• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.3
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• pp.303-314
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• 2010

A study for the nonlinear analysis method of prestressed concrete(PSC) girders with external tendons is presented. The PSC girders with external tendons show the complex nonlinear behavior due to the slip of external tendons at deviator and the change of eccentricity between the girders and external tendons. The external tendon between anchorage-deviator or deviator-deviator is modeled as an assemblage of the curved elements. The slip effect of the external tendon at deviator is taken into account using the force equilibrium relationship between the friction force and the driving force at each deviator. The finite element model and analysis method of the external tendon suggested herein are integrated in the nonlinear analysis program of segmentally erected PSC frames developed by the authors. The proposed analysis method is verified through the comparison of the analysis and experimental results obtained from other investigators. From the ultimate analysis results of PSC beams with external tendons having different number of deviators, the yielding and ultimate loads of PSC beams found to be increased as the number of deviators are increased. In addition, the ultimate capacity of the PSC beam increases according to the increase of friction coefficient between deviator and external tendon, whereas found to decease over the certain value of friction due to the effect of the moment transmitted to the member by the friction force exerted from the external tendon.

• Journal of Adhesion and Interface
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• v.11 no.2
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• pp.41-49
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• 2010

Furan-containing epoxide monomers (8, 9) were designed and synthesized as carbon-neutral, environment-friendly adhesion material. Bicyclic skeleton were constructed using the Diels-Alder reaction of furan and methyl acrylate, both readily accessible starting material from a biomass via bio-refinery process. After reduction of ester functionality, resulting hydroxyl moieties were coupled to epichlorohydrin to provide the epoxy-functionalized furanic monomers (8, 9). The structure of new furanic monomers was confirmed by $^1H$ and $^{13}C$ NMR spectroscopy. As UV-curable monomers, basic properties such as UV curing time and the extent of UV curing were evaluated by photo DSC. Photo-curing shrinkages were measured by linear variable differential transformer transducer (LVDT) and the effect of molecular structure on shrinkage was considered. In addition, new synthetic compounds showed the shear strength over 3 MPa when they were photo-cured between polycarbonate plates, which indicates these compounds are feasible to use as photo-curable adhesive materials.

• Journal of Conservation Science
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• v.28 no.4
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• pp.353-366
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• 2012

This study was interpreted the making techniques of the Four Guardian Statues in Wanju Songkwangsa Temple, and retained basic data necessary for conservation treatment and restoration of the same material by estimating the soil source. The molding clay used in the Statues showed a variety of material characteristics according to different layers. The first and mid layers estimated as the original molding clay are composed of the same kind of soil. The soil of the finish layer was also confirmed to be genetically similar to that of the first and mid layers, despite little discrepancy. The former restoration layer was inconsistent in material characteristics with the original molding clay in every result of analysis. As a result of gamma radiography, making techniques of the Statues were able to identify the figure of the frame connecting the woods of main pillar frame to sub-frame and steel wire with ㄷ-clamp, nails and straw ropes, and the molding clay constructed upon the frame. Meanwhile, provenance interpretation confirmed that the soil of the estimated provenance area is of the same origin as the soil of the finish layer, and therefore is an appropriate material for conservation treatment. This result will contribute to the research on making techniques of the molding clay Statues.

• Journal of Life Science
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• v.26 no.7
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• pp.789-795
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• 2016

A lymph node (LN) is one of the secondary lymphoid organs. An LN consists of a complicated 3 dimensional frame structure and several stromal cells. Fibroblastic reticular cells (FRC) are distributed in the T zone for interaction with T cells. FRC secrete homing chemokines such as CCL19 and CCL21. Moreover, FRC play a pivotal role in the production of extracellular matrix (ECM) into LN for ECM reorganization against pathogen infections. However, not much is known about the involvement of the immune reaction of FRC. The present report is for the characterization of FRC on immune response. For this, FRC were positioned in several infected situations such as co-culture with macrophage, lipopolysaccharide (LPS), and TNFα stimulation. When a co-culture between FRC and macrophage was performed, a morphological change in FRC was observed, and empty space between FRCs was created by this change. The soluble ICAM-1 protein level was up-regulated by co-culturing with Raw264.7 and the treatment of the ROCK inhibitor Y27632. The activity of matrix metalloproteinase (MMP) was up-regulated by LPS onto FRC. Furthermore, the inflammatory cytokine TNFα regulated the expression of ECM in FRC by a gene chip assay. Collectively, it suggests that FRC are involved in immune reactions.

• Journal of Life Science
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• v.23 no.11
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• pp.1409-1414
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• 2013

Lymph node (LN) is the sites where mature lymphocytes become stimulated to respond to invading pathogens in the body. Lymphocytes screen the surfaces of pathogen-carrying antigen-presenting cells for cognate antigens, while moving along stromal structural back bone. Fibroblastic reticular cells (FRC) is stromal cell forming the 3 dimensional structure networks of the T cell rich zones in LN, and provide a guidance path for immigrating T lymphocytes. In these cooperative environments, the cell to cell bidirectional interactions between FRC and T cells in LN are therefore essential to the normal functioning of these tissues. Not only do FRCs physically construct LN architecture but they are essential for regulating T cell biology within these domains. FRC interact closely with T lymphocytes, is providing scaffolds, secreting soluble factors including cytokine in which FRCs influence T cell immune response. More recently, FRC have been found to induce peripheral T cell tolerance and regulate the extent to which newly activated T cells proliferate within LN. Thus, FRC-T cell crosstalk has important consequences for regulating immune cell function within LN. In addition, FRC have profound effects on innate immune response by secreting anti-microbial peptides and complement, etc in the inflammatory milieu. In summary, we propose a model in which FRC engage in a bidirectional touch to increase the T cell biological efficiency between FRC and T cells. This collaborative feedback loop may help to maintain tissue function during inflammation response.

• Anatomy & Biological Anthropology
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• v.29 no.2
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• pp.35-46
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• 2016

Leonardo da Vinci is remembered as the greatest genius of the Renaissance. He left outstanding achievements as an artist, scientist and inventor, and contributes up to today's science. He ranks the best in a variety of fields, such as botany, mathematics, geology, astronomy, geometry and optics. It has well known that Leonardo is an artist, scientist, inventor and philosopher. And he was a great anatomist that dissected dead bodies and animals directly and left many anatomical drawings. He took an interest in anatomy from the point of view of the artist, which is why the human body structure and function to know the sakes were "ignorant of the anatomy should not be upset." Over time, he became interested in the structure and function of the body, even get the human body in a difficult environment; he dissected many the human bodies directly. His scientific inquiry and infatuation made him as an advanced pioneer for more than 100 years, and got enough level to surpass the artistry. Leonardo left about 1,800 anatomical figures of the muscular, skeletal, vascular, nervous and urogenital system, and they are also very scientific and high artistic achievements. The aim of this article is to take a look at Leonardo da Vinci's anatomical achievements and thoughts. In addition, the goal is to knowledge today's anatomists about Leonardo da Vinci's astonishing achievements as a great pioneer in anatomy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.56-68
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• 2019

Safety-conscious design on site is required for site constructions because of the introduction of the design for safety, but it still leaves much to be desired. This study compared the site where the design was applied and the site where it was not applied. The applied case examined the underground wall construction during frame construction, which corresponds to the skeleton of the building construction. The underground wall construction is quite risky due to the exposure to exterior environments and involvement of various stages, such as scaffolding, formwork, reinforcing work, and concrete casting work. Therefore, the risk factors for each stage were identified and a risk assessment was carried out to select an alternative method to reduce the risk. The risk factors of the selected alternative construction method were also identified and a risk assessment was conducted. The risk assessment weight was calculated by comparing the site where the construction method was applied and the site where it was not, explaining the necessity of the design for safety in reducing the risk. In addition, an actual case where an alternative construction method was used was studied to highlight the necessity for a design for safety.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.1-6
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• 2019

Organic dye-doped silica nanoparticles are used as a promising nanomaterials for bio-labeling, bio-imaging and bio-sensing. Fluorescent silica nanoparticles(NPs) have been synthesized by the modified $St{\ddot{o}}ber$ method. In this study, dye-free fluorescent silica NPs of various sized were synthesized by Sol-Gel process as the modified $St{\ddot{o}}ber$ method. The functional material of APTES((3-aminopropyl)triethoxysilane) was added as an additive during the Sol-Gel process. The as-synthesized silica NPs were calcined at $400^{\circ}C$ for 2 hours. The surface morphology and particle size of the as-synthesized silica NPs were characterized by field-emission scanning electron microscopy. The fluorescent characteristics of the as-synthesized silica NPs was confirmed by UV lamp irradiation of 365 nm wavelength. The photoluminescence (PL) of the as-synthesized silica NPs with different size was analyzed by fluorometry. As the results, the as-synthesized silica NPs exhibits same blue fluorescent characteristics for different NPs size. Especially, as increased of the silica NPs size, the intensity of PL was decreased. The blue fluorescence of dye-free silica NPs was attributed to linkage of $NH_2$ groups of the APTES layer and oxygen-related defects in the silica matrix skeleton.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.1
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• pp.203-217
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• 2021

Purpose: The purpose of this meta-analysis was to examine the high-level evidence of the effects of manual therapy on musculoskeletal diseases. Methods: Domestic databases were searched for studies that conducted clinical trials associated with manual therapy on chronic musculoskeletal diseases. A total of 591 studies published between 2005 and 2018 were identified, with 18 studies satisfying the inclusion data. The studies were classified according to patient, intervention, comparison, and outcome (PICO). The search outcomes were items associated with pain and physical function. The 18 studies included in the study were evaluated by using the R meta-analysis (version 4.0). The quality of 18 randomized control trials was evaluated by using the Cochrane risk of bias (ROB). The effect sizes were computed as the corrected standardized mean difference (SMD). Subgroup and meta-regression analyses were also used. Egger's regression test was carried out in order to analyze the publication bias. Cumulative meta-analysis and sensitivity analysis were also conducted in order to analyze the data error. Results: The following factors showed the large effect size of manual therapy on chronic musculoskeletal diseases: pain (Hedges's g = 2.66; 95% CI = 1.47 ~ 3.85), and physical function (Hedges's g = 2.15; 95% CI: 1.22 ~ 3.08). The subgroup analysis only showed a statistical difference in the type of manual therapy (pain) and outcome (physical function). No statistically significant difference was found in the meta-regression analysis. Publication bias was found in the data, but the results of the trim-and-fill method showed that such bias did not largely affect the obtained data. Furthermore, there were no data errors in the cumulative meta-analysis and sensitivity analysis. Conclusion: This study provides evidence for the effectiveness of manual therapy on chronic musculoskeletal diseases in pain and physical function. Subgroup analysis suggests that only the type of manual therapy for pain and the type of outcome for physical function differed in effect size.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.599-606
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• 2022

Strain gauges and the bridge weigh-in-motion (BWIM) method are the representative field measurement methods used for fatigue evaluationsof a steel bridge-in-service. For a fatigue reliability evaluation to assess fatigue damage accumulation, the effective stress range and the number of stress cycles applied as the fatigue details can be estimated based on the AASHTO Manual for Bridge Evaluations with the field measurement data of the target bridge. However, the procedure for estimating the effective stress range and the stress cycles from field measurement data has not been explicitly presented. Furthermore, studies that quantitatively compare differences in fatigue evaluation results according to the field measurement data type or processing method used are still insufficient. Here, a fatigue reliability evaluation is conducted using strain and BWIM data that are measured simultaneously. A frame model and a shell-solid model were generated to examine the effect of the accuracy of the structural analysis model when using BWIM data. Also, two methods of handling BWIM data when estimating the effective stress range and average daily cycles are defined. As a result, differences in evaluation results according to the type of field measurement data used, the accuracy of the structural analysis model, and the data handling method could be quantitatively confirmed.