• Title/Summary/Keyword: State Structure Function

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Nonlinear Inelastic Optimal Design Using Genetic Algorithm (유전자 알고리즘을 이용한 비선형 비탄성 최적설계)

  • 마상수;김승억
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.145-152
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    • 2003
  • An optimal design method in cooperated with nonlinear inelastic analysis method is presented. The proposed nonlinear inelastic method overcomes the difficulties due to incompatibility between the elastic global analysis and the limit state member design in the conventional LRFD method. The genetic algorithm uses a procedure based on Darwinian notions of survival of the fittest, where selection, crossover, and mutation operators are used among sections in the database to look for high performance ones. They satisfy the constraint functions and give the lightest weight to the structure. The objective function is set to the total weight of the steel structure and the constraint functions are load-carrying capacities, serviceability, and ductility requirement. Case studies of a three-dimensional frame and a three-dimensional steel arch bridge are presented.

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Performance functions for laterally loaded single concrete piles in homogeneous clays

  • Imancli, Gokhan;Kahyaoglu, M. Rifat;Ozden, Gurkan;Kayalar, Arif S.
    • Structural Engineering and Mechanics
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    • v.33 no.4
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    • pp.529-537
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    • 2009
  • A key parameter in the design of a laterally loaded pile is the determination of its performance level. Performance level of a pile is usually expressed as the maximum head deflection and bending moment. In general, uncertainties in the performance of a pile originates from many factors such as inherent variability of soil properties, inadequate soil exploration programs, errors taking place in the determination of soil parameters, limited calculation models as well as uncertainties in loads. This makes it difficult for practicing engineers to decide for the reliability of laterally loaded piles both in cohesive and cohesionless soils. In this paper, limit state functions and consequent performance functions are obtained for single concrete piles to predict the maximum bending moment, a widely accepted design criterion along with the permissible pile head displacement. Analyses were made utilizing three dimensional finite element method and soil-structure-interaction (SSI) effects were accounted for.

In-cell nuclear magnetic resonance spectroscopy for studying intermolecular interactions

  • Sugiki, Toshihiko;Lin, Yuxi;Lee, Young-Ho
    • Journal of the Korean Magnetic Resonance Society
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    • v.23 no.1
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    • pp.33-39
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    • 2019
  • Studies on the interactions of proteins with partner molecules at the atomic resolution are essential for understanding the biological function of proteins in cells and for developing drug molecules. Solution NMR spectroscopy has shown remarkably useful capability for investigating properties on the weak to strong intermolecular interactions in both diluted and crowded solution such as cell lysates. Of note, the state-of-the-art in-cell NMR method has made it possible to obtain atomistic information on natures of intermolecular interactions between target proteins with partner molecules in living cells. In this mini-review, we comprehensively describe the several technological advances and developments in the in-cell NMR spectroscopy.

Load carrying capacity of CFRP retrofitted broken concrete arch

  • Wang, Peng;Jiang, Meirong;Chen, Hailong;Jin, Fengnian;Zhou, Jiannan;Zheng, Qing;Fan, Hualin
    • Steel and Composite Structures
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    • v.23 no.2
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    • pp.187-194
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    • 2017
  • To reuse a broken plain concrete (PC) arch, a retrofitting method was proposed to ensure excellent structural performances, in which carbon fiber reinforced polymers (CFRPs) were applied to repair and strengthen the damaged PC arch through bonding and wrapping techniques. Experiments were carried out to reveal the deformation and the load carrying capacity of the retrofitted composite arch. Based on the experiments, repairing and strengthening effects of the CFRP retrofitted broken arch were revealed. Simplified analysing model was suggested to predict the peak load of the CFRP retrofitted broken arch. According to the research, it is confirmed that absolutely broken PC arch can be completely repaired and reinforced, and even behaves more excellent than the intact PC arch when bonded together and strengthened with CFRP sheets. Using CFRP bonding/wrapping technique a novel efficient composite PC arch structure can be constructed, the comparison between rebar reinforced concrete (RC) arch and composite PC arch reveals that CFRP reinforcements can replace the function of steel bars in concrete arch.

Seismic Reliability Analysis of Offshore Wind Turbine Support Structure (해상풍력발전기 지지구조물의 지진신뢰성해석)

  • Lee, Gee-Nam;Kim, Dong-Hyawn
    • Journal of Ocean Engineering and Technology
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    • v.29 no.5
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    • pp.342-350
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    • 2015
  • A seismic reliability analysis of the jacket-type support structure for an offshore wind turbine was performed. When defining the limit state function using the dynamic response of the support structure, numerous dynamic calculations should be performedin an approach like the FORM (first-order reliability method). This causes a substantial increase in the analysis cost. Therefore, in this paper, a new reliability analysis approach using the static response is used. The dynamic effect of the response is considered by introducing a new parameter called the peak response factor (PRF). The probability distribution of the PRF could be estimated using the peak value of the dynamic response. The probability distribution of the PRF was obtained for a set of ground motions. A numerical example is considered to compare the proposed approach with the conventional static-response-based approach.

Development of Proximity Exposure System with Vertical Structure for Plasama Display Panel (PDP용 수직형 구조의 근접 노광장치 개발)

  • Park, Jeong-Gyu;Jeong, Su-Hwa;Lee, Hang-Bu
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.9 s.180
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    • pp.2371-2380
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    • 2000
  • In this paper, we developed the proximity exposure system with the vertical structure of glass and mask stage to minimize the mask's warp caused by the pull of gravity. This system, which canirradiate the ultra violet through 1440 H 850 $\textrm{mm}^2$ and 1330X 1015 $\textrm{mm}^2$ exposure area, has the followingcharacteristics. The glass stage can be inclined by 80 degrees at vertical structure to load substrate withsafety on it. When the glass stage is the vertical state, the gap control, alignment control and exposureof ultra violet are executed. So, it enhances the pattern uniformity by minimizing the mask's warp. Theglass stage can also control the gap between the mask and the substrate by the coarse and fine motioncontrol. The mask stage can adjust the posture of photomask to the position of substrate by imageprecessing method. The galss stage for the gap control and the mask stage for the alignment aredesigned independently for each function.

Identifying Novel B Cell Epitopes within Toxoplasma gondii GRA6

  • Wang, Yanhua;Wang, Guangxiang;Cai, Jian Ping
    • Parasites, Hosts and Diseases
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    • v.54 no.4
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    • pp.431-437
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    • 2016
  • The study of antigenic epitopes from Toxoplasma gondii has not only enhanced our understanding of the structure and function of antigens, the reactions between antigens and antibodies, and many other aspects of immunology, but it also plays a significant role in the development of new diagnostic reagents and vaccines. In the present study, T. gondii GRA6 epitopes were identified using bioinformatics tools and a synthetic peptide technique. The potential B cell epitopes of GRA6 predicted by bioinformatics tools concentrated upon 3 regions of GRA6, 1-20 aa, 44-103 aa, and 172-221 aa. Ten shorter peptides from the 3 regions were synthesized and assessed by ELISA using pig sera from different time points after infection. Three of the 10 peptides (amino acids 44-63, 172-191, and 192-211) tested were recognized by all sera and determined to be immunodominant B-cell epitopes of GRA6. The results indicated that we precisely and accurately located the T. gondii GRA6 epitopes using pig sera collected at different time points after infection. The identified epitopes may be very useful for further studies of epitope-based vaccines and diagnostic reagents.

Minimum life-cycle cost design of ice-resistant offshore platforms

  • Li, Gang;Zhang, Da-Yong;Yue, Qian-Jin
    • Structural Engineering and Mechanics
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    • v.31 no.1
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    • pp.11-24
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    • 2009
  • In China, the oil and natural gas resources of Bohai Bay are mainly marginal oil fields. It is necessary to build both ice-resistant and economical offshore platforms. However, risk is involved in the design, construction, utilization, maintenance of offshore platforms as uncertain events may occur within the life-cycle of a platform under the extreme ice load. In this study, the optimum design model of the expected life-cycle cost for ice-resistant platforms based on cost-effectiveness criterion is proposed. Multiple performance demands of the structure, facilities and crew members, associated with the failure assessment criteria and evaluation functions of costs of construction, consequences of structural failure modes including damage, revenue loss, death and injury as well as discounting cost over time are considered. An efficient approximate method of the global reliability analysis for the offshore platforms is provided, which converts the implicit nonlinear performance function in the conventional reliability analysis to linear explicit one. The proposed life-cycle optimum design formula are applied to a typical ice-resistant platform in Bohai Bay, and the results demonstrate that the life-cycle cost-effective optimum design model is more rational compared to the conventional design.

Quantitative Analysis of ″Polymer-Balls″ in Aqueous Solutions by Small-Angle Neutron Scattering

  • Shibayama, Mitsuhiro;Okabe, Satoshi;Nagao, Michihiro;Sugihara, Shinji;Aoshima, Sadahito;Harada, Tamotsu;Matsuoka, Hideki
    • Macromolecular Research
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    • v.10 no.6
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    • pp.311-317
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    • 2002
  • The quantitative analysis of polymer micelles consisting of amphiphilic block copolymers was carried out by small-angle neutron scattering (SANS). The block copolymers, made of poly(2-ethoxyethyl vinyl ether-b-2-hydroxyethyl vinyl ether)(poly(EOVE-b-HOVE)), exhibited a sharp morphological transition from a homogeneous solution to a micelle structure with increasing temperature. This transition is accompanied by a formation of spherical domains of poly(EOVE) with a radius around 200 $\AA$. The variations of the size and its distribution of the domains were investigated as a function of polymer concentration and temperature. The validity of SANS analysis, including the wavelength- and incident-beam-smearing effects of the SANS instrument, was examined with a pre-calibrated polystyrene latex.

Characterization of the Spatial Variability of Paper Formation Using a Continuous Wavelet Transform

  • Keller, D.Steven;Luner, Philip;Pawlak, Joel J.
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.32 no.5
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    • pp.14-25
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    • 2000
  • In this investigation, a wavelet transform analysis was used to decompose beta-radiographic formation images into spectral and spatial components. Conventional formation analysis may use spectral analysis, based on Fourier transformation or variance vs. zone size, to describe the grammage distribution of features such as flocs, streaks and mean fiber orientation. However, these methods have limited utility for the analysis of statistically stationary data sets where variance is not uniform with position, e.g. paper machine CD profiles (especially those that contain streaks). A continuous wavelet transform was used to analyze formation data arrays obtained from radiographic imaging of handsheets and cross machine paper samples. The response of the analytical method to grammage, floc size distribution, mean fiber orientation an sensitivity to feature localization were assessed. From wavelet analysis, the change in scale of grammage variation as a function of position was used to demonstrate regular and isolated differences in the formed structure.

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