dynamics of carotenoids are exceedingly complex. In this paper, recent infrared and visible transient absorption measurements and excitation dependent dynamics of 8'-apo-${\beta}$-caroten-8'-al and 7',7'-dicyano-7'-apo-${\beta}$-carotene will be reviewed. The recent visible transient absorption measurements of 8'-apo-${\beta}$-caroten-8'-al in polar and nonpolar solvents will also be introduced to emphasize the complex excited-state dynamics and unsolved problems in the $S_2$ and $S_1$ excited states.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1995년도 추계 학술대회논문집
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• pp.90-103
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• 1995

최근 전산 유체 역학은 Navier-Stokes 방정식을 보다 복잡한 유동장 형상에 대해 풀 수 있을 만큼 발달해 왔으나 아직도 유동장 형상이 복잡할 때는 많은 애로를 느끼고 있다. 특히 격자 구성 문제에 있어서 많은 시간과 노력을 기울이고 있으며 심지어 격자 구성 문제를 해결하지 못해 유동해석을 하지 못하는 경우가 많은 실정이다. 따라서 본 연구에서는 주로 내부 유동인 변형 도관를 예로 유동장 형상에 따라 격자구성이 어떻게 달라지는가를 살펴 보았다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 추계 학술대회논문집
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• pp.194-199
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• 2007

IB (immersed boundary) method is one of the prominent tool in computational fluid dynamics for the analysis of flows over complex geometries. The IB technique simplyfies the solution procedure by eliminating the requirement of complex body fitted grids and it is also superior in terms of memory requirement. In this study we have developed numerical code (FOTRAN) for the analysis of 2D flow over a cylinder using IB technique. The code is validated by comparing the wake lengths and separation angles given by Guo et. al. We employed fractional-step procedure for solving the Navier-Stokes equations governing the flow and discrete forcing IB technique for imposing boundary conditions. Also we have developed a 3D code for the backward-facing-step flow and flow over a sphere. The reattachment length in backward-facing-step flow was compared with the one given by Nie and Armaly, which has proven the validity of our code.

• Bulletin of the Korean Chemical Society
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• 제23권3호
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• pp.404-412
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• 2002

Nine copper(Ⅱ) oxyanion, and mixed oxyanion complexes that have four- or five-coordinate geometries around copper(Ⅱ) centers were derived from sparteine copper(Ⅱ) dinitrate precursor [Cu($C_{15}$$H_{26}$N2)(NO3)2]. The precursor complex undergoes an anion exchange with various oxyanions, and an interchange reaction with other sparteine copper(Ⅱ) complexes. The [Cu($C_{15}$$H_{26}$N2)(CH3CO2)2] also undergoes "halogen atom abstraction" reaction with CCl4 to produce the mixed anion complex [Cu($C_{15}$$H_{26}$N2)(CH3CO2)Cl]. The whole set of prepared complexes has been used for the comparative electrochemical and spectroscopic studies.

• 한국산학기술학회논문지
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• 제6권4호
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• pp.302-308
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• 2005

구조가 복잡한 챔버의 온도분포와 유속변화를 연구하였다. 압축성 혹은 비압축성 유체, 층류 혹은 난류의 유속변화를 모델링 할 수 있는 FLUENT 프로그램으로 모사실험을 하였다. 챔버의 구조는 매우 복잡하여 단순화한 구조를 표준 $\kappa-\varepsilon$ 모델과 RNG $\kappa-\varepsilon$ 난류 모델 모사 실험하였다. 평가지역의 온도편차가 적은 것이 중요하다. 본 연구에서 얻은 챔버 내부의 온도분포와 유속변화 자료를 챔버의 제어 알고리즘을 향상하는 제공하였다. 개선된 제어 알고리즘을 이용하여 실제계에 적용한 결과 평가지역의 온도편차가 매우 개선되었다.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1232-1236
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• 2013

The Cu cation binding sites of $[Cu(I){\cdot}d(CpG){\cdot}d(CpG)-2H]^{-1}$ complex have been investigated to explain the $[Cu{\cdot}DNA]$ biological activity caused by the Cu association to DNA. The structure of $[Cu(I){\cdot}d(CpG){\cdot}d(CpG)-2H]^{-1}$ complex was investigated by electrospray ionization mass spectrometry (ESI-MS). The fragmentation patterns of $[Cu(I){\cdot}d(CpG){\cdot}d(CpG)-2H]^{-1}$ complex were analyzed by MS/MS spectra. In the MS/MS spectra of $[Cu(I){\cdot}d(CpG){\cdot}d(CpG)-2H]^{-1}$ complex, three fragment ions were observed with the loss of d(CpG), {d(CpG) + Cyt}, and {d(CpG) + Cyt + dR}. The Cu cation binds to d(CpG) mainly by substituting the $H^+$ of phosphate group. Simultaneously, the Cu cation prefers to bind to a guanine base rather than a cytosine base. Five possible geometries were considered in the attempt to optimize the $[Cu(I){\cdot}d(CpG){\cdot}d(CpG)-2H]^{-1}$ complex structure. The ab initio calculations were performed at B3LYP/6-31G(d) level.