• Computers and Concrete
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• v.32 no.2
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• pp.217-232
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• 2023

Numerous studies have been performed on the behavior of pile foundations in cold regions. This study first attempted to employ artificial neural networks (ANN) to predict pile-bearing capacity focusing on pile data recorded primarily on cold regions. As the ANN technique has disadvantages such as finding global minima or slower convergence rates, this study in the second phase deals with the development of an ANN-based predictive model improved with an Elephant herding optimizer (EHO), Dragonfly Algorithm (DA), Genetic Algorithm (GA), and Evolution Strategy (ES) methods for predicting the piles' bearing capacity. The network inputs included the pile geometrical features, pile area (m²), pile length (m), internal friction angle along the pile body and pile tip (Ø°), and effective vertical stress. The MLP model pile's output was the ultimate bearing capacity. A sensitivity analysis was performed to determine the optimum parameters to select the best predictive model. A trial-and-error technique was also used to find the optimum network architecture and the number of hidden nodes. According to the results, there is a good consistency between the pile-bearing DA-MLP-predicted capacities and the measured bearing capacities. Based on the R2 and determination coefficient as 0.90364 and 0.8643 for testing and training datasets, respectively, it is suggested that the DA-MLP model can be effectively implemented with higher reliability, efficiency, and practicability to predict the bearing capacity of piles.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.81-92
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• 2013

The ultimate flexural strength of HSB I-girders, considering the effect of local bucking, was investigated through a series of nonlinear finite element analysis. The girders were selected such that the inelastic local flange buckling or the plastic yielding of compression flanges governs the flexural strength. Both homogeneous sections fabricated from HSB600 or HSB800 steel and hybrid sections with HSB800 flanges and SM570-TMC web were considered. In the FE analysis, the flanges and web were modeled using thin shell elements and initial imperfections and residual stresses were imposed on the FE model. An elasto-plastic strain hardening material was used for steels. After establishing the validity of present FE analysis by comparing FE results with test results published in the literature, the effects of initial imperfection and residual stress on the inelastic flange local buckling behavior were assessed. The ultimate flexural strengths of 60 I-girders with various compression flange slenderness were obtained by FE analysis and compared with those calculated from the KHBDC, AASHTO LRFD and Eurocode 3 provisions. Based on the comparison, the applicability of design equations in these specifications for the flexural strength of I-girder considering flange local buckling was evaluated.

• Proceedings of the Ginseng society Conference
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• 2004.05a
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• pp.17-28
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• 2004

As Korean ginseng is hybrid, an individual variation is very severe, and it takes long times in new breeding because it is required 4 years to pick the seed. But, transformation technique makes the high-functional breeding in short time. The focus of these ginseng studies is to find and secure the useful gene. And it is urgent to accumulate the fundamental data for the molecular breeding and secure the useful genes. Therefore, transformation and soil acclimatization technique are necessary to molecular breeding in use of the introduction of functional genes. In this study, it add to secure of new regulation gene and useful gene as to accumulate the fundamental data for the place where it will contribute to raise the national competitive power. To analyze the useful genes in large scale, we constructed CDNA libraries with various tissues, species, and treated tissue. EST analysis of ginseng perform in large scale and build the EST database of ginseng. We perform the full length sequencing about the selected lots of clones that include the entire open reading frame of the amino acid residues and construct cDNA chip with the parental EST clones. Establishment of the transformation and a soil acclimatization system throuth the re-introduction of the selected ginseng gene that related with the secondary metabolism and anti-stress into the ginseng.

• The Journal of the Korea Contents Association
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• v.4 no.4
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• pp.45-51
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• 2004

The number of development in educational software is currently decreasing despite rapid improvement in computer technology. This is partly due to the fact that the current software relies on the conventional hypermedia method or on the hierarchical method, both of which have inherent limitations. To compensate their limitations while keeping their merits, a hybrid method called the structured hypermedia link method has recently been proposed in the literature. It has been found that the structured hypermedia link method is far superior than the conventional methods in terms of educational effectiveness because it can help a learner to search various data by navigating between the study topics on his own while maintaining his level of cognitively overloaded stress to the minimum. The clinical microbiology laboratories were chosen as the candidate site for this study because its educational system has not been standardized and has been relying heavily on the personal experience. In this study, the hypermedia link method was applied to the development of an education system for the image analysis in clinical microbiology laboratories. For this purpose, a web-based computer aided instruction(CAI) program was designed to systematically organize the Gram stain method based on the standardized image data. In the future, CAI program must be intended to educate for beginner and developed to accept for variable knowledge. And it will be useful program for technicians in case of applying various examinations based Gram stain method of this study.

• Journal of the Microelectronics and Packaging Society
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• v.13 no.1 s.38
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• pp.7-15
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• 2006

In-situ observation of electromigration in thin film pattern of 63Sn-37Pb solder was performed using a scanning electron microscope system. The 63Sn-37Pb solder had the incubation stage of electromigration for edge movement when the current density of $6.0{\times}10^{4}A/cm^2$ was applied the temperature between $90^{\circ}C\;and\;110^{\circ}C$. The major diffusion elements due to electromigration were Pb and Sn at temperatures of $90-110^{\circ}C\;and\;25-50^{\circ}C$, respectively, while no major diffusion of any element due to electromigration was detected when the test temperature was $70^{\circ}C$. The reason was that both the elements of Sn and Pb were migrated simultaneously under such a stress condition. The existence of the incubation stage was observed due to Pb migration before Sn migration at $90-110^{\circ}C$. Electromigration behavior of 63Sn-37Pb solder had an incubation time in common for edge drift and void nucleation, which seemed to be related the lifetime of flip chip solder bump. Diffusivity with $Z^*$(effective charges number) of Pb and Sn were strongly affect the electromigration-induced major diffusion element in SnPb solder by temperature, respectively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.201-205
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• 2004

In these several years, as many people have been attracted by the functional cosmetics, there are a lot of study to enhance the stability of active ingredients for light, heat, oxygen, etc. in the academic and industrial field. Especially, catechin is well known as strong anti-oxidant, anti-inflammatory and reducing agent for oxidative stress but it is very unstable for light, heat, oxygen. etc. In this study, the stability and skin penetration of catechin are improved by 3-dimensional method. As I-dimension, porous silica is prepared using sol-gel method, and then catechin is adsorbed in pores of silica. As 2-dimension, solid lipid nanoparticles (SLN) are obtained using non-phospholipid vesicles. Finally 3-dimension is completion through lamellar phase self-organization that combines SLN catechin with skin lipid matrix. We used laser light scattering system, cyro-SEM, chromameter, HPLC and image analyzer to analyze our 3-dimentional systems. According to chromameter date, the color stability of 3-dimensional catechin is enhanced by 5-10 times compared with general liposome systems. We also confirmed through HPLC analysis that 3-dimensional catechin is more long lasting. The effect of skin penetration and wrinkle reduction are improved, too.